dbx_lmdb: code cleanup

git-svn-id: http://svn.miranda-ng.org/main/trunk@17056 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c

12 files changed, 11128 insertions, 15049 deletions

diff --git a/plugins/Dbx_mdb/src/dbcontacts.cpp b/plugins/Dbx_mdb/src/dbcontacts.cpp
index a4f6e2ac74..2645a12db2 100644
--- a/plugins/Dbx_mdb/src/dbcontacts.cpp
+++ b/plugins/Dbx_mdb/src/dbcontacts.cpp
@@ -52,7 +52,6 @@ STDMETHODIMP_(LONG) CDbxMdb::GetContactSize(void)
 

 STDMETHODIMP_(MCONTACT) CDbxMdb::FindFirstContact(const char *szProto)

 {

-	mir_cslock lck(m_csDbAccess);

 	DBCachedContact *cc = m_cache->GetFirstContact();

 	if (cc == NULL)

 		return NULL;

@@ -69,7 +68,6 @@ STDMETHODIMP_(MCONTACT) CDbxMdb::FindFirstContact(const char *szProto)
 

 STDMETHODIMP_(MCONTACT) CDbxMdb::FindNextContact(MCONTACT contactID, const char *szProto)

 {

-	mir_cslock lck(m_csDbAccess);

 	while (contactID) {

 		DBCachedContact *cc = m_cache->GetNextContact(contactID);

 		if (cc == NULL)

@@ -104,7 +102,6 @@ STDMETHODIMP_(LONG) CDbxMdb::DeleteContact(MCONTACT contactID)
 	{

 		MDB_val key, data;

 		DBSettingKey keyS = { contactID, 0 };

-		memset(keyS.szSettingName, 0, sizeof(keyS.szSettingName));

 

 		txn_ptr txn(m_pMdbEnv);

 		cursor_ptr cursor(txn, m_dbSettings);

@@ -114,7 +111,7 @@ STDMETHODIMP_(LONG) CDbxMdb::DeleteContact(MCONTACT contactID)
 		for (int res = mdb_cursor_get(cursor, &key, &data, MDB_SET_RANGE); res == MDB_SUCCESS; res = mdb_cursor_get(cursor, &key, &data, MDB_NEXT))

 		{

 			const DBSettingKey *pKey = (const DBSettingKey*)key.mv_data;

-			if (pKey->dwContactID != contactID)

+			if (pKey->hContact != contactID)

 				break;

 			mdb_cursor_del(cursor, 0);

 		}

@@ -127,7 +124,7 @@ STDMETHODIMP_(LONG) CDbxMdb::DeleteContact(MCONTACT contactID)
 	{

 		txn_ptr trnlck(m_pMdbEnv);

 		MDB_CHECK(mdb_del(trnlck, m_dbContacts, &key, nullptr), 1);

-		if (trnlck.commit())

+		if (trnlck.commit() == MDB_SUCCESS)

 			break;

 	}

 

@@ -142,25 +139,21 @@ STDMETHODIMP_(LONG) CDbxMdb::DeleteContact(MCONTACT contactID)
 

 STDMETHODIMP_(MCONTACT) CDbxMdb::AddContact()

 {

-	DWORD dwContactId;

-	{

-		dwContactId = InterlockedIncrement(&m_dwMaxContactId);

+	MCONTACT dwContactId = InterlockedIncrement(&m_maxContactId);

 

-		DBCachedContact *cc = m_cache->AddContactToCache(dwContactId);

-		cc->dbc.dwSignature = DBCONTACT_SIGNATURE;

+	DBCachedContact *cc = m_cache->AddContactToCache(dwContactId);

 

-		MDB_val key = { sizeof(MCONTACT), &dwContactId };

-		MDB_val data = { sizeof(cc->dbc), &cc->dbc };

+	MDB_val key = { sizeof(MCONTACT), &dwContactId };

+	MDB_val data = { sizeof(cc->dbc), &cc->dbc };

 

-		for (;; Remap()) {

-			txn_ptr trnlck(m_pMdbEnv);

-			MDB_CHECK(mdb_put(trnlck, m_dbContacts, &key, &data, 0), 0);

-			if (trnlck.commit())

-				break;

-		}

-		InterlockedIncrement(&m_contactCount);

+	for (;; Remap()) {

+		txn_ptr trnlck(m_pMdbEnv);

+		MDB_CHECK(mdb_put(trnlck, m_dbContacts, &key, &data, 0), 0);

+		if (trnlck.commit() == MDB_SUCCESS)

+			break;

 	}

 

+	InterlockedIncrement(&m_contactCount);

 	NotifyEventHooks(hContactAddedEvent, dwContactId, 0);

 	return dwContactId;

 }

@@ -221,7 +214,7 @@ BOOL CDbxMdb::MetaMergeHistory(DBCachedContact *ccMeta, DBCachedContact *ccSub)
 			DBEventSortingKey insVal = { EI->eventId, EI->ts, ccMeta->contactID };

 			MDB_val key = { sizeof(insVal), &insVal }, data = { 1, "" };

 			mdb_put(trnlck, m_dbEventsSort, &key, &data, 0);

-			if (trnlck.commit())

+			if (trnlck.commit() == MDB_SUCCESS)

 				break;

 		}

 		ccMeta->dbc.dwEventCount++;

@@ -234,7 +227,7 @@ BOOL CDbxMdb::MetaMergeHistory(DBCachedContact *ccMeta, DBCachedContact *ccSub)
 	{

 		txn_ptr trnlck(m_pMdbEnv);

 		MDB_CHECK(mdb_put(trnlck, m_dbContacts, &keyc, &datac, 0), 1);

-		if (trnlck.commit())

+		if (trnlck.commit() == MDB_SUCCESS)

 			break;

 	}

 	return 0;

@@ -257,7 +250,7 @@ BOOL CDbxMdb::MetaSplitHistory(DBCachedContact *ccMeta, DBCachedContact *ccSub)
 			DBEventSortingKey insVal = { EI->eventId, EI->ts, ccMeta->contactID };

 			MDB_val key = { sizeof(insVal), &insVal }, data = { 1, "" };

 			mdb_del(trnlck, m_dbEventsSort, &key, &data);

-			if (trnlck.commit())

+			if (trnlck.commit() == MDB_SUCCESS)

 				break;

 		}

 		ccMeta->dbc.dwEventCount--;

@@ -270,7 +263,7 @@ BOOL CDbxMdb::MetaSplitHistory(DBCachedContact *ccMeta, DBCachedContact *ccSub)
 	{

 		txn_ptr trnlck(m_pMdbEnv);

 		MDB_CHECK(mdb_put(trnlck, m_dbContacts, &keyc, &datac, 0), 1);

-		if (trnlck.commit())

+		if (trnlck.commit() == MDB_SUCCESS)

 			break;

 	}

 	return 0;

@@ -306,21 +299,18 @@ void DBCachedContact::Revert()
 

 void CDbxMdb::FillContacts()

 {

-	LIST<DBCachedContact> arContacts(10);

+	LIST<DBCachedContact> arContacts(m_contactCount);

 

 	{

 		txn_ptr_ro trnlck(m_txn);

 		cursor_ptr_ro cursor(m_curContacts);

 

 		MDB_val key, data;

-		while (mdb_cursor_get(cursor, &key, &data, MDB_NEXT) == MDB_SUCCESS) 

+		while (mdb_cursor_get(cursor, &key, &data, MDB_NEXT) == MDB_SUCCESS)

 		{

 			const DBContact *dbc = (const DBContact*)data.mv_data;

-			if (dbc->dwSignature != DBCONTACT_SIGNATURE)

-				DatabaseCorruption(NULL);

 

-			DBCachedContact *cc = m_cache->AddContactToCache(*(DWORD*)key.mv_data);

-			cc->dbc.dwSignature = DBCONTACT_SIGNATURE;

+			DBCachedContact *cc = m_cache->AddContactToCache(*(MCONTACT*)key.mv_data);

 			cc->dbc.dwEventCount = dbc->dwEventCount;

 			cc->dbc.dwFirstUnread = dbc->dwFirstUnread;

 			cc->dbc.tsFirstUnread = dbc->tsFirstUnread;

@@ -328,18 +318,15 @@ void CDbxMdb::FillContacts()
 		}

 	}

 

-	m_contactCount = 0;

-	for (int i = 0; i < arContacts.getCount(); i++) 

+	for (int i = 0; i < arContacts.getCount(); i++)

 	{

 		DBCachedContact *cc = arContacts[i];

 		CheckProto(cc, "");

 

-		m_contactCount++;

-

 		DBVARIANT dbv; dbv.type = DBVT_DWORD;

 		cc->nSubs = (0 != GetContactSetting(cc->contactID, META_PROTO, "NumContacts", &dbv)) ? -1 : dbv.dVal;

 		if (cc->nSubs != -1) {

-			cc->pSubs = (MCONTACT*)mir_alloc(cc->nSubs*sizeof(MCONTACT));

+			cc->pSubs = (MCONTACT*)mir_alloc(cc->nSubs * sizeof(MCONTACT));

 			for (int k = 0; k < cc->nSubs; k++) {

 				char setting[100];

 				mir_snprintf(setting, _countof(setting), "Handle%d", k);

diff --git a/plugins/Dbx_mdb/src/dbcrypt.cpp b/plugins/Dbx_mdb/src/dbcrypt.cpp
index 76e92cbea8..e860a3c86e 100644
--- a/plugins/Dbx_mdb/src/dbcrypt.cpp
+++ b/plugins/Dbx_mdb/src/dbcrypt.cpp
@@ -53,13 +53,13 @@ CRYPTO_PROVIDER* CDbxMdb::SelectProvider()
 	{

 		txn_ptr txn(m_pMdbEnv);

 

-		MDB_val key = { sizeof(DBKEY_PROVIDER), DBKEY_PROVIDER }, value = { mir_strlen(pProv->pszName) + 1, pProv->pszName };

+		MDB_val key = { sizeof(DBKEY_PROVIDER), (char*)(DBKEY_PROVIDER) }, value = { mir_strlen(pProv->pszName) + 1, pProv->pszName };

 		MDB_CHECK(mdb_put(txn, m_dbCrypto, &key, &value, 0), nullptr);

 

-		key.mv_size = sizeof(DBKEY_IS_ENCRYPTED); key.mv_data = DBKEY_IS_ENCRYPTED; value.mv_size = sizeof(bool); value.mv_data = &bTotalCrypt;

+		key.mv_size = sizeof(DBKEY_IS_ENCRYPTED); key.mv_data = (char*)(DBKEY_IS_ENCRYPTED); value.mv_size = sizeof(bool); value.mv_data = &bTotalCrypt;

 		MDB_CHECK(mdb_put(txn, m_dbCrypto, &key, &value, 0), nullptr);

 

-		if (txn.commit())

+		if (txn.commit() == MDB_SUCCESS)

 			break;

 	}

 

@@ -72,7 +72,7 @@ int CDbxMdb::InitCrypt()
 

 	txn_ptr_ro txn(m_txn);

 

-	MDB_val key = { sizeof(DBKEY_PROVIDER), DBKEY_PROVIDER }, value;

+	MDB_val key = { sizeof(DBKEY_PROVIDER), (char*)(DBKEY_PROVIDER) }, value;

 	if (mdb_get(txn, m_dbCrypto, &key, &value) == MDB_SUCCESS)

 	{

 		pProvider = Crypto_GetProvider((const char*)value.mv_data);

@@ -89,7 +89,7 @@ int CDbxMdb::InitCrypt()
 	if ((m_crypto = pProvider->pFactory()) == nullptr)

 		return 3;

 

-	key.mv_size = sizeof(DBKEY_KEY); key.mv_data = DBKEY_KEY;

+	key.mv_size = sizeof(DBKEY_KEY); key.mv_data = (char*)(DBKEY_KEY);

 	if (mdb_get(txn, m_dbCrypto, &key, &value) == MDB_SUCCESS && (value.mv_size == m_crypto->getKeyLength()))

 	{

 		if (!m_crypto->setKey((const BYTE*)value.mv_data, value.mv_size))

@@ -118,7 +118,7 @@ int CDbxMdb::InitCrypt()
 		StoreKey();

 	}

 

-	key.mv_size = sizeof(DBKEY_IS_ENCRYPTED); key.mv_data = DBKEY_IS_ENCRYPTED;

+	key.mv_size = sizeof(DBKEY_IS_ENCRYPTED); key.mv_data = (char*)(DBKEY_IS_ENCRYPTED);

 	

 	if (mdb_get(txn, m_dbCrypto, &key, &value) == MDB_SUCCESS)

 		m_bEncrypted = *(const bool*)value.mv_data;

@@ -138,9 +138,9 @@ void CDbxMdb::StoreKey()
 	for (;; Remap())

 	{

 		txn_ptr txn(m_pMdbEnv);

-		MDB_val key = { sizeof(DBKEY_KEY), DBKEY_KEY }, value = { iKeyLength, pKey };

+		MDB_val key = { sizeof(DBKEY_KEY), (char*)(DBKEY_KEY) }, value = { iKeyLength, pKey };

 		mdb_put(txn, m_dbCrypto, &key, &value, 0);

-		if (txn.commit())

+		if (txn.commit() == MDB_SUCCESS)

 			break;

 	}

 	SecureZeroMemory(pKey, iKeyLength);

@@ -173,7 +173,13 @@ int CDbxMdb::EnableEncryption(bool bEncrypted)
 #ifdef DEBUG

 	{

 		txn_ptr_ro txn(m_txn);

+

+		MDB_stat st;

+		mdb_stat(txn, m_dbEvents, &st);

+

 		std::vector<MEVENT> lstEvents;

+		lstEvents.reserve(st.ms_entries);

+

 		{

 			cursor_ptr_ro cursor(m_curEvents);

 			MDB_val key, data;

@@ -183,8 +189,9 @@ int CDbxMdb::EnableEncryption(bool bEncrypted)
 				lstEvents.push_back(hDbEvent);

 			}

 		}

-		for (MEVENT &hDbEvent : lstEvents)

+		for (auto it = lstEvents.begin(); it != lstEvents.end(); ++it)

 		{

+			MEVENT &hDbEvent = *it;

 			MDB_val key = { sizeof(MEVENT), &hDbEvent }, data;

 			mdb_get(txn, m_dbEvents, &key, &data);

 

@@ -224,7 +231,7 @@ int CDbxMdb::EnableEncryption(bool bEncrypted)
 					memcpy(pNewDBEvent, pNewEvent, sizeof(DBEvent));

 					memcpy(pNewDBEvent + sizeof(DBEvent), pNewBlob, nNewBlob);

 

-					if (txn.commit())

+					if (txn.commit() == MDB_SUCCESS)

 						break;

 				}

 			}

@@ -235,9 +242,9 @@ int CDbxMdb::EnableEncryption(bool bEncrypted)
 	for (;; Remap())

 	{

 		txn_ptr txn(m_pMdbEnv);

-		MDB_val key = { sizeof(DBKEY_IS_ENCRYPTED), DBKEY_IS_ENCRYPTED }, value = { sizeof(bool), &bEncrypted };

+		MDB_val key = { sizeof(DBKEY_IS_ENCRYPTED), (char*)(DBKEY_IS_ENCRYPTED) }, value = { sizeof(bool), &bEncrypted };

 		MDB_CHECK(mdb_put(txn, m_dbCrypto, &key, &value, 0), 1);

-		if (txn.commit())

+		if (txn.commit() == MDB_SUCCESS)

 			break;

 	}

 	m_bEncrypted = bEncrypted;

diff --git a/plugins/Dbx_mdb/src/dbevents.cpp b/plugins/Dbx_mdb/src/dbevents.cpp
index f8505825ae..5436cbca38 100644
--- a/plugins/Dbx_mdb/src/dbevents.cpp
+++ b/plugins/Dbx_mdb/src/dbevents.cpp
@@ -35,7 +35,6 @@ STDMETHODIMP_(MEVENT) CDbxMdb::AddEvent(MCONTACT contactID, DBEVENTINFO *dbei)
 	if (dbei->timestamp == 0) return 0;

 

 	DBEvent dbe;

-	dbe.dwSignature = DBEVENT_SIGNATURE;

 	dbe.contactID = contactID; // store native or subcontact's id

 	dbe.ofsModuleName = GetModuleNameOfs(dbei->szModule);

 

@@ -97,7 +96,7 @@ STDMETHODIMP_(MEVENT) CDbxMdb::AddEvent(MCONTACT contactID, DBEVENTINFO *dbei)
 		// add a sorting key

 		DBEventSortingKey key2 = { dwEventId, dbe.timestamp, contactID };

 		key.mv_size = sizeof(key2); key.mv_data = &key2;

-		data.mv_size = 1; data.mv_data = "";

+		data.mv_size = 1; data.mv_data = (char*)("");

 		MDB_CHECK(mdb_put(txn, m_dbEventsSort, &key, &data, 0), 0);

 

 		cc->Advance(dwEventId, dbe);

@@ -115,7 +114,7 @@ STDMETHODIMP_(MEVENT) CDbxMdb::AddEvent(MCONTACT contactID, DBEVENTINFO *dbei)
 			MDB_CHECK(mdb_put(txn, m_dbContacts, &keyc, &datac, 0), 0);

 		}

 

-		if (txn.commit())

+		if (txn.commit() == MDB_SUCCESS)

 			break;

 	}

 

@@ -148,7 +147,7 @@ STDMETHODIMP_(BOOL) CDbxMdb::DeleteEvent(MCONTACT contactID, MEVENT hDbEvent)
 

 	const auto Snapshot = [&]() { cc->Snapshot(); if (cc2) cc2->Snapshot(); };

 	const auto Revert = [&]() { cc->Revert(); if (cc2) cc2->Revert(); };

-

+	

 	for (Snapshot();; Revert(), Remap())

 	{

 		DBEventSortingKey key2 = { hDbEvent, dbe.timestamp, contactID };

@@ -187,7 +186,7 @@ STDMETHODIMP_(BOOL) CDbxMdb::DeleteEvent(MCONTACT contactID, MEVENT hDbEvent)
 		key.mv_size = sizeof(MEVENT); key.mv_data = &hDbEvent;

 		MDB_CHECK(mdb_del(txn, m_dbEvents, &key, &data), 1);

 

-		if (txn.commit())

+		if (txn.commit() == MDB_SUCCESS)

 			break;

 	}

 

@@ -203,9 +202,7 @@ STDMETHODIMP_(LONG) CDbxMdb::GetBlobSize(MEVENT hDbEvent)
 	MDB_val key = { sizeof(MEVENT), &hDbEvent }, data;

 	if (mdb_get(txn, m_dbEvents, &key, &data) != MDB_SUCCESS)

 		return -1;

-

-	const DBEvent *dbe = (const DBEvent*)data.mv_data;

-	return (dbe->dwSignature == DBEVENT_SIGNATURE) ? dbe->cbBlob : 0;

+	return ((const DBEvent*)data.mv_data)->cbBlob;

 }

 

 STDMETHODIMP_(BOOL) CDbxMdb::GetEvent(MEVENT hDbEvent, DBEVENTINFO *dbei)

@@ -223,8 +220,6 @@ STDMETHODIMP_(BOOL) CDbxMdb::GetEvent(MEVENT hDbEvent, DBEVENTINFO *dbei)
 		return 1;

 

 	const DBEvent *dbe = (const DBEvent*)data.mv_data;

-	if (dbe->dwSignature != DBEVENT_SIGNATURE)

-		return 1;

 

 	dbei->szModule = GetModuleNameByOfs(dbe->ofsModuleName);

 	dbei->timestamp = dbe->timestamp;

@@ -283,7 +278,7 @@ STDMETHODIMP_(BOOL) CDbxMdb::MarkEventRead(MCONTACT contactID, MEVENT hDbEvent)
 		return -1;

 

 	DWORD wRetVal = -1;

-

+	

 	for (cc->Snapshot();; cc->Revert(), Remap())

 	{

 		txn_ptr txn(m_pMdbEnv);

@@ -292,8 +287,7 @@ STDMETHODIMP_(BOOL) CDbxMdb::MarkEventRead(MCONTACT contactID, MEVENT hDbEvent)
 		MDB_CHECK(mdb_get(txn, m_dbEvents, &key, &data), -1);

 

 		const DBEvent *cdbe = (const DBEvent*)data.mv_data;

-		if (cdbe->dwSignature != DBEVENT_SIGNATURE)

-			return -1;

+

 		if (cdbe->markedRead())

 			return cdbe->flags;

 

@@ -309,7 +303,7 @@ STDMETHODIMP_(BOOL) CDbxMdb::MarkEventRead(MCONTACT contactID, MEVENT hDbEvent)
 		data.mv_data = &cc->dbc; data.mv_size = sizeof(cc->dbc);

 		MDB_CHECK(mdb_put(txn, m_dbContacts, &key, &data, 0), -1);

 

-		if (txn.commit())

+		if (txn.commit() == MDB_SUCCESS)

 			break;

 	}

 

@@ -329,11 +323,11 @@ STDMETHODIMP_(MCONTACT) CDbxMdb::GetEventContact(MEVENT hDbEvent)
 		return INVALID_CONTACT_ID;

 

 	const DBEvent *dbe = (const DBEvent*)data.mv_data;

-	return (dbe->dwSignature == DBEVENT_SIGNATURE) ? dbe->contactID : INVALID_CONTACT_ID;

+	return dbe->contactID;

 }

 

-thread_local DWORD t_tsLast;

-thread_local MEVENT t_evLast;

+thread_local DWORD t_tsLast = 0;

+thread_local MEVENT t_evLast = 0;

 

 STDMETHODIMP_(MEVENT) CDbxMdb::FindFirstEvent(MCONTACT contactID)

 {

@@ -420,7 +414,8 @@ STDMETHODIMP_(MEVENT) CDbxMdb::FindPrevEvent(MCONTACT contactID, MEVENT hDbEvent
 

 	txn_ptr_ro txn(m_txn);

 

-	if (t_evLast != hDbEvent) {

+	if (t_evLast != hDbEvent) 

+	{

 		MDB_val key = { sizeof(MEVENT), &hDbEvent };

 		if (mdb_get(txn, m_dbEvents, &key, &data) != MDB_SUCCESS)

 			return 0;

diff --git a/plugins/Dbx_mdb/src/dbintf.cpp b/plugins/Dbx_mdb/src/dbintf.cpp
index 353fc0cd5a..1f0befba61 100644
--- a/plugins/Dbx_mdb/src/dbintf.cpp
+++ b/plugins/Dbx_mdb/src/dbintf.cpp
@@ -25,19 +25,19 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 

 static int ModCompare(const ModuleName *mn1, const ModuleName *mn2)

 {

-	return strcmp(mn1->name, mn2->name);

+	return strcmp(mn1->szName, mn2->szName);

 }

 

 static int OfsCompare(const ModuleName *mn1, const ModuleName *mn2)

 {

-	return (mn1->ofs - mn2->ofs);

+	return (mn1->dwId - mn2->dwId);

 }

 

 CDbxMdb::CDbxMdb(const TCHAR *tszFileName, int iMode) :

 	m_safetyMode(true),

 	m_bReadOnly((iMode & DBMODE_READONLY) != 0),

 	m_bShared((iMode & DBMODE_SHARED) != 0),

-	m_dwMaxContactId(1),

+	m_maxContactId(1),

 	m_lMods(50, ModCompare),

 	m_lOfs(50, OfsCompare),

 	m_lResidentSettings(50, strcmp)

@@ -117,7 +117,7 @@ int CDbxMdb::Load(bool bSkipInit)
 			mdb_put(trnlck, m_dbGlobal, &key, &data, 0);

 

 			keyVal = 0;

-			DBContact dbc = { DBCONTACT_SIGNATURE, 0, 0, 0 };

+			DBContact dbc = { 0, 0, 0 };

 			data.mv_data = &dbc; data.mv_size = sizeof(dbc);

 			mdb_put(trnlck, m_dbContacts, &key, &data, 0);

 		}

@@ -130,15 +130,21 @@ int CDbxMdb::Load(bool bSkipInit)
 

 			mdb_cursor_open(m_txn, m_dbEvents, &m_curEvents);

 			if (mdb_cursor_get(m_curEvents, &key, &val, MDB_LAST) == MDB_SUCCESS)

-				m_dwMaxEventId = *(MEVENT*)key.mv_data + 1;

+				m_dwMaxEventId = *(MEVENT*)key.mv_data;

 

 			mdb_cursor_open(m_txn, m_dbEventsSort, &m_curEventsSort);

 			mdb_cursor_open(m_txn, m_dbSettings, &m_curSettings);

 			mdb_cursor_open(m_txn, m_dbModules, &m_curModules);

+			if (mdb_cursor_get(m_curModules, &key, &val, MDB_LAST) == MDB_SUCCESS)

+				m_maxModuleID = *(DWORD*)key.mv_data;

 

 			mdb_cursor_open(m_txn, m_dbContacts, &m_curContacts);

 			if (mdb_cursor_get(m_curContacts, &key, &val, MDB_LAST) == MDB_SUCCESS)

-				m_dwMaxContactId = *(DWORD*)key.mv_data + 1;

+				m_maxContactId = *(MCONTACT*)key.mv_data;

+

+			MDB_stat st;

+			mdb_stat(m_txn, m_dbContacts, &st);

+			m_contactCount = st.ms_entries;

 

 			mdb_txn_reset(m_txn);

 		}

@@ -174,25 +180,23 @@ int CDbxMdb::Create(void)
 	return (Map() == MDB_SUCCESS) ? 0 : EGROKPRF_CANTREAD;

 }

 

+size_t iDefHeaderOffset = 16;

+BYTE bDefHeader[] = { 0xDE, 0xC0, 0xEF, 0xBE };

+

 int CDbxMdb::Check(void)

 {

-	HANDLE hFile = CreateFile(m_tszProfileName, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);

-	if (hFile == INVALID_HANDLE_VALUE)

+	FILE *pFile = _tfopen(m_tszProfileName, _T("rb"));

+	if (pFile == nullptr)

 		return EGROKPRF_CANTREAD;

 

-	LARGE_INTEGER iFileSize;

-	GetFileSizeEx(hFile, &iFileSize);

-	m_dwFileSize = iFileSize.LowPart;

+	fseek(pFile, iDefHeaderOffset, SEEK_SET);

+	BYTE buf[_countof(bDefHeader)];

+	if (fread(buf, 1, _countof(buf), pFile) != _countof(buf))

+		return EGROKPRF_DAMAGED;

 

-	DWORD dummy = 0;

-	char buf[32];

-	if (!ReadFile(hFile, buf, sizeof(buf), &dummy, NULL)) {

-		CloseHandle(hFile);

-		return EGROKPRF_CANTREAD;

-	}

+	fclose(pFile);

 

-	CloseHandle(hFile);

-	return (memcmp(buf + 16, "\xDE\xC0\xEF\xBE", 4)) ? EGROKPRF_UNKHEADER : 0;

+	return (memcmp(buf, bDefHeader, _countof(bDefHeader))) ? EGROKPRF_UNKHEADER : 0;

 }

 

 int CDbxMdb::PrepareCheck(int*)

@@ -209,10 +213,7 @@ STDMETHODIMP_(void) CDbxMdb::SetCacheSafetyMode(BOOL bIsSet)
 

 int CDbxMdb::Map()

 {

-	m_dwFileSize += 0x100000;

-	mdb_env_set_mapsize(m_pMdbEnv, m_dwFileSize);

-

-	unsigned int mode = MDB_NOSYNC | MDB_NOSUBDIR | MDB_NOLOCK | MDB_NOTLS | MDB_WRITEMAP;

+	unsigned int mode = MDB_NOSYNC | MDB_NOSUBDIR | /*MDB_NOLOCK |*/ MDB_NOTLS | MDB_WRITEMAP;

 	if (m_bReadOnly)

 		mode |= MDB_RDONLY;

 	return mdb_env_open(m_pMdbEnv, _T2A(m_tszProfileName), mode, 0664);

@@ -220,11 +221,12 @@ int CDbxMdb::Map()
 

 bool CDbxMdb::Remap()

 {

-	mir_cslock lck(m_csDbAccess);

-	m_dwFileSize += 0x100000;

-	return mdb_env_set_mapsize(m_pMdbEnv, m_dwFileSize) == MDB_SUCCESS;

+	MDB_envinfo ei;

+	mdb_env_info(m_pMdbEnv, &ei);

+	return mdb_env_set_mapsize(m_pMdbEnv, ei.me_mapsize + 0x100000) == MDB_SUCCESS;

 }

 

+

 /////////////////////////////////////////////////////////////////////////////////////////

 

 static DWORD DatabaseCorrupted = 0;

@@ -253,6 +255,14 @@ EXTERN_C void LMDB_FailAssert(void *p, const char *text)
 	((CDbxMdb*)p)->DatabaseCorruption(_A2T(text));

 }

 

+EXTERN_C void LMDB_Log(const char *fmt, ...)

+{

+	va_list args;

+	va_start(args, fmt);

+	CallService(MS_NETLIB_LOG, 0, (LPARAM)(CMStringA().FormatV(fmt, args)));

+	va_end(args);

+}

+

 void CDbxMdb::DatabaseCorruption(const TCHAR *text)

 {

 	int kill = 0;

diff --git a/plugins/Dbx_mdb/src/dbintf.h b/plugins/Dbx_mdb/src/dbintf.h
index 97ec416295..5aeadf3488 100644
--- a/plugins/Dbx_mdb/src/dbintf.h
+++ b/plugins/Dbx_mdb/src/dbintf.h
@@ -37,13 +37,14 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 

 struct ModuleName

 {

-	char *name;

-	DWORD ofs;

+	DWORD dwId;

+	char szName[];

 };

 

 #include <pshpack1.h>

 

-#define DBHEADER_VERSION 3

+#define DBHEADER_VERSION MAKELONG(1, 2)

+

 #define DBHEADER_SIGNATURE  0x40DECADEu

 struct DBHeader

 {

@@ -51,27 +52,15 @@ struct DBHeader
 	DWORD dwVersion;			// database format version

 };

 

-#define DBCONTACT_SIGNATURE 0x43DECADEu

 struct DBContact

 {

-	DWORD dwSignature;

 	DWORD dwEventCount;       // number of events in the chain for this contact

 	DWORD tsFirstUnread;

 	DWORD dwFirstUnread;

 };

 

-#define DBMODULENAME_SIGNATURE 0x4DDECADEu

-struct DBModuleName

-{

-	DWORD dwSignature;

-	BYTE cbName;            // number of characters in this module name

-	char name[];           // name, no nul terminator

-};

-

-#define DBEVENT_SIGNATURE  0x45DECADEu

 struct DBEvent

 {

-	DWORD dwSignature;

 	MCONTACT contactID;     // a contact this event belongs to

 	DWORD ofsModuleName;	// offset to a DBModuleName struct of the name of

 	DWORD timestamp;        // seconds since 00:00:00 01/01/1970

@@ -92,9 +81,27 @@ struct DBEventSortingKey
 

 struct DBSettingKey

 {

-	DWORD dwContactID;

-	DWORD dwOfsModule;

-	char  szSettingName[100];

+	MCONTACT hContact;

+	DWORD dwModuleId;

+	char  szSettingName[];

+};

+

+struct DBSettingValue

+{

+	BYTE type;

+	union

+	{

+		BYTE bVal;

+		WORD wVal;

+		DWORD dwVal;

+		char szVal[];

+

+		struct

+		{

+			size_t nLength;

+			BYTE bVal[];

+		} blob;

+	};

 };

 

 #include <poppack.h>

@@ -124,7 +131,7 @@ struct CDbxMdb : public MIDatabase, public MIDatabaseChecker, public MZeroedObje
 	friend class LMDBEventCursor;

 

 	CDbxMdb(const TCHAR *tszFileName, int mode);

-	~CDbxMdb();

+	virtual ~CDbxMdb();

 

 	int Load(bool bSkipInit);

 	int Create(void);

@@ -138,7 +145,7 @@ struct CDbxMdb : public MIDatabase, public MIDatabaseChecker, public MZeroedObje
 

 	int  PrepareCheck(int*);

 

-	__forceinline LPSTR GetMenuTitle() const { return m_bUsesPassword ? LPGEN("Change/remove password") : LPGEN("Set password"); }

+	__forceinline LPSTR GetMenuTitle() const { return m_bUsesPassword ? (char*)LPGEN("Change/remove password") : (char*)LPGEN("Set password"); }

 

 	__forceinline bool isEncrypted() const { return m_bEncrypted; }

 	__forceinline bool usesPassword() const { return m_bUsesPassword; }

@@ -195,8 +202,8 @@ protected:
 

 	void  FillContacts(void);

 

-	bool  Remap();

 	int   Map();

+	bool  Remap();

 

 protected:

 	TCHAR*   m_tszProfileName;

@@ -235,7 +242,8 @@ protected:
 	MDB_dbi	m_dbContacts;

 	MDB_cursor *m_curContacts;

 

-	DWORD    m_contactCount, m_dwMaxContactId;

+	DWORD    m_contactCount;

+	MCONTACT m_maxContactId;

 

 	void     GatherContactHistory(MCONTACT hContact, LIST<EventItem> &items);

 

@@ -259,10 +267,9 @@ protected:
 	LIST<char> m_lResidentSettings;

 	HANDLE   hEventAddedEvent, hEventDeletedEvent, hEventFilterAddedEvent;

 	MCONTACT m_hLastCachedContact;

-	int      m_maxModuleID;

-	ModuleName *m_lastmn;

+	DWORD      m_maxModuleID;

 

-	void     AddToList(char *name, DWORD ofs);

+	void     AddToList(const char *name, DWORD ofs);

 	DWORD    FindExistingModuleNameOfs(const char *szName);

 	int      InitModuleNames(void);

 	DWORD    GetModuleNameOfs(const char *szName);

diff --git a/plugins/Dbx_mdb/src/dbmodulechain.cpp b/plugins/Dbx_mdb/src/dbmodulechain.cpp
index ddd2296f7f..fc86bad6bc 100644
--- a/plugins/Dbx_mdb/src/dbmodulechain.cpp
+++ b/plugins/Dbx_mdb/src/dbmodulechain.cpp
@@ -23,11 +23,12 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 

 #include "stdafx.h"

 

-void CDbxMdb::AddToList(char *name, DWORD ofs)

+void CDbxMdb::AddToList(const char *szName, DWORD dwId)

 {

-	ModuleName *mn = (ModuleName*)HeapAlloc(m_hModHeap, 0, sizeof(ModuleName));

-	mn->name = name;

-	mn->ofs = ofs;

+	size_t iNameLength = strlen(szName) + 1;

+	ModuleName *mn = (ModuleName*)HeapAlloc(m_hModHeap, 0, sizeof(ModuleName) + iNameLength);

+	mn->dwId = dwId;

+	memcpy(&mn->szName, szName, iNameLength);

 

 	if (m_lMods.getIndex(mn) != -1)

 		DatabaseCorruption(_T("%s (Module Name not unique)"));

@@ -40,44 +41,32 @@ void CDbxMdb::AddToList(char *name, DWORD ofs)
 

 int CDbxMdb::InitModuleNames(void)

 {

-	m_maxModuleID = 0;

-

 	txn_ptr_ro trnlck(m_txn);

 	cursor_ptr_ro cursor(m_curModules);

 

 	MDB_val key, data;

 	while (mdb_cursor_get(cursor, &key, &data, MDB_NEXT) == MDB_SUCCESS) 

 	{

-		DBModuleName *pmod = (DBModuleName*)data.mv_data;

-		if (pmod->dwSignature != DBMODULENAME_SIGNATURE)

-			DatabaseCorruption(NULL);

-

-		char *pVal = (char*)HeapAlloc(m_hModHeap, 0, pmod->cbName+1);

-		memcpy(pVal, pmod->name, pmod->cbName);

-		pVal[pmod->cbName] = 0;

-

-		int moduleId = *(int*)key.mv_data;

-		AddToList(pVal, moduleId);

-

-		if (moduleId > m_maxModuleID)

-			m_maxModuleID = moduleId;

+		DWORD iMod = *(DWORD*)key.mv_data;

+		const char *szMod = (const char*)data.mv_data;

+		AddToList(szMod, iMod);

 	}

 	return 0;

 }

 

+thread_local ModuleName *t_lastmn = nullptr;

+

 DWORD CDbxMdb::FindExistingModuleNameOfs(const char *szName)

 {

-	ModuleName mn = { (char*)szName, 0 };

-	if (m_lastmn && !strcmp(mn.name, m_lastmn->name))

-		return m_lastmn->ofs;

-

-	int index = m_lMods.getIndex(&mn);

-	if (index != -1) {

-		ModuleName *pmn = m_lMods[index];

-		m_lastmn = pmn;

-		return pmn->ofs;

-	}

+	if (t_lastmn && !strcmp(szName, t_lastmn->szName))

+		return t_lastmn->dwId;

 

+	ModuleName *pmn = m_lMods.find((ModuleName*)(szName - sizeof(DWORD))); // crazy hack

+	if (pmn != nullptr)

+	{

+		t_lastmn = pmn;

+		return pmn->dwId;

+	}

 	return 0;

 }

 

@@ -91,30 +80,23 @@ DWORD CDbxMdb::GetModuleNameOfs(const char *szName)
 	if (m_bReadOnly)

 		return 0;

 

-	int nameLen = (int)strlen(szName);

+	size_t nameLen = strlen(szName);

 

-	mir_cslock lck(m_csDbAccess);

+//	mir_cslock lck(m_csDbAccess);

 

 	// need to create the module name

-	int newIdx = ++m_maxModuleID;

-	DBModuleName *pmod = (DBModuleName*)_alloca(sizeof(DBModuleName) + nameLen + 1);

-	pmod->dwSignature = DBMODULENAME_SIGNATURE;

-	pmod->cbName = (char)nameLen;

-	strcpy(pmod->name, szName);

+	DWORD newIdx = InterlockedIncrement(&m_maxModuleID);

 	

-	MDB_val key = { sizeof(int), &newIdx }, data = { sizeof(DBModuleName) + nameLen + 1, pmod };

+	MDB_val key = { sizeof(DWORD), &newIdx }, data = { nameLen + 1, (void*)szName };

 

 	for (;; Remap()) {

 		txn_ptr trnlck(m_pMdbEnv);

 		MDB_CHECK(mdb_put(trnlck, m_dbModules, &key, &data, 0), -1);

-		if (trnlck.commit())

+		if (trnlck.commit() == MDB_SUCCESS)

 			break;

 	}

 

-	// add to cache

-	char *mod = (char*)HeapAlloc(m_hModHeap, 0, nameLen + 1);

-	strcpy(mod, szName);

-	AddToList(mod, newIdx);

+	AddToList(szName, newIdx);

 

 	// quit

 	return newIdx;

@@ -122,19 +104,15 @@ DWORD CDbxMdb::GetModuleNameOfs(const char *szName)
 

 char* CDbxMdb::GetModuleNameByOfs(DWORD ofs)

 {

-	ModuleName mn = { NULL, ofs };

-	int index = m_lOfs.getIndex(&mn);

-	if (index != -1)

-		return m_lOfs[index]->name;

-

-	return NULL;

+	ModuleName *mn = m_lOfs.find((ModuleName*)&ofs);

+	return mn ? mn->szName : nullptr;

 }

 

 STDMETHODIMP_(BOOL) CDbxMdb::EnumModuleNames(DBMODULEENUMPROC pFunc, void *pParam)

 {

 	for (int i = 0; i < m_lMods.getCount(); i++) {

 		ModuleName *pmn = m_lMods[i];

-		if (int ret = pFunc(pmn->name, pmn->ofs, (LPARAM)pParam))

+		if (int ret = pFunc(pmn->szName, pmn->dwId, (LPARAM)pParam))

 			return ret;

 	}

 	return 0;

diff --git a/plugins/Dbx_mdb/src/dbsettings.cpp b/plugins/Dbx_mdb/src/dbsettings.cpp
index ca31bb59c9..ec9a2549be 100644
--- a/plugins/Dbx_mdb/src/dbsettings.cpp
+++ b/plugins/Dbx_mdb/src/dbsettings.cpp
@@ -58,9 +58,8 @@ int CDbxMdb::GetContactSettingWorker(MCONTACT contactID, LPCSTR szModule, LPCSTR
 	if (szSetting == NULL || szModule == NULL)

 		return 1;

 

-	// the db format can't tolerate more than 255 bytes of space (incl. null) for settings+module name

-	int settingNameLen = (int)strlen(szSetting);

-	int moduleNameLen = (int)strlen(szModule);

+	size_t settingNameLen = strlen(szSetting);

+	size_t moduleNameLen = strlen(szModule);

 

 LBL_Seek:

 	char *szCachedSettingName = m_cache->GetCachedSetting(szModule, szSetting, moduleNameLen, settingNameLen);

@@ -106,10 +105,13 @@ LBL_Seek:
 

 	txn_ptr_ro trnlck(m_txn);

 

-	DBSettingKey keySearch = { contactID, GetModuleNameOfs(szModule) };

-	strncpy_s(keySearch.szSettingName, szSetting, _TRUNCATE);

+	DBSettingKey *keyVal = (DBSettingKey *)_alloca(sizeof(DBSettingKey) + settingNameLen + 1);

+	keyVal->hContact = contactID;

+	keyVal->dwModuleId = GetModuleNameOfs(szModule);

+	memcpy(&keyVal->szSettingName, szSetting, settingNameLen + 1);

+

 

-	MDB_val key = { 2 * sizeof(DWORD) + settingNameLen, &keySearch }, data;

+	MDB_val key = { sizeof(DBSettingKey) + settingNameLen + 1, keyVal }, data;

 	if (mdb_get(trnlck, m_dbSettings, &key, &data) != MDB_SUCCESS) 

 	{

 		// try to get the missing mc setting from the active sub

@@ -119,7 +121,7 @@ LBL_Seek:
 			{

 				if (szModule = GetContactProto(contactID)) 

 				{

-					moduleNameLen = (int)strlen(szModule);

+					moduleNameLen = strlen(szModule);

 					goto LBL_Seek;

 				}

 			}

@@ -361,8 +363,8 @@ STDMETHODIMP_(BOOL) CDbxMdb::WriteContactSetting(MCONTACT contactID, DBCONTACTWR
 		return 1;

 

 	// the db format can't tolerate more than 255 bytes of space (incl. null) for settings+module name

-	int settingNameLen = (int)strlen(dbcws->szSetting);

-	int moduleNameLen = (int)strlen(dbcws->szModule);

+	size_t settingNameLen = strlen(dbcws->szSetting);

+	size_t moduleNameLen = strlen(dbcws->szModule);

 

 	// used for notifications

 	DBCONTACTWRITESETTING dbcwNotif = *dbcws;

@@ -455,12 +457,13 @@ STDMETHODIMP_(BOOL) CDbxMdb::WriteContactSetting(MCONTACT contactID, DBCONTACTWR
 	}

 	else m_cache->GetCachedValuePtr(contactID, szCachedSettingName, -1);

 

-	DBSettingKey keySearch;

-	keySearch.dwContactID = contactID;

-	keySearch.dwOfsModule = GetModuleNameOfs(dbcws->szModule);

-	strncpy_s(keySearch.szSettingName, dbcws->szSetting, _TRUNCATE);

+	DBSettingKey *keyVal = (DBSettingKey *)_alloca(sizeof(DBSettingKey) + settingNameLen + 1);

+	keyVal->hContact = contactID;

+	keyVal->dwModuleId = GetModuleNameOfs(dbcws->szModule);

+	memcpy(&keyVal->szSettingName, dbcws->szSetting, settingNameLen + 1);

 

-	MDB_val key = { 2 * sizeof(DWORD) + settingNameLen, &keySearch }, data;

+

+	MDB_val key = { sizeof(DBSettingKey) + settingNameLen + 1, keyVal }, data;

 

 	switch (dbcwWork.value.type) {

 	case DBVT_BYTE:  data.mv_size = 2; break;

@@ -501,7 +504,7 @@ STDMETHODIMP_(BOOL) CDbxMdb::WriteContactSetting(MCONTACT contactID, DBCONTACTWR
 			memcpy(pBlob, dbcwWork.value.pbVal, dbcwWork.value.cpbVal);

 		}

 

-		if (trnlck.commit())

+		if (trnlck.commit() == MDB_SUCCESS)

 			break;

 	}

 

@@ -515,55 +518,49 @@ STDMETHODIMP_(BOOL) CDbxMdb::DeleteContactSetting(MCONTACT contactID, LPCSTR szM
 	if (!szModule || !szSetting)

 		return 1;

 

-	int settingNameLen = (int)strlen(szSetting);

-	int moduleNameLen = (int)strlen(szModule);

+	size_t settingNameLen = strlen(szSetting);

+	size_t moduleNameLen = strlen(szModule);

 

-	MCONTACT saveContact = contactID;

+	char *szCachedSettingName = m_cache->GetCachedSetting(szModule, szSetting, moduleNameLen, settingNameLen);

+

+	if (szCachedSettingName[-1] == 0)  // it's not a resident variable

 	{

-		mir_cslock lck(m_csDbAccess);

-		char *szCachedSettingName = m_cache->GetCachedSetting(szModule, szSetting, moduleNameLen, settingNameLen);

-		if (szCachedSettingName[-1] == 0) { // it's not a resident variable

-			DBSettingKey keySearch;

-			keySearch.dwContactID = contactID;

-			keySearch.dwOfsModule = GetModuleNameOfs(szModule);

-			strncpy_s(keySearch.szSettingName, szSetting, _TRUNCATE);

+		DBSettingKey *keyVal = (DBSettingKey*)_alloca(sizeof(DBSettingKey) + settingNameLen + 1);

+		keyVal->hContact = contactID;

+		keyVal->dwModuleId = GetModuleNameOfs(szModule);

+		memcpy(&keyVal->szSettingName, szSetting, settingNameLen + 1);

 

-			MDB_val key = { 2 * sizeof(DWORD) + settingNameLen, &keySearch }, data;

+		MDB_val key = { sizeof(DBSettingKey) + settingNameLen + 1, keyVal };

 

-			for (;; Remap()) 

-			{

-				txn_ptr trnlck(m_pMdbEnv);

-				MDB_CHECK(mdb_del(trnlck, m_dbSettings, &key, &data), 1);

-				if (trnlck.commit())

-					break;

-			}

+		for (;; Remap()) 

+		{

+			txn_ptr trnlck(m_pMdbEnv);

+			MDB_CHECK(mdb_del(trnlck, m_dbSettings, &key, nullptr), 1);

+			if (trnlck.commit() == MDB_SUCCESS)

+				break;

 		}

-

-		m_cache->GetCachedValuePtr(saveContact, szCachedSettingName, -1);

 	}

 

+	m_cache->GetCachedValuePtr(contactID, szCachedSettingName, -1);

+

 	// notify

 	DBCONTACTWRITESETTING dbcws = { 0 };

 	dbcws.szModule = szModule;

 	dbcws.szSetting = szSetting;

 	dbcws.value.type = DBVT_DELETED;

-	NotifyEventHooks(hSettingChangeEvent, saveContact, (LPARAM)&dbcws);

+	NotifyEventHooks(hSettingChangeEvent, contactID, (LPARAM)&dbcws);

 	return 0;

 }

 

 STDMETHODIMP_(BOOL) CDbxMdb::EnumContactSettings(MCONTACT contactID, DBCONTACTENUMSETTINGS* dbces)

 {

-	if (!dbces->szModule)

-		return -1;

-

 	int result = -1;

 

-	DBSettingKey keySearch;

-	keySearch.dwContactID = contactID;

-	keySearch.dwOfsModule = GetModuleNameOfs(dbces->szModule);

-	memset(keySearch.szSettingName, 0, sizeof(keySearch.szSettingName));

+	DBSettingKey keySearch = { 0 };

+	keySearch.hContact = contactID;

+	keySearch.dwModuleId = GetModuleNameOfs(dbces->szModule);

 

-	txn_ptr_ro trnlck(m_txn);

+	txn_ptr_ro txn(m_txn);

 	cursor_ptr_ro cursor(m_curSettings);

 

 	MDB_val key = { sizeof(keySearch), &keySearch }, data;

@@ -571,12 +568,9 @@ STDMETHODIMP_(BOOL) CDbxMdb::EnumContactSettings(MCONTACT contactID, DBCONTACTEN
 	for (int res = mdb_cursor_get(cursor, &key, &data, MDB_SET_RANGE); res == MDB_SUCCESS; res = mdb_cursor_get(cursor, &key, &data, MDB_NEXT))

 	{

 		const DBSettingKey *pKey = (const DBSettingKey*)key.mv_data;

-		if (pKey->dwContactID != contactID || pKey->dwOfsModule != keySearch.dwOfsModule)

-			return result;

-

-		char szSetting[256];

-		strncpy_s(szSetting, pKey->szSettingName, key.mv_size - sizeof(DWORD)* 2);

-		result = (dbces->pfnEnumProc)(szSetting, dbces->lParam);

+		if (pKey->hContact != contactID || pKey->dwModuleId != keySearch.dwModuleId)

+			break;

+		result = (dbces->pfnEnumProc)(pKey->szSettingName, dbces->lParam);

 	}

 

 	return result;

diff --git a/plugins/Dbx_mdb/src/lmdb/lmdb.h b/plugins/Dbx_mdb/src/lmdb/lmdb.h
index 747d2bbadd..3cce100537 100644
--- a/plugins/Dbx_mdb/src/lmdb/lmdb.h
+++ b/plugins/Dbx_mdb/src/lmdb/lmdb.h
@@ -172,8 +172,6 @@
 #	include <inttypes.h>
 #endif
 
-#define MDB_VL32 1
-
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/plugins/Dbx_mdb/src/lmdb/mdb.c b/plugins/Dbx_mdb/src/lmdb/mdb.c
index 4ea8982871..5fbe9beb9e 100644
--- a/plugins/Dbx_mdb/src/lmdb/mdb.c
+++ b/plugins/Dbx_mdb/src/lmdb/mdb.c
@@ -1,10914 +1,10924 @@
-/** @file mdb.c

- *	@brief Lightning memory-mapped database library

- *

- *	A Btree-based database management library modeled loosely on the

- *	BerkeleyDB API, but much simplified.

- */

-/*

- * Copyright 2011-2016 Howard Chu, Symas Corp.

- * All rights reserved.

- *

- * Redistribution and use in source and binary forms, with or without

- * modification, are permitted only as authorized by the OpenLDAP

- * Public License.

- *

- * A copy of this license is available in the file LICENSE in the

- * top-level directory of the distribution or, alternatively, at

- * <http://www.OpenLDAP.org/license.html>.

- *

- * This code is derived from btree.c written by Martin Hedenfalk.

- *

- * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>

- *

- * Permission to use, copy, modify, and distribute this software for any

- * purpose with or without fee is hereby granted, provided that the above

- * copyright notice and this permission notice appear in all copies.

- *

- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

- */

-#ifndef _GNU_SOURCE

-#define _GNU_SOURCE 1

-#endif

-

-#define MDB_VL32 1

-

-#ifdef _WIN64

-#	pragma comment(lib, "lib/x64/ntdll.lib")

-#else

-#	pragma comment(lib, "lib/x86/ntdll.lib")

-#endif

-

-#pragma warning(disable: 4706)

-

-#if defined(MDB_VL32) || defined(__WIN64__)

-#define _FILE_OFFSET_BITS	64

-#endif

-#ifdef _WIN32

-#include <malloc.h>

-#include <windows.h>

-

-/* We use native NT APIs to setup the memory map, so that we can

- * let the DB file grow incrementally instead of always preallocating

- * the full size. These APIs are defined in <wdm.h> and <ntifs.h>

- * but those headers are meant for driver-level development and

- * conflict with the regular user-level headers, so we explicitly

- * declare them here. Using these APIs also means we must link to

- * ntdll.dll, which is not linked by default in user code.

- */

-

-NTSTATUS WINAPI

-	NtCreateSection(OUT PHANDLE sh, IN ACCESS_MASK acc,

-	IN void * oa OPTIONAL,

-	IN PLARGE_INTEGER ms OPTIONAL,

-	IN ULONG pp, IN ULONG aa, IN HANDLE fh OPTIONAL);

-

-typedef enum _SECTION_INHERIT {

-	ViewShare = 1,

-	ViewUnmap = 2

-} SECTION_INHERIT;

-

-NTSTATUS WINAPI

-	NtMapViewOfSection(IN PHANDLE sh, IN HANDLE ph,

-	IN OUT PVOID *addr, IN ULONG_PTR zbits,

-	IN SIZE_T cs, IN OUT PLARGE_INTEGER off OPTIONAL,

-	IN OUT PSIZE_T vs, IN SECTION_INHERIT ih,

-	IN ULONG at, IN ULONG pp);

-

-NTSTATUS WINAPI

-	NtClose(HANDLE h);

-

-/** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it

- *  as int64 which is wrong. MSVC doesn't define it at all, so just

- *  don't use it.

- */

-#define MDB_PID_T	int

-#define MDB_THR_T	DWORD

-#include <sys/types.h>

-#include <sys/stat.h>

-#ifdef __GNUC__

-# include <sys/param.h>

-#else

-# define LITTLE_ENDIAN	1234

-# define BIG_ENDIAN	4321

-# define BYTE_ORDER	LITTLE_ENDIAN

-# ifndef SSIZE_MAX

-#  define SSIZE_MAX	INT_MAX

-# endif

-#endif

-#else

-#include <sys/types.h>

-#include <sys/stat.h>

-#define MDB_PID_T	pid_t

-#define MDB_THR_T	pthread_t

-#include <sys/param.h>

-#include <sys/uio.h>

-#include <sys/mman.h>

-#ifdef HAVE_SYS_FILE_H

-#include <sys/file.h>

-#endif

-#include <fcntl.h>

-#endif

-

-#if defined(__mips) && defined(__linux)

-/* MIPS has cache coherency issues, requires explicit cache control */

-#include <asm/cachectl.h>

-extern int cacheflush(char *addr, int nbytes, int cache);

-#define CACHEFLUSH(addr, bytes, cache)	cacheflush(addr, bytes, cache)

-#else

-#define CACHEFLUSH(addr, bytes, cache)

-#endif

-

-#if defined(__linux) && !defined(MDB_FDATASYNC_WORKS)

-/** fdatasync is broken on ext3/ext4fs on older kernels, see

- *	description in #mdb_env_open2 comments. You can safely

- *	define MDB_FDATASYNC_WORKS if this code will only be run

- *	on kernels 3.6 and newer.

- */

-#define	BROKEN_FDATASYNC

-#endif

-

-#include <errno.h>

-#include <limits.h>

-#include <stddef.h>

-#if _MSC_VER < 1800

-#	include <msapi/inttypes.h>

-#else

-#	include <inttypes.h>

-#endif

-#include <stdio.h>

-#include <stdlib.h>

-#include <string.h>

-#include <time.h>

-

-#ifdef _MSC_VER

-#include <io.h>

-typedef SSIZE_T	ssize_t;

-#else

-#include <unistd.h>

-#endif

-

-#if defined(__sun) || defined(ANDROID)

-/* Most platforms have posix_memalign, older may only have memalign */

-#define HAVE_MEMALIGN	1

-#include <malloc.h>

-#endif

-

-#if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))

-#include <netinet/in.h>

-#include <resolv.h>	/* defines BYTE_ORDER on HPUX and Solaris */

-#endif

-

-#if defined(__APPLE__) || defined (BSD)

-# if !(defined(MDB_USE_POSIX_MUTEX) || defined(MDB_USE_POSIX_SEM))

-# define MDB_USE_SYSV_SEM	1

-# endif

-# define MDB_FDATASYNC		fsync

-#elif defined(ANDROID)

-# define MDB_FDATASYNC		fsync

-#endif

-

-#ifndef _WIN32

-#include <pthread.h>

-#ifdef MDB_USE_POSIX_SEM

-# define MDB_USE_HASH		1

-#include <semaphore.h>

-#elif defined(MDB_USE_SYSV_SEM)

-#include <sys/ipc.h>

-#include <sys/sem.h>

-#ifdef _SEM_SEMUN_UNDEFINED

-union semun {

-	int val;

-	struct semid_ds *buf;

-	unsigned short *array;

-};

-#endif /* _SEM_SEMUN_UNDEFINED */

-#else

-#define MDB_USE_POSIX_MUTEX	1

-#endif /* MDB_USE_POSIX_SEM */

-#endif /* !_WIN32 */

-

-#if defined(_WIN32) + defined(MDB_USE_POSIX_SEM) + defined(MDB_USE_SYSV_SEM) \

-	+ defined(MDB_USE_POSIX_MUTEX) != 1

-# error "Ambiguous shared-lock implementation"

-#endif

-

-#ifdef USE_VALGRIND

-#include <valgrind/memcheck.h>

-#define VGMEMP_CREATE(h,r,z)    VALGRIND_CREATE_MEMPOOL(h,r,z)

-#define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)

-#define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)

-#define VGMEMP_DESTROY(h)	VALGRIND_DESTROY_MEMPOOL(h)

-#define VGMEMP_DEFINED(a,s)	VALGRIND_MAKE_MEM_DEFINED(a,s)

-#else

-#define VGMEMP_CREATE(h,r,z)

-#define VGMEMP_ALLOC(h,a,s)

-#define VGMEMP_FREE(h,a)

-#define VGMEMP_DESTROY(h)

-#define VGMEMP_DEFINED(a,s)

-#endif

-

-#ifndef BYTE_ORDER

-# if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))

-/* Solaris just defines one or the other */

-#  define LITTLE_ENDIAN	1234

-#  define BIG_ENDIAN	4321

-#  ifdef _LITTLE_ENDIAN

-#   define BYTE_ORDER  LITTLE_ENDIAN

-#  else

-#   define BYTE_ORDER  BIG_ENDIAN

-#  endif

-# else

-#  define BYTE_ORDER   __BYTE_ORDER

-# endif

-#endif

-

-#ifndef LITTLE_ENDIAN

-#define LITTLE_ENDIAN	__LITTLE_ENDIAN

-#endif

-#ifndef BIG_ENDIAN

-#define BIG_ENDIAN	__BIG_ENDIAN

-#endif

-

-#if defined(__i386) || defined(__x86_64) || defined(_M_IX86)

-#define MISALIGNED_OK	1

-#endif

-

-#include "lmdb.h"

-#include "midl.h"

-

-#if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)

-# error "Unknown or unsupported endianness (BYTE_ORDER)"

-#elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF

-# error "Two's complement, reasonably sized integer types, please"

-#endif

-

-#ifdef __GNUC__

-/** Put infrequently used env functions in separate section */

-# ifdef __APPLE__

-#  define	ESECT	__attribute__ ((section("__TEXT,text_env")))

-# else

-#  define	ESECT	__attribute__ ((section("text_env")))

-# endif

-#else

-#define ESECT

-#endif

-

-#ifdef _WIN32

-#define CALL_CONV WINAPI

-#else

-#define CALL_CONV

-#endif

-

-/** @defgroup internal	LMDB Internals

- *	@{

- */

-/** @defgroup compat	Compatibility Macros

- *	A bunch of macros to minimize the amount of platform-specific ifdefs

- *	needed throughout the rest of the code. When the features this library

- *	needs are similar enough to POSIX to be hidden in a one-or-two line

- *	replacement, this macro approach is used.

- *	@{

- */

-

-	/** Features under development */

-#ifndef MDB_DEVEL

-#define MDB_DEVEL 0

-#endif

-

-	/** Wrapper around __func__, which is a C99 feature */

-#if __STDC_VERSION__ >= 199901L

-# define mdb_func_	__func__

-#elif __GNUC__ >= 2 || _MSC_VER >= 1300

-# define mdb_func_	__FUNCTION__

-#else

-/* If a debug message says <mdb_unknown>(), update the #if statements above */

-# define mdb_func_	"<mdb_unknown>"

-#endif

-

-/* Internal error codes, not exposed outside liblmdb */

-#define	MDB_NO_ROOT		(MDB_LAST_ERRCODE + 10)

-#ifdef _WIN32

-#define MDB_OWNERDEAD	((int) WAIT_ABANDONED)

-#elif defined MDB_USE_SYSV_SEM

-#define MDB_OWNERDEAD	(MDB_LAST_ERRCODE + 11)

-#elif defined(MDB_USE_POSIX_MUTEX) && defined(EOWNERDEAD)

-#define MDB_OWNERDEAD	EOWNERDEAD	/**< #LOCK_MUTEX0() result if dead owner */

-#endif

-

-#ifdef __GLIBC__

-#define	GLIBC_VER	((__GLIBC__ << 16 )| __GLIBC_MINOR__)

-#endif

-/** Some platforms define the EOWNERDEAD error code

- * even though they don't support Robust Mutexes.

- * Compile with -DMDB_USE_ROBUST=0, or use some other

- * mechanism like -DMDB_USE_SYSV_SEM instead of

- * -DMDB_USE_POSIX_MUTEX. (SysV semaphores are

- * also Robust, but some systems don't support them

- * either.)

- */

-#ifndef MDB_USE_ROBUST

-/* Android currently lacks Robust Mutex support. So does glibc < 2.4. */

-# if defined(MDB_USE_POSIX_MUTEX) && (defined(ANDROID) || \

-	(defined(__GLIBC__) && GLIBC_VER < 0x020004))

-#  define MDB_USE_ROBUST	0

-# else

-#  define MDB_USE_ROBUST	1

-/* glibc < 2.12 only provided _np API */

-#  if defined(__GLIBC__) && GLIBC_VER < 0x02000c

-#   define PTHREAD_MUTEX_ROBUST	PTHREAD_MUTEX_ROBUST_NP

-#   define pthread_mutexattr_setrobust(attr, flag)	pthread_mutexattr_setrobust_np(attr, flag)

-#   define pthread_mutex_consistent(mutex)	pthread_mutex_consistent_np(mutex)

-#  endif

-# endif

-#endif /* MDB_USE_ROBUST */

-

-#if defined(MDB_OWNERDEAD) && MDB_USE_ROBUST

-#define MDB_ROBUST_SUPPORTED	1

-#endif

-

-#ifdef _WIN32

-#define MDB_USE_HASH	1

-#define MDB_PIDLOCK	0

-#define THREAD_RET	DWORD

-#define pthread_t	HANDLE

-#define pthread_mutex_t	HANDLE

-#define pthread_cond_t	HANDLE

-typedef HANDLE mdb_mutex_t, mdb_mutexref_t;

-#define pthread_key_t	DWORD

-#define pthread_self()	GetCurrentThreadId()

-#define pthread_key_create(x,y)	\

-	((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)

-#define pthread_key_delete(x)	TlsFree(x)

-#define pthread_getspecific(x)	TlsGetValue(x)

-#define pthread_setspecific(x,y)	(TlsSetValue(x,y) ? 0 : ErrCode())

-#define pthread_mutex_unlock(x)	ReleaseMutex(*x)

-#define pthread_mutex_lock(x)	WaitForSingleObject(*x, INFINITE)

-#define pthread_cond_signal(x)	SetEvent(*x)

-#define pthread_cond_wait(cond,mutex)	do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)

-#define THREAD_CREATE(thr,start,arg)	thr=CreateThread(NULL,0,start,arg,0,NULL)

-#define THREAD_FINISH(thr)	WaitForSingleObject(thr, INFINITE)

-#define LOCK_MUTEX0(mutex)		WaitForSingleObject(mutex, INFINITE)

-#define UNLOCK_MUTEX(mutex)		ReleaseMutex(mutex)

-#define mdb_mutex_consistent(mutex)	0

-#define getpid()	GetCurrentProcessId()

-#define	MDB_FDATASYNC(fd)	(!FlushFileBuffers(fd))

-#define	MDB_MSYNC(addr,len,flags)	(!FlushViewOfFile(addr,len))

-#define	ErrCode()	GetLastError()

-#define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}

-#define	close(fd)	(CloseHandle(fd) ? 0 : -1)

-#define	munmap(ptr,len)	UnmapViewOfFile(ptr)

-#ifdef PROCESS_QUERY_LIMITED_INFORMATION

-#define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION

-#else

-#define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000

-#endif

-#define	Z	"I"

-#else

-#define THREAD_RET	void *

-#define THREAD_CREATE(thr,start,arg)	pthread_create(&thr,NULL,start,arg)

-#define THREAD_FINISH(thr)	pthread_join(thr,NULL)

-#define	Z	"z"			/**< printf format modifier for size_t */

-

-	/** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */

-#define MDB_PIDLOCK			1

-

-#ifdef MDB_USE_POSIX_SEM

-

-typedef sem_t *mdb_mutex_t, *mdb_mutexref_t;

-#define LOCK_MUTEX0(mutex)		mdb_sem_wait(mutex)

-#define UNLOCK_MUTEX(mutex)		sem_post(mutex)

-

-static int

-mdb_sem_wait(sem_t *sem)

-{

-   int rc;

-   while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;

-   return rc;

-}

-

-#elif defined MDB_USE_SYSV_SEM

-

-typedef struct mdb_mutex {

-	int semid;

-	int semnum;

-	int *locked;

-} mdb_mutex_t[1], *mdb_mutexref_t;

-

-#define LOCK_MUTEX0(mutex)		mdb_sem_wait(mutex)

-#define UNLOCK_MUTEX(mutex)		do { \

-	struct sembuf sb = { 0, 1, SEM_UNDO }; \

-	sb.sem_num = (mutex)->semnum; \

-	*(mutex)->locked = 0; \

-	semop((mutex)->semid, &sb, 1); \

-} while(0)

-

-static int

-mdb_sem_wait(mdb_mutexref_t sem)

-{

-	int rc, *locked = sem->locked;

-	struct sembuf sb = { 0, -1, SEM_UNDO };

-	sb.sem_num = sem->semnum;

-	do {

-		if (!semop(sem->semid, &sb, 1)) {

-			rc = *locked ? MDB_OWNERDEAD : MDB_SUCCESS;

-			*locked = 1;

-			break;

-		}

-	} while ((rc = errno) == EINTR);

-	return rc;

-}

-

-#define mdb_mutex_consistent(mutex)	0

-

-#else	/* MDB_USE_POSIX_MUTEX: */

-	/** Shared mutex/semaphore as it is stored (mdb_mutex_t), and as

-	 *	local variables keep it (mdb_mutexref_t).

-	 *

-	 *	An mdb_mutex_t can be assigned to an mdb_mutexref_t.  They can

-	 *	be the same, or an array[size 1] and a pointer.

-	 *	@{

-	 */

-typedef pthread_mutex_t mdb_mutex_t[1], *mdb_mutexref_t;

-	/*	@} */

-	/** Lock the reader or writer mutex.

-	 *	Returns 0 or a code to give #mdb_mutex_failed(), as in #LOCK_MUTEX().

-	 */

-#define LOCK_MUTEX0(mutex)	pthread_mutex_lock(mutex)

-	/** Unlock the reader or writer mutex.

-	 */

-#define UNLOCK_MUTEX(mutex)	pthread_mutex_unlock(mutex)

-	/** Mark mutex-protected data as repaired, after death of previous owner.

-	 */

-#define mdb_mutex_consistent(mutex)	pthread_mutex_consistent(mutex)

-#endif	/* MDB_USE_POSIX_SEM || MDB_USE_SYSV_SEM */

-

-	/** Get the error code for the last failed system function.

-	 */

-#define	ErrCode()	errno

-

-	/** An abstraction for a file handle.

-	 *	On POSIX systems file handles are small integers. On Windows

-	 *	they're opaque pointers.

-	 */

-#define	HANDLE	int

-

-	/**	A value for an invalid file handle.

-	 *	Mainly used to initialize file variables and signify that they are

-	 *	unused.

-	 */

-#define INVALID_HANDLE_VALUE	(-1)

-

-	/** Get the size of a memory page for the system.

-	 *	This is the basic size that the platform's memory manager uses, and is

-	 *	fundamental to the use of memory-mapped files.

-	 */

-#define	GET_PAGESIZE(x)	((x) = sysconf(_SC_PAGE_SIZE))

-#endif

-

-#ifdef MDB_VL32

-#ifdef _WIN32

-#define	Y	"I64"

-#else

-#define	Y	"ll"

-#endif

-#else

-#define Y	Z

-#endif

-

-#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)

-#define MNAME_LEN	32

-#elif defined(MDB_USE_SYSV_SEM)

-#define MNAME_LEN	(sizeof(int))

-#else

-#define MNAME_LEN	(sizeof(pthread_mutex_t))

-#endif

-

-#ifdef MDB_USE_SYSV_SEM

-#define SYSV_SEM_FLAG	1		/**< SysV sems in lockfile format */

-#else

-#define SYSV_SEM_FLAG	0

-#endif

-

-/** @} */

-

-#ifdef MDB_ROBUST_SUPPORTED

-	/** Lock mutex, handle any error, set rc = result.

-	 *	Return 0 on success, nonzero (not rc) on error.

-	 */

-#define LOCK_MUTEX(rc, env, mutex) \

-	(((rc) = LOCK_MUTEX0(mutex)) && \

-	 ((rc) = mdb_mutex_failed(env, mutex, rc)))

-static int mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc);

-#else

-#define LOCK_MUTEX(rc, env, mutex) ((rc) = LOCK_MUTEX0(mutex))

-#define mdb_mutex_failed(env, mutex, rc) (rc)

-#endif

-

-#ifndef _WIN32

-/**	A flag for opening a file and requesting synchronous data writes.

- *	This is only used when writing a meta page. It's not strictly needed;

- *	we could just do a normal write and then immediately perform a flush.

- *	But if this flag is available it saves us an extra system call.

- *

- *	@note If O_DSYNC is undefined but exists in /usr/include,

- * preferably set some compiler flag to get the definition.

- */

-#ifndef MDB_DSYNC

-# ifdef O_DSYNC

-# define MDB_DSYNC	O_DSYNC

-# else

-# define MDB_DSYNC	O_SYNC

-# endif

-#endif

-#endif

-

-/** Function for flushing the data of a file. Define this to fsync

- *	if fdatasync() is not supported.

- */

-#ifndef MDB_FDATASYNC

-# define MDB_FDATASYNC	fdatasync

-#endif

-

-#ifndef MDB_MSYNC

-# define MDB_MSYNC(addr,len,flags)	msync(addr,len,flags)

-#endif

-

-#ifndef MS_SYNC

-#define	MS_SYNC	1

-#endif

-

-#ifndef MS_ASYNC

-#define	MS_ASYNC	0

-#endif

-

-	/** A page number in the database.

-	 *	Note that 64 bit page numbers are overkill, since pages themselves

-	 *	already represent 12-13 bits of addressable memory, and the OS will

-	 *	always limit applications to a maximum of 63 bits of address space.

-	 *

-	 *	@note In the #MDB_node structure, we only store 48 bits of this value,

-	 *	which thus limits us to only 60 bits of addressable data.

-	 */

-typedef MDB_ID	pgno_t;

-

-	/** A transaction ID.

-	 *	See struct MDB_txn.mt_txnid for details.

-	 */

-typedef MDB_ID	txnid_t;

-

-/** @defgroup debug	Debug Macros

- *	@{

- */

-#ifndef MDB_DEBUG

-	/**	Enable debug output.  Needs variable argument macros (a C99 feature).

-	 *	Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs

-	 *	read from and written to the database (used for free space management).

-	 */

-#define MDB_DEBUG 0

-#endif

-

-#if MDB_DEBUG

-static int mdb_debug;

-static txnid_t mdb_debug_start;

-

-	/**	Print a debug message with printf formatting.

-	 *	Requires double parenthesis around 2 or more args.

-	 */

-# define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))

-# define DPRINTF0(fmt, ...) \

-	fprintf(stderr, "%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__)

-#else

-# define DPRINTF(args)	((void) 0)

-#endif

-	/**	Print a debug string.

-	 *	The string is printed literally, with no format processing.

-	 */

-#define DPUTS(arg)	DPRINTF(("%s", arg))

-	/** Debuging output value of a cursor DBI: Negative in a sub-cursor. */

-#define DDBI(mc) \

-	(((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi)

-/** @} */

-

-	/**	@brief The maximum size of a database page.

-	 *

-	 *	It is 32k or 64k, since value-PAGEBASE must fit in

-	 *	#MDB_page.%mp_upper.

-	 *

-	 *	LMDB will use database pages < OS pages if needed.

-	 *	That causes more I/O in write transactions: The OS must

-	 *	know (read) the whole page before writing a partial page.

-	 *

-	 *	Note that we don't currently support Huge pages. On Linux,

-	 *	regular data files cannot use Huge pages, and in general

-	 *	Huge pages aren't actually pageable. We rely on the OS

-	 *	demand-pager to read our data and page it out when memory

-	 *	pressure from other processes is high. So until OSs have

-	 *	actual paging support for Huge pages, they're not viable.

-	 */

-#define MAX_PAGESIZE	 (PAGEBASE ? 0x10000 : 0x8000)

-

-	/** The minimum number of keys required in a database page.

-	 *	Setting this to a larger value will place a smaller bound on the

-	 *	maximum size of a data item. Data items larger than this size will

-	 *	be pushed into overflow pages instead of being stored directly in

-	 *	the B-tree node. This value used to default to 4. With a page size

-	 *	of 4096 bytes that meant that any item larger than 1024 bytes would

-	 *	go into an overflow page. That also meant that on average 2-3KB of

-	 *	each overflow page was wasted space. The value cannot be lower than

-	 *	2 because then there would no longer be a tree structure. With this

-	 *	value, items larger than 2KB will go into overflow pages, and on

-	 *	average only 1KB will be wasted.

-	 */

-#define MDB_MINKEYS	 2

-

-	/**	A stamp that identifies a file as an LMDB file.

-	 *	There's nothing special about this value other than that it is easily

-	 *	recognizable, and it will reflect any byte order mismatches.

-	 */

-#define MDB_MAGIC	 0xBEEFC0DE

-

-	/**	The version number for a database's datafile format. */

-#define MDB_DATA_VERSION	 ((MDB_DEVEL) ? 999 : 1)

-	/**	The version number for a database's lockfile format. */

-#define MDB_LOCK_VERSION	 ((MDB_DEVEL) ? 999 : 1)

-

-	/**	@brief The max size of a key we can write, or 0 for computed max.

-	 *

-	 *	This macro should normally be left alone or set to 0.

-	 *	Note that a database with big keys or dupsort data cannot be

-	 *	reliably modified by a liblmdb which uses a smaller max.

-	 *	The default is 511 for backwards compat, or 0 when #MDB_DEVEL.

-	 *

-	 *	Other values are allowed, for backwards compat.  However:

-	 *	A value bigger than the computed max can break if you do not

-	 *	know what you are doing, and liblmdb <= 0.9.10 can break when

-	 *	modifying a DB with keys/dupsort data bigger than its max.

-	 *

-	 *	Data items in an #MDB_DUPSORT database are also limited to

-	 *	this size, since they're actually keys of a sub-DB.  Keys and

-	 *	#MDB_DUPSORT data items must fit on a node in a regular page.

-	 */

-#ifndef MDB_MAXKEYSIZE

-#define MDB_MAXKEYSIZE	 ((MDB_DEVEL) ? 0 : 511)

-#endif

-

-	/**	The maximum size of a key we can write to the environment. */

-#if MDB_MAXKEYSIZE

-#define ENV_MAXKEY(env)	(MDB_MAXKEYSIZE)

-#else

-#define ENV_MAXKEY(env)	((env)->me_maxkey)

-#endif

-

-	/**	@brief The maximum size of a data item.

-	 *

-	 *	We only store a 32 bit value for node sizes.

-	 */

-#define MAXDATASIZE	0xffffffffUL

-

-#if MDB_DEBUG

-	/**	Key size which fits in a #DKBUF.

-	 *	@ingroup debug

-	 */

-#define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511)

-	/**	A key buffer.

-	 *	@ingroup debug

-	 *	This is used for printing a hex dump of a key's contents.

-	 */

-#define DKBUF	char kbuf[DKBUF_MAXKEYSIZE*2+1]

-	/**	Display a key in hex.

-	 *	@ingroup debug

-	 *	Invoke a function to display a key in hex.

-	 */

-#define	DKEY(x)	mdb_dkey(x, kbuf)

-#else

-#define	DKBUF

-#define DKEY(x)	0

-#endif

-

-	/** An invalid page number.

-	 *	Mainly used to denote an empty tree.

-	 */

-#define P_INVALID	 (~(pgno_t)0)

-

-	/** Test if the flags \b f are set in a flag word \b w. */

-#define F_ISSET(w, f)	 (((w) & (f)) == (f))

-

-	/** Round \b n up to an even number. */

-#define EVEN(n)		(((n) + 1U) & -2) /* sign-extending -2 to match n+1U */

-

-	/**	Used for offsets within a single page.

-	 *	Since memory pages are typically 4 or 8KB in size, 12-13 bits,

-	 *	this is plenty.

-	 */

-typedef uint16_t	 indx_t;

-

-	/**	Default size of memory map.

-	 *	This is certainly too small for any actual applications. Apps should always set

-	 *	the size explicitly using #mdb_env_set_mapsize().

-	 */

-#define DEFAULT_MAPSIZE	1048576

-

-/**	@defgroup readers	Reader Lock Table

- *	Readers don't acquire any locks for their data access. Instead, they

- *	simply record their transaction ID in the reader table. The reader

- *	mutex is needed just to find an empty slot in the reader table. The

- *	slot's address is saved in thread-specific data so that subsequent read

- *	transactions started by the same thread need no further locking to proceed.

- *

- *	If #MDB_NOTLS is set, the slot address is not saved in thread-specific data.

- *

- *	No reader table is used if the database is on a read-only filesystem, or

- *	if #MDB_NOLOCK is set.

- *

- *	Since the database uses multi-version concurrency control, readers don't

- *	actually need any locking. This table is used to keep track of which

- *	readers are using data from which old transactions, so that we'll know

- *	when a particular old transaction is no longer in use. Old transactions

- *	that have discarded any data pages can then have those pages reclaimed

- *	for use by a later write transaction.

- *

- *	The lock table is constructed such that reader slots are aligned with the

- *	processor's cache line size. Any slot is only ever used by one thread.

- *	This alignment guarantees that there will be no contention or cache

- *	thrashing as threads update their own slot info, and also eliminates

- *	any need for locking when accessing a slot.

- *

- *	A writer thread will scan every slot in the table to determine the oldest

- *	outstanding reader transaction. Any freed pages older than this will be

- *	reclaimed by the writer. The writer doesn't use any locks when scanning

- *	this table. This means that there's no guarantee that the writer will

- *	see the most up-to-date reader info, but that's not required for correct

- *	operation - all we need is to know the upper bound on the oldest reader,

- *	we don't care at all about the newest reader. So the only consequence of

- *	reading stale information here is that old pages might hang around a

- *	while longer before being reclaimed. That's actually good anyway, because

- *	the longer we delay reclaiming old pages, the more likely it is that a

- *	string of contiguous pages can be found after coalescing old pages from

- *	many old transactions together.

- *	@{

- */

-	/**	Number of slots in the reader table.

-	 *	This value was chosen somewhat arbitrarily. 126 readers plus a

-	 *	couple mutexes fit exactly into 8KB on my development machine.

-	 *	Applications should set the table size using #mdb_env_set_maxreaders().

-	 */

-#define DEFAULT_READERS	126

-

-	/**	The size of a CPU cache line in bytes. We want our lock structures

-	 *	aligned to this size to avoid false cache line sharing in the

-	 *	lock table.

-	 *	This value works for most CPUs. For Itanium this should be 128.

-	 */

-#ifndef CACHELINE

-#define CACHELINE	64

-#endif

-

-	/**	The information we store in a single slot of the reader table.

-	 *	In addition to a transaction ID, we also record the process and

-	 *	thread ID that owns a slot, so that we can detect stale information,

-	 *	e.g. threads or processes that went away without cleaning up.

-	 *	@note We currently don't check for stale records. We simply re-init

-	 *	the table when we know that we're the only process opening the

-	 *	lock file.

-	 */

-typedef struct MDB_rxbody {

-	/**	Current Transaction ID when this transaction began, or (txnid_t)-1.

-	 *	Multiple readers that start at the same time will probably have the

-	 *	same ID here. Again, it's not important to exclude them from

-	 *	anything; all we need to know is which version of the DB they

-	 *	started from so we can avoid overwriting any data used in that

-	 *	particular version.

-	 */

-	volatile txnid_t		mrb_txnid;

-	/** The process ID of the process owning this reader txn. */

-	volatile MDB_PID_T	mrb_pid;

-	/** The thread ID of the thread owning this txn. */

-	volatile MDB_THR_T	mrb_tid;

-} MDB_rxbody;

-

-	/** The actual reader record, with cacheline padding. */

-typedef struct MDB_reader {

-	union {

-		MDB_rxbody mrx;

-		/** shorthand for mrb_txnid */

-#define	mr_txnid	mru.mrx.mrb_txnid

-#define	mr_pid	mru.mrx.mrb_pid

-#define	mr_tid	mru.mrx.mrb_tid

-		/** cache line alignment */

-		char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];

-	} mru;

-} MDB_reader;

-

-	/** The header for the reader table.

-	 *	The table resides in a memory-mapped file. (This is a different file

-	 *	than is used for the main database.)

-	 *

-	 *	For POSIX the actual mutexes reside in the shared memory of this

-	 *	mapped file. On Windows, mutexes are named objects allocated by the

-	 *	kernel; we store the mutex names in this mapped file so that other

-	 *	processes can grab them. This same approach is also used on

-	 *	MacOSX/Darwin (using named semaphores) since MacOSX doesn't support

-	 *	process-shared POSIX mutexes. For these cases where a named object

-	 *	is used, the object name is derived from a 64 bit FNV hash of the

-	 *	environment pathname. As such, naming collisions are extremely

-	 *	unlikely. If a collision occurs, the results are unpredictable.

-	 */

-typedef struct MDB_txbody {

-		/** Stamp identifying this as an LMDB file. It must be set

-		 *	to #MDB_MAGIC. */

-	uint32_t	mtb_magic;

-		/** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */

-	uint32_t	mtb_format;

-#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)

-	char	mtb_rmname[MNAME_LEN];

-#elif defined(MDB_USE_SYSV_SEM)

-	int 	mtb_semid;

-	int		mtb_rlocked;

-#else

-		/** Mutex protecting access to this table.

-		 *	This is the reader table lock used with LOCK_MUTEX().

-		 */

-	mdb_mutex_t	mtb_rmutex;

-#endif

-		/**	The ID of the last transaction committed to the database.

-		 *	This is recorded here only for convenience; the value can always

-		 *	be determined by reading the main database meta pages.

-		 */

-	volatile txnid_t		mtb_txnid;

-		/** The number of slots that have been used in the reader table.

-		 *	This always records the maximum count, it is not decremented

-		 *	when readers release their slots.

-		 */

-	volatile unsigned	mtb_numreaders;

-} MDB_txbody;

-

-	/** The actual reader table definition. */

-typedef struct MDB_txninfo {

-	union {

-		MDB_txbody mtb;

-#define mti_magic	mt1.mtb.mtb_magic

-#define mti_format	mt1.mtb.mtb_format

-#define mti_rmutex	mt1.mtb.mtb_rmutex

-#define mti_rmname	mt1.mtb.mtb_rmname

-#define mti_txnid	mt1.mtb.mtb_txnid

-#define mti_numreaders	mt1.mtb.mtb_numreaders

-#ifdef MDB_USE_SYSV_SEM

-#define	mti_semid	mt1.mtb.mtb_semid

-#define	mti_rlocked	mt1.mtb.mtb_rlocked

-#endif

-		char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];

-	} mt1;

-	union {

-#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)

-		char mt2_wmname[MNAME_LEN];

-#define	mti_wmname	mt2.mt2_wmname

-#elif defined MDB_USE_SYSV_SEM

-		int mt2_wlocked;

-#define mti_wlocked	mt2.mt2_wlocked

-#else

-		mdb_mutex_t	mt2_wmutex;

-#define mti_wmutex	mt2.mt2_wmutex

-#endif

-		char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];

-	} mt2;

-	MDB_reader	mti_readers[1];

-} MDB_txninfo;

-

-	/** Lockfile format signature: version, features and field layout */

-#define MDB_LOCK_FORMAT \

-	((uint32_t) \

-	 ((MDB_LOCK_VERSION) \

-	  /* Flags which describe functionality */ \

-	  + (SYSV_SEM_FLAG << 18) \

-	  + (((MDB_PIDLOCK) != 0) << 16)))

-/** @} */

-

-/** Common header for all page types.

- * Overflow records occupy a number of contiguous pages with no

- * headers on any page after the first.

- */

-typedef struct MDB_page {

-#define	mp_pgno	mp_p.p_pgno

-#define	mp_next	mp_p.p_next

-	union {

-		pgno_t		p_pgno;	/**< page number */

-		struct MDB_page *p_next; /**< for in-memory list of freed pages */

-	} mp_p;

-	uint16_t	mp_pad;

-/**	@defgroup mdb_page	Page Flags

- *	@ingroup internal

- *	Flags for the page headers.

- *	@{

- */

-#define	P_BRANCH	 0x01		/**< branch page */

-#define	P_LEAF		 0x02		/**< leaf page */

-#define	P_OVERFLOW	 0x04		/**< overflow page */

-#define	P_META		 0x08		/**< meta page */

-#define	P_DIRTY		 0x10		/**< dirty page, also set for #P_SUBP pages */

-#define	P_LEAF2		 0x20		/**< for #MDB_DUPFIXED records */

-#define	P_SUBP		 0x40		/**< for #MDB_DUPSORT sub-pages */

-#define	P_LOOSE		 0x4000		/**< page was dirtied then freed, can be reused */

-#define	P_KEEP		 0x8000		/**< leave this page alone during spill */

-/** @} */

-	uint16_t	mp_flags;		/**< @ref mdb_page */

-#define mp_lower	mp_pb.pb.pb_lower

-#define mp_upper	mp_pb.pb.pb_upper

-#define mp_pages	mp_pb.pb_pages

-	union {

-		struct {

-			indx_t		pb_lower;		/**< lower bound of free space */

-			indx_t		pb_upper;		/**< upper bound of free space */

-		} pb;

-		uint32_t	pb_pages;	/**< number of overflow pages */

-	} mp_pb;

-	indx_t		mp_ptrs[1];		/**< dynamic size */

-} MDB_page;

-

-	/** Size of the page header, excluding dynamic data at the end */

-#define PAGEHDRSZ	 ((unsigned) offsetof(MDB_page, mp_ptrs))

-

-	/** Address of first usable data byte in a page, after the header */

-#define METADATA(p)	 ((void *)((char *)(p) + PAGEHDRSZ))

-

-	/** ITS#7713, change PAGEBASE to handle 65536 byte pages */

-#define	PAGEBASE	((MDB_DEVEL) ? PAGEHDRSZ : 0)

-

-	/** Number of nodes on a page */

-#define NUMKEYS(p)	 (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1)

-

-	/** The amount of space remaining in the page */

-#define SIZELEFT(p)	 (indx_t)((p)->mp_upper - (p)->mp_lower)

-

-	/** The percentage of space used in the page, in tenths of a percent. */

-#define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \

-				((env)->me_psize - PAGEHDRSZ))

-	/** The minimum page fill factor, in tenths of a percent.

-	 *	Pages emptier than this are candidates for merging.

-	 */

-#define FILL_THRESHOLD	 250

-

-	/** Test if a page is a leaf page */

-#define IS_LEAF(p)	 F_ISSET((p)->mp_flags, P_LEAF)

-	/** Test if a page is a LEAF2 page */

-#define IS_LEAF2(p)	 F_ISSET((p)->mp_flags, P_LEAF2)

-	/** Test if a page is a branch page */

-#define IS_BRANCH(p)	 F_ISSET((p)->mp_flags, P_BRANCH)

-	/** Test if a page is an overflow page */

-#define IS_OVERFLOW(p)	 F_ISSET((p)->mp_flags, P_OVERFLOW)

-	/** Test if a page is a sub page */

-#define IS_SUBP(p)	 F_ISSET((p)->mp_flags, P_SUBP)

-

-	/** The number of overflow pages needed to store the given size. */

-#define OVPAGES(size, psize)	((PAGEHDRSZ-1 + (size)) / (psize) + 1)

-

-	/** Link in #MDB_txn.%mt_loose_pgs list */

-#define NEXT_LOOSE_PAGE(p)		(*(MDB_page **)((p) + 2))

-

-	/** Header for a single key/data pair within a page.

-	 * Used in pages of type #P_BRANCH and #P_LEAF without #P_LEAF2.

-	 * We guarantee 2-byte alignment for 'MDB_node's.

-	 */

-typedef struct MDB_node {

-	/** lo and hi are used for data size on leaf nodes and for

-	 * child pgno on branch nodes. On 64 bit platforms, flags

-	 * is also used for pgno. (Branch nodes have no flags).

-	 * They are in host byte order in case that lets some

-	 * accesses be optimized into a 32-bit word access.

-	 */

-#if BYTE_ORDER == LITTLE_ENDIAN

-	unsigned short	mn_lo, mn_hi;	/**< part of data size or pgno */

-#else

-	unsigned short	mn_hi, mn_lo;

-#endif

-/** @defgroup mdb_node Node Flags

- *	@ingroup internal

- *	Flags for node headers.

- *	@{

- */

-#define F_BIGDATA	 0x01			/**< data put on overflow page */

-#define F_SUBDATA	 0x02			/**< data is a sub-database */

-#define F_DUPDATA	 0x04			/**< data has duplicates */

-

-/** valid flags for #mdb_node_add() */

-#define	NODE_ADD_FLAGS	(F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)

-

-/** @} */

-	unsigned short	mn_flags;		/**< @ref mdb_node */

-	unsigned short	mn_ksize;		/**< key size */

-	char		mn_data[1];			/**< key and data are appended here */

-} MDB_node;

-

-	/** Size of the node header, excluding dynamic data at the end */

-#define NODESIZE	 offsetof(MDB_node, mn_data)

-

-	/** Bit position of top word in page number, for shifting mn_flags */

-#define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)

-

-	/** Size of a node in a branch page with a given key.

-	 *	This is just the node header plus the key, there is no data.

-	 */

-#define INDXSIZE(k)	 (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))

-

-	/** Size of a node in a leaf page with a given key and data.

-	 *	This is node header plus key plus data size.

-	 */

-#define LEAFSIZE(k, d)	 (NODESIZE + (k)->mv_size + (d)->mv_size)

-

-	/** Address of node \b i in page \b p */

-#define NODEPTR(p, i)	 ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE))

-

-	/** Address of the key for the node */

-#define NODEKEY(node)	 (void *)((node)->mn_data)

-

-	/** Address of the data for a node */

-#define NODEDATA(node)	 (void *)((char *)(node)->mn_data + (node)->mn_ksize)

-

-	/** Get the page number pointed to by a branch node */

-#define NODEPGNO(node) \

-	((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \

-	 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))

-	/** Set the page number in a branch node */

-#define SETPGNO(node,pgno)	do { \

-	(node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \

-	if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)

-

-	/** Get the size of the data in a leaf node */

-#define NODEDSZ(node)	 ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))

-	/** Set the size of the data for a leaf node */

-#define SETDSZ(node,size)	do { \

-	(node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)

-	/** The size of a key in a node */

-#define NODEKSZ(node)	 ((node)->mn_ksize)

-

-	/** Copy a page number from src to dst */

-#ifdef MISALIGNED_OK

-#define COPY_PGNO(dst,src)	dst = src

-#else

-#if SIZE_MAX > 4294967295UL

-#define COPY_PGNO(dst,src)	do { \

-	unsigned short *s, *d;	\

-	s = (unsigned short *)&(src);	\

-	d = (unsigned short *)&(dst);	\

-	*d++ = *s++;	\

-	*d++ = *s++;	\

-	*d++ = *s++;	\

-	*d = *s;	\

-} while (0)

-#else

-#define COPY_PGNO(dst,src)	do { \

-	unsigned short *s, *d;	\

-	s = (unsigned short *)&(src);	\

-	d = (unsigned short *)&(dst);	\

-	*d++ = *s++;	\

-	*d = *s;	\

-} while (0)

-#endif

-#endif

-	/** The address of a key in a LEAF2 page.

-	 *	LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.

-	 *	There are no node headers, keys are stored contiguously.

-	 */

-#define LEAF2KEY(p, i, ks)	((char *)(p) + PAGEHDRSZ + ((i)*(ks)))

-

-	/** Set the \b node's key into \b keyptr, if requested. */

-#define MDB_GET_KEY(node, keyptr)	{ if ((keyptr) != NULL) { \

-	(keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }

-

-	/** Set the \b node's key into \b key. */

-#define MDB_GET_KEY2(node, key)	{ key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }

-

-	/** Information about a single database in the environment. */

-typedef struct MDB_db {

-	uint32_t	md_pad;		/**< also ksize for LEAF2 pages */

-	uint16_t	md_flags;	/**< @ref mdb_dbi_open */

-	uint16_t	md_depth;	/**< depth of this tree */

-	pgno_t		md_branch_pages;	/**< number of internal pages */

-	pgno_t		md_leaf_pages;		/**< number of leaf pages */

-	pgno_t		md_overflow_pages;	/**< number of overflow pages */

-	mdb_size_t	md_entries;		/**< number of data items */

-	pgno_t		md_root;		/**< the root page of this tree */

-} MDB_db;

-

-	/** mdb_dbi_open flags */

-#define MDB_VALID	0x8000		/**< DB handle is valid, for me_dbflags */

-#define PERSISTENT_FLAGS	(0xffff & ~(MDB_VALID))

-#define VALID_FLAGS	(MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\

-	MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)

-

-	/** Handle for the DB used to track free pages. */

-#define	FREE_DBI	0

-	/** Handle for the default DB. */

-#define	MAIN_DBI	1

-	/** Number of DBs in metapage (free and main) - also hardcoded elsewhere */

-#define CORE_DBS	2

-

-	/** Number of meta pages - also hardcoded elsewhere */

-#define NUM_METAS	2

-

-	/** Meta page content.

-	 *	A meta page is the start point for accessing a database snapshot.

-	 *	Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2).

-	 */

-typedef struct MDB_meta {

-		/** Stamp identifying this as an LMDB file. It must be set

-		 *	to #MDB_MAGIC. */

-	uint32_t	mm_magic;

-		/** Version number of this file. Must be set to #MDB_DATA_VERSION. */

-	uint32_t	mm_version;

-#ifdef MDB_VL32

-	union {		/* always zero since we don't support fixed mapping in MDB_VL32 */

-		MDB_ID	mmun_ull;

-		void *mmun_address;

-	} mm_un;

-#define	mm_address mm_un.mmun_address

-#else

-	void		*mm_address;		/**< address for fixed mapping */

-#endif

-	pgno_t		mm_mapsize;			/**< size of mmap region */

-	MDB_db		mm_dbs[CORE_DBS];	/**< first is free space, 2nd is main db */

-	/** The size of pages used in this DB */

-#define	mm_psize	mm_dbs[FREE_DBI].md_pad

-	/** Any persistent environment flags. @ref mdb_env */

-#define	mm_flags	mm_dbs[FREE_DBI].md_flags

-	pgno_t		mm_last_pg;			/**< last used page in file */

-	volatile txnid_t	mm_txnid;	/**< txnid that committed this page */

-} MDB_meta;

-

-	/** Buffer for a stack-allocated meta page.

-	 *	The members define size and alignment, and silence type

-	 *	aliasing warnings.  They are not used directly; that could

-	 *	mean incorrectly using several union members in parallel.

-	 */

-typedef union MDB_metabuf {

-	MDB_page	mb_page;

-	struct {

-		char		mm_pad[PAGEHDRSZ];

-		MDB_meta	mm_meta;

-	} mb_metabuf;

-} MDB_metabuf;

-

-	/** Auxiliary DB info.

-	 *	The information here is mostly static/read-only. There is

-	 *	only a single copy of this record in the environment.

-	 */

-typedef struct MDB_dbx {

-	MDB_val		md_name;		/**< name of the database */

-	MDB_cmp_func	*md_cmp;	/**< function for comparing keys */

-	MDB_cmp_func	*md_dcmp;	/**< function for comparing data items */

-	MDB_rel_func	*md_rel;	/**< user relocate function */

-	void		*md_relctx;		/**< user-provided context for md_rel */

-} MDB_dbx;

-

-	/** A database transaction.

-	 *	Every operation requires a transaction handle.

-	 */

-struct MDB_txn {

-	MDB_txn		*mt_parent;		/**< parent of a nested txn */

-	/** Nested txn under this txn, set together with flag #MDB_TXN_HAS_CHILD */

-	MDB_txn		*mt_child;

-	pgno_t		mt_next_pgno;	/**< next unallocated page */

-#ifdef MDB_VL32

-	pgno_t		mt_last_pgno;	/**< last written page */

-#endif

-	/** The ID of this transaction. IDs are integers incrementing from 1.

-	 *	Only committed write transactions increment the ID. If a transaction

-	 *	aborts, the ID may be re-used by the next writer.

-	 */

-	txnid_t		mt_txnid;

-	MDB_env		*mt_env;		/**< the DB environment */

-	/** The list of pages that became unused during this transaction.

-	 */

-	MDB_IDL		mt_free_pgs;

-	/** The list of loose pages that became unused and may be reused

-	 *	in this transaction, linked through #NEXT_LOOSE_PAGE(page).

-	 */

-	MDB_page	*mt_loose_pgs;

-	/* #Number of loose pages (#mt_loose_pgs) */

-	int			mt_loose_count;

-	/** The sorted list of dirty pages we temporarily wrote to disk

-	 *	because the dirty list was full. page numbers in here are

-	 *	shifted left by 1, deleted slots have the LSB set.

-	 */

-	MDB_IDL		mt_spill_pgs;

-	union {

-		/** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */

-		MDB_ID2L	dirty_list;

-		/** For read txns: This thread/txn's reader table slot, or NULL. */

-		MDB_reader	*reader;

-	} mt_u;

-	/** Array of records for each DB known in the environment. */

-	MDB_dbx		*mt_dbxs;

-	/** Array of MDB_db records for each known DB */

-	MDB_db		*mt_dbs;

-	/** Array of sequence numbers for each DB handle */

-	unsigned int	*mt_dbiseqs;

-/** @defgroup mt_dbflag	Transaction DB Flags

- *	@ingroup internal

- * @{

- */

-#define DB_DIRTY	0x01		/**< DB was modified or is DUPSORT data */

-#define DB_STALE	0x02		/**< Named-DB record is older than txnID */

-#define DB_NEW		0x04		/**< Named-DB handle opened in this txn */

-#define DB_VALID	0x08		/**< DB handle is valid, see also #MDB_VALID */

-#define DB_USRVALID	0x10		/**< As #DB_VALID, but not set for #FREE_DBI */

-/** @} */

-	/** In write txns, array of cursors for each DB */

-	MDB_cursor	**mt_cursors;

-	/** Array of flags for each DB */

-	unsigned char	*mt_dbflags;

-#ifdef MDB_VL32

-	/** List of read-only pages (actually chunks) */

-	MDB_ID3L	mt_rpages;

-	/** We map chunks of 16 pages. Even though Windows uses 4KB pages, all

-	 * mappings must begin on 64KB boundaries. So we round off all pgnos to

-	 * a chunk boundary. We do the same on Linux for symmetry, and also to

-	 * reduce the frequency of mmap/munmap calls.

-	 */

-#define MDB_RPAGE_CHUNK	16

-#define MDB_TRPAGE_SIZE	4096	/**< size of #mt_rpages array of chunks */

-#define MDB_TRPAGE_MAX	(MDB_TRPAGE_SIZE-1)	/**< maximum chunk index */

-	unsigned int mt_rpcheck;	/**< threshold for reclaiming unref'd chunks */

-#endif

-	/**	Number of DB records in use, or 0 when the txn is finished.

-	 *	This number only ever increments until the txn finishes; we

-	 *	don't decrement it when individual DB handles are closed.

-	 */

-	MDB_dbi		mt_numdbs;

-

-/** @defgroup mdb_txn	Transaction Flags

- *	@ingroup internal

- *	@{

- */

-	/** #mdb_txn_begin() flags */

-#define MDB_TXN_BEGIN_FLAGS	(MDB_NOMETASYNC|MDB_NOSYNC|MDB_RDONLY)

-#define MDB_TXN_NOMETASYNC	MDB_NOMETASYNC	/**< don't sync meta for this txn on commit */

-#define MDB_TXN_NOSYNC		MDB_NOSYNC	/**< don't sync this txn on commit */

-#define MDB_TXN_RDONLY		MDB_RDONLY	/**< read-only transaction */

-	/* internal txn flags */

-#define MDB_TXN_WRITEMAP	MDB_WRITEMAP	/**< copy of #MDB_env flag in writers */

-#define MDB_TXN_FINISHED	0x01		/**< txn is finished or never began */

-#define MDB_TXN_ERROR		0x02		/**< txn is unusable after an error */

-#define MDB_TXN_DIRTY		0x04		/**< must write, even if dirty list is empty */

-#define MDB_TXN_SPILLS		0x08		/**< txn or a parent has spilled pages */

-#define MDB_TXN_HAS_CHILD	0x10		/**< txn has an #MDB_txn.%mt_child */

-	/** most operations on the txn are currently illegal */

-#define MDB_TXN_BLOCKED		(MDB_TXN_FINISHED|MDB_TXN_ERROR|MDB_TXN_HAS_CHILD)

-/** @} */

-	unsigned int	mt_flags;		/**< @ref mdb_txn */

-	/** #dirty_list room: Array size - \#dirty pages visible to this txn.

-	 *	Includes ancestor txns' dirty pages not hidden by other txns'

-	 *	dirty/spilled pages. Thus commit(nested txn) has room to merge

-	 *	dirty_list into mt_parent after freeing hidden mt_parent pages.

-	 */

-	unsigned int	mt_dirty_room;

-};

-

-/** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.

- * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to

- * raise this on a 64 bit machine.

- */

-#define CURSOR_STACK		 32

-

-struct MDB_xcursor;

-

-	/** Cursors are used for all DB operations.

-	 *	A cursor holds a path of (page pointer, key index) from the DB

-	 *	root to a position in the DB, plus other state. #MDB_DUPSORT

-	 *	cursors include an xcursor to the current data item. Write txns

-	 *	track their cursors and keep them up to date when data moves.

-	 *	Exception: An xcursor's pointer to a #P_SUBP page can be stale.

-	 *	(A node with #F_DUPDATA but no #F_SUBDATA contains a subpage).

-	 */

-struct MDB_cursor {

-	/** Next cursor on this DB in this txn */

-	MDB_cursor	*mc_next;

-	/** Backup of the original cursor if this cursor is a shadow */

-	MDB_cursor	*mc_backup;

-	/** Context used for databases with #MDB_DUPSORT, otherwise NULL */

-	struct MDB_xcursor	*mc_xcursor;

-	/** The transaction that owns this cursor */

-	MDB_txn		*mc_txn;

-	/** The database handle this cursor operates on */

-	MDB_dbi		mc_dbi;

-	/** The database record for this cursor */

-	MDB_db		*mc_db;

-	/** The database auxiliary record for this cursor */

-	MDB_dbx		*mc_dbx;

-	/** The @ref mt_dbflag for this database */

-	unsigned char	*mc_dbflag;

-	unsigned short 	mc_snum;	/**< number of pushed pages */

-	unsigned short	mc_top;		/**< index of top page, normally mc_snum-1 */

-/** @defgroup mdb_cursor	Cursor Flags

- *	@ingroup internal

- *	Cursor state flags.

- *	@{

- */

-#define C_INITIALIZED	0x01	/**< cursor has been initialized and is valid */

-#define C_EOF	0x02			/**< No more data */

-#define C_SUB	0x04			/**< Cursor is a sub-cursor */

-#define C_DEL	0x08			/**< last op was a cursor_del */

-#define C_UNTRACK	0x40		/**< Un-track cursor when closing */

-#define C_WRITEMAP	MDB_TXN_WRITEMAP /**< Copy of txn flag */

-/** Read-only cursor into the txn's original snapshot in the map.

- *	Set for read-only txns, and in #mdb_page_alloc() for #FREE_DBI when

- *	#MDB_DEVEL & 2. Only implements code which is necessary for this.

- */

-#define C_ORIG_RDONLY	MDB_TXN_RDONLY

-/** @} */

-	unsigned int	mc_flags;	/**< @ref mdb_cursor */

-	MDB_page	*mc_pg[CURSOR_STACK];	/**< stack of pushed pages */

-	indx_t		mc_ki[CURSOR_STACK];	/**< stack of page indices */

-#ifdef MDB_VL32

-	MDB_page	*mc_ovpg;		/**< a referenced overflow page */

-#endif

-};

-

-	/** Context for sorted-dup records.

-	 *	We could have gone to a fully recursive design, with arbitrarily

-	 *	deep nesting of sub-databases. But for now we only handle these

-	 *	levels - main DB, optional sub-DB, sorted-duplicate DB.

-	 */

-typedef struct MDB_xcursor {

-	/** A sub-cursor for traversing the Dup DB */

-	MDB_cursor mx_cursor;

-	/** The database record for this Dup DB */

-	MDB_db	mx_db;

-	/**	The auxiliary DB record for this Dup DB */

-	MDB_dbx	mx_dbx;

-	/** The @ref mt_dbflag for this Dup DB */

-	unsigned char mx_dbflag;

-} MDB_xcursor;

-

-	/** State of FreeDB old pages, stored in the MDB_env */

-typedef struct MDB_pgstate {

-	pgno_t		*mf_pghead;	/**< Reclaimed freeDB pages, or NULL before use */

-	txnid_t		mf_pglast;	/**< ID of last used record, or 0 if !mf_pghead */

-} MDB_pgstate;

-

-	/** The database environment. */

-struct MDB_env {

-	HANDLE		me_fd;		/**< The main data file */

-	HANDLE		me_lfd;		/**< The lock file */

-	HANDLE		me_mfd;			/**< just for writing the meta pages */

-#if defined(MDB_VL32) && defined(_WIN32)

-	HANDLE		me_fmh;		/**< File Mapping handle */

-#endif

-	/** Failed to update the meta page. Probably an I/O error. */

-#define	MDB_FATAL_ERROR	0x80000000U

-	/** Some fields are initialized. */

-#define	MDB_ENV_ACTIVE	0x20000000U

-	/** me_txkey is set */

-#define	MDB_ENV_TXKEY	0x10000000U

-	/** fdatasync is unreliable */

-#define	MDB_FSYNCONLY	0x08000000U

-	uint32_t 	me_flags;		/**< @ref mdb_env */

-	unsigned int	me_psize;	/**< DB page size, inited from me_os_psize */

-	unsigned int	me_os_psize;	/**< OS page size, from #GET_PAGESIZE */

-	unsigned int	me_maxreaders;	/**< size of the reader table */

-	/** Max #MDB_txninfo.%mti_numreaders of interest to #mdb_env_close() */

-	volatile int	me_close_readers;

-	MDB_dbi		me_numdbs;		/**< number of DBs opened */

-	MDB_dbi		me_maxdbs;		/**< size of the DB table */

-	MDB_PID_T	me_pid;		/**< process ID of this env */

-	char		*me_path;		/**< path to the DB files */

-	char		*me_map;		/**< the memory map of the data file */

-	MDB_txninfo	*me_txns;		/**< the memory map of the lock file or NULL */

-	MDB_meta	*me_metas[NUM_METAS];	/**< pointers to the two meta pages */

-	void		*me_pbuf;		/**< scratch area for DUPSORT put() */

-	MDB_txn		*me_txn;		/**< current write transaction */

-	MDB_txn		*me_txn0;		/**< prealloc'd write transaction */

-	mdb_size_t	me_mapsize;		/**< size of the data memory map */

-	off_t		me_size;		/**< current file size */

-	pgno_t		me_maxpg;		/**< me_mapsize / me_psize */

-	MDB_dbx		*me_dbxs;		/**< array of static DB info */

-	uint16_t	*me_dbflags;	/**< array of flags from MDB_db.md_flags */

-	unsigned int	*me_dbiseqs;	/**< array of dbi sequence numbers */

-	pthread_key_t	me_txkey;	/**< thread-key for readers */

-	txnid_t		me_pgoldest;	/**< ID of oldest reader last time we looked */

-	MDB_pgstate	me_pgstate;		/**< state of old pages from freeDB */

-#	define		me_pglast	me_pgstate.mf_pglast

-#	define		me_pghead	me_pgstate.mf_pghead

-	MDB_page	*me_dpages;		/**< list of malloc'd blocks for re-use */

-	/** IDL of pages that became unused in a write txn */

-	MDB_IDL		me_free_pgs;

-	/** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */

-	MDB_ID2L	me_dirty_list;

-	/** Max number of freelist items that can fit in a single overflow page */

-	int			me_maxfree_1pg;

-	/** Max size of a node on a page */

-	unsigned int	me_nodemax;

-#if !(MDB_MAXKEYSIZE)

-	unsigned int	me_maxkey;	/**< max size of a key */

-#endif

-	int		me_live_reader;		/**< have liveness lock in reader table */

-#ifdef _WIN32

-	int		me_pidquery;		/**< Used in OpenProcess */

-#endif

-#ifdef MDB_USE_POSIX_MUTEX	/* Posix mutexes reside in shared mem */

-#	define		me_rmutex	me_txns->mti_rmutex /**< Shared reader lock */

-#	define		me_wmutex	me_txns->mti_wmutex /**< Shared writer lock */

-#else

-	mdb_mutex_t	me_rmutex;

-	mdb_mutex_t	me_wmutex;

-#endif

-#ifdef MDB_VL32

-	MDB_ID3L	me_rpages;	/**< like #mt_rpages, but global to env */

-	pthread_mutex_t	me_rpmutex;	/**< control access to #me_rpages */

-#define MDB_ERPAGE_SIZE	16384

-#define MDB_ERPAGE_MAX	(MDB_ERPAGE_SIZE-1)

-	unsigned int me_rpcheck;

-#endif

-	void		*me_userctx;	 /**< User-settable context */

-	MDB_assert_func *me_assert_func; /**< Callback for assertion failures */

-};

-

-	/** Nested transaction */

-typedef struct MDB_ntxn {

-	MDB_txn		mnt_txn;		/**< the transaction */

-	MDB_pgstate	mnt_pgstate;	/**< parent transaction's saved freestate */

-} MDB_ntxn;

-

-	/** max number of pages to commit in one writev() call */

-#define MDB_COMMIT_PAGES	 64

-#if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES

-#undef MDB_COMMIT_PAGES

-#define MDB_COMMIT_PAGES	IOV_MAX

-#endif

-

-	/** max bytes to write in one call */

-#define MAX_WRITE		(0x40000000U >> (sizeof(ssize_t) == 4))

-

-	/** Check \b txn and \b dbi arguments to a function */

-#define TXN_DBI_EXIST(txn, dbi, validity) \

-	((txn) && (dbi)<(txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & (validity)))

-

-	/** Check for misused \b dbi handles */

-#define TXN_DBI_CHANGED(txn, dbi) \

-	((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])

-

-static int  mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);

-static int  mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);

-static int  mdb_page_touch(MDB_cursor *mc);

-

-#define MDB_END_NAMES {"committed", "empty-commit", "abort", "reset", \

-	"reset-tmp", "fail-begin", "fail-beginchild"}

-enum {

-	/* mdb_txn_end operation number, for logging */

-	MDB_END_COMMITTED, MDB_END_EMPTY_COMMIT, MDB_END_ABORT, MDB_END_RESET,

-	MDB_END_RESET_TMP, MDB_END_FAIL_BEGIN, MDB_END_FAIL_BEGINCHILD

-};

-#define MDB_END_OPMASK	0x0F	/**< mask for #mdb_txn_end() operation number */

-#define MDB_END_UPDATE	0x10	/**< update env state (DBIs) */

-#define MDB_END_FREE	0x20	/**< free txn unless it is #MDB_env.%me_txn0 */

-#define MDB_END_SLOT MDB_NOTLS	/**< release any reader slot if #MDB_NOTLS */

-static void mdb_txn_end(MDB_txn *txn, unsigned mode);

-

-static int  mdb_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **mp, int *lvl);

-static int  mdb_page_search_root(MDB_cursor *mc,

-			    MDB_val *key, int modify);

-#define MDB_PS_MODIFY	1

-#define MDB_PS_ROOTONLY	2

-#define MDB_PS_FIRST	4

-#define MDB_PS_LAST		8

-static int  mdb_page_search(MDB_cursor *mc,

-			    MDB_val *key, int flags);

-static int	mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);

-

-#define MDB_SPLIT_REPLACE	MDB_APPENDDUP	/**< newkey is not new */

-static int	mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,

-				pgno_t newpgno, unsigned int nflags);

-

-static int  mdb_env_read_header(MDB_env *env, MDB_meta *meta);

-static MDB_meta *mdb_env_pick_meta(const MDB_env *env);

-static int  mdb_env_write_meta(MDB_txn *txn);

-#ifdef MDB_USE_POSIX_MUTEX /* Drop unused excl arg */

-# define mdb_env_close0(env, excl) mdb_env_close1(env)

-#endif

-static void mdb_env_close0(MDB_env *env, int excl);

-

-static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);

-static int  mdb_node_add(MDB_cursor *mc, indx_t indx,

-			    MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);

-static void mdb_node_del(MDB_cursor *mc, int ksize);

-static void mdb_node_shrink(MDB_page *mp, indx_t indx);

-static int	mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft);

-static int  mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data);

-static size_t	mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);

-static size_t	mdb_branch_size(MDB_env *env, MDB_val *key);

-

-static int	mdb_rebalance(MDB_cursor *mc);

-static int	mdb_update_key(MDB_cursor *mc, MDB_val *key);

-

-static void	mdb_cursor_pop(MDB_cursor *mc);

-static int	mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);

-

-static int	mdb_cursor_del0(MDB_cursor *mc);

-static int	mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags);

-static int	mdb_cursor_sibling(MDB_cursor *mc, int move_right);

-static int	mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);

-static int	mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);

-static int	mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,

-				int *exactp);

-static int	mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);

-static int	mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);

-

-static void	mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);

-static void	mdb_xcursor_init0(MDB_cursor *mc);

-static void	mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);

-static void	mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int force);

-

-static int	mdb_drop0(MDB_cursor *mc, int subs);

-static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);

-static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead);

-

-/** @cond */

-static MDB_cmp_func	mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;

-/** @endcond */

-

-/** Compare two items pointing at size_t's of unknown alignment. */

-#ifdef MISALIGNED_OK

-# define mdb_cmp_clong mdb_cmp_long

-#else

-# define mdb_cmp_clong mdb_cmp_cint

-#endif

-

-#ifdef _WIN32

-static SECURITY_DESCRIPTOR mdb_null_sd;

-static SECURITY_ATTRIBUTES mdb_all_sa;

-static int mdb_sec_inited;

-

-static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize);

-#endif

-

-/** Return the library version info. */

-char * ESECT

-mdb_version(int *major, int *minor, int *patch)

-{

-	if (major) *major = MDB_VERSION_MAJOR;

-	if (minor) *minor = MDB_VERSION_MINOR;

-	if (patch) *patch = MDB_VERSION_PATCH;

-	return MDB_VERSION_STRING;

-}

-

-/** Table of descriptions for LMDB @ref errors */

-static char *const mdb_errstr[] = {

-	"MDB_KEYEXIST: Key/data pair already exists",

-	"MDB_NOTFOUND: No matching key/data pair found",

-	"MDB_PAGE_NOTFOUND: Requested page not found",

-	"MDB_CORRUPTED: Located page was wrong type",

-	"MDB_PANIC: Update of meta page failed or environment had fatal error",

-	"MDB_VERSION_MISMATCH: Database environment version mismatch",

-	"MDB_INVALID: File is not an LMDB file",

-	"MDB_MAP_FULL: Environment mapsize limit reached",

-	"MDB_DBS_FULL: Environment maxdbs limit reached",

-	"MDB_READERS_FULL: Environment maxreaders limit reached",

-	"MDB_TLS_FULL: Thread-local storage keys full - too many environments open",

-	"MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",

-	"MDB_CURSOR_FULL: Internal error - cursor stack limit reached",

-	"MDB_PAGE_FULL: Internal error - page has no more space",

-	"MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",

-	"MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",

-	"MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",

-	"MDB_BAD_TXN: Transaction must abort, has a child, or is invalid",

-	"MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size",

-	"MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly",

-};

-

-char *

-mdb_strerror(int err)

-{

-#ifdef _WIN32

-	/** HACK: pad 4KB on stack over the buf. Return system msgs in buf.

-	 *	This works as long as no function between the call to mdb_strerror

-	 *	and the actual use of the message uses more than 4K of stack.

-	 */

-#define MSGSIZE	1024

-#define PADSIZE	4096

-	char buf[MSGSIZE+PADSIZE], *ptr = buf;

-#endif

-	int i;

-	if (!err)

-		return ("Successful return: 0");

-

-	if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {

-		i = err - MDB_KEYEXIST;

-		return mdb_errstr[i];

-	}

-

-#ifdef _WIN32

-	/* These are the C-runtime error codes we use. The comment indicates

-	 * their numeric value, and the Win32 error they would correspond to

-	 * if the error actually came from a Win32 API. A major mess, we should

-	 * have used LMDB-specific error codes for everything.

-	 */

-	switch(err) {

-	case ENOENT:	/* 2, FILE_NOT_FOUND */

-	case EIO:		/* 5, ACCESS_DENIED */

-	case ENOMEM:	/* 12, INVALID_ACCESS */

-	case EACCES:	/* 13, INVALID_DATA */

-	case EBUSY:		/* 16, CURRENT_DIRECTORY */

-	case EINVAL:	/* 22, BAD_COMMAND */

-	case ENOSPC:	/* 28, OUT_OF_PAPER */

-		return strerror(err);

-	default:

-		;

-	}

-	buf[0] = 0;

-	FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |

-		FORMAT_MESSAGE_IGNORE_INSERTS,

-		NULL, err, 0, ptr, MSGSIZE, (va_list *)buf+MSGSIZE);

-	return ptr;

-#else

-	return strerror(err);

-#endif

-}

-

-/** assert(3) variant in cursor context */

-#define mdb_cassert(mc, expr)	mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)

-/** assert(3) variant in transaction context */

-#define mdb_tassert(txn, expr)	mdb_assert0((txn)->mt_env, expr, #expr)

-/** assert(3) variant in environment context */

-#define mdb_eassert(env, expr)	mdb_assert0(env, expr, #expr)

-

-#ifndef NDEBUG

-# define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \

-		mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))

-

-static void ESECT

-mdb_assert_fail(MDB_env *env, const char *expr_txt,

-	const char *func, const char *file, int line)

-{

-	char buf[400];

-	sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",

-		file, line, expr_txt, func);

-	if (env->me_assert_func)

-		env->me_assert_func(env, buf);

-	fprintf(stderr, "%s\n", buf);

-	abort();

-}

-#else

-# define mdb_assert0(env, expr, expr_txt) ((void) 0)

-#endif /* NDEBUG */

-

-#if MDB_DEBUG

-/** Return the page number of \b mp which may be sub-page, for debug output */

-static pgno_t

-mdb_dbg_pgno(MDB_page *mp)

-{

-	pgno_t ret;

-	COPY_PGNO(ret, mp->mp_pgno);

-	return ret;

-}

-

-/** Display a key in hexadecimal and return the address of the result.

- * @param[in] key the key to display

- * @param[in] buf the buffer to write into. Should always be #DKBUF.

- * @return The key in hexadecimal form.

- */

-char *

-mdb_dkey(MDB_val *key, char *buf)

-{

-	char *ptr = buf;

-	unsigned char *c = key->mv_data;

-	unsigned int i;

-

-	if (!key)

-		return "";

-

-	if (key->mv_size > DKBUF_MAXKEYSIZE)

-		return "MDB_MAXKEYSIZE";

-	/* may want to make this a dynamic check: if the key is mostly

-	 * printable characters, print it as-is instead of converting to hex.

-	 */

-#if 1

-	buf[0] = '\0';

-	for (i=0; i<key->mv_size; i++)

-		ptr += sprintf(ptr, "%02x", *c++);

-#else

-	sprintf(buf, "%.*s", key->mv_size, key->mv_data);

-#endif

-	return buf;

-}

-

-static const char *

-mdb_leafnode_type(MDB_node *n)

-{

-	static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}};

-	return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" :

-		tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)];

-}

-

-/** Display all the keys in the page. */

-void

-mdb_page_list(MDB_page *mp)

-{

-	pgno_t pgno = mdb_dbg_pgno(mp);

-	const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : "";

-	MDB_node *node;

-	unsigned int i, nkeys, nsize, total = 0;

-	MDB_val key;

-	DKBUF;

-

-	switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) {

-	case P_BRANCH:              type = "Branch page";		break;

-	case P_LEAF:                type = "Leaf page";			break;

-	case P_LEAF|P_SUBP:         type = "Sub-page";			break;

-	case P_LEAF|P_LEAF2:        type = "LEAF2 page";		break;

-	case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page";	break;

-	case P_OVERFLOW:

-		fprintf(stderr, "Overflow page %"Y"u pages %u%s\n",

-			pgno, mp->mp_pages, state);

-		return;

-	case P_META:

-		fprintf(stderr, "Meta-page %"Y"u txnid %"Y"u\n",

-			pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);

-		return;

-	default:

-		fprintf(stderr, "Bad page %"Y"u flags 0x%u\n", pgno, mp->mp_flags);

-		return;

-	}

-

-	nkeys = NUMKEYS(mp);

-	fprintf(stderr, "%s %"Y"u numkeys %d%s\n", type, pgno, nkeys, state);

-

-	for (i=0; i<nkeys; i++) {

-		if (IS_LEAF2(mp)) {	/* LEAF2 pages have no mp_ptrs[] or node headers */

-			key.mv_size = nsize = mp->mp_pad;

-			key.mv_data = LEAF2KEY(mp, i, nsize);

-			total += nsize;

-			fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));

-			continue;

-		}

-		node = NODEPTR(mp, i);

-		key.mv_size = node->mn_ksize;

-		key.mv_data = node->mn_data;

-		nsize = NODESIZE + key.mv_size;

-		if (IS_BRANCH(mp)) {

-			fprintf(stderr, "key %d: page %"Y"u, %s\n", i, NODEPGNO(node),

-				DKEY(&key));

-			total += nsize;

-		} else {

-			if (F_ISSET(node->mn_flags, F_BIGDATA))

-				nsize += sizeof(pgno_t);

-			else

-				nsize += NODEDSZ(node);

-			total += nsize;

-			nsize += sizeof(indx_t);

-			fprintf(stderr, "key %d: nsize %d, %s%s\n",

-				i, nsize, DKEY(&key), mdb_leafnode_type(node));

-		}

-		total = EVEN(total);

-	}

-	fprintf(stderr, "Total: header %d + contents %d + unused %d\n",

-		IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp));

-}

-

-void

-mdb_cursor_chk(MDB_cursor *mc)

-{

-	unsigned int i;

-	MDB_node *node;

-	MDB_page *mp;

-

-	if (!mc->mc_snum || !(mc->mc_flags & C_INITIALIZED)) return;

-	for (i=0; i<mc->mc_top; i++) {

-		mp = mc->mc_pg[i];

-		node = NODEPTR(mp, mc->mc_ki[i]);

-		if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)

-			printf("oops!\n");

-	}

-	if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))

-		printf("ack!\n");

-	if (mc->mc_xcursor && (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {

-		node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);

-		if (((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA) &&

-			mc->mc_xcursor->mx_cursor.mc_pg[0] != NODEDATA(node)) {

-			printf("blah!\n");

-		}

-	}

-}

-#endif

-

-#if (MDB_DEBUG) > 2

-/** Count all the pages in each DB and in the freelist

- *  and make sure it matches the actual number of pages

- *  being used.

- *  All named DBs must be open for a correct count.

- */

-static void mdb_audit(MDB_txn *txn)

-{

-	MDB_cursor mc;

-	MDB_val key, data;

-	MDB_ID freecount, count;

-	MDB_dbi i;

-	int rc;

-

-	freecount = 0;

-	mdb_cursor_init(&mc, txn, FREE_DBI, NULL);

-	while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)

-		freecount += *(MDB_ID *)data.mv_data;

-	mdb_tassert(txn, rc == MDB_NOTFOUND);

-

-	count = 0;

-	for (i = 0; i<txn->mt_numdbs; i++) {

-		MDB_xcursor mx;

-		if (!(txn->mt_dbflags[i] & DB_VALID))

-			continue;

-		mdb_cursor_init(&mc, txn, i, &mx);

-		if (txn->mt_dbs[i].md_root == P_INVALID)

-			continue;

-		count += txn->mt_dbs[i].md_branch_pages +

-			txn->mt_dbs[i].md_leaf_pages +

-			txn->mt_dbs[i].md_overflow_pages;

-		if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {

-			rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);

-			for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {

-				unsigned j;

-				MDB_page *mp;

-				mp = mc.mc_pg[mc.mc_top];

-				for (j=0; j<NUMKEYS(mp); j++) {

-					MDB_node *leaf = NODEPTR(mp, j);

-					if (leaf->mn_flags & F_SUBDATA) {

-						MDB_db db;

-						memcpy(&db, NODEDATA(leaf), sizeof(db));

-						count += db.md_branch_pages + db.md_leaf_pages +

-							db.md_overflow_pages;

-					}

-				}

-			}

-			mdb_tassert(txn, rc == MDB_NOTFOUND);

-		}

-	}

-	if (freecount + count + NUM_METAS != txn->mt_next_pgno) {

-		fprintf(stderr, "audit: %"Y"u freecount: %"Y"u count: %"Y"u total: %"Y"u next_pgno: %"Y"u\n",

-			txn->mt_txnid, freecount, count+NUM_METAS,

-			freecount+count+NUM_METAS, txn->mt_next_pgno);

-	}

-}

-#endif

-

-int

-mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)

-{

-	return txn->mt_dbxs[dbi].md_cmp(a, b);

-}

-

-int

-mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)

-{

-	MDB_cmp_func *dcmp = txn->mt_dbxs[dbi].md_dcmp;

-#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)

-	if (dcmp == mdb_cmp_int && a->mv_size == sizeof(mdb_size_t))

-		dcmp = mdb_cmp_clong;

-#endif

-	return dcmp(a, b);

-}

-

-/** Allocate memory for a page.

- * Re-use old malloc'd pages first for singletons, otherwise just malloc.

- */

-static MDB_page *

-mdb_page_malloc(MDB_txn *txn, unsigned num)

-{

-	MDB_env *env = txn->mt_env;

-	MDB_page *ret = env->me_dpages;

-	size_t psize = env->me_psize, sz = psize, off;

-	/* For ! #MDB_NOMEMINIT, psize counts how much to init.

-	 * For a single page alloc, we init everything after the page header.

-	 * For multi-page, we init the final page; if the caller needed that

-	 * many pages they will be filling in at least up to the last page.

-	 */

-	if (num == 1) {

-		if (ret) {

-			VGMEMP_ALLOC(env, ret, sz);

-			VGMEMP_DEFINED(ret, sizeof(ret->mp_next));

-			env->me_dpages = ret->mp_next;

-			return ret;

-		}

-		psize -= off = PAGEHDRSZ;

-	} else {

-		sz *= num;

-		off = sz - psize;

-	}

-	if ((ret = malloc(sz)) != NULL) {

-		VGMEMP_ALLOC(env, ret, sz);

-		if (!(env->me_flags & MDB_NOMEMINIT)) {

-			memset((char *)ret + off, 0, psize);

-			ret->mp_pad = 0;

-		}

-	} else {

-		txn->mt_flags |= MDB_TXN_ERROR;

-	}

-	return ret;

-}

-/** Free a single page.

- * Saves single pages to a list, for future reuse.

- * (This is not used for multi-page overflow pages.)

- */

-static void

-mdb_page_free(MDB_env *env, MDB_page *mp)

-{

-	mp->mp_next = env->me_dpages;

-	VGMEMP_FREE(env, mp);

-	env->me_dpages = mp;

-}

-

-/** Free a dirty page */

-static void

-mdb_dpage_free(MDB_env *env, MDB_page *dp)

-{

-	if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {

-		mdb_page_free(env, dp);

-	} else {

-		/* large pages just get freed directly */

-		VGMEMP_FREE(env, dp);

-		free(dp);

-	}

-}

-

-/**	Return all dirty pages to dpage list */

-static void

-mdb_dlist_free(MDB_txn *txn)

-{

-	MDB_env *env = txn->mt_env;

-	MDB_ID2L dl = txn->mt_u.dirty_list;

-	unsigned i, n = dl[0].mid;

-

-	for (i = 1; i <= n; i++) {

-		mdb_dpage_free(env, dl[i].mptr);

-	}

-	dl[0].mid = 0;

-}

-

-#ifdef MDB_VL32

-static void

-mdb_page_unref(MDB_txn *txn, MDB_page *mp)

-{

-	pgno_t pgno;

-	MDB_ID3L tl = txn->mt_rpages;

-	unsigned x, rem;

-	if (mp->mp_flags & (P_SUBP|P_DIRTY))

-		return;

-	rem = mp->mp_pgno & (MDB_RPAGE_CHUNK-1);

-	pgno = mp->mp_pgno ^ rem;

-	x = mdb_mid3l_search(tl, pgno);

-	if (x != tl[0].mid && tl[x+1].mid == mp->mp_pgno)

-		x++;

-	if (tl[x].mref)

-		tl[x].mref--;

-}

-#define MDB_PAGE_UNREF(txn, mp)	mdb_page_unref(txn, mp)

-

-static void

-mdb_cursor_unref(MDB_cursor *mc)

-{

-	int i;

-	if (!mc->mc_snum || !mc->mc_pg[0] || IS_SUBP(mc->mc_pg[0]))

-		return;

-	for (i=0; i<mc->mc_snum; i++)

-		mdb_page_unref(mc->mc_txn, mc->mc_pg[i]);

-	if (mc->mc_ovpg) {

-		mdb_page_unref(mc->mc_txn, mc->mc_ovpg);

-		mc->mc_ovpg = 0;

-	}

-	mc->mc_snum = mc->mc_top = 0;

-	mc->mc_pg[0] = NULL;

-	mc->mc_flags &= ~C_INITIALIZED;

-}

-#else

-#define MDB_PAGE_UNREF(txn, mp)

-#endif /* MDB_VL32 */

-

-/** Loosen or free a single page.

- * Saves single pages to a list for future reuse

- * in this same txn. It has been pulled from the freeDB

- * and already resides on the dirty list, but has been

- * deleted. Use these pages first before pulling again

- * from the freeDB.

- *

- * If the page wasn't dirtied in this txn, just add it

- * to this txn's free list.

- */

-static int

-mdb_page_loose(MDB_cursor *mc, MDB_page *mp)

-{

-	int loose = 0;

-	pgno_t pgno = mp->mp_pgno;

-	MDB_txn *txn = mc->mc_txn;

-

-	if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) {

-		if (txn->mt_parent) {

-			MDB_ID2 *dl = txn->mt_u.dirty_list;

-			/* If txn has a parent, make sure the page is in our

-			 * dirty list.

-			 */

-			if (dl[0].mid) {

-				unsigned x = mdb_mid2l_search(dl, pgno);

-				if (x <= dl[0].mid && dl[x].mid == pgno) {

-					if (mp != dl[x].mptr) { /* bad cursor? */

-						mc->mc_flags &= ~(C_INITIALIZED|C_EOF);

-						txn->mt_flags |= MDB_TXN_ERROR;

-						return MDB_CORRUPTED;

-					}

-					/* ok, it's ours */

-					loose = 1;

-				}

-			}

-		} else {

-			/* no parent txn, so it's just ours */

-			loose = 1;

-		}

-	}

-	if (loose) {

-		DPRINTF(("loosen db %d page %"Y"u", DDBI(mc),

-			mp->mp_pgno));

-		NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs;

-		txn->mt_loose_pgs = mp;

-		txn->mt_loose_count++;

-		mp->mp_flags |= P_LOOSE;

-	} else {

-		int rc = mdb_midl_append(&txn->mt_free_pgs, pgno);

-		if (rc)

-			return rc;

-	}

-

-	return MDB_SUCCESS;

-}

-

-/** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.

- * @param[in] mc A cursor handle for the current operation.

- * @param[in] pflags Flags of the pages to update:

- * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.

- * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)

-{

-	enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP };

-	MDB_txn *txn = mc->mc_txn;

-	MDB_cursor *m3, *m0 = mc;

-	MDB_xcursor *mx;

-	MDB_page *dp, *mp;

-	MDB_node *leaf;

-	unsigned i, j;

-	int rc = MDB_SUCCESS, level;

-

-	/* Mark pages seen by cursors */

-	if (mc->mc_flags & C_UNTRACK)

-		mc = NULL;				/* will find mc in mt_cursors */

-	for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {

-		for (; mc; mc=mc->mc_next) {

-			if (!(mc->mc_flags & C_INITIALIZED))

-				continue;

-			for (m3 = mc;; m3 = &mx->mx_cursor) {

-				mp = NULL;

-				for (j=0; j<m3->mc_snum; j++) {

-					mp = m3->mc_pg[j];

-					if ((mp->mp_flags & Mask) == pflags)

-						mp->mp_flags ^= P_KEEP;

-				}

-				mx = m3->mc_xcursor;

-				/* Proceed to mx if it is at a sub-database */

-				if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))

-					break;

-				if (! (mp && (mp->mp_flags & P_LEAF)))

-					break;

-				leaf = NODEPTR(mp, m3->mc_ki[j-1]);

-				if (!(leaf->mn_flags & F_SUBDATA))

-					break;

-			}

-		}

-		if (i == 0)

-			break;

-	}

-

-	if (all) {

-		/* Mark dirty root pages */

-		for (i=0; i<txn->mt_numdbs; i++) {

-			if (txn->mt_dbflags[i] & DB_DIRTY) {

-				pgno_t pgno = txn->mt_dbs[i].md_root;

-				if (pgno == P_INVALID)

-					continue;

-				if ((rc = mdb_page_get(m0, pgno, &dp, &level)) != MDB_SUCCESS)

-					break;

-				if ((dp->mp_flags & Mask) == pflags && level <= 1)

-					dp->mp_flags ^= P_KEEP;

-			}

-		}

-	}

-

-	return rc;

-}

-

-static int mdb_page_flush(MDB_txn *txn, int keep);

-

-/**	Spill pages from the dirty list back to disk.

- * This is intended to prevent running into #MDB_TXN_FULL situations,

- * but note that they may still occur in a few cases:

- *	1) our estimate of the txn size could be too small. Currently this

- *	 seems unlikely, except with a large number of #MDB_MULTIPLE items.

- *	2) child txns may run out of space if their parents dirtied a

- *	 lot of pages and never spilled them. TODO: we probably should do

- *	 a preemptive spill during #mdb_txn_begin() of a child txn, if

- *	 the parent's dirty_room is below a given threshold.

- *

- * Otherwise, if not using nested txns, it is expected that apps will

- * not run into #MDB_TXN_FULL any more. The pages are flushed to disk

- * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.

- * If the txn never references them again, they can be left alone.

- * If the txn only reads them, they can be used without any fuss.

- * If the txn writes them again, they can be dirtied immediately without

- * going thru all of the work of #mdb_page_touch(). Such references are

- * handled by #mdb_page_unspill().

- *

- * Also note, we never spill DB root pages, nor pages of active cursors,

- * because we'll need these back again soon anyway. And in nested txns,

- * we can't spill a page in a child txn if it was already spilled in a

- * parent txn. That would alter the parent txns' data even though

- * the child hasn't committed yet, and we'd have no way to undo it if

- * the child aborted.

- *

- * @param[in] m0 cursor A cursor handle identifying the transaction and

- *	database for which we are checking space.

- * @param[in] key For a put operation, the key being stored.

- * @param[in] data For a put operation, the data being stored.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)

-{

-	MDB_txn *txn = m0->mc_txn;

-	MDB_page *dp;

-	MDB_ID2L dl = txn->mt_u.dirty_list;

-	unsigned int i, j, need;

-	int rc;

-

-	if (m0->mc_flags & C_SUB)

-		return MDB_SUCCESS;

-

-	/* Estimate how much space this op will take */

-	i = m0->mc_db->md_depth;

-	/* Named DBs also dirty the main DB */

-	if (m0->mc_dbi >= CORE_DBS)

-		i += txn->mt_dbs[MAIN_DBI].md_depth;

-	/* For puts, roughly factor in the key+data size */

-	if (key)

-		i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;

-	i += i;	/* double it for good measure */

-	need = i;

-

-	if (txn->mt_dirty_room > i)

-		return MDB_SUCCESS;

-

-	if (!txn->mt_spill_pgs) {

-		txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);

-		if (!txn->mt_spill_pgs)

-			return ENOMEM;

-	} else {

-		/* purge deleted slots */

-		MDB_IDL sl = txn->mt_spill_pgs;

-		unsigned int num = sl[0];

-		j=0;

-		for (i=1; i<=num; i++) {

-			if (!(sl[i] & 1))

-				sl[++j] = sl[i];

-		}

-		sl[0] = j;

-	}

-

-	/* Preserve pages which may soon be dirtied again */

-	if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)

-		goto done;

-

-	/* Less aggressive spill - we originally spilled the entire dirty list,

-	 * with a few exceptions for cursor pages and DB root pages. But this

-	 * turns out to be a lot of wasted effort because in a large txn many

-	 * of those pages will need to be used again. So now we spill only 1/8th

-	 * of the dirty pages. Testing revealed this to be a good tradeoff,

-	 * better than 1/2, 1/4, or 1/10.

-	 */

-	if (need < MDB_IDL_UM_MAX / 8)

-		need = MDB_IDL_UM_MAX / 8;

-

-	/* Save the page IDs of all the pages we're flushing */

-	/* flush from the tail forward, this saves a lot of shifting later on. */

-	for (i=dl[0].mid; i && need; i--) {

-		MDB_ID pn = dl[i].mid << 1;

-		dp = dl[i].mptr;

-		if (dp->mp_flags & (P_LOOSE|P_KEEP))

-			continue;

-		/* Can't spill twice, make sure it's not already in a parent's

-		 * spill list.

-		 */

-		if (txn->mt_parent) {

-			MDB_txn *tx2;

-			for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {

-				if (tx2->mt_spill_pgs) {

-					j = mdb_midl_search(tx2->mt_spill_pgs, pn);

-					if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {

-						dp->mp_flags |= P_KEEP;

-						break;

-					}

-				}

-			}

-			if (tx2)

-				continue;

-		}

-		if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))

-			goto done;

-		need--;

-	}

-	mdb_midl_sort(txn->mt_spill_pgs);

-

-	/* Flush the spilled part of dirty list */

-	if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)

-		goto done;

-

-	/* Reset any dirty pages we kept that page_flush didn't see */

-	rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);

-

-done:

-	txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;

-	return rc;

-}

-

-/** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */

-static txnid_t

-mdb_find_oldest(MDB_txn *txn)

-{

-	int i;

-	txnid_t mr, oldest = txn->mt_txnid - 1;

-	if (txn->mt_env->me_txns) {

-		MDB_reader *r = txn->mt_env->me_txns->mti_readers;

-		for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {

-			if (r[i].mr_pid) {

-				mr = r[i].mr_txnid;

-				if (oldest > mr)

-					oldest = mr;

-			}

-		}

-	}

-	return oldest;

-}

-

-/** Add a page to the txn's dirty list */

-static void

-mdb_page_dirty(MDB_txn *txn, MDB_page *mp)

-{

-	MDB_ID2 mid;

-	int rc, (*insert)(MDB_ID2L, MDB_ID2 *);

-

-	if (txn->mt_flags & MDB_TXN_WRITEMAP) {

-		insert = mdb_mid2l_append;

-	} else {

-		insert = mdb_mid2l_insert;

-	}

-	mid.mid = mp->mp_pgno;

-	mid.mptr = mp;

-	rc = insert(txn->mt_u.dirty_list, &mid);

-	mdb_tassert(txn, rc == 0);

-	txn->mt_dirty_room--;

-}

-

-/** Allocate page numbers and memory for writing.  Maintain me_pglast,

- * me_pghead and mt_next_pgno.

- *

- * If there are free pages available from older transactions, they

- * are re-used first. Otherwise allocate a new page at mt_next_pgno.

- * Do not modify the freedB, just merge freeDB records into me_pghead[]

- * and move me_pglast to say which records were consumed.  Only this

- * function can create me_pghead and move me_pglast/mt_next_pgno.

- * When #MDB_DEVEL & 2, it is not affected by #mdb_freelist_save(): it

- * then uses the transaction's original snapshot of the freeDB.

- * @param[in] mc cursor A cursor handle identifying the transaction and

- *	database for which we are allocating.

- * @param[in] num the number of pages to allocate.

- * @param[out] mp Address of the allocated page(s). Requests for multiple pages

- *  will always be satisfied by a single contiguous chunk of memory.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)

-{

-#ifdef MDB_PARANOID	/* Seems like we can ignore this now */

-	/* Get at most <Max_retries> more freeDB records once me_pghead

-	 * has enough pages.  If not enough, use new pages from the map.

-	 * If <Paranoid> and mc is updating the freeDB, only get new

-	 * records if me_pghead is empty. Then the freelist cannot play

-	 * catch-up with itself by growing while trying to save it.

-	 */

-	enum { Paranoid = 1, Max_retries = 500 };

-#else

-	enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };

-#endif

-	int rc, retry = num * 60;

-	MDB_txn *txn = mc->mc_txn;

-	MDB_env *env = txn->mt_env;

-	pgno_t pgno, *mop = env->me_pghead;

-	unsigned i, j, mop_len = mop ? mop[0] : 0, n2 = num-1;

-	MDB_page *np;

-	txnid_t oldest = 0, last;

-	MDB_cursor_op op;

-	MDB_cursor m2;

-	int found_old = 0;

-

-	/* If there are any loose pages, just use them */

-	if (num == 1 && txn->mt_loose_pgs) {

-		np = txn->mt_loose_pgs;

-		txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);

-		txn->mt_loose_count--;

-		DPRINTF(("db %d use loose page %"Y"u", DDBI(mc),

-				np->mp_pgno));

-		*mp = np;

-		return MDB_SUCCESS;

-	}

-

-	*mp = NULL;

-

-	/* If our dirty list is already full, we can't do anything */

-	if (txn->mt_dirty_room == 0) {

-		rc = MDB_TXN_FULL;

-		goto fail;

-	}

-

-	for (op = MDB_FIRST;; op = MDB_NEXT) {

-		MDB_val key, data;

-		MDB_node *leaf;

-		pgno_t *idl;

-

-		/* Seek a big enough contiguous page range. Prefer

-		 * pages at the tail, just truncating the list.

-		 */

-		if (mop_len > n2) {

-			i = mop_len;

-			do {

-				pgno = mop[i];

-				if (mop[i-n2] == pgno+n2)

-					goto search_done;

-			} while (--i > n2);

-			if (--retry < 0)

-				break;

-		}

-

-		if (op == MDB_FIRST) {	/* 1st iteration */

-			/* Prepare to fetch more and coalesce */

-			last = env->me_pglast;

-			oldest = env->me_pgoldest;

-			mdb_cursor_init(&m2, txn, FREE_DBI, NULL);

-#if (MDB_DEVEL) & 2	/* "& 2" so MDB_DEVEL=1 won't hide bugs breaking freeDB */

-			/* Use original snapshot. TODO: Should need less care in code

-			 * which modifies the database. Maybe we can delete some code?

-			 */

-			m2.mc_flags |= C_ORIG_RDONLY;

-			m2.mc_db = &env->me_metas[(txn->mt_txnid-1) & 1]->mm_dbs[FREE_DBI];

-			m2.mc_dbflag = (unsigned char *)""; /* probably unnecessary */

-#endif

-			if (last) {

-				op = MDB_SET_RANGE;

-				key.mv_data = &last; /* will look up last+1 */

-				key.mv_size = sizeof(last);

-			}

-			if (Paranoid && mc->mc_dbi == FREE_DBI)

-				retry = -1;

-		}

-		if (Paranoid && retry < 0 && mop_len)

-			break;

-

-		last++;

-		/* Do not fetch more if the record will be too recent */

-		if (oldest <= last) {

-			if (!found_old) {

-				oldest = mdb_find_oldest(txn);

-				env->me_pgoldest = oldest;

-				found_old = 1;

-			}

-			if (oldest <= last)

-				break;

-		}

-		rc = mdb_cursor_get(&m2, &key, NULL, op);

-		if (rc) {

-			if (rc == MDB_NOTFOUND)

-				break;

-			goto fail;

-		}

-		last = *(txnid_t*)key.mv_data;

-		if (oldest <= last) {

-			if (!found_old) {

-				oldest = mdb_find_oldest(txn);

-				env->me_pgoldest = oldest;

-				found_old = 1;

-			}

-			if (oldest <= last)

-				break;

-		}

-		np = m2.mc_pg[m2.mc_top];

-		leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);

-		if ((rc = mdb_node_read(&m2, leaf, &data)) != MDB_SUCCESS)

-			return rc;

-

-		idl = (MDB_ID *) data.mv_data;

-		i = idl[0];

-		if (!mop) {

-			if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {

-				rc = ENOMEM;

-				goto fail;

-			}

-		} else {

-			if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)

-				goto fail;

-			mop = env->me_pghead;

-		}

-		env->me_pglast = last;

-#if (MDB_DEBUG) > 1

-		DPRINTF(("IDL read txn %"Y"u root %"Y"u num %u",

-			last, txn->mt_dbs[FREE_DBI].md_root, i));

-		for (j = i; j; j--)

-			DPRINTF(("IDL %"Y"u", idl[j]));

-#endif

-		/* Merge in descending sorted order */

-		mdb_midl_xmerge(mop, idl);

-		mop_len = mop[0];

-	}

-

-	/* Use new pages from the map when nothing suitable in the freeDB */

-	i = 0;

-	pgno = txn->mt_next_pgno;

-	if (pgno + num >= env->me_maxpg) {

-			DPUTS("DB size maxed out");

-			rc = MDB_MAP_FULL;

-			goto fail;

-	}

-#if defined(_WIN32) && !defined(MDB_VL32)

-	if (!(env->me_flags & MDB_RDONLY)) {

-		void *p;

-		p = (MDB_page *)(env->me_map + env->me_psize * pgno);

-		p = VirtualAlloc(p, env->me_psize * num, MEM_COMMIT,

-			(env->me_flags & MDB_WRITEMAP) ? PAGE_READWRITE:

-			PAGE_READONLY);

-		if (!p) {

-			DPUTS("VirtualAlloc failed");

-			rc = ErrCode();

-			goto fail;

-		}

-	}

-#endif

-

-search_done:

-	if (env->me_flags & MDB_WRITEMAP) {

-		np = (MDB_page *)(env->me_map + env->me_psize * pgno);

-	} else {

-		if (!(np = mdb_page_malloc(txn, num))) {

-			rc = ENOMEM;

-			goto fail;

-		}

-	}

-	if (i) {

-		mop[0] = mop_len -= num;

-		/* Move any stragglers down */

-		for (j = i-num; j < mop_len; )

-			mop[++j] = mop[++i];

-	} else {

-		txn->mt_next_pgno = pgno + num;

-	}

-	np->mp_pgno = pgno;

-	mdb_page_dirty(txn, np);

-	*mp = np;

-

-	return MDB_SUCCESS;

-

-fail:

-	txn->mt_flags |= MDB_TXN_ERROR;

-	return rc;

-}

-

-/** Copy the used portions of a non-overflow page.

- * @param[in] dst page to copy into

- * @param[in] src page to copy from

- * @param[in] psize size of a page

- */

-static void

-mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)

-{

-	enum { Align = sizeof(pgno_t) };

-	indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;

-

-	/* If page isn't full, just copy the used portion. Adjust

-	 * alignment so memcpy may copy words instead of bytes.

-	 */

-	if ((unused &= -Align) && !IS_LEAF2(src)) {

-		upper = (upper + PAGEBASE) & -Align;

-		memcpy(dst, src, (lower + PAGEBASE + (Align-1)) & -Align);

-		memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),

-			psize - upper);

-	} else {

-		memcpy(dst, src, psize - unused);

-	}

-}

-

-/** Pull a page off the txn's spill list, if present.

- * If a page being referenced was spilled to disk in this txn, bring

- * it back and make it dirty/writable again.

- * @param[in] txn the transaction handle.

- * @param[in] mp the page being referenced. It must not be dirty.

- * @param[out] ret the writable page, if any. ret is unchanged if

- * mp wasn't spilled.

- */

-static int

-mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)

-{

-	MDB_env *env = txn->mt_env;

-	const MDB_txn *tx2;

-	unsigned x;

-	pgno_t pgno = mp->mp_pgno, pn = pgno << 1;

-

-	for (tx2 = txn; tx2; tx2=tx2->mt_parent) {

-		if (!tx2->mt_spill_pgs)

-			continue;

-		x = mdb_midl_search(tx2->mt_spill_pgs, pn);

-		if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {

-			MDB_page *np;

-			int num;

-			if (txn->mt_dirty_room == 0)

-				return MDB_TXN_FULL;

-			if (IS_OVERFLOW(mp))

-				num = mp->mp_pages;

-			else

-				num = 1;

-			if (env->me_flags & MDB_WRITEMAP) {

-				np = mp;

-			} else {

-				np = mdb_page_malloc(txn, num);

-				if (!np)

-					return ENOMEM;

-				if (num > 1)

-					memcpy(np, mp, num * env->me_psize);

-				else

-					mdb_page_copy(np, mp, env->me_psize);

-			}

-			if (tx2 == txn) {

-				/* If in current txn, this page is no longer spilled.

-				 * If it happens to be the last page, truncate the spill list.

-				 * Otherwise mark it as deleted by setting the LSB.

-				 */

-				if (x == txn->mt_spill_pgs[0])

-					txn->mt_spill_pgs[0]--;

-				else

-					txn->mt_spill_pgs[x] |= 1;

-			}	/* otherwise, if belonging to a parent txn, the

-				 * page remains spilled until child commits

-				 */

-

-			mdb_page_dirty(txn, np);

-			np->mp_flags |= P_DIRTY;

-			*ret = np;

-			break;

-		}

-	}

-	return MDB_SUCCESS;

-}

-

-/** Touch a page: make it dirty and re-insert into tree with updated pgno.

- * @param[in] mc cursor pointing to the page to be touched

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_page_touch(MDB_cursor *mc)

-{

-	MDB_page *mp = mc->mc_pg[mc->mc_top], *np;

-	MDB_txn *txn = mc->mc_txn;

-	MDB_cursor *m2, *m3;

-	pgno_t	pgno;

-	int rc;

-

-	if (!F_ISSET(mp->mp_flags, P_DIRTY)) {

-		if (txn->mt_flags & MDB_TXN_SPILLS) {

-			np = NULL;

-			rc = mdb_page_unspill(txn, mp, &np);

-			if (rc)

-				goto fail;

-			if (np)

-				goto done;

-		}

-		if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||

-			(rc = mdb_page_alloc(mc, 1, &np)))

-			goto fail;

-		pgno = np->mp_pgno;

-		DPRINTF(("touched db %d page %"Y"u -> %"Y"u", DDBI(mc),

-			mp->mp_pgno, pgno));

-		mdb_cassert(mc, mp->mp_pgno != pgno);

-		mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);

-		/* Update the parent page, if any, to point to the new page */

-		if (mc->mc_top) {

-			MDB_page *parent = mc->mc_pg[mc->mc_top-1];

-			MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);

-			SETPGNO(node, pgno);

-		} else {

-			mc->mc_db->md_root = pgno;

-		}

-	} else if (txn->mt_parent && !IS_SUBP(mp)) {

-		MDB_ID2 mid, *dl = txn->mt_u.dirty_list;

-		pgno = mp->mp_pgno;

-		/* If txn has a parent, make sure the page is in our

-		 * dirty list.

-		 */

-		if (dl[0].mid) {

-			unsigned x = mdb_mid2l_search(dl, pgno);

-			if (x <= dl[0].mid && dl[x].mid == pgno) {

-				if (mp != dl[x].mptr) { /* bad cursor? */

-					mc->mc_flags &= ~(C_INITIALIZED|C_EOF);

-					txn->mt_flags |= MDB_TXN_ERROR;

-					return MDB_CORRUPTED;

-				}

-				return 0;

-			}

-		}

-		mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);

-		/* No - copy it */

-		np = mdb_page_malloc(txn, 1);

-		if (!np)

-			return ENOMEM;

-		mid.mid = pgno;

-		mid.mptr = np;

-		rc = mdb_mid2l_insert(dl, &mid);

-		mdb_cassert(mc, rc == 0);

-	} else {

-		return 0;

-	}

-

-	mdb_page_copy(np, mp, txn->mt_env->me_psize);

-	np->mp_pgno = pgno;

-	np->mp_flags |= P_DIRTY;

-

-done:

-	/* Adjust cursors pointing to mp */

-	mc->mc_pg[mc->mc_top] = np;

-	m2 = txn->mt_cursors[mc->mc_dbi];

-	if (mc->mc_flags & C_SUB) {

-		for (; m2; m2=m2->mc_next) {

-			m3 = &m2->mc_xcursor->mx_cursor;

-			if (m3->mc_snum < mc->mc_snum) continue;

-			if (m3->mc_pg[mc->mc_top] == mp)

-				m3->mc_pg[mc->mc_top] = np;

-		}

-	} else {

-		for (; m2; m2=m2->mc_next) {

-			if (m2->mc_snum < mc->mc_snum) continue;

-			if (m2 == mc) continue;

-			if (m2->mc_pg[mc->mc_top] == mp) {

-				m2->mc_pg[mc->mc_top] = np;

-				if ((mc->mc_db->md_flags & MDB_DUPSORT) &&

-					IS_LEAF(np) &&

-					(m2->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))

-				{

-					MDB_node *leaf = NODEPTR(np, m2->mc_ki[mc->mc_top]);

-					if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)

-						m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);

-				}

-			}

-		}

-	}

-	MDB_PAGE_UNREF(mc->mc_txn, mp);

-	return 0;

-

-fail:

-	txn->mt_flags |= MDB_TXN_ERROR;

-	return rc;

-}

-

-int

-mdb_env_sync0(MDB_env *env, int force, pgno_t numpgs)

-{

-	int rc = 0;

-	if (env->me_flags & MDB_RDONLY)

-		return EACCES;

-	if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {

-		if (env->me_flags & MDB_WRITEMAP) {

-			int flags = ((env->me_flags & MDB_MAPASYNC) && !force)

-				? MS_ASYNC : MS_SYNC;

-			if (MDB_MSYNC(env->me_map, env->me_psize * numpgs, flags))

-				rc = ErrCode();

-#ifdef _WIN32

-			else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))

-				rc = ErrCode();

-#endif

-		} else {

-#ifdef BROKEN_FDATASYNC

-			if (env->me_flags & MDB_FSYNCONLY) {

-				if (fsync(env->me_fd))

-					rc = ErrCode();

-			} else

-#endif

-			if (MDB_FDATASYNC(env->me_fd))

-				rc = ErrCode();

-		}

-	}

-	return rc;

-}

-

-int

-mdb_env_sync(MDB_env *env, int force)

-{

-	MDB_meta *m = mdb_env_pick_meta(env);

-	return mdb_env_sync0(env, force, m->mm_last_pg+1);

-}

-

-/** Back up parent txn's cursors, then grab the originals for tracking */

-static int

-mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)

-{

-	MDB_cursor *mc, *bk;

-	MDB_xcursor *mx;

-	size_t size;

-	int i;

-

-	for (i = src->mt_numdbs; --i >= 0; ) {

-		if ((mc = src->mt_cursors[i]) != NULL) {

-			size = sizeof(MDB_cursor);

-			if (mc->mc_xcursor)

-				size += sizeof(MDB_xcursor);

-			for (; mc; mc = bk->mc_next) {

-				bk = malloc(size);

-				if (!bk)

-					return ENOMEM;

-				*bk = *mc;

-				mc->mc_backup = bk;

-				mc->mc_db = &dst->mt_dbs[i];

-				/* Kill pointers into src to reduce abuse: The

-				 * user may not use mc until dst ends. But we need a valid

-				 * txn pointer here for cursor fixups to keep working.

-				 */

-				mc->mc_txn    = dst;

-				mc->mc_dbflag = &dst->mt_dbflags[i];

-				if ((mx = mc->mc_xcursor) != NULL) {

-					*(MDB_xcursor *)(bk+1) = *mx;

-					mx->mx_cursor.mc_txn = dst;

-				}

-				mc->mc_next = dst->mt_cursors[i];

-				dst->mt_cursors[i] = mc;

-			}

-		}

-	}

-	return MDB_SUCCESS;

-}

-

-/** Close this write txn's cursors, give parent txn's cursors back to parent.

- * @param[in] txn the transaction handle.

- * @param[in] merge true to keep changes to parent cursors, false to revert.

- * @return 0 on success, non-zero on failure.

- */

-static void

-mdb_cursors_close(MDB_txn *txn, unsigned merge)

-{

-	MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;

-	MDB_xcursor *mx;

-	int i;

-

-	for (i = txn->mt_numdbs; --i >= 0; ) {

-		for (mc = cursors[i]; mc; mc = next) {

-			next = mc->mc_next;

-			if ((bk = mc->mc_backup) != NULL) {

-				if (merge) {

-					/* Commit changes to parent txn */

-					mc->mc_next = bk->mc_next;

-					mc->mc_backup = bk->mc_backup;

-					mc->mc_txn = bk->mc_txn;

-					mc->mc_db = bk->mc_db;

-					mc->mc_dbflag = bk->mc_dbflag;

-					if ((mx = mc->mc_xcursor) != NULL)

-						mx->mx_cursor.mc_txn = bk->mc_txn;

-				} else {

-					/* Abort nested txn */

-					*mc = *bk;

-					if ((mx = mc->mc_xcursor) != NULL)

-						*mx = *(MDB_xcursor *)(bk+1);

-				}

-				mc = bk;

-			}

-			/* Only malloced cursors are permanently tracked. */

-			free(mc);

-		}

-		cursors[i] = NULL;

-	}

-}

-

-#if !(MDB_PIDLOCK)		/* Currently the same as defined(_WIN32) */

-enum Pidlock_op {

-	Pidset, Pidcheck

-};

-#else

-enum Pidlock_op {

-	Pidset = F_SETLK, Pidcheck = F_GETLK

-};

-#endif

-

-/** Set or check a pid lock. Set returns 0 on success.

- * Check returns 0 if the process is certainly dead, nonzero if it may

- * be alive (the lock exists or an error happened so we do not know).

- *

- * On Windows Pidset is a no-op, we merely check for the existence

- * of the process with the given pid. On POSIX we use a single byte

- * lock on the lockfile, set at an offset equal to the pid.

- */

-static int

-mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)

-{

-#if !(MDB_PIDLOCK)		/* Currently the same as defined(_WIN32) */

-	int ret = 0;

-	HANDLE h;

-	if (op == Pidcheck) {

-		h = OpenProcess(env->me_pidquery, FALSE, pid);

-		/* No documented "no such process" code, but other program use this: */

-		if (!h)

-			return ErrCode() != ERROR_INVALID_PARAMETER;

-		/* A process exists until all handles to it close. Has it exited? */

-		ret = WaitForSingleObject(h, 0) != 0;

-		CloseHandle(h);

-	}

-	return ret;

-#else

-	for (;;) {

-		int rc;

-		struct flock lock_info;

-		memset(&lock_info, 0, sizeof(lock_info));

-		lock_info.l_type = F_WRLCK;

-		lock_info.l_whence = SEEK_SET;

-		lock_info.l_start = pid;

-		lock_info.l_len = 1;

-		if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {

-			if (op == F_GETLK && lock_info.l_type != F_UNLCK)

-				rc = -1;

-		} else if ((rc = ErrCode()) == EINTR) {

-			continue;

-		}

-		return rc;

-	}

-#endif

-}

-

-/** Common code for #mdb_txn_begin() and #mdb_txn_renew().

- * @param[in] txn the transaction handle to initialize

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_txn_renew0(MDB_txn *txn)

-{

-	MDB_env *env = txn->mt_env;

-	MDB_txninfo *ti = env->me_txns;

-	MDB_meta *meta;

-	unsigned int i, nr, flags = txn->mt_flags;

-	uint16_t x;

-	int rc, new_notls = 0;

-

-	if ((flags &= MDB_TXN_RDONLY) != 0) {

-		if (!ti) {

-			meta = mdb_env_pick_meta(env);

-			txn->mt_txnid = meta->mm_txnid;

-			txn->mt_u.reader = NULL;

-		} else {

-			MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :

-				pthread_getspecific(env->me_txkey);

-			if (r) {

-				if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)

-					return MDB_BAD_RSLOT;

-			} else {

-				MDB_PID_T pid = env->me_pid;

-				MDB_THR_T tid = pthread_self();

-				mdb_mutexref_t rmutex = env->me_rmutex;

-

-				if (!env->me_live_reader) {

-					rc = mdb_reader_pid(env, Pidset, pid);

-					if (rc)

-						return rc;

-					env->me_live_reader = 1;

-				}

-

-				if (LOCK_MUTEX(rc, env, rmutex))

-					return rc;

-				nr = ti->mti_numreaders;

-				for (i=0; i<nr; i++)

-					if (ti->mti_readers[i].mr_pid == 0)

-						break;

-				if (i == env->me_maxreaders) {

-					UNLOCK_MUTEX(rmutex);

-					return MDB_READERS_FULL;

-				}

-				r = &ti->mti_readers[i];

-				/* Claim the reader slot, carefully since other code

-				 * uses the reader table un-mutexed: First reset the

-				 * slot, next publish it in mti_numreaders.  After

-				 * that, it is safe for mdb_env_close() to touch it.

-				 * When it will be closed, we can finally claim it.

-				 */

-				r->mr_pid = 0;

-				r->mr_txnid = (txnid_t)-1;

-				r->mr_tid = tid;

-				if (i == nr)

-					ti->mti_numreaders = ++nr;

-				env->me_close_readers = nr;

-				r->mr_pid = pid;

-				UNLOCK_MUTEX(rmutex);

-

-				new_notls = (env->me_flags & MDB_NOTLS);

-				if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {

-					r->mr_pid = 0;

-					return rc;

-				}

-			}

-			do /* LY: Retry on a race, ITS#7970. */

-				r->mr_txnid = ti->mti_txnid;

-			while(r->mr_txnid != ti->mti_txnid);

-			txn->mt_txnid = r->mr_txnid;

-			txn->mt_u.reader = r;

-			meta = env->me_metas[txn->mt_txnid & 1];

-		}

-

-	} else {

-		/* Not yet touching txn == env->me_txn0, it may be active */

-		if (ti) {

-			if (LOCK_MUTEX(rc, env, env->me_wmutex))

-				return rc;

-			txn->mt_txnid = ti->mti_txnid;

-			meta = env->me_metas[txn->mt_txnid & 1];

-		} else {

-			meta = mdb_env_pick_meta(env);

-			txn->mt_txnid = meta->mm_txnid;

-		}

-		txn->mt_txnid++;

-#if MDB_DEBUG

-		if (txn->mt_txnid == mdb_debug_start)

-			mdb_debug = 1;

-#endif

-		txn->mt_child = NULL;

-		txn->mt_loose_pgs = NULL;

-		txn->mt_loose_count = 0;

-		txn->mt_dirty_room = MDB_IDL_UM_MAX;

-		txn->mt_u.dirty_list = env->me_dirty_list;

-		txn->mt_u.dirty_list[0].mid = 0;

-		txn->mt_free_pgs = env->me_free_pgs;

-		txn->mt_free_pgs[0] = 0;

-		txn->mt_spill_pgs = NULL;

-		env->me_txn = txn;

-		memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));

-	}

-

-	/* Copy the DB info and flags */

-	memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDB_db));

-

-	/* Moved to here to avoid a data race in read TXNs */

-	txn->mt_next_pgno = meta->mm_last_pg+1;

-#ifdef MDB_VL32

-	txn->mt_last_pgno = txn->mt_next_pgno - 1;

-#endif

-

-	txn->mt_flags = flags;

-

-	/* Setup db info */

-	txn->mt_numdbs = env->me_numdbs;

-	for (i=CORE_DBS; i<txn->mt_numdbs; i++) {

-		x = env->me_dbflags[i];

-		txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;

-		txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_USRVALID|DB_STALE : 0;

-	}

-	txn->mt_dbflags[MAIN_DBI] = DB_VALID|DB_USRVALID;

-	txn->mt_dbflags[FREE_DBI] = DB_VALID;

-

-	if (env->me_flags & MDB_FATAL_ERROR) {

-		DPUTS("environment had fatal error, must shutdown!");

-		rc = MDB_PANIC;

-	} else if (env->me_maxpg < txn->mt_next_pgno) {

-		rc = MDB_MAP_RESIZED;

-	} else {

-		return MDB_SUCCESS;

-	}

-	mdb_txn_end(txn, new_notls /*0 or MDB_END_SLOT*/ | MDB_END_FAIL_BEGIN);

-	return rc;

-}

-

-int

-mdb_txn_renew(MDB_txn *txn)

-{

-	int rc;

-

-	if (!txn || !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY|MDB_TXN_FINISHED))

-		return EINVAL;

-

-	rc = mdb_txn_renew0(txn);

-	if (rc == MDB_SUCCESS) {

-		DPRINTF(("renew txn %"Y"u%c %p on mdbenv %p, root page %"Y"u",

-			txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',

-			(void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));

-	}

-	return rc;

-}

-

-int

-mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)

-{

-	MDB_txn *txn;

-	MDB_ntxn *ntxn;

-	int rc, size, tsize;

-

-	flags &= MDB_TXN_BEGIN_FLAGS;

-	flags |= env->me_flags & MDB_WRITEMAP;

-

-	if (env->me_flags & MDB_RDONLY & ~flags) /* write txn in RDONLY env */

-		return EACCES;

-

-	if (parent) {

-		/* Nested transactions: Max 1 child, write txns only, no writemap */

-		flags |= parent->mt_flags;

-		if (flags & (MDB_RDONLY|MDB_WRITEMAP|MDB_TXN_BLOCKED)) {

-			return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;

-		}

-		/* Child txns save MDB_pgstate and use own copy of cursors */

-		size = env->me_maxdbs * (sizeof(MDB_db)+sizeof(MDB_cursor *)+1);

-		size += tsize = sizeof(MDB_ntxn);

-	} else if (flags & MDB_RDONLY) {

-		size = env->me_maxdbs * (sizeof(MDB_db)+1);

-		size += tsize = sizeof(MDB_txn);

-	} else {

-		/* Reuse preallocated write txn. However, do not touch it until

-		 * mdb_txn_renew0() succeeds, since it currently may be active.

-		 */

-		txn = env->me_txn0;

-		goto renew;

-	}

-	if ((txn = calloc(1, size)) == NULL) {

-		DPRINTF(("calloc: %s", strerror(errno)));

-		return ENOMEM;

-	}

-#ifdef MDB_VL32

-	if (!parent) {

-		txn->mt_rpages = malloc(MDB_TRPAGE_SIZE * sizeof(MDB_ID3));

-		if (!txn->mt_rpages) {

-			free(txn);

-			return ENOMEM;

-		}

-		txn->mt_rpages[0].mid = 0;

-		txn->mt_rpcheck = MDB_TRPAGE_SIZE/2;

-	}

-#endif

-	txn->mt_dbxs = env->me_dbxs;	/* static */

-	txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);

-	txn->mt_dbflags = (unsigned char *)txn + size - env->me_maxdbs;

-	txn->mt_flags = flags;

-	txn->mt_env = env;

-

-	if (parent) {

-		unsigned int i;

-		txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);

-		txn->mt_dbiseqs = parent->mt_dbiseqs;

-		txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);

-		if (!txn->mt_u.dirty_list ||

-			!(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))

-		{

-			free(txn->mt_u.dirty_list);

-			free(txn);

-			return ENOMEM;

-		}

-		txn->mt_txnid = parent->mt_txnid;

-		txn->mt_dirty_room = parent->mt_dirty_room;

-		txn->mt_u.dirty_list[0].mid = 0;

-		txn->mt_spill_pgs = NULL;

-		txn->mt_next_pgno = parent->mt_next_pgno;

-		parent->mt_flags |= MDB_TXN_HAS_CHILD;

-		parent->mt_child = txn;

-		txn->mt_parent = parent;

-		txn->mt_numdbs = parent->mt_numdbs;

-#ifdef MDB_VL32

-		txn->mt_rpages = parent->mt_rpages;

-#endif

-		memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));

-		/* Copy parent's mt_dbflags, but clear DB_NEW */

-		for (i=0; i<txn->mt_numdbs; i++)

-			txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;

-		rc = 0;

-		ntxn = (MDB_ntxn *)txn;

-		ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */

-		if (env->me_pghead) {

-			size = MDB_IDL_SIZEOF(env->me_pghead);

-			env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);

-			if (env->me_pghead)

-				memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);

-			else

-				rc = ENOMEM;

-		}

-		if (!rc)

-			rc = mdb_cursor_shadow(parent, txn);

-		if (rc)

-			mdb_txn_end(txn, MDB_END_FAIL_BEGINCHILD);

-	} else { /* MDB_RDONLY */

-		txn->mt_dbiseqs = env->me_dbiseqs;

-renew:

-		rc = mdb_txn_renew0(txn);

-	}

-	if (rc) {

-		if (txn != env->me_txn0) {

-#ifdef MDB_VL32

-			free(txn->mt_rpages);

-#endif

-			free(txn);

-		}

-	} else {

-		txn->mt_flags |= flags;	/* could not change txn=me_txn0 earlier */

-		*ret = txn;

-		DPRINTF(("begin txn %"Y"u%c %p on mdbenv %p, root page %"Y"u",

-			txn->mt_txnid, (flags & MDB_RDONLY) ? 'r' : 'w',

-			(void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));

-	}

-

-	return rc;

-}

-

-MDB_env *

-mdb_txn_env(MDB_txn *txn)

-{

-	if(!txn) return NULL;

-	return txn->mt_env;

-}

-

-mdb_size_t

-mdb_txn_id(MDB_txn *txn)

-{

-    if(!txn) return 0;

-    return txn->mt_txnid;

-}

-

-/** Export or close DBI handles opened in this txn. */

-static void

-mdb_dbis_update(MDB_txn *txn, int keep)

-{

-	int i;

-	MDB_dbi n = txn->mt_numdbs;

-	MDB_env *env = txn->mt_env;

-	unsigned char *tdbflags = txn->mt_dbflags;

-

-	for (i = n; --i >= CORE_DBS;) {

-		if (tdbflags[i] & DB_NEW) {

-			if (keep) {

-				env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;

-			} else {

-				char *ptr = env->me_dbxs[i].md_name.mv_data;

-				if (ptr) {

-					env->me_dbxs[i].md_name.mv_data = NULL;

-					env->me_dbxs[i].md_name.mv_size = 0;

-					env->me_dbflags[i] = 0;

-					env->me_dbiseqs[i]++;

-					free(ptr);

-				}

-			}

-		}

-	}

-	if (keep && env->me_numdbs < n)

-		env->me_numdbs = n;

-}

-

-/** End a transaction, except successful commit of a nested transaction.

- * May be called twice for readonly txns: First reset it, then abort.

- * @param[in] txn the transaction handle to end

- * @param[in] mode why and how to end the transaction

- */

-static void

-mdb_txn_end(MDB_txn *txn, unsigned mode)

-{

-	MDB_env	*env = txn->mt_env;

-#if MDB_DEBUG

-	static const char *const names[] = MDB_END_NAMES;

-#endif

-

-	/* Export or close DBI handles opened in this txn */

-	mdb_dbis_update(txn, mode & MDB_END_UPDATE);

-

-	DPRINTF(("%s txn %"Y"u%c %p on mdbenv %p, root page %"Y"u",

-		names[mode & MDB_END_OPMASK],

-		txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',

-		(void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));

-

-	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {

-		if (txn->mt_u.reader) {

-			txn->mt_u.reader->mr_txnid = (txnid_t)-1;

-			if (!(env->me_flags & MDB_NOTLS)) {

-				txn->mt_u.reader = NULL; /* txn does not own reader */

-			} else if (mode & MDB_END_SLOT) {

-				txn->mt_u.reader->mr_pid = 0;

-				txn->mt_u.reader = NULL;

-			} /* else txn owns the slot until it does MDB_END_SLOT */

-		}

-		txn->mt_numdbs = 0;		/* prevent further DBI activity */

-		txn->mt_flags |= MDB_TXN_FINISHED;

-

-	} else if (!F_ISSET(txn->mt_flags, MDB_TXN_FINISHED)) {

-		pgno_t *pghead = env->me_pghead;

-

-		if (!(mode & MDB_END_UPDATE)) /* !(already closed cursors) */

-			mdb_cursors_close(txn, 0);

-		if (!(env->me_flags & MDB_WRITEMAP)) {

-			mdb_dlist_free(txn);

-		}

-

-		txn->mt_numdbs = 0;

-		txn->mt_flags = MDB_TXN_FINISHED;

-

-		if (!txn->mt_parent) {

-			mdb_midl_shrink(&txn->mt_free_pgs);

-			env->me_free_pgs = txn->mt_free_pgs;

-			/* me_pgstate: */

-			env->me_pghead = NULL;

-			env->me_pglast = 0;

-

-			env->me_txn = NULL;

-			mode = 0;	/* txn == env->me_txn0, do not free() it */

-

-			/* The writer mutex was locked in mdb_txn_begin. */

-			if (env->me_txns)

-				UNLOCK_MUTEX(env->me_wmutex);

-		} else {

-			txn->mt_parent->mt_child = NULL;

-			txn->mt_parent->mt_flags &= ~MDB_TXN_HAS_CHILD;

-			env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;

-			mdb_midl_free(txn->mt_free_pgs);

-			mdb_midl_free(txn->mt_spill_pgs);

-			free(txn->mt_u.dirty_list);

-		}

-

-		mdb_midl_free(pghead);

-	}

-#ifdef MDB_VL32

-	if (!txn->mt_parent) {

-		MDB_ID3L el = env->me_rpages, tl = txn->mt_rpages;

-		unsigned i, x, n = tl[0].mid;

-		pthread_mutex_lock(&env->me_rpmutex);

-		for (i = 1; i <= n; i++) {

-			if (tl[i].mid & (MDB_RPAGE_CHUNK-1)) {

-				/* tmp overflow pages that we didn't share in env */

-				munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);

-			} else {

-				x = mdb_mid3l_search(el, tl[i].mid);

-				if (tl[i].mptr == el[x].mptr) {

-					el[x].mref--;

-				} else {

-					/* another tmp overflow page */

-					munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);

-				}

-			}

-		}

-		pthread_mutex_unlock(&env->me_rpmutex);

-		tl[0].mid = 0;

-		if (mode & MDB_END_FREE)

-			free(tl);

-	}

-#endif

-	if (mode & MDB_END_FREE)

-		free(txn);

-}

-

-void

-mdb_txn_reset(MDB_txn *txn)

-{

-	if (txn == NULL)

-		return;

-

-	/* This call is only valid for read-only txns */

-	if (!(txn->mt_flags & MDB_TXN_RDONLY))

-		return;

-

-	mdb_txn_end(txn, MDB_END_RESET);

-}

-

-void

-mdb_txn_abort(MDB_txn *txn)

-{

-	if (txn == NULL)

-		return;

-

-	if (txn->mt_child)

-		mdb_txn_abort(txn->mt_child);

-

-	mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);

-}

-

-/** Save the freelist as of this transaction to the freeDB.

- * This changes the freelist. Keep trying until it stabilizes.

- *

- * When (MDB_DEVEL) & 2, the changes do not affect #mdb_page_alloc(),

- * it then uses the transaction's original snapshot of the freeDB.

- */

-static int

-mdb_freelist_save(MDB_txn *txn)

-{

-	/* env->me_pghead[] can grow and shrink during this call.

-	 * env->me_pglast and txn->mt_free_pgs[] can only grow.

-	 * Page numbers cannot disappear from txn->mt_free_pgs[].

-	 */

-	MDB_cursor mc;

-	MDB_env	*env = txn->mt_env;

-	int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;

-	txnid_t	pglast = 0, head_id = 0;

-	pgno_t	freecnt = 0, *free_pgs, *mop;

-	ssize_t	head_room = 0, total_room = 0, mop_len, clean_limit;

-

-	mdb_cursor_init(&mc, txn, FREE_DBI, NULL);

-

-	if (env->me_pghead) {

-		/* Make sure first page of freeDB is touched and on freelist */

-		rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);

-		if (rc && rc != MDB_NOTFOUND)

-			return rc;

-	}

-

-	if (!env->me_pghead && txn->mt_loose_pgs) {

-		/* Put loose page numbers in mt_free_pgs, since

-		 * we may be unable to return them to me_pghead.

-		 */

-		MDB_page *mp = txn->mt_loose_pgs;

-		if ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)

-			return rc;

-		for (; mp; mp = NEXT_LOOSE_PAGE(mp))

-			mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);

-		txn->mt_loose_pgs = NULL;

-		txn->mt_loose_count = 0;

-	}

-

-	/* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */

-	clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))

-		? SSIZE_MAX : maxfree_1pg;

-

-	for (;;) {

-		/* Come back here after each Put() in case freelist changed */

-		MDB_val key, data;

-		pgno_t *pgs;

-		ssize_t j;

-

-		/* If using records from freeDB which we have not yet

-		 * deleted, delete them and any we reserved for me_pghead.

-		 */

-		while (pglast < env->me_pglast) {

-			rc = mdb_cursor_first(&mc, &key, NULL);

-			if (rc)

-				return rc;

-			pglast = head_id = *(txnid_t *)key.mv_data;

-			total_room = head_room = 0;

-			mdb_tassert(txn, pglast <= env->me_pglast);

-			rc = mdb_cursor_del(&mc, 0);

-			if (rc)

-				return rc;

-		}

-

-		/* Save the IDL of pages freed by this txn, to a single record */

-		if (freecnt < txn->mt_free_pgs[0]) {

-			if (!freecnt) {

-				/* Make sure last page of freeDB is touched and on freelist */

-				rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);

-				if (rc && rc != MDB_NOTFOUND)

-					return rc;

-			}

-			free_pgs = txn->mt_free_pgs;

-			/* Write to last page of freeDB */

-			key.mv_size = sizeof(txn->mt_txnid);

-			key.mv_data = &txn->mt_txnid;

-			do {

-				freecnt = free_pgs[0];

-				data.mv_size = MDB_IDL_SIZEOF(free_pgs);

-				rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);

-				if (rc)

-					return rc;

-				/* Retry if mt_free_pgs[] grew during the Put() */

-				free_pgs = txn->mt_free_pgs;

-			} while (freecnt < free_pgs[0]);

-			mdb_midl_sort(free_pgs);

-			memcpy(data.mv_data, free_pgs, data.mv_size);

-#if (MDB_DEBUG) > 1

-			{

-				unsigned int i = free_pgs[0];

-				DPRINTF(("IDL write txn %"Y"u root %"Y"u num %u",

-					txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));

-				for (; i; i--)

-					DPRINTF(("IDL %"Y"u", free_pgs[i]));

-			}

-#endif

-			continue;

-		}

-

-		mop = env->me_pghead;

-		mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count;

-

-		/* Reserve records for me_pghead[]. Split it if multi-page,

-		 * to avoid searching freeDB for a page range. Use keys in

-		 * range [1,me_pglast]: Smaller than txnid of oldest reader.

-		 */

-		if (total_room >= mop_len) {

-			if (total_room == mop_len || --more < 0)

-				break;

-		} else if (head_room >= maxfree_1pg && head_id > 1) {

-			/* Keep current record (overflow page), add a new one */

-			head_id--;

-			head_room = 0;

-		}

-		/* (Re)write {key = head_id, IDL length = head_room} */

-		total_room -= head_room;

-		head_room = mop_len - total_room;

-		if (head_room > maxfree_1pg && head_id > 1) {

-			/* Overflow multi-page for part of me_pghead */

-			head_room /= head_id; /* amortize page sizes */

-			head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);

-		} else if (head_room < 0) {

-			/* Rare case, not bothering to delete this record */

-			head_room = 0;

-		}

-		key.mv_size = sizeof(head_id);

-		key.mv_data = &head_id;

-		data.mv_size = (head_room + 1) * sizeof(pgno_t);

-		rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);

-		if (rc)

-			return rc;

-		/* IDL is initially empty, zero out at least the length */

-		pgs = (pgno_t *)data.mv_data;

-		j = head_room > clean_limit ? head_room : 0;

-		do {

-			pgs[j] = 0;

-		} while (--j >= 0);

-		total_room += head_room;

-	}

-

-	/* Return loose page numbers to me_pghead, though usually none are

-	 * left at this point.  The pages themselves remain in dirty_list.

-	 */

-	if (txn->mt_loose_pgs) {

-		MDB_page *mp = txn->mt_loose_pgs;

-		unsigned count = txn->mt_loose_count;

-		MDB_IDL loose;

-		/* Room for loose pages + temp IDL with same */

-		if ((rc = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0)

-			return rc;

-		mop = env->me_pghead;

-		loose = mop + MDB_IDL_ALLOCLEN(mop) - count;

-		for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp))

-			loose[ ++count ] = mp->mp_pgno;

-		loose[0] = count;

-		mdb_midl_sort(loose);

-		mdb_midl_xmerge(mop, loose);

-		txn->mt_loose_pgs = NULL;

-		txn->mt_loose_count = 0;

-		mop_len = mop[0];

-	}

-

-	/* Fill in the reserved me_pghead records */

-	rc = MDB_SUCCESS;

-	if (mop_len) {

-		MDB_val key, data;

-

-		mop += mop_len;

-		rc = mdb_cursor_first(&mc, &key, &data);

-		for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {

-			txnid_t id = *(txnid_t *)key.mv_data;

-			ssize_t	len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;

-			MDB_ID save;

-

-			mdb_tassert(txn, len >= 0 && id <= env->me_pglast);

-			key.mv_data = &id;

-			if (len > mop_len) {

-				len = mop_len;

-				data.mv_size = (len + 1) * sizeof(MDB_ID);

-			}

-			data.mv_data = mop -= len;

-			save = mop[0];

-			mop[0] = len;

-			rc = mdb_cursor_put(&mc, &key, &data, MDB_CURRENT);

-			mop[0] = save;

-			if (rc || !(mop_len -= len))

-				break;

-		}

-	}

-	return rc;

-}

-

-/** Flush (some) dirty pages to the map, after clearing their dirty flag.

- * @param[in] txn the transaction that's being committed

- * @param[in] keep number of initial pages in dirty_list to keep dirty.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_page_flush(MDB_txn *txn, int keep)

-{

-	MDB_env		*env = txn->mt_env;

-	MDB_ID2L	dl = txn->mt_u.dirty_list;

-	unsigned	psize = env->me_psize, j;

-	int			i, pagecount = dl[0].mid, rc;

-	size_t		size = 0;

-	off_t		pos = 0;

-	pgno_t		pgno = 0;

-	MDB_page	*dp = NULL;

-#ifdef _WIN32

-	OVERLAPPED	ov;

-#else

-	struct iovec iov[MDB_COMMIT_PAGES];

-	ssize_t		wsize = 0, wres;

-	off_t		wpos = 0, next_pos = 1; /* impossible pos, so pos != next_pos */

-	int			n = 0;

-#endif

-

-	j = i = keep;

-

-	if (env->me_flags & MDB_WRITEMAP) {

-		/* Clear dirty flags */

-		while (++i <= pagecount) {

-			dp = dl[i].mptr;

-			/* Don't flush this page yet */

-			if (dp->mp_flags & (P_LOOSE|P_KEEP)) {

-				dp->mp_flags &= ~P_KEEP;

-				dl[++j] = dl[i];

-				continue;

-			}

-			dp->mp_flags &= ~P_DIRTY;

-		}

-		goto done;

-	}

-

-	/* Write the pages */

-	for (;;) {

-		if (++i <= pagecount) {

-			dp = dl[i].mptr;

-			/* Don't flush this page yet */

-			if (dp->mp_flags & (P_LOOSE|P_KEEP)) {

-				dp->mp_flags &= ~P_KEEP;

-				dl[i].mid = 0;

-				continue;

-			}

-			pgno = dl[i].mid;

-			/* clear dirty flag */

-			dp->mp_flags &= ~P_DIRTY;

-			pos = pgno * psize;

-			size = psize;

-			if (IS_OVERFLOW(dp)) size *= dp->mp_pages;

-		}

-#ifdef _WIN32

-		else break;

-

-		/* Windows actually supports scatter/gather I/O, but only on

-		 * unbuffered file handles. Since we're relying on the OS page

-		 * cache for all our data, that's self-defeating. So we just

-		 * write pages one at a time. We use the ov structure to set

-		 * the write offset, to at least save the overhead of a Seek

-		 * system call.

-		 */

-		DPRINTF(("committing page %"Z"u", pgno));

-		memset(&ov, 0, sizeof(ov));

-		ov.Offset = pos & 0xffffffff;

-		ov.OffsetHigh = pos >> 16 >> 16;

-		if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {

-			rc = ErrCode();

-			DPRINTF(("WriteFile: %d", rc));

-			return rc;

-		}

-#else

-		/* Write up to MDB_COMMIT_PAGES dirty pages at a time. */

-		if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {

-			if (n) {

-retry_write:

-				/* Write previous page(s) */

-#ifdef MDB_USE_PWRITEV

-				wres = pwritev(env->me_fd, iov, n, wpos);

-#else

-				if (n == 1) {

-					wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);

-				} else {

-retry_seek:

-					if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {

-						rc = ErrCode();

-						if (rc == EINTR)

-							goto retry_seek;

-						DPRINTF(("lseek: %s", strerror(rc)));

-						return rc;

-					}

-					wres = writev(env->me_fd, iov, n);

-				}

-#endif

-				if (wres != wsize) {

-					if (wres < 0) {

-						rc = ErrCode();

-						if (rc == EINTR)

-							goto retry_write;

-						DPRINTF(("Write error: %s", strerror(rc)));

-					} else {

-						rc = EIO; /* TODO: Use which error code? */

-						DPUTS("short write, filesystem full?");

-					}

-					return rc;

-				}

-				n = 0;

-			}

-			if (i > pagecount)

-				break;

-			wpos = pos;

-			wsize = 0;

-		}

-		DPRINTF(("committing page %"Y"u", pgno));

-		next_pos = pos + size;

-		iov[n].iov_len = size;

-		iov[n].iov_base = (char *)dp;

-		wsize += size;

-		n++;

-#endif	/* _WIN32 */

-	}

-#ifdef MDB_VL32

-	if (pgno > txn->mt_last_pgno)

-		txn->mt_last_pgno = pgno;

-#endif

-

-	/* MIPS has cache coherency issues, this is a no-op everywhere else

-	 * Note: for any size >= on-chip cache size, entire on-chip cache is

-	 * flushed.

-	 */

-	CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE);

-

-	for (i = keep; ++i <= pagecount; ) {

-		dp = dl[i].mptr;

-		/* This is a page we skipped above */

-		if (!dl[i].mid) {

-			dl[++j] = dl[i];

-			dl[j].mid = dp->mp_pgno;

-			continue;

-		}

-		mdb_dpage_free(env, dp);

-	}

-

-done:

-	i--;

-	txn->mt_dirty_room += i - j;

-	dl[0].mid = j;

-	return MDB_SUCCESS;

-}

-

-int

-mdb_txn_commit(MDB_txn *txn)

-{

-	int		rc;

-	unsigned int i, end_mode;

-	MDB_env	*env;

-

-	if (txn == NULL)

-		return EINVAL;

-

-	/* mdb_txn_end() mode for a commit which writes nothing */

-	end_mode = MDB_END_EMPTY_COMMIT|MDB_END_UPDATE|MDB_END_SLOT|MDB_END_FREE;

-

-	if (txn->mt_child) {

-		rc = mdb_txn_commit(txn->mt_child);

-		if (rc)

-			goto fail;

-	}

-

-	env = txn->mt_env;

-

-	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {

-		goto done;

-	}

-

-	if (txn->mt_flags & (MDB_TXN_FINISHED|MDB_TXN_ERROR)) {

-		DPUTS("txn has failed/finished, can't commit");

-		if (txn->mt_parent)

-			txn->mt_parent->mt_flags |= MDB_TXN_ERROR;

-		rc = MDB_BAD_TXN;

-		goto fail;

-	}

-

-	if (txn->mt_parent) {

-		MDB_txn *parent = txn->mt_parent;

-		MDB_page **lp;

-		MDB_ID2L dst, src;

-		MDB_IDL pspill;

-		unsigned x, y, len, ps_len;

-

-		/* Append our free list to parent's */

-		rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);

-		if (rc)

-			goto fail;

-		mdb_midl_free(txn->mt_free_pgs);

-		/* Failures after this must either undo the changes

-		 * to the parent or set MDB_TXN_ERROR in the parent.

-		 */

-

-		parent->mt_next_pgno = txn->mt_next_pgno;

-		parent->mt_flags = txn->mt_flags;

-

-		/* Merge our cursors into parent's and close them */

-		mdb_cursors_close(txn, 1);

-

-		/* Update parent's DB table. */

-		memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));

-		parent->mt_numdbs = txn->mt_numdbs;

-		parent->mt_dbflags[FREE_DBI] = txn->mt_dbflags[FREE_DBI];

-		parent->mt_dbflags[MAIN_DBI] = txn->mt_dbflags[MAIN_DBI];

-		for (i=CORE_DBS; i<txn->mt_numdbs; i++) {

-			/* preserve parent's DB_NEW status */

-			x = parent->mt_dbflags[i] & DB_NEW;

-			parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;

-		}

-

-		dst = parent->mt_u.dirty_list;

-		src = txn->mt_u.dirty_list;

-		/* Remove anything in our dirty list from parent's spill list */

-		if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {

-			x = y = ps_len;

-			pspill[0] = (pgno_t)-1;

-			/* Mark our dirty pages as deleted in parent spill list */

-			for (i=0, len=src[0].mid; ++i <= len; ) {

-				MDB_ID pn = src[i].mid << 1;

-				while (pn > pspill[x])

-					x--;

-				if (pn == pspill[x]) {

-					pspill[x] = 1;

-					y = --x;

-				}

-			}

-			/* Squash deleted pagenums if we deleted any */

-			for (x=y; ++x <= ps_len; )

-				if (!(pspill[x] & 1))

-					pspill[++y] = pspill[x];

-			pspill[0] = y;

-		}

-

-		/* Remove anything in our spill list from parent's dirty list */

-		if (txn->mt_spill_pgs && txn->mt_spill_pgs[0]) {

-			for (i=1; i<=txn->mt_spill_pgs[0]; i++) {

-				MDB_ID pn = txn->mt_spill_pgs[i];

-				if (pn & 1)

-					continue;	/* deleted spillpg */

-				pn >>= 1;

-				y = mdb_mid2l_search(dst, pn);

-				if (y <= dst[0].mid && dst[y].mid == pn) {

-					free(dst[y].mptr);

-					while (y < dst[0].mid) {

-						dst[y] = dst[y+1];

-						y++;

-					}

-					dst[0].mid--;

-				}

-			}

-		}

-

-		/* Find len = length of merging our dirty list with parent's */

-		x = dst[0].mid;

-		dst[0].mid = 0;		/* simplify loops */

-		if (parent->mt_parent) {

-			len = x + src[0].mid;

-			y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;

-			for (i = x; y && i; y--) {

-				pgno_t yp = src[y].mid;

-				while (yp < dst[i].mid)

-					i--;

-				if (yp == dst[i].mid) {

-					i--;

-					len--;

-				}

-			}

-		} else { /* Simplify the above for single-ancestor case */

-			len = MDB_IDL_UM_MAX - txn->mt_dirty_room;

-		}

-		/* Merge our dirty list with parent's */

-		y = src[0].mid;

-		for (i = len; y; dst[i--] = src[y--]) {

-			pgno_t yp = src[y].mid;

-			while (yp < dst[x].mid)

-				dst[i--] = dst[x--];

-			if (yp == dst[x].mid)

-				free(dst[x--].mptr);

-		}

-		mdb_tassert(txn, i == x);

-		dst[0].mid = len;

-		free(txn->mt_u.dirty_list);

-		parent->mt_dirty_room = txn->mt_dirty_room;

-		if (txn->mt_spill_pgs) {

-			if (parent->mt_spill_pgs) {

-				/* TODO: Prevent failure here, so parent does not fail */

-				rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);

-				if (rc)

-					parent->mt_flags |= MDB_TXN_ERROR;

-				mdb_midl_free(txn->mt_spill_pgs);

-				mdb_midl_sort(parent->mt_spill_pgs);

-			} else {

-				parent->mt_spill_pgs = txn->mt_spill_pgs;

-			}

-		}

-

-		/* Append our loose page list to parent's */

-		for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(*lp))

-			;

-		*lp = txn->mt_loose_pgs;

-		parent->mt_loose_count += txn->mt_loose_count;

-

-		parent->mt_child = NULL;

-		mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);

-		free(txn);

-		return rc;

-	}

-

-	if (txn != env->me_txn) {

-		DPUTS("attempt to commit unknown transaction");

-		rc = EINVAL;

-		goto fail;

-	}

-

-	mdb_cursors_close(txn, 0);

-

-	if (!txn->mt_u.dirty_list[0].mid &&

-		!(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))

-		goto done;

-

-	DPRINTF(("committing txn %"Y"u %p on mdbenv %p, root page %"Y"u",

-	    txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));

-

-	/* Update DB root pointers */

-	if (txn->mt_numdbs > CORE_DBS) {

-		MDB_cursor mc;

-		MDB_dbi i;

-		MDB_val data;

-		data.mv_size = sizeof(MDB_db);

-

-		mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);

-		for (i = CORE_DBS; i < txn->mt_numdbs; i++) {

-			if (txn->mt_dbflags[i] & DB_DIRTY) {

-				if (TXN_DBI_CHANGED(txn, i)) {

-					rc = MDB_BAD_DBI;

-					goto fail;

-				}

-				data.mv_data = &txn->mt_dbs[i];

-				rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data,

-					F_SUBDATA);

-				if (rc)

-					goto fail;

-			}

-		}

-	}

-

-	rc = mdb_freelist_save(txn);

-	if (rc)

-		goto fail;

-

-	mdb_midl_free(env->me_pghead);

-	env->me_pghead = NULL;

-	mdb_midl_shrink(&txn->mt_free_pgs);

-

-#if (MDB_DEBUG) > 2

-	mdb_audit(txn);

-#endif

-

-	if ((rc = mdb_page_flush(txn, 0)))

-		goto fail;

-	if (!F_ISSET(txn->mt_flags, MDB_TXN_NOSYNC) &&

-		(rc = mdb_env_sync0(env, 0, txn->mt_next_pgno)))

-		goto fail;

-	if ((rc = mdb_env_write_meta(txn)))

-		goto fail;

-	end_mode = MDB_END_COMMITTED|MDB_END_UPDATE;

-

-done:

-	mdb_txn_end(txn, end_mode);

-	return MDB_SUCCESS;

-

-fail:

-	mdb_txn_abort(txn);

-	return rc;

-}

-

-/** Read the environment parameters of a DB environment before

- * mapping it into memory.

- * @param[in] env the environment handle

- * @param[out] meta address of where to store the meta information

- * @return 0 on success, non-zero on failure.

- */

-static int ESECT

-mdb_env_read_header(MDB_env *env, MDB_meta *meta)

-{

-	MDB_metabuf	pbuf;

-	MDB_page	*p;

-	MDB_meta	*m;

-	int			i, rc, off;

-	enum { Size = sizeof(pbuf) };

-

-	/* We don't know the page size yet, so use a minimum value.

-	 * Read both meta pages so we can use the latest one.

-	 */

-

-	for (i=off=0; i<NUM_METAS; i++, off += meta->mm_psize) {

-#ifdef _WIN32

-		DWORD len;

-		OVERLAPPED ov;

-		memset(&ov, 0, sizeof(ov));

-		ov.Offset = off;

-		rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;

-		if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)

-			rc = 0;

-#else

-		rc = pread(env->me_fd, &pbuf, Size, off);

-#endif

-		if (rc != Size) {

-			if (rc == 0 && off == 0)

-				return ENOENT;

-			rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;

-			DPRINTF(("read: %s", mdb_strerror(rc)));

-			return rc;

-		}

-

-		p = (MDB_page *)&pbuf;

-

-		if (!F_ISSET(p->mp_flags, P_META)) {

-			DPRINTF(("page %"Y"u not a meta page", p->mp_pgno));

-			return MDB_INVALID;

-		}

-

-		m = METADATA(p);

-		if (m->mm_magic != MDB_MAGIC) {

-			DPUTS("meta has invalid magic");

-			return MDB_INVALID;

-		}

-

-		if (m->mm_version != MDB_DATA_VERSION) {

-			DPRINTF(("database is version %u, expected version %u",

-				m->mm_version, MDB_DATA_VERSION));

-			return MDB_VERSION_MISMATCH;

-		}

-

-		if (off == 0 || m->mm_txnid > meta->mm_txnid)

-			*meta = *m;

-	}

-	return 0;

-}

-

-/** Fill in most of the zeroed #MDB_meta for an empty database environment */

-static void ESECT

-mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)

-{

-	meta->mm_magic = MDB_MAGIC;

-	meta->mm_version = MDB_DATA_VERSION;

-	meta->mm_mapsize = env->me_mapsize;

-	meta->mm_psize = env->me_psize;

-	meta->mm_last_pg = NUM_METAS-1;

-	meta->mm_flags = env->me_flags & 0xffff;

-	meta->mm_flags |= MDB_INTEGERKEY; /* this is mm_dbs[FREE_DBI].md_flags */

-	meta->mm_dbs[FREE_DBI].md_root = P_INVALID;

-	meta->mm_dbs[MAIN_DBI].md_root = P_INVALID;

-}

-

-/** Write the environment parameters of a freshly created DB environment.

- * @param[in] env the environment handle

- * @param[in] meta the #MDB_meta to write

- * @return 0 on success, non-zero on failure.

- */

-static int ESECT

-mdb_env_init_meta(MDB_env *env, MDB_meta *meta)

-{

-	MDB_page *p, *q;

-	int rc;

-	unsigned int	 psize;

-#ifdef _WIN32

-	DWORD len;

-	OVERLAPPED ov;

-	memset(&ov, 0, sizeof(ov));

-#define DO_PWRITE(rc, fd, ptr, size, len, pos)	do { \

-	ov.Offset = pos;	\

-	rc = WriteFile(fd, ptr, size, &len, &ov);	} while(0)

-#else

-	int len;

-#define DO_PWRITE(rc, fd, ptr, size, len, pos)	do { \

-	len = pwrite(fd, ptr, size, pos);	\

-	if (len == -1 && ErrCode() == EINTR) continue; \

-	rc = (len >= 0); break; } while(1)

-#endif

-

-	DPUTS("writing new meta page");

-

-	psize = env->me_psize;

-

-	p = calloc(NUM_METAS, psize);

-	if (!p)

-		return ENOMEM;

-	p->mp_pgno = 0;

-	p->mp_flags = P_META;

-	*(MDB_meta *)METADATA(p) = *meta;

-

-	q = (MDB_page *)((char *)p + psize);

-	q->mp_pgno = 1;

-	q->mp_flags = P_META;

-	*(MDB_meta *)METADATA(q) = *meta;

-

-	DO_PWRITE(rc, env->me_fd, p, psize * NUM_METAS, len, 0);

-	if (!rc)

-		rc = ErrCode();

-	else if ((unsigned) len == psize * NUM_METAS)

-		rc = MDB_SUCCESS;

-	else

-		rc = ENOSPC;

-	free(p);

-	return rc;

-}

-

-/** Update the environment info to commit a transaction.

- * @param[in] txn the transaction that's being committed

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_env_write_meta(MDB_txn *txn)

-{

-	MDB_env *env;

-	MDB_meta	meta, metab, *mp;

-	unsigned flags;

-	mdb_size_t mapsize;

-	off_t off;

-	int rc, len, toggle;

-	char *ptr;

-	HANDLE mfd;

-#ifdef _WIN32

-	OVERLAPPED ov;

-#else

-	int r2;

-#endif

-

-	toggle = txn->mt_txnid & 1;

-	DPRINTF(("writing meta page %d for root page %"Y"u",

-		toggle, txn->mt_dbs[MAIN_DBI].md_root));

-

-	env = txn->mt_env;

-	flags = txn->mt_flags | env->me_flags;

-	mp = env->me_metas[toggle];

-	mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;

-	/* Persist any increases of mapsize config */

-	if (mapsize < env->me_mapsize)

-		mapsize = env->me_mapsize;

-

-	if (flags & MDB_WRITEMAP) {

-		mp->mm_mapsize = mapsize;

-		mp->mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];

-		mp->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];

-		mp->mm_last_pg = txn->mt_next_pgno - 1;

-#if (__GNUC__ * 100 + __GNUC_MINOR__ >= 404) && /* TODO: portability */	\

-	!(defined(__i386__) || defined(__x86_64__))

-		/* LY: issue a memory barrier, if not x86. ITS#7969 */

-		__sync_synchronize();

-#endif

-		mp->mm_txnid = txn->mt_txnid;

-		if (!(flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {

-			unsigned meta_size = env->me_psize;

-			rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;

-			ptr = (char *)mp - PAGEHDRSZ;

-#ifndef _WIN32	/* POSIX msync() requires ptr = start of OS page */

-			r2 = (ptr - env->me_map) & (env->me_os_psize - 1);

-			ptr -= r2;

-			meta_size += r2;

-#endif

-			if (MDB_MSYNC(ptr, meta_size, rc)) {

-				rc = ErrCode();

-				goto fail;

-			}

-		}

-		goto done;

-	}

-	metab.mm_txnid = mp->mm_txnid;

-	metab.mm_last_pg = mp->mm_last_pg;

-

-	meta.mm_mapsize = mapsize;

-	meta.mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];

-	meta.mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];

-	meta.mm_last_pg = txn->mt_next_pgno - 1;

-	meta.mm_txnid = txn->mt_txnid;

-

-	off = offsetof(MDB_meta, mm_mapsize);

-	ptr = (char *)&meta + off;

-	len = sizeof(MDB_meta) - off;

-	off += (char *)mp - env->me_map;

-

-	/* Write to the SYNC fd */

-	mfd = (flags & (MDB_NOSYNC|MDB_NOMETASYNC)) ? env->me_fd : env->me_mfd;

-#ifdef _WIN32

-	{

-		memset(&ov, 0, sizeof(ov));

-		ov.Offset = off;

-		if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))

-			rc = -1;

-	}

-#else

-retry_write:

-	rc = pwrite(mfd, ptr, len, off);

-#endif

-	if (rc != len) {

-		rc = rc < 0 ? ErrCode() : EIO;

-#ifndef _WIN32

-		if (rc == EINTR)

-			goto retry_write;

-#endif

-		DPUTS("write failed, disk error?");

-		/* On a failure, the pagecache still contains the new data.

-		 * Write some old data back, to prevent it from being used.

-		 * Use the non-SYNC fd; we know it will fail anyway.

-		 */

-		meta.mm_last_pg = metab.mm_last_pg;

-		meta.mm_txnid = metab.mm_txnid;

-#ifdef _WIN32

-		memset(&ov, 0, sizeof(ov));

-		ov.Offset = off;

-		WriteFile(env->me_fd, ptr, len, NULL, &ov);

-#else

-		r2 = pwrite(env->me_fd, ptr, len, off);

-		(void)r2;	/* Silence warnings. We don't care about pwrite's return value */

-#endif

-fail:

-		env->me_flags |= MDB_FATAL_ERROR;

-		return rc;

-	}

-	/* MIPS has cache coherency issues, this is a no-op everywhere else */

-	CACHEFLUSH(env->me_map + off, len, DCACHE);

-done:

-	/* Memory ordering issues are irrelevant; since the entire writer

-	 * is wrapped by wmutex, all of these changes will become visible

-	 * after the wmutex is unlocked. Since the DB is multi-version,

-	 * readers will get consistent data regardless of how fresh or

-	 * how stale their view of these values is.

-	 */

-	if (env->me_txns)

-		env->me_txns->mti_txnid = txn->mt_txnid;

-

-	return MDB_SUCCESS;

-}

-

-/** Check both meta pages to see which one is newer.

- * @param[in] env the environment handle

- * @return newest #MDB_meta.

- */

-static MDB_meta *

-mdb_env_pick_meta(const MDB_env *env)

-{

-	MDB_meta *const *metas = env->me_metas;

-	return metas[ metas[0]->mm_txnid < metas[1]->mm_txnid ];

-}

-

-int ESECT

-mdb_env_create(MDB_env **env)

-{

-	MDB_env *e;

-

-	e = calloc(1, sizeof(MDB_env));

-	if (!e)

-		return ENOMEM;

-

-	e->me_maxreaders = DEFAULT_READERS;

-	e->me_maxdbs = e->me_numdbs = CORE_DBS;

-	e->me_fd = INVALID_HANDLE_VALUE;

-	e->me_lfd = INVALID_HANDLE_VALUE;

-	e->me_mfd = INVALID_HANDLE_VALUE;

-#ifdef MDB_USE_POSIX_SEM

-	e->me_rmutex = SEM_FAILED;

-	e->me_wmutex = SEM_FAILED;

-#elif defined MDB_USE_SYSV_SEM

-	e->me_rmutex->semid = -1;

-	e->me_wmutex->semid = -1;

-#endif

-	e->me_pid = getpid();

-	GET_PAGESIZE(e->me_os_psize);

-	VGMEMP_CREATE(e,0,0);

-	*env = e;

-	return MDB_SUCCESS;

-}

-

-#ifdef _WIN32

-/** @brief Map a result from an NTAPI call to WIN32. */

-static DWORD

-mdb_nt2win32(NTSTATUS st)

-{

-	OVERLAPPED o = {0};

-	DWORD br;

-	o.Internal = st;

-	GetOverlappedResult(NULL, &o, &br, FALSE);

-	return GetLastError();

-}

-#endif

-

-static int ESECT

-mdb_env_map(MDB_env *env, void *addr)

-{

-	MDB_page *p;

-	unsigned int flags = env->me_flags;

-#ifdef _WIN32

-	int rc;

-	int access = SECTION_MAP_READ;

-	HANDLE mh;

-	void *map;

-	SIZE_T msize;

-	ULONG pageprot = PAGE_READONLY, secprot, alloctype;

-

-	if (flags & MDB_WRITEMAP) {

-		access |= SECTION_MAP_WRITE;

-		pageprot = PAGE_READWRITE;

-	}

-	if (flags & MDB_RDONLY) {

-		secprot = PAGE_READONLY;

-		msize = 0;

-		alloctype = 0;

-	} else {

-		secprot = PAGE_READWRITE;

-		msize = env->me_mapsize;

-		alloctype = MEM_RESERVE;

-	}

-

-	rc = NtCreateSection(&mh, access, NULL, NULL, secprot, SEC_RESERVE, env->me_fd);

-	if (rc)

-		return mdb_nt2win32(rc);

-	map = addr;

-#ifdef MDB_VL32

-	msize = NUM_METAS * env->me_psize;

-#endif

-	rc = NtMapViewOfSection(mh, GetCurrentProcess(), &map, 0, 0, NULL, &msize, ViewUnmap, alloctype, pageprot);

-#ifdef MDB_VL32

-	env->me_fmh = mh;

-#else

-	NtClose(mh);

-#endif

-	if (rc)

-		return mdb_nt2win32(rc);

-	env->me_map = map;

-#else

-#ifdef MDB_VL32

-	(void) flags;

-	env->me_map = mmap(addr, NUM_METAS * env->me_psize, PROT_READ, MAP_SHARED,

-		env->me_fd, 0);

-	if (env->me_map == MAP_FAILED) {

-		env->me_map = NULL;

-		return ErrCode();

-	}

-#else

-	int prot = PROT_READ;

-	if (flags & MDB_WRITEMAP) {

-		prot |= PROT_WRITE;

-		if (ftruncate(env->me_fd, env->me_mapsize) < 0)

-			return ErrCode();

-	}

-	env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,

-		env->me_fd, 0);

-	if (env->me_map == MAP_FAILED) {

-		env->me_map = NULL;

-		return ErrCode();

-	}

-

-	if (flags & MDB_NORDAHEAD) {

-		/* Turn off readahead. It's harmful when the DB is larger than RAM. */

-#ifdef MADV_RANDOM

-		madvise(env->me_map, env->me_mapsize, MADV_RANDOM);

-#else

-#ifdef POSIX_MADV_RANDOM

-		posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);

-#endif /* POSIX_MADV_RANDOM */

-#endif /* MADV_RANDOM */

-	}

-#endif /* _WIN32 */

-

-	/* Can happen because the address argument to mmap() is just a

-	 * hint.  mmap() can pick another, e.g. if the range is in use.

-	 * The MAP_FIXED flag would prevent that, but then mmap could

-	 * instead unmap existing pages to make room for the new map.

-	 */

-	if (addr && env->me_map != addr)

-		return EBUSY;	/* TODO: Make a new MDB_* error code? */

-#endif

-

-	p = (MDB_page *)env->me_map;

-	env->me_metas[0] = METADATA(p);

-	env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);

-

-	return MDB_SUCCESS;

-}

-

-int ESECT

-mdb_env_set_mapsize(MDB_env *env, mdb_size_t size)

-{

-	/* If env is already open, caller is responsible for making

-	 * sure there are no active txns.

-	 */

-	if (env->me_map) {

-		MDB_meta *meta;

-#ifndef MDB_VL32

-		void *old;

-		int rc;

-#endif

-		if (env->me_txn)

-			return EINVAL;

-		meta = mdb_env_pick_meta(env);

-		if (!size)

-			size = meta->mm_mapsize;

-		{

-			/* Silently round up to minimum if the size is too small */

-			mdb_size_t minsize = (meta->mm_last_pg + 1) * env->me_psize;

-			if (size < minsize)

-				size = minsize;

-		}

-#ifndef MDB_VL32

-		/* For MDB_VL32 this bit is a noop since we dynamically remap

-		 * chunks of the DB anyway.

-		 */

-		munmap(env->me_map, env->me_mapsize);

-		env->me_mapsize = size;

-		old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;

-		rc = mdb_env_map(env, old);

-		if (rc)

-			return rc;

-#endif /* !MDB_VL32 */

-	}

-	env->me_mapsize = size;

-	if (env->me_psize)

-		env->me_maxpg = env->me_mapsize / env->me_psize;

-	return MDB_SUCCESS;

-}

-

-int ESECT

-mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)

-{

-	if (env->me_map)

-		return EINVAL;

-	env->me_maxdbs = dbs + CORE_DBS;

-	return MDB_SUCCESS;

-}

-

-int ESECT

-mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)

-{

-	if (env->me_map || readers < 1)

-		return EINVAL;

-	env->me_maxreaders = readers;

-	return MDB_SUCCESS;

-}

-

-int ESECT

-mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)

-{

-	if (!env || !readers)

-		return EINVAL;

-	*readers = env->me_maxreaders;

-	return MDB_SUCCESS;

-}

-

-static int ESECT

-mdb_fsize(HANDLE fd, mdb_size_t *size)

-{

-#ifdef _WIN32

-	LARGE_INTEGER fsize;

-

-	if (!GetFileSizeEx(fd, &fsize))

-		return ErrCode();

-

-	*size = fsize.QuadPart;

-#else

-	struct stat st;

-

-	if (fstat(fd, &st))

-		return ErrCode();

-

-	*size = st.st_size;

-#endif

-	return MDB_SUCCESS;

-}

-

-#ifdef BROKEN_FDATASYNC

-#include <sys/utsname.h>

-#include <sys/vfs.h>

-#endif

-

-/** Further setup required for opening an LMDB environment

- */

-static int ESECT

-mdb_env_open2(MDB_env *env)

-{

-	unsigned int flags = env->me_flags;

-	int i, newenv = 0, rc;

-	MDB_meta meta;

-

-#ifdef _WIN32

-	/* See if we should use QueryLimited */

-	rc = GetVersion();

-	if ((rc & 0xff) > 5)

-		env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;

-	else

-		env->me_pidquery = PROCESS_QUERY_INFORMATION;

-#endif /* _WIN32 */

-

-#ifdef BROKEN_FDATASYNC

-	/* ext3/ext4 fdatasync is broken on some older Linux kernels.

-	 * https://lkml.org/lkml/2012/9/3/83

-	 * Kernels after 3.6-rc6 are known good.

-	 * https://lkml.org/lkml/2012/9/10/556

-	 * See if the DB is on ext3/ext4, then check for new enough kernel

-	 * Kernels 2.6.32.60, 2.6.34.15, 3.2.30, and 3.5.4 are also known

-	 * to be patched.

-	 */

-	{

-		struct statfs st;

-		fstatfs(env->me_fd, &st);

-		while (st.f_type == 0xEF53) {

-			struct utsname uts;

-			int i;

-			uname(&uts);

-			if (uts.release[0] < '3') {

-				if (!strncmp(uts.release, "2.6.32.", 7)) {

-					i = atoi(uts.release+7);

-					if (i >= 60)

-						break;	/* 2.6.32.60 and newer is OK */

-				} else if (!strncmp(uts.release, "2.6.34.", 7)) {

-					i = atoi(uts.release+7);

-					if (i >= 15)

-						break;	/* 2.6.34.15 and newer is OK */

-				}

-			} else if (uts.release[0] == '3') {

-				i = atoi(uts.release+2);

-				if (i > 5)

-					break;	/* 3.6 and newer is OK */

-				if (i == 5) {

-					i = atoi(uts.release+4);

-					if (i >= 4)

-						break;	/* 3.5.4 and newer is OK */

-				} else if (i == 2) {

-					i = atoi(uts.release+4);

-					if (i >= 30)

-						break;	/* 3.2.30 and newer is OK */

-				}

-			} else {	/* 4.x and newer is OK */

-				break;

-			}

-			env->me_flags |= MDB_FSYNCONLY;

-			break;

-		}

-	}

-#endif

-

-	if ((i = mdb_env_read_header(env, &meta)) != 0) {

-		if (i != ENOENT)

-			return i;

-		DPUTS("new mdbenv");

-		newenv = 1;

-		env->me_psize = env->me_os_psize;

-		if (env->me_psize > MAX_PAGESIZE)

-			env->me_psize = MAX_PAGESIZE;

-		memset(&meta, 0, sizeof(meta));

-		mdb_env_init_meta0(env, &meta);

-		meta.mm_mapsize = DEFAULT_MAPSIZE;

-	} else {

-		env->me_psize = meta.mm_psize;

-	}

-

-	/* Was a mapsize configured? */

-	if (!env->me_mapsize) {

-		env->me_mapsize = meta.mm_mapsize;

-	}

-	{

-		/* Make sure mapsize >= committed data size.  Even when using

-		 * mm_mapsize, which could be broken in old files (ITS#7789).

-		 */

-		mdb_size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;

-		if (env->me_mapsize < minsize)

-			env->me_mapsize = minsize;

-	}

-	meta.mm_mapsize = env->me_mapsize;

-

-	if (newenv && !(flags & MDB_FIXEDMAP)) {

-		/* mdb_env_map() may grow the datafile.  Write the metapages

-		 * first, so the file will be valid if initialization fails.

-		 * Except with FIXEDMAP, since we do not yet know mm_address.

-		 * We could fill in mm_address later, but then a different

-		 * program might end up doing that - one with a memory layout

-		 * and map address which does not suit the main program.

-		 */

-		rc = mdb_env_init_meta(env, &meta);

-		if (rc)

-			return rc;

-		newenv = 0;

-	}

-#ifdef _WIN32

-	/* For FIXEDMAP, make sure the file is non-empty before we attempt to map it */

-	if (newenv) {

-		char dummy = 0;

-		DWORD len;

-		rc = WriteFile(env->me_fd, &dummy, 1, &len, NULL);

-		if (!rc) {

-			rc = ErrCode();

-			return rc;

-		}

-	}

-#endif

-

-	rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);

-	if (rc)

-		return rc;

-

-	if (newenv) {

-		if (flags & MDB_FIXEDMAP)

-			meta.mm_address = env->me_map;

-		i = mdb_env_init_meta(env, &meta);

-		if (i != MDB_SUCCESS) {

-			return i;

-		}

-	}

-

-	env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;

-	env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2)

-		- sizeof(indx_t);

-#if !(MDB_MAXKEYSIZE)

-	env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));

-#endif

-	env->me_maxpg = env->me_mapsize / env->me_psize;

-

-#if MDB_DEBUG

-	{

-		MDB_meta *meta = mdb_env_pick_meta(env);

-		MDB_db *db = &meta->mm_dbs[MAIN_DBI];

-

-		DPRINTF(("opened database version %u, pagesize %u",

-			meta->mm_version, env->me_psize));

-		DPRINTF(("using meta page %d",    (int) (meta->mm_txnid & 1)));

-		DPRINTF(("depth: %u",             db->md_depth));

-		DPRINTF(("entries: %"Y"u",        db->md_entries));

-		DPRINTF(("branch pages: %"Y"u",   db->md_branch_pages));

-		DPRINTF(("leaf pages: %"Y"u",     db->md_leaf_pages));

-		DPRINTF(("overflow pages: %"Y"u", db->md_overflow_pages));

-		DPRINTF(("root: %"Y"u",           db->md_root));

-	}

-#endif

-

-	return MDB_SUCCESS;

-}

-

-

-/** Release a reader thread's slot in the reader lock table.

- *	This function is called automatically when a thread exits.

- * @param[in] ptr This points to the slot in the reader lock table.

- */

-static void

-mdb_env_reader_dest(void *ptr)

-{

-	MDB_reader *reader = ptr;

-

-	reader->mr_pid = 0;

-}

-

-#ifdef _WIN32

-/** Junk for arranging thread-specific callbacks on Windows. This is

- *	necessarily platform and compiler-specific. Windows supports up

- *	to 1088 keys. Let's assume nobody opens more than 64 environments

- *	in a single process, for now. They can override this if needed.

- */

-#ifndef MAX_TLS_KEYS

-#define MAX_TLS_KEYS	64

-#endif

-static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];

-static int mdb_tls_nkeys;

-

-static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)

-{

-	int i;

-	switch(reason) {

-	case DLL_PROCESS_ATTACH: break;

-	case DLL_THREAD_ATTACH: break;

-	case DLL_THREAD_DETACH:

-		for (i=0; i<mdb_tls_nkeys; i++) {

-			MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);

-			if (r) {

-				mdb_env_reader_dest(r);

-			}

-		}

-		break;

-	case DLL_PROCESS_DETACH: break;

-	}

-}

-#ifdef __GNUC__

-#ifdef _WIN64

-const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;

-#else

-PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;

-#endif

-#else

-#ifdef _WIN64

-/* Force some symbol references.

- *	_tls_used forces the linker to create the TLS directory if not already done

- *	mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.

- */

-#pragma comment(linker, "/INCLUDE:_tls_used")

-#pragma comment(linker, "/INCLUDE:mdb_tls_cbp")

-#pragma const_seg(".CRT$XLB")

-extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;

-const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;

-#pragma const_seg()

-#else	/* _WIN32 */

-#pragma comment(linker, "/INCLUDE:__tls_used")

-#pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")

-#pragma data_seg(".CRT$XLB")

-PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;

-#pragma data_seg()

-#endif	/* WIN 32/64 */

-#endif	/* !__GNUC__ */

-#endif

-

-/** Downgrade the exclusive lock on the region back to shared */

-static int ESECT

-mdb_env_share_locks(MDB_env *env, int *excl)

-{

-	int rc = 0;

-	MDB_meta *meta = mdb_env_pick_meta(env);

-

-	env->me_txns->mti_txnid = meta->mm_txnid;

-

-#ifdef _WIN32

-	{

-		OVERLAPPED ov;

-		/* First acquire a shared lock. The Unlock will

-		 * then release the existing exclusive lock.

-		 */

-		memset(&ov, 0, sizeof(ov));

-		if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {

-			rc = ErrCode();

-		} else {

-			UnlockFile(env->me_lfd, 0, 0, 1, 0);

-			*excl = 0;

-		}

-	}

-#else

-	{

-		struct flock lock_info;

-		/* The shared lock replaces the existing lock */

-		memset((void *)&lock_info, 0, sizeof(lock_info));

-		lock_info.l_type = F_RDLCK;

-		lock_info.l_whence = SEEK_SET;

-		lock_info.l_start = 0;

-		lock_info.l_len = 1;

-		while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&

-				(rc = ErrCode()) == EINTR) ;

-		*excl = rc ? -1 : 0;	/* error may mean we lost the lock */

-	}

-#endif

-

-	return rc;

-}

-

-/** Try to get exclusive lock, otherwise shared.

- *	Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.

- */

-static int ESECT

-mdb_env_excl_lock(MDB_env *env, int *excl)

-{

-	int rc = 0;

-#ifdef _WIN32

-	if (LockFile(env->me_lfd, 0, 0, 1, 0)) {

-		*excl = 1;

-	} else {

-		OVERLAPPED ov;

-		memset(&ov, 0, sizeof(ov));

-		if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {

-			*excl = 0;

-		} else {

-			rc = ErrCode();

-		}

-	}

-#else

-	struct flock lock_info;

-	memset((void *)&lock_info, 0, sizeof(lock_info));

-	lock_info.l_type = F_WRLCK;

-	lock_info.l_whence = SEEK_SET;

-	lock_info.l_start = 0;

-	lock_info.l_len = 1;

-	while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&

-			(rc = ErrCode()) == EINTR) ;

-	if (!rc) {

-		*excl = 1;

-	} else

-# ifndef MDB_USE_POSIX_MUTEX

-	if (*excl < 0) /* always true when MDB_USE_POSIX_MUTEX */

-# endif

-	{

-		lock_info.l_type = F_RDLCK;

-		while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&

-				(rc = ErrCode()) == EINTR) ;

-		if (rc == 0)

-			*excl = 0;

-	}

-#endif

-	return rc;

-}

-

-#ifdef MDB_USE_HASH

-/*

- * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code

- *

- * @(#) $Revision: 5.1 $

- * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $

- * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $

- *

- *	  http://www.isthe.com/chongo/tech/comp/fnv/index.html

- *

- ***

- *

- * Please do not copyright this code.  This code is in the public domain.

- *

- * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,

- * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO

- * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR

- * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF

- * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR

- * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR

- * PERFORMANCE OF THIS SOFTWARE.

- *

- * By:

- *	chongo <Landon Curt Noll> /\oo/\

- *	  http://www.isthe.com/chongo/

- *

- * Share and Enjoy!	:-)

- */

-

-typedef unsigned long long	mdb_hash_t;

-#define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)

-

-/** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer

- * @param[in] val	value to hash

- * @param[in] hval	initial value for hash

- * @return 64 bit hash

- *

- * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the

- * 	 hval arg on the first call.

- */

-static mdb_hash_t

-mdb_hash_val(MDB_val *val, mdb_hash_t hval)

-{

-	unsigned char *s = (unsigned char *)val->mv_data;	/* unsigned string */

-	unsigned char *end = s + val->mv_size;

-	/*

-	 * FNV-1a hash each octet of the string

-	 */

-	while (s < end) {

-		/* xor the bottom with the current octet */

-		hval ^= (mdb_hash_t)*s++;

-

-		/* multiply by the 64 bit FNV magic prime mod 2^64 */

-		hval += (hval << 1) + (hval << 4) + (hval << 5) +

-			(hval << 7) + (hval << 8) + (hval << 40);

-	}

-	/* return our new hash value */

-	return hval;

-}

-

-/** Hash the string and output the encoded hash.

- * This uses modified RFC1924 Ascii85 encoding to accommodate systems with

- * very short name limits. We don't care about the encoding being reversible,

- * we just want to preserve as many bits of the input as possible in a

- * small printable string.

- * @param[in] str string to hash

- * @param[out] encbuf an array of 11 chars to hold the hash

- */

-static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";

-

-static void ESECT

-mdb_pack85(unsigned long l, char *out)

-{

-	int i;

-

-	for (i=0; i<5; i++) {

-		*out++ = mdb_a85[l % 85];

-		l /= 85;

-	}

-}

-

-static void ESECT

-mdb_hash_enc(MDB_val *val, char *encbuf)

-{

-	mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);

-

-	mdb_pack85(h, encbuf);

-	mdb_pack85(h>>32, encbuf+5);

-	encbuf[10] = '\0';

-}

-#endif

-

-/** Open and/or initialize the lock region for the environment.

- * @param[in] env The LMDB environment.

- * @param[in] lpath The pathname of the file used for the lock region.

- * @param[in] mode The Unix permissions for the file, if we create it.

- * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive

- * @return 0 on success, non-zero on failure.

- */

-static int ESECT

-mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)

-{

-#ifdef _WIN32

-#	define MDB_ERRCODE_ROFS	ERROR_WRITE_PROTECT

-#else

-#	define MDB_ERRCODE_ROFS	EROFS

-#ifdef O_CLOEXEC	/* Linux: Open file and set FD_CLOEXEC atomically */

-#	define MDB_CLOEXEC		O_CLOEXEC

-#else

-	int fdflags;

-#	define MDB_CLOEXEC		0

-#endif

-#endif

-#ifdef MDB_USE_SYSV_SEM

-	int semid;

-	union semun semu;

-#endif

-	int rc;

-	off_t size, rsize;

-

-#ifdef _WIN32

-	wchar_t *wlpath;

-	rc = utf8_to_utf16(lpath, -1, &wlpath, NULL);

-	if (rc)

-		return rc;

-	env->me_lfd = CreateFileW(wlpath, GENERIC_READ|GENERIC_WRITE,

-		FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,

-		FILE_ATTRIBUTE_NORMAL, NULL);

-	free(wlpath);

-#else

-	env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);

-#endif

-	if (env->me_lfd == INVALID_HANDLE_VALUE) {

-		rc = ErrCode();

-		if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {

-			return MDB_SUCCESS;

-		}

-		goto fail_errno;

-	}

-#if ! ((MDB_CLOEXEC) || defined(_WIN32))

-	/* Lose record locks when exec*() */

-	if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)

-			fcntl(env->me_lfd, F_SETFD, fdflags);

-#endif

-

-	if (!(env->me_flags & MDB_NOTLS)) {

-		rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);

-		if (rc)

-			goto fail;

-		env->me_flags |= MDB_ENV_TXKEY;

-#ifdef _WIN32

-		/* Windows TLS callbacks need help finding their TLS info. */

-		if (mdb_tls_nkeys >= MAX_TLS_KEYS) {

-			rc = MDB_TLS_FULL;

-			goto fail;

-		}

-		mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;

-#endif

-	}

-

-	/* Try to get exclusive lock. If we succeed, then

-	 * nobody is using the lock region and we should initialize it.

-	 */

-	if ((rc = mdb_env_excl_lock(env, excl))) goto fail;

-

-#ifdef _WIN32

-	size = GetFileSize(env->me_lfd, NULL);

-#else

-	size = lseek(env->me_lfd, 0, SEEK_END);

-	if (size == -1) goto fail_errno;

-#endif

-	rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);

-	if (size < rsize && *excl > 0) {

-#ifdef _WIN32

-		if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize

-			|| !SetEndOfFile(env->me_lfd))

-			goto fail_errno;

-#else

-		if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;

-#endif

-	} else {

-		rsize = size;

-		size = rsize - sizeof(MDB_txninfo);

-		env->me_maxreaders = size/sizeof(MDB_reader) + 1;

-	}

-	{

-#ifdef _WIN32

-		HANDLE mh;

-		mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,

-			0, 0, NULL);

-		if (!mh) goto fail_errno;

-		env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);

-		CloseHandle(mh);

-		if (!env->me_txns) goto fail_errno;

-#else

-		void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,

-			env->me_lfd, 0);

-		if (m == MAP_FAILED) goto fail_errno;

-		env->me_txns = m;

-#endif

-	}

-	if (*excl > 0) {

-#ifdef _WIN32

-		BY_HANDLE_FILE_INFORMATION stbuf;

-		struct {

-			DWORD volume;

-			DWORD nhigh;

-			DWORD nlow;

-		} idbuf;

-		MDB_val val;

-		char encbuf[11];

-

-		if (!mdb_sec_inited) {

-			InitializeSecurityDescriptor(&mdb_null_sd,

-				SECURITY_DESCRIPTOR_REVISION);

-			SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);

-			mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);

-			mdb_all_sa.bInheritHandle = FALSE;

-			mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;

-			mdb_sec_inited = 1;

-		}

-		if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;

-		idbuf.volume = stbuf.dwVolumeSerialNumber;

-		idbuf.nhigh  = stbuf.nFileIndexHigh;

-		idbuf.nlow   = stbuf.nFileIndexLow;

-		val.mv_data = &idbuf;

-		val.mv_size = sizeof(idbuf);

-		mdb_hash_enc(&val, encbuf);

-		sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);

-		sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);

-		env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);

-		if (!env->me_rmutex) goto fail_errno;

-		env->me_wmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);

-		if (!env->me_wmutex) goto fail_errno;

-#elif defined(MDB_USE_POSIX_SEM)

-		struct stat stbuf;

-		struct {

-			dev_t dev;

-			ino_t ino;

-		} idbuf;

-		MDB_val val;

-		char encbuf[11];

-

-#if defined(__NetBSD__)

-#define	MDB_SHORT_SEMNAMES	1	/* limited to 14 chars */

-#endif

-		if (fstat(env->me_lfd, &stbuf)) goto fail_errno;

-		idbuf.dev = stbuf.st_dev;

-		idbuf.ino = stbuf.st_ino;

-		val.mv_data = &idbuf;

-		val.mv_size = sizeof(idbuf);

-		mdb_hash_enc(&val, encbuf);

-#ifdef MDB_SHORT_SEMNAMES

-		encbuf[9] = '\0';	/* drop name from 15 chars to 14 chars */

-#endif

-		sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);

-		sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);

-		/* Clean up after a previous run, if needed:  Try to

-		 * remove both semaphores before doing anything else.

-		 */

-		sem_unlink(env->me_txns->mti_rmname);

-		sem_unlink(env->me_txns->mti_wmname);

-		env->me_rmutex = sem_open(env->me_txns->mti_rmname,

-			O_CREAT|O_EXCL, mode, 1);

-		if (env->me_rmutex == SEM_FAILED) goto fail_errno;

-		env->me_wmutex = sem_open(env->me_txns->mti_wmname,

-			O_CREAT|O_EXCL, mode, 1);

-		if (env->me_wmutex == SEM_FAILED) goto fail_errno;

-#elif defined(MDB_USE_SYSV_SEM)

-		unsigned short vals[2] = {1, 1};

-		key_t key = ftok(lpath, 'M');

-		if (key == -1)

-			goto fail_errno;

-		semid = semget(key, 2, (mode & 0777) | IPC_CREAT);

-		if (semid < 0)

-			goto fail_errno;

-		semu.array = vals;

-		if (semctl(semid, 0, SETALL, semu) < 0)

-			goto fail_errno;

-		env->me_txns->mti_semid = semid;

-#else	/* MDB_USE_POSIX_MUTEX: */

-		pthread_mutexattr_t mattr;

-

-		if ((rc = pthread_mutexattr_init(&mattr))

-			|| (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))

-#ifdef MDB_ROBUST_SUPPORTED

-			|| (rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST))

-#endif

-			|| (rc = pthread_mutex_init(env->me_txns->mti_rmutex, &mattr))

-			|| (rc = pthread_mutex_init(env->me_txns->mti_wmutex, &mattr)))

-			goto fail;

-		pthread_mutexattr_destroy(&mattr);

-#endif	/* _WIN32 || ... */

-

-		env->me_txns->mti_magic = MDB_MAGIC;

-		env->me_txns->mti_format = MDB_LOCK_FORMAT;

-		env->me_txns->mti_txnid = 0;

-		env->me_txns->mti_numreaders = 0;

-

-	} else {

-#ifdef MDB_USE_SYSV_SEM

-		struct semid_ds buf;

-#endif

-		if (env->me_txns->mti_magic != MDB_MAGIC) {

-			DPUTS("lock region has invalid magic");

-			rc = MDB_INVALID;

-			goto fail;

-		}

-		if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {

-			DPRINTF(("lock region has format+version 0x%x, expected 0x%x",

-				env->me_txns->mti_format, MDB_LOCK_FORMAT));

-			rc = MDB_VERSION_MISMATCH;

-			goto fail;

-		}

-		rc = ErrCode();

-		if (rc && rc != EACCES && rc != EAGAIN) {

-			goto fail;

-		}

-#ifdef _WIN32

-		env->me_rmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);

-		if (!env->me_rmutex) goto fail_errno;

-		env->me_wmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);

-		if (!env->me_wmutex) goto fail_errno;

-#elif defined(MDB_USE_POSIX_SEM)

-		env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);

-		if (env->me_rmutex == SEM_FAILED) goto fail_errno;

-		env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);

-		if (env->me_wmutex == SEM_FAILED) goto fail_errno;

-#elif defined(MDB_USE_SYSV_SEM)

-		semid = env->me_txns->mti_semid;

-		semu.buf = &buf;

-		/* check for read access */

-		if (semctl(semid, 0, IPC_STAT, semu) < 0)

-			goto fail_errno;

-		/* check for write access */

-		if (semctl(semid, 0, IPC_SET, semu) < 0)

-			goto fail_errno;

-#endif

-	}

-#ifdef MDB_USE_SYSV_SEM

-	env->me_rmutex->semid = semid;

-	env->me_wmutex->semid = semid;

-	env->me_rmutex->semnum = 0;

-	env->me_wmutex->semnum = 1;

-	env->me_rmutex->locked = &env->me_txns->mti_rlocked;

-	env->me_wmutex->locked = &env->me_txns->mti_wlocked;

-#endif

-#ifdef MDB_VL32

-#ifdef _WIN32

-	env->me_rpmutex = CreateMutex(NULL, FALSE, NULL);

-#else

-	pthread_mutex_init(&env->me_rpmutex, NULL);

-#endif

-#endif

-

-	return MDB_SUCCESS;

-

-fail_errno:

-	rc = ErrCode();

-fail:

-	return rc;

-}

-

-	/** The name of the lock file in the DB environment */

-#define LOCKNAME	"/lock.mdb"

-	/** The name of the data file in the DB environment */

-#define DATANAME	"/data.mdb"

-	/** The suffix of the lock file when no subdir is used */

-#define LOCKSUFF	"-lock"

-	/** Only a subset of the @ref mdb_env flags can be changed

-	 *	at runtime. Changing other flags requires closing the

-	 *	environment and re-opening it with the new flags.

-	 */

-#define	CHANGEABLE	(MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)

-#define	CHANGELESS	(MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \

-	MDB_WRITEMAP|MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)

-

-#if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)

-# error "Persistent DB flags & env flags overlap, but both go in mm_flags"

-#endif

-

-int ESECT

-mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)

-{

-	int		oflags, rc, len, excl = -1;

-	char *lpath, *dpath;

-#ifdef _WIN32

-	wchar_t *wpath;

-#endif

-

-	if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))

-		return EINVAL;

-

-#ifdef MDB_VL32

-	if (flags & MDB_WRITEMAP) {

-		/* silently ignore WRITEMAP in 32 bit mode */

-		flags ^= MDB_WRITEMAP;

-	}

-	if (flags & MDB_FIXEDMAP) {

-		/* cannot support FIXEDMAP */

-		return EINVAL;

-	}

-#endif

-

-	len = strlen(path);

-	if (flags & MDB_NOSUBDIR) {

-		rc = len + sizeof(LOCKSUFF) + len + 1;

-	} else {

-		rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);

-	}

-	lpath = malloc(rc);

-	if (!lpath)

-		return ENOMEM;

-	if (flags & MDB_NOSUBDIR) {

-		dpath = lpath + len + sizeof(LOCKSUFF);

-		sprintf(lpath, "%s" LOCKSUFF, path);

-		strcpy(dpath, path);

-	} else {

-		dpath = lpath + len + sizeof(LOCKNAME);

-		sprintf(lpath, "%s" LOCKNAME, path);

-		sprintf(dpath, "%s" DATANAME, path);

-	}

-

-	rc = MDB_SUCCESS;

-	flags |= env->me_flags;

-	if (flags & MDB_RDONLY) {

-		/* silently ignore WRITEMAP when we're only getting read access */

-		flags &= ~MDB_WRITEMAP;

-	} else {

-		if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&

-			  (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))

-			rc = ENOMEM;

-	}

-#ifdef MDB_VL32

-	if (!rc) {

-		env->me_rpages = malloc(MDB_ERPAGE_SIZE * sizeof(MDB_ID3));

-		if (!env->me_rpages) {

-			rc = ENOMEM;

-			goto leave;

-		}

-		env->me_rpages[0].mid = 0;

-		env->me_rpcheck = MDB_ERPAGE_SIZE/2;

-	}

-#endif

-	env->me_flags = flags |= MDB_ENV_ACTIVE;

-	if (rc)

-		goto leave;

-

-	env->me_path = strdup(path);

-	env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));

-	env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));

-	env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned int));

-	if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) {

-		rc = ENOMEM;

-		goto leave;

-	}

-	env->me_dbxs[FREE_DBI].md_cmp = mdb_cmp_long; /* aligned MDB_INTEGERKEY */

-

-	/* For RDONLY, get lockfile after we know datafile exists */

-	if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {

-		rc = mdb_env_setup_locks(env, lpath, mode, &excl);

-		if (rc)

-			goto leave;

-	}

-

-#ifdef _WIN32

-	if (F_ISSET(flags, MDB_RDONLY)) {

-		oflags = GENERIC_READ;

-		len = OPEN_EXISTING;

-	} else {

-		oflags = GENERIC_READ|GENERIC_WRITE;

-		len = OPEN_ALWAYS;

-	}

-	mode = FILE_ATTRIBUTE_NORMAL;

-	rc = utf8_to_utf16(dpath, -1, &wpath, NULL);

-	if (rc)

-		goto leave;

-	env->me_fd = CreateFileW(wpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,

-		NULL, len, mode, NULL);

-	free(wpath);

-#else

-	if (F_ISSET(flags, MDB_RDONLY))

-		oflags = O_RDONLY;

-	else

-		oflags = O_RDWR | O_CREAT;

-

-	env->me_fd = open(dpath, oflags, mode);

-#endif

-	if (env->me_fd == INVALID_HANDLE_VALUE) {

-		rc = ErrCode();

-		goto leave;

-	}

-

-	if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {

-		rc = mdb_env_setup_locks(env, lpath, mode, &excl);

-		if (rc)

-			goto leave;

-	}

-

-	if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {

-		if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {

-			env->me_mfd = env->me_fd;

-		} else {

-			/* Synchronous fd for meta writes. Needed even with

-			 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.

-			 */

-#ifdef _WIN32

-			len = OPEN_EXISTING;

-			rc = utf8_to_utf16(dpath, -1, &wpath, NULL);

-			if (rc)

-				goto leave;

-			env->me_mfd = CreateFileW(wpath, oflags,

-				FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,

-				mode | FILE_FLAG_WRITE_THROUGH, NULL);

-			free(wpath);

-#else

-			oflags &= ~O_CREAT;

-			env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);

-#endif

-			if (env->me_mfd == INVALID_HANDLE_VALUE) {

-				rc = ErrCode();

-				goto leave;

-			}

-		}

-		DPRINTF(("opened dbenv %p", (void *) env));

-		if (excl > 0) {

-			rc = mdb_env_share_locks(env, &excl);

-			if (rc)

-				goto leave;

-		}

-		if (!(flags & MDB_RDONLY)) {

-			MDB_txn *txn;

-			int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs *

-				(sizeof(MDB_db)+sizeof(MDB_cursor *)+sizeof(unsigned int)+1);

-			if ((env->me_pbuf = calloc(1, env->me_psize)) &&

-				(txn = calloc(1, size)))

-			{

-				txn->mt_dbs = (MDB_db *)((char *)txn + tsize);

-				txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);

-				txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);

-				txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);

-				txn->mt_env = env;

-#ifdef MDB_VL32

-				txn->mt_rpages = malloc(MDB_TRPAGE_SIZE * sizeof(MDB_ID3));

-				if (!txn->mt_rpages) {

-					free(txn);

-					rc = ENOMEM;

-					goto leave;

-				}

-				txn->mt_rpages[0].mid = 0;

-				txn->mt_rpcheck = MDB_TRPAGE_SIZE/2;

-#endif

-				txn->mt_dbxs = env->me_dbxs;

-				txn->mt_flags = MDB_TXN_FINISHED;

-				env->me_txn0 = txn;

-			} else {

-				rc = ENOMEM;

-			}

-		}

-	}

-

-leave:

-	if (rc) {

-		mdb_env_close0(env, excl);

-	}

-	free(lpath);

-	return rc;

-}

-

-/** Destroy resources from mdb_env_open(), clear our readers & DBIs */

-static void ESECT

-mdb_env_close0(MDB_env *env, int excl)

-{

-	int i;

-

-	if (!(env->me_flags & MDB_ENV_ACTIVE))

-		return;

-

-	/* Doing this here since me_dbxs may not exist during mdb_env_close */

-	if (env->me_dbxs) {

-		for (i = env->me_maxdbs; --i >= CORE_DBS; )

-			free(env->me_dbxs[i].md_name.mv_data);

-		free(env->me_dbxs);

-	}

-

-	free(env->me_pbuf);

-	free(env->me_dbiseqs);

-	free(env->me_dbflags);

-	free(env->me_path);

-	free(env->me_dirty_list);

-#ifdef MDB_VL32

-	if (env->me_txn0 && env->me_txn0->mt_rpages)

-		free(env->me_txn0->mt_rpages);

-	{ unsigned int x;

-		for (x=1; x<=env->me_rpages[0].mid; x++)

-		munmap(env->me_rpages[x].mptr, env->me_rpages[x].mcnt * env->me_psize);

-	}

-	free(env->me_rpages);

-#endif

-	free(env->me_txn0);

-	mdb_midl_free(env->me_free_pgs);

-

-	if (env->me_flags & MDB_ENV_TXKEY) {

-		pthread_key_delete(env->me_txkey);

-#ifdef _WIN32

-		/* Delete our key from the global list */

-		for (i=0; i<mdb_tls_nkeys; i++)

-			if (mdb_tls_keys[i] == env->me_txkey) {

-				mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];

-				mdb_tls_nkeys--;

-				break;

-			}

-#endif

-	}

-

-	if (env->me_map) {

-#ifdef MDB_VL32

-		munmap(env->me_map, NUM_METAS*env->me_psize);

-#else

-		munmap(env->me_map, env->me_mapsize);

-#endif

-	}

-	if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)

-		(void) close(env->me_mfd);

-	if (env->me_fd != INVALID_HANDLE_VALUE)

-		(void) close(env->me_fd);

-	if (env->me_txns) {

-		MDB_PID_T pid = env->me_pid;

-		/* Clearing readers is done in this function because

-		 * me_txkey with its destructor must be disabled first.

-		 *

-		 * We skip the the reader mutex, so we touch only

-		 * data owned by this process (me_close_readers and

-		 * our readers), and clear each reader atomically.

-		 */

-		for (i = env->me_close_readers; --i >= 0; )

-			if (env->me_txns->mti_readers[i].mr_pid == pid)

-				env->me_txns->mti_readers[i].mr_pid = 0;

-#ifdef _WIN32

-		if (env->me_rmutex) {

-			CloseHandle(env->me_rmutex);

-			if (env->me_wmutex) CloseHandle(env->me_wmutex);

-		}

-		/* Windows automatically destroys the mutexes when

-		 * the last handle closes.

-		 */

-#elif defined(MDB_USE_POSIX_SEM)

-		if (env->me_rmutex != SEM_FAILED) {

-			sem_close(env->me_rmutex);

-			if (env->me_wmutex != SEM_FAILED)

-				sem_close(env->me_wmutex);

-			/* If we have the filelock:  If we are the

-			 * only remaining user, clean up semaphores.

-			 */

-			if (excl == 0)

-				mdb_env_excl_lock(env, &excl);

-			if (excl > 0) {

-				sem_unlink(env->me_txns->mti_rmname);

-				sem_unlink(env->me_txns->mti_wmname);

-			}

-		}

-#elif defined(MDB_USE_SYSV_SEM)

-		if (env->me_rmutex->semid != -1) {

-			/* If we have the filelock:  If we are the

-			 * only remaining user, clean up semaphores.

-			 */

-			if (excl == 0)

-				mdb_env_excl_lock(env, &excl);

-			if (excl > 0)

-				semctl(env->me_rmutex->semid, 0, IPC_RMID);

-		}

-#endif

-		munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));

-	}

-	if (env->me_lfd != INVALID_HANDLE_VALUE) {

-#ifdef _WIN32

-		if (excl >= 0) {

-			/* Unlock the lockfile.  Windows would have unlocked it

-			 * after closing anyway, but not necessarily at once.

-			 */

-			UnlockFile(env->me_lfd, 0, 0, 1, 0);

-		}

-#endif

-		(void) close(env->me_lfd);

-	}

-#ifdef MDB_VL32

-#ifdef _WIN32

-	if (env->me_fmh) CloseHandle(env->me_fmh);

-	if (env->me_rpmutex) CloseHandle(env->me_rpmutex);

-#else

-	pthread_mutex_destroy(&env->me_rpmutex);

-#endif

-#endif

-

-	env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);

-}

-

-void ESECT

-mdb_env_close(MDB_env *env)

-{

-	MDB_page *dp;

-

-	if (env == NULL)

-		return;

-

-	VGMEMP_DESTROY(env);

-	while ((dp = env->me_dpages) != NULL) {

-		VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));

-		env->me_dpages = dp->mp_next;

-		free(dp);

-	}

-

-	mdb_env_close0(env, 0);

-	free(env);

-}

-

-/** Compare two items pointing at aligned mdb_size_t's */

-static int

-mdb_cmp_long(const MDB_val *a, const MDB_val *b)

-{

-	return (*(mdb_size_t *)a->mv_data < *(mdb_size_t *)b->mv_data) ? -1 :

-		*(mdb_size_t *)a->mv_data > *(mdb_size_t *)b->mv_data;

-}

-

-/** Compare two items pointing at aligned unsigned int's.

- *

- *	This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,

- *	but #mdb_cmp_clong() is called instead if the data type is mdb_size_t.

- */

-static int

-mdb_cmp_int(const MDB_val *a, const MDB_val *b)

-{

-	return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :

-		*(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;

-}

-

-/** Compare two items pointing at unsigned ints of unknown alignment.

- *	Nodes and keys are guaranteed to be 2-byte aligned.

- */

-static int

-mdb_cmp_cint(const MDB_val *a, const MDB_val *b)

-{

-#if BYTE_ORDER == LITTLE_ENDIAN

-	unsigned short *u, *c;

-	int x;

-

-	u = (unsigned short *) ((char *) a->mv_data + a->mv_size);

-	c = (unsigned short *) ((char *) b->mv_data + a->mv_size);

-	do {

-		x = *--u - *--c;

-	} while(!x && u > (unsigned short *)a->mv_data);

-	return x;

-#else

-	unsigned short *u, *c, *end;

-	int x;

-

-	end = (unsigned short *) ((char *) a->mv_data + a->mv_size);

-	u = (unsigned short *)a->mv_data;

-	c = (unsigned short *)b->mv_data;

-	do {

-		x = *u++ - *c++;

-	} while(!x && u < end);

-	return x;

-#endif

-}

-

-/** Compare two items lexically */

-static int

-mdb_cmp_memn(const MDB_val *a, const MDB_val *b)

-{

-	int diff;

-	ssize_t len_diff;

-	unsigned int len;

-

-	len = a->mv_size;

-	len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;

-	if (len_diff > 0) {

-		len = b->mv_size;

-		len_diff = 1;

-	}

-

-	diff = memcmp(a->mv_data, b->mv_data, len);

-	return diff ? diff : len_diff<0 ? -1 : len_diff;

-}

-

-/** Compare two items in reverse byte order */

-static int

-mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)

-{

-	const unsigned char	*p1, *p2, *p1_lim;

-	ssize_t len_diff;

-	int diff;

-

-	p1_lim = (const unsigned char *)a->mv_data;

-	p1 = (const unsigned char *)a->mv_data + a->mv_size;

-	p2 = (const unsigned char *)b->mv_data + b->mv_size;

-

-	len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;

-	if (len_diff > 0) {

-		p1_lim += len_diff;

-		len_diff = 1;

-	}

-

-	while (p1 > p1_lim) {

-		diff = *--p1 - *--p2;

-		if (diff)

-			return diff;

-	}

-	return len_diff<0 ? -1 : len_diff;

-}

-

-/** Search for key within a page, using binary search.

- * Returns the smallest entry larger or equal to the key.

- * If exactp is non-null, stores whether the found entry was an exact match

- * in *exactp (1 or 0).

- * Updates the cursor index with the index of the found entry.

- * If no entry larger or equal to the key is found, returns NULL.

- */

-static MDB_node *

-mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)

-{

-	unsigned int	 i = 0, nkeys;

-	int		 low, high;

-	int		 rc = 0;

-	MDB_page *mp = mc->mc_pg[mc->mc_top];

-	MDB_node	*node = NULL;

-	MDB_val	 nodekey;

-	MDB_cmp_func *cmp;

-	DKBUF;

-

-	nkeys = NUMKEYS(mp);

-

-	DPRINTF(("searching %u keys in %s %spage %"Y"u",

-	    nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",

-	    mdb_dbg_pgno(mp)));

-

-	low = IS_LEAF(mp) ? 0 : 1;

-	high = nkeys - 1;

-	cmp = mc->mc_dbx->md_cmp;

-

-	/* Branch pages have no data, so if using integer keys,

-	 * alignment is guaranteed. Use faster mdb_cmp_int.

-	 */

-	if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {

-		if (NODEPTR(mp, 1)->mn_ksize == sizeof(mdb_size_t))

-			cmp = mdb_cmp_long;

-		else if(NODEPTR(mp, 1)->mn_ksize == sizeof(int))

-			cmp = mdb_cmp_int;

-	}

-

-	if (IS_LEAF2(mp)) {

-		nodekey.mv_size = mc->mc_db->md_pad;

-		node = NODEPTR(mp, 0);	/* fake */

-		while (low <= high) {

-			i = (low + high) >> 1;

-			nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);

-			rc = cmp(key, &nodekey);

-			DPRINTF(("found leaf index %u [%s], rc = %i",

-			    i, DKEY(&nodekey), rc));

-			if (rc == 0)

-				break;

-			if (rc > 0)

-				low = i + 1;

-			else

-				high = i - 1;

-		}

-	} else {

-		while (low <= high) {

-			i = (low + high) >> 1;

-

-			node = NODEPTR(mp, i);

-			nodekey.mv_size = NODEKSZ(node);

-			nodekey.mv_data = NODEKEY(node);

-

-			rc = cmp(key, &nodekey);

-#if MDB_DEBUG

-			if (IS_LEAF(mp))

-				DPRINTF(("found leaf index %u [%s], rc = %i",

-				    i, DKEY(&nodekey), rc));

-			else

-				DPRINTF(("found branch index %u [%s -> %"Y"u], rc = %i",

-				    i, DKEY(&nodekey), NODEPGNO(node), rc));

-#endif

-			if (rc == 0)

-				break;

-			if (rc > 0)

-				low = i + 1;

-			else

-				high = i - 1;

-		}

-	}

-

-	if (rc > 0) {	/* Found entry is less than the key. */

-		i++;	/* Skip to get the smallest entry larger than key. */

-		if (!IS_LEAF2(mp))

-			node = NODEPTR(mp, i);

-	}

-	if (exactp)

-		*exactp = (rc == 0 && nkeys > 0);

-	/* store the key index */

-	mc->mc_ki[mc->mc_top] = i;

-	if (i >= nkeys)

-		/* There is no entry larger or equal to the key. */

-		return NULL;

-

-	/* nodeptr is fake for LEAF2 */

-	return node;

-}

-

-#if 0

-static void

-mdb_cursor_adjust(MDB_cursor *mc, func)

-{

-	MDB_cursor *m2;

-

-	for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {

-		if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {

-			func(mc, m2);

-		}

-	}

-}

-#endif

-

-/** Pop a page off the top of the cursor's stack. */

-static void

-mdb_cursor_pop(MDB_cursor *mc)

-{

-	if (mc->mc_snum) {

-		DPRINTF(("popping page %"Y"u off db %d cursor %p",

-			mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *) mc));

-

-		mc->mc_snum--;

-		if (mc->mc_snum) {

-			mc->mc_top--;

-		} else {

-			mc->mc_flags &= ~C_INITIALIZED;

-		}

-	}

-}

-

-/** Push a page onto the top of the cursor's stack. */

-static int

-mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)

-{

-	DPRINTF(("pushing page %"Y"u on db %d cursor %p", mp->mp_pgno,

-		DDBI(mc), (void *) mc));

-

-	if (mc->mc_snum >= CURSOR_STACK) {

-		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;

-		return MDB_CURSOR_FULL;

-	}

-

-	mc->mc_top = mc->mc_snum++;

-	mc->mc_pg[mc->mc_top] = mp;

-	mc->mc_ki[mc->mc_top] = 0;

-

-	return MDB_SUCCESS;

-}

-

-#ifdef MDB_VL32

-/** Map a read-only page.

- * There are two levels of tracking in use, a per-txn list and a per-env list.

- * ref'ing and unref'ing the per-txn list is faster since it requires no

- * locking. Pages are cached in the per-env list for global reuse, and a lock

- * is required. Pages are not immediately unmapped when their refcnt goes to

- * zero; they hang around in case they will be reused again soon.

- *

- * When the per-txn list gets full, all pages with refcnt=0 are purged from the

- * list and their refcnts in the per-env list are decremented.

- *

- * When the per-env list gets full, all pages with refcnt=0 are purged from the

- * list and their pages are unmapped.

- *

- * @note "full" means the list has reached its respective rpcheck threshold.

- * This threshold slowly raises if no pages could be purged on a given check,

- * and returns to its original value when enough pages were purged.

- *

- * If purging doesn't free any slots, filling the per-txn list will return

- * MDB_TXN_FULL, and filling the per-env list returns MDB_MAP_FULL.

- *

- * Reference tracking in a txn is imperfect, pages can linger with non-zero

- * refcnt even without active references. It was deemed to be too invasive

- * to add unrefs in every required location. However, all pages are unref'd

- * at the end of the transaction. This guarantees that no stale references

- * linger in the per-env list.

- *

- * Usually we map chunks of 16 pages at a time, but if an overflow page begins

- * at the tail of the chunk we extend the chunk to include the entire overflow

- * page. Unfortunately, pages can be turned into overflow pages after their

- * chunk was already mapped. In that case we must remap the chunk if the

- * overflow page is referenced. If the chunk's refcnt is 0 we can just remap

- * it, otherwise we temporarily map a new chunk just for the overflow page.

- *

- * @note this chunk handling means we cannot guarantee that a data item

- * returned from the DB will stay alive for the duration of the transaction:

- *   We unref pages as soon as a cursor moves away from the page

- *   A subsequent op may cause a purge, which may unmap any unref'd chunks

- * The caller must copy the data if it must be used later in the same txn.

- *

- * Also - our reference counting revolves around cursors, but overflow pages

- * aren't pointed to by a cursor's page stack. We have to remember them

- * explicitly, in the added mc_ovpg field. A single cursor can only hold a

- * reference to one overflow page at a time.

- *

- * @param[in] txn the transaction for this access.

- * @param[in] pgno the page number for the page to retrieve.

- * @param[out] ret address of a pointer where the page's address will be stored.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_rpage_get(MDB_txn *txn, pgno_t pg0, MDB_page **ret)

-{

-	MDB_env *env = txn->mt_env;

-	MDB_page *p;

-	MDB_ID3L tl = txn->mt_rpages;

-	MDB_ID3L el = env->me_rpages;

-	MDB_ID3 id3;

-	unsigned x, rem;

-	pgno_t pgno;

-	int rc, retries = 1;

-#ifdef _WIN32

-	LARGE_INTEGER off;

-	SIZE_T len;

-#define SET_OFF(off,val)	off.QuadPart = val

-#define MAP(rc,env,addr,len,off)	\

-	addr = NULL; \

-	rc = NtMapViewOfSection(env->me_fmh, GetCurrentProcess(), &addr, 0, \

-		len, &off, &len, ViewUnmap, (env->me_flags & MDB_RDONLY) ? 0 : MEM_RESERVE, PAGE_READONLY); \

-	if (rc) rc = mdb_nt2win32(rc)

-#else

-	off_t off;

-	size_t len;

-#define SET_OFF(off,val)	off = val

-#define MAP(rc,env,addr,len,off)	\

-	addr = mmap(NULL, len, PROT_READ, MAP_SHARED, env->me_fd, off); \

-	rc = (addr == MAP_FAILED) ? errno : 0

-#endif

-

-	/* remember the offset of the actual page number, so we can

-	 * return the correct pointer at the end.

-	 */

-	rem = pg0 & (MDB_RPAGE_CHUNK-1);

-	pgno = pg0 ^ rem;

-

-	id3.mid = 0;

-	x = mdb_mid3l_search(tl, pgno);

-	if (x <= tl[0].mid && tl[x].mid == pgno) {

-		if (x != tl[0].mid && tl[x+1].mid == pg0)

-			x++;

-		/* check for overflow size */

-		p = (MDB_page *)((char *)tl[x].mptr + rem * env->me_psize);

-		if (IS_OVERFLOW(p) && p->mp_pages + rem > tl[x].mcnt) {

-			id3.mcnt = p->mp_pages + rem;

-			len = id3.mcnt * env->me_psize;

-			SET_OFF(off, pgno * env->me_psize);

-			MAP(rc, env, id3.mptr, len, off);

-			if (rc)

-				return rc;

-			/* check for local-only page */

-			if (rem) {

-				mdb_tassert(txn, tl[x].mid != pg0);

-				/* hope there's room to insert this locally.

-				 * setting mid here tells later code to just insert

-				 * this id3 instead of searching for a match.

-				 */

-				id3.mid = pg0;

-				goto notlocal;

-			} else {

-				/* ignore the mapping we got from env, use new one */

-				tl[x].mptr = id3.mptr;

-				tl[x].mcnt = id3.mcnt;

-				/* if no active ref, see if we can replace in env */

-				if (!tl[x].mref) {

-					unsigned i;

-					pthread_mutex_lock(&env->me_rpmutex);

-					i = mdb_mid3l_search(el, tl[x].mid);

-					if (el[i].mref == 1) {

-						/* just us, replace it */

-						munmap(el[i].mptr, el[i].mcnt * env->me_psize);

-						el[i].mptr = tl[x].mptr;

-						el[i].mcnt = tl[x].mcnt;

-					} else {

-						/* there are others, remove ourself */

-						el[i].mref--;

-					}

-					pthread_mutex_unlock(&env->me_rpmutex);

-				}

-			}

-		}

-		id3.mptr = tl[x].mptr;

-		id3.mcnt = tl[x].mcnt;

-		tl[x].mref++;

-		goto ok;

-	}

-

-notlocal:

-	if (tl[0].mid >= MDB_TRPAGE_MAX - txn->mt_rpcheck) {

-		unsigned i, y;

-		/* purge unref'd pages from our list and unref in env */

-		pthread_mutex_lock(&env->me_rpmutex);

-retry:

-		y = 0;

-		for (i=1; i<=tl[0].mid; i++) {

-			if (!tl[i].mref) {

-				if (!y) y = i;

-				/* tmp overflow pages don't go to env */

-				if (tl[i].mid & (MDB_RPAGE_CHUNK-1)) {

-					munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);

-					continue;

-				}

-				x = mdb_mid3l_search(el, tl[i].mid);

-				el[x].mref--;

-			}

-		}

-		pthread_mutex_unlock(&env->me_rpmutex);

-		if (!y) {

-			/* we didn't find any unref'd chunks.

-			 * if we're out of room, fail.

-			 */

-			if (tl[0].mid >= MDB_TRPAGE_MAX)

-				return MDB_TXN_FULL;

-			/* otherwise, raise threshold for next time around

-			 * and let this go.

-			 */

-			txn->mt_rpcheck /= 2;

-		} else {

-			/* we found some unused; consolidate the list */

-			for (i=y+1; i<= tl[0].mid; i++)

-				if (tl[i].mref)

-					tl[y++] = tl[i];

-			tl[0].mid = y-1;

-			/* decrease the check threshold toward its original value */

-			if (!txn->mt_rpcheck)

-				txn->mt_rpcheck = 1;

-			while (txn->mt_rpcheck < tl[0].mid && txn->mt_rpcheck < MDB_TRPAGE_SIZE/2)

-				txn->mt_rpcheck *= 2;

-		}

-	}

-	if (tl[0].mid < MDB_TRPAGE_SIZE) {

-		id3.mref = 1;

-		if (id3.mid)

-			goto found;

-		/* don't map past last written page in read-only envs */

-		if ((env->me_flags & MDB_RDONLY) && pgno + MDB_RPAGE_CHUNK-1 > txn->mt_last_pgno)

-			id3.mcnt = txn->mt_last_pgno + 1 - pgno;

-		else

-			id3.mcnt = MDB_RPAGE_CHUNK;

-		len = id3.mcnt * env->me_psize;

-		id3.mid = pgno;

-

-		/* search for page in env */

-		pthread_mutex_lock(&env->me_rpmutex);

-		x = mdb_mid3l_search(el, pgno);

-		if (x <= el[0].mid && el[x].mid == pgno) {

-			id3.mptr = el[x].mptr;

-			id3.mcnt = el[x].mcnt;

-			/* check for overflow size */

-			p = (MDB_page *)((char *)id3.mptr + rem * env->me_psize);

-			if (IS_OVERFLOW(p) && p->mp_pages + rem > id3.mcnt) {

-				id3.mcnt = p->mp_pages + rem;

-				len = id3.mcnt * env->me_psize;

-				SET_OFF(off, pgno * env->me_psize);

-				MAP(rc, env, id3.mptr, len, off);

-				if (rc)

-					goto fail;

-				if (!el[x].mref) {

-					munmap(el[x].mptr, env->me_psize * el[x].mcnt);

-					el[x].mptr = id3.mptr;

-					el[x].mcnt = id3.mcnt;

-				} else {

-					id3.mid = pg0;

-					pthread_mutex_unlock(&env->me_rpmutex);

-					goto found;

-				}

-			}

-			el[x].mref++;

-			pthread_mutex_unlock(&env->me_rpmutex);

-			goto found;

-		}

-		if (el[0].mid >= MDB_ERPAGE_MAX - env->me_rpcheck) {

-			/* purge unref'd pages */

-			unsigned i, y = 0;

-			for (i=1; i<=el[0].mid; i++) {

-				if (!el[i].mref) {

-					if (!y) y = i;

-					munmap(el[i].mptr, env->me_psize * el[i].mcnt);

-				}

-			}

-			if (!y) {

-				if (retries) {

-					/* see if we can unref some local pages */

-					retries--;

-					id3.mid = 0;

-					goto retry;

-				}

-				if (el[0].mid >= MDB_ERPAGE_MAX) {

-					pthread_mutex_unlock(&env->me_rpmutex);

-					return MDB_MAP_FULL;

-				}

-				env->me_rpcheck /= 2;

-			} else {

-				for (i=y+1; i<= el[0].mid; i++)

-					if (el[i].mref)

-						el[y++] = el[i];

-				el[0].mid = y-1;

-				if (!env->me_rpcheck)

-					env->me_rpcheck = 1;

-				while (env->me_rpcheck < el[0].mid && env->me_rpcheck < MDB_ERPAGE_SIZE/2)

-					env->me_rpcheck *= 2;

-			}

-		}

-		SET_OFF(off, pgno * env->me_psize);

-		MAP(rc, env, id3.mptr, len, off);

-		if (rc) {

-fail:

-			pthread_mutex_unlock(&env->me_rpmutex);

-			return rc;

-		}

-		/* check for overflow size */

-		p = (MDB_page *)((char *)id3.mptr + rem * env->me_psize);

-		if (IS_OVERFLOW(p) && p->mp_pages + rem > id3.mcnt) {

-			id3.mcnt = p->mp_pages + rem;

-			munmap(id3.mptr, len);

-			len = id3.mcnt * env->me_psize;

-			MAP(rc, env, id3.mptr, len, off);

-			if (rc)

-				goto fail;

-		}

-		mdb_mid3l_insert(el, &id3);

-		pthread_mutex_unlock(&env->me_rpmutex);

-found:

-		mdb_mid3l_insert(tl, &id3);

-	} else {

-		return MDB_TXN_FULL;

-	}

-ok:

-	p = (MDB_page *)((char *)id3.mptr + rem * env->me_psize);

-#if MDB_DEBUG	/* we don't need this check any more */

-	if (IS_OVERFLOW(p)) {

-		mdb_tassert(txn, p->mp_pages + rem <= id3.mcnt);

-	}

-#endif

-	*ret = p;

-	return MDB_SUCCESS;

-}

-#endif

-

-/** Find the address of the page corresponding to a given page number.

- * @param[in] mc the cursor accessing the page.

- * @param[in] pgno the page number for the page to retrieve.

- * @param[out] ret address of a pointer where the page's address will be stored.

- * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **ret, int *lvl)

-{

-	MDB_txn *txn = mc->mc_txn;

-#ifndef MDB_VL32

-	MDB_env *env = txn->mt_env;

-#endif

-	MDB_page *p = NULL;

-	int level;

-

-	if (! (mc->mc_flags & (C_ORIG_RDONLY|C_WRITEMAP))) {

-		MDB_txn *tx2 = txn;

-		level = 1;

-		do {

-			MDB_ID2L dl = tx2->mt_u.dirty_list;

-			unsigned x;

-			/* Spilled pages were dirtied in this txn and flushed

-			 * because the dirty list got full. Bring this page

-			 * back in from the map (but don't unspill it here,

-			 * leave that unless page_touch happens again).

-			 */

-			if (tx2->mt_spill_pgs) {

-				MDB_ID pn = pgno << 1;

-				x = mdb_midl_search(tx2->mt_spill_pgs, pn);

-				if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {

-#ifdef MDB_VL32

-					int rc = mdb_rpage_get(txn, pgno, &p);

-					if (rc)

-						return rc;

-#else

-					p = (MDB_page *)(env->me_map + env->me_psize * pgno);

-#endif

-					goto done;

-				}

-			}

-			if (dl[0].mid) {

-				unsigned x = mdb_mid2l_search(dl, pgno);

-				if (x <= dl[0].mid && dl[x].mid == pgno) {

-					p = dl[x].mptr;

-					goto done;

-				}

-			}

-			level++;

-		} while ((tx2 = tx2->mt_parent) != NULL);

-	}

-

-	if (pgno < txn->mt_next_pgno) {

-		level = 0;

-#ifdef MDB_VL32

-		{

-			int rc = mdb_rpage_get(txn, pgno, &p);

-			if (rc)

-				return rc;

-		}

-#else

-		p = (MDB_page *)(env->me_map + env->me_psize * pgno);

-#endif

-	} else {

-		DPRINTF(("page %"Y"u not found", pgno));

-		txn->mt_flags |= MDB_TXN_ERROR;

-		return MDB_PAGE_NOTFOUND;

-	}

-

-done:

-	*ret = p;

-	if (lvl)

-		*lvl = level;

-	return MDB_SUCCESS;

-}

-

-/** Finish #mdb_page_search() / #mdb_page_search_lowest().

- *	The cursor is at the root page, set up the rest of it.

- */

-static int

-mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)

-{

-	MDB_page	*mp = mc->mc_pg[mc->mc_top];

-	int rc;

-	DKBUF;

-

-	while (IS_BRANCH(mp)) {

-		MDB_node	*node;

-		indx_t		i;

-

-		DPRINTF(("branch page %"Y"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));

-		/* Don't assert on branch pages in the FreeDB. We can get here

-		 * while in the process of rebalancing a FreeDB branch page; we must

-		 * let that proceed. ITS#8336

-		 */

-		mdb_cassert(mc, !mc->mc_dbi || NUMKEYS(mp) > 1);

-		DPRINTF(("found index 0 to page %"Y"u", NODEPGNO(NODEPTR(mp, 0))));

-

-		if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {

-			i = 0;

-			if (flags & MDB_PS_LAST)

-				i = NUMKEYS(mp) - 1;

-		} else {

-			int	 exact;

-			node = mdb_node_search(mc, key, &exact);

-			if (node == NULL)

-				i = NUMKEYS(mp) - 1;

-			else {

-				i = mc->mc_ki[mc->mc_top];

-				if (!exact) {

-					mdb_cassert(mc, i > 0);

-					i--;

-				}

-			}

-			DPRINTF(("following index %u for key [%s]", i, DKEY(key)));

-		}

-

-		mdb_cassert(mc, i < NUMKEYS(mp));

-		node = NODEPTR(mp, i);

-

-		if ((rc = mdb_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)

-			return rc;

-

-		mc->mc_ki[mc->mc_top] = i;

-		if ((rc = mdb_cursor_push(mc, mp)))

-			return rc;

-

-		if (flags & MDB_PS_MODIFY) {

-			if ((rc = mdb_page_touch(mc)) != 0)

-				return rc;

-			mp = mc->mc_pg[mc->mc_top];

-		}

-	}

-

-	if (!IS_LEAF(mp)) {

-		DPRINTF(("internal error, index points to a %02X page!?",

-		    mp->mp_flags));

-		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;

-		return MDB_CORRUPTED;

-	}

-

-	DPRINTF(("found leaf page %"Y"u for key [%s]", mp->mp_pgno,

-	    key ? DKEY(key) : "null"));

-	mc->mc_flags |= C_INITIALIZED;

-	mc->mc_flags &= ~C_EOF;

-

-	return MDB_SUCCESS;

-}

-

-/** Search for the lowest key under the current branch page.

- * This just bypasses a NUMKEYS check in the current page

- * before calling mdb_page_search_root(), because the callers

- * are all in situations where the current page is known to

- * be underfilled.

- */

-static int

-mdb_page_search_lowest(MDB_cursor *mc)

-{

-	MDB_page	*mp = mc->mc_pg[mc->mc_top];

-	MDB_node	*node = NODEPTR(mp, 0);

-	int rc;

-

-	if ((rc = mdb_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)

-		return rc;

-

-	mc->mc_ki[mc->mc_top] = 0;

-	if ((rc = mdb_cursor_push(mc, mp)))

-		return rc;

-	return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);

-}

-

-/** Search for the page a given key should be in.

- * Push it and its parent pages on the cursor stack.

- * @param[in,out] mc the cursor for this operation.

- * @param[in] key the key to search for, or NULL for first/last page.

- * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB

- *   are touched (updated with new page numbers).

- *   If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.

- *   This is used by #mdb_cursor_first() and #mdb_cursor_last().

- *   If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)

-{

-	int		 rc;

-	pgno_t		 root;

-

-	/* Make sure the txn is still viable, then find the root from

-	 * the txn's db table and set it as the root of the cursor's stack.

-	 */

-	if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED) {

-		DPUTS("transaction may not be used now");

-		return MDB_BAD_TXN;

-	} else {

-		/* Make sure we're using an up-to-date root */

-		if (*mc->mc_dbflag & DB_STALE) {

-				MDB_cursor mc2;

-				if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))

-					return MDB_BAD_DBI;

-				mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);

-				rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);

-				if (rc)

-					return rc;

-				{

-					MDB_val data;

-					int exact = 0;

-					uint16_t flags;

-					MDB_node *leaf = mdb_node_search(&mc2,

-						&mc->mc_dbx->md_name, &exact);

-					if (!exact)

-						return MDB_NOTFOUND;

-					if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)

-						return MDB_INCOMPATIBLE; /* not a named DB */

-					rc = mdb_node_read(&mc2, leaf, &data);

-					if (rc)

-						return rc;

-					memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),

-						sizeof(uint16_t));

-					/* The txn may not know this DBI, or another process may

-					 * have dropped and recreated the DB with other flags.

-					 */

-					if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)

-						return MDB_INCOMPATIBLE;

-					memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));

-				}

-				*mc->mc_dbflag &= ~DB_STALE;

-		}

-		root = mc->mc_db->md_root;

-

-		if (root == P_INVALID) {		/* Tree is empty. */

-			DPUTS("tree is empty");

-			return MDB_NOTFOUND;

-		}

-	}

-

-	mdb_cassert(mc, root > 1);

-	if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root) {

-#ifdef MDB_VL32

-		if (mc->mc_pg[0])

-			MDB_PAGE_UNREF(mc->mc_txn, mc->mc_pg[0]);

-#endif

-		if ((rc = mdb_page_get(mc, root, &mc->mc_pg[0], NULL)) != 0)

-			return rc;

-	}

-

-#ifdef MDB_VL32

-	{

-		int i;

-		for (i=1; i<mc->mc_snum; i++)

-			MDB_PAGE_UNREF(mc->mc_txn, mc->mc_pg[i]);

-	}

-#endif

-	mc->mc_snum = 1;

-	mc->mc_top = 0;

-

-	DPRINTF(("db %d root page %"Y"u has flags 0x%X",

-		DDBI(mc), root, mc->mc_pg[0]->mp_flags));

-

-	if (flags & MDB_PS_MODIFY) {

-		if ((rc = mdb_page_touch(mc)))

-			return rc;

-	}

-

-	if (flags & MDB_PS_ROOTONLY)

-		return MDB_SUCCESS;

-

-	return mdb_page_search_root(mc, key, flags);

-}

-

-static int

-mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)

-{

-	MDB_txn *txn = mc->mc_txn;

-	pgno_t pg = mp->mp_pgno;

-	unsigned x = 0, ovpages = mp->mp_pages;

-	MDB_env *env = txn->mt_env;

-	MDB_IDL sl = txn->mt_spill_pgs;

-	MDB_ID pn = pg << 1;

-	int rc;

-

-	DPRINTF(("free ov page %"Y"u (%d)", pg, ovpages));

-	/* If the page is dirty or on the spill list we just acquired it,

-	 * so we should give it back to our current free list, if any.

-	 * Otherwise put it onto the list of pages we freed in this txn.

-	 *

-	 * Won't create me_pghead: me_pglast must be inited along with it.

-	 * Unsupported in nested txns: They would need to hide the page

-	 * range in ancestor txns' dirty and spilled lists.

-	 */

-	if (env->me_pghead &&

-		!txn->mt_parent &&

-		((mp->mp_flags & P_DIRTY) ||

-		 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))

-	{

-		unsigned i, j;

-		pgno_t *mop;

-		MDB_ID2 *dl, ix, iy;

-		rc = mdb_midl_need(&env->me_pghead, ovpages);

-		if (rc)

-			return rc;

-		if (!(mp->mp_flags & P_DIRTY)) {

-			/* This page is no longer spilled */

-			if (x == sl[0])

-				sl[0]--;

-			else

-				sl[x] |= 1;

-			goto release;

-		}

-		/* Remove from dirty list */

-		dl = txn->mt_u.dirty_list;

-		x = dl[0].mid--;

-		for (ix = dl[x]; ix.mptr != mp; ix = iy) {

-			if (x > 1) {

-				x--;

-				iy = dl[x];

-				dl[x] = ix;

-			} else {

-				mdb_cassert(mc, x > 1);

-				j = ++(dl[0].mid);

-				dl[j] = ix;		/* Unsorted. OK when MDB_TXN_ERROR. */

-				txn->mt_flags |= MDB_TXN_ERROR;

-				return MDB_CORRUPTED;

-			}

-		}

-		txn->mt_dirty_room++;

-		if (!(env->me_flags & MDB_WRITEMAP))

-			mdb_dpage_free(env, mp);

-release:

-		/* Insert in me_pghead */

-		mop = env->me_pghead;

-		j = mop[0] + ovpages;

-		for (i = mop[0]; i && mop[i] < pg; i--)

-			mop[j--] = mop[i];

-		while (j>i)

-			mop[j--] = pg++;

-		mop[0] += ovpages;

-	} else {

-		rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);

-		if (rc)

-			return rc;

-	}

-	mc->mc_db->md_overflow_pages -= ovpages;

-	return 0;

-}

-

-/** Return the data associated with a given node.

- * @param[in] mc The cursor for this operation.

- * @param[in] leaf The node being read.

- * @param[out] data Updated to point to the node's data.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data)

-{

-	MDB_page	*omp;		/* overflow page */

-	pgno_t		 pgno;

-	int rc;

-

-#ifdef MDB_VL32

-	if (mc->mc_ovpg) {

-		MDB_PAGE_UNREF(mc->mc_txn, mc->mc_ovpg);

-		mc->mc_ovpg = 0;

-	}

-#endif

-	if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {

-		data->mv_size = NODEDSZ(leaf);

-		data->mv_data = NODEDATA(leaf);

-		return MDB_SUCCESS;

-	}

-

-	/* Read overflow data.

-	 */

-	data->mv_size = NODEDSZ(leaf);

-	memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));

-	if ((rc = mdb_page_get(mc, pgno, &omp, NULL)) != 0) {

-		DPRINTF(("read overflow page %"Y"u failed", pgno));

-		return rc;

-	}

-	data->mv_data = METADATA(omp);

-#ifdef MDB_VL32

-	mc->mc_ovpg = omp;

-#endif

-

-	return MDB_SUCCESS;

-}

-

-int

-mdb_get(MDB_txn *txn, MDB_dbi dbi,

-    MDB_val *key, MDB_val *data)

-{

-	MDB_cursor	mc;

-	MDB_xcursor	mx;

-	int exact = 0, rc;

-	DKBUF;

-

-	DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));

-

-	if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))

-		return EINVAL;

-

-	if (txn->mt_flags & MDB_TXN_BLOCKED)

-		return MDB_BAD_TXN;

-

-	mdb_cursor_init(&mc, txn, dbi, &mx);

-	rc = mdb_cursor_set(&mc, key, data, MDB_SET, &exact);

-#ifdef MDB_VL32

-	{

-		/* unref all the pages - caller must copy the data

-		 * before doing anything else

-		 */

-		mdb_cursor_unref(&mc);

-	}

-#endif

-	return rc;

-}

-

-/** Find a sibling for a page.

- * Replaces the page at the top of the cursor's stack with the

- * specified sibling, if one exists.

- * @param[in] mc The cursor for this operation.

- * @param[in] move_right Non-zero if the right sibling is requested,

- * otherwise the left sibling.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_cursor_sibling(MDB_cursor *mc, int move_right)

-{

-	int		 rc;

-	MDB_node	*indx;

-	MDB_page	*mp;

-#ifdef MDB_VL32

-	MDB_page	*op;

-#endif

-

-	if (mc->mc_snum < 2) {

-		return MDB_NOTFOUND;		/* root has no siblings */

-	}

-

-#ifdef MDB_VL32

-	op = mc->mc_pg[mc->mc_top];

-#endif

-	mdb_cursor_pop(mc);

-	DPRINTF(("parent page is page %"Y"u, index %u",

-		mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));

-

-	if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))

-		       : (mc->mc_ki[mc->mc_top] == 0)) {

-		DPRINTF(("no more keys left, moving to %s sibling",

-		    move_right ? "right" : "left"));

-		if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {

-			/* undo cursor_pop before returning */

-			mc->mc_top++;

-			mc->mc_snum++;

-			return rc;

-		}

-	} else {

-		if (move_right)

-			mc->mc_ki[mc->mc_top]++;

-		else

-			mc->mc_ki[mc->mc_top]--;

-		DPRINTF(("just moving to %s index key %u",

-		    move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));

-	}

-	mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));

-

-	MDB_PAGE_UNREF(mc->mc_txn, op);

-

-	indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);

-	if ((rc = mdb_page_get(mc, NODEPGNO(indx), &mp, NULL)) != 0) {

-		/* mc will be inconsistent if caller does mc_snum++ as above */

-		mc->mc_flags &= ~(C_INITIALIZED|C_EOF);

-		return rc;

-	}

-

-	mdb_cursor_push(mc, mp);

-	if (!move_right)

-		mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;

-

-	return MDB_SUCCESS;

-}

-

-/** Move the cursor to the next data item. */

-static int

-mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)

-{

-	MDB_page	*mp;

-	MDB_node	*leaf;

-	int rc;

-

-	if (mc->mc_flags & C_EOF) {

-		return MDB_NOTFOUND;

-	}

-	if (!(mc->mc_flags & C_INITIALIZED))

-		return mdb_cursor_first(mc, key, data);

-

-	mp = mc->mc_pg[mc->mc_top];

-

-	if (mc->mc_db->md_flags & MDB_DUPSORT) {

-		leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);

-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-			if (op == MDB_NEXT || op == MDB_NEXT_DUP) {

-				rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);

-				if (op != MDB_NEXT || rc != MDB_NOTFOUND) {

-					if (rc == MDB_SUCCESS)

-						MDB_GET_KEY(leaf, key);

-					return rc;

-				}

-			}

-#ifdef MDB_VL32

-			else {

-				if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {

-					mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);

-				}

-			}

-#endif

-		} else {

-			mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);

-			if (op == MDB_NEXT_DUP)

-				return MDB_NOTFOUND;

-		}

-	}

-

-	DPRINTF(("cursor_next: top page is %"Y"u in cursor %p",

-		mdb_dbg_pgno(mp), (void *) mc));

-	if (mc->mc_flags & C_DEL) {

-		mc->mc_flags ^= C_DEL;

-		goto skip;

-	}

-

-	if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {

-		DPUTS("=====> move to next sibling page");

-		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {

-			mc->mc_flags |= C_EOF;

-			return rc;

-		}

-		mp = mc->mc_pg[mc->mc_top];

-		DPRINTF(("next page is %"Y"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));

-	} else

-		mc->mc_ki[mc->mc_top]++;

-

-skip:

-	DPRINTF(("==> cursor points to page %"Y"u with %u keys, key index %u",

-	    mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));

-

-	if (IS_LEAF2(mp)) {

-		key->mv_size = mc->mc_db->md_pad;

-		key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);

-		return MDB_SUCCESS;

-	}

-

-	mdb_cassert(mc, IS_LEAF(mp));

-	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);

-

-	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-		mdb_xcursor_init1(mc, leaf);

-	}

-	if (data) {

-		if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)

-			return rc;

-

-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-			rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);

-			if (rc != MDB_SUCCESS)

-				return rc;

-		}

-	}

-

-	MDB_GET_KEY(leaf, key);

-	return MDB_SUCCESS;

-}

-

-/** Move the cursor to the previous data item. */

-static int

-mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)

-{

-	MDB_page	*mp;

-	MDB_node	*leaf;

-	int rc;

-

-	if (!(mc->mc_flags & C_INITIALIZED)) {

-		rc = mdb_cursor_last(mc, key, data);

-		if (rc)

-			return rc;

-		mc->mc_ki[mc->mc_top]++;

-	}

-

-	mp = mc->mc_pg[mc->mc_top];

-

-	if (mc->mc_db->md_flags & MDB_DUPSORT) {

-		leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);

-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-			if (op == MDB_PREV || op == MDB_PREV_DUP) {

-				rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);

-				if (op != MDB_PREV || rc != MDB_NOTFOUND) {

-					if (rc == MDB_SUCCESS) {

-						MDB_GET_KEY(leaf, key);

-						mc->mc_flags &= ~C_EOF;

-					}

-					return rc;

-				}

-			}

-#ifdef MDB_VL32

-			else {

-				if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {

-					mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);

-				}

-			}

-#endif

-		} else {

-			mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);

-			if (op == MDB_PREV_DUP)

-				return MDB_NOTFOUND;

-		}

-	}

-

-	DPRINTF(("cursor_prev: top page is %"Y"u in cursor %p",

-		mdb_dbg_pgno(mp), (void *) mc));

-

-	mc->mc_flags &= ~(C_EOF|C_DEL);

-

-	if (mc->mc_ki[mc->mc_top] == 0)  {

-		DPUTS("=====> move to prev sibling page");

-		if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {

-			return rc;

-		}

-		mp = mc->mc_pg[mc->mc_top];

-		mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;

-		DPRINTF(("prev page is %"Y"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));

-	} else

-		mc->mc_ki[mc->mc_top]--;

-

-	mc->mc_flags &= ~C_EOF;

-

-	DPRINTF(("==> cursor points to page %"Y"u with %u keys, key index %u",

-	    mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));

-

-	if (IS_LEAF2(mp)) {

-		key->mv_size = mc->mc_db->md_pad;

-		key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);

-		return MDB_SUCCESS;

-	}

-

-	mdb_cassert(mc, IS_LEAF(mp));

-	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);

-

-	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-		mdb_xcursor_init1(mc, leaf);

-	}

-	if (data) {

-		if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)

-			return rc;

-

-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-			rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);

-			if (rc != MDB_SUCCESS)

-				return rc;

-		}

-	}

-

-	MDB_GET_KEY(leaf, key);

-	return MDB_SUCCESS;

-}

-

-/** Set the cursor on a specific data item. */

-static int

-mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,

-    MDB_cursor_op op, int *exactp)

-{

-	int		 rc;

-	MDB_page	*mp;

-	MDB_node	*leaf = NULL;

-	DKBUF;

-

-	if (key->mv_size == 0)

-		return MDB_BAD_VALSIZE;

-

-	if (mc->mc_xcursor)

-		mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);

-

-	/* See if we're already on the right page */

-	if (mc->mc_flags & C_INITIALIZED) {

-		MDB_val nodekey;

-

-		mp = mc->mc_pg[mc->mc_top];

-		if (!NUMKEYS(mp)) {

-			mc->mc_ki[mc->mc_top] = 0;

-			return MDB_NOTFOUND;

-		}

-		if (mp->mp_flags & P_LEAF2) {

-			nodekey.mv_size = mc->mc_db->md_pad;

-			nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);

-		} else {

-			leaf = NODEPTR(mp, 0);

-			MDB_GET_KEY2(leaf, nodekey);

-		}

-		rc = mc->mc_dbx->md_cmp(key, &nodekey);

-		if (rc == 0) {

-			/* Probably happens rarely, but first node on the page

-			 * was the one we wanted.

-			 */

-			mc->mc_ki[mc->mc_top] = 0;

-			if (exactp)

-				*exactp = 1;

-			goto set1;

-		}

-		if (rc > 0) {

-			unsigned int i;

-			unsigned int nkeys = NUMKEYS(mp);

-			if (nkeys > 1) {

-				if (mp->mp_flags & P_LEAF2) {

-					nodekey.mv_data = LEAF2KEY(mp,

-						 nkeys-1, nodekey.mv_size);

-				} else {

-					leaf = NODEPTR(mp, nkeys-1);

-					MDB_GET_KEY2(leaf, nodekey);

-				}

-				rc = mc->mc_dbx->md_cmp(key, &nodekey);

-				if (rc == 0) {

-					/* last node was the one we wanted */

-					mc->mc_ki[mc->mc_top] = nkeys-1;

-					if (exactp)

-						*exactp = 1;

-					goto set1;

-				}

-				if (rc < 0) {

-					if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {

-						/* This is definitely the right page, skip search_page */

-						if (mp->mp_flags & P_LEAF2) {

-							nodekey.mv_data = LEAF2KEY(mp,

-								 mc->mc_ki[mc->mc_top], nodekey.mv_size);

-						} else {

-							leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);

-							MDB_GET_KEY2(leaf, nodekey);

-						}

-						rc = mc->mc_dbx->md_cmp(key, &nodekey);

-						if (rc == 0) {

-							/* current node was the one we wanted */

-							if (exactp)

-								*exactp = 1;

-							goto set1;

-						}

-					}

-					rc = 0;

-					goto set2;

-				}

-			}

-			/* If any parents have right-sibs, search.

-			 * Otherwise, there's nothing further.

-			 */

-			for (i=0; i<mc->mc_top; i++)

-				if (mc->mc_ki[i] <

-					NUMKEYS(mc->mc_pg[i])-1)

-					break;

-			if (i == mc->mc_top) {

-				/* There are no other pages */

-				mc->mc_ki[mc->mc_top] = nkeys;

-				return MDB_NOTFOUND;

-			}

-		}

-		if (!mc->mc_top) {

-			/* There are no other pages */

-			mc->mc_ki[mc->mc_top] = 0;

-			if (op == MDB_SET_RANGE && !exactp) {

-				rc = 0;

-				goto set1;

-			} else

-				return MDB_NOTFOUND;

-		}

-	} else {

-		mc->mc_pg[0] = 0;

-	}

-

-	rc = mdb_page_search(mc, key, 0);

-	if (rc != MDB_SUCCESS)

-		return rc;

-

-	mp = mc->mc_pg[mc->mc_top];

-	mdb_cassert(mc, IS_LEAF(mp));

-

-set2:

-	leaf = mdb_node_search(mc, key, exactp);

-	if (exactp != NULL && !*exactp) {

-		/* MDB_SET specified and not an exact match. */

-		return MDB_NOTFOUND;

-	}

-

-	if (leaf == NULL) {

-		DPUTS("===> inexact leaf not found, goto sibling");

-		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {

-			mc->mc_flags |= C_EOF;

-			return rc;		/* no entries matched */

-		}

-		mp = mc->mc_pg[mc->mc_top];

-		mdb_cassert(mc, IS_LEAF(mp));

-		leaf = NODEPTR(mp, 0);

-	}

-

-set1:

-	mc->mc_flags |= C_INITIALIZED;

-	mc->mc_flags &= ~C_EOF;

-

-	if (IS_LEAF2(mp)) {

-		if (op == MDB_SET_RANGE || op == MDB_SET_KEY) {

-			key->mv_size = mc->mc_db->md_pad;

-			key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);

-		}

-		return MDB_SUCCESS;

-	}

-

-#ifdef MDB_VL32

-	if (mc->mc_xcursor && mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {

-		mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);

-	}

-#endif

-	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-		mdb_xcursor_init1(mc, leaf);

-	}

-	if (data) {

-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-			if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {

-				rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);

-			} else {

-				int ex2, *ex2p;

-				if (op == MDB_GET_BOTH) {

-					ex2p = &ex2;

-					ex2 = 0;

-				} else {

-					ex2p = NULL;

-				}

-				rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);

-				if (rc != MDB_SUCCESS)

-					return rc;

-			}

-		} else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {

-			MDB_val olddata;

-			MDB_cmp_func *dcmp;

-			if ((rc = mdb_node_read(mc, leaf, &olddata)) != MDB_SUCCESS)

-				return rc;

-			dcmp = mc->mc_dbx->md_dcmp;

-#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)

-			if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(mdb_size_t))

-				dcmp = mdb_cmp_clong;

-#endif

-			rc = dcmp(data, &olddata);

-			if (rc) {

-				if (op == MDB_GET_BOTH || rc > 0)

-					return MDB_NOTFOUND;

-				rc = 0;

-			}

-			*data = olddata;

-

-		} else {

-			if (mc->mc_xcursor)

-				mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);

-			if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)

-				return rc;

-		}

-	}

-

-	/* The key already matches in all other cases */

-	if (op == MDB_SET_RANGE || op == MDB_SET_KEY)

-		MDB_GET_KEY(leaf, key);

-	DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));

-

-	return rc;

-}

-

-/** Move the cursor to the first item in the database. */

-static int

-mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)

-{

-	int		 rc;

-	MDB_node	*leaf;

-

-	if (mc->mc_xcursor) {

-#ifdef MDB_VL32

-		if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {

-			mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);

-		}

-#endif

-		mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);

-	}

-

-	if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {

-		rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);

-		if (rc != MDB_SUCCESS)

-			return rc;

-	}

-	mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));

-

-	leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);

-	mc->mc_flags |= C_INITIALIZED;

-	mc->mc_flags &= ~C_EOF;

-

-	mc->mc_ki[mc->mc_top] = 0;

-

-	if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {

-		key->mv_size = mc->mc_db->md_pad;

-		key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);

-		return MDB_SUCCESS;

-	}

-

-	if (data) {

-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-			mdb_xcursor_init1(mc, leaf);

-			rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);

-			if (rc)

-				return rc;

-		} else {

-			if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)

-				return rc;

-		}

-	}

-	MDB_GET_KEY(leaf, key);

-	return MDB_SUCCESS;

-}

-

-/** Move the cursor to the last item in the database. */

-static int

-mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)

-{

-	int		 rc;

-	MDB_node	*leaf;

-

-	if (mc->mc_xcursor) {

-#ifdef MDB_VL32

-		if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {

-			mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);

-		}

-#endif

-		mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);

-	}

-

-	if (!(mc->mc_flags & C_EOF)) {

-

-		if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {

-			rc = mdb_page_search(mc, NULL, MDB_PS_LAST);

-			if (rc != MDB_SUCCESS)

-				return rc;

-		}

-		mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));

-

-	}

-	mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;

-	mc->mc_flags |= C_INITIALIZED|C_EOF;

-	leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);

-

-	if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {

-		key->mv_size = mc->mc_db->md_pad;

-		key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);

-		return MDB_SUCCESS;

-	}

-

-	if (data) {

-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-			mdb_xcursor_init1(mc, leaf);

-			rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);

-			if (rc)

-				return rc;

-		} else {

-			if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)

-				return rc;

-		}

-	}

-

-	MDB_GET_KEY(leaf, key);

-	return MDB_SUCCESS;

-}

-

-int

-mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,

-    MDB_cursor_op op)

-{

-	int		 rc;

-	int		 exact = 0;

-	int		 (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);

-

-	if (mc == NULL)

-		return EINVAL;

-

-	if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)

-		return MDB_BAD_TXN;

-

-	switch (op) {

-	case MDB_GET_CURRENT:

-		if (!(mc->mc_flags & C_INITIALIZED)) {

-			rc = EINVAL;

-		} else {

-			MDB_page *mp = mc->mc_pg[mc->mc_top];

-			int nkeys = NUMKEYS(mp);

-			if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {

-				mc->mc_ki[mc->mc_top] = nkeys;

-				rc = MDB_NOTFOUND;

-				break;

-			}

-			rc = MDB_SUCCESS;

-			if (IS_LEAF2(mp)) {

-				key->mv_size = mc->mc_db->md_pad;

-				key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);

-			} else {

-				MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);

-				MDB_GET_KEY(leaf, key);

-				if (data) {

-					if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-						rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);

-					} else {

-						rc = mdb_node_read(mc, leaf, data);

-					}

-				}

-			}

-		}

-		break;

-	case MDB_GET_BOTH:

-	case MDB_GET_BOTH_RANGE:

-		if (data == NULL) {

-			rc = EINVAL;

-			break;

-		}

-		if (mc->mc_xcursor == NULL) {

-			rc = MDB_INCOMPATIBLE;

-			break;

-		}

-		/* FALLTHRU */

-	case MDB_SET:

-	case MDB_SET_KEY:

-	case MDB_SET_RANGE:

-		if (key == NULL) {

-			rc = EINVAL;

-		} else {

-			rc = mdb_cursor_set(mc, key, data, op,

-				op == MDB_SET_RANGE ? NULL : &exact);

-		}

-		break;

-	case MDB_GET_MULTIPLE:

-		if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {

-			rc = EINVAL;

-			break;

-		}

-		if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {

-			rc = MDB_INCOMPATIBLE;

-			break;

-		}

-		rc = MDB_SUCCESS;

-		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||

-			(mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))

-			break;

-		goto fetchm;

-	case MDB_NEXT_MULTIPLE:

-		if (data == NULL) {

-			rc = EINVAL;

-			break;

-		}

-		if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {

-			rc = MDB_INCOMPATIBLE;

-			break;

-		}

-		rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);

-		if (rc == MDB_SUCCESS) {

-			if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {

-				MDB_cursor *mx;

-fetchm:

-				mx = &mc->mc_xcursor->mx_cursor;

-				data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *

-					mx->mc_db->md_pad;

-				data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);

-				mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;

-			} else {

-				rc = MDB_NOTFOUND;

-			}

-		}

-		break;

-	case MDB_PREV_MULTIPLE:

-		if (data == NULL) {

-			rc = EINVAL;

-			break;

-		}

-		if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {

-			rc = MDB_INCOMPATIBLE;

-			break;

-		}

-		if (!(mc->mc_flags & C_INITIALIZED))

-			rc = mdb_cursor_last(mc, key, data);

-		else

-			rc = MDB_SUCCESS;

-		if (rc == MDB_SUCCESS) {

-			MDB_cursor *mx = &mc->mc_xcursor->mx_cursor;

-			if (mx->mc_flags & C_INITIALIZED) {

-				rc = mdb_cursor_sibling(mx, 0);

-				if (rc == MDB_SUCCESS)

-					goto fetchm;

-			} else {

-				rc = MDB_NOTFOUND;

-			}

-		}

-		break;

-	case MDB_NEXT:

-	case MDB_NEXT_DUP:

-	case MDB_NEXT_NODUP:

-		rc = mdb_cursor_next(mc, key, data, op);

-		break;

-	case MDB_PREV:

-	case MDB_PREV_DUP:

-	case MDB_PREV_NODUP:

-		rc = mdb_cursor_prev(mc, key, data, op);

-		break;

-	case MDB_FIRST:

-		rc = mdb_cursor_first(mc, key, data);

-		break;

-	case MDB_FIRST_DUP:

-		mfunc = mdb_cursor_first;

-	mmove:

-		if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {

-			rc = EINVAL;

-			break;

-		}

-		if (mc->mc_xcursor == NULL) {

-			rc = MDB_INCOMPATIBLE;

-			break;

-		}

-		{

-			MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);

-			if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-				MDB_GET_KEY(leaf, key);

-				rc = mdb_node_read(mc, leaf, data);

-				break;

-			}

-		}

-		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {

-			rc = EINVAL;

-			break;

-		}

-		rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);

-		break;

-	case MDB_LAST:

-		rc = mdb_cursor_last(mc, key, data);

-		break;

-	case MDB_LAST_DUP:

-		mfunc = mdb_cursor_last;

-		goto mmove;

-	default:

-		DPRINTF(("unhandled/unimplemented cursor operation %u", op));

-		rc = EINVAL;

-		break;

-	}

-

-	if (mc->mc_flags & C_DEL)

-		mc->mc_flags ^= C_DEL;

-

-	return rc;

-}

-

-/** Touch all the pages in the cursor stack. Set mc_top.

- *	Makes sure all the pages are writable, before attempting a write operation.

- * @param[in] mc The cursor to operate on.

- */

-static int

-mdb_cursor_touch(MDB_cursor *mc)

-{

-	int rc = MDB_SUCCESS;

-

-	if (mc->mc_dbi >= CORE_DBS && !(*mc->mc_dbflag & DB_DIRTY)) {

-		MDB_cursor mc2;

-		MDB_xcursor mcx;

-		if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))

-			return MDB_BAD_DBI;

-		mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);

-		rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);

-		if (rc)

-			 return rc;

-		*mc->mc_dbflag |= DB_DIRTY;

-	}

-	mc->mc_top = 0;

-	if (mc->mc_snum) {

-		do {

-			rc = mdb_page_touch(mc);

-		} while (!rc && ++(mc->mc_top) < mc->mc_snum);

-		mc->mc_top = mc->mc_snum-1;

-	}

-	return rc;

-}

-

-/** Do not spill pages to disk if txn is getting full, may fail instead */

-#define MDB_NOSPILL	0x8000

-

-int

-mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,

-    unsigned int flags)

-{

-	MDB_env		*env;

-	MDB_node	*leaf = NULL;

-	MDB_page	*fp, *mp, *sub_root = NULL;

-	uint16_t	fp_flags;

-	MDB_val		xdata, *rdata, dkey, olddata;

-	MDB_db dummy;

-	int do_sub = 0, insert_key, insert_data;

-	unsigned int mcount = 0, dcount = 0, nospill;

-	size_t nsize;

-	int rc, rc2;

-	unsigned int nflags;

-	DKBUF;

-

-	if (mc == NULL || key == NULL)

-		return EINVAL;

-

-	env = mc->mc_txn->mt_env;

-

-	/* Check this first so counter will always be zero on any

-	 * early failures.

-	 */

-	if (flags & MDB_MULTIPLE) {

-		dcount = data[1].mv_size;

-		data[1].mv_size = 0;

-		if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))

-			return MDB_INCOMPATIBLE;

-	}

-

-	nospill = flags & MDB_NOSPILL;

-	flags &= ~MDB_NOSPILL;

-

-	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))

-		return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;

-

-	if (key->mv_size-1 >= ENV_MAXKEY(env))

-		return MDB_BAD_VALSIZE;

-

-#if SIZE_MAX > MAXDATASIZE

-	if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))

-		return MDB_BAD_VALSIZE;

-#else

-	if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env))

-		return MDB_BAD_VALSIZE;

-#endif

-

-	DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",

-		DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));

-

-	dkey.mv_size = 0;

-

-	if (flags == MDB_CURRENT) {

-		if (!(mc->mc_flags & C_INITIALIZED))

-			return EINVAL;

-		rc = MDB_SUCCESS;

-	} else if (mc->mc_db->md_root == P_INVALID) {

-		/* new database, cursor has nothing to point to */

-		mc->mc_snum = 0;

-		mc->mc_top = 0;

-		mc->mc_flags &= ~C_INITIALIZED;

-		rc = MDB_NO_ROOT;

-	} else {

-		int exact = 0;

-		MDB_val d2;

-		if (flags & MDB_APPEND) {

-			MDB_val k2;

-			rc = mdb_cursor_last(mc, &k2, &d2);

-			if (rc == 0) {

-				rc = mc->mc_dbx->md_cmp(key, &k2);

-				if (rc > 0) {

-					rc = MDB_NOTFOUND;

-					mc->mc_ki[mc->mc_top]++;

-				} else {

-					/* new key is <= last key */

-					rc = MDB_KEYEXIST;

-				}

-			}

-		} else {

-			rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);

-		}

-		if ((flags & MDB_NOOVERWRITE) && rc == 0) {

-			DPRINTF(("duplicate key [%s]", DKEY(key)));

-			*data = d2;

-			return MDB_KEYEXIST;

-		}

-		if (rc && rc != MDB_NOTFOUND)

-			return rc;

-	}

-

-	if (mc->mc_flags & C_DEL)

-		mc->mc_flags ^= C_DEL;

-

-	/* Cursor is positioned, check for room in the dirty list */

-	if (!nospill) {

-		if (flags & MDB_MULTIPLE) {

-			rdata = &xdata;

-			xdata.mv_size = data->mv_size * dcount;

-		} else {

-			rdata = data;

-		}

-		if ((rc2 = mdb_page_spill(mc, key, rdata)))

-			return rc2;

-	}

-

-	if (rc == MDB_NO_ROOT) {

-		MDB_page *np;

-		/* new database, write a root leaf page */

-		DPUTS("allocating new root leaf page");

-		if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {

-			return rc2;

-		}

-		mdb_cursor_push(mc, np);

-		mc->mc_db->md_root = np->mp_pgno;

-		mc->mc_db->md_depth++;

-		*mc->mc_dbflag |= DB_DIRTY;

-		if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))

-			== MDB_DUPFIXED)

-			np->mp_flags |= P_LEAF2;

-		mc->mc_flags |= C_INITIALIZED;

-	} else {

-		/* make sure all cursor pages are writable */

-		rc2 = mdb_cursor_touch(mc);

-		if (rc2)

-			return rc2;

-	}

-

-	insert_key = insert_data = rc;

-	if (insert_key) {

-		/* The key does not exist */

-		DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));

-		if ((mc->mc_db->md_flags & MDB_DUPSORT) &&

-			LEAFSIZE(key, data) > env->me_nodemax)

-		{

-			/* Too big for a node, insert in sub-DB.  Set up an empty

-			 * "old sub-page" for prep_subDB to expand to a full page.

-			 */

-			fp_flags = P_LEAF|P_DIRTY;

-			fp = env->me_pbuf;

-			fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */

-			fp->mp_lower = fp->mp_upper = (PAGEHDRSZ-PAGEBASE);

-			olddata.mv_size = PAGEHDRSZ;

-			goto prep_subDB;

-		}

-	} else {

-		/* there's only a key anyway, so this is a no-op */

-		if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {

-			char *ptr;

-			unsigned int ksize = mc->mc_db->md_pad;

-			if (key->mv_size != ksize)

-				return MDB_BAD_VALSIZE;

-			ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);

-			memcpy(ptr, key->mv_data, ksize);

-fix_parent:

-			/* if overwriting slot 0 of leaf, need to

-			 * update branch key if there is a parent page

-			 */

-			if (mc->mc_top && !mc->mc_ki[mc->mc_top]) {

-				unsigned short dtop = 1;

-				mc->mc_top--;

-				/* slot 0 is always an empty key, find real slot */

-				while (mc->mc_top && !mc->mc_ki[mc->mc_top]) {

-					mc->mc_top--;

-					dtop++;

-				}

-				if (mc->mc_ki[mc->mc_top])

-					rc2 = mdb_update_key(mc, key);

-				else

-					rc2 = MDB_SUCCESS;

-				mc->mc_top += dtop;

-				if (rc2)

-					return rc2;

-			}

-			return MDB_SUCCESS;

-		}

-

-more:

-		leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);

-		olddata.mv_size = NODEDSZ(leaf);

-		olddata.mv_data = NODEDATA(leaf);

-

-		/* DB has dups? */

-		if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {

-			/* Prepare (sub-)page/sub-DB to accept the new item,

-			 * if needed.  fp: old sub-page or a header faking

-			 * it.  mp: new (sub-)page.  offset: growth in page

-			 * size.  xdata: node data with new page or DB.

-			 */

-			unsigned	i, offset = 0;

-			mp = fp = xdata.mv_data = env->me_pbuf;

-			mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;

-

-			/* Was a single item before, must convert now */

-			if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-				MDB_cmp_func *dcmp;

-				/* Just overwrite the current item */

-				if (flags == MDB_CURRENT)

-					goto current;

-				dcmp = mc->mc_dbx->md_dcmp;

-#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)

-				if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(mdb_size_t))

-					dcmp = mdb_cmp_clong;

-#endif

-				/* does data match? */

-				if (!dcmp(data, &olddata)) {

-					if (flags & (MDB_NODUPDATA|MDB_APPENDDUP))

-						return MDB_KEYEXIST;

-					/* overwrite it */

-					goto current;

-				}

-

-				/* Back up original data item */

-				dkey.mv_size = olddata.mv_size;

-				dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);

-

-				/* Make sub-page header for the dup items, with dummy body */

-				fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;

-				fp->mp_lower = (PAGEHDRSZ-PAGEBASE);

-				xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;

-				if (mc->mc_db->md_flags & MDB_DUPFIXED) {

-					fp->mp_flags |= P_LEAF2;

-					fp->mp_pad = data->mv_size;

-					xdata.mv_size += 2 * data->mv_size;	/* leave space for 2 more */

-				} else {

-					xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +

-						(dkey.mv_size & 1) + (data->mv_size & 1);

-				}

-				fp->mp_upper = xdata.mv_size - PAGEBASE;

-				olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */

-			} else if (leaf->mn_flags & F_SUBDATA) {

-				/* Data is on sub-DB, just store it */

-				flags |= F_DUPDATA|F_SUBDATA;

-				goto put_sub;

-			} else {

-				/* Data is on sub-page */

-				fp = olddata.mv_data;

-				switch (flags) {

-				default:

-					if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {

-						offset = EVEN(NODESIZE + sizeof(indx_t) +

-							data->mv_size);

-						break;

-					}

-					offset = fp->mp_pad;

-					if (SIZELEFT(fp) < offset) {

-						offset *= 4; /* space for 4 more */

-						break;

-					}

-					/* FALLTHRU: Big enough MDB_DUPFIXED sub-page */

-				case MDB_CURRENT:

-					fp->mp_flags |= P_DIRTY;

-					COPY_PGNO(fp->mp_pgno, mp->mp_pgno);

-					mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;

-					flags |= F_DUPDATA;

-					goto put_sub;

-				}

-				xdata.mv_size = olddata.mv_size + offset;

-			}

-

-			fp_flags = fp->mp_flags;

-			if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {

-					/* Too big for a sub-page, convert to sub-DB */

-					fp_flags &= ~P_SUBP;

-prep_subDB:

-					if (mc->mc_db->md_flags & MDB_DUPFIXED) {

-						fp_flags |= P_LEAF2;

-						dummy.md_pad = fp->mp_pad;

-						dummy.md_flags = MDB_DUPFIXED;

-						if (mc->mc_db->md_flags & MDB_INTEGERDUP)

-							dummy.md_flags |= MDB_INTEGERKEY;

-					} else {

-						dummy.md_pad = 0;

-						dummy.md_flags = 0;

-					}

-					dummy.md_depth = 1;

-					dummy.md_branch_pages = 0;

-					dummy.md_leaf_pages = 1;

-					dummy.md_overflow_pages = 0;

-					dummy.md_entries = NUMKEYS(fp);

-					xdata.mv_size = sizeof(MDB_db);

-					xdata.mv_data = &dummy;

-					if ((rc = mdb_page_alloc(mc, 1, &mp)))

-						return rc;

-					offset = env->me_psize - olddata.mv_size;

-					flags |= F_DUPDATA|F_SUBDATA;

-					dummy.md_root = mp->mp_pgno;

-					sub_root = mp;

-			}

-			if (mp != fp) {

-				mp->mp_flags = fp_flags | P_DIRTY;

-				mp->mp_pad   = fp->mp_pad;

-				mp->mp_lower = fp->mp_lower;

-				mp->mp_upper = fp->mp_upper + offset;

-				if (fp_flags & P_LEAF2) {

-					memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);

-				} else {

-					memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE,

-						olddata.mv_size - fp->mp_upper - PAGEBASE);

-					for (i=0; i<NUMKEYS(fp); i++)

-						mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;

-				}

-			}

-

-			rdata = &xdata;

-			flags |= F_DUPDATA;

-			do_sub = 1;

-			if (!insert_key)

-				mdb_node_del(mc, 0);

-			goto new_sub;

-		}

-current:

-		/* LMDB passes F_SUBDATA in 'flags' to write a DB record */

-		if ((leaf->mn_flags ^ flags) & F_SUBDATA)

-			return MDB_INCOMPATIBLE;

-		/* overflow page overwrites need special handling */

-		if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {

-			MDB_page *omp;

-			pgno_t pg;

-			int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);

-

-			memcpy(&pg, olddata.mv_data, sizeof(pg));

-			if ((rc2 = mdb_page_get(mc, pg, &omp, &level)) != 0)

-				return rc2;

-			ovpages = omp->mp_pages;

-

-			/* Is the ov page large enough? */

-			if (ovpages >= dpages) {

-			  if (!(omp->mp_flags & P_DIRTY) &&

-				  (level || (env->me_flags & MDB_WRITEMAP)))

-			  {

-				rc = mdb_page_unspill(mc->mc_txn, omp, &omp);

-				if (rc)

-					return rc;

-				level = 0;		/* dirty in this txn or clean */

-			  }

-			  /* Is it dirty? */

-			  if (omp->mp_flags & P_DIRTY) {

-				/* yes, overwrite it. Note in this case we don't

-				 * bother to try shrinking the page if the new data

-				 * is smaller than the overflow threshold.

-				 */

-				if (level > 1) {

-					/* It is writable only in a parent txn */

-					size_t sz = (size_t) env->me_psize * ovpages, off;

-					MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);

-					MDB_ID2 id2;

-					if (!np)

-						return ENOMEM;

-					id2.mid = pg;

-					id2.mptr = np;

-					/* Note - this page is already counted in parent's dirty_room */

-					rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);

-					mdb_cassert(mc, rc2 == 0);

-					if (!(flags & MDB_RESERVE)) {

-						/* Copy end of page, adjusting alignment so

-						 * compiler may copy words instead of bytes.

-						 */

-						off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);

-						memcpy((size_t *)((char *)np + off),

-							(size_t *)((char *)omp + off), sz - off);

-						sz = PAGEHDRSZ;

-					}

-					memcpy(np, omp, sz); /* Copy beginning of page */

-					omp = np;

-				}

-				SETDSZ(leaf, data->mv_size);

-				if (F_ISSET(flags, MDB_RESERVE))

-					data->mv_data = METADATA(omp);

-				else

-					memcpy(METADATA(omp), data->mv_data, data->mv_size);

-				return MDB_SUCCESS;

-			  }

-			}

-			if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)

-				return rc2;

-		} else if (data->mv_size == olddata.mv_size) {

-			/* same size, just replace it. Note that we could

-			 * also reuse this node if the new data is smaller,

-			 * but instead we opt to shrink the node in that case.

-			 */

-			if (F_ISSET(flags, MDB_RESERVE))

-				data->mv_data = olddata.mv_data;

-			else if (!(mc->mc_flags & C_SUB))

-				memcpy(olddata.mv_data, data->mv_data, data->mv_size);

-			else {

-				memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);

-				goto fix_parent;

-			}

-			return MDB_SUCCESS;

-		}

-		mdb_node_del(mc, 0);

-	}

-

-	rdata = data;

-

-new_sub:

-	nflags = flags & NODE_ADD_FLAGS;

-	nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);

-	if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {

-		if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )

-			nflags &= ~MDB_APPEND; /* sub-page may need room to grow */

-		if (!insert_key)

-			nflags |= MDB_SPLIT_REPLACE;

-		rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);

-	} else {

-		/* There is room already in this leaf page. */

-		rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);

-		if (rc == 0) {

-			/* Adjust other cursors pointing to mp */

-			MDB_cursor *m2, *m3;

-			MDB_dbi dbi = mc->mc_dbi;

-			unsigned i = mc->mc_top;

-			MDB_page *mp = mc->mc_pg[i];

-

-			for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {

-				if (mc->mc_flags & C_SUB)

-					m3 = &m2->mc_xcursor->mx_cursor;

-				else

-					m3 = m2;

-				if (m3 == mc || m3->mc_snum < mc->mc_snum || m3->mc_pg[i] != mp) continue;

-				if (m3->mc_ki[i] >= mc->mc_ki[i] && insert_key) {

-					m3->mc_ki[i]++;

-				}

-				if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {

-					MDB_node *n2 = NODEPTR(mp, m3->mc_ki[i]);

-					if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)

-						m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);

-				}

-			}

-		}

-	}

-

-	if (rc == MDB_SUCCESS) {

-		/* Now store the actual data in the child DB. Note that we're

-		 * storing the user data in the keys field, so there are strict

-		 * size limits on dupdata. The actual data fields of the child

-		 * DB are all zero size.

-		 */

-		if (do_sub) {

-			int xflags, new_dupdata;

-			mdb_size_t ecount;

-put_sub:

-			xdata.mv_size = 0;

-			xdata.mv_data = "";

-			leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);

-			if (flags & MDB_CURRENT) {

-				xflags = MDB_CURRENT|MDB_NOSPILL;

-			} else {

-				mdb_xcursor_init1(mc, leaf);

-				xflags = (flags & MDB_NODUPDATA) ?

-					MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;

-			}

-			if (sub_root)

-				mc->mc_xcursor->mx_cursor.mc_pg[0] = sub_root;

-			new_dupdata = (int)dkey.mv_size;

-			/* converted, write the original data first */

-			if (dkey.mv_size) {

-				rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);

-				if (rc)

-					goto bad_sub;

-				/* we've done our job */

-				dkey.mv_size = 0;

-			}

-			if (!(leaf->mn_flags & F_SUBDATA) || sub_root) {

-				/* Adjust other cursors pointing to mp */

-				MDB_cursor *m2;

-				MDB_xcursor *mx = mc->mc_xcursor;

-				unsigned i = mc->mc_top;

-				MDB_page *mp = mc->mc_pg[i];

-				int nkeys = NUMKEYS(mp);

-

-				for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {

-					if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;

-					if (!(m2->mc_flags & C_INITIALIZED)) continue;

-					if (m2->mc_pg[i] == mp) {

-						if (m2->mc_ki[i] == mc->mc_ki[i]) {

-							mdb_xcursor_init2(m2, mx, new_dupdata);

-						} else if (!insert_key && m2->mc_ki[i] < nkeys) {

-							MDB_node *n2 = NODEPTR(mp, m2->mc_ki[i]);

-							if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)

-								m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);

-						}

-					}

-				}

-			}

-			ecount = mc->mc_xcursor->mx_db.md_entries;

-			if (flags & MDB_APPENDDUP)

-				xflags |= MDB_APPEND;

-			rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);

-			if (flags & F_SUBDATA) {

-				void *db = NODEDATA(leaf);

-				memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));

-			}

-			insert_data = mc->mc_xcursor->mx_db.md_entries - ecount;

-		}

-		/* Increment count unless we just replaced an existing item. */

-		if (insert_data)

-			mc->mc_db->md_entries++;

-		if (insert_key) {

-			/* Invalidate txn if we created an empty sub-DB */

-			if (rc)

-				goto bad_sub;

-			/* If we succeeded and the key didn't exist before,

-			 * make sure the cursor is marked valid.

-			 */

-			mc->mc_flags |= C_INITIALIZED;

-		}

-		if (flags & MDB_MULTIPLE) {

-			if (!rc) {

-				mcount++;

-				/* let caller know how many succeeded, if any */

-				data[1].mv_size = mcount;

-				if (mcount < dcount) {

-					data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;

-					insert_key = insert_data = 0;

-					goto more;

-				}

-			}

-		}

-		return rc;

-bad_sub:

-		if (rc == MDB_KEYEXIST)	/* should not happen, we deleted that item */

-			rc = MDB_CORRUPTED;

-	}

-	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;

-	return rc;

-}

-

-int

-mdb_cursor_del(MDB_cursor *mc, unsigned int flags)

-{

-	MDB_node	*leaf;

-	MDB_page	*mp;

-	int rc;

-

-	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))

-		return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;

-

-	if (!(mc->mc_flags & C_INITIALIZED))

-		return EINVAL;

-

-	if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))

-		return MDB_NOTFOUND;

-

-	if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))

-		return rc;

-

-	rc = mdb_cursor_touch(mc);

-	if (rc)

-		return rc;

-

-	mp = mc->mc_pg[mc->mc_top];

-	if (IS_LEAF2(mp))

-		goto del_key;

-	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);

-

-	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-		if (flags & MDB_NODUPDATA) {

-			/* mdb_cursor_del0() will subtract the final entry */

-			mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;

-			mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;

-		} else {

-			if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {

-				mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);

-			}

-			rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);

-			if (rc)

-				return rc;

-			/* If sub-DB still has entries, we're done */

-			if (mc->mc_xcursor->mx_db.md_entries) {

-				if (leaf->mn_flags & F_SUBDATA) {

-					/* update subDB info */

-					void *db = NODEDATA(leaf);

-					memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));

-				} else {

-					MDB_cursor *m2;

-					/* shrink fake page */

-					mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);

-					leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);

-					mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);

-					/* fix other sub-DB cursors pointed at fake pages on this page */

-					for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {

-						if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;

-						if (!(m2->mc_flags & C_INITIALIZED)) continue;

-						if (m2->mc_pg[mc->mc_top] == mp) {

-							if (m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top]) {

-								m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);

-							} else {

-								MDB_node *n2 = NODEPTR(mp, m2->mc_ki[mc->mc_top]);

-								if (!(n2->mn_flags & F_SUBDATA))

-									m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);

-							}

-						}

-					}

-				}

-				mc->mc_db->md_entries--;

-				return rc;

-			} else {

-				mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;

-			}

-			/* otherwise fall thru and delete the sub-DB */

-		}

-

-		if (leaf->mn_flags & F_SUBDATA) {

-			/* add all the child DB's pages to the free list */

-			rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);

-			if (rc)

-				goto fail;

-		}

-	}

-	/* LMDB passes F_SUBDATA in 'flags' to delete a DB record */

-	else if ((leaf->mn_flags ^ flags) & F_SUBDATA) {

-		rc = MDB_INCOMPATIBLE;

-		goto fail;

-	}

-

-	/* add overflow pages to free list */

-	if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {

-		MDB_page *omp;

-		pgno_t pg;

-

-		memcpy(&pg, NODEDATA(leaf), sizeof(pg));

-		if ((rc = mdb_page_get(mc, pg, &omp, NULL)) ||

-			(rc = mdb_ovpage_free(mc, omp)))

-			goto fail;

-	}

-

-del_key:

-	return mdb_cursor_del0(mc);

-

-fail:

-	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;

-	return rc;

-}

-

-/** Allocate and initialize new pages for a database.

- * @param[in] mc a cursor on the database being added to.

- * @param[in] flags flags defining what type of page is being allocated.

- * @param[in] num the number of pages to allocate. This is usually 1,

- * unless allocating overflow pages for a large record.

- * @param[out] mp Address of a page, or NULL on failure.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)

-{

-	MDB_page	*np;

-	int rc;

-

-	if ((rc = mdb_page_alloc(mc, num, &np)))

-		return rc;

-	DPRINTF(("allocated new mpage %"Y"u, page size %u",

-	    np->mp_pgno, mc->mc_txn->mt_env->me_psize));

-	np->mp_flags = flags | P_DIRTY;

-	np->mp_lower = (PAGEHDRSZ-PAGEBASE);

-	np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE;

-

-	if (IS_BRANCH(np))

-		mc->mc_db->md_branch_pages++;

-	else if (IS_LEAF(np))

-		mc->mc_db->md_leaf_pages++;

-	else if (IS_OVERFLOW(np)) {

-		mc->mc_db->md_overflow_pages += num;

-		np->mp_pages = num;

-	}

-	*mp = np;

-

-	return 0;

-}

-

-/** Calculate the size of a leaf node.

- * The size depends on the environment's page size; if a data item

- * is too large it will be put onto an overflow page and the node

- * size will only include the key and not the data. Sizes are always

- * rounded up to an even number of bytes, to guarantee 2-byte alignment

- * of the #MDB_node headers.

- * @param[in] env The environment handle.

- * @param[in] key The key for the node.

- * @param[in] data The data for the node.

- * @return The number of bytes needed to store the node.

- */

-static size_t

-mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)

-{

-	size_t		 sz;

-

-	sz = LEAFSIZE(key, data);

-	if (sz > env->me_nodemax) {

-		/* put on overflow page */

-		sz -= data->mv_size - sizeof(pgno_t);

-	}

-

-	return EVEN(sz + sizeof(indx_t));

-}

-

-/** Calculate the size of a branch node.

- * The size should depend on the environment's page size but since

- * we currently don't support spilling large keys onto overflow

- * pages, it's simply the size of the #MDB_node header plus the

- * size of the key. Sizes are always rounded up to an even number

- * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.

- * @param[in] env The environment handle.

- * @param[in] key The key for the node.

- * @return The number of bytes needed to store the node.

- */

-static size_t

-mdb_branch_size(MDB_env *env, MDB_val *key)

-{

-	size_t		 sz;

-

-	sz = INDXSIZE(key);

-	if (sz > env->me_nodemax) {

-		/* put on overflow page */

-		/* not implemented */

-		/* sz -= key->size - sizeof(pgno_t); */

-	}

-

-	return sz + sizeof(indx_t);

-}

-

-/** Add a node to the page pointed to by the cursor.

- * @param[in] mc The cursor for this operation.

- * @param[in] indx The index on the page where the new node should be added.

- * @param[in] key The key for the new node.

- * @param[in] data The data for the new node, if any.

- * @param[in] pgno The page number, if adding a branch node.

- * @param[in] flags Flags for the node.

- * @return 0 on success, non-zero on failure. Possible errors are:

- * <ul>

- *	<li>ENOMEM - failed to allocate overflow pages for the node.

- *	<li>MDB_PAGE_FULL - there is insufficient room in the page. This error

- *	should never happen since all callers already calculate the

- *	page's free space before calling this function.

- * </ul>

- */

-static int

-mdb_node_add(MDB_cursor *mc, indx_t indx,

-    MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)

-{

-	unsigned int	 i;

-	size_t		 node_size = NODESIZE;

-	ssize_t		 room;

-	indx_t		 ofs;

-	MDB_node	*node;

-	MDB_page	*mp = mc->mc_pg[mc->mc_top];

-	MDB_page	*ofp = NULL;		/* overflow page */

-	void		*ndata;

-	DKBUF;

-

-	mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);

-

-	DPRINTF(("add to %s %spage %"Y"u index %i, data size %"Z"u key size %"Z"u [%s]",

-	    IS_LEAF(mp) ? "leaf" : "branch",

-		IS_SUBP(mp) ? "sub-" : "",

-		mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,

-		key ? key->mv_size : 0, key ? DKEY(key) : "null"));

-

-	if (IS_LEAF2(mp)) {

-		/* Move higher keys up one slot. */

-		int ksize = mc->mc_db->md_pad, dif;

-		char *ptr = LEAF2KEY(mp, indx, ksize);

-		dif = NUMKEYS(mp) - indx;

-		if (dif > 0)

-			memmove(ptr+ksize, ptr, dif*ksize);

-		/* insert new key */

-		memcpy(ptr, key->mv_data, ksize);

-

-		/* Just using these for counting */

-		mp->mp_lower += sizeof(indx_t);

-		mp->mp_upper -= ksize - sizeof(indx_t);

-		return MDB_SUCCESS;

-	}

-

-	room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);

-	if (key != NULL)

-		node_size += key->mv_size;

-	if (IS_LEAF(mp)) {

-		mdb_cassert(mc, key && data);

-		if (F_ISSET(flags, F_BIGDATA)) {

-			/* Data already on overflow page. */

-			node_size += sizeof(pgno_t);

-		} else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {

-			int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);

-			int rc;

-			/* Put data on overflow page. */

-			DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",

-			    data->mv_size, node_size+data->mv_size));

-			node_size = EVEN(node_size + sizeof(pgno_t));

-			if ((ssize_t)node_size > room)

-				goto full;

-			if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))

-				return rc;

-			DPRINTF(("allocated overflow page %"Y"u", ofp->mp_pgno));

-			flags |= F_BIGDATA;

-			goto update;

-		} else {

-			node_size += data->mv_size;

-		}

-	}

-	node_size = EVEN(node_size);

-	if ((ssize_t)node_size > room)

-		goto full;

-

-update:

-	/* Move higher pointers up one slot. */

-	for (i = NUMKEYS(mp); i > indx; i--)

-		mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];

-

-	/* Adjust free space offsets. */

-	ofs = mp->mp_upper - node_size;

-	mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t));

-	mp->mp_ptrs[indx] = ofs;

-	mp->mp_upper = ofs;

-	mp->mp_lower += sizeof(indx_t);

-

-	/* Write the node data. */

-	node = NODEPTR(mp, indx);

-	node->mn_ksize = (key == NULL) ? 0 : key->mv_size;

-	node->mn_flags = flags;

-	if (IS_LEAF(mp))

-		SETDSZ(node,data->mv_size);

-	else

-		SETPGNO(node,pgno);

-

-	if (key)

-		memcpy(NODEKEY(node), key->mv_data, key->mv_size);

-

-	if (IS_LEAF(mp)) {

-		ndata = NODEDATA(node);

-		if (ofp == NULL) {

-			if (F_ISSET(flags, F_BIGDATA))

-				memcpy(ndata, data->mv_data, sizeof(pgno_t));

-			else if (F_ISSET(flags, MDB_RESERVE))

-				data->mv_data = ndata;

-			else

-				memcpy(ndata, data->mv_data, data->mv_size);

-		} else {

-			memcpy(ndata, &ofp->mp_pgno, sizeof(pgno_t));

-			ndata = METADATA(ofp);

-			if (F_ISSET(flags, MDB_RESERVE))

-				data->mv_data = ndata;

-			else

-				memcpy(ndata, data->mv_data, data->mv_size);

-		}

-	}

-

-	return MDB_SUCCESS;

-

-full:

-	DPRINTF(("not enough room in page %"Y"u, got %u ptrs",

-		mdb_dbg_pgno(mp), NUMKEYS(mp)));

-	DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));

-	DPRINTF(("node size = %"Z"u", node_size));

-	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;

-	return MDB_PAGE_FULL;

-}

-

-/** Delete the specified node from a page.

- * @param[in] mc Cursor pointing to the node to delete.

- * @param[in] ksize The size of a node. Only used if the page is

- * part of a #MDB_DUPFIXED database.

- */

-static void

-mdb_node_del(MDB_cursor *mc, int ksize)

-{

-	MDB_page *mp = mc->mc_pg[mc->mc_top];

-	indx_t	indx = mc->mc_ki[mc->mc_top];

-	unsigned int	 sz;

-	indx_t		 i, j, numkeys, ptr;

-	MDB_node	*node;

-	char		*base;

-

-	DPRINTF(("delete node %u on %s page %"Y"u", indx,

-	    IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));

-	numkeys = NUMKEYS(mp);

-	mdb_cassert(mc, indx < numkeys);

-

-	if (IS_LEAF2(mp)) {

-		int x = numkeys - 1 - indx;

-		base = LEAF2KEY(mp, indx, ksize);

-		if (x)

-			memmove(base, base + ksize, x * ksize);

-		mp->mp_lower -= sizeof(indx_t);

-		mp->mp_upper += ksize - sizeof(indx_t);

-		return;

-	}

-

-	node = NODEPTR(mp, indx);

-	sz = NODESIZE + node->mn_ksize;

-	if (IS_LEAF(mp)) {

-		if (F_ISSET(node->mn_flags, F_BIGDATA))

-			sz += sizeof(pgno_t);

-		else

-			sz += NODEDSZ(node);

-	}

-	sz = EVEN(sz);

-

-	ptr = mp->mp_ptrs[indx];

-	for (i = j = 0; i < numkeys; i++) {

-		if (i != indx) {

-			mp->mp_ptrs[j] = mp->mp_ptrs[i];

-			if (mp->mp_ptrs[i] < ptr)

-				mp->mp_ptrs[j] += sz;

-			j++;

-		}

-	}

-

-	base = (char *)mp + mp->mp_upper + PAGEBASE;

-	memmove(base + sz, base, ptr - mp->mp_upper);

-

-	mp->mp_lower -= sizeof(indx_t);

-	mp->mp_upper += sz;

-}

-

-/** Compact the main page after deleting a node on a subpage.

- * @param[in] mp The main page to operate on.

- * @param[in] indx The index of the subpage on the main page.

- */

-static void

-mdb_node_shrink(MDB_page *mp, indx_t indx)

-{

-	MDB_node *node;

-	MDB_page *sp, *xp;

-	char *base;

-	indx_t delta, nsize, len, ptr;

-	int i;

-

-	node = NODEPTR(mp, indx);

-	sp = (MDB_page *)NODEDATA(node);

-	delta = SIZELEFT(sp);

-	nsize = NODEDSZ(node) - delta;

-

-	/* Prepare to shift upward, set len = length(subpage part to shift) */

-	if (IS_LEAF2(sp)) {

-		len = nsize;

-		if (nsize & 1)

-			return;		/* do not make the node uneven-sized */

-	} else {

-		xp = (MDB_page *)((char *)sp + delta); /* destination subpage */

-		for (i = NUMKEYS(sp); --i >= 0; )

-			xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;

-		len = PAGEHDRSZ;

-	}

-	sp->mp_upper = sp->mp_lower;

-	COPY_PGNO(sp->mp_pgno, mp->mp_pgno);

-	SETDSZ(node, nsize);

-

-	/* Shift <lower nodes...initial part of subpage> upward */

-	base = (char *)mp + mp->mp_upper + PAGEBASE;

-	memmove(base + delta, base, (char *)sp + len - base);

-

-	ptr = mp->mp_ptrs[indx];

-	for (i = NUMKEYS(mp); --i >= 0; ) {

-		if (mp->mp_ptrs[i] <= ptr)

-			mp->mp_ptrs[i] += delta;

-	}

-	mp->mp_upper += delta;

-}

-

-/** Initial setup of a sorted-dups cursor.

- * Sorted duplicates are implemented as a sub-database for the given key.

- * The duplicate data items are actually keys of the sub-database.

- * Operations on the duplicate data items are performed using a sub-cursor

- * initialized when the sub-database is first accessed. This function does

- * the preliminary setup of the sub-cursor, filling in the fields that

- * depend only on the parent DB.

- * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.

- */

-static void

-mdb_xcursor_init0(MDB_cursor *mc)

-{

-	MDB_xcursor *mx = mc->mc_xcursor;

-

-	mx->mx_cursor.mc_xcursor = NULL;

-	mx->mx_cursor.mc_txn = mc->mc_txn;

-	mx->mx_cursor.mc_db = &mx->mx_db;

-	mx->mx_cursor.mc_dbx = &mx->mx_dbx;

-	mx->mx_cursor.mc_dbi = mc->mc_dbi;

-	mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;

-	mx->mx_cursor.mc_snum = 0;

-	mx->mx_cursor.mc_top = 0;

-#ifdef MDB_VL32

-	mx->mx_cursor.mc_ovpg = 0;

-#endif

-	mx->mx_cursor.mc_flags = C_SUB | (mc->mc_flags & (C_ORIG_RDONLY|C_WRITEMAP));

-	mx->mx_dbx.md_name.mv_size = 0;

-	mx->mx_dbx.md_name.mv_data = NULL;

-	mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;

-	mx->mx_dbx.md_dcmp = NULL;

-	mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;

-}

-

-/** Final setup of a sorted-dups cursor.

- *	Sets up the fields that depend on the data from the main cursor.

- * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.

- * @param[in] node The data containing the #MDB_db record for the

- * sorted-dup database.

- */

-static void

-mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)

-{

-	MDB_xcursor *mx = mc->mc_xcursor;

-

-	mx->mx_cursor.mc_flags &= C_SUB|C_ORIG_RDONLY|C_WRITEMAP;

-	if (node->mn_flags & F_SUBDATA) {

-		memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));

-		mx->mx_cursor.mc_pg[0] = 0;

-		mx->mx_cursor.mc_snum = 0;

-		mx->mx_cursor.mc_top = 0;

-	} else {

-		MDB_page *fp = NODEDATA(node);

-		mx->mx_db.md_pad = 0;

-		mx->mx_db.md_flags = 0;

-		mx->mx_db.md_depth = 1;

-		mx->mx_db.md_branch_pages = 0;

-		mx->mx_db.md_leaf_pages = 1;

-		mx->mx_db.md_overflow_pages = 0;

-		mx->mx_db.md_entries = NUMKEYS(fp);

-		COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);

-		mx->mx_cursor.mc_snum = 1;

-		mx->mx_cursor.mc_top = 0;

-		mx->mx_cursor.mc_flags |= C_INITIALIZED;

-		mx->mx_cursor.mc_pg[0] = fp;

-		mx->mx_cursor.mc_ki[0] = 0;

-		if (mc->mc_db->md_flags & MDB_DUPFIXED) {

-			mx->mx_db.md_flags = MDB_DUPFIXED;

-			mx->mx_db.md_pad = fp->mp_pad;

-			if (mc->mc_db->md_flags & MDB_INTEGERDUP)

-				mx->mx_db.md_flags |= MDB_INTEGERKEY;

-		}

-	}

-	DPRINTF(("Sub-db -%u root page %"Y"u", mx->mx_cursor.mc_dbi,

-		mx->mx_db.md_root));

-	mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */

-#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)

-	if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(mdb_size_t))

-		mx->mx_dbx.md_cmp = mdb_cmp_clong;

-#endif

-}

-

-

-/** Fixup a sorted-dups cursor due to underlying update.

- *	Sets up some fields that depend on the data from the main cursor.

- *	Almost the same as init1, but skips initialization steps if the

- *	xcursor had already been used.

- * @param[in] mc The main cursor whose sorted-dups cursor is to be fixed up.

- * @param[in] src_mx The xcursor of an up-to-date cursor.

- * @param[in] new_dupdata True if converting from a non-#F_DUPDATA item.

- */

-static void

-mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int new_dupdata)

-{

-	MDB_xcursor *mx = mc->mc_xcursor;

-

-	if (new_dupdata) {

-		mx->mx_cursor.mc_snum = 1;

-		mx->mx_cursor.mc_top = 0;

-		mx->mx_cursor.mc_flags |= C_INITIALIZED;

-		mx->mx_cursor.mc_ki[0] = 0;

-		mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */

-#if UINT_MAX < SIZE_MAX

-		mx->mx_dbx.md_cmp = src_mx->mx_dbx.md_cmp;

-#endif

-	} else if (!(mx->mx_cursor.mc_flags & C_INITIALIZED)) {

-		return;

-	}

-	mx->mx_db = src_mx->mx_db;

-	mx->mx_cursor.mc_pg[0] = src_mx->mx_cursor.mc_pg[0];

-	DPRINTF(("Sub-db -%u root page %"Y"u", mx->mx_cursor.mc_dbi,

-		mx->mx_db.md_root));

-}

-

-/** Initialize a cursor for a given transaction and database. */

-static void

-mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)

-{

-	mc->mc_next = NULL;

-	mc->mc_backup = NULL;

-	mc->mc_dbi = dbi;

-	mc->mc_txn = txn;

-	mc->mc_db = &txn->mt_dbs[dbi];

-	mc->mc_dbx = &txn->mt_dbxs[dbi];

-	mc->mc_dbflag = &txn->mt_dbflags[dbi];

-	mc->mc_snum = 0;

-	mc->mc_top = 0;

-	mc->mc_pg[0] = 0;

-	mc->mc_ki[0] = 0;

-#ifdef MDB_VL32

-	mc->mc_ovpg = 0;

-#endif

-	mc->mc_flags = txn->mt_flags & (C_ORIG_RDONLY|C_WRITEMAP);

-	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {

-		mdb_tassert(txn, mx != NULL);

-		mc->mc_xcursor = mx;

-		mdb_xcursor_init0(mc);

-	} else {

-		mc->mc_xcursor = NULL;

-	}

-	if (*mc->mc_dbflag & DB_STALE) {

-		mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);

-	}

-}

-

-int

-mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)

-{

-	MDB_cursor	*mc;

-	size_t size = sizeof(MDB_cursor);

-

-	if (!ret || !TXN_DBI_EXIST(txn, dbi, DB_VALID))

-		return EINVAL;

-

-	if (txn->mt_flags & MDB_TXN_BLOCKED)

-		return MDB_BAD_TXN;

-

-	if (dbi == FREE_DBI && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))

-		return EINVAL;

-

-	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)

-		size += sizeof(MDB_xcursor);

-

-	if ((mc = malloc(size)) != NULL) {

-		mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));

-		if (txn->mt_cursors) {

-			mc->mc_next = txn->mt_cursors[dbi];

-			txn->mt_cursors[dbi] = mc;

-			mc->mc_flags |= C_UNTRACK;

-		}

-	} else {

-		return ENOMEM;

-	}

-

-	*ret = mc;

-

-	return MDB_SUCCESS;

-}

-

-int

-mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)

-{

-	if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi, DB_VALID))

-		return EINVAL;

-

-	if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)

-		return EINVAL;

-

-	if (txn->mt_flags & MDB_TXN_BLOCKED)

-		return MDB_BAD_TXN;

-

-	mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);

-	return MDB_SUCCESS;

-}

-

-/* Return the count of duplicate data items for the current key */

-int

-mdb_cursor_count(MDB_cursor *mc, mdb_size_t *countp)

-{

-	MDB_node	*leaf;

-

-	if (mc == NULL || countp == NULL)

-		return EINVAL;

-

-	if (mc->mc_xcursor == NULL)

-		return MDB_INCOMPATIBLE;

-

-	if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)

-		return MDB_BAD_TXN;

-

-	if (!(mc->mc_flags & C_INITIALIZED))

-		return EINVAL;

-

-	if (!mc->mc_snum || (mc->mc_flags & C_EOF))

-		return MDB_NOTFOUND;

-

-	leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);

-	if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {

-		*countp = 1;

-	} else {

-		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))

-			return EINVAL;

-

-		*countp = mc->mc_xcursor->mx_db.md_entries;

-	}

-	return MDB_SUCCESS;

-}

-

-void

-mdb_cursor_close(MDB_cursor *mc)

-{

-	if (mc && !mc->mc_backup) {

-		/* remove from txn, if tracked */

-		if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {

-			MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];

-			while (*prev && *prev != mc) prev = &(*prev)->mc_next;

-			if (*prev == mc)

-				*prev = mc->mc_next;

-		}

-		free(mc);

-	}

-}

-

-MDB_txn *

-mdb_cursor_txn(MDB_cursor *mc)

-{

-	if (!mc) return NULL;

-	return mc->mc_txn;

-}

-

-MDB_dbi

-mdb_cursor_dbi(MDB_cursor *mc)

-{

-	return mc->mc_dbi;

-}

-

-/** Replace the key for a branch node with a new key.

- * @param[in] mc Cursor pointing to the node to operate on.

- * @param[in] key The new key to use.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_update_key(MDB_cursor *mc, MDB_val *key)

-{

-	MDB_page		*mp;

-	MDB_node		*node;

-	char			*base;

-	size_t			 len;

-	int				 delta, ksize, oksize;

-	indx_t			 ptr, i, numkeys, indx;

-	DKBUF;

-

-	indx = mc->mc_ki[mc->mc_top];

-	mp = mc->mc_pg[mc->mc_top];

-	node = NODEPTR(mp, indx);

-	ptr = mp->mp_ptrs[indx];

-#if MDB_DEBUG

-	{

-		MDB_val	k2;

-		char kbuf2[DKBUF_MAXKEYSIZE*2+1];

-		k2.mv_data = NODEKEY(node);

-		k2.mv_size = node->mn_ksize;

-		DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Y"u",

-			indx, ptr,

-			mdb_dkey(&k2, kbuf2),

-			DKEY(key),

-			mp->mp_pgno));

-	}

-#endif

-

-	/* Sizes must be 2-byte aligned. */

-	ksize = EVEN(key->mv_size);

-	oksize = EVEN(node->mn_ksize);

-	delta = ksize - oksize;

-

-	/* Shift node contents if EVEN(key length) changed. */

-	if (delta) {

-		if (delta > 0 && SIZELEFT(mp) < delta) {

-			pgno_t pgno;

-			/* not enough space left, do a delete and split */

-			DPRINTF(("Not enough room, delta = %d, splitting...", delta));

-			pgno = NODEPGNO(node);

-			mdb_node_del(mc, 0);

-			return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);

-		}

-

-		numkeys = NUMKEYS(mp);

-		for (i = 0; i < numkeys; i++) {

-			if (mp->mp_ptrs[i] <= ptr)

-				mp->mp_ptrs[i] -= delta;

-		}

-

-		base = (char *)mp + mp->mp_upper + PAGEBASE;

-		len = ptr - mp->mp_upper + NODESIZE;

-		memmove(base - delta, base, len);

-		mp->mp_upper -= delta;

-

-		node = NODEPTR(mp, indx);

-	}

-

-	/* But even if no shift was needed, update ksize */

-	if (node->mn_ksize != key->mv_size)

-		node->mn_ksize = key->mv_size;

-

-	if (key->mv_size)

-		memcpy(NODEKEY(node), key->mv_data, key->mv_size);

-

-	return MDB_SUCCESS;

-}

-

-static void

-mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);

-

-/** Perform \b act while tracking temporary cursor \b mn */

-#define WITH_CURSOR_TRACKING(mn, act) do { \

-	MDB_cursor dummy, *tracked, **tp = &(mn).mc_txn->mt_cursors[mn.mc_dbi]; \

-	if ((mn).mc_flags & C_SUB) { \

-		dummy.mc_flags =  C_INITIALIZED; \

-		dummy.mc_xcursor = (MDB_xcursor *)&(mn);	\

-		tracked = &dummy; \

-	} else { \

-		tracked = &(mn); \

-	} \

-	tracked->mc_next = *tp; \

-	*tp = tracked; \

-	{ act; } \

-	*tp = tracked->mc_next; \

-} while (0)

-

-/** Move a node from csrc to cdst.

- */

-static int

-mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft)

-{

-	MDB_node		*srcnode;

-	MDB_val		 key, data;

-	pgno_t	srcpg;

-	MDB_cursor mn;

-	int			 rc;

-	unsigned short flags;

-

-	DKBUF;

-

-	/* Mark src and dst as dirty. */

-	if ((rc = mdb_page_touch(csrc)) ||

-	    (rc = mdb_page_touch(cdst)))

-		return rc;

-

-	if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {

-		key.mv_size = csrc->mc_db->md_pad;

-		key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);

-		data.mv_size = 0;

-		data.mv_data = NULL;

-		srcpg = 0;

-		flags = 0;

-	} else {

-		srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);

-		mdb_cassert(csrc, !((size_t)srcnode & 1));

-		srcpg = NODEPGNO(srcnode);

-		flags = srcnode->mn_flags;

-		if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {

-			unsigned int snum = csrc->mc_snum;

-			MDB_node *s2;

-			/* must find the lowest key below src */

-			rc = mdb_page_search_lowest(csrc);

-			if (rc)

-				return rc;

-			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {

-				key.mv_size = csrc->mc_db->md_pad;

-				key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);

-			} else {

-				s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);

-				key.mv_size = NODEKSZ(s2);

-				key.mv_data = NODEKEY(s2);

-			}

-			csrc->mc_snum = snum--;

-			csrc->mc_top = snum;

-		} else {

-			key.mv_size = NODEKSZ(srcnode);

-			key.mv_data = NODEKEY(srcnode);

-		}

-		data.mv_size = NODEDSZ(srcnode);

-		data.mv_data = NODEDATA(srcnode);

-	}

-	mn.mc_xcursor = NULL;

-	if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {

-		unsigned int snum = cdst->mc_snum;

-		MDB_node *s2;

-		MDB_val bkey;

-		/* must find the lowest key below dst */

-		mdb_cursor_copy(cdst, &mn);

-		rc = mdb_page_search_lowest(&mn);

-		if (rc)

-			return rc;

-		if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {

-			bkey.mv_size = mn.mc_db->md_pad;

-			bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size);

-		} else {

-			s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);

-			bkey.mv_size = NODEKSZ(s2);

-			bkey.mv_data = NODEKEY(s2);

-		}

-		mn.mc_snum = snum--;

-		mn.mc_top = snum;

-		mn.mc_ki[snum] = 0;

-		rc = mdb_update_key(&mn, &bkey);

-		if (rc)

-			return rc;

-	}

-

-	DPRINTF(("moving %s node %u [%s] on page %"Y"u to node %u on page %"Y"u",

-	    IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",

-	    csrc->mc_ki[csrc->mc_top],

-		DKEY(&key),

-	    csrc->mc_pg[csrc->mc_top]->mp_pgno,

-	    cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));

-

-	/* Add the node to the destination page.

-	 */

-	rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);

-	if (rc != MDB_SUCCESS)

-		return rc;

-

-	/* Delete the node from the source page.

-	 */

-	mdb_node_del(csrc, key.mv_size);

-

-	{

-		/* Adjust other cursors pointing to mp */

-		MDB_cursor *m2, *m3;

-		MDB_dbi dbi = csrc->mc_dbi;

-		MDB_page *mpd, *mps;

-

-		mps = csrc->mc_pg[csrc->mc_top];

-		/* If we're adding on the left, bump others up */

-		if (fromleft) {

-			mpd = cdst->mc_pg[csrc->mc_top];

-			for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {

-				if (csrc->mc_flags & C_SUB)

-					m3 = &m2->mc_xcursor->mx_cursor;

-				else

-					m3 = m2;

-				if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)

-					continue;

-				if (m3 != cdst &&

-					m3->mc_pg[csrc->mc_top] == mpd &&

-					m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) {

-					m3->mc_ki[csrc->mc_top]++;

-				}

-				if (m3 !=csrc &&

-					m3->mc_pg[csrc->mc_top] == mps &&

-					m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) {

-					m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];

-					m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];

-					m3->mc_ki[csrc->mc_top-1]++;

-				}

-				if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&

-					IS_LEAF(mps)) {

-					MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);

-					if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)

-						m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);

-				}

-			}

-		} else

-		/* Adding on the right, bump others down */

-		{

-			for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {

-				if (csrc->mc_flags & C_SUB)

-					m3 = &m2->mc_xcursor->mx_cursor;

-				else

-					m3 = m2;

-				if (m3 == csrc) continue;

-				if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)

-					continue;

-				if (m3->mc_pg[csrc->mc_top] == mps) {

-					if (!m3->mc_ki[csrc->mc_top]) {

-						m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];

-						m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];

-						m3->mc_ki[csrc->mc_top-1]--;

-					} else {

-						m3->mc_ki[csrc->mc_top]--;

-					}

-					if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&

-						IS_LEAF(mps)) {

-						MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);

-						if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)

-							m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);

-					}

-				}

-			}

-		}

-	}

-

-	/* Update the parent separators.

-	 */

-	if (csrc->mc_ki[csrc->mc_top] == 0) {

-		if (csrc->mc_ki[csrc->mc_top-1] != 0) {

-			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {

-				key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);

-			} else {

-				srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);

-				key.mv_size = NODEKSZ(srcnode);

-				key.mv_data = NODEKEY(srcnode);

-			}

-			DPRINTF(("update separator for source page %"Y"u to [%s]",

-				csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));

-			mdb_cursor_copy(csrc, &mn);

-			mn.mc_snum--;

-			mn.mc_top--;

-			/* We want mdb_rebalance to find mn when doing fixups */

-			WITH_CURSOR_TRACKING(mn,

-				rc = mdb_update_key(&mn, &key));

-			if (rc)

-				return rc;

-		}

-		if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {

-			MDB_val	 nullkey;

-			indx_t	ix = csrc->mc_ki[csrc->mc_top];

-			nullkey.mv_size = 0;

-			csrc->mc_ki[csrc->mc_top] = 0;

-			rc = mdb_update_key(csrc, &nullkey);

-			csrc->mc_ki[csrc->mc_top] = ix;

-			mdb_cassert(csrc, rc == MDB_SUCCESS);

-		}

-	}

-

-	if (cdst->mc_ki[cdst->mc_top] == 0) {

-		if (cdst->mc_ki[cdst->mc_top-1] != 0) {

-			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {

-				key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);

-			} else {

-				srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);

-				key.mv_size = NODEKSZ(srcnode);

-				key.mv_data = NODEKEY(srcnode);

-			}

-			DPRINTF(("update separator for destination page %"Y"u to [%s]",

-				cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));

-			mdb_cursor_copy(cdst, &mn);

-			mn.mc_snum--;

-			mn.mc_top--;

-			/* We want mdb_rebalance to find mn when doing fixups */

-			WITH_CURSOR_TRACKING(mn,

-				rc = mdb_update_key(&mn, &key));

-			if (rc)

-				return rc;

-		}

-		if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {

-			MDB_val	 nullkey;

-			indx_t	ix = cdst->mc_ki[cdst->mc_top];

-			nullkey.mv_size = 0;

-			cdst->mc_ki[cdst->mc_top] = 0;

-			rc = mdb_update_key(cdst, &nullkey);

-			cdst->mc_ki[cdst->mc_top] = ix;

-			mdb_cassert(cdst, rc == MDB_SUCCESS);

-		}

-	}

-

-	return MDB_SUCCESS;

-}

-

-/** Merge one page into another.

- *  The nodes from the page pointed to by \b csrc will

- *	be copied to the page pointed to by \b cdst and then

- *	the \b csrc page will be freed.

- * @param[in] csrc Cursor pointing to the source page.

- * @param[in] cdst Cursor pointing to the destination page.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)

-{

-	MDB_page	*psrc, *pdst;

-	MDB_node	*srcnode;

-	MDB_val		 key, data;

-	unsigned	 nkeys;

-	int			 rc;

-	indx_t		 i, j;

-

-	psrc = csrc->mc_pg[csrc->mc_top];

-	pdst = cdst->mc_pg[cdst->mc_top];

-

-	DPRINTF(("merging page %"Y"u into %"Y"u", psrc->mp_pgno, pdst->mp_pgno));

-

-	mdb_cassert(csrc, csrc->mc_snum > 1);	/* can't merge root page */

-	mdb_cassert(csrc, cdst->mc_snum > 1);

-

-	/* Mark dst as dirty. */

-	if ((rc = mdb_page_touch(cdst)))

-		return rc;

-

-	/* get dst page again now that we've touched it. */

-	pdst = cdst->mc_pg[cdst->mc_top];

-

-	/* Move all nodes from src to dst.

-	 */

-	j = nkeys = NUMKEYS(pdst);

-	if (IS_LEAF2(psrc)) {

-		key.mv_size = csrc->mc_db->md_pad;

-		key.mv_data = METADATA(psrc);

-		for (i = 0; i < NUMKEYS(psrc); i++, j++) {

-			rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);

-			if (rc != MDB_SUCCESS)

-				return rc;

-			key.mv_data = (char *)key.mv_data + key.mv_size;

-		}

-	} else {

-		for (i = 0; i < NUMKEYS(psrc); i++, j++) {

-			srcnode = NODEPTR(psrc, i);

-			if (i == 0 && IS_BRANCH(psrc)) {

-				MDB_cursor mn;

-				MDB_node *s2;

-				mdb_cursor_copy(csrc, &mn);

-				mn.mc_xcursor = NULL;

-				/* must find the lowest key below src */

-				rc = mdb_page_search_lowest(&mn);

-				if (rc)

-					return rc;

-				if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {

-					key.mv_size = mn.mc_db->md_pad;

-					key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size);

-				} else {

-					s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);

-					key.mv_size = NODEKSZ(s2);

-					key.mv_data = NODEKEY(s2);

-				}

-			} else {

-				key.mv_size = srcnode->mn_ksize;

-				key.mv_data = NODEKEY(srcnode);

-			}

-

-			data.mv_size = NODEDSZ(srcnode);

-			data.mv_data = NODEDATA(srcnode);

-			rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);

-			if (rc != MDB_SUCCESS)

-				return rc;

-		}

-	}

-

-	DPRINTF(("dst page %"Y"u now has %u keys (%.1f%% filled)",

-	    pdst->mp_pgno, NUMKEYS(pdst),

-		(float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));

-

-	/* Unlink the src page from parent and add to free list.

-	 */

-	csrc->mc_top--;

-	mdb_node_del(csrc, 0);

-	if (csrc->mc_ki[csrc->mc_top] == 0) {

-		key.mv_size = 0;

-		rc = mdb_update_key(csrc, &key);

-		if (rc) {

-			csrc->mc_top++;

-			return rc;

-		}

-	}

-	csrc->mc_top++;

-

-	psrc = csrc->mc_pg[csrc->mc_top];

-	/* If not operating on FreeDB, allow this page to be reused

-	 * in this txn. Otherwise just add to free list.

-	 */

-	rc = mdb_page_loose(csrc, psrc);

-	if (rc)

-		return rc;

-	if (IS_LEAF(psrc))

-		csrc->mc_db->md_leaf_pages--;

-	else

-		csrc->mc_db->md_branch_pages--;

-	{

-		/* Adjust other cursors pointing to mp */

-		MDB_cursor *m2, *m3;

-		MDB_dbi dbi = csrc->mc_dbi;

-		unsigned int top = csrc->mc_top;

-

-		for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {

-			if (csrc->mc_flags & C_SUB)

-				m3 = &m2->mc_xcursor->mx_cursor;

-			else

-				m3 = m2;

-			if (m3 == csrc) continue;

-			if (m3->mc_snum < csrc->mc_snum) continue;

-			if (m3->mc_pg[top] == psrc) {

-				m3->mc_pg[top] = pdst;

-				m3->mc_ki[top] += nkeys;

-				m3->mc_ki[top-1] = cdst->mc_ki[top-1];

-			} else if (m3->mc_pg[top-1] == csrc->mc_pg[top-1] &&

-				m3->mc_ki[top-1] > csrc->mc_ki[top-1]) {

-				m3->mc_ki[top-1]--;

-			}

-			if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&

-				IS_LEAF(psrc)) {

-				MDB_node *node = NODEPTR(m3->mc_pg[top], m3->mc_ki[top]);

-				if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)

-					m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);

-			}

-		}

-	}

-	{

-		unsigned int snum = cdst->mc_snum;

-		uint16_t depth = cdst->mc_db->md_depth;

-		mdb_cursor_pop(cdst);

-		rc = mdb_rebalance(cdst);

-		/* Did the tree height change? */

-		if (depth != cdst->mc_db->md_depth)

-			snum += cdst->mc_db->md_depth - depth;

-		cdst->mc_snum = snum;

-		cdst->mc_top = snum-1;

-	}

-	return rc;

-}

-

-/** Copy the contents of a cursor.

- * @param[in] csrc The cursor to copy from.

- * @param[out] cdst The cursor to copy to.

- */

-static void

-mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)

-{

-	unsigned int i;

-

-	cdst->mc_txn = csrc->mc_txn;

-	cdst->mc_dbi = csrc->mc_dbi;

-	cdst->mc_db  = csrc->mc_db;

-	cdst->mc_dbx = csrc->mc_dbx;

-	cdst->mc_snum = csrc->mc_snum;

-	cdst->mc_top = csrc->mc_top;

-	cdst->mc_flags = csrc->mc_flags;

-#ifdef MDB_VL32

-	cdst->mc_ovpg = csrc->mc_ovpg;

-#endif

-

-	for (i=0; i<csrc->mc_snum; i++) {

-		cdst->mc_pg[i] = csrc->mc_pg[i];

-		cdst->mc_ki[i] = csrc->mc_ki[i];

-	}

-}

-

-/** Rebalance the tree after a delete operation.

- * @param[in] mc Cursor pointing to the page where rebalancing

- * should begin.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_rebalance(MDB_cursor *mc)

-{

-	MDB_node	*node;

-	int rc, fromleft;

-	unsigned int ptop, minkeys, thresh;

-	MDB_cursor	mn;

-	indx_t oldki;

-

-	if (IS_BRANCH(mc->mc_pg[mc->mc_top])) {

-		minkeys = 2;

-		thresh = 1;

-	} else {

-		minkeys = 1;

-		thresh = FILL_THRESHOLD;

-	}

-	DPRINTF(("rebalancing %s page %"Y"u (has %u keys, %.1f%% full)",

-	    IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",

-	    mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),

-		(float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));

-

-	if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= thresh &&

-		NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {

-		DPRINTF(("no need to rebalance page %"Y"u, above fill threshold",

-		    mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));

-		return MDB_SUCCESS;

-	}

-

-	if (mc->mc_snum < 2) {

-		MDB_page *mp = mc->mc_pg[0];

-		if (IS_SUBP(mp)) {

-			DPUTS("Can't rebalance a subpage, ignoring");

-			return MDB_SUCCESS;

-		}

-		if (NUMKEYS(mp) == 0) {

-			DPUTS("tree is completely empty");

-			mc->mc_db->md_root = P_INVALID;

-			mc->mc_db->md_depth = 0;

-			mc->mc_db->md_leaf_pages = 0;

-			rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);

-			if (rc)

-				return rc;

-			/* Adjust cursors pointing to mp */

-			mc->mc_snum = 0;

-			mc->mc_top = 0;

-			mc->mc_flags &= ~C_INITIALIZED;

-			{

-				MDB_cursor *m2, *m3;

-				MDB_dbi dbi = mc->mc_dbi;

-

-				for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {

-					if (mc->mc_flags & C_SUB)

-						m3 = &m2->mc_xcursor->mx_cursor;

-					else

-						m3 = m2;

-					if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))

-						continue;

-					if (m3->mc_pg[0] == mp) {

-						m3->mc_snum = 0;

-						m3->mc_top = 0;

-						m3->mc_flags &= ~C_INITIALIZED;

-					}

-				}

-			}

-		} else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {

-			int i;

-			DPUTS("collapsing root page!");

-			rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);

-			if (rc)

-				return rc;

-			mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));

-			rc = mdb_page_get(mc, mc->mc_db->md_root, &mc->mc_pg[0], NULL);

-			if (rc)

-				return rc;

-			mc->mc_db->md_depth--;

-			mc->mc_db->md_branch_pages--;

-			mc->mc_ki[0] = mc->mc_ki[1];

-			for (i = 1; i<mc->mc_db->md_depth; i++) {

-				mc->mc_pg[i] = mc->mc_pg[i+1];

-				mc->mc_ki[i] = mc->mc_ki[i+1];

-			}

-			{

-				/* Adjust other cursors pointing to mp */

-				MDB_cursor *m2, *m3;

-				MDB_dbi dbi = mc->mc_dbi;

-

-				for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {

-					if (mc->mc_flags & C_SUB)

-						m3 = &m2->mc_xcursor->mx_cursor;

-					else

-						m3 = m2;

-					if (m3 == mc) continue;

-					if (!(m3->mc_flags & C_INITIALIZED))

-						continue;

-					if (m3->mc_pg[0] == mp) {

-						for (i=0; i<mc->mc_db->md_depth; i++) {

-							m3->mc_pg[i] = m3->mc_pg[i+1];

-							m3->mc_ki[i] = m3->mc_ki[i+1];

-						}

-						m3->mc_snum--;

-						m3->mc_top--;

-					}

-				}

-			}

-		} else

-			DPUTS("root page doesn't need rebalancing");

-		return MDB_SUCCESS;

-	}

-

-	/* The parent (branch page) must have at least 2 pointers,

-	 * otherwise the tree is invalid.

-	 */

-	ptop = mc->mc_top-1;

-	mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1);

-

-	/* Leaf page fill factor is below the threshold.

-	 * Try to move keys from left or right neighbor, or

-	 * merge with a neighbor page.

-	 */

-

-	/* Find neighbors.

-	 */

-	mdb_cursor_copy(mc, &mn);

-	mn.mc_xcursor = NULL;

-

-	oldki = mc->mc_ki[mc->mc_top];

-	if (mc->mc_ki[ptop] == 0) {

-		/* We're the leftmost leaf in our parent.

-		 */

-		DPUTS("reading right neighbor");

-		mn.mc_ki[ptop]++;

-		node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);

-		rc = mdb_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL);

-		if (rc)

-			return rc;

-		mn.mc_ki[mn.mc_top] = 0;

-		mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);

-		fromleft = 0;

-	} else {

-		/* There is at least one neighbor to the left.

-		 */

-		DPUTS("reading left neighbor");

-		mn.mc_ki[ptop]--;

-		node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);

-		rc = mdb_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL);

-		if (rc)

-			return rc;

-		mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;

-		mc->mc_ki[mc->mc_top] = 0;

-		fromleft = 1;

-	}

-

-	DPRINTF(("found neighbor page %"Y"u (%u keys, %.1f%% full)",

-	    mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),

-		(float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));

-

-	/* If the neighbor page is above threshold and has enough keys,

-	 * move one key from it. Otherwise we should try to merge them.

-	 * (A branch page must never have less than 2 keys.)

-	 */

-	if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {

-		rc = mdb_node_move(&mn, mc, fromleft);

-		if (fromleft) {

-			/* if we inserted on left, bump position up */

-			oldki++;

-		}

-	} else {

-		if (!fromleft) {

-			rc = mdb_page_merge(&mn, mc);

-		} else {

-			oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);

-			mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;

-			/* We want mdb_rebalance to find mn when doing fixups */

-			WITH_CURSOR_TRACKING(mn,

-				rc = mdb_page_merge(mc, &mn));

-			mdb_cursor_copy(&mn, mc);

-		}

-		mc->mc_flags &= ~C_EOF;

-	}

-	mc->mc_ki[mc->mc_top] = oldki;

-	return rc;

-}

-

-/** Complete a delete operation started by #mdb_cursor_del(). */

-static int

-mdb_cursor_del0(MDB_cursor *mc)

-{

-	int rc;

-	MDB_page *mp;

-	indx_t ki;

-	unsigned int nkeys;

-	MDB_cursor *m2, *m3;

-	MDB_dbi dbi = mc->mc_dbi;

-

-	ki = mc->mc_ki[mc->mc_top];

-	mp = mc->mc_pg[mc->mc_top];

-	mdb_node_del(mc, mc->mc_db->md_pad);

-	mc->mc_db->md_entries--;

-	{

-		/* Adjust other cursors pointing to mp */

-		for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {

-			m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;

-			if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))

-				continue;

-			if (m3 == mc || m3->mc_snum < mc->mc_snum)

-				continue;

-			if (m3->mc_pg[mc->mc_top] == mp) {

-				if (m3->mc_ki[mc->mc_top] == ki) {

-					m3->mc_flags |= C_DEL;

-				} else if (m3->mc_ki[mc->mc_top] > ki) {

-					m3->mc_ki[mc->mc_top]--;

-				}

-				if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {

-					MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);

-					if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)

-						m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);

-				}

-			}

-		}

-	}

-	rc = mdb_rebalance(mc);

-

-	if (rc == MDB_SUCCESS) {

-		/* DB is totally empty now, just bail out.

-		 * Other cursors adjustments were already done

-		 * by mdb_rebalance and aren't needed here.

-		 */

-		if (!mc->mc_snum)

-			return rc;

-

-		mp = mc->mc_pg[mc->mc_top];

-		nkeys = NUMKEYS(mp);

-

-		/* Adjust other cursors pointing to mp */

-		for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {

-			m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;

-			if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))

-				continue;

-			if (m3->mc_snum < mc->mc_snum)

-				continue;

-			if (m3->mc_pg[mc->mc_top] == mp) {

-				/* if m3 points past last node in page, find next sibling */

-				if (m3->mc_ki[mc->mc_top] >= mc->mc_ki[mc->mc_top]) {

-					if (m3->mc_ki[mc->mc_top] >= nkeys) {

-						rc = mdb_cursor_sibling(m3, 1);

-						if (rc == MDB_NOTFOUND) {

-							m3->mc_flags |= C_EOF;

-							rc = MDB_SUCCESS;

-							continue;

-						}

-					}

-					if (mc->mc_db->md_flags & MDB_DUPSORT) {

-						MDB_node *node = NODEPTR(m3->mc_pg[m3->mc_top], m3->mc_ki[m3->mc_top]);

-						if (node->mn_flags & F_DUPDATA) {

-							mdb_xcursor_init1(m3, node);

-							m3->mc_xcursor->mx_cursor.mc_flags |= C_DEL;

-						}

-					}

-				}

-			}

-		}

-		mc->mc_flags |= C_DEL;

-	}

-

-	if (rc)

-		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;

-	return rc;

-}

-

-int

-mdb_del(MDB_txn *txn, MDB_dbi dbi,

-    MDB_val *key, MDB_val *data)

-{

-	if (!key || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))

-		return EINVAL;

-

-	if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))

-		return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;

-

-	if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {

-		/* must ignore any data */

-		data = NULL;

-	}

-

-	return mdb_del0(txn, dbi, key, data, 0);

-}

-

-static int

-mdb_del0(MDB_txn *txn, MDB_dbi dbi,

-	MDB_val *key, MDB_val *data, unsigned flags)

-{

-	MDB_cursor mc;

-	MDB_xcursor mx;

-	MDB_cursor_op op;

-	MDB_val rdata, *xdata;

-	int		 rc, exact = 0;

-	DKBUF;

-

-	DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));

-

-	mdb_cursor_init(&mc, txn, dbi, &mx);

-

-	if (data) {

-		op = MDB_GET_BOTH;

-		rdata = *data;

-		xdata = &rdata;

-	} else {

-		op = MDB_SET;

-		xdata = NULL;

-		flags |= MDB_NODUPDATA;

-	}

-	rc = mdb_cursor_set(&mc, key, xdata, op, &exact);

-	if (rc == 0) {

-		/* let mdb_page_split know about this cursor if needed:

-		 * delete will trigger a rebalance; if it needs to move

-		 * a node from one page to another, it will have to

-		 * update the parent's separator key(s). If the new sepkey

-		 * is larger than the current one, the parent page may

-		 * run out of space, triggering a split. We need this

-		 * cursor to be consistent until the end of the rebalance.

-		 */

-		mc.mc_flags |= C_UNTRACK;

-		mc.mc_next = txn->mt_cursors[dbi];

-		txn->mt_cursors[dbi] = &mc;

-		rc = mdb_cursor_del(&mc, flags);

-		txn->mt_cursors[dbi] = mc.mc_next;

-	}

-	return rc;

-}

-

-/** Split a page and insert a new node.

- * @param[in,out] mc Cursor pointing to the page and desired insertion index.

- * The cursor will be updated to point to the actual page and index where

- * the node got inserted after the split.

- * @param[in] newkey The key for the newly inserted node.

- * @param[in] newdata The data for the newly inserted node.

- * @param[in] newpgno The page number, if the new node is a branch node.

- * @param[in] nflags The #NODE_ADD_FLAGS for the new node.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,

-	unsigned int nflags)

-{

-	unsigned int flags;

-	int		 rc = MDB_SUCCESS, new_root = 0, did_split = 0;

-	indx_t		 newindx;

-	pgno_t		 pgno = 0;

-	int	 i, j, split_indx, nkeys, pmax;

-	MDB_env 	*env = mc->mc_txn->mt_env;

-	MDB_node	*node;

-	MDB_val	 sepkey, rkey, xdata, *rdata = &xdata;

-	MDB_page	*copy = NULL;

-	MDB_page	*mp, *rp, *pp;

-	int ptop;

-	MDB_cursor	mn;

-	DKBUF;

-

-	mp = mc->mc_pg[mc->mc_top];

-	newindx = mc->mc_ki[mc->mc_top];

-	nkeys = NUMKEYS(mp);

-

-	DPRINTF(("-----> splitting %s page %"Y"u and adding [%s] at index %i/%i",

-	    IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,

-	    DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));

-

-	/* Create a right sibling. */

-	if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))

-		return rc;

-	rp->mp_pad = mp->mp_pad;

-	DPRINTF(("new right sibling: page %"Y"u", rp->mp_pgno));

-

-	/* Usually when splitting the root page, the cursor

-	 * height is 1. But when called from mdb_update_key,

-	 * the cursor height may be greater because it walks

-	 * up the stack while finding the branch slot to update.

-	 */

-	if (mc->mc_top < 1) {

-		if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))

-			goto done;

-		/* shift current top to make room for new parent */

-		for (i=mc->mc_snum; i>0; i--) {

-			mc->mc_pg[i] = mc->mc_pg[i-1];

-			mc->mc_ki[i] = mc->mc_ki[i-1];

-		}

-		mc->mc_pg[0] = pp;

-		mc->mc_ki[0] = 0;

-		mc->mc_db->md_root = pp->mp_pgno;

-		DPRINTF(("root split! new root = %"Y"u", pp->mp_pgno));

-		new_root = mc->mc_db->md_depth++;

-

-		/* Add left (implicit) pointer. */

-		if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {

-			/* undo the pre-push */

-			mc->mc_pg[0] = mc->mc_pg[1];

-			mc->mc_ki[0] = mc->mc_ki[1];

-			mc->mc_db->md_root = mp->mp_pgno;

-			mc->mc_db->md_depth--;

-			goto done;

-		}

-		mc->mc_snum++;

-		mc->mc_top++;

-		ptop = 0;

-	} else {

-		ptop = mc->mc_top-1;

-		DPRINTF(("parent branch page is %"Y"u", mc->mc_pg[ptop]->mp_pgno));

-	}

-

-	mdb_cursor_copy(mc, &mn);

-	mn.mc_xcursor = NULL;

-	mn.mc_pg[mn.mc_top] = rp;

-	mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;

-

-	if (nflags & MDB_APPEND) {

-		mn.mc_ki[mn.mc_top] = 0;

-		sepkey = *newkey;

-		split_indx = newindx;

-		nkeys = 0;

-	} else {

-

-		split_indx = (nkeys+1) / 2;

-

-		if (IS_LEAF2(rp)) {

-			char *split, *ins;

-			int x;

-			unsigned int lsize, rsize, ksize;

-			/* Move half of the keys to the right sibling */

-			x = mc->mc_ki[mc->mc_top] - split_indx;

-			ksize = mc->mc_db->md_pad;

-			split = LEAF2KEY(mp, split_indx, ksize);

-			rsize = (nkeys - split_indx) * ksize;

-			lsize = (nkeys - split_indx) * sizeof(indx_t);

-			mp->mp_lower -= lsize;

-			rp->mp_lower += lsize;

-			mp->mp_upper += rsize - lsize;

-			rp->mp_upper -= rsize - lsize;

-			sepkey.mv_size = ksize;

-			if (newindx == split_indx) {

-				sepkey.mv_data = newkey->mv_data;

-			} else {

-				sepkey.mv_data = split;

-			}

-			if (x<0) {

-				ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);

-				memcpy(rp->mp_ptrs, split, rsize);

-				sepkey.mv_data = rp->mp_ptrs;

-				memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);

-				memcpy(ins, newkey->mv_data, ksize);

-				mp->mp_lower += sizeof(indx_t);

-				mp->mp_upper -= ksize - sizeof(indx_t);

-			} else {

-				if (x)

-					memcpy(rp->mp_ptrs, split, x * ksize);

-				ins = LEAF2KEY(rp, x, ksize);

-				memcpy(ins, newkey->mv_data, ksize);

-				memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);

-				rp->mp_lower += sizeof(indx_t);

-				rp->mp_upper -= ksize - sizeof(indx_t);

-				mc->mc_ki[mc->mc_top] = x;

-			}

-		} else {

-			int psize, nsize, k;

-			/* Maximum free space in an empty page */

-			pmax = env->me_psize - PAGEHDRSZ;

-			if (IS_LEAF(mp))

-				nsize = mdb_leaf_size(env, newkey, newdata);

-			else

-				nsize = mdb_branch_size(env, newkey);

-			nsize = EVEN(nsize);

-

-			/* grab a page to hold a temporary copy */

-			copy = mdb_page_malloc(mc->mc_txn, 1);

-			if (copy == NULL) {

-				rc = ENOMEM;

-				goto done;

-			}

-			copy->mp_pgno  = mp->mp_pgno;

-			copy->mp_flags = mp->mp_flags;

-			copy->mp_lower = (PAGEHDRSZ-PAGEBASE);

-			copy->mp_upper = env->me_psize - PAGEBASE;

-

-			/* prepare to insert */

-			for (i=0, j=0; i<nkeys; i++) {

-				if (i == newindx) {

-					copy->mp_ptrs[j++] = 0;

-				}

-				copy->mp_ptrs[j++] = mp->mp_ptrs[i];

-			}

-

-			/* When items are relatively large the split point needs

-			 * to be checked, because being off-by-one will make the

-			 * difference between success or failure in mdb_node_add.

-			 *

-			 * It's also relevant if a page happens to be laid out

-			 * such that one half of its nodes are all "small" and

-			 * the other half of its nodes are "large." If the new

-			 * item is also "large" and falls on the half with

-			 * "large" nodes, it also may not fit.

-			 *

-			 * As a final tweak, if the new item goes on the last

-			 * spot on the page (and thus, onto the new page), bias

-			 * the split so the new page is emptier than the old page.

-			 * This yields better packing during sequential inserts.

-			 */

-			if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) {

-				/* Find split point */

-				psize = 0;

-				if (newindx <= split_indx || newindx >= nkeys) {

-					i = 0; j = 1;

-					k = newindx >= nkeys ? nkeys : split_indx+1+IS_LEAF(mp);

-				} else {

-					i = nkeys; j = -1;

-					k = split_indx-1;

-				}

-				for (; i!=k; i+=j) {

-					if (i == newindx) {

-						psize += nsize;

-						node = NULL;

-					} else {

-						node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);

-						psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);

-						if (IS_LEAF(mp)) {

-							if (F_ISSET(node->mn_flags, F_BIGDATA))

-								psize += sizeof(pgno_t);

-							else

-								psize += NODEDSZ(node);

-						}

-						psize = EVEN(psize);

-					}

-					if (psize > pmax || i == k-j) {

-						split_indx = i + (j<0);

-						break;

-					}

-				}

-			}

-			if (split_indx == newindx) {

-				sepkey.mv_size = newkey->mv_size;

-				sepkey.mv_data = newkey->mv_data;

-			} else {

-				node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE);

-				sepkey.mv_size = node->mn_ksize;

-				sepkey.mv_data = NODEKEY(node);

-			}

-		}

-	}

-

-	DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));

-

-	/* Copy separator key to the parent.

-	 */

-	if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {

-		int snum = mc->mc_snum;

-		mn.mc_snum--;

-		mn.mc_top--;

-		did_split = 1;

-		/* We want other splits to find mn when doing fixups */

-		WITH_CURSOR_TRACKING(mn,

-			rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0));

-		if (rc)

-			goto done;

-

-		/* root split? */

-		if (mc->mc_snum > snum) {

-			ptop++;

-		}

-		/* Right page might now have changed parent.

-		 * Check if left page also changed parent.

-		 */

-		if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&

-		    mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {

-			for (i=0; i<ptop; i++) {

-				mc->mc_pg[i] = mn.mc_pg[i];

-				mc->mc_ki[i] = mn.mc_ki[i];

-			}

-			mc->mc_pg[ptop] = mn.mc_pg[ptop];

-			if (mn.mc_ki[ptop]) {

-				mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;

-			} else {

-				/* find right page's left sibling */

-				mc->mc_ki[ptop] = mn.mc_ki[ptop];

-				mdb_cursor_sibling(mc, 0);

-			}

-		}

-	} else {

-		mn.mc_top--;

-		rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);

-		mn.mc_top++;

-	}

-	if (rc != MDB_SUCCESS) {

-		goto done;

-	}

-	if (nflags & MDB_APPEND) {

-		mc->mc_pg[mc->mc_top] = rp;

-		mc->mc_ki[mc->mc_top] = 0;

-		rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);

-		if (rc)

-			goto done;

-		for (i=0; i<mc->mc_top; i++)

-			mc->mc_ki[i] = mn.mc_ki[i];

-	} else if (!IS_LEAF2(mp)) {

-		/* Move nodes */

-		mc->mc_pg[mc->mc_top] = rp;

-		i = split_indx;

-		j = 0;

-		do {

-			if (i == newindx) {

-				rkey.mv_data = newkey->mv_data;

-				rkey.mv_size = newkey->mv_size;

-				if (IS_LEAF(mp)) {

-					rdata = newdata;

-				} else

-					pgno = newpgno;

-				flags = nflags;

-				/* Update index for the new key. */

-				mc->mc_ki[mc->mc_top] = j;

-			} else {

-				node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);

-				rkey.mv_data = NODEKEY(node);

-				rkey.mv_size = node->mn_ksize;

-				if (IS_LEAF(mp)) {

-					xdata.mv_data = NODEDATA(node);

-					xdata.mv_size = NODEDSZ(node);

-					rdata = &xdata;

-				} else

-					pgno = NODEPGNO(node);

-				flags = node->mn_flags;

-			}

-

-			if (!IS_LEAF(mp) && j == 0) {

-				/* First branch index doesn't need key data. */

-				rkey.mv_size = 0;

-			}

-

-			rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);

-			if (rc)

-				goto done;

-			if (i == nkeys) {

-				i = 0;

-				j = 0;

-				mc->mc_pg[mc->mc_top] = copy;

-			} else {

-				i++;

-				j++;

-			}

-		} while (i != split_indx);

-

-		nkeys = NUMKEYS(copy);

-		for (i=0; i<nkeys; i++)

-			mp->mp_ptrs[i] = copy->mp_ptrs[i];

-		mp->mp_lower = copy->mp_lower;

-		mp->mp_upper = copy->mp_upper;

-		memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),

-			env->me_psize - copy->mp_upper - PAGEBASE);

-

-		/* reset back to original page */

-		if (newindx < split_indx) {

-			mc->mc_pg[mc->mc_top] = mp;

-		} else {

-			mc->mc_pg[mc->mc_top] = rp;

-			mc->mc_ki[ptop]++;

-			/* Make sure mc_ki is still valid.

-			 */

-			if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&

-				mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {

-				for (i=0; i<=ptop; i++) {

-					mc->mc_pg[i] = mn.mc_pg[i];

-					mc->mc_ki[i] = mn.mc_ki[i];

-				}

-			}

-		}

-		if (nflags & MDB_RESERVE) {

-			node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);

-			if (!(node->mn_flags & F_BIGDATA))

-				newdata->mv_data = NODEDATA(node);

-		}

-	} else {

-		if (newindx >= split_indx) {

-			mc->mc_pg[mc->mc_top] = rp;

-			mc->mc_ki[ptop]++;

-			/* Make sure mc_ki is still valid.

-			 */

-			if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&

-				mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {

-				for (i=0; i<=ptop; i++) {

-					mc->mc_pg[i] = mn.mc_pg[i];

-					mc->mc_ki[i] = mn.mc_ki[i];

-				}

-			}

-		}

-	}

-

-	{

-		/* Adjust other cursors pointing to mp */

-		MDB_cursor *m2, *m3;

-		MDB_dbi dbi = mc->mc_dbi;

-		nkeys = NUMKEYS(mp);

-

-		for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {

-			if (mc->mc_flags & C_SUB)

-				m3 = &m2->mc_xcursor->mx_cursor;

-			else

-				m3 = m2;

-			if (m3 == mc)

-				continue;

-			if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))

-				continue;

-			if (new_root) {

-				int k;

-				/* sub cursors may be on different DB */

-				if (m3->mc_pg[0] != mp)

-					continue;

-				/* root split */

-				for (k=new_root; k>=0; k--) {

-					m3->mc_ki[k+1] = m3->mc_ki[k];

-					m3->mc_pg[k+1] = m3->mc_pg[k];

-				}

-				if (m3->mc_ki[0] >= nkeys) {

-					m3->mc_ki[0] = 1;

-				} else {

-					m3->mc_ki[0] = 0;

-				}

-				m3->mc_pg[0] = mc->mc_pg[0];

-				m3->mc_snum++;

-				m3->mc_top++;

-			}

-			if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {

-				if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))

-					m3->mc_ki[mc->mc_top]++;

-				if (m3->mc_ki[mc->mc_top] >= nkeys) {

-					m3->mc_pg[mc->mc_top] = rp;

-					m3->mc_ki[mc->mc_top] -= nkeys;

-					for (i=0; i<mc->mc_top; i++) {

-						m3->mc_ki[i] = mn.mc_ki[i];

-						m3->mc_pg[i] = mn.mc_pg[i];

-					}

-				}

-			} else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&

-				m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {

-				m3->mc_ki[ptop]++;

-			}

-			if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&

-				IS_LEAF(mp)) {

-				MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);

-				if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)

-					m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);

-			}

-		}

-	}

-	DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));

-

-done:

-	if (copy)					/* tmp page */

-		mdb_page_free(env, copy);

-	if (rc)

-		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;

-	return rc;

-}

-

-int

-mdb_put(MDB_txn *txn, MDB_dbi dbi,

-    MDB_val *key, MDB_val *data, unsigned int flags)

-{

-	MDB_cursor mc;

-	MDB_xcursor mx;

-	int rc;

-

-	if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))

-		return EINVAL;

-

-	if (flags & ~(MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP))

-		return EINVAL;

-

-	if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))

-		return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;

-

-	mdb_cursor_init(&mc, txn, dbi, &mx);

-	mc.mc_next = txn->mt_cursors[dbi];

-	txn->mt_cursors[dbi] = &mc;

-	rc = mdb_cursor_put(&mc, key, data, flags);

-	txn->mt_cursors[dbi] = mc.mc_next;

-	return rc;

-}

-

-#ifndef MDB_WBUF

-#define MDB_WBUF	(1024*1024)

-#endif

-

-	/** State needed for a compacting copy. */

-typedef struct mdb_copy {

-	pthread_mutex_t mc_mutex;

-	pthread_cond_t mc_cond;

-	char *mc_wbuf[2];

-	char *mc_over[2];

-	MDB_env *mc_env;

-	MDB_txn *mc_txn;

-	int mc_wlen[2];

-	int mc_olen[2];

-	pgno_t mc_next_pgno;

-	HANDLE mc_fd;

-	int mc_status;

-	volatile int mc_new;

-	int mc_toggle;

-

-} mdb_copy;

-

-	/** Dedicated writer thread for compacting copy. */

-static THREAD_RET ESECT CALL_CONV

-mdb_env_copythr(void *arg)

-{

-	mdb_copy *my = arg;

-	char *ptr;

-	int toggle = 0, wsize, rc;

-#ifdef _WIN32

-	DWORD len;

-#define DO_WRITE(rc, fd, ptr, w2, len)	rc = WriteFile(fd, ptr, w2, &len, NULL)

-#else

-	int len;

-#define DO_WRITE(rc, fd, ptr, w2, len)	len = write(fd, ptr, w2); rc = (len >= 0)

-#endif

-

-	pthread_mutex_lock(&my->mc_mutex);

-	my->mc_new = 0;

-	pthread_cond_signal(&my->mc_cond);

-	for(;;) {

-		while (!my->mc_new)

-			pthread_cond_wait(&my->mc_cond, &my->mc_mutex);

-		if (my->mc_new < 0) {

-			my->mc_new = 0;

-			break;

-		}

-		my->mc_new = 0;

-		wsize = my->mc_wlen[toggle];

-		ptr = my->mc_wbuf[toggle];

-again:

-		while (wsize > 0) {

-			DO_WRITE(rc, my->mc_fd, ptr, wsize, len);

-			if (!rc) {

-				rc = ErrCode();

-				break;

-			} else if (len > 0) {

-				rc = MDB_SUCCESS;

-				ptr += len;

-				wsize -= len;

-				continue;

-			} else {

-				rc = EIO;

-				break;

-			}

-		}

-		if (rc) {

-			my->mc_status = rc;

-			break;

-		}

-		/* If there's an overflow page tail, write it too */

-		if (my->mc_olen[toggle]) {

-			wsize = my->mc_olen[toggle];

-			ptr = my->mc_over[toggle];

-			my->mc_olen[toggle] = 0;

-			goto again;

-		}

-		my->mc_wlen[toggle] = 0;

-		toggle ^= 1;

-		pthread_cond_signal(&my->mc_cond);

-	}

-	pthread_cond_signal(&my->mc_cond);

-	pthread_mutex_unlock(&my->mc_mutex);

-	return (THREAD_RET)0;

-#undef DO_WRITE

-}

-

-	/** Tell the writer thread there's a buffer ready to write */

-static int ESECT

-mdb_env_cthr_toggle(mdb_copy *my, int st)

-{

-	int toggle = my->mc_toggle ^ 1;

-	pthread_mutex_lock(&my->mc_mutex);

-	if (my->mc_status) {

-		pthread_mutex_unlock(&my->mc_mutex);

-		return my->mc_status;

-	}

-	while (my->mc_new == 1)

-		pthread_cond_wait(&my->mc_cond, &my->mc_mutex);

-	my->mc_new = st;

-	my->mc_toggle = toggle;

-	pthread_cond_signal(&my->mc_cond);

-	pthread_mutex_unlock(&my->mc_mutex);

-	return 0;

-}

-

-	/** Depth-first tree traversal for compacting copy. */

-static int ESECT

-mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)

-{

-	MDB_cursor mc;

-	MDB_node *ni;

-	MDB_page *mo, *mp, *leaf;

-	char *buf, *ptr;

-	int rc, toggle;

-	unsigned int i;

-

-	/* Empty DB, nothing to do */

-	if (*pg == P_INVALID)

-		return MDB_SUCCESS;

-

-	mc.mc_snum = 1;

-	mc.mc_top = 0;

-	mc.mc_txn = my->mc_txn;

-

-	rc = mdb_page_get(&mc, *pg, &mc.mc_pg[0], NULL);

-	if (rc)

-		return rc;

-	rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);

-	if (rc)

-		return rc;

-

-	/* Make cursor pages writable */

-	buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum);

-	if (buf == NULL)

-		return ENOMEM;

-

-	for (i=0; i<mc.mc_top; i++) {

-		mdb_page_copy((MDB_page *)ptr, mc.mc_pg[i], my->mc_env->me_psize);

-		mc.mc_pg[i] = (MDB_page *)ptr;

-		ptr += my->mc_env->me_psize;

-	}

-

-	/* This is writable space for a leaf page. Usually not needed. */

-	leaf = (MDB_page *)ptr;

-

-	toggle = my->mc_toggle;

-	while (mc.mc_snum > 0) {

-		unsigned n;

-		mp = mc.mc_pg[mc.mc_top];

-		n = NUMKEYS(mp);

-

-		if (IS_LEAF(mp)) {

-			if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {

-				for (i=0; i<n; i++) {

-					ni = NODEPTR(mp, i);

-					if (ni->mn_flags & F_BIGDATA) {

-						MDB_page *omp;

-						pgno_t pg;

-

-						/* Need writable leaf */

-						if (mp != leaf) {

-							mc.mc_pg[mc.mc_top] = leaf;

-							mdb_page_copy(leaf, mp, my->mc_env->me_psize);

-							mp = leaf;

-							ni = NODEPTR(mp, i);

-						}

-

-						memcpy(&pg, NODEDATA(ni), sizeof(pg));

-						rc = mdb_page_get(&mc, pg, &omp, NULL);

-						if (rc)

-							goto done;

-						if (my->mc_wlen[toggle] >= MDB_WBUF) {

-							rc = mdb_env_cthr_toggle(my, 1);

-							if (rc)

-								goto done;

-							toggle = my->mc_toggle;

-						}

-						mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);

-						memcpy(mo, omp, my->mc_env->me_psize);

-						mo->mp_pgno = my->mc_next_pgno;

-						my->mc_next_pgno += omp->mp_pages;

-						my->mc_wlen[toggle] += my->mc_env->me_psize;

-						if (omp->mp_pages > 1) {

-							my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1);

-							my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;

-							rc = mdb_env_cthr_toggle(my, 1);

-							if (rc)

-								goto done;

-							toggle = my->mc_toggle;

-						}

-						memcpy(NODEDATA(ni), &mo->mp_pgno, sizeof(pgno_t));

-					} else if (ni->mn_flags & F_SUBDATA) {

-						MDB_db db;

-

-						/* Need writable leaf */

-						if (mp != leaf) {

-							mc.mc_pg[mc.mc_top] = leaf;

-							mdb_page_copy(leaf, mp, my->mc_env->me_psize);

-							mp = leaf;

-							ni = NODEPTR(mp, i);

-						}

-

-						memcpy(&db, NODEDATA(ni), sizeof(db));

-						my->mc_toggle = toggle;

-						rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA);

-						if (rc)

-							goto done;

-						toggle = my->mc_toggle;

-						memcpy(NODEDATA(ni), &db, sizeof(db));

-					}

-				}

-			}

-		} else {

-			mc.mc_ki[mc.mc_top]++;

-			if (mc.mc_ki[mc.mc_top] < n) {

-				pgno_t pg;

-again:

-				ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]);

-				pg = NODEPGNO(ni);

-				rc = mdb_page_get(&mc, pg, &mp, NULL);

-				if (rc)

-					goto done;

-				mc.mc_top++;

-				mc.mc_snum++;

-				mc.mc_ki[mc.mc_top] = 0;

-				if (IS_BRANCH(mp)) {

-					/* Whenever we advance to a sibling branch page,

-					 * we must proceed all the way down to its first leaf.

-					 */

-					mdb_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize);

-					goto again;

-				} else

-					mc.mc_pg[mc.mc_top] = mp;

-				continue;

-			}

-		}

-		if (my->mc_wlen[toggle] >= MDB_WBUF) {

-			rc = mdb_env_cthr_toggle(my, 1);

-			if (rc)

-				goto done;

-			toggle = my->mc_toggle;

-		}

-		mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);

-		mdb_page_copy(mo, mp, my->mc_env->me_psize);

-		mo->mp_pgno = my->mc_next_pgno++;

-		my->mc_wlen[toggle] += my->mc_env->me_psize;

-		if (mc.mc_top) {

-			/* Update parent if there is one */

-			ni = NODEPTR(mc.mc_pg[mc.mc_top-1], mc.mc_ki[mc.mc_top-1]);

-			SETPGNO(ni, mo->mp_pgno);

-			mdb_cursor_pop(&mc);

-		} else {

-			/* Otherwise we're done */

-			*pg = mo->mp_pgno;

-			break;

-		}

-	}

-done:

-	free(buf);

-	return rc;

-}

-

-	/** Copy environment with compaction. */

-static int ESECT

-mdb_env_copyfd1(MDB_env *env, HANDLE fd)

-{

-	MDB_meta *mm;

-	MDB_page *mp;

-	mdb_copy my;

-	MDB_txn *txn = NULL;

-	pthread_t thr;

-	int rc;

-

-#ifdef _WIN32

-	my.mc_mutex = CreateMutex(NULL, FALSE, NULL);

-	my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL);

-	my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_os_psize);

-	if (my.mc_wbuf[0] == NULL)

-		return errno;

-#else

-	pthread_mutex_init(&my.mc_mutex, NULL);

-	pthread_cond_init(&my.mc_cond, NULL);

-#ifdef HAVE_MEMALIGN

-	my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2);

-	if (my.mc_wbuf[0] == NULL)

-		return errno;

-#else

-	rc = posix_memalign((void **)&my.mc_wbuf[0], env->me_os_psize, MDB_WBUF*2);

-	if (rc)

-		return rc;

-#endif

-#endif

-	memset(my.mc_wbuf[0], 0, MDB_WBUF*2);

-	my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;

-	my.mc_wlen[0] = 0;

-	my.mc_wlen[1] = 0;

-	my.mc_olen[0] = 0;

-	my.mc_olen[1] = 0;

-	my.mc_next_pgno = NUM_METAS;

-	my.mc_status = 0;

-	my.mc_new = 1;

-	my.mc_toggle = 0;

-	my.mc_env = env;

-	my.mc_fd = fd;

-	THREAD_CREATE(thr, mdb_env_copythr, &my);

-

-	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);

-	if (rc)

-		return rc;

-

-	mp = (MDB_page *)my.mc_wbuf[0];

-	memset(mp, 0, NUM_METAS * env->me_psize);

-	mp->mp_pgno = 0;

-	mp->mp_flags = P_META;

-	mm = (MDB_meta *)METADATA(mp);

-	mdb_env_init_meta0(env, mm);

-	mm->mm_address = env->me_metas[0]->mm_address;

-

-	mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize);

-	mp->mp_pgno = 1;

-	mp->mp_flags = P_META;

-	*(MDB_meta *)METADATA(mp) = *mm;

-	mm = (MDB_meta *)METADATA(mp);

-

-	/* Count the number of free pages, subtract from lastpg to find

-	 * number of active pages

-	 */

-	{

-		MDB_ID freecount = 0;

-		MDB_cursor mc;

-		MDB_val key, data;

-		mdb_cursor_init(&mc, txn, FREE_DBI, NULL);

-		while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)

-			freecount += *(MDB_ID *)data.mv_data;

-		freecount += txn->mt_dbs[FREE_DBI].md_branch_pages +

-			txn->mt_dbs[FREE_DBI].md_leaf_pages +

-			txn->mt_dbs[FREE_DBI].md_overflow_pages;

-

-		/* Set metapage 1 */

-		mm->mm_last_pg = txn->mt_next_pgno - freecount - 1;

-		mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];

-		if (mm->mm_last_pg > NUM_METAS-1) {

-			mm->mm_dbs[MAIN_DBI].md_root = mm->mm_last_pg;

-			mm->mm_txnid = 1;

-		} else {

-			mm->mm_dbs[MAIN_DBI].md_root = P_INVALID;

-		}

-	}

-	my.mc_wlen[0] = env->me_psize * NUM_METAS;

-	my.mc_txn = txn;

-	pthread_mutex_lock(&my.mc_mutex);

-	while(my.mc_new)

-		pthread_cond_wait(&my.mc_cond, &my.mc_mutex);

-	pthread_mutex_unlock(&my.mc_mutex);

-	rc = mdb_env_cwalk(&my, &txn->mt_dbs[MAIN_DBI].md_root, 0);

-	if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle])

-		rc = mdb_env_cthr_toggle(&my, 1);

-	mdb_env_cthr_toggle(&my, -1);

-	pthread_mutex_lock(&my.mc_mutex);

-	while(my.mc_new)

-		pthread_cond_wait(&my.mc_cond, &my.mc_mutex);

-	pthread_mutex_unlock(&my.mc_mutex);

-	THREAD_FINISH(thr);

-

-	mdb_txn_abort(txn);

-#ifdef _WIN32

-	CloseHandle(my.mc_cond);

-	CloseHandle(my.mc_mutex);

-	_aligned_free(my.mc_wbuf[0]);

-#else

-	pthread_cond_destroy(&my.mc_cond);

-	pthread_mutex_destroy(&my.mc_mutex);

-	free(my.mc_wbuf[0]);

-#endif

-	return rc;

-}

-

-	/** Copy environment as-is. */

-static int ESECT

-mdb_env_copyfd0(MDB_env *env, HANDLE fd)

-{

-	MDB_txn *txn = NULL;

-	mdb_mutexref_t wmutex = NULL;

-	int rc;

-	mdb_size_t wsize, w3;

-	char *ptr;

-#ifdef _WIN32

-	DWORD len, w2;

-#define DO_WRITE(rc, fd, ptr, w2, len)	rc = WriteFile(fd, ptr, w2, &len, NULL)

-#else

-	ssize_t len;

-	size_t w2;

-#define DO_WRITE(rc, fd, ptr, w2, len)	len = write(fd, ptr, w2); rc = (len >= 0)

-#endif

-

-	/* Do the lock/unlock of the reader mutex before starting the

-	 * write txn.  Otherwise other read txns could block writers.

-	 */

-	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);

-	if (rc)

-		return rc;

-

-	if (env->me_txns) {

-		/* We must start the actual read txn after blocking writers */

-		mdb_txn_end(txn, MDB_END_RESET_TMP);

-

-		/* Temporarily block writers until we snapshot the meta pages */

-		wmutex = env->me_wmutex;

-		if (LOCK_MUTEX(rc, env, wmutex))

-			goto leave;

-

-		rc = mdb_txn_renew0(txn);

-		if (rc) {

-			UNLOCK_MUTEX(wmutex);

-			goto leave;

-		}

-	}

-

-	wsize = env->me_psize * NUM_METAS;

-	ptr = env->me_map;

-	w2 = wsize;

-	while (w2 > 0) {

-		DO_WRITE(rc, fd, ptr, w2, len);

-		if (!rc) {

-			rc = ErrCode();

-			break;

-		} else if (len > 0) {

-			rc = MDB_SUCCESS;

-			ptr += len;

-			w2 -= len;

-			continue;

-		} else {

-			/* Non-blocking or async handles are not supported */

-			rc = EIO;

-			break;

-		}

-	}

-	if (wmutex)

-		UNLOCK_MUTEX(wmutex);

-

-	if (rc)

-		goto leave;

-

-	w3 = txn->mt_next_pgno * env->me_psize;

-	{

-		mdb_size_t fsize = 0;

-		if ((rc = mdb_fsize(env->me_fd, &fsize)))

-			goto leave;

-		if (w3 > fsize)

-			w3 = fsize;

-	}

-	wsize = w3 - wsize;

-	while (wsize > 0) {

-		if (wsize > MAX_WRITE)

-			w2 = MAX_WRITE;

-		else

-			w2 = wsize;

-		DO_WRITE(rc, fd, ptr, w2, len);

-		if (!rc) {

-			rc = ErrCode();

-			break;

-		} else if (len > 0) {

-			rc = MDB_SUCCESS;

-			ptr += len;

-			wsize -= len;

-			continue;

-		} else {

-			rc = EIO;

-			break;

-		}

-	}

-

-leave:

-	mdb_txn_abort(txn);

-	return rc;

-}

-

-int ESECT

-mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags)

-{

-	if (flags & MDB_CP_COMPACT)

-		return mdb_env_copyfd1(env, fd);

-	else

-		return mdb_env_copyfd0(env, fd);

-}

-

-int ESECT

-mdb_env_copyfd(MDB_env *env, HANDLE fd)

-{

-	return mdb_env_copyfd2(env, fd, 0);

-}

-

-int ESECT

-mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)

-{

-	int rc, len;

-	char *lpath;

-	HANDLE newfd = INVALID_HANDLE_VALUE;

-#ifdef _WIN32

-	wchar_t *wpath;

-#endif

-

-	if (env->me_flags & MDB_NOSUBDIR) {

-		lpath = (char *)path;

-	} else {

-		len = strlen(path);

-		len += sizeof(DATANAME);

-		lpath = malloc(len);

-		if (!lpath)

-			return ENOMEM;

-		sprintf(lpath, "%s" DATANAME, path);

-	}

-

-	/* The destination path must exist, but the destination file must not.

-	 * We don't want the OS to cache the writes, since the source data is

-	 * already in the OS cache.

-	 */

-#ifdef _WIN32

-	rc = utf8_to_utf16(lpath, -1, &wpath, NULL);

-	if (rc)

-		goto leave;

-	newfd = CreateFileW(wpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,

-				FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);

-	free(wpath);

-#else

-	newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);

-#endif

-	if (newfd == INVALID_HANDLE_VALUE) {

-		rc = ErrCode();

-		goto leave;

-	}

-

-	if (env->me_psize >= env->me_os_psize) {

-#ifdef O_DIRECT

-	/* Set O_DIRECT if the file system supports it */

-	if ((rc = fcntl(newfd, F_GETFL)) != -1)

-		(void) fcntl(newfd, F_SETFL, rc | O_DIRECT);

-#endif

-#ifdef F_NOCACHE	/* __APPLE__ */

-	rc = fcntl(newfd, F_NOCACHE, 1);

-	if (rc) {

-		rc = ErrCode();

-		goto leave;

-	}

-#endif

-	}

-

-	rc = mdb_env_copyfd2(env, newfd, flags);

-

-leave:

-	if (!(env->me_flags & MDB_NOSUBDIR))

-		free(lpath);

-	if (newfd != INVALID_HANDLE_VALUE)

-		if (close(newfd) < 0 && rc == MDB_SUCCESS)

-			rc = ErrCode();

-

-	return rc;

-}

-

-int ESECT

-mdb_env_copy(MDB_env *env, const char *path)

-{

-	return mdb_env_copy2(env, path, 0);

-}

-

-int ESECT

-mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)

-{

-	if (flag & ~CHANGEABLE)

-		return EINVAL;

-	if (onoff)

-		env->me_flags |= flag;

-	else

-		env->me_flags &= ~flag;

-	return MDB_SUCCESS;

-}

-

-int ESECT

-mdb_env_get_flags(MDB_env *env, unsigned int *arg)

-{

-	if (!env || !arg)

-		return EINVAL;

-

-	*arg = env->me_flags & (CHANGEABLE|CHANGELESS);

-	return MDB_SUCCESS;

-}

-

-int ESECT

-mdb_env_set_userctx(MDB_env *env, void *ctx)

-{

-	if (!env)

-		return EINVAL;

-	env->me_userctx = ctx;

-	return MDB_SUCCESS;

-}

-

-void * ESECT

-mdb_env_get_userctx(MDB_env *env)

-{

-	return env ? env->me_userctx : NULL;

-}

-

-int ESECT

-mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)

-{

-	if (!env)

-		return EINVAL;

-#ifndef NDEBUG

-	env->me_assert_func = func;

-#endif

-	return MDB_SUCCESS;

-}

-

-int ESECT

-mdb_env_get_path(MDB_env *env, const char **arg)

-{

-	if (!env || !arg)

-		return EINVAL;

-

-	*arg = env->me_path;

-	return MDB_SUCCESS;

-}

-

-int ESECT

-mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)

-{

-	if (!env || !arg)

-		return EINVAL;

-

-	*arg = env->me_fd;

-	return MDB_SUCCESS;

-}

-

-/** Common code for #mdb_stat() and #mdb_env_stat().

- * @param[in] env the environment to operate in.

- * @param[in] db the #MDB_db record containing the stats to return.

- * @param[out] arg the address of an #MDB_stat structure to receive the stats.

- * @return 0, this function always succeeds.

- */

-static int ESECT

-mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)

-{

-	arg->ms_psize = env->me_psize;

-	arg->ms_depth = db->md_depth;

-	arg->ms_branch_pages = db->md_branch_pages;

-	arg->ms_leaf_pages = db->md_leaf_pages;

-	arg->ms_overflow_pages = db->md_overflow_pages;

-	arg->ms_entries = db->md_entries;

-

-	return MDB_SUCCESS;

-}

-

-int ESECT

-mdb_env_stat(MDB_env *env, MDB_stat *arg)

-{

-	MDB_meta *meta;

-

-	if (env == NULL || arg == NULL)

-		return EINVAL;

-

-	meta = mdb_env_pick_meta(env);

-

-	return mdb_stat0(env, &meta->mm_dbs[MAIN_DBI], arg);

-}

-

-int ESECT

-mdb_env_info(MDB_env *env, MDB_envinfo *arg)

-{

-	MDB_meta *meta;

-

-	if (env == NULL || arg == NULL)

-		return EINVAL;

-

-	meta = mdb_env_pick_meta(env);

-	arg->me_mapaddr = meta->mm_address;

-	arg->me_last_pgno = meta->mm_last_pg;

-	arg->me_last_txnid = meta->mm_txnid;

-

-	arg->me_mapsize = env->me_mapsize;

-	arg->me_maxreaders = env->me_maxreaders;

-	arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : 0;

-	return MDB_SUCCESS;

-}

-

-/** Set the default comparison functions for a database.

- * Called immediately after a database is opened to set the defaults.

- * The user can then override them with #mdb_set_compare() or

- * #mdb_set_dupsort().

- * @param[in] txn A transaction handle returned by #mdb_txn_begin()

- * @param[in] dbi A database handle returned by #mdb_dbi_open()

- */

-static void

-mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)

-{

-	uint16_t f = txn->mt_dbs[dbi].md_flags;

-

-	txn->mt_dbxs[dbi].md_cmp =

-		(f & MDB_REVERSEKEY) ? mdb_cmp_memnr :

-		(f & MDB_INTEGERKEY) ? mdb_cmp_cint  : mdb_cmp_memn;

-

-	txn->mt_dbxs[dbi].md_dcmp =

-		!(f & MDB_DUPSORT) ? 0 :

-		((f & MDB_INTEGERDUP)

-		 ? ((f & MDB_DUPFIXED)   ? mdb_cmp_int   : mdb_cmp_cint)

-		 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));

-}

-

-int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)

-{

-	MDB_val key, data;

-	MDB_dbi i;

-	MDB_cursor mc;

-	MDB_db dummy;

-	int rc, dbflag, exact;

-	unsigned int unused = 0, seq;

-	char *namedup;

-	size_t len;

-

-	if (flags & ~VALID_FLAGS)

-		return EINVAL;

-	if (txn->mt_flags & MDB_TXN_BLOCKED)

-		return MDB_BAD_TXN;

-

-	/* main DB? */

-	if (!name) {

-		*dbi = MAIN_DBI;

-		if (flags & PERSISTENT_FLAGS) {

-			uint16_t f2 = flags & PERSISTENT_FLAGS;

-			/* make sure flag changes get committed */

-			if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {

-				txn->mt_dbs[MAIN_DBI].md_flags |= f2;

-				txn->mt_flags |= MDB_TXN_DIRTY;

-			}

-		}

-		mdb_default_cmp(txn, MAIN_DBI);

-		return MDB_SUCCESS;

-	}

-

-	if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {

-		mdb_default_cmp(txn, MAIN_DBI);

-	}

-

-	/* Is the DB already open? */

-	len = strlen(name);

-	for (i=CORE_DBS; i<txn->mt_numdbs; i++) {

-		if (!txn->mt_dbxs[i].md_name.mv_size) {

-			/* Remember this free slot */

-			if (!unused) unused = i;

-			continue;

-		}

-		if (len == txn->mt_dbxs[i].md_name.mv_size &&

-			!strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {

-			*dbi = i;

-			return MDB_SUCCESS;

-		}

-	}

-

-	/* If no free slot and max hit, fail */

-	if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)

-		return MDB_DBS_FULL;

-

-	/* Cannot mix named databases with some mainDB flags */

-	if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))

-		return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;

-

-	/* Find the DB info */

-	dbflag = DB_NEW|DB_VALID|DB_USRVALID;

-	exact = 0;

-	key.mv_size = len;

-	key.mv_data = (void *)name;

-	mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);

-	rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);

-	if (rc == MDB_SUCCESS) {

-		/* make sure this is actually a DB */

-		MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);

-		if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)

-			return MDB_INCOMPATIBLE;

-	} else if (! (rc == MDB_NOTFOUND && (flags & MDB_CREATE))) {

-		return rc;

-	}

-

-	/* Done here so we cannot fail after creating a new DB */

-	if ((namedup = strdup(name)) == NULL)

-		return ENOMEM;

-

-	if (rc) {

-		/* MDB_NOTFOUND and MDB_CREATE: Create new DB */

-		data.mv_size = sizeof(MDB_db);

-		data.mv_data = &dummy;

-		memset(&dummy, 0, sizeof(dummy));

-		dummy.md_root = P_INVALID;

-		dummy.md_flags = flags & PERSISTENT_FLAGS;

-		rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);

-		dbflag |= DB_DIRTY;

-	}

-

-	if (rc) {

-		free(namedup);

-	} else {

-		/* Got info, register DBI in this txn */

-		unsigned int slot = unused ? unused : txn->mt_numdbs;

-		txn->mt_dbxs[slot].md_name.mv_data = namedup;

-		txn->mt_dbxs[slot].md_name.mv_size = len;

-		txn->mt_dbxs[slot].md_rel = NULL;

-		txn->mt_dbflags[slot] = dbflag;

-		/* txn-> and env-> are the same in read txns, use

-		 * tmp variable to avoid undefined assignment

-		 */

-		seq = ++txn->mt_env->me_dbiseqs[slot];

-		txn->mt_dbiseqs[slot] = seq;

-

-		memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));

-		*dbi = slot;

-		mdb_default_cmp(txn, slot);

-		if (!unused) {

-			txn->mt_numdbs++;

-		}

-	}

-

-	return rc;

-}

-

-int ESECT

-mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)

-{

-	if (!arg || !TXN_DBI_EXIST(txn, dbi, DB_VALID))

-		return EINVAL;

-

-	if (txn->mt_flags & MDB_TXN_BLOCKED)

-		return MDB_BAD_TXN;

-

-	if (txn->mt_dbflags[dbi] & DB_STALE) {

-		MDB_cursor mc;

-		MDB_xcursor mx;

-		/* Stale, must read the DB's root. cursor_init does it for us. */

-		mdb_cursor_init(&mc, txn, dbi, &mx);

-	}

-	return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);

-}

-

-void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)

-{

-	char *ptr;

-	if (dbi < CORE_DBS || dbi >= env->me_maxdbs)

-		return;

-	ptr = env->me_dbxs[dbi].md_name.mv_data;

-	/* If there was no name, this was already closed */

-	if (ptr) {

-		env->me_dbxs[dbi].md_name.mv_data = NULL;

-		env->me_dbxs[dbi].md_name.mv_size = 0;

-		env->me_dbflags[dbi] = 0;

-		env->me_dbiseqs[dbi]++;

-		free(ptr);

-	}

-}

-

-int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)

-{

-	/* We could return the flags for the FREE_DBI too but what's the point? */

-	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))

-		return EINVAL;

-	*flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;

-	return MDB_SUCCESS;

-}

-

-/** Add all the DB's pages to the free list.

- * @param[in] mc Cursor on the DB to free.

- * @param[in] subs non-Zero to check for sub-DBs in this DB.

- * @return 0 on success, non-zero on failure.

- */

-static int

-mdb_drop0(MDB_cursor *mc, int subs)

-{

-	int rc;

-

-	rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);

-	if (rc == MDB_SUCCESS) {

-		MDB_txn *txn = mc->mc_txn;

-		MDB_node *ni;

-		MDB_cursor mx;

-		unsigned int i;

-

-		/* DUPSORT sub-DBs have no ovpages/DBs. Omit scanning leaves.

-		 * This also avoids any P_LEAF2 pages, which have no nodes.

-		 * Also if the DB doesn't have sub-DBs and has no overflow

-		 * pages, omit scanning leaves.

-		 */

-		if ((mc->mc_flags & C_SUB) ||

-			(!subs && !mc->mc_db->md_overflow_pages))

-			mdb_cursor_pop(mc);

-

-		mdb_cursor_copy(mc, &mx);

-#ifdef MDB_VL32

-		/* bump refcount for mx's pages */

-		for (i=0; i<mc->mc_snum; i++)

-			mdb_page_get(&mx, mc->mc_pg[i]->mp_pgno, &mx.mc_pg[i], NULL);

-#endif

-		while (mc->mc_snum > 0) {

-			MDB_page *mp = mc->mc_pg[mc->mc_top];

-			unsigned n = NUMKEYS(mp);

-			if (IS_LEAF(mp)) {

-				for (i=0; i<n; i++) {

-					ni = NODEPTR(mp, i);

-					if (ni->mn_flags & F_BIGDATA) {

-						MDB_page *omp;

-						pgno_t pg;

-						memcpy(&pg, NODEDATA(ni), sizeof(pg));

-						rc = mdb_page_get(mc, pg, &omp, NULL);

-						if (rc != 0)

-							goto done;

-						mdb_cassert(mc, IS_OVERFLOW(omp));

-						rc = mdb_midl_append_range(&txn->mt_free_pgs,

-							pg, omp->mp_pages);

-						if (rc)

-							goto done;

-						mc->mc_db->md_overflow_pages -= omp->mp_pages;

-						if (!mc->mc_db->md_overflow_pages && !subs)

-							break;

-					} else if (subs && (ni->mn_flags & F_SUBDATA)) {

-						mdb_xcursor_init1(mc, ni);

-						rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);

-						if (rc)

-							goto done;

-					}

-				}

-				if (!subs && !mc->mc_db->md_overflow_pages)

-					goto pop;

-			} else {

-				if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)

-					goto done;

-				for (i=0; i<n; i++) {

-					pgno_t pg;

-					ni = NODEPTR(mp, i);

-					pg = NODEPGNO(ni);

-					/* free it */

-					mdb_midl_xappend(txn->mt_free_pgs, pg);

-				}

-			}

-			if (!mc->mc_top)

-				break;

-			mc->mc_ki[mc->mc_top] = i;

-			rc = mdb_cursor_sibling(mc, 1);

-			if (rc) {

-				if (rc != MDB_NOTFOUND)

-					goto done;

-				/* no more siblings, go back to beginning

-				 * of previous level.

-				 */

-pop:

-				mdb_cursor_pop(mc);

-				mc->mc_ki[0] = 0;

-				for (i=1; i<mc->mc_snum; i++) {

-					mc->mc_ki[i] = 0;

-					mc->mc_pg[i] = mx.mc_pg[i];

-				}

-			}

-		}

-		/* free it */

-		rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);

-done:

-		if (rc)

-			txn->mt_flags |= MDB_TXN_ERROR;

-#ifdef MDB_VL32

-		/* drop refcount for mx's pages */

-		mdb_cursor_unref(&mx);

-#endif

-	} else if (rc == MDB_NOTFOUND) {

-		rc = MDB_SUCCESS;

-	}

-	mc->mc_flags &= ~C_INITIALIZED;

-	return rc;

-}

-

-int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)

-{

-	MDB_cursor *mc, *m2;

-	int rc;

-

-	if ((unsigned)del > 1 || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))

-		return EINVAL;

-

-	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))

-		return EACCES;

-

-	if (TXN_DBI_CHANGED(txn, dbi))

-		return MDB_BAD_DBI;

-

-	rc = mdb_cursor_open(txn, dbi, &mc);

-	if (rc)

-		return rc;

-

-	rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);

-	/* Invalidate the dropped DB's cursors */

-	for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)

-		m2->mc_flags &= ~(C_INITIALIZED|C_EOF);

-	if (rc)

-		goto leave;

-

-	/* Can't delete the main DB */

-	if (del && dbi >= CORE_DBS) {

-		rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA);

-		if (!rc) {

-			txn->mt_dbflags[dbi] = DB_STALE;

-			mdb_dbi_close(txn->mt_env, dbi);

-		} else {

-			txn->mt_flags |= MDB_TXN_ERROR;

-		}

-	} else {

-		/* reset the DB record, mark it dirty */

-		txn->mt_dbflags[dbi] |= DB_DIRTY;

-		txn->mt_dbs[dbi].md_depth = 0;

-		txn->mt_dbs[dbi].md_branch_pages = 0;

-		txn->mt_dbs[dbi].md_leaf_pages = 0;

-		txn->mt_dbs[dbi].md_overflow_pages = 0;

-		txn->mt_dbs[dbi].md_entries = 0;

-		txn->mt_dbs[dbi].md_root = P_INVALID;

-

-		txn->mt_flags |= MDB_TXN_DIRTY;

-	}

-leave:

-	mdb_cursor_close(mc);

-	return rc;

-}

-

-int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)

-{

-	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))

-		return EINVAL;

-

-	txn->mt_dbxs[dbi].md_cmp = cmp;

-	return MDB_SUCCESS;

-}

-

-int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)

-{

-	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))

-		return EINVAL;

-

-	txn->mt_dbxs[dbi].md_dcmp = cmp;

-	return MDB_SUCCESS;

-}

-

-int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)

-{

-	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))

-		return EINVAL;

-

-	txn->mt_dbxs[dbi].md_rel = rel;

-	return MDB_SUCCESS;

-}

-

-int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)

-{

-	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))

-		return EINVAL;

-

-	txn->mt_dbxs[dbi].md_relctx = ctx;

-	return MDB_SUCCESS;

-}

-

-int ESECT

-mdb_env_get_maxkeysize(MDB_env *env)

-{

-	return ENV_MAXKEY(env);

-}

-

-int ESECT

-mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)

-{

-	unsigned int i, rdrs;

-	MDB_reader *mr;

-	char buf[64];

-	int rc = 0, first = 1;

-

-	if (!env || !func)

-		return -1;

-	if (!env->me_txns) {

-		return func("(no reader locks)\n", ctx);

-	}

-	rdrs = env->me_txns->mti_numreaders;

-	mr = env->me_txns->mti_readers;

-	for (i=0; i<rdrs; i++) {

-		if (mr[i].mr_pid) {

-			txnid_t	txnid = mr[i].mr_txnid;

-			sprintf(buf, txnid == (txnid_t)-1 ?

-				"%10d %"Z"x -\n" : "%10d %"Z"x %"Y"u\n",

-				(int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);

-			if (first) {

-				first = 0;

-				rc = func("    pid     thread     txnid\n", ctx);

-				if (rc < 0)

-					break;

-			}

-			rc = func(buf, ctx);

-			if (rc < 0)

-				break;

-		}

-	}

-	if (first) {

-		rc = func("(no active readers)\n", ctx);

-	}

-	return rc;

-}

-

-/** Insert pid into list if not already present.

- * return -1 if already present.

- */

-static int ESECT

-mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)

-{

-	/* binary search of pid in list */

-	unsigned base = 0;

-	unsigned cursor = 1;

-	int val = 0;

-	unsigned n = ids[0];

-

-	while( 0 < n ) {

-		unsigned pivot = n >> 1;

-		cursor = base + pivot + 1;

-		val = pid - ids[cursor];

-

-		if( val < 0 ) {

-			n = pivot;

-

-		} else if ( val > 0 ) {

-			base = cursor;

-			n -= pivot + 1;

-

-		} else {

-			/* found, so it's a duplicate */

-			return -1;

-		}

-	}

-

-	if( val > 0 ) {

-		++cursor;

-	}

-	ids[0]++;

-	for (n = ids[0]; n > cursor; n--)

-		ids[n] = ids[n-1];

-	ids[n] = pid;

-	return 0;

-}

-

-int ESECT

-mdb_reader_check(MDB_env *env, int *dead)

-{

-	if (!env)

-		return EINVAL;

-	if (dead)

-		*dead = 0;

-	return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS;

-}

-

-/** As #mdb_reader_check(). rlocked = <caller locked the reader mutex>. */

-static int ESECT

-mdb_reader_check0(MDB_env *env, int rlocked, int *dead)

-{

-	mdb_mutexref_t rmutex = rlocked ? NULL : env->me_rmutex;

-	unsigned int i, j, rdrs;

-	MDB_reader *mr;

-	MDB_PID_T *pids, pid;

-	int rc = MDB_SUCCESS, count = 0;

-

-	rdrs = env->me_txns->mti_numreaders;

-	pids = malloc((rdrs+1) * sizeof(MDB_PID_T));

-	if (!pids)

-		return ENOMEM;

-	pids[0] = 0;

-	mr = env->me_txns->mti_readers;

-	for (i=0; i<rdrs; i++) {

-		pid = mr[i].mr_pid;

-		if (pid && pid != env->me_pid) {

-			if (mdb_pid_insert(pids, pid) == 0) {

-				if (!mdb_reader_pid(env, Pidcheck, pid)) {

-					/* Stale reader found */

-					j = i;

-					if (rmutex) {

-						if ((rc = LOCK_MUTEX0(rmutex)) != 0) {

-							if ((rc = mdb_mutex_failed(env, rmutex, rc)))

-								break;

-							rdrs = 0; /* the above checked all readers */

-						} else {

-							/* Recheck, a new process may have reused pid */

-							if (mdb_reader_pid(env, Pidcheck, pid))

-								j = rdrs;

-						}

-					}

-					for (; j<rdrs; j++)

-							if (mr[j].mr_pid == pid) {

-								DPRINTF(("clear stale reader pid %u txn %"Y"d",

-									(unsigned) pid, mr[j].mr_txnid));

-								mr[j].mr_pid = 0;

-								count++;

-							}

-					if (rmutex)

-						UNLOCK_MUTEX(rmutex);

-				}

-			}

-		}

-	}

-	free(pids);

-	if (dead)

-		*dead = count;

-	return rc;

-}

-

-#ifdef MDB_ROBUST_SUPPORTED

-/** Handle #LOCK_MUTEX0() failure.

- * Try to repair the lock file if the mutex owner died.

- * @param[in] env	the environment handle

- * @param[in] mutex	LOCK_MUTEX0() mutex

- * @param[in] rc	LOCK_MUTEX0() error (nonzero)

- * @return 0 on success with the mutex locked, or an error code on failure.

- */

-static int ESECT

-mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc)

-{

-	int rlocked, rc2;

-	MDB_meta *meta;

-

-	if (rc == MDB_OWNERDEAD) {

-		/* We own the mutex. Clean up after dead previous owner. */

-		rc = MDB_SUCCESS;

-		rlocked = (mutex == env->me_rmutex);

-		if (!rlocked) {

-			/* Keep mti_txnid updated, otherwise next writer can

-			 * overwrite data which latest meta page refers to.

-			 */

-			meta = mdb_env_pick_meta(env);

-			env->me_txns->mti_txnid = meta->mm_txnid;

-			/* env is hosed if the dead thread was ours */

-			if (env->me_txn) {

-				env->me_flags |= MDB_FATAL_ERROR;

-				env->me_txn = NULL;

-				rc = MDB_PANIC;

-			}

-		}

-		DPRINTF(("%cmutex owner died, %s", (rlocked ? 'r' : 'w'),

-			(rc ? "this process' env is hosed" : "recovering")));

-		rc2 = mdb_reader_check0(env, rlocked, NULL);

-		if (rc2 == 0)

-			rc2 = mdb_mutex_consistent(mutex);

-		if (rc || (rc = rc2)) {

-			DPRINTF(("LOCK_MUTEX recovery failed, %s", mdb_strerror(rc)));

-			UNLOCK_MUTEX(mutex);

-		}

-	} else {

-#ifdef _WIN32

-		rc = ErrCode();

-#endif

-		DPRINTF(("LOCK_MUTEX failed, %s", mdb_strerror(rc)));

-	}

-

-	return rc;

-}

-#endif	/* MDB_ROBUST_SUPPORTED */

-/** @} */

-

-#if defined(_WIN32)

-static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize)

-{

-	int need;

-	wchar_t *result;

-	need = MultiByteToWideChar(CP_UTF8, 0, src, srcsize, NULL, 0);

-	if (need == 0xFFFD)

-		return EILSEQ;

-	if (need == 0)

-		return EINVAL;

-	result = malloc(sizeof(wchar_t) * need);

-	if (!result)

-		return ENOMEM;

-	MultiByteToWideChar(CP_UTF8, 0, src, srcsize, result, need);

-	if (dstsize)

-		*dstsize = need;

-	*dst = result;

-	return 0;

-}

-#endif /* defined(_WIN32) */

+/** @file mdb.c
+ *	@brief Lightning memory-mapped database library
+ *
+ *	A Btree-based database management library modeled loosely on the
+ *	BerkeleyDB API, but much simplified.
+ */
+/*
+ * Copyright 2011-2016 Howard Chu, Symas Corp.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ *
+ * This code is derived from btree.c written by Martin Hedenfalk.
+ *
+ * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE 1
+#endif
+#if defined(MDB_VL32) || defined(__WIN64__)
+#define _FILE_OFFSET_BITS	64
+#endif
+#ifdef _WIN32
+#include <malloc.h>
+#include <windows.h>
+
+#ifdef _WIN64
+#	pragma comment(lib, "lib/x64/ntdll.lib")
+#else
+#	pragma comment(lib, "lib/x86/ntdll.lib")
+#endif
+
+#pragma warning(disable: 4706)
+
+/* We use native NT APIs to setup the memory map, so that we can
+ * let the DB file grow incrementally instead of always preallocating
+ * the full size. These APIs are defined in <wdm.h> and <ntifs.h>
+ * but those headers are meant for driver-level development and
+ * conflict with the regular user-level headers, so we explicitly
+ * declare them here. Using these APIs also means we must link to
+ * ntdll.dll, which is not linked by default in user code.
+ */
+NTSTATUS WINAPI
+NtCreateSection(OUT PHANDLE sh, IN ACCESS_MASK acc,
+  IN void * oa OPTIONAL,
+  IN PLARGE_INTEGER ms OPTIONAL,
+  IN ULONG pp, IN ULONG aa, IN HANDLE fh OPTIONAL);
+
+typedef enum _SECTION_INHERIT {
+	ViewShare = 1,
+	ViewUnmap = 2
+} SECTION_INHERIT;
+
+NTSTATUS WINAPI
+NtMapViewOfSection(IN PHANDLE sh, IN HANDLE ph,
+  IN OUT PVOID *addr, IN ULONG_PTR zbits,
+  IN SIZE_T cs, IN OUT PLARGE_INTEGER off OPTIONAL,
+  IN OUT PSIZE_T vs, IN SECTION_INHERIT ih,
+  IN ULONG at, IN ULONG pp);
+
+NTSTATUS WINAPI
+NtClose(HANDLE h);
+
+/** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it
+ *  as int64 which is wrong. MSVC doesn't define it at all, so just
+ *  don't use it.
+ */
+#define MDB_PID_T	int
+#define MDB_THR_T	DWORD
+#include <sys/types.h>
+#include <sys/stat.h>
+#ifdef __GNUC__
+# include <sys/param.h>
+#else
+# define LITTLE_ENDIAN	1234
+# define BIG_ENDIAN	4321
+# define BYTE_ORDER	LITTLE_ENDIAN
+# ifndef SSIZE_MAX
+#  define SSIZE_MAX	INT_MAX
+# endif
+#endif
+#else
+#include <sys/types.h>
+#include <sys/stat.h>
+#define MDB_PID_T	pid_t
+#define MDB_THR_T	pthread_t
+#include <sys/param.h>
+#include <sys/uio.h>
+#include <sys/mman.h>
+#ifdef HAVE_SYS_FILE_H
+#include <sys/file.h>
+#endif
+#include <fcntl.h>
+#endif
+
+#if defined(__mips) && defined(__linux)
+/* MIPS has cache coherency issues, requires explicit cache control */
+#include <asm/cachectl.h>
+extern int cacheflush(char *addr, int nbytes, int cache);
+#define CACHEFLUSH(addr, bytes, cache)	cacheflush(addr, bytes, cache)
+#else
+#define CACHEFLUSH(addr, bytes, cache)
+#endif
+
+#if defined(__linux) && !defined(MDB_FDATASYNC_WORKS)
+/** fdatasync is broken on ext3/ext4fs on older kernels, see
+ *	description in #mdb_env_open2 comments. You can safely
+ *	define MDB_FDATASYNC_WORKS if this code will only be run
+ *	on kernels 3.6 and newer.
+ */
+#define	BROKEN_FDATASYNC
+#endif
+
+#include <errno.h>
+#include <limits.h>
+#include <stddef.h>
+#if _MSC_VER < 1800
+#	include <msapi/inttypes.h>
+#else
+#	include <inttypes.h>
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#ifdef _MSC_VER
+#include <io.h>
+typedef SSIZE_T	ssize_t;
+#else
+#include <unistd.h>
+#endif
+
+#if defined(__sun) || defined(ANDROID)
+/* Most platforms have posix_memalign, older may only have memalign */
+#define HAVE_MEMALIGN	1
+#include <malloc.h>
+#endif
+
+#if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
+#include <netinet/in.h>
+#include <resolv.h>	/* defines BYTE_ORDER on HPUX and Solaris */
+#endif
+
+#if defined(__APPLE__) || defined (BSD)
+# if !(defined(MDB_USE_POSIX_MUTEX) || defined(MDB_USE_POSIX_SEM))
+# define MDB_USE_SYSV_SEM	1
+# endif
+# define MDB_FDATASYNC		fsync
+#elif defined(ANDROID)
+# define MDB_FDATASYNC		fsync
+#endif
+
+#ifndef _WIN32
+#include <pthread.h>
+#ifdef MDB_USE_POSIX_SEM
+# define MDB_USE_HASH		1
+#include <semaphore.h>
+#elif defined(MDB_USE_SYSV_SEM)
+#include <sys/ipc.h>
+#include <sys/sem.h>
+#ifdef _SEM_SEMUN_UNDEFINED
+union semun {
+	int val;
+	struct semid_ds *buf;
+	unsigned short *array;
+};
+#endif /* _SEM_SEMUN_UNDEFINED */
+#else
+#define MDB_USE_POSIX_MUTEX	1
+#endif /* MDB_USE_POSIX_SEM */
+#endif /* !_WIN32 */
+
+#if defined(_WIN32) + defined(MDB_USE_POSIX_SEM) + defined(MDB_USE_SYSV_SEM) \
+	+ defined(MDB_USE_POSIX_MUTEX) != 1
+# error "Ambiguous shared-lock implementation"
+#endif
+
+#ifdef USE_VALGRIND
+#include <valgrind/memcheck.h>
+#define VGMEMP_CREATE(h,r,z)    VALGRIND_CREATE_MEMPOOL(h,r,z)
+#define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
+#define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
+#define VGMEMP_DESTROY(h)	VALGRIND_DESTROY_MEMPOOL(h)
+#define VGMEMP_DEFINED(a,s)	VALGRIND_MAKE_MEM_DEFINED(a,s)
+#else
+#define VGMEMP_CREATE(h,r,z)
+#define VGMEMP_ALLOC(h,a,s)
+#define VGMEMP_FREE(h,a)
+#define VGMEMP_DESTROY(h)
+#define VGMEMP_DEFINED(a,s)
+#endif
+
+#ifndef BYTE_ORDER
+# if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
+/* Solaris just defines one or the other */
+#  define LITTLE_ENDIAN	1234
+#  define BIG_ENDIAN	4321
+#  ifdef _LITTLE_ENDIAN
+#   define BYTE_ORDER  LITTLE_ENDIAN
+#  else
+#   define BYTE_ORDER  BIG_ENDIAN
+#  endif
+# else
+#  define BYTE_ORDER   __BYTE_ORDER
+# endif
+#endif
+
+#ifndef LITTLE_ENDIAN
+#define LITTLE_ENDIAN	__LITTLE_ENDIAN
+#endif
+#ifndef BIG_ENDIAN
+#define BIG_ENDIAN	__BIG_ENDIAN
+#endif
+
+#if defined(__i386) || defined(__x86_64) || defined(_M_IX86)
+#define MISALIGNED_OK	1
+#endif
+
+#include "lmdb.h"
+#include "midl.h"
+
+#if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
+# error "Unknown or unsupported endianness (BYTE_ORDER)"
+#elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
+# error "Two's complement, reasonably sized integer types, please"
+#endif
+
+#ifdef __GNUC__
+/** Put infrequently used env functions in separate section */
+# ifdef __APPLE__
+#  define	ESECT	__attribute__ ((section("__TEXT,text_env")))
+# else
+#  define	ESECT	__attribute__ ((section("text_env")))
+# endif
+#else
+#define ESECT
+#endif
+
+#ifdef _WIN32
+#define CALL_CONV WINAPI
+#else
+#define CALL_CONV
+#endif
+
+/** @defgroup internal	LMDB Internals
+ *	@{
+ */
+/** @defgroup compat	Compatibility Macros
+ *	A bunch of macros to minimize the amount of platform-specific ifdefs
+ *	needed throughout the rest of the code. When the features this library
+ *	needs are similar enough to POSIX to be hidden in a one-or-two line
+ *	replacement, this macro approach is used.
+ *	@{
+ */
+
+	/** Features under development */
+#ifndef MDB_DEVEL
+#define MDB_DEVEL 0
+#endif
+
+	/** Wrapper around __func__, which is a C99 feature */
+#if __STDC_VERSION__ >= 199901L
+# define mdb_func_	__func__
+#elif __GNUC__ >= 2 || _MSC_VER >= 1300
+# define mdb_func_	__FUNCTION__
+#else
+/* If a debug message says <mdb_unknown>(), update the #if statements above */
+# define mdb_func_	"<mdb_unknown>"
+#endif
+
+/* Internal error codes, not exposed outside liblmdb */
+#define	MDB_NO_ROOT		(MDB_LAST_ERRCODE + 10)
+#ifdef _WIN32
+#define MDB_OWNERDEAD	((int) WAIT_ABANDONED)
+#elif defined MDB_USE_SYSV_SEM
+#define MDB_OWNERDEAD	(MDB_LAST_ERRCODE + 11)
+#elif defined(MDB_USE_POSIX_MUTEX) && defined(EOWNERDEAD)
+#define MDB_OWNERDEAD	EOWNERDEAD	/**< #LOCK_MUTEX0() result if dead owner */
+#endif
+
+#ifdef __GLIBC__
+#define	GLIBC_VER	((__GLIBC__ << 16 )| __GLIBC_MINOR__)
+#endif
+/** Some platforms define the EOWNERDEAD error code
+ * even though they don't support Robust Mutexes.
+ * Compile with -DMDB_USE_ROBUST=0, or use some other
+ * mechanism like -DMDB_USE_SYSV_SEM instead of
+ * -DMDB_USE_POSIX_MUTEX. (SysV semaphores are
+ * also Robust, but some systems don't support them
+ * either.)
+ */
+#ifndef MDB_USE_ROBUST
+/* Android currently lacks Robust Mutex support. So does glibc < 2.4. */
+# if defined(MDB_USE_POSIX_MUTEX) && (defined(ANDROID) || \
+	(defined(__GLIBC__) && GLIBC_VER < 0x020004))
+#  define MDB_USE_ROBUST	0
+# else
+#  define MDB_USE_ROBUST	1
+/* glibc < 2.12 only provided _np API */
+#  if (defined(__GLIBC__) && GLIBC_VER < 0x02000c) || \
+	(defined(PTHREAD_MUTEX_ROBUST_NP) && !defined(PTHREAD_MUTEX_ROBUST))
+#   define PTHREAD_MUTEX_ROBUST	PTHREAD_MUTEX_ROBUST_NP
+#   define pthread_mutexattr_setrobust(attr, flag)	pthread_mutexattr_setrobust_np(attr, flag)
+#   define pthread_mutex_consistent(mutex)	pthread_mutex_consistent_np(mutex)
+#  endif
+# endif
+#endif /* MDB_USE_ROBUST */
+
+#if defined(MDB_OWNERDEAD) && MDB_USE_ROBUST
+#define MDB_ROBUST_SUPPORTED	1
+#endif
+
+#ifdef _WIN32
+#define MDB_USE_HASH	1
+#define MDB_PIDLOCK	0
+#define THREAD_RET	DWORD
+#define pthread_t	HANDLE
+#define pthread_mutex_t	HANDLE
+#define pthread_cond_t	HANDLE
+typedef HANDLE mdb_mutex_t, mdb_mutexref_t;
+#define pthread_key_t	DWORD
+#define pthread_self()	GetCurrentThreadId()
+#define pthread_key_create(x,y)	\
+	((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
+#define pthread_key_delete(x)	TlsFree(x)
+#define pthread_getspecific(x)	TlsGetValue(x)
+#define pthread_setspecific(x,y)	(TlsSetValue(x,y) ? 0 : ErrCode())
+#define pthread_mutex_unlock(x)	ReleaseMutex(*x)
+#define pthread_mutex_lock(x)	WaitForSingleObject(*x, INFINITE)
+#define pthread_cond_signal(x)	SetEvent(*x)
+#define pthread_cond_wait(cond,mutex)	do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)
+#define THREAD_CREATE(thr,start,arg)	thr=CreateThread(NULL,0,start,arg,0,NULL)
+#define THREAD_FINISH(thr)	WaitForSingleObject(thr, INFINITE)
+#define LOCK_MUTEX0(mutex)		WaitForSingleObject(mutex, INFINITE)
+#define UNLOCK_MUTEX(mutex)		ReleaseMutex(mutex)
+#define mdb_mutex_consistent(mutex)	0
+#define getpid()	GetCurrentProcessId()
+#define	MDB_FDATASYNC(fd)	(!FlushFileBuffers(fd))
+#define	MDB_MSYNC(addr,len,flags)	(!FlushViewOfFile(addr,len))
+#define	ErrCode()	GetLastError()
+#define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
+#define	close(fd)	(CloseHandle(fd) ? 0 : -1)
+#define	munmap(ptr,len)	UnmapViewOfFile(ptr)
+#ifdef PROCESS_QUERY_LIMITED_INFORMATION
+#define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION
+#else
+#define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000
+#endif
+#define	Z	"I"
+#else
+#define THREAD_RET	void *
+#define THREAD_CREATE(thr,start,arg)	pthread_create(&thr,NULL,start,arg)
+#define THREAD_FINISH(thr)	pthread_join(thr,NULL)
+#define	Z	"z"			/**< printf format modifier for size_t */
+
+	/** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
+#define MDB_PIDLOCK			1
+
+#ifdef MDB_USE_POSIX_SEM
+
+typedef sem_t *mdb_mutex_t, *mdb_mutexref_t;
+#define LOCK_MUTEX0(mutex)		mdb_sem_wait(mutex)
+#define UNLOCK_MUTEX(mutex)		sem_post(mutex)
+
+static int
+mdb_sem_wait(sem_t *sem)
+{
+   int rc;
+   while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
+   return rc;
+}
+
+#elif defined MDB_USE_SYSV_SEM
+
+typedef struct mdb_mutex {
+	int semid;
+	int semnum;
+	int *locked;
+} mdb_mutex_t[1], *mdb_mutexref_t;
+
+#define LOCK_MUTEX0(mutex)		mdb_sem_wait(mutex)
+#define UNLOCK_MUTEX(mutex)		do { \
+	struct sembuf sb = { 0, 1, SEM_UNDO }; \
+	sb.sem_num = (mutex)->semnum; \
+	*(mutex)->locked = 0; \
+	semop((mutex)->semid, &sb, 1); \
+} while(0)
+
+static int
+mdb_sem_wait(mdb_mutexref_t sem)
+{
+	int rc, *locked = sem->locked;
+	struct sembuf sb = { 0, -1, SEM_UNDO };
+	sb.sem_num = sem->semnum;
+	do {
+		if (!semop(sem->semid, &sb, 1)) {
+			rc = *locked ? MDB_OWNERDEAD : MDB_SUCCESS;
+			*locked = 1;
+			break;
+		}
+	} while ((rc = errno) == EINTR);
+	return rc;
+}
+
+#define mdb_mutex_consistent(mutex)	0
+
+#else	/* MDB_USE_POSIX_MUTEX: */
+	/** Shared mutex/semaphore as it is stored (mdb_mutex_t), and as
+	 *	local variables keep it (mdb_mutexref_t).
+	 *
+	 *	An mdb_mutex_t can be assigned to an mdb_mutexref_t.  They can
+	 *	be the same, or an array[size 1] and a pointer.
+	 *	@{
+	 */
+typedef pthread_mutex_t mdb_mutex_t[1], *mdb_mutexref_t;
+	/*	@} */
+	/** Lock the reader or writer mutex.
+	 *	Returns 0 or a code to give #mdb_mutex_failed(), as in #LOCK_MUTEX().
+	 */
+#define LOCK_MUTEX0(mutex)	pthread_mutex_lock(mutex)
+	/** Unlock the reader or writer mutex.
+	 */
+#define UNLOCK_MUTEX(mutex)	pthread_mutex_unlock(mutex)
+	/** Mark mutex-protected data as repaired, after death of previous owner.
+	 */
+#define mdb_mutex_consistent(mutex)	pthread_mutex_consistent(mutex)
+#endif	/* MDB_USE_POSIX_SEM || MDB_USE_SYSV_SEM */
+
+	/** Get the error code for the last failed system function.
+	 */
+#define	ErrCode()	errno
+
+	/** An abstraction for a file handle.
+	 *	On POSIX systems file handles are small integers. On Windows
+	 *	they're opaque pointers.
+	 */
+#define	HANDLE	int
+
+	/**	A value for an invalid file handle.
+	 *	Mainly used to initialize file variables and signify that they are
+	 *	unused.
+	 */
+#define INVALID_HANDLE_VALUE	(-1)
+
+	/** Get the size of a memory page for the system.
+	 *	This is the basic size that the platform's memory manager uses, and is
+	 *	fundamental to the use of memory-mapped files.
+	 */
+#define	GET_PAGESIZE(x)	((x) = sysconf(_SC_PAGE_SIZE))
+#endif
+
+#ifdef MDB_VL32
+#ifdef _WIN32
+#define	Y	"I64"
+#else
+#define	Y	"ll"
+#endif
+#else
+#define Y	Z
+#endif
+
+#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
+#define MNAME_LEN	32
+#elif defined(MDB_USE_SYSV_SEM)
+#define MNAME_LEN	(sizeof(int))
+#else
+#define MNAME_LEN	(sizeof(pthread_mutex_t))
+#endif
+
+#ifdef MDB_USE_SYSV_SEM
+#define SYSV_SEM_FLAG	1		/**< SysV sems in lockfile format */
+#else
+#define SYSV_SEM_FLAG	0
+#endif
+
+/** @} */
+
+#ifdef MDB_ROBUST_SUPPORTED
+	/** Lock mutex, handle any error, set rc = result.
+	 *	Return 0 on success, nonzero (not rc) on error.
+	 */
+#define LOCK_MUTEX(rc, env, mutex) \
+	(((rc) = LOCK_MUTEX0(mutex)) && \
+	 ((rc) = mdb_mutex_failed(env, mutex, rc)))
+static int mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc);
+#else
+#define LOCK_MUTEX(rc, env, mutex) ((rc) = LOCK_MUTEX0(mutex))
+#define mdb_mutex_failed(env, mutex, rc) (rc)
+#endif
+
+#ifndef _WIN32
+/**	A flag for opening a file and requesting synchronous data writes.
+ *	This is only used when writing a meta page. It's not strictly needed;
+ *	we could just do a normal write and then immediately perform a flush.
+ *	But if this flag is available it saves us an extra system call.
+ *
+ *	@note If O_DSYNC is undefined but exists in /usr/include,
+ * preferably set some compiler flag to get the definition.
+ */
+#ifndef MDB_DSYNC
+# ifdef O_DSYNC
+# define MDB_DSYNC	O_DSYNC
+# else
+# define MDB_DSYNC	O_SYNC
+# endif
+#endif
+#endif
+
+/** Function for flushing the data of a file. Define this to fsync
+ *	if fdatasync() is not supported.
+ */
+#ifndef MDB_FDATASYNC
+# define MDB_FDATASYNC	fdatasync
+#endif
+
+#ifndef MDB_MSYNC
+# define MDB_MSYNC(addr,len,flags)	msync(addr,len,flags)
+#endif
+
+#ifndef MS_SYNC
+#define	MS_SYNC	1
+#endif
+
+#ifndef MS_ASYNC
+#define	MS_ASYNC	0
+#endif
+
+	/** A page number in the database.
+	 *	Note that 64 bit page numbers are overkill, since pages themselves
+	 *	already represent 12-13 bits of addressable memory, and the OS will
+	 *	always limit applications to a maximum of 63 bits of address space.
+	 *
+	 *	@note In the #MDB_node structure, we only store 48 bits of this value,
+	 *	which thus limits us to only 60 bits of addressable data.
+	 */
+typedef MDB_ID	pgno_t;
+
+	/** A transaction ID.
+	 *	See struct MDB_txn.mt_txnid for details.
+	 */
+typedef MDB_ID	txnid_t;
+
+/** @defgroup debug	Debug Macros
+ *	@{
+ */
+#ifndef MDB_DEBUG
+	/**	Enable debug output.  Needs variable argument macros (a C99 feature).
+	 *	Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
+	 *	read from and written to the database (used for free space management).
+	 */
+#define MDB_DEBUG 0
+#endif
+
+#if MDB_DEBUG
+static int mdb_debug;
+static txnid_t mdb_debug_start;
+
+	/**	Print a debug message with printf formatting.
+	 *	Requires double parenthesis around 2 or more args.
+	 */
+# define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))
+# define DPRINTF0(fmt, ...) \
+	LMDB_Log("%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__)
+#else
+# define DPRINTF(args)	((void) 0)
+#endif
+	/**	Print a debug string.
+	 *	The string is printed literally, with no format processing.
+	 */
+#define DPUTS(arg)	DPRINTF(("%s", arg))
+	/** Debuging output value of a cursor DBI: Negative in a sub-cursor. */
+#define DDBI(mc) \
+	(((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi)
+/** @} */
+
+	/**	@brief The maximum size of a database page.
+	 *
+	 *	It is 32k or 64k, since value-PAGEBASE must fit in
+	 *	#MDB_page.%mp_upper.
+	 *
+	 *	LMDB will use database pages < OS pages if needed.
+	 *	That causes more I/O in write transactions: The OS must
+	 *	know (read) the whole page before writing a partial page.
+	 *
+	 *	Note that we don't currently support Huge pages. On Linux,
+	 *	regular data files cannot use Huge pages, and in general
+	 *	Huge pages aren't actually pageable. We rely on the OS
+	 *	demand-pager to read our data and page it out when memory
+	 *	pressure from other processes is high. So until OSs have
+	 *	actual paging support for Huge pages, they're not viable.
+	 */
+#define MAX_PAGESIZE	 (PAGEBASE ? 0x10000 : 0x8000)
+
+	/** The minimum number of keys required in a database page.
+	 *	Setting this to a larger value will place a smaller bound on the
+	 *	maximum size of a data item. Data items larger than this size will
+	 *	be pushed into overflow pages instead of being stored directly in
+	 *	the B-tree node. This value used to default to 4. With a page size
+	 *	of 4096 bytes that meant that any item larger than 1024 bytes would
+	 *	go into an overflow page. That also meant that on average 2-3KB of
+	 *	each overflow page was wasted space. The value cannot be lower than
+	 *	2 because then there would no longer be a tree structure. With this
+	 *	value, items larger than 2KB will go into overflow pages, and on
+	 *	average only 1KB will be wasted.
+	 */
+#define MDB_MINKEYS	 2
+
+	/**	A stamp that identifies a file as an LMDB file.
+	 *	There's nothing special about this value other than that it is easily
+	 *	recognizable, and it will reflect any byte order mismatches.
+	 */
+#define MDB_MAGIC	 0xBEEFC0DE
+
+	/**	The version number for a database's datafile format. */
+#define MDB_DATA_VERSION	 ((MDB_DEVEL) ? 999 : 1)
+	/**	The version number for a database's lockfile format. */
+#define MDB_LOCK_VERSION	 ((MDB_DEVEL) ? 999 : 1)
+
+	/**	@brief The max size of a key we can write, or 0 for computed max.
+	 *
+	 *	This macro should normally be left alone or set to 0.
+	 *	Note that a database with big keys or dupsort data cannot be
+	 *	reliably modified by a liblmdb which uses a smaller max.
+	 *	The default is 511 for backwards compat, or 0 when #MDB_DEVEL.
+	 *
+	 *	Other values are allowed, for backwards compat.  However:
+	 *	A value bigger than the computed max can break if you do not
+	 *	know what you are doing, and liblmdb <= 0.9.10 can break when
+	 *	modifying a DB with keys/dupsort data bigger than its max.
+	 *
+	 *	Data items in an #MDB_DUPSORT database are also limited to
+	 *	this size, since they're actually keys of a sub-DB.  Keys and
+	 *	#MDB_DUPSORT data items must fit on a node in a regular page.
+	 */
+#ifndef MDB_MAXKEYSIZE
+#define MDB_MAXKEYSIZE	 ((MDB_DEVEL) ? 0 : 511)
+#endif
+
+	/**	The maximum size of a key we can write to the environment. */
+#if MDB_MAXKEYSIZE
+#define ENV_MAXKEY(env)	(MDB_MAXKEYSIZE)
+#else
+#define ENV_MAXKEY(env)	((env)->me_maxkey)
+#endif
+
+	/**	@brief The maximum size of a data item.
+	 *
+	 *	We only store a 32 bit value for node sizes.
+	 */
+#define MAXDATASIZE	0xffffffffUL
+
+#if MDB_DEBUG
+	/**	Key size which fits in a #DKBUF.
+	 *	@ingroup debug
+	 */
+#define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511)
+	/**	A key buffer.
+	 *	@ingroup debug
+	 *	This is used for printing a hex dump of a key's contents.
+	 */
+#define DKBUF	char kbuf[DKBUF_MAXKEYSIZE*2+1]
+	/**	Display a key in hex.
+	 *	@ingroup debug
+	 *	Invoke a function to display a key in hex.
+	 */
+#define	DKEY(x)	mdb_dkey(x, kbuf)
+#else
+#define	DKBUF
+#define DKEY(x)	0
+#endif
+
+	/** An invalid page number.
+	 *	Mainly used to denote an empty tree.
+	 */
+#define P_INVALID	 (~(pgno_t)0)
+
+	/** Test if the flags \b f are set in a flag word \b w. */
+#define F_ISSET(w, f)	 (((w) & (f)) == (f))
+
+	/** Round \b n up to an even number. */
+#define EVEN(n)		(((n) + 1U) & -2) /* sign-extending -2 to match n+1U */
+
+	/**	Used for offsets within a single page.
+	 *	Since memory pages are typically 4 or 8KB in size, 12-13 bits,
+	 *	this is plenty.
+	 */
+typedef uint16_t	 indx_t;
+
+	/**	Default size of memory map.
+	 *	This is certainly too small for any actual applications. Apps should always set
+	 *	the size explicitly using #mdb_env_set_mapsize().
+	 */
+#define DEFAULT_MAPSIZE	1048576
+
+/**	@defgroup readers	Reader Lock Table
+ *	Readers don't acquire any locks for their data access. Instead, they
+ *	simply record their transaction ID in the reader table. The reader
+ *	mutex is needed just to find an empty slot in the reader table. The
+ *	slot's address is saved in thread-specific data so that subsequent read
+ *	transactions started by the same thread need no further locking to proceed.
+ *
+ *	If #MDB_NOTLS is set, the slot address is not saved in thread-specific data.
+ *
+ *	No reader table is used if the database is on a read-only filesystem, or
+ *	if #MDB_NOLOCK is set.
+ *
+ *	Since the database uses multi-version concurrency control, readers don't
+ *	actually need any locking. This table is used to keep track of which
+ *	readers are using data from which old transactions, so that we'll know
+ *	when a particular old transaction is no longer in use. Old transactions
+ *	that have discarded any data pages can then have those pages reclaimed
+ *	for use by a later write transaction.
+ *
+ *	The lock table is constructed such that reader slots are aligned with the
+ *	processor's cache line size. Any slot is only ever used by one thread.
+ *	This alignment guarantees that there will be no contention or cache
+ *	thrashing as threads update their own slot info, and also eliminates
+ *	any need for locking when accessing a slot.
+ *
+ *	A writer thread will scan every slot in the table to determine the oldest
+ *	outstanding reader transaction. Any freed pages older than this will be
+ *	reclaimed by the writer. The writer doesn't use any locks when scanning
+ *	this table. This means that there's no guarantee that the writer will
+ *	see the most up-to-date reader info, but that's not required for correct
+ *	operation - all we need is to know the upper bound on the oldest reader,
+ *	we don't care at all about the newest reader. So the only consequence of
+ *	reading stale information here is that old pages might hang around a
+ *	while longer before being reclaimed. That's actually good anyway, because
+ *	the longer we delay reclaiming old pages, the more likely it is that a
+ *	string of contiguous pages can be found after coalescing old pages from
+ *	many old transactions together.
+ *	@{
+ */
+	/**	Number of slots in the reader table.
+	 *	This value was chosen somewhat arbitrarily. 126 readers plus a
+	 *	couple mutexes fit exactly into 8KB on my development machine.
+	 *	Applications should set the table size using #mdb_env_set_maxreaders().
+	 */
+#define DEFAULT_READERS	126
+
+	/**	The size of a CPU cache line in bytes. We want our lock structures
+	 *	aligned to this size to avoid false cache line sharing in the
+	 *	lock table.
+	 *	This value works for most CPUs. For Itanium this should be 128.
+	 */
+#ifndef CACHELINE
+#define CACHELINE	64
+#endif
+
+	/**	The information we store in a single slot of the reader table.
+	 *	In addition to a transaction ID, we also record the process and
+	 *	thread ID that owns a slot, so that we can detect stale information,
+	 *	e.g. threads or processes that went away without cleaning up.
+	 *	@note We currently don't check for stale records. We simply re-init
+	 *	the table when we know that we're the only process opening the
+	 *	lock file.
+	 */
+typedef struct MDB_rxbody {
+	/**	Current Transaction ID when this transaction began, or (txnid_t)-1.
+	 *	Multiple readers that start at the same time will probably have the
+	 *	same ID here. Again, it's not important to exclude them from
+	 *	anything; all we need to know is which version of the DB they
+	 *	started from so we can avoid overwriting any data used in that
+	 *	particular version.
+	 */
+	volatile txnid_t		mrb_txnid;
+	/** The process ID of the process owning this reader txn. */
+	volatile MDB_PID_T	mrb_pid;
+	/** The thread ID of the thread owning this txn. */
+	volatile MDB_THR_T	mrb_tid;
+} MDB_rxbody;
+
+	/** The actual reader record, with cacheline padding. */
+typedef struct MDB_reader {
+	union {
+		MDB_rxbody mrx;
+		/** shorthand for mrb_txnid */
+#define	mr_txnid	mru.mrx.mrb_txnid
+#define	mr_pid	mru.mrx.mrb_pid
+#define	mr_tid	mru.mrx.mrb_tid
+		/** cache line alignment */
+		char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
+	} mru;
+} MDB_reader;
+
+	/** The header for the reader table.
+	 *	The table resides in a memory-mapped file. (This is a different file
+	 *	than is used for the main database.)
+	 *
+	 *	For POSIX the actual mutexes reside in the shared memory of this
+	 *	mapped file. On Windows, mutexes are named objects allocated by the
+	 *	kernel; we store the mutex names in this mapped file so that other
+	 *	processes can grab them. This same approach is also used on
+	 *	MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
+	 *	process-shared POSIX mutexes. For these cases where a named object
+	 *	is used, the object name is derived from a 64 bit FNV hash of the
+	 *	environment pathname. As such, naming collisions are extremely
+	 *	unlikely. If a collision occurs, the results are unpredictable.
+	 */
+typedef struct MDB_txbody {
+		/** Stamp identifying this as an LMDB file. It must be set
+		 *	to #MDB_MAGIC. */
+	uint32_t	mtb_magic;
+		/** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */
+	uint32_t	mtb_format;
+#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
+	char	mtb_rmname[MNAME_LEN];
+#elif defined(MDB_USE_SYSV_SEM)
+	int 	mtb_semid;
+	int		mtb_rlocked;
+#else
+		/** Mutex protecting access to this table.
+		 *	This is the reader table lock used with LOCK_MUTEX().
+		 */
+	mdb_mutex_t	mtb_rmutex;
+#endif
+		/**	The ID of the last transaction committed to the database.
+		 *	This is recorded here only for convenience; the value can always
+		 *	be determined by reading the main database meta pages.
+		 */
+	volatile txnid_t		mtb_txnid;
+		/** The number of slots that have been used in the reader table.
+		 *	This always records the maximum count, it is not decremented
+		 *	when readers release their slots.
+		 */
+	volatile unsigned	mtb_numreaders;
+} MDB_txbody;
+
+	/** The actual reader table definition. */
+typedef struct MDB_txninfo {
+	union {
+		MDB_txbody mtb;
+#define mti_magic	mt1.mtb.mtb_magic
+#define mti_format	mt1.mtb.mtb_format
+#define mti_rmutex	mt1.mtb.mtb_rmutex
+#define mti_rmname	mt1.mtb.mtb_rmname
+#define mti_txnid	mt1.mtb.mtb_txnid
+#define mti_numreaders	mt1.mtb.mtb_numreaders
+#ifdef MDB_USE_SYSV_SEM
+#define	mti_semid	mt1.mtb.mtb_semid
+#define	mti_rlocked	mt1.mtb.mtb_rlocked
+#endif
+		char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
+	} mt1;
+	union {
+#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
+		char mt2_wmname[MNAME_LEN];
+#define	mti_wmname	mt2.mt2_wmname
+#elif defined MDB_USE_SYSV_SEM
+		int mt2_wlocked;
+#define mti_wlocked	mt2.mt2_wlocked
+#else
+		mdb_mutex_t	mt2_wmutex;
+#define mti_wmutex	mt2.mt2_wmutex
+#endif
+		char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
+	} mt2;
+	MDB_reader	mti_readers[1];
+} MDB_txninfo;
+
+	/** Lockfile format signature: version, features and field layout */
+#define MDB_LOCK_FORMAT \
+	((uint32_t) \
+	 ((MDB_LOCK_VERSION) \
+	  /* Flags which describe functionality */ \
+	  + (SYSV_SEM_FLAG << 18) \
+	  + (((MDB_PIDLOCK) != 0) << 16)))
+/** @} */
+
+/** Common header for all page types.
+ * Overflow records occupy a number of contiguous pages with no
+ * headers on any page after the first.
+ */
+typedef struct MDB_page {
+#define	mp_pgno	mp_p.p_pgno
+#define	mp_next	mp_p.p_next
+	union {
+		pgno_t		p_pgno;	/**< page number */
+		struct MDB_page *p_next; /**< for in-memory list of freed pages */
+	} mp_p;
+	uint16_t	mp_pad;
+/**	@defgroup mdb_page	Page Flags
+ *	@ingroup internal
+ *	Flags for the page headers.
+ *	@{
+ */
+#define	P_BRANCH	 0x01		/**< branch page */
+#define	P_LEAF		 0x02		/**< leaf page */
+#define	P_OVERFLOW	 0x04		/**< overflow page */
+#define	P_META		 0x08		/**< meta page */
+#define	P_DIRTY		 0x10		/**< dirty page, also set for #P_SUBP pages */
+#define	P_LEAF2		 0x20		/**< for #MDB_DUPFIXED records */
+#define	P_SUBP		 0x40		/**< for #MDB_DUPSORT sub-pages */
+#define	P_LOOSE		 0x4000		/**< page was dirtied then freed, can be reused */
+#define	P_KEEP		 0x8000		/**< leave this page alone during spill */
+/** @} */
+	uint16_t	mp_flags;		/**< @ref mdb_page */
+#define mp_lower	mp_pb.pb.pb_lower
+#define mp_upper	mp_pb.pb.pb_upper
+#define mp_pages	mp_pb.pb_pages
+	union {
+		struct {
+			indx_t		pb_lower;		/**< lower bound of free space */
+			indx_t		pb_upper;		/**< upper bound of free space */
+		} pb;
+		uint32_t	pb_pages;	/**< number of overflow pages */
+	} mp_pb;
+	indx_t		mp_ptrs[1];		/**< dynamic size */
+} MDB_page;
+
+	/** Size of the page header, excluding dynamic data at the end */
+#define PAGEHDRSZ	 ((unsigned) offsetof(MDB_page, mp_ptrs))
+
+	/** Address of first usable data byte in a page, after the header */
+#define METADATA(p)	 ((void *)((char *)(p) + PAGEHDRSZ))
+
+	/** ITS#7713, change PAGEBASE to handle 65536 byte pages */
+#define	PAGEBASE	((MDB_DEVEL) ? PAGEHDRSZ : 0)
+
+	/** Number of nodes on a page */
+#define NUMKEYS(p)	 (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1)
+
+	/** The amount of space remaining in the page */
+#define SIZELEFT(p)	 (indx_t)((p)->mp_upper - (p)->mp_lower)
+
+	/** The percentage of space used in the page, in tenths of a percent. */
+#define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
+				((env)->me_psize - PAGEHDRSZ))
+	/** The minimum page fill factor, in tenths of a percent.
+	 *	Pages emptier than this are candidates for merging.
+	 */
+#define FILL_THRESHOLD	 250
+
+	/** Test if a page is a leaf page */
+#define IS_LEAF(p)	 F_ISSET((p)->mp_flags, P_LEAF)
+	/** Test if a page is a LEAF2 page */
+#define IS_LEAF2(p)	 F_ISSET((p)->mp_flags, P_LEAF2)
+	/** Test if a page is a branch page */
+#define IS_BRANCH(p)	 F_ISSET((p)->mp_flags, P_BRANCH)
+	/** Test if a page is an overflow page */
+#define IS_OVERFLOW(p)	 F_ISSET((p)->mp_flags, P_OVERFLOW)
+	/** Test if a page is a sub page */
+#define IS_SUBP(p)	 F_ISSET((p)->mp_flags, P_SUBP)
+
+	/** The number of overflow pages needed to store the given size. */
+#define OVPAGES(size, psize)	((PAGEHDRSZ-1 + (size)) / (psize) + 1)
+
+	/** Link in #MDB_txn.%mt_loose_pgs list */
+#define NEXT_LOOSE_PAGE(p)		(*(MDB_page **)((p) + 2))
+
+	/** Header for a single key/data pair within a page.
+	 * Used in pages of type #P_BRANCH and #P_LEAF without #P_LEAF2.
+	 * We guarantee 2-byte alignment for 'MDB_node's.
+	 */
+typedef struct MDB_node {
+	/** lo and hi are used for data size on leaf nodes and for
+	 * child pgno on branch nodes. On 64 bit platforms, flags
+	 * is also used for pgno. (Branch nodes have no flags).
+	 * They are in host byte order in case that lets some
+	 * accesses be optimized into a 32-bit word access.
+	 */
+#if BYTE_ORDER == LITTLE_ENDIAN
+	unsigned short	mn_lo, mn_hi;	/**< part of data size or pgno */
+#else
+	unsigned short	mn_hi, mn_lo;
+#endif
+/** @defgroup mdb_node Node Flags
+ *	@ingroup internal
+ *	Flags for node headers.
+ *	@{
+ */
+#define F_BIGDATA	 0x01			/**< data put on overflow page */
+#define F_SUBDATA	 0x02			/**< data is a sub-database */
+#define F_DUPDATA	 0x04			/**< data has duplicates */
+
+/** valid flags for #mdb_node_add() */
+#define	NODE_ADD_FLAGS	(F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
+
+/** @} */
+	unsigned short	mn_flags;		/**< @ref mdb_node */
+	unsigned short	mn_ksize;		/**< key size */
+	char		mn_data[1];			/**< key and data are appended here */
+} MDB_node;
+
+	/** Size of the node header, excluding dynamic data at the end */
+#define NODESIZE	 offsetof(MDB_node, mn_data)
+
+	/** Bit position of top word in page number, for shifting mn_flags */
+#define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
+
+	/** Size of a node in a branch page with a given key.
+	 *	This is just the node header plus the key, there is no data.
+	 */
+#define INDXSIZE(k)	 (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
+
+	/** Size of a node in a leaf page with a given key and data.
+	 *	This is node header plus key plus data size.
+	 */
+#define LEAFSIZE(k, d)	 (NODESIZE + (k)->mv_size + (d)->mv_size)
+
+	/** Address of node \b i in page \b p */
+#define NODEPTR(p, i)	 ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE))
+
+	/** Address of the key for the node */
+#define NODEKEY(node)	 (void *)((node)->mn_data)
+
+	/** Address of the data for a node */
+#define NODEDATA(node)	 (void *)((char *)(node)->mn_data + (node)->mn_ksize)
+
+	/** Get the page number pointed to by a branch node */
+#define NODEPGNO(node) \
+	((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
+	 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
+	/** Set the page number in a branch node */
+#define SETPGNO(node,pgno)	do { \
+	(node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
+	if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
+
+	/** Get the size of the data in a leaf node */
+#define NODEDSZ(node)	 ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
+	/** Set the size of the data for a leaf node */
+#define SETDSZ(node,size)	do { \
+	(node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
+	/** The size of a key in a node */
+#define NODEKSZ(node)	 ((node)->mn_ksize)
+
+	/** Copy a page number from src to dst */
+#ifdef MISALIGNED_OK
+#define COPY_PGNO(dst,src)	dst = src
+#else
+#if SIZE_MAX > 4294967295UL
+#define COPY_PGNO(dst,src)	do { \
+	unsigned short *s, *d;	\
+	s = (unsigned short *)&(src);	\
+	d = (unsigned short *)&(dst);	\
+	*d++ = *s++;	\
+	*d++ = *s++;	\
+	*d++ = *s++;	\
+	*d = *s;	\
+} while (0)
+#else
+#define COPY_PGNO(dst,src)	do { \
+	unsigned short *s, *d;	\
+	s = (unsigned short *)&(src);	\
+	d = (unsigned short *)&(dst);	\
+	*d++ = *s++;	\
+	*d = *s;	\
+} while (0)
+#endif
+#endif
+	/** The address of a key in a LEAF2 page.
+	 *	LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
+	 *	There are no node headers, keys are stored contiguously.
+	 */
+#define LEAF2KEY(p, i, ks)	((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
+
+	/** Set the \b node's key into \b keyptr, if requested. */
+#define MDB_GET_KEY(node, keyptr)	{ if ((keyptr) != NULL) { \
+	(keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
+
+	/** Set the \b node's key into \b key. */
+#define MDB_GET_KEY2(node, key)	{ key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
+
+	/** Information about a single database in the environment. */
+typedef struct MDB_db {
+	uint32_t	md_pad;		/**< also ksize for LEAF2 pages */
+	uint16_t	md_flags;	/**< @ref mdb_dbi_open */
+	uint16_t	md_depth;	/**< depth of this tree */
+	pgno_t		md_branch_pages;	/**< number of internal pages */
+	pgno_t		md_leaf_pages;		/**< number of leaf pages */
+	pgno_t		md_overflow_pages;	/**< number of overflow pages */
+	mdb_size_t	md_entries;		/**< number of data items */
+	pgno_t		md_root;		/**< the root page of this tree */
+} MDB_db;
+
+	/** mdb_dbi_open flags */
+#define MDB_VALID	0x8000		/**< DB handle is valid, for me_dbflags */
+#define PERSISTENT_FLAGS	(0xffff & ~(MDB_VALID))
+#define VALID_FLAGS	(MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\
+	MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)
+
+	/** Handle for the DB used to track free pages. */
+#define	FREE_DBI	0
+	/** Handle for the default DB. */
+#define	MAIN_DBI	1
+	/** Number of DBs in metapage (free and main) - also hardcoded elsewhere */
+#define CORE_DBS	2
+
+	/** Number of meta pages - also hardcoded elsewhere */
+#define NUM_METAS	2
+
+	/** Meta page content.
+	 *	A meta page is the start point for accessing a database snapshot.
+	 *	Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2).
+	 */
+typedef struct MDB_meta {
+		/** Stamp identifying this as an LMDB file. It must be set
+		 *	to #MDB_MAGIC. */
+	uint32_t	mm_magic;
+		/** Version number of this file. Must be set to #MDB_DATA_VERSION. */
+	uint32_t	mm_version;
+#ifdef MDB_VL32
+	union {		/* always zero since we don't support fixed mapping in MDB_VL32 */
+		MDB_ID	mmun_ull;
+		void *mmun_address;
+	} mm_un;
+#define	mm_address mm_un.mmun_address
+#else
+	void		*mm_address;		/**< address for fixed mapping */
+#endif
+	pgno_t		mm_mapsize;			/**< size of mmap region */
+	MDB_db		mm_dbs[CORE_DBS];	/**< first is free space, 2nd is main db */
+	/** The size of pages used in this DB */
+#define	mm_psize	mm_dbs[FREE_DBI].md_pad
+	/** Any persistent environment flags. @ref mdb_env */
+#define	mm_flags	mm_dbs[FREE_DBI].md_flags
+	pgno_t		mm_last_pg;			/**< last used page in file */
+	volatile txnid_t	mm_txnid;	/**< txnid that committed this page */
+} MDB_meta;
+
+	/** Buffer for a stack-allocated meta page.
+	 *	The members define size and alignment, and silence type
+	 *	aliasing warnings.  They are not used directly; that could
+	 *	mean incorrectly using several union members in parallel.
+	 */
+typedef union MDB_metabuf {
+	MDB_page	mb_page;
+	struct {
+		char		mm_pad[PAGEHDRSZ];
+		MDB_meta	mm_meta;
+	} mb_metabuf;
+} MDB_metabuf;
+
+	/** Auxiliary DB info.
+	 *	The information here is mostly static/read-only. There is
+	 *	only a single copy of this record in the environment.
+	 */
+typedef struct MDB_dbx {
+	MDB_val		md_name;		/**< name of the database */
+	MDB_cmp_func	*md_cmp;	/**< function for comparing keys */
+	MDB_cmp_func	*md_dcmp;	/**< function for comparing data items */
+	MDB_rel_func	*md_rel;	/**< user relocate function */
+	void		*md_relctx;		/**< user-provided context for md_rel */
+} MDB_dbx;
+
+	/** A database transaction.
+	 *	Every operation requires a transaction handle.
+	 */
+struct MDB_txn {
+	MDB_txn		*mt_parent;		/**< parent of a nested txn */
+	/** Nested txn under this txn, set together with flag #MDB_TXN_HAS_CHILD */
+	MDB_txn		*mt_child;
+	pgno_t		mt_next_pgno;	/**< next unallocated page */
+#ifdef MDB_VL32
+	pgno_t		mt_last_pgno;	/**< last written page */
+#endif
+	/** The ID of this transaction. IDs are integers incrementing from 1.
+	 *	Only committed write transactions increment the ID. If a transaction
+	 *	aborts, the ID may be re-used by the next writer.
+	 */
+	txnid_t		mt_txnid;
+	MDB_env		*mt_env;		/**< the DB environment */
+	/** The list of pages that became unused during this transaction.
+	 */
+	MDB_IDL		mt_free_pgs;
+	/** The list of loose pages that became unused and may be reused
+	 *	in this transaction, linked through #NEXT_LOOSE_PAGE(page).
+	 */
+	MDB_page	*mt_loose_pgs;
+	/* #Number of loose pages (#mt_loose_pgs) */
+	int			mt_loose_count;
+	/** The sorted list of dirty pages we temporarily wrote to disk
+	 *	because the dirty list was full. page numbers in here are
+	 *	shifted left by 1, deleted slots have the LSB set.
+	 */
+	MDB_IDL		mt_spill_pgs;
+	union {
+		/** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */
+		MDB_ID2L	dirty_list;
+		/** For read txns: This thread/txn's reader table slot, or NULL. */
+		MDB_reader	*reader;
+	} mt_u;
+	/** Array of records for each DB known in the environment. */
+	MDB_dbx		*mt_dbxs;
+	/** Array of MDB_db records for each known DB */
+	MDB_db		*mt_dbs;
+	/** Array of sequence numbers for each DB handle */
+	unsigned int	*mt_dbiseqs;
+/** @defgroup mt_dbflag	Transaction DB Flags
+ *	@ingroup internal
+ * @{
+ */
+#define DB_DIRTY	0x01		/**< DB was modified or is DUPSORT data */
+#define DB_STALE	0x02		/**< Named-DB record is older than txnID */
+#define DB_NEW		0x04		/**< Named-DB handle opened in this txn */
+#define DB_VALID	0x08		/**< DB handle is valid, see also #MDB_VALID */
+#define DB_USRVALID	0x10		/**< As #DB_VALID, but not set for #FREE_DBI */
+/** @} */
+	/** In write txns, array of cursors for each DB */
+	MDB_cursor	**mt_cursors;
+	/** Array of flags for each DB */
+	unsigned char	*mt_dbflags;
+#ifdef MDB_VL32
+	/** List of read-only pages (actually chunks) */
+	MDB_ID3L	mt_rpages;
+	/** We map chunks of 16 pages. Even though Windows uses 4KB pages, all
+	 * mappings must begin on 64KB boundaries. So we round off all pgnos to
+	 * a chunk boundary. We do the same on Linux for symmetry, and also to
+	 * reduce the frequency of mmap/munmap calls.
+	 */
+#define MDB_RPAGE_CHUNK	16
+#define MDB_TRPAGE_SIZE	4096	/**< size of #mt_rpages array of chunks */
+#define MDB_TRPAGE_MAX	(MDB_TRPAGE_SIZE-1)	/**< maximum chunk index */
+	unsigned int mt_rpcheck;	/**< threshold for reclaiming unref'd chunks */
+#endif
+	/**	Number of DB records in use, or 0 when the txn is finished.
+	 *	This number only ever increments until the txn finishes; we
+	 *	don't decrement it when individual DB handles are closed.
+	 */
+	MDB_dbi		mt_numdbs;
+
+/** @defgroup mdb_txn	Transaction Flags
+ *	@ingroup internal
+ *	@{
+ */
+	/** #mdb_txn_begin() flags */
+#define MDB_TXN_BEGIN_FLAGS	(MDB_NOMETASYNC|MDB_NOSYNC|MDB_RDONLY)
+#define MDB_TXN_NOMETASYNC	MDB_NOMETASYNC	/**< don't sync meta for this txn on commit */
+#define MDB_TXN_NOSYNC		MDB_NOSYNC	/**< don't sync this txn on commit */
+#define MDB_TXN_RDONLY		MDB_RDONLY	/**< read-only transaction */
+	/* internal txn flags */
+#define MDB_TXN_WRITEMAP	MDB_WRITEMAP	/**< copy of #MDB_env flag in writers */
+#define MDB_TXN_FINISHED	0x01		/**< txn is finished or never began */
+#define MDB_TXN_ERROR		0x02		/**< txn is unusable after an error */
+#define MDB_TXN_DIRTY		0x04		/**< must write, even if dirty list is empty */
+#define MDB_TXN_SPILLS		0x08		/**< txn or a parent has spilled pages */
+#define MDB_TXN_HAS_CHILD	0x10		/**< txn has an #MDB_txn.%mt_child */
+	/** most operations on the txn are currently illegal */
+#define MDB_TXN_BLOCKED		(MDB_TXN_FINISHED|MDB_TXN_ERROR|MDB_TXN_HAS_CHILD)
+/** @} */
+	unsigned int	mt_flags;		/**< @ref mdb_txn */
+	/** #dirty_list room: Array size - \#dirty pages visible to this txn.
+	 *	Includes ancestor txns' dirty pages not hidden by other txns'
+	 *	dirty/spilled pages. Thus commit(nested txn) has room to merge
+	 *	dirty_list into mt_parent after freeing hidden mt_parent pages.
+	 */
+	unsigned int	mt_dirty_room;
+};
+
+/** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
+ * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
+ * raise this on a 64 bit machine.
+ */
+#define CURSOR_STACK		 32
+
+struct MDB_xcursor;
+
+	/** Cursors are used for all DB operations.
+	 *	A cursor holds a path of (page pointer, key index) from the DB
+	 *	root to a position in the DB, plus other state. #MDB_DUPSORT
+	 *	cursors include an xcursor to the current data item. Write txns
+	 *	track their cursors and keep them up to date when data moves.
+	 *	Exception: An xcursor's pointer to a #P_SUBP page can be stale.
+	 *	(A node with #F_DUPDATA but no #F_SUBDATA contains a subpage).
+	 */
+struct MDB_cursor {
+	/** Next cursor on this DB in this txn */
+	MDB_cursor	*mc_next;
+	/** Backup of the original cursor if this cursor is a shadow */
+	MDB_cursor	*mc_backup;
+	/** Context used for databases with #MDB_DUPSORT, otherwise NULL */
+	struct MDB_xcursor	*mc_xcursor;
+	/** The transaction that owns this cursor */
+	MDB_txn		*mc_txn;
+	/** The database handle this cursor operates on */
+	MDB_dbi		mc_dbi;
+	/** The database record for this cursor */
+	MDB_db		*mc_db;
+	/** The database auxiliary record for this cursor */
+	MDB_dbx		*mc_dbx;
+	/** The @ref mt_dbflag for this database */
+	unsigned char	*mc_dbflag;
+	unsigned short 	mc_snum;	/**< number of pushed pages */
+	unsigned short	mc_top;		/**< index of top page, normally mc_snum-1 */
+/** @defgroup mdb_cursor	Cursor Flags
+ *	@ingroup internal
+ *	Cursor state flags.
+ *	@{
+ */
+#define C_INITIALIZED	0x01	/**< cursor has been initialized and is valid */
+#define C_EOF	0x02			/**< No more data */
+#define C_SUB	0x04			/**< Cursor is a sub-cursor */
+#define C_DEL	0x08			/**< last op was a cursor_del */
+#define C_UNTRACK	0x40		/**< Un-track cursor when closing */
+#define C_WRITEMAP	MDB_TXN_WRITEMAP /**< Copy of txn flag */
+/** Read-only cursor into the txn's original snapshot in the map.
+ *	Set for read-only txns, and in #mdb_page_alloc() for #FREE_DBI when
+ *	#MDB_DEVEL & 2. Only implements code which is necessary for this.
+ */
+#define C_ORIG_RDONLY	MDB_TXN_RDONLY
+/** @} */
+	unsigned int	mc_flags;	/**< @ref mdb_cursor */
+	MDB_page	*mc_pg[CURSOR_STACK];	/**< stack of pushed pages */
+	indx_t		mc_ki[CURSOR_STACK];	/**< stack of page indices */
+#ifdef MDB_VL32
+	MDB_page	*mc_ovpg;		/**< a referenced overflow page */
+#endif
+};
+
+	/** Context for sorted-dup records.
+	 *	We could have gone to a fully recursive design, with arbitrarily
+	 *	deep nesting of sub-databases. But for now we only handle these
+	 *	levels - main DB, optional sub-DB, sorted-duplicate DB.
+	 */
+typedef struct MDB_xcursor {
+	/** A sub-cursor for traversing the Dup DB */
+	MDB_cursor mx_cursor;
+	/** The database record for this Dup DB */
+	MDB_db	mx_db;
+	/**	The auxiliary DB record for this Dup DB */
+	MDB_dbx	mx_dbx;
+	/** The @ref mt_dbflag for this Dup DB */
+	unsigned char mx_dbflag;
+} MDB_xcursor;
+
+	/** State of FreeDB old pages, stored in the MDB_env */
+typedef struct MDB_pgstate {
+	pgno_t		*mf_pghead;	/**< Reclaimed freeDB pages, or NULL before use */
+	txnid_t		mf_pglast;	/**< ID of last used record, or 0 if !mf_pghead */
+} MDB_pgstate;
+
+	/** The database environment. */
+struct MDB_env {
+	HANDLE		me_fd;		/**< The main data file */
+	HANDLE		me_lfd;		/**< The lock file */
+	HANDLE		me_mfd;			/**< just for writing the meta pages */
+#if defined(MDB_VL32) && defined(_WIN32)
+	HANDLE		me_fmh;		/**< File Mapping handle */
+#endif
+	/** Failed to update the meta page. Probably an I/O error. */
+#define	MDB_FATAL_ERROR	0x80000000U
+	/** Some fields are initialized. */
+#define	MDB_ENV_ACTIVE	0x20000000U
+	/** me_txkey is set */
+#define	MDB_ENV_TXKEY	0x10000000U
+	/** fdatasync is unreliable */
+#define	MDB_FSYNCONLY	0x08000000U
+	uint32_t 	me_flags;		/**< @ref mdb_env */
+	unsigned int	me_psize;	/**< DB page size, inited from me_os_psize */
+	unsigned int	me_os_psize;	/**< OS page size, from #GET_PAGESIZE */
+	unsigned int	me_maxreaders;	/**< size of the reader table */
+	/** Max #MDB_txninfo.%mti_numreaders of interest to #mdb_env_close() */
+	volatile int	me_close_readers;
+	MDB_dbi		me_numdbs;		/**< number of DBs opened */
+	MDB_dbi		me_maxdbs;		/**< size of the DB table */
+	MDB_PID_T	me_pid;		/**< process ID of this env */
+	char		*me_path;		/**< path to the DB files */
+	char		*me_map;		/**< the memory map of the data file */
+	MDB_txninfo	*me_txns;		/**< the memory map of the lock file or NULL */
+	MDB_meta	*me_metas[NUM_METAS];	/**< pointers to the two meta pages */
+	void		*me_pbuf;		/**< scratch area for DUPSORT put() */
+	MDB_txn		*me_txn;		/**< current write transaction */
+	MDB_txn		*me_txn0;		/**< prealloc'd write transaction */
+	mdb_size_t	me_mapsize;		/**< size of the data memory map */
+	off_t		me_size;		/**< current file size */
+	pgno_t		me_maxpg;		/**< me_mapsize / me_psize */
+	MDB_dbx		*me_dbxs;		/**< array of static DB info */
+	uint16_t	*me_dbflags;	/**< array of flags from MDB_db.md_flags */
+	unsigned int	*me_dbiseqs;	/**< array of dbi sequence numbers */
+	pthread_key_t	me_txkey;	/**< thread-key for readers */
+	txnid_t		me_pgoldest;	/**< ID of oldest reader last time we looked */
+	MDB_pgstate	me_pgstate;		/**< state of old pages from freeDB */
+#	define		me_pglast	me_pgstate.mf_pglast
+#	define		me_pghead	me_pgstate.mf_pghead
+	MDB_page	*me_dpages;		/**< list of malloc'd blocks for re-use */
+	/** IDL of pages that became unused in a write txn */
+	MDB_IDL		me_free_pgs;
+	/** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
+	MDB_ID2L	me_dirty_list;
+	/** Max number of freelist items that can fit in a single overflow page */
+	int			me_maxfree_1pg;
+	/** Max size of a node on a page */
+	unsigned int	me_nodemax;
+#if !(MDB_MAXKEYSIZE)
+	unsigned int	me_maxkey;	/**< max size of a key */
+#endif
+	int		me_live_reader;		/**< have liveness lock in reader table */
+#ifdef _WIN32
+	int		me_pidquery;		/**< Used in OpenProcess */
+#endif
+#ifdef MDB_USE_POSIX_MUTEX	/* Posix mutexes reside in shared mem */
+#	define		me_rmutex	me_txns->mti_rmutex /**< Shared reader lock */
+#	define		me_wmutex	me_txns->mti_wmutex /**< Shared writer lock */
+#else
+	mdb_mutex_t	me_rmutex;
+	mdb_mutex_t	me_wmutex;
+#endif
+#ifdef MDB_VL32
+	MDB_ID3L	me_rpages;	/**< like #mt_rpages, but global to env */
+	pthread_mutex_t	me_rpmutex;	/**< control access to #me_rpages */
+#define MDB_ERPAGE_SIZE	16384
+#define MDB_ERPAGE_MAX	(MDB_ERPAGE_SIZE-1)
+	unsigned int me_rpcheck;
+#endif
+	void		*me_userctx;	 /**< User-settable context */
+	MDB_assert_func *me_assert_func; /**< Callback for assertion failures */
+};
+
+	/** Nested transaction */
+typedef struct MDB_ntxn {
+	MDB_txn		mnt_txn;		/**< the transaction */
+	MDB_pgstate	mnt_pgstate;	/**< parent transaction's saved freestate */
+} MDB_ntxn;
+
+	/** max number of pages to commit in one writev() call */
+#define MDB_COMMIT_PAGES	 64
+#if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
+#undef MDB_COMMIT_PAGES
+#define MDB_COMMIT_PAGES	IOV_MAX
+#endif
+
+	/** max bytes to write in one call */
+#define MAX_WRITE		(0x40000000U >> (sizeof(ssize_t) == 4))
+
+	/** Check \b txn and \b dbi arguments to a function */
+#define TXN_DBI_EXIST(txn, dbi, validity) \
+	((txn) && (dbi)<(txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & (validity)))
+
+	/** Check for misused \b dbi handles */
+#define TXN_DBI_CHANGED(txn, dbi) \
+	((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])
+
+static int  mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
+static int  mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
+static int  mdb_page_touch(MDB_cursor *mc);
+
+#define MDB_END_NAMES {"committed", "empty-commit", "abort", "reset", \
+	"reset-tmp", "fail-begin", "fail-beginchild"}
+enum {
+	/* mdb_txn_end operation number, for logging */
+	MDB_END_COMMITTED, MDB_END_EMPTY_COMMIT, MDB_END_ABORT, MDB_END_RESET,
+	MDB_END_RESET_TMP, MDB_END_FAIL_BEGIN, MDB_END_FAIL_BEGINCHILD
+};
+#define MDB_END_OPMASK	0x0F	/**< mask for #mdb_txn_end() operation number */
+#define MDB_END_UPDATE	0x10	/**< update env state (DBIs) */
+#define MDB_END_FREE	0x20	/**< free txn unless it is #MDB_env.%me_txn0 */
+#define MDB_END_SLOT MDB_NOTLS	/**< release any reader slot if #MDB_NOTLS */
+static void mdb_txn_end(MDB_txn *txn, unsigned mode);
+
+static int  mdb_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **mp, int *lvl);
+static int  mdb_page_search_root(MDB_cursor *mc,
+			    MDB_val *key, int modify);
+#define MDB_PS_MODIFY	1
+#define MDB_PS_ROOTONLY	2
+#define MDB_PS_FIRST	4
+#define MDB_PS_LAST		8
+static int  mdb_page_search(MDB_cursor *mc,
+			    MDB_val *key, int flags);
+static int	mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
+
+#define MDB_SPLIT_REPLACE	MDB_APPENDDUP	/**< newkey is not new */
+static int	mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
+				pgno_t newpgno, unsigned int nflags);
+
+static int  mdb_env_read_header(MDB_env *env, MDB_meta *meta);
+static MDB_meta *mdb_env_pick_meta(const MDB_env *env);
+static int  mdb_env_write_meta(MDB_txn *txn);
+#ifdef MDB_USE_POSIX_MUTEX /* Drop unused excl arg */
+# define mdb_env_close0(env, excl) mdb_env_close1(env)
+#endif
+static void mdb_env_close0(MDB_env *env, int excl);
+
+static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
+static int  mdb_node_add(MDB_cursor *mc, indx_t indx,
+			    MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
+static void mdb_node_del(MDB_cursor *mc, int ksize);
+static void mdb_node_shrink(MDB_page *mp, indx_t indx);
+static int	mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft);
+static int  mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data);
+static size_t	mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
+static size_t	mdb_branch_size(MDB_env *env, MDB_val *key);
+
+static int	mdb_rebalance(MDB_cursor *mc);
+static int	mdb_update_key(MDB_cursor *mc, MDB_val *key);
+
+static void	mdb_cursor_pop(MDB_cursor *mc);
+static int	mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
+
+static int	mdb_cursor_del0(MDB_cursor *mc);
+static int	mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags);
+static int	mdb_cursor_sibling(MDB_cursor *mc, int move_right);
+static int	mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
+static int	mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
+static int	mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
+				int *exactp);
+static int	mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
+static int	mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
+
+static void	mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
+static void	mdb_xcursor_init0(MDB_cursor *mc);
+static void	mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
+static void	mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int force);
+
+static int	mdb_drop0(MDB_cursor *mc, int subs);
+static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
+static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead);
+
+/** @cond */
+static MDB_cmp_func	mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
+/** @endcond */
+
+/** Compare two items pointing at size_t's of unknown alignment. */
+#ifdef MISALIGNED_OK
+# define mdb_cmp_clong mdb_cmp_long
+#else
+# define mdb_cmp_clong mdb_cmp_cint
+#endif
+
+#ifdef _WIN32
+static SECURITY_DESCRIPTOR mdb_null_sd;
+static SECURITY_ATTRIBUTES mdb_all_sa;
+static int mdb_sec_inited;
+
+static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize);
+#endif
+
+/** Return the library version info. */
+char * ESECT
+mdb_version(int *major, int *minor, int *patch)
+{
+	if (major) *major = MDB_VERSION_MAJOR;
+	if (minor) *minor = MDB_VERSION_MINOR;
+	if (patch) *patch = MDB_VERSION_PATCH;
+	return MDB_VERSION_STRING;
+}
+
+/** Table of descriptions for LMDB @ref errors */
+static char *const mdb_errstr[] = {
+	"MDB_KEYEXIST: Key/data pair already exists",
+	"MDB_NOTFOUND: No matching key/data pair found",
+	"MDB_PAGE_NOTFOUND: Requested page not found",
+	"MDB_CORRUPTED: Located page was wrong type",
+	"MDB_PANIC: Update of meta page failed or environment had fatal error",
+	"MDB_VERSION_MISMATCH: Database environment version mismatch",
+	"MDB_INVALID: File is not an LMDB file",
+	"MDB_MAP_FULL: Environment mapsize limit reached",
+	"MDB_DBS_FULL: Environment maxdbs limit reached",
+	"MDB_READERS_FULL: Environment maxreaders limit reached",
+	"MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
+	"MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
+	"MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
+	"MDB_PAGE_FULL: Internal error - page has no more space",
+	"MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
+	"MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
+	"MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
+	"MDB_BAD_TXN: Transaction must abort, has a child, or is invalid",
+	"MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size",
+	"MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly",
+};
+
+char *
+mdb_strerror(int err)
+{
+#ifdef _WIN32
+	/** HACK: pad 4KB on stack over the buf. Return system msgs in buf.
+	 *	This works as long as no function between the call to mdb_strerror
+	 *	and the actual use of the message uses more than 4K of stack.
+	 */
+#define MSGSIZE	1024
+#define PADSIZE	4096
+	char buf[MSGSIZE+PADSIZE], *ptr = buf;
+#endif
+	int i;
+	if (!err)
+		return ("Successful return: 0");
+
+	if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
+		i = err - MDB_KEYEXIST;
+		return mdb_errstr[i];
+	}
+
+#ifdef _WIN32
+	/* These are the C-runtime error codes we use. The comment indicates
+	 * their numeric value, and the Win32 error they would correspond to
+	 * if the error actually came from a Win32 API. A major mess, we should
+	 * have used LMDB-specific error codes for everything.
+	 */
+	switch(err) {
+	case ENOENT:	/* 2, FILE_NOT_FOUND */
+	case EIO:		/* 5, ACCESS_DENIED */
+	case ENOMEM:	/* 12, INVALID_ACCESS */
+	case EACCES:	/* 13, INVALID_DATA */
+	case EBUSY:		/* 16, CURRENT_DIRECTORY */
+	case EINVAL:	/* 22, BAD_COMMAND */
+	case ENOSPC:	/* 28, OUT_OF_PAPER */
+		return strerror(err);
+	default:
+		;
+	}
+	buf[0] = 0;
+	FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |
+		FORMAT_MESSAGE_IGNORE_INSERTS,
+		NULL, err, 0, ptr, MSGSIZE, (va_list *)buf+MSGSIZE);
+	return ptr;
+#else
+	return strerror(err);
+#endif
+}
+
+/** assert(3) variant in cursor context */
+#define mdb_cassert(mc, expr)	mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)
+/** assert(3) variant in transaction context */
+#define mdb_tassert(txn, expr)	mdb_assert0((txn)->mt_env, expr, #expr)
+/** assert(3) variant in environment context */
+#define mdb_eassert(env, expr)	mdb_assert0(env, expr, #expr)
+
+#ifndef NDEBUG
+# define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \
+		mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))
+
+static void ESECT
+mdb_assert_fail(MDB_env *env, const char *expr_txt,
+	const char *func, const char *file, int line)
+{
+	char buf[400];
+	sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",
+		file, line, expr_txt, func);
+	if (env->me_assert_func)
+		env->me_assert_func(env, buf);
+	fprintf(stderr, "%s\n", buf);
+	abort();
+}
+#else
+# define mdb_assert0(env, expr, expr_txt) ((void) 0)
+#endif /* NDEBUG */
+
+#if MDB_DEBUG
+/** Return the page number of \b mp which may be sub-page, for debug output */
+static pgno_t
+mdb_dbg_pgno(MDB_page *mp)
+{
+	pgno_t ret;
+	COPY_PGNO(ret, mp->mp_pgno);
+	return ret;
+}
+
+/** Display a key in hexadecimal and return the address of the result.
+ * @param[in] key the key to display
+ * @param[in] buf the buffer to write into. Should always be #DKBUF.
+ * @return The key in hexadecimal form.
+ */
+char *
+mdb_dkey(MDB_val *key, char *buf)
+{
+	char *ptr = buf;
+	unsigned char *c = key->mv_data;
+	unsigned int i;
+
+	if (!key)
+		return "";
+
+	if (key->mv_size > DKBUF_MAXKEYSIZE)
+		return "MDB_MAXKEYSIZE";
+	/* may want to make this a dynamic check: if the key is mostly
+	 * printable characters, print it as-is instead of converting to hex.
+	 */
+#if 1
+	buf[0] = '\0';
+	for (i=0; i<key->mv_size; i++)
+		ptr += sprintf(ptr, "%02x", *c++);
+#else
+	sprintf(buf, "%.*s", key->mv_size, key->mv_data);
+#endif
+	return buf;
+}
+
+static const char *
+mdb_leafnode_type(MDB_node *n)
+{
+	static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}};
+	return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" :
+		tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)];
+}
+
+/** Display all the keys in the page. */
+void
+mdb_page_list(MDB_page *mp)
+{
+	pgno_t pgno = mdb_dbg_pgno(mp);
+	const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : "";
+	MDB_node *node;
+	unsigned int i, nkeys, nsize, total = 0;
+	MDB_val key;
+	DKBUF;
+
+	switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) {
+	case P_BRANCH:              type = "Branch page";		break;
+	case P_LEAF:                type = "Leaf page";			break;
+	case P_LEAF|P_SUBP:         type = "Sub-page";			break;
+	case P_LEAF|P_LEAF2:        type = "LEAF2 page";		break;
+	case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page";	break;
+	case P_OVERFLOW:
+		fprintf(stderr, "Overflow page %"Y"u pages %u%s\n",
+			pgno, mp->mp_pages, state);
+		return;
+	case P_META:
+		fprintf(stderr, "Meta-page %"Y"u txnid %"Y"u\n",
+			pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);
+		return;
+	default:
+		fprintf(stderr, "Bad page %"Y"u flags 0x%u\n", pgno, mp->mp_flags);
+		return;
+	}
+
+	nkeys = NUMKEYS(mp);
+	fprintf(stderr, "%s %"Y"u numkeys %d%s\n", type, pgno, nkeys, state);
+
+	for (i=0; i<nkeys; i++) {
+		if (IS_LEAF2(mp)) {	/* LEAF2 pages have no mp_ptrs[] or node headers */
+			key.mv_size = nsize = mp->mp_pad;
+			key.mv_data = LEAF2KEY(mp, i, nsize);
+			total += nsize;
+			fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
+			continue;
+		}
+		node = NODEPTR(mp, i);
+		key.mv_size = node->mn_ksize;
+		key.mv_data = node->mn_data;
+		nsize = NODESIZE + key.mv_size;
+		if (IS_BRANCH(mp)) {
+			fprintf(stderr, "key %d: page %"Y"u, %s\n", i, NODEPGNO(node),
+				DKEY(&key));
+			total += nsize;
+		} else {
+			if (F_ISSET(node->mn_flags, F_BIGDATA))
+				nsize += sizeof(pgno_t);
+			else
+				nsize += NODEDSZ(node);
+			total += nsize;
+			nsize += sizeof(indx_t);
+			fprintf(stderr, "key %d: nsize %d, %s%s\n",
+				i, nsize, DKEY(&key), mdb_leafnode_type(node));
+		}
+		total = EVEN(total);
+	}
+	fprintf(stderr, "Total: header %d + contents %d + unused %d\n",
+		IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp));
+}
+
+void
+mdb_cursor_chk(MDB_cursor *mc)
+{
+	unsigned int i;
+	MDB_node *node;
+	MDB_page *mp;
+
+	if (!mc->mc_snum || !(mc->mc_flags & C_INITIALIZED)) return;
+	for (i=0; i<mc->mc_top; i++) {
+		mp = mc->mc_pg[i];
+		node = NODEPTR(mp, mc->mc_ki[i]);
+		if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
+			printf("oops!\n");
+	}
+	if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
+		printf("ack!\n");
+	if (mc->mc_xcursor && (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
+		node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+		if (((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA) &&
+			mc->mc_xcursor->mx_cursor.mc_pg[0] != NODEDATA(node)) {
+			printf("blah!\n");
+		}
+	}
+}
+#endif
+
+#if (MDB_DEBUG) > 2
+/** Count all the pages in each DB and in the freelist
+ *  and make sure it matches the actual number of pages
+ *  being used.
+ *  All named DBs must be open for a correct count.
+ */
+static void mdb_audit(MDB_txn *txn)
+{
+	MDB_cursor mc;
+	MDB_val key, data;
+	MDB_ID freecount, count;
+	MDB_dbi i;
+	int rc;
+
+	freecount = 0;
+	mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
+	while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
+		freecount += *(MDB_ID *)data.mv_data;
+	mdb_tassert(txn, rc == MDB_NOTFOUND);
+
+	count = 0;
+	for (i = 0; i<txn->mt_numdbs; i++) {
+		MDB_xcursor mx;
+		if (!(txn->mt_dbflags[i] & DB_VALID))
+			continue;
+		mdb_cursor_init(&mc, txn, i, &mx);
+		if (txn->mt_dbs[i].md_root == P_INVALID)
+			continue;
+		count += txn->mt_dbs[i].md_branch_pages +
+			txn->mt_dbs[i].md_leaf_pages +
+			txn->mt_dbs[i].md_overflow_pages;
+		if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
+			rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);
+			for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {
+				unsigned j;
+				MDB_page *mp;
+				mp = mc.mc_pg[mc.mc_top];
+				for (j=0; j<NUMKEYS(mp); j++) {
+					MDB_node *leaf = NODEPTR(mp, j);
+					if (leaf->mn_flags & F_SUBDATA) {
+						MDB_db db;
+						memcpy(&db, NODEDATA(leaf), sizeof(db));
+						count += db.md_branch_pages + db.md_leaf_pages +
+							db.md_overflow_pages;
+					}
+				}
+			}
+			mdb_tassert(txn, rc == MDB_NOTFOUND);
+		}
+	}
+	if (freecount + count + NUM_METAS != txn->mt_next_pgno) {
+		fprintf(stderr, "audit: %"Y"u freecount: %"Y"u count: %"Y"u total: %"Y"u next_pgno: %"Y"u\n",
+			txn->mt_txnid, freecount, count+NUM_METAS,
+			freecount+count+NUM_METAS, txn->mt_next_pgno);
+	}
+}
+#endif
+
+int
+mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
+{
+	return txn->mt_dbxs[dbi].md_cmp(a, b);
+}
+
+int
+mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
+{
+	MDB_cmp_func *dcmp = txn->mt_dbxs[dbi].md_dcmp;
+#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)
+	if (dcmp == mdb_cmp_int && a->mv_size == sizeof(mdb_size_t))
+		dcmp = mdb_cmp_clong;
+#endif
+	return dcmp(a, b);
+}
+
+/** Allocate memory for a page.
+ * Re-use old malloc'd pages first for singletons, otherwise just malloc.
+ */
+static MDB_page *
+mdb_page_malloc(MDB_txn *txn, unsigned num)
+{
+	MDB_env *env = txn->mt_env;
+	MDB_page *ret = env->me_dpages;
+	size_t psize = env->me_psize, sz = psize, off;
+	/* For ! #MDB_NOMEMINIT, psize counts how much to init.
+	 * For a single page alloc, we init everything after the page header.
+	 * For multi-page, we init the final page; if the caller needed that
+	 * many pages they will be filling in at least up to the last page.
+	 */
+	if (num == 1) {
+		if (ret) {
+			VGMEMP_ALLOC(env, ret, sz);
+			VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
+			env->me_dpages = ret->mp_next;
+			return ret;
+		}
+		psize -= off = PAGEHDRSZ;
+	} else {
+		sz *= num;
+		off = sz - psize;
+	}
+	if ((ret = malloc(sz)) != NULL) {
+		VGMEMP_ALLOC(env, ret, sz);
+		if (!(env->me_flags & MDB_NOMEMINIT)) {
+			memset((char *)ret + off, 0, psize);
+			ret->mp_pad = 0;
+		}
+	} else {
+		txn->mt_flags |= MDB_TXN_ERROR;
+	}
+	return ret;
+}
+/** Free a single page.
+ * Saves single pages to a list, for future reuse.
+ * (This is not used for multi-page overflow pages.)
+ */
+static void
+mdb_page_free(MDB_env *env, MDB_page *mp)
+{
+	mp->mp_next = env->me_dpages;
+	VGMEMP_FREE(env, mp);
+	env->me_dpages = mp;
+}
+
+/** Free a dirty page */
+static void
+mdb_dpage_free(MDB_env *env, MDB_page *dp)
+{
+	if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
+		mdb_page_free(env, dp);
+	} else {
+		/* large pages just get freed directly */
+		VGMEMP_FREE(env, dp);
+		free(dp);
+	}
+}
+
+/**	Return all dirty pages to dpage list */
+static void
+mdb_dlist_free(MDB_txn *txn)
+{
+	MDB_env *env = txn->mt_env;
+	MDB_ID2L dl = txn->mt_u.dirty_list;
+	unsigned i, n = dl[0].mid;
+
+	for (i = 1; i <= n; i++) {
+		mdb_dpage_free(env, dl[i].mptr);
+	}
+	dl[0].mid = 0;
+}
+
+#ifdef MDB_VL32
+static void
+mdb_page_unref(MDB_txn *txn, MDB_page *mp)
+{
+	pgno_t pgno;
+	MDB_ID3L tl = txn->mt_rpages;
+	unsigned x, rem;
+	if (mp->mp_flags & (P_SUBP|P_DIRTY))
+		return;
+	rem = mp->mp_pgno & (MDB_RPAGE_CHUNK-1);
+	pgno = mp->mp_pgno ^ rem;
+	x = mdb_mid3l_search(tl, pgno);
+	if (x != tl[0].mid && tl[x+1].mid == mp->mp_pgno)
+		x++;
+	if (tl[x].mref)
+		tl[x].mref--;
+}
+#define MDB_PAGE_UNREF(txn, mp)	mdb_page_unref(txn, mp)
+
+static void
+mdb_cursor_unref(MDB_cursor *mc)
+{
+	int i;
+	if (!mc->mc_snum || !mc->mc_pg[0] || IS_SUBP(mc->mc_pg[0]))
+		return;
+	for (i=0; i<mc->mc_snum; i++)
+		mdb_page_unref(mc->mc_txn, mc->mc_pg[i]);
+	if (mc->mc_ovpg) {
+		mdb_page_unref(mc->mc_txn, mc->mc_ovpg);
+		mc->mc_ovpg = 0;
+	}
+	mc->mc_snum = mc->mc_top = 0;
+	mc->mc_pg[0] = NULL;
+	mc->mc_flags &= ~C_INITIALIZED;
+}
+#else
+#define MDB_PAGE_UNREF(txn, mp)
+#endif /* MDB_VL32 */
+
+/** Loosen or free a single page.
+ * Saves single pages to a list for future reuse
+ * in this same txn. It has been pulled from the freeDB
+ * and already resides on the dirty list, but has been
+ * deleted. Use these pages first before pulling again
+ * from the freeDB.
+ *
+ * If the page wasn't dirtied in this txn, just add it
+ * to this txn's free list.
+ */
+static int
+mdb_page_loose(MDB_cursor *mc, MDB_page *mp)
+{
+	int loose = 0;
+	pgno_t pgno = mp->mp_pgno;
+	MDB_txn *txn = mc->mc_txn;
+
+	if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) {
+		if (txn->mt_parent) {
+			MDB_ID2 *dl = txn->mt_u.dirty_list;
+			/* If txn has a parent, make sure the page is in our
+			 * dirty list.
+			 */
+			if (dl[0].mid) {
+				unsigned x = mdb_mid2l_search(dl, pgno);
+				if (x <= dl[0].mid && dl[x].mid == pgno) {
+					if (mp != dl[x].mptr) { /* bad cursor? */
+						mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
+						txn->mt_flags |= MDB_TXN_ERROR;
+						return MDB_CORRUPTED;
+					}
+					/* ok, it's ours */
+					loose = 1;
+				}
+			}
+		} else {
+			/* no parent txn, so it's just ours */
+			loose = 1;
+		}
+	}
+	if (loose) {
+		DPRINTF(("loosen db %d page %"Y"u", DDBI(mc),
+			mp->mp_pgno));
+		NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs;
+		txn->mt_loose_pgs = mp;
+		txn->mt_loose_count++;
+		mp->mp_flags |= P_LOOSE;
+	} else {
+		int rc = mdb_midl_append(&txn->mt_free_pgs, pgno);
+		if (rc)
+			return rc;
+	}
+
+	return MDB_SUCCESS;
+}
+
+/** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
+ * @param[in] mc A cursor handle for the current operation.
+ * @param[in] pflags Flags of the pages to update:
+ * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
+ * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
+{
+	enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP };
+	MDB_txn *txn = mc->mc_txn;
+	MDB_cursor *m3, *m0 = mc;
+	MDB_xcursor *mx;
+	MDB_page *dp, *mp;
+	MDB_node *leaf;
+	unsigned i, j;
+	int rc = MDB_SUCCESS, level;
+
+	/* Mark pages seen by cursors */
+	if (mc->mc_flags & C_UNTRACK)
+		mc = NULL;				/* will find mc in mt_cursors */
+	for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
+		for (; mc; mc=mc->mc_next) {
+			if (!(mc->mc_flags & C_INITIALIZED))
+				continue;
+			for (m3 = mc;; m3 = &mx->mx_cursor) {
+				mp = NULL;
+				for (j=0; j<m3->mc_snum; j++) {
+					mp = m3->mc_pg[j];
+					if ((mp->mp_flags & Mask) == pflags)
+						mp->mp_flags ^= P_KEEP;
+				}
+				mx = m3->mc_xcursor;
+				/* Proceed to mx if it is at a sub-database */
+				if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))
+					break;
+				if (! (mp && (mp->mp_flags & P_LEAF)))
+					break;
+				leaf = NODEPTR(mp, m3->mc_ki[j-1]);
+				if (!(leaf->mn_flags & F_SUBDATA))
+					break;
+			}
+		}
+		if (i == 0)
+			break;
+	}
+
+	if (all) {
+		/* Mark dirty root pages */
+		for (i=0; i<txn->mt_numdbs; i++) {
+			if (txn->mt_dbflags[i] & DB_DIRTY) {
+				pgno_t pgno = txn->mt_dbs[i].md_root;
+				if (pgno == P_INVALID)
+					continue;
+				if ((rc = mdb_page_get(m0, pgno, &dp, &level)) != MDB_SUCCESS)
+					break;
+				if ((dp->mp_flags & Mask) == pflags && level <= 1)
+					dp->mp_flags ^= P_KEEP;
+			}
+		}
+	}
+
+	return rc;
+}
+
+static int mdb_page_flush(MDB_txn *txn, int keep);
+
+/**	Spill pages from the dirty list back to disk.
+ * This is intended to prevent running into #MDB_TXN_FULL situations,
+ * but note that they may still occur in a few cases:
+ *	1) our estimate of the txn size could be too small. Currently this
+ *	 seems unlikely, except with a large number of #MDB_MULTIPLE items.
+ *	2) child txns may run out of space if their parents dirtied a
+ *	 lot of pages and never spilled them. TODO: we probably should do
+ *	 a preemptive spill during #mdb_txn_begin() of a child txn, if
+ *	 the parent's dirty_room is below a given threshold.
+ *
+ * Otherwise, if not using nested txns, it is expected that apps will
+ * not run into #MDB_TXN_FULL any more. The pages are flushed to disk
+ * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.
+ * If the txn never references them again, they can be left alone.
+ * If the txn only reads them, they can be used without any fuss.
+ * If the txn writes them again, they can be dirtied immediately without
+ * going thru all of the work of #mdb_page_touch(). Such references are
+ * handled by #mdb_page_unspill().
+ *
+ * Also note, we never spill DB root pages, nor pages of active cursors,
+ * because we'll need these back again soon anyway. And in nested txns,
+ * we can't spill a page in a child txn if it was already spilled in a
+ * parent txn. That would alter the parent txns' data even though
+ * the child hasn't committed yet, and we'd have no way to undo it if
+ * the child aborted.
+ *
+ * @param[in] m0 cursor A cursor handle identifying the transaction and
+ *	database for which we are checking space.
+ * @param[in] key For a put operation, the key being stored.
+ * @param[in] data For a put operation, the data being stored.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
+{
+	MDB_txn *txn = m0->mc_txn;
+	MDB_page *dp;
+	MDB_ID2L dl = txn->mt_u.dirty_list;
+	unsigned int i, j, need;
+	int rc;
+
+	if (m0->mc_flags & C_SUB)
+		return MDB_SUCCESS;
+
+	/* Estimate how much space this op will take */
+	i = m0->mc_db->md_depth;
+	/* Named DBs also dirty the main DB */
+	if (m0->mc_dbi >= CORE_DBS)
+		i += txn->mt_dbs[MAIN_DBI].md_depth;
+	/* For puts, roughly factor in the key+data size */
+	if (key)
+		i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;
+	i += i;	/* double it for good measure */
+	need = i;
+
+	if (txn->mt_dirty_room > i)
+		return MDB_SUCCESS;
+
+	if (!txn->mt_spill_pgs) {
+		txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);
+		if (!txn->mt_spill_pgs)
+			return ENOMEM;
+	} else {
+		/* purge deleted slots */
+		MDB_IDL sl = txn->mt_spill_pgs;
+		unsigned int num = sl[0];
+		j=0;
+		for (i=1; i<=num; i++) {
+			if (!(sl[i] & 1))
+				sl[++j] = sl[i];
+		}
+		sl[0] = j;
+	}
+
+	/* Preserve pages which may soon be dirtied again */
+	if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
+		goto done;
+
+	/* Less aggressive spill - we originally spilled the entire dirty list,
+	 * with a few exceptions for cursor pages and DB root pages. But this
+	 * turns out to be a lot of wasted effort because in a large txn many
+	 * of those pages will need to be used again. So now we spill only 1/8th
+	 * of the dirty pages. Testing revealed this to be a good tradeoff,
+	 * better than 1/2, 1/4, or 1/10.
+	 */
+	if (need < MDB_IDL_UM_MAX / 8)
+		need = MDB_IDL_UM_MAX / 8;
+
+	/* Save the page IDs of all the pages we're flushing */
+	/* flush from the tail forward, this saves a lot of shifting later on. */
+	for (i=dl[0].mid; i && need; i--) {
+		MDB_ID pn = dl[i].mid << 1;
+		dp = dl[i].mptr;
+		if (dp->mp_flags & (P_LOOSE|P_KEEP))
+			continue;
+		/* Can't spill twice, make sure it's not already in a parent's
+		 * spill list.
+		 */
+		if (txn->mt_parent) {
+			MDB_txn *tx2;
+			for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
+				if (tx2->mt_spill_pgs) {
+					j = mdb_midl_search(tx2->mt_spill_pgs, pn);
+					if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
+						dp->mp_flags |= P_KEEP;
+						break;
+					}
+				}
+			}
+			if (tx2)
+				continue;
+		}
+		if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
+			goto done;
+		need--;
+	}
+	mdb_midl_sort(txn->mt_spill_pgs);
+
+	/* Flush the spilled part of dirty list */
+	if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
+		goto done;
+
+	/* Reset any dirty pages we kept that page_flush didn't see */
+	rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
+
+done:
+	txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
+	return rc;
+}
+
+/** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
+static txnid_t
+mdb_find_oldest(MDB_txn *txn)
+{
+	int i;
+	txnid_t mr, oldest = txn->mt_txnid - 1;
+	if (txn->mt_env->me_txns) {
+		MDB_reader *r = txn->mt_env->me_txns->mti_readers;
+		for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
+			if (r[i].mr_pid) {
+				mr = r[i].mr_txnid;
+				if (oldest > mr)
+					oldest = mr;
+			}
+		}
+	}
+	return oldest;
+}
+
+/** Add a page to the txn's dirty list */
+static void
+mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
+{
+	MDB_ID2 mid;
+	int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
+
+	if (txn->mt_flags & MDB_TXN_WRITEMAP) {
+		insert = mdb_mid2l_append;
+	} else {
+		insert = mdb_mid2l_insert;
+	}
+	mid.mid = mp->mp_pgno;
+	mid.mptr = mp;
+	rc = insert(txn->mt_u.dirty_list, &mid);
+	mdb_tassert(txn, rc == 0);
+	txn->mt_dirty_room--;
+}
+
+/** Allocate page numbers and memory for writing.  Maintain me_pglast,
+ * me_pghead and mt_next_pgno.
+ *
+ * If there are free pages available from older transactions, they
+ * are re-used first. Otherwise allocate a new page at mt_next_pgno.
+ * Do not modify the freedB, just merge freeDB records into me_pghead[]
+ * and move me_pglast to say which records were consumed.  Only this
+ * function can create me_pghead and move me_pglast/mt_next_pgno.
+ * When #MDB_DEVEL & 2, it is not affected by #mdb_freelist_save(): it
+ * then uses the transaction's original snapshot of the freeDB.
+ * @param[in] mc cursor A cursor handle identifying the transaction and
+ *	database for which we are allocating.
+ * @param[in] num the number of pages to allocate.
+ * @param[out] mp Address of the allocated page(s). Requests for multiple pages
+ *  will always be satisfied by a single contiguous chunk of memory.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
+{
+#ifdef MDB_PARANOID	/* Seems like we can ignore this now */
+	/* Get at most <Max_retries> more freeDB records once me_pghead
+	 * has enough pages.  If not enough, use new pages from the map.
+	 * If <Paranoid> and mc is updating the freeDB, only get new
+	 * records if me_pghead is empty. Then the freelist cannot play
+	 * catch-up with itself by growing while trying to save it.
+	 */
+	enum { Paranoid = 1, Max_retries = 500 };
+#else
+	enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
+#endif
+	int rc, retry = num * 60;
+	MDB_txn *txn = mc->mc_txn;
+	MDB_env *env = txn->mt_env;
+	pgno_t pgno, *mop = env->me_pghead;
+	unsigned i, j, mop_len = mop ? mop[0] : 0, n2 = num-1;
+	MDB_page *np;
+	txnid_t oldest = 0, last;
+	MDB_cursor_op op;
+	MDB_cursor m2;
+	int found_old = 0;
+
+	/* If there are any loose pages, just use them */
+	if (num == 1 && txn->mt_loose_pgs) {
+		np = txn->mt_loose_pgs;
+		txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
+		txn->mt_loose_count--;
+		DPRINTF(("db %d use loose page %"Y"u", DDBI(mc),
+				np->mp_pgno));
+		*mp = np;
+		return MDB_SUCCESS;
+	}
+
+	*mp = NULL;
+
+	/* If our dirty list is already full, we can't do anything */
+	if (txn->mt_dirty_room == 0) {
+		rc = MDB_TXN_FULL;
+		goto fail;
+	}
+
+	for (op = MDB_FIRST;; op = MDB_NEXT) {
+		MDB_val key, data;
+		MDB_node *leaf;
+		pgno_t *idl;
+
+		/* Seek a big enough contiguous page range. Prefer
+		 * pages at the tail, just truncating the list.
+		 */
+		if (mop_len > n2) {
+			i = mop_len;
+			do {
+				pgno = mop[i];
+				if (mop[i-n2] == pgno+n2)
+					goto search_done;
+			} while (--i > n2);
+			if (--retry < 0)
+				break;
+		}
+
+		if (op == MDB_FIRST) {	/* 1st iteration */
+			/* Prepare to fetch more and coalesce */
+			last = env->me_pglast;
+			oldest = env->me_pgoldest;
+			mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
+#if (MDB_DEVEL) & 2	/* "& 2" so MDB_DEVEL=1 won't hide bugs breaking freeDB */
+			/* Use original snapshot. TODO: Should need less care in code
+			 * which modifies the database. Maybe we can delete some code?
+			 */
+			m2.mc_flags |= C_ORIG_RDONLY;
+			m2.mc_db = &env->me_metas[(txn->mt_txnid-1) & 1]->mm_dbs[FREE_DBI];
+			m2.mc_dbflag = (unsigned char *)""; /* probably unnecessary */
+#endif
+			if (last) {
+				op = MDB_SET_RANGE;
+				key.mv_data = &last; /* will look up last+1 */
+				key.mv_size = sizeof(last);
+			}
+			if (Paranoid && mc->mc_dbi == FREE_DBI)
+				retry = -1;
+		}
+		if (Paranoid && retry < 0 && mop_len)
+			break;
+
+		last++;
+		/* Do not fetch more if the record will be too recent */
+		if (oldest <= last) {
+			if (!found_old) {
+				oldest = mdb_find_oldest(txn);
+				env->me_pgoldest = oldest;
+				found_old = 1;
+			}
+			if (oldest <= last)
+				break;
+		}
+		rc = mdb_cursor_get(&m2, &key, NULL, op);
+		if (rc) {
+			if (rc == MDB_NOTFOUND)
+				break;
+			goto fail;
+		}
+		last = *(txnid_t*)key.mv_data;
+		if (oldest <= last) {
+			if (!found_old) {
+				oldest = mdb_find_oldest(txn);
+				env->me_pgoldest = oldest;
+				found_old = 1;
+			}
+			if (oldest <= last)
+				break;
+		}
+		np = m2.mc_pg[m2.mc_top];
+		leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
+		if ((rc = mdb_node_read(&m2, leaf, &data)) != MDB_SUCCESS)
+			return rc;
+
+		idl = (MDB_ID *) data.mv_data;
+		i = idl[0];
+		if (!mop) {
+			if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
+				rc = ENOMEM;
+				goto fail;
+			}
+		} else {
+			if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
+				goto fail;
+			mop = env->me_pghead;
+		}
+		env->me_pglast = last;
+#if (MDB_DEBUG) > 1
+		DPRINTF(("IDL read txn %"Y"u root %"Y"u num %u",
+			last, txn->mt_dbs[FREE_DBI].md_root, i));
+		for (j = i; j; j--)
+			DPRINTF(("IDL %"Y"u", idl[j]));
+#endif
+		/* Merge in descending sorted order */
+		mdb_midl_xmerge(mop, idl);
+		mop_len = mop[0];
+	}
+
+	/* Use new pages from the map when nothing suitable in the freeDB */
+	i = 0;
+	pgno = txn->mt_next_pgno;
+	if (pgno + num >= env->me_maxpg) {
+			DPUTS("DB size maxed out");
+			rc = MDB_MAP_FULL;
+			goto fail;
+	}
+#if defined(_WIN32) && !defined(MDB_VL32)
+	if (!(env->me_flags & MDB_RDONLY)) {
+		void *p;
+		p = (MDB_page *)(env->me_map + env->me_psize * pgno);
+		p = VirtualAlloc(p, env->me_psize * num, MEM_COMMIT,
+			(env->me_flags & MDB_WRITEMAP) ? PAGE_READWRITE:
+			PAGE_READONLY);
+		if (!p) {
+			DPUTS("VirtualAlloc failed");
+			rc = ErrCode();
+			goto fail;
+		}
+	}
+#endif
+
+search_done:
+	if (env->me_flags & MDB_WRITEMAP) {
+		np = (MDB_page *)(env->me_map + env->me_psize * pgno);
+	} else {
+		if (!(np = mdb_page_malloc(txn, num))) {
+			rc = ENOMEM;
+			goto fail;
+		}
+	}
+	if (i) {
+		mop[0] = mop_len -= num;
+		/* Move any stragglers down */
+		for (j = i-num; j < mop_len; )
+			mop[++j] = mop[++i];
+	} else {
+		txn->mt_next_pgno = pgno + num;
+	}
+	np->mp_pgno = pgno;
+	mdb_page_dirty(txn, np);
+	*mp = np;
+
+	return MDB_SUCCESS;
+
+fail:
+	txn->mt_flags |= MDB_TXN_ERROR;
+	return rc;
+}
+
+/** Copy the used portions of a non-overflow page.
+ * @param[in] dst page to copy into
+ * @param[in] src page to copy from
+ * @param[in] psize size of a page
+ */
+static void
+mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
+{
+	enum { Align = sizeof(pgno_t) };
+	indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;
+
+	/* If page isn't full, just copy the used portion. Adjust
+	 * alignment so memcpy may copy words instead of bytes.
+	 */
+	if ((unused &= -Align) && !IS_LEAF2(src)) {
+		upper = (upper + PAGEBASE) & -Align;
+		memcpy(dst, src, (lower + PAGEBASE + (Align-1)) & -Align);
+		memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),
+			psize - upper);
+	} else {
+		memcpy(dst, src, psize - unused);
+	}
+}
+
+/** Pull a page off the txn's spill list, if present.
+ * If a page being referenced was spilled to disk in this txn, bring
+ * it back and make it dirty/writable again.
+ * @param[in] txn the transaction handle.
+ * @param[in] mp the page being referenced. It must not be dirty.
+ * @param[out] ret the writable page, if any. ret is unchanged if
+ * mp wasn't spilled.
+ */
+static int
+mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
+{
+	MDB_env *env = txn->mt_env;
+	const MDB_txn *tx2;
+	unsigned x;
+	pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
+
+	for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
+		if (!tx2->mt_spill_pgs)
+			continue;
+		x = mdb_midl_search(tx2->mt_spill_pgs, pn);
+		if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
+			MDB_page *np;
+			int num;
+			if (txn->mt_dirty_room == 0)
+				return MDB_TXN_FULL;
+			if (IS_OVERFLOW(mp))
+				num = mp->mp_pages;
+			else
+				num = 1;
+			if (env->me_flags & MDB_WRITEMAP) {
+				np = mp;
+			} else {
+				np = mdb_page_malloc(txn, num);
+				if (!np)
+					return ENOMEM;
+				if (num > 1)
+					memcpy(np, mp, num * env->me_psize);
+				else
+					mdb_page_copy(np, mp, env->me_psize);
+			}
+			if (tx2 == txn) {
+				/* If in current txn, this page is no longer spilled.
+				 * If it happens to be the last page, truncate the spill list.
+				 * Otherwise mark it as deleted by setting the LSB.
+				 */
+				if (x == txn->mt_spill_pgs[0])
+					txn->mt_spill_pgs[0]--;
+				else
+					txn->mt_spill_pgs[x] |= 1;
+			}	/* otherwise, if belonging to a parent txn, the
+				 * page remains spilled until child commits
+				 */
+
+			mdb_page_dirty(txn, np);
+			np->mp_flags |= P_DIRTY;
+			*ret = np;
+			break;
+		}
+	}
+	return MDB_SUCCESS;
+}
+
+/** Touch a page: make it dirty and re-insert into tree with updated pgno.
+ * @param[in] mc cursor pointing to the page to be touched
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_page_touch(MDB_cursor *mc)
+{
+	MDB_page *mp = mc->mc_pg[mc->mc_top], *np;
+	MDB_txn *txn = mc->mc_txn;
+	MDB_cursor *m2, *m3;
+	pgno_t	pgno;
+	int rc;
+
+	if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
+		if (txn->mt_flags & MDB_TXN_SPILLS) {
+			np = NULL;
+			rc = mdb_page_unspill(txn, mp, &np);
+			if (rc)
+				goto fail;
+			if (np)
+				goto done;
+		}
+		if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
+			(rc = mdb_page_alloc(mc, 1, &np)))
+			goto fail;
+		pgno = np->mp_pgno;
+		DPRINTF(("touched db %d page %"Y"u -> %"Y"u", DDBI(mc),
+			mp->mp_pgno, pgno));
+		mdb_cassert(mc, mp->mp_pgno != pgno);
+		mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
+		/* Update the parent page, if any, to point to the new page */
+		if (mc->mc_top) {
+			MDB_page *parent = mc->mc_pg[mc->mc_top-1];
+			MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);
+			SETPGNO(node, pgno);
+		} else {
+			mc->mc_db->md_root = pgno;
+		}
+	} else if (txn->mt_parent && !IS_SUBP(mp)) {
+		MDB_ID2 mid, *dl = txn->mt_u.dirty_list;
+		pgno = mp->mp_pgno;
+		/* If txn has a parent, make sure the page is in our
+		 * dirty list.
+		 */
+		if (dl[0].mid) {
+			unsigned x = mdb_mid2l_search(dl, pgno);
+			if (x <= dl[0].mid && dl[x].mid == pgno) {
+				if (mp != dl[x].mptr) { /* bad cursor? */
+					mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
+					txn->mt_flags |= MDB_TXN_ERROR;
+					return MDB_CORRUPTED;
+				}
+				return 0;
+			}
+		}
+		mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);
+		/* No - copy it */
+		np = mdb_page_malloc(txn, 1);
+		if (!np)
+			return ENOMEM;
+		mid.mid = pgno;
+		mid.mptr = np;
+		rc = mdb_mid2l_insert(dl, &mid);
+		mdb_cassert(mc, rc == 0);
+	} else {
+		return 0;
+	}
+
+	mdb_page_copy(np, mp, txn->mt_env->me_psize);
+	np->mp_pgno = pgno;
+	np->mp_flags |= P_DIRTY;
+
+done:
+	/* Adjust cursors pointing to mp */
+	mc->mc_pg[mc->mc_top] = np;
+	m2 = txn->mt_cursors[mc->mc_dbi];
+	if (mc->mc_flags & C_SUB) {
+		for (; m2; m2=m2->mc_next) {
+			m3 = &m2->mc_xcursor->mx_cursor;
+			if (m3->mc_snum < mc->mc_snum) continue;
+			if (m3->mc_pg[mc->mc_top] == mp)
+				m3->mc_pg[mc->mc_top] = np;
+		}
+	} else {
+		for (; m2; m2=m2->mc_next) {
+			if (m2->mc_snum < mc->mc_snum) continue;
+			if (m2 == mc) continue;
+			if (m2->mc_pg[mc->mc_top] == mp) {
+				m2->mc_pg[mc->mc_top] = np;
+				if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
+					IS_LEAF(np) &&
+					(m2->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
+				{
+					MDB_node *leaf = NODEPTR(np, m2->mc_ki[mc->mc_top]);
+					if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
+						m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
+				}
+			}
+		}
+	}
+	MDB_PAGE_UNREF(mc->mc_txn, mp);
+	return 0;
+
+fail:
+	txn->mt_flags |= MDB_TXN_ERROR;
+	return rc;
+}
+
+int
+mdb_env_sync0(MDB_env *env, int force, pgno_t numpgs)
+{
+	int rc = 0;
+	if (env->me_flags & MDB_RDONLY)
+		return EACCES;
+	if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
+		if (env->me_flags & MDB_WRITEMAP) {
+			int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
+				? MS_ASYNC : MS_SYNC;
+			if (MDB_MSYNC(env->me_map, env->me_psize * numpgs, flags))
+				rc = ErrCode();
+#ifdef _WIN32
+			else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
+				rc = ErrCode();
+#endif
+		} else {
+#ifdef BROKEN_FDATASYNC
+			if (env->me_flags & MDB_FSYNCONLY) {
+				if (fsync(env->me_fd))
+					rc = ErrCode();
+			} else
+#endif
+			if (MDB_FDATASYNC(env->me_fd))
+				rc = ErrCode();
+		}
+	}
+	return rc;
+}
+
+int
+mdb_env_sync(MDB_env *env, int force)
+{
+	MDB_meta *m = mdb_env_pick_meta(env);
+	return mdb_env_sync0(env, force, m->mm_last_pg+1);
+}
+
+/** Back up parent txn's cursors, then grab the originals for tracking */
+static int
+mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
+{
+	MDB_cursor *mc, *bk;
+	MDB_xcursor *mx;
+	size_t size;
+	int i;
+
+	for (i = src->mt_numdbs; --i >= 0; ) {
+		if ((mc = src->mt_cursors[i]) != NULL) {
+			size = sizeof(MDB_cursor);
+			if (mc->mc_xcursor)
+				size += sizeof(MDB_xcursor);
+			for (; mc; mc = bk->mc_next) {
+				bk = malloc(size);
+				if (!bk)
+					return ENOMEM;
+				*bk = *mc;
+				mc->mc_backup = bk;
+				mc->mc_db = &dst->mt_dbs[i];
+				/* Kill pointers into src to reduce abuse: The
+				 * user may not use mc until dst ends. But we need a valid
+				 * txn pointer here for cursor fixups to keep working.
+				 */
+				mc->mc_txn    = dst;
+				mc->mc_dbflag = &dst->mt_dbflags[i];
+				if ((mx = mc->mc_xcursor) != NULL) {
+					*(MDB_xcursor *)(bk+1) = *mx;
+					mx->mx_cursor.mc_txn = dst;
+				}
+				mc->mc_next = dst->mt_cursors[i];
+				dst->mt_cursors[i] = mc;
+			}
+		}
+	}
+	return MDB_SUCCESS;
+}
+
+/** Close this write txn's cursors, give parent txn's cursors back to parent.
+ * @param[in] txn the transaction handle.
+ * @param[in] merge true to keep changes to parent cursors, false to revert.
+ * @return 0 on success, non-zero on failure.
+ */
+static void
+mdb_cursors_close(MDB_txn *txn, unsigned merge)
+{
+	MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;
+	MDB_xcursor *mx;
+	int i;
+
+	for (i = txn->mt_numdbs; --i >= 0; ) {
+		for (mc = cursors[i]; mc; mc = next) {
+			next = mc->mc_next;
+			if ((bk = mc->mc_backup) != NULL) {
+				if (merge) {
+					/* Commit changes to parent txn */
+					mc->mc_next = bk->mc_next;
+					mc->mc_backup = bk->mc_backup;
+					mc->mc_txn = bk->mc_txn;
+					mc->mc_db = bk->mc_db;
+					mc->mc_dbflag = bk->mc_dbflag;
+					if ((mx = mc->mc_xcursor) != NULL)
+						mx->mx_cursor.mc_txn = bk->mc_txn;
+				} else {
+					/* Abort nested txn */
+					*mc = *bk;
+					if ((mx = mc->mc_xcursor) != NULL)
+						*mx = *(MDB_xcursor *)(bk+1);
+				}
+				mc = bk;
+			}
+			/* Only malloced cursors are permanently tracked. */
+			free(mc);
+		}
+		cursors[i] = NULL;
+	}
+}
+
+#if !(MDB_PIDLOCK)		/* Currently the same as defined(_WIN32) */
+enum Pidlock_op {
+	Pidset, Pidcheck
+};
+#else
+enum Pidlock_op {
+	Pidset = F_SETLK, Pidcheck = F_GETLK
+};
+#endif
+
+/** Set or check a pid lock. Set returns 0 on success.
+ * Check returns 0 if the process is certainly dead, nonzero if it may
+ * be alive (the lock exists or an error happened so we do not know).
+ *
+ * On Windows Pidset is a no-op, we merely check for the existence
+ * of the process with the given pid. On POSIX we use a single byte
+ * lock on the lockfile, set at an offset equal to the pid.
+ */
+static int
+mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)
+{
+#if !(MDB_PIDLOCK)		/* Currently the same as defined(_WIN32) */
+	int ret = 0;
+	HANDLE h;
+	if (op == Pidcheck) {
+		h = OpenProcess(env->me_pidquery, FALSE, pid);
+		/* No documented "no such process" code, but other program use this: */
+		if (!h)
+			return ErrCode() != ERROR_INVALID_PARAMETER;
+		/* A process exists until all handles to it close. Has it exited? */
+		ret = WaitForSingleObject(h, 0) != 0;
+		CloseHandle(h);
+	}
+	return ret;
+#else
+	for (;;) {
+		int rc;
+		struct flock lock_info;
+		memset(&lock_info, 0, sizeof(lock_info));
+		lock_info.l_type = F_WRLCK;
+		lock_info.l_whence = SEEK_SET;
+		lock_info.l_start = pid;
+		lock_info.l_len = 1;
+		if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {
+			if (op == F_GETLK && lock_info.l_type != F_UNLCK)
+				rc = -1;
+		} else if ((rc = ErrCode()) == EINTR) {
+			continue;
+		}
+		return rc;
+	}
+#endif
+}
+
+/** Common code for #mdb_txn_begin() and #mdb_txn_renew().
+ * @param[in] txn the transaction handle to initialize
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_txn_renew0(MDB_txn *txn)
+{
+	MDB_env *env = txn->mt_env;
+	MDB_txninfo *ti = env->me_txns;
+	MDB_meta *meta;
+	unsigned int i, nr, flags = txn->mt_flags;
+	uint16_t x;
+	int rc, new_notls = 0;
+
+	if ((flags &= MDB_TXN_RDONLY) != 0) {
+		if (!ti) {
+			meta = mdb_env_pick_meta(env);
+			txn->mt_txnid = meta->mm_txnid;
+			txn->mt_u.reader = NULL;
+		} else {
+			MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
+				pthread_getspecific(env->me_txkey);
+			if (r) {
+				if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
+					return MDB_BAD_RSLOT;
+			} else {
+				MDB_PID_T pid = env->me_pid;
+				MDB_THR_T tid = pthread_self();
+				mdb_mutexref_t rmutex = env->me_rmutex;
+
+				if (!env->me_live_reader) {
+					rc = mdb_reader_pid(env, Pidset, pid);
+					if (rc)
+						return rc;
+					env->me_live_reader = 1;
+				}
+
+				if (LOCK_MUTEX(rc, env, rmutex))
+					return rc;
+				nr = ti->mti_numreaders;
+				for (i=0; i<nr; i++)
+					if (ti->mti_readers[i].mr_pid == 0)
+						break;
+				if (i == env->me_maxreaders) {
+					UNLOCK_MUTEX(rmutex);
+					return MDB_READERS_FULL;
+				}
+				r = &ti->mti_readers[i];
+				/* Claim the reader slot, carefully since other code
+				 * uses the reader table un-mutexed: First reset the
+				 * slot, next publish it in mti_numreaders.  After
+				 * that, it is safe for mdb_env_close() to touch it.
+				 * When it will be closed, we can finally claim it.
+				 */
+				r->mr_pid = 0;
+				r->mr_txnid = (txnid_t)-1;
+				r->mr_tid = tid;
+				if (i == nr)
+					ti->mti_numreaders = ++nr;
+				env->me_close_readers = nr;
+				r->mr_pid = pid;
+				UNLOCK_MUTEX(rmutex);
+
+				new_notls = (env->me_flags & MDB_NOTLS);
+				if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
+					r->mr_pid = 0;
+					return rc;
+				}
+			}
+			do /* LY: Retry on a race, ITS#7970. */
+				r->mr_txnid = ti->mti_txnid;
+			while(r->mr_txnid != ti->mti_txnid);
+			txn->mt_txnid = r->mr_txnid;
+			txn->mt_u.reader = r;
+			meta = env->me_metas[txn->mt_txnid & 1];
+		}
+
+	} else {
+		/* Not yet touching txn == env->me_txn0, it may be active */
+		if (ti) {
+			if (LOCK_MUTEX(rc, env, env->me_wmutex))
+				return rc;
+			txn->mt_txnid = ti->mti_txnid;
+			meta = env->me_metas[txn->mt_txnid & 1];
+		} else {
+			meta = mdb_env_pick_meta(env);
+			txn->mt_txnid = meta->mm_txnid;
+		}
+		txn->mt_txnid++;
+#if MDB_DEBUG
+		if (txn->mt_txnid == mdb_debug_start)
+			mdb_debug = 1;
+#endif
+		txn->mt_child = NULL;
+		txn->mt_loose_pgs = NULL;
+		txn->mt_loose_count = 0;
+		txn->mt_dirty_room = MDB_IDL_UM_MAX;
+		txn->mt_u.dirty_list = env->me_dirty_list;
+		txn->mt_u.dirty_list[0].mid = 0;
+		txn->mt_free_pgs = env->me_free_pgs;
+		txn->mt_free_pgs[0] = 0;
+		txn->mt_spill_pgs = NULL;
+		env->me_txn = txn;
+		memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));
+	}
+
+	/* Copy the DB info and flags */
+	memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDB_db));
+
+	/* Moved to here to avoid a data race in read TXNs */
+	txn->mt_next_pgno = meta->mm_last_pg+1;
+#ifdef MDB_VL32
+	txn->mt_last_pgno = txn->mt_next_pgno - 1;
+#endif
+
+	txn->mt_flags = flags;
+
+	/* Setup db info */
+	txn->mt_numdbs = env->me_numdbs;
+	for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
+		x = env->me_dbflags[i];
+		txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
+		txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_USRVALID|DB_STALE : 0;
+	}
+	txn->mt_dbflags[MAIN_DBI] = DB_VALID|DB_USRVALID;
+	txn->mt_dbflags[FREE_DBI] = DB_VALID;
+
+	if (env->me_flags & MDB_FATAL_ERROR) {
+		DPUTS("environment had fatal error, must shutdown!");
+		rc = MDB_PANIC;
+	} else if (env->me_maxpg < txn->mt_next_pgno) {
+		rc = MDB_MAP_RESIZED;
+	} else {
+		return MDB_SUCCESS;
+	}
+	mdb_txn_end(txn, new_notls /*0 or MDB_END_SLOT*/ | MDB_END_FAIL_BEGIN);
+	return rc;
+}
+
+int
+mdb_txn_renew(MDB_txn *txn)
+{
+	int rc;
+
+	if (!txn || !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY|MDB_TXN_FINISHED))
+		return EINVAL;
+
+	rc = mdb_txn_renew0(txn);
+	if (rc == MDB_SUCCESS) {
+		DPRINTF(("renew txn %"Y"u%c %p on mdbenv %p, root page %"Y"u",
+			txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
+			(void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
+	}
+	return rc;
+}
+
+int
+mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
+{
+	MDB_txn *txn;
+	MDB_ntxn *ntxn;
+	int rc, size, tsize;
+
+	flags &= MDB_TXN_BEGIN_FLAGS;
+	flags |= env->me_flags & MDB_WRITEMAP;
+
+	if (env->me_flags & MDB_RDONLY & ~flags) /* write txn in RDONLY env */
+		return EACCES;
+
+	if (parent) {
+		/* Nested transactions: Max 1 child, write txns only, no writemap */
+		flags |= parent->mt_flags;
+		if (flags & (MDB_RDONLY|MDB_WRITEMAP|MDB_TXN_BLOCKED)) {
+			return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
+		}
+		/* Child txns save MDB_pgstate and use own copy of cursors */
+		size = env->me_maxdbs * (sizeof(MDB_db)+sizeof(MDB_cursor *)+1);
+		size += tsize = sizeof(MDB_ntxn);
+	} else if (flags & MDB_RDONLY) {
+		size = env->me_maxdbs * (sizeof(MDB_db)+1);
+		size += tsize = sizeof(MDB_txn);
+	} else {
+		/* Reuse preallocated write txn. However, do not touch it until
+		 * mdb_txn_renew0() succeeds, since it currently may be active.
+		 */
+		txn = env->me_txn0;
+		goto renew;
+	}
+	if ((txn = calloc(1, size)) == NULL) {
+		DPRINTF(("calloc: %s", strerror(errno)));
+		return ENOMEM;
+	}
+#ifdef MDB_VL32
+	if (!parent) {
+		txn->mt_rpages = malloc(MDB_TRPAGE_SIZE * sizeof(MDB_ID3));
+		if (!txn->mt_rpages) {
+			free(txn);
+			return ENOMEM;
+		}
+		txn->mt_rpages[0].mid = 0;
+		txn->mt_rpcheck = MDB_TRPAGE_SIZE/2;
+	}
+#endif
+	txn->mt_dbxs = env->me_dbxs;	/* static */
+	txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
+	txn->mt_dbflags = (unsigned char *)txn + size - env->me_maxdbs;
+	txn->mt_flags = flags;
+	txn->mt_env = env;
+
+	if (parent) {
+		unsigned int i;
+		txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
+		txn->mt_dbiseqs = parent->mt_dbiseqs;
+		txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
+		if (!txn->mt_u.dirty_list ||
+			!(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
+		{
+			free(txn->mt_u.dirty_list);
+			free(txn);
+			return ENOMEM;
+		}
+		txn->mt_txnid = parent->mt_txnid;
+		txn->mt_dirty_room = parent->mt_dirty_room;
+		txn->mt_u.dirty_list[0].mid = 0;
+		txn->mt_spill_pgs = NULL;
+		txn->mt_next_pgno = parent->mt_next_pgno;
+		parent->mt_flags |= MDB_TXN_HAS_CHILD;
+		parent->mt_child = txn;
+		txn->mt_parent = parent;
+		txn->mt_numdbs = parent->mt_numdbs;
+#ifdef MDB_VL32
+		txn->mt_rpages = parent->mt_rpages;
+#endif
+		memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
+		/* Copy parent's mt_dbflags, but clear DB_NEW */
+		for (i=0; i<txn->mt_numdbs; i++)
+			txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;
+		rc = 0;
+		ntxn = (MDB_ntxn *)txn;
+		ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */
+		if (env->me_pghead) {
+			size = MDB_IDL_SIZEOF(env->me_pghead);
+			env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);
+			if (env->me_pghead)
+				memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
+			else
+				rc = ENOMEM;
+		}
+		if (!rc)
+			rc = mdb_cursor_shadow(parent, txn);
+		if (rc)
+			mdb_txn_end(txn, MDB_END_FAIL_BEGINCHILD);
+	} else { /* MDB_RDONLY */
+		txn->mt_dbiseqs = env->me_dbiseqs;
+renew:
+		rc = mdb_txn_renew0(txn);
+	}
+	if (rc) {
+		if (txn != env->me_txn0) {
+#ifdef MDB_VL32
+			free(txn->mt_rpages);
+#endif
+			free(txn);
+		}
+	} else {
+		txn->mt_flags |= flags;	/* could not change txn=me_txn0 earlier */
+		*ret = txn;
+		DPRINTF(("begin txn %"Y"u%c %p on mdbenv %p, root page %"Y"u",
+			txn->mt_txnid, (flags & MDB_RDONLY) ? 'r' : 'w',
+			(void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
+	}
+
+	return rc;
+}
+
+MDB_env *
+mdb_txn_env(MDB_txn *txn)
+{
+	if(!txn) return NULL;
+	return txn->mt_env;
+}
+
+mdb_size_t
+mdb_txn_id(MDB_txn *txn)
+{
+    if(!txn) return 0;
+    return txn->mt_txnid;
+}
+
+/** Export or close DBI handles opened in this txn. */
+static void
+mdb_dbis_update(MDB_txn *txn, int keep)
+{
+	int i;
+	MDB_dbi n = txn->mt_numdbs;
+	MDB_env *env = txn->mt_env;
+	unsigned char *tdbflags = txn->mt_dbflags;
+
+	for (i = n; --i >= CORE_DBS;) {
+		if (tdbflags[i] & DB_NEW) {
+			if (keep) {
+				env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
+			} else {
+				char *ptr = env->me_dbxs[i].md_name.mv_data;
+				if (ptr) {
+					env->me_dbxs[i].md_name.mv_data = NULL;
+					env->me_dbxs[i].md_name.mv_size = 0;
+					env->me_dbflags[i] = 0;
+					env->me_dbiseqs[i]++;
+					free(ptr);
+				}
+			}
+		}
+	}
+	if (keep && env->me_numdbs < n)
+		env->me_numdbs = n;
+}
+
+/** End a transaction, except successful commit of a nested transaction.
+ * May be called twice for readonly txns: First reset it, then abort.
+ * @param[in] txn the transaction handle to end
+ * @param[in] mode why and how to end the transaction
+ */
+static void
+mdb_txn_end(MDB_txn *txn, unsigned mode)
+{
+	MDB_env	*env = txn->mt_env;
+#if MDB_DEBUG
+	static const char *const names[] = MDB_END_NAMES;
+#endif
+
+	/* Export or close DBI handles opened in this txn */
+	mdb_dbis_update(txn, mode & MDB_END_UPDATE);
+
+	DPRINTF(("%s txn %"Y"u%c %p on mdbenv %p, root page %"Y"u",
+		names[mode & MDB_END_OPMASK],
+		txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
+		(void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
+
+	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
+		if (txn->mt_u.reader) {
+			txn->mt_u.reader->mr_txnid = (txnid_t)-1;
+			if (!(env->me_flags & MDB_NOTLS)) {
+				txn->mt_u.reader = NULL; /* txn does not own reader */
+			} else if (mode & MDB_END_SLOT) {
+				txn->mt_u.reader->mr_pid = 0;
+				txn->mt_u.reader = NULL;
+			} /* else txn owns the slot until it does MDB_END_SLOT */
+		}
+		txn->mt_numdbs = 0;		/* prevent further DBI activity */
+		txn->mt_flags |= MDB_TXN_FINISHED;
+
+	} else if (!F_ISSET(txn->mt_flags, MDB_TXN_FINISHED)) {
+		pgno_t *pghead = env->me_pghead;
+
+		if (!(mode & MDB_END_UPDATE)) /* !(already closed cursors) */
+			mdb_cursors_close(txn, 0);
+		if (!(env->me_flags & MDB_WRITEMAP)) {
+			mdb_dlist_free(txn);
+		}
+
+		txn->mt_numdbs = 0;
+		txn->mt_flags = MDB_TXN_FINISHED;
+
+		if (!txn->mt_parent) {
+			mdb_midl_shrink(&txn->mt_free_pgs);
+			env->me_free_pgs = txn->mt_free_pgs;
+			/* me_pgstate: */
+			env->me_pghead = NULL;
+			env->me_pglast = 0;
+
+			env->me_txn = NULL;
+			mode = 0;	/* txn == env->me_txn0, do not free() it */
+
+			/* The writer mutex was locked in mdb_txn_begin. */
+			if (env->me_txns)
+				UNLOCK_MUTEX(env->me_wmutex);
+		} else {
+			txn->mt_parent->mt_child = NULL;
+			txn->mt_parent->mt_flags &= ~MDB_TXN_HAS_CHILD;
+			env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
+			mdb_midl_free(txn->mt_free_pgs);
+			mdb_midl_free(txn->mt_spill_pgs);
+			free(txn->mt_u.dirty_list);
+		}
+
+		mdb_midl_free(pghead);
+	}
+#ifdef MDB_VL32
+	if (!txn->mt_parent) {
+		MDB_ID3L el = env->me_rpages, tl = txn->mt_rpages;
+		unsigned i, x, n = tl[0].mid;
+		pthread_mutex_lock(&env->me_rpmutex);
+		for (i = 1; i <= n; i++) {
+			if (tl[i].mid & (MDB_RPAGE_CHUNK-1)) {
+				/* tmp overflow pages that we didn't share in env */
+				munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);
+			} else {
+				x = mdb_mid3l_search(el, tl[i].mid);
+				if (tl[i].mptr == el[x].mptr) {
+					el[x].mref--;
+				} else {
+					/* another tmp overflow page */
+					munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);
+				}
+			}
+		}
+		pthread_mutex_unlock(&env->me_rpmutex);
+		tl[0].mid = 0;
+		if (mode & MDB_END_FREE)
+			free(tl);
+	}
+#endif
+	if (mode & MDB_END_FREE)
+		free(txn);
+}
+
+void
+mdb_txn_reset(MDB_txn *txn)
+{
+	if (txn == NULL)
+		return;
+
+	/* This call is only valid for read-only txns */
+	if (!(txn->mt_flags & MDB_TXN_RDONLY))
+		return;
+
+	mdb_txn_end(txn, MDB_END_RESET);
+}
+
+void
+mdb_txn_abort(MDB_txn *txn)
+{
+	if (txn == NULL)
+		return;
+
+	if (txn->mt_child)
+		mdb_txn_abort(txn->mt_child);
+
+	mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);
+}
+
+/** Save the freelist as of this transaction to the freeDB.
+ * This changes the freelist. Keep trying until it stabilizes.
+ *
+ * When (MDB_DEVEL) & 2, the changes do not affect #mdb_page_alloc(),
+ * it then uses the transaction's original snapshot of the freeDB.
+ */
+static int
+mdb_freelist_save(MDB_txn *txn)
+{
+	/* env->me_pghead[] can grow and shrink during this call.
+	 * env->me_pglast and txn->mt_free_pgs[] can only grow.
+	 * Page numbers cannot disappear from txn->mt_free_pgs[].
+	 */
+	MDB_cursor mc;
+	MDB_env	*env = txn->mt_env;
+	int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;
+	txnid_t	pglast = 0, head_id = 0;
+	pgno_t	freecnt = 0, *free_pgs, *mop;
+	ssize_t	head_room = 0, total_room = 0, mop_len, clean_limit;
+
+	mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
+
+	if (env->me_pghead) {
+		/* Make sure first page of freeDB is touched and on freelist */
+		rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
+		if (rc && rc != MDB_NOTFOUND)
+			return rc;
+	}
+
+	if (!env->me_pghead && txn->mt_loose_pgs) {
+		/* Put loose page numbers in mt_free_pgs, since
+		 * we may be unable to return them to me_pghead.
+		 */
+		MDB_page *mp = txn->mt_loose_pgs;
+		if ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)
+			return rc;
+		for (; mp; mp = NEXT_LOOSE_PAGE(mp))
+			mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
+		txn->mt_loose_pgs = NULL;
+		txn->mt_loose_count = 0;
+	}
+
+	/* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
+	clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))
+		? SSIZE_MAX : maxfree_1pg;
+
+	for (;;) {
+		/* Come back here after each Put() in case freelist changed */
+		MDB_val key, data;
+		pgno_t *pgs;
+		ssize_t j;
+
+		/* If using records from freeDB which we have not yet
+		 * deleted, delete them and any we reserved for me_pghead.
+		 */
+		while (pglast < env->me_pglast) {
+			rc = mdb_cursor_first(&mc, &key, NULL);
+			if (rc)
+				return rc;
+			pglast = head_id = *(txnid_t *)key.mv_data;
+			total_room = head_room = 0;
+			mdb_tassert(txn, pglast <= env->me_pglast);
+			rc = mdb_cursor_del(&mc, 0);
+			if (rc)
+				return rc;
+		}
+
+		/* Save the IDL of pages freed by this txn, to a single record */
+		if (freecnt < txn->mt_free_pgs[0]) {
+			if (!freecnt) {
+				/* Make sure last page of freeDB is touched and on freelist */
+				rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
+				if (rc && rc != MDB_NOTFOUND)
+					return rc;
+			}
+			free_pgs = txn->mt_free_pgs;
+			/* Write to last page of freeDB */
+			key.mv_size = sizeof(txn->mt_txnid);
+			key.mv_data = &txn->mt_txnid;
+			do {
+				freecnt = free_pgs[0];
+				data.mv_size = MDB_IDL_SIZEOF(free_pgs);
+				rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
+				if (rc)
+					return rc;
+				/* Retry if mt_free_pgs[] grew during the Put() */
+				free_pgs = txn->mt_free_pgs;
+			} while (freecnt < free_pgs[0]);
+			mdb_midl_sort(free_pgs);
+			memcpy(data.mv_data, free_pgs, data.mv_size);
+#if (MDB_DEBUG) > 1
+			{
+				unsigned int i = free_pgs[0];
+				DPRINTF(("IDL write txn %"Y"u root %"Y"u num %u",
+					txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
+				for (; i; i--)
+					DPRINTF(("IDL %"Y"u", free_pgs[i]));
+			}
+#endif
+			continue;
+		}
+
+		mop = env->me_pghead;
+		mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count;
+
+		/* Reserve records for me_pghead[]. Split it if multi-page,
+		 * to avoid searching freeDB for a page range. Use keys in
+		 * range [1,me_pglast]: Smaller than txnid of oldest reader.
+		 */
+		if (total_room >= mop_len) {
+			if (total_room == mop_len || --more < 0)
+				break;
+		} else if (head_room >= maxfree_1pg && head_id > 1) {
+			/* Keep current record (overflow page), add a new one */
+			head_id--;
+			head_room = 0;
+		}
+		/* (Re)write {key = head_id, IDL length = head_room} */
+		total_room -= head_room;
+		head_room = mop_len - total_room;
+		if (head_room > maxfree_1pg && head_id > 1) {
+			/* Overflow multi-page for part of me_pghead */
+			head_room /= head_id; /* amortize page sizes */
+			head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);
+		} else if (head_room < 0) {
+			/* Rare case, not bothering to delete this record */
+			head_room = 0;
+		}
+		key.mv_size = sizeof(head_id);
+		key.mv_data = &head_id;
+		data.mv_size = (head_room + 1) * sizeof(pgno_t);
+		rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
+		if (rc)
+			return rc;
+		/* IDL is initially empty, zero out at least the length */
+		pgs = (pgno_t *)data.mv_data;
+		j = head_room > clean_limit ? head_room : 0;
+		do {
+			pgs[j] = 0;
+		} while (--j >= 0);
+		total_room += head_room;
+	}
+
+	/* Return loose page numbers to me_pghead, though usually none are
+	 * left at this point.  The pages themselves remain in dirty_list.
+	 */
+	if (txn->mt_loose_pgs) {
+		MDB_page *mp = txn->mt_loose_pgs;
+		unsigned count = txn->mt_loose_count;
+		MDB_IDL loose;
+		/* Room for loose pages + temp IDL with same */
+		if ((rc = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0)
+			return rc;
+		mop = env->me_pghead;
+		loose = mop + MDB_IDL_ALLOCLEN(mop) - count;
+		for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp))
+			loose[ ++count ] = mp->mp_pgno;
+		loose[0] = count;
+		mdb_midl_sort(loose);
+		mdb_midl_xmerge(mop, loose);
+		txn->mt_loose_pgs = NULL;
+		txn->mt_loose_count = 0;
+		mop_len = mop[0];
+	}
+
+	/* Fill in the reserved me_pghead records */
+	rc = MDB_SUCCESS;
+	if (mop_len) {
+		MDB_val key, data;
+
+		mop += mop_len;
+		rc = mdb_cursor_first(&mc, &key, &data);
+		for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
+			txnid_t id = *(txnid_t *)key.mv_data;
+			ssize_t	len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
+			MDB_ID save;
+
+			mdb_tassert(txn, len >= 0 && id <= env->me_pglast);
+			key.mv_data = &id;
+			if (len > mop_len) {
+				len = mop_len;
+				data.mv_size = (len + 1) * sizeof(MDB_ID);
+			}
+			data.mv_data = mop -= len;
+			save = mop[0];
+			mop[0] = len;
+			rc = mdb_cursor_put(&mc, &key, &data, MDB_CURRENT);
+			mop[0] = save;
+			if (rc || !(mop_len -= len))
+				break;
+		}
+	}
+	return rc;
+}
+
+/** Flush (some) dirty pages to the map, after clearing their dirty flag.
+ * @param[in] txn the transaction that's being committed
+ * @param[in] keep number of initial pages in dirty_list to keep dirty.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_page_flush(MDB_txn *txn, int keep)
+{
+	MDB_env		*env = txn->mt_env;
+	MDB_ID2L	dl = txn->mt_u.dirty_list;
+	unsigned	psize = env->me_psize, j;
+	int			i, pagecount = dl[0].mid, rc;
+	size_t		size = 0;
+	off_t		pos = 0;
+	pgno_t		pgno = 0;
+	MDB_page	*dp = NULL;
+#ifdef _WIN32
+	OVERLAPPED	ov;
+#else
+	struct iovec iov[MDB_COMMIT_PAGES];
+	ssize_t		wsize = 0, wres;
+	off_t		wpos = 0, next_pos = 1; /* impossible pos, so pos != next_pos */
+	int			n = 0;
+#endif
+
+	j = i = keep;
+
+	if (env->me_flags & MDB_WRITEMAP) {
+		/* Clear dirty flags */
+		while (++i <= pagecount) {
+			dp = dl[i].mptr;
+			/* Don't flush this page yet */
+			if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
+				dp->mp_flags &= ~P_KEEP;
+				dl[++j] = dl[i];
+				continue;
+			}
+			dp->mp_flags &= ~P_DIRTY;
+		}
+		goto done;
+	}
+
+	/* Write the pages */
+	for (;;) {
+		if (++i <= pagecount) {
+			dp = dl[i].mptr;
+			/* Don't flush this page yet */
+			if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
+				dp->mp_flags &= ~P_KEEP;
+				dl[i].mid = 0;
+				continue;
+			}
+			pgno = dl[i].mid;
+			/* clear dirty flag */
+			dp->mp_flags &= ~P_DIRTY;
+			pos = pgno * psize;
+			size = psize;
+			if (IS_OVERFLOW(dp)) size *= dp->mp_pages;
+		}
+#ifdef _WIN32
+		else break;
+
+		/* Windows actually supports scatter/gather I/O, but only on
+		 * unbuffered file handles. Since we're relying on the OS page
+		 * cache for all our data, that's self-defeating. So we just
+		 * write pages one at a time. We use the ov structure to set
+		 * the write offset, to at least save the overhead of a Seek
+		 * system call.
+		 */
+		DPRINTF(("committing page %"Z"u", pgno));
+		memset(&ov, 0, sizeof(ov));
+		ov.Offset = pos & 0xffffffff;
+		ov.OffsetHigh = pos >> 16 >> 16;
+		if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
+			rc = ErrCode();
+			DPRINTF(("WriteFile: %d", rc));
+			return rc;
+		}
+#else
+		/* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
+		if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
+			if (n) {
+retry_write:
+				/* Write previous page(s) */
+#ifdef MDB_USE_PWRITEV
+				wres = pwritev(env->me_fd, iov, n, wpos);
+#else
+				if (n == 1) {
+					wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
+				} else {
+retry_seek:
+					if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
+						rc = ErrCode();
+						if (rc == EINTR)
+							goto retry_seek;
+						DPRINTF(("lseek: %s", strerror(rc)));
+						return rc;
+					}
+					wres = writev(env->me_fd, iov, n);
+				}
+#endif
+				if (wres != wsize) {
+					if (wres < 0) {
+						rc = ErrCode();
+						if (rc == EINTR)
+							goto retry_write;
+						DPRINTF(("Write error: %s", strerror(rc)));
+					} else {
+						rc = EIO; /* TODO: Use which error code? */
+						DPUTS("short write, filesystem full?");
+					}
+					return rc;
+				}
+				n = 0;
+			}
+			if (i > pagecount)
+				break;
+			wpos = pos;
+			wsize = 0;
+		}
+		DPRINTF(("committing page %"Y"u", pgno));
+		next_pos = pos + size;
+		iov[n].iov_len = size;
+		iov[n].iov_base = (char *)dp;
+		wsize += size;
+		n++;
+#endif	/* _WIN32 */
+	}
+#ifdef MDB_VL32
+	if (pgno > txn->mt_last_pgno)
+		txn->mt_last_pgno = pgno;
+#endif
+
+	/* MIPS has cache coherency issues, this is a no-op everywhere else
+	 * Note: for any size >= on-chip cache size, entire on-chip cache is
+	 * flushed.
+	 */
+	CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE);
+
+	for (i = keep; ++i <= pagecount; ) {
+		dp = dl[i].mptr;
+		/* This is a page we skipped above */
+		if (!dl[i].mid) {
+			dl[++j] = dl[i];
+			dl[j].mid = dp->mp_pgno;
+			continue;
+		}
+		mdb_dpage_free(env, dp);
+	}
+
+done:
+	i--;
+	txn->mt_dirty_room += i - j;
+	dl[0].mid = j;
+	return MDB_SUCCESS;
+}
+
+int
+mdb_txn_commit(MDB_txn *txn)
+{
+	int		rc;
+	unsigned int i, end_mode;
+	MDB_env	*env;
+
+	if (txn == NULL)
+		return EINVAL;
+
+	/* mdb_txn_end() mode for a commit which writes nothing */
+	end_mode = MDB_END_EMPTY_COMMIT|MDB_END_UPDATE|MDB_END_SLOT|MDB_END_FREE;
+
+	if (txn->mt_child) {
+		rc = mdb_txn_commit(txn->mt_child);
+		if (rc)
+			goto fail;
+	}
+
+	env = txn->mt_env;
+
+	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
+		goto done;
+	}
+
+	if (txn->mt_flags & (MDB_TXN_FINISHED|MDB_TXN_ERROR)) {
+		DPUTS("txn has failed/finished, can't commit");
+		if (txn->mt_parent)
+			txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
+		rc = MDB_BAD_TXN;
+		goto fail;
+	}
+
+	if (txn->mt_parent) {
+		MDB_txn *parent = txn->mt_parent;
+		MDB_page **lp;
+		MDB_ID2L dst, src;
+		MDB_IDL pspill;
+		unsigned x, y, len, ps_len;
+
+		/* Append our free list to parent's */
+		rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
+		if (rc)
+			goto fail;
+		mdb_midl_free(txn->mt_free_pgs);
+		/* Failures after this must either undo the changes
+		 * to the parent or set MDB_TXN_ERROR in the parent.
+		 */
+
+		parent->mt_next_pgno = txn->mt_next_pgno;
+		parent->mt_flags = txn->mt_flags;
+
+		/* Merge our cursors into parent's and close them */
+		mdb_cursors_close(txn, 1);
+
+		/* Update parent's DB table. */
+		memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
+		parent->mt_numdbs = txn->mt_numdbs;
+		parent->mt_dbflags[FREE_DBI] = txn->mt_dbflags[FREE_DBI];
+		parent->mt_dbflags[MAIN_DBI] = txn->mt_dbflags[MAIN_DBI];
+		for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
+			/* preserve parent's DB_NEW status */
+			x = parent->mt_dbflags[i] & DB_NEW;
+			parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
+		}
+
+		dst = parent->mt_u.dirty_list;
+		src = txn->mt_u.dirty_list;
+		/* Remove anything in our dirty list from parent's spill list */
+		if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {
+			x = y = ps_len;
+			pspill[0] = (pgno_t)-1;
+			/* Mark our dirty pages as deleted in parent spill list */
+			for (i=0, len=src[0].mid; ++i <= len; ) {
+				MDB_ID pn = src[i].mid << 1;
+				while (pn > pspill[x])
+					x--;
+				if (pn == pspill[x]) {
+					pspill[x] = 1;
+					y = --x;
+				}
+			}
+			/* Squash deleted pagenums if we deleted any */
+			for (x=y; ++x <= ps_len; )
+				if (!(pspill[x] & 1))
+					pspill[++y] = pspill[x];
+			pspill[0] = y;
+		}
+
+		/* Remove anything in our spill list from parent's dirty list */
+		if (txn->mt_spill_pgs && txn->mt_spill_pgs[0]) {
+			for (i=1; i<=txn->mt_spill_pgs[0]; i++) {
+				MDB_ID pn = txn->mt_spill_pgs[i];
+				if (pn & 1)
+					continue;	/* deleted spillpg */
+				pn >>= 1;
+				y = mdb_mid2l_search(dst, pn);
+				if (y <= dst[0].mid && dst[y].mid == pn) {
+					free(dst[y].mptr);
+					while (y < dst[0].mid) {
+						dst[y] = dst[y+1];
+						y++;
+					}
+					dst[0].mid--;
+				}
+			}
+		}
+
+		/* Find len = length of merging our dirty list with parent's */
+		x = dst[0].mid;
+		dst[0].mid = 0;		/* simplify loops */
+		if (parent->mt_parent) {
+			len = x + src[0].mid;
+			y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;
+			for (i = x; y && i; y--) {
+				pgno_t yp = src[y].mid;
+				while (yp < dst[i].mid)
+					i--;
+				if (yp == dst[i].mid) {
+					i--;
+					len--;
+				}
+			}
+		} else { /* Simplify the above for single-ancestor case */
+			len = MDB_IDL_UM_MAX - txn->mt_dirty_room;
+		}
+		/* Merge our dirty list with parent's */
+		y = src[0].mid;
+		for (i = len; y; dst[i--] = src[y--]) {
+			pgno_t yp = src[y].mid;
+			while (yp < dst[x].mid)
+				dst[i--] = dst[x--];
+			if (yp == dst[x].mid)
+				free(dst[x--].mptr);
+		}
+		mdb_tassert(txn, i == x);
+		dst[0].mid = len;
+		free(txn->mt_u.dirty_list);
+		parent->mt_dirty_room = txn->mt_dirty_room;
+		if (txn->mt_spill_pgs) {
+			if (parent->mt_spill_pgs) {
+				/* TODO: Prevent failure here, so parent does not fail */
+				rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
+				if (rc)
+					parent->mt_flags |= MDB_TXN_ERROR;
+				mdb_midl_free(txn->mt_spill_pgs);
+				mdb_midl_sort(parent->mt_spill_pgs);
+			} else {
+				parent->mt_spill_pgs = txn->mt_spill_pgs;
+			}
+		}
+
+		/* Append our loose page list to parent's */
+		for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(*lp))
+			;
+		*lp = txn->mt_loose_pgs;
+		parent->mt_loose_count += txn->mt_loose_count;
+
+		parent->mt_child = NULL;
+		mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
+		free(txn);
+		return rc;
+	}
+
+	if (txn != env->me_txn) {
+		DPUTS("attempt to commit unknown transaction");
+		rc = EINVAL;
+		goto fail;
+	}
+
+	mdb_cursors_close(txn, 0);
+
+	if (!txn->mt_u.dirty_list[0].mid &&
+		!(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
+		goto done;
+
+	DPRINTF(("committing txn %"Y"u %p on mdbenv %p, root page %"Y"u",
+	    txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
+
+	/* Update DB root pointers */
+	if (txn->mt_numdbs > CORE_DBS) {
+		MDB_cursor mc;
+		MDB_dbi i;
+		MDB_val data;
+		data.mv_size = sizeof(MDB_db);
+
+		mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
+		for (i = CORE_DBS; i < txn->mt_numdbs; i++) {
+			if (txn->mt_dbflags[i] & DB_DIRTY) {
+				if (TXN_DBI_CHANGED(txn, i)) {
+					rc = MDB_BAD_DBI;
+					goto fail;
+				}
+				data.mv_data = &txn->mt_dbs[i];
+				rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data,
+					F_SUBDATA);
+				if (rc)
+					goto fail;
+			}
+		}
+	}
+
+	rc = mdb_freelist_save(txn);
+	if (rc)
+		goto fail;
+
+	mdb_midl_free(env->me_pghead);
+	env->me_pghead = NULL;
+	mdb_midl_shrink(&txn->mt_free_pgs);
+
+#if (MDB_DEBUG) > 2
+	mdb_audit(txn);
+#endif
+
+	if ((rc = mdb_page_flush(txn, 0)))
+		goto fail;
+	if (!F_ISSET(txn->mt_flags, MDB_TXN_NOSYNC) &&
+		(rc = mdb_env_sync0(env, 0, txn->mt_next_pgno)))
+		goto fail;
+	if ((rc = mdb_env_write_meta(txn)))
+		goto fail;
+	end_mode = MDB_END_COMMITTED|MDB_END_UPDATE;
+
+done:
+	mdb_txn_end(txn, end_mode);
+	return MDB_SUCCESS;
+
+fail:
+	mdb_txn_abort(txn);
+	return rc;
+}
+
+/** Read the environment parameters of a DB environment before
+ * mapping it into memory.
+ * @param[in] env the environment handle
+ * @param[out] meta address of where to store the meta information
+ * @return 0 on success, non-zero on failure.
+ */
+static int ESECT
+mdb_env_read_header(MDB_env *env, MDB_meta *meta)
+{
+	MDB_metabuf	pbuf;
+	MDB_page	*p;
+	MDB_meta	*m;
+	int			i, rc, off;
+	enum { Size = sizeof(pbuf) };
+
+	/* We don't know the page size yet, so use a minimum value.
+	 * Read both meta pages so we can use the latest one.
+	 */
+
+	for (i=off=0; i<NUM_METAS; i++, off += meta->mm_psize) {
+#ifdef _WIN32
+		DWORD len;
+		OVERLAPPED ov;
+		memset(&ov, 0, sizeof(ov));
+		ov.Offset = off;
+		rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;
+		if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
+			rc = 0;
+#else
+		rc = pread(env->me_fd, &pbuf, Size, off);
+#endif
+		if (rc != Size) {
+			if (rc == 0 && off == 0)
+				return ENOENT;
+			rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
+			DPRINTF(("read: %s", mdb_strerror(rc)));
+			return rc;
+		}
+
+		p = (MDB_page *)&pbuf;
+
+		if (!F_ISSET(p->mp_flags, P_META)) {
+			DPRINTF(("page %"Y"u not a meta page", p->mp_pgno));
+			return MDB_INVALID;
+		}
+
+		m = METADATA(p);
+		if (m->mm_magic != MDB_MAGIC) {
+			DPUTS("meta has invalid magic");
+			return MDB_INVALID;
+		}
+
+		if (m->mm_version != MDB_DATA_VERSION) {
+			DPRINTF(("database is version %u, expected version %u",
+				m->mm_version, MDB_DATA_VERSION));
+			return MDB_VERSION_MISMATCH;
+		}
+
+		if (off == 0 || m->mm_txnid > meta->mm_txnid)
+			*meta = *m;
+	}
+	return 0;
+}
+
+/** Fill in most of the zeroed #MDB_meta for an empty database environment */
+static void ESECT
+mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
+{
+	meta->mm_magic = MDB_MAGIC;
+	meta->mm_version = MDB_DATA_VERSION;
+	meta->mm_mapsize = env->me_mapsize;
+	meta->mm_psize = env->me_psize;
+	meta->mm_last_pg = NUM_METAS-1;
+	meta->mm_flags = env->me_flags & 0xffff;
+	meta->mm_flags |= MDB_INTEGERKEY; /* this is mm_dbs[FREE_DBI].md_flags */
+	meta->mm_dbs[FREE_DBI].md_root = P_INVALID;
+	meta->mm_dbs[MAIN_DBI].md_root = P_INVALID;
+}
+
+/** Write the environment parameters of a freshly created DB environment.
+ * @param[in] env the environment handle
+ * @param[in] meta the #MDB_meta to write
+ * @return 0 on success, non-zero on failure.
+ */
+static int ESECT
+mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
+{
+	MDB_page *p, *q;
+	int rc;
+	unsigned int	 psize;
+#ifdef _WIN32
+	DWORD len;
+	OVERLAPPED ov;
+	memset(&ov, 0, sizeof(ov));
+#define DO_PWRITE(rc, fd, ptr, size, len, pos)	do { \
+	ov.Offset = pos;	\
+	rc = WriteFile(fd, ptr, size, &len, &ov);	} while(0)
+#else
+	int len;
+#define DO_PWRITE(rc, fd, ptr, size, len, pos)	do { \
+	len = pwrite(fd, ptr, size, pos);	\
+	if (len == -1 && ErrCode() == EINTR) continue; \
+	rc = (len >= 0); break; } while(1)
+#endif
+
+	DPUTS("writing new meta page");
+
+	psize = env->me_psize;
+
+	p = calloc(NUM_METAS, psize);
+	if (!p)
+		return ENOMEM;
+	p->mp_pgno = 0;
+	p->mp_flags = P_META;
+	*(MDB_meta *)METADATA(p) = *meta;
+
+	q = (MDB_page *)((char *)p + psize);
+	q->mp_pgno = 1;
+	q->mp_flags = P_META;
+	*(MDB_meta *)METADATA(q) = *meta;
+
+	DO_PWRITE(rc, env->me_fd, p, psize * NUM_METAS, len, 0);
+	if (!rc)
+		rc = ErrCode();
+	else if ((unsigned) len == psize * NUM_METAS)
+		rc = MDB_SUCCESS;
+	else
+		rc = ENOSPC;
+	free(p);
+	return rc;
+}
+
+/** Update the environment info to commit a transaction.
+ * @param[in] txn the transaction that's being committed
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_env_write_meta(MDB_txn *txn)
+{
+	MDB_env *env;
+	MDB_meta	meta, metab, *mp;
+	unsigned flags;
+	mdb_size_t mapsize;
+	off_t off;
+	int rc, len, toggle;
+	char *ptr;
+	HANDLE mfd;
+#ifdef _WIN32
+	OVERLAPPED ov;
+#else
+	int r2;
+#endif
+
+	toggle = txn->mt_txnid & 1;
+	DPRINTF(("writing meta page %d for root page %"Y"u",
+		toggle, txn->mt_dbs[MAIN_DBI].md_root));
+
+	env = txn->mt_env;
+	flags = txn->mt_flags | env->me_flags;
+	mp = env->me_metas[toggle];
+	mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;
+	/* Persist any increases of mapsize config */
+	if (mapsize < env->me_mapsize)
+		mapsize = env->me_mapsize;
+
+	if (flags & MDB_WRITEMAP) {
+		mp->mm_mapsize = mapsize;
+		mp->mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
+		mp->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
+		mp->mm_last_pg = txn->mt_next_pgno - 1;
+#if (__GNUC__ * 100 + __GNUC_MINOR__ >= 404) && /* TODO: portability */	\
+	!(defined(__i386__) || defined(__x86_64__))
+		/* LY: issue a memory barrier, if not x86. ITS#7969 */
+		__sync_synchronize();
+#endif
+		mp->mm_txnid = txn->mt_txnid;
+		if (!(flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
+			unsigned meta_size = env->me_psize;
+			rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
+			ptr = (char *)mp - PAGEHDRSZ;
+#ifndef _WIN32	/* POSIX msync() requires ptr = start of OS page */
+			r2 = (ptr - env->me_map) & (env->me_os_psize - 1);
+			ptr -= r2;
+			meta_size += r2;
+#endif
+			if (MDB_MSYNC(ptr, meta_size, rc)) {
+				rc = ErrCode();
+				goto fail;
+			}
+		}
+		goto done;
+	}
+	metab.mm_txnid = mp->mm_txnid;
+	metab.mm_last_pg = mp->mm_last_pg;
+
+	meta.mm_mapsize = mapsize;
+	meta.mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
+	meta.mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
+	meta.mm_last_pg = txn->mt_next_pgno - 1;
+	meta.mm_txnid = txn->mt_txnid;
+
+	off = offsetof(MDB_meta, mm_mapsize);
+	ptr = (char *)&meta + off;
+	len = sizeof(MDB_meta) - off;
+	off += (char *)mp - env->me_map;
+
+	/* Write to the SYNC fd */
+	mfd = (flags & (MDB_NOSYNC|MDB_NOMETASYNC)) ? env->me_fd : env->me_mfd;
+#ifdef _WIN32
+	{
+		memset(&ov, 0, sizeof(ov));
+		ov.Offset = off;
+		if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
+			rc = -1;
+	}
+#else
+retry_write:
+	rc = pwrite(mfd, ptr, len, off);
+#endif
+	if (rc != len) {
+		rc = rc < 0 ? ErrCode() : EIO;
+#ifndef _WIN32
+		if (rc == EINTR)
+			goto retry_write;
+#endif
+		DPUTS("write failed, disk error?");
+		/* On a failure, the pagecache still contains the new data.
+		 * Write some old data back, to prevent it from being used.
+		 * Use the non-SYNC fd; we know it will fail anyway.
+		 */
+		meta.mm_last_pg = metab.mm_last_pg;
+		meta.mm_txnid = metab.mm_txnid;
+#ifdef _WIN32
+		memset(&ov, 0, sizeof(ov));
+		ov.Offset = off;
+		WriteFile(env->me_fd, ptr, len, NULL, &ov);
+#else
+		r2 = pwrite(env->me_fd, ptr, len, off);
+		(void)r2;	/* Silence warnings. We don't care about pwrite's return value */
+#endif
+fail:
+		env->me_flags |= MDB_FATAL_ERROR;
+		return rc;
+	}
+	/* MIPS has cache coherency issues, this is a no-op everywhere else */
+	CACHEFLUSH(env->me_map + off, len, DCACHE);
+done:
+	/* Memory ordering issues are irrelevant; since the entire writer
+	 * is wrapped by wmutex, all of these changes will become visible
+	 * after the wmutex is unlocked. Since the DB is multi-version,
+	 * readers will get consistent data regardless of how fresh or
+	 * how stale their view of these values is.
+	 */
+	if (env->me_txns)
+		env->me_txns->mti_txnid = txn->mt_txnid;
+
+	return MDB_SUCCESS;
+}
+
+/** Check both meta pages to see which one is newer.
+ * @param[in] env the environment handle
+ * @return newest #MDB_meta.
+ */
+static MDB_meta *
+mdb_env_pick_meta(const MDB_env *env)
+{
+	MDB_meta *const *metas = env->me_metas;
+	return metas[ metas[0]->mm_txnid < metas[1]->mm_txnid ];
+}
+
+int ESECT
+mdb_env_create(MDB_env **env)
+{
+	MDB_env *e;
+
+	e = calloc(1, sizeof(MDB_env));
+	if (!e)
+		return ENOMEM;
+
+	e->me_maxreaders = DEFAULT_READERS;
+	e->me_maxdbs = e->me_numdbs = CORE_DBS;
+	e->me_fd = INVALID_HANDLE_VALUE;
+	e->me_lfd = INVALID_HANDLE_VALUE;
+	e->me_mfd = INVALID_HANDLE_VALUE;
+#ifdef MDB_USE_POSIX_SEM
+	e->me_rmutex = SEM_FAILED;
+	e->me_wmutex = SEM_FAILED;
+#elif defined MDB_USE_SYSV_SEM
+	e->me_rmutex->semid = -1;
+	e->me_wmutex->semid = -1;
+#endif
+	e->me_pid = getpid();
+	GET_PAGESIZE(e->me_os_psize);
+	VGMEMP_CREATE(e,0,0);
+	*env = e;
+	return MDB_SUCCESS;
+}
+
+#ifdef _WIN32
+/** @brief Map a result from an NTAPI call to WIN32. */
+static DWORD
+mdb_nt2win32(NTSTATUS st)
+{
+	OVERLAPPED o = {0};
+	DWORD br;
+	o.Internal = st;
+	GetOverlappedResult(NULL, &o, &br, FALSE);
+	return GetLastError();
+}
+#endif
+
+static int ESECT
+mdb_env_map(MDB_env *env, void *addr)
+{
+	MDB_page *p;
+	unsigned int flags = env->me_flags;
+#ifdef _WIN32
+	int rc;
+	int access = SECTION_MAP_READ;
+	HANDLE mh;
+	void *map;
+	SIZE_T msize;
+	ULONG pageprot = PAGE_READONLY, secprot, alloctype;
+
+	if (flags & MDB_WRITEMAP) {
+		access |= SECTION_MAP_WRITE;
+		pageprot = PAGE_READWRITE;
+	}
+	if (flags & MDB_RDONLY) {
+		secprot = PAGE_READONLY;
+		msize = 0;
+		alloctype = 0;
+	} else {
+		secprot = PAGE_READWRITE;
+		msize = env->me_mapsize;
+		alloctype = MEM_RESERVE;
+	}
+
+	rc = NtCreateSection(&mh, access, NULL, NULL, secprot, SEC_RESERVE, env->me_fd);
+	if (rc)
+		return mdb_nt2win32(rc);
+	map = addr;
+#ifdef MDB_VL32
+	msize = NUM_METAS * env->me_psize;
+#endif
+	rc = NtMapViewOfSection(mh, GetCurrentProcess(), &map, 0, 0, NULL, &msize, ViewUnmap, alloctype, pageprot);
+#ifdef MDB_VL32
+	env->me_fmh = mh;
+#else
+	NtClose(mh);
+#endif
+	if (rc)
+		return mdb_nt2win32(rc);
+	env->me_map = map;
+#else
+#ifdef MDB_VL32
+	(void) flags;
+	env->me_map = mmap(addr, NUM_METAS * env->me_psize, PROT_READ, MAP_SHARED,
+		env->me_fd, 0);
+	if (env->me_map == MAP_FAILED) {
+		env->me_map = NULL;
+		return ErrCode();
+	}
+#else
+	int prot = PROT_READ;
+	if (flags & MDB_WRITEMAP) {
+		prot |= PROT_WRITE;
+		if (ftruncate(env->me_fd, env->me_mapsize) < 0)
+			return ErrCode();
+	}
+	env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
+		env->me_fd, 0);
+	if (env->me_map == MAP_FAILED) {
+		env->me_map = NULL;
+		return ErrCode();
+	}
+
+	if (flags & MDB_NORDAHEAD) {
+		/* Turn off readahead. It's harmful when the DB is larger than RAM. */
+#ifdef MADV_RANDOM
+		madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
+#else
+#ifdef POSIX_MADV_RANDOM
+		posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
+#endif /* POSIX_MADV_RANDOM */
+#endif /* MADV_RANDOM */
+	}
+#endif /* _WIN32 */
+
+	/* Can happen because the address argument to mmap() is just a
+	 * hint.  mmap() can pick another, e.g. if the range is in use.
+	 * The MAP_FIXED flag would prevent that, but then mmap could
+	 * instead unmap existing pages to make room for the new map.
+	 */
+	if (addr && env->me_map != addr)
+		return EBUSY;	/* TODO: Make a new MDB_* error code? */
+#endif
+
+	p = (MDB_page *)env->me_map;
+	env->me_metas[0] = METADATA(p);
+	env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
+
+	return MDB_SUCCESS;
+}
+
+int ESECT
+mdb_env_set_mapsize(MDB_env *env, mdb_size_t size)
+{
+	/* If env is already open, caller is responsible for making
+	 * sure there are no active txns.
+	 */
+	if (env->me_map) {
+		MDB_meta *meta;
+#ifndef MDB_VL32
+		void *old;
+		int rc;
+#endif
+		if (env->me_txn)
+			return EINVAL;
+		meta = mdb_env_pick_meta(env);
+		if (!size)
+			size = meta->mm_mapsize;
+		{
+			/* Silently round up to minimum if the size is too small */
+			mdb_size_t minsize = (meta->mm_last_pg + 1) * env->me_psize;
+			if (size < minsize)
+				size = minsize;
+		}
+#ifndef MDB_VL32
+		/* For MDB_VL32 this bit is a noop since we dynamically remap
+		 * chunks of the DB anyway.
+		 */
+		munmap(env->me_map, env->me_mapsize);
+		env->me_mapsize = size;
+		old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
+		rc = mdb_env_map(env, old);
+		if (rc)
+			return rc;
+#endif /* !MDB_VL32 */
+	}
+	env->me_mapsize = size;
+	if (env->me_psize)
+		env->me_maxpg = env->me_mapsize / env->me_psize;
+	return MDB_SUCCESS;
+}
+
+int ESECT
+mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
+{
+	if (env->me_map)
+		return EINVAL;
+	env->me_maxdbs = dbs + CORE_DBS;
+	return MDB_SUCCESS;
+}
+
+int ESECT
+mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
+{
+	if (env->me_map || readers < 1)
+		return EINVAL;
+	env->me_maxreaders = readers;
+	return MDB_SUCCESS;
+}
+
+int ESECT
+mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
+{
+	if (!env || !readers)
+		return EINVAL;
+	*readers = env->me_maxreaders;
+	return MDB_SUCCESS;
+}
+
+static int ESECT
+mdb_fsize(HANDLE fd, mdb_size_t *size)
+{
+#ifdef _WIN32
+	LARGE_INTEGER fsize;
+
+	if (!GetFileSizeEx(fd, &fsize))
+		return ErrCode();
+
+	*size = fsize.QuadPart;
+#else
+	struct stat st;
+
+	if (fstat(fd, &st))
+		return ErrCode();
+
+	*size = st.st_size;
+#endif
+	return MDB_SUCCESS;
+}
+
+#ifdef BROKEN_FDATASYNC
+#include <sys/utsname.h>
+#include <sys/vfs.h>
+#endif
+
+/** Further setup required for opening an LMDB environment
+ */
+static int ESECT
+mdb_env_open2(MDB_env *env)
+{
+	unsigned int flags = env->me_flags;
+	int i, newenv = 0, rc;
+	MDB_meta meta;
+
+#ifdef _WIN32
+	/* See if we should use QueryLimited */
+	rc = GetVersion();
+	if ((rc & 0xff) > 5)
+		env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
+	else
+		env->me_pidquery = PROCESS_QUERY_INFORMATION;
+#endif /* _WIN32 */
+
+#ifdef BROKEN_FDATASYNC
+	/* ext3/ext4 fdatasync is broken on some older Linux kernels.
+	 * https://lkml.org/lkml/2012/9/3/83
+	 * Kernels after 3.6-rc6 are known good.
+	 * https://lkml.org/lkml/2012/9/10/556
+	 * See if the DB is on ext3/ext4, then check for new enough kernel
+	 * Kernels 2.6.32.60, 2.6.34.15, 3.2.30, and 3.5.4 are also known
+	 * to be patched.
+	 */
+	{
+		struct statfs st;
+		fstatfs(env->me_fd, &st);
+		while (st.f_type == 0xEF53) {
+			struct utsname uts;
+			int i;
+			uname(&uts);
+			if (uts.release[0] < '3') {
+				if (!strncmp(uts.release, "2.6.32.", 7)) {
+					i = atoi(uts.release+7);
+					if (i >= 60)
+						break;	/* 2.6.32.60 and newer is OK */
+				} else if (!strncmp(uts.release, "2.6.34.", 7)) {
+					i = atoi(uts.release+7);
+					if (i >= 15)
+						break;	/* 2.6.34.15 and newer is OK */
+				}
+			} else if (uts.release[0] == '3') {
+				i = atoi(uts.release+2);
+				if (i > 5)
+					break;	/* 3.6 and newer is OK */
+				if (i == 5) {
+					i = atoi(uts.release+4);
+					if (i >= 4)
+						break;	/* 3.5.4 and newer is OK */
+				} else if (i == 2) {
+					i = atoi(uts.release+4);
+					if (i >= 30)
+						break;	/* 3.2.30 and newer is OK */
+				}
+			} else {	/* 4.x and newer is OK */
+				break;
+			}
+			env->me_flags |= MDB_FSYNCONLY;
+			break;
+		}
+	}
+#endif
+
+	if ((i = mdb_env_read_header(env, &meta)) != 0) {
+		if (i != ENOENT)
+			return i;
+		DPUTS("new mdbenv");
+		newenv = 1;
+		env->me_psize = env->me_os_psize;
+		if (env->me_psize > MAX_PAGESIZE)
+			env->me_psize = MAX_PAGESIZE;
+		memset(&meta, 0, sizeof(meta));
+		mdb_env_init_meta0(env, &meta);
+		meta.mm_mapsize = DEFAULT_MAPSIZE;
+	} else {
+		env->me_psize = meta.mm_psize;
+	}
+
+	/* Was a mapsize configured? */
+	if (!env->me_mapsize) {
+		env->me_mapsize = meta.mm_mapsize;
+	}
+	{
+		/* Make sure mapsize >= committed data size.  Even when using
+		 * mm_mapsize, which could be broken in old files (ITS#7789).
+		 */
+		mdb_size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
+		if (env->me_mapsize < minsize)
+			env->me_mapsize = minsize;
+	}
+	meta.mm_mapsize = env->me_mapsize;
+
+	if (newenv && !(flags & MDB_FIXEDMAP)) {
+		/* mdb_env_map() may grow the datafile.  Write the metapages
+		 * first, so the file will be valid if initialization fails.
+		 * Except with FIXEDMAP, since we do not yet know mm_address.
+		 * We could fill in mm_address later, but then a different
+		 * program might end up doing that - one with a memory layout
+		 * and map address which does not suit the main program.
+		 */
+		rc = mdb_env_init_meta(env, &meta);
+		if (rc)
+			return rc;
+		newenv = 0;
+	}
+#ifdef _WIN32
+	/* For FIXEDMAP, make sure the file is non-empty before we attempt to map it */
+	if (newenv) {
+		char dummy = 0;
+		DWORD len;
+		rc = WriteFile(env->me_fd, &dummy, 1, &len, NULL);
+		if (!rc) {
+			rc = ErrCode();
+			return rc;
+		}
+	}
+#endif
+
+	rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);
+	if (rc)
+		return rc;
+
+	if (newenv) {
+		if (flags & MDB_FIXEDMAP)
+			meta.mm_address = env->me_map;
+		i = mdb_env_init_meta(env, &meta);
+		if (i != MDB_SUCCESS) {
+			return i;
+		}
+	}
+
+	env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
+	env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2)
+		- sizeof(indx_t);
+#if !(MDB_MAXKEYSIZE)
+	env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));
+#endif
+	env->me_maxpg = env->me_mapsize / env->me_psize;
+
+#if MDB_DEBUG
+	{
+		MDB_meta *meta = mdb_env_pick_meta(env);
+		MDB_db *db = &meta->mm_dbs[MAIN_DBI];
+
+		DPRINTF(("opened database version %u, pagesize %u",
+			meta->mm_version, env->me_psize));
+		DPRINTF(("using meta page %d",    (int) (meta->mm_txnid & 1)));
+		DPRINTF(("depth: %u",             db->md_depth));
+		DPRINTF(("entries: %"Y"u",        db->md_entries));
+		DPRINTF(("branch pages: %"Y"u",   db->md_branch_pages));
+		DPRINTF(("leaf pages: %"Y"u",     db->md_leaf_pages));
+		DPRINTF(("overflow pages: %"Y"u", db->md_overflow_pages));
+		DPRINTF(("root: %"Y"u",           db->md_root));
+	}
+#endif
+
+	return MDB_SUCCESS;
+}
+
+
+/** Release a reader thread's slot in the reader lock table.
+ *	This function is called automatically when a thread exits.
+ * @param[in] ptr This points to the slot in the reader lock table.
+ */
+static void
+mdb_env_reader_dest(void *ptr)
+{
+	MDB_reader *reader = ptr;
+
+	reader->mr_pid = 0;
+}
+
+#ifdef _WIN32
+/** Junk for arranging thread-specific callbacks on Windows. This is
+ *	necessarily platform and compiler-specific. Windows supports up
+ *	to 1088 keys. Let's assume nobody opens more than 64 environments
+ *	in a single process, for now. They can override this if needed.
+ */
+#ifndef MAX_TLS_KEYS
+#define MAX_TLS_KEYS	64
+#endif
+static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
+static int mdb_tls_nkeys;
+
+static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
+{
+	int i;
+	switch(reason) {
+	case DLL_PROCESS_ATTACH: break;
+	case DLL_THREAD_ATTACH: break;
+	case DLL_THREAD_DETACH:
+		for (i=0; i<mdb_tls_nkeys; i++) {
+			MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
+			if (r) {
+				mdb_env_reader_dest(r);
+			}
+		}
+		break;
+	case DLL_PROCESS_DETACH: break;
+	}
+}
+#ifdef __GNUC__
+#ifdef _WIN64
+const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
+#else
+PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
+#endif
+#else
+#ifdef _WIN64
+/* Force some symbol references.
+ *	_tls_used forces the linker to create the TLS directory if not already done
+ *	mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
+ */
+#pragma comment(linker, "/INCLUDE:_tls_used")
+#pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
+#pragma const_seg(".CRT$XLB")
+extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;
+const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
+#pragma const_seg()
+#else	/* _WIN32 */
+#pragma comment(linker, "/INCLUDE:__tls_used")
+#pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
+#pragma data_seg(".CRT$XLB")
+PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
+#pragma data_seg()
+#endif	/* WIN 32/64 */
+#endif	/* !__GNUC__ */
+#endif
+
+/** Downgrade the exclusive lock on the region back to shared */
+static int ESECT
+mdb_env_share_locks(MDB_env *env, int *excl)
+{
+	int rc = 0;
+	MDB_meta *meta = mdb_env_pick_meta(env);
+
+	env->me_txns->mti_txnid = meta->mm_txnid;
+
+#ifdef _WIN32
+	{
+		OVERLAPPED ov;
+		/* First acquire a shared lock. The Unlock will
+		 * then release the existing exclusive lock.
+		 */
+		memset(&ov, 0, sizeof(ov));
+		if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
+			rc = ErrCode();
+		} else {
+			UnlockFile(env->me_lfd, 0, 0, 1, 0);
+			*excl = 0;
+		}
+	}
+#else
+	{
+		struct flock lock_info;
+		/* The shared lock replaces the existing lock */
+		memset((void *)&lock_info, 0, sizeof(lock_info));
+		lock_info.l_type = F_RDLCK;
+		lock_info.l_whence = SEEK_SET;
+		lock_info.l_start = 0;
+		lock_info.l_len = 1;
+		while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
+				(rc = ErrCode()) == EINTR) ;
+		*excl = rc ? -1 : 0;	/* error may mean we lost the lock */
+	}
+#endif
+
+	return rc;
+}
+
+/** Try to get exclusive lock, otherwise shared.
+ *	Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
+ */
+static int ESECT
+mdb_env_excl_lock(MDB_env *env, int *excl)
+{
+	int rc = 0;
+#ifdef _WIN32
+	if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
+		*excl = 1;
+	} else {
+		OVERLAPPED ov;
+		memset(&ov, 0, sizeof(ov));
+		if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
+			*excl = 0;
+		} else {
+			rc = ErrCode();
+		}
+	}
+#else
+	struct flock lock_info;
+	memset((void *)&lock_info, 0, sizeof(lock_info));
+	lock_info.l_type = F_WRLCK;
+	lock_info.l_whence = SEEK_SET;
+	lock_info.l_start = 0;
+	lock_info.l_len = 1;
+	while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
+			(rc = ErrCode()) == EINTR) ;
+	if (!rc) {
+		*excl = 1;
+	} else
+# ifndef MDB_USE_POSIX_MUTEX
+	if (*excl < 0) /* always true when MDB_USE_POSIX_MUTEX */
+# endif
+	{
+		lock_info.l_type = F_RDLCK;
+		while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
+				(rc = ErrCode()) == EINTR) ;
+		if (rc == 0)
+			*excl = 0;
+	}
+#endif
+	return rc;
+}
+
+#ifdef MDB_USE_HASH
+/*
+ * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
+ *
+ * @(#) $Revision: 5.1 $
+ * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
+ * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
+ *
+ *	  http://www.isthe.com/chongo/tech/comp/fnv/index.html
+ *
+ ***
+ *
+ * Please do not copyright this code.  This code is in the public domain.
+ *
+ * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+ * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
+ * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ *
+ * By:
+ *	chongo <Landon Curt Noll> /\oo/\
+ *	  http://www.isthe.com/chongo/
+ *
+ * Share and Enjoy!	:-)
+ */
+
+typedef unsigned long long	mdb_hash_t;
+#define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
+
+/** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
+ * @param[in] val	value to hash
+ * @param[in] hval	initial value for hash
+ * @return 64 bit hash
+ *
+ * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
+ * 	 hval arg on the first call.
+ */
+static mdb_hash_t
+mdb_hash_val(MDB_val *val, mdb_hash_t hval)
+{
+	unsigned char *s = (unsigned char *)val->mv_data;	/* unsigned string */
+	unsigned char *end = s + val->mv_size;
+	/*
+	 * FNV-1a hash each octet of the string
+	 */
+	while (s < end) {
+		/* xor the bottom with the current octet */
+		hval ^= (mdb_hash_t)*s++;
+
+		/* multiply by the 64 bit FNV magic prime mod 2^64 */
+		hval += (hval << 1) + (hval << 4) + (hval << 5) +
+			(hval << 7) + (hval << 8) + (hval << 40);
+	}
+	/* return our new hash value */
+	return hval;
+}
+
+/** Hash the string and output the encoded hash.
+ * This uses modified RFC1924 Ascii85 encoding to accommodate systems with
+ * very short name limits. We don't care about the encoding being reversible,
+ * we just want to preserve as many bits of the input as possible in a
+ * small printable string.
+ * @param[in] str string to hash
+ * @param[out] encbuf an array of 11 chars to hold the hash
+ */
+static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
+
+static void ESECT
+mdb_pack85(unsigned long l, char *out)
+{
+	int i;
+
+	for (i=0; i<5; i++) {
+		*out++ = mdb_a85[l % 85];
+		l /= 85;
+	}
+}
+
+static void ESECT
+mdb_hash_enc(MDB_val *val, char *encbuf)
+{
+	mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
+
+	mdb_pack85(h, encbuf);
+	mdb_pack85(h>>32, encbuf+5);
+	encbuf[10] = '\0';
+}
+#endif
+
+/** Open and/or initialize the lock region for the environment.
+ * @param[in] env The LMDB environment.
+ * @param[in] lpath The pathname of the file used for the lock region.
+ * @param[in] mode The Unix permissions for the file, if we create it.
+ * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive
+ * @return 0 on success, non-zero on failure.
+ */
+static int ESECT
+mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
+{
+#ifdef _WIN32
+#	define MDB_ERRCODE_ROFS	ERROR_WRITE_PROTECT
+#else
+#	define MDB_ERRCODE_ROFS	EROFS
+#ifdef O_CLOEXEC	/* Linux: Open file and set FD_CLOEXEC atomically */
+#	define MDB_CLOEXEC		O_CLOEXEC
+#else
+	int fdflags;
+#	define MDB_CLOEXEC		0
+#endif
+#endif
+#ifdef MDB_USE_SYSV_SEM
+	int semid;
+	union semun semu;
+#endif
+	int rc;
+	off_t size, rsize;
+
+#ifdef _WIN32
+	wchar_t *wlpath;
+	rc = utf8_to_utf16(lpath, -1, &wlpath, NULL);
+	if (rc)
+		return rc;
+	env->me_lfd = CreateFileW(wlpath, GENERIC_READ|GENERIC_WRITE,
+		FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
+		FILE_ATTRIBUTE_NORMAL, NULL);
+	free(wlpath);
+#else
+	env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
+#endif
+	if (env->me_lfd == INVALID_HANDLE_VALUE) {
+		rc = ErrCode();
+		if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
+			return MDB_SUCCESS;
+		}
+		goto fail_errno;
+	}
+#if ! ((MDB_CLOEXEC) || defined(_WIN32))
+	/* Lose record locks when exec*() */
+	if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
+			fcntl(env->me_lfd, F_SETFD, fdflags);
+#endif
+
+	if (!(env->me_flags & MDB_NOTLS)) {
+		rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
+		if (rc)
+			goto fail;
+		env->me_flags |= MDB_ENV_TXKEY;
+#ifdef _WIN32
+		/* Windows TLS callbacks need help finding their TLS info. */
+		if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
+			rc = MDB_TLS_FULL;
+			goto fail;
+		}
+		mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
+#endif
+	}
+
+	/* Try to get exclusive lock. If we succeed, then
+	 * nobody is using the lock region and we should initialize it.
+	 */
+	if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
+
+#ifdef _WIN32
+	size = GetFileSize(env->me_lfd, NULL);
+#else
+	size = lseek(env->me_lfd, 0, SEEK_END);
+	if (size == -1) goto fail_errno;
+#endif
+	rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
+	if (size < rsize && *excl > 0) {
+#ifdef _WIN32
+		if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize
+			|| !SetEndOfFile(env->me_lfd))
+			goto fail_errno;
+#else
+		if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
+#endif
+	} else {
+		rsize = size;
+		size = rsize - sizeof(MDB_txninfo);
+		env->me_maxreaders = size/sizeof(MDB_reader) + 1;
+	}
+	{
+#ifdef _WIN32
+		HANDLE mh;
+		mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
+			0, 0, NULL);
+		if (!mh) goto fail_errno;
+		env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
+		CloseHandle(mh);
+		if (!env->me_txns) goto fail_errno;
+#else
+		void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
+			env->me_lfd, 0);
+		if (m == MAP_FAILED) goto fail_errno;
+		env->me_txns = m;
+#endif
+	}
+	if (*excl > 0) {
+#ifdef _WIN32
+		BY_HANDLE_FILE_INFORMATION stbuf;
+		struct {
+			DWORD volume;
+			DWORD nhigh;
+			DWORD nlow;
+		} idbuf;
+		MDB_val val;
+		char encbuf[11];
+
+		if (!mdb_sec_inited) {
+			InitializeSecurityDescriptor(&mdb_null_sd,
+				SECURITY_DESCRIPTOR_REVISION);
+			SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
+			mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
+			mdb_all_sa.bInheritHandle = FALSE;
+			mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
+			mdb_sec_inited = 1;
+		}
+		if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
+		idbuf.volume = stbuf.dwVolumeSerialNumber;
+		idbuf.nhigh  = stbuf.nFileIndexHigh;
+		idbuf.nlow   = stbuf.nFileIndexLow;
+		val.mv_data = &idbuf;
+		val.mv_size = sizeof(idbuf);
+		mdb_hash_enc(&val, encbuf);
+		sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
+		sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
+		env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
+		if (!env->me_rmutex) goto fail_errno;
+		env->me_wmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
+		if (!env->me_wmutex) goto fail_errno;
+#elif defined(MDB_USE_POSIX_SEM)
+		struct stat stbuf;
+		struct {
+			dev_t dev;
+			ino_t ino;
+		} idbuf;
+		MDB_val val;
+		char encbuf[11];
+
+#if defined(__NetBSD__)
+#define	MDB_SHORT_SEMNAMES	1	/* limited to 14 chars */
+#endif
+		if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
+		idbuf.dev = stbuf.st_dev;
+		idbuf.ino = stbuf.st_ino;
+		val.mv_data = &idbuf;
+		val.mv_size = sizeof(idbuf);
+		mdb_hash_enc(&val, encbuf);
+#ifdef MDB_SHORT_SEMNAMES
+		encbuf[9] = '\0';	/* drop name from 15 chars to 14 chars */
+#endif
+		sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
+		sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
+		/* Clean up after a previous run, if needed:  Try to
+		 * remove both semaphores before doing anything else.
+		 */
+		sem_unlink(env->me_txns->mti_rmname);
+		sem_unlink(env->me_txns->mti_wmname);
+		env->me_rmutex = sem_open(env->me_txns->mti_rmname,
+			O_CREAT|O_EXCL, mode, 1);
+		if (env->me_rmutex == SEM_FAILED) goto fail_errno;
+		env->me_wmutex = sem_open(env->me_txns->mti_wmname,
+			O_CREAT|O_EXCL, mode, 1);
+		if (env->me_wmutex == SEM_FAILED) goto fail_errno;
+#elif defined(MDB_USE_SYSV_SEM)
+		unsigned short vals[2] = {1, 1};
+		key_t key = ftok(lpath, 'M');
+		if (key == -1)
+			goto fail_errno;
+		semid = semget(key, 2, (mode & 0777) | IPC_CREAT);
+		if (semid < 0)
+			goto fail_errno;
+		semu.array = vals;
+		if (semctl(semid, 0, SETALL, semu) < 0)
+			goto fail_errno;
+		env->me_txns->mti_semid = semid;
+#else	/* MDB_USE_POSIX_MUTEX: */
+		pthread_mutexattr_t mattr;
+
+		/* Solaris needs this before initing a robust mutex.  Otherwise
+		 * it may skip the init and return EBUSY "seems someone already
+		 * inited" or EINVAL "it was inited differently".
+		 */
+		memset(env->me_txns->mti_rmutex, 0, sizeof(*env->me_txns->mti_rmutex));
+		memset(env->me_txns->mti_wmutex, 0, sizeof(*env->me_txns->mti_wmutex));
+
+		if ((rc = pthread_mutexattr_init(&mattr))
+			|| (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
+#ifdef MDB_ROBUST_SUPPORTED
+			|| (rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST))
+#endif
+			|| (rc = pthread_mutex_init(env->me_txns->mti_rmutex, &mattr))
+			|| (rc = pthread_mutex_init(env->me_txns->mti_wmutex, &mattr)))
+			goto fail;
+		pthread_mutexattr_destroy(&mattr);
+#endif	/* _WIN32 || ... */
+
+		env->me_txns->mti_magic = MDB_MAGIC;
+		env->me_txns->mti_format = MDB_LOCK_FORMAT;
+		env->me_txns->mti_txnid = 0;
+		env->me_txns->mti_numreaders = 0;
+
+	} else {
+#ifdef MDB_USE_SYSV_SEM
+		struct semid_ds buf;
+#endif
+		if (env->me_txns->mti_magic != MDB_MAGIC) {
+			DPUTS("lock region has invalid magic");
+			rc = MDB_INVALID;
+			goto fail;
+		}
+		if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
+			DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
+				env->me_txns->mti_format, MDB_LOCK_FORMAT));
+			rc = MDB_VERSION_MISMATCH;
+			goto fail;
+		}
+		rc = ErrCode();
+		if (rc && rc != EACCES && rc != EAGAIN) {
+			goto fail;
+		}
+#ifdef _WIN32
+		env->me_rmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
+		if (!env->me_rmutex) goto fail_errno;
+		env->me_wmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
+		if (!env->me_wmutex) goto fail_errno;
+#elif defined(MDB_USE_POSIX_SEM)
+		env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
+		if (env->me_rmutex == SEM_FAILED) goto fail_errno;
+		env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
+		if (env->me_wmutex == SEM_FAILED) goto fail_errno;
+#elif defined(MDB_USE_SYSV_SEM)
+		semid = env->me_txns->mti_semid;
+		semu.buf = &buf;
+		/* check for read access */
+		if (semctl(semid, 0, IPC_STAT, semu) < 0)
+			goto fail_errno;
+		/* check for write access */
+		if (semctl(semid, 0, IPC_SET, semu) < 0)
+			goto fail_errno;
+#endif
+	}
+#ifdef MDB_USE_SYSV_SEM
+	env->me_rmutex->semid = semid;
+	env->me_wmutex->semid = semid;
+	env->me_rmutex->semnum = 0;
+	env->me_wmutex->semnum = 1;
+	env->me_rmutex->locked = &env->me_txns->mti_rlocked;
+	env->me_wmutex->locked = &env->me_txns->mti_wlocked;
+#endif
+#ifdef MDB_VL32
+#ifdef _WIN32
+	env->me_rpmutex = CreateMutex(NULL, FALSE, NULL);
+#else
+	pthread_mutex_init(&env->me_rpmutex, NULL);
+#endif
+#endif
+
+	return MDB_SUCCESS;
+
+fail_errno:
+	rc = ErrCode();
+fail:
+	return rc;
+}
+
+	/** The name of the lock file in the DB environment */
+#define LOCKNAME	"/lock.mdb"
+	/** The name of the data file in the DB environment */
+#define DATANAME	"/data.mdb"
+	/** The suffix of the lock file when no subdir is used */
+#define LOCKSUFF	"-lock"
+	/** Only a subset of the @ref mdb_env flags can be changed
+	 *	at runtime. Changing other flags requires closing the
+	 *	environment and re-opening it with the new flags.
+	 */
+#define	CHANGEABLE	(MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
+#define	CHANGELESS	(MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \
+	MDB_WRITEMAP|MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
+
+#if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
+# error "Persistent DB flags & env flags overlap, but both go in mm_flags"
+#endif
+
+int ESECT
+mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
+{
+	int		oflags, rc, len, excl = -1;
+	char *lpath, *dpath;
+#ifdef _WIN32
+	wchar_t *wpath;
+#endif
+
+	if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
+		return EINVAL;
+
+#ifdef MDB_VL32
+	if (flags & MDB_WRITEMAP) {
+		/* silently ignore WRITEMAP in 32 bit mode */
+		flags ^= MDB_WRITEMAP;
+	}
+	if (flags & MDB_FIXEDMAP) {
+		/* cannot support FIXEDMAP */
+		return EINVAL;
+	}
+#endif
+
+	len = strlen(path);
+	if (flags & MDB_NOSUBDIR) {
+		rc = len + sizeof(LOCKSUFF) + len + 1;
+	} else {
+		rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
+	}
+	lpath = malloc(rc);
+	if (!lpath)
+		return ENOMEM;
+	if (flags & MDB_NOSUBDIR) {
+		dpath = lpath + len + sizeof(LOCKSUFF);
+		sprintf(lpath, "%s" LOCKSUFF, path);
+		strcpy(dpath, path);
+	} else {
+		dpath = lpath + len + sizeof(LOCKNAME);
+		sprintf(lpath, "%s" LOCKNAME, path);
+		sprintf(dpath, "%s" DATANAME, path);
+	}
+
+	rc = MDB_SUCCESS;
+	flags |= env->me_flags;
+	if (flags & MDB_RDONLY) {
+		/* silently ignore WRITEMAP when we're only getting read access */
+		flags &= ~MDB_WRITEMAP;
+	} else {
+		if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&
+			  (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
+			rc = ENOMEM;
+	}
+#ifdef MDB_VL32
+	if (!rc) {
+		env->me_rpages = malloc(MDB_ERPAGE_SIZE * sizeof(MDB_ID3));
+		if (!env->me_rpages) {
+			rc = ENOMEM;
+			goto leave;
+		}
+		env->me_rpages[0].mid = 0;
+		env->me_rpcheck = MDB_ERPAGE_SIZE/2;
+	}
+#endif
+	env->me_flags = flags |= MDB_ENV_ACTIVE;
+	if (rc)
+		goto leave;
+
+	env->me_path = strdup(path);
+	env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
+	env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
+	env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned int));
+	if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) {
+		rc = ENOMEM;
+		goto leave;
+	}
+	env->me_dbxs[FREE_DBI].md_cmp = mdb_cmp_long; /* aligned MDB_INTEGERKEY */
+
+	/* For RDONLY, get lockfile after we know datafile exists */
+	if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
+		rc = mdb_env_setup_locks(env, lpath, mode, &excl);
+		if (rc)
+			goto leave;
+	}
+
+#ifdef _WIN32
+	if (F_ISSET(flags, MDB_RDONLY)) {
+		oflags = GENERIC_READ;
+		len = OPEN_EXISTING;
+	} else {
+		oflags = GENERIC_READ|GENERIC_WRITE;
+		len = OPEN_ALWAYS;
+	}
+	mode = FILE_ATTRIBUTE_NORMAL;
+	rc = utf8_to_utf16(dpath, -1, &wpath, NULL);
+	if (rc)
+		goto leave;
+	env->me_fd = CreateFileW(wpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
+		NULL, len, mode, NULL);
+	free(wpath);
+#else
+	if (F_ISSET(flags, MDB_RDONLY))
+		oflags = O_RDONLY;
+	else
+		oflags = O_RDWR | O_CREAT;
+
+	env->me_fd = open(dpath, oflags, mode);
+#endif
+	if (env->me_fd == INVALID_HANDLE_VALUE) {
+		rc = ErrCode();
+		goto leave;
+	}
+
+	if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
+		rc = mdb_env_setup_locks(env, lpath, mode, &excl);
+		if (rc)
+			goto leave;
+	}
+
+	if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
+		if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
+			env->me_mfd = env->me_fd;
+		} else {
+			/* Synchronous fd for meta writes. Needed even with
+			 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
+			 */
+#ifdef _WIN32
+			len = OPEN_EXISTING;
+			rc = utf8_to_utf16(dpath, -1, &wpath, NULL);
+			if (rc)
+				goto leave;
+			env->me_mfd = CreateFileW(wpath, oflags,
+				FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
+				mode | FILE_FLAG_WRITE_THROUGH, NULL);
+			free(wpath);
+#else
+			oflags &= ~O_CREAT;
+			env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
+#endif
+			if (env->me_mfd == INVALID_HANDLE_VALUE) {
+				rc = ErrCode();
+				goto leave;
+			}
+		}
+		DPRINTF(("opened dbenv %p", (void *) env));
+		if (excl > 0) {
+			rc = mdb_env_share_locks(env, &excl);
+			if (rc)
+				goto leave;
+		}
+		if (!(flags & MDB_RDONLY)) {
+			MDB_txn *txn;
+			int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs *
+				(sizeof(MDB_db)+sizeof(MDB_cursor *)+sizeof(unsigned int)+1);
+			if ((env->me_pbuf = calloc(1, env->me_psize)) &&
+				(txn = calloc(1, size)))
+			{
+				txn->mt_dbs = (MDB_db *)((char *)txn + tsize);
+				txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
+				txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
+				txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
+				txn->mt_env = env;
+#ifdef MDB_VL32
+				txn->mt_rpages = malloc(MDB_TRPAGE_SIZE * sizeof(MDB_ID3));
+				if (!txn->mt_rpages) {
+					free(txn);
+					rc = ENOMEM;
+					goto leave;
+				}
+				txn->mt_rpages[0].mid = 0;
+				txn->mt_rpcheck = MDB_TRPAGE_SIZE/2;
+#endif
+				txn->mt_dbxs = env->me_dbxs;
+				txn->mt_flags = MDB_TXN_FINISHED;
+				env->me_txn0 = txn;
+			} else {
+				rc = ENOMEM;
+			}
+		}
+	}
+
+leave:
+	if (rc) {
+		mdb_env_close0(env, excl);
+	}
+	free(lpath);
+	return rc;
+}
+
+/** Destroy resources from mdb_env_open(), clear our readers & DBIs */
+static void ESECT
+mdb_env_close0(MDB_env *env, int excl)
+{
+	int i;
+
+	if (!(env->me_flags & MDB_ENV_ACTIVE))
+		return;
+
+	/* Doing this here since me_dbxs may not exist during mdb_env_close */
+	if (env->me_dbxs) {
+		for (i = env->me_maxdbs; --i >= CORE_DBS; )
+			free(env->me_dbxs[i].md_name.mv_data);
+		free(env->me_dbxs);
+	}
+
+	free(env->me_pbuf);
+	free(env->me_dbiseqs);
+	free(env->me_dbflags);
+	free(env->me_path);
+	free(env->me_dirty_list);
+#ifdef MDB_VL32
+	if (env->me_txn0 && env->me_txn0->mt_rpages)
+		free(env->me_txn0->mt_rpages);
+	{ unsigned int x;
+		for (x=1; x<=env->me_rpages[0].mid; x++)
+		munmap(env->me_rpages[x].mptr, env->me_rpages[x].mcnt * env->me_psize);
+	}
+	free(env->me_rpages);
+#endif
+	free(env->me_txn0);
+	mdb_midl_free(env->me_free_pgs);
+
+	if (env->me_flags & MDB_ENV_TXKEY) {
+		pthread_key_delete(env->me_txkey);
+#ifdef _WIN32
+		/* Delete our key from the global list */
+		for (i=0; i<mdb_tls_nkeys; i++)
+			if (mdb_tls_keys[i] == env->me_txkey) {
+				mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
+				mdb_tls_nkeys--;
+				break;
+			}
+#endif
+	}
+
+	if (env->me_map) {
+#ifdef MDB_VL32
+		munmap(env->me_map, NUM_METAS*env->me_psize);
+#else
+		munmap(env->me_map, env->me_mapsize);
+#endif
+	}
+	if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
+		(void) close(env->me_mfd);
+	if (env->me_fd != INVALID_HANDLE_VALUE)
+		(void) close(env->me_fd);
+	if (env->me_txns) {
+		MDB_PID_T pid = env->me_pid;
+		/* Clearing readers is done in this function because
+		 * me_txkey with its destructor must be disabled first.
+		 *
+		 * We skip the the reader mutex, so we touch only
+		 * data owned by this process (me_close_readers and
+		 * our readers), and clear each reader atomically.
+		 */
+		for (i = env->me_close_readers; --i >= 0; )
+			if (env->me_txns->mti_readers[i].mr_pid == pid)
+				env->me_txns->mti_readers[i].mr_pid = 0;
+#ifdef _WIN32
+		if (env->me_rmutex) {
+			CloseHandle(env->me_rmutex);
+			if (env->me_wmutex) CloseHandle(env->me_wmutex);
+		}
+		/* Windows automatically destroys the mutexes when
+		 * the last handle closes.
+		 */
+#elif defined(MDB_USE_POSIX_SEM)
+		if (env->me_rmutex != SEM_FAILED) {
+			sem_close(env->me_rmutex);
+			if (env->me_wmutex != SEM_FAILED)
+				sem_close(env->me_wmutex);
+			/* If we have the filelock:  If we are the
+			 * only remaining user, clean up semaphores.
+			 */
+			if (excl == 0)
+				mdb_env_excl_lock(env, &excl);
+			if (excl > 0) {
+				sem_unlink(env->me_txns->mti_rmname);
+				sem_unlink(env->me_txns->mti_wmname);
+			}
+		}
+#elif defined(MDB_USE_SYSV_SEM)
+		if (env->me_rmutex->semid != -1) {
+			/* If we have the filelock:  If we are the
+			 * only remaining user, clean up semaphores.
+			 */
+			if (excl == 0)
+				mdb_env_excl_lock(env, &excl);
+			if (excl > 0)
+				semctl(env->me_rmutex->semid, 0, IPC_RMID);
+		}
+#endif
+		munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
+	}
+	if (env->me_lfd != INVALID_HANDLE_VALUE) {
+#ifdef _WIN32
+		if (excl >= 0) {
+			/* Unlock the lockfile.  Windows would have unlocked it
+			 * after closing anyway, but not necessarily at once.
+			 */
+			UnlockFile(env->me_lfd, 0, 0, 1, 0);
+		}
+#endif
+		(void) close(env->me_lfd);
+	}
+#ifdef MDB_VL32
+#ifdef _WIN32
+	if (env->me_fmh) CloseHandle(env->me_fmh);
+	if (env->me_rpmutex) CloseHandle(env->me_rpmutex);
+#else
+	pthread_mutex_destroy(&env->me_rpmutex);
+#endif
+#endif
+
+	env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
+}
+
+void ESECT
+mdb_env_close(MDB_env *env)
+{
+	MDB_page *dp;
+
+	if (env == NULL)
+		return;
+
+	VGMEMP_DESTROY(env);
+	while ((dp = env->me_dpages) != NULL) {
+		VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
+		env->me_dpages = dp->mp_next;
+		free(dp);
+	}
+
+	mdb_env_close0(env, 0);
+	free(env);
+}
+
+/** Compare two items pointing at aligned mdb_size_t's */
+static int
+mdb_cmp_long(const MDB_val *a, const MDB_val *b)
+{
+	return (*(mdb_size_t *)a->mv_data < *(mdb_size_t *)b->mv_data) ? -1 :
+		*(mdb_size_t *)a->mv_data > *(mdb_size_t *)b->mv_data;
+}
+
+/** Compare two items pointing at aligned unsigned int's.
+ *
+ *	This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,
+ *	but #mdb_cmp_clong() is called instead if the data type is mdb_size_t.
+ */
+static int
+mdb_cmp_int(const MDB_val *a, const MDB_val *b)
+{
+	return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
+		*(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
+}
+
+/** Compare two items pointing at unsigned ints of unknown alignment.
+ *	Nodes and keys are guaranteed to be 2-byte aligned.
+ */
+static int
+mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
+{
+#if BYTE_ORDER == LITTLE_ENDIAN
+	unsigned short *u, *c;
+	int x;
+
+	u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
+	c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
+	do {
+		x = *--u - *--c;
+	} while(!x && u > (unsigned short *)a->mv_data);
+	return x;
+#else
+	unsigned short *u, *c, *end;
+	int x;
+
+	end = (unsigned short *) ((char *) a->mv_data + a->mv_size);
+	u = (unsigned short *)a->mv_data;
+	c = (unsigned short *)b->mv_data;
+	do {
+		x = *u++ - *c++;
+	} while(!x && u < end);
+	return x;
+#endif
+}
+
+/** Compare two items lexically */
+static int
+mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
+{
+	int diff;
+	ssize_t len_diff;
+	unsigned int len;
+
+	len = a->mv_size;
+	len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
+	if (len_diff > 0) {
+		len = b->mv_size;
+		len_diff = 1;
+	}
+
+	diff = memcmp(a->mv_data, b->mv_data, len);
+	return diff ? diff : len_diff<0 ? -1 : len_diff;
+}
+
+/** Compare two items in reverse byte order */
+static int
+mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
+{
+	const unsigned char	*p1, *p2, *p1_lim;
+	ssize_t len_diff;
+	int diff;
+
+	p1_lim = (const unsigned char *)a->mv_data;
+	p1 = (const unsigned char *)a->mv_data + a->mv_size;
+	p2 = (const unsigned char *)b->mv_data + b->mv_size;
+
+	len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
+	if (len_diff > 0) {
+		p1_lim += len_diff;
+		len_diff = 1;
+	}
+
+	while (p1 > p1_lim) {
+		diff = *--p1 - *--p2;
+		if (diff)
+			return diff;
+	}
+	return len_diff<0 ? -1 : len_diff;
+}
+
+/** Search for key within a page, using binary search.
+ * Returns the smallest entry larger or equal to the key.
+ * If exactp is non-null, stores whether the found entry was an exact match
+ * in *exactp (1 or 0).
+ * Updates the cursor index with the index of the found entry.
+ * If no entry larger or equal to the key is found, returns NULL.
+ */
+static MDB_node *
+mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
+{
+	unsigned int	 i = 0, nkeys;
+	int		 low, high;
+	int		 rc = 0;
+	MDB_page *mp = mc->mc_pg[mc->mc_top];
+	MDB_node	*node = NULL;
+	MDB_val	 nodekey;
+	MDB_cmp_func *cmp;
+	DKBUF;
+
+	nkeys = NUMKEYS(mp);
+
+	DPRINTF(("searching %u keys in %s %spage %"Y"u",
+	    nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
+	    mdb_dbg_pgno(mp)));
+
+	low = IS_LEAF(mp) ? 0 : 1;
+	high = nkeys - 1;
+	cmp = mc->mc_dbx->md_cmp;
+
+	/* Branch pages have no data, so if using integer keys,
+	 * alignment is guaranteed. Use faster mdb_cmp_int.
+	 */
+	if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
+		if (NODEPTR(mp, 1)->mn_ksize == sizeof(mdb_size_t))
+			cmp = mdb_cmp_long;
+		else if(NODEPTR(mp, 1)->mn_ksize == sizeof(int))
+			cmp = mdb_cmp_int;
+	}
+
+	if (IS_LEAF2(mp)) {
+		nodekey.mv_size = mc->mc_db->md_pad;
+		node = NODEPTR(mp, 0);	/* fake */
+		while (low <= high) {
+			i = (low + high) >> 1;
+			nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
+			rc = cmp(key, &nodekey);
+			DPRINTF(("found leaf index %u [%s], rc = %i",
+			    i, DKEY(&nodekey), rc));
+			if (rc == 0)
+				break;
+			if (rc > 0)
+				low = i + 1;
+			else
+				high = i - 1;
+		}
+	} else {
+		while (low <= high) {
+			i = (low + high) >> 1;
+
+			node = NODEPTR(mp, i);
+			nodekey.mv_size = NODEKSZ(node);
+			nodekey.mv_data = NODEKEY(node);
+
+			rc = cmp(key, &nodekey);
+#if MDB_DEBUG
+			if (IS_LEAF(mp))
+				DPRINTF(("found leaf index %u [%s], rc = %i",
+				    i, DKEY(&nodekey), rc));
+			else
+				DPRINTF(("found branch index %u [%s -> %"Y"u], rc = %i",
+				    i, DKEY(&nodekey), NODEPGNO(node), rc));
+#endif
+			if (rc == 0)
+				break;
+			if (rc > 0)
+				low = i + 1;
+			else
+				high = i - 1;
+		}
+	}
+
+	if (rc > 0) {	/* Found entry is less than the key. */
+		i++;	/* Skip to get the smallest entry larger than key. */
+		if (!IS_LEAF2(mp))
+			node = NODEPTR(mp, i);
+	}
+	if (exactp)
+		*exactp = (rc == 0 && nkeys > 0);
+	/* store the key index */
+	mc->mc_ki[mc->mc_top] = i;
+	if (i >= nkeys)
+		/* There is no entry larger or equal to the key. */
+		return NULL;
+
+	/* nodeptr is fake for LEAF2 */
+	return node;
+}
+
+#if 0
+static void
+mdb_cursor_adjust(MDB_cursor *mc, func)
+{
+	MDB_cursor *m2;
+
+	for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
+		if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
+			func(mc, m2);
+		}
+	}
+}
+#endif
+
+/** Pop a page off the top of the cursor's stack. */
+static void
+mdb_cursor_pop(MDB_cursor *mc)
+{
+	if (mc->mc_snum) {
+		DPRINTF(("popping page %"Y"u off db %d cursor %p",
+			mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *) mc));
+
+		mc->mc_snum--;
+		if (mc->mc_snum) {
+			mc->mc_top--;
+		} else {
+			mc->mc_flags &= ~C_INITIALIZED;
+		}
+	}
+}
+
+/** Push a page onto the top of the cursor's stack. */
+static int
+mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
+{
+	DPRINTF(("pushing page %"Y"u on db %d cursor %p", mp->mp_pgno,
+		DDBI(mc), (void *) mc));
+
+	if (mc->mc_snum >= CURSOR_STACK) {
+		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
+		return MDB_CURSOR_FULL;
+	}
+
+	mc->mc_top = mc->mc_snum++;
+	mc->mc_pg[mc->mc_top] = mp;
+	mc->mc_ki[mc->mc_top] = 0;
+
+	return MDB_SUCCESS;
+}
+
+#ifdef MDB_VL32
+/** Map a read-only page.
+ * There are two levels of tracking in use, a per-txn list and a per-env list.
+ * ref'ing and unref'ing the per-txn list is faster since it requires no
+ * locking. Pages are cached in the per-env list for global reuse, and a lock
+ * is required. Pages are not immediately unmapped when their refcnt goes to
+ * zero; they hang around in case they will be reused again soon.
+ *
+ * When the per-txn list gets full, all pages with refcnt=0 are purged from the
+ * list and their refcnts in the per-env list are decremented.
+ *
+ * When the per-env list gets full, all pages with refcnt=0 are purged from the
+ * list and their pages are unmapped.
+ *
+ * @note "full" means the list has reached its respective rpcheck threshold.
+ * This threshold slowly raises if no pages could be purged on a given check,
+ * and returns to its original value when enough pages were purged.
+ *
+ * If purging doesn't free any slots, filling the per-txn list will return
+ * MDB_TXN_FULL, and filling the per-env list returns MDB_MAP_FULL.
+ *
+ * Reference tracking in a txn is imperfect, pages can linger with non-zero
+ * refcnt even without active references. It was deemed to be too invasive
+ * to add unrefs in every required location. However, all pages are unref'd
+ * at the end of the transaction. This guarantees that no stale references
+ * linger in the per-env list.
+ *
+ * Usually we map chunks of 16 pages at a time, but if an overflow page begins
+ * at the tail of the chunk we extend the chunk to include the entire overflow
+ * page. Unfortunately, pages can be turned into overflow pages after their
+ * chunk was already mapped. In that case we must remap the chunk if the
+ * overflow page is referenced. If the chunk's refcnt is 0 we can just remap
+ * it, otherwise we temporarily map a new chunk just for the overflow page.
+ *
+ * @note this chunk handling means we cannot guarantee that a data item
+ * returned from the DB will stay alive for the duration of the transaction:
+ *   We unref pages as soon as a cursor moves away from the page
+ *   A subsequent op may cause a purge, which may unmap any unref'd chunks
+ * The caller must copy the data if it must be used later in the same txn.
+ *
+ * Also - our reference counting revolves around cursors, but overflow pages
+ * aren't pointed to by a cursor's page stack. We have to remember them
+ * explicitly, in the added mc_ovpg field. A single cursor can only hold a
+ * reference to one overflow page at a time.
+ *
+ * @param[in] txn the transaction for this access.
+ * @param[in] pgno the page number for the page to retrieve.
+ * @param[out] ret address of a pointer where the page's address will be stored.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_rpage_get(MDB_txn *txn, pgno_t pg0, MDB_page **ret)
+{
+	MDB_env *env = txn->mt_env;
+	MDB_page *p;
+	MDB_ID3L tl = txn->mt_rpages;
+	MDB_ID3L el = env->me_rpages;
+	MDB_ID3 id3;
+	unsigned x, rem;
+	pgno_t pgno;
+	int rc, retries = 1;
+#ifdef _WIN32
+	LARGE_INTEGER off;
+	SIZE_T len;
+#define SET_OFF(off,val)	off.QuadPart = val
+#define MAP(rc,env,addr,len,off)	\
+	addr = NULL; \
+	rc = NtMapViewOfSection(env->me_fmh, GetCurrentProcess(), &addr, 0, \
+		len, &off, &len, ViewUnmap, (env->me_flags & MDB_RDONLY) ? 0 : MEM_RESERVE, PAGE_READONLY); \
+	if (rc) rc = mdb_nt2win32(rc)
+#else
+	off_t off;
+	size_t len;
+#define SET_OFF(off,val)	off = val
+#define MAP(rc,env,addr,len,off)	\
+	addr = mmap(NULL, len, PROT_READ, MAP_SHARED, env->me_fd, off); \
+	rc = (addr == MAP_FAILED) ? errno : 0
+#endif
+
+	/* remember the offset of the actual page number, so we can
+	 * return the correct pointer at the end.
+	 */
+	rem = pg0 & (MDB_RPAGE_CHUNK-1);
+	pgno = pg0 ^ rem;
+
+	id3.mid = 0;
+	x = mdb_mid3l_search(tl, pgno);
+	if (x <= tl[0].mid && tl[x].mid == pgno) {
+		if (x != tl[0].mid && tl[x+1].mid == pg0)
+			x++;
+		/* check for overflow size */
+		p = (MDB_page *)((char *)tl[x].mptr + rem * env->me_psize);
+		if (IS_OVERFLOW(p) && p->mp_pages + rem > tl[x].mcnt) {
+			id3.mcnt = p->mp_pages + rem;
+			len = id3.mcnt * env->me_psize;
+			SET_OFF(off, pgno * env->me_psize);
+			MAP(rc, env, id3.mptr, len, off);
+			if (rc)
+				return rc;
+			/* check for local-only page */
+			if (rem) {
+				mdb_tassert(txn, tl[x].mid != pg0);
+				/* hope there's room to insert this locally.
+				 * setting mid here tells later code to just insert
+				 * this id3 instead of searching for a match.
+				 */
+				id3.mid = pg0;
+				goto notlocal;
+			} else {
+				/* ignore the mapping we got from env, use new one */
+				tl[x].mptr = id3.mptr;
+				tl[x].mcnt = id3.mcnt;
+				/* if no active ref, see if we can replace in env */
+				if (!tl[x].mref) {
+					unsigned i;
+					pthread_mutex_lock(&env->me_rpmutex);
+					i = mdb_mid3l_search(el, tl[x].mid);
+					if (el[i].mref == 1) {
+						/* just us, replace it */
+						munmap(el[i].mptr, el[i].mcnt * env->me_psize);
+						el[i].mptr = tl[x].mptr;
+						el[i].mcnt = tl[x].mcnt;
+					} else {
+						/* there are others, remove ourself */
+						el[i].mref--;
+					}
+					pthread_mutex_unlock(&env->me_rpmutex);
+				}
+			}
+		}
+		id3.mptr = tl[x].mptr;
+		id3.mcnt = tl[x].mcnt;
+		tl[x].mref++;
+		goto ok;
+	}
+
+notlocal:
+	if (tl[0].mid >= MDB_TRPAGE_MAX - txn->mt_rpcheck) {
+		unsigned i, y;
+		/* purge unref'd pages from our list and unref in env */
+		pthread_mutex_lock(&env->me_rpmutex);
+retry:
+		y = 0;
+		for (i=1; i<=tl[0].mid; i++) {
+			if (!tl[i].mref) {
+				if (!y) y = i;
+				/* tmp overflow pages don't go to env */
+				if (tl[i].mid & (MDB_RPAGE_CHUNK-1)) {
+					munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);
+					continue;
+				}
+				x = mdb_mid3l_search(el, tl[i].mid);
+				el[x].mref--;
+			}
+		}
+		pthread_mutex_unlock(&env->me_rpmutex);
+		if (!y) {
+			/* we didn't find any unref'd chunks.
+			 * if we're out of room, fail.
+			 */
+			if (tl[0].mid >= MDB_TRPAGE_MAX)
+				return MDB_TXN_FULL;
+			/* otherwise, raise threshold for next time around
+			 * and let this go.
+			 */
+			txn->mt_rpcheck /= 2;
+		} else {
+			/* we found some unused; consolidate the list */
+			for (i=y+1; i<= tl[0].mid; i++)
+				if (tl[i].mref)
+					tl[y++] = tl[i];
+			tl[0].mid = y-1;
+			/* decrease the check threshold toward its original value */
+			if (!txn->mt_rpcheck)
+				txn->mt_rpcheck = 1;
+			while (txn->mt_rpcheck < tl[0].mid && txn->mt_rpcheck < MDB_TRPAGE_SIZE/2)
+				txn->mt_rpcheck *= 2;
+		}
+	}
+	if (tl[0].mid < MDB_TRPAGE_SIZE) {
+		id3.mref = 1;
+		if (id3.mid)
+			goto found;
+		/* don't map past last written page in read-only envs */
+		if ((env->me_flags & MDB_RDONLY) && pgno + MDB_RPAGE_CHUNK-1 > txn->mt_last_pgno)
+			id3.mcnt = txn->mt_last_pgno + 1 - pgno;
+		else
+			id3.mcnt = MDB_RPAGE_CHUNK;
+		len = id3.mcnt * env->me_psize;
+		id3.mid = pgno;
+
+		/* search for page in env */
+		pthread_mutex_lock(&env->me_rpmutex);
+		x = mdb_mid3l_search(el, pgno);
+		if (x <= el[0].mid && el[x].mid == pgno) {
+			id3.mptr = el[x].mptr;
+			id3.mcnt = el[x].mcnt;
+			/* check for overflow size */
+			p = (MDB_page *)((char *)id3.mptr + rem * env->me_psize);
+			if (IS_OVERFLOW(p) && p->mp_pages + rem > id3.mcnt) {
+				id3.mcnt = p->mp_pages + rem;
+				len = id3.mcnt * env->me_psize;
+				SET_OFF(off, pgno * env->me_psize);
+				MAP(rc, env, id3.mptr, len, off);
+				if (rc)
+					goto fail;
+				if (!el[x].mref) {
+					munmap(el[x].mptr, env->me_psize * el[x].mcnt);
+					el[x].mptr = id3.mptr;
+					el[x].mcnt = id3.mcnt;
+				} else {
+					id3.mid = pg0;
+					pthread_mutex_unlock(&env->me_rpmutex);
+					goto found;
+				}
+			}
+			el[x].mref++;
+			pthread_mutex_unlock(&env->me_rpmutex);
+			goto found;
+		}
+		if (el[0].mid >= MDB_ERPAGE_MAX - env->me_rpcheck) {
+			/* purge unref'd pages */
+			unsigned i, y = 0;
+			for (i=1; i<=el[0].mid; i++) {
+				if (!el[i].mref) {
+					if (!y) y = i;
+					munmap(el[i].mptr, env->me_psize * el[i].mcnt);
+				}
+			}
+			if (!y) {
+				if (retries) {
+					/* see if we can unref some local pages */
+					retries--;
+					id3.mid = 0;
+					goto retry;
+				}
+				if (el[0].mid >= MDB_ERPAGE_MAX) {
+					pthread_mutex_unlock(&env->me_rpmutex);
+					return MDB_MAP_FULL;
+				}
+				env->me_rpcheck /= 2;
+			} else {
+				for (i=y+1; i<= el[0].mid; i++)
+					if (el[i].mref)
+						el[y++] = el[i];
+				el[0].mid = y-1;
+				if (!env->me_rpcheck)
+					env->me_rpcheck = 1;
+				while (env->me_rpcheck < el[0].mid && env->me_rpcheck < MDB_ERPAGE_SIZE/2)
+					env->me_rpcheck *= 2;
+			}
+		}
+		SET_OFF(off, pgno * env->me_psize);
+		MAP(rc, env, id3.mptr, len, off);
+		if (rc) {
+fail:
+			pthread_mutex_unlock(&env->me_rpmutex);
+			return rc;
+		}
+		/* check for overflow size */
+		p = (MDB_page *)((char *)id3.mptr + rem * env->me_psize);
+		if (IS_OVERFLOW(p) && p->mp_pages + rem > id3.mcnt) {
+			id3.mcnt = p->mp_pages + rem;
+			munmap(id3.mptr, len);
+			len = id3.mcnt * env->me_psize;
+			MAP(rc, env, id3.mptr, len, off);
+			if (rc)
+				goto fail;
+		}
+		mdb_mid3l_insert(el, &id3);
+		pthread_mutex_unlock(&env->me_rpmutex);
+found:
+		mdb_mid3l_insert(tl, &id3);
+	} else {
+		return MDB_TXN_FULL;
+	}
+ok:
+	p = (MDB_page *)((char *)id3.mptr + rem * env->me_psize);
+#if MDB_DEBUG	/* we don't need this check any more */
+	if (IS_OVERFLOW(p)) {
+		mdb_tassert(txn, p->mp_pages + rem <= id3.mcnt);
+	}
+#endif
+	*ret = p;
+	return MDB_SUCCESS;
+}
+#endif
+
+/** Find the address of the page corresponding to a given page number.
+ * @param[in] mc the cursor accessing the page.
+ * @param[in] pgno the page number for the page to retrieve.
+ * @param[out] ret address of a pointer where the page's address will be stored.
+ * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **ret, int *lvl)
+{
+	MDB_txn *txn = mc->mc_txn;
+#ifndef MDB_VL32
+	MDB_env *env = txn->mt_env;
+#endif
+	MDB_page *p = NULL;
+	int level;
+
+	if (! (mc->mc_flags & (C_ORIG_RDONLY|C_WRITEMAP))) {
+		MDB_txn *tx2 = txn;
+		level = 1;
+		do {
+			MDB_ID2L dl = tx2->mt_u.dirty_list;
+			unsigned x;
+			/* Spilled pages were dirtied in this txn and flushed
+			 * because the dirty list got full. Bring this page
+			 * back in from the map (but don't unspill it here,
+			 * leave that unless page_touch happens again).
+			 */
+			if (tx2->mt_spill_pgs) {
+				MDB_ID pn = pgno << 1;
+				x = mdb_midl_search(tx2->mt_spill_pgs, pn);
+				if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
+#ifdef MDB_VL32
+					int rc = mdb_rpage_get(txn, pgno, &p);
+					if (rc)
+						return rc;
+#else
+					p = (MDB_page *)(env->me_map + env->me_psize * pgno);
+#endif
+					goto done;
+				}
+			}
+			if (dl[0].mid) {
+				unsigned x = mdb_mid2l_search(dl, pgno);
+				if (x <= dl[0].mid && dl[x].mid == pgno) {
+					p = dl[x].mptr;
+					goto done;
+				}
+			}
+			level++;
+		} while ((tx2 = tx2->mt_parent) != NULL);
+	}
+
+	if (pgno < txn->mt_next_pgno) {
+		level = 0;
+#ifdef MDB_VL32
+		{
+			int rc = mdb_rpage_get(txn, pgno, &p);
+			if (rc)
+				return rc;
+		}
+#else
+		p = (MDB_page *)(env->me_map + env->me_psize * pgno);
+#endif
+	} else {
+		DPRINTF(("page %"Y"u not found", pgno));
+		txn->mt_flags |= MDB_TXN_ERROR;
+		return MDB_PAGE_NOTFOUND;
+	}
+
+done:
+	*ret = p;
+	if (lvl)
+		*lvl = level;
+	return MDB_SUCCESS;
+}
+
+/** Finish #mdb_page_search() / #mdb_page_search_lowest().
+ *	The cursor is at the root page, set up the rest of it.
+ */
+static int
+mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
+{
+	MDB_page	*mp = mc->mc_pg[mc->mc_top];
+	int rc;
+	DKBUF;
+
+	while (IS_BRANCH(mp)) {
+		MDB_node	*node;
+		indx_t		i;
+
+		DPRINTF(("branch page %"Y"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
+		/* Don't assert on branch pages in the FreeDB. We can get here
+		 * while in the process of rebalancing a FreeDB branch page; we must
+		 * let that proceed. ITS#8336
+		 */
+		mdb_cassert(mc, !mc->mc_dbi || NUMKEYS(mp) > 1);
+		DPRINTF(("found index 0 to page %"Y"u", NODEPGNO(NODEPTR(mp, 0))));
+
+		if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
+			i = 0;
+			if (flags & MDB_PS_LAST)
+				i = NUMKEYS(mp) - 1;
+		} else {
+			int	 exact;
+			node = mdb_node_search(mc, key, &exact);
+			if (node == NULL)
+				i = NUMKEYS(mp) - 1;
+			else {
+				i = mc->mc_ki[mc->mc_top];
+				if (!exact) {
+					mdb_cassert(mc, i > 0);
+					i--;
+				}
+			}
+			DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
+		}
+
+		mdb_cassert(mc, i < NUMKEYS(mp));
+		node = NODEPTR(mp, i);
+
+		if ((rc = mdb_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)
+			return rc;
+
+		mc->mc_ki[mc->mc_top] = i;
+		if ((rc = mdb_cursor_push(mc, mp)))
+			return rc;
+
+		if (flags & MDB_PS_MODIFY) {
+			if ((rc = mdb_page_touch(mc)) != 0)
+				return rc;
+			mp = mc->mc_pg[mc->mc_top];
+		}
+	}
+
+	if (!IS_LEAF(mp)) {
+		DPRINTF(("internal error, index points to a %02X page!?",
+		    mp->mp_flags));
+		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
+		return MDB_CORRUPTED;
+	}
+
+	DPRINTF(("found leaf page %"Y"u for key [%s]", mp->mp_pgno,
+	    key ? DKEY(key) : "null"));
+	mc->mc_flags |= C_INITIALIZED;
+	mc->mc_flags &= ~C_EOF;
+
+	return MDB_SUCCESS;
+}
+
+/** Search for the lowest key under the current branch page.
+ * This just bypasses a NUMKEYS check in the current page
+ * before calling mdb_page_search_root(), because the callers
+ * are all in situations where the current page is known to
+ * be underfilled.
+ */
+static int
+mdb_page_search_lowest(MDB_cursor *mc)
+{
+	MDB_page	*mp = mc->mc_pg[mc->mc_top];
+	MDB_node	*node = NODEPTR(mp, 0);
+	int rc;
+
+	if ((rc = mdb_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)
+		return rc;
+
+	mc->mc_ki[mc->mc_top] = 0;
+	if ((rc = mdb_cursor_push(mc, mp)))
+		return rc;
+	return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);
+}
+
+/** Search for the page a given key should be in.
+ * Push it and its parent pages on the cursor stack.
+ * @param[in,out] mc the cursor for this operation.
+ * @param[in] key the key to search for, or NULL for first/last page.
+ * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB
+ *   are touched (updated with new page numbers).
+ *   If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.
+ *   This is used by #mdb_cursor_first() and #mdb_cursor_last().
+ *   If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
+{
+	int		 rc;
+	pgno_t		 root;
+
+	/* Make sure the txn is still viable, then find the root from
+	 * the txn's db table and set it as the root of the cursor's stack.
+	 */
+	if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED) {
+		DPUTS("transaction may not be used now");
+		return MDB_BAD_TXN;
+	} else {
+		/* Make sure we're using an up-to-date root */
+		if (*mc->mc_dbflag & DB_STALE) {
+				MDB_cursor mc2;
+				if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
+					return MDB_BAD_DBI;
+				mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
+				rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);
+				if (rc)
+					return rc;
+				{
+					MDB_val data;
+					int exact = 0;
+					uint16_t flags;
+					MDB_node *leaf = mdb_node_search(&mc2,
+						&mc->mc_dbx->md_name, &exact);
+					if (!exact)
+						return MDB_NOTFOUND;
+					if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
+						return MDB_INCOMPATIBLE; /* not a named DB */
+					rc = mdb_node_read(&mc2, leaf, &data);
+					if (rc)
+						return rc;
+					memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
+						sizeof(uint16_t));
+					/* The txn may not know this DBI, or another process may
+					 * have dropped and recreated the DB with other flags.
+					 */
+					if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)
+						return MDB_INCOMPATIBLE;
+					memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
+				}
+				*mc->mc_dbflag &= ~DB_STALE;
+		}
+		root = mc->mc_db->md_root;
+
+		if (root == P_INVALID) {		/* Tree is empty. */
+			DPUTS("tree is empty");
+			return MDB_NOTFOUND;
+		}
+	}
+
+	mdb_cassert(mc, root > 1);
+	if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root) {
+#ifdef MDB_VL32
+		if (mc->mc_pg[0])
+			MDB_PAGE_UNREF(mc->mc_txn, mc->mc_pg[0]);
+#endif
+		if ((rc = mdb_page_get(mc, root, &mc->mc_pg[0], NULL)) != 0)
+			return rc;
+	}
+
+#ifdef MDB_VL32
+	{
+		int i;
+		for (i=1; i<mc->mc_snum; i++)
+			MDB_PAGE_UNREF(mc->mc_txn, mc->mc_pg[i]);
+	}
+#endif
+	mc->mc_snum = 1;
+	mc->mc_top = 0;
+
+	DPRINTF(("db %d root page %"Y"u has flags 0x%X",
+		DDBI(mc), root, mc->mc_pg[0]->mp_flags));
+
+	if (flags & MDB_PS_MODIFY) {
+		if ((rc = mdb_page_touch(mc)))
+			return rc;
+	}
+
+	if (flags & MDB_PS_ROOTONLY)
+		return MDB_SUCCESS;
+
+	return mdb_page_search_root(mc, key, flags);
+}
+
+static int
+mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
+{
+	MDB_txn *txn = mc->mc_txn;
+	pgno_t pg = mp->mp_pgno;
+	unsigned x = 0, ovpages = mp->mp_pages;
+	MDB_env *env = txn->mt_env;
+	MDB_IDL sl = txn->mt_spill_pgs;
+	MDB_ID pn = pg << 1;
+	int rc;
+
+	DPRINTF(("free ov page %"Y"u (%d)", pg, ovpages));
+	/* If the page is dirty or on the spill list we just acquired it,
+	 * so we should give it back to our current free list, if any.
+	 * Otherwise put it onto the list of pages we freed in this txn.
+	 *
+	 * Won't create me_pghead: me_pglast must be inited along with it.
+	 * Unsupported in nested txns: They would need to hide the page
+	 * range in ancestor txns' dirty and spilled lists.
+	 */
+	if (env->me_pghead &&
+		!txn->mt_parent &&
+		((mp->mp_flags & P_DIRTY) ||
+		 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
+	{
+		unsigned i, j;
+		pgno_t *mop;
+		MDB_ID2 *dl, ix, iy;
+		rc = mdb_midl_need(&env->me_pghead, ovpages);
+		if (rc)
+			return rc;
+		if (!(mp->mp_flags & P_DIRTY)) {
+			/* This page is no longer spilled */
+			if (x == sl[0])
+				sl[0]--;
+			else
+				sl[x] |= 1;
+			goto release;
+		}
+		/* Remove from dirty list */
+		dl = txn->mt_u.dirty_list;
+		x = dl[0].mid--;
+		for (ix = dl[x]; ix.mptr != mp; ix = iy) {
+			if (x > 1) {
+				x--;
+				iy = dl[x];
+				dl[x] = ix;
+			} else {
+				mdb_cassert(mc, x > 1);
+				j = ++(dl[0].mid);
+				dl[j] = ix;		/* Unsorted. OK when MDB_TXN_ERROR. */
+				txn->mt_flags |= MDB_TXN_ERROR;
+				return MDB_CORRUPTED;
+			}
+		}
+		txn->mt_dirty_room++;
+		if (!(env->me_flags & MDB_WRITEMAP))
+			mdb_dpage_free(env, mp);
+release:
+		/* Insert in me_pghead */
+		mop = env->me_pghead;
+		j = mop[0] + ovpages;
+		for (i = mop[0]; i && mop[i] < pg; i--)
+			mop[j--] = mop[i];
+		while (j>i)
+			mop[j--] = pg++;
+		mop[0] += ovpages;
+	} else {
+		rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
+		if (rc)
+			return rc;
+	}
+	mc->mc_db->md_overflow_pages -= ovpages;
+	return 0;
+}
+
+/** Return the data associated with a given node.
+ * @param[in] mc The cursor for this operation.
+ * @param[in] leaf The node being read.
+ * @param[out] data Updated to point to the node's data.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data)
+{
+	MDB_page	*omp;		/* overflow page */
+	pgno_t		 pgno;
+	int rc;
+
+#ifdef MDB_VL32
+	if (mc->mc_ovpg) {
+		MDB_PAGE_UNREF(mc->mc_txn, mc->mc_ovpg);
+		mc->mc_ovpg = 0;
+	}
+#endif
+	if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
+		data->mv_size = NODEDSZ(leaf);
+		data->mv_data = NODEDATA(leaf);
+		return MDB_SUCCESS;
+	}
+
+	/* Read overflow data.
+	 */
+	data->mv_size = NODEDSZ(leaf);
+	memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
+	if ((rc = mdb_page_get(mc, pgno, &omp, NULL)) != 0) {
+		DPRINTF(("read overflow page %"Y"u failed", pgno));
+		return rc;
+	}
+	data->mv_data = METADATA(omp);
+#ifdef MDB_VL32
+	mc->mc_ovpg = omp;
+#endif
+
+	return MDB_SUCCESS;
+}
+
+int
+mdb_get(MDB_txn *txn, MDB_dbi dbi,
+    MDB_val *key, MDB_val *data)
+{
+	MDB_cursor	mc;
+	MDB_xcursor	mx;
+	int exact = 0, rc;
+	DKBUF;
+
+	DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
+
+	if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
+		return EINVAL;
+
+	if (txn->mt_flags & MDB_TXN_BLOCKED)
+		return MDB_BAD_TXN;
+
+	mdb_cursor_init(&mc, txn, dbi, &mx);
+	rc = mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
+#ifdef MDB_VL32
+	{
+		/* unref all the pages - caller must copy the data
+		 * before doing anything else
+		 */
+		mdb_cursor_unref(&mc);
+	}
+#endif
+	return rc;
+}
+
+/** Find a sibling for a page.
+ * Replaces the page at the top of the cursor's stack with the
+ * specified sibling, if one exists.
+ * @param[in] mc The cursor for this operation.
+ * @param[in] move_right Non-zero if the right sibling is requested,
+ * otherwise the left sibling.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_cursor_sibling(MDB_cursor *mc, int move_right)
+{
+	int		 rc;
+	MDB_node	*indx;
+	MDB_page	*mp;
+#ifdef MDB_VL32
+	MDB_page	*op;
+#endif
+
+	if (mc->mc_snum < 2) {
+		return MDB_NOTFOUND;		/* root has no siblings */
+	}
+
+#ifdef MDB_VL32
+	op = mc->mc_pg[mc->mc_top];
+#endif
+	mdb_cursor_pop(mc);
+	DPRINTF(("parent page is page %"Y"u, index %u",
+		mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
+
+	if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
+		       : (mc->mc_ki[mc->mc_top] == 0)) {
+		DPRINTF(("no more keys left, moving to %s sibling",
+		    move_right ? "right" : "left"));
+		if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
+			/* undo cursor_pop before returning */
+			mc->mc_top++;
+			mc->mc_snum++;
+			return rc;
+		}
+	} else {
+		if (move_right)
+			mc->mc_ki[mc->mc_top]++;
+		else
+			mc->mc_ki[mc->mc_top]--;
+		DPRINTF(("just moving to %s index key %u",
+		    move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
+	}
+	mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));
+
+	MDB_PAGE_UNREF(mc->mc_txn, op);
+
+	indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+	if ((rc = mdb_page_get(mc, NODEPGNO(indx), &mp, NULL)) != 0) {
+		/* mc will be inconsistent if caller does mc_snum++ as above */
+		mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
+		return rc;
+	}
+
+	mdb_cursor_push(mc, mp);
+	if (!move_right)
+		mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
+
+	return MDB_SUCCESS;
+}
+
+/** Move the cursor to the next data item. */
+static int
+mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
+{
+	MDB_page	*mp;
+	MDB_node	*leaf;
+	int rc;
+
+	if ((mc->mc_flags & C_EOF) ||
+		((mc->mc_flags & C_DEL) && op == MDB_NEXT_DUP)) {
+		return MDB_NOTFOUND;
+	}
+	if (!(mc->mc_flags & C_INITIALIZED))
+		return mdb_cursor_first(mc, key, data);
+
+	mp = mc->mc_pg[mc->mc_top];
+
+	if (mc->mc_db->md_flags & MDB_DUPSORT) {
+		leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+			if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
+				rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
+				if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
+					if (rc == MDB_SUCCESS)
+						MDB_GET_KEY(leaf, key);
+					return rc;
+				}
+			}
+#ifdef MDB_VL32
+			else {
+				if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
+					mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);
+				}
+			}
+#endif
+		} else {
+			mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
+			if (op == MDB_NEXT_DUP)
+				return MDB_NOTFOUND;
+		}
+	}
+
+	DPRINTF(("cursor_next: top page is %"Y"u in cursor %p",
+		mdb_dbg_pgno(mp), (void *) mc));
+	if (mc->mc_flags & C_DEL) {
+		mc->mc_flags ^= C_DEL;
+		goto skip;
+	}
+
+	if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
+		DPUTS("=====> move to next sibling page");
+		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
+			mc->mc_flags |= C_EOF;
+			return rc;
+		}
+		mp = mc->mc_pg[mc->mc_top];
+		DPRINTF(("next page is %"Y"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
+	} else
+		mc->mc_ki[mc->mc_top]++;
+
+skip:
+	DPRINTF(("==> cursor points to page %"Y"u with %u keys, key index %u",
+	    mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
+
+	if (IS_LEAF2(mp)) {
+		key->mv_size = mc->mc_db->md_pad;
+		key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
+		return MDB_SUCCESS;
+	}
+
+	mdb_cassert(mc, IS_LEAF(mp));
+	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
+
+	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+		mdb_xcursor_init1(mc, leaf);
+	}
+	if (data) {
+		if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
+			return rc;
+
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+			rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
+			if (rc != MDB_SUCCESS)
+				return rc;
+		}
+	}
+
+	MDB_GET_KEY(leaf, key);
+	return MDB_SUCCESS;
+}
+
+/** Move the cursor to the previous data item. */
+static int
+mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
+{
+	MDB_page	*mp;
+	MDB_node	*leaf;
+	int rc;
+
+	if (!(mc->mc_flags & C_INITIALIZED)) {
+		rc = mdb_cursor_last(mc, key, data);
+		if (rc)
+			return rc;
+		mc->mc_ki[mc->mc_top]++;
+	}
+
+	mp = mc->mc_pg[mc->mc_top];
+
+	if (mc->mc_db->md_flags & MDB_DUPSORT) {
+		leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+			if (op == MDB_PREV || op == MDB_PREV_DUP) {
+				rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
+				if (op != MDB_PREV || rc != MDB_NOTFOUND) {
+					if (rc == MDB_SUCCESS) {
+						MDB_GET_KEY(leaf, key);
+						mc->mc_flags &= ~C_EOF;
+					}
+					return rc;
+				}
+			}
+#ifdef MDB_VL32
+			else {
+				if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
+					mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);
+				}
+			}
+#endif
+		} else {
+			mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
+			if (op == MDB_PREV_DUP)
+				return MDB_NOTFOUND;
+		}
+	}
+
+	DPRINTF(("cursor_prev: top page is %"Y"u in cursor %p",
+		mdb_dbg_pgno(mp), (void *) mc));
+
+	mc->mc_flags &= ~(C_EOF|C_DEL);
+
+	if (mc->mc_ki[mc->mc_top] == 0)  {
+		DPUTS("=====> move to prev sibling page");
+		if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
+			return rc;
+		}
+		mp = mc->mc_pg[mc->mc_top];
+		mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
+		DPRINTF(("prev page is %"Y"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
+	} else
+		mc->mc_ki[mc->mc_top]--;
+
+	mc->mc_flags &= ~C_EOF;
+
+	DPRINTF(("==> cursor points to page %"Y"u with %u keys, key index %u",
+	    mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
+
+	if (IS_LEAF2(mp)) {
+		key->mv_size = mc->mc_db->md_pad;
+		key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
+		return MDB_SUCCESS;
+	}
+
+	mdb_cassert(mc, IS_LEAF(mp));
+	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
+
+	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+		mdb_xcursor_init1(mc, leaf);
+	}
+	if (data) {
+		if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
+			return rc;
+
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+			rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
+			if (rc != MDB_SUCCESS)
+				return rc;
+		}
+	}
+
+	MDB_GET_KEY(leaf, key);
+	return MDB_SUCCESS;
+}
+
+/** Set the cursor on a specific data item. */
+static int
+mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
+    MDB_cursor_op op, int *exactp)
+{
+	int		 rc;
+	MDB_page	*mp;
+	MDB_node	*leaf = NULL;
+	DKBUF;
+
+	if (key->mv_size == 0)
+		return MDB_BAD_VALSIZE;
+
+	if (mc->mc_xcursor)
+		mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
+
+	/* See if we're already on the right page */
+	if (mc->mc_flags & C_INITIALIZED) {
+		MDB_val nodekey;
+
+		mp = mc->mc_pg[mc->mc_top];
+		if (!NUMKEYS(mp)) {
+			mc->mc_ki[mc->mc_top] = 0;
+			return MDB_NOTFOUND;
+		}
+		if (mp->mp_flags & P_LEAF2) {
+			nodekey.mv_size = mc->mc_db->md_pad;
+			nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
+		} else {
+			leaf = NODEPTR(mp, 0);
+			MDB_GET_KEY2(leaf, nodekey);
+		}
+		rc = mc->mc_dbx->md_cmp(key, &nodekey);
+		if (rc == 0) {
+			/* Probably happens rarely, but first node on the page
+			 * was the one we wanted.
+			 */
+			mc->mc_ki[mc->mc_top] = 0;
+			if (exactp)
+				*exactp = 1;
+			goto set1;
+		}
+		if (rc > 0) {
+			unsigned int i;
+			unsigned int nkeys = NUMKEYS(mp);
+			if (nkeys > 1) {
+				if (mp->mp_flags & P_LEAF2) {
+					nodekey.mv_data = LEAF2KEY(mp,
+						 nkeys-1, nodekey.mv_size);
+				} else {
+					leaf = NODEPTR(mp, nkeys-1);
+					MDB_GET_KEY2(leaf, nodekey);
+				}
+				rc = mc->mc_dbx->md_cmp(key, &nodekey);
+				if (rc == 0) {
+					/* last node was the one we wanted */
+					mc->mc_ki[mc->mc_top] = nkeys-1;
+					if (exactp)
+						*exactp = 1;
+					goto set1;
+				}
+				if (rc < 0) {
+					if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
+						/* This is definitely the right page, skip search_page */
+						if (mp->mp_flags & P_LEAF2) {
+							nodekey.mv_data = LEAF2KEY(mp,
+								 mc->mc_ki[mc->mc_top], nodekey.mv_size);
+						} else {
+							leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
+							MDB_GET_KEY2(leaf, nodekey);
+						}
+						rc = mc->mc_dbx->md_cmp(key, &nodekey);
+						if (rc == 0) {
+							/* current node was the one we wanted */
+							if (exactp)
+								*exactp = 1;
+							goto set1;
+						}
+					}
+					rc = 0;
+					goto set2;
+				}
+			}
+			/* If any parents have right-sibs, search.
+			 * Otherwise, there's nothing further.
+			 */
+			for (i=0; i<mc->mc_top; i++)
+				if (mc->mc_ki[i] <
+					NUMKEYS(mc->mc_pg[i])-1)
+					break;
+			if (i == mc->mc_top) {
+				/* There are no other pages */
+				mc->mc_ki[mc->mc_top] = nkeys;
+				return MDB_NOTFOUND;
+			}
+		}
+		if (!mc->mc_top) {
+			/* There are no other pages */
+			mc->mc_ki[mc->mc_top] = 0;
+			if (op == MDB_SET_RANGE && !exactp) {
+				rc = 0;
+				goto set1;
+			} else
+				return MDB_NOTFOUND;
+		}
+	} else {
+		mc->mc_pg[0] = 0;
+	}
+
+	rc = mdb_page_search(mc, key, 0);
+	if (rc != MDB_SUCCESS)
+		return rc;
+
+	mp = mc->mc_pg[mc->mc_top];
+	mdb_cassert(mc, IS_LEAF(mp));
+
+set2:
+	leaf = mdb_node_search(mc, key, exactp);
+	if (exactp != NULL && !*exactp) {
+		/* MDB_SET specified and not an exact match. */
+		return MDB_NOTFOUND;
+	}
+
+	if (leaf == NULL) {
+		DPUTS("===> inexact leaf not found, goto sibling");
+		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
+			mc->mc_flags |= C_EOF;
+			return rc;		/* no entries matched */
+		}
+		mp = mc->mc_pg[mc->mc_top];
+		mdb_cassert(mc, IS_LEAF(mp));
+		leaf = NODEPTR(mp, 0);
+	}
+
+set1:
+	mc->mc_flags |= C_INITIALIZED;
+	mc->mc_flags &= ~C_EOF;
+
+	if (IS_LEAF2(mp)) {
+		if (op == MDB_SET_RANGE || op == MDB_SET_KEY) {
+			key->mv_size = mc->mc_db->md_pad;
+			key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
+		}
+		return MDB_SUCCESS;
+	}
+
+#ifdef MDB_VL32
+	if (mc->mc_xcursor && mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
+		mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);
+	}
+#endif
+	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+		mdb_xcursor_init1(mc, leaf);
+	}
+	if (data) {
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+			if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
+				rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
+			} else {
+				int ex2, *ex2p;
+				if (op == MDB_GET_BOTH) {
+					ex2p = &ex2;
+					ex2 = 0;
+				} else {
+					ex2p = NULL;
+				}
+				rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
+				if (rc != MDB_SUCCESS)
+					return rc;
+			}
+		} else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
+			MDB_val olddata;
+			MDB_cmp_func *dcmp;
+			if ((rc = mdb_node_read(mc, leaf, &olddata)) != MDB_SUCCESS)
+				return rc;
+			dcmp = mc->mc_dbx->md_dcmp;
+#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)
+			if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(mdb_size_t))
+				dcmp = mdb_cmp_clong;
+#endif
+			rc = dcmp(data, &olddata);
+			if (rc) {
+				if (op == MDB_GET_BOTH || rc > 0)
+					return MDB_NOTFOUND;
+				rc = 0;
+			}
+			*data = olddata;
+
+		} else {
+			if (mc->mc_xcursor)
+				mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
+			if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
+				return rc;
+		}
+	}
+
+	/* The key already matches in all other cases */
+	if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
+		MDB_GET_KEY(leaf, key);
+	DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
+
+	return rc;
+}
+
+/** Move the cursor to the first item in the database. */
+static int
+mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
+{
+	int		 rc;
+	MDB_node	*leaf;
+
+	if (mc->mc_xcursor) {
+#ifdef MDB_VL32
+		if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
+			mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);
+		}
+#endif
+		mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
+	}
+
+	if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
+		rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
+		if (rc != MDB_SUCCESS)
+			return rc;
+	}
+	mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
+
+	leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
+	mc->mc_flags |= C_INITIALIZED;
+	mc->mc_flags &= ~C_EOF;
+
+	mc->mc_ki[mc->mc_top] = 0;
+
+	if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
+		key->mv_size = mc->mc_db->md_pad;
+		key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
+		return MDB_SUCCESS;
+	}
+
+	if (data) {
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+			mdb_xcursor_init1(mc, leaf);
+			rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
+			if (rc)
+				return rc;
+		} else {
+			if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
+				return rc;
+		}
+	}
+	MDB_GET_KEY(leaf, key);
+	return MDB_SUCCESS;
+}
+
+/** Move the cursor to the last item in the database. */
+static int
+mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
+{
+	int		 rc;
+	MDB_node	*leaf;
+
+	if (mc->mc_xcursor) {
+#ifdef MDB_VL32
+		if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
+			mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);
+		}
+#endif
+		mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
+	}
+
+	if (!(mc->mc_flags & C_EOF)) {
+
+		if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
+			rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
+			if (rc != MDB_SUCCESS)
+				return rc;
+		}
+		mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
+
+	}
+	mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
+	mc->mc_flags |= C_INITIALIZED|C_EOF;
+	leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+
+	if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
+		key->mv_size = mc->mc_db->md_pad;
+		key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
+		return MDB_SUCCESS;
+	}
+
+	if (data) {
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+			mdb_xcursor_init1(mc, leaf);
+			rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
+			if (rc)
+				return rc;
+		} else {
+			if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
+				return rc;
+		}
+	}
+
+	MDB_GET_KEY(leaf, key);
+	return MDB_SUCCESS;
+}
+
+int
+mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
+    MDB_cursor_op op)
+{
+	int		 rc;
+	int		 exact = 0;
+	int		 (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
+
+	if (mc == NULL)
+		return EINVAL;
+
+	if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
+		return MDB_BAD_TXN;
+
+	switch (op) {
+	case MDB_GET_CURRENT:
+		if (!(mc->mc_flags & C_INITIALIZED)) {
+			rc = EINVAL;
+		} else {
+			MDB_page *mp = mc->mc_pg[mc->mc_top];
+			int nkeys = NUMKEYS(mp);
+			if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {
+				mc->mc_ki[mc->mc_top] = nkeys;
+				rc = MDB_NOTFOUND;
+				break;
+			}
+			rc = MDB_SUCCESS;
+			if (IS_LEAF2(mp)) {
+				key->mv_size = mc->mc_db->md_pad;
+				key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
+			} else {
+				MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
+				MDB_GET_KEY(leaf, key);
+				if (data) {
+					if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+						rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
+					} else {
+						rc = mdb_node_read(mc, leaf, data);
+					}
+				}
+			}
+		}
+		break;
+	case MDB_GET_BOTH:
+	case MDB_GET_BOTH_RANGE:
+		if (data == NULL) {
+			rc = EINVAL;
+			break;
+		}
+		if (mc->mc_xcursor == NULL) {
+			rc = MDB_INCOMPATIBLE;
+			break;
+		}
+		/* FALLTHRU */
+	case MDB_SET:
+	case MDB_SET_KEY:
+	case MDB_SET_RANGE:
+		if (key == NULL) {
+			rc = EINVAL;
+		} else {
+			rc = mdb_cursor_set(mc, key, data, op,
+				op == MDB_SET_RANGE ? NULL : &exact);
+		}
+		break;
+	case MDB_GET_MULTIPLE:
+		if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
+			rc = EINVAL;
+			break;
+		}
+		if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
+			rc = MDB_INCOMPATIBLE;
+			break;
+		}
+		rc = MDB_SUCCESS;
+		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
+			(mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
+			break;
+		goto fetchm;
+	case MDB_NEXT_MULTIPLE:
+		if (data == NULL) {
+			rc = EINVAL;
+			break;
+		}
+		if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
+			rc = MDB_INCOMPATIBLE;
+			break;
+		}
+		rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
+		if (rc == MDB_SUCCESS) {
+			if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
+				MDB_cursor *mx;
+fetchm:
+				mx = &mc->mc_xcursor->mx_cursor;
+				data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
+					mx->mc_db->md_pad;
+				data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
+				mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
+			} else {
+				rc = MDB_NOTFOUND;
+			}
+		}
+		break;
+	case MDB_PREV_MULTIPLE:
+		if (data == NULL) {
+			rc = EINVAL;
+			break;
+		}
+		if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
+			rc = MDB_INCOMPATIBLE;
+			break;
+		}
+		if (!(mc->mc_flags & C_INITIALIZED))
+			rc = mdb_cursor_last(mc, key, data);
+		else
+			rc = MDB_SUCCESS;
+		if (rc == MDB_SUCCESS) {
+			MDB_cursor *mx = &mc->mc_xcursor->mx_cursor;
+			if (mx->mc_flags & C_INITIALIZED) {
+				rc = mdb_cursor_sibling(mx, 0);
+				if (rc == MDB_SUCCESS)
+					goto fetchm;
+			} else {
+				rc = MDB_NOTFOUND;
+			}
+		}
+		break;
+	case MDB_NEXT:
+	case MDB_NEXT_DUP:
+	case MDB_NEXT_NODUP:
+		rc = mdb_cursor_next(mc, key, data, op);
+		break;
+	case MDB_PREV:
+	case MDB_PREV_DUP:
+	case MDB_PREV_NODUP:
+		rc = mdb_cursor_prev(mc, key, data, op);
+		break;
+	case MDB_FIRST:
+		rc = mdb_cursor_first(mc, key, data);
+		break;
+	case MDB_FIRST_DUP:
+		mfunc = mdb_cursor_first;
+	mmove:
+		if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
+			rc = EINVAL;
+			break;
+		}
+		if (mc->mc_xcursor == NULL) {
+			rc = MDB_INCOMPATIBLE;
+			break;
+		}
+		{
+			MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+			if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+				MDB_GET_KEY(leaf, key);
+				rc = mdb_node_read(mc, leaf, data);
+				break;
+			}
+		}
+		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
+			rc = EINVAL;
+			break;
+		}
+		rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
+		break;
+	case MDB_LAST:
+		rc = mdb_cursor_last(mc, key, data);
+		break;
+	case MDB_LAST_DUP:
+		mfunc = mdb_cursor_last;
+		goto mmove;
+	default:
+		DPRINTF(("unhandled/unimplemented cursor operation %u", op));
+		rc = EINVAL;
+		break;
+	}
+
+	if (mc->mc_flags & C_DEL)
+		mc->mc_flags ^= C_DEL;
+
+	return rc;
+}
+
+/** Touch all the pages in the cursor stack. Set mc_top.
+ *	Makes sure all the pages are writable, before attempting a write operation.
+ * @param[in] mc The cursor to operate on.
+ */
+static int
+mdb_cursor_touch(MDB_cursor *mc)
+{
+	int rc = MDB_SUCCESS;
+
+	if (mc->mc_dbi >= CORE_DBS && !(*mc->mc_dbflag & DB_DIRTY)) {
+		MDB_cursor mc2;
+		MDB_xcursor mcx;
+		if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
+			return MDB_BAD_DBI;
+		mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
+		rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
+		if (rc)
+			 return rc;
+		*mc->mc_dbflag |= DB_DIRTY;
+	}
+	mc->mc_top = 0;
+	if (mc->mc_snum) {
+		do {
+			rc = mdb_page_touch(mc);
+		} while (!rc && ++(mc->mc_top) < mc->mc_snum);
+		mc->mc_top = mc->mc_snum-1;
+	}
+	return rc;
+}
+
+/** Do not spill pages to disk if txn is getting full, may fail instead */
+#define MDB_NOSPILL	0x8000
+
+int
+mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
+    unsigned int flags)
+{
+	MDB_env		*env;
+	MDB_node	*leaf = NULL;
+	MDB_page	*fp, *mp, *sub_root = NULL;
+	uint16_t	fp_flags;
+	MDB_val		xdata, *rdata, dkey, olddata;
+	MDB_db dummy;
+	int do_sub = 0, insert_key, insert_data;
+	unsigned int mcount = 0, dcount = 0, nospill;
+	size_t nsize;
+	int rc, rc2;
+	unsigned int nflags;
+	DKBUF;
+
+	if (mc == NULL || key == NULL)
+		return EINVAL;
+
+	env = mc->mc_txn->mt_env;
+
+	/* Check this first so counter will always be zero on any
+	 * early failures.
+	 */
+	if (flags & MDB_MULTIPLE) {
+		dcount = data[1].mv_size;
+		data[1].mv_size = 0;
+		if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
+			return MDB_INCOMPATIBLE;
+	}
+
+	nospill = flags & MDB_NOSPILL;
+	flags &= ~MDB_NOSPILL;
+
+	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
+		return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
+
+	if (key->mv_size-1 >= ENV_MAXKEY(env))
+		return MDB_BAD_VALSIZE;
+
+#if SIZE_MAX > MAXDATASIZE
+	if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))
+		return MDB_BAD_VALSIZE;
+#else
+	if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env))
+		return MDB_BAD_VALSIZE;
+#endif
+
+	DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",
+		DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));
+
+	dkey.mv_size = 0;
+
+	if (flags == MDB_CURRENT) {
+		if (!(mc->mc_flags & C_INITIALIZED))
+			return EINVAL;
+		rc = MDB_SUCCESS;
+	} else if (mc->mc_db->md_root == P_INVALID) {
+		/* new database, cursor has nothing to point to */
+		mc->mc_snum = 0;
+		mc->mc_top = 0;
+		mc->mc_flags &= ~C_INITIALIZED;
+		rc = MDB_NO_ROOT;
+	} else {
+		int exact = 0;
+		MDB_val d2;
+		if (flags & MDB_APPEND) {
+			MDB_val k2;
+			rc = mdb_cursor_last(mc, &k2, &d2);
+			if (rc == 0) {
+				rc = mc->mc_dbx->md_cmp(key, &k2);
+				if (rc > 0) {
+					rc = MDB_NOTFOUND;
+					mc->mc_ki[mc->mc_top]++;
+				} else {
+					/* new key is <= last key */
+					rc = MDB_KEYEXIST;
+				}
+			}
+		} else {
+			rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
+		}
+		if ((flags & MDB_NOOVERWRITE) && rc == 0) {
+			DPRINTF(("duplicate key [%s]", DKEY(key)));
+			*data = d2;
+			return MDB_KEYEXIST;
+		}
+		if (rc && rc != MDB_NOTFOUND)
+			return rc;
+	}
+
+	if (mc->mc_flags & C_DEL)
+		mc->mc_flags ^= C_DEL;
+
+	/* Cursor is positioned, check for room in the dirty list */
+	if (!nospill) {
+		if (flags & MDB_MULTIPLE) {
+			rdata = &xdata;
+			xdata.mv_size = data->mv_size * dcount;
+		} else {
+			rdata = data;
+		}
+		if ((rc2 = mdb_page_spill(mc, key, rdata)))
+			return rc2;
+	}
+
+	if (rc == MDB_NO_ROOT) {
+		MDB_page *np;
+		/* new database, write a root leaf page */
+		DPUTS("allocating new root leaf page");
+		if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
+			return rc2;
+		}
+		mdb_cursor_push(mc, np);
+		mc->mc_db->md_root = np->mp_pgno;
+		mc->mc_db->md_depth++;
+		*mc->mc_dbflag |= DB_DIRTY;
+		if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
+			== MDB_DUPFIXED)
+			np->mp_flags |= P_LEAF2;
+		mc->mc_flags |= C_INITIALIZED;
+	} else {
+		/* make sure all cursor pages are writable */
+		rc2 = mdb_cursor_touch(mc);
+		if (rc2)
+			return rc2;
+	}
+
+	insert_key = insert_data = rc;
+	if (insert_key) {
+		/* The key does not exist */
+		DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
+		if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
+			LEAFSIZE(key, data) > env->me_nodemax)
+		{
+			/* Too big for a node, insert in sub-DB.  Set up an empty
+			 * "old sub-page" for prep_subDB to expand to a full page.
+			 */
+			fp_flags = P_LEAF|P_DIRTY;
+			fp = env->me_pbuf;
+			fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */
+			fp->mp_lower = fp->mp_upper = (PAGEHDRSZ-PAGEBASE);
+			olddata.mv_size = PAGEHDRSZ;
+			goto prep_subDB;
+		}
+	} else {
+		/* there's only a key anyway, so this is a no-op */
+		if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
+			char *ptr;
+			unsigned int ksize = mc->mc_db->md_pad;
+			if (key->mv_size != ksize)
+				return MDB_BAD_VALSIZE;
+			ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
+			memcpy(ptr, key->mv_data, ksize);
+fix_parent:
+			/* if overwriting slot 0 of leaf, need to
+			 * update branch key if there is a parent page
+			 */
+			if (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
+				unsigned short dtop = 1;
+				mc->mc_top--;
+				/* slot 0 is always an empty key, find real slot */
+				while (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
+					mc->mc_top--;
+					dtop++;
+				}
+				if (mc->mc_ki[mc->mc_top])
+					rc2 = mdb_update_key(mc, key);
+				else
+					rc2 = MDB_SUCCESS;
+				mc->mc_top += dtop;
+				if (rc2)
+					return rc2;
+			}
+			return MDB_SUCCESS;
+		}
+
+more:
+		leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+		olddata.mv_size = NODEDSZ(leaf);
+		olddata.mv_data = NODEDATA(leaf);
+
+		/* DB has dups? */
+		if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
+			/* Prepare (sub-)page/sub-DB to accept the new item,
+			 * if needed.  fp: old sub-page or a header faking
+			 * it.  mp: new (sub-)page.  offset: growth in page
+			 * size.  xdata: node data with new page or DB.
+			 */
+			unsigned	i, offset = 0;
+			mp = fp = xdata.mv_data = env->me_pbuf;
+			mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
+
+			/* Was a single item before, must convert now */
+			if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+				MDB_cmp_func *dcmp;
+				/* Just overwrite the current item */
+				if (flags == MDB_CURRENT)
+					goto current;
+				dcmp = mc->mc_dbx->md_dcmp;
+#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)
+				if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(mdb_size_t))
+					dcmp = mdb_cmp_clong;
+#endif
+				/* does data match? */
+				if (!dcmp(data, &olddata)) {
+					if (flags & (MDB_NODUPDATA|MDB_APPENDDUP))
+						return MDB_KEYEXIST;
+					/* overwrite it */
+					goto current;
+				}
+
+				/* Back up original data item */
+				dkey.mv_size = olddata.mv_size;
+				dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);
+
+				/* Make sub-page header for the dup items, with dummy body */
+				fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
+				fp->mp_lower = (PAGEHDRSZ-PAGEBASE);
+				xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
+				if (mc->mc_db->md_flags & MDB_DUPFIXED) {
+					fp->mp_flags |= P_LEAF2;
+					fp->mp_pad = data->mv_size;
+					xdata.mv_size += 2 * data->mv_size;	/* leave space for 2 more */
+				} else {
+					xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
+						(dkey.mv_size & 1) + (data->mv_size & 1);
+				}
+				fp->mp_upper = xdata.mv_size - PAGEBASE;
+				olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */
+			} else if (leaf->mn_flags & F_SUBDATA) {
+				/* Data is on sub-DB, just store it */
+				flags |= F_DUPDATA|F_SUBDATA;
+				goto put_sub;
+			} else {
+				/* Data is on sub-page */
+				fp = olddata.mv_data;
+				switch (flags) {
+				default:
+					if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
+						offset = EVEN(NODESIZE + sizeof(indx_t) +
+							data->mv_size);
+						break;
+					}
+					offset = fp->mp_pad;
+					if (SIZELEFT(fp) < offset) {
+						offset *= 4; /* space for 4 more */
+						break;
+					}
+					/* FALLTHRU: Big enough MDB_DUPFIXED sub-page */
+				case MDB_CURRENT:
+					fp->mp_flags |= P_DIRTY;
+					COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
+					mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
+					flags |= F_DUPDATA;
+					goto put_sub;
+				}
+				xdata.mv_size = olddata.mv_size + offset;
+			}
+
+			fp_flags = fp->mp_flags;
+			if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {
+					/* Too big for a sub-page, convert to sub-DB */
+					fp_flags &= ~P_SUBP;
+prep_subDB:
+					if (mc->mc_db->md_flags & MDB_DUPFIXED) {
+						fp_flags |= P_LEAF2;
+						dummy.md_pad = fp->mp_pad;
+						dummy.md_flags = MDB_DUPFIXED;
+						if (mc->mc_db->md_flags & MDB_INTEGERDUP)
+							dummy.md_flags |= MDB_INTEGERKEY;
+					} else {
+						dummy.md_pad = 0;
+						dummy.md_flags = 0;
+					}
+					dummy.md_depth = 1;
+					dummy.md_branch_pages = 0;
+					dummy.md_leaf_pages = 1;
+					dummy.md_overflow_pages = 0;
+					dummy.md_entries = NUMKEYS(fp);
+					xdata.mv_size = sizeof(MDB_db);
+					xdata.mv_data = &dummy;
+					if ((rc = mdb_page_alloc(mc, 1, &mp)))
+						return rc;
+					offset = env->me_psize - olddata.mv_size;
+					flags |= F_DUPDATA|F_SUBDATA;
+					dummy.md_root = mp->mp_pgno;
+					sub_root = mp;
+			}
+			if (mp != fp) {
+				mp->mp_flags = fp_flags | P_DIRTY;
+				mp->mp_pad   = fp->mp_pad;
+				mp->mp_lower = fp->mp_lower;
+				mp->mp_upper = fp->mp_upper + offset;
+				if (fp_flags & P_LEAF2) {
+					memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
+				} else {
+					memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE,
+						olddata.mv_size - fp->mp_upper - PAGEBASE);
+					for (i=0; i<NUMKEYS(fp); i++)
+						mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
+				}
+			}
+
+			rdata = &xdata;
+			flags |= F_DUPDATA;
+			do_sub = 1;
+			if (!insert_key)
+				mdb_node_del(mc, 0);
+			goto new_sub;
+		}
+current:
+		/* LMDB passes F_SUBDATA in 'flags' to write a DB record */
+		if ((leaf->mn_flags ^ flags) & F_SUBDATA)
+			return MDB_INCOMPATIBLE;
+		/* overflow page overwrites need special handling */
+		if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
+			MDB_page *omp;
+			pgno_t pg;
+			int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
+
+			memcpy(&pg, olddata.mv_data, sizeof(pg));
+			if ((rc2 = mdb_page_get(mc, pg, &omp, &level)) != 0)
+				return rc2;
+			ovpages = omp->mp_pages;
+
+			/* Is the ov page large enough? */
+			if (ovpages >= dpages) {
+			  if (!(omp->mp_flags & P_DIRTY) &&
+				  (level || (env->me_flags & MDB_WRITEMAP)))
+			  {
+				rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
+				if (rc)
+					return rc;
+				level = 0;		/* dirty in this txn or clean */
+			  }
+			  /* Is it dirty? */
+			  if (omp->mp_flags & P_DIRTY) {
+				/* yes, overwrite it. Note in this case we don't
+				 * bother to try shrinking the page if the new data
+				 * is smaller than the overflow threshold.
+				 */
+				if (level > 1) {
+					/* It is writable only in a parent txn */
+					size_t sz = (size_t) env->me_psize * ovpages, off;
+					MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
+					MDB_ID2 id2;
+					if (!np)
+						return ENOMEM;
+					id2.mid = pg;
+					id2.mptr = np;
+					/* Note - this page is already counted in parent's dirty_room */
+					rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
+					mdb_cassert(mc, rc2 == 0);
+					/* Currently we make the page look as with put() in the
+					 * parent txn, in case the user peeks at MDB_RESERVEd
+					 * or unused parts. Some users treat ovpages specially.
+					 */
+					if (!(flags & MDB_RESERVE)) {
+						/* Skip the part where LMDB will put *data.
+						 * Copy end of page, adjusting alignment so
+						 * compiler may copy words instead of bytes.
+						 */
+						off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
+						memcpy((size_t *)((char *)np + off),
+							(size_t *)((char *)omp + off), sz - off);
+						sz = PAGEHDRSZ;
+					}
+					memcpy(np, omp, sz); /* Copy beginning of page */
+					omp = np;
+				}
+				SETDSZ(leaf, data->mv_size);
+				if (F_ISSET(flags, MDB_RESERVE))
+					data->mv_data = METADATA(omp);
+				else
+					memcpy(METADATA(omp), data->mv_data, data->mv_size);
+				return MDB_SUCCESS;
+			  }
+			}
+			if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
+				return rc2;
+		} else if (data->mv_size == olddata.mv_size) {
+			/* same size, just replace it. Note that we could
+			 * also reuse this node if the new data is smaller,
+			 * but instead we opt to shrink the node in that case.
+			 */
+			if (F_ISSET(flags, MDB_RESERVE))
+				data->mv_data = olddata.mv_data;
+			else if (!(mc->mc_flags & C_SUB))
+				memcpy(olddata.mv_data, data->mv_data, data->mv_size);
+			else {
+				memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
+				goto fix_parent;
+			}
+			return MDB_SUCCESS;
+		}
+		mdb_node_del(mc, 0);
+	}
+
+	rdata = data;
+
+new_sub:
+	nflags = flags & NODE_ADD_FLAGS;
+	nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
+	if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
+		if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
+			nflags &= ~MDB_APPEND; /* sub-page may need room to grow */
+		if (!insert_key)
+			nflags |= MDB_SPLIT_REPLACE;
+		rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
+	} else {
+		/* There is room already in this leaf page. */
+		rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
+		if (rc == 0) {
+			/* Adjust other cursors pointing to mp */
+			MDB_cursor *m2, *m3;
+			MDB_dbi dbi = mc->mc_dbi;
+			unsigned i = mc->mc_top;
+			MDB_page *mp = mc->mc_pg[i];
+
+			for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+				if (mc->mc_flags & C_SUB)
+					m3 = &m2->mc_xcursor->mx_cursor;
+				else
+					m3 = m2;
+				if (m3 == mc || m3->mc_snum < mc->mc_snum || m3->mc_pg[i] != mp) continue;
+				if (m3->mc_ki[i] >= mc->mc_ki[i] && insert_key) {
+					m3->mc_ki[i]++;
+				}
+				if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
+					MDB_node *n2 = NODEPTR(mp, m3->mc_ki[i]);
+					if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
+						m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
+				}
+			}
+		}
+	}
+
+	if (rc == MDB_SUCCESS) {
+		/* Now store the actual data in the child DB. Note that we're
+		 * storing the user data in the keys field, so there are strict
+		 * size limits on dupdata. The actual data fields of the child
+		 * DB are all zero size.
+		 */
+		if (do_sub) {
+			int xflags, new_dupdata;
+			mdb_size_t ecount;
+put_sub:
+			xdata.mv_size = 0;
+			xdata.mv_data = "";
+			leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+			if (flags & MDB_CURRENT) {
+				xflags = MDB_CURRENT|MDB_NOSPILL;
+			} else {
+				mdb_xcursor_init1(mc, leaf);
+				xflags = (flags & MDB_NODUPDATA) ?
+					MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
+			}
+			if (sub_root)
+				mc->mc_xcursor->mx_cursor.mc_pg[0] = sub_root;
+			new_dupdata = (int)dkey.mv_size;
+			/* converted, write the original data first */
+			if (dkey.mv_size) {
+				rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
+				if (rc)
+					goto bad_sub;
+				/* we've done our job */
+				dkey.mv_size = 0;
+			}
+			if (!(leaf->mn_flags & F_SUBDATA) || sub_root) {
+				/* Adjust other cursors pointing to mp */
+				MDB_cursor *m2;
+				MDB_xcursor *mx = mc->mc_xcursor;
+				unsigned i = mc->mc_top;
+				MDB_page *mp = mc->mc_pg[i];
+				int nkeys = NUMKEYS(mp);
+
+				for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
+					if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
+					if (!(m2->mc_flags & C_INITIALIZED)) continue;
+					if (m2->mc_pg[i] == mp) {
+						if (m2->mc_ki[i] == mc->mc_ki[i]) {
+							mdb_xcursor_init2(m2, mx, new_dupdata);
+						} else if (!insert_key && m2->mc_ki[i] < nkeys) {
+							MDB_node *n2 = NODEPTR(mp, m2->mc_ki[i]);
+							if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
+								m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
+						}
+					}
+				}
+			}
+			ecount = mc->mc_xcursor->mx_db.md_entries;
+			if (flags & MDB_APPENDDUP)
+				xflags |= MDB_APPEND;
+			rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
+			if (flags & F_SUBDATA) {
+				void *db = NODEDATA(leaf);
+				memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
+			}
+			insert_data = mc->mc_xcursor->mx_db.md_entries - ecount;
+		}
+		/* Increment count unless we just replaced an existing item. */
+		if (insert_data)
+			mc->mc_db->md_entries++;
+		if (insert_key) {
+			/* Invalidate txn if we created an empty sub-DB */
+			if (rc)
+				goto bad_sub;
+			/* If we succeeded and the key didn't exist before,
+			 * make sure the cursor is marked valid.
+			 */
+			mc->mc_flags |= C_INITIALIZED;
+		}
+		if (flags & MDB_MULTIPLE) {
+			if (!rc) {
+				mcount++;
+				/* let caller know how many succeeded, if any */
+				data[1].mv_size = mcount;
+				if (mcount < dcount) {
+					data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
+					insert_key = insert_data = 0;
+					goto more;
+				}
+			}
+		}
+		return rc;
+bad_sub:
+		if (rc == MDB_KEYEXIST)	/* should not happen, we deleted that item */
+			rc = MDB_CORRUPTED;
+	}
+	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
+	return rc;
+}
+
+int
+mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
+{
+	MDB_node	*leaf;
+	MDB_page	*mp;
+	int rc;
+
+	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
+		return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
+
+	if (!(mc->mc_flags & C_INITIALIZED))
+		return EINVAL;
+
+	if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))
+		return MDB_NOTFOUND;
+
+	if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
+		return rc;
+
+	rc = mdb_cursor_touch(mc);
+	if (rc)
+		return rc;
+
+	mp = mc->mc_pg[mc->mc_top];
+	if (IS_LEAF2(mp))
+		goto del_key;
+	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
+
+	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+		if (flags & MDB_NODUPDATA) {
+			/* mdb_cursor_del0() will subtract the final entry */
+			mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;
+			mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
+		} else {
+			if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
+				mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
+			}
+			rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
+			if (rc)
+				return rc;
+			/* If sub-DB still has entries, we're done */
+			if (mc->mc_xcursor->mx_db.md_entries) {
+				if (leaf->mn_flags & F_SUBDATA) {
+					/* update subDB info */
+					void *db = NODEDATA(leaf);
+					memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
+				} else {
+					MDB_cursor *m2;
+					/* shrink fake page */
+					mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);
+					leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
+					mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
+					/* fix other sub-DB cursors pointed at fake pages on this page */
+					for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
+						if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
+						if (!(m2->mc_flags & C_INITIALIZED)) continue;
+						if (m2->mc_pg[mc->mc_top] == mp) {
+							if (m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top]) {
+								m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
+							} else {
+								MDB_node *n2 = NODEPTR(mp, m2->mc_ki[mc->mc_top]);
+								if (!(n2->mn_flags & F_SUBDATA))
+									m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
+							}
+						}
+					}
+				}
+				mc->mc_db->md_entries--;
+				return rc;
+			} else {
+				mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
+			}
+			/* otherwise fall thru and delete the sub-DB */
+		}
+
+		if (leaf->mn_flags & F_SUBDATA) {
+			/* add all the child DB's pages to the free list */
+			rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
+			if (rc)
+				goto fail;
+		}
+	}
+	/* LMDB passes F_SUBDATA in 'flags' to delete a DB record */
+	else if ((leaf->mn_flags ^ flags) & F_SUBDATA) {
+		rc = MDB_INCOMPATIBLE;
+		goto fail;
+	}
+
+	/* add overflow pages to free list */
+	if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
+		MDB_page *omp;
+		pgno_t pg;
+
+		memcpy(&pg, NODEDATA(leaf), sizeof(pg));
+		if ((rc = mdb_page_get(mc, pg, &omp, NULL)) ||
+			(rc = mdb_ovpage_free(mc, omp)))
+			goto fail;
+	}
+
+del_key:
+	return mdb_cursor_del0(mc);
+
+fail:
+	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
+	return rc;
+}
+
+/** Allocate and initialize new pages for a database.
+ * @param[in] mc a cursor on the database being added to.
+ * @param[in] flags flags defining what type of page is being allocated.
+ * @param[in] num the number of pages to allocate. This is usually 1,
+ * unless allocating overflow pages for a large record.
+ * @param[out] mp Address of a page, or NULL on failure.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
+{
+	MDB_page	*np;
+	int rc;
+
+	if ((rc = mdb_page_alloc(mc, num, &np)))
+		return rc;
+	DPRINTF(("allocated new mpage %"Y"u, page size %u",
+	    np->mp_pgno, mc->mc_txn->mt_env->me_psize));
+	np->mp_flags = flags | P_DIRTY;
+	np->mp_lower = (PAGEHDRSZ-PAGEBASE);
+	np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE;
+
+	if (IS_BRANCH(np))
+		mc->mc_db->md_branch_pages++;
+	else if (IS_LEAF(np))
+		mc->mc_db->md_leaf_pages++;
+	else if (IS_OVERFLOW(np)) {
+		mc->mc_db->md_overflow_pages += num;
+		np->mp_pages = num;
+	}
+	*mp = np;
+
+	return 0;
+}
+
+/** Calculate the size of a leaf node.
+ * The size depends on the environment's page size; if a data item
+ * is too large it will be put onto an overflow page and the node
+ * size will only include the key and not the data. Sizes are always
+ * rounded up to an even number of bytes, to guarantee 2-byte alignment
+ * of the #MDB_node headers.
+ * @param[in] env The environment handle.
+ * @param[in] key The key for the node.
+ * @param[in] data The data for the node.
+ * @return The number of bytes needed to store the node.
+ */
+static size_t
+mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
+{
+	size_t		 sz;
+
+	sz = LEAFSIZE(key, data);
+	if (sz > env->me_nodemax) {
+		/* put on overflow page */
+		sz -= data->mv_size - sizeof(pgno_t);
+	}
+
+	return EVEN(sz + sizeof(indx_t));
+}
+
+/** Calculate the size of a branch node.
+ * The size should depend on the environment's page size but since
+ * we currently don't support spilling large keys onto overflow
+ * pages, it's simply the size of the #MDB_node header plus the
+ * size of the key. Sizes are always rounded up to an even number
+ * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
+ * @param[in] env The environment handle.
+ * @param[in] key The key for the node.
+ * @return The number of bytes needed to store the node.
+ */
+static size_t
+mdb_branch_size(MDB_env *env, MDB_val *key)
+{
+	size_t		 sz;
+
+	sz = INDXSIZE(key);
+	if (sz > env->me_nodemax) {
+		/* put on overflow page */
+		/* not implemented */
+		/* sz -= key->size - sizeof(pgno_t); */
+	}
+
+	return sz + sizeof(indx_t);
+}
+
+/** Add a node to the page pointed to by the cursor.
+ * @param[in] mc The cursor for this operation.
+ * @param[in] indx The index on the page where the new node should be added.
+ * @param[in] key The key for the new node.
+ * @param[in] data The data for the new node, if any.
+ * @param[in] pgno The page number, if adding a branch node.
+ * @param[in] flags Flags for the node.
+ * @return 0 on success, non-zero on failure. Possible errors are:
+ * <ul>
+ *	<li>ENOMEM - failed to allocate overflow pages for the node.
+ *	<li>MDB_PAGE_FULL - there is insufficient room in the page. This error
+ *	should never happen since all callers already calculate the
+ *	page's free space before calling this function.
+ * </ul>
+ */
+static int
+mdb_node_add(MDB_cursor *mc, indx_t indx,
+    MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
+{
+	unsigned int	 i;
+	size_t		 node_size = NODESIZE;
+	ssize_t		 room;
+	indx_t		 ofs;
+	MDB_node	*node;
+	MDB_page	*mp = mc->mc_pg[mc->mc_top];
+	MDB_page	*ofp = NULL;		/* overflow page */
+	void		*ndata;
+	DKBUF;
+
+	mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);
+
+	DPRINTF(("add to %s %spage %"Y"u index %i, data size %"Z"u key size %"Z"u [%s]",
+	    IS_LEAF(mp) ? "leaf" : "branch",
+		IS_SUBP(mp) ? "sub-" : "",
+		mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,
+		key ? key->mv_size : 0, key ? DKEY(key) : "null"));
+
+	if (IS_LEAF2(mp)) {
+		/* Move higher keys up one slot. */
+		int ksize = mc->mc_db->md_pad, dif;
+		char *ptr = LEAF2KEY(mp, indx, ksize);
+		dif = NUMKEYS(mp) - indx;
+		if (dif > 0)
+			memmove(ptr+ksize, ptr, dif*ksize);
+		/* insert new key */
+		memcpy(ptr, key->mv_data, ksize);
+
+		/* Just using these for counting */
+		mp->mp_lower += sizeof(indx_t);
+		mp->mp_upper -= ksize - sizeof(indx_t);
+		return MDB_SUCCESS;
+	}
+
+	room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);
+	if (key != NULL)
+		node_size += key->mv_size;
+	if (IS_LEAF(mp)) {
+		mdb_cassert(mc, key && data);
+		if (F_ISSET(flags, F_BIGDATA)) {
+			/* Data already on overflow page. */
+			node_size += sizeof(pgno_t);
+		} else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {
+			int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
+			int rc;
+			/* Put data on overflow page. */
+			DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",
+			    data->mv_size, node_size+data->mv_size));
+			node_size = EVEN(node_size + sizeof(pgno_t));
+			if ((ssize_t)node_size > room)
+				goto full;
+			if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
+				return rc;
+			DPRINTF(("allocated overflow page %"Y"u", ofp->mp_pgno));
+			flags |= F_BIGDATA;
+			goto update;
+		} else {
+			node_size += data->mv_size;
+		}
+	}
+	node_size = EVEN(node_size);
+	if ((ssize_t)node_size > room)
+		goto full;
+
+update:
+	/* Move higher pointers up one slot. */
+	for (i = NUMKEYS(mp); i > indx; i--)
+		mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
+
+	/* Adjust free space offsets. */
+	ofs = mp->mp_upper - node_size;
+	mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t));
+	mp->mp_ptrs[indx] = ofs;
+	mp->mp_upper = ofs;
+	mp->mp_lower += sizeof(indx_t);
+
+	/* Write the node data. */
+	node = NODEPTR(mp, indx);
+	node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
+	node->mn_flags = flags;
+	if (IS_LEAF(mp))
+		SETDSZ(node,data->mv_size);
+	else
+		SETPGNO(node,pgno);
+
+	if (key)
+		memcpy(NODEKEY(node), key->mv_data, key->mv_size);
+
+	if (IS_LEAF(mp)) {
+		ndata = NODEDATA(node);
+		if (ofp == NULL) {
+			if (F_ISSET(flags, F_BIGDATA))
+				memcpy(ndata, data->mv_data, sizeof(pgno_t));
+			else if (F_ISSET(flags, MDB_RESERVE))
+				data->mv_data = ndata;
+			else
+				memcpy(ndata, data->mv_data, data->mv_size);
+		} else {
+			memcpy(ndata, &ofp->mp_pgno, sizeof(pgno_t));
+			ndata = METADATA(ofp);
+			if (F_ISSET(flags, MDB_RESERVE))
+				data->mv_data = ndata;
+			else
+				memcpy(ndata, data->mv_data, data->mv_size);
+		}
+	}
+
+	return MDB_SUCCESS;
+
+full:
+	DPRINTF(("not enough room in page %"Y"u, got %u ptrs",
+		mdb_dbg_pgno(mp), NUMKEYS(mp)));
+	DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
+	DPRINTF(("node size = %"Z"u", node_size));
+	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
+	return MDB_PAGE_FULL;
+}
+
+/** Delete the specified node from a page.
+ * @param[in] mc Cursor pointing to the node to delete.
+ * @param[in] ksize The size of a node. Only used if the page is
+ * part of a #MDB_DUPFIXED database.
+ */
+static void
+mdb_node_del(MDB_cursor *mc, int ksize)
+{
+	MDB_page *mp = mc->mc_pg[mc->mc_top];
+	indx_t	indx = mc->mc_ki[mc->mc_top];
+	unsigned int	 sz;
+	indx_t		 i, j, numkeys, ptr;
+	MDB_node	*node;
+	char		*base;
+
+	DPRINTF(("delete node %u on %s page %"Y"u", indx,
+	    IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));
+	numkeys = NUMKEYS(mp);
+	mdb_cassert(mc, indx < numkeys);
+
+	if (IS_LEAF2(mp)) {
+		int x = numkeys - 1 - indx;
+		base = LEAF2KEY(mp, indx, ksize);
+		if (x)
+			memmove(base, base + ksize, x * ksize);
+		mp->mp_lower -= sizeof(indx_t);
+		mp->mp_upper += ksize - sizeof(indx_t);
+		return;
+	}
+
+	node = NODEPTR(mp, indx);
+	sz = NODESIZE + node->mn_ksize;
+	if (IS_LEAF(mp)) {
+		if (F_ISSET(node->mn_flags, F_BIGDATA))
+			sz += sizeof(pgno_t);
+		else
+			sz += NODEDSZ(node);
+	}
+	sz = EVEN(sz);
+
+	ptr = mp->mp_ptrs[indx];
+	for (i = j = 0; i < numkeys; i++) {
+		if (i != indx) {
+			mp->mp_ptrs[j] = mp->mp_ptrs[i];
+			if (mp->mp_ptrs[i] < ptr)
+				mp->mp_ptrs[j] += sz;
+			j++;
+		}
+	}
+
+	base = (char *)mp + mp->mp_upper + PAGEBASE;
+	memmove(base + sz, base, ptr - mp->mp_upper);
+
+	mp->mp_lower -= sizeof(indx_t);
+	mp->mp_upper += sz;
+}
+
+/** Compact the main page after deleting a node on a subpage.
+ * @param[in] mp The main page to operate on.
+ * @param[in] indx The index of the subpage on the main page.
+ */
+static void
+mdb_node_shrink(MDB_page *mp, indx_t indx)
+{
+	MDB_node *node;
+	MDB_page *sp, *xp;
+	char *base;
+	indx_t delta, nsize, len, ptr;
+	int i;
+
+	node = NODEPTR(mp, indx);
+	sp = (MDB_page *)NODEDATA(node);
+	delta = SIZELEFT(sp);
+	nsize = NODEDSZ(node) - delta;
+
+	/* Prepare to shift upward, set len = length(subpage part to shift) */
+	if (IS_LEAF2(sp)) {
+		len = nsize;
+		if (nsize & 1)
+			return;		/* do not make the node uneven-sized */
+	} else {
+		xp = (MDB_page *)((char *)sp + delta); /* destination subpage */
+		for (i = NUMKEYS(sp); --i >= 0; )
+			xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
+		len = PAGEHDRSZ;
+	}
+	sp->mp_upper = sp->mp_lower;
+	COPY_PGNO(sp->mp_pgno, mp->mp_pgno);
+	SETDSZ(node, nsize);
+
+	/* Shift <lower nodes...initial part of subpage> upward */
+	base = (char *)mp + mp->mp_upper + PAGEBASE;
+	memmove(base + delta, base, (char *)sp + len - base);
+
+	ptr = mp->mp_ptrs[indx];
+	for (i = NUMKEYS(mp); --i >= 0; ) {
+		if (mp->mp_ptrs[i] <= ptr)
+			mp->mp_ptrs[i] += delta;
+	}
+	mp->mp_upper += delta;
+}
+
+/** Initial setup of a sorted-dups cursor.
+ * Sorted duplicates are implemented as a sub-database for the given key.
+ * The duplicate data items are actually keys of the sub-database.
+ * Operations on the duplicate data items are performed using a sub-cursor
+ * initialized when the sub-database is first accessed. This function does
+ * the preliminary setup of the sub-cursor, filling in the fields that
+ * depend only on the parent DB.
+ * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
+ */
+static void
+mdb_xcursor_init0(MDB_cursor *mc)
+{
+	MDB_xcursor *mx = mc->mc_xcursor;
+
+	mx->mx_cursor.mc_xcursor = NULL;
+	mx->mx_cursor.mc_txn = mc->mc_txn;
+	mx->mx_cursor.mc_db = &mx->mx_db;
+	mx->mx_cursor.mc_dbx = &mx->mx_dbx;
+	mx->mx_cursor.mc_dbi = mc->mc_dbi;
+	mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
+	mx->mx_cursor.mc_snum = 0;
+	mx->mx_cursor.mc_top = 0;
+#ifdef MDB_VL32
+	mx->mx_cursor.mc_ovpg = 0;
+#endif
+	mx->mx_cursor.mc_flags = C_SUB | (mc->mc_flags & (C_ORIG_RDONLY|C_WRITEMAP));
+	mx->mx_dbx.md_name.mv_size = 0;
+	mx->mx_dbx.md_name.mv_data = NULL;
+	mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
+	mx->mx_dbx.md_dcmp = NULL;
+	mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
+}
+
+/** Final setup of a sorted-dups cursor.
+ *	Sets up the fields that depend on the data from the main cursor.
+ * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
+ * @param[in] node The data containing the #MDB_db record for the
+ * sorted-dup database.
+ */
+static void
+mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
+{
+	MDB_xcursor *mx = mc->mc_xcursor;
+
+	mx->mx_cursor.mc_flags &= C_SUB|C_ORIG_RDONLY|C_WRITEMAP;
+	if (node->mn_flags & F_SUBDATA) {
+		memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
+		mx->mx_cursor.mc_pg[0] = 0;
+		mx->mx_cursor.mc_snum = 0;
+		mx->mx_cursor.mc_top = 0;
+	} else {
+		MDB_page *fp = NODEDATA(node);
+		mx->mx_db.md_pad = 0;
+		mx->mx_db.md_flags = 0;
+		mx->mx_db.md_depth = 1;
+		mx->mx_db.md_branch_pages = 0;
+		mx->mx_db.md_leaf_pages = 1;
+		mx->mx_db.md_overflow_pages = 0;
+		mx->mx_db.md_entries = NUMKEYS(fp);
+		COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
+		mx->mx_cursor.mc_snum = 1;
+		mx->mx_cursor.mc_top = 0;
+		mx->mx_cursor.mc_flags |= C_INITIALIZED;
+		mx->mx_cursor.mc_pg[0] = fp;
+		mx->mx_cursor.mc_ki[0] = 0;
+		if (mc->mc_db->md_flags & MDB_DUPFIXED) {
+			mx->mx_db.md_flags = MDB_DUPFIXED;
+			mx->mx_db.md_pad = fp->mp_pad;
+			if (mc->mc_db->md_flags & MDB_INTEGERDUP)
+				mx->mx_db.md_flags |= MDB_INTEGERKEY;
+		}
+	}
+	DPRINTF(("Sub-db -%u root page %"Y"u", mx->mx_cursor.mc_dbi,
+		mx->mx_db.md_root));
+	mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
+#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)
+	if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(mdb_size_t))
+		mx->mx_dbx.md_cmp = mdb_cmp_clong;
+#endif
+}
+
+
+/** Fixup a sorted-dups cursor due to underlying update.
+ *	Sets up some fields that depend on the data from the main cursor.
+ *	Almost the same as init1, but skips initialization steps if the
+ *	xcursor had already been used.
+ * @param[in] mc The main cursor whose sorted-dups cursor is to be fixed up.
+ * @param[in] src_mx The xcursor of an up-to-date cursor.
+ * @param[in] new_dupdata True if converting from a non-#F_DUPDATA item.
+ */
+static void
+mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int new_dupdata)
+{
+	MDB_xcursor *mx = mc->mc_xcursor;
+
+	if (new_dupdata) {
+		mx->mx_cursor.mc_snum = 1;
+		mx->mx_cursor.mc_top = 0;
+		mx->mx_cursor.mc_flags |= C_INITIALIZED;
+		mx->mx_cursor.mc_ki[0] = 0;
+		mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
+#if UINT_MAX < SIZE_MAX
+		mx->mx_dbx.md_cmp = src_mx->mx_dbx.md_cmp;
+#endif
+	} else if (!(mx->mx_cursor.mc_flags & C_INITIALIZED)) {
+		return;
+	}
+	mx->mx_db = src_mx->mx_db;
+	mx->mx_cursor.mc_pg[0] = src_mx->mx_cursor.mc_pg[0];
+	DPRINTF(("Sub-db -%u root page %"Y"u", mx->mx_cursor.mc_dbi,
+		mx->mx_db.md_root));
+}
+
+/** Initialize a cursor for a given transaction and database. */
+static void
+mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
+{
+	mc->mc_next = NULL;
+	mc->mc_backup = NULL;
+	mc->mc_dbi = dbi;
+	mc->mc_txn = txn;
+	mc->mc_db = &txn->mt_dbs[dbi];
+	mc->mc_dbx = &txn->mt_dbxs[dbi];
+	mc->mc_dbflag = &txn->mt_dbflags[dbi];
+	mc->mc_snum = 0;
+	mc->mc_top = 0;
+	mc->mc_pg[0] = 0;
+	mc->mc_ki[0] = 0;
+#ifdef MDB_VL32
+	mc->mc_ovpg = 0;
+#endif
+	mc->mc_flags = txn->mt_flags & (C_ORIG_RDONLY|C_WRITEMAP);
+	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
+		mdb_tassert(txn, mx != NULL);
+		mc->mc_xcursor = mx;
+		mdb_xcursor_init0(mc);
+	} else {
+		mc->mc_xcursor = NULL;
+	}
+	if (*mc->mc_dbflag & DB_STALE) {
+		mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
+	}
+}
+
+int
+mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
+{
+	MDB_cursor	*mc;
+	size_t size = sizeof(MDB_cursor);
+
+	if (!ret || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
+		return EINVAL;
+
+	if (txn->mt_flags & MDB_TXN_BLOCKED)
+		return MDB_BAD_TXN;
+
+	if (dbi == FREE_DBI && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
+		return EINVAL;
+
+	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
+		size += sizeof(MDB_xcursor);
+
+	if ((mc = malloc(size)) != NULL) {
+		mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));
+		if (txn->mt_cursors) {
+			mc->mc_next = txn->mt_cursors[dbi];
+			txn->mt_cursors[dbi] = mc;
+			mc->mc_flags |= C_UNTRACK;
+		}
+	} else {
+		return ENOMEM;
+	}
+
+	*ret = mc;
+
+	return MDB_SUCCESS;
+}
+
+int
+mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
+{
+	if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi, DB_VALID))
+		return EINVAL;
+
+	if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
+		return EINVAL;
+
+	if (txn->mt_flags & MDB_TXN_BLOCKED)
+		return MDB_BAD_TXN;
+
+	mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
+	return MDB_SUCCESS;
+}
+
+/* Return the count of duplicate data items for the current key */
+int
+mdb_cursor_count(MDB_cursor *mc, mdb_size_t *countp)
+{
+	MDB_node	*leaf;
+
+	if (mc == NULL || countp == NULL)
+		return EINVAL;
+
+	if (mc->mc_xcursor == NULL)
+		return MDB_INCOMPATIBLE;
+
+	if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
+		return MDB_BAD_TXN;
+
+	if (!(mc->mc_flags & C_INITIALIZED))
+		return EINVAL;
+
+	if (!mc->mc_snum || (mc->mc_flags & C_EOF))
+		return MDB_NOTFOUND;
+
+	leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+	if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+		*countp = 1;
+	} else {
+		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
+			return EINVAL;
+
+		*countp = mc->mc_xcursor->mx_db.md_entries;
+	}
+	return MDB_SUCCESS;
+}
+
+void
+mdb_cursor_close(MDB_cursor *mc)
+{
+	if (mc && !mc->mc_backup) {
+		/* remove from txn, if tracked */
+		if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {
+			MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
+			while (*prev && *prev != mc) prev = &(*prev)->mc_next;
+			if (*prev == mc)
+				*prev = mc->mc_next;
+		}
+		free(mc);
+	}
+}
+
+MDB_txn *
+mdb_cursor_txn(MDB_cursor *mc)
+{
+	if (!mc) return NULL;
+	return mc->mc_txn;
+}
+
+MDB_dbi
+mdb_cursor_dbi(MDB_cursor *mc)
+{
+	return mc->mc_dbi;
+}
+
+/** Replace the key for a branch node with a new key.
+ * @param[in] mc Cursor pointing to the node to operate on.
+ * @param[in] key The new key to use.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_update_key(MDB_cursor *mc, MDB_val *key)
+{
+	MDB_page		*mp;
+	MDB_node		*node;
+	char			*base;
+	size_t			 len;
+	int				 delta, ksize, oksize;
+	indx_t			 ptr, i, numkeys, indx;
+	DKBUF;
+
+	indx = mc->mc_ki[mc->mc_top];
+	mp = mc->mc_pg[mc->mc_top];
+	node = NODEPTR(mp, indx);
+	ptr = mp->mp_ptrs[indx];
+#if MDB_DEBUG
+	{
+		MDB_val	k2;
+		char kbuf2[DKBUF_MAXKEYSIZE*2+1];
+		k2.mv_data = NODEKEY(node);
+		k2.mv_size = node->mn_ksize;
+		DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Y"u",
+			indx, ptr,
+			mdb_dkey(&k2, kbuf2),
+			DKEY(key),
+			mp->mp_pgno));
+	}
+#endif
+
+	/* Sizes must be 2-byte aligned. */
+	ksize = EVEN(key->mv_size);
+	oksize = EVEN(node->mn_ksize);
+	delta = ksize - oksize;
+
+	/* Shift node contents if EVEN(key length) changed. */
+	if (delta) {
+		if (delta > 0 && SIZELEFT(mp) < delta) {
+			pgno_t pgno;
+			/* not enough space left, do a delete and split */
+			DPRINTF(("Not enough room, delta = %d, splitting...", delta));
+			pgno = NODEPGNO(node);
+			mdb_node_del(mc, 0);
+			return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);
+		}
+
+		numkeys = NUMKEYS(mp);
+		for (i = 0; i < numkeys; i++) {
+			if (mp->mp_ptrs[i] <= ptr)
+				mp->mp_ptrs[i] -= delta;
+		}
+
+		base = (char *)mp + mp->mp_upper + PAGEBASE;
+		len = ptr - mp->mp_upper + NODESIZE;
+		memmove(base - delta, base, len);
+		mp->mp_upper -= delta;
+
+		node = NODEPTR(mp, indx);
+	}
+
+	/* But even if no shift was needed, update ksize */
+	if (node->mn_ksize != key->mv_size)
+		node->mn_ksize = key->mv_size;
+
+	if (key->mv_size)
+		memcpy(NODEKEY(node), key->mv_data, key->mv_size);
+
+	return MDB_SUCCESS;
+}
+
+static void
+mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
+
+/** Perform \b act while tracking temporary cursor \b mn */
+#define WITH_CURSOR_TRACKING(mn, act) do { \
+	MDB_cursor dummy, *tracked, **tp = &(mn).mc_txn->mt_cursors[mn.mc_dbi]; \
+	if ((mn).mc_flags & C_SUB) { \
+		dummy.mc_flags =  C_INITIALIZED; \
+		dummy.mc_xcursor = (MDB_xcursor *)&(mn);	\
+		tracked = &dummy; \
+	} else { \
+		tracked = &(mn); \
+	} \
+	tracked->mc_next = *tp; \
+	*tp = tracked; \
+	{ act; } \
+	*tp = tracked->mc_next; \
+} while (0)
+
+/** Move a node from csrc to cdst.
+ */
+static int
+mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft)
+{
+	MDB_node		*srcnode;
+	MDB_val		 key, data;
+	pgno_t	srcpg;
+	MDB_cursor mn;
+	int			 rc;
+	unsigned short flags;
+
+	DKBUF;
+
+	/* Mark src and dst as dirty. */
+	if ((rc = mdb_page_touch(csrc)) ||
+	    (rc = mdb_page_touch(cdst)))
+		return rc;
+
+	if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
+		key.mv_size = csrc->mc_db->md_pad;
+		key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
+		data.mv_size = 0;
+		data.mv_data = NULL;
+		srcpg = 0;
+		flags = 0;
+	} else {
+		srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
+		mdb_cassert(csrc, !((size_t)srcnode & 1));
+		srcpg = NODEPGNO(srcnode);
+		flags = srcnode->mn_flags;
+		if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
+			unsigned int snum = csrc->mc_snum;
+			MDB_node *s2;
+			/* must find the lowest key below src */
+			rc = mdb_page_search_lowest(csrc);
+			if (rc)
+				return rc;
+			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
+				key.mv_size = csrc->mc_db->md_pad;
+				key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
+			} else {
+				s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
+				key.mv_size = NODEKSZ(s2);
+				key.mv_data = NODEKEY(s2);
+			}
+			csrc->mc_snum = snum--;
+			csrc->mc_top = snum;
+		} else {
+			key.mv_size = NODEKSZ(srcnode);
+			key.mv_data = NODEKEY(srcnode);
+		}
+		data.mv_size = NODEDSZ(srcnode);
+		data.mv_data = NODEDATA(srcnode);
+	}
+	mn.mc_xcursor = NULL;
+	if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
+		unsigned int snum = cdst->mc_snum;
+		MDB_node *s2;
+		MDB_val bkey;
+		/* must find the lowest key below dst */
+		mdb_cursor_copy(cdst, &mn);
+		rc = mdb_page_search_lowest(&mn);
+		if (rc)
+			return rc;
+		if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
+			bkey.mv_size = mn.mc_db->md_pad;
+			bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size);
+		} else {
+			s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
+			bkey.mv_size = NODEKSZ(s2);
+			bkey.mv_data = NODEKEY(s2);
+		}
+		mn.mc_snum = snum--;
+		mn.mc_top = snum;
+		mn.mc_ki[snum] = 0;
+		rc = mdb_update_key(&mn, &bkey);
+		if (rc)
+			return rc;
+	}
+
+	DPRINTF(("moving %s node %u [%s] on page %"Y"u to node %u on page %"Y"u",
+	    IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
+	    csrc->mc_ki[csrc->mc_top],
+		DKEY(&key),
+	    csrc->mc_pg[csrc->mc_top]->mp_pgno,
+	    cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));
+
+	/* Add the node to the destination page.
+	 */
+	rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
+	if (rc != MDB_SUCCESS)
+		return rc;
+
+	/* Delete the node from the source page.
+	 */
+	mdb_node_del(csrc, key.mv_size);
+
+	{
+		/* Adjust other cursors pointing to mp */
+		MDB_cursor *m2, *m3;
+		MDB_dbi dbi = csrc->mc_dbi;
+		MDB_page *mpd, *mps;
+
+		mps = csrc->mc_pg[csrc->mc_top];
+		/* If we're adding on the left, bump others up */
+		if (fromleft) {
+			mpd = cdst->mc_pg[csrc->mc_top];
+			for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+				if (csrc->mc_flags & C_SUB)
+					m3 = &m2->mc_xcursor->mx_cursor;
+				else
+					m3 = m2;
+				if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
+					continue;
+				if (m3 != cdst &&
+					m3->mc_pg[csrc->mc_top] == mpd &&
+					m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) {
+					m3->mc_ki[csrc->mc_top]++;
+				}
+				if (m3 !=csrc &&
+					m3->mc_pg[csrc->mc_top] == mps &&
+					m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) {
+					m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
+					m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
+					m3->mc_ki[csrc->mc_top-1]++;
+				}
+				if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
+					IS_LEAF(mps)) {
+					MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);
+					if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
+						m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
+				}
+			}
+		} else
+		/* Adding on the right, bump others down */
+		{
+			for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+				if (csrc->mc_flags & C_SUB)
+					m3 = &m2->mc_xcursor->mx_cursor;
+				else
+					m3 = m2;
+				if (m3 == csrc) continue;
+				if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
+					continue;
+				if (m3->mc_pg[csrc->mc_top] == mps) {
+					if (!m3->mc_ki[csrc->mc_top]) {
+						m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
+						m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
+						m3->mc_ki[csrc->mc_top-1]--;
+					} else {
+						m3->mc_ki[csrc->mc_top]--;
+					}
+					if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
+						IS_LEAF(mps)) {
+						MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);
+						if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
+							m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
+					}
+				}
+			}
+		}
+	}
+
+	/* Update the parent separators.
+	 */
+	if (csrc->mc_ki[csrc->mc_top] == 0) {
+		if (csrc->mc_ki[csrc->mc_top-1] != 0) {
+			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
+				key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
+			} else {
+				srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
+				key.mv_size = NODEKSZ(srcnode);
+				key.mv_data = NODEKEY(srcnode);
+			}
+			DPRINTF(("update separator for source page %"Y"u to [%s]",
+				csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
+			mdb_cursor_copy(csrc, &mn);
+			mn.mc_snum--;
+			mn.mc_top--;
+			/* We want mdb_rebalance to find mn when doing fixups */
+			WITH_CURSOR_TRACKING(mn,
+				rc = mdb_update_key(&mn, &key));
+			if (rc)
+				return rc;
+		}
+		if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
+			MDB_val	 nullkey;
+			indx_t	ix = csrc->mc_ki[csrc->mc_top];
+			nullkey.mv_size = 0;
+			csrc->mc_ki[csrc->mc_top] = 0;
+			rc = mdb_update_key(csrc, &nullkey);
+			csrc->mc_ki[csrc->mc_top] = ix;
+			mdb_cassert(csrc, rc == MDB_SUCCESS);
+		}
+	}
+
+	if (cdst->mc_ki[cdst->mc_top] == 0) {
+		if (cdst->mc_ki[cdst->mc_top-1] != 0) {
+			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
+				key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
+			} else {
+				srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
+				key.mv_size = NODEKSZ(srcnode);
+				key.mv_data = NODEKEY(srcnode);
+			}
+			DPRINTF(("update separator for destination page %"Y"u to [%s]",
+				cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
+			mdb_cursor_copy(cdst, &mn);
+			mn.mc_snum--;
+			mn.mc_top--;
+			/* We want mdb_rebalance to find mn when doing fixups */
+			WITH_CURSOR_TRACKING(mn,
+				rc = mdb_update_key(&mn, &key));
+			if (rc)
+				return rc;
+		}
+		if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
+			MDB_val	 nullkey;
+			indx_t	ix = cdst->mc_ki[cdst->mc_top];
+			nullkey.mv_size = 0;
+			cdst->mc_ki[cdst->mc_top] = 0;
+			rc = mdb_update_key(cdst, &nullkey);
+			cdst->mc_ki[cdst->mc_top] = ix;
+			mdb_cassert(cdst, rc == MDB_SUCCESS);
+		}
+	}
+
+	return MDB_SUCCESS;
+}
+
+/** Merge one page into another.
+ *  The nodes from the page pointed to by \b csrc will
+ *	be copied to the page pointed to by \b cdst and then
+ *	the \b csrc page will be freed.
+ * @param[in] csrc Cursor pointing to the source page.
+ * @param[in] cdst Cursor pointing to the destination page.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
+{
+	MDB_page	*psrc, *pdst;
+	MDB_node	*srcnode;
+	MDB_val		 key, data;
+	unsigned	 nkeys;
+	int			 rc;
+	indx_t		 i, j;
+
+	psrc = csrc->mc_pg[csrc->mc_top];
+	pdst = cdst->mc_pg[cdst->mc_top];
+
+	DPRINTF(("merging page %"Y"u into %"Y"u", psrc->mp_pgno, pdst->mp_pgno));
+
+	mdb_cassert(csrc, csrc->mc_snum > 1);	/* can't merge root page */
+	mdb_cassert(csrc, cdst->mc_snum > 1);
+
+	/* Mark dst as dirty. */
+	if ((rc = mdb_page_touch(cdst)))
+		return rc;
+
+	/* get dst page again now that we've touched it. */
+	pdst = cdst->mc_pg[cdst->mc_top];
+
+	/* Move all nodes from src to dst.
+	 */
+	j = nkeys = NUMKEYS(pdst);
+	if (IS_LEAF2(psrc)) {
+		key.mv_size = csrc->mc_db->md_pad;
+		key.mv_data = METADATA(psrc);
+		for (i = 0; i < NUMKEYS(psrc); i++, j++) {
+			rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
+			if (rc != MDB_SUCCESS)
+				return rc;
+			key.mv_data = (char *)key.mv_data + key.mv_size;
+		}
+	} else {
+		for (i = 0; i < NUMKEYS(psrc); i++, j++) {
+			srcnode = NODEPTR(psrc, i);
+			if (i == 0 && IS_BRANCH(psrc)) {
+				MDB_cursor mn;
+				MDB_node *s2;
+				mdb_cursor_copy(csrc, &mn);
+				mn.mc_xcursor = NULL;
+				/* must find the lowest key below src */
+				rc = mdb_page_search_lowest(&mn);
+				if (rc)
+					return rc;
+				if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
+					key.mv_size = mn.mc_db->md_pad;
+					key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size);
+				} else {
+					s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
+					key.mv_size = NODEKSZ(s2);
+					key.mv_data = NODEKEY(s2);
+				}
+			} else {
+				key.mv_size = srcnode->mn_ksize;
+				key.mv_data = NODEKEY(srcnode);
+			}
+
+			data.mv_size = NODEDSZ(srcnode);
+			data.mv_data = NODEDATA(srcnode);
+			rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
+			if (rc != MDB_SUCCESS)
+				return rc;
+		}
+	}
+
+	DPRINTF(("dst page %"Y"u now has %u keys (%.1f%% filled)",
+	    pdst->mp_pgno, NUMKEYS(pdst),
+		(float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));
+
+	/* Unlink the src page from parent and add to free list.
+	 */
+	csrc->mc_top--;
+	mdb_node_del(csrc, 0);
+	if (csrc->mc_ki[csrc->mc_top] == 0) {
+		key.mv_size = 0;
+		rc = mdb_update_key(csrc, &key);
+		if (rc) {
+			csrc->mc_top++;
+			return rc;
+		}
+	}
+	csrc->mc_top++;
+
+	psrc = csrc->mc_pg[csrc->mc_top];
+	/* If not operating on FreeDB, allow this page to be reused
+	 * in this txn. Otherwise just add to free list.
+	 */
+	rc = mdb_page_loose(csrc, psrc);
+	if (rc)
+		return rc;
+	if (IS_LEAF(psrc))
+		csrc->mc_db->md_leaf_pages--;
+	else
+		csrc->mc_db->md_branch_pages--;
+	{
+		/* Adjust other cursors pointing to mp */
+		MDB_cursor *m2, *m3;
+		MDB_dbi dbi = csrc->mc_dbi;
+		unsigned int top = csrc->mc_top;
+
+		for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+			if (csrc->mc_flags & C_SUB)
+				m3 = &m2->mc_xcursor->mx_cursor;
+			else
+				m3 = m2;
+			if (m3 == csrc) continue;
+			if (m3->mc_snum < csrc->mc_snum) continue;
+			if (m3->mc_pg[top] == psrc) {
+				m3->mc_pg[top] = pdst;
+				m3->mc_ki[top] += nkeys;
+				m3->mc_ki[top-1] = cdst->mc_ki[top-1];
+			} else if (m3->mc_pg[top-1] == csrc->mc_pg[top-1] &&
+				m3->mc_ki[top-1] > csrc->mc_ki[top-1]) {
+				m3->mc_ki[top-1]--;
+			}
+			if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
+				IS_LEAF(psrc)) {
+				MDB_node *node = NODEPTR(m3->mc_pg[top], m3->mc_ki[top]);
+				if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
+					m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
+			}
+		}
+	}
+	{
+		unsigned int snum = cdst->mc_snum;
+		uint16_t depth = cdst->mc_db->md_depth;
+		mdb_cursor_pop(cdst);
+		rc = mdb_rebalance(cdst);
+		/* Did the tree height change? */
+		if (depth != cdst->mc_db->md_depth)
+			snum += cdst->mc_db->md_depth - depth;
+		cdst->mc_snum = snum;
+		cdst->mc_top = snum-1;
+	}
+	return rc;
+}
+
+/** Copy the contents of a cursor.
+ * @param[in] csrc The cursor to copy from.
+ * @param[out] cdst The cursor to copy to.
+ */
+static void
+mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
+{
+	unsigned int i;
+
+	cdst->mc_txn = csrc->mc_txn;
+	cdst->mc_dbi = csrc->mc_dbi;
+	cdst->mc_db  = csrc->mc_db;
+	cdst->mc_dbx = csrc->mc_dbx;
+	cdst->mc_snum = csrc->mc_snum;
+	cdst->mc_top = csrc->mc_top;
+	cdst->mc_flags = csrc->mc_flags;
+#ifdef MDB_VL32
+	cdst->mc_ovpg = csrc->mc_ovpg;
+#endif
+
+	for (i=0; i<csrc->mc_snum; i++) {
+		cdst->mc_pg[i] = csrc->mc_pg[i];
+		cdst->mc_ki[i] = csrc->mc_ki[i];
+	}
+}
+
+/** Rebalance the tree after a delete operation.
+ * @param[in] mc Cursor pointing to the page where rebalancing
+ * should begin.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_rebalance(MDB_cursor *mc)
+{
+	MDB_node	*node;
+	int rc, fromleft;
+	unsigned int ptop, minkeys, thresh;
+	MDB_cursor	mn;
+	indx_t oldki;
+
+	if (IS_BRANCH(mc->mc_pg[mc->mc_top])) {
+		minkeys = 2;
+		thresh = 1;
+	} else {
+		minkeys = 1;
+		thresh = FILL_THRESHOLD;
+	}
+	DPRINTF(("rebalancing %s page %"Y"u (has %u keys, %.1f%% full)",
+	    IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
+	    mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),
+		(float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
+
+	if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= thresh &&
+		NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
+		DPRINTF(("no need to rebalance page %"Y"u, above fill threshold",
+		    mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
+		return MDB_SUCCESS;
+	}
+
+	if (mc->mc_snum < 2) {
+		MDB_page *mp = mc->mc_pg[0];
+		if (IS_SUBP(mp)) {
+			DPUTS("Can't rebalance a subpage, ignoring");
+			return MDB_SUCCESS;
+		}
+		if (NUMKEYS(mp) == 0) {
+			DPUTS("tree is completely empty");
+			mc->mc_db->md_root = P_INVALID;
+			mc->mc_db->md_depth = 0;
+			mc->mc_db->md_leaf_pages = 0;
+			rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
+			if (rc)
+				return rc;
+			/* Adjust cursors pointing to mp */
+			mc->mc_snum = 0;
+			mc->mc_top = 0;
+			mc->mc_flags &= ~C_INITIALIZED;
+			{
+				MDB_cursor *m2, *m3;
+				MDB_dbi dbi = mc->mc_dbi;
+
+				for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+					if (mc->mc_flags & C_SUB)
+						m3 = &m2->mc_xcursor->mx_cursor;
+					else
+						m3 = m2;
+					if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))
+						continue;
+					if (m3->mc_pg[0] == mp) {
+						m3->mc_snum = 0;
+						m3->mc_top = 0;
+						m3->mc_flags &= ~C_INITIALIZED;
+					}
+				}
+			}
+		} else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
+			int i;
+			DPUTS("collapsing root page!");
+			rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
+			if (rc)
+				return rc;
+			mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
+			rc = mdb_page_get(mc, mc->mc_db->md_root, &mc->mc_pg[0], NULL);
+			if (rc)
+				return rc;
+			mc->mc_db->md_depth--;
+			mc->mc_db->md_branch_pages--;
+			mc->mc_ki[0] = mc->mc_ki[1];
+			for (i = 1; i<mc->mc_db->md_depth; i++) {
+				mc->mc_pg[i] = mc->mc_pg[i+1];
+				mc->mc_ki[i] = mc->mc_ki[i+1];
+			}
+			{
+				/* Adjust other cursors pointing to mp */
+				MDB_cursor *m2, *m3;
+				MDB_dbi dbi = mc->mc_dbi;
+
+				for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+					if (mc->mc_flags & C_SUB)
+						m3 = &m2->mc_xcursor->mx_cursor;
+					else
+						m3 = m2;
+					if (m3 == mc) continue;
+					if (!(m3->mc_flags & C_INITIALIZED))
+						continue;
+					if (m3->mc_pg[0] == mp) {
+						for (i=0; i<mc->mc_db->md_depth; i++) {
+							m3->mc_pg[i] = m3->mc_pg[i+1];
+							m3->mc_ki[i] = m3->mc_ki[i+1];
+						}
+						m3->mc_snum--;
+						m3->mc_top--;
+					}
+				}
+			}
+		} else
+			DPUTS("root page doesn't need rebalancing");
+		return MDB_SUCCESS;
+	}
+
+	/* The parent (branch page) must have at least 2 pointers,
+	 * otherwise the tree is invalid.
+	 */
+	ptop = mc->mc_top-1;
+	mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1);
+
+	/* Leaf page fill factor is below the threshold.
+	 * Try to move keys from left or right neighbor, or
+	 * merge with a neighbor page.
+	 */
+
+	/* Find neighbors.
+	 */
+	mdb_cursor_copy(mc, &mn);
+	mn.mc_xcursor = NULL;
+
+	oldki = mc->mc_ki[mc->mc_top];
+	if (mc->mc_ki[ptop] == 0) {
+		/* We're the leftmost leaf in our parent.
+		 */
+		DPUTS("reading right neighbor");
+		mn.mc_ki[ptop]++;
+		node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
+		rc = mdb_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL);
+		if (rc)
+			return rc;
+		mn.mc_ki[mn.mc_top] = 0;
+		mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
+		fromleft = 0;
+	} else {
+		/* There is at least one neighbor to the left.
+		 */
+		DPUTS("reading left neighbor");
+		mn.mc_ki[ptop]--;
+		node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
+		rc = mdb_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL);
+		if (rc)
+			return rc;
+		mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
+		mc->mc_ki[mc->mc_top] = 0;
+		fromleft = 1;
+	}
+
+	DPRINTF(("found neighbor page %"Y"u (%u keys, %.1f%% full)",
+	    mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
+		(float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
+
+	/* If the neighbor page is above threshold and has enough keys,
+	 * move one key from it. Otherwise we should try to merge them.
+	 * (A branch page must never have less than 2 keys.)
+	 */
+	if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
+		rc = mdb_node_move(&mn, mc, fromleft);
+		if (fromleft) {
+			/* if we inserted on left, bump position up */
+			oldki++;
+		}
+	} else {
+		if (!fromleft) {
+			rc = mdb_page_merge(&mn, mc);
+		} else {
+			oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
+			mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
+			/* We want mdb_rebalance to find mn when doing fixups */
+			WITH_CURSOR_TRACKING(mn,
+				rc = mdb_page_merge(mc, &mn));
+			mdb_cursor_copy(&mn, mc);
+		}
+		mc->mc_flags &= ~C_EOF;
+	}
+	mc->mc_ki[mc->mc_top] = oldki;
+	return rc;
+}
+
+/** Complete a delete operation started by #mdb_cursor_del(). */
+static int
+mdb_cursor_del0(MDB_cursor *mc)
+{
+	int rc;
+	MDB_page *mp;
+	indx_t ki;
+	unsigned int nkeys;
+	MDB_cursor *m2, *m3;
+	MDB_dbi dbi = mc->mc_dbi;
+
+	ki = mc->mc_ki[mc->mc_top];
+	mp = mc->mc_pg[mc->mc_top];
+	mdb_node_del(mc, mc->mc_db->md_pad);
+	mc->mc_db->md_entries--;
+	{
+		/* Adjust other cursors pointing to mp */
+		for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+			m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
+			if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
+				continue;
+			if (m3 == mc || m3->mc_snum < mc->mc_snum)
+				continue;
+			if (m3->mc_pg[mc->mc_top] == mp) {
+				if (m3->mc_ki[mc->mc_top] == ki) {
+					m3->mc_flags |= C_DEL;
+				} else if (m3->mc_ki[mc->mc_top] > ki) {
+					m3->mc_ki[mc->mc_top]--;
+				}
+				if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
+					MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);
+					if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
+						m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
+				}
+			}
+		}
+	}
+	rc = mdb_rebalance(mc);
+
+	if (rc == MDB_SUCCESS) {
+		/* DB is totally empty now, just bail out.
+		 * Other cursors adjustments were already done
+		 * by mdb_rebalance and aren't needed here.
+		 */
+		if (!mc->mc_snum)
+			return rc;
+
+		mp = mc->mc_pg[mc->mc_top];
+		nkeys = NUMKEYS(mp);
+
+		/* Adjust other cursors pointing to mp */
+		for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {
+			m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
+			if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
+				continue;
+			if (m3->mc_snum < mc->mc_snum)
+				continue;
+			if (m3->mc_pg[mc->mc_top] == mp) {
+				/* if m3 points past last node in page, find next sibling */
+				if (m3->mc_ki[mc->mc_top] >= mc->mc_ki[mc->mc_top]) {
+					if (m3->mc_ki[mc->mc_top] >= nkeys) {
+						rc = mdb_cursor_sibling(m3, 1);
+						if (rc == MDB_NOTFOUND) {
+							m3->mc_flags |= C_EOF;
+							rc = MDB_SUCCESS;
+							continue;
+						}
+					}
+					if (mc->mc_db->md_flags & MDB_DUPSORT) {
+						MDB_node *node = NODEPTR(m3->mc_pg[m3->mc_top], m3->mc_ki[m3->mc_top]);
+						if (node->mn_flags & F_DUPDATA) {
+							mdb_xcursor_init1(m3, node);
+							m3->mc_xcursor->mx_cursor.mc_flags |= C_DEL;
+						}
+					}
+				}
+			}
+		}
+		mc->mc_flags |= C_DEL;
+	}
+
+	if (rc)
+		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
+	return rc;
+}
+
+int
+mdb_del(MDB_txn *txn, MDB_dbi dbi,
+    MDB_val *key, MDB_val *data)
+{
+	if (!key || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
+		return EINVAL;
+
+	if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
+		return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
+
+	if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
+		/* must ignore any data */
+		data = NULL;
+	}
+
+	return mdb_del0(txn, dbi, key, data, 0);
+}
+
+static int
+mdb_del0(MDB_txn *txn, MDB_dbi dbi,
+	MDB_val *key, MDB_val *data, unsigned flags)
+{
+	MDB_cursor mc;
+	MDB_xcursor mx;
+	MDB_cursor_op op;
+	MDB_val rdata, *xdata;
+	int		 rc, exact = 0;
+	DKBUF;
+
+	DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
+
+	mdb_cursor_init(&mc, txn, dbi, &mx);
+
+	if (data) {
+		op = MDB_GET_BOTH;
+		rdata = *data;
+		xdata = &rdata;
+	} else {
+		op = MDB_SET;
+		xdata = NULL;
+		flags |= MDB_NODUPDATA;
+	}
+	rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
+	if (rc == 0) {
+		/* let mdb_page_split know about this cursor if needed:
+		 * delete will trigger a rebalance; if it needs to move
+		 * a node from one page to another, it will have to
+		 * update the parent's separator key(s). If the new sepkey
+		 * is larger than the current one, the parent page may
+		 * run out of space, triggering a split. We need this
+		 * cursor to be consistent until the end of the rebalance.
+		 */
+		mc.mc_flags |= C_UNTRACK;
+		mc.mc_next = txn->mt_cursors[dbi];
+		txn->mt_cursors[dbi] = &mc;
+		rc = mdb_cursor_del(&mc, flags);
+		txn->mt_cursors[dbi] = mc.mc_next;
+	}
+	return rc;
+}
+
+/** Split a page and insert a new node.
+ * @param[in,out] mc Cursor pointing to the page and desired insertion index.
+ * The cursor will be updated to point to the actual page and index where
+ * the node got inserted after the split.
+ * @param[in] newkey The key for the newly inserted node.
+ * @param[in] newdata The data for the newly inserted node.
+ * @param[in] newpgno The page number, if the new node is a branch node.
+ * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
+	unsigned int nflags)
+{
+	unsigned int flags;
+	int		 rc = MDB_SUCCESS, new_root = 0, did_split = 0;
+	indx_t		 newindx;
+	pgno_t		 pgno = 0;
+	int	 i, j, split_indx, nkeys, pmax;
+	MDB_env 	*env = mc->mc_txn->mt_env;
+	MDB_node	*node;
+	MDB_val	 sepkey, rkey, xdata, *rdata = &xdata;
+	MDB_page	*copy = NULL;
+	MDB_page	*mp, *rp, *pp;
+	int ptop;
+	MDB_cursor	mn;
+	DKBUF;
+
+	mp = mc->mc_pg[mc->mc_top];
+	newindx = mc->mc_ki[mc->mc_top];
+	nkeys = NUMKEYS(mp);
+
+	DPRINTF(("-----> splitting %s page %"Y"u and adding [%s] at index %i/%i",
+	    IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
+	    DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));
+
+	/* Create a right sibling. */
+	if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
+		return rc;
+	rp->mp_pad = mp->mp_pad;
+	DPRINTF(("new right sibling: page %"Y"u", rp->mp_pgno));
+
+	/* Usually when splitting the root page, the cursor
+	 * height is 1. But when called from mdb_update_key,
+	 * the cursor height may be greater because it walks
+	 * up the stack while finding the branch slot to update.
+	 */
+	if (mc->mc_top < 1) {
+		if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
+			goto done;
+		/* shift current top to make room for new parent */
+		for (i=mc->mc_snum; i>0; i--) {
+			mc->mc_pg[i] = mc->mc_pg[i-1];
+			mc->mc_ki[i] = mc->mc_ki[i-1];
+		}
+		mc->mc_pg[0] = pp;
+		mc->mc_ki[0] = 0;
+		mc->mc_db->md_root = pp->mp_pgno;
+		DPRINTF(("root split! new root = %"Y"u", pp->mp_pgno));
+		new_root = mc->mc_db->md_depth++;
+
+		/* Add left (implicit) pointer. */
+		if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
+			/* undo the pre-push */
+			mc->mc_pg[0] = mc->mc_pg[1];
+			mc->mc_ki[0] = mc->mc_ki[1];
+			mc->mc_db->md_root = mp->mp_pgno;
+			mc->mc_db->md_depth--;
+			goto done;
+		}
+		mc->mc_snum++;
+		mc->mc_top++;
+		ptop = 0;
+	} else {
+		ptop = mc->mc_top-1;
+		DPRINTF(("parent branch page is %"Y"u", mc->mc_pg[ptop]->mp_pgno));
+	}
+
+	mdb_cursor_copy(mc, &mn);
+	mn.mc_xcursor = NULL;
+	mn.mc_pg[mn.mc_top] = rp;
+	mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
+
+	if (nflags & MDB_APPEND) {
+		mn.mc_ki[mn.mc_top] = 0;
+		sepkey = *newkey;
+		split_indx = newindx;
+		nkeys = 0;
+	} else {
+
+		split_indx = (nkeys+1) / 2;
+
+		if (IS_LEAF2(rp)) {
+			char *split, *ins;
+			int x;
+			unsigned int lsize, rsize, ksize;
+			/* Move half of the keys to the right sibling */
+			x = mc->mc_ki[mc->mc_top] - split_indx;
+			ksize = mc->mc_db->md_pad;
+			split = LEAF2KEY(mp, split_indx, ksize);
+			rsize = (nkeys - split_indx) * ksize;
+			lsize = (nkeys - split_indx) * sizeof(indx_t);
+			mp->mp_lower -= lsize;
+			rp->mp_lower += lsize;
+			mp->mp_upper += rsize - lsize;
+			rp->mp_upper -= rsize - lsize;
+			sepkey.mv_size = ksize;
+			if (newindx == split_indx) {
+				sepkey.mv_data = newkey->mv_data;
+			} else {
+				sepkey.mv_data = split;
+			}
+			if (x<0) {
+				ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
+				memcpy(rp->mp_ptrs, split, rsize);
+				sepkey.mv_data = rp->mp_ptrs;
+				memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
+				memcpy(ins, newkey->mv_data, ksize);
+				mp->mp_lower += sizeof(indx_t);
+				mp->mp_upper -= ksize - sizeof(indx_t);
+			} else {
+				if (x)
+					memcpy(rp->mp_ptrs, split, x * ksize);
+				ins = LEAF2KEY(rp, x, ksize);
+				memcpy(ins, newkey->mv_data, ksize);
+				memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
+				rp->mp_lower += sizeof(indx_t);
+				rp->mp_upper -= ksize - sizeof(indx_t);
+				mc->mc_ki[mc->mc_top] = x;
+			}
+		} else {
+			int psize, nsize, k;
+			/* Maximum free space in an empty page */
+			pmax = env->me_psize - PAGEHDRSZ;
+			if (IS_LEAF(mp))
+				nsize = mdb_leaf_size(env, newkey, newdata);
+			else
+				nsize = mdb_branch_size(env, newkey);
+			nsize = EVEN(nsize);
+
+			/* grab a page to hold a temporary copy */
+			copy = mdb_page_malloc(mc->mc_txn, 1);
+			if (copy == NULL) {
+				rc = ENOMEM;
+				goto done;
+			}
+			copy->mp_pgno  = mp->mp_pgno;
+			copy->mp_flags = mp->mp_flags;
+			copy->mp_lower = (PAGEHDRSZ-PAGEBASE);
+			copy->mp_upper = env->me_psize - PAGEBASE;
+
+			/* prepare to insert */
+			for (i=0, j=0; i<nkeys; i++) {
+				if (i == newindx) {
+					copy->mp_ptrs[j++] = 0;
+				}
+				copy->mp_ptrs[j++] = mp->mp_ptrs[i];
+			}
+
+			/* When items are relatively large the split point needs
+			 * to be checked, because being off-by-one will make the
+			 * difference between success or failure in mdb_node_add.
+			 *
+			 * It's also relevant if a page happens to be laid out
+			 * such that one half of its nodes are all "small" and
+			 * the other half of its nodes are "large." If the new
+			 * item is also "large" and falls on the half with
+			 * "large" nodes, it also may not fit.
+			 *
+			 * As a final tweak, if the new item goes on the last
+			 * spot on the page (and thus, onto the new page), bias
+			 * the split so the new page is emptier than the old page.
+			 * This yields better packing during sequential inserts.
+			 */
+			if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) {
+				/* Find split point */
+				psize = 0;
+				if (newindx <= split_indx || newindx >= nkeys) {
+					i = 0; j = 1;
+					k = newindx >= nkeys ? nkeys : split_indx+1+IS_LEAF(mp);
+				} else {
+					i = nkeys; j = -1;
+					k = split_indx-1;
+				}
+				for (; i!=k; i+=j) {
+					if (i == newindx) {
+						psize += nsize;
+						node = NULL;
+					} else {
+						node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
+						psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
+						if (IS_LEAF(mp)) {
+							if (F_ISSET(node->mn_flags, F_BIGDATA))
+								psize += sizeof(pgno_t);
+							else
+								psize += NODEDSZ(node);
+						}
+						psize = EVEN(psize);
+					}
+					if (psize > pmax || i == k-j) {
+						split_indx = i + (j<0);
+						break;
+					}
+				}
+			}
+			if (split_indx == newindx) {
+				sepkey.mv_size = newkey->mv_size;
+				sepkey.mv_data = newkey->mv_data;
+			} else {
+				node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE);
+				sepkey.mv_size = node->mn_ksize;
+				sepkey.mv_data = NODEKEY(node);
+			}
+		}
+	}
+
+	DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));
+
+	/* Copy separator key to the parent.
+	 */
+	if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
+		int snum = mc->mc_snum;
+		mn.mc_snum--;
+		mn.mc_top--;
+		did_split = 1;
+		/* We want other splits to find mn when doing fixups */
+		WITH_CURSOR_TRACKING(mn,
+			rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0));
+		if (rc)
+			goto done;
+
+		/* root split? */
+		if (mc->mc_snum > snum) {
+			ptop++;
+		}
+		/* Right page might now have changed parent.
+		 * Check if left page also changed parent.
+		 */
+		if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
+		    mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
+			for (i=0; i<ptop; i++) {
+				mc->mc_pg[i] = mn.mc_pg[i];
+				mc->mc_ki[i] = mn.mc_ki[i];
+			}
+			mc->mc_pg[ptop] = mn.mc_pg[ptop];
+			if (mn.mc_ki[ptop]) {
+				mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
+			} else {
+				/* find right page's left sibling */
+				mc->mc_ki[ptop] = mn.mc_ki[ptop];
+				mdb_cursor_sibling(mc, 0);
+			}
+		}
+	} else {
+		mn.mc_top--;
+		rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
+		mn.mc_top++;
+	}
+	if (rc != MDB_SUCCESS) {
+		goto done;
+	}
+	if (nflags & MDB_APPEND) {
+		mc->mc_pg[mc->mc_top] = rp;
+		mc->mc_ki[mc->mc_top] = 0;
+		rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
+		if (rc)
+			goto done;
+		for (i=0; i<mc->mc_top; i++)
+			mc->mc_ki[i] = mn.mc_ki[i];
+	} else if (!IS_LEAF2(mp)) {
+		/* Move nodes */
+		mc->mc_pg[mc->mc_top] = rp;
+		i = split_indx;
+		j = 0;
+		do {
+			if (i == newindx) {
+				rkey.mv_data = newkey->mv_data;
+				rkey.mv_size = newkey->mv_size;
+				if (IS_LEAF(mp)) {
+					rdata = newdata;
+				} else
+					pgno = newpgno;
+				flags = nflags;
+				/* Update index for the new key. */
+				mc->mc_ki[mc->mc_top] = j;
+			} else {
+				node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
+				rkey.mv_data = NODEKEY(node);
+				rkey.mv_size = node->mn_ksize;
+				if (IS_LEAF(mp)) {
+					xdata.mv_data = NODEDATA(node);
+					xdata.mv_size = NODEDSZ(node);
+					rdata = &xdata;
+				} else
+					pgno = NODEPGNO(node);
+				flags = node->mn_flags;
+			}
+
+			if (!IS_LEAF(mp) && j == 0) {
+				/* First branch index doesn't need key data. */
+				rkey.mv_size = 0;
+			}
+
+			rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
+			if (rc)
+				goto done;
+			if (i == nkeys) {
+				i = 0;
+				j = 0;
+				mc->mc_pg[mc->mc_top] = copy;
+			} else {
+				i++;
+				j++;
+			}
+		} while (i != split_indx);
+
+		nkeys = NUMKEYS(copy);
+		for (i=0; i<nkeys; i++)
+			mp->mp_ptrs[i] = copy->mp_ptrs[i];
+		mp->mp_lower = copy->mp_lower;
+		mp->mp_upper = copy->mp_upper;
+		memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
+			env->me_psize - copy->mp_upper - PAGEBASE);
+
+		/* reset back to original page */
+		if (newindx < split_indx) {
+			mc->mc_pg[mc->mc_top] = mp;
+		} else {
+			mc->mc_pg[mc->mc_top] = rp;
+			mc->mc_ki[ptop]++;
+			/* Make sure mc_ki is still valid.
+			 */
+			if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
+				mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
+				for (i=0; i<=ptop; i++) {
+					mc->mc_pg[i] = mn.mc_pg[i];
+					mc->mc_ki[i] = mn.mc_ki[i];
+				}
+			}
+		}
+		if (nflags & MDB_RESERVE) {
+			node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+			if (!(node->mn_flags & F_BIGDATA))
+				newdata->mv_data = NODEDATA(node);
+		}
+	} else {
+		if (newindx >= split_indx) {
+			mc->mc_pg[mc->mc_top] = rp;
+			mc->mc_ki[ptop]++;
+			/* Make sure mc_ki is still valid.
+			 */
+			if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
+				mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
+				for (i=0; i<=ptop; i++) {
+					mc->mc_pg[i] = mn.mc_pg[i];
+					mc->mc_ki[i] = mn.mc_ki[i];
+				}
+			}
+		}
+	}
+
+	{
+		/* Adjust other cursors pointing to mp */
+		MDB_cursor *m2, *m3;
+		MDB_dbi dbi = mc->mc_dbi;
+		nkeys = NUMKEYS(mp);
+
+		for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+			if (mc->mc_flags & C_SUB)
+				m3 = &m2->mc_xcursor->mx_cursor;
+			else
+				m3 = m2;
+			if (m3 == mc)
+				continue;
+			if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
+				continue;
+			if (new_root) {
+				int k;
+				/* sub cursors may be on different DB */
+				if (m3->mc_pg[0] != mp)
+					continue;
+				/* root split */
+				for (k=new_root; k>=0; k--) {
+					m3->mc_ki[k+1] = m3->mc_ki[k];
+					m3->mc_pg[k+1] = m3->mc_pg[k];
+				}
+				if (m3->mc_ki[0] >= nkeys) {
+					m3->mc_ki[0] = 1;
+				} else {
+					m3->mc_ki[0] = 0;
+				}
+				m3->mc_pg[0] = mc->mc_pg[0];
+				m3->mc_snum++;
+				m3->mc_top++;
+			}
+			if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
+				if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
+					m3->mc_ki[mc->mc_top]++;
+				if (m3->mc_ki[mc->mc_top] >= nkeys) {
+					m3->mc_pg[mc->mc_top] = rp;
+					m3->mc_ki[mc->mc_top] -= nkeys;
+					for (i=0; i<mc->mc_top; i++) {
+						m3->mc_ki[i] = mn.mc_ki[i];
+						m3->mc_pg[i] = mn.mc_pg[i];
+					}
+				}
+			} else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
+				m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
+				m3->mc_ki[ptop]++;
+			}
+			if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
+				IS_LEAF(mp)) {
+				MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);
+				if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
+					m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
+			}
+		}
+	}
+	DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
+
+done:
+	if (copy)					/* tmp page */
+		mdb_page_free(env, copy);
+	if (rc)
+		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
+	return rc;
+}
+
+int
+mdb_put(MDB_txn *txn, MDB_dbi dbi,
+    MDB_val *key, MDB_val *data, unsigned int flags)
+{
+	MDB_cursor mc;
+	MDB_xcursor mx;
+	int rc;
+
+	if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
+		return EINVAL;
+
+	if (flags & ~(MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP))
+		return EINVAL;
+
+	if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
+		return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
+
+	mdb_cursor_init(&mc, txn, dbi, &mx);
+	mc.mc_next = txn->mt_cursors[dbi];
+	txn->mt_cursors[dbi] = &mc;
+	rc = mdb_cursor_put(&mc, key, data, flags);
+	txn->mt_cursors[dbi] = mc.mc_next;
+	return rc;
+}
+
+#ifndef MDB_WBUF
+#define MDB_WBUF	(1024*1024)
+#endif
+
+	/** State needed for a compacting copy. */
+typedef struct mdb_copy {
+	pthread_mutex_t mc_mutex;
+	pthread_cond_t mc_cond;
+	char *mc_wbuf[2];
+	char *mc_over[2];
+	MDB_env *mc_env;
+	MDB_txn *mc_txn;
+	int mc_wlen[2];
+	int mc_olen[2];
+	pgno_t mc_next_pgno;
+	HANDLE mc_fd;
+	int mc_status;
+	volatile int mc_new;
+	int mc_toggle;
+
+} mdb_copy;
+
+	/** Dedicated writer thread for compacting copy. */
+static THREAD_RET ESECT CALL_CONV
+mdb_env_copythr(void *arg)
+{
+	mdb_copy *my = arg;
+	char *ptr;
+	int toggle = 0, wsize, rc;
+#ifdef _WIN32
+	DWORD len;
+#define DO_WRITE(rc, fd, ptr, w2, len)	rc = WriteFile(fd, ptr, w2, &len, NULL)
+#else
+	int len;
+#define DO_WRITE(rc, fd, ptr, w2, len)	len = write(fd, ptr, w2); rc = (len >= 0)
+#endif
+
+	pthread_mutex_lock(&my->mc_mutex);
+	my->mc_new = 0;
+	pthread_cond_signal(&my->mc_cond);
+	for(;;) {
+		while (!my->mc_new)
+			pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
+		if (my->mc_new < 0) {
+			my->mc_new = 0;
+			break;
+		}
+		my->mc_new = 0;
+		wsize = my->mc_wlen[toggle];
+		ptr = my->mc_wbuf[toggle];
+again:
+		while (wsize > 0) {
+			DO_WRITE(rc, my->mc_fd, ptr, wsize, len);
+			if (!rc) {
+				rc = ErrCode();
+				break;
+			} else if (len > 0) {
+				rc = MDB_SUCCESS;
+				ptr += len;
+				wsize -= len;
+				continue;
+			} else {
+				rc = EIO;
+				break;
+			}
+		}
+		if (rc) {
+			my->mc_status = rc;
+			break;
+		}
+		/* If there's an overflow page tail, write it too */
+		if (my->mc_olen[toggle]) {
+			wsize = my->mc_olen[toggle];
+			ptr = my->mc_over[toggle];
+			my->mc_olen[toggle] = 0;
+			goto again;
+		}
+		my->mc_wlen[toggle] = 0;
+		toggle ^= 1;
+		pthread_cond_signal(&my->mc_cond);
+	}
+	pthread_cond_signal(&my->mc_cond);
+	pthread_mutex_unlock(&my->mc_mutex);
+	return (THREAD_RET)0;
+#undef DO_WRITE
+}
+
+	/** Tell the writer thread there's a buffer ready to write */
+static int ESECT
+mdb_env_cthr_toggle(mdb_copy *my, int st)
+{
+	int toggle = my->mc_toggle ^ 1;
+	pthread_mutex_lock(&my->mc_mutex);
+	if (my->mc_status) {
+		pthread_mutex_unlock(&my->mc_mutex);
+		return my->mc_status;
+	}
+	while (my->mc_new == 1)
+		pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
+	my->mc_new = st;
+	my->mc_toggle = toggle;
+	pthread_cond_signal(&my->mc_cond);
+	pthread_mutex_unlock(&my->mc_mutex);
+	return 0;
+}
+
+	/** Depth-first tree traversal for compacting copy. */
+static int ESECT
+mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
+{
+	MDB_cursor mc = {0};
+	MDB_node *ni;
+	MDB_page *mo, *mp, *leaf;
+	char *buf, *ptr;
+	int rc, toggle;
+	unsigned int i;
+
+	/* Empty DB, nothing to do */
+	if (*pg == P_INVALID)
+		return MDB_SUCCESS;
+
+	mc.mc_snum = 1;
+	mc.mc_txn = my->mc_txn;
+	mc.mc_flags = my->mc_txn->mt_flags & (C_ORIG_RDONLY|C_WRITEMAP);
+
+	rc = mdb_page_get(&mc, *pg, &mc.mc_pg[0], NULL);
+	if (rc)
+		return rc;
+	rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);
+	if (rc)
+		return rc;
+
+	/* Make cursor pages writable */
+	buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum);
+	if (buf == NULL)
+		return ENOMEM;
+
+	for (i=0; i<mc.mc_top; i++) {
+		mdb_page_copy((MDB_page *)ptr, mc.mc_pg[i], my->mc_env->me_psize);
+		mc.mc_pg[i] = (MDB_page *)ptr;
+		ptr += my->mc_env->me_psize;
+	}
+
+	/* This is writable space for a leaf page. Usually not needed. */
+	leaf = (MDB_page *)ptr;
+
+	toggle = my->mc_toggle;
+	while (mc.mc_snum > 0) {
+		unsigned n;
+		mp = mc.mc_pg[mc.mc_top];
+		n = NUMKEYS(mp);
+
+		if (IS_LEAF(mp)) {
+			if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {
+				for (i=0; i<n; i++) {
+					ni = NODEPTR(mp, i);
+					if (ni->mn_flags & F_BIGDATA) {
+						MDB_page *omp;
+						pgno_t pg;
+
+						/* Need writable leaf */
+						if (mp != leaf) {
+							mc.mc_pg[mc.mc_top] = leaf;
+							mdb_page_copy(leaf, mp, my->mc_env->me_psize);
+							mp = leaf;
+							ni = NODEPTR(mp, i);
+						}
+
+						memcpy(&pg, NODEDATA(ni), sizeof(pg));
+						rc = mdb_page_get(&mc, pg, &omp, NULL);
+						if (rc)
+							goto done;
+						if (my->mc_wlen[toggle] >= MDB_WBUF) {
+							rc = mdb_env_cthr_toggle(my, 1);
+							if (rc)
+								goto done;
+							toggle = my->mc_toggle;
+						}
+						mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
+						memcpy(mo, omp, my->mc_env->me_psize);
+						mo->mp_pgno = my->mc_next_pgno;
+						my->mc_next_pgno += omp->mp_pages;
+						my->mc_wlen[toggle] += my->mc_env->me_psize;
+						if (omp->mp_pages > 1) {
+							my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1);
+							my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;
+							rc = mdb_env_cthr_toggle(my, 1);
+							if (rc)
+								goto done;
+							toggle = my->mc_toggle;
+						}
+						memcpy(NODEDATA(ni), &mo->mp_pgno, sizeof(pgno_t));
+					} else if (ni->mn_flags & F_SUBDATA) {
+						MDB_db db;
+
+						/* Need writable leaf */
+						if (mp != leaf) {
+							mc.mc_pg[mc.mc_top] = leaf;
+							mdb_page_copy(leaf, mp, my->mc_env->me_psize);
+							mp = leaf;
+							ni = NODEPTR(mp, i);
+						}
+
+						memcpy(&db, NODEDATA(ni), sizeof(db));
+						my->mc_toggle = toggle;
+						rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA);
+						if (rc)
+							goto done;
+						toggle = my->mc_toggle;
+						memcpy(NODEDATA(ni), &db, sizeof(db));
+					}
+				}
+			}
+		} else {
+			mc.mc_ki[mc.mc_top]++;
+			if (mc.mc_ki[mc.mc_top] < n) {
+				pgno_t pg;
+again:
+				ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]);
+				pg = NODEPGNO(ni);
+				rc = mdb_page_get(&mc, pg, &mp, NULL);
+				if (rc)
+					goto done;
+				mc.mc_top++;
+				mc.mc_snum++;
+				mc.mc_ki[mc.mc_top] = 0;
+				if (IS_BRANCH(mp)) {
+					/* Whenever we advance to a sibling branch page,
+					 * we must proceed all the way down to its first leaf.
+					 */
+					mdb_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize);
+					goto again;
+				} else
+					mc.mc_pg[mc.mc_top] = mp;
+				continue;
+			}
+		}
+		if (my->mc_wlen[toggle] >= MDB_WBUF) {
+			rc = mdb_env_cthr_toggle(my, 1);
+			if (rc)
+				goto done;
+			toggle = my->mc_toggle;
+		}
+		mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
+		mdb_page_copy(mo, mp, my->mc_env->me_psize);
+		mo->mp_pgno = my->mc_next_pgno++;
+		my->mc_wlen[toggle] += my->mc_env->me_psize;
+		if (mc.mc_top) {
+			/* Update parent if there is one */
+			ni = NODEPTR(mc.mc_pg[mc.mc_top-1], mc.mc_ki[mc.mc_top-1]);
+			SETPGNO(ni, mo->mp_pgno);
+			mdb_cursor_pop(&mc);
+		} else {
+			/* Otherwise we're done */
+			*pg = mo->mp_pgno;
+			break;
+		}
+	}
+done:
+	free(buf);
+	return rc;
+}
+
+	/** Copy environment with compaction. */
+static int ESECT
+mdb_env_copyfd1(MDB_env *env, HANDLE fd)
+{
+	MDB_meta *mm;
+	MDB_page *mp;
+	mdb_copy my;
+	MDB_txn *txn = NULL;
+	pthread_t thr;
+	int rc;
+
+#ifdef _WIN32
+	my.mc_mutex = CreateMutex(NULL, FALSE, NULL);
+	my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL);
+	my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_os_psize);
+	if (my.mc_wbuf[0] == NULL)
+		return errno;
+#else
+	pthread_mutex_init(&my.mc_mutex, NULL);
+	pthread_cond_init(&my.mc_cond, NULL);
+#ifdef HAVE_MEMALIGN
+	my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2);
+	if (my.mc_wbuf[0] == NULL)
+		return errno;
+#else
+	rc = posix_memalign((void **)&my.mc_wbuf[0], env->me_os_psize, MDB_WBUF*2);
+	if (rc)
+		return rc;
+#endif
+#endif
+	memset(my.mc_wbuf[0], 0, MDB_WBUF*2);
+	my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;
+	my.mc_wlen[0] = 0;
+	my.mc_wlen[1] = 0;
+	my.mc_olen[0] = 0;
+	my.mc_olen[1] = 0;
+	my.mc_next_pgno = NUM_METAS;
+	my.mc_status = 0;
+	my.mc_new = 1;
+	my.mc_toggle = 0;
+	my.mc_env = env;
+	my.mc_fd = fd;
+	THREAD_CREATE(thr, mdb_env_copythr, &my);
+
+	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
+	if (rc)
+		return rc;
+
+	mp = (MDB_page *)my.mc_wbuf[0];
+	memset(mp, 0, NUM_METAS * env->me_psize);
+	mp->mp_pgno = 0;
+	mp->mp_flags = P_META;
+	mm = (MDB_meta *)METADATA(mp);
+	mdb_env_init_meta0(env, mm);
+	mm->mm_address = env->me_metas[0]->mm_address;
+
+	mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize);
+	mp->mp_pgno = 1;
+	mp->mp_flags = P_META;
+	*(MDB_meta *)METADATA(mp) = *mm;
+	mm = (MDB_meta *)METADATA(mp);
+
+	/* Count the number of free pages, subtract from lastpg to find
+	 * number of active pages
+	 */
+	{
+		MDB_ID freecount = 0;
+		MDB_cursor mc;
+		MDB_val key, data;
+		mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
+		while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
+			freecount += *(MDB_ID *)data.mv_data;
+		freecount += txn->mt_dbs[FREE_DBI].md_branch_pages +
+			txn->mt_dbs[FREE_DBI].md_leaf_pages +
+			txn->mt_dbs[FREE_DBI].md_overflow_pages;
+
+		/* Set metapage 1 */
+		mm->mm_last_pg = txn->mt_next_pgno - freecount - 1;
+		mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
+		if (mm->mm_last_pg > NUM_METAS-1) {
+			mm->mm_dbs[MAIN_DBI].md_root = mm->mm_last_pg;
+			mm->mm_txnid = 1;
+		} else {
+			mm->mm_dbs[MAIN_DBI].md_root = P_INVALID;
+		}
+	}
+	my.mc_wlen[0] = env->me_psize * NUM_METAS;
+	my.mc_txn = txn;
+	pthread_mutex_lock(&my.mc_mutex);
+	while(my.mc_new)
+		pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
+	pthread_mutex_unlock(&my.mc_mutex);
+	rc = mdb_env_cwalk(&my, &txn->mt_dbs[MAIN_DBI].md_root, 0);
+	if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle])
+		rc = mdb_env_cthr_toggle(&my, 1);
+	mdb_env_cthr_toggle(&my, -1);
+	pthread_mutex_lock(&my.mc_mutex);
+	while(my.mc_new)
+		pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
+	pthread_mutex_unlock(&my.mc_mutex);
+	THREAD_FINISH(thr);
+
+	mdb_txn_abort(txn);
+#ifdef _WIN32
+	CloseHandle(my.mc_cond);
+	CloseHandle(my.mc_mutex);
+	_aligned_free(my.mc_wbuf[0]);
+#else
+	pthread_cond_destroy(&my.mc_cond);
+	pthread_mutex_destroy(&my.mc_mutex);
+	free(my.mc_wbuf[0]);
+#endif
+	return rc;
+}
+
+	/** Copy environment as-is. */
+static int ESECT
+mdb_env_copyfd0(MDB_env *env, HANDLE fd)
+{
+	MDB_txn *txn = NULL;
+	mdb_mutexref_t wmutex = NULL;
+	int rc;
+	mdb_size_t wsize, w3;
+	char *ptr;
+#ifdef _WIN32
+	DWORD len, w2;
+#define DO_WRITE(rc, fd, ptr, w2, len)	rc = WriteFile(fd, ptr, w2, &len, NULL)
+#else
+	ssize_t len;
+	size_t w2;
+#define DO_WRITE(rc, fd, ptr, w2, len)	len = write(fd, ptr, w2); rc = (len >= 0)
+#endif
+
+	/* Do the lock/unlock of the reader mutex before starting the
+	 * write txn.  Otherwise other read txns could block writers.
+	 */
+	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
+	if (rc)
+		return rc;
+
+	if (env->me_txns) {
+		/* We must start the actual read txn after blocking writers */
+		mdb_txn_end(txn, MDB_END_RESET_TMP);
+
+		/* Temporarily block writers until we snapshot the meta pages */
+		wmutex = env->me_wmutex;
+		if (LOCK_MUTEX(rc, env, wmutex))
+			goto leave;
+
+		rc = mdb_txn_renew0(txn);
+		if (rc) {
+			UNLOCK_MUTEX(wmutex);
+			goto leave;
+		}
+	}
+
+	wsize = env->me_psize * NUM_METAS;
+	ptr = env->me_map;
+	w2 = wsize;
+	while (w2 > 0) {
+		DO_WRITE(rc, fd, ptr, w2, len);
+		if (!rc) {
+			rc = ErrCode();
+			break;
+		} else if (len > 0) {
+			rc = MDB_SUCCESS;
+			ptr += len;
+			w2 -= len;
+			continue;
+		} else {
+			/* Non-blocking or async handles are not supported */
+			rc = EIO;
+			break;
+		}
+	}
+	if (wmutex)
+		UNLOCK_MUTEX(wmutex);
+
+	if (rc)
+		goto leave;
+
+	w3 = txn->mt_next_pgno * env->me_psize;
+	{
+		mdb_size_t fsize = 0;
+		if ((rc = mdb_fsize(env->me_fd, &fsize)))
+			goto leave;
+		if (w3 > fsize)
+			w3 = fsize;
+	}
+	wsize = w3 - wsize;
+	while (wsize > 0) {
+		if (wsize > MAX_WRITE)
+			w2 = MAX_WRITE;
+		else
+			w2 = wsize;
+		DO_WRITE(rc, fd, ptr, w2, len);
+		if (!rc) {
+			rc = ErrCode();
+			break;
+		} else if (len > 0) {
+			rc = MDB_SUCCESS;
+			ptr += len;
+			wsize -= len;
+			continue;
+		} else {
+			rc = EIO;
+			break;
+		}
+	}
+
+leave:
+	mdb_txn_abort(txn);
+	return rc;
+}
+
+int ESECT
+mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags)
+{
+	if (flags & MDB_CP_COMPACT)
+		return mdb_env_copyfd1(env, fd);
+	else
+		return mdb_env_copyfd0(env, fd);
+}
+
+int ESECT
+mdb_env_copyfd(MDB_env *env, HANDLE fd)
+{
+	return mdb_env_copyfd2(env, fd, 0);
+}
+
+int ESECT
+mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)
+{
+	int rc, len;
+	char *lpath;
+	HANDLE newfd = INVALID_HANDLE_VALUE;
+#ifdef _WIN32
+	wchar_t *wpath;
+#endif
+
+	if (env->me_flags & MDB_NOSUBDIR) {
+		lpath = (char *)path;
+	} else {
+		len = strlen(path);
+		len += sizeof(DATANAME);
+		lpath = malloc(len);
+		if (!lpath)
+			return ENOMEM;
+		sprintf(lpath, "%s" DATANAME, path);
+	}
+
+	/* The destination path must exist, but the destination file must not.
+	 * We don't want the OS to cache the writes, since the source data is
+	 * already in the OS cache.
+	 */
+#ifdef _WIN32
+	rc = utf8_to_utf16(lpath, -1, &wpath, NULL);
+	if (rc)
+		goto leave;
+	newfd = CreateFileW(wpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
+				FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
+	free(wpath);
+#else
+	newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
+#endif
+	if (newfd == INVALID_HANDLE_VALUE) {
+		rc = ErrCode();
+		goto leave;
+	}
+
+	if (env->me_psize >= env->me_os_psize) {
+#ifdef O_DIRECT
+	/* Set O_DIRECT if the file system supports it */
+	if ((rc = fcntl(newfd, F_GETFL)) != -1)
+		(void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
+#endif
+#ifdef F_NOCACHE	/* __APPLE__ */
+	rc = fcntl(newfd, F_NOCACHE, 1);
+	if (rc) {
+		rc = ErrCode();
+		goto leave;
+	}
+#endif
+	}
+
+	rc = mdb_env_copyfd2(env, newfd, flags);
+
+leave:
+	if (!(env->me_flags & MDB_NOSUBDIR))
+		free(lpath);
+	if (newfd != INVALID_HANDLE_VALUE)
+		if (close(newfd) < 0 && rc == MDB_SUCCESS)
+			rc = ErrCode();
+
+	return rc;
+}
+
+int ESECT
+mdb_env_copy(MDB_env *env, const char *path)
+{
+	return mdb_env_copy2(env, path, 0);
+}
+
+int ESECT
+mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
+{
+	if (flag & ~CHANGEABLE)
+		return EINVAL;
+	if (onoff)
+		env->me_flags |= flag;
+	else
+		env->me_flags &= ~flag;
+	return MDB_SUCCESS;
+}
+
+int ESECT
+mdb_env_get_flags(MDB_env *env, unsigned int *arg)
+{
+	if (!env || !arg)
+		return EINVAL;
+
+	*arg = env->me_flags & (CHANGEABLE|CHANGELESS);
+	return MDB_SUCCESS;
+}
+
+int ESECT
+mdb_env_set_userctx(MDB_env *env, void *ctx)
+{
+	if (!env)
+		return EINVAL;
+	env->me_userctx = ctx;
+	return MDB_SUCCESS;
+}
+
+void * ESECT
+mdb_env_get_userctx(MDB_env *env)
+{
+	return env ? env->me_userctx : NULL;
+}
+
+int ESECT
+mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)
+{
+	if (!env)
+		return EINVAL;
+#ifndef NDEBUG
+	env->me_assert_func = func;
+#endif
+	return MDB_SUCCESS;
+}
+
+int ESECT
+mdb_env_get_path(MDB_env *env, const char **arg)
+{
+	if (!env || !arg)
+		return EINVAL;
+
+	*arg = env->me_path;
+	return MDB_SUCCESS;
+}
+
+int ESECT
+mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)
+{
+	if (!env || !arg)
+		return EINVAL;
+
+	*arg = env->me_fd;
+	return MDB_SUCCESS;
+}
+
+/** Common code for #mdb_stat() and #mdb_env_stat().
+ * @param[in] env the environment to operate in.
+ * @param[in] db the #MDB_db record containing the stats to return.
+ * @param[out] arg the address of an #MDB_stat structure to receive the stats.
+ * @return 0, this function always succeeds.
+ */
+static int ESECT
+mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
+{
+	arg->ms_psize = env->me_psize;
+	arg->ms_depth = db->md_depth;
+	arg->ms_branch_pages = db->md_branch_pages;
+	arg->ms_leaf_pages = db->md_leaf_pages;
+	arg->ms_overflow_pages = db->md_overflow_pages;
+	arg->ms_entries = db->md_entries;
+
+	return MDB_SUCCESS;
+}
+
+int ESECT
+mdb_env_stat(MDB_env *env, MDB_stat *arg)
+{
+	MDB_meta *meta;
+
+	if (env == NULL || arg == NULL)
+		return EINVAL;
+
+	meta = mdb_env_pick_meta(env);
+
+	return mdb_stat0(env, &meta->mm_dbs[MAIN_DBI], arg);
+}
+
+int ESECT
+mdb_env_info(MDB_env *env, MDB_envinfo *arg)
+{
+	MDB_meta *meta;
+
+	if (env == NULL || arg == NULL)
+		return EINVAL;
+
+	meta = mdb_env_pick_meta(env);
+	arg->me_mapaddr = meta->mm_address;
+	arg->me_last_pgno = meta->mm_last_pg;
+	arg->me_last_txnid = meta->mm_txnid;
+
+	arg->me_mapsize = env->me_mapsize;
+	arg->me_maxreaders = env->me_maxreaders;
+	arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : 0;
+	return MDB_SUCCESS;
+}
+
+/** Set the default comparison functions for a database.
+ * Called immediately after a database is opened to set the defaults.
+ * The user can then override them with #mdb_set_compare() or
+ * #mdb_set_dupsort().
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] dbi A database handle returned by #mdb_dbi_open()
+ */
+static void
+mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
+{
+	uint16_t f = txn->mt_dbs[dbi].md_flags;
+
+	txn->mt_dbxs[dbi].md_cmp =
+		(f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
+		(f & MDB_INTEGERKEY) ? mdb_cmp_cint  : mdb_cmp_memn;
+
+	txn->mt_dbxs[dbi].md_dcmp =
+		!(f & MDB_DUPSORT) ? 0 :
+		((f & MDB_INTEGERDUP)
+		 ? ((f & MDB_DUPFIXED)   ? mdb_cmp_int   : mdb_cmp_cint)
+		 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
+}
+
+int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
+{
+	MDB_val key, data;
+	MDB_dbi i;
+	MDB_cursor mc;
+	MDB_db dummy;
+	int rc, dbflag, exact;
+	unsigned int unused = 0, seq;
+	char *namedup;
+	size_t len;
+
+	if (flags & ~VALID_FLAGS)
+		return EINVAL;
+	if (txn->mt_flags & MDB_TXN_BLOCKED)
+		return MDB_BAD_TXN;
+
+	/* main DB? */
+	if (!name) {
+		*dbi = MAIN_DBI;
+		if (flags & PERSISTENT_FLAGS) {
+			uint16_t f2 = flags & PERSISTENT_FLAGS;
+			/* make sure flag changes get committed */
+			if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
+				txn->mt_dbs[MAIN_DBI].md_flags |= f2;
+				txn->mt_flags |= MDB_TXN_DIRTY;
+			}
+		}
+		mdb_default_cmp(txn, MAIN_DBI);
+		return MDB_SUCCESS;
+	}
+
+	if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
+		mdb_default_cmp(txn, MAIN_DBI);
+	}
+
+	/* Is the DB already open? */
+	len = strlen(name);
+	for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
+		if (!txn->mt_dbxs[i].md_name.mv_size) {
+			/* Remember this free slot */
+			if (!unused) unused = i;
+			continue;
+		}
+		if (len == txn->mt_dbxs[i].md_name.mv_size &&
+			!strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
+			*dbi = i;
+			return MDB_SUCCESS;
+		}
+	}
+
+	/* If no free slot and max hit, fail */
+	if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
+		return MDB_DBS_FULL;
+
+	/* Cannot mix named databases with some mainDB flags */
+	if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))
+		return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
+
+	/* Find the DB info */
+	dbflag = DB_NEW|DB_VALID|DB_USRVALID;
+	exact = 0;
+	key.mv_size = len;
+	key.mv_data = (void *)name;
+	mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
+	rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
+	if (rc == MDB_SUCCESS) {
+		/* make sure this is actually a DB */
+		MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
+		if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
+			return MDB_INCOMPATIBLE;
+	} else if (! (rc == MDB_NOTFOUND && (flags & MDB_CREATE))) {
+		return rc;
+	}
+
+	/* Done here so we cannot fail after creating a new DB */
+	if ((namedup = strdup(name)) == NULL)
+		return ENOMEM;
+
+	if (rc) {
+		/* MDB_NOTFOUND and MDB_CREATE: Create new DB */
+		data.mv_size = sizeof(MDB_db);
+		data.mv_data = &dummy;
+		memset(&dummy, 0, sizeof(dummy));
+		dummy.md_root = P_INVALID;
+		dummy.md_flags = flags & PERSISTENT_FLAGS;
+		rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
+		dbflag |= DB_DIRTY;
+	}
+
+	if (rc) {
+		free(namedup);
+	} else {
+		/* Got info, register DBI in this txn */
+		unsigned int slot = unused ? unused : txn->mt_numdbs;
+		txn->mt_dbxs[slot].md_name.mv_data = namedup;
+		txn->mt_dbxs[slot].md_name.mv_size = len;
+		txn->mt_dbxs[slot].md_rel = NULL;
+		txn->mt_dbflags[slot] = dbflag;
+		/* txn-> and env-> are the same in read txns, use
+		 * tmp variable to avoid undefined assignment
+		 */
+		seq = ++txn->mt_env->me_dbiseqs[slot];
+		txn->mt_dbiseqs[slot] = seq;
+
+		memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
+		*dbi = slot;
+		mdb_default_cmp(txn, slot);
+		if (!unused) {
+			txn->mt_numdbs++;
+		}
+	}
+
+	return rc;
+}
+
+int ESECT
+mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
+{
+	if (!arg || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
+		return EINVAL;
+
+	if (txn->mt_flags & MDB_TXN_BLOCKED)
+		return MDB_BAD_TXN;
+
+	if (txn->mt_dbflags[dbi] & DB_STALE) {
+		MDB_cursor mc;
+		MDB_xcursor mx;
+		/* Stale, must read the DB's root. cursor_init does it for us. */
+		mdb_cursor_init(&mc, txn, dbi, &mx);
+	}
+	return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
+}
+
+void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
+{
+	char *ptr;
+	if (dbi < CORE_DBS || dbi >= env->me_maxdbs)
+		return;
+	ptr = env->me_dbxs[dbi].md_name.mv_data;
+	/* If there was no name, this was already closed */
+	if (ptr) {
+		env->me_dbxs[dbi].md_name.mv_data = NULL;
+		env->me_dbxs[dbi].md_name.mv_size = 0;
+		env->me_dbflags[dbi] = 0;
+		env->me_dbiseqs[dbi]++;
+		free(ptr);
+	}
+}
+
+int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
+{
+	/* We could return the flags for the FREE_DBI too but what's the point? */
+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
+		return EINVAL;
+	*flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
+	return MDB_SUCCESS;
+}
+
+/** Add all the DB's pages to the free list.
+ * @param[in] mc Cursor on the DB to free.
+ * @param[in] subs non-Zero to check for sub-DBs in this DB.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_drop0(MDB_cursor *mc, int subs)
+{
+	int rc;
+
+	rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
+	if (rc == MDB_SUCCESS) {
+		MDB_txn *txn = mc->mc_txn;
+		MDB_node *ni;
+		MDB_cursor mx;
+		unsigned int i;
+
+		/* DUPSORT sub-DBs have no ovpages/DBs. Omit scanning leaves.
+		 * This also avoids any P_LEAF2 pages, which have no nodes.
+		 * Also if the DB doesn't have sub-DBs and has no overflow
+		 * pages, omit scanning leaves.
+		 */
+		if ((mc->mc_flags & C_SUB) ||
+			(!subs && !mc->mc_db->md_overflow_pages))
+			mdb_cursor_pop(mc);
+
+		mdb_cursor_copy(mc, &mx);
+#ifdef MDB_VL32
+		/* bump refcount for mx's pages */
+		for (i=0; i<mc->mc_snum; i++)
+			mdb_page_get(&mx, mc->mc_pg[i]->mp_pgno, &mx.mc_pg[i], NULL);
+#endif
+		while (mc->mc_snum > 0) {
+			MDB_page *mp = mc->mc_pg[mc->mc_top];
+			unsigned n = NUMKEYS(mp);
+			if (IS_LEAF(mp)) {
+				for (i=0; i<n; i++) {
+					ni = NODEPTR(mp, i);
+					if (ni->mn_flags & F_BIGDATA) {
+						MDB_page *omp;
+						pgno_t pg;
+						memcpy(&pg, NODEDATA(ni), sizeof(pg));
+						rc = mdb_page_get(mc, pg, &omp, NULL);
+						if (rc != 0)
+							goto done;
+						mdb_cassert(mc, IS_OVERFLOW(omp));
+						rc = mdb_midl_append_range(&txn->mt_free_pgs,
+							pg, omp->mp_pages);
+						if (rc)
+							goto done;
+						mc->mc_db->md_overflow_pages -= omp->mp_pages;
+						if (!mc->mc_db->md_overflow_pages && !subs)
+							break;
+					} else if (subs && (ni->mn_flags & F_SUBDATA)) {
+						mdb_xcursor_init1(mc, ni);
+						rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
+						if (rc)
+							goto done;
+					}
+				}
+				if (!subs && !mc->mc_db->md_overflow_pages)
+					goto pop;
+			} else {
+				if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
+					goto done;
+				for (i=0; i<n; i++) {
+					pgno_t pg;
+					ni = NODEPTR(mp, i);
+					pg = NODEPGNO(ni);
+					/* free it */
+					mdb_midl_xappend(txn->mt_free_pgs, pg);
+				}
+			}
+			if (!mc->mc_top)
+				break;
+			mc->mc_ki[mc->mc_top] = i;
+			rc = mdb_cursor_sibling(mc, 1);
+			if (rc) {
+				if (rc != MDB_NOTFOUND)
+					goto done;
+				/* no more siblings, go back to beginning
+				 * of previous level.
+				 */
+pop:
+				mdb_cursor_pop(mc);
+				mc->mc_ki[0] = 0;
+				for (i=1; i<mc->mc_snum; i++) {
+					mc->mc_ki[i] = 0;
+					mc->mc_pg[i] = mx.mc_pg[i];
+				}
+			}
+		}
+		/* free it */
+		rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
+done:
+		if (rc)
+			txn->mt_flags |= MDB_TXN_ERROR;
+#ifdef MDB_VL32
+		/* drop refcount for mx's pages */
+		mdb_cursor_unref(&mx);
+#endif
+	} else if (rc == MDB_NOTFOUND) {
+		rc = MDB_SUCCESS;
+	}
+	mc->mc_flags &= ~C_INITIALIZED;
+	return rc;
+}
+
+int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
+{
+	MDB_cursor *mc, *m2;
+	int rc;
+
+	if ((unsigned)del > 1 || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
+		return EINVAL;
+
+	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
+		return EACCES;
+
+	if (TXN_DBI_CHANGED(txn, dbi))
+		return MDB_BAD_DBI;
+
+	rc = mdb_cursor_open(txn, dbi, &mc);
+	if (rc)
+		return rc;
+
+	rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
+	/* Invalidate the dropped DB's cursors */
+	for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)
+		m2->mc_flags &= ~(C_INITIALIZED|C_EOF);
+	if (rc)
+		goto leave;
+
+	/* Can't delete the main DB */
+	if (del && dbi >= CORE_DBS) {
+		rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA);
+		if (!rc) {
+			txn->mt_dbflags[dbi] = DB_STALE;
+			mdb_dbi_close(txn->mt_env, dbi);
+		} else {
+			txn->mt_flags |= MDB_TXN_ERROR;
+		}
+	} else {
+		/* reset the DB record, mark it dirty */
+		txn->mt_dbflags[dbi] |= DB_DIRTY;
+		txn->mt_dbs[dbi].md_depth = 0;
+		txn->mt_dbs[dbi].md_branch_pages = 0;
+		txn->mt_dbs[dbi].md_leaf_pages = 0;
+		txn->mt_dbs[dbi].md_overflow_pages = 0;
+		txn->mt_dbs[dbi].md_entries = 0;
+		txn->mt_dbs[dbi].md_root = P_INVALID;
+
+		txn->mt_flags |= MDB_TXN_DIRTY;
+	}
+leave:
+	mdb_cursor_close(mc);
+	return rc;
+}
+
+int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
+{
+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
+		return EINVAL;
+
+	txn->mt_dbxs[dbi].md_cmp = cmp;
+	return MDB_SUCCESS;
+}
+
+int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
+{
+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
+		return EINVAL;
+
+	txn->mt_dbxs[dbi].md_dcmp = cmp;
+	return MDB_SUCCESS;
+}
+
+int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
+{
+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
+		return EINVAL;
+
+	txn->mt_dbxs[dbi].md_rel = rel;
+	return MDB_SUCCESS;
+}
+
+int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
+{
+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
+		return EINVAL;
+
+	txn->mt_dbxs[dbi].md_relctx = ctx;
+	return MDB_SUCCESS;
+}
+
+int ESECT
+mdb_env_get_maxkeysize(MDB_env *env)
+{
+	return ENV_MAXKEY(env);
+}
+
+int ESECT
+mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
+{
+	unsigned int i, rdrs;
+	MDB_reader *mr;
+	char buf[64];
+	int rc = 0, first = 1;
+
+	if (!env || !func)
+		return -1;
+	if (!env->me_txns) {
+		return func("(no reader locks)\n", ctx);
+	}
+	rdrs = env->me_txns->mti_numreaders;
+	mr = env->me_txns->mti_readers;
+	for (i=0; i<rdrs; i++) {
+		if (mr[i].mr_pid) {
+			txnid_t	txnid = mr[i].mr_txnid;
+			sprintf(buf, txnid == (txnid_t)-1 ?
+				"%10d %"Z"x -\n" : "%10d %"Z"x %"Y"u\n",
+				(int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);
+			if (first) {
+				first = 0;
+				rc = func("    pid     thread     txnid\n", ctx);
+				if (rc < 0)
+					break;
+			}
+			rc = func(buf, ctx);
+			if (rc < 0)
+				break;
+		}
+	}
+	if (first) {
+		rc = func("(no active readers)\n", ctx);
+	}
+	return rc;
+}
+
+/** Insert pid into list if not already present.
+ * return -1 if already present.
+ */
+static int ESECT
+mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
+{
+	/* binary search of pid in list */
+	unsigned base = 0;
+	unsigned cursor = 1;
+	int val = 0;
+	unsigned n = ids[0];
+
+	while( 0 < n ) {
+		unsigned pivot = n >> 1;
+		cursor = base + pivot + 1;
+		val = pid - ids[cursor];
+
+		if( val < 0 ) {
+			n = pivot;
+
+		} else if ( val > 0 ) {
+			base = cursor;
+			n -= pivot + 1;
+
+		} else {
+			/* found, so it's a duplicate */
+			return -1;
+		}
+	}
+
+	if( val > 0 ) {
+		++cursor;
+	}
+	ids[0]++;
+	for (n = ids[0]; n > cursor; n--)
+		ids[n] = ids[n-1];
+	ids[n] = pid;
+	return 0;
+}
+
+int ESECT
+mdb_reader_check(MDB_env *env, int *dead)
+{
+	if (!env)
+		return EINVAL;
+	if (dead)
+		*dead = 0;
+	return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS;
+}
+
+/** As #mdb_reader_check(). rlocked = <caller locked the reader mutex>. */
+static int ESECT
+mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
+{
+	mdb_mutexref_t rmutex = rlocked ? NULL : env->me_rmutex;
+	unsigned int i, j, rdrs;
+	MDB_reader *mr;
+	MDB_PID_T *pids, pid;
+	int rc = MDB_SUCCESS, count = 0;
+
+	rdrs = env->me_txns->mti_numreaders;
+	pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
+	if (!pids)
+		return ENOMEM;
+	pids[0] = 0;
+	mr = env->me_txns->mti_readers;
+	for (i=0; i<rdrs; i++) {
+		pid = mr[i].mr_pid;
+		if (pid && pid != env->me_pid) {
+			if (mdb_pid_insert(pids, pid) == 0) {
+				if (!mdb_reader_pid(env, Pidcheck, pid)) {
+					/* Stale reader found */
+					j = i;
+					if (rmutex) {
+						if ((rc = LOCK_MUTEX0(rmutex)) != 0) {
+							if ((rc = mdb_mutex_failed(env, rmutex, rc)))
+								break;
+							rdrs = 0; /* the above checked all readers */
+						} else {
+							/* Recheck, a new process may have reused pid */
+							if (mdb_reader_pid(env, Pidcheck, pid))
+								j = rdrs;
+						}
+					}
+					for (; j<rdrs; j++)
+							if (mr[j].mr_pid == pid) {
+								DPRINTF(("clear stale reader pid %u txn %"Y"d",
+									(unsigned) pid, mr[j].mr_txnid));
+								mr[j].mr_pid = 0;
+								count++;
+							}
+					if (rmutex)
+						UNLOCK_MUTEX(rmutex);
+				}
+			}
+		}
+	}
+	free(pids);
+	if (dead)
+		*dead = count;
+	return rc;
+}
+
+#ifdef MDB_ROBUST_SUPPORTED
+/** Handle #LOCK_MUTEX0() failure.
+ * Try to repair the lock file if the mutex owner died.
+ * @param[in] env	the environment handle
+ * @param[in] mutex	LOCK_MUTEX0() mutex
+ * @param[in] rc	LOCK_MUTEX0() error (nonzero)
+ * @return 0 on success with the mutex locked, or an error code on failure.
+ */
+static int ESECT
+mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc)
+{
+	int rlocked, rc2;
+	MDB_meta *meta;
+
+	if (rc == MDB_OWNERDEAD) {
+		/* We own the mutex. Clean up after dead previous owner. */
+		rc = MDB_SUCCESS;
+		rlocked = (mutex == env->me_rmutex);
+		if (!rlocked) {
+			/* Keep mti_txnid updated, otherwise next writer can
+			 * overwrite data which latest meta page refers to.
+			 */
+			meta = mdb_env_pick_meta(env);
+			env->me_txns->mti_txnid = meta->mm_txnid;
+			/* env is hosed if the dead thread was ours */
+			if (env->me_txn) {
+				env->me_flags |= MDB_FATAL_ERROR;
+				env->me_txn = NULL;
+				rc = MDB_PANIC;
+			}
+		}
+		DPRINTF(("%cmutex owner died, %s", (rlocked ? 'r' : 'w'),
+			(rc ? "this process' env is hosed" : "recovering")));
+		rc2 = mdb_reader_check0(env, rlocked, NULL);
+		if (rc2 == 0)
+			rc2 = mdb_mutex_consistent(mutex);
+		if (rc || (rc = rc2)) {
+			DPRINTF(("LOCK_MUTEX recovery failed, %s", mdb_strerror(rc)));
+			UNLOCK_MUTEX(mutex);
+		}
+	} else {
+#ifdef _WIN32
+		rc = ErrCode();
+#endif
+		DPRINTF(("LOCK_MUTEX failed, %s", mdb_strerror(rc)));
+	}
+
+	return rc;
+}
+#endif	/* MDB_ROBUST_SUPPORTED */
+/** @} */
+
+#if defined(_WIN32)
+static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize)
+{
+	int need;
+	wchar_t *result;
+	need = MultiByteToWideChar(CP_UTF8, 0, src, srcsize, NULL, 0);
+	if (need == 0xFFFD)
+		return EILSEQ;
+	if (need == 0)
+		return EINVAL;
+	result = malloc(sizeof(wchar_t) * need);
+	if (!result)
+		return ENOMEM;
+	MultiByteToWideChar(CP_UTF8, 0, src, srcsize, result, need);
+	if (dstsize)
+		*dstsize = need;
+	*dst = result;
+	return 0;
+}
+#endif /* defined(_WIN32) */
diff --git a/plugins/Dbx_mdb/src/lmdb/midl.c b/plugins/Dbx_mdb/src/lmdb/midl.c
index f6a2d4c7ed..9748d8dba8 100644
--- a/plugins/Dbx_mdb/src/lmdb/midl.c
+++ b/plugins/Dbx_mdb/src/lmdb/midl.c
@@ -15,8 +15,6 @@
  * <http://www.OpenLDAP.org/license.html>.
  */
 
-#define MDB_VL32 1
-
 #include <limits.h>
 #include <string.h>
 #include <stdlib.h>
diff --git a/plugins/Dbx_mdb/src/lmdb/ntapi.h b/plugins/Dbx_mdb/src/lmdb/ntapi.h
deleted file mode 100644
index 10d4aa7f50..0000000000
--- a/plugins/Dbx_mdb/src/lmdb/ntapi.h
+++ /dev/null
@@ -1,3909 +0,0 @@
-/*
- * ntapi.h
- *
- * Windows NT Native API
- *
- * Most structures in this file is obtained from Windows NT/2000 Native API
- * Reference by Gary Nebbett, ISBN 1578701996.
- *
- * This file is part of the w32api package.
- *
- * Contributors:
- *   Created by Casper S. Hornstrup <chorns@users.sourceforge.net>
- *
- * THIS SOFTWARE IS NOT COPYRIGHTED
- *
- * This source code is offered for use in the public domain. You may
- * use, modify or distribute it freely.
- *
- * This code is distributed in the hope that it will be useful but
- * WITHOUT ANY WARRANTY. ALL WARRANTIES, EXPRESS OR IMPLIED ARE HEREBY
- * DISCLAIMED. This includes but is not limited to warranties of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- *
- */
-
-#ifndef __NTAPI_H
-#define __NTAPI_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#include <stdarg.h>
-//#include <winbase.h>
-#include <windef.h>
-
-
-#pragma pack(push,4)
-
-//typedef struct _PEB *PPEB;
-
-/* FIXME: Unknown definitions */
-//typedef PVOID POBJECT_TYPE_LIST;
-typedef PVOID PEXECUTION_STATE;
-typedef PVOID PLANGID;
-
-#ifndef NtCurrentProcess
-#define NtCurrentProcess() ((HANDLE)0xFFFFFFFF)
-#endif /* NtCurrentProcess */
-#ifndef NtCurrentThread
-#define NtCurrentThread() ((HANDLE)0xFFFFFFFE)
-#endif /* NtCurrentThread */
-
-
-
-#define	RTL_REGISTRY_ABSOLUTE	0
-//add by SevenCat
-
-#define STATUS_UNSUCCESSFUL              ((NTSTATUS)0xC0000001L)
-#define STATUS_NOT_IMPLEMENTED           ((NTSTATUS)0xC0000002L)
-#define STATUS_INVALID_INFO_CLASS        ((NTSTATUS)0xC0000003L)    // ntsubauth
-#define STATUS_INFO_LENGTH_MISMATCH      ((NTSTATUS)0xC0000004L)
-//#define STATUS_ACCESS_VIOLATION          ((NTSTATUS)0xC0000005L)    // winnt
-//#define STATUS_IN_PAGE_ERROR             ((NTSTATUS)0xC0000006L)    // winnt
-#define STATUS_PAGEFILE_QUOTA            ((NTSTATUS)0xC0000007L)
-//#define STATUS_INVALID_HANDLE            ((NTSTATUS)0xC0000008L)    // winnt
-#define STATUS_BAD_INITIAL_STACK         ((NTSTATUS)0xC0000009L)
-#define STATUS_BAD_INITIAL_PC            ((NTSTATUS)0xC000000AL)
-#define STATUS_INVALID_CID               ((NTSTATUS)0xC000000BL)
-#define STATUS_TIMER_NOT_CANCELED        ((NTSTATUS)0xC000000CL)
-// #define STATUS_INVALID_PARAMETER         ((NTSTATUS)0xC000000DL)
-#define STATUS_NO_SUCH_DEVICE            ((NTSTATUS)0xC000000EL)
-#define STATUS_NO_SUCH_FILE              ((NTSTATUS)0xC000000FL)
-#define	STATUS_OBJECT_NAME_NOT_FOUND	0xC0000034
-
-#define RTL_CONSTANT_STRING(s) { sizeof( s ) - sizeof( (s)[0] ), sizeof( s ), s }
-
-#define __WTEXT(quote) L##quote
-#define WTEXT(quote) __WTEXT(quote)
-
-#define DIRECTORY_ALL_ACCESS	(STANDARD_RIGHTS_REQUIRED|0xF)
-#define OBJ_PERMANENT		0x00000010L
-
-#ifndef NT_SUCCESS
-#define NT_SUCCESS(x) ((x)>=0)
-#define STATUS_SUCCESS ((NTSTATUS)0)
-#endif
-
-#define DDKAPI __stdcall
-#define DDKFASTAPI __fastcall
-#define DDKCDECLAPI __cdecl
-
-typedef struct _CLIENT_ID {
-  HANDLE  UniqueProcess;
-  HANDLE  UniqueThread;
-} CLIENT_ID, *PCLIENT_ID;
-
-
-/////////////
-
-
-
-typedef enum _KEY_INFORMATION_CLASS
-{
-  KeyBasicInformation,
-  KeyNodeInformation,
-  KeyFullInformation
-} KEY_INFORMATION_CLASS;
-
-typedef struct _KEY_BASIC_INFORMATION
-{
-  LARGE_INTEGER  LastWriteTime;
-  ULONG  TitleIndex;
-  ULONG  NameLength;
-  WCHAR  Name[1];
-} KEY_BASIC_INFORMATION, *PKEY_BASIC_INFORMATION;
-
-typedef struct _KEY_FULL_INFORMATION
-{
-  LARGE_INTEGER  LastWriteTime;
-  ULONG  TitleIndex;
-  ULONG  ClassOffset;
-  ULONG  ClassLength;
-  ULONG  SubKeys;
-  ULONG  MaxNameLen;
-  ULONG  MaxClassLen;
-  ULONG  Values;
-  ULONG  MaxValueNameLen;
-  ULONG  MaxValueDataLen;
-  WCHAR  Class[1];
-} KEY_FULL_INFORMATION, *PKEY_FULL_INFORMATION;
-
-typedef struct _KEY_NODE_INFORMATION
-{
-  LARGE_INTEGER  LastWriteTime;
-  ULONG  TitleIndex;
-  ULONG  ClassOffset;
-  ULONG  ClassLength;
-  ULONG  NameLength;
-  WCHAR  Name[1];
-} KEY_NODE_INFORMATION, *PKEY_NODE_INFORMATION;
-
-/* key set information class */
-/*
- * KeyWriteTimeInformation
- */
-
-/* key value information class */
-
-typedef enum _KEY_VALUE_INFORMATION_CLASS
-{
-  KeyValueBasicInformation,
-  KeyValueFullInformation,
-  KeyValuePartialInformation
-} KEY_VALUE_INFORMATION_CLASS;
-
-typedef struct _KEY_VALUE_BASIC_INFORMATION
-{
-  ULONG  TitleIndex;
-  ULONG  Type;
-  ULONG  NameLength;
-  WCHAR  Name[1];
-} KEY_VALUE_BASIC_INFORMATION, *PKEY_VALUE_BASIC_INFORMATION;
-
-typedef struct _KEY_VALUE_FULL_INFORMATION
-{
-  ULONG  TitleIndex;
-  ULONG  Type;
-  ULONG  DataOffset;
-  ULONG  DataLength;
-  ULONG  NameLength;
-  WCHAR  Name[1];
-} KEY_VALUE_FULL_INFORMATION, *PKEY_VALUE_FULL_INFORMATION;
-
-typedef struct _KEY_VALUE_PARTIAL_INFORMATION
-{
-  ULONG  TitleIndex;
-  ULONG  Type;
-  ULONG  DataLength;
-  UCHAR  Data[1];
-} KEY_VALUE_PARTIAL_INFORMATION, *PKEY_VALUE_PARTIAL_INFORMATION;
-
-
-
-
-
-///////////
-
-typedef LONG KPRIORITY;
-
-typedef enum _KWAIT_REASON {
-  Executive,
-  FreePage,
-  PageIn,
-  PoolAllocation,
-  DelayExecution,
-  Suspended,
-  UserRequest,
-  WrExecutive,
-  WrFreePage,
-  WrPageIn,
-  WrPoolAllocation,
-  WrDelayExecution,
-  WrSuspended,
-  WrUserRequest,
-  WrEventPair,
-  WrQueue,
-  WrLpcReceive,
-  WrLpcReply,
-  WrVirtualMemory,
-  WrPageOut,
-  WrRendezvous,
-  Spare2,
-  Spare3,
-  Spare4,
-  Spare5,
-  Spare6,
-  WrKernel,
-  MaximumWaitReason
-} KWAIT_REASON;
-
-#define FILE_SUPERSEDE                    0x00000000
-#define FILE_OPEN                         0x00000001
-#define FILE_CREATE                       0x00000002
-#define FILE_OPEN_IF                      0x00000003
-#define FILE_OVERWRITE                    0x00000004
-#define FILE_OVERWRITE_IF                 0x00000005
-#define FILE_MAXIMUM_DISPOSITION          0x00000005
-
-
-typedef struct _STRING {
-    USHORT Length;
-    USHORT MaximumLength;
-    PCHAR Buffer;
-} STRING;
-typedef STRING *PSTRING;
-
-typedef STRING ANSI_STRING;
-typedef PSTRING PANSI_STRING;
-typedef PSTRING PCANSI_STRING;
-
-typedef STRING OEM_STRING;
-typedef PSTRING POEM_STRING;
-typedef CONST STRING* PCOEM_STRING;
-
-typedef struct _UNICODE_STRING {
-    USHORT Length;
-    USHORT MaximumLength;
-    PWSTR  Buffer;
-} UNICODE_STRING;
-typedef UNICODE_STRING *PUNICODE_STRING;
-typedef const UNICODE_STRING *PCUNICODE_STRING;
-
-
-typedef enum _POOL_TYPE {
-  NonPagedPool,
-  PagedPool,
-  NonPagedPoolMustSucceed,
-  DontUseThisType,
-  NonPagedPoolCacheAligned,
-  PagedPoolCacheAligned,
-  NonPagedPoolCacheAlignedMustS,
-	MaxPoolType,
-	NonPagedPoolSession = 32,
-	PagedPoolSession,
-	NonPagedPoolMustSucceedSession,
-	DontUseThisTypeSession,
-	NonPagedPoolCacheAlignedSession,
-	PagedPoolCacheAlignedSession,
-	NonPagedPoolCacheAlignedMustSSession
-} POOL_TYPE;
-
-#ifndef DECL_IMPORT
-#define DECL_IMPORT __declspec(dllimport)
-#endif
-
-#ifndef NTOSAPI
-#define NTOSAPI DECL_IMPORT
-#endif
-#define DECLARE_INTERNAL_OBJECT(x) struct _##x; typedef struct _##x *P##x;
-#define DECLARE_INTERNAL_OBJECT2(x,y) struct _##x; typedef struct _##x *P##y;
-
-typedef LONG NTSTATUS;
-
-typedef struct _OBJECT_ATTRIBUTES {
-    ULONG Length;
-    HANDLE RootDirectory;
-    PUNICODE_STRING ObjectName;
-    ULONG Attributes;
-    PVOID SecurityDescriptor;
-    PVOID SecurityQualityOfService;
-} OBJECT_ATTRIBUTES;
-typedef OBJECT_ATTRIBUTES *POBJECT_ATTRIBUTES;
-
-#define InitializeObjectAttributes( p, n, a, r, s ) { \
-    (p)->Length = sizeof( OBJECT_ATTRIBUTES );          \
-    (p)->RootDirectory = r;                             \
-    (p)->Attributes = a;                                \
-    (p)->ObjectName = n;                                \
-    (p)->SecurityDescriptor = s;                        \
-    (p)->SecurityQualityOfService = NULL;               \
-    }
-
-
-typedef struct _FILE_NETWORK_OPEN_INFORMATION {
-  LARGE_INTEGER  CreationTime;
-  LARGE_INTEGER  LastAccessTime;
-  LARGE_INTEGER  LastWriteTime;
-  LARGE_INTEGER  ChangeTime;
-  LARGE_INTEGER  AllocationSize;
-  LARGE_INTEGER  EndOfFile;
-  ULONG  FileAttributes;
-} FILE_NETWORK_OPEN_INFORMATION, *PFILE_NETWORK_OPEN_INFORMATION;
-
-typedef struct _IO_STATUS_BLOCK {
-    union {
-        NTSTATUS Status;
-        PVOID Pointer;
-    };
-
-    ULONG_PTR Information;
-} IO_STATUS_BLOCK, *PIO_STATUS_BLOCK;
-
-
-typedef VOID (NTAPI *PKNORMAL_ROUTINE)(
-  IN PVOID  NormalContext,
-  IN PVOID  SystemArgument1,
-  IN PVOID  SystemArgument2);
-
-typedef enum _PROCESSINFOCLASS {
-  ProcessBasicInformation,
-  ProcessQuotaLimits,
-  ProcessIoCounters,
-  ProcessVmCounters,
-  ProcessTimes,
-  ProcessBasePriority,
-  ProcessRaisePriority,
-  ProcessDebugPort,
-  ProcessExceptionPort,
-  ProcessAccessToken,
-  ProcessLdtInformation,
-  ProcessLdtSize,
-  ProcessDefaultHardErrorMode,
-  ProcessIoPortHandlers,
-  ProcessPooledUsageAndLimits,
-  ProcessWorkingSetWatch,
-  ProcessUserModeIOPL,
-  ProcessEnableAlignmentFaultFixup,
-  ProcessPriorityClass,
-  ProcessWx86Information,
-  ProcessHandleCount,
-  ProcessAffinityMask,
-  ProcessPriorityBoost,
-  ProcessDeviceMap,
-  ProcessSessionInformation,
-  ProcessForegroundInformation,
-  ProcessWow64Information,
-  ProcessImageFileName,
-  ProcessLUIDDeviceMapsEnabled,
-  ProcessBreakOnTermination,
-  ProcessDebugObjectHandle,
-  ProcessDebugFlags,
-  ProcessHandleTracing,
-  MaxProcessInfoClass
-} PROCESSINFOCLASS;
-
-typedef enum _THREADINFOCLASS {
-  ThreadBasicInformation,
-  ThreadTimes,
-  ThreadPriority,
-  ThreadBasePriority,
-  ThreadAffinityMask,
-  ThreadImpersonationToken,
-  ThreadDescriptorTableEntry,
-  ThreadEnableAlignmentFaultFixup,
-  ThreadEventPair_Reusable,
-  ThreadQuerySetWin32StartAddress,
-  ThreadZeroTlsCell,
-  ThreadPerformanceCount,
-  ThreadAmILastThread,
-  ThreadIdealProcessor,
-  ThreadPriorityBoost,
-  ThreadSetTlsArrayAddress,
-  ThreadIsIoPending,
-  ThreadHideFromDebugger,
-  ThreadBreakOnTermination,
-  MaxThreadInfoClass
-} THREADINFOCLASS;
-
-typedef enum _KPROFILE_SOURCE {
-  ProfileTime,
-  ProfileAlignmentFixup,
-  ProfileTotalIssues,
-  ProfilePipelineDry,
-  ProfileLoadInstructions,
-  ProfilePipelineFrozen,
-  ProfileBranchInstructions,
-  ProfileTotalNonissues,
-  ProfileDcacheMisses,
-  ProfileIcacheMisses,
-  ProfileCacheMisses,
-  ProfileBranchMispredictions,
-  ProfileStoreInstructions,
-  ProfileFpInstructions,
-  ProfileIntegerInstructions,
-  Profile2Issue,
-  Profile3Issue,
-  Profile4Issue,
-  ProfileSpecialInstructions,
-  ProfileTotalCycles,
-  ProfileIcacheIssues,
-  ProfileDcacheAccesses,
-  ProfileMemoryBarrierCycles,
-  ProfileLoadLinkedIssues,
-  ProfileMaximum
-} KPROFILE_SOURCE;
-
-
-typedef VOID
-(NTAPI *PIO_APC_ROUTINE)(
-  IN PVOID ApcContext,
-  IN PIO_STATUS_BLOCK IoStatusBlock,
-  IN ULONG Reserved);
-
-typedef struct _KEY_VALUE_ENTRY {
-    PUNICODE_STRING ValueName;
-    ULONG           DataLength;
-    ULONG           DataOffset;
-    ULONG           Type;
-} KEY_VALUE_ENTRY, *PKEY_VALUE_ENTRY;
-
-//end add
-
-/* System information and control */
-
-typedef enum _SYSTEM_INFORMATION_CLASS {
-	SystemInformationClassMin = 0,
-	SystemBasicInformation = 0,
-	SystemProcessorInformation = 1,
-	SystemPerformanceInformation = 2,
-	SystemTimeOfDayInformation = 3,
-	SystemPathInformation = 4,
-	SystemNotImplemented1 = 4,
-	SystemProcessInformation = 5,
-	SystemProcessesAndThreadsInformation = 5,
-	SystemCallCountInfoInformation = 6,
-	SystemCallCounts = 6,
-	SystemDeviceInformation = 7,
-	SystemConfigurationInformation = 7,
-	SystemProcessorPerformanceInformation = 8,
-	SystemProcessorTimes = 8,
-	SystemFlagsInformation = 9,
-	SystemGlobalFlag = 9,
-	SystemCallTimeInformation = 10,
-	SystemNotImplemented2 = 10,
-	SystemModuleInformation = 11,
-	SystemLocksInformation = 12,
-	SystemLockInformation = 12,
-	SystemStackTraceInformation = 13,
-	SystemNotImplemented3 = 13,
-	SystemPagedPoolInformation = 14,
-	SystemNotImplemented4 = 14,
-	SystemNonPagedPoolInformation = 15,
-	SystemNotImplemented5 = 15,
-	SystemHandleInformation = 16,
-	SystemObjectInformation = 17,
-	SystemPageFileInformation = 18,
-	SystemPagefileInformation = 18,
-	SystemVdmInstemulInformation = 19,
-	SystemInstructionEmulationCounts = 19,
-	SystemVdmBopInformation = 20,
-	SystemInvalidInfoClass1 = 20,
-	SystemFileCacheInformation = 21,
-	SystemCacheInformation = 21,
-	SystemPoolTagInformation = 22,
-	SystemInterruptInformation = 23,
-	SystemProcessorStatistics = 23,
-	SystemDpcBehaviourInformation = 24,
-	SystemDpcInformation = 24,
-	SystemFullMemoryInformation = 25,
-	SystemNotImplemented6 = 25,
-	SystemLoadImage = 26,
-	SystemUnloadImage = 27,
-	SystemTimeAdjustmentInformation = 28,
-	SystemTimeAdjustment = 28,
-	SystemSummaryMemoryInformation = 29,
-	SystemNotImplemented7 = 29,
-	SystemNextEventIdInformation = 30,
-	SystemNotImplemented8 = 30,
-	SystemEventIdsInformation = 31,
-	SystemNotImplemented9 = 31,
-	SystemCrashDumpInformation = 32,
-	SystemExceptionInformation = 33,
-	SystemCrashDumpStateInformation = 34,
-	SystemKernelDebuggerInformation = 35,
-	SystemContextSwitchInformation = 36,
-	SystemRegistryQuotaInformation = 37,
-	SystemLoadAndCallImage = 38,
-	SystemPrioritySeparation = 39,
-	SystemPlugPlayBusInformation = 40,
-	SystemNotImplemented10 = 40,
-	SystemDockInformation = 41,
-	SystemNotImplemented11 = 41,
-	/* SystemPowerInformation = 42, Conflicts with POWER_INFORMATION_LEVEL 1 */
-	SystemInvalidInfoClass2 = 42,
-	SystemProcessorSpeedInformation = 43,
-	SystemInvalidInfoClass3 = 43,
-	SystemCurrentTimeZoneInformation = 44,
-	SystemTimeZoneInformation = 44,
-	SystemLookasideInformation = 45,
-	SystemSetTimeSlipEvent = 46,
-	SystemCreateSession = 47,
-	SystemDeleteSession = 48,
-	SystemInvalidInfoClass4 = 49,
-	SystemRangeStartInformation = 50,
-	SystemVerifierInformation = 51,
-	SystemAddVerifier = 52,
-	SystemSessionProcessesInformation	= 53,
-	SystemInformationClassMax
-} SYSTEM_INFORMATION_CLASS;
-
-typedef struct _SYSTEM_BASIC_INFORMATION {
-	ULONG  Unknown;
-	ULONG  MaximumIncrement;
-	ULONG  PhysicalPageSize;
-	ULONG  NumberOfPhysicalPages;
-	ULONG  LowestPhysicalPage;
-	ULONG  HighestPhysicalPage;
-	ULONG  AllocationGranularity;
-	ULONG  LowestUserAddress;
-	ULONG  HighestUserAddress;
-	ULONG  ActiveProcessors;
-	UCHAR  NumberProcessors;
-} SYSTEM_BASIC_INFORMATION, *PSYSTEM_BASIC_INFORMATION;
-
-typedef struct _SYSTEM_PROCESSOR_INFORMATION {
-	USHORT  ProcessorArchitecture;
-	USHORT  ProcessorLevel;
-	USHORT  ProcessorRevision;
-	USHORT  Unknown;
-	ULONG  FeatureBits;
-} SYSTEM_PROCESSOR_INFORMATION, *PSYSTEM_PROCESSOR_INFORMATION;
-
-typedef struct _SYSTEM_PERFORMANCE_INFORMATION {
-	LARGE_INTEGER  IdleTime;
-	LARGE_INTEGER  ReadTransferCount;
-	LARGE_INTEGER  WriteTransferCount;
-	LARGE_INTEGER  OtherTransferCount;
-	ULONG  ReadOperationCount;
-	ULONG  WriteOperationCount;
-	ULONG  OtherOperationCount;
-	ULONG  AvailablePages;
-	ULONG  TotalCommittedPages;
-	ULONG  TotalCommitLimit;
-	ULONG  PeakCommitment;
-	ULONG  PageFaults;
-	ULONG  WriteCopyFaults;
-	ULONG  TransitionFaults;
-	ULONG  CacheTransitionFaults;
-	ULONG  DemandZeroFaults;
-	ULONG  PagesRead;
-	ULONG  PageReadIos;
-	ULONG	 CacheReads;
-	ULONG	 CacheIos;
-	ULONG  PagefilePagesWritten;
-	ULONG  PagefilePageWriteIos;
-	ULONG  MappedFilePagesWritten;
-	ULONG  MappedFilePageWriteIos;
-	ULONG  PagedPoolUsage;
-	ULONG  NonPagedPoolUsage;
-	ULONG  PagedPoolAllocs;
-	ULONG  PagedPoolFrees;
-	ULONG  NonPagedPoolAllocs;
-	ULONG  NonPagedPoolFrees;
-	ULONG  TotalFreeSystemPtes;
-	ULONG  SystemCodePage;
-	ULONG  TotalSystemDriverPages;
-	ULONG  TotalSystemCodePages;
-	ULONG  SmallNonPagedLookasideListAllocateHits;
-	ULONG  SmallPagedLookasideListAllocateHits;
-	ULONG  Reserved3;
-	ULONG  MmSystemCachePage;
-	ULONG  PagedPoolPage;
-	ULONG  SystemDriverPage;
-	ULONG  FastReadNoWait;
-	ULONG  FastReadWait;
-	ULONG  FastReadResourceMiss;
-	ULONG  FastReadNotPossible;
-	ULONG  FastMdlReadNoWait;
-	ULONG  FastMdlReadWait;
-	ULONG  FastMdlReadResourceMiss;
-	ULONG  FastMdlReadNotPossible;
-	ULONG  MapDataNoWait;
-	ULONG  MapDataWait;
-	ULONG  MapDataNoWaitMiss;
-	ULONG  MapDataWaitMiss;
-	ULONG  PinMappedDataCount;
-	ULONG  PinReadNoWait;
-	ULONG  PinReadWait;
-	ULONG  PinReadNoWaitMiss;
-	ULONG  PinReadWaitMiss;
-	ULONG  CopyReadNoWait;
-	ULONG  CopyReadWait;
-	ULONG  CopyReadNoWaitMiss;
-	ULONG  CopyReadWaitMiss;
-	ULONG  MdlReadNoWait;
-	ULONG  MdlReadWait;
-	ULONG  MdlReadNoWaitMiss;
-	ULONG  MdlReadWaitMiss;
-	ULONG  ReadAheadIos;
-	ULONG  LazyWriteIos;
-	ULONG  LazyWritePages;
-	ULONG  DataFlushes;
-	ULONG  DataPages;
-	ULONG  ContextSwitches;
-	ULONG  FirstLevelTbFills;
-	ULONG  SecondLevelTbFills;
-	ULONG  SystemCalls;
-} SYSTEM_PERFORMANCE_INFORMATION, *PSYSTEM_PERFORMANCE_INFORMATION;
-
-typedef struct _SYSTEM_TIME_OF_DAY_INFORMATION {
-	LARGE_INTEGER  BootTime;
-	LARGE_INTEGER  CurrentTime;
-	LARGE_INTEGER  TimeZoneBias;
-	ULONG  CurrentTimeZoneId;
-} SYSTEM_TIME_OF_DAY_INFORMATION, *PSYSTEM_TIME_OF_DAY_INFORMATION;
-
-typedef struct _VM_COUNTERS {
-	ULONG  PeakVirtualSize;
-	ULONG  VirtualSize;
-	ULONG  PageFaultCount;
-	ULONG  PeakWorkingSetSize;
-	ULONG  WorkingSetSize;
-	ULONG  QuotaPeakPagedPoolUsage;
-	ULONG  QuotaPagedPoolUsage;
-	ULONG  QuotaPeakNonPagedPoolUsage;
-	ULONG  QuotaNonPagedPoolUsage;
-	ULONG  PagefileUsage;
-	ULONG  PeakPagefileUsage;
-} VM_COUNTERS;
-
-typedef enum _THREAD_STATE {
-	StateInitialized,
-	StateReady,
-	StateRunning,
-	StateStandby,
-	StateTerminated,
-	StateWait,
-	StateTransition,
-	StateUnknown
-} THREAD_STATE;
-
-typedef struct _SYSTEM_THREADS {
-	LARGE_INTEGER  KernelTime;
-	LARGE_INTEGER  UserTime;
-	LARGE_INTEGER  CreateTime;
-	ULONG  WaitTime;
-	PVOID  StartAddress;
-	CLIENT_ID  ClientId;
-	KPRIORITY  Priority;
-	KPRIORITY  BasePriority;
-	ULONG  ContextSwitchCount;
-	THREAD_STATE  State;
-	KWAIT_REASON  WaitReason;
-} SYSTEM_THREADS, *PSYSTEM_THREADS;
-
-typedef struct _SYSTEM_PROCESSES {
-    ULONG NextEntryOffset;
-    BYTE Reserved1[52];
-    PVOID Reserved2[3];
-    HANDLE UniqueProcessId;
-    PVOID Reserved3;
-    ULONG HandleCount;
-    BYTE Reserved4[4];
-    PVOID Reserved5[11];
-    SIZE_T PeakPagefileUsage;
-    SIZE_T PrivatePageCount;
-    LARGE_INTEGER Reserved6[6];
-} SYSTEM_PROCESSES, *PSYSTEM_PROCESSES;
-
-typedef struct _SYSTEM_CALLS_INFORMATION {
-	ULONG  Size;
-	ULONG  NumberOfDescriptorTables;
-	ULONG  NumberOfRoutinesInTable[1];
-	ULONG  CallCounts[ANYSIZE_ARRAY];
-} SYSTEM_CALLS_INFORMATION, *PSYSTEM_CALLS_INFORMATION;
-
-typedef struct _SYSTEM_CONFIGURATION_INFORMATION {
-	ULONG  DiskCount;
-	ULONG  FloppyCount;
-	ULONG  CdRomCount;
-	ULONG  TapeCount;
-	ULONG  SerialCount;
-	ULONG  ParallelCount;
-} SYSTEM_CONFIGURATION_INFORMATION, *PSYSTEM_CONFIGURATION_INFORMATION;
-
-typedef struct _SYSTEM_PROCESSOR_TIMES {
-	LARGE_INTEGER  IdleTime;
-	LARGE_INTEGER  KernelTime;
-	LARGE_INTEGER  UserTime;
-	LARGE_INTEGER  DpcTime;
-	LARGE_INTEGER  InterruptTime;
-	ULONG  InterruptCount;
-} SYSTEM_PROCESSOR_TIMES, *PSYSTEM_PROCESSOR_TIMES;
-
-/* SYSTEM_GLOBAL_FLAG.GlobalFlag constants */
-#define FLG_STOP_ON_EXCEPTION             0x00000001
-#define FLG_SHOW_LDR_SNAPS                0x00000002
-#define FLG_DEBUG_INITIAL_COMMAND         0x00000004
-#define FLG_STOP_ON_HUNG_GUI              0x00000008
-#define FLG_HEAP_ENABLE_TAIL_CHECK        0x00000010
-#define FLG_HEAP_ENABLE_FREE_CHECK        0x00000020
-#define FLG_HEAP_VALIDATE_PARAMETERS      0x00000040
-#define FLG_HEAP_VALIDATE_ALL             0x00000080
-#define FLG_POOL_ENABLE_TAIL_CHECK        0x00000100
-#define FLG_POOL_ENABLE_FREE_CHECK        0x00000200
-#define FLG_POOL_ENABLE_TAGGING           0x00000400
-#define FLG_HEAP_ENABLE_TAGGING           0x00000800
-#define FLG_USER_STACK_TRACE_DB           0x00001000
-#define FLG_KERNEL_STACK_TRACE_DB         0x00002000
-#define FLG_MAINTAIN_OBJECT_TYPELIST      0x00004000
-#define FLG_HEAP_ENABLE_TAG_BY_DLL        0x00008000
-#define FLG_IGNORE_DEBUG_PRIV             0x00010000
-#define FLG_ENABLE_CSRDEBUG               0x00020000
-#define FLG_ENABLE_KDEBUG_SYMBOL_LOAD     0x00040000
-#define FLG_DISABLE_PAGE_KERNEL_STACKS    0x00080000
-#define FLG_HEAP_ENABLE_CALL_TRACING      0x00100000
-#define FLG_HEAP_DISABLE_COALESCING       0x00200000
-#define FLG_ENABLE_CLOSE_EXCEPTIONS       0x00400000
-#define FLG_ENABLE_EXCEPTION_LOGGING      0x00800000
-#define FLG_ENABLE_DBGPRINT_BUFFERING     0x08000000
-
-
-NTOSAPI
-PVOID
-NTAPI
-RtlImageDirectoryEntryToData(
-    PVOID Base,
-    BOOLEAN MappedAsImage,
-    USHORT DirectoryEntry,
-    PULONG Size
-    );
-
-
-//
-// Loader Data Table Entry
-//
-typedef struct _LDR_DATA_TABLE_ENTRY
-{
-    LIST_ENTRY InLoadOrderLinks;
-    LIST_ENTRY InMemoryOrderModuleList;
-    LIST_ENTRY InInitializationOrderModuleList;
-    ULONG DllBase;
-    ULONG EntryPoint;
-    ULONG SizeOfImage;
-    UNICODE_STRING FullDllName;
-    UNICODE_STRING BaseDllName;
-    ULONG Flags;
-    USHORT LoadCount;
-    USHORT TlsIndex;
-    union
-    {
-        LIST_ENTRY HashLinks;
-        PVOID SectionPointer;
-    };
-    ULONG CheckSum;
-    union
-    {
-        ULONG TimeDateStamp;
-        PVOID LoadedImports;
-    };
-    PVOID EntryPointActivationContext;
-    PVOID PatchInformation;
-} LDR_DATA_TABLE_ENTRY, *PLDR_DATA_TABLE_ENTRY;
-
-typedef struct _PEB_LDR_DATA {
-  ULONG                   Length;
-  BOOLEAN                 Initialized;
-  PVOID                   SsHandle;
-  LIST_ENTRY              InLoadOrderModuleList;
-  LIST_ENTRY              InMemoryOrderModuleList;
-  LIST_ENTRY              InInitializationOrderModuleList;
-} PEB_LDR_DATA, *PPEB_LDR_DATA;
-
-
-typedef struct _LDR_MODULE {
-  LIST_ENTRY              InLoadOrderModuleList;
-  LIST_ENTRY              InMemoryOrderModuleList;
-  LIST_ENTRY              InInitializationOrderModuleList;
-  PVOID                   BaseAddress;
-  PVOID                   EntryPoint;
-  ULONG                   SizeOfImage;
-  UNICODE_STRING          FullDllName;
-  UNICODE_STRING          BaseDllName;
-  ULONG                   Flags;
-  SHORT                   LoadCount;
-  SHORT                   TlsIndex;
-  LIST_ENTRY              HashTableEntry;
-  ULONG                   TimeDateStamp;
-} LDR_MODULE, *PLDR_MODULE;
-
-
-typedef struct _PEB {
-  BOOLEAN                 InheritedAddressSpace;
-  BOOLEAN                 ReadImageFileExecOptions;
-  BOOLEAN                 BeingDebugged;
-  BOOLEAN                 Spare;
-  HANDLE                  Mutant;
-  PVOID                   ImageBaseAddress;
-  PPEB_LDR_DATA           LoaderData;
-  PVOID					  ProcessParameters;
-  PVOID                   SubSystemData;
-  PVOID                   ProcessHeap;
-  PVOID                   FastPebLock;
-  PVOID					  FastPebLockRoutine;
-  PVOID					  FastPebUnlockRoutine;
-  ULONG                   EnvironmentUpdateCount;
-  PVOID*                  KernelCallbackTable;
-  PVOID                   EventLogSection;
-  PVOID                   EventLog;
-  PVOID			          FreeList;
-  ULONG                   TlsExpansionCounter;
-  PVOID                   TlsBitmap;
-  ULONG                   TlsBitmapBits[0x2];
-  PVOID                   ReadOnlySharedMemoryBase;
-  PVOID                   ReadOnlySharedMemoryHeap;
-  PVOID*                  ReadOnlyStaticServerData;
-  PVOID                   AnsiCodePageData;
-  PVOID                   OemCodePageData;
-  PVOID                   UnicodeCaseTableData;
-  ULONG                   NumberOfProcessors;
-  ULONG                   NtGlobalFlag;
-  BYTE                    Spare2[0x4];
-  LARGE_INTEGER           CriticalSectionTimeout;
-  ULONG                   HeapSegmentReserve;
-  ULONG                   HeapSegmentCommit;
-  ULONG                   HeapDeCommitTotalFreeThreshold;
-  ULONG                   HeapDeCommitFreeBlockThreshold;
-  ULONG                   NumberOfHeaps;
-  ULONG                   MaximumNumberOfHeaps;
-  PVOID*                  *ProcessHeaps;
-  PVOID                   GdiSharedHandleTable;
-  PVOID                   ProcessStarterHelper;
-  PVOID                   GdiDCAttributeList;
-  PVOID                   LoaderLock;
-  ULONG                   OSMajorVersion;
-  ULONG                   OSMinorVersion;
-  ULONG                   OSBuildNumber;
-  ULONG                   OSPlatformId;
-  ULONG                   ImageSubSystem;
-  ULONG                   ImageSubSystemMajorVersion;
-  ULONG                   ImageSubSystemMinorVersion;
-  ULONG                   GdiHandleBuffer[0x22];
-  ULONG                   PostProcessInitRoutine;
-  ULONG                   TlsExpansionBitmap;
-  BYTE                    TlsExpansionBitmapBits[0x80];
-  ULONG                   SessionId;
-} PEB, *PPEB;
-
-typedef struct _SYSTEM_GLOBAL_FLAG {
-  ULONG  GlobalFlag;
-} SYSTEM_GLOBAL_FLAG, *PSYSTEM_GLOBAL_FLAG;
-
-typedef struct _SYSTEM_MODULE_INFORMATION_ENTRY {
-	ULONG	 Unknown1;
-	ULONG	 Unknown2;
-	PVOID  Base;
-	ULONG  Size;
-	ULONG  Flags;
-	USHORT  Index;
-  /* Length of module name not including the path, this
-     field contains valid value only for NTOSKRNL module */
-	USHORT	NameLength;
-	USHORT  LoadCount;
-	USHORT  PathLength;
-	CHAR  ImageName[256];
-} SYSTEM_MODULE_INFORMATION_ENTRY, *PSYSTEM_MODULE_INFORMATION_ENTRY;
-
-typedef struct _SYSTEM_MODULE_INFORMATION {
-	ULONG  Count;
-  SYSTEM_MODULE_INFORMATION_ENTRY Module[1];
-} SYSTEM_MODULE_INFORMATION, *PSYSTEM_MODULE_INFORMATION;
-
-typedef struct _SYSTEM_LOCK_INFORMATION {
-	PVOID  Address;
-	USHORT  Type;
-	USHORT  Reserved1;
-	ULONG  ExclusiveOwnerThreadId;
-	ULONG  ActiveCount;
-	ULONG  ContentionCount;
-	ULONG  Reserved2[2];
-	ULONG  NumberOfSharedWaiters;
-	ULONG  NumberOfExclusiveWaiters;
-} SYSTEM_LOCK_INFORMATION, *PSYSTEM_LOCK_INFORMATION;
-
-/*SYSTEM_HANDLE_INFORMATION.Flags cosntants */
-#define PROTECT_FROM_CLOSE                0x01
-#define INHERIT                           0x02
-
-typedef struct _SYSTEM_HANDLE_INFORMATION {
-	ULONG  ProcessId;
-	UCHAR  ObjectTypeNumber;
-	UCHAR  Flags;
-	USHORT  Handle;
-	PVOID  Object;
-	ACCESS_MASK  GrantedAccess;
-} SYSTEM_HANDLE_INFORMATION, *PSYSTEM_HANDLE_INFORMATION;
-
-typedef struct _SYSTEM_OBJECT_TYPE_INFORMATION {
-	ULONG  NextEntryOffset;
-	ULONG  ObjectCount;
-	ULONG  HandleCount;
-	ULONG  TypeNumber;
-	ULONG  InvalidAttributes;
-	GENERIC_MAPPING  GenericMapping;
-	ACCESS_MASK  ValidAccessMask;
-	POOL_TYPE  PoolType;
-	UCHAR  Unknown;
-	UNICODE_STRING  Name;
-} SYSTEM_OBJECT_TYPE_INFORMATION, *PSYSTEM_OBJECT_TYPE_INFORMATION;
-
-/* SYSTEM_OBJECT_INFORMATION.Flags constants */
-#define FLG_SYSOBJINFO_SINGLE_HANDLE_ENTRY    0x40
-#define FLG_SYSOBJINFO_DEFAULT_SECURITY_QUOTA 0x20
-#define FLG_SYSOBJINFO_PERMANENT              0x10
-#define FLG_SYSOBJINFO_EXCLUSIVE              0x08
-#define FLG_SYSOBJINFO_CREATOR_INFO           0x04
-#define FLG_SYSOBJINFO_KERNEL_MODE            0x02
-
-typedef struct _SYSTEM_OBJECT_INFORMATION {
-	ULONG  NextEntryOffset;
-	PVOID  Object;
-	ULONG  CreatorProcessId;
-	USHORT  Unknown;
-	USHORT  Flags;
-	ULONG  PointerCount;
-	ULONG  HandleCount;
-	ULONG  PagedPoolUsage;
-	ULONG  NonPagedPoolUsage;
-	ULONG  ExclusiveProcessId;
-	PSECURITY_DESCRIPTOR  SecurityDescriptor;
-	UNICODE_STRING  Name;
-} SYSTEM_OBJECT_INFORMATION, *PSYSTEM_OBJECT_INFORMATION;
-
-typedef struct _SYSTEM_PAGEFILE_INFORMATION {
-	ULONG  NextEntryOffset;
-	ULONG  CurrentSize;
-	ULONG  TotalUsed;
-	ULONG  PeakUsed;
-	UNICODE_STRING  FileName;
-} SYSTEM_PAGEFILE_INFORMATION, *PSYSTEM_PAGEFILE_INFORMATION;
-
-typedef struct _SYSTEM_INSTRUCTION_EMULATION_INFORMATION {
-	ULONG  SegmentNotPresent;
-	ULONG  TwoByteOpcode;
-	ULONG  ESprefix;
-	ULONG  CSprefix;
-	ULONG  SSprefix;
-	ULONG  DSprefix;
-	ULONG  FSPrefix;
-	ULONG  GSprefix;
-	ULONG  OPER32prefix;
-	ULONG  ADDR32prefix;
-	ULONG  INSB;
-	ULONG  INSW;
-	ULONG  OUTSB;
-	ULONG  OUTSW;
-	ULONG  PUSHFD;
-	ULONG  POPFD;
-	ULONG  INTnn;
-	ULONG  INTO;
-	ULONG  IRETD;
-	ULONG  INBimm;
-	ULONG  INWimm;
-	ULONG  OUTBimm;
-	ULONG  OUTWimm;
-	ULONG  INB;
-	ULONG  INW;
-	ULONG  OUTB;
-	ULONG  OUTW;
-	ULONG  LOCKprefix;
-	ULONG  REPNEprefix;
-	ULONG  REPprefix;
-	ULONG  HLT;
-	ULONG  CLI;
-	ULONG  STI;
-	ULONG  GenericInvalidOpcode;
-} SYSTEM_INSTRUCTION_EMULATION_INFORMATION, *PSYSTEM_INSTRUCTION_EMULATION_INFORMATION;
-
-typedef struct _SYSTEM_POOL_TAG_INFORMATION {
-	CHAR  Tag[4];
-	ULONG  PagedPoolAllocs;
-	ULONG  PagedPoolFrees;
-	ULONG  PagedPoolUsage;
-	ULONG  NonPagedPoolAllocs;
-	ULONG  NonPagedPoolFrees;
-	ULONG  NonPagedPoolUsage;
-} SYSTEM_POOL_TAG_INFORMATION, *PSYSTEM_POOL_TAG_INFORMATION;
-
-typedef struct _SYSTEM_PROCESSOR_STATISTICS {
-	ULONG  ContextSwitches;
-	ULONG  DpcCount;
-	ULONG  DpcRequestRate;
-	ULONG  TimeIncrement;
-	ULONG  DpcBypassCount;
-	ULONG  ApcBypassCount;
-} SYSTEM_PROCESSOR_STATISTICS, *PSYSTEM_PROCESSOR_STATISTICS;
-
-typedef struct _SYSTEM_DPC_INFORMATION {
-	ULONG  Reserved;
-	ULONG  MaximumDpcQueueDepth;
-	ULONG  MinimumDpcRate;
-	ULONG  AdjustDpcThreshold;
-	ULONG  IdealDpcRate;
-} SYSTEM_DPC_INFORMATION, *PSYSTEM_DPC_INFORMATION;
-
-typedef struct _SYSTEM_LOAD_IMAGE {
-	UNICODE_STRING  ModuleName;
-	PVOID  ModuleBase;
-	PVOID  SectionPointer;
-	PVOID  EntryPoint;
-	PVOID  ExportDirectory;
-} SYSTEM_LOAD_IMAGE, *PSYSTEM_LOAD_IMAGE;
-
-typedef struct _SYSTEM_UNLOAD_IMAGE {
-  PVOID  ModuleBase;
-} SYSTEM_UNLOAD_IMAGE, *PSYSTEM_UNLOAD_IMAGE;
-
-typedef struct _SYSTEM_QUERY_TIME_ADJUSTMENT {
-	ULONG  TimeAdjustment;
-	ULONG  MaximumIncrement;
-	BOOLEAN  TimeSynchronization;
-} SYSTEM_QUERY_TIME_ADJUSTMENT, *PSYSTEM_QUERY_TIME_ADJUSTMENT;
-
-typedef struct _SYSTEM_SET_TIME_ADJUSTMENT {
-	ULONG  TimeAdjustment;
-	BOOLEAN  TimeSynchronization;
-} SYSTEM_SET_TIME_ADJUSTMENT, *PSYSTEM_SET_TIME_ADJUSTMENT;
-
-typedef struct _SYSTEM_CRASH_DUMP_INFORMATION {
-	HANDLE  CrashDumpSectionHandle;
-	HANDLE  Unknown;
-} SYSTEM_CRASH_DUMP_INFORMATION, *PSYSTEM_CRASH_DUMP_INFORMATION;
-
-typedef struct _SYSTEM_EXCEPTION_INFORMATION {
-	ULONG  AlignmentFixupCount;
-	ULONG  ExceptionDispatchCount;
-	ULONG  FloatingEmulationCount;
-	ULONG  Reserved;
-} SYSTEM_EXCEPTION_INFORMATION, *PSYSTEM_EXCEPTION_INFORMATION;
-
-typedef struct _SYSTEM_CRASH_DUMP_STATE_INFORMATION {
-	ULONG  CrashDumpSectionExists;
-	ULONG  Unknown;
-} SYSTEM_CRASH_DUMP_STATE_INFORMATION, *PSYSTEM_CRASH_DUMP_STATE_INFORMATION;
-
-typedef struct _SYSTEM_KERNEL_DEBUGGER_INFORMATION {
-	BOOLEAN  DebuggerEnabled;
-	BOOLEAN  DebuggerNotPresent;
-} SYSTEM_KERNEL_DEBUGGER_INFORMATION, *PSYSTEM_KERNEL_DEBUGGER_INFORMATION;
-
-typedef struct _SYSTEM_CONTEXT_SWITCH_INFORMATION {
-	ULONG  ContextSwitches;
-	ULONG  ContextSwitchCounters[11];
-} SYSTEM_CONTEXT_SWITCH_INFORMATION, *PSYSTEM_CONTEXT_SWITCH_INFORMATION;
-
-typedef struct _SYSTEM_REGISTRY_QUOTA_INFORMATION {
-	ULONG  RegistryQuota;
-	ULONG  RegistryQuotaInUse;
-	ULONG  PagedPoolSize;
-} SYSTEM_REGISTRY_QUOTA_INFORMATION, *PSYSTEM_REGISTRY_QUOTA_INFORMATION;
-
-typedef struct _SYSTEM_LOAD_AND_CALL_IMAGE {
-  UNICODE_STRING  ModuleName;
-} SYSTEM_LOAD_AND_CALL_IMAGE, *PSYSTEM_LOAD_AND_CALL_IMAGE;
-
-typedef struct _SYSTEM_PRIORITY_SEPARATION {
-  ULONG  PrioritySeparation;
-} SYSTEM_PRIORITY_SEPARATION, *PSYSTEM_PRIORITY_SEPARATION;
-
-typedef struct _SYSTEM_TIME_ZONE_INFORMATION {
-	LONG  Bias;
-	WCHAR  StandardName[32];
-	LARGE_INTEGER  StandardDate;
-	LONG  StandardBias;
-	WCHAR  DaylightName[32];
-	LARGE_INTEGER  DaylightDate;
-	LONG  DaylightBias;
-} SYSTEM_TIME_ZONE_INFORMATION, *PSYSTEM_TIME_ZONE_INFORMATION;
-
-typedef struct _SYSTEM_LOOKASIDE_INFORMATION {
-	USHORT  Depth;
-	USHORT  MaximumDepth;
-	ULONG  TotalAllocates;
-	ULONG  AllocateMisses;
-	ULONG  TotalFrees;
-	ULONG  FreeMisses;
-	POOL_TYPE  Type;
-	ULONG  Tag;
-	ULONG  Size;
-} SYSTEM_LOOKASIDE_INFORMATION, *PSYSTEM_LOOKASIDE_INFORMATION;
-
-typedef struct _SYSTEM_SET_TIME_SLIP_EVENT {
-  HANDLE  TimeSlipEvent;
-} SYSTEM_SET_TIME_SLIP_EVENT, *PSYSTEM_SET_TIME_SLIP_EVENT;
-
-typedef struct _SYSTEM_CREATE_SESSION {
-  ULONG  SessionId;
-} SYSTEM_CREATE_SESSION, *PSYSTEM_CREATE_SESSION;
-
-typedef struct _SYSTEM_DELETE_SESSION {
-  ULONG  SessionId;
-} SYSTEM_DELETE_SESSION, *PSYSTEM_DELETE_SESSION;
-
-typedef struct _SYSTEM_RANGE_START_INFORMATION {
-  PVOID  SystemRangeStart;
-} SYSTEM_RANGE_START_INFORMATION, *PSYSTEM_RANGE_START_INFORMATION;
-
-typedef struct _SYSTEM_SESSION_PROCESSES_INFORMATION {
-	ULONG  SessionId;
-	ULONG  BufferSize;
-	PVOID  Buffer;
-} SYSTEM_SESSION_PROCESSES_INFORMATION, *PSYSTEM_SESSION_PROCESSES_INFORMATION;
-
-typedef struct _SYSTEM_POOL_BLOCK {
-	BOOLEAN  Allocated;
-	USHORT  Unknown;
-	ULONG  Size;
-	CHAR  Tag[4];
-} SYSTEM_POOL_BLOCK, *PSYSTEM_POOL_BLOCK;
-
-typedef struct _SYSTEM_POOL_BLOCKS_INFORMATION {
-	ULONG  PoolSize;
-	PVOID  PoolBase;
-	USHORT  Unknown;
-	ULONG  NumberOfBlocks;
-	SYSTEM_POOL_BLOCK  PoolBlocks[1];
-} SYSTEM_POOL_BLOCKS_INFORMATION, *PSYSTEM_POOL_BLOCKS_INFORMATION;
-
-typedef struct _SYSTEM_MEMORY_USAGE {
-	PVOID  Name;
-	USHORT  Valid;
-	USHORT  Standby;
-	USHORT  Modified;
-	USHORT  PageTables;
-} SYSTEM_MEMORY_USAGE, *PSYSTEM_MEMORY_USAGE;
-
-typedef struct _SYSTEM_MEMORY_USAGE_INFORMATION {
-  	ULONG  Reserved;
-	PVOID  EndOfData;
-	SYSTEM_MEMORY_USAGE  MemoryUsage[1];
-} SYSTEM_MEMORY_USAGE_INFORMATION, *PSYSTEM_MEMORY_USAGE_INFORMATION;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtQuerySystemInformation(
-  IN SYSTEM_INFORMATION_CLASS  SystemInformationClass,
-  IN OUT PVOID  SystemInformation,
-  IN ULONG  SystemInformationLength,
-  OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQuerySystemInformation(
-  IN SYSTEM_INFORMATION_CLASS  SystemInformationClass,
-  IN OUT PVOID  SystemInformation,
-  IN ULONG  SystemInformationLength,
-  OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtQueryFullAttributesFile(
-	IN POBJECT_ATTRIBUTES ObjectAttributes,
-	OUT PFILE_NETWORK_OPEN_INFORMATION FileInformation);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryFullAttributesFile(
-	IN POBJECT_ATTRIBUTES ObjectAttributes,
- 	OUT PFILE_NETWORK_OPEN_INFORMATION FileInformation);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetSystemInformation(
-	IN SYSTEM_INFORMATION_CLASS  SystemInformationClass,
-	IN OUT PVOID  SystemInformation,
-	IN ULONG  SystemInformationLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQuerySystemEnvironmentValue(
-	IN PUNICODE_STRING  Name,
-	OUT PVOID  Value,
-	IN ULONG  ValueLength,
-	OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetSystemEnvironmentValue(
-	IN PUNICODE_STRING  Name,
-	IN PUNICODE_STRING  Value);
-
-typedef enum _SHUTDOWN_ACTION {
-	ShutdownNoReboot,
-	ShutdownReboot,
-	ShutdownPowerOff
-} SHUTDOWN_ACTION;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtShutdownSystem(
-  IN SHUTDOWN_ACTION  Action);
-
-typedef enum _DEBUG_CONTROL_CODE {
-  DebugGetTraceInformation = 1,
-	DebugSetInternalBreakpoint,
-	DebugSetSpecialCall,
-	DebugClearSpecialCalls,
-	DebugQuerySpecialCalls,
-	DebugDbgBreakPoint,
-	DebugMaximum
-} DEBUG_CONTROL_CODE;
-
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSystemDebugControl(
-	IN DEBUG_CONTROL_CODE  ControlCode,
-	IN PVOID  InputBuffer  OPTIONAL,
-	IN ULONG  InputBufferLength,
-	OUT PVOID  OutputBuffer  OPTIONAL,
-	IN ULONG  OutputBufferLength,
-	OUT PULONG  ReturnLength  OPTIONAL);
-
-
-
-/* Objects, Object directories, and symbolic links */
-
-typedef enum _OBJECT_INFORMATION_CLASS {
-	ObjectBasicInformation,
-	ObjectNameInformation,
-	ObjectTypeInformation,
-	ObjectAllTypesInformation,
-	ObjectHandleInformation
-} OBJECT_INFORMATION_CLASS;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryObject(
-	IN HANDLE  ObjectHandle,
-	IN OBJECT_INFORMATION_CLASS  ObjectInformationClass,
-	OUT PVOID  ObjectInformation,
-	IN ULONG  ObjectInformationLength,
-	OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetInformationObject(
-	IN HANDLE  ObjectHandle,
-	IN OBJECT_INFORMATION_CLASS  ObjectInformationClass,
-	IN PVOID  ObjectInformation,
-	IN ULONG  ObjectInformationLength);
-
-/* OBJECT_BASIC_INFORMATION.Attributes constants */
-/* also in winbase.h */
-//#define HANDLE_FLAG_INHERIT               0x01
-//#define HANDLE_FLAG_PROTECT_FROM_CLOSE    0x02
-/* end winbase.h */
-#define PERMANENT                         0x10
-#define EXCLUSIVE                         0x20
-
-typedef struct _OBJECT_BASIC_INFORMATION {
-	ULONG  Attributes;
-	ACCESS_MASK  GrantedAccess;
-	ULONG  HandleCount;
-	ULONG  PointerCount;
-	ULONG  PagedPoolUsage;
-	ULONG  NonPagedPoolUsage;
-	ULONG  Reserved[3];
-	ULONG  NameInformationLength;
-	ULONG  TypeInformationLength;
-	ULONG  SecurityDescriptorLength;
-	LARGE_INTEGER  CreateTime;
-} OBJECT_BASIC_INFORMATION, *POBJECT_BASIC_INFORMATION;
-#if 0
-/* FIXME: Enable later */
-typedef struct _OBJECT_TYPE_INFORMATION {
-	UNICODE_STRING  Name;
-	ULONG  ObjectCount;
-	ULONG  HandleCount;
-	ULONG  Reserved1[4];
-	ULONG  PeakObjectCount;
-	ULONG  PeakHandleCount;
-	ULONG  Reserved2[4];
-	ULONG  InvalidAttributes;
-	GENERIC_MAPPING  GenericMapping;
-	ULONG  ValidAccess;
-	UCHAR  Unknown;
-	BOOLEAN  MaintainHandleDatabase;
-	POOL_TYPE  PoolType;
-	ULONG  PagedPoolUsage;
-	ULONG  NonPagedPoolUsage;
-} OBJECT_TYPE_INFORMATION, *POBJECT_TYPE_INFORMATION;
-
-typedef struct _OBJECT_ALL_TYPES_INFORMATION {
-  ULONG  NumberOfTypes;
-  OBJECT_TYPE_INFORMATION  TypeInformation;
-} OBJECT_ALL_TYPES_INFORMATION, *POBJECT_ALL_TYPES_INFORMATION;
-#endif
-typedef struct _OBJECT_HANDLE_ATTRIBUTE_INFORMATION {
-  BOOLEAN  Inherit;
-  BOOLEAN  ProtectFromClose;
-} OBJECT_HANDLE_ATTRIBUTE_INFORMATION, *POBJECT_HANDLE_ATTRIBUTE_INFORMATION;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtDuplicateObject(
-  IN HANDLE  SourceProcessHandle,
-  IN HANDLE  SourceHandle,
-  IN HANDLE  TargetProcessHandle,
-  OUT PHANDLE  TargetHandle  OPTIONAL,
-  IN ACCESS_MASK  DesiredAccess,
-  IN ULONG  Attributes,
-  IN ULONG  Options);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwDuplicateObject(
-  IN HANDLE  SourceProcessHandle,
-  IN HANDLE  SourceHandle,
-  IN HANDLE  TargetProcessHandle,
-  OUT PHANDLE  TargetHandle  OPTIONAL,
-  IN ACCESS_MASK  DesiredAccess,
-  IN ULONG  Attributes,
-  IN ULONG  Options);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtQuerySecurityObject(
-  IN HANDLE Handle,
-  IN SECURITY_INFORMATION  SecurityInformation,
-  OUT PSECURITY_DESCRIPTOR  SecurityDescriptor,
-  IN ULONG  SecurityDescriptorLength,
-  OUT PULONG  ReturnLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQuerySecurityObject(
-  IN HANDLE Handle,
-  IN SECURITY_INFORMATION  SecurityInformation,
-  OUT PSECURITY_DESCRIPTOR  SecurityDescriptor,
-  IN ULONG  SecurityDescriptorLength,
-  OUT PULONG  ReturnLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtSetSecurityObject(
-  IN HANDLE  Handle,
-  IN SECURITY_INFORMATION  SecurityInformation,
-  IN PSECURITY_DESCRIPTOR  SecurityDescriptor);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetSecurityObject(
-  IN HANDLE  Handle,
-  IN SECURITY_INFORMATION  SecurityInformation,
-  IN PSECURITY_DESCRIPTOR  SecurityDescriptor);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwOpenDirectoryObject(
-  OUT PHANDLE  DirectoryHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  IN POBJECT_ATTRIBUTES  ObjectAttributes);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryDirectoryObject(
-  IN HANDLE  DirectoryHandle,
-  OUT PVOID  Buffer,
-  IN ULONG  BufferLength,
-  IN BOOLEAN  ReturnSingleEntry,
-  IN BOOLEAN  RestartScan,
-  IN OUT PULONG  Context,
-  OUT PULONG  ReturnLength  OPTIONAL);
-
-typedef struct _DIRECTORY_BASIC_INFORMATION {
-  UNICODE_STRING  ObjectName;
-  UNICODE_STRING  ObjectTypeName;
-} DIRECTORY_BASIC_INFORMATION, *PDIRECTORY_BASIC_INFORMATION;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreateSymbolicLinkObject(
-  OUT PHANDLE  SymbolicLinkHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  IN POBJECT_ATTRIBUTES  ObjectAttributes,
-  IN PUNICODE_STRING  TargetName);
-
-
-
-
-/* Virtual memory */
-
-typedef enum _MEMORY_INFORMATION_CLASS {
-MemoryBasicInformation,
-MemoryWorkingSetList,
-MemorySectionName,
-MemoryBasicVlmInformation
-} MEMORY_INFORMATION_CLASS;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtAllocateVirtualMemory(
-  IN HANDLE  ProcessHandle,
-  IN OUT PVOID  *BaseAddress,
-  IN ULONG  ZeroBits,
-  IN OUT PULONG  AllocationSize,
-  IN ULONG  AllocationType,
-  IN ULONG  Protect);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAllocateVirtualMemory(
-  IN HANDLE  ProcessHandle,
-  IN OUT PVOID  *BaseAddress,
-  IN ULONG  ZeroBits,
-  IN OUT PULONG  AllocationSize,
-  IN ULONG  AllocationType,
-  IN ULONG  Protect);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtFreeVirtualMemory(
-  IN HANDLE  ProcessHandle,
-  IN OUT PVOID  *BaseAddress,
-  IN OUT PULONG  FreeSize,
-  IN ULONG  FreeType);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwFreeVirtualMemory(
-  IN HANDLE  ProcessHandle,
-  IN OUT PVOID  *BaseAddress,
-  IN OUT PULONG  FreeSize,
-  IN ULONG  FreeType);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryVirtualMemory(
-	IN HANDLE  ProcessHandle,
-	IN PVOID  BaseAddress,
-	IN MEMORY_INFORMATION_CLASS  MemoryInformationClass,
-	OUT PVOID  MemoryInformation,
-	IN ULONG  MemoryInformationLength,
-	OUT PULONG  ReturnLength  OPTIONAL);
-
-/* MEMORY_WORKING_SET_LIST.WorkingSetList constants */
-#define WSLE_PAGE_READONLY                0x001
-#define WSLE_PAGE_EXECUTE                 0x002
-#define WSLE_PAGE_READWRITE               0x004
-#define WSLE_PAGE_EXECUTE_READ            0x003
-#define WSLE_PAGE_WRITECOPY               0x005
-#define WSLE_PAGE_EXECUTE_READWRITE       0x006
-#define WSLE_PAGE_EXECUTE_WRITECOPY       0x007
-#define WSLE_PAGE_SHARE_COUNT_MASK        0x0E0
-#define WSLE_PAGE_SHAREABLE               0x100
-
-typedef struct _MEMORY_WORKING_SET_LIST {
-  ULONG  NumberOfPages;
-  ULONG  WorkingSetList[1];
-} MEMORY_WORKING_SET_LIST, *PMEMORY_WORKING_SET_LIST;
-
-typedef struct _MEMORY_SECTION_NAME {
-  UNICODE_STRING  SectionFileName;
-} MEMORY_SECTION_NAME, *PMEMORY_SECTION_NAME;
-
-/* Zw[Lock|Unlock]VirtualMemory.LockType constants */
-#define LOCK_VM_IN_WSL                    0x01
-#define LOCK_VM_IN_RAM                    0x02
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwLockVirtualMemory(
-	IN HANDLE  ProcessHandle,
-	IN OUT PVOID  *BaseAddress,
-	IN OUT PULONG  LockSize,
-	IN ULONG  LockType);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwUnlockVirtualMemory(
-	IN HANDLE  ProcessHandle,
-	IN OUT PVOID  *BaseAddress,
-	IN OUT PULONG  LockSize,
-	IN ULONG  LockType);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwReadVirtualMemory(
-	IN HANDLE  ProcessHandle,
-	IN PVOID  BaseAddress,
-	OUT PVOID  Buffer,
-	IN ULONG  BufferLength,
-	OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwWriteVirtualMemory(
-	IN HANDLE  ProcessHandle,
-	IN PVOID  BaseAddress,
-	IN PVOID  Buffer,
-	IN ULONG  BufferLength,
-	OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwProtectVirtualMemory(
-	IN HANDLE  ProcessHandle,
-	IN OUT PVOID  *BaseAddress,
-	IN OUT PULONG  ProtectSize,
-	IN ULONG  NewProtect,
-	OUT PULONG  OldProtect);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwFlushVirtualMemory(
-	IN HANDLE  ProcessHandle,
-	IN OUT PVOID  *BaseAddress,
-	IN OUT PULONG  FlushSize,
-	OUT PIO_STATUS_BLOCK  IoStatusBlock);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAllocateUserPhysicalPages(
-	IN HANDLE  ProcessHandle,
-	IN PULONG  NumberOfPages,
-	OUT PULONG  PageFrameNumbers);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwFreeUserPhysicalPages(
-	IN HANDLE  ProcessHandle,
-	IN OUT PULONG  NumberOfPages,
-	IN PULONG  PageFrameNumbers);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwMapUserPhysicalPages(
-	IN PVOID  BaseAddress,
-	IN PULONG  NumberOfPages,
-	IN PULONG  PageFrameNumbers);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwMapUserPhysicalPagesScatter(
-	IN PVOID  *BaseAddresses,
-	IN PULONG  NumberOfPages,
-	IN PULONG  PageFrameNumbers);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwGetWriteWatch(
-	IN HANDLE  ProcessHandle,
-	IN ULONG  Flags,
-	IN PVOID  BaseAddress,
-	IN ULONG  RegionSize,
-	OUT PULONG  Buffer,
-	IN OUT PULONG  BufferEntries,
-	OUT PULONG  Granularity);
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwOpenSection(
-    OUT PHANDLE SectionHandle,
-    IN ACCESS_MASK DesiredAccess,
-    IN POBJECT_ATTRIBUTES ObjectAttributes
-    );
-
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwResetWriteWatch(
-	IN HANDLE  ProcessHandle,
-	IN PVOID  BaseAddress,
-	IN ULONG  RegionSize);
-
-
-
-
-/* Sections */
-
-typedef enum _SECTION_INFORMATION_CLASS {
-  SectionBasicInformation,
-  SectionImageInformation
-} SECTION_INFORMATION_CLASS;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtCreateSection(
-  OUT PHANDLE  SectionHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  IN POBJECT_ATTRIBUTES  ObjectAttributes,
-  IN PLARGE_INTEGER  SectionSize  OPTIONAL,
-  IN ULONG  Protect,
-  IN ULONG  Attributes,
-  IN HANDLE  FileHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreateSection(
-  OUT PHANDLE  SectionHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  IN POBJECT_ATTRIBUTES  ObjectAttributes,
-  IN PLARGE_INTEGER  SectionSize  OPTIONAL,
-  IN ULONG  Protect,
-  IN ULONG  Attributes,
-  IN HANDLE  FileHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQuerySection(
-	IN HANDLE  SectionHandle,
-	IN SECTION_INFORMATION_CLASS  SectionInformationClass,
-	OUT PVOID  SectionInformation,
-	IN ULONG  SectionInformationLength,
-  OUT PULONG  ResultLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwExtendSection(
-	IN HANDLE  SectionHandle,
-	IN PLARGE_INTEGER  SectionSize);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAreMappedFilesTheSame(
-	IN PVOID  Address1,
-	IN PVOID  Address2);
-
-
-
-
-/* Threads */
-
-typedef struct _USER_STACK {
-	PVOID  FixedStackBase;
-	PVOID  FixedStackLimit;
-	PVOID  ExpandableStackBase;
-	PVOID  ExpandableStackLimit;
-	PVOID  ExpandableStackBottom;
-} USER_STACK, *PUSER_STACK;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreateThread(
-	OUT PHANDLE  ThreadHandle,
-	IN ACCESS_MASK  DesiredAccess,
-	IN POBJECT_ATTRIBUTES  ObjectAttributes,
-	IN HANDLE  ProcessHandle,
-	OUT PCLIENT_ID  ClientId,
-	IN PCONTEXT  ThreadContext,
-	IN PUSER_STACK  UserStack,
-	IN BOOLEAN  CreateSuspended);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtOpenThread(
-  OUT PHANDLE  ThreadHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  IN POBJECT_ATTRIBUTES  ObjectAttributes,
-  IN PCLIENT_ID  ClientId);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwOpenThread(
-  OUT PHANDLE  ThreadHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  IN POBJECT_ATTRIBUTES  ObjectAttributes,
-  IN PCLIENT_ID  ClientId);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwTerminateThread(
-	IN HANDLE  ThreadHandle  OPTIONAL,
-	IN NTSTATUS  ExitStatus);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtQueryInformationThread(
-  IN HANDLE  ThreadHandle,
-  IN THREADINFOCLASS  ThreadInformationClass,
-  OUT PVOID  ThreadInformation,
-  IN ULONG  ThreadInformationLength,
-  OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryInformationThread(
-  IN HANDLE  ThreadHandle,
-  IN THREADINFOCLASS  ThreadInformationClass,
-  OUT PVOID  ThreadInformation,
-  IN ULONG  ThreadInformationLength,
-  OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtSetInformationThread(
-  IN HANDLE  ThreadHandle,
-  IN THREADINFOCLASS  ThreadInformationClass,
-  IN PVOID  ThreadInformation,
-  IN ULONG  ThreadInformationLength);
-
-typedef struct _THREAD_BASIC_INFORMATION {
-	NTSTATUS  ExitStatus;
-	PNT_TIB  TebBaseAddress;
-	CLIENT_ID  ClientId;
-	KAFFINITY  AffinityMask;
-	KPRIORITY  Priority;
-	KPRIORITY  BasePriority;
-} THREAD_BASIC_INFORMATION, *PTHREAD_BASIC_INFORMATION;
-
-typedef struct _KERNEL_USER_TIMES {
-	LARGE_INTEGER  CreateTime;
-	LARGE_INTEGER  ExitTime;
-	LARGE_INTEGER  KernelTime;
-	LARGE_INTEGER  UserTime;
-} KERNEL_USER_TIMES, *PKERNEL_USER_TIMES;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSuspendThread(
-  IN HANDLE  ThreadHandle,
-  OUT PULONG  PreviousSuspendCount  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwResumeThread(
-  IN HANDLE  ThreadHandle,
-  OUT PULONG  PreviousSuspendCount  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwGetContextThread(
-  IN HANDLE  ThreadHandle,
-  OUT PCONTEXT  Context);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetContextThread(
-	IN HANDLE  ThreadHandle,
-	IN PCONTEXT  Context);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueueApcThread(
-	IN HANDLE  ThreadHandle,
-	IN PKNORMAL_ROUTINE  ApcRoutine,
-	IN PVOID  ApcContext  OPTIONAL,
-	IN PVOID  Argument1  OPTIONAL,
-	IN PVOID  Argument2  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwTestAlert(
-  VOID);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAlertThread(
-  IN HANDLE  ThreadHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAlertResumeThread(
-  IN HANDLE  ThreadHandle,
-  OUT PULONG  PreviousSuspendCount  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwRegisterThreadTerminatePort(
-  IN HANDLE  PortHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwImpersonateThread(
-	IN HANDLE  ThreadHandle,
-	IN HANDLE  TargetThreadHandle,
-	IN PSECURITY_QUALITY_OF_SERVICE  SecurityQos);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwImpersonateAnonymousToken(
-  IN HANDLE  ThreadHandle);
-
-
-
-
-/* Processes */
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreateProcess(
-	OUT PHANDLE  ProcessHandle,
-	IN ACCESS_MASK  DesiredAccess,
-	IN POBJECT_ATTRIBUTES  ObjectAttributes,
-	IN HANDLE  InheritFromProcessHandle,
-	IN BOOLEAN  InheritHandles,
-	IN HANDLE  SectionHandle  OPTIONAL,
-	IN HANDLE  DebugPort  OPTIONAL,
-	IN HANDLE  ExceptionPort  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreateProcess(
-	OUT PHANDLE  ProcessHandle,
-	IN ACCESS_MASK  DesiredAccess,
-	IN POBJECT_ATTRIBUTES  ObjectAttributes,
-	IN HANDLE  InheritFromProcessHandle,
-	IN BOOLEAN  InheritHandles,
-	IN HANDLE  SectionHandle  OPTIONAL,
-	IN HANDLE  DebugPort  OPTIONAL,
-	IN HANDLE  ExceptionPort  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwTerminateProcess(
-	IN HANDLE  ProcessHandle  OPTIONAL,
-	IN NTSTATUS  ExitStatus);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryInformationProcess(
-  IN HANDLE  ProcessHandle,
-  IN PROCESSINFOCLASS  ProcessInformationClass,
-  OUT PVOID  ProcessInformation,
-  IN ULONG  ProcessInformationLength,
-  OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtSetInformationProcess(
-  IN HANDLE  ProcessHandle,
-  IN PROCESSINFOCLASS  ProcessInformationClass,
-  IN PVOID  ProcessInformation,
-  IN ULONG  ProcessInformationLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetInformationProcess(
-  IN HANDLE  ProcessHandle,
-  IN PROCESSINFOCLASS  ProcessInformationClass,
-  IN PVOID  ProcessInformation,
-  IN ULONG  ProcessInformationLength);
-
-typedef struct _PROCESS_BASIC_INFORMATION {
-	NTSTATUS  ExitStatus;
-	PPEB  PebBaseAddress;
-	KAFFINITY  AffinityMask;
-	KPRIORITY  BasePriority;
-	ULONG  UniqueProcessId;
-	ULONG  InheritedFromUniqueProcessId;
-} PROCESS_BASIC_INFORMATION, *PPROCESS_BASIC_INFORMATION;
-
-typedef struct _PROCESS_ACCESS_TOKEN {
-  HANDLE  Token;
-  HANDLE  Thread;
-} PROCESS_ACCESS_TOKEN, *PPROCESS_ACCESS_TOKEN;
-
-/* DefaultHardErrorMode constants */
-/* also in winbase.h */
-#define SEM_FAILCRITICALERRORS            0x0001
-#define SEM_NOGPFAULTERRORBOX             0x0002
-#define SEM_NOALIGNMENTFAULTEXCEPT        0x0004
-#define SEM_NOOPENFILEERRORBOX            0x8000
-/* end winbase.h */
-typedef struct _POOLED_USAGE_AND_LIMITS {
-	ULONG  PeakPagedPoolUsage;
-	ULONG  PagedPoolUsage;
-	ULONG  PagedPoolLimit;
-	ULONG  PeakNonPagedPoolUsage;
-	ULONG  NonPagedPoolUsage;
-	ULONG  NonPagedPoolLimit;
-	ULONG  PeakPagefileUsage;
-	ULONG  PagefileUsage;
-	ULONG  PagefileLimit;
-} POOLED_USAGE_AND_LIMITS, *PPOOLED_USAGE_AND_LIMITS;
-
-typedef struct _PROCESS_WS_WATCH_INFORMATION {
-  PVOID  FaultingPc;
-  PVOID  FaultingVa;
-} PROCESS_WS_WATCH_INFORMATION, *PPROCESS_WS_WATCH_INFORMATION;
-
-/* PROCESS_PRIORITY_CLASS.PriorityClass constants */
-#define PC_IDLE                           1
-#define PC_NORMAL                         2
-#define PC_HIGH                           3
-#define PC_REALTIME                       4
-#define PC_BELOW_NORMAL                   5
-#define PC_ABOVE_NORMAL                   6
-
-typedef struct _PROCESS_PRIORITY_CLASS {
-  BOOLEAN  Foreground;
-  UCHAR  PriorityClass;
-} PROCESS_PRIORITY_CLASS, *PPROCESS_PRIORITY_CLASS;
-
-/* PROCESS_DEVICEMAP_INFORMATION.DriveType constants */
-#define DRIVE_UNKNOWN                     0
-#define DRIVE_NO_ROOT_DIR                 1
-#define DRIVE_REMOVABLE                   2
-#define DRIVE_FIXED                       3
-#define DRIVE_REMOTE                      4
-#define DRIVE_CDROM                       5
-#define DRIVE_RAMDISK                     6
-
-typedef struct _PROCESS_DEVICEMAP_INFORMATION {
-    union {
-        struct {
-            HANDLE DirectoryHandle;
-        } Set;
-        struct {
-            ULONG DriveMap;
-            UCHAR DriveType[ 32 ];
-        } Query;
-    };
-} PROCESS_DEVICEMAP_INFORMATION, *PPROCESS_DEVICEMAP_INFORMATION;
-
-typedef struct _PROCESS_SESSION_INFORMATION {
-  ULONG  SessionId;
-} PROCESS_SESSION_INFORMATION, *PPROCESS_SESSION_INFORMATION;
-
-typedef struct _RTL_USER_PROCESS_PARAMETERS {
-	ULONG  AllocationSize;
-	ULONG  Size;
-	ULONG  Flags;
-	ULONG  DebugFlags;
-	HANDLE  hConsole;
-	ULONG  ProcessGroup;
-	HANDLE  hStdInput;
-	HANDLE  hStdOutput;
-	HANDLE  hStdError;
-	UNICODE_STRING  CurrentDirectoryName;
-	HANDLE  CurrentDirectoryHandle;
-	UNICODE_STRING  DllPath;
-	UNICODE_STRING  ImagePathName;
-	UNICODE_STRING  CommandLine;
-	PWSTR  Environment;
-	ULONG  dwX;
-	ULONG  dwY;
-	ULONG  dwXSize;
-	ULONG  dwYSize;
-	ULONG  dwXCountChars;
-	ULONG  dwYCountChars;
-	ULONG  dwFillAttribute;
-	ULONG  dwFlags;
-	ULONG  wShowWindow;
-	UNICODE_STRING  WindowTitle;
-	UNICODE_STRING  DesktopInfo;
-	UNICODE_STRING  ShellInfo;
-	UNICODE_STRING  RuntimeInfo;
-} RTL_USER_PROCESS_PARAMETERS, *PRTL_USER_PROCESS_PARAMETERS;
-
-NTSTATUS
-NTAPI
-RtlCreateProcessParameters(
-	OUT PRTL_USER_PROCESS_PARAMETERS  *ProcessParameters,
-	IN PUNICODE_STRING  ImageFile,
-	IN PUNICODE_STRING  DllPath  OPTIONAL,
-	IN PUNICODE_STRING  CurrentDirectory  OPTIONAL,
-	IN PUNICODE_STRING  CommandLine  OPTIONAL,
-	IN PWSTR  Environment OPTIONAL,
-	IN PUNICODE_STRING  WindowTitle  OPTIONAL,
-	IN PUNICODE_STRING  DesktopInfo  OPTIONAL,
-	IN PUNICODE_STRING  ShellInfo  OPTIONAL,
-	IN PUNICODE_STRING  RuntimeInfo  OPTIONAL);
-
-NTSTATUS
-NTAPI
-RtlDestroyProcessParameters(
-  IN PRTL_USER_PROCESS_PARAMETERS  ProcessParameters);
-
-typedef struct _DEBUG_BUFFER {
-	HANDLE  SectionHandle;
-	PVOID  SectionBase;
-	PVOID  RemoteSectionBase;
-	ULONG  SectionBaseDelta;
-	HANDLE  EventPairHandle;
-	ULONG  Unknown[2];
-	HANDLE  RemoteThreadHandle;
-	ULONG  InfoClassMask;
-	ULONG  SizeOfInfo;
-	ULONG  AllocatedSize;
-	ULONG  SectionSize;
-	PVOID  ModuleInformation;
-	PVOID  BackTraceInformation;
-	PVOID  HeapInformation;
-	PVOID  LockInformation;
-	PVOID  Reserved[8];
-} DEBUG_BUFFER, *PDEBUG_BUFFER;
-
-PDEBUG_BUFFER
-NTAPI
-RtlCreateQueryDebugBuffer(
-	IN ULONG  Size,
-	IN BOOLEAN  EventPair);
-
-/* RtlQueryProcessDebugInformation.DebugInfoClassMask constants */
-#define PDI_MODULES                       0x01
-#define PDI_BACKTRACE                     0x02
-#define PDI_HEAPS                         0x04
-#define PDI_HEAP_TAGS                     0x08
-#define PDI_HEAP_BLOCKS                   0x10
-#define PDI_LOCKS                         0x20
-
-NTSTATUS
-NTAPI
-RtlQueryProcessDebugInformation(
-	IN ULONG  ProcessId,
-	IN ULONG  DebugInfoClassMask,
-	IN OUT PDEBUG_BUFFER  DebugBuffer);
-
-NTSTATUS
-NTAPI
-RtlDestroyQueryDebugBuffer(
-  IN PDEBUG_BUFFER  DebugBuffer);
-
-/* DEBUG_MODULE_INFORMATION.Flags constants */
-#define LDRP_STATIC_LINK                  0x00000002
-#define LDRP_IMAGE_DLL                    0x00000004
-#define LDRP_LOAD_IN_PROGRESS             0x00001000
-#define LDRP_UNLOAD_IN_PROGRESS           0x00002000
-#define LDRP_ENTRY_PROCESSED              0x00004000
-#define LDRP_ENTRY_INSERTED               0x00008000
-#define LDRP_CURRENT_LOAD                 0x00010000
-#define LDRP_FAILED_BUILTIN_LOAD          0x00020000
-#define LDRP_DONT_CALL_FOR_THREADS        0x00040000
-#define LDRP_PROCESS_ATTACH_CALLED        0x00080000
-#define LDRP_DEBUG_SYMBOLS_LOADED         0x00100000
-#define LDRP_IMAGE_NOT_AT_BASE            0x00200000
-#define LDRP_WX86_IGNORE_MACHINETYPE      0x00400000
-
-typedef struct _DEBUG_MODULE_INFORMATION {
-	ULONG  Reserved[2];
-	ULONG  Base;
-	ULONG  Size;
-	ULONG  Flags;
-	USHORT  Index;
-	USHORT  Unknown;
-	USHORT  LoadCount;
-	USHORT  ModuleNameOffset;
-	CHAR  ImageName[256];
-} DEBUG_MODULE_INFORMATION, *PDEBUG_MODULE_INFORMATION;
-
-typedef struct _DEBUG_HEAP_INFORMATION {
-	ULONG  Base;
-	ULONG  Flags;
-	USHORT  Granularity;
-	USHORT  Unknown;
-	ULONG  Allocated;
-	ULONG  Committed;
-	ULONG  TagCount;
-	ULONG  BlockCount;
-	ULONG  Reserved[7];
-	PVOID  Tags;
-	PVOID  Blocks;
-} DEBUG_HEAP_INFORMATION, *PDEBUG_HEAP_INFORMATION;
-
-typedef struct _DEBUG_LOCK_INFORMATION {
-	PVOID  Address;
-	USHORT  Type;
-	USHORT  CreatorBackTraceIndex;
-	ULONG  OwnerThreadId;
-	ULONG  ActiveCount;
-	ULONG  ContentionCount;
-	ULONG  EntryCount;
-	ULONG  RecursionCount;
-	ULONG  NumberOfSharedWaiters;
-	ULONG  NumberOfExclusiveWaiters;
-} DEBUG_LOCK_INFORMATION, *PDEBUG_LOCK_INFORMATION;
-
-
-
-/* Jobs */
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreateJobObject(
-	OUT PHANDLE  JobHandle,
-	IN ACCESS_MASK  DesiredAccess,
-	IN POBJECT_ATTRIBUTES  ObjectAttributes);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwOpenJobObject(
-	OUT PHANDLE  JobHandle,
-	IN ACCESS_MASK  DesiredAccess,
-	IN POBJECT_ATTRIBUTES  ObjectAttributes);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwTerminateJobObject(
-	IN HANDLE  JobHandle,
-	IN NTSTATUS  ExitStatus);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAssignProcessToJobObject(
-	IN HANDLE  JobHandle,
-	IN HANDLE  ProcessHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryInformationJobObject(
-	IN HANDLE  JobHandle,
-	IN JOBOBJECTINFOCLASS  JobInformationClass,
-	OUT PVOID  JobInformation,
-	IN ULONG  JobInformationLength,
-	OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetInformationJobObject(
-	IN HANDLE  JobHandle,
-	IN JOBOBJECTINFOCLASS  JobInformationClass,
-	IN PVOID  JobInformation,
-	IN ULONG  JobInformationLength);
-
-
-/* Tokens */
-
-#define SE_DEBUG_PRIVILEGE			20L
-#define STATUS_NOT_ALL_ASSIGNED		((NTSTATUS)0x00000106L)
-#define STATUS_PRIVILEGE_NOT_HELD	((NTSTATUS)0xC0000061L)
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreateToken(
-OUT PHANDLE TokenHandle,
-IN ACCESS_MASK DesiredAccess,
-IN POBJECT_ATTRIBUTES ObjectAttributes,
-IN TOKEN_TYPE Type,
-IN PLUID AuthenticationId,
-IN PLARGE_INTEGER ExpirationTime,
-IN PTOKEN_USER User,
-IN PTOKEN_GROUPS Groups,
-IN PTOKEN_PRIVILEGES Privileges,
-IN PTOKEN_OWNER Owner,
-IN PTOKEN_PRIMARY_GROUP PrimaryGroup,
-IN PTOKEN_DEFAULT_DACL DefaultDacl,
-IN PTOKEN_SOURCE Source
-);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwOpenProcess (
-    __out PHANDLE  ProcessHandle,
-    __in ACCESS_MASK  DesiredAccess,
-    __in POBJECT_ATTRIBUTES  ObjectAttributes,
-    __in_opt PCLIENT_ID  ClientId
-    );
-
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwClose(
-    IN HANDLE  Handle
-    );
-
-
-NTOSAPI
-NTSTATUS
-NTAPI
-  ZwMakeTemporaryObject(
-    IN HANDLE  Handle
-    );
-
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtOpenProcessToken(
-  IN HANDLE  ProcessHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  OUT PHANDLE  TokenHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwOpenProcessToken(
-  IN HANDLE  ProcessHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  OUT PHANDLE  TokenHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtOpenThreadToken(
-  IN HANDLE  ThreadHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  IN BOOLEAN  OpenAsSelf,
-  OUT PHANDLE  TokenHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwOpenThreadToken(
-  IN HANDLE  ThreadHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  IN BOOLEAN  OpenAsSelf,
-  OUT PHANDLE  TokenHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtDuplicateToken(
-  IN HANDLE  ExistingTokenHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  IN POBJECT_ATTRIBUTES  ObjectAttributes,
-  IN BOOLEAN  EffectiveOnly,
-  IN TOKEN_TYPE  TokenType,
-  OUT PHANDLE  NewTokenHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwDuplicateToken(
-  IN HANDLE  ExistingTokenHandle,
-  IN ACCESS_MASK  DesiredAccess,
-  IN POBJECT_ATTRIBUTES  ObjectAttributes,
-  IN BOOLEAN  EffectiveOnly,
-  IN TOKEN_TYPE  TokenType,
-  OUT PHANDLE  NewTokenHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwFilterToken(
-	IN HANDLE  ExistingTokenHandle,
-	IN ULONG  Flags,
-	IN PTOKEN_GROUPS  SidsToDisable,
-	IN PTOKEN_PRIVILEGES  PrivilegesToDelete,
-	IN PTOKEN_GROUPS  SidsToRestricted,
-	OUT PHANDLE  NewTokenHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtAdjustPrivilegesToken(
-  IN HANDLE  TokenHandle,
-  IN BOOLEAN  DisableAllPrivileges,
-  IN PTOKEN_PRIVILEGES  NewState,
-  IN ULONG  BufferLength,
-  OUT PTOKEN_PRIVILEGES  PreviousState  OPTIONAL,
-  OUT PULONG  ReturnLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAdjustPrivilegesToken(
-  IN HANDLE  TokenHandle,
-  IN BOOLEAN  DisableAllPrivileges,
-  IN PTOKEN_PRIVILEGES  NewState,
-  IN ULONG  BufferLength,
-  OUT PTOKEN_PRIVILEGES  PreviousState  OPTIONAL,
-  OUT PULONG  ReturnLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAdjustGroupsToken(
-	IN HANDLE  TokenHandle,
-	IN BOOLEAN  ResetToDefault,
-	IN PTOKEN_GROUPS  NewState,
-	IN ULONG  BufferLength,
-	OUT PTOKEN_GROUPS  PreviousState  OPTIONAL,
-	OUT PULONG  ReturnLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtQueryInformationToken(
-  IN HANDLE  TokenHandle,
-  IN TOKEN_INFORMATION_CLASS  TokenInformationClass,
-  OUT PVOID  TokenInformation,
-  IN ULONG  TokenInformationLength,
-  OUT PULONG  ReturnLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryInformationToken(
-  IN HANDLE  TokenHandle,
-  IN TOKEN_INFORMATION_CLASS  TokenInformationClass,
-  OUT PVOID  TokenInformation,
-  IN ULONG  TokenInformationLength,
-  OUT PULONG  ReturnLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetInformationToken(
-	IN HANDLE  TokenHandle,
-	IN TOKEN_INFORMATION_CLASS  TokenInformationClass,
-	IN PVOID  TokenInformation,
-  IN ULONG  TokenInformationLength);
-
-
-
-
-/* Time */
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQuerySystemTime(
-  OUT PLARGE_INTEGER  CurrentTime);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetSystemTime(
-  IN PLARGE_INTEGER  NewTime,
-  OUT PLARGE_INTEGER  OldTime  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryPerformanceCounter(
-  OUT PLARGE_INTEGER  PerformanceCount,
-  OUT PLARGE_INTEGER  PerformanceFrequency  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryPerformanceCounter(
-  OUT PLARGE_INTEGER  PerformanceCount,
-  OUT PLARGE_INTEGER  PerformanceFrequency  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryTimerResolution(
-	OUT PULONG  CoarsestResolution,
-	OUT PULONG  FinestResolution,
-	OUT PULONG  ActualResolution);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwDelayExecution(
-  IN BOOLEAN  Alertable,
-  IN PLARGE_INTEGER  Interval);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwYieldExecution(
-  VOID);
-
-NTOSAPI
-ULONG
-NTAPI
-ZwGetTickCount(
-  VOID);
-
-
-
-
-/* Execution profiling */
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreateProfile(
-	OUT PHANDLE  ProfileHandle,
-	IN HANDLE  ProcessHandle,
-	IN PVOID  Base,
-	IN ULONG  Size,
-	IN ULONG  BucketShift,
-	IN PULONG  Buffer,
-	IN ULONG  BufferLength,
-	IN KPROFILE_SOURCE  Source,
-	IN ULONG  ProcessorMask);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetIntervalProfile(
-  IN ULONG  Interval,
-  IN KPROFILE_SOURCE  Source);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryIntervalProfile(
-	IN KPROFILE_SOURCE  Source,
-	OUT PULONG  Interval);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwStartProfile(
-  IN HANDLE  ProfileHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwStopProfile(
-  IN HANDLE  ProfileHandle);
-
-/* Local Procedure Call (LPC) */
-
-typedef struct _LPC_MESSAGE {
-	USHORT  DataSize;
-	USHORT  MessageSize;
-	USHORT  MessageType;
-	USHORT  VirtualRangesOffset;
-	CLIENT_ID  ClientId;
-	ULONG  MessageId;
-	ULONG  SectionSize;
-	UCHAR  Data[ANYSIZE_ARRAY];
-} LPC_MESSAGE, *PLPC_MESSAGE;
-
-#define LPC_MESSAGE_BASE_SIZE	24
-
-typedef enum _LPC_TYPE {
-	LPC_NEW_MESSAGE,
-	LPC_REQUEST,
-	LPC_REPLY,
-	LPC_DATAGRAM,
-	LPC_LOST_REPLY,
-	LPC_PORT_CLOSED,
-	LPC_CLIENT_DIED,
-	LPC_EXCEPTION,
-	LPC_DEBUG_EVENT,
-	LPC_ERROR_EVENT,
-	LPC_CONNECTION_REQUEST,
-	LPC_CONNECTION_REFUSED,
-  LPC_MAXIMUM
-} LPC_TYPE;
-
-typedef struct _LPC_SECTION_WRITE {
-	ULONG  Length;
-	HANDLE  SectionHandle;
-	ULONG  SectionOffset;
-	ULONG  ViewSize;
-	PVOID  ViewBase;
-	PVOID  TargetViewBase;
-} LPC_SECTION_WRITE, *PLPC_SECTION_WRITE;
-
-typedef struct _LPC_SECTION_READ {
-	ULONG  Length;
-	ULONG  ViewSize;
-	PVOID  ViewBase;
-} LPC_SECTION_READ, *PLPC_SECTION_READ;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreatePort(
-	OUT PHANDLE  PortHandle,
-	IN POBJECT_ATTRIBUTES  ObjectAttributes,
-	IN ULONG  MaxDataSize,
-	IN ULONG  MaxMessageSize,
-	IN ULONG  Reserved);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreateWaitablePort(
-	OUT PHANDLE  PortHandle,
-	IN POBJECT_ATTRIBUTES  ObjectAttributes,
-	IN ULONG  MaxDataSize,
-	IN ULONG  MaxMessageSize,
-	IN ULONG  Reserved);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtConnectPort(
-  OUT PHANDLE  PortHandle,
-  IN PUNICODE_STRING  PortName,
-  IN PSECURITY_QUALITY_OF_SERVICE  SecurityQos,
-  IN OUT PLPC_SECTION_WRITE  WriteSection  OPTIONAL,
-  IN OUT PLPC_SECTION_READ  ReadSection  OPTIONAL,
-  OUT PULONG  MaxMessageSize  OPTIONAL,
-  IN OUT PVOID  ConnectData  OPTIONAL,
-  IN OUT PULONG  ConnectDataLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwConnectPort(
-  OUT PHANDLE  PortHandle,
-  IN PUNICODE_STRING  PortName,
-  IN PSECURITY_QUALITY_OF_SERVICE  SecurityQos,
-  IN OUT PLPC_SECTION_WRITE  WriteSection  OPTIONAL,
-  IN OUT PLPC_SECTION_READ  ReadSection  OPTIONAL,
-  OUT PULONG  MaxMessageSize  OPTIONAL,
-  IN OUT PVOID  ConnectData  OPTIONAL,
-  IN OUT PULONG  ConnectDataLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwConnectPort(
-	OUT PHANDLE  PortHandle,
-	IN PUNICODE_STRING  PortName,
-	IN PSECURITY_QUALITY_OF_SERVICE  SecurityQos,
-	IN OUT PLPC_SECTION_WRITE  WriteSection  OPTIONAL,
-	IN OUT PLPC_SECTION_READ  ReadSection  OPTIONAL,
-	OUT PULONG  MaxMessageSize  OPTIONAL,
-	IN OUT PVOID  ConnectData  OPTIONAL,
-	IN OUT PULONG  ConnectDataLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwListenPort(
-  IN HANDLE  PortHandle,
-  OUT PLPC_MESSAGE  Message);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAcceptConnectPort(
-	OUT PHANDLE  PortHandle,
-	IN ULONG  PortIdentifier,
-	IN PLPC_MESSAGE  Message,
-	IN BOOLEAN  Accept,
-	IN OUT PLPC_SECTION_WRITE  WriteSection  OPTIONAL,
-	IN OUT PLPC_SECTION_READ  ReadSection  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCompleteConnectPort(
-  IN HANDLE  PortHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtRequestPort(
-  IN HANDLE  PortHandle,
-  IN PLPC_MESSAGE  RequestMessage);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtRequestWaitReplyPort(
-  IN HANDLE  PortHandle,
-  IN PLPC_MESSAGE  RequestMessage,
-  OUT PLPC_MESSAGE  ReplyMessage);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwRequestWaitReplyPort(
-  IN HANDLE  PortHandle,
-  IN PLPC_MESSAGE  RequestMessage,
-  OUT PLPC_MESSAGE  ReplyMessage);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwReplyPort(
-	IN HANDLE  PortHandle,
-	IN PLPC_MESSAGE  ReplyMessage);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwReplyWaitReplyPort(
-	IN HANDLE  PortHandle,
-	IN OUT PLPC_MESSAGE  ReplyMessage);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwReplyWaitReceivePort(
-	IN HANDLE  PortHandle,
-	OUT PULONG  PortIdentifier  OPTIONAL,
-	IN PLPC_MESSAGE  ReplyMessage  OPTIONAL,
-	OUT PLPC_MESSAGE  Message);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwReplyWaitReceivePortEx(
-	IN HANDLE  PortHandle,
-	OUT PULONG  PortIdentifier  OPTIONAL,
-	IN PLPC_MESSAGE  ReplyMessage  OPTIONAL,
-	OUT PLPC_MESSAGE  Message,
-	IN PLARGE_INTEGER  Timeout);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwOpenFile(
-    OUT PHANDLE FileHandle,
-    IN ACCESS_MASK DesiredAccess,
-    IN POBJECT_ATTRIBUTES ObjectAttributes,
-    OUT PIO_STATUS_BLOCK IoStatusBlock,
-    IN ULONG ShareAccess,
-    IN ULONG OpenOptions
-);
-
-
-#define	OBJ_CASE_INSENSITIVE	0x00000040L
-#define	FILE_NON_DIRECTORY_FILE	0x00000040
-#define FILE_SYNCHRONOUS_IO_NONALERT	0x00000020
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwReadRequestData(
-	IN HANDLE  PortHandle,
-	IN PLPC_MESSAGE  Message,
-	IN ULONG  Index,
-	OUT PVOID  Buffer,
-	IN ULONG  BufferLength,
-	OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwWriteRequestData(
-	IN HANDLE  PortHandle,
-	IN PLPC_MESSAGE  Message,
-	IN ULONG  Index,
-	IN PVOID  Buffer,
-	IN ULONG  BufferLength,
-	OUT PULONG  ReturnLength  OPTIONAL);
-
-typedef enum _PORT_INFORMATION_CLASS {
-  PortBasicInformation
-} PORT_INFORMATION_CLASS;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryInformationPort(
-	IN HANDLE  PortHandle,
-	IN PORT_INFORMATION_CLASS  PortInformationClass,
-	OUT PVOID  PortInformation,
-	IN ULONG  PortInformationLength,
-  OUT PULONG  ReturnLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwImpersonateClientOfPort(
-  IN HANDLE  PortHandle,
-  IN PLPC_MESSAGE  Message);
-
-
-
-
-/* Files */
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtDeleteFile(
-  IN POBJECT_ATTRIBUTES  ObjectAttributes);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwDeleteFile(
-  IN POBJECT_ATTRIBUTES  ObjectAttributes);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwFlushBuffersFile(
-	IN HANDLE  FileHandle,
-	OUT PIO_STATUS_BLOCK  IoStatusBlock);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCancelIoFile(
-	IN HANDLE  FileHandle,
-	OUT PIO_STATUS_BLOCK  IoStatusBlock);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwReadFileScatter(
-	IN HANDLE  FileHandle,
-	IN HANDLE  Event OPTIONAL,
-	IN PIO_APC_ROUTINE  ApcRoutine  OPTIONAL,
-	IN PVOID  ApcContext  OPTIONAL,
-	OUT PIO_STATUS_BLOCK  IoStatusBlock,
-	IN PFILE_SEGMENT_ELEMENT  Buffer,
-	IN ULONG  Length,
-	IN PLARGE_INTEGER  ByteOffset  OPTIONAL,
-	IN PULONG  Key  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwWriteFileGather(
-	IN HANDLE  FileHandle,
-	IN HANDLE  Event  OPTIONAL,
-	IN PIO_APC_ROUTINE  ApcRoutine  OPTIONAL,
-	IN PVOID  ApcContext  OPTIONAL,
-	OUT PIO_STATUS_BLOCK  IoStatusBlock,
-	IN PFILE_SEGMENT_ELEMENT  Buffer,
-	IN ULONG  Length,
-	IN PLARGE_INTEGER  ByteOffset  OPTIONAL,
-	IN PULONG  Key  OPTIONAL);
-
-
-
-
-/* Registry keys */
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSaveKey(
-	IN HANDLE  KeyHandle,
-	IN HANDLE  FileHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSaveMergedKeys(
-	IN HANDLE  KeyHandle1,
-	IN HANDLE  KeyHandle2,
-	IN HANDLE  FileHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwRestoreKey(
-  IN HANDLE  KeyHandle,
-  IN HANDLE  FileHandle,
-  IN ULONG  Flags);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwLoadKey(
-  IN POBJECT_ATTRIBUTES  KeyObjectAttributes,
-  IN POBJECT_ATTRIBUTES  FileObjectAttributes);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwLoadKey2(
-	IN POBJECT_ATTRIBUTES  KeyObjectAttributes,
-	IN POBJECT_ATTRIBUTES  FileObjectAttributes,
-	IN ULONG  Flags);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwUnloadKey(
-  IN POBJECT_ATTRIBUTES  KeyObjectAttributes);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryOpenSubKeys(
-	IN POBJECT_ATTRIBUTES  KeyObjectAttributes,
-	OUT PULONG  NumberOfKeys);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwReplaceKey(
-	IN POBJECT_ATTRIBUTES  NewFileObjectAttributes,
-	IN HANDLE  KeyHandle,
-	IN POBJECT_ATTRIBUTES  OldFileObjectAttributes);
-
-typedef enum _KEY_SET_INFORMATION_CLASS {
-  KeyLastWriteTimeInformation
-} KEY_SET_INFORMATION_CLASS;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetInformationKey(
-	IN HANDLE  KeyHandle,
-	IN KEY_SET_INFORMATION_CLASS  KeyInformationClass,
-	IN PVOID  KeyInformation,
-	IN ULONG  KeyInformationLength);
-
-typedef struct _KEY_LAST_WRITE_TIME_INFORMATION {
-  LARGE_INTEGER LastWriteTime;
-} KEY_LAST_WRITE_TIME_INFORMATION, *PKEY_LAST_WRITE_TIME_INFORMATION;
-
-typedef struct _KEY_NAME_INFORMATION {
-	ULONG NameLength;
-	WCHAR Name[1];
-} KEY_NAME_INFORMATION, *PKEY_NAME_INFORMATION;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwNotifyChangeKey(
-	IN HANDLE  KeyHandle,
-	IN HANDLE  EventHandle  OPTIONAL,
-	IN PIO_APC_ROUTINE  ApcRoutine  OPTIONAL,
-	IN PVOID  ApcContext  OPTIONAL,
-	OUT PIO_STATUS_BLOCK  IoStatusBlock,
-	IN ULONG  NotifyFilter,
-	IN BOOLEAN  WatchSubtree,
-	IN PVOID  Buffer,
-	IN ULONG  BufferLength,
-	IN BOOLEAN  Asynchronous);
-
-/* ZwNotifyChangeMultipleKeys.Flags constants */
-#define REG_MONITOR_SINGLE_KEY            0x00
-#define REG_MONITOR_SECOND_KEY            0x01
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwNotifyChangeMultipleKeys(
-	IN HANDLE  KeyHandle,
-	IN ULONG  Flags,
-	IN POBJECT_ATTRIBUTES  KeyObjectAttributes,
-	IN HANDLE  EventHandle  OPTIONAL,
-	IN PIO_APC_ROUTINE  ApcRoutine  OPTIONAL,
-	IN PVOID  ApcContext  OPTIONAL,
-	OUT PIO_STATUS_BLOCK  IoStatusBlock,
-	IN ULONG  NotifyFilter,
-	IN BOOLEAN  WatchSubtree,
-	IN PVOID  Buffer,
-	IN ULONG  BufferLength,
-	IN BOOLEAN  Asynchronous);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryMultipleValueKey(
-	IN HANDLE  KeyHandle,
-	IN OUT  PKEY_VALUE_ENTRY  ValueList,
-	IN ULONG  NumberOfValues,
-	OUT PVOID  Buffer,
-	IN OUT PULONG  Length,
-	OUT PULONG  ReturnLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwInitializeRegistry(
-  IN BOOLEAN  Setup);
-
-
-
-
-/* Security and auditing */
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwPrivilegeCheck(
-	IN HANDLE  TokenHandle,
-	IN PPRIVILEGE_SET  RequiredPrivileges,
-	OUT PBOOLEAN  Result);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwPrivilegeObjectAuditAlarm(
-	IN PUNICODE_STRING  SubsystemName,
-	IN PVOID  HandleId,
-	IN HANDLE  TokenHandle,
-	IN ACCESS_MASK  DesiredAccess,
-	IN PPRIVILEGE_SET  Privileges,
-	IN BOOLEAN  AccessGranted);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwPrivilegeObjectAuditAlarm(
-	IN PUNICODE_STRING  SubsystemName,
-	IN PVOID  HandleId,
-	IN HANDLE  TokenHandle,
-	IN ACCESS_MASK  DesiredAccess,
-	IN PPRIVILEGE_SET  Privileges,
-	IN BOOLEAN  AccessGranted);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAccessCheck(
-	IN PSECURITY_DESCRIPTOR  SecurityDescriptor,
-	IN HANDLE  TokenHandle,
-	IN ACCESS_MASK  DesiredAccess,
-	IN PGENERIC_MAPPING  GenericMapping,
-	IN PPRIVILEGE_SET  PrivilegeSet,
-	IN PULONG  PrivilegeSetLength,
-	OUT PACCESS_MASK  GrantedAccess,
-	OUT PBOOLEAN  AccessStatus);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAccessCheckAndAuditAlarm(
-	IN PUNICODE_STRING  SubsystemName,
-	IN PVOID  HandleId,
-	IN PUNICODE_STRING  ObjectTypeName,
-	IN PUNICODE_STRING  ObjectName,
-	IN PSECURITY_DESCRIPTOR  SecurityDescriptor,
-	IN ACCESS_MASK  DesiredAccess,
-	IN PGENERIC_MAPPING  GenericMapping,
-	IN BOOLEAN  ObjectCreation,
-	OUT PACCESS_MASK  GrantedAccess,
-	OUT PBOOLEAN  AccessStatus,
-	OUT PBOOLEAN  GenerateOnClose);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAccessCheckByType(
-	IN PSECURITY_DESCRIPTOR  SecurityDescriptor,
-	IN PSID  PrincipalSelfSid,
-	IN HANDLE  TokenHandle,
-	IN ULONG  DesiredAccess,
-	IN POBJECT_TYPE_LIST  ObjectTypeList,
-	IN ULONG  ObjectTypeListLength,
-	IN PGENERIC_MAPPING  GenericMapping,
-	IN PPRIVILEGE_SET  PrivilegeSet,
-	IN PULONG  PrivilegeSetLength,
-	OUT PACCESS_MASK  GrantedAccess,
-	OUT PULONG  AccessStatus);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAccessCheckByTypeAndAuditAlarm(
-	IN PUNICODE_STRING  SubsystemName,
-	IN PVOID  HandleId,
-	IN PUNICODE_STRING  ObjectTypeName,
-	IN PUNICODE_STRING  ObjectName,
-	IN PSECURITY_DESCRIPTOR  SecurityDescriptor,
-	IN PSID  PrincipalSelfSid,
-	IN ACCESS_MASK  DesiredAccess,
-	IN AUDIT_EVENT_TYPE  AuditType,
-	IN ULONG  Flags,
-	IN POBJECT_TYPE_LIST  ObjectTypeList,
-	IN ULONG  ObjectTypeListLength,
-	IN PGENERIC_MAPPING  GenericMapping,
-	IN BOOLEAN  ObjectCreation,
-	OUT PACCESS_MASK  GrantedAccess,
-	OUT PULONG  AccessStatus,
-	OUT PBOOLEAN  GenerateOnClose);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAccessCheckByTypeResultList(
-	IN PSECURITY_DESCRIPTOR  SecurityDescriptor,
-	IN PSID  PrincipalSelfSid,
-	IN HANDLE  TokenHandle,
-	IN ACCESS_MASK  DesiredAccess,
-	IN POBJECT_TYPE_LIST  ObjectTypeList,
-	IN ULONG  ObjectTypeListLength,
-	IN PGENERIC_MAPPING  GenericMapping,
-	IN PPRIVILEGE_SET  PrivilegeSet,
-	IN PULONG  PrivilegeSetLength,
-	OUT PACCESS_MASK  GrantedAccessList,
-	OUT PULONG  AccessStatusList);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAccessCheckByTypeResultListAndAuditAlarm(
-	IN PUNICODE_STRING  SubsystemName,
-	IN PVOID  HandleId,
-	IN PUNICODE_STRING  ObjectTypeName,
-	IN PUNICODE_STRING  ObjectName,
-	IN PSECURITY_DESCRIPTOR  SecurityDescriptor,
-	IN PSID  PrincipalSelfSid,
-	IN ACCESS_MASK  DesiredAccess,
-	IN AUDIT_EVENT_TYPE  AuditType,
-	IN ULONG  Flags,
-	IN POBJECT_TYPE_LIST  ObjectTypeList,
-	IN ULONG  ObjectTypeListLength,
-	IN PGENERIC_MAPPING  GenericMapping,
-	IN BOOLEAN  ObjectCreation,
-	OUT PACCESS_MASK  GrantedAccessList,
-	OUT PULONG  AccessStatusList,
-	OUT PULONG  GenerateOnClose);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwAccessCheckByTypeResultListAndAuditAlarmByHandle(
-	IN PUNICODE_STRING  SubsystemName,
-	IN PVOID  HandleId,
-	IN HANDLE  TokenHandle,
-	IN PUNICODE_STRING  ObjectTypeName,
-	IN PUNICODE_STRING  ObjectName,
-	IN PSECURITY_DESCRIPTOR  SecurityDescriptor,
-	IN PSID  PrincipalSelfSid,
-	IN ACCESS_MASK  DesiredAccess,
-	IN AUDIT_EVENT_TYPE  AuditType,
-	IN ULONG  Flags,
-	IN POBJECT_TYPE_LIST  ObjectTypeList,
-	IN ULONG  ObjectTypeListLength,
-	IN PGENERIC_MAPPING  GenericMapping,
-	IN BOOLEAN  ObjectCreation,
-	OUT PACCESS_MASK  GrantedAccessList,
-	OUT PULONG  AccessStatusList,
-	OUT PULONG  GenerateOnClose);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwOpenObjectAuditAlarm(
-	IN PUNICODE_STRING  SubsystemName,
-	IN PVOID  *HandleId,
-	IN PUNICODE_STRING  ObjectTypeName,
-	IN PUNICODE_STRING  ObjectName,
-	IN PSECURITY_DESCRIPTOR  SecurityDescriptor,
-	IN HANDLE  TokenHandle,
-	IN ACCESS_MASK  DesiredAccess,
-	IN ACCESS_MASK  GrantedAccess,
-	IN PPRIVILEGE_SET  Privileges  OPTIONAL,
-	IN BOOLEAN  ObjectCreation,
-	IN BOOLEAN  AccessGranted,
-	OUT PBOOLEAN  GenerateOnClose);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCloseObjectAuditAlarm(
-  IN PUNICODE_STRING  SubsystemName,
-  IN PVOID  HandleId,
-  IN BOOLEAN  GenerateOnClose);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwDeleteObjectAuditAlarm(
-  IN PUNICODE_STRING  SubsystemName,
-  IN PVOID  HandleId,
-  IN BOOLEAN  GenerateOnClose);
-
-
-
-
-/* Plug and play and power management */
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwRequestWakeupLatency(
-  IN LATENCY_TIME  Latency);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwRequestDeviceWakeup(
-  IN HANDLE  DeviceHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCancelDeviceWakeupRequest(
-  IN HANDLE  DeviceHandle);
-
-NTOSAPI
-BOOLEAN
-NTAPI
-ZwIsSystemResumeAutomatic(
-  VOID);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetThreadExecutionState(
-	IN EXECUTION_STATE  ExecutionState,
-	OUT PEXECUTION_STATE  PreviousExecutionState);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwGetDevicePowerState(
-  IN HANDLE  DeviceHandle,
-  OUT PDEVICE_POWER_STATE  DevicePowerState);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetSystemPowerState(
-	IN POWER_ACTION  SystemAction,
-	IN SYSTEM_POWER_STATE  MinSystemState,
-	IN ULONG  Flags);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwInitiatePowerAction(
-	IN POWER_ACTION  SystemAction,
-	IN SYSTEM_POWER_STATE  MinSystemState,
-	IN ULONG  Flags,
-	IN BOOLEAN  Asynchronous);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwPowerInformation(
-	IN POWER_INFORMATION_LEVEL  PowerInformationLevel,
-	IN PVOID  InputBuffer  OPTIONAL,
-	IN ULONG  InputBufferLength,
-	OUT PVOID  OutputBuffer  OPTIONAL,
-	IN ULONG  OutputBufferLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwPlugPlayControl(
-  IN ULONG  ControlCode,
-  IN OUT PVOID  Buffer,
-  IN ULONG  BufferLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwGetPlugPlayEvent(
-	IN ULONG  Reserved1,
-	IN ULONG  Reserved2,
-	OUT PVOID  Buffer,
-	IN ULONG  BufferLength);
-
-
-/* Miscellany */
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwRaiseException(
-  IN PEXCEPTION_RECORD  ExceptionRecord,
-  IN PCONTEXT  Context,
-  IN BOOLEAN  SearchFrames);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwContinue(
-  IN PCONTEXT  Context,
-  IN BOOLEAN  TestAlert);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwW32Call(
-	IN ULONG  RoutineIndex,
-	IN PVOID  Argument,
-	IN ULONG  ArgumentLength,
-	OUT PVOID  *Result  OPTIONAL,
-	OUT PULONG  ResultLength  OPTIONAL);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetLowWaitHighThread(
-  VOID);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetHighWaitLowThread(
-  VOID);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwLoadDriver(
-  IN PUNICODE_STRING  DriverServiceName);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwUnloadDriver(
-  IN PUNICODE_STRING  DriverServiceName);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwFlushInstructionCache(
-	IN HANDLE  ProcessHandle,
-	IN PVOID  BaseAddress  OPTIONAL,
-	IN ULONG  FlushSize);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwFlushWriteBuffer(
-  VOID);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryDefaultLocale(
-	IN BOOLEAN  ThreadOrSystem,
-	OUT PLCID  Locale);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetDefaultLocale(
-  IN BOOLEAN  ThreadOrSystem,
-  IN LCID  Locale);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryDefaultUILanguage(
-  OUT PLANGID  LanguageId);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetDefaultUILanguage(
-  IN LANGID  LanguageId);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryInstallUILanguage(
-  OUT PLANGID  LanguageId);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtAllocateLocallyUniqueId(
-  OUT PLUID  Luid);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtAllocateUuids(
-  OUT PLARGE_INTEGER  UuidLastTimeAllocated,
-  OUT PULONG  UuidDeltaTime,
-  OUT PULONG  UuidSequenceNumber,
-  OUT PUCHAR  UuidSeed);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetUuidSeed(
-  IN PUCHAR  UuidSeed);
-
-typedef enum _HARDERROR_RESPONSE_OPTION {
-	OptionAbortRetryIgnore,
-	OptionOk,
-	OptionOkCancel,
-	OptionRetryCancel,
-	OptionYesNo,
-	OptionYesNoCancel,
-	OptionShutdownSystem
-} HARDERROR_RESPONSE_OPTION, *PHARDERROR_RESPONSE_OPTION;
-
-typedef enum _HARDERROR_RESPONSE {
-	ResponseReturnToCaller,
-	ResponseNotHandled,
-	ResponseAbort,
-	ResponseCancel,
-	ResponseIgnore,
-	ResponseNo,
-	ResponseOk,
-	ResponseRetry,
-	ResponseYes
-} HARDERROR_RESPONSE, *PHARDERROR_RESPONSE;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwRaiseHardError(
-	IN NTSTATUS  Status,
-	IN ULONG  NumberOfArguments,
-	IN ULONG  StringArgumentsMask,
-	IN PULONG  Arguments,
-	IN HARDERROR_RESPONSE_OPTION  ResponseOption,
-	OUT PHARDERROR_RESPONSE  Response);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetDefaultHardErrorPort(
-  IN HANDLE  PortHandle);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwDisplayString(
-  IN PUNICODE_STRING  String);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreatePagingFile(
-  IN PUNICODE_STRING  FileName,
-  IN PULARGE_INTEGER  InitialSize,
-  IN PULARGE_INTEGER  MaximumSize,
-  IN ULONG  Reserved);
-
-typedef USHORT RTL_ATOM, *PRTL_ATOM;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtAddAtom(
-  IN PWSTR  AtomName,
-  IN ULONG  AtomNameLength,
-  OUT PRTL_ATOM  Atom);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtFindAtom(
-  IN PWSTR  AtomName,
-  IN ULONG  AtomNameLength,
-  OUT PRTL_ATOM  Atom);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtDeleteAtom(
-  IN RTL_ATOM  Atom);
-
-typedef enum _ATOM_INFORMATION_CLASS {
-	AtomBasicInformation,
-	AtomListInformation
-} ATOM_INFORMATION_CLASS;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtQueryInformationAtom(
-  IN RTL_ATOM  Atom,
-  IN ATOM_INFORMATION_CLASS  AtomInformationClass,
-  OUT PVOID  AtomInformation,
-  IN ULONG  AtomInformationLength,
-  OUT PULONG  ReturnLength  OPTIONAL);
-
-typedef struct _ATOM_BASIC_INFORMATION {
-	USHORT  ReferenceCount;
-	USHORT  Pinned;
-	USHORT  NameLength;
-	WCHAR  Name[1];
-} ATOM_BASIC_INFORMATION, *PATOM_BASIC_INFORMATION;
-
-typedef struct _ATOM_LIST_INFORMATION {
-  ULONG  NumberOfAtoms;
-  ATOM  Atoms[1];
-} ATOM_LIST_INFORMATION, *PATOM_LIST_INFORMATION;
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetLdtEntries(
-	IN ULONG  Selector1,
-	IN LDT_ENTRY  LdtEntry1,
-	IN ULONG  Selector2,
-	IN LDT_ENTRY  LdtEntry2);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwSetInformationThread(
-  IN HANDLE  ThreadHandle,
-  IN THREADINFOCLASS  ThreadInformationClass,
-  IN PVOID  ThreadInformation,
-  IN ULONG  ThreadInformationLength);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwTerminateThread(
-	IN HANDLE  ThreadHandle  OPTIONAL,
-	IN NTSTATUS  ExitStatus);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-NtVdmControl(
-  IN ULONG  ControlCode,
-  IN PVOID  ControlData);
-
-BOOLEAN
-WINAPI
-RtlCreateUnicodeStringFromAsciiz (
-	OUT PUNICODE_STRING Destination,
-	IN PCSTR Source
-	);
-
-VOID
-WINAPI
-RtlInitUnicodeString(
-  IN OUT PUNICODE_STRING  DestinationString,
-  IN PCWSTR  SourceString);
-
-VOID
-RtlFreeUnicodeString(
-IN OUT PUNICODE_STRING  DestinationString);
-
-
-LONG
-WINAPI
-RtlCompareUnicodeString(
-  IN PUNICODE_STRING  String1,
-  IN PUNICODE_STRING  String2,
-  IN BOOLEAN  CaseInSensitive);
-
-BOOLEAN
-WINAPI
-RtlEqualUnicodeString(
-  IN CONST UNICODE_STRING  *String1,
-  IN CONST UNICODE_STRING  *String2,
-  IN BOOLEAN  CaseInSensitive);
-
-
-VOID
-WINAPI
-  RtlInitAnsiString(
-    IN OUT PANSI_STRING  DestinationString,
-    IN PCHAR  SourceString
-    );
-
-
-PPEB
-WINAPI
-RtlGetCurrentPeb(
-	VOID
-	);
-
-NTSTATUS WINAPI
-RtlAdjustPrivilege(ULONG Privilege,
-                   BOOLEAN Enable,
-                   BOOLEAN CurrentThread,
-                   PBOOLEAN Enabled);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwQueryInformationThread(
-  /*IN*/ HANDLE  ThreadHandle,
-  /*IN*/ THREADINFOCLASS  ThreadInformationClass,
-  /*OUT*/ PVOID  ThreadInformation,
-  /*IN*/ ULONG  ThreadInformationLength,
-  /*OUT*/ PULONG  ReturnLength  /*OPTIONAL*/);
-
-NTSTATUS  WINAPI LdrGetDllHandle(ULONG, ULONG, const UNICODE_STRING*, HMODULE*);
-NTSTATUS  WINAPI LdrGetProcedureAddress(HMODULE, const ANSI_STRING*, ULONG, void**);
-
-NTSTATUS  WINAPI
-RtlCreateUserThread(
-
-IN HANDLE ProcessHandle, IN PSECURITY_DESCRIPTOR SecurityDescriptor OPTIONAL, IN BOOLEAN CreateSuspended, IN ULONG StackZeroBits, IN OUT PULONG StackReserved, IN OUT PULONG StackCommit, IN PVOID StartAddress, IN PVOID StartParameter OPTIONAL, OUT PHANDLE ThreadHandle, OUT PCLIENT_ID ClientID );
-
-BOOLEAN
-RtlDosPathNameToNtPathName_U (
-	PCWSTR DosName,
-	PUNICODE_STRING NtName,
-	PWSTR *DosFilePath,
-	PVOID NtFilePath // Some special structure, first member being UNICODE_STRING
-	);
-
-BOOLEAN  RtlFreeHeap(     IN PVOID  HeapHandle,    IN ULONG  Flags,    IN PVOID  HeapBase    );
-PVOID  RtlAllocateHeap(     IN PVOID  HeapHandle,    IN ULONG  Flags,    IN SIZE_T  Size    );
-PVOID RtlReAllocateHeap(
-				  IN PVOID                HeapHandle,
-				  IN ULONG                Flags,
-				  IN PVOID                MemoryPointer,
-				  IN ULONG                Size );
-NTSYSAPI BOOLEAN NTAPI
-RtlValidateHeap(
-				IN PVOID                HeapHandle,
-				IN ULONG                Flags,
-				IN PVOID                AddressToValidate OPTIONAL );
-
-typedef struct _TEB
-{
-    NT_TIB          Tib;                        /* 000 */
-    PVOID           EnvironmentPointer;         /* 01c */
-    CLIENT_ID       ClientId;                   /* 020 */
-    PVOID           ActiveRpcHandle;            /* 028 */
-    PVOID           ThreadLocalStoragePointer;  /* 02c */
-    PPEB            Peb;                        /* 030 */
-    ULONG           LastErrorValue;             /* 034 */
-    BYTE            __pad038[140];              /* 038 */
-    ULONG           CurrentLocale;              /* 0c4 */
-    BYTE            __pad0c8[1752];             /* 0c8 */
-    PVOID           Reserved2[277];             /* 7a0 */
-    ULONG           LastStatusValue;            /* bf4 */
-    UNICODE_STRING  StaticUnicodeString;        /* bf8 used by advapi32 */
-    WCHAR           StaticUnicodeBuffer[261];   /* c00 used by advapi32 */
-    PVOID           DeallocationStack;          /* e0c */
-    PVOID           TlsSlots[64];               /* e10 */
-    LIST_ENTRY      TlsLinks;                   /* f10 */
-    PVOID           Reserved4[26];              /* f18 */
-    PVOID           ReservedForOle;             /* f80 Windows 2000 only */
-    PVOID           Reserved5[4];               /* f84 */
-    PVOID           TlsExpansionSlots;          /* f94 */
-} TEB, *PTEB;
-
-
-typedef struct _FILE_STANDARD_INFORMATION {
-  LARGE_INTEGER  AllocationSize;
-  LARGE_INTEGER  EndOfFile;
-  ULONG  NumberOfLinks;
-  BOOLEAN  DeletePending;
-  BOOLEAN  Directory;
-} FILE_STANDARD_INFORMATION, *PFILE_STANDARD_INFORMATION;
-
-
-typedef enum _FILE_INFORMATION_CLASS {
-    FileDirectoryInformation       = 1,
-    FileFullDirectoryInformation, // 2
-    FileBothDirectoryInformation, // 3
-    FileBasicInformation,         // 4
-    FileStandardInformation,      // 5
-    FileInternalInformation,      // 6
-    FileEaInformation,            // 7
-    FileAccessInformation,        // 8
-    FileNameInformation,          // 9
-    FileRenameInformation,        // 10
-    FileLinkInformation,          // 11
-    FileNamesInformation,         // 12
-    FileDispositionInformation,   // 13
-    FilePositionInformation,      // 14
-    FileFullEaInformation,        // 15
-    FileModeInformation,          // 16
-    FileAlignmentInformation,     // 17
-    FileAllInformation,           // 18
-    FileAllocationInformation,    // 19
-    FileEndOfFileInformation,     // 20
-    FileAlternateNameInformation, // 21
-    FileStreamInformation,        // 22
-    FilePipeInformation,          // 23
-    FilePipeLocalInformation,     // 24
-    FilePipeRemoteInformation,    // 25
-    FileMailslotQueryInformation, // 26
-    FileMailslotSetInformation,   // 27
-    FileCompressionInformation,   // 28
-    FileObjectIdInformation,      // 29
-    FileCompletionInformation,    // 30
-    FileMoveClusterInformation,   // 31
-    FileInformationReserved32,    // 32
-    FileInformationReserved33,    // 33
-    FileNetworkOpenInformation,   // 34
-	FileAttributeTagInformation,    // 35
-    FileTrackingInformation,        // 36
-    FileIdBothDirectoryInformation,     // 37
-    FileIdFullDirectoryInformation, // 38
-    FileValidDataLengthInformation, // 39
-    FileShortNameInformation,       // 40
-    FileMaximumInformation
-} FILE_INFORMATION_CLASS, *PFILE_INFORMATION_CLASS;
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwQueryInformationFile(
-IN HANDLE FileHandle,
-OUT PIO_STATUS_BLOCK IoStatusBlock,
-OUT PVOID FileInformation,
-IN ULONG FileInformationLength,
-IN FILE_INFORMATION_CLASS FileInformationClass
-);
-
-NTOSAPI
-NTSTATUS
-NTAPI
-ZwCreateFile(
-OUT PHANDLE FileHandle,
-IN ACCESS_MASK DesiredAccess,
-IN POBJECT_ATTRIBUTES ObjectAttributes,
-OUT PIO_STATUS_BLOCK IoStatusBlock,
-IN PLARGE_INTEGER AllocationSize OPTIONAL,
-IN ULONG FileAttributes,
-IN ULONG ShareAccess,
-IN ULONG CreateDisposition,
-IN ULONG CreateOptions,
-IN PVOID EaBuffer OPTIONAL,
-IN ULONG EaLength
-);
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwReadFile(
-IN HANDLE FileHandle,
-IN HANDLE Event OPTIONAL,
-IN PIO_APC_ROUTINE ApcRoutine OPTIONAL,
-IN PVOID ApcContext OPTIONAL,
-OUT PIO_STATUS_BLOCK IoStatusBlock,
-OUT PVOID Buffer,
-IN ULONG Length,
-IN PLARGE_INTEGER ByteOffset OPTIONAL,
-IN PULONG Key OPTIONAL
-);
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwWriteFile(
-IN HANDLE FileHandle,
-IN HANDLE Event OPTIONAL,
-IN PIO_APC_ROUTINE ApcRoutine OPTIONAL,
-IN PVOID ApcContext OPTIONAL,
-OUT PIO_STATUS_BLOCK IoStatusBlock,
-IN PVOID Buffer,
-IN ULONG Length,
-IN PLARGE_INTEGER ByteOffset OPTIONAL,
-IN PULONG Key OPTIONAL
-);
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwSetInformationFile(
-IN HANDLE FileHandle,
-OUT PIO_STATUS_BLOCK IoStatusBlock,
-IN PVOID FileInformation,
-IN ULONG FileInformationLength,
-IN FILE_INFORMATION_CLASS FileInformationClass
-);
-
-typedef enum _SECTION_INHERIT {
-ViewShare = 1,
-ViewUnmap = 2
-} SECTION_INHERIT;
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwMapViewOfSection(
-IN HANDLE SectionHandle,
-IN HANDLE ProcessHandle,
-IN OUT PVOID *BaseAddress,
-IN ULONG ZeroBits,
-IN ULONG CommitSize,
-IN OUT PLARGE_INTEGER SectionOffset OPTIONAL,
-IN OUT PULONG ViewSize,
-IN SECTION_INHERIT InheritDisposition,
-IN ULONG AllocationType,
-IN ULONG Protect
-);
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwUnmapViewOfSection(
-IN HANDLE ProcessHandle,
-IN PVOID BaseAddress
-);
-
-typedef enum _EVENT_TYPE {
-NotificationEvent, // A manual-reset event
-SynchronizationEvent // An auto-reset event
-} EVENT_TYPE;
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwCreateEvent(
-OUT PHANDLE EventHandle,
-IN ACCESS_MASK DesiredAccess,
-IN POBJECT_ATTRIBUTES ObjectAttributes,
-IN EVENT_TYPE EventType,
-IN BOOLEAN InitialState
-);
-
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwFindAtom(
-IN PWSTR String,
-IN ULONG StringLength,
-OUT PUSHORT Atom
-);
-
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwAddAtom(
-IN PWSTR String,
-IN ULONG StringLength,
-OUT PUSHORT Atom
-);
-
-
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwCreateMutant(
-OUT PHANDLE MutantHandle,
-IN ACCESS_MASK DesiredAccess,
-IN POBJECT_ATTRIBUTES ObjectAttributes,
-IN BOOLEAN InitialOwner
-);
-
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwOpenMutant(
-OUT PHANDLE MutantHandle,
-IN ACCESS_MASK DesiredAccess,
-IN POBJECT_ATTRIBUTES ObjectAttributes
-);
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwMakePermanentObject(
-        IN HANDLE Object
-        );
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwWaitForSingleObject(
-IN HANDLE Handle,
-IN BOOLEAN Alertable,
-IN PLARGE_INTEGER Timeout OPTIONAL
-);
-
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwSetValueKey(
-IN HANDLE KeyHandle,
-IN PUNICODE_STRING ValueName,
-IN ULONG TitleIndex,
-IN ULONG Type,
-IN PVOID Data,
-IN ULONG DataSize
-);
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-  RtlCreateRegistryKey(
-    IN ULONG  RelativeTo,
-    IN PWSTR  Path
-    );
-
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-  RtlWriteRegistryValue(
-    IN ULONG  RelativeTo,
-    IN PCWSTR  Path,
-    IN PCWSTR  ValueName,
-    IN ULONG  ValueType,
-    IN PVOID  ValueData,
-    IN ULONG  ValueLength
-    );
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-  ZwOpenKey(
-    OUT PHANDLE  KeyHandle,
-    IN ACCESS_MASK  DesiredAccess,
-    IN POBJECT_ATTRIBUTES  ObjectAttributes
-    );
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-  ZwSetEvent(
-    __in HANDLE  EventHandle,
-    __out_opt PLONG  PreviousState
-    );
-
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-  ZwQueryValueKey(
-    IN HANDLE  KeyHandle,
-    IN PUNICODE_STRING  ValueName,
-    IN KEY_VALUE_INFORMATION_CLASS  KeyValueInformationClass,
-    OUT PVOID  KeyValueInformation,
-    IN ULONG  Length,
-    OUT PULONG  ResultLength
-    );
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-ZwCreateKey(
-OUT PHANDLE KeyHandle,
-IN ACCESS_MASK DesiredAccess,
-IN POBJECT_ATTRIBUTES ObjectAttributes,
-IN ULONG TitleIndex,
-IN PUNICODE_STRING Class OPTIONAL,
-IN ULONG CreateOptions,
-OUT PULONG Disposition OPTIONAL
-);
-
-NTSTATUS WINAPI LdrFindEntryForAddress(const void*, PLDR_MODULE*);
-
-NTSYSAPI
-PIMAGE_NT_HEADERS
-NTAPI
-RtlImageNtHeader(IN PVOID	ModuleAddress);
-
-NTSYSAPI
-NTSTATUS
-NTAPI
-NtProtectVirtualMemory(
-					   IN HANDLE               ProcessHandle,
-					   IN OUT PVOID            *BaseAddress,
-					   IN OUT PULONG           NumberOfBytesToProtect,
-					   IN ULONG                NewAccessProtection,
-					   OUT PULONG              OldAccessProtection );
-
-#pragma pack(pop)
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* __NTAPI_H */
diff --git a/plugins/Dbx_mdb/src/stdafx.h b/plugins/Dbx_mdb/src/stdafx.h
index ebb0c8cc7f..32fbfff7f1 100644
--- a/plugins/Dbx_mdb/src/stdafx.h
+++ b/plugins/Dbx_mdb/src/stdafx.h
@@ -26,6 +26,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #include <process.h>

 #include <memory>

 #include <vector>

+#include <functional>

 

 #include <newpluginapi.h>

 #include <win2k.h>

@@ -50,10 +51,10 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 

 class txn_ptr

 {

+	MDB_env *m_env;

 	MDB_txn *m_txn;

-

 public:

-	__forceinline txn_ptr(MDB_env *pEnv)

+	__forceinline txn_ptr(MDB_env *pEnv) : m_env(pEnv)

 	{

 		mdb_txn_begin(pEnv, NULL, 0, &m_txn);

 	}

@@ -66,11 +67,11 @@ public:
 

 	__forceinline operator MDB_txn*() const { return m_txn; }

 

-	__forceinline bool commit()

+	__forceinline int commit()

 	{

-		bool bRes = (mdb_txn_commit(m_txn) != MDB_MAP_FULL);

-		m_txn = NULL;

-		return bRes;

+		MDB_txn *tmp = m_txn;

+		m_txn = nullptr;

+		return mdb_txn_commit(tmp);

 	}

 

 	__forceinline void abort()

@@ -121,17 +122,20 @@ class cursor_ptr_ro
 public:

 	__forceinline cursor_ptr_ro(MDB_cursor *cursor) : m_cursor(cursor)

 	{

-		mdb_cursor_renew(mdb_cursor_txn(m_cursor), m_cursor); //--

+		mdb_cursor_renew(mdb_cursor_txn(m_cursor), m_cursor);

 	}

 	__forceinline operator MDB_cursor*() const { return m_cursor; }

 };

 

 #define MDB_CHECK(A,B) \

-	switch(A) { \

+	switch (A) { \

 	case MDB_SUCCESS: break; \

 	case MDB_MAP_FULL: continue; \

 	default: return (B); }

 

+

+

+

 #include "dbintf.h"

 #include "resource.h"

 #include "version.h"