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Diffstat (limited to 'plugins/Dbx_mdb/src/mdbx/mdbx.h')
| -rw-r--r-- | plugins/Dbx_mdb/src/mdbx/mdbx.h | 1825 |
1 files changed, 0 insertions, 1825 deletions
diff --git a/plugins/Dbx_mdb/src/mdbx/mdbx.h b/plugins/Dbx_mdb/src/mdbx/mdbx.h deleted file mode 100644 index 421d833b70..0000000000 --- a/plugins/Dbx_mdb/src/mdbx/mdbx.h +++ /dev/null @@ -1,1825 +0,0 @@ -/* LICENSE AND COPYRUSTING ***************************************************** - * - * Copyright 2015-2017 Leonid Yuriev <leo@yuriev.ru> - * and other libmdbx authors: please see AUTHORS file. - * 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 "LMDB engine" written by - * Howard Chu (Symas Corporation), which itself derived from btree.c - * written by Martin Hedenfalk. - * - * --- - * - * Portions Copyright 2011-2015 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>. - * - * --- - * - * Portions 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. */ - -/* ACKNOWLEDGEMENTS ************************************************************ - * - * Howard Chu (Symas Corporation) - the author of LMDB, - * from which originated the MDBX in 2015. - * - * Martin Hedenfalk <martin@bzero.se> - the author of `btree.c` code, - * which was used for begin development of LMDB. */ - -#pragma once -#ifndef LIBMDBX_H -#define LIBMDBX_H - -/* IMPENDING CHANGES WARNING *************************************************** - * - * Now MDBX is under active development and until November 2017 is expected a - * big change both of API and database format. Unfortunately those update will - * lead to loss of compatibility with previous versions. - * - * The aim of this revolution in providing a clearer robust API and adding new - * features, including the database properties. */ - -/*--------------------------------------------------------------------------*/ - -#ifdef _MSC_VER -#pragma warning(push, 1) -#pragma warning(disable : 4548) /* expression before comma has no effect; \ - expected expression with side - effect */ -#pragma warning(disable : 4530) /* C++ exception handler used, but unwind \ - * semantics are not enabled. Specify /EHsc */ -#pragma warning(disable : 4577) /* 'noexcept' used with no exception handling \ - * mode specified; termination on exception is \ - * not guaranteed. Specify /EHsc */ -#endif /* _MSC_VER (warnings) */ - -#include <stdarg.h> -#include <stddef.h> -#include <stdint.h> - -#if defined(_WIN32) || defined(_WIN64) - -#include <windows.h> -#include <winnt.h> -#ifndef __mode_t_defined -typedef unsigned short mode_t; -#endif -typedef HANDLE mdbx_filehandle_t; -typedef DWORD mdbx_pid_t; -typedef DWORD mdbx_tid_t; -#define MDBX_ENODATA ERROR_HANDLE_EOF -#define MDBX_EINVAL ERROR_INVALID_PARAMETER -#define MDBX_EACCESS ERROR_ACCESS_DENIED -#define MDBX_ENOMEM ERROR_OUTOFMEMORY -#define MDBX_EROFS ERROR_FILE_READ_ONLY -#define MDBX_ENOSYS ERROR_NOT_SUPPORTED -#define MDBX_EIO ERROR_WRITE_FAULT -#define MDBX_EPERM ERROR_INVALID_FUNCTION -#define MDBX_EINTR ERROR_CANCELLED - -#else - -#include <errno.h> /* for error codes */ -#include <pthread.h> /* for pthread_t */ -#include <sys/types.h> /* for pid_t */ -#include <sys/uio.h> /* for truct iovec */ -#define HAVE_STRUCT_IOVEC 1 -typedef int mdbx_filehandle_t; -typedef pid_t mdbx_pid_t; -typedef pthread_t mdbx_tid_t; -#define MDBX_ENODATA ENODATA -#define MDBX_EINVAL EINVAL -#define MDBX_EACCESS EACCES -#define MDBX_ENOMEM ENOMEM -#define MDBX_EROFS EROFS -#define MDBX_ENOSYS ENOSYS -#define MDBX_EIO EIO -#define MDBX_EPERM EPERM -#define MDBX_EINTR EINTR -#endif - -#ifdef _MSC_VER -#pragma warning(pop) -#endif - -/*--------------------------------------------------------------------------*/ - -#ifndef __has_attribute -#define __has_attribute(x) (0) -#endif - -#ifndef __dll_export -#if defined(_WIN32) || defined(__CYGWIN__) -#if defined(__GNUC__) || __has_attribute(dllexport) -#define __dll_export __attribute__((dllexport)) -#elif defined(_MSC_VER) -#define __dll_export __declspec(dllexport) -#else -#define __dll_export -#endif -#elif defined(__GNUC__) || __has_attribute(visibility) -#define __dll_export __attribute__((visibility("default"))) -#else -#define __dll_export -#endif -#endif /* __dll_export */ - -#ifndef __dll_import -#if defined(_WIN32) || defined(__CYGWIN__) -#if defined(__GNUC__) || __has_attribute(dllimport) -#define __dll_import __attribute__((dllimport)) -#elif defined(_MSC_VER) -#define __dll_import __declspec(dllimport) -#else -#define __dll_import -#endif -#else -#define __dll_import -#endif -#endif /* __dll_import */ - -/*--------------------------------------------------------------------------*/ - -#define MDBX_VERSION_MAJOR 0 -#define MDBX_VERSION_MINOR 0 - -#if defined(LIBMDBX_EXPORTS) -#define LIBMDBX_API __dll_export -#elif defined(LIBMDBX_IMPORTS) -#define LIBMDBX_API __dll_import -#else -#define LIBMDBX_API -#endif /* LIBMDBX_API */ - -#ifdef __cplusplus -extern "C" { -#endif - -typedef struct mdbx_version_info { - uint8_t major; - uint8_t minor; - uint16_t release; - uint32_t revision; - struct { - const char *datetime; - const char *tree; - const char *commit; - const char *describe; - } git; -} mdbx_version_info; - -typedef struct mdbx_build_info { - const char *datetime; - const char *target; - const char *options; - const char *compiler; - const char *flags; -} mdbx_build_info; - -extern LIBMDBX_API const mdbx_version_info mdbx_version; -extern LIBMDBX_API const mdbx_build_info mdbx_build; - -/* The name of the lock file in the DB environment */ -#define MDBX_LOCKNAME "/mdbx.lck" -/* The name of the data file in the DB environment */ -#define MDBX_DATANAME "/mdbx.dat" -/* The suffix of the lock file when no subdir is used */ -#define MDBX_LOCK_SUFFIX "-lck" - -/* Opaque structure for a database environment. - * - * A DB environment supports multiple databases, all residing in the same - * shared-memory map. */ -typedef struct MDBX_env MDBX_env; - -/* Opaque structure for a transaction handle. - * - * All database operations require a transaction handle. Transactions may be - * read-only or read-write. */ -typedef struct MDBX_txn MDBX_txn; - -/* A handle for an individual database in the DB environment. */ -typedef uint32_t MDBX_dbi; - -/* Opaque structure for navigating through a database */ -typedef struct MDBX_cursor MDBX_cursor; - -/* Generic structure used for passing keys and data in and out - * of the database. - * - * Values returned from the database are valid only until a subsequent - * update operation, or the end of the transaction. Do not modify or - * free them, they commonly point into the database itself. - * - * Key sizes must be between 1 and mdbx_env_get_maxkeysize() inclusive. - * The same applies to data sizes in databases with the MDBX_DUPSORT flag. - * Other data items can in theory be from 0 to 0xffffffff bytes long. */ -#ifndef HAVE_STRUCT_IOVEC -struct iovec { - void *iov_base; - size_t iov_len; -}; -#define HAVE_STRUCT_IOVEC -#endif /* HAVE_STRUCT_IOVEC */ - -typedef struct iovec MDBX_val; - -/* The maximum size of a data item. - * MDBX only store a 32 bit value for node sizes. */ -#define MDBX_MAXDATASIZE INT32_MAX - -/* A callback function used to compare two keys in a database */ -typedef int(MDBX_cmp_func)(const MDBX_val *a, const MDBX_val *b); - -/* Environment Flags */ -/* no environment directory */ -#define MDBX_NOSUBDIR 0x4000u -/* don't fsync after commit */ -#define MDBX_NOSYNC 0x10000u -/* read only */ -#define MDBX_RDONLY 0x20000u -/* don't fsync metapage after commit */ -#define MDBX_NOMETASYNC 0x40000u -/* use writable mmap */ -#define MDBX_WRITEMAP 0x80000u -/* use asynchronous msync when MDBX_WRITEMAP is used */ -#define MDBX_MAPASYNC 0x100000u -/* tie reader locktable slots to MDBX_txn objects instead of to threads */ -#define MDBX_NOTLS 0x200000u -/* don't do any locking, caller must manage their own locks - * WARNING: libmdbx don't support this mode. */ -#define MDBX_NOLOCK__UNSUPPORTED 0x400000u -/* don't do readahead */ -#define MDBX_NORDAHEAD 0x800000u -/* don't initialize malloc'd memory before writing to datafile */ -#define MDBX_NOMEMINIT 0x1000000u -/* aim to coalesce FreeDB records */ -#define MDBX_COALESCE 0x2000000u -/* LIFO policy for reclaiming FreeDB records */ -#define MDBX_LIFORECLAIM 0x4000000u -/* make a steady-sync only on close and explicit env-sync */ -#define MDBX_UTTERLY_NOSYNC (MDBX_NOSYNC | MDBX_MAPASYNC) -/* debuging option, fill/perturb released pages */ -#define MDBX_PAGEPERTURB 0x8000000u - -/* Database Flags */ -/* use reverse string keys */ -#define MDBX_REVERSEKEY 0x02u -/* use sorted duplicates */ -#define MDBX_DUPSORT 0x04u -/* numeric keys in native byte order, either uint32_t or uint64_t. - * The keys must all be of the same size. */ -#define MDBX_INTEGERKEY 0x08u -/* with MDBX_DUPSORT, sorted dup items have fixed size */ -#define MDBX_DUPFIXED 0x10u -/* with MDBX_DUPSORT, dups are MDBX_INTEGERKEY-style integers */ -#define MDBX_INTEGERDUP 0x20u -/* with MDBX_DUPSORT, use reverse string dups */ -#define MDBX_REVERSEDUP 0x40u -/* create DB if not already existing */ -#define MDBX_CREATE 0x40000u - -/* Write Flags */ -/* For put: Don't write if the key already exists. */ -#define MDBX_NOOVERWRITE 0x10u -/* Only for MDBX_DUPSORT - * For put: don't write if the key and data pair already exist. - * For mdbx_cursor_del: remove all duplicate data items. */ -#define MDBX_NODUPDATA 0x20u -/* For mdbx_cursor_put: overwrite the current key/data pair - * MDBX allows this flag for mdbx_put() for explicit overwrite/update without - * insertion. */ -#define MDBX_CURRENT 0x40u -/* For put: Just reserve space for data, don't copy it. Return a - * pointer to the reserved space. */ -#define MDBX_RESERVE 0x10000u -/* Data is being appended, don't split full pages. */ -#define MDBX_APPEND 0x20000u -/* Duplicate data is being appended, don't split full pages. */ -#define MDBX_APPENDDUP 0x40000u -/* Store multiple data items in one call. Only for MDBX_DUPFIXED. */ -#define MDBX_MULTIPLE 0x80000u - -/* Transaction Flags */ -/* Do not block when starting a write transaction */ -#define MDBX_TRYTXN 0x10000000u - -/* Copy Flags */ -/* Compacting copy: Omit free space from copy, and renumber all - * pages sequentially. */ -#define MDBX_CP_COMPACT 1u - -/* Cursor Get operations. - * - * This is the set of all operations for retrieving data - * using a cursor. */ -typedef enum MDBX_cursor_op { - MDBX_FIRST, /* Position at first key/data item */ - MDBX_FIRST_DUP, /* MDBX_DUPSORT-only: Position at first data item - * of current key. */ - MDBX_GET_BOTH, /* MDBX_DUPSORT-only: Position at key/data pair. */ - MDBX_GET_BOTH_RANGE, /* MDBX_DUPSORT-only: position at key, nearest data. */ - MDBX_GET_CURRENT, /* Return key/data at current cursor position */ - MDBX_GET_MULTIPLE, /* MDBX_DUPFIXED-only: Return key and up to a page of - * duplicate data items from current cursor position. - * Move cursor to prepare for MDBX_NEXT_MULTIPLE.*/ - MDBX_LAST, /* Position at last key/data item */ - MDBX_LAST_DUP, /* MDBX_DUPSORT-only: Position at last data item - * of current key. */ - MDBX_NEXT, /* Position at next data item */ - MDBX_NEXT_DUP, /* MDBX_DUPSORT-only: Position at next data item - * of current key. */ - MDBX_NEXT_MULTIPLE, /* MDBX_DUPFIXED-only: Return key and up to a page of - * duplicate data items from next cursor position. - * Move cursor to prepare for MDBX_NEXT_MULTIPLE. */ - MDBX_NEXT_NODUP, /* Position at first data item of next key */ - MDBX_PREV, /* Position at previous data item */ - MDBX_PREV_DUP, /* MDBX_DUPSORT-only: Position at previous data item - * of current key. */ - MDBX_PREV_NODUP, /* Position at last data item of previous key */ - MDBX_SET, /* Position at specified key */ - MDBX_SET_KEY, /* Position at specified key, return both key and data */ - MDBX_SET_RANGE, /* Position at first key greater than or equal to - * specified key. */ - MDBX_PREV_MULTIPLE /* MDBX_DUPFIXED-only: Position at previous page and - * return key and up to a page of duplicate data items. */ -} MDBX_cursor_op; - -/* Return Codes - * BerkeleyDB uses -30800 to -30999, we'll go under them */ - -/* Successful result */ -#define MDBX_SUCCESS 0 -#define MDBX_RESULT_FALSE MDBX_SUCCESS -#define MDBX_RESULT_TRUE (-1) - -/* key/data pair already exists */ -#define MDBX_KEYEXIST (-30799) -/* key/data pair not found (EOF) */ -#define MDBX_NOTFOUND (-30798) -/* Requested page not found - this usually indicates corruption */ -#define MDBX_PAGE_NOTFOUND (-30797) -/* Located page was wrong type */ -#define MDBX_CORRUPTED (-30796) -/* Update of meta page failed or environment had fatal error */ -#define MDBX_PANIC (-30795) -/* DB file version mismatch with libmdbx */ -#define MDBX_VERSION_MISMATCH (-30794) -/* File is not a valid MDBX file */ -#define MDBX_INVALID (-30793) -/* Environment mapsize reached */ -#define MDBX_MAP_FULL (-30792) -/* Environment maxdbs reached */ -#define MDBX_DBS_FULL (-30791) -/* Environment maxreaders reached */ -#define MDBX_READERS_FULL (-30790) -/* Txn has too many dirty pages */ -#define MDBX_TXN_FULL (-30788) -/* Cursor stack too deep - internal error */ -#define MDBX_CURSOR_FULL (-30787) -/* Page has not enough space - internal error */ -#define MDBX_PAGE_FULL (-30786) -/* Database contents grew beyond environment mapsize */ -#define MDBX_MAP_RESIZED (-30785) -/* Operation and DB incompatible, or DB type changed. This can mean: - * - The operation expects an MDBX_DUPSORT / MDBX_DUPFIXED database. - * - Opening a named DB when the unnamed DB has MDBX_DUPSORT/MDBX_INTEGERKEY. - * - Accessing a data record as a database, or vice versa. - * - The database was dropped and recreated with different flags. */ -#define MDBX_INCOMPATIBLE (-30784) -/* Invalid reuse of reader locktable slot */ -#define MDBX_BAD_RSLOT (-30783) -/* Transaction must abort, has a child, or is invalid */ -#define MDBX_BAD_TXN (-30782) -/* Unsupported size of key/DB name/data, or wrong DUPFIXED size */ -#define MDBX_BAD_VALSIZE (-30781) -/* The specified DBI was changed unexpectedly */ -#define MDBX_BAD_DBI (-30780) -/* Unexpected problem - txn should abort */ -#define MDBX_PROBLEM (-30779) -/* Unexpected problem - txn should abort */ -#define MDBX_BUSY (-30778) -/* The last defined error code */ -#define MDBX_LAST_ERRCODE MDBX_BUSY - -/* The mdbx_put() or mdbx_replace() was called for key, - that has more that one associated value. */ -#define MDBX_EMULTIVAL (-30421) - -/* Bad signature of a runtime object(s), this can mean: - * - memory corruption or double-free; - * - ABI version mismatch (rare case); */ -#define MDBX_EBADSIGN (-30420) - -/* Database should be recovered, but this could NOT be done automatically - * right now (e.g. in readonly mode and so forth). */ -#define MDBX_WANNA_RECOVERY (-30419) - -/* The given key value is mismatched to the current cursor position, - * when mdbx_cursor_put() called with MDBX_CURRENT option. */ -#define MDBX_EKEYMISMATCH (-30418) - -/* Database is too large for current system, - * e.g. could NOT be mapped into RAM. */ -#define MDBX_TOO_LARGE (-30417) - -/* A thread has attempted to use a not owned object, - * e.g. a transaction that started by another thread. */ -#define MDBX_THREAD_MISMATCH (-30416) - -/* Statistics for a database in the environment */ -typedef struct MDBX_stat { - uint32_t ms_psize; /* Size of a database page. - * This is currently the same for all databases. */ - uint32_t ms_depth; /* Depth (height) of the B-tree */ - uint64_t ms_branch_pages; /* Number of internal (non-leaf) pages */ - uint64_t ms_leaf_pages; /* Number of leaf pages */ - uint64_t ms_overflow_pages; /* Number of overflow pages */ - uint64_t ms_entries; /* Number of data items */ -} MDBX_stat; - -/* Information about the environment */ -typedef struct MDBX_envinfo { - struct { - uint64_t lower; /* lower limit for datafile size */ - uint64_t upper; /* upper limit for datafile size */ - uint64_t current; /* current datafile size */ - uint64_t shrink; /* shrink theshold for datafile */ - uint64_t grow; /* growth step for datafile */ - } mi_geo; - uint64_t mi_mapsize; /* Size of the data memory map */ - uint64_t mi_last_pgno; /* ID of the last used page */ - uint64_t mi_recent_txnid; /* ID of the last committed transaction */ - uint64_t mi_latter_reader_txnid; /* ID of the last reader transaction */ - uint64_t mi_meta0_txnid, mi_meta0_sign; - uint64_t mi_meta1_txnid, mi_meta1_sign; - uint64_t mi_meta2_txnid, mi_meta2_sign; - uint32_t mi_maxreaders; /* max reader slots in the environment */ - uint32_t mi_numreaders; /* max reader slots used in the environment */ - uint32_t mi_dxb_pagesize; /* database pagesize */ - uint32_t mi_sys_pagesize; /* system pagesize */ -} MDBX_envinfo; - -/* Return a string describing a given error code. - * - * This function is a superset of the ANSI C X3.159-1989 (ANSI C) strerror(3) - * function. If the error code is greater than or equal to 0, then the string - * returned by the system function strerror(3) is returned. If the error code - * is less than 0, an error string corresponding to the MDBX library error is - * returned. See errors for a list of MDBX-specific error codes. - * - * [in] err The error code - * - * Returns "error message" The description of the error */ -LIBMDBX_API const char *mdbx_strerror(int errnum); -LIBMDBX_API const char *mdbx_strerror_r(int errnum, char *buf, size_t buflen); - -/* Create an MDBX environment handle. - * - * This function allocates memory for a MDBX_env structure. To release - * the allocated memory and discard the handle, call mdbx_env_close(). - * Before the handle may be used, it must be opened using mdbx_env_open(). - * Various other options may also need to be set before opening the handle, - * e.g. mdbx_env_set_mapsize(), mdbx_env_set_maxreaders(), - * mdbx_env_set_maxdbs(), depending on usage requirements. - * - * [out] env The address where the new handle will be stored - * - * Returns A non-zero error value on failure and 0 on success. */ -LIBMDBX_API int mdbx_env_create(MDBX_env **penv); - -/* Open an environment handle. - * - * If this function fails, mdbx_env_close() must be called to discard - * the MDBX_env handle. - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] path The directory in which the database files reside. - * This directory must already exist and be writable. - * [in] flags Special options for this environment. This parameter - * must be set to 0 or by bitwise OR'ing together one - * or more of the values described here. - * - * Flags set by mdbx_env_set_flags() are also used: - * - MDBX_NOSUBDIR - * By default, MDBX creates its environment in a directory whose - * pathname is given in path, and creates its data and lock files - * under that directory. With this option, path is used as-is for - * the database main data file. The database lock file is the path - * with "-lock" appended. - * - * - MDBX_RDONLY - * Open the environment in read-only mode. No write operations will - * be allowed. MDBX will still modify the lock file - except on - * read-only filesystems, where MDBX does not use locks. - * - * - MDBX_WRITEMAP - * Use a writeable memory map unless MDBX_RDONLY is set. This uses fewer - * mallocs but loses protection from application bugs like wild pointer - * writes and other bad updates into the database. - * This may be slightly faster for DBs that fit entirely in RAM, - * but is slower for DBs larger than RAM. - * Incompatible with nested transactions. - * Do not mix processes with and without MDBX_WRITEMAP on the same - * environment. This can defeat durability (mdbx_env_sync etc). - * - * - MDBX_NOMETASYNC - * Flush system buffers to disk only once per transaction, omit the - * metadata flush. Defer that until the system flushes files to disk, - * or next non-MDBX_RDONLY commit or mdbx_env_sync(). This optimization - * maintains database integrity, but a system crash may undo the last - * committed transaction. I.e. it preserves the ACI (atomicity, - * consistency, isolation) but not D (durability) database property. - * This flag may be changed at any time using mdbx_env_set_flags(). - * - * - MDBX_NOSYNC - * Don't flush system buffers to disk when committing a transaction. - * This optimization means a system crash can corrupt the database or - * lose the last transactions if buffers are not yet flushed to disk. - * The risk is governed by how often the system flushes dirty buffers - * to disk and how often mdbx_env_sync() is called. However, if the - * filesystem preserves write order and the MDBX_WRITEMAP and/or - * MDBX_LIFORECLAIM flags are not used, transactions exhibit ACI - * (atomicity, consistency, isolation) properties and only lose D - * (durability). I.e. database integrity is maintained, but a system - * crash may undo the final transactions. - * - * Note that (MDBX_NOSYNC | MDBX_WRITEMAP) leaves the system with no - * hint for when to write transactions to disk. - * Therefore the (MDBX_MAPASYNC | MDBX_WRITEMAP) may be preferable. - * This flag may be changed at any time using mdbx_env_set_flags(). - * - * - MDBX_UTTERLY_NOSYNC (internally MDBX_NOSYNC | MDBX_MAPASYNC) - * FIXME: TODO - * - * - MDBX_MAPASYNC - * When using MDBX_WRITEMAP, use asynchronous flushes to disk. As with - * MDBX_NOSYNC, a system crash can then corrupt the database or lose - * the last transactions. Calling mdbx_env_sync() ensures on-disk - * database integrity until next commit. This flag may be changed at - * any time using mdbx_env_set_flags(). - * - * - MDBX_NOTLS - * Don't use Thread-Local Storage. Tie reader locktable slots to - * MDBX_txn objects instead of to threads. I.e. mdbx_txn_reset() keeps - * the slot reseved for the MDBX_txn object. A thread may use parallel - * read-only transactions. A read-only transaction may span threads if - * the user synchronizes its use. Applications that multiplex many - * user threads over individual OS threads need this option. Such an - * application must also serialize the write transactions in an OS - * thread, since MDBX's write locking is unaware of the user threads. - * - * - MDBX_NOLOCK (don't supported by MDBX) - * Don't do any locking. If concurrent access is anticipated, the - * caller must manage all concurrency itself. For proper operation - * the caller must enforce single-writer semantics, and must ensure - * that no readers are using old transactions while a writer is - * active. The simplest approach is to use an exclusive lock so that - * no readers may be active at all when a writer begins. - * - * - MDBX_NORDAHEAD - * Turn off readahead. Most operating systems perform readahead on - * read requests by default. This option turns it off if the OS - * supports it. Turning it off may help random read performance - * when the DB is larger than RAM and system RAM is full. - * - * - MDBX_NOMEMINIT - * Don't initialize malloc'd memory before writing to unused spaces - * in the data file. By default, memory for pages written to the data - * file is obtained using malloc. While these pages may be reused in - * subsequent transactions, freshly malloc'd pages will be initialized - * to zeroes before use. This avoids persisting leftover data from other - * code (that used the heap and subsequently freed the memory) into the - * data file. Note that many other system libraries may allocate and free - * memory from the heap for arbitrary uses. E.g., stdio may use the heap - * for file I/O buffers. This initialization step has a modest performance - * cost so some applications may want to disable it using this flag. This - * option can be a problem for applications which handle sensitive data - * like passwords, and it makes memory checkers like Valgrind noisy. This - * flag is not needed with MDBX_WRITEMAP, which writes directly to the - * mmap instead of using malloc for pages. The initialization is also - * skipped if MDBX_RESERVE is used; the caller is expected to overwrite - * all of the memory that was reserved in that case. This flag may be - * changed at any time using mdbx_env_set_flags(). - * - * - MDBX_COALESCE - * Aim to coalesce records while reclaiming FreeDB. This flag may be - * changed at any time using mdbx_env_set_flags(). - * FIXME: TODO - * - * - MDBX_LIFORECLAIM - * LIFO policy for reclaiming FreeDB records. This significantly reduce - * write IPOs in case MDBX_NOSYNC with periodically checkpoints. - * FIXME: TODO - * - * [in] mode The UNIX permissions to set on created files. - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_VERSION_MISMATCH - the version of the MDBX library doesn't match the - * version that created the database environment. - * - MDBX_INVALID - the environment file headers are corrupted. - * - MDBX_ENOENT - the directory specified by the path parameter - * doesn't exist. - * - MDBX_EACCES - the user didn't have permission to access - * the environment files. - * - MDBX_EAGAIN - the environment was locked by another process. */ -LIBMDBX_API int mdbx_env_open(MDBX_env *env, const char *path, unsigned flags, - mode_t mode); -LIBMDBX_API int mdbx_env_open_ex(MDBX_env *env, const char *path, - unsigned flags, mode_t mode, int *exclusive); - -/* Copy an MDBX environment to the specified path, with options. - * - * This function may be used to make a backup of an existing environment. - * No lockfile is created, since it gets recreated at need. - * NOTE: This call can trigger significant file size growth if run in - * parallel with write transactions, because it employs a read-only - * transaction. See long-lived transactions under "Caveats" section. - * - * [in] env An environment handle returned by mdbx_env_create(). It must - * have already been opened successfully. - * [in] path The directory in which the copy will reside. This directory - * must already exist and be writable but must otherwise be empty. - * [in] flags Special options for this operation. This parameter must be set - * to 0 or by bitwise OR'ing together one or more of the values - * described here: - * - * - MDBX_CP_COMPACT - * Perform compaction while copying: omit free pages and sequentially - * renumber all pages in output. This option consumes little bit more - * CPU for processing, but may running quickly than the default, on - * account skipping free pages. - * - * NOTE: Currently it fails if the environment has suffered a page leak. - * - * Returns A non-zero error value on failure and 0 on success. */ -LIBMDBX_API int mdbx_env_copy(MDBX_env *env, const char *path, unsigned flags); - -/* Copy an MDBX environment to the specified file descriptor, - * with options. - * - * This function may be used to make a backup of an existing environment. - * No lockfile is created, since it gets recreated at need. See - * mdbx_env_copy() for further details. - * - * NOTE: This call can trigger significant file size growth if run in - * parallel with write transactions, because it employs a read-only - * transaction. See long-lived transactions under "Caveats" section. - * - * [in] env An environment handle returned by mdbx_env_create(). It must - * have already been opened successfully. - * [in] fd The filedescriptor to write the copy to. It must have already - * been opened for Write access. - * [in] flags Special options for this operation. See mdbx_env_copy() for - * options. - * - * Returns A non-zero error value on failure and 0 on success. */ -LIBMDBX_API int mdbx_env_copy2fd(MDBX_env *env, mdbx_filehandle_t fd, - unsigned flags); - -/* Return statistics about the MDBX environment. - * - * [in] env An environment handle returned by mdbx_env_create() - * [out] stat The address of an MDBX_stat structure where the statistics - * will be copied */ -LIBMDBX_API int mdbx_env_stat(MDBX_env *env, MDBX_stat *stat, size_t bytes); - -/* Return information about the MDBX environment. - * - * [in] env An environment handle returned by mdbx_env_create() - * [out] stat The address of an MDBX_envinfo structure - * where the information will be copied */ -LIBMDBX_API int mdbx_env_info(MDBX_env *env, MDBX_envinfo *info, size_t bytes); - -/* Flush the data buffers to disk. - * - * Data is always written to disk when mdbx_txn_commit() is called, - * but the operating system may keep it buffered. MDBX always flushes - * the OS buffers upon commit as well, unless the environment was - * opened with MDBX_NOSYNC or in part MDBX_NOMETASYNC. This call is - * not valid if the environment was opened with MDBX_RDONLY. - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] force If non-zero, force a synchronous flush. Otherwise if the - * environment has the MDBX_NOSYNC flag set the flushes will be - * omitted, and with MDBX_MAPASYNC they will be asynchronous. - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EACCES - the environment is read-only. - * - MDBX_EINVAL - an invalid parameter was specified. - * - MDBX_EIO - an error occurred during synchronization. */ -LIBMDBX_API int mdbx_env_sync(MDBX_env *env, int force); - -/* Close the environment and release the memory map. - * - * Only a single thread may call this function. All transactions, databases, - * and cursors must already be closed before calling this function. Attempts - * to use any such handles after calling this function will cause a SIGSEGV. - * The environment handle will be freed and must not be used again after this - * call. - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] dont_sync A dont'sync flag, if non-zero the last checkpoint (meta-page - * update) will be kept "as is" and may be still "weak" in the - * NOSYNC/MAPASYNC modes. Such "weak" checkpoint will be - * ignored on opening next time, and transactions since the - * last non-weak checkpoint (meta-page update) will rolledback - * for consistency guarantee. */ -LIBMDBX_API void mdbx_env_close(MDBX_env *env); - -/* Set environment flags. - * - * This may be used to set some flags in addition to those from - * mdbx_env_open(), or to unset these flags. If several threads - * change the flags at the same time, the result is undefined. - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] flags The flags to change, bitwise OR'ed together - * [in] onoff A non-zero value sets the flags, zero clears them. - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_env_set_flags(MDBX_env *env, unsigned flags, int onoff); - -/* Get environment flags. - * - * [in] env An environment handle returned by mdbx_env_create() - * [out] flags The address of an integer to store the flags - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_env_get_flags(MDBX_env *env, unsigned *flags); - -/* Return the path that was used in mdbx_env_open(). - * - * [in] env An environment handle returned by mdbx_env_create() - * [out] path Address of a string pointer to contain the path. - * This is the actual string in the environment, not a copy. - * It should not be altered in any way. - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_env_get_path(MDBX_env *env, const char **path); - -/* Return the file descriptor for the given environment. - * - * NOTE: All MDBX file descriptors have FD_CLOEXEC and - * could't be used after exec() and or fork(). - * - * [in] env An environment handle returned by mdbx_env_create() - * [out] fd Address of a int to contain the descriptor. - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_env_get_fd(MDBX_env *env, mdbx_filehandle_t *fd); - -/* Set the size of the memory map to use for this environment. - * - * The size should be a multiple of the OS page size. The default is - * 10485760 bytes. The size of the memory map is also the maximum size - * of the database. The value should be chosen as large as possible, - * to accommodate future growth of the database. - * This function should be called after mdbx_env_create() and before - * mdbx_env_open(). It may be called at later times if no transactions - * are active in this process. Note that the library does not check for - * this condition, the caller must ensure it explicitly. - * - * The new size takes effect immediately for the current process but - * will not be persisted to any others until a write transaction has been - * committed by the current process. Also, only mapsize increases are - * persisted into the environment. - * - * If the mapsize is increased by another process, and data has grown - * beyond the range of the current mapsize, mdbx_txn_begin() will - * return MDBX_MAP_RESIZED. This function may be called with a size - * of zero to adopt the new size. - * - * Any attempt to set a size smaller than the space already consumed by the - * environment will be silently changed to the current size of the used space. - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] size The size in bytes - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified, - * or the environment has an active write transaction. */ -LIBMDBX_API int mdbx_env_set_mapsize(MDBX_env *env, size_t size); -LIBMDBX_API int mdbx_env_set_geometry(MDBX_env *env, intptr_t size_lower, - intptr_t size_now, intptr_t size_upper, - intptr_t growth_step, - intptr_t shrink_threshold, - intptr_t pagesize); - -/* Set the maximum number of threads/reader slots for the environment. - * - * This defines the number of slots in the lock table that is used to track - * readers in the the environment. The default is 61. - * Starting a read-only transaction normally ties a lock table slot to the - * current thread until the environment closes or the thread exits. If - * MDBX_NOTLS is in use, mdbx_txn_begin() instead ties the slot to the - * MDBX_txn object until it or the MDBX_env object is destroyed. - * This function may only be called after mdbx_env_create() and before - * mdbx_env_open(). - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] readers The maximum number of reader lock table slots - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified, - * or the environment is already open. */ -LIBMDBX_API int mdbx_env_set_maxreaders(MDBX_env *env, unsigned readers); - -/* Get the maximum number of threads/reader slots for the environment. - * - * [in] env An environment handle returned by mdbx_env_create() - * [out] readers Address of an integer to store the number of readers - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_env_get_maxreaders(MDBX_env *env, unsigned *readers); - -/* Set the maximum number of named databases for the environment. - * - * This function is only needed if multiple databases will be used in the - * environment. Simpler applications that use the environment as a single - * unnamed database can ignore this option. - * This function may only be called after mdbx_env_create() and before - * mdbx_env_open(). - * - * Currently a moderate number of slots are cheap but a huge number gets - * expensive: 7-120 words per transaction, and every mdbx_dbi_open() - * does a linear search of the opened slots. - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] dbs The maximum number of databases - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified, - * or the environment is already open. */ -LIBMDBX_API int mdbx_env_set_maxdbs(MDBX_env *env, MDBX_dbi dbs); - -/* Get the maximum size of keys and MDBX_DUPSORT data we can write. - * - * [in] env An environment handle returned by mdbx_env_create() - * - * Returns The maximum size of a key we can write. */ -LIBMDBX_API int mdbx_env_get_maxkeysize(MDBX_env *env); -LIBMDBX_API int mdbx_get_maxkeysize(size_t pagesize); - -/* Set application information associated with the MDBX_env. - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] ctx An arbitrary pointer for whatever the application needs. - * - * Returns A non-zero error value on failure and 0 on success. */ -LIBMDBX_API int mdbx_env_set_userctx(MDBX_env *env, void *ctx); - -/* Get the application information associated with the MDBX_env. - * - * [in] env An environment handle returned by mdbx_env_create() - * Returns The pointer set by mdbx_env_set_userctx(). */ -LIBMDBX_API void *mdbx_env_get_userctx(MDBX_env *env); - -/* A callback function for most MDBX assert() failures, - * called before printing the message and aborting. - * - * [in] env An environment handle returned by mdbx_env_create(). - * [in] msg The assertion message, not including newline. */ -typedef void MDBX_assert_func(const MDBX_env *env, const char *msg, - const char *function, unsigned line); - -/* Set or reset the assert() callback of the environment. - * - * Disabled if libmdbx is buillt with MDBX_DEBUG=0. - * NOTE: This hack should become obsolete as mdbx's error handling matures. - * - * [in] env An environment handle returned by mdbx_env_create(). - * [in] func An MDBX_assert_func function, or 0. - * - * Returns A non-zero error value on failure and 0 on success. */ -LIBMDBX_API int mdbx_env_set_assert(MDBX_env *env, MDBX_assert_func *func); - -/* Create a transaction for use with the environment. - * - * The transaction handle may be discarded using mdbx_txn_abort() - * or mdbx_txn_commit(). - * NOTE: A transaction and its cursors must only be used by a single - * thread, and a thread may only have a single transaction at a time. - * If MDBX_NOTLS is in use, this does not apply to read-only transactions. - * NOTE: Cursors may not span transactions. - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] parent If this parameter is non-NULL, the new transaction will be - * a nested transaction, with the transaction indicated by parent - * as its parent. Transactions may be nested to any level. - * A parent transaction and its cursors may not issue any other - * operations than mdbx_txn_commit and mdbx_txn_abort while it - * has active child transactions. - * [in] flags Special options for this transaction. This parameter - * must be set to 0 or by bitwise OR'ing together one or more - * of the values described here. - * - * - MDBX_RDONLY - * This transaction will not perform any write operations. - * - * - MDBX_TRYTXN - * Do not block when starting a write transaction - * - * [out] txn Address where the new MDBX_txn handle will be stored - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_PANIC - a fatal error occurred earlier and the environment - * must be shut down. - * - MDBX_MAP_RESIZED - another process wrote data beyond this MDBX_env's - * mapsize and this environment's map must be resized - * as well. See mdbx_env_set_mapsize(). - * - MDBX_READERS_FULL - a read-only transaction was requested and the reader - * lock table is full. See mdbx_env_set_maxreaders(). - * - MDBX_ENOMEM - out of memory. - * - MDBX_BUSY - a write transaction is already started. */ -LIBMDBX_API int mdbx_txn_begin(MDBX_env *env, MDBX_txn *parent, unsigned flags, - MDBX_txn **txn); - -/* Returns the transaction's MDBX_env - * - * [in] txn A transaction handle returned by mdbx_txn_begin() */ -LIBMDBX_API MDBX_env *mdbx_txn_env(MDBX_txn *txn); - -/* Return the transaction's ID. - * - * This returns the identifier associated with this transaction. For a - * read-only transaction, this corresponds to the snapshot being read; - * concurrent readers will frequently have the same transaction ID. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * - * Returns A transaction ID, valid if input is an active transaction. */ -LIBMDBX_API uint64_t mdbx_txn_id(MDBX_txn *txn); - -/* Commit all the operations of a transaction into the database. - * - * The transaction handle is freed. It and its cursors must not be used - * again after this call, except with mdbx_cursor_renew(). - * - * A cursor must be closed explicitly always, before - * or after its transaction ends. It can be reused with - * mdbx_cursor_renew() before finally closing it. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified. - * - MDBX_ENOSPC - no more disk space. - * - MDBX_EIO - a low-level I/O error occurred while writing. - * - MDBX_ENOMEM - out of memory. */ -LIBMDBX_API int mdbx_txn_commit(MDBX_txn *txn); - -/* Abandon all the operations of the transaction instead of saving them. - * - * The transaction handle is freed. It and its cursors must not be used - * again after this call, except with mdbx_cursor_renew(). - * - * A cursor must be closed explicitly always, before or after its transaction - * ends. It can be reused with mdbx_cursor_renew() before finally closing it. - * - * [in] txn A transaction handle returned by mdbx_txn_begin(). */ -LIBMDBX_API int mdbx_txn_abort(MDBX_txn *txn); - -/* Reset a read-only transaction. - * - * Abort the transaction like mdbx_txn_abort(), but keep the transaction - * handle. Therefore mdbx_txn_renew() may reuse the handle. This saves - * allocation overhead if the process will start a new read-only transaction - * soon, and also locking overhead if MDBX_NOTLS is in use. The reader table - * lock is released, but the table slot stays tied to its thread or - * MDBX_txn. Use mdbx_txn_abort() to discard a reset handle, and to free - * its lock table slot if MDBX_NOTLS is in use. - * - * Cursors opened within the transaction must not be used - * again after this call, except with mdbx_cursor_renew(). - * - * Reader locks generally don't interfere with writers, but they keep old - * versions of database pages allocated. Thus they prevent the old pages - * from being reused when writers commit new data, and so under heavy load - * the database size may grow much more rapidly than otherwise. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() */ -LIBMDBX_API int mdbx_txn_reset(MDBX_txn *txn); - -/* Renew a read-only transaction. - * - * This acquires a new reader lock for a transaction handle that had been - * released by mdbx_txn_reset(). It must be called before a reset transaction - * may be used again. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_PANIC - a fatal error occurred earlier and the environment - * must be shut down. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_txn_renew(MDBX_txn *txn); - -/* Open a table in the environment. - * - * A table handle denotes the name and parameters of a table, independently - * of whether such a table exists. The table handle may be discarded by - * calling mdbx_dbi_close(). The old table handle is returned if the table - * was already open. The handle may only be closed once. - * - * The table handle will be private to the current transaction until - * the transaction is successfully committed. If the transaction is - * aborted the handle will be closed automatically. - * After a successful commit the handle will reside in the shared - * environment, and may be used by other transactions. - * - * This function must not be called from multiple concurrent - * transactions in the same process. A transaction that uses - * this function must finish (either commit or abort) before - * any other transaction in the process may use this function. - * - * To use named table (with name != NULL), mdbx_env_set_maxdbs() - * must be called before opening the environment. Table names are - * keys in the internal unnamed table, and may be read but not written. - * - * [in] txn transaction handle returned by mdbx_txn_begin() - * [in] name The name of the table to open. If only a single - * table is needed in the environment, this value may be NULL. - * [in] flags Special options for this table. This parameter must be set - * to 0 or by bitwise OR'ing together one or more of the values - * described here: - * - MDBX_REVERSEKEY - * Keys are strings to be compared in reverse order, from the end - * of the strings to the beginning. By default, Keys are treated as - * strings and compared from beginning to end. - * - MDBX_DUPSORT - * Duplicate keys may be used in the table. Or, from another point of - * view, keys may have multiple data items, stored in sorted order. By - * default keys must be unique and may have only a single data item. - * - MDBX_INTEGERKEY - * Keys are binary integers in native byte order, either uin32_t or - * uint64_t, and will be sorted as such. The keys must all be of the - * same size. - * - MDBX_DUPFIXED - * This flag may only be used in combination with MDBX_DUPSORT. This - * option tells the library that the data items for this database are - * all the same size, which allows further optimizations in storage and - * retrieval. When all data items are the same size, the MDBX_GET_MULTIPLE, - * MDBX_NEXT_MULTIPLE and MDBX_PREV_MULTIPLE cursor operations may be used - * to retrieve multiple items at once. - * - MDBX_INTEGERDUP - * This option specifies that duplicate data items are binary integers, - * similar to MDBX_INTEGERKEY keys. - * - MDBX_REVERSEDUP - * This option specifies that duplicate data items should be compared as - * strings in reverse order (the comparison is performed in the direction - * from the last byte to the first). - * - MDBX_CREATE - * Create the named database if it doesn't exist. This option is not - * allowed in a read-only transaction or a read-only environment. - * - * [out] dbi Address where the new MDBX_dbi handle will be stored - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_NOTFOUND - the specified database doesn't exist in the - * environment and MDBX_CREATE was not specified. - * - MDBX_DBS_FULL - too many databases have been opened. - * See mdbx_env_set_maxdbs(). */ -LIBMDBX_API int mdbx_dbi_open_ex(MDBX_txn *txn, const char *name, - unsigned flags, MDBX_dbi *dbi, - MDBX_cmp_func *keycmp, MDBX_cmp_func *datacmp); -LIBMDBX_API int mdbx_dbi_open(MDBX_txn *txn, const char *name, unsigned flags, - MDBX_dbi *dbi); - -/* Retrieve statistics for a database. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [in] dbi A database handle returned by mdbx_dbi_open() - * [out] stat The address of an MDBX_stat structure where the statistics - * will be copied - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_dbi_stat(MDBX_txn *txn, MDBX_dbi dbi, MDBX_stat *stat, - size_t bytes); - -/* Retrieve the DB flags for a database handle. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [in] dbi A database handle returned by mdbx_dbi_open() - * [out] flags Address where the flags will be returned. - * [out] state Address where the state will be returned. - * - * Returns A non-zero error value on failure and 0 on success. */ -#define MDBX_TBL_DIRTY 0x01 /* DB was written in this txn */ -#define MDBX_TBL_STALE 0x02 /* Named-DB record is older than txnID */ -#define MDBX_TBL_NEW 0x04 /* Named-DB handle opened in this txn */ -LIBMDBX_API int mdbx_dbi_flags_ex(MDBX_txn *txn, MDBX_dbi dbi, unsigned *flags, - unsigned *state); -LIBMDBX_API int mdbx_dbi_flags(MDBX_txn *txn, MDBX_dbi dbi, unsigned *flags); - -/* Close a database handle. Normally unnecessary. - * - * Use with care: - * FIXME: This call is not mutex protected. Handles should only be closed by - * a single thread, and only if no other threads are going to reference - * the database handle or one of its cursors any further. Do not close - * a handle if an existing transaction has modified its database. - * Doing so can cause misbehavior from database corruption to errors - * like MDBX_BAD_VALSIZE (since the DB name is gone). - * - * Closing a database handle is not necessary, but lets mdbx_dbi_open() - * reuse the handle value. Usually it's better to set a bigger - * mdbx_env_set_maxdbs(), unless that value would be large. - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] dbi A database handle returned by mdbx_dbi_open() - */ -LIBMDBX_API int mdbx_dbi_close(MDBX_env *env, MDBX_dbi dbi); - -/* Empty or delete+close a database. - * - * See mdbx_dbi_close() for restrictions about closing the DB handle. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [in] dbi A database handle returned by mdbx_dbi_open() - * [in] del 0 to empty the DB, 1 to delete it from the environment - * and close the DB handle. - * - * Returns A non-zero error value on failure and 0 on success. */ -LIBMDBX_API int mdbx_drop(MDBX_txn *txn, MDBX_dbi dbi, int del); - -/* Get items from a database. - * - * This function retrieves key/data pairs from the database. The address - * and length of the data associated with the specified key are returned - * in the structure to which data refers. - * If the database supports duplicate keys (MDBX_DUPSORT) then the - * first data item for the key will be returned. Retrieval of other - * items requires the use of mdbx_cursor_get(). - * - * NOTE: The memory pointed to by the returned values is owned by the - * database. The caller need not dispose of the memory, and may not - * modify it in any way. For values returned in a read-only transaction - * any modification attempts will cause a SIGSEGV. - * - * NOTE: Values returned from the database are valid only until a - * subsequent update operation, or the end of the transaction. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [in] dbi A database handle returned by mdbx_dbi_open() - * [in] key The key to search for in the database - * [in,out] data The data corresponding to the key - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_NOTFOUND - the key was not in the database. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_get(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, - MDBX_val *data); - -/* Store items into a database. - * - * This function stores key/data pairs in the database. The default behavior - * is to enter the new key/data pair, replacing any previously existing key - * if duplicates are disallowed, or adding a duplicate data item if - * duplicates are allowed (MDBX_DUPSORT). - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [in] dbi A database handle returned by mdbx_dbi_open() - * [in] key The key to store in the database - * [in,out] data The data to store - * [in] flags Special options for this operation. This parameter must be - * set to 0 or by bitwise OR'ing together one or more of the - * values described here. - * - * - MDBX_NODUPDATA - * Enter the new key/data pair only if it does not already appear - * in the database. This flag may only be specified if the database - * was opened with MDBX_DUPSORT. The function will return MDBX_KEYEXIST - * if the key/data pair already appears in the database. - * - * - MDBX_NOOVERWRITE - * Enter the new key/data pair only if the key does not already appear - * in the database. The function will return MDBX_KEYEXIST if the key - * already appears in the database, even if the database supports - * duplicates (MDBX_DUPSORT). The data parameter will be set to point - * to the existing item. - * - * - MDBX_CURRENT - * Update an single existing entry, but not add new ones. The function - * will return MDBX_NOTFOUND if the given key not exist in the database. - * Or the MDBX_EMULTIVAL in case duplicates for the given key. - * - * - MDBX_RESERVE - * Reserve space for data of the given size, but don't copy the given - * data. Instead, return a pointer to the reserved space, which the - * caller can fill in later - before the next update operation or the - * transaction ends. This saves an extra memcpy if the data is being - * generated later. MDBX does nothing else with this memory, the caller - * is expected to modify all of the space requested. This flag must not - * be specified if the database was opened with MDBX_DUPSORT. - * - * - MDBX_APPEND - * Append the given key/data pair to the end of the database. This option - * allows fast bulk loading when keys are already known to be in the - * correct order. Loading unsorted keys with this flag will cause - * a MDBX_EKEYMISMATCH error. - * - * - MDBX_APPENDDUP - * As above, but for sorted dup data. - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_KEYEXIST - * - MDBX_MAP_FULL - the database is full, see mdbx_env_set_mapsize(). - * - MDBX_TXN_FULL - the transaction has too many dirty pages. - * - MDBX_EACCES - an attempt was made to write in a read-only transaction. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_put(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, - MDBX_val *data, unsigned flags); - -/* Delete items from a database. - * - * This function removes key/data pairs from the database. - * - * The data parameter is NOT ignored regardless the database does - * support sorted duplicate data items or not. If the data parameter - * is non-NULL only the matching data item will be deleted. - * - * This function will return MDBX_NOTFOUND if the specified key/data - * pair is not in the database. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [in] dbi A database handle returned by mdbx_dbi_open() - * [in] key The key to delete from the database - * [in] data The data to delete - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EACCES - an attempt was made to write in a read-only transaction. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_del(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, - MDBX_val *data); - -/* Create a cursor handle. - * - * A cursor is associated with a specific transaction and database. - * A cursor cannot be used when its database handle is closed. Nor - * when its transaction has ended, except with mdbx_cursor_renew(). - * It can be discarded with mdbx_cursor_close(). - * - * A cursor must be closed explicitly always, before - * or after its transaction ends. It can be reused with - * mdbx_cursor_renew() before finally closing it. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [in] dbi A database handle returned by mdbx_dbi_open() - * [out] cursor Address where the new MDBX_cursor handle will be stored - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_cursor_open(MDBX_txn *txn, MDBX_dbi dbi, - MDBX_cursor **cursor); - -/* Close a cursor handle. - * - * The cursor handle will be freed and must not be used again after this call. - * Its transaction must still be live if it is a write-transaction. - * - * [in] cursor A cursor handle returned by mdbx_cursor_open() */ -LIBMDBX_API void mdbx_cursor_close(MDBX_cursor *cursor); - -/* Renew a cursor handle. - * - * A cursor is associated with a specific transaction and database. - * Cursors that are only used in read-only transactions may be re-used, - * to avoid unnecessary malloc/free overhead. The cursor may be associated - * with a new read-only transaction, and referencing the same database handle - * as it was created with. - * - * This may be done whether the previous transaction is live or dead. - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [in] cursor A cursor handle returned by mdbx_cursor_open() - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_cursor_renew(MDBX_txn *txn, MDBX_cursor *cursor); - -/* Return the cursor's transaction handle. - * - * [in] cursor A cursor handle returned by mdbx_cursor_open() */ -LIBMDBX_API MDBX_txn *mdbx_cursor_txn(MDBX_cursor *cursor); - -/* Return the cursor's database handle. - * - * [in] cursor A cursor handle returned by mdbx_cursor_open() */ -LIBMDBX_API MDBX_dbi mdbx_cursor_dbi(MDBX_cursor *cursor); - -/* Retrieve by cursor. - * - * This function retrieves key/data pairs from the database. The address and - * length of the key are returned in the object to which key refers (except - * for the case of the MDBX_SET option, in which the key object is unchanged), - * and the address and length of the data are returned in the object to which - * data refers. See mdbx_get() for restrictions on using the output values. - * - * [in] cursor A cursor handle returned by mdbx_cursor_open() - * [in,out] key The key for a retrieved item - * [in,out] data The data of a retrieved item - * [in] op A cursor operation MDBX_cursor_op - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_NOTFOUND - no matching key found. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_cursor_get(MDBX_cursor *cursor, MDBX_val *key, - MDBX_val *data, MDBX_cursor_op op); - -/* Store by cursor. - * - * This function stores key/data pairs into the database. The cursor is - * positioned at the new item, or on failure usually near it. - * - * [in] cursor A cursor handle returned by mdbx_cursor_open() - * [in] key The key operated on. - * [in] data The data operated on. - * [in] flags Options for this operation. This parameter - * must be set to 0 or one of the values described here: - * - * - MDBX_CURRENT - * Replace the item at the current cursor position. The key parameter - * must still be provided, and must match it, otherwise the function - * return MDBX_EKEYMISMATCH. - * - * NOTE: MDBX unlike LMDB allows you to change the size of the data and - * automatically handles reordering for sorted duplicates (MDBX_DUPSORT). - * - * - MDBX_NODUPDATA - * Enter the new key/data pair only if it does not already appear in the - * database. This flag may only be specified if the database was opened - * with MDBX_DUPSORT. The function will return MDBX_KEYEXIST if the - * key/data pair already appears in the database. - * - * - MDBX_NOOVERWRITE - * Enter the new key/data pair only if the key does not already appear - * in the database. The function will return MDBX_KEYEXIST if the key - * already appears in the database, even if the database supports - * duplicates (MDBX_DUPSORT). - * - * - MDBX_RESERVE - * Reserve space for data of the given size, but don't copy the given - * data. Instead, return a pointer to the reserved space, which the - * caller can fill in later - before the next update operation or the - * transaction ends. This saves an extra memcpy if the data is being - * generated later. This flag must not be specified if the database - * was opened with MDBX_DUPSORT. - * - * - MDBX_APPEND - * Append the given key/data pair to the end of the database. No key - * comparisons are performed. This option allows fast bulk loading when - * keys are already known to be in the correct order. Loading unsorted - * keys with this flag will cause a MDBX_KEYEXIST error. - * - * - MDBX_APPENDDUP - * As above, but for sorted dup data. - * - * - MDBX_MULTIPLE - * Store multiple contiguous data elements in a single request. This flag - * may only be specified if the database was opened with MDBX_DUPFIXED. - * The data argument must be an array of two MDBX_vals. The iov_len of the - * first MDBX_val must be the size of a single data element. The iov_base - * of the first MDBX_val must point to the beginning of the array of - * contiguous data elements. The iov_len of the second MDBX_val must be - * the count of the number of data elements to store. On return this - * field will be set to the count of the number of elements actually - * written. The iov_base of the second MDBX_val is unused. - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EKEYMISMATCH - * - MDBX_MAP_FULL - the database is full, see mdbx_env_set_mapsize(). - * - MDBX_TXN_FULL - the transaction has too many dirty pages. - * - MDBX_EACCES - an attempt was made to write in a read-only transaction. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_cursor_put(MDBX_cursor *cursor, MDBX_val *key, - MDBX_val *data, unsigned flags); - -/* Delete current key/data pair - * - * This function deletes the key/data pair to which the cursor refers. - * - * [in] cursor A cursor handle returned by mdbx_cursor_open() - * [in] flags Options for this operation. This parameter must be set to 0 - * or one of the values described here. - * - * - MDBX_NODUPDATA - * Delete all of the data items for the current key. This flag may only - * be specified if the database was opened with MDBX_DUPSORT. - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EACCES - an attempt was made to write in a read-only transaction. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_cursor_del(MDBX_cursor *cursor, unsigned flags); - -/* Return count of duplicates for current key. - * - * This call is only valid on databases that support sorted duplicate data - * items MDBX_DUPSORT. - * - * [in] cursor A cursor handle returned by mdbx_cursor_open() - * [out] countp Address where the count will be stored - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EINVAL - cursor is not initialized, or an invalid parameter - * was specified. */ -LIBMDBX_API int mdbx_cursor_count(MDBX_cursor *cursor, size_t *countp); - -/* Compare two data items according to a particular database. - * - * This returns a comparison as if the two data items were keys in the - * specified database. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [in] dbi A database handle returned by mdbx_dbi_open() - * [in] a The first item to compare - * [in] b The second item to compare - * - * Returns < 0 if a < b, 0 if a == b, > 0 if a > b */ -LIBMDBX_API int mdbx_cmp(MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *a, - const MDBX_val *b); - -/* Compare two data items according to a particular database. - * - * This returns a comparison as if the two items were data items of - * the specified database. The database must have the MDBX_DUPSORT flag. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [in] dbi A database handle returned by mdbx_dbi_open() - * [in] a The first item to compare - * [in] b The second item to compare - * - * Returns < 0 if a < b, 0 if a == b, > 0 if a > b */ -LIBMDBX_API int mdbx_dcmp(MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *a, - const MDBX_val *b); - -/* A callback function used to print a message from the library. - * - * [in] msg The string to be printed. - * [in] ctx An arbitrary context pointer for the callback. - * - * Returns < 0 on failure, >= 0 on success. */ -typedef int(MDBX_msg_func)(const char *msg, void *ctx); - -/* Dump the entries in the reader lock table. - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] func A MDBX_msg_func function - * [in] ctx Anything the message function needs - * - * Returns < 0 on failure, >= 0 on success. */ -LIBMDBX_API int mdbx_reader_list(MDBX_env *env, MDBX_msg_func *func, void *ctx); - -/* Check for stale entries in the reader lock table. - * - * [in] env An environment handle returned by mdbx_env_create() - * [out] dead Number of stale slots that were cleared - * - * Returns 0 on success, non-zero on failure. */ -LIBMDBX_API int mdbx_reader_check(MDBX_env *env, int *dead); - -LIBMDBX_API char *mdbx_dkey(const MDBX_val *key, char *const buf, - const size_t bufsize); - -LIBMDBX_API int mdbx_env_close_ex(MDBX_env *env, int dont_sync); - -/* Set threshold to force flush the data buffers to disk, - * even of MDBX_NOSYNC, MDBX_NOMETASYNC and MDBX_MAPASYNC flags - * in the environment. - * - * Data is always written to disk when mdbx_txn_commit() is called, - * but the operating system may keep it buffered. MDBX always flushes - * the OS buffers upon commit as well, unless the environment was - * opened with MDBX_NOSYNC or in part MDBX_NOMETASYNC. - * - * The default is 0, than mean no any threshold checked, and no additional - * flush will be made. - * - * [in] env An environment handle returned by mdbx_env_create() - * [in] bytes The size in bytes of summary changes when a synchronous - * flush would be made. - * - * Returns A non-zero error value on failure and 0 on success. */ -LIBMDBX_API int mdbx_env_set_syncbytes(MDBX_env *env, size_t bytes); - -/* Returns a lag of the reading for the given transaction. - * - * Returns an information for estimate how much given read-only - * transaction is lagging relative the to actual head. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [out] percent Percentage of page allocation in the database. - * - * Returns Number of transactions committed after the given was started for - * read, or -1 on failure. */ -LIBMDBX_API int mdbx_txn_straggler(MDBX_txn *txn, int *percent); - -/* A callback function for killing a laggard readers, - * but also could waiting ones. Called in case of MDBX_MAP_FULL error. - * - * [in] env An environment handle returned by mdbx_env_create(). - * [in] pid pid of the reader process. - * [in] tid thread_id of the reader thread. - * [in] txn Transaction number on which stalled. - * [in] gap A lag from the last commited txn. - * [in] retry A retry number, less that zero for notify end of OOM-loop. - * - * Returns -1 on failure (reader is not killed), - * 0 should wait or retry, - * 1 drop reader txn-lock (reading-txn was aborted), - * >1 drop reader registration (reader process was killed). */ -typedef int(MDBX_oom_func)(MDBX_env *env, int pid, mdbx_tid_t tid, uint64_t txn, - unsigned gap, int retry); - -/* Set the OOM callback. - * - * Callback will be called only on out-of-pages case for killing - * a laggard readers to allowing reclaiming of freeDB. - * - * [in] env An environment handle returned by mdbx_env_create(). - * [in] oomfunc A MDBX_oom_func function or NULL to disable. - * - * Returns A non-zero error value on failure and 0 on success. */ -LIBMDBX_API int mdbx_env_set_oomfunc(MDBX_env *env, MDBX_oom_func *oom_func); - -/* Get the current oom_func callback. - * - * Callback will be called only on out-of-pages case for killing - * a laggard readers to allowing reclaiming of freeDB. - * - * [in] env An environment handle returned by mdbx_env_create(). - * - * Returns A MDBX_oom_func function or NULL if disabled. */ -LIBMDBX_API MDBX_oom_func *mdbx_env_get_oomfunc(MDBX_env *env); - -#define MDBX_DBG_ASSERT 1 -#define MDBX_DBG_PRINT 2 -#define MDBX_DBG_TRACE 4 -#define MDBX_DBG_EXTRA 8 -#define MDBX_DBG_AUDIT 16 -#define MDBX_DBG_JITTER 32 -#define MDBX_DBG_DUMP 64 - -typedef void MDBX_debug_func(int type, const char *function, int line, - const char *msg, va_list args); - -LIBMDBX_API int mdbx_setup_debug(int flags, MDBX_debug_func *logger); - -typedef int MDBX_pgvisitor_func(uint64_t pgno, unsigned pgnumber, void *ctx, - const char *dbi, const char *type, - size_t nentries, size_t payload_bytes, - size_t header_bytes, size_t unused_bytes); -LIBMDBX_API int mdbx_env_pgwalk(MDBX_txn *txn, MDBX_pgvisitor_func *visitor, - void *ctx); - -typedef struct mdbx_canary { uint64_t x, y, z, v; } mdbx_canary; - -LIBMDBX_API int mdbx_canary_put(MDBX_txn *txn, const mdbx_canary *canary); -LIBMDBX_API int mdbx_canary_get(MDBX_txn *txn, mdbx_canary *canary); - -/* Returns: - * - MDBX_RESULT_TRUE - * when no more data available or cursor not positioned; - * - MDBX_RESULT_FALSE - * when data available; - * - Otherwise the error code. */ -LIBMDBX_API int mdbx_cursor_eof(MDBX_cursor *mc); - -/* Returns: MDBX_RESULT_TRUE, MDBX_RESULT_FALSE or Error code. */ -LIBMDBX_API int mdbx_cursor_on_first(MDBX_cursor *mc); - -/* Returns: MDBX_RESULT_TRUE, MDBX_RESULT_FALSE or Error code. */ -LIBMDBX_API int mdbx_cursor_on_last(MDBX_cursor *mc); - -LIBMDBX_API int mdbx_replace(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, - MDBX_val *new_data, MDBX_val *old_data, - unsigned flags); -/* Same as mdbx_get(), but: - * 1) if values_count is not NULL, then returns the count - * of multi-values/duplicates for a given key. - * 2) updates the key for pointing to the actual key's data inside DB. */ -LIBMDBX_API int mdbx_get_ex(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, - MDBX_val *data, size_t *values_count); - -LIBMDBX_API int mdbx_is_dirty(const MDBX_txn *txn, const void *ptr); - -LIBMDBX_API int mdbx_dbi_sequence(MDBX_txn *txn, MDBX_dbi dbi, uint64_t *result, - uint64_t increment); - -/*----------------------------------------------------------------------------*/ -/* attribute support functions for Nexenta */ -typedef uint_fast64_t mdbx_attr_t; - -/* Store by cursor with attribute. - * - * This function stores key/data pairs into the database. The cursor is - * positioned at the new item, or on failure usually near it. - * - * NOTE: Internally based on MDBX_RESERVE feature, - * therefore doesn't support MDBX_DUPSORT. - * - * [in] cursor A cursor handle returned by mdbx_cursor_open() - * [in] key The key operated on. - * [in] data The data operated on. - * [in] attr The attribute. - * [in] flags Options for this operation. This parameter must be set to 0 - * or one of the values described here: - * - * - MDBX_CURRENT - * Replace the item at the current cursor position. The key parameter - * must still be provided, and must match it, otherwise the function - * return MDBX_EKEYMISMATCH. - * - * - MDBX_APPEND - * Append the given key/data pair to the end of the database. No key - * comparisons are performed. This option allows fast bulk loading when - * keys are already known to be in the correct order. Loading unsorted - * keys with this flag will cause a MDBX_KEYEXIST error. - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_EKEYMISMATCH - * - MDBX_MAP_FULL - the database is full, see mdbx_env_set_mapsize(). - * - MDBX_TXN_FULL - the transaction has too many dirty pages. - * - MDBX_EACCES - an attempt was made to write in a read-only transaction. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_cursor_put_attr(MDBX_cursor *cursor, MDBX_val *key, - MDBX_val *data, mdbx_attr_t attr, - unsigned flags); - -/* Store items and attributes into a database. - * - * This function stores key/data pairs in the database. The default behavior - * is to enter the new key/data pair, replacing any previously existing key - * if duplicates are disallowed. - * - * NOTE: Internally based on MDBX_RESERVE feature, - * therefore doesn't support MDBX_DUPSORT. - * - * [in] txn A transaction handle returned by mdbx_txn_begin(). - * [in] dbi A database handle returned by mdbx_dbi_open(). - * [in] key The key to store in the database. - * [in] attr The attribute to store in the database. - * [in,out] data The data to store. - * [in] flags Special options for this operation. This parameter must be - * set to 0 or by bitwise OR'ing together one or more of the - * values described here: - * - * - MDBX_NOOVERWRITE - * Enter the new key/data pair only if the key does not already appear - * in the database. The function will return MDBX_KEYEXIST if the key - * already appears in the database. The data parameter will be set to - * point to the existing item. - * - * - MDBX_CURRENT - * Update an single existing entry, but not add new ones. The function - * will return MDBX_NOTFOUND if the given key not exist in the database. - * Or the MDBX_EMULTIVAL in case duplicates for the given key. - * - * - MDBX_APPEND - * Append the given key/data pair to the end of the database. This option - * allows fast bulk loading when keys are already known to be in the - * correct order. Loading unsorted keys with this flag will cause - * a MDBX_EKEYMISMATCH error. - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_KEYEXIST - * - MDBX_MAP_FULL - the database is full, see mdbx_env_set_mapsize(). - * - MDBX_TXN_FULL - the transaction has too many dirty pages. - * - MDBX_EACCES - an attempt was made to write in a read-only transaction. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_put_attr(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, - MDBX_val *data, mdbx_attr_t attr, unsigned flags); - -/* Set items attribute from a database. - * - * This function stores key/data pairs attribute to the database. - * - * NOTE: Internally based on MDBX_RESERVE feature, - * therefore doesn't support MDBX_DUPSORT. - * - * [in] txn A transaction handle returned by mdbx_txn_begin(). - * [in] dbi A database handle returned by mdbx_dbi_open(). - * [in] key The key to search for in the database. - * [in] data The data to be stored or NULL to save previous value. - * [in] attr The attribute to be stored. - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_NOTFOUND - the key-value pair was not in the database. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_set_attr(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, - MDBX_val *data, mdbx_attr_t attr); - -/* Get items attribute from a database cursor. - * - * This function retrieves key/data pairs from the database. The address and - * length of the key are returned in the object to which key refers (except - * for the case of the MDBX_SET option, in which the key object is unchanged), - * and the address and length of the data are returned in the object to which - * data refers. See mdbx_get() for restrictions on using the output values. - * - * [in] cursor A cursor handle returned by mdbx_cursor_open() - * [in,out] key The key for a retrieved item - * [in,out] data The data of a retrieved item - * [in] op A cursor operation MDBX_cursor_op - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_NOTFOUND - no matching key found. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_cursor_get_attr(MDBX_cursor *mc, MDBX_val *key, - MDBX_val *data, mdbx_attr_t *attrptr, - MDBX_cursor_op op); - -/* Get items attribute from a database. - * - * This function retrieves key/data pairs from the database. The address - * and length of the data associated with the specified key are returned - * in the structure to which data refers. - * If the database supports duplicate keys (MDBX_DUPSORT) then the - * first data item for the key will be returned. Retrieval of other - * items requires the use of mdbx_cursor_get(). - * - * NOTE: The memory pointed to by the returned values is owned by the - * database. The caller need not dispose of the memory, and may not - * modify it in any way. For values returned in a read-only transaction - * any modification attempts will cause a SIGSEGV. - * - * NOTE: Values returned from the database are valid only until a - * subsequent update operation, or the end of the transaction. - * - * [in] txn A transaction handle returned by mdbx_txn_begin() - * [in] dbi A database handle returned by mdbx_dbi_open() - * [in] key The key to search for in the database - * [in,out] data The data corresponding to the key - * - * Returns A non-zero error value on failure and 0 on success, some - * possible errors are: - * - MDBX_NOTFOUND - the key was not in the database. - * - MDBX_EINVAL - an invalid parameter was specified. */ -LIBMDBX_API int mdbx_get_attr(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, - MDBX_val *data, mdbx_attr_t *attrptr); - -#ifdef __cplusplus -} -#endif - -#endif /* LIBMDBX_H */ |