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/*
Miranda IM: the free IM client for Microsoft* Windows*
Copyright 2000-2003 Miranda ICQ/IM project,
all portions of this codebase are copyrighted to the people
listed in contributors.txt.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "commonheaders.h"
BOOL safetyMode = TRUE;
static UINT_PTR flushBuffersTimerId;
static PBYTE pNull = 0;
static PBYTE pDbCache = NULL;
static HANDLE hMap = NULL;
static DWORD dwFileSize = 0;
static DWORD ChunkSize = 65536;
static DWORD flushFailTick = 0;
void Map()
{
hMap = CreateFileMapping(hDbFile, NULL, PAGE_READWRITE, 0, dwFileSize, NULL);
if (hMap)
{
pDbCache = (PBYTE)MapViewOfFile(hMap, FILE_MAP_ALL_ACCESS/*FILE_MAP_WRITE*/, 0, 0 ,0);
if (!pDbCache)
DatabaseCorruption( _T("%s (MapViewOfFile failed. Code: %d)"));
}
else
DatabaseCorruption( _T("%s (CreateFileMapping failed. Code: %d)"));
}
void ReMap(DWORD needed)
{
KillTimer(NULL,flushBuffersTimerId);
log3("remapping %d + %d (file end: %d)",dwFileSize,needed,dbHeader.ofsFileEnd);
if (needed > ChunkSize)
{
if (needed + dwFileSize > dbHeader.ofsFileEnd + ChunkSize)
DatabaseCorruption( _T("%s (Too large increment)"));
else
{
DWORD x = dbHeader.ofsFileEnd/ChunkSize;
dwFileSize = (x+1)*ChunkSize;
}
}
else
dwFileSize += ChunkSize;
// FlushViewOfFile(pDbCache, 0);
UnmapViewOfFile(pDbCache);
pDbCache = NULL;
CloseHandle(hMap);
Map();
}
void DBMoveChunk(DWORD ofsDest,DWORD ofsSource,int bytes)
{
int x = 0;
log3("move %d %08x->%08x",bytes,ofsSource,ofsDest);
if (ofsDest+bytes>dwFileSize) ReMap(ofsDest+bytes-dwFileSize);
if (ofsSource+bytes>dwFileSize) {
x = ofsSource+bytes-dwFileSize;
log0("buggy move!");
_ASSERT(0);
}
if (x > 0)
ZeroMemory(pDbCache+ofsDest+bytes-x, x);
if (ofsSource < dwFileSize)
MoveMemory(pDbCache+ofsDest,pDbCache+ofsSource, bytes-x);
logg();
}
//we are assumed to be in a mutex here
PBYTE DBRead(DWORD ofs,int bytesRequired,int *bytesAvail)
{
// buggy read
if (ofs>=dwFileSize) {
log2("read from outside %d@%08x",bytesRequired,ofs);
if (bytesAvail!=NULL) *bytesAvail = ChunkSize;
return pNull;
}
log3((ofs+bytesRequired>dwFileSize)?"read %d@%08x, only %d avaliable":"read %d@%08x",bytesRequired,ofs,dwFileSize-ofs);
if (bytesAvail!=NULL) *bytesAvail = dwFileSize - ofs;
return pDbCache+ofs;
}
//we are assumed to be in a mutex here
void DBWrite(DWORD ofs,PVOID pData,int bytes)
{
log2("write %d@%08x",bytes,ofs);
if (ofs+bytes>dwFileSize) ReMap(ofs+bytes-dwFileSize);
MoveMemory(pDbCache+ofs,pData,bytes);
logg();
}
//we are assumed to be in a mutex here
void DBFill(DWORD ofs,int bytes)
{
log2("zerofill %d@%08x",bytes,ofs);
if (ofs+bytes<=dwFileSize)
ZeroMemory(pDbCache+ofs,bytes);
logg();
}
static VOID CALLBACK DoBufferFlushTimerProc(HWND hwnd, UINT message, UINT_PTR idEvent, DWORD dwTime)
{
if (!pDbCache) return;
KillTimer(NULL,flushBuffersTimerId);
log0("tflush1");
if (FlushViewOfFile(pDbCache, 0) == 0) {
if (flushFailTick == 0)
flushFailTick = GetTickCount();
else if (GetTickCount() - flushFailTick > 5000)
DatabaseCorruption(NULL);
}
else
flushFailTick = 0;
log0("tflush2");
}
void DBFlush(int setting)
{
if (!setting) {
log0("nflush1");
if(safetyMode && pDbCache) {
if (FlushViewOfFile(pDbCache, 0) == 0) {
if (flushFailTick == 0)
flushFailTick = GetTickCount();
else if (GetTickCount() - flushFailTick > 5000)
DatabaseCorruption(NULL);
}
else
flushFailTick = 0;
}
log0("nflush2");
return;
}
KillTimer(NULL,flushBuffersTimerId);
flushBuffersTimerId=SetTimer(NULL,flushBuffersTimerId,50,DoBufferFlushTimerProc);
}
static INT_PTR CacheSetSafetyMode(WPARAM wParam,LPARAM lParam)
{
EnterCriticalSection(&csDbAccess);
safetyMode=wParam;
LeaveCriticalSection(&csDbAccess);
DBFlush(1);
return 0;
}
int InitCache(void)
{
DWORD x;
SYSTEM_INFO sinf;
GetSystemInfo(&sinf);
ChunkSize = sinf.dwAllocationGranularity;
dwFileSize = GetFileSize(hDbFile, NULL);
// Align to chunk
x = dwFileSize % ChunkSize;
if (x) dwFileSize += ChunkSize - x;
Map();
// zero region for reads outside the file
pNull = (PBYTE)calloc(ChunkSize, 1);
CreateServiceFunction(MS_DB_SETSAFETYMODE, CacheSetSafetyMode);
return 0;
}
void UninitCache(void)
{
KillTimer(NULL,flushBuffersTimerId);
FlushViewOfFile(pDbCache, 0);
UnmapViewOfFile(pDbCache);
CloseHandle(hMap);
if (pNull) free(pNull);
}
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