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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"
int CDb3x::FindSectionForOffset(const DWORD ofs)
{
for (int i = 0; i < CACHESECTIONCOUNT; i++)
if (ofs >= cacheSectionInfo[i].ofsBase && ofs<cacheSectionInfo[i].ofsBase + CACHESECTIONSIZE)
return i;
return -1;
}
int CDb3x::FindLRUSection(void)
{
int lru = 0;
DWORD lowestLastUse = cacheSectionInfo[0].lastUsed;
for (int i = 1; i < CACHESECTIONCOUNT; i++)
if (cacheSectionInfo[i].lastUsed < lowestLastUse) {
lru = i;
lowestLastUse = cacheSectionInfo[i].lastUsed;
}
return lru;
}
void CDb3x::LoadSection(const int i,DWORD ofs)
{
cacheSectionInfo[i].ofsBase = ofs - ofs%CACHESECTIONSIZE;
log1("readsect %08x",ofs);
SetFilePointer(m_hDbFile,cacheSectionInfo[i].ofsBase,NULL,FILE_BEGIN);
ReadFile(m_hDbFile,m_pDbCache+i*CACHESECTIONSIZE,CACHESECTIONSIZE,&ofs,NULL);
}
void CDb3x::MoveSection(int *sectId,int dest)
{
CopyMemory(m_pDbCache+dest*CACHESECTIONSIZE,m_pDbCache+(*sectId)*CACHESECTIONSIZE,CACHESECTIONSIZE);
cacheSectionInfo[dest].ofsBase = cacheSectionInfo[*sectId].ofsBase;
*sectId = dest;
}
//we are assumed to be in a mutex here
PBYTE CDb3x::DBRead(DWORD ofs,int bytesRequired,int *bytesAvail)
{
int part1sect = FindSectionForOffset(ofs);
if (ofs%CACHESECTIONSIZE+bytesRequired<CACHESECTIONSIZE) {
//only one section required
if (part1sect == -1) {
part1sect = FindLRUSection();
LoadSection(part1sect,ofs);
}
cacheSectionInfo[part1sect].lastUsed = ++m_lastUseCounter;
if (bytesAvail!= NULL) *bytesAvail = cacheSectionInfo[part1sect].ofsBase+CACHESECTIONSIZE-ofs;
return m_pDbCache+part1sect*CACHESECTIONSIZE+(ofs-cacheSectionInfo[part1sect].ofsBase);
}
//two sections are required
int part2sect = FindSectionForOffset(ofs+CACHESECTIONSIZE);
if (part1sect != -1) {
if (part2sect == -1) { //first part in cache, but not second part
if (part1sect == CACHESECTIONCOUNT-1) MoveSection(&part1sect,0);
LoadSection(part1sect+1,ofs+CACHESECTIONSIZE);
}
else if (part2sect!= part1sect+1) { //both parts are in cache, but not already consecutive
if (part1sect == CACHESECTIONCOUNT-1) {
//first part is at end, move to before second part
if (part2sect == 0) //second part is at start: need to move both
MoveSection(&part2sect,1);
MoveSection(&part1sect,part2sect-1);
}
else //move second part to after first part
MoveSection(&part2sect,part1sect+1);
}
}
else {
if (part2sect == -1) { //neither section is in cache
part1sect = 0; part2sect = 1;
LoadSection(part1sect,ofs); LoadSection(part2sect,ofs+CACHESECTIONSIZE);
}
else { //part 2 is in cache, but not part 1
if (part2sect == 0) MoveSection(&part2sect,1);
part1sect = part2sect-1;
LoadSection(part1sect,ofs);
}
}
//both sections are now consecutive, starting at part1sect
cacheSectionInfo[part1sect].lastUsed = ++m_lastUseCounter;
cacheSectionInfo[part1sect+1].lastUsed = ++m_lastUseCounter;
if (bytesAvail!= NULL)
*bytesAvail = cacheSectionInfo[part1sect+1].ofsBase+CACHESECTIONSIZE-ofs;
return m_pDbCache+part1sect*CACHESECTIONSIZE+(ofs-cacheSectionInfo[part1sect].ofsBase);
}
//we are assumed to be in a mutex here
void CDb3x::DBWrite(DWORD ofs,PVOID pData,int bytes)
{
//write direct, and rely on Windows' write caching
log2("write %d@%08x", bytes, ofs);
SetFilePointer(m_hDbFile, ofs, NULL, FILE_BEGIN);
DWORD bytesWritten;
if ( WriteFile(m_hDbFile, pData, bytes, &bytesWritten, NULL) == 0)
DatabaseCorruption( _T("%s (Write error)"));
logg();
//check if any of the cache sections contain this bit
for(int i = 0; i < CACHESECTIONCOUNT; i++) {
if (ofs+bytes >= cacheSectionInfo[i].ofsBase && ofs<cacheSectionInfo[i].ofsBase+CACHESECTIONSIZE) {
if (ofs<cacheSectionInfo[i].ofsBase) { //don't start at beginning
if (ofs+bytes >= cacheSectionInfo[i].ofsBase+CACHESECTIONSIZE) //don't finish at end
CopyMemory(m_pDbCache+i*CACHESECTIONSIZE,(PBYTE)pData+cacheSectionInfo[i].ofsBase-ofs,CACHESECTIONSIZE);
else CopyMemory(m_pDbCache+i*CACHESECTIONSIZE,(PBYTE)pData+cacheSectionInfo[i].ofsBase-ofs,bytes-(cacheSectionInfo[i].ofsBase-ofs));
}
else { //start at beginning
if (ofs+bytes >= cacheSectionInfo[i].ofsBase+CACHESECTIONSIZE) //don't finish at end
CopyMemory(m_pDbCache+i*CACHESECTIONSIZE+ofs-cacheSectionInfo[i].ofsBase,pData,cacheSectionInfo[i].ofsBase+CACHESECTIONSIZE-ofs);
else CopyMemory(m_pDbCache+i*CACHESECTIONSIZE+ofs-cacheSectionInfo[i].ofsBase,pData,bytes);
}
}
}
}
void CDb3x::DBMoveChunk(DWORD ofsDest,DWORD ofsSource,int bytes)
{
DWORD bytesRead;
PBYTE buf;
log3("move %d %08x->%08x",bytes,ofsSource,ofsDest);
buf = (PBYTE)mir_alloc(bytes);
SetFilePointer(m_hDbFile,ofsSource,NULL,FILE_BEGIN);
ReadFile(m_hDbFile,buf,bytes,&bytesRead,NULL);
DBWrite(ofsDest,buf,bytes);
mir_free(buf);
logg();
}
static VOID CALLBACK DoBufferFlushTimerProc(HWND hwnd,UINT message,UINT_PTR idEvent,DWORD dwTime)
{
for (int i=0; i < g_Dbs.getCount(); i++) {
CDb3x* db = g_Dbs[i];
KillTimer(NULL, db->m_flushBuffersTimerId);
log0("tflush1");
FlushFileBuffers(db->getFile());
log0("tflush2");
}
}
void CDb3x::DBFlush(int setting)
{
if (!setting) {
log0("nflush1");
if (m_safetyMode) FlushFileBuffers(m_hDbFile);
log0("nflush2");
return;
}
KillTimer(NULL,m_flushBuffersTimerId);
m_flushBuffersTimerId = SetTimer(NULL,m_flushBuffersTimerId,50,DoBufferFlushTimerProc);
}
void CDb3x::DBFill(DWORD ofs,int bytes)
{
}
int CDb3x::InitCache(void)
{
m_pDbCache = (PBYTE)mir_alloc(CACHESECTIONSIZE*CACHESECTIONCOUNT);
m_lastUseCounter = CACHESECTIONCOUNT;
for(int i = 0; i < CACHESECTIONCOUNT; i++) {
cacheSectionInfo[i].ofsBase = 0;
cacheSectionInfo[i].lastUsed = i;
SetFilePointer(m_hDbFile,cacheSectionInfo[i].ofsBase,NULL,FILE_BEGIN);
DWORD bytesRead;
ReadFile(m_hDbFile,m_pDbCache+i*CACHESECTIONSIZE,CACHESECTIONSIZE,&bytesRead,NULL);
}
return 0;
}
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