database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-08-07 02:42:48 +03:00
Code Activity

Allow the database file to be memory mapped in wal mode.

Browse Source 
FossilOrigin-Name: d190ddabc386bc9654b99e33fb81b2f6e67b54d6
This commit is contained in:
dan
2013-03-22 18:20:14 +00:00
parent c00033125d
commit 99bd10979a
6 changed files with 124 additions and 62 deletions
Download Patch File Download Diff File Expand all files Collapse all files

88
src/pager.c
View File

@@ -2095,7 +2095,7 @@ static void pagerReportSize(Pager *pPager){
** Return SQLITE_OK if successful, or an SQLite error code if an error
** occurs.
*/
static int pagerWriteData(Pager *pPager, const void *pBuf, int nBuf, i64 iOff){
int sqlite3PagerWriteData(Pager *pPager, const void *pBuf, int nBuf, i64 iOff){
int rc = SQLITE_OK;
if( pPager->nMapValid>=(iOff+nBuf) ){
memcpy(&((u8 *)(pPager->pMap))[iOff], pBuf, nBuf);
@@ -2279,7 +2279,7 @@ static int pager_playback_one_page(
i64 ofst = (pgno-1)*(i64)pPager->pageSize;
testcase( !isSavepnt && pPg!=0 && (pPg->flags&PGHDR_NEED_SYNC)!=0 );
assert( !pagerUseWal(pPager) );
rc = pagerWriteData(pPager, aData, pPager->pageSize, ofst);
rc = sqlite3PagerWriteData(pPager, aData, pPager->pageSize, ofst);
if( pgno>pPager->dbFileSize ){
pPager->dbFileSize = pgno;
}
@@ -2864,11 +2864,10 @@ end_playback:
** If an IO error occurs, then the IO error is returned to the caller.
** Otherwise, SQLITE_OK is returned.
*/
static int readDbPage(PgHdr *pPg){
static int readDbPage(PgHdr *pPg, u32 iFrame){
Pager *pPager = pPg->pPager; /* Pager object associated with page pPg */
Pgno pgno = pPg->pgno; /* Page number to read */
int rc = SQLITE_OK; /* Return code */
int isInWal = 0; /* True if page is in log file */
int pgsz = pPager->pageSize; /* Number of bytes to read */
assert( pPager->eState>=PAGER_READER && !MEMDB );
@@ -2880,11 +2879,10 @@ static int readDbPage(PgHdr *pPg){
return SQLITE_OK;
}
if( pagerUseWal(pPager) ){
if( iFrame ){
/* Try to pull the page from the write-ahead log. */
rc = sqlite3WalRead(pPager->pWal, pgno, &isInWal, pgsz, pPg->pData);
}
if( rc==SQLITE_OK && !isInWal ){
rc = sqlite3WalReadFrame(pPager->pWal, iFrame, pgsz, pPg->pData);
}else{
i64 iOffset = (pgno-1)*(i64)pPager->pageSize;
if( pPager->pMap && pPager->nMapValid>=iOffset+pPager->pageSize ){
memcpy(pPg->pData, &((u8 *)(pPager->pMap))[iOffset], pPager->pageSize);
@@ -2972,7 +2970,13 @@ static int pagerUndoCallback(void *pCtx, Pgno iPg){
if( sqlite3PcachePageRefcount(pPg)==1 ){
sqlite3PcacheDrop(pPg);
}else{
rc = readDbPage(pPg);
u32 iFrame = 0;
if( pagerUseWal(pPager) ){
rc = sqlite3WalFindFrame(pPager->pWal, pPg->pgno, &iFrame);
}
if( rc==SQLITE_OK ){
rc = readDbPage(pPg, iFrame);
}
if( rc==SQLITE_OK ){
pPager->xReiniter(pPg);
}
@@ -3388,7 +3392,6 @@ static void pagerFixMaplimit(Pager *pPager){
|| pPager->fd->pMethods->iVersion<3
|| pPager->fd->pMethods->xMremap==0
|| pPager->tempFile
|| pPager->pWal
){
pPager->nMapLimit = 0;
}else if( pPager->nMapCfgLimit<0 ){
@@ -3888,9 +3891,9 @@ static int pagerMap(Pager *pPager, int bExtend){
Pgno nPg; /* Size of mapping to request in pages */
i64 sz; /* Size of mapping to request in bytes */
assert( pPager->pWal==0 && isOpen(pPager->fd) && pPager->tempFile==0 );
assert( isOpen(pPager->fd) && pPager->tempFile==0 );
assert( pPager->pMap==0 || pPager->nMap>0 );
assert( pPager->eState>=1 );
/* assert( pPager->eState>=1 ); */
assert( pPager->nMmapOut==0 );
assert( pPager->nMapLimit>0 );
@@ -4213,6 +4216,46 @@ static int syncJournal(Pager *pPager, int newHdr){
return SQLITE_OK;
}
/*
** This is called by the wal.c module at the start of a checkpoint. If the
** checkpoint runs to completion, it will set the database file size to
** szReq bytes. This function performs two tasks:
**
** * If the file is currently less than szReq bytes in size, an
** xFileControl(SQLITE_FNCTL_SIZE_HINT) is issued to inform the OS
** layer of the expected file size, and
**
** * If mmap is being used, then the mapping is extended to szReq
** bytes in size.
**
** SQLITE_OK is returned if successful, or an error code if an error occurs.
*/
int sqlite3PagerSetFilesize(Pager *pPager, i64 szReq){
int rc;
sqlite3_int64 sz;
assert( pPager->eState==PAGER_OPEN );
assert( pPager->nMmapOut==0 );
rc = sqlite3OsFileSize(pPager->fd, &sz);
if( rc==SQLITE_OK ){
if( sz>szReq ){
sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &sz);
}
}
if( rc==SQLITE_OK
&& pPager->nMapLimit>0
&& pPager->nMapValid<szReq
&& pPager->nMapValid<pPager->nMapLimit
){
pPager->dbFileSize = (szReq / pPager->pageSize);
rc = pagerMap(pPager, 1);
}
return rc;
}
/*
** The argument is the first in a linked list of dirty pages connected
** by the PgHdr.pDirty pointer. This function writes each one of the
@@ -4275,7 +4318,7 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
if( pPager->nMmapOut==0 && pPager->nMapLimit>0 ){
pPager->dbFileSize = pPager->dbSize;
pagerMap(pPager, 1);
rc = pagerMap(pPager, 1);
}
}
@@ -4301,7 +4344,7 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
CODEC2(pPager, pList->pData, pgno, 6, return SQLITE_NOMEM, pData);
/* Write out the page data. */
pagerWriteData(pPager, pData, pPager->pageSize, offset);
rc = sqlite3PagerWriteData(pPager, pData, pPager->pageSize, offset);
/* If page 1 was just written, update Pager.dbFileVers to match
** the value now stored in the database file. If writing this
@@ -5275,6 +5318,7 @@ int sqlite3PagerAcquire(
){
int rc = SQLITE_OK;
PgHdr *pPg = 0;
u32 iFrame = 0; /* Frame to read from WAL file */
const int noContent = (flags & PAGER_ACQUIRE_NOCONTENT);
/* It is acceptable to use a read-only (mmap) page for any page except
@@ -5287,6 +5331,7 @@ int sqlite3PagerAcquire(
assert( pPager->eState>=PAGER_READER );
assert( assert_pager_state(pPager) );
assert( noContent==0 || bMmapOk==0 );
if( pgno==0 ){
return SQLITE_CORRUPT_BKPT;
@@ -5298,7 +5343,12 @@ int sqlite3PagerAcquire(
rc = pPager->errCode;
}else{
if( bMmapOk ){
if( bMmapOk && pagerUseWal(pPager) ){
rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);
if( rc!=SQLITE_OK ) goto pager_acquire_err;
}
if( iFrame==0 && bMmapOk ){
if( pPager->pMap==0 || (pPager->bMapResize && pPager->nMmapOut==0) ){
rc = pagerMap(pPager, 0);
}
@@ -5378,9 +5428,13 @@ int sqlite3PagerAcquire(
memset(pPg->pData, 0, pPager->pageSize);
IOTRACE(("ZERO %p %d\n", pPager, pgno));
}else{
if( pagerUseWal(pPager) && bMmapOk==0 ){
rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);
if( rc!=SQLITE_OK ) goto pager_acquire_err;
}
assert( pPg->pPager==pPager );
pPager->aStat[PAGER_STAT_MISS]++;
rc = readDbPage(pPg);
rc = readDbPage(pPg, iFrame);
if( rc!=SQLITE_OK ){
goto pager_acquire_err;
}
@@ -7063,7 +7117,7 @@ static int pagerOpenWal(Pager *pPager){
** (e.g. due to malloc() failure), return an error code.
*/
if( rc==SQLITE_OK ){
rc = sqlite3WalOpen(pPager->pVfs,
rc = sqlite3WalOpen(pPager->pVfs, pPager,
pPager->fd, pPager->zWal, pPager->exclusiveMode,
pPager->journalSizeLimit, &pPager->pWal
);