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Refactor wal.c to use the VFS. This check-in compiles and links and works

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ok as long as you leave WAL turned off, but WAL does not work.

FossilOrigin-Name: 62db5fa3b61be885b2d94e9b9ce3877b2c588350
This commit is contained in:
drh
2010-04-29 22:34:07 +00:00
parent 31cbbbad1c
commit 7ed91f2344
14 changed files with 534 additions and 1210 deletions
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140
src/pager.c
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@@ -399,7 +399,7 @@ struct Pager {
char *pTmpSpace; /* Pager.pageSize bytes of space for tmp use */
PCache *pPCache; /* Pointer to page cache object */
sqlite3_backup *pBackup; /* Pointer to list of ongoing backup processes */
Log *pLog; /* Log used by "journal_mode=wal" */
Wal *pWal; /* Write-ahead log used by "journal_mode=wal" */
};
/*
@@ -1192,8 +1192,8 @@ static int addToSavepointBitvecs(Pager *pPager, Pgno pgno){
** Return true if this pager uses a write-ahead log instead of the usual
** rollback journal. Otherwise false.
*/
static int pagerUseLog(Pager *pPager){
return (pPager->pLog!=0);
static int pagerUseWal(Pager *pPager){
return (pPager->pWal!=0);
}
/*
@@ -1227,8 +1227,8 @@ static void pager_unlock(Pager *pPager){
*/
pPager->dbSizeValid = 0;
if( pagerUseLog(pPager) ){
sqlite3WalCloseSnapshot(pPager->pLog);
if( pagerUseWal(pPager) ){
sqlite3WalCloseSnapshot(pPager->pWal);
}else{
rc = osUnlock(pPager->fd, NO_LOCK);
}
@@ -1380,7 +1380,7 @@ static int pager_end_transaction(Pager *pPager, int hasMaster){
assert( isOpen(pPager->jfd) || pPager->pInJournal==0 );
if( isOpen(pPager->jfd) ){
assert( !pagerUseLog(pPager) );
assert( !pagerUseWal(pPager) );
/* Finalize the journal file. */
if( sqlite3IsMemJournal(pPager->jfd) ){
@@ -1426,8 +1426,8 @@ static int pager_end_transaction(Pager *pPager, int hasMaster){
pPager->nRec = 0;
sqlite3PcacheCleanAll(pPager->pPCache);
if( pagerUseLog(pPager) ){
rc2 = sqlite3WalWriteLock(pPager->pLog, 0);
if( pagerUseWal(pPager) ){
rc2 = sqlite3WalWriteLock(pPager->pWal, 0);
pPager->state = PAGER_SHARED;
}else if( !pPager->exclusiveMode ){
rc2 = osUnlock(pPager->fd, SHARED_LOCK);
@@ -1540,7 +1540,7 @@ static int pager_playback_one_page(
aData = pPager->pTmpSpace;
assert( aData ); /* Temp storage must have already been allocated */
assert( pagerUseLog(pPager)==0 || (!isMainJrnl && isSavepnt) );
assert( pagerUseWal(pPager)==0 || (!isMainJrnl && isSavepnt) );
/* Read the page number and page data from the journal or sub-journal
** file. Return an error code to the caller if an IO error occurs.
@@ -1610,7 +1610,7 @@ static int pager_playback_one_page(
** is possible to fail a statement on a database that does not yet exist.
** Do not attempt to write if database file has never been opened.
*/
if( pagerUseLog(pPager) ){
if( pagerUseWal(pPager) ){
pPg = 0;
}else{
pPg = pager_lookup(pPager, pgno);
@@ -1631,7 +1631,7 @@ static int pager_playback_one_page(
){
i64 ofst = (pgno-1)*(i64)pPager->pageSize;
testcase( !isSavepnt && pPg!=0 && (pPg->flags&PGHDR_NEED_SYNC)!=0 );
assert( !pagerUseLog(pPager) );
assert( !pagerUseWal(pPager) );
rc = sqlite3OsWrite(pPager->fd, (u8*)aData, pPager->pageSize, ofst);
if( pgno>pPager->dbFileSize ){
pPager->dbFileSize = pgno;
@@ -1696,7 +1696,7 @@ static int pager_playback_one_page(
** segment is synced. If a crash occurs during or following this,
** database corruption may ensue.
*/
assert( !pagerUseLog(pPager) );
assert( !pagerUseWal(pPager) );
sqlite3PcacheMakeClean(pPg);
}
#ifdef SQLITE_CHECK_PAGES
@@ -2188,7 +2188,7 @@ static int readDbPage(PgHdr *pPg){
Pgno pgno = pPg->pgno; /* Page number to read */
int rc = SQLITE_OK; /* Return code */
i64 iOffset; /* Byte offset of file to read from */
int isInLog = 0; /* True if page is in log file */
int isInWal = 0; /* True if page is in log file */
assert( pPager->state>=PAGER_SHARED && !MEMDB );
assert( isOpen(pPager->fd) );
@@ -2199,11 +2199,11 @@ static int readDbPage(PgHdr *pPg){
return SQLITE_OK;
}
if( pagerUseLog(pPager) ){
if( pagerUseWal(pPager) ){
/* Try to pull the page from the write-ahead log. */
rc = sqlite3WalRead(pPager->pLog, pgno, &isInLog, pPg->pData);
rc = sqlite3WalRead(pPager->pWal, pgno, &isInWal, pPg->pData);
}
if( rc==SQLITE_OK && !isInLog ){
if( rc==SQLITE_OK && !isInWal ){
iOffset = (pgno-1)*(i64)pPager->pageSize;
rc = sqlite3OsRead(pPager->fd, pPg->pData, pPager->pageSize, iOffset);
if( rc==SQLITE_IOERR_SHORT_READ ){
@@ -2278,7 +2278,7 @@ static int pagerUndoCallback(void *pCtx, Pgno iPg){
/*
** This function is called to rollback a transaction on a WAL database.
*/
static int pagerRollbackLog(Pager *pPager){
static int pagerRollbackWal(Pager *pPager){
int rc; /* Return Code */
PgHdr *pList; /* List of dirty pages to revert */
@@ -2290,7 +2290,7 @@ static int pagerRollbackLog(Pager *pPager){
** also copied into the backup databases) as part of this transaction,
** the backups must be restarted.
*/
if( sqlite3WalDirty(pPager->pLog) ){
if( sqlite3WalDirty(pPager->pWal) ){
sqlite3BackupRestart(pPager->pBackup);
}
@@ -2302,7 +2302,7 @@ static int pagerRollbackLog(Pager *pPager){
** + Reload page content from the database (if refcount>0).
*/
pPager->dbSize = pPager->dbOrigSize;
rc = sqlite3WalUndo(pPager->pLog, pagerUndoCallback, (void *)pPager);
rc = sqlite3WalUndo(pPager->pWal, pagerUndoCallback, (void *)pPager);
pList = sqlite3PcacheDirtyList(pPager->pPCache);
while( pList && rc==SQLITE_OK ){
PgHdr *pNext = pList->pDirty;
@@ -2370,8 +2370,8 @@ static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){
*/
pPager->dbSize = pSavepoint ? pSavepoint->nOrig : pPager->dbOrigSize;
if( !pSavepoint && pagerUseLog(pPager) ){
return pagerRollbackLog(pPager);
if( !pSavepoint && pagerUseWal(pPager) ){
return pagerRollbackWal(pPager);
}
/* Use pPager->journalOff as the effective size of the main rollback
@@ -2380,7 +2380,7 @@ static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){
** past pPager->journalOff is off-limits to us.
*/
szJ = pPager->journalOff;
assert( pagerUseLog(pPager)==0 || szJ==0 );
assert( pagerUseWal(pPager)==0 || szJ==0 );
/* Begin by rolling back records from the main journal starting at
** PagerSavepoint.iOffset and continuing to the next journal header.
@@ -2389,7 +2389,7 @@ static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){
** will be skipped automatically. Pages are added to pDone as they
** are played back.
*/
if( pSavepoint && !pagerUseLog(pPager) ){
if( pSavepoint && !pagerUseWal(pPager) ){
iHdrOff = pSavepoint->iHdrOffset ? pSavepoint->iHdrOffset : szJ;
pPager->journalOff = pSavepoint->iOffset;
while( rc==SQLITE_OK && pPager->journalOff<iHdrOff ){
@@ -2437,8 +2437,8 @@ static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){
u32 ii; /* Loop counter */
i64 offset = pSavepoint->iSubRec*(4+pPager->pageSize);
if( pagerUseLog(pPager) ){
rc = sqlite3WalSavepointUndo(pPager->pLog, pSavepoint->iFrame);
if( pagerUseWal(pPager) ){
rc = sqlite3WalSavepointUndo(pPager->pWal, pSavepoint->iFrame);
}
for(ii=pSavepoint->iSubRec; rc==SQLITE_OK && ii<pPager->nSubRec; ii++){
assert( offset==ii*(4+pPager->pageSize) );
@@ -2750,8 +2750,8 @@ int sqlite3PagerPagecount(Pager *pPager, int *pnPage){
int rc; /* Error returned by OsFileSize() */
i64 n = 0; /* File size in bytes returned by OsFileSize() */
if( pagerUseLog(pPager) ){
sqlite3WalDbsize(pPager->pLog, &nPage);
if( pagerUseWal(pPager) ){
sqlite3WalDbsize(pPager->pWal, &nPage);
}
if( nPage==0 ){
@@ -2936,10 +2936,10 @@ int sqlite3PagerClose(Pager *pPager){
sqlite3BeginBenignMalloc();
pPager->errCode = 0;
pPager->exclusiveMode = 0;
sqlite3WalClose(pPager->pLog, pPager->fd,
sqlite3WalClose(pPager->pWal, pPager->fd,
(pPager->noSync ? 0 : pPager->sync_flags), pTmp
);
pPager->pLog = 0;
pPager->pWal = 0;
pager_reset(pPager);
if( MEMDB ){
pager_unlock(pPager);
@@ -3176,7 +3176,7 @@ static int pager_write_pagelist(PgHdr *pList){
** EXCLUSIVE, it means the database file has been changed and any rollback
** will require a journal playback.
*/
assert( !pagerUseLog(pList->pPager) );
assert( !pagerUseWal(pList->pPager) );
assert( pPager->state>=PAGER_RESERVED );
rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
@@ -3265,7 +3265,7 @@ static int subjournalPage(PgHdr *pPg){
CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
PAGERTRACE(("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno));
assert( pagerUseLog(pPager)
assert( pagerUseWal(pPager)
|| pageInJournal(pPg)
|| pPg->pgno>pPager->dbOrigSize
);
@@ -3288,7 +3288,7 @@ static int subjournalPage(PgHdr *pPg){
** this function notifies any active backup processes that the pages have
** changed.
*/
static int pagerLogFrames(
static int pagerWalFrames(
Pager *pPager, /* Pager object */
PgHdr *pList, /* List of frames to log */
Pgno nTruncate, /* Database size after this commit */
@@ -3297,8 +3297,8 @@ static int pagerLogFrames(
){
int rc; /* Return code */
assert( pPager->pLog );
rc = sqlite3WalFrames(pPager->pLog,
assert( pPager->pWal );
rc = sqlite3WalFrames(pPager->pWal,
pPager->pageSize, pList, nTruncate, isCommit, sync_flags
);
if( rc==SQLITE_OK && pPager->pBackup ){
@@ -3337,13 +3337,13 @@ static int pagerStress(void *p, PgHdr *pPg){
assert( pPg->flags&PGHDR_DIRTY );
pPg->pDirty = 0;
if( pagerUseLog(pPager) ){
if( pagerUseWal(pPager) ){
/* Write a single frame for this page to the log. */
if( subjRequiresPage(pPg) ){
rc = subjournalPage(pPg);
}
if( rc==SQLITE_OK ){
rc = pagerLogFrames(pPager, pPg, 0, 0, 0);
rc = pagerWalFrames(pPager, pPg, 0, 0, 0);
}
}else{
/* The doNotSync flag is set by the sqlite3PagerWrite() function while it
@@ -3836,12 +3836,12 @@ static int pagerHasWAL(Pager *pPager, int *pExists){
int rc; /* Return code */
if( !pPager->tempFile ){
char *zLog = sqlite3_mprintf("%s-wal", pPager->zFilename);
if( !zLog ){
char *zWal = sqlite3_mprintf("%s-wal", pPager->zFilename);
if( !zWal ){
rc = SQLITE_NOMEM;
}else{
rc = sqlite3OsAccess(pPager->pVfs, zLog, SQLITE_ACCESS_EXISTS, pExists);
sqlite3_free(zLog);
rc = sqlite3OsAccess(pPager->pVfs, zWal, SQLITE_ACCESS_EXISTS, pExists);
sqlite3_free(zWal);
}
}else{
rc = SQLITE_OK;
@@ -3854,9 +3854,9 @@ static int pagerOpenSnapshot(Pager *pPager){
int rc; /* Return code */
int changed = 0; /* True if cache must be reset */
assert( pagerUseLog(pPager) );
assert( pagerUseWal(pPager) );
rc = sqlite3WalOpenSnapshot(pPager->pLog, &changed);
rc = sqlite3WalOpenSnapshot(pPager->pWal, &changed);
if( rc==SQLITE_OK ){
int dummy;
if( changed ){
@@ -3923,7 +3923,7 @@ int sqlite3PagerSharedLock(Pager *pPager){
pager_reset(pPager);
}
if( pagerUseLog(pPager) ){
if( pagerUseWal(pPager) ){
rc = pagerOpenSnapshot(pPager);
}else if( pPager->state==PAGER_UNLOCK || isErrorReset ){
sqlite3_vfs * const pVfs = pPager->pVfs;
@@ -4089,7 +4089,7 @@ int sqlite3PagerSharedLock(Pager *pPager){
}
if( isWal ){
pager_reset(pPager);
rc = sqlite3PagerOpenLog(pPager, 0);
rc = sqlite3PagerOpenWal(pPager, 0);
if( rc==SQLITE_OK ){
rc = pagerOpenSnapshot(pPager);
}
@@ -4332,7 +4332,7 @@ void sqlite3PagerUnref(DbPage *pPg){
*/
static int openSubJournal(Pager *pPager){
int rc = SQLITE_OK;
if( (pagerUseLog(pPager) || isOpen(pPager->jfd)) && !isOpen(pPager->sjfd) ){
if( (pagerUseWal(pPager) || isOpen(pPager->jfd)) && !isOpen(pPager->sjfd) ){
if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY || pPager->subjInMemory ){
sqlite3MemJournalOpen(pPager->sjfd);
}else{
@@ -4468,13 +4468,13 @@ int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory){
assert( pPager->pInJournal==0 );
assert( !MEMDB && !pPager->tempFile );
if( pagerUseLog(pPager) ){
if( pagerUseWal(pPager) ){
/* Grab the write lock on the log file. If successful, upgrade to
** PAGER_EXCLUSIVE state. Otherwise, return an error code to the caller.
** The busy-handler is not invoked if another connection already
** holds the write-lock. If possible, the upper layer will call it.
*/
rc = sqlite3WalWriteLock(pPager->pLog, 1);
rc = sqlite3WalWriteLock(pPager->pWal, 1);
if( rc==SQLITE_OK ){
pPager->dbOrigSize = pPager->dbSize;
pPager->state = PAGER_RESERVED;
@@ -4507,7 +4507,7 @@ int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory){
** kept open and either was truncated to 0 bytes or its header was
** overwritten with zeros.
*/
assert( pagerUseLog(pPager)==0 );
assert( pagerUseWal(pPager)==0 );
assert( pPager->nRec==0 );
assert( pPager->dbOrigSize==0 );
assert( pPager->pInJournal==0 );
@@ -4562,7 +4562,7 @@ static int pager_write(PgHdr *pPg){
*/
sqlite3PcacheMakeDirty(pPg);
if( pageInJournal(pPg) && !subjRequiresPage(pPg) ){
assert( !pagerUseLog(pPager) );
assert( !pagerUseWal(pPager) );
pPager->dbModified = 1;
}else{
@@ -4580,7 +4580,7 @@ static int pager_write(PgHdr *pPg){
}
if( !isOpen(pPager->jfd)
&& pPager->journalMode!=PAGER_JOURNALMODE_OFF
&& !pagerUseLog(pPager)
&& !pagerUseWal(pPager)
){
assert( pPager->useJournal );
rc = pager_open_journal(pPager);
@@ -4593,7 +4593,7 @@ static int pager_write(PgHdr *pPg){
** the transaction journal if it is not there already.
*/
if( !pageInJournal(pPg) && isOpen(pPager->jfd) ){
assert( !pagerUseLog(pPager) );
assert( !pagerUseWal(pPager) );
if( pPg->pgno<=pPager->dbOrigSize ){
u32 cksum;
char *pData2;
@@ -4974,10 +4974,10 @@ int sqlite3PagerCommitPhaseOne(
*/
sqlite3BackupRestart(pPager->pBackup);
}else if( pPager->state!=PAGER_SYNCED && pPager->dbModified ){
if( pagerUseLog(pPager) ){
if( pagerUseWal(pPager) ){
PgHdr *pList = sqlite3PcacheDirtyList(pPager->pPCache);
if( pList ){
rc = pagerLogFrames(pPager, pList, pPager->dbSize, 1,
rc = pagerWalFrames(pPager, pList, pPager->dbSize, 1,
(pPager->fullSync ? pPager->sync_flags : 0)
);
}
@@ -5213,7 +5213,7 @@ int sqlite3PagerCommitPhaseTwo(Pager *pPager){
int sqlite3PagerRollback(Pager *pPager){
int rc = SQLITE_OK; /* Return code */
PAGERTRACE(("ROLLBACK %d\n", PAGERID(pPager)));
if( pagerUseLog(pPager) ){
if( pagerUseWal(pPager) ){
int rc2;
rc = sqlite3PagerSavepoint(pPager, SAVEPOINT_ROLLBACK, -1);
@@ -5360,8 +5360,8 @@ int sqlite3PagerOpenSavepoint(Pager *pPager, int nSavepoint){
if( !aNew[ii].pInSavepoint ){
return SQLITE_NOMEM;
}
if( pagerUseLog(pPager) ){
aNew[ii].iFrame = sqlite3WalSavepoint(pPager->pLog);
if( pagerUseWal(pPager) ){
aNew[ii].iFrame = sqlite3WalSavepoint(pPager->pWal);
}
}
@@ -5440,7 +5440,7 @@ int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint){
** not yet been opened. In this case there have been no changes to
** the database file, so the playback operation can be skipped.
*/
else if( pagerUseLog(pPager) || isOpen(pPager->jfd) ){
else if( pagerUseWal(pPager) || isOpen(pPager->jfd) ){
PagerSavepoint *pSavepoint = (nNew==0)?0:&pPager->aSavepoint[nNew-1];
rc = pagerPlaybackSavepoint(pPager, pSavepoint);
assert(rc!=SQLITE_DONE);
@@ -5796,9 +5796,9 @@ sqlite3_backup **sqlite3PagerBackupPtr(Pager *pPager){
*/
int sqlite3PagerCheckpoint(Pager *pPager){
int rc = SQLITE_OK;
if( pPager->pLog ){
if( pPager->pWal ){
u8 *zBuf = (u8 *)pPager->pTmpSpace;
rc = sqlite3WalCheckpoint(pPager->pLog, pPager->fd,
rc = sqlite3WalCheckpoint(pPager->pWal, pPager->fd,
(pPager->noSync ? 0 : pPager->sync_flags),
zBuf, pPager->xBusyHandler, pPager->pBusyHandlerArg
);
@@ -5806,8 +5806,8 @@ int sqlite3PagerCheckpoint(Pager *pPager){
return rc;
}
int sqlite3PagerLogCallback(Pager *pPager){
return sqlite3WalCallback(pPager->pLog);
int sqlite3PagerWalCallback(Pager *pPager){
return sqlite3WalCallback(pPager->pWal);
}
/*
@@ -5817,17 +5817,17 @@ int sqlite3PagerLogCallback(Pager *pPager){
** The caller must be holding a SHARED lock on the database file to call
** this function.
*/
int sqlite3PagerOpenLog(Pager *pPager, int *pisOpen){
int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen){
int rc = SQLITE_OK; /* Return code */
assert( pPager->state>=PAGER_SHARED );
if( !pPager->pLog ){
if( !pPager->pWal ){
/* Open the connection to the log file. If this operation fails,
** (e.g. due to malloc() failure), unlock the database file and
** return an error code.
*/
rc = sqlite3WalOpen(pPager->pVfs, pPager->zFilename, &pPager->pLog);
rc = sqlite3WalOpen(pPager->pVfs, pPager->zFilename, &pPager->pWal);
if( rc==SQLITE_OK ){
pPager->journalMode = PAGER_JOURNALMODE_WAL;
}
@@ -5848,7 +5848,7 @@ int sqlite3PagerOpenLog(Pager *pPager, int *pisOpen){
** error (SQLITE_BUSY) is returned and the log connection is not closed.
** If successful, the EXCLUSIVE lock is not released before returning.
*/
int sqlite3PagerCloseLog(Pager *pPager){
int sqlite3PagerCloseWal(Pager *pPager){
int rc = SQLITE_OK;
assert( pPager->journalMode==PAGER_JOURNALMODE_WAL );
@@ -5857,28 +5857,28 @@ int sqlite3PagerCloseLog(Pager *pPager){
** it may need to be checkpointed before the connection can switch to
** rollback mode. Open it now so this can happen.
*/
if( !pPager->pLog ){
if( !pPager->pWal ){
int logexists = 0;
rc = sqlite3OsLock(pPager->fd, SQLITE_LOCK_SHARED);
if( rc==SQLITE_OK ){
rc = pagerHasWAL(pPager, &logexists);
}
if( rc==SQLITE_OK && logexists ){
rc = sqlite3WalOpen(pPager->pVfs, pPager->zFilename, &pPager->pLog);
rc = sqlite3WalOpen(pPager->pVfs, pPager->zFilename, &pPager->pWal);
}
}
/* Checkpoint and close the log. Because an EXCLUSIVE lock is held on
** the database file, the log and log-summary files will be deleted.
*/
if( rc==SQLITE_OK && pPager->pLog ){
if( rc==SQLITE_OK && pPager->pWal ){
rc = sqlite3OsLock(pPager->fd, SQLITE_LOCK_EXCLUSIVE);
if( rc==SQLITE_OK ){
rc = sqlite3WalClose(pPager->pLog, pPager->fd,
rc = sqlite3WalClose(pPager->pWal, pPager->fd,
(pPager->noSync ? 0 : pPager->sync_flags),
(u8*)pPager->pTmpSpace
);
pPager->pLog = 0;
pPager->pWal = 0;
}
}
return rc;