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

Merge the fix for [a1fa75cbdd02] from the experimental branch. Also

Browse Source 
fix the persistent-wal mode feature of truncating the WAL on close so that
it always truncates the WAL to zero bytes.

FossilOrigin-Name: 09ccc4a1be7ba81890f10aac6623dd90dab4f990
This commit is contained in:
drh
2011-12-16 15:38:52 +00:00
parent 84968c051d f60b7f36c1
commit eed4250598
5 changed files with 132 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files

64
src/wal.c
View File

@@ -421,6 +421,7 @@ struct Wal {
u8 writeLock; /* True if in a write transaction */
u8 ckptLock; /* True if holding a checkpoint lock */
u8 readOnly; /* WAL_RDWR, WAL_RDONLY, or WAL_SHM_RDONLY */
u8 truncateOnCommit; /* True to truncate WAL file on commit */
WalIndexHdr hdr; /* Wal-index header for current transaction */
const char *zWalName; /* Name of WAL file */
u32 nCkpt; /* Checkpoint sequence counter in the wal-header */
@@ -1782,22 +1783,20 @@ static int walCheckpoint(
}
/*
** Attempt to limit the WAL size to the size limit defined by
** PRAGMA journal_size_limit.
** If the WAL file is currently larger than nMax bytes in size, truncate
** it to exactly nMax bytes. If an error occurs while doing so, ignore it.
*/
static void walLimitSize(Wal *pWal){
if( pWal->mxWalSize>=0 ){
i64 sz;
int rx;
sqlite3BeginBenignMalloc();
rx = sqlite3OsFileSize(pWal->pWalFd, &sz);
if( rx==SQLITE_OK && (sz > pWal->mxWalSize) ){
rx = sqlite3OsTruncate(pWal->pWalFd, pWal->mxWalSize);
}
sqlite3EndBenignMalloc();
if( rx ){
sqlite3_log(rx, "cannot limit WAL size: %s", pWal->zWalName);
}
static void walLimitSize(Wal *pWal, i64 nMax){
i64 sz;
int rx;
sqlite3BeginBenignMalloc();
rx = sqlite3OsFileSize(pWal->pWalFd, &sz);
if( rx==SQLITE_OK && (sz > nMax ) ){
rx = sqlite3OsTruncate(pWal->pWalFd, nMax);
}
sqlite3EndBenignMalloc();
if( rx ){
sqlite3_log(rx, "cannot limit WAL size: %s", pWal->zWalName);
}
}
@@ -1824,18 +1823,29 @@ int sqlite3WalClose(
*/
rc = sqlite3OsLock(pWal->pDbFd, SQLITE_LOCK_EXCLUSIVE);
if( rc==SQLITE_OK ){
int bPersistWal = -1;
if( pWal->exclusiveMode==WAL_NORMAL_MODE ){
pWal->exclusiveMode = WAL_EXCLUSIVE_MODE;
}
rc = sqlite3WalCheckpoint(
pWal, SQLITE_CHECKPOINT_PASSIVE, 0, 0, sync_flags, nBuf, zBuf, 0, 0
);
sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_PERSIST_WAL, &bPersistWal);
if( rc==SQLITE_OK && bPersistWal!=1 ){
isDelete = 1;
}else{
walLimitSize(pWal);
if( rc==SQLITE_OK ){
int bPersist = -1;
sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_PERSIST_WAL, &bPersist);
if( bPersist!=1 ){
/* Try to delete the WAL file if the checkpoint completed and
** fsyned (rc==SQLITE_OK) and if we are not in persistent-wal
** mode (!bPersist) */
isDelete = 1;
}else if( pWal->mxWalSize>=0 ){
/* Try to truncate the WAL file to zero bytes if the checkpoint
** completed and fsynced (rc==SQLITE_OK) and we are in persistent
** WAL mode (bPersist) and if the PRAGMA journal_size_limit is a
** non-negative value (pWal->mxWalSize>=0). Note that we truncate
** to zero bytes as truncating to the journal_size_limit might
** leave a corrupt WAL file on disk. */
walLimitSize(pWal, 0);
}
}
}
@@ -2444,6 +2454,7 @@ int sqlite3WalEndWriteTransaction(Wal *pWal){
if( pWal->writeLock ){
walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);
pWal->writeLock = 0;
pWal->truncateOnCommit = 0;
}
return SQLITE_OK;
}
@@ -2578,7 +2589,6 @@ static int walRestartLog(Wal *pWal){
int i; /* Loop counter */
u32 *aSalt = pWal->hdr.aSalt; /* Big-endian salt values */
walLimitSize(pWal);
pWal->nCkpt++;
pWal->hdr.mxFrame = 0;
sqlite3Put4byte((u8*)&aSalt[0], 1 + sqlite3Get4byte((u8*)&aSalt[0]));
@@ -2666,6 +2676,7 @@ int sqlite3WalFrames(
pWal->hdr.bigEndCksum = SQLITE_BIGENDIAN;
pWal->hdr.aFrameCksum[0] = aCksum[0];
pWal->hdr.aFrameCksum[1] = aCksum[1];
pWal->truncateOnCommit = 1;
rc = sqlite3OsWrite(pWal->pWalFd, aWalHdr, sizeof(aWalHdr), 0);
WALTRACE(("WAL%p: wal-header write %s\n", pWal, rc ? "failed" : "ok"));
@@ -2739,6 +2750,15 @@ int sqlite3WalFrames(
rc = sqlite3OsSync(pWal->pWalFd, sync_flags);
}
if( isCommit && pWal->truncateOnCommit && pWal->mxWalSize>=0 ){
i64 sz = pWal->mxWalSize;
if( walFrameOffset(iFrame+nLast+1, szPage)>pWal->mxWalSize ){
sz = walFrameOffset(iFrame+nLast+1, szPage);
}
walLimitSize(pWal, sz);
pWal->truncateOnCommit = 0;
}
/* Append data to the wal-index. It is not necessary to lock the
** wal-index to do this as the SQLITE_SHM_WRITE lock held on the wal-index
** guarantees that there are no other writers, and no data that may