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mirror of https://github.com/sqlite/sqlite.git synced 2025-08-08 14:02:16 +03:00

Update the mechanism used to keep track of what kind of syncing to do for

WAL transaction commits and checkpoint operations.  Use the checkpoint-style
of syncing to sync the header of a new or restarted WAL file.

FossilOrigin-Name: bf65dae8d4297c57ac63228ccf0100f9fabf2fb600438c9f2e10a29c4b118168
This commit is contained in:
drh
2017-08-25 01:14:43 +00:00
parent 9c6e07d2fa
commit daaae7b9d1
7 changed files with 53 additions and 46 deletions

View File

@@ -616,6 +616,18 @@ struct PagerSavepoint {
** is set to zero in all other states. In PAGER_ERROR state, Pager.errCode
** is always set to SQLITE_FULL, SQLITE_IOERR or one of the SQLITE_IOERR_XXX
** sub-codes.
**
** syncFlags, walSyncFlags
**
** syncFlags is either SQLITE_SYNC_NORMAL (0x02) or SQLITE_SYNC_FULL (0x03).
** syncFlags is used for rollback mode. walSyncFlags is used for WAL mode
** and contains the flags used to sync the checkpoint operations in the
** lower two bits, and sync flags used for transaction commits in the WAL
** file in bits 0x04 and 0x08. In other words, to get the correct sync flags
** for checkpoint operations, use (walSyncFlags&0x03) and to get the correct
** sync flags for transaction commit, use ((walSyncFlags>>2)&0x03). Note
** that with synchronous=NORMAL in WAL mode, transaction commit is not synced
** meaning that the 0x04 and 0x08 bits are both zero.
*/
struct Pager {
sqlite3_vfs *pVfs; /* OS functions to use for IO */
@@ -625,9 +637,8 @@ struct Pager {
u8 noSync; /* Do not sync the journal if true */
u8 fullSync; /* Do extra syncs of the journal for robustness */
u8 extraSync; /* sync directory after journal delete */
u8 ckptSyncFlags; /* SYNC_NORMAL or SYNC_FULL for checkpoint */
u8 walSyncFlags; /* SYNC_NORMAL or SYNC_FULL for wal writes */
u8 syncFlags; /* SYNC_NORMAL or SYNC_FULL otherwise */
u8 walSyncFlags; /* See description above */
u8 tempFile; /* zFilename is a temporary or immutable file */
u8 noLock; /* Do not lock (except in WAL mode) */
u8 readOnly; /* True for a read-only database */
@@ -3598,20 +3609,17 @@ void sqlite3PagerSetFlags(
}
if( pPager->noSync ){
pPager->syncFlags = 0;
pPager->ckptSyncFlags = 0;
}else if( pgFlags & PAGER_FULLFSYNC ){
pPager->syncFlags = SQLITE_SYNC_FULL;
pPager->ckptSyncFlags = SQLITE_SYNC_FULL;
}else if( pgFlags & PAGER_CKPT_FULLFSYNC ){
pPager->syncFlags = SQLITE_SYNC_NORMAL;
pPager->ckptSyncFlags = SQLITE_SYNC_FULL;
}else{
pPager->syncFlags = SQLITE_SYNC_NORMAL;
pPager->ckptSyncFlags = SQLITE_SYNC_NORMAL;
}
pPager->walSyncFlags = pPager->syncFlags;
pPager->walSyncFlags = (pPager->syncFlags<<2);
if( pPager->fullSync ){
pPager->walSyncFlags |= WAL_SYNC_TRANSACTIONS;
pPager->walSyncFlags |= pPager->syncFlags;
}
if( (pgFlags & PAGER_CKPT_FULLFSYNC) && !pPager->noSync ){
pPager->walSyncFlags |= (SQLITE_SYNC_FULL<<2);
}
if( pgFlags & PAGER_CACHESPILL ){
pPager->doNotSpill &= ~SPILLFLAG_OFF;
@@ -4110,7 +4118,7 @@ int sqlite3PagerClose(Pager *pPager, sqlite3 *db){
pPager->exclusiveMode = 0;
#ifndef SQLITE_OMIT_WAL
assert( db || pPager->pWal==0 );
sqlite3WalClose(pPager->pWal, db, pPager->ckptSyncFlags, pPager->pageSize,
sqlite3WalClose(pPager->pWal, db, pPager->walSyncFlags, pPager->pageSize,
(db && (db->flags & SQLITE_NoCkptOnClose) ? 0 : pTmp)
);
pPager->pWal = 0;
@@ -4918,13 +4926,11 @@ act_like_temp_file:
assert( pPager->extraSync==0 );
assert( pPager->syncFlags==0 );
assert( pPager->walSyncFlags==0 );
assert( pPager->ckptSyncFlags==0 );
}else{
pPager->fullSync = 1;
pPager->extraSync = 0;
pPager->syncFlags = SQLITE_SYNC_NORMAL;
pPager->walSyncFlags = SQLITE_SYNC_NORMAL | WAL_SYNC_TRANSACTIONS;
pPager->ckptSyncFlags = SQLITE_SYNC_NORMAL;
pPager->walSyncFlags = SQLITE_SYNC_NORMAL | (SQLITE_SYNC_NORMAL<<2);
}
/* pPager->pFirst = 0; */
/* pPager->pFirstSynced = 0; */
@@ -7372,7 +7378,7 @@ int sqlite3PagerCheckpoint(
rc = sqlite3WalCheckpoint(pPager->pWal, db, eMode,
(eMode==SQLITE_CHECKPOINT_PASSIVE ? 0 : pPager->xBusyHandler),
pPager->pBusyHandlerArg,
pPager->ckptSyncFlags, pPager->pageSize, (u8 *)pPager->pTmpSpace,
pPager->walSyncFlags, pPager->pageSize, (u8 *)pPager->pTmpSpace,
pnLog, pnCkpt
);
}
@@ -7529,7 +7535,7 @@ int sqlite3PagerCloseWal(Pager *pPager, sqlite3 *db){
if( rc==SQLITE_OK && pPager->pWal ){
rc = pagerExclusiveLock(pPager);
if( rc==SQLITE_OK ){
rc = sqlite3WalClose(pPager->pWal, db, pPager->ckptSyncFlags,
rc = sqlite3WalClose(pPager->pWal, db, pPager->walSyncFlags,
pPager->pageSize, (u8*)pPager->pTmpSpace);
pPager->pWal = 0;
pagerFixMaplimit(pPager);