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Fixes and tests for backup of a WAL database.

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FossilOrigin-Name: 480d12db4c0ebcc37598f7620d39193875eab15b
This commit is contained in:
dan
2010-04-23 19:15:00 +00:00
parent d5c99c3939
commit 3306c4a945
7 changed files with 181 additions and 20 deletions
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55
src/pager.c
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@@ -2234,9 +2234,30 @@ static int readDbPage(PgHdr *pPg){
return rc;
}
/*
** This function is called when a transaction on a WAL database is rolled
** back. For each dirty page in the cache, do one of the following:
**
** * If the page has no outstanding references, simply discard it.
** * Otherwise, if the page has one or more outstanding references,
** reload the original content from the database (or log file).
*/
static int pagerRollbackLog(Pager *pPager){
int rc = SQLITE_OK;
PgHdr *pList = sqlite3PcacheDirtyList(pPager->pPCache);
/* Normally, if a transaction is rolled back, any backup processes are
** updated as data is copied out of the rollback journal and into the
** database. This is not generally possible with a WAL database, as
** rollback involves simply truncating the log file. Therefore, if one
** or more frames have already been written to the log (and therefore
** also copied into the backup databases) as part of this transaction,
** the backups must be restarted.
*/
if( sqlite3LogDirty(pPager->pLog) ){
sqlite3BackupRestart(pPager->pBackup);
}
pPager->dbSize = pPager->dbOrigSize;
while( pList && rc==SQLITE_OK ){
PgHdr *pNext = pList->pDirty;
@@ -3218,6 +3239,33 @@ static int subjournalPage(PgHdr *pPg){
return rc;
}
/*
** This function is a wrapper around sqlite3LogFrames(). As well as logging
** the contents of the list of pages headed by pList (connected by pDirty),
** this function notifies any active backup processes that the pages have
** changed.
*/
static int pagerLogFrames(
Pager *pPager, /* Pager object */
PgHdr *pList, /* List of frames to log */
Pgno nTruncate, /* Database size after this commit */
int isCommit, /* True if this is a commit */
int sync_flags /* Flags to pass to OsSync() (or 0) */
){
int rc; /* Return code */
assert( pPager->pLog );
rc = sqlite3LogFrames(pPager->pLog,
pPager->pageSize, pList, nTruncate, isCommit, sync_flags
);
if( rc==SQLITE_OK && pPager->pBackup ){
PgHdr *p;
for(p=pList; p; p=p->pDirty){
sqlite3BackupUpdate(pPager->pBackup, p->pgno, (u8 *)p->pData);
}
}
return rc;
}
/*
** This function is called by the pcache layer when it has reached some
@@ -3248,7 +3296,7 @@ static int pagerStress(void *p, PgHdr *pPg){
pPg->pDirty = 0;
if( pagerUseLog(pPager) ){
/* Write a single frame for this page to the log. */
rc = sqlite3LogFrames(pPager->pLog, pPager->pageSize, pPg, 0, 0, 0);
rc = pagerLogFrames(pPager, pPg, 0, 0, 0);
}else{
/* The doNotSync flag is set by the sqlite3PagerWrite() function while it
** is journalling a set of two or more database pages that are stored
@@ -4881,8 +4929,8 @@ int sqlite3PagerCommitPhaseOne(
if( pagerUseLog(pPager) ){
PgHdr *pList = sqlite3PcacheDirtyList(pPager->pPCache);
if( pList ){
rc = sqlite3LogFrames(pPager->pLog, pPager->pageSize, pList,
pPager->dbSize, 1, (pPager->fullSync ? pPager->sync_flags : 0)
rc = pagerLogFrames(pPager, pList, pPager->dbSize, 1,
(pPager->fullSync ? pPager->sync_flags : 0)
);
}
sqlite3PcacheCleanAll(pPager->pPCache);
@@ -5119,6 +5167,7 @@ int sqlite3PagerRollback(Pager *pPager){
PAGERTRACE(("ROLLBACK %d\n", PAGERID(pPager)));
if( pagerUseLog(pPager) ){
int rc2;
rc = sqlite3PagerSavepoint(pPager, SAVEPOINT_ROLLBACK, -1);
rc2 = pager_end_transaction(pPager, pPager->setMaster);
if( rc==SQLITE_OK ) rc = rc2;