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Get the ABORT conflict resolution algorithm working. (CVS 362)

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FossilOrigin-Name: 9be4d4c6f12056782966396dca0b8e2d384d0cf2
This commit is contained in:
drh
2002-02-02 18:49:19 +00:00
parent fa86c4127d
commit 663fc63a77
12 changed files with 508 additions and 234 deletions
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65
src/pager.c
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@@ -18,7 +18,7 @@
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.37 2002/02/02 15:01:16 drh Exp $
** @(#) $Id: pager.c,v 1.38 2002/02/02 18:49:20 drh Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
@@ -45,10 +45,6 @@
** threads can be reading or writing while one
** process is writing.
**
** SQLITE_CHECKPOINT The page cache is writing to the database and
** preserving its changes so that it can back them
** out later if need be.
**
** The page cache comes up in SQLITE_UNLOCK. The first time a
** sqlite_page_get() occurs, the state transitions to SQLITE_READLOCK.
** After all pages have been released using sqlite_page_unref(),
@@ -59,20 +55,10 @@
** be in SQLITE_READLOCK before it transitions to SQLITE_WRITELOCK.)
** The sqlite_page_rollback() and sqlite_page_commit() functions
** transition the state from SQLITE_WRITELOCK back to SQLITE_READLOCK.
**
** The sqlite_ckpt_begin() function moves the state from SQLITE_WRITELOCK
** to SQLITE_CHECKPOINT. The state transitions back to SQLITE_WRITELOCK
** on calls to sqlite_ckpt_commit() or sqlite_ckpt_rollback(). While
** in SQLITE_CHECKPOINT, calls to sqlite_commit() or sqlite_rollback()
** transition directly back to SQLITE_READLOCK.
**
** The code does unequality comparisons on these constants so the order
** must be preserved.
*/
#define SQLITE_UNLOCK 0
#define SQLITE_READLOCK 1
#define SQLITE_WRITELOCK 2
#define SQLITE_CHECKPOINT 3
/*
@@ -254,12 +240,12 @@ static int pager_unwritelock(Pager *pPager){
int rc;
PgHdr *pPg;
if( pPager->state<SQLITE_WRITELOCK ) return SQLITE_OK;
sqlitepager_ckpt_commit(pPager);
sqliteOsClose(&pPager->jfd);
pPager->journalOpen = 0;
sqliteOsDelete(pPager->zJournal);
rc = sqliteOsReadLock(&pPager->fd);
assert( rc==SQLITE_OK );
sqliteFree( pPager->aInCkpt );
sqliteFree( pPager->aInJournal );
pPager->aInJournal = 0;
for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
@@ -279,7 +265,7 @@ static int pager_playback_one_page(Pager *pPager, OsFile *jfd){
PgHdr *pPg; /* An existing page in the cache */
PageRecord pgRec;
rc = sqliteOsRead(&pPager->jfd, &pgRec, sizeof(pgRec));
rc = sqliteOsRead(jfd, &pgRec, sizeof(pgRec));
if( rc!=SQLITE_OK ) return rc;
/* Sanity checking on the page */
@@ -383,8 +369,9 @@ end_playback:
** This is similar to playing back the transaction journal but with
** a few extra twists.
**
** (1) The original size of the database file is stored in
** pPager->ckptSize, not in the journal file itself.
** (1) The number of pages in the database file at the start of
** the checkpoint is stored in pPager->ckptSize, not in the
** journal file itself.
**
** (2) In addition to playing back the checkpoint journal, also
** playback all pages of the transaction journal beginning
@@ -397,7 +384,7 @@ static int pager_ckpt_playback(Pager *pPager){
/* Truncate the database back to its original size.
*/
rc = sqliteOsTruncate(&pPager->fd, pPager->ckptSize);
rc = sqliteOsTruncate(&pPager->fd, pPager->ckptSize*SQLITE_PAGE_SIZE);
pPager->dbSize = pPager->ckptSize;
/* Figure out how many records are in the checkpoint journal.
@@ -437,14 +424,9 @@ static int pager_ckpt_playback(Pager *pPager){
end_ckpt_playback:
sqliteOsClose(&pPager->cpfd);
pPager->ckptOpen = 0;
if( rc!=SQLITE_OK ){
pager_unwritelock(pPager);
pPager->errMask |= PAGER_ERR_CORRUPT;
rc = SQLITE_CORRUPT;
}else{
rc = pager_unwritelock(pPager);
}
return rc;
}
@@ -595,7 +577,6 @@ int sqlitepager_pagecount(Pager *pPager){
int sqlitepager_close(Pager *pPager){
PgHdr *pPg, *pNext;
switch( pPager->state ){
case SQLITE_CHECKPOINT:
case SQLITE_WRITELOCK: {
sqlitepager_rollback(pPager);
sqliteOsUnlock(&pPager->fd);
@@ -883,7 +864,7 @@ int sqlitepager_get(Pager *pPager, Pgno pgno, void **ppPage){
}else{
pPg->inJournal = 0;
}
if( pPager->aInCkpt && (int)pgno*SQLITE_PAGE_SIZE<=pPager->ckptSize ){
if( pPager->aInCkpt && (int)pgno<=pPager->ckptSize ){
pPg->inCkpt = (pPager->aInCkpt[pgno/8] & (1<<(pgno&7)))!=0;
}else{
pPg->inCkpt = 0;
@@ -1111,8 +1092,7 @@ int sqlitepager_write(void *pData){
/* If the checkpoint journal is open and the page is not in it,
** then write the current page to the checkpoint journal.
*/
if( pPager->ckptOpen && !pPg->inCkpt
&& (int)pPg->pgno*SQLITE_PAGE_SIZE < pPager->ckptSize ){
if( pPager->ckptOpen && !pPg->inCkpt && (int)pPg->pgno<=pPager->ckptSize ){
assert( pPg->inJournal );
rc = sqliteOsWrite(&pPager->cpfd, &pPg->pgno, sizeof(Pgno));
if( rc==SQLITE_OK ){
@@ -1268,7 +1248,7 @@ int sqlitepager_ckpt_begin(Pager *pPager){
}
rc = sqliteOsFileSize(&pPager->jfd, &pPager->ckptJSize);
if( rc ) goto ckpt_begin_failed;
pPager->ckptSize = pPager->dbSize * SQLITE_PAGE_SIZE;
pPager->ckptSize = pPager->dbSize;
rc = sqlitepager_opentemp(zTemp, &pPager->cpfd);
if( rc ) goto ckpt_begin_failed;
pPager->ckptOpen = 1;
@@ -1286,10 +1266,16 @@ ckpt_begin_failed:
** Commit a checkpoint.
*/
int sqlitepager_ckpt_commit(Pager *pPager){
assert( pPager->ckptOpen );
sqliteOsClose(&pPager->cpfd);
sqliteFree(pPager->aInCkpt);
pPager->ckptOpen = 0;
if( pPager->ckptOpen ){
PgHdr *pPg;
sqliteOsClose(&pPager->cpfd);
pPager->ckptOpen = 0;
sqliteFree( pPager->aInCkpt );
pPager->aInCkpt = 0;
for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
pPg->inCkpt = 0;
}
}
return SQLITE_OK;
}
@@ -1298,11 +1284,12 @@ int sqlitepager_ckpt_commit(Pager *pPager){
*/
int sqlitepager_ckpt_rollback(Pager *pPager){
int rc;
assert( pPager->ckptOpen );
rc = pager_ckpt_playback(pPager);
sqliteOsClose(&pPager->cpfd);
sqliteFree(pPager->aInCkpt);
pPager->ckptOpen = 0;
if( pPager->ckptOpen ){
rc = pager_ckpt_playback(pPager);
sqlitepager_ckpt_commit(pPager);
}else{
rc = SQLITE_OK;
}
return rc;
}