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-rw-r--r--src/btree.c113
1 files changed, 79 insertions, 34 deletions
diff --git a/src/btree.c b/src/btree.c
index 96140d68c..616d40368 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -1581,13 +1581,17 @@ static int btreeGetPage(
BtShared *pBt, /* The btree */
Pgno pgno, /* Number of the page to fetch */
MemPage **ppPage, /* Return the page in this parameter */
- int noContent /* Do not load page content if true */
+ int noContent, /* Do not load page content if true */
+ int bReadonly /* True if a read-only (mmap) page is ok */
){
int rc;
DbPage *pDbPage;
+ int flags = (noContent ? PAGER_ACQUIRE_NOCONTENT : 0)
+ | (bReadonly ? PAGER_ACQUIRE_READONLY : 0);
+ assert( noContent==0 || bReadonly==0 );
assert( sqlite3_mutex_held(pBt->mutex) );
- rc = sqlite3PagerAcquire(pBt->pPager, pgno, (DbPage**)&pDbPage, noContent);
+ rc = sqlite3PagerAcquire(pBt->pPager, pgno, (DbPage**)&pDbPage, flags);
if( rc ) return rc;
*ppPage = btreePageFromDbPage(pDbPage, pgno, pBt);
return SQLITE_OK;
@@ -1630,9 +1634,10 @@ u32 sqlite3BtreeLastPage(Btree *p){
** may remain unchanged, or it may be set to an invalid value.
*/
static int getAndInitPage(
- BtShared *pBt, /* The database file */
- Pgno pgno, /* Number of the page to get */
- MemPage **ppPage /* Write the page pointer here */
+ BtShared *pBt, /* The database file */
+ Pgno pgno, /* Number of the page to get */
+ MemPage **ppPage, /* Write the page pointer here */
+ int bReadonly /* True if a read-only (mmap) page is ok */
){
int rc;
assert( sqlite3_mutex_held(pBt->mutex) );
@@ -1640,7 +1645,7 @@ static int getAndInitPage(
if( pgno>btreePagecount(pBt) ){
rc = SQLITE_CORRUPT_BKPT;
}else{
- rc = btreeGetPage(pBt, pgno, ppPage, 0);
+ rc = btreeGetPage(pBt, pgno, ppPage, 0, bReadonly);
if( rc==SQLITE_OK ){
rc = btreeInitPage(*ppPage);
if( rc!=SQLITE_OK ){
@@ -1871,6 +1876,7 @@ int sqlite3BtreeOpen(
rc = sqlite3PagerOpen(pVfs, &pBt->pPager, zFilename,
EXTRA_SIZE, flags, vfsFlags, pageReinit);
if( rc==SQLITE_OK ){
+ sqlite3PagerSetMmapLimit(pBt->pPager, db->szMmap);
rc = sqlite3PagerReadFileheader(pBt->pPager,sizeof(zDbHeader),zDbHeader);
}
if( rc!=SQLITE_OK ){
@@ -2138,6 +2144,19 @@ int sqlite3BtreeSetCacheSize(Btree *p, int mxPage){
}
/*
+** Change the limit on the amount of the database file that may be
+** memory mapped.
+*/
+int sqlite3BtreeSetMmapLimit(Btree *p, sqlite3_int64 szMmap){
+ BtShared *pBt = p->pBt;
+ assert( sqlite3_mutex_held(p->db->mutex) );
+ sqlite3BtreeEnter(p);
+ sqlite3PagerSetMmapLimit(pBt->pPager, szMmap);
+ sqlite3BtreeLeave(p);
+ return SQLITE_OK;
+}
+
+/*
** Change the way data is synced to disk in order to increase or decrease
** how well the database resists damage due to OS crashes and power
** failures. Level 1 is the same as asynchronous (no syncs() occur and
@@ -2362,7 +2381,7 @@ static int lockBtree(BtShared *pBt){
assert( pBt->pPage1==0 );
rc = sqlite3PagerSharedLock(pBt->pPager);
if( rc!=SQLITE_OK ) return rc;
- rc = btreeGetPage(pBt, 1, &pPage1, 0);
+ rc = btreeGetPage(pBt, 1, &pPage1, 0, 0);
if( rc!=SQLITE_OK ) return rc;
/* Do some checking to help insure the file we opened really is
@@ -2921,7 +2940,7 @@ static int relocatePage(
** iPtrPage.
*/
if( eType!=PTRMAP_ROOTPAGE ){
- rc = btreeGetPage(pBt, iPtrPage, &pPtrPage, 0);
+ rc = btreeGetPage(pBt, iPtrPage, &pPtrPage, 0, 0);
if( rc!=SQLITE_OK ){
return rc;
}
@@ -3005,7 +3024,7 @@ static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg, int bCommit){
u8 eMode = BTALLOC_ANY; /* Mode parameter for allocateBtreePage() */
Pgno iNear = 0; /* nearby parameter for allocateBtreePage() */
- rc = btreeGetPage(pBt, iLastPg, &pLastPg, 0);
+ rc = btreeGetPage(pBt, iLastPg, &pLastPg, 0, 0);
if( rc!=SQLITE_OK ){
return rc;
}
@@ -3097,8 +3116,11 @@ int sqlite3BtreeIncrVacuum(Btree *p){
if( nOrig<nFin ){
rc = SQLITE_CORRUPT_BKPT;
}else if( nFree>0 ){
- invalidateAllOverflowCache(pBt);
- rc = incrVacuumStep(pBt, nFin, nOrig, 0);
+ rc = saveAllCursors(pBt, 0, 0);
+ if( rc==SQLITE_OK ){
+ invalidateAllOverflowCache(pBt);
+ rc = incrVacuumStep(pBt, nFin, nOrig, 0);
+ }
if( rc==SQLITE_OK ){
rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
put4byte(&pBt->pPage1->aData[28], pBt->nPage);
@@ -3146,7 +3168,9 @@ static int autoVacuumCommit(BtShared *pBt){
nFree = get4byte(&pBt->pPage1->aData[36]);
nFin = finalDbSize(pBt, nOrig, nFree);
if( nFin>nOrig ) return SQLITE_CORRUPT_BKPT;
-
+ if( nFin<nOrig ){
+ rc = saveAllCursors(pBt, 0, 0);
+ }
for(iFree=nOrig; iFree>nFin && rc==SQLITE_OK; iFree--){
rc = incrVacuumStep(pBt, nFin, iFree, 1);
}
@@ -3163,7 +3187,7 @@ static int autoVacuumCommit(BtShared *pBt){
}
}
- assert( nRef==sqlite3PagerRefcount(pPager) );
+ assert( nRef>=sqlite3PagerRefcount(pPager) );
return rc;
}
@@ -3419,7 +3443,7 @@ int sqlite3BtreeRollback(Btree *p, int tripCode){
/* The rollback may have destroyed the pPage1->aData value. So
** call btreeGetPage() on page 1 again to make
** sure pPage1->aData is set correctly. */
- if( btreeGetPage(pBt, 1, &pPage1, 0)==SQLITE_OK ){
+ if( btreeGetPage(pBt, 1, &pPage1, 0, 0)==SQLITE_OK ){
int nPage = get4byte(28+(u8*)pPage1->aData);
testcase( nPage==0 );
if( nPage==0 ) sqlite3PagerPagecount(pBt->pPager, &nPage);
@@ -3853,7 +3877,7 @@ static int getOverflowPage(
assert( next==0 || rc==SQLITE_DONE );
if( rc==SQLITE_OK ){
- rc = btreeGetPage(pBt, ovfl, &pPage, 0);
+ rc = btreeGetPage(pBt, ovfl, &pPage, 0, (ppPage==0));
assert( rc==SQLITE_OK || pPage==0 );
if( rc==SQLITE_OK ){
next = get4byte(pPage->aData);
@@ -4074,7 +4098,9 @@ static int accessPayload(
{
DbPage *pDbPage;
- rc = sqlite3PagerGet(pBt->pPager, nextPage, &pDbPage);
+ rc = sqlite3PagerAcquire(pBt->pPager, nextPage, &pDbPage,
+ (eOp==0 ? PAGER_ACQUIRE_READONLY : 0)
+ );
if( rc==SQLITE_OK ){
aPayload = sqlite3PagerGetData(pDbPage);
nextPage = get4byte(aPayload);
@@ -4253,10 +4279,11 @@ static int moveToChild(BtCursor *pCur, u32 newPgno){
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState==CURSOR_VALID );
assert( pCur->iPage<BTCURSOR_MAX_DEPTH );
+ assert( pCur->iPage>=0 );
if( pCur->iPage>=(BTCURSOR_MAX_DEPTH-1) ){
return SQLITE_CORRUPT_BKPT;
}
- rc = getAndInitPage(pBt, newPgno, &pNewPage);
+ rc = getAndInitPage(pBt, newPgno, &pNewPage, (pCur->wrFlag==0));
if( rc ) return rc;
pCur->apPage[i+1] = pNewPage;
pCur->aiIdx[i+1] = 0;
@@ -4373,7 +4400,7 @@ static int moveToRoot(BtCursor *pCur){
pCur->eState = CURSOR_INVALID;
return SQLITE_OK;
}else{
- rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0]);
+ rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0], pCur->wrFlag==0);
if( rc!=SQLITE_OK ){
pCur->eState = CURSOR_INVALID;
return rc;
@@ -4987,7 +5014,7 @@ static int allocateBtreePage(
if( iTrunk>mxPage ){
rc = SQLITE_CORRUPT_BKPT;
}else{
- rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
+ rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0, 0);
}
if( rc ){
pTrunk = 0;
@@ -5051,7 +5078,7 @@ static int allocateBtreePage(
goto end_allocate_page;
}
testcase( iNewTrunk==mxPage );
- rc = btreeGetPage(pBt, iNewTrunk, &pNewTrunk, 0);
+ rc = btreeGetPage(pBt, iNewTrunk, &pNewTrunk, 0, 0);
if( rc!=SQLITE_OK ){
goto end_allocate_page;
}
@@ -5131,7 +5158,7 @@ static int allocateBtreePage(
}
put4byte(&aData[4], k-1);
noContent = !btreeGetHasContent(pBt, *pPgno);
- rc = btreeGetPage(pBt, *pPgno, ppPage, noContent);
+ rc = btreeGetPage(pBt, *pPgno, ppPage, noContent, 0);
if( rc==SQLITE_OK ){
rc = sqlite3PagerWrite((*ppPage)->pDbPage);
if( rc!=SQLITE_OK ){
@@ -5179,7 +5206,7 @@ static int allocateBtreePage(
MemPage *pPg = 0;
TRACE(("ALLOCATE: %d from end of file (pointer-map page)\n", pBt->nPage));
assert( pBt->nPage!=PENDING_BYTE_PAGE(pBt) );
- rc = btreeGetPage(pBt, pBt->nPage, &pPg, bNoContent);
+ rc = btreeGetPage(pBt, pBt->nPage, &pPg, bNoContent, 0);
if( rc==SQLITE_OK ){
rc = sqlite3PagerWrite(pPg->pDbPage);
releasePage(pPg);
@@ -5193,7 +5220,7 @@ static int allocateBtreePage(
*pPgno = pBt->nPage;
assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
- rc = btreeGetPage(pBt, *pPgno, ppPage, bNoContent);
+ rc = btreeGetPage(pBt, *pPgno, ppPage, bNoContent, 0);
if( rc ) return rc;
rc = sqlite3PagerWrite((*ppPage)->pDbPage);
if( rc!=SQLITE_OK ){
@@ -5261,7 +5288,7 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
/* If the secure_delete option is enabled, then
** always fully overwrite deleted information with zeros.
*/
- if( (!pPage && ((rc = btreeGetPage(pBt, iPage, &pPage, 0))!=0) )
+ if( (!pPage && ((rc = btreeGetPage(pBt, iPage, &pPage, 0, 0))!=0) )
|| ((rc = sqlite3PagerWrite(pPage->pDbPage))!=0)
){
goto freepage_out;
@@ -5288,7 +5315,7 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
u32 nLeaf; /* Initial number of leaf cells on trunk page */
iTrunk = get4byte(&pPage1->aData[32]);
- rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
+ rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0, 0);
if( rc!=SQLITE_OK ){
goto freepage_out;
}
@@ -5334,7 +5361,7 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
** first trunk in the free-list is full. Either way, the page being freed
** will become the new first trunk page in the free-list.
*/
- if( pPage==0 && SQLITE_OK!=(rc = btreeGetPage(pBt, iPage, &pPage, 0)) ){
+ if( pPage==0 && SQLITE_OK!=(rc = btreeGetPage(pBt, iPage, &pPage, 0, 0)) ){
goto freepage_out;
}
rc = sqlite3PagerWrite(pPage->pDbPage);
@@ -6135,7 +6162,7 @@ static int balance_nonroot(
}
pgno = get4byte(pRight);
while( 1 ){
- rc = getAndInitPage(pBt, pgno, &apOld[i]);
+ rc = getAndInitPage(pBt, pgno, &apOld[i], 0);
if( rc ){
memset(apOld, 0, (i+1)*sizeof(MemPage*));
goto balance_cleanup;
@@ -7223,10 +7250,17 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
u8 eType = 0;
Pgno iPtrPage = 0;
+ /* Save the positions of any open cursors. This is required in
+ ** case they are holding a reference to an xFetch reference
+ ** corresponding to page pgnoRoot. */
+ rc = saveAllCursors(pBt, 0, 0);
releasePage(pPageMove);
+ if( rc!=SQLITE_OK ){
+ return rc;
+ }
/* Move the page currently at pgnoRoot to pgnoMove. */
- rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0);
+ rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0, 0);
if( rc!=SQLITE_OK ){
return rc;
}
@@ -7247,7 +7281,7 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
if( rc!=SQLITE_OK ){
return rc;
}
- rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0);
+ rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0, 0);
if( rc!=SQLITE_OK ){
return rc;
}
@@ -7323,7 +7357,7 @@ static int clearDatabasePage(
return SQLITE_CORRUPT_BKPT;
}
- rc = getAndInitPage(pBt, pgno, &pPage);
+ rc = getAndInitPage(pBt, pgno, &pPage, 0);
if( rc ) return rc;
for(i=0; i<pPage->nCell; i++){
pCell = findCell(pPage, i);
@@ -7425,7 +7459,7 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
return SQLITE_LOCKED_SHAREDCACHE;
}
- rc = btreeGetPage(pBt, (Pgno)iTable, &pPage, 0);
+ rc = btreeGetPage(pBt, (Pgno)iTable, &pPage, 0, 0);
if( rc ) return rc;
rc = sqlite3BtreeClearTable(p, iTable, 0);
if( rc ){
@@ -7460,7 +7494,7 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
*/
MemPage *pMove;
releasePage(pPage);
- rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
+ rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0, 0);
if( rc!=SQLITE_OK ){
return rc;
}
@@ -7470,7 +7504,7 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
return rc;
}
pMove = 0;
- rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
+ rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0, 0);
freePage(pMove, &rc);
releasePage(pMove);
if( rc!=SQLITE_OK ){
@@ -7882,7 +7916,7 @@ static int checkTreePage(
usableSize = pBt->usableSize;
if( iPage==0 ) return 0;
if( checkRef(pCheck, iPage, zParentContext) ) return 0;
- if( (rc = btreeGetPage(pBt, (Pgno)iPage, &pPage, 0))!=0 ){
+ if( (rc = btreeGetPage(pBt, (Pgno)iPage, &pPage, 0, 0))!=0 ){
checkAppendMsg(pCheck, zContext,
"unable to get the page. error code=%d", rc);
return 0;
@@ -8354,6 +8388,17 @@ int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void *z){
return SQLITE_ABORT;
}
+ /* Save the positions of all other cursors open on this table. This is
+ ** required in case any of them are holding references to an xFetch
+ ** version of the b-tree page modified by the accessPayload call below.
+ **
+ ** Note that pCsr must be open on a BTREE_INTKEY table and saveCursorPosition()
+ ** and hence saveAllCursors() cannot fail on a BTREE_INTKEY table, hence
+ ** saveAllCursors can only return SQLITE_OK.
+ */
+ VVA_ONLY(rc =) saveAllCursors(pCsr->pBt, pCsr->pgnoRoot, pCsr);
+ assert( rc==SQLITE_OK );
+
/* Check some assumptions:
** (a) the cursor is open for writing,
** (b) there is a read/write transaction open,
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-19 10:46:21 +0000