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Unified Diff: third_party/sqlite/sqlite-src-3100200/src/btree.c

Issue 1610543003: [sql] Import reference version of SQLite 3.10.2. (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Created 4 years, 11 months ago
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Index: third_party/sqlite/sqlite-src-3100200/src/btree.c
diff --git a/third_party/sqlite/src/src/btree.c b/third_party/sqlite/sqlite-src-3100200/src/btree.c
similarity index 78%
copy from third_party/sqlite/src/src/btree.c
copy to third_party/sqlite/sqlite-src-3100200/src/btree.c
index 7ea66e0d3be94e88c344f06b969bffafc69ecd0c..f5feff8a4c597c8b490c9e154dfa5b056e9b93a1 100644
--- a/third_party/sqlite/src/src/btree.c
+++ b/third_party/sqlite/sqlite-src-3100200/src/btree.c
@@ -175,6 +175,12 @@ static int hasSharedCacheTableLock(
for(p=sqliteHashFirst(&pSchema->idxHash); p; p=sqliteHashNext(p)){
Index *pIdx = (Index *)sqliteHashData(p);
if( pIdx->tnum==(int)iRoot ){
+ if( iTab ){
+ /* Two or more indexes share the same root page. There must
+ ** be imposter tables. So just return true. The assert is not
+ ** useful in that case. */
+ return 1;
+ }
iTab = pIdx->pTable->tnum;
}
}
@@ -484,13 +490,15 @@ static void invalidateIncrblobCursors(
int isClearTable /* True if all rows are being deleted */
){
BtCursor *p;
- BtShared *pBt = pBtree->pBt;
+ if( pBtree->hasIncrblobCur==0 ) return;
assert( sqlite3BtreeHoldsMutex(pBtree) );
- for(p=pBt->pCursor; p; p=p->pNext){
- if( (p->curFlags & BTCF_Incrblob)!=0
- && (isClearTable || p->info.nKey==iRow)
- ){
- p->eState = CURSOR_INVALID;
+ pBtree->hasIncrblobCur = 0;
+ for(p=pBtree->pBt->pCursor; p; p=p->pNext){
+ if( (p->curFlags & BTCF_Incrblob)!=0 ){
+ pBtree->hasIncrblobCur = 1;
+ if( isClearTable || p->info.nKey==iRow ){
+ p->eState = CURSOR_INVALID;
+ }
}
}
}
@@ -583,17 +591,21 @@ static void btreeReleaseAllCursorPages(BtCursor *pCur){
pCur->iPage = -1;
}
-
/*
-** Save the current cursor position in the variables BtCursor.nKey
-** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
+** The cursor passed as the only argument must point to a valid entry
+** when this function is called (i.e. have eState==CURSOR_VALID). This
+** function saves the current cursor key in variables pCur->nKey and
+** pCur->pKey. SQLITE_OK is returned if successful or an SQLite error
+** code otherwise.
**
-** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)
-** prior to calling this routine.
+** If the cursor is open on an intkey table, then the integer key
+** (the rowid) is stored in pCur->nKey and pCur->pKey is left set to
+** NULL. If the cursor is open on a non-intkey table, then pCur->pKey is
+** set to point to a malloced buffer pCur->nKey bytes in size containing
+** the key.
*/
-static int saveCursorPosition(BtCursor *pCur){
+static int saveCursorKey(BtCursor *pCur){
int rc;
-
assert( CURSOR_VALID==pCur->eState );
assert( 0==pCur->pKey );
assert( cursorHoldsMutex(pCur) );
@@ -605,9 +617,8 @@ static int saveCursorPosition(BtCursor *pCur){
** stores the integer key in pCur->nKey. In this case this value is
** all that is required. Otherwise, if pCur is not open on an intKey
** table, then malloc space for and store the pCur->nKey bytes of key
- ** data.
- */
- if( 0==pCur->apPage[0]->intKey ){
+ ** data. */
+ if( 0==pCur->curIntKey ){
void *pKey = sqlite3Malloc( pCur->nKey );
if( pKey ){
rc = sqlite3BtreeKey(pCur, 0, (int)pCur->nKey, pKey);
@@ -620,14 +631,37 @@ static int saveCursorPosition(BtCursor *pCur){
rc = SQLITE_NOMEM;
}
}
- assert( !pCur->apPage[0]->intKey || !pCur->pKey );
+ assert( !pCur->curIntKey || !pCur->pKey );
+ return rc;
+}
+
+/*
+** Save the current cursor position in the variables BtCursor.nKey
+** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
+**
+** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)
+** prior to calling this routine.
+*/
+static int saveCursorPosition(BtCursor *pCur){
+ int rc;
+
+ assert( CURSOR_VALID==pCur->eState || CURSOR_SKIPNEXT==pCur->eState );
+ assert( 0==pCur->pKey );
+ assert( cursorHoldsMutex(pCur) );
+
+ if( pCur->eState==CURSOR_SKIPNEXT ){
+ pCur->eState = CURSOR_VALID;
+ }else{
+ pCur->skipNext = 0;
+ }
+ rc = saveCursorKey(pCur);
if( rc==SQLITE_OK ){
btreeReleaseAllCursorPages(pCur);
pCur->eState = CURSOR_REQUIRESEEK;
}
- invalidateOverflowCache(pCur);
+ pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl|BTCF_AtLast);
return rc;
}
@@ -642,6 +676,15 @@ static int SQLITE_NOINLINE saveCursorsOnList(BtCursor*,Pgno,BtCursor*);
** routine is called just before cursor pExcept is used to modify the
** table, for example in BtreeDelete() or BtreeInsert().
**
+** If there are two or more cursors on the same btree, then all such
+** cursors should have their BTCF_Multiple flag set. The btreeCursor()
+** routine enforces that rule. This routine only needs to be called in
+** the uncommon case when pExpect has the BTCF_Multiple flag set.
+**
+** If pExpect!=NULL and if no other cursors are found on the same root-page,
+** then the BTCF_Multiple flag on pExpect is cleared, to avoid another
+** pointless call to this routine.
+**
** Implementation note: This routine merely checks to see if any cursors
** need to be saved. It calls out to saveCursorsOnList() in the (unusual)
** event that cursors are in need to being saved.
@@ -653,7 +696,9 @@ static int saveAllCursors(BtShared *pBt, Pgno iRoot, BtCursor *pExcept){
for(p=pBt->pCursor; p; p=p->pNext){
if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ) break;
}
- return p ? saveCursorsOnList(p, iRoot, pExcept) : SQLITE_OK;
+ if( p ) return saveCursorsOnList(p, iRoot, pExcept);
+ if( pExcept ) pExcept->curFlags &= ~BTCF_Multiple;
+ return SQLITE_OK;
}
/* This helper routine to saveAllCursors does the actual work of saving
@@ -668,7 +713,7 @@ static int SQLITE_NOINLINE saveCursorsOnList(
){
do{
if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ){
- if( p->eState==CURSOR_VALID ){
+ if( p->eState==CURSOR_VALID || p->eState==CURSOR_SKIPNEXT ){
int rc = saveCursorPosition(p);
if( SQLITE_OK!=rc ){
return rc;
@@ -740,17 +785,19 @@ static int btreeMoveto(
*/
static int btreeRestoreCursorPosition(BtCursor *pCur){
int rc;
+ int skipNext;
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState>=CURSOR_REQUIRESEEK );
if( pCur->eState==CURSOR_FAULT ){
return pCur->skipNext;
}
pCur->eState = CURSOR_INVALID;
- rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &pCur->skipNext);
+ rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &skipNext);
if( rc==SQLITE_OK ){
sqlite3_free(pCur->pKey);
pCur->pKey = 0;
assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_INVALID );
+ pCur->skipNext |= skipNext;
if( pCur->skipNext && pCur->eState==CURSOR_VALID ){
pCur->eState = CURSOR_SKIPNEXT;
}
@@ -802,14 +849,35 @@ int sqlite3BtreeCursorRestore(BtCursor *pCur, int *pDifferentRow){
*pDifferentRow = 1;
return rc;
}
- if( pCur->eState!=CURSOR_VALID || NEVER(pCur->skipNext!=0) ){
+ if( pCur->eState!=CURSOR_VALID ){
*pDifferentRow = 1;
}else{
+ assert( pCur->skipNext==0 );
*pDifferentRow = 0;
}
return SQLITE_OK;
}
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+/*
+** Provide hints to the cursor. The particular hint given (and the type
+** and number of the varargs parameters) is determined by the eHintType
+** parameter. See the definitions of the BTREE_HINT_* macros for details.
+*/
+void sqlite3BtreeCursorHint(BtCursor *pCur, int eHintType, ...){
+ /* Used only by system that substitute their own storage engine */
+}
+#endif
+
+/*
+** Provide flag hints to the cursor.
+*/
+void sqlite3BtreeCursorHintFlags(BtCursor *pCur, unsigned x){
+ assert( x==BTREE_SEEK_EQ || x==BTREE_BULKLOAD || x==0 );
+ pCur->hints = x;
+}
+
+
#ifndef SQLITE_OMIT_AUTOVACUUM
/*
** Given a page number of a regular database page, return the page
@@ -863,7 +931,7 @@ static void ptrmapPut(BtShared *pBt, Pgno key, u8 eType, Pgno parent, int *pRC){
return;
}
iPtrmap = PTRMAP_PAGENO(pBt, key);
- rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage);
+ rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage, 0);
if( rc!=SQLITE_OK ){
*pRC = rc;
return;
@@ -906,7 +974,7 @@ static int ptrmapGet(BtShared *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
assert( sqlite3_mutex_held(pBt->mutex) );
iPtrmap = PTRMAP_PAGENO(pBt, key);
- rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage);
+ rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage, 0);
if( rc!=0 ){
return rc;
}
@@ -938,39 +1006,86 @@ static int ptrmapGet(BtShared *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
** the page, 1 means the second cell, and so forth) return a pointer
** to the cell content.
**
+** findCellPastPtr() does the same except it skips past the initial
+** 4-byte child pointer found on interior pages, if there is one.
+**
** This routine works only for pages that do not contain overflow cells.
*/
#define findCell(P,I) \
- ((P)->aData + ((P)->maskPage & get2byte(&(P)->aCellIdx[2*(I)])))
-#define findCellv2(D,M,O,I) (D+(M&get2byte(D+(O+2*(I)))))
+ ((P)->aData + ((P)->maskPage & get2byteAligned(&(P)->aCellIdx[2*(I)])))
+#define findCellPastPtr(P,I) \
+ ((P)->aDataOfst + ((P)->maskPage & get2byteAligned(&(P)->aCellIdx[2*(I)])))
/*
-** This a more complex version of findCell() that works for
-** pages that do contain overflow cells.
+** This is common tail processing for btreeParseCellPtr() and
+** btreeParseCellPtrIndex() for the case when the cell does not fit entirely
+** on a single B-tree page. Make necessary adjustments to the CellInfo
+** structure.
*/
-static u8 *findOverflowCell(MemPage *pPage, int iCell){
- int i;
- assert( sqlite3_mutex_held(pPage->pBt->mutex) );
- for(i=pPage->nOverflow-1; i>=0; i--){
- int k;
- k = pPage->aiOvfl[i];
- if( k<=iCell ){
- if( k==iCell ){
- return pPage->apOvfl[i];
- }
- iCell--;
- }
+static SQLITE_NOINLINE void btreeParseCellAdjustSizeForOverflow(
+ MemPage *pPage, /* Page containing the cell */
+ u8 *pCell, /* Pointer to the cell text. */
+ CellInfo *pInfo /* Fill in this structure */
+){
+ /* If the payload will not fit completely on the local page, we have
+ ** to decide how much to store locally and how much to spill onto
+ ** overflow pages. The strategy is to minimize the amount of unused
+ ** space on overflow pages while keeping the amount of local storage
+ ** in between minLocal and maxLocal.
+ **
+ ** Warning: changing the way overflow payload is distributed in any
+ ** way will result in an incompatible file format.
+ */
+ int minLocal; /* Minimum amount of payload held locally */
+ int maxLocal; /* Maximum amount of payload held locally */
+ int surplus; /* Overflow payload available for local storage */
+
+ minLocal = pPage->minLocal;
+ maxLocal = pPage->maxLocal;
+ surplus = minLocal + (pInfo->nPayload - minLocal)%(pPage->pBt->usableSize-4);
+ testcase( surplus==maxLocal );
+ testcase( surplus==maxLocal+1 );
+ if( surplus <= maxLocal ){
+ pInfo->nLocal = (u16)surplus;
+ }else{
+ pInfo->nLocal = (u16)minLocal;
}
- return findCell(pPage, iCell);
+ pInfo->nSize = (u16)(&pInfo->pPayload[pInfo->nLocal] - pCell) + 4;
}
/*
-** Parse a cell content block and fill in the CellInfo structure. There
-** are two versions of this function. btreeParseCell() takes a
-** cell index as the second argument and btreeParseCellPtr()
-** takes a pointer to the body of the cell as its second argument.
+** The following routines are implementations of the MemPage.xParseCell()
+** method.
+**
+** Parse a cell content block and fill in the CellInfo structure.
+**
+** btreeParseCellPtr() => table btree leaf nodes
+** btreeParseCellNoPayload() => table btree internal nodes
+** btreeParseCellPtrIndex() => index btree nodes
+**
+** There is also a wrapper function btreeParseCell() that works for
+** all MemPage types and that references the cell by index rather than
+** by pointer.
*/
+static void btreeParseCellPtrNoPayload(
+ MemPage *pPage, /* Page containing the cell */
+ u8 *pCell, /* Pointer to the cell text. */
+ CellInfo *pInfo /* Fill in this structure */
+){
+ assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+ assert( pPage->leaf==0 );
+ assert( pPage->noPayload );
+ assert( pPage->childPtrSize==4 );
+#ifndef SQLITE_DEBUG
+ UNUSED_PARAMETER(pPage);
+#endif
+ pInfo->nSize = 4 + getVarint(&pCell[4], (u64*)&pInfo->nKey);
+ pInfo->nPayload = 0;
+ pInfo->nLocal = 0;
+ pInfo->pPayload = 0;
+ return;
+}
static void btreeParseCellPtr(
MemPage *pPage, /* Page containing the cell */
u8 *pCell, /* Pointer to the cell text. */
@@ -978,26 +1093,54 @@ static void btreeParseCellPtr(
){
u8 *pIter; /* For scanning through pCell */
u32 nPayload; /* Number of bytes of cell payload */
+ u64 iKey; /* Extracted Key value */
assert( sqlite3_mutex_held(pPage->pBt->mutex) );
assert( pPage->leaf==0 || pPage->leaf==1 );
- if( pPage->intKeyLeaf ){
- assert( pPage->childPtrSize==0 );
- pIter = pCell + getVarint32(pCell, nPayload);
- pIter += getVarint(pIter, (u64*)&pInfo->nKey);
- }else if( pPage->noPayload ){
- assert( pPage->childPtrSize==4 );
- pInfo->nSize = 4 + getVarint(&pCell[4], (u64*)&pInfo->nKey);
- pInfo->nPayload = 0;
- pInfo->nLocal = 0;
- pInfo->iOverflow = 0;
- pInfo->pPayload = 0;
- return;
- }else{
- pIter = pCell + pPage->childPtrSize;
- pIter += getVarint32(pIter, nPayload);
- pInfo->nKey = nPayload;
+ assert( pPage->intKeyLeaf || pPage->noPayload );
+ assert( pPage->noPayload==0 );
+ assert( pPage->intKeyLeaf );
+ assert( pPage->childPtrSize==0 );
+ pIter = pCell;
+
+ /* The next block of code is equivalent to:
+ **
+ ** pIter += getVarint32(pIter, nPayload);
+ **
+ ** The code is inlined to avoid a function call.
+ */
+ nPayload = *pIter;
+ if( nPayload>=0x80 ){
+ u8 *pEnd = &pIter[8];
+ nPayload &= 0x7f;
+ do{
+ nPayload = (nPayload<<7) | (*++pIter & 0x7f);
+ }while( (*pIter)>=0x80 && pIter<pEnd );
+ }
+ pIter++;
+
+ /* The next block of code is equivalent to:
+ **
+ ** pIter += getVarint(pIter, (u64*)&pInfo->nKey);
+ **
+ ** The code is inlined to avoid a function call.
+ */
+ iKey = *pIter;
+ if( iKey>=0x80 ){
+ u8 *pEnd = &pIter[7];
+ iKey &= 0x7f;
+ while(1){
+ iKey = (iKey<<7) | (*++pIter & 0x7f);
+ if( (*pIter)<0x80 ) break;
+ if( pIter>=pEnd ){
+ iKey = (iKey<<8) | *++pIter;
+ break;
+ }
+ }
}
+ pIter++;
+
+ pInfo->nKey = *(i64*)&iKey;
pInfo->nPayload = nPayload;
pInfo->pPayload = pIter;
testcase( nPayload==pPage->maxLocal );
@@ -1009,33 +1152,46 @@ static void btreeParseCellPtr(
pInfo->nSize = nPayload + (u16)(pIter - pCell);
if( pInfo->nSize<4 ) pInfo->nSize = 4;
pInfo->nLocal = (u16)nPayload;
- pInfo->iOverflow = 0;
}else{
- /* If the payload will not fit completely on the local page, we have
- ** to decide how much to store locally and how much to spill onto
- ** overflow pages. The strategy is to minimize the amount of unused
- ** space on overflow pages while keeping the amount of local storage
- ** in between minLocal and maxLocal.
- **
- ** Warning: changing the way overflow payload is distributed in any
- ** way will result in an incompatible file format.
+ btreeParseCellAdjustSizeForOverflow(pPage, pCell, pInfo);
+ }
+}
+static void btreeParseCellPtrIndex(
+ MemPage *pPage, /* Page containing the cell */
+ u8 *pCell, /* Pointer to the cell text. */
+ CellInfo *pInfo /* Fill in this structure */
+){
+ u8 *pIter; /* For scanning through pCell */
+ u32 nPayload; /* Number of bytes of cell payload */
+
+ assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+ assert( pPage->leaf==0 || pPage->leaf==1 );
+ assert( pPage->intKeyLeaf==0 );
+ assert( pPage->noPayload==0 );
+ pIter = pCell + pPage->childPtrSize;
+ nPayload = *pIter;
+ if( nPayload>=0x80 ){
+ u8 *pEnd = &pIter[8];
+ nPayload &= 0x7f;
+ do{
+ nPayload = (nPayload<<7) | (*++pIter & 0x7f);
+ }while( *(pIter)>=0x80 && pIter<pEnd );
+ }
+ pIter++;
+ pInfo->nKey = nPayload;
+ pInfo->nPayload = nPayload;
+ pInfo->pPayload = pIter;
+ testcase( nPayload==pPage->maxLocal );
+ testcase( nPayload==pPage->maxLocal+1 );
+ if( nPayload<=pPage->maxLocal ){
+ /* This is the (easy) common case where the entire payload fits
+ ** on the local page. No overflow is required.
*/
- int minLocal; /* Minimum amount of payload held locally */
- int maxLocal; /* Maximum amount of payload held locally */
- int surplus; /* Overflow payload available for local storage */
-
- minLocal = pPage->minLocal;
- maxLocal = pPage->maxLocal;
- surplus = minLocal + (nPayload - minLocal)%(pPage->pBt->usableSize - 4);
- testcase( surplus==maxLocal );
- testcase( surplus==maxLocal+1 );
- if( surplus <= maxLocal ){
- pInfo->nLocal = (u16)surplus;
- }else{
- pInfo->nLocal = (u16)minLocal;
- }
- pInfo->iOverflow = (u16)(&pInfo->pPayload[pInfo->nLocal] - pCell);
- pInfo->nSize = pInfo->iOverflow + 4;
+ pInfo->nSize = nPayload + (u16)(pIter - pCell);
+ if( pInfo->nSize<4 ) pInfo->nSize = 4;
+ pInfo->nLocal = (u16)nPayload;
+ }else{
+ btreeParseCellAdjustSizeForOverflow(pPage, pCell, pInfo);
}
}
static void btreeParseCell(
@@ -1043,14 +1199,20 @@ static void btreeParseCell(
int iCell, /* The cell index. First cell is 0 */
CellInfo *pInfo /* Fill in this structure */
){
- btreeParseCellPtr(pPage, findCell(pPage, iCell), pInfo);
+ pPage->xParseCell(pPage, findCell(pPage, iCell), pInfo);
}
/*
+** The following routines are implementations of the MemPage.xCellSize
+** method.
+**
** Compute the total number of bytes that a Cell needs in the cell
** data area of the btree-page. The return number includes the cell
** data header and the local payload, but not any overflow page or
** the space used by the cell pointer.
+**
+** cellSizePtrNoPayload() => table internal nodes
+** cellSizePtr() => all index nodes & table leaf nodes
*/
static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
u8 *pIter = pCell + pPage->childPtrSize; /* For looping over bytes of pCell */
@@ -1063,18 +1225,13 @@ static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of
** this function verifies that this invariant is not violated. */
CellInfo debuginfo;
- btreeParseCellPtr(pPage, pCell, &debuginfo);
+ pPage->xParseCell(pPage, pCell, &debuginfo);
#endif
- if( pPage->noPayload ){
- pEnd = &pIter[9];
- while( (*pIter++)&0x80 && pIter<pEnd );
- assert( pPage->childPtrSize==4 );
- return (u16)(pIter - pCell);
- }
+ assert( pPage->noPayload==0 );
nSize = *pIter;
if( nSize>=0x80 ){
- pEnd = &pIter[9];
+ pEnd = &pIter[8];
nSize &= 0x7f;
do{
nSize = (nSize<<7) | (*++pIter & 0x7f);
@@ -1106,12 +1263,34 @@ static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
assert( nSize==debuginfo.nSize || CORRUPT_DB );
return (u16)nSize;
}
+static u16 cellSizePtrNoPayload(MemPage *pPage, u8 *pCell){
+ u8 *pIter = pCell + 4; /* For looping over bytes of pCell */
+ u8 *pEnd; /* End mark for a varint */
+
+#ifdef SQLITE_DEBUG
+ /* The value returned by this function should always be the same as
+ ** the (CellInfo.nSize) value found by doing a full parse of the
+ ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of
+ ** this function verifies that this invariant is not violated. */
+ CellInfo debuginfo;
+ pPage->xParseCell(pPage, pCell, &debuginfo);
+#else
+ UNUSED_PARAMETER(pPage);
+#endif
+
+ assert( pPage->childPtrSize==4 );
+ pEnd = pIter + 9;
+ while( (*pIter++)&0x80 && pIter<pEnd );
+ assert( debuginfo.nSize==(u16)(pIter - pCell) || CORRUPT_DB );
+ return (u16)(pIter - pCell);
+}
+
#ifdef SQLITE_DEBUG
/* This variation on cellSizePtr() is used inside of assert() statements
** only. */
static u16 cellSize(MemPage *pPage, int iCell){
- return cellSizePtr(pPage, findCell(pPage, iCell));
+ return pPage->xCellSize(pPage, findCell(pPage, iCell));
}
#endif
@@ -1125,9 +1304,9 @@ static void ptrmapPutOvflPtr(MemPage *pPage, u8 *pCell, int *pRC){
CellInfo info;
if( *pRC ) return;
assert( pCell!=0 );
- btreeParseCellPtr(pPage, pCell, &info);
- if( info.iOverflow ){
- Pgno ovfl = get4byte(&pCell[info.iOverflow]);
+ pPage->xParseCell(pPage, pCell, &info);
+ if( info.nLocal<info.nPayload ){
+ Pgno ovfl = get4byte(&pCell[info.nSize-4]);
ptrmapPut(pPage->pBt, ovfl, PTRMAP_OVERFLOW1, pPage->pgno, pRC);
}
}
@@ -1139,6 +1318,11 @@ static void ptrmapPutOvflPtr(MemPage *pPage, u8 *pCell, int *pRC){
** end of the page and all free space is collected into one
** big FreeBlk that occurs in between the header and cell
** pointer array and the cell content area.
+**
+** EVIDENCE-OF: R-44582-60138 SQLite may from time to time reorganize a
+** b-tree page so that there are no freeblocks or fragment bytes, all
+** unused bytes are contained in the unallocated space region, and all
+** cells are packed tightly at the end of the page.
*/
static int defragmentPage(MemPage *pPage){
int i; /* Loop counter */
@@ -1151,6 +1335,7 @@ static int defragmentPage(MemPage *pPage){
int nCell; /* Number of cells on the page */
unsigned char *data; /* The page data */
unsigned char *temp; /* Temp area for cell content */
+ unsigned char *src; /* Source of content */
int iCellFirst; /* First allowable cell index */
int iCellLast; /* Last possible cell index */
@@ -1160,15 +1345,13 @@ static int defragmentPage(MemPage *pPage){
assert( pPage->pBt->usableSize <= SQLITE_MAX_PAGE_SIZE );
assert( pPage->nOverflow==0 );
assert( sqlite3_mutex_held(pPage->pBt->mutex) );
- temp = sqlite3PagerTempSpace(pPage->pBt->pPager);
- data = pPage->aData;
+ temp = 0;
+ src = data = pPage->aData;
hdr = pPage->hdrOffset;
cellOffset = pPage->cellOffset;
nCell = pPage->nCell;
assert( nCell==get2byte(&data[hdr+3]) );
usableSize = pPage->pBt->usableSize;
- cbrk = get2byte(&data[hdr+5]);
- memcpy(&temp[cbrk], &data[cbrk], usableSize - cbrk);
cbrk = usableSize;
iCellFirst = cellOffset + 2*nCell;
iCellLast = usableSize - 4;
@@ -1178,31 +1361,31 @@ static int defragmentPage(MemPage *pPage){
pc = get2byte(pAddr);
testcase( pc==iCellFirst );
testcase( pc==iCellLast );
-#if !defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
/* These conditions have already been verified in btreeInitPage()
- ** if SQLITE_ENABLE_OVERSIZE_CELL_CHECK is defined
+ ** if PRAGMA cell_size_check=ON.
*/
if( pc<iCellFirst || pc>iCellLast ){
return SQLITE_CORRUPT_BKPT;
}
-#endif
assert( pc>=iCellFirst && pc<=iCellLast );
- size = cellSizePtr(pPage, &temp[pc]);
+ size = pPage->xCellSize(pPage, &src[pc]);
cbrk -= size;
-#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
- if( cbrk<iCellFirst ){
- return SQLITE_CORRUPT_BKPT;
- }
-#else
if( cbrk<iCellFirst || pc+size>usableSize ){
return SQLITE_CORRUPT_BKPT;
}
-#endif
assert( cbrk+size<=usableSize && cbrk>=iCellFirst );
testcase( cbrk+size==usableSize );
testcase( pc+size==usableSize );
- memcpy(&data[cbrk], &temp[pc], size);
put2byte(pAddr, cbrk);
+ if( temp==0 ){
+ int x;
+ if( cbrk==pc ) continue;
+ temp = sqlite3PagerTempSpace(pPage->pBt->pPager);
+ x = get2byte(&data[hdr+5]);
+ memcpy(&temp[x], &data[x], (cbrk+size) - x);
+ src = temp;
+ }
+ memcpy(&data[cbrk], &src[pc], size);
}
assert( cbrk>=iCellFirst );
put2byte(&data[hdr+5], cbrk);
@@ -1218,6 +1401,70 @@ static int defragmentPage(MemPage *pPage){
}
/*
+** Search the free-list on page pPg for space to store a cell nByte bytes in
+** size. If one can be found, return a pointer to the space and remove it
+** from the free-list.
+**
+** If no suitable space can be found on the free-list, return NULL.
+**
+** This function may detect corruption within pPg. If corruption is
+** detected then *pRc is set to SQLITE_CORRUPT and NULL is returned.
+**
+** Slots on the free list that are between 1 and 3 bytes larger than nByte
+** will be ignored if adding the extra space to the fragmentation count
+** causes the fragmentation count to exceed 60.
+*/
+static u8 *pageFindSlot(MemPage *pPg, int nByte, int *pRc){
+ const int hdr = pPg->hdrOffset;
+ u8 * const aData = pPg->aData;
+ int iAddr = hdr + 1;
+ int pc = get2byte(&aData[iAddr]);
+ int x;
+ int usableSize = pPg->pBt->usableSize;
+
+ assert( pc>0 );
+ do{
+ int size; /* Size of the free slot */
+ /* EVIDENCE-OF: R-06866-39125 Freeblocks are always connected in order of
+ ** increasing offset. */
+ if( pc>usableSize-4 || pc<iAddr+4 ){
+ *pRc = SQLITE_CORRUPT_BKPT;
+ return 0;
+ }
+ /* EVIDENCE-OF: R-22710-53328 The third and fourth bytes of each
+ ** freeblock form a big-endian integer which is the size of the freeblock
+ ** in bytes, including the 4-byte header. */
+ size = get2byte(&aData[pc+2]);
+ if( (x = size - nByte)>=0 ){
+ testcase( x==4 );
+ testcase( x==3 );
+ if( pc < pPg->cellOffset+2*pPg->nCell || size+pc > usableSize ){
+ *pRc = SQLITE_CORRUPT_BKPT;
+ return 0;
+ }else if( x<4 ){
+ /* EVIDENCE-OF: R-11498-58022 In a well-formed b-tree page, the total
+ ** number of bytes in fragments may not exceed 60. */
+ if( aData[hdr+7]>57 ) return 0;
+
+ /* Remove the slot from the free-list. Update the number of
+ ** fragmented bytes within the page. */
+ memcpy(&aData[iAddr], &aData[pc], 2);
+ aData[hdr+7] += (u8)x;
+ }else{
+ /* The slot remains on the free-list. Reduce its size to account
+ ** for the portion used by the new allocation. */
+ put2byte(&aData[pc+2], x);
+ }
+ return &aData[pc + x];
+ }
+ iAddr = pc;
+ pc = get2byte(&aData[pc]);
+ }while( pc );
+
+ return 0;
+}
+
+/*
** Allocate nByte bytes of space from within the B-Tree page passed
** as the first argument. Write into *pIdx the index into pPage->aData[]
** of the first byte of allocated space. Return either SQLITE_OK or
@@ -1234,9 +1481,8 @@ static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
const int hdr = pPage->hdrOffset; /* Local cache of pPage->hdrOffset */
u8 * const data = pPage->aData; /* Local cache of pPage->aData */
int top; /* First byte of cell content area */
+ int rc = SQLITE_OK; /* Integer return code */
int gap; /* First byte of gap between cell pointers and cell content */
- int rc; /* Integer return code */
- int usableSize; /* Usable size of the page */
assert( sqlite3PagerIswriteable(pPage->pDbPage) );
assert( pPage->pBt );
@@ -1244,15 +1490,20 @@ static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
assert( nByte>=0 ); /* Minimum cell size is 4 */
assert( pPage->nFree>=nByte );
assert( pPage->nOverflow==0 );
- usableSize = pPage->pBt->usableSize;
- assert( nByte < usableSize-8 );
+ assert( nByte < (int)(pPage->pBt->usableSize-8) );
assert( pPage->cellOffset == hdr + 12 - 4*pPage->leaf );
gap = pPage->cellOffset + 2*pPage->nCell;
assert( gap<=65536 );
+ /* EVIDENCE-OF: R-29356-02391 If the database uses a 65536-byte page size
+ ** and the reserved space is zero (the usual value for reserved space)
+ ** then the cell content offset of an empty page wants to be 65536.
+ ** However, that integer is too large to be stored in a 2-byte unsigned
+ ** integer, so a value of 0 is used in its place. */
top = get2byte(&data[hdr+5]);
+ assert( top<=(int)pPage->pBt->usableSize ); /* Prevent by getAndInitPage() */
if( gap>top ){
- if( top==0 ){
+ if( top==0 && pPage->pBt->usableSize==65536 ){
top = 65536;
}else{
return SQLITE_CORRUPT_BKPT;
@@ -1266,34 +1517,14 @@ static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
testcase( gap+2==top );
testcase( gap+1==top );
testcase( gap==top );
- if( gap+2<=top && (data[hdr+1] || data[hdr+2]) ){
- int pc, addr;
- for(addr=hdr+1; (pc = get2byte(&data[addr]))>0; addr=pc){
- int size; /* Size of the free slot */
- if( pc>usableSize-4 || pc<addr+4 ){
- return SQLITE_CORRUPT_BKPT;
- }
- size = get2byte(&data[pc+2]);
- if( size>=nByte ){
- int x = size - nByte;
- testcase( x==4 );
- testcase( x==3 );
- if( x<4 ){
- if( data[hdr+7]>=60 ) goto defragment_page;
- /* Remove the slot from the free-list. Update the number of
- ** fragmented bytes within the page. */
- memcpy(&data[addr], &data[pc], 2);
- data[hdr+7] += (u8)x;
- }else if( size+pc > usableSize ){
- return SQLITE_CORRUPT_BKPT;
- }else{
- /* The slot remains on the free-list. Reduce its size to account
- ** for the portion used by the new allocation. */
- put2byte(&data[pc+2], x);
- }
- *pIdx = pc + x;
- return SQLITE_OK;
- }
+ if( (data[hdr+2] || data[hdr+1]) && gap+2<=top ){
+ u8 *pSpace = pageFindSlot(pPage, nByte, &rc);
+ if( pSpace ){
+ assert( pSpace>=data && (pSpace - data)<65536 );
+ *pIdx = (int)(pSpace - data);
+ return SQLITE_OK;
+ }else if( rc ){
+ return rc;
}
}
@@ -1302,8 +1533,7 @@ static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
*/
testcase( gap+2+nByte==top );
if( gap+2+nByte>top ){
-defragment_page:
- testcase( pPage->nCell==0 );
+ assert( pPage->nCell>0 || CORRUPT_DB );
rc = defragmentPage(pPage);
if( rc ) return rc;
top = get2byteNotZero(&data[hdr+5]);
@@ -1349,8 +1579,8 @@ static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
assert( pPage->pBt!=0 );
assert( sqlite3PagerIswriteable(pPage->pDbPage) );
- assert( iStart>=pPage->hdrOffset+6+pPage->childPtrSize );
- assert( iEnd <= pPage->pBt->usableSize );
+ assert( CORRUPT_DB || iStart>=pPage->hdrOffset+6+pPage->childPtrSize );
+ assert( CORRUPT_DB || iEnd <= pPage->pBt->usableSize );
assert( sqlite3_mutex_held(pPage->pBt->mutex) );
assert( iSize>=4 ); /* Minimum cell size is 4 */
assert( iStart<=iLast );
@@ -1378,7 +1608,7 @@ static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
/* At this point:
** iFreeBlk: First freeblock after iStart, or zero if none
- ** iPtr: The address of a pointer iFreeBlk
+ ** iPtr: The address of a pointer to iFreeBlk
**
** Check to see if iFreeBlk should be coalesced onto the end of iStart.
*/
@@ -1386,6 +1616,7 @@ static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
nFrag = iFreeBlk - iEnd;
if( iEnd>iFreeBlk ) return SQLITE_CORRUPT_BKPT;
iEnd = iFreeBlk + get2byte(&data[iFreeBlk+2]);
+ if( iEnd > pPage->pBt->usableSize ) return SQLITE_CORRUPT_BKPT;
iSize = iEnd - iStart;
iFreeBlk = get2byte(&data[iFreeBlk]);
}
@@ -1443,20 +1674,44 @@ static int decodeFlags(MemPage *pPage, int flagByte){
pPage->leaf = (u8)(flagByte>>3); assert( PTF_LEAF == 1<<3 );
flagByte &= ~PTF_LEAF;
pPage->childPtrSize = 4-4*pPage->leaf;
+ pPage->xCellSize = cellSizePtr;
pBt = pPage->pBt;
if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){
+ /* EVIDENCE-OF: R-03640-13415 A value of 5 means the page is an interior
+ ** table b-tree page. */
+ assert( (PTF_LEAFDATA|PTF_INTKEY)==5 );
+ /* EVIDENCE-OF: R-20501-61796 A value of 13 means the page is a leaf
+ ** table b-tree page. */
+ assert( (PTF_LEAFDATA|PTF_INTKEY|PTF_LEAF)==13 );
pPage->intKey = 1;
- pPage->intKeyLeaf = pPage->leaf;
- pPage->noPayload = !pPage->leaf;
+ if( pPage->leaf ){
+ pPage->intKeyLeaf = 1;
+ pPage->noPayload = 0;
+ pPage->xParseCell = btreeParseCellPtr;
+ }else{
+ pPage->intKeyLeaf = 0;
+ pPage->noPayload = 1;
+ pPage->xCellSize = cellSizePtrNoPayload;
+ pPage->xParseCell = btreeParseCellPtrNoPayload;
+ }
pPage->maxLocal = pBt->maxLeaf;
pPage->minLocal = pBt->minLeaf;
}else if( flagByte==PTF_ZERODATA ){
+ /* EVIDENCE-OF: R-27225-53936 A value of 2 means the page is an interior
+ ** index b-tree page. */
+ assert( (PTF_ZERODATA)==2 );
+ /* EVIDENCE-OF: R-16571-11615 A value of 10 means the page is a leaf
+ ** index b-tree page. */
+ assert( (PTF_ZERODATA|PTF_LEAF)==10 );
pPage->intKey = 0;
pPage->intKeyLeaf = 0;
pPage->noPayload = 0;
+ pPage->xParseCell = btreeParseCellPtrIndex;
pPage->maxLocal = pBt->maxLocal;
pPage->minLocal = pBt->minLocal;
}else{
+ /* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is
+ ** an error. */
return SQLITE_CORRUPT_BKPT;
}
pPage->max1bytePayload = pBt->max1bytePayload;
@@ -1475,6 +1730,7 @@ static int decodeFlags(MemPage *pPage, int flagByte){
static int btreeInitPage(MemPage *pPage){
assert( pPage->pBt!=0 );
+ assert( pPage->pBt->db!=0 );
assert( sqlite3_mutex_held(pPage->pBt->mutex) );
assert( pPage->pgno==sqlite3PagerPagenumber(pPage->pDbPage) );
assert( pPage == sqlite3PagerGetExtra(pPage->pDbPage) );
@@ -1496,21 +1752,34 @@ static int btreeInitPage(MemPage *pPage){
hdr = pPage->hdrOffset;
data = pPage->aData;
+ /* EVIDENCE-OF: R-28594-02890 The one-byte flag at offset 0 indicating
+ ** the b-tree page type. */
if( decodeFlags(pPage, data[hdr]) ) return SQLITE_CORRUPT_BKPT;
assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );
pPage->maskPage = (u16)(pBt->pageSize - 1);
pPage->nOverflow = 0;
usableSize = pBt->usableSize;
- pPage->cellOffset = cellOffset = hdr + 12 - 4*pPage->leaf;
+ pPage->cellOffset = cellOffset = hdr + 8 + pPage->childPtrSize;
pPage->aDataEnd = &data[usableSize];
pPage->aCellIdx = &data[cellOffset];
+ pPage->aDataOfst = &data[pPage->childPtrSize];
+ /* EVIDENCE-OF: R-58015-48175 The two-byte integer at offset 5 designates
+ ** the start of the cell content area. A zero value for this integer is
+ ** interpreted as 65536. */
top = get2byteNotZero(&data[hdr+5]);
+ /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
+ ** number of cells on the page. */
pPage->nCell = get2byte(&data[hdr+3]);
if( pPage->nCell>MX_CELL(pBt) ){
/* To many cells for a single page. The page must be corrupt */
return SQLITE_CORRUPT_BKPT;
}
testcase( pPage->nCell==MX_CELL(pBt) );
+ /* EVIDENCE-OF: R-24089-57979 If a page contains no cells (which is only
+ ** possible for a root page of a table that contains no rows) then the
+ ** offset to the cell content area will equal the page size minus the
+ ** bytes of reserved space. */
+ assert( pPage->nCell>0 || top==usableSize || CORRUPT_DB );
/* A malformed database page might cause us to read past the end
** of page when parsing a cell.
@@ -1521,20 +1790,19 @@ static int btreeInitPage(MemPage *pPage){
*/
iCellFirst = cellOffset + 2*pPage->nCell;
iCellLast = usableSize - 4;
-#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
- {
+ if( pBt->db->flags & SQLITE_CellSizeCk ){
int i; /* Index into the cell pointer array */
int sz; /* Size of a cell */
if( !pPage->leaf ) iCellLast--;
for(i=0; i<pPage->nCell; i++){
- pc = get2byte(&data[cellOffset+i*2]);
+ pc = get2byteAligned(&data[cellOffset+i*2]);
testcase( pc==iCellFirst );
testcase( pc==iCellLast );
if( pc<iCellFirst || pc>iCellLast ){
return SQLITE_CORRUPT_BKPT;
}
- sz = cellSizePtr(pPage, &data[pc]);
+ sz = pPage->xCellSize(pPage, &data[pc]);
testcase( pc+sz==usableSize );
if( pc+sz>usableSize ){
return SQLITE_CORRUPT_BKPT;
@@ -1542,15 +1810,21 @@ static int btreeInitPage(MemPage *pPage){
}
if( !pPage->leaf ) iCellLast++;
}
-#endif
- /* Compute the total free space on the page */
+ /* Compute the total free space on the page
+ ** EVIDENCE-OF: R-23588-34450 The two-byte integer at offset 1 gives the
+ ** start of the first freeblock on the page, or is zero if there are no
+ ** freeblocks. */
pc = get2byte(&data[hdr+1]);
- nFree = data[hdr+7] + top;
+ nFree = data[hdr+7] + top; /* Init nFree to non-freeblock free space */
while( pc>0 ){
u16 next, size;
if( pc<iCellFirst || pc>iCellLast ){
- /* Start of free block is off the page */
+ /* EVIDENCE-OF: R-55530-52930 In a well-formed b-tree page, there will
+ ** always be at least one cell before the first freeblock.
+ **
+ ** Or, the freeblock is off the end of the page
+ */
return SQLITE_CORRUPT_BKPT;
}
next = get2byte(&data[pc]);
@@ -1608,6 +1882,7 @@ static void zeroPage(MemPage *pPage, int flags){
pPage->cellOffset = first;
pPage->aDataEnd = &data[pBt->usableSize];
pPage->aCellIdx = &data[first];
+ pPage->aDataOfst = &data[pPage->childPtrSize];
pPage->nOverflow = 0;
assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );
pPage->maskPage = (u16)(pBt->pageSize - 1);
@@ -1622,20 +1897,23 @@ static void zeroPage(MemPage *pPage, int flags){
*/
static MemPage *btreePageFromDbPage(DbPage *pDbPage, Pgno pgno, BtShared *pBt){
MemPage *pPage = (MemPage*)sqlite3PagerGetExtra(pDbPage);
- pPage->aData = sqlite3PagerGetData(pDbPage);
- pPage->pDbPage = pDbPage;
- pPage->pBt = pBt;
- pPage->pgno = pgno;
- pPage->hdrOffset = pPage->pgno==1 ? 100 : 0;
+ if( pgno!=pPage->pgno ){
+ pPage->aData = sqlite3PagerGetData(pDbPage);
+ pPage->pDbPage = pDbPage;
+ pPage->pBt = pBt;
+ pPage->pgno = pgno;
+ pPage->hdrOffset = pgno==1 ? 100 : 0;
+ }
+ assert( pPage->aData==sqlite3PagerGetData(pDbPage) );
return pPage;
}
/*
** Get a page from the pager. Initialize the MemPage.pBt and
-** MemPage.aData elements if needed.
+** MemPage.aData elements if needed. See also: btreeGetUnusedPage().
**
-** If the noContent flag is set, it means that we do not care about
-** the content of the page at this time. So do not go to the disk
+** If the PAGER_GET_NOCONTENT flag is set, it means that we do not care
+** about the content of the page at this time. So do not go to the disk
** to fetch the content. Just fill in the content with zeros for now.
** If in the future we call sqlite3PagerWrite() on this page, that
** means we have started to be concerned about content and the disk
@@ -1652,7 +1930,7 @@ static int btreeGetPage(
assert( flags==0 || flags==PAGER_GET_NOCONTENT || flags==PAGER_GET_READONLY );
assert( sqlite3_mutex_held(pBt->mutex) );
- rc = sqlite3PagerAcquire(pBt->pPager, pgno, (DbPage**)&pDbPage, flags);
+ rc = sqlite3PagerGet(pBt->pPager, pgno, (DbPage**)&pDbPage, flags);
if( rc ) return rc;
*ppPage = btreePageFromDbPage(pDbPage, pgno, pBt);
return SQLITE_OK;
@@ -1687,35 +1965,63 @@ u32 sqlite3BtreeLastPage(Btree *p){
}
/*
-** Get a page from the pager and initialize it. This routine is just a
-** convenience wrapper around separate calls to btreeGetPage() and
-** btreeInitPage().
+** Get a page from the pager and initialize it.
+**
+** If pCur!=0 then the page is being fetched as part of a moveToChild()
+** call. Do additional sanity checking on the page in this case.
+** And if the fetch fails, this routine must decrement pCur->iPage.
**
-** If an error occurs, then the value *ppPage is set to is undefined. It
+** The page is fetched as read-write unless pCur is not NULL and is
+** a read-only cursor.
+**
+** If an error occurs, then *ppPage is undefined. It
** 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 */
- int bReadonly /* PAGER_GET_READONLY or 0 */
+ BtCursor *pCur, /* Cursor to receive the page, or NULL */
+ int bReadOnly /* True for a read-only page */
){
int rc;
+ DbPage *pDbPage;
assert( sqlite3_mutex_held(pBt->mutex) );
- assert( bReadonly==PAGER_GET_READONLY || bReadonly==0 );
+ assert( pCur==0 || ppPage==&pCur->apPage[pCur->iPage] );
+ assert( pCur==0 || bReadOnly==pCur->curPagerFlags );
+ assert( pCur==0 || pCur->iPage>0 );
if( pgno>btreePagecount(pBt) ){
rc = SQLITE_CORRUPT_BKPT;
- }else{
- rc = btreeGetPage(pBt, pgno, ppPage, bReadonly);
- if( rc==SQLITE_OK && (*ppPage)->isInit==0 ){
- rc = btreeInitPage(*ppPage);
- if( rc!=SQLITE_OK ){
- releasePage(*ppPage);
- }
+ goto getAndInitPage_error;
+ }
+ rc = sqlite3PagerGet(pBt->pPager, pgno, (DbPage**)&pDbPage, bReadOnly);
+ if( rc ){
+ goto getAndInitPage_error;
+ }
+ *ppPage = (MemPage*)sqlite3PagerGetExtra(pDbPage);
+ if( (*ppPage)->isInit==0 ){
+ btreePageFromDbPage(pDbPage, pgno, pBt);
+ rc = btreeInitPage(*ppPage);
+ if( rc!=SQLITE_OK ){
+ releasePage(*ppPage);
+ goto getAndInitPage_error;
}
}
+ assert( (*ppPage)->pgno==pgno );
+ assert( (*ppPage)->aData==sqlite3PagerGetData(pDbPage) );
+
+ /* If obtaining a child page for a cursor, we must verify that the page is
+ ** compatible with the root page. */
+ if( pCur && ((*ppPage)->nCell<1 || (*ppPage)->intKey!=pCur->curIntKey) ){
+ rc = SQLITE_CORRUPT_BKPT;
+ releasePage(*ppPage);
+ goto getAndInitPage_error;
+ }
+ return SQLITE_OK;
+getAndInitPage_error:
+ if( pCur ) pCur->iPage--;
testcase( pgno==0 );
assert( pgno!=0 || rc==SQLITE_CORRUPT );
return rc;
@@ -1725,18 +2031,49 @@ static int getAndInitPage(
** Release a MemPage. This should be called once for each prior
** call to btreeGetPage.
*/
+static void releasePageNotNull(MemPage *pPage){
+ assert( pPage->aData );
+ assert( pPage->pBt );
+ assert( pPage->pDbPage!=0 );
+ assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
+ assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
+ assert( sqlite3_mutex_held(pPage->pBt->mutex) );
+ sqlite3PagerUnrefNotNull(pPage->pDbPage);
+}
static void releasePage(MemPage *pPage){
- if( pPage ){
- assert( pPage->aData );
- assert( pPage->pBt );
- assert( pPage->pDbPage!=0 );
- assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
- assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
- assert( sqlite3_mutex_held(pPage->pBt->mutex) );
- sqlite3PagerUnrefNotNull(pPage->pDbPage);
+ if( pPage ) releasePageNotNull(pPage);
+}
+
+/*
+** Get an unused page.
+**
+** This works just like btreeGetPage() with the addition:
+**
+** * If the page is already in use for some other purpose, immediately
+** release it and return an SQLITE_CURRUPT error.
+** * Make sure the isInit flag is clear
+*/
+static int btreeGetUnusedPage(
+ BtShared *pBt, /* The btree */
+ Pgno pgno, /* Number of the page to fetch */
+ MemPage **ppPage, /* Return the page in this parameter */
+ int flags /* PAGER_GET_NOCONTENT or PAGER_GET_READONLY */
+){
+ int rc = btreeGetPage(pBt, pgno, ppPage, flags);
+ if( rc==SQLITE_OK ){
+ if( sqlite3PagerPageRefcount((*ppPage)->pDbPage)>1 ){
+ releasePage(*ppPage);
+ *ppPage = 0;
+ return SQLITE_CORRUPT_BKPT;
+ }
+ (*ppPage)->isInit = 0;
+ }else{
+ *ppPage = 0;
}
+ return rc;
}
+
/*
** During a rollback, when the pager reloads information into the cache
** so that the cache is restored to its original state at the start of
@@ -1859,16 +2196,18 @@ int sqlite3BtreeOpen(
*/
if( isTempDb==0 && (isMemdb==0 || (vfsFlags&SQLITE_OPEN_URI)!=0) ){
if( vfsFlags & SQLITE_OPEN_SHAREDCACHE ){
+ int nFilename = sqlite3Strlen30(zFilename)+1;
int nFullPathname = pVfs->mxPathname+1;
- char *zFullPathname = sqlite3Malloc(nFullPathname);
+ char *zFullPathname = sqlite3Malloc(MAX(nFullPathname,nFilename));
MUTEX_LOGIC( sqlite3_mutex *mutexShared; )
+
p->sharable = 1;
if( !zFullPathname ){
sqlite3_free(p);
return SQLITE_NOMEM;
}
if( isMemdb ){
- memcpy(zFullPathname, zFilename, sqlite3Strlen30(zFilename)+1);
+ memcpy(zFullPathname, zFilename, nFilename);
}else{
rc = sqlite3OsFullPathname(pVfs, zFilename,
nFullPathname, zFullPathname);
@@ -1925,8 +2264,8 @@ int sqlite3BtreeOpen(
** the right size. This is to guard against size changes that result
** when compiling on a different architecture.
*/
- assert( sizeof(i64)==8 || sizeof(i64)==4 );
- assert( sizeof(u64)==8 || sizeof(u64)==4 );
+ assert( sizeof(i64)==8 );
+ assert( sizeof(u64)==8 );
assert( sizeof(u32)==4 );
assert( sizeof(u16)==2 );
assert( sizeof(Pgno)==4 );
@@ -1956,6 +2295,9 @@ int sqlite3BtreeOpen(
#ifdef SQLITE_SECURE_DELETE
pBt->btsFlags |= BTS_SECURE_DELETE;
#endif
+ /* EVIDENCE-OF: R-51873-39618 The page size for a database file is
+ ** determined by the 2-byte integer located at an offset of 16 bytes from
+ ** the beginning of the database file. */
pBt->pageSize = (zDbHeader[16]<<8) | (zDbHeader[17]<<16);
if( pBt->pageSize<512 || pBt->pageSize>SQLITE_MAX_PAGE_SIZE
|| ((pBt->pageSize-1)&pBt->pageSize)!=0 ){
@@ -1974,6 +2316,9 @@ int sqlite3BtreeOpen(
#endif
nReserve = 0;
}else{
+ /* EVIDENCE-OF: R-37497-42412 The size of the reserved region is
+ ** determined by the one-byte unsigned integer found at an offset of 20
+ ** into the database file header. */
nReserve = zDbHeader[20];
pBt->btsFlags |= BTS_PAGESIZE_FIXED;
#ifndef SQLITE_OMIT_AUTOVACUUM
@@ -2207,19 +2552,11 @@ int sqlite3BtreeClose(Btree *p){
}
/*
-** Change the limit on the number of pages allowed in the cache.
-**
-** The maximum number of cache pages is set to the absolute
-** value of mxPage. If mxPage is negative, the pager will
-** operate asynchronously - it will not stop to do fsync()s
-** to insure data is written to the disk surface before
-** continuing. Transactions still work if synchronous is off,
-** and the database cannot be corrupted if this program
-** crashes. But if the operating system crashes or there is
-** an abrupt power failure when synchronous is off, the database
-** could be left in an inconsistent and unrecoverable state.
-** Synchronous is on by default so database corruption is not
-** normally a worry.
+** Change the "soft" limit on the number of pages in the cache.
+** Unused and unmodified pages will be recycled when the number of
+** pages in the cache exceeds this soft limit. But the size of the
+** cache is allowed to grow larger than this limit if it contains
+** dirty pages or pages still in active use.
*/
int sqlite3BtreeSetCacheSize(Btree *p, int mxPage){
BtShared *pBt = p->pBt;
@@ -2230,6 +2567,26 @@ int sqlite3BtreeSetCacheSize(Btree *p, int mxPage){
return SQLITE_OK;
}
+/*
+** Change the "spill" limit on the number of pages in the cache.
+** If the number of pages exceeds this limit during a write transaction,
+** the pager might attempt to "spill" pages to the journal early in
+** order to free up memory.
+**
+** The value returned is the current spill size. If zero is passed
+** as an argument, no changes are made to the spill size setting, so
+** using mxPage of 0 is a way to query the current spill size.
+*/
+int sqlite3BtreeSetSpillSize(Btree *p, int mxPage){
+ BtShared *pBt = p->pBt;
+ int res;
+ assert( sqlite3_mutex_held(p->db->mutex) );
+ sqlite3BtreeEnter(p);
+ res = sqlite3PagerSetSpillsize(pBt->pPager, mxPage);
+ sqlite3BtreeLeave(p);
+ return res;
+}
+
#if SQLITE_MAX_MMAP_SIZE>0
/*
** Change the limit on the amount of the database file that may be
@@ -2307,6 +2664,9 @@ int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve, int iFix){
BtShared *pBt = p->pBt;
assert( nReserve>=-1 && nReserve<=255 );
sqlite3BtreeEnter(p);
+#if SQLITE_HAS_CODEC
+ if( nReserve>pBt->optimalReserve ) pBt->optimalReserve = (u8)nReserve;
+#endif
if( pBt->btsFlags & BTS_PAGESIZE_FIXED ){
sqlite3BtreeLeave(p);
return SQLITE_READONLY;
@@ -2318,7 +2678,7 @@ int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve, int iFix){
if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE &&
((pageSize-1)&pageSize)==0 ){
assert( (pageSize & 7)==0 );
- assert( !pBt->pPage1 && !pBt->pCursor );
+ assert( !pBt->pCursor );
pBt->pageSize = (u32)pageSize;
freeTempSpace(pBt);
}
@@ -2336,7 +2696,6 @@ int sqlite3BtreeGetPageSize(Btree *p){
return p->pBt->pageSize;
}
-#if defined(SQLITE_HAS_CODEC) || defined(SQLITE_DEBUG)
/*
** This function is similar to sqlite3BtreeGetReserve(), except that it
** may only be called if it is guaranteed that the b-tree mutex is already
@@ -2349,25 +2708,33 @@ int sqlite3BtreeGetPageSize(Btree *p){
** database handle that owns *p, causing undefined behavior.
*/
int sqlite3BtreeGetReserveNoMutex(Btree *p){
+ int n;
assert( sqlite3_mutex_held(p->pBt->mutex) );
- return p->pBt->pageSize - p->pBt->usableSize;
+ n = p->pBt->pageSize - p->pBt->usableSize;
+ return n;
}
-#endif /* SQLITE_HAS_CODEC || SQLITE_DEBUG */
-#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM)
/*
** Return the number of bytes of space at the end of every page that
** are intentually left unused. This is the "reserved" space that is
** sometimes used by extensions.
+**
+** If SQLITE_HAS_MUTEX is defined then the number returned is the
+** greater of the current reserved space and the maximum requested
+** reserve space.
*/
-int sqlite3BtreeGetReserve(Btree *p){
+int sqlite3BtreeGetOptimalReserve(Btree *p){
int n;
sqlite3BtreeEnter(p);
- n = p->pBt->pageSize - p->pBt->usableSize;
+ n = sqlite3BtreeGetReserveNoMutex(p);
+#ifdef SQLITE_HAS_CODEC
+ if( n<p->pBt->optimalReserve ) n = p->pBt->optimalReserve;
+#endif
sqlite3BtreeLeave(p);
return n;
}
+
/*
** Set the maximum page count for a database if mxPage is positive.
** No changes are made if mxPage is 0 or negative.
@@ -2398,7 +2765,6 @@ int sqlite3BtreeSecureDelete(Btree *p, int newFlag){
sqlite3BtreeLeave(p);
return b;
}
-#endif /* !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM) */
/*
** Change the 'auto-vacuum' property of the database. If the 'autoVacuum'
@@ -2483,6 +2849,9 @@ static int lockBtree(BtShared *pBt){
u32 usableSize;
u8 *page1 = pPage1->aData;
rc = SQLITE_NOTADB;
+ /* EVIDENCE-OF: R-43737-39999 Every valid SQLite database file begins
+ ** with the following 16 bytes (in hex): 53 51 4c 69 74 65 20 66 6f 72 6d
+ ** 61 74 20 33 00. */
if( memcmp(page1, zMagicHeader, 16)!=0 ){
goto page1_init_failed;
}
@@ -2523,15 +2892,21 @@ static int lockBtree(BtShared *pBt){
}
#endif
- /* The maximum embedded fraction must be exactly 25%. And the minimum
- ** embedded fraction must be 12.5% for both leaf-data and non-leaf-data.
+ /* EVIDENCE-OF: R-15465-20813 The maximum and minimum embedded payload
+ ** fractions and the leaf payload fraction values must be 64, 32, and 32.
+ **
** The original design allowed these amounts to vary, but as of
** version 3.6.0, we require them to be fixed.
*/
if( memcmp(&page1[21], "\100\040\040",3)!=0 ){
goto page1_init_failed;
}
+ /* EVIDENCE-OF: R-51873-39618 The page size for a database file is
+ ** determined by the 2-byte integer located at an offset of 16 bytes from
+ ** the beginning of the database file. */
pageSize = (page1[16]<<8) | (page1[17]<<16);
+ /* EVIDENCE-OF: R-25008-21688 The size of a page is a power of two
+ ** between 512 and 65536 inclusive. */
if( ((pageSize-1)&pageSize)!=0
|| pageSize>SQLITE_MAX_PAGE_SIZE
|| pageSize<=256
@@ -2539,6 +2914,13 @@ static int lockBtree(BtShared *pBt){
goto page1_init_failed;
}
assert( (pageSize & 7)==0 );
+ /* EVIDENCE-OF: R-59310-51205 The "reserved space" size in the 1-byte
+ ** integer at offset 20 is the number of bytes of space at the end of
+ ** each page to reserve for extensions.
+ **
+ ** EVIDENCE-OF: R-37497-42412 The size of the reserved region is
+ ** determined by the one-byte unsigned integer found at an offset of 20
+ ** into the database file header. */
usableSize = pageSize - page1[20];
if( (u32)pageSize!=pBt->pageSize ){
/* After reading the first page of the database assuming a page size
@@ -2559,6 +2941,9 @@ static int lockBtree(BtShared *pBt){
rc = SQLITE_CORRUPT_BKPT;
goto page1_init_failed;
}
+ /* EVIDENCE-OF: R-28312-64704 However, the usable size is not allowed to
+ ** be less than 480. In other words, if the page size is 512, then the
+ ** reserved space size cannot exceed 32. */
if( usableSize<480 ){
goto page1_init_failed;
}
@@ -2643,7 +3028,7 @@ static void unlockBtreeIfUnused(BtShared *pBt){
assert( pPage1->aData );
assert( sqlite3PagerRefcount(pBt->pPager)==1 );
pBt->pPage1 = 0;
- releasePage(pPage1);
+ releasePageNotNull(pPage1);
}
}
@@ -2948,20 +3333,22 @@ static int modifyPagePointer(MemPage *pPage, Pgno iFrom, Pgno iTo, u8 eType){
u8 isInitOrig = pPage->isInit;
int i;
int nCell;
+ int rc;
- btreeInitPage(pPage);
+ rc = btreeInitPage(pPage);
+ if( rc ) return rc;
nCell = pPage->nCell;
for(i=0; i<nCell; i++){
u8 *pCell = findCell(pPage, i);
if( eType==PTRMAP_OVERFLOW1 ){
CellInfo info;
- btreeParseCellPtr(pPage, pCell, &info);
- if( info.iOverflow
- && pCell+info.iOverflow+3<=pPage->aData+pPage->maskPage
- && iFrom==get4byte(&pCell[info.iOverflow])
+ pPage->xParseCell(pPage, pCell, &info);
+ if( info.nLocal<info.nPayload
+ && pCell+info.nSize-1<=pPage->aData+pPage->maskPage
+ && iFrom==get4byte(pCell+info.nSize-4)
){
- put4byte(&pCell[info.iOverflow], iTo);
+ put4byte(pCell+info.nSize-4, iTo);
break;
}
}else{
@@ -3255,7 +3642,7 @@ int sqlite3BtreeIncrVacuum(Btree *p){
static int autoVacuumCommit(BtShared *pBt){
int rc = SQLITE_OK;
Pager *pPager = pBt->pPager;
- VVA_ONLY( int nRef = sqlite3PagerRefcount(pPager) );
+ VVA_ONLY( int nRef = sqlite3PagerRefcount(pPager); )
assert( sqlite3_mutex_held(pBt->mutex) );
invalidateAllOverflowCache(pBt);
@@ -3439,6 +3826,7 @@ int sqlite3BtreeCommitPhaseTwo(Btree *p, int bCleanup){
sqlite3BtreeLeave(p);
return rc;
}
+ p->iDataVersion--; /* Compensate for pPager->iDataVersion++; */
pBt->inTransaction = TRANS_READ;
btreeClearHasContent(pBt);
}
@@ -3498,7 +3886,7 @@ int sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode, int writeOnly){
for(p=pBtree->pBt->pCursor; p; p=p->pNext){
int i;
if( writeOnly && (p->curFlags & BTCF_WriteFlag)==0 ){
- if( p->eState==CURSOR_VALID ){
+ if( p->eState==CURSOR_VALID || p->eState==CURSOR_SKIPNEXT ){
rc = saveCursorPosition(p);
if( rc!=SQLITE_OK ){
(void)sqlite3BtreeTripAllCursors(pBtree, rc, 0);
@@ -3696,25 +4084,27 @@ static int btreeCursor(
BtCursor *pCur /* Space for new cursor */
){
BtShared *pBt = p->pBt; /* Shared b-tree handle */
+ BtCursor *pX; /* Looping over other all cursors */
assert( sqlite3BtreeHoldsMutex(p) );
- assert( wrFlag==0 || wrFlag==1 );
+ assert( wrFlag==0
+ || wrFlag==BTREE_WRCSR
+ || wrFlag==(BTREE_WRCSR|BTREE_FORDELETE)
+ );
/* The following assert statements verify that if this is a sharable
** b-tree database, the connection is holding the required table locks,
** and that no other connection has any open cursor that conflicts with
** this lock. */
- assert( hasSharedCacheTableLock(p, iTable, pKeyInfo!=0, wrFlag+1) );
+ assert( hasSharedCacheTableLock(p, iTable, pKeyInfo!=0, (wrFlag?2:1)) );
assert( wrFlag==0 || !hasReadConflicts(p, iTable) );
/* Assert that the caller has opened the required transaction. */
assert( p->inTrans>TRANS_NONE );
assert( wrFlag==0 || p->inTrans==TRANS_WRITE );
assert( pBt->pPage1 && pBt->pPage1->aData );
+ assert( wrFlag==0 || (pBt->btsFlags & BTS_READ_ONLY)==0 );
- if( NEVER(wrFlag && (pBt->btsFlags & BTS_READ_ONLY)!=0) ){
- return SQLITE_READONLY;
- }
if( wrFlag ){
allocateTempSpace(pBt);
if( pBt->pTmpSpace==0 ) return SQLITE_NOMEM;
@@ -3731,12 +4121,17 @@ static int btreeCursor(
pCur->pKeyInfo = pKeyInfo;
pCur->pBtree = p;
pCur->pBt = pBt;
- assert( wrFlag==0 || wrFlag==BTCF_WriteFlag );
- pCur->curFlags = wrFlag;
- pCur->pNext = pBt->pCursor;
- if( pCur->pNext ){
- pCur->pNext->pPrev = pCur;
+ pCur->curFlags = wrFlag ? BTCF_WriteFlag : 0;
+ pCur->curPagerFlags = wrFlag ? 0 : PAGER_GET_READONLY;
+ /* If there are two or more cursors on the same btree, then all such
+ ** cursors *must* have the BTCF_Multiple flag set. */
+ for(pX=pBt->pCursor; pX; pX=pX->pNext){
+ if( pX->pgnoRoot==(Pgno)iTable ){
+ pX->curFlags |= BTCF_Multiple;
+ pCur->curFlags |= BTCF_Multiple;
+ }
}
+ pCur->pNext = pBt->pCursor;
pBt->pCursor = pCur;
pCur->eState = CURSOR_INVALID;
return SQLITE_OK;
@@ -3749,9 +4144,13 @@ int sqlite3BtreeCursor(
BtCursor *pCur /* Write new cursor here */
){
int rc;
- sqlite3BtreeEnter(p);
- rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, pCur);
- sqlite3BtreeLeave(p);
+ if( iTable<1 ){
+ rc = SQLITE_CORRUPT_BKPT;
+ }else{
+ sqlite3BtreeEnter(p);
+ rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, pCur);
+ sqlite3BtreeLeave(p);
+ }
return rc;
}
@@ -3790,19 +4189,24 @@ int sqlite3BtreeCloseCursor(BtCursor *pCur){
BtShared *pBt = pCur->pBt;
sqlite3BtreeEnter(pBtree);
sqlite3BtreeClearCursor(pCur);
- if( pCur->pPrev ){
- pCur->pPrev->pNext = pCur->pNext;
- }else{
+ assert( pBt->pCursor!=0 );
+ if( pBt->pCursor==pCur ){
pBt->pCursor = pCur->pNext;
- }
- if( pCur->pNext ){
- pCur->pNext->pPrev = pCur->pPrev;
+ }else{
+ BtCursor *pPrev = pBt->pCursor;
+ do{
+ if( pPrev->pNext==pCur ){
+ pPrev->pNext = pCur->pNext;
+ break;
+ }
+ pPrev = pPrev->pNext;
+ }while( ALWAYS(pPrev) );
}
for(i=0; i<=pCur->iPage; i++){
releasePage(pCur->apPage[i]);
}
unlockBtreeIfUnused(pBt);
- sqlite3DbFree(pBtree->db, pCur->aOverflow);
+ sqlite3_free(pCur->aOverflow);
/* sqlite3_free(pCur); */
sqlite3BtreeLeave(pBtree);
}
@@ -3816,13 +4220,6 @@ int sqlite3BtreeCloseCursor(BtCursor *pCur){
**
** BtCursor.info is a cache of the information in the current cell.
** Using this cache reduces the number of calls to btreeParseCell().
-**
-** 2007-06-25: There is a bug in some versions of MSVC that cause the
-** compiler to crash when getCellInfo() is implemented as a macro.
-** But there is a measureable speed advantage to using the macro on gcc
-** (when less compiler optimizations like -Os or -O0 are used and the
-** compiler is not doing aggressive inlining.) So we use a real function
-** for MSVC and a macro for everything else. Ticket #2457.
*/
#ifndef NDEBUG
static void assertCellInfo(BtCursor *pCur){
@@ -3835,28 +4232,15 @@ int sqlite3BtreeCloseCursor(BtCursor *pCur){
#else
#define assertCellInfo(x)
#endif
-#ifdef _MSC_VER
- /* Use a real function in MSVC to work around bugs in that compiler. */
- static void getCellInfo(BtCursor *pCur){
- if( pCur->info.nSize==0 ){
- int iPage = pCur->iPage;
- btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info);
- pCur->curFlags |= BTCF_ValidNKey;
- }else{
- assertCellInfo(pCur);
- }
- }
-#else /* if not _MSC_VER */
- /* Use a macro in all other compilers so that the function is inlined */
-#define getCellInfo(pCur) \
- if( pCur->info.nSize==0 ){ \
- int iPage = pCur->iPage; \
- btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info); \
- pCur->curFlags |= BTCF_ValidNKey; \
- }else{ \
- assertCellInfo(pCur); \
+static SQLITE_NOINLINE void getCellInfo(BtCursor *pCur){
+ if( pCur->info.nSize==0 ){
+ int iPage = pCur->iPage;
+ pCur->curFlags |= BTCF_ValidNKey;
+ btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info);
+ }else{
+ assertCellInfo(pCur);
}
-#endif /* _MSC_VER */
+}
#ifndef NDEBUG /* The next routine used only within assert() statements */
/*
@@ -3904,6 +4288,8 @@ int sqlite3BtreeKeySize(BtCursor *pCur, i64 *pSize){
int sqlite3BtreeDataSize(BtCursor *pCur, u32 *pSize){
assert( cursorHoldsMutex(pCur) );
assert( pCur->eState==CURSOR_VALID );
+ assert( pCur->iPage>=0 );
+ assert( pCur->iPage<BTCURSOR_MAX_DEPTH );
assert( pCur->apPage[pCur->iPage]->intKeyLeaf==1 );
getCellInfo(pCur);
*pSize = pCur->info.nPayload;
@@ -4097,6 +4483,7 @@ static int accessPayload(
offset -= pCur->info.nLocal;
}
+
if( rc==SQLITE_OK && amt>0 ){
const u32 ovflSize = pBt->usableSize - 4; /* Bytes content per ovfl page */
Pgno nextPage;
@@ -4114,8 +4501,8 @@ static int accessPayload(
if( eOp!=2 && (pCur->curFlags & BTCF_ValidOvfl)==0 ){
int nOvfl = (pCur->info.nPayload-pCur->info.nLocal+ovflSize-1)/ovflSize;
if( nOvfl>pCur->nOvflAlloc ){
- Pgno *aNew = (Pgno*)sqlite3DbRealloc(
- pCur->pBtree->db, pCur->aOverflow, nOvfl*2*sizeof(Pgno)
+ Pgno *aNew = (Pgno*)sqlite3Realloc(
+ pCur->aOverflow, nOvfl*2*sizeof(Pgno)
);
if( aNew==0 ){
rc = SQLITE_NOMEM;
@@ -4146,7 +4533,9 @@ static int accessPayload(
/* If required, populate the overflow page-list cache. */
if( (pCur->curFlags & BTCF_ValidOvfl)!=0 ){
- assert(!pCur->aOverflow[iIdx] || pCur->aOverflow[iIdx]==nextPage);
+ assert( pCur->aOverflow[iIdx]==0
+ || pCur->aOverflow[iIdx]==nextPage
+ || CORRUPT_DB );
pCur->aOverflow[iIdx] = nextPage;
}
@@ -4162,6 +4551,7 @@ static int accessPayload(
*/
assert( eOp!=2 );
assert( pCur->curFlags & BTCF_ValidOvfl );
+ assert( pCur->pBtree->db==pBt->db );
if( pCur->aOverflow[iIdx+1] ){
nextPage = pCur->aOverflow[iIdx+1];
}else{
@@ -4215,7 +4605,7 @@ static int accessPayload(
{
DbPage *pDbPage;
- rc = sqlite3PagerAcquire(pBt->pPager, nextPage, &pDbPage,
+ rc = sqlite3PagerGet(pBt->pPager, nextPage, &pDbPage,
((eOp&0x01)==0 ? PAGER_GET_READONLY : 0)
);
if( rc==SQLITE_OK ){
@@ -4310,13 +4700,18 @@ static const void *fetchPayload(
BtCursor *pCur, /* Cursor pointing to entry to read from */
u32 *pAmt /* Write the number of available bytes here */
){
+ u32 amt;
assert( pCur!=0 && pCur->iPage>=0 && pCur->apPage[pCur->iPage]);
assert( pCur->eState==CURSOR_VALID );
assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
assert( cursorHoldsMutex(pCur) );
assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
assert( pCur->info.nSize>0 );
- *pAmt = pCur->info.nLocal;
+ assert( pCur->info.pPayload>pCur->apPage[pCur->iPage]->aData || CORRUPT_DB );
+ assert( pCur->info.pPayload<pCur->apPage[pCur->iPage]->aDataEnd ||CORRUPT_DB);
+ amt = (int)(pCur->apPage[pCur->iPage]->aDataEnd - pCur->info.pPayload);
+ if( pCur->info.nLocal<amt ) amt = pCur->info.nLocal;
+ *pAmt = amt;
return (void*)pCur->info.pPayload;
}
@@ -4353,9 +4748,6 @@ const void *sqlite3BtreeDataFetch(BtCursor *pCur, u32 *pAmt){
** vice-versa).
*/
static int moveToChild(BtCursor *pCur, u32 newPgno){
- int rc;
- int i = pCur->iPage;
- MemPage *pNewPage;
BtShared *pBt = pCur->pBt;
assert( cursorHoldsMutex(pCur) );
@@ -4365,22 +4757,15 @@ static int moveToChild(BtCursor *pCur, u32 newPgno){
if( pCur->iPage>=(BTCURSOR_MAX_DEPTH-1) ){
return SQLITE_CORRUPT_BKPT;
}
- rc = getAndInitPage(pBt, newPgno, &pNewPage,
- (pCur->curFlags & BTCF_WriteFlag)==0 ? PAGER_GET_READONLY : 0);
- if( rc ) return rc;
- pCur->apPage[i+1] = pNewPage;
- pCur->aiIdx[i+1] = 0;
- pCur->iPage++;
-
pCur->info.nSize = 0;
pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
- if( pNewPage->nCell<1 || pNewPage->intKey!=pCur->apPage[i]->intKey ){
- return SQLITE_CORRUPT_BKPT;
- }
- return SQLITE_OK;
+ pCur->iPage++;
+ pCur->aiIdx[pCur->iPage] = 0;
+ return getAndInitPage(pBt, newPgno, &pCur->apPage[pCur->iPage],
+ pCur, pCur->curPagerFlags);
}
-#if 0
+#if SQLITE_DEBUG
/*
** Page pParent is an internal (non-leaf) tree page. This function
** asserts that page number iChild is the left-child if the iIdx'th
@@ -4389,6 +4774,8 @@ static int moveToChild(BtCursor *pCur, u32 newPgno){
** the page.
*/
static void assertParentIndex(MemPage *pParent, int iIdx, Pgno iChild){
+ if( CORRUPT_DB ) return; /* The conditions tested below might not be true
+ ** in a corrupt database */
assert( iIdx<=pParent->nCell );
if( iIdx==pParent->nCell ){
assert( get4byte(&pParent->aData[pParent->hdrOffset+8])==iChild );
@@ -4413,25 +4800,15 @@ static void moveToParent(BtCursor *pCur){
assert( pCur->eState==CURSOR_VALID );
assert( pCur->iPage>0 );
assert( pCur->apPage[pCur->iPage] );
-
- /* UPDATE: It is actually possible for the condition tested by the assert
- ** below to be untrue if the database file is corrupt. This can occur if
- ** one cursor has modified page pParent while a reference to it is held
- ** by a second cursor. Which can only happen if a single page is linked
- ** into more than one b-tree structure in a corrupt database. */
-#if 0
assertParentIndex(
pCur->apPage[pCur->iPage-1],
pCur->aiIdx[pCur->iPage-1],
pCur->apPage[pCur->iPage]->pgno
);
-#endif
testcase( pCur->aiIdx[pCur->iPage-1] > pCur->apPage[pCur->iPage-1]->nCell );
-
- releasePage(pCur->apPage[pCur->iPage]);
- pCur->iPage--;
pCur->info.nSize = 0;
pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
+ releasePageNotNull(pCur->apPage[pCur->iPage--]);
}
/*
@@ -4472,18 +4849,23 @@ static int moveToRoot(BtCursor *pCur){
}
if( pCur->iPage>=0 ){
- while( pCur->iPage ) releasePage(pCur->apPage[pCur->iPage--]);
+ while( pCur->iPage ){
+ assert( pCur->apPage[pCur->iPage]!=0 );
+ releasePageNotNull(pCur->apPage[pCur->iPage--]);
+ }
}else if( pCur->pgnoRoot==0 ){
pCur->eState = CURSOR_INVALID;
return SQLITE_OK;
}else{
+ assert( pCur->iPage==(-1) );
rc = getAndInitPage(pCur->pBtree->pBt, pCur->pgnoRoot, &pCur->apPage[0],
- (pCur->curFlags & BTCF_WriteFlag)==0 ? PAGER_GET_READONLY : 0);
+ 0, pCur->curPagerFlags);
if( rc!=SQLITE_OK ){
pCur->eState = CURSOR_INVALID;
return rc;
}
pCur->iPage = 0;
+ pCur->curIntKey = pCur->apPage[0]->intKey;
}
pRoot = pCur->apPage[0];
assert( pRoot->pgno==pCur->pgnoRoot );
@@ -4667,6 +5049,8 @@ int sqlite3BtreeLast(BtCursor *pCur, int *pRes){
** *pRes>0 The cursor is left pointing at an entry that
** is larger than intKey/pIdxKey.
**
+** For index tables, the pIdxKey->eqSeen field is set to 1 if there
+** exists an entry in the table that exactly matches pIdxKey.
*/
int sqlite3BtreeMovetoUnpacked(
BtCursor *pCur, /* The cursor to be moved */
@@ -4686,7 +5070,7 @@ int sqlite3BtreeMovetoUnpacked(
/* If the cursor is already positioned at the point we are trying
** to move to, then just return without doing any work */
if( pCur->eState==CURSOR_VALID && (pCur->curFlags & BTCF_ValidNKey)!=0
- && pCur->apPage[0]->intKey
+ && pCur->curIntKey
){
if( pCur->info.nKey==intKey ){
*pRes = 0;
@@ -4721,7 +5105,8 @@ int sqlite3BtreeMovetoUnpacked(
assert( pCur->pgnoRoot==0 || pCur->apPage[pCur->iPage]->nCell==0 );
return SQLITE_OK;
}
- assert( pCur->apPage[0]->intKey || pIdxKey );
+ assert( pCur->apPage[0]->intKey==pCur->curIntKey );
+ assert( pCur->curIntKey || pIdxKey );
for(;;){
int lwr, upr, idx, c;
Pgno chldPg;
@@ -4744,7 +5129,7 @@ int sqlite3BtreeMovetoUnpacked(
if( xRecordCompare==0 ){
for(;;){
i64 nCellKey;
- pCell = findCell(pPage, idx) + pPage->childPtrSize;
+ pCell = findCellPastPtr(pPage, idx);
if( pPage->intKeyLeaf ){
while( 0x80 <= *(pCell++) ){
if( pCell>=pPage->aDataEnd ) return SQLITE_CORRUPT_BKPT;
@@ -4776,8 +5161,8 @@ int sqlite3BtreeMovetoUnpacked(
}
}else{
for(;;){
- int nCell;
- pCell = findCell(pPage, idx) + pPage->childPtrSize;
+ int nCell; /* Size of the pCell cell in bytes */
+ pCell = findCellPastPtr(pPage, idx);
/* The maximum supported page-size is 65536 bytes. This means that
** the maximum number of record bytes stored on an index B-Tree
@@ -4805,12 +5190,25 @@ int sqlite3BtreeMovetoUnpacked(
/* The record flows over onto one or more overflow pages. In
** this case the whole cell needs to be parsed, a buffer allocated
** and accessPayload() used to retrieve the record into the
- ** buffer before VdbeRecordCompare() can be called. */
+ ** buffer before VdbeRecordCompare() can be called.
+ **
+ ** If the record is corrupt, the xRecordCompare routine may read
+ ** up to two varints past the end of the buffer. An extra 18
+ ** bytes of padding is allocated at the end of the buffer in
+ ** case this happens. */
void *pCellKey;
u8 * const pCellBody = pCell - pPage->childPtrSize;
- btreeParseCellPtr(pPage, pCellBody, &pCur->info);
+ pPage->xParseCell(pPage, pCellBody, &pCur->info);
nCell = (int)pCur->info.nKey;
- pCellKey = sqlite3Malloc( nCell );
+ testcase( nCell<0 ); /* True if key size is 2^32 or more */
+ testcase( nCell==0 ); /* Invalid key size: 0x80 0x80 0x00 */
+ testcase( nCell==1 ); /* Invalid key size: 0x80 0x80 0x01 */
+ testcase( nCell==2 ); /* Minimum legal index key size */
+ if( nCell<2 ){
+ rc = SQLITE_CORRUPT_BKPT;
+ goto moveto_finish;
+ }
+ pCellKey = sqlite3Malloc( nCell+18 );
if( pCellKey==0 ){
rc = SQLITE_NOMEM;
goto moveto_finish;
@@ -5103,8 +5501,7 @@ int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
** sqlite3PagerUnref() on the new page when it is done.
**
** SQLITE_OK is returned on success. Any other return value indicates
-** an error. *ppPage and *pPgno are undefined in the event of an error.
-** Do not invoke sqlite3PagerUnref() on *ppPage if an error is returned.
+** an error. *ppPage is set to NULL in the event of an error.
**
** If the "nearby" parameter is not 0, then an effort is made to
** locate a page close to the page number "nearby". This can be used in an
@@ -5136,6 +5533,8 @@ static int allocateBtreePage(
assert( eMode==BTALLOC_ANY || (nearby>0 && IfNotOmitAV(pBt->autoVacuum)) );
pPage1 = pBt->pPage1;
mxPage = btreePagecount(pBt);
+ /* EVIDENCE-OF: R-05119-02637 The 4-byte big-endian integer at offset 36
+ ** stores stores the total number of pages on the freelist. */
n = get4byte(&pPage1->aData[36]);
testcase( n==mxPage-1 );
if( n>=mxPage ){
@@ -5145,6 +5544,7 @@ static int allocateBtreePage(
/* There are pages on the freelist. Reuse one of those pages. */
Pgno iTrunk;
u8 searchList = 0; /* If the free-list must be searched for 'nearby' */
+ u32 nSearch = 0; /* Count of the number of search attempts */
/* If eMode==BTALLOC_EXACT and a query of the pointer-map
** shows that the page 'nearby' is somewhere on the free-list, then
@@ -5182,15 +5582,21 @@ static int allocateBtreePage(
do {
pPrevTrunk = pTrunk;
if( pPrevTrunk ){
+ /* EVIDENCE-OF: R-01506-11053 The first integer on a freelist trunk page
+ ** is the page number of the next freelist trunk page in the list or
+ ** zero if this is the last freelist trunk page. */
iTrunk = get4byte(&pPrevTrunk->aData[0]);
}else{
+ /* EVIDENCE-OF: R-59841-13798 The 4-byte big-endian integer at offset 32
+ ** stores the page number of the first page of the freelist, or zero if
+ ** the freelist is empty. */
iTrunk = get4byte(&pPage1->aData[32]);
}
testcase( iTrunk==mxPage );
- if( iTrunk>mxPage ){
+ if( iTrunk>mxPage || nSearch++ > n ){
rc = SQLITE_CORRUPT_BKPT;
}else{
- rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
+ rc = btreeGetUnusedPage(pBt, iTrunk, &pTrunk, 0);
}
if( rc ){
pTrunk = 0;
@@ -5198,8 +5604,9 @@ static int allocateBtreePage(
}
assert( pTrunk!=0 );
assert( pTrunk->aData!=0 );
-
- k = get4byte(&pTrunk->aData[4]); /* # of leaves on this trunk page */
+ /* EVIDENCE-OF: R-13523-04394 The second integer on a freelist trunk page
+ ** is the number of leaf page pointers to follow. */
+ k = get4byte(&pTrunk->aData[4]);
if( k==0 && !searchList ){
/* The trunk has no leaves and the list is not being searched.
** So extract the trunk page itself and use it as the newly
@@ -5254,7 +5661,7 @@ static int allocateBtreePage(
goto end_allocate_page;
}
testcase( iNewTrunk==mxPage );
- rc = btreeGetPage(pBt, iNewTrunk, &pNewTrunk, 0);
+ rc = btreeGetUnusedPage(pBt, iNewTrunk, &pNewTrunk, 0);
if( rc!=SQLITE_OK ){
goto end_allocate_page;
}
@@ -5334,11 +5741,12 @@ static int allocateBtreePage(
}
put4byte(&aData[4], k-1);
noContent = !btreeGetHasContent(pBt, *pPgno)? PAGER_GET_NOCONTENT : 0;
- rc = btreeGetPage(pBt, *pPgno, ppPage, noContent);
+ rc = btreeGetUnusedPage(pBt, *pPgno, ppPage, noContent);
if( rc==SQLITE_OK ){
rc = sqlite3PagerWrite((*ppPage)->pDbPage);
if( rc!=SQLITE_OK ){
releasePage(*ppPage);
+ *ppPage = 0;
}
}
searchList = 0;
@@ -5382,7 +5790,7 @@ 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 = btreeGetUnusedPage(pBt, pBt->nPage, &pPg, bNoContent);
if( rc==SQLITE_OK ){
rc = sqlite3PagerWrite(pPg->pDbPage);
releasePage(pPg);
@@ -5396,11 +5804,12 @@ static int allocateBtreePage(
*pPgno = pBt->nPage;
assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
- rc = btreeGetPage(pBt, *pPgno, ppPage, bNoContent);
+ rc = btreeGetUnusedPage(pBt, *pPgno, ppPage, bNoContent);
if( rc ) return rc;
rc = sqlite3PagerWrite((*ppPage)->pDbPage);
if( rc!=SQLITE_OK ){
releasePage(*ppPage);
+ *ppPage = 0;
}
TRACE(("ALLOCATE: %d from end of file\n", *pPgno));
}
@@ -5410,17 +5819,8 @@ static int allocateBtreePage(
end_allocate_page:
releasePage(pTrunk);
releasePage(pPrevTrunk);
- if( rc==SQLITE_OK ){
- if( sqlite3PagerPageRefcount((*ppPage)->pDbPage)>1 ){
- releasePage(*ppPage);
- *ppPage = 0;
- return SQLITE_CORRUPT_BKPT;
- }
- (*ppPage)->isInit = 0;
- }else{
- *ppPage = 0;
- }
- assert( rc!=SQLITE_OK || sqlite3PagerIswriteable((*ppPage)->pDbPage) );
+ assert( rc!=SQLITE_OK || sqlite3PagerPageRefcount((*ppPage)->pDbPage)<=1 );
+ assert( rc!=SQLITE_OK || (*ppPage)->isInit==0 );
return rc;
}
@@ -5445,9 +5845,10 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
int nFree; /* Initial number of pages on free-list */
assert( sqlite3_mutex_held(pBt->mutex) );
- assert( iPage>1 );
+ assert( CORRUPT_DB || iPage>1 );
assert( !pMemPage || pMemPage->pgno==iPage );
+ if( iPage<2 ) return SQLITE_CORRUPT_BKPT;
if( pMemPage ){
pPage = pMemPage;
sqlite3PagerRef(pPage->pDbPage);
@@ -5517,6 +5918,11 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
** for now. At some point in the future (once everyone has upgraded
** to 3.6.0 or later) we should consider fixing the conditional above
** to read "usableSize/4-2" instead of "usableSize/4-8".
+ **
+ ** EVIDENCE-OF: R-19920-11576 However, newer versions of SQLite still
+ ** avoid using the last six entries in the freelist trunk page array in
+ ** order that database files created by newer versions of SQLite can be
+ ** read by older versions of SQLite.
*/
rc = sqlite3PagerWrite(pTrunk->pDbPage);
if( rc==SQLITE_OK ){
@@ -5582,19 +5988,21 @@ static int clearCell(
u32 ovflPageSize;
assert( sqlite3_mutex_held(pPage->pBt->mutex) );
- btreeParseCellPtr(pPage, pCell, &info);
+ pPage->xParseCell(pPage, pCell, &info);
*pnSize = info.nSize;
- if( info.iOverflow==0 ){
+ if( info.nLocal==info.nPayload ){
return SQLITE_OK; /* No overflow pages. Return without doing anything */
}
- if( pCell+info.iOverflow+3 > pPage->aData+pPage->maskPage ){
+ if( pCell+info.nSize-1 > pPage->aData+pPage->maskPage ){
return SQLITE_CORRUPT_BKPT; /* Cell extends past end of page */
}
- ovflPgno = get4byte(&pCell[info.iOverflow]);
+ ovflPgno = get4byte(pCell + info.nSize - 4);
assert( pBt->usableSize > 4 );
ovflPageSize = pBt->usableSize - 4;
nOvfl = (info.nPayload - info.nLocal + ovflPageSize - 1)/ovflPageSize;
- assert( ovflPgno==0 || nOvfl>0 );
+ assert( nOvfl>0 ||
+ (CORRUPT_DB && (info.nPayload + ovflPageSize)<ovflPageSize)
+ );
while( nOvfl-- ){
Pgno iNext = 0;
MemPage *pOvfl = 0;
@@ -5692,9 +6100,7 @@ static int fillInCell(
nSrc = nData;
nData = 0;
}else{
- if( NEVER(nKey>0x7fffffff || pKey==0) ){
- return SQLITE_CORRUPT_BKPT;
- }
+ assert( nKey<=0x7fffffff && pKey!=0 );
nPayload = (int)nKey;
pSrc = pKey;
nSrc = (int)nKey;
@@ -5734,12 +6140,11 @@ static int fillInCell(
#if SQLITE_DEBUG
{
CellInfo info;
- btreeParseCellPtr(pPage, pCell, &info);
+ pPage->xParseCell(pPage, pCell, &info);
assert( nHeader=(int)(info.pPayload - pCell) );
assert( info.nKey==nKey );
assert( *pnSize == info.nSize );
assert( spaceLeft == info.nLocal );
- assert( pPrior == &pCell[info.iOverflow] );
}
#endif
@@ -5849,7 +6254,7 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
if( *pRC ) return;
assert( idx>=0 && idx<pPage->nCell );
- assert( sz==cellSize(pPage, idx) );
+ assert( CORRUPT_DB || sz==cellSize(pPage, idx) );
assert( sqlite3PagerIswriteable(pPage->pDbPage) );
assert( sqlite3_mutex_held(pPage->pBt->mutex) );
data = pPage->aData;
@@ -5868,9 +6273,17 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
return;
}
pPage->nCell--;
- memmove(ptr, ptr+2, 2*(pPage->nCell - idx));
- put2byte(&data[hdr+3], pPage->nCell);
- pPage->nFree += 2;
+ if( pPage->nCell==0 ){
+ memset(&data[hdr+1], 0, 4);
+ data[hdr+7] = 0;
+ put2byte(&data[hdr+5], pPage->pBt->usableSize);
+ pPage->nFree = pPage->pBt->usableSize - pPage->hdrOffset
+ - pPage->childPtrSize - 8;
+ }else{
+ memmove(ptr, ptr+2, 2*(pPage->nCell - idx));
+ put2byte(&data[hdr+3], pPage->nCell);
+ pPage->nFree += 2;
+ }
}
/*
@@ -5896,10 +6309,8 @@ static void insertCell(
){
int idx = 0; /* Where to write new cell content in data[] */
int j; /* Loop counter */
- int end; /* First byte past the last cell pointer in data[] */
- int ins; /* Index in data[] where new cell pointer is inserted */
- int cellOffset; /* Address of first cell pointer in data[] */
u8 *data; /* The content of the whole page */
+ u8 *pIns; /* The point in pPage->aCellIdx[] where no cell inserted */
if( *pRC ) return;
@@ -5914,7 +6325,7 @@ static void insertCell(
** wanted to be less than 4 but got rounded up to 4 on the leaf, then size
** might be less than 8 (leaf-size + pointer) on the interior node. Hence
** the term after the || in the following assert(). */
- assert( sz==cellSizePtr(pPage, pCell) || (sz==8 && iChild>0) );
+ assert( sz==pPage->xCellSize(pPage, pCell) || (sz==8 && iChild>0) );
if( pPage->nOverflow || sz+2>pPage->nFree ){
if( pTemp ){
memcpy(pTemp, pCell, sz);
@@ -5927,6 +6338,14 @@ static void insertCell(
assert( j<(int)(sizeof(pPage->apOvfl)/sizeof(pPage->apOvfl[0])) );
pPage->apOvfl[j] = pCell;
pPage->aiOvfl[j] = (u16)i;
+
+ /* When multiple overflows occur, they are always sequential and in
+ ** sorted order. This invariants arise because multiple overflows can
+ ** only occur when inserting divider cells into the parent page during
+ ** balancing, and the dividers are adjacent and sorted.
+ */
+ assert( j==0 || pPage->aiOvfl[j-1]<(u16)i ); /* Overflows in sorted order */
+ assert( j==0 || i==pPage->aiOvfl[j-1]+1 ); /* Overflows are sequential */
}else{
int rc = sqlite3PagerWrite(pPage->pDbPage);
if( rc!=SQLITE_OK ){
@@ -5935,24 +6354,26 @@ static void insertCell(
}
assert( sqlite3PagerIswriteable(pPage->pDbPage) );
data = pPage->aData;
- cellOffset = pPage->cellOffset;
- end = cellOffset + 2*pPage->nCell;
- ins = cellOffset + 2*i;
+ assert( &data[pPage->cellOffset]==pPage->aCellIdx );
rc = allocateSpace(pPage, sz, &idx);
if( rc ){ *pRC = rc; return; }
- /* The allocateSpace() routine guarantees the following two properties
- ** if it returns success */
- assert( idx >= end+2 );
+ /* The allocateSpace() routine guarantees the following properties
+ ** if it returns successfully */
+ assert( idx >= 0 );
+ assert( idx >= pPage->cellOffset+2*pPage->nCell+2 || CORRUPT_DB );
assert( idx+sz <= (int)pPage->pBt->usableSize );
- pPage->nCell++;
pPage->nFree -= (u16)(2 + sz);
memcpy(&data[idx], pCell, sz);
if( iChild ){
put4byte(&data[idx], iChild);
}
- memmove(&data[ins+2], &data[ins], end-ins);
- put2byte(&data[ins], idx);
- put2byte(&data[pPage->hdrOffset+3], pPage->nCell);
+ pIns = pPage->aCellIdx + i*2;
+ memmove(pIns+2, pIns, 2*(pPage->nCell - i));
+ put2byte(pIns, idx);
+ pPage->nCell++;
+ /* increment the cell count */
+ if( (++data[pPage->hdrOffset+4])==0 ) data[pPage->hdrOffset+3]++;
+ assert( get2byte(&data[pPage->hdrOffset+3])==pPage->nCell );
#ifndef SQLITE_OMIT_AUTOVACUUM
if( pPage->pBt->autoVacuum ){
/* The cell may contain a pointer to an overflow page. If so, write
@@ -5965,45 +6386,328 @@ static void insertCell(
}
/*
-** Add a list of cells to a page. The page should be initially empty.
-** The cells are guaranteed to fit on the page.
+** A CellArray object contains a cache of pointers and sizes for a
+** consecutive sequence of cells that might be held multiple pages.
*/
-static void assemblePage(
- MemPage *pPage, /* The page to be assembled */
- int nCell, /* The number of cells to add to this page */
- u8 **apCell, /* Pointers to cell bodies */
- u16 *aSize /* Sizes of the cells */
+typedef struct CellArray CellArray;
+struct CellArray {
+ int nCell; /* Number of cells in apCell[] */
+ MemPage *pRef; /* Reference page */
+ u8 **apCell; /* All cells begin balanced */
+ u16 *szCell; /* Local size of all cells in apCell[] */
+};
+
+/*
+** Make sure the cell sizes at idx, idx+1, ..., idx+N-1 have been
+** computed.
+*/
+static void populateCellCache(CellArray *p, int idx, int N){
+ assert( idx>=0 && idx+N<=p->nCell );
+ while( N>0 ){
+ assert( p->apCell[idx]!=0 );
+ if( p->szCell[idx]==0 ){
+ p->szCell[idx] = p->pRef->xCellSize(p->pRef, p->apCell[idx]);
+ }else{
+ assert( CORRUPT_DB ||
+ p->szCell[idx]==p->pRef->xCellSize(p->pRef, p->apCell[idx]) );
+ }
+ idx++;
+ N--;
+ }
+}
+
+/*
+** Return the size of the Nth element of the cell array
+*/
+static SQLITE_NOINLINE u16 computeCellSize(CellArray *p, int N){
+ assert( N>=0 && N<p->nCell );
+ assert( p->szCell[N]==0 );
+ p->szCell[N] = p->pRef->xCellSize(p->pRef, p->apCell[N]);
+ return p->szCell[N];
+}
+static u16 cachedCellSize(CellArray *p, int N){
+ assert( N>=0 && N<p->nCell );
+ if( p->szCell[N] ) return p->szCell[N];
+ return computeCellSize(p, N);
+}
+
+/*
+** Array apCell[] contains pointers to nCell b-tree page cells. The
+** szCell[] array contains the size in bytes of each cell. This function
+** replaces the current contents of page pPg with the contents of the cell
+** array.
+**
+** Some of the cells in apCell[] may currently be stored in pPg. This
+** function works around problems caused by this by making a copy of any
+** such cells before overwriting the page data.
+**
+** The MemPage.nFree field is invalidated by this function. It is the
+** responsibility of the caller to set it correctly.
+*/
+static int rebuildPage(
+ MemPage *pPg, /* Edit this page */
+ int nCell, /* Final number of cells on page */
+ u8 **apCell, /* Array of cells */
+ u16 *szCell /* Array of cell sizes */
){
- int i; /* Loop counter */
- u8 *pCellptr; /* Address of next cell pointer */
- int cellbody; /* Address of next cell body */
- u8 * const data = pPage->aData; /* Pointer to data for pPage */
- const int hdr = pPage->hdrOffset; /* Offset of header on pPage */
- const int nUsable = pPage->pBt->usableSize; /* Usable size of page */
+ const int hdr = pPg->hdrOffset; /* Offset of header on pPg */
+ u8 * const aData = pPg->aData; /* Pointer to data for pPg */
+ const int usableSize = pPg->pBt->usableSize;
+ u8 * const pEnd = &aData[usableSize];
+ int i;
+ u8 *pCellptr = pPg->aCellIdx;
+ u8 *pTmp = sqlite3PagerTempSpace(pPg->pBt->pPager);
+ u8 *pData;
- assert( pPage->nOverflow==0 );
- assert( sqlite3_mutex_held(pPage->pBt->mutex) );
- assert( nCell>=0 && nCell<=(int)MX_CELL(pPage->pBt)
- && (int)MX_CELL(pPage->pBt)<=10921);
- assert( sqlite3PagerIswriteable(pPage->pDbPage) );
+ i = get2byte(&aData[hdr+5]);
+ memcpy(&pTmp[i], &aData[i], usableSize - i);
+
+ pData = pEnd;
+ for(i=0; i<nCell; i++){
+ u8 *pCell = apCell[i];
+ if( SQLITE_WITHIN(pCell,aData,pEnd) ){
+ pCell = &pTmp[pCell - aData];
+ }
+ pData -= szCell[i];
+ put2byte(pCellptr, (pData - aData));
+ pCellptr += 2;
+ if( pData < pCellptr ) return SQLITE_CORRUPT_BKPT;
+ memcpy(pData, pCell, szCell[i]);
+ assert( szCell[i]==pPg->xCellSize(pPg, pCell) || CORRUPT_DB );
+ testcase( szCell[i]!=pPg->xCellSize(pPg,pCell) );
+ }
+
+ /* The pPg->nFree field is now set incorrectly. The caller will fix it. */
+ pPg->nCell = nCell;
+ pPg->nOverflow = 0;
+
+ put2byte(&aData[hdr+1], 0);
+ put2byte(&aData[hdr+3], pPg->nCell);
+ put2byte(&aData[hdr+5], pData - aData);
+ aData[hdr+7] = 0x00;
+ return SQLITE_OK;
+}
+
+/*
+** Array apCell[] contains nCell pointers to b-tree cells. Array szCell
+** contains the size in bytes of each such cell. This function attempts to
+** add the cells stored in the array to page pPg. If it cannot (because
+** the page needs to be defragmented before the cells will fit), non-zero
+** is returned. Otherwise, if the cells are added successfully, zero is
+** returned.
+**
+** Argument pCellptr points to the first entry in the cell-pointer array
+** (part of page pPg) to populate. After cell apCell[0] is written to the
+** page body, a 16-bit offset is written to pCellptr. And so on, for each
+** cell in the array. It is the responsibility of the caller to ensure
+** that it is safe to overwrite this part of the cell-pointer array.
+**
+** When this function is called, *ppData points to the start of the
+** content area on page pPg. If the size of the content area is extended,
+** *ppData is updated to point to the new start of the content area
+** before returning.
+**
+** Finally, argument pBegin points to the byte immediately following the
+** end of the space required by this page for the cell-pointer area (for
+** all cells - not just those inserted by the current call). If the content
+** area must be extended to before this point in order to accomodate all
+** cells in apCell[], then the cells do not fit and non-zero is returned.
+*/
+static int pageInsertArray(
+ MemPage *pPg, /* Page to add cells to */
+ u8 *pBegin, /* End of cell-pointer array */
+ u8 **ppData, /* IN/OUT: Page content -area pointer */
+ u8 *pCellptr, /* Pointer to cell-pointer area */
+ int iFirst, /* Index of first cell to add */
+ int nCell, /* Number of cells to add to pPg */
+ CellArray *pCArray /* Array of cells */
+){
+ int i;
+ u8 *aData = pPg->aData;
+ u8 *pData = *ppData;
+ int iEnd = iFirst + nCell;
+ assert( CORRUPT_DB || pPg->hdrOffset==0 ); /* Never called on page 1 */
+ for(i=iFirst; i<iEnd; i++){
+ int sz, rc;
+ u8 *pSlot;
+ sz = cachedCellSize(pCArray, i);
+ if( (aData[1]==0 && aData[2]==0) || (pSlot = pageFindSlot(pPg,sz,&rc))==0 ){
+ pData -= sz;
+ if( pData<pBegin ) return 1;
+ pSlot = pData;
+ }
+ /* pSlot and pCArray->apCell[i] will never overlap on a well-formed
+ ** database. But they might for a corrupt database. Hence use memmove()
+ ** since memcpy() sends SIGABORT with overlapping buffers on OpenBSD */
+ assert( (pSlot+sz)<=pCArray->apCell[i]
+ || pSlot>=(pCArray->apCell[i]+sz)
+ || CORRUPT_DB );
+ memmove(pSlot, pCArray->apCell[i], sz);
+ put2byte(pCellptr, (pSlot - aData));
+ pCellptr += 2;
+ }
+ *ppData = pData;
+ return 0;
+}
- /* Check that the page has just been zeroed by zeroPage() */
- assert( pPage->nCell==0 );
- assert( get2byteNotZero(&data[hdr+5])==nUsable );
+/*
+** Array apCell[] contains nCell pointers to b-tree cells. Array szCell
+** contains the size in bytes of each such cell. This function adds the
+** space associated with each cell in the array that is currently stored
+** within the body of pPg to the pPg free-list. The cell-pointers and other
+** fields of the page are not updated.
+**
+** This function returns the total number of cells added to the free-list.
+*/
+static int pageFreeArray(
+ MemPage *pPg, /* Page to edit */
+ int iFirst, /* First cell to delete */
+ int nCell, /* Cells to delete */
+ CellArray *pCArray /* Array of cells */
+){
+ u8 * const aData = pPg->aData;
+ u8 * const pEnd = &aData[pPg->pBt->usableSize];
+ u8 * const pStart = &aData[pPg->hdrOffset + 8 + pPg->childPtrSize];
+ int nRet = 0;
+ int i;
+ int iEnd = iFirst + nCell;
+ u8 *pFree = 0;
+ int szFree = 0;
- pCellptr = &pPage->aCellIdx[nCell*2];
- cellbody = nUsable;
- for(i=nCell-1; i>=0; i--){
- u16 sz = aSize[i];
- pCellptr -= 2;
- cellbody -= sz;
- put2byte(pCellptr, cellbody);
- memcpy(&data[cellbody], apCell[i], sz);
+ for(i=iFirst; i<iEnd; i++){
+ u8 *pCell = pCArray->apCell[i];
+ if( SQLITE_WITHIN(pCell, pStart, pEnd) ){
+ int sz;
+ /* No need to use cachedCellSize() here. The sizes of all cells that
+ ** are to be freed have already been computing while deciding which
+ ** cells need freeing */
+ sz = pCArray->szCell[i]; assert( sz>0 );
+ if( pFree!=(pCell + sz) ){
+ if( pFree ){
+ assert( pFree>aData && (pFree - aData)<65536 );
+ freeSpace(pPg, (u16)(pFree - aData), szFree);
+ }
+ pFree = pCell;
+ szFree = sz;
+ if( pFree+sz>pEnd ) return 0;
+ }else{
+ pFree = pCell;
+ szFree += sz;
+ }
+ nRet++;
+ }
+ }
+ if( pFree ){
+ assert( pFree>aData && (pFree - aData)<65536 );
+ freeSpace(pPg, (u16)(pFree - aData), szFree);
}
- put2byte(&data[hdr+3], nCell);
- put2byte(&data[hdr+5], cellbody);
- pPage->nFree -= (nCell*2 + nUsable - cellbody);
- pPage->nCell = (u16)nCell;
+ return nRet;
+}
+
+/*
+** apCell[] and szCell[] contains pointers to and sizes of all cells in the
+** pages being balanced. The current page, pPg, has pPg->nCell cells starting
+** with apCell[iOld]. After balancing, this page should hold nNew cells
+** starting at apCell[iNew].
+**
+** This routine makes the necessary adjustments to pPg so that it contains
+** the correct cells after being balanced.
+**
+** The pPg->nFree field is invalid when this function returns. It is the
+** responsibility of the caller to set it correctly.
+*/
+static int editPage(
+ MemPage *pPg, /* Edit this page */
+ int iOld, /* Index of first cell currently on page */
+ int iNew, /* Index of new first cell on page */
+ int nNew, /* Final number of cells on page */
+ CellArray *pCArray /* Array of cells and sizes */
+){
+ u8 * const aData = pPg->aData;
+ const int hdr = pPg->hdrOffset;
+ u8 *pBegin = &pPg->aCellIdx[nNew * 2];
+ int nCell = pPg->nCell; /* Cells stored on pPg */
+ u8 *pData;
+ u8 *pCellptr;
+ int i;
+ int iOldEnd = iOld + pPg->nCell + pPg->nOverflow;
+ int iNewEnd = iNew + nNew;
+
+#ifdef SQLITE_DEBUG
+ u8 *pTmp = sqlite3PagerTempSpace(pPg->pBt->pPager);
+ memcpy(pTmp, aData, pPg->pBt->usableSize);
+#endif
+
+ /* Remove cells from the start and end of the page */
+ if( iOld<iNew ){
+ int nShift = pageFreeArray(pPg, iOld, iNew-iOld, pCArray);
+ memmove(pPg->aCellIdx, &pPg->aCellIdx[nShift*2], nCell*2);
+ nCell -= nShift;
+ }
+ if( iNewEnd < iOldEnd ){
+ nCell -= pageFreeArray(pPg, iNewEnd, iOldEnd - iNewEnd, pCArray);
+ }
+
+ pData = &aData[get2byteNotZero(&aData[hdr+5])];
+ if( pData<pBegin ) goto editpage_fail;
+
+ /* Add cells to the start of the page */
+ if( iNew<iOld ){
+ int nAdd = MIN(nNew,iOld-iNew);
+ assert( (iOld-iNew)<nNew || nCell==0 || CORRUPT_DB );
+ pCellptr = pPg->aCellIdx;
+ memmove(&pCellptr[nAdd*2], pCellptr, nCell*2);
+ if( pageInsertArray(
+ pPg, pBegin, &pData, pCellptr,
+ iNew, nAdd, pCArray
+ ) ) goto editpage_fail;
+ nCell += nAdd;
+ }
+
+ /* Add any overflow cells */
+ for(i=0; i<pPg->nOverflow; i++){
+ int iCell = (iOld + pPg->aiOvfl[i]) - iNew;
+ if( iCell>=0 && iCell<nNew ){
+ pCellptr = &pPg->aCellIdx[iCell * 2];
+ memmove(&pCellptr[2], pCellptr, (nCell - iCell) * 2);
+ nCell++;
+ if( pageInsertArray(
+ pPg, pBegin, &pData, pCellptr,
+ iCell+iNew, 1, pCArray
+ ) ) goto editpage_fail;
+ }
+ }
+
+ /* Append cells to the end of the page */
+ pCellptr = &pPg->aCellIdx[nCell*2];
+ if( pageInsertArray(
+ pPg, pBegin, &pData, pCellptr,
+ iNew+nCell, nNew-nCell, pCArray
+ ) ) goto editpage_fail;
+
+ pPg->nCell = nNew;
+ pPg->nOverflow = 0;
+
+ put2byte(&aData[hdr+3], pPg->nCell);
+ put2byte(&aData[hdr+5], pData - aData);
+
+#ifdef SQLITE_DEBUG
+ for(i=0; i<nNew && !CORRUPT_DB; i++){
+ u8 *pCell = pCArray->apCell[i+iNew];
+ int iOff = get2byteAligned(&pPg->aCellIdx[i*2]);
+ if( pCell>=aData && pCell<&aData[pPg->pBt->usableSize] ){
+ pCell = &pTmp[pCell - aData];
+ }
+ assert( 0==memcmp(pCell, &aData[iOff],
+ pCArray->pRef->xCellSize(pCArray->pRef, pCArray->apCell[i+iNew])) );
+ }
+#endif
+
+ return SQLITE_OK;
+ editpage_fail:
+ /* Unable to edit this page. Rebuild it from scratch instead. */
+ populateCellCache(pCArray, iNew, nNew);
+ return rebuildPage(pPg, nNew, &pCArray->apCell[iNew], &pCArray->szCell[iNew]);
}
/*
@@ -6057,7 +6761,7 @@ static int balance_quick(MemPage *pParent, MemPage *pPage, u8 *pSpace){
assert( pPage->nOverflow==1 );
/* This error condition is now caught prior to reaching this function */
- if( pPage->nCell==0 ) return SQLITE_CORRUPT_BKPT;
+ if( NEVER(pPage->nCell==0) ) return SQLITE_CORRUPT_BKPT;
/* Allocate a new page. This page will become the right-sibling of
** pPage. Make the parent page writable, so that the new divider cell
@@ -6069,13 +6773,15 @@ static int balance_quick(MemPage *pParent, MemPage *pPage, u8 *pSpace){
u8 *pOut = &pSpace[4];
u8 *pCell = pPage->apOvfl[0];
- u16 szCell = cellSizePtr(pPage, pCell);
+ u16 szCell = pPage->xCellSize(pPage, pCell);
u8 *pStop;
assert( sqlite3PagerIswriteable(pNew->pDbPage) );
assert( pPage->aData[0]==(PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF) );
zeroPage(pNew, PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF);
- assemblePage(pNew, 1, &pCell, &szCell);
+ rc = rebuildPage(pNew, 1, &pCell, &szCell);
+ if( NEVER(rc) ) return rc;
+ pNew->nFree = pBt->usableSize - pNew->cellOffset - 2 - szCell;
/* If this is an auto-vacuum database, update the pointer map
** with entries for the new page, and any pointer from the
@@ -6147,9 +6853,9 @@ static int ptrmapCheckPages(MemPage **apPage, int nPage){
u8 *z;
z = findCell(pPage, j);
- btreeParseCellPtr(pPage, z, &info);
- if( info.iOverflow ){
- Pgno ovfl = get4byte(&z[info.iOverflow]);
+ pPage->xParseCell(pPage, z, &info);
+ if( info.nLocal<info.nPayload ){
+ Pgno ovfl = get4byte(&z[info.nSize-4]);
ptrmapGet(pBt, ovfl, &e, &n);
assert( n==pPage->pgno && e==PTRMAP_OVERFLOW1 );
}
@@ -6267,9 +6973,6 @@ static void copyNodeContent(MemPage *pFrom, MemPage *pTo, int *pRC){
** If aOvflSpace is set to a null pointer, this function returns
** SQLITE_NOMEM.
*/
-#if defined(_MSC_VER) && _MSC_VER >= 1700 && defined(_M_ARM)
-#pragma optimize("", off)
-#endif
static int balance_nonroot(
MemPage *pParent, /* Parent page of siblings being balanced */
int iParentIdx, /* Index of "the page" in pParent */
@@ -6278,7 +6981,6 @@ static int balance_nonroot(
int bBulk /* True if this call is part of a bulk load */
){
BtShared *pBt; /* The whole database */
- int nCell = 0; /* Number of cells in apCell[] */
int nMaxCells = 0; /* Allocated size of apCell, szCell, aFrom. */
int nNew = 0; /* Number of pages in apNew[] */
int nOld; /* Number of pages in apOld[] */
@@ -6289,22 +6991,27 @@ static int balance_nonroot(
int leafData; /* True if pPage is a leaf of a LEAFDATA tree */
int usableSpace; /* Bytes in pPage beyond the header */
int pageFlags; /* Value of pPage->aData[0] */
- int subtotal; /* Subtotal of bytes in cells on one page */
int iSpace1 = 0; /* First unused byte of aSpace1[] */
int iOvflSpace = 0; /* First unused byte of aOvflSpace[] */
int szScratch; /* Size of scratch memory requested */
MemPage *apOld[NB]; /* pPage and up to two siblings */
- MemPage *apCopy[NB]; /* Private copies of apOld[] pages */
MemPage *apNew[NB+2]; /* pPage and up to NB siblings after balancing */
u8 *pRight; /* Location in parent of right-sibling pointer */
u8 *apDiv[NB-1]; /* Divider cells in pParent */
- int cntNew[NB+2]; /* Index in aCell[] of cell after i-th page */
- int szNew[NB+2]; /* Combined size of cells place on i-th page */
- u8 **apCell = 0; /* All cells begin balanced */
- u16 *szCell; /* Local size of all cells in apCell[] */
+ int cntNew[NB+2]; /* Index in b.paCell[] of cell after i-th page */
+ int cntOld[NB+2]; /* Old index in b.apCell[] */
+ int szNew[NB+2]; /* Combined size of cells placed on i-th page */
u8 *aSpace1; /* Space for copies of dividers cells */
Pgno pgno; /* Temp var to store a page number in */
-
+ u8 abDone[NB+2]; /* True after i'th new page is populated */
+ Pgno aPgno[NB+2]; /* Page numbers of new pages before shuffling */
+ Pgno aPgOrder[NB+2]; /* Copy of aPgno[] used for sorting pages */
+ u16 aPgFlags[NB+2]; /* flags field of new pages before shuffling */
+ CellArray b; /* Parsed information on cells being balanced */
+
+ memset(abDone, 0, sizeof(abDone));
+ b.nCell = 0;
+ b.apCell = 0;
pBt = pParent->pBt;
assert( sqlite3_mutex_held(pBt->mutex) );
assert( sqlite3PagerIswriteable(pParent->pDbPage) );
@@ -6346,7 +7053,6 @@ static int balance_nonroot(
}else if( iParentIdx==i ){
nxDiv = i-2+bBulk;
}else{
- assert( bBulk==0 );
nxDiv = iParentIdx-1;
}
i = 2-bBulk;
@@ -6359,7 +7065,7 @@ static int balance_nonroot(
}
pgno = get4byte(pRight);
while( 1 ){
- rc = getAndInitPage(pBt, pgno, &apOld[i], 0);
+ rc = getAndInitPage(pBt, pgno, &apOld[i], 0, 0);
if( rc ){
memset(apOld, 0, (i+1)*sizeof(MemPage*));
goto balance_cleanup;
@@ -6370,12 +7076,12 @@ static int balance_nonroot(
if( i+nxDiv==pParent->aiOvfl[0] && pParent->nOverflow ){
apDiv[i] = pParent->apOvfl[0];
pgno = get4byte(apDiv[i]);
- szNew[i] = cellSizePtr(pParent, apDiv[i]);
+ szNew[i] = pParent->xCellSize(pParent, apDiv[i]);
pParent->nOverflow = 0;
}else{
apDiv[i] = findCell(pParent, i+nxDiv-pParent->nOverflow);
pgno = get4byte(apDiv[i]);
- szNew[i] = cellSizePtr(pParent, apDiv[i]);
+ szNew[i] = pParent->xCellSize(pParent, apDiv[i]);
/* Drop the cell from the parent page. apDiv[i] still points to
** the cell within the parent, even though it has been dropped.
@@ -6413,138 +7119,209 @@ static int balance_nonroot(
/*
** Allocate space for memory structures
*/
- k = pBt->pageSize + ROUND8(sizeof(MemPage));
szScratch =
- nMaxCells*sizeof(u8*) /* apCell */
- + nMaxCells*sizeof(u16) /* szCell */
- + pBt->pageSize /* aSpace1 */
- + k*nOld; /* Page copies (apCopy) */
- apCell = sqlite3ScratchMalloc( szScratch );
- if( apCell==0 ){
+ nMaxCells*sizeof(u8*) /* b.apCell */
+ + nMaxCells*sizeof(u16) /* b.szCell */
+ + pBt->pageSize; /* aSpace1 */
+
+ /* EVIDENCE-OF: R-28375-38319 SQLite will never request a scratch buffer
+ ** that is more than 6 times the database page size. */
+ assert( szScratch<=6*(int)pBt->pageSize );
+ b.apCell = sqlite3ScratchMalloc( szScratch );
+ if( b.apCell==0 ){
rc = SQLITE_NOMEM;
goto balance_cleanup;
}
- szCell = (u16*)&apCell[nMaxCells];
- aSpace1 = (u8*)&szCell[nMaxCells];
+ b.szCell = (u16*)&b.apCell[nMaxCells];
+ aSpace1 = (u8*)&b.szCell[nMaxCells];
assert( EIGHT_BYTE_ALIGNMENT(aSpace1) );
/*
** Load pointers to all cells on sibling pages and the divider cells
- ** into the local apCell[] array. Make copies of the divider cells
- ** into space obtained from aSpace1[] and remove the divider cells
- ** from pParent.
+ ** into the local b.apCell[] array. Make copies of the divider cells
+ ** into space obtained from aSpace1[]. The divider cells have already
+ ** been removed from pParent.
**
** If the siblings are on leaf pages, then the child pointers of the
** divider cells are stripped from the cells before they are copied
- ** into aSpace1[]. In this way, all cells in apCell[] are without
+ ** into aSpace1[]. In this way, all cells in b.apCell[] are without
** child pointers. If siblings are not leaves, then all cell in
- ** apCell[] include child pointers. Either way, all cells in apCell[]
+ ** b.apCell[] include child pointers. Either way, all cells in b.apCell[]
** are alike.
**
** leafCorrection: 4 if pPage is a leaf. 0 if pPage is not a leaf.
** leafData: 1 if pPage holds key+data and pParent holds only keys.
*/
- leafCorrection = apOld[0]->leaf*4;
- leafData = apOld[0]->intKeyLeaf;
+ b.pRef = apOld[0];
+ leafCorrection = b.pRef->leaf*4;
+ leafData = b.pRef->intKeyLeaf;
for(i=0; i<nOld; i++){
- int limit;
-
- /* Before doing anything else, take a copy of the i'th original sibling
- ** The rest of this function will use data from the copies rather
- ** that the original pages since the original pages will be in the
- ** process of being overwritten. */
- MemPage *pOld = apCopy[i] = (MemPage*)&aSpace1[pBt->pageSize + k*i];
- memcpy(pOld, apOld[i], sizeof(MemPage));
- pOld->aData = (void*)&pOld[1];
- memcpy(pOld->aData, apOld[i]->aData, pBt->pageSize);
-
- limit = pOld->nCell+pOld->nOverflow;
+ MemPage *pOld = apOld[i];
+ int limit = pOld->nCell;
+ u8 *aData = pOld->aData;
+ u16 maskPage = pOld->maskPage;
+ u8 *piCell = aData + pOld->cellOffset;
+ u8 *piEnd;
+
+ /* Verify that all sibling pages are of the same "type" (table-leaf,
+ ** table-interior, index-leaf, or index-interior).
+ */
+ if( pOld->aData[0]!=apOld[0]->aData[0] ){
+ rc = SQLITE_CORRUPT_BKPT;
+ goto balance_cleanup;
+ }
+
+ /* Load b.apCell[] with pointers to all cells in pOld. If pOld
+ ** constains overflow cells, include them in the b.apCell[] array
+ ** in the correct spot.
+ **
+ ** Note that when there are multiple overflow cells, it is always the
+ ** case that they are sequential and adjacent. This invariant arises
+ ** because multiple overflows can only occurs when inserting divider
+ ** cells into a parent on a prior balance, and divider cells are always
+ ** adjacent and are inserted in order. There is an assert() tagged
+ ** with "NOTE 1" in the overflow cell insertion loop to prove this
+ ** invariant.
+ **
+ ** This must be done in advance. Once the balance starts, the cell
+ ** offset section of the btree page will be overwritten and we will no
+ ** long be able to find the cells if a pointer to each cell is not saved
+ ** first.
+ */
+ memset(&b.szCell[b.nCell], 0, sizeof(b.szCell[0])*limit);
if( pOld->nOverflow>0 ){
+ memset(&b.szCell[b.nCell+limit], 0, sizeof(b.szCell[0])*pOld->nOverflow);
+ limit = pOld->aiOvfl[0];
for(j=0; j<limit; j++){
- assert( nCell<nMaxCells );
- apCell[nCell] = findOverflowCell(pOld, j);
- szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
- nCell++;
+ b.apCell[b.nCell] = aData + (maskPage & get2byteAligned(piCell));
+ piCell += 2;
+ b.nCell++;
}
- }else{
- u8 *aData = pOld->aData;
- u16 maskPage = pOld->maskPage;
- u16 cellOffset = pOld->cellOffset;
- for(j=0; j<limit; j++){
- assert( nCell<nMaxCells );
- apCell[nCell] = findCellv2(aData, maskPage, cellOffset, j);
- szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
- nCell++;
+ for(k=0; k<pOld->nOverflow; k++){
+ assert( k==0 || pOld->aiOvfl[k-1]+1==pOld->aiOvfl[k] );/* NOTE 1 */
+ b.apCell[b.nCell] = pOld->apOvfl[k];
+ b.nCell++;
}
- }
+ }
+ piEnd = aData + pOld->cellOffset + 2*pOld->nCell;
+ while( piCell<piEnd ){
+ assert( b.nCell<nMaxCells );
+ b.apCell[b.nCell] = aData + (maskPage & get2byteAligned(piCell));
+ piCell += 2;
+ b.nCell++;
+ }
+
+ cntOld[i] = b.nCell;
if( i<nOld-1 && !leafData){
u16 sz = (u16)szNew[i];
u8 *pTemp;
- assert( nCell<nMaxCells );
- szCell[nCell] = sz;
+ assert( b.nCell<nMaxCells );
+ b.szCell[b.nCell] = sz;
pTemp = &aSpace1[iSpace1];
iSpace1 += sz;
assert( sz<=pBt->maxLocal+23 );
assert( iSpace1 <= (int)pBt->pageSize );
memcpy(pTemp, apDiv[i], sz);
- apCell[nCell] = pTemp+leafCorrection;
+ b.apCell[b.nCell] = pTemp+leafCorrection;
assert( leafCorrection==0 || leafCorrection==4 );
- szCell[nCell] = szCell[nCell] - leafCorrection;
+ b.szCell[b.nCell] = b.szCell[b.nCell] - leafCorrection;
if( !pOld->leaf ){
assert( leafCorrection==0 );
assert( pOld->hdrOffset==0 );
/* The right pointer of the child page pOld becomes the left
** pointer of the divider cell */
- memcpy(apCell[nCell], &pOld->aData[8], 4);
+ memcpy(b.apCell[b.nCell], &pOld->aData[8], 4);
}else{
assert( leafCorrection==4 );
- if( szCell[nCell]<4 ){
- /* Do not allow any cells smaller than 4 bytes. */
- szCell[nCell] = 4;
+ while( b.szCell[b.nCell]<4 ){
+ /* Do not allow any cells smaller than 4 bytes. If a smaller cell
+ ** does exist, pad it with 0x00 bytes. */
+ assert( b.szCell[b.nCell]==3 || CORRUPT_DB );
+ assert( b.apCell[b.nCell]==&aSpace1[iSpace1-3] || CORRUPT_DB );
+ aSpace1[iSpace1++] = 0x00;
+ b.szCell[b.nCell]++;
}
}
- nCell++;
+ b.nCell++;
}
}
/*
- ** Figure out the number of pages needed to hold all nCell cells.
+ ** Figure out the number of pages needed to hold all b.nCell cells.
** Store this number in "k". Also compute szNew[] which is the total
** size of all cells on the i-th page and cntNew[] which is the index
- ** in apCell[] of the cell that divides page i from page i+1.
- ** cntNew[k] should equal nCell.
+ ** in b.apCell[] of the cell that divides page i from page i+1.
+ ** cntNew[k] should equal b.nCell.
**
** Values computed by this block:
**
** k: The total number of sibling pages
** szNew[i]: Spaced used on the i-th sibling page.
- ** cntNew[i]: Index in apCell[] and szCell[] for the first cell to
+ ** cntNew[i]: Index in b.apCell[] and b.szCell[] for the first cell to
** the right of the i-th sibling page.
** usableSpace: Number of bytes of space available on each sibling.
**
*/
usableSpace = pBt->usableSize - 12 + leafCorrection;
- for(subtotal=k=i=0; i<nCell; i++){
- assert( i<nMaxCells );
- subtotal += szCell[i] + 2;
- if( subtotal > usableSpace ){
- szNew[k] = subtotal - szCell[i];
- cntNew[k] = i;
- if( leafData ){ i--; }
- subtotal = 0;
- k++;
- if( k>NB+1 ){ rc = SQLITE_CORRUPT_BKPT; goto balance_cleanup; }
- }
- }
- szNew[k] = subtotal;
- cntNew[k] = nCell;
- k++;
+ for(i=0; i<nOld; i++){
+ MemPage *p = apOld[i];
+ szNew[i] = usableSpace - p->nFree;
+ if( szNew[i]<0 ){ rc = SQLITE_CORRUPT_BKPT; goto balance_cleanup; }
+ for(j=0; j<p->nOverflow; j++){
+ szNew[i] += 2 + p->xCellSize(p, p->apOvfl[j]);
+ }
+ cntNew[i] = cntOld[i];
+ }
+ k = nOld;
+ for(i=0; i<k; i++){
+ int sz;
+ while( szNew[i]>usableSpace ){
+ if( i+1>=k ){
+ k = i+2;
+ if( k>NB+2 ){ rc = SQLITE_CORRUPT_BKPT; goto balance_cleanup; }
+ szNew[k-1] = 0;
+ cntNew[k-1] = b.nCell;
+ }
+ sz = 2 + cachedCellSize(&b, cntNew[i]-1);
+ szNew[i] -= sz;
+ if( !leafData ){
+ if( cntNew[i]<b.nCell ){
+ sz = 2 + cachedCellSize(&b, cntNew[i]);
+ }else{
+ sz = 0;
+ }
+ }
+ szNew[i+1] += sz;
+ cntNew[i]--;
+ }
+ while( cntNew[i]<b.nCell ){
+ sz = 2 + cachedCellSize(&b, cntNew[i]);
+ if( szNew[i]+sz>usableSpace ) break;
+ szNew[i] += sz;
+ cntNew[i]++;
+ if( !leafData ){
+ if( cntNew[i]<b.nCell ){
+ sz = 2 + cachedCellSize(&b, cntNew[i]);
+ }else{
+ sz = 0;
+ }
+ }
+ szNew[i+1] -= sz;
+ }
+ if( cntNew[i]>=b.nCell ){
+ k = i+1;
+ }else if( cntNew[i] <= (i>0 ? cntNew[i-1] : 0) ){
+ rc = SQLITE_CORRUPT_BKPT;
+ goto balance_cleanup;
+ }
+ }
/*
** The packing computed by the previous block is biased toward the siblings
- ** on the left side. The left siblings are always nearly full, while the
- ** right-most sibling might be nearly empty. This block of code attempts
- ** to adjust the packing of siblings to get a better balance.
+ ** on the left side (siblings with smaller keys). The left siblings are
+ ** always nearly full, while the right-most sibling might be nearly empty.
+ ** The next block of code attempts to adjust the packing of siblings to
+ ** get a better balance.
**
** This adjustment is more than an optimization. The packing above might
** be so out of balance as to be illegal. For example, the right-most
@@ -6558,46 +7335,46 @@ static int balance_nonroot(
r = cntNew[i-1] - 1;
d = r + 1 - leafData;
- assert( d<nMaxCells );
- assert( r<nMaxCells );
- while( szRight==0
- || (!bBulk && szRight+szCell[d]+2<=szLeft-(szCell[r]+2))
- ){
- szRight += szCell[d] + 2;
- szLeft -= szCell[r] + 2;
- cntNew[i-1]--;
- r = cntNew[i-1] - 1;
- d = r + 1 - leafData;
- }
+ (void)cachedCellSize(&b, d);
+ do{
+ assert( d<nMaxCells );
+ assert( r<nMaxCells );
+ (void)cachedCellSize(&b, r);
+ if( szRight!=0
+ && (bBulk || szRight+b.szCell[d]+2 > szLeft-(b.szCell[r]+2)) ){
+ break;
+ }
+ szRight += b.szCell[d] + 2;
+ szLeft -= b.szCell[r] + 2;
+ cntNew[i-1] = r;
+ r--;
+ d--;
+ }while( r>=0 );
szNew[i] = szRight;
szNew[i-1] = szLeft;
+ if( cntNew[i-1] <= (i>1 ? cntNew[i-2] : 0) ){
+ rc = SQLITE_CORRUPT_BKPT;
+ goto balance_cleanup;
+ }
}
- /* Either we found one or more cells (cntnew[0])>0) or pPage is
- ** a virtual root page. A virtual root page is when the real root
- ** page is page 1 and we are the only child of that page.
- **
- ** UPDATE: The assert() below is not necessarily true if the database
- ** file is corrupt. The corruption will be detected and reported later
- ** in this procedure so there is no need to act upon it now.
+ /* Sanity check: For a non-corrupt database file one of the follwing
+ ** must be true:
+ ** (1) We found one or more cells (cntNew[0])>0), or
+ ** (2) pPage is a virtual root page. A virtual root page is when
+ ** the real root page is page 1 and we are the only child of
+ ** that page.
*/
-#if 0
- assert( cntNew[0]>0 || (pParent->pgno==1 && pParent->nCell==0) );
-#endif
-
- TRACE(("BALANCE: old: %d %d %d ",
- apOld[0]->pgno,
- nOld>=2 ? apOld[1]->pgno : 0,
- nOld>=3 ? apOld[2]->pgno : 0
+ assert( cntNew[0]>0 || (pParent->pgno==1 && pParent->nCell==0) || CORRUPT_DB);
+ TRACE(("BALANCE: old: %d(nc=%d) %d(nc=%d) %d(nc=%d)\n",
+ apOld[0]->pgno, apOld[0]->nCell,
+ nOld>=2 ? apOld[1]->pgno : 0, nOld>=2 ? apOld[1]->nCell : 0,
+ nOld>=3 ? apOld[2]->pgno : 0, nOld>=3 ? apOld[2]->nCell : 0
));
/*
** Allocate k new pages. Reuse old pages where possible.
*/
- if( apOld[0]->pgno<=1 ){
- rc = SQLITE_CORRUPT_BKPT;
- goto balance_cleanup;
- }
pageFlags = apOld[0]->aData[0];
for(i=0; i<k; i++){
MemPage *pNew;
@@ -6611,8 +7388,10 @@ static int balance_nonroot(
assert( i>0 );
rc = allocateBtreePage(pBt, &pNew, &pgno, (bBulk ? 1 : pgno), 0);
if( rc ) goto balance_cleanup;
+ zeroPage(pNew, pageFlags);
apNew[i] = pNew;
nNew++;
+ cntOld[i] = b.nCell;
/* Set the pointer-map entry for the new sibling page. */
if( ISAUTOVACUUM ){
@@ -6624,135 +7403,249 @@ static int balance_nonroot(
}
}
- /* Free any old pages that were not reused as new pages.
- */
- while( i<nOld ){
- freePage(apOld[i], &rc);
- if( rc ) goto balance_cleanup;
- releasePage(apOld[i]);
- apOld[i] = 0;
- i++;
- }
-
/*
- ** Put the new pages in ascending order. This helps to
- ** keep entries in the disk file in order so that a scan
- ** of the table is a linear scan through the file. That
- ** in turn helps the operating system to deliver pages
- ** from the disk more rapidly.
+ ** Reassign page numbers so that the new pages are in ascending order.
+ ** This helps to keep entries in the disk file in order so that a scan
+ ** of the table is closer to a linear scan through the file. That in turn
+ ** helps the operating system to deliver pages from the disk more rapidly.
**
- ** An O(n^2) insertion sort algorithm is used, but since
- ** n is never more than NB (a small constant), that should
- ** not be a problem.
+ ** An O(n^2) insertion sort algorithm is used, but since n is never more
+ ** than (NB+2) (a small constant), that should not be a problem.
**
- ** When NB==3, this one optimization makes the database
- ** about 25% faster for large insertions and deletions.
+ ** When NB==3, this one optimization makes the database about 25% faster
+ ** for large insertions and deletions.
*/
- for(i=0; i<k-1; i++){
- int minV = apNew[i]->pgno;
- int minI = i;
- for(j=i+1; j<k; j++){
- if( apNew[j]->pgno<(unsigned)minV ){
- minI = j;
- minV = apNew[j]->pgno;
+ for(i=0; i<nNew; i++){
+ aPgOrder[i] = aPgno[i] = apNew[i]->pgno;
+ aPgFlags[i] = apNew[i]->pDbPage->flags;
+ for(j=0; j<i; j++){
+ if( aPgno[j]==aPgno[i] ){
+ /* This branch is taken if the set of sibling pages somehow contains
+ ** duplicate entries. This can happen if the database is corrupt.
+ ** It would be simpler to detect this as part of the loop below, but
+ ** we do the detection here in order to avoid populating the pager
+ ** cache with two separate objects associated with the same
+ ** page number. */
+ assert( CORRUPT_DB );
+ rc = SQLITE_CORRUPT_BKPT;
+ goto balance_cleanup;
}
}
- if( minI>i ){
- MemPage *pT;
- pT = apNew[i];
- apNew[i] = apNew[minI];
- apNew[minI] = pT;
+ }
+ for(i=0; i<nNew; i++){
+ int iBest = 0; /* aPgno[] index of page number to use */
+ for(j=1; j<nNew; j++){
+ if( aPgOrder[j]<aPgOrder[iBest] ) iBest = j;
+ }
+ pgno = aPgOrder[iBest];
+ aPgOrder[iBest] = 0xffffffff;
+ if( iBest!=i ){
+ if( iBest>i ){
+ sqlite3PagerRekey(apNew[iBest]->pDbPage, pBt->nPage+iBest+1, 0);
+ }
+ sqlite3PagerRekey(apNew[i]->pDbPage, pgno, aPgFlags[iBest]);
+ apNew[i]->pgno = pgno;
}
}
- TRACE(("new: %d(%d) %d(%d) %d(%d) %d(%d) %d(%d)\n",
- apNew[0]->pgno, szNew[0],
+
+ TRACE(("BALANCE: new: %d(%d nc=%d) %d(%d nc=%d) %d(%d nc=%d) "
+ "%d(%d nc=%d) %d(%d nc=%d)\n",
+ apNew[0]->pgno, szNew[0], cntNew[0],
nNew>=2 ? apNew[1]->pgno : 0, nNew>=2 ? szNew[1] : 0,
+ nNew>=2 ? cntNew[1] - cntNew[0] - !leafData : 0,
nNew>=3 ? apNew[2]->pgno : 0, nNew>=3 ? szNew[2] : 0,
+ nNew>=3 ? cntNew[2] - cntNew[1] - !leafData : 0,
nNew>=4 ? apNew[3]->pgno : 0, nNew>=4 ? szNew[3] : 0,
- nNew>=5 ? apNew[4]->pgno : 0, nNew>=5 ? szNew[4] : 0));
+ nNew>=4 ? cntNew[3] - cntNew[2] - !leafData : 0,
+ nNew>=5 ? apNew[4]->pgno : 0, nNew>=5 ? szNew[4] : 0,
+ nNew>=5 ? cntNew[4] - cntNew[3] - !leafData : 0
+ ));
assert( sqlite3PagerIswriteable(pParent->pDbPage) );
put4byte(pRight, apNew[nNew-1]->pgno);
- /*
- ** Evenly distribute the data in apCell[] across the new pages.
- ** Insert divider cells into pParent as necessary.
+ /* If the sibling pages are not leaves, ensure that the right-child pointer
+ ** of the right-most new sibling page is set to the value that was
+ ** originally in the same field of the right-most old sibling page. */
+ if( (pageFlags & PTF_LEAF)==0 && nOld!=nNew ){
+ MemPage *pOld = (nNew>nOld ? apNew : apOld)[nOld-1];
+ memcpy(&apNew[nNew-1]->aData[8], &pOld->aData[8], 4);
+ }
+
+ /* Make any required updates to pointer map entries associated with
+ ** cells stored on sibling pages following the balance operation. Pointer
+ ** map entries associated with divider cells are set by the insertCell()
+ ** routine. The associated pointer map entries are:
+ **
+ ** a) if the cell contains a reference to an overflow chain, the
+ ** entry associated with the first page in the overflow chain, and
+ **
+ ** b) if the sibling pages are not leaves, the child page associated
+ ** with the cell.
+ **
+ ** If the sibling pages are not leaves, then the pointer map entry
+ ** associated with the right-child of each sibling may also need to be
+ ** updated. This happens below, after the sibling pages have been
+ ** populated, not here.
*/
- j = 0;
- for(i=0; i<nNew; i++){
- /* Assemble the new sibling page. */
+ if( ISAUTOVACUUM ){
+ MemPage *pNew = apNew[0];
+ u8 *aOld = pNew->aData;
+ int cntOldNext = pNew->nCell + pNew->nOverflow;
+ int usableSize = pBt->usableSize;
+ int iNew = 0;
+ int iOld = 0;
+
+ for(i=0; i<b.nCell; i++){
+ u8 *pCell = b.apCell[i];
+ if( i==cntOldNext ){
+ MemPage *pOld = (++iOld)<nNew ? apNew[iOld] : apOld[iOld];
+ cntOldNext += pOld->nCell + pOld->nOverflow + !leafData;
+ aOld = pOld->aData;
+ }
+ if( i==cntNew[iNew] ){
+ pNew = apNew[++iNew];
+ if( !leafData ) continue;
+ }
+
+ /* Cell pCell is destined for new sibling page pNew. Originally, it
+ ** was either part of sibling page iOld (possibly an overflow cell),
+ ** or else the divider cell to the left of sibling page iOld. So,
+ ** if sibling page iOld had the same page number as pNew, and if
+ ** pCell really was a part of sibling page iOld (not a divider or
+ ** overflow cell), we can skip updating the pointer map entries. */
+ if( iOld>=nNew
+ || pNew->pgno!=aPgno[iOld]
+ || !SQLITE_WITHIN(pCell,aOld,&aOld[usableSize])
+ ){
+ if( !leafCorrection ){
+ ptrmapPut(pBt, get4byte(pCell), PTRMAP_BTREE, pNew->pgno, &rc);
+ }
+ if( cachedCellSize(&b,i)>pNew->minLocal ){
+ ptrmapPutOvflPtr(pNew, pCell, &rc);
+ }
+ if( rc ) goto balance_cleanup;
+ }
+ }
+ }
+
+ /* Insert new divider cells into pParent. */
+ for(i=0; i<nNew-1; i++){
+ u8 *pCell;
+ u8 *pTemp;
+ int sz;
MemPage *pNew = apNew[i];
+ j = cntNew[i];
+
assert( j<nMaxCells );
- zeroPage(pNew, pageFlags);
- assemblePage(pNew, cntNew[i]-j, &apCell[j], &szCell[j]);
- assert( pNew->nCell>0 || (nNew==1 && cntNew[0]==0) );
- assert( pNew->nOverflow==0 );
+ assert( b.apCell[j]!=0 );
+ pCell = b.apCell[j];
+ sz = b.szCell[j] + leafCorrection;
+ pTemp = &aOvflSpace[iOvflSpace];
+ if( !pNew->leaf ){
+ memcpy(&pNew->aData[8], pCell, 4);
+ }else if( leafData ){
+ /* If the tree is a leaf-data tree, and the siblings are leaves,
+ ** then there is no divider cell in b.apCell[]. Instead, the divider
+ ** cell consists of the integer key for the right-most cell of
+ ** the sibling-page assembled above only.
+ */
+ CellInfo info;
+ j--;
+ pNew->xParseCell(pNew, b.apCell[j], &info);
+ pCell = pTemp;
+ sz = 4 + putVarint(&pCell[4], info.nKey);
+ pTemp = 0;
+ }else{
+ pCell -= 4;
+ /* Obscure case for non-leaf-data trees: If the cell at pCell was
+ ** previously stored on a leaf node, and its reported size was 4
+ ** bytes, then it may actually be smaller than this
+ ** (see btreeParseCellPtr(), 4 bytes is the minimum size of
+ ** any cell). But it is important to pass the correct size to
+ ** insertCell(), so reparse the cell now.
+ **
+ ** Note that this can never happen in an SQLite data file, as all
+ ** cells are at least 4 bytes. It only happens in b-trees used
+ ** to evaluate "IN (SELECT ...)" and similar clauses.
+ */
+ if( b.szCell[j]==4 ){
+ assert(leafCorrection==4);
+ sz = pParent->xCellSize(pParent, pCell);
+ }
+ }
+ iOvflSpace += sz;
+ assert( sz<=pBt->maxLocal+23 );
+ assert( iOvflSpace <= (int)pBt->pageSize );
+ insertCell(pParent, nxDiv+i, pCell, sz, pTemp, pNew->pgno, &rc);
+ if( rc!=SQLITE_OK ) goto balance_cleanup;
+ assert( sqlite3PagerIswriteable(pParent->pDbPage) );
+ }
- j = cntNew[i];
+ /* Now update the actual sibling pages. The order in which they are updated
+ ** is important, as this code needs to avoid disrupting any page from which
+ ** cells may still to be read. In practice, this means:
+ **
+ ** (1) If cells are moving left (from apNew[iPg] to apNew[iPg-1])
+ ** then it is not safe to update page apNew[iPg] until after
+ ** the left-hand sibling apNew[iPg-1] has been updated.
+ **
+ ** (2) If cells are moving right (from apNew[iPg] to apNew[iPg+1])
+ ** then it is not safe to update page apNew[iPg] until after
+ ** the right-hand sibling apNew[iPg+1] has been updated.
+ **
+ ** If neither of the above apply, the page is safe to update.
+ **
+ ** The iPg value in the following loop starts at nNew-1 goes down
+ ** to 0, then back up to nNew-1 again, thus making two passes over
+ ** the pages. On the initial downward pass, only condition (1) above
+ ** needs to be tested because (2) will always be true from the previous
+ ** step. On the upward pass, both conditions are always true, so the
+ ** upwards pass simply processes pages that were missed on the downward
+ ** pass.
+ */
+ for(i=1-nNew; i<nNew; i++){
+ int iPg = i<0 ? -i : i;
+ assert( iPg>=0 && iPg<nNew );
+ if( abDone[iPg] ) continue; /* Skip pages already processed */
+ if( i>=0 /* On the upwards pass, or... */
+ || cntOld[iPg-1]>=cntNew[iPg-1] /* Condition (1) is true */
+ ){
+ int iNew;
+ int iOld;
+ int nNewCell;
- /* If the sibling page assembled above was not the right-most sibling,
- ** insert a divider cell into the parent page.
- */
- assert( i<nNew-1 || j==nCell );
- if( j<nCell ){
- u8 *pCell;
- u8 *pTemp;
- int sz;
+ /* Verify condition (1): If cells are moving left, update iPg
+ ** only after iPg-1 has already been updated. */
+ assert( iPg==0 || cntOld[iPg-1]>=cntNew[iPg-1] || abDone[iPg-1] );
- assert( j<nMaxCells );
- pCell = apCell[j];
- sz = szCell[j] + leafCorrection;
- pTemp = &aOvflSpace[iOvflSpace];
- if( !pNew->leaf ){
- memcpy(&pNew->aData[8], pCell, 4);
- }else if( leafData ){
- /* If the tree is a leaf-data tree, and the siblings are leaves,
- ** then there is no divider cell in apCell[]. Instead, the divider
- ** cell consists of the integer key for the right-most cell of
- ** the sibling-page assembled above only.
- */
- CellInfo info;
- j--;
- btreeParseCellPtr(pNew, apCell[j], &info);
- pCell = pTemp;
- sz = 4 + putVarint(&pCell[4], info.nKey);
- pTemp = 0;
+ /* Verify condition (2): If cells are moving right, update iPg
+ ** only after iPg+1 has already been updated. */
+ assert( cntNew[iPg]>=cntOld[iPg] || abDone[iPg+1] );
+
+ if( iPg==0 ){
+ iNew = iOld = 0;
+ nNewCell = cntNew[0];
}else{
- pCell -= 4;
- /* Obscure case for non-leaf-data trees: If the cell at pCell was
- ** previously stored on a leaf node, and its reported size was 4
- ** bytes, then it may actually be smaller than this
- ** (see btreeParseCellPtr(), 4 bytes is the minimum size of
- ** any cell). But it is important to pass the correct size to
- ** insertCell(), so reparse the cell now.
- **
- ** Note that this can never happen in an SQLite data file, as all
- ** cells are at least 4 bytes. It only happens in b-trees used
- ** to evaluate "IN (SELECT ...)" and similar clauses.
- */
- if( szCell[j]==4 ){
- assert(leafCorrection==4);
- sz = cellSizePtr(pParent, pCell);
- }
+ iOld = iPg<nOld ? (cntOld[iPg-1] + !leafData) : b.nCell;
+ iNew = cntNew[iPg-1] + !leafData;
+ nNewCell = cntNew[iPg] - iNew;
}
- iOvflSpace += sz;
- assert( sz<=pBt->maxLocal+23 );
- assert( iOvflSpace <= (int)pBt->pageSize );
- insertCell(pParent, nxDiv, pCell, sz, pTemp, pNew->pgno, &rc);
- if( rc!=SQLITE_OK ) goto balance_cleanup;
- assert( sqlite3PagerIswriteable(pParent->pDbPage) );
- j++;
- nxDiv++;
+ rc = editPage(apNew[iPg], iOld, iNew, nNewCell, &b);
+ if( rc ) goto balance_cleanup;
+ abDone[iPg]++;
+ apNew[iPg]->nFree = usableSpace-szNew[iPg];
+ assert( apNew[iPg]->nOverflow==0 );
+ assert( apNew[iPg]->nCell==nNewCell );
}
}
- assert( j==nCell );
+
+ /* All pages have been processed exactly once */
+ assert( memcmp(abDone, "\01\01\01\01\01", nNew)==0 );
+
assert( nOld>0 );
assert( nNew>0 );
- if( (pageFlags & PTF_LEAF)==0 ){
- u8 *zChild = &apCopy[nOld-1]->aData[8];
- memcpy(&apNew[nNew-1]->aData[8], zChild, 4);
- }
if( isRoot && pParent->nCell==0 && pParent->hdrOffset<=apNew[0]->nFree ){
/* The root page of the b-tree now contains no cells. The only sibling
@@ -6765,132 +7658,56 @@ static int balance_nonroot(
** sets all pointer-map entries corresponding to database image pages
** for which the pointer is stored within the content being copied.
**
- ** The second assert below verifies that the child page is defragmented
- ** (it must be, as it was just reconstructed using assemblePage()). This
- ** is important if the parent page happens to be page 1 of the database
- ** image. */
- assert( nNew==1 );
+ ** It is critical that the child page be defragmented before being
+ ** copied into the parent, because if the parent is page 1 then it will
+ ** by smaller than the child due to the database header, and so all the
+ ** free space needs to be up front.
+ */
+ assert( nNew==1 || CORRUPT_DB );
+ rc = defragmentPage(apNew[0]);
+ testcase( rc!=SQLITE_OK );
assert( apNew[0]->nFree ==
- (get2byte(&apNew[0]->aData[5])-apNew[0]->cellOffset-apNew[0]->nCell*2)
+ (get2byte(&apNew[0]->aData[5])-apNew[0]->cellOffset-apNew[0]->nCell*2)
+ || rc!=SQLITE_OK
);
copyNodeContent(apNew[0], pParent, &rc);
freePage(apNew[0], &rc);
- }else if( ISAUTOVACUUM ){
- /* Fix the pointer-map entries for all the cells that were shifted around.
- ** There are several different types of pointer-map entries that need to
- ** be dealt with by this routine. Some of these have been set already, but
- ** many have not. The following is a summary:
- **
- ** 1) The entries associated with new sibling pages that were not
- ** siblings when this function was called. These have already
- ** been set. We don't need to worry about old siblings that were
- ** moved to the free-list - the freePage() code has taken care
- ** of those.
- **
- ** 2) The pointer-map entries associated with the first overflow
- ** page in any overflow chains used by new divider cells. These
- ** have also already been taken care of by the insertCell() code.
- **
- ** 3) If the sibling pages are not leaves, then the child pages of
- ** cells stored on the sibling pages may need to be updated.
- **
- ** 4) If the sibling pages are not internal intkey nodes, then any
- ** overflow pages used by these cells may need to be updated
- ** (internal intkey nodes never contain pointers to overflow pages).
- **
- ** 5) If the sibling pages are not leaves, then the pointer-map
- ** entries for the right-child pages of each sibling may need
- ** to be updated.
- **
- ** Cases 1 and 2 are dealt with above by other code. The next
- ** block deals with cases 3 and 4 and the one after that, case 5. Since
- ** setting a pointer map entry is a relatively expensive operation, this
- ** code only sets pointer map entries for child or overflow pages that have
- ** actually moved between pages. */
- MemPage *pNew = apNew[0];
- MemPage *pOld = apCopy[0];
- int nOverflow = pOld->nOverflow;
- int iNextOld = pOld->nCell + nOverflow;
- int iOverflow = (nOverflow ? pOld->aiOvfl[0] : -1);
- j = 0; /* Current 'old' sibling page */
- k = 0; /* Current 'new' sibling page */
- for(i=0; i<nCell; i++){
- int isDivider = 0;
- while( i==iNextOld ){
- /* Cell i is the cell immediately following the last cell on old
- ** sibling page j. If the siblings are not leaf pages of an
- ** intkey b-tree, then cell i was a divider cell. */
- assert( j+1 < ArraySize(apCopy) );
- assert( j+1 < nOld );
- pOld = apCopy[++j];
- iNextOld = i + !leafData + pOld->nCell + pOld->nOverflow;
- if( pOld->nOverflow ){
- nOverflow = pOld->nOverflow;
- iOverflow = i + !leafData + pOld->aiOvfl[0];
- }
- isDivider = !leafData;
- }
-
- assert(nOverflow>0 || iOverflow<i );
- assert(nOverflow<2 || pOld->aiOvfl[0]==pOld->aiOvfl[1]-1);
- assert(nOverflow<3 || pOld->aiOvfl[1]==pOld->aiOvfl[2]-1);
- if( i==iOverflow ){
- isDivider = 1;
- if( (--nOverflow)>0 ){
- iOverflow++;
- }
- }
-
- if( i==cntNew[k] ){
- /* Cell i is the cell immediately following the last cell on new
- ** sibling page k. If the siblings are not leaf pages of an
- ** intkey b-tree, then cell i is a divider cell. */
- pNew = apNew[++k];
- if( !leafData ) continue;
- }
- assert( j<nOld );
- assert( k<nNew );
-
- /* If the cell was originally divider cell (and is not now) or
- ** an overflow cell, or if the cell was located on a different sibling
- ** page before the balancing, then the pointer map entries associated
- ** with any child or overflow pages need to be updated. */
- if( isDivider || pOld->pgno!=pNew->pgno ){
- if( !leafCorrection ){
- ptrmapPut(pBt, get4byte(apCell[i]), PTRMAP_BTREE, pNew->pgno, &rc);
- }
- if( szCell[i]>pNew->minLocal ){
- ptrmapPutOvflPtr(pNew, apCell[i], &rc);
- }
- }
+ }else if( ISAUTOVACUUM && !leafCorrection ){
+ /* Fix the pointer map entries associated with the right-child of each
+ ** sibling page. All other pointer map entries have already been taken
+ ** care of. */
+ for(i=0; i<nNew; i++){
+ u32 key = get4byte(&apNew[i]->aData[8]);
+ ptrmapPut(pBt, key, PTRMAP_BTREE, apNew[i]->pgno, &rc);
}
+ }
- if( !leafCorrection ){
- for(i=0; i<nNew; i++){
- u32 key = get4byte(&apNew[i]->aData[8]);
- ptrmapPut(pBt, key, PTRMAP_BTREE, apNew[i]->pgno, &rc);
- }
- }
+ assert( pParent->isInit );
+ TRACE(("BALANCE: finished: old=%d new=%d cells=%d\n",
+ nOld, nNew, b.nCell));
+
+ /* Free any old pages that were not reused as new pages.
+ */
+ for(i=nNew; i<nOld; i++){
+ freePage(apOld[i], &rc);
+ }
#if 0
+ if( ISAUTOVACUUM && rc==SQLITE_OK && apNew[0]->isInit ){
/* The ptrmapCheckPages() contains assert() statements that verify that
** all pointer map pages are set correctly. This is helpful while
** debugging. This is usually disabled because a corrupt database may
** cause an assert() statement to fail. */
ptrmapCheckPages(apNew, nNew);
ptrmapCheckPages(&pParent, 1);
-#endif
}
-
- assert( pParent->isInit );
- TRACE(("BALANCE: finished: old=%d new=%d cells=%d\n",
- nOld, nNew, nCell));
+#endif
/*
** Cleanup before returning.
*/
balance_cleanup:
- sqlite3ScratchFree(apCell);
+ sqlite3ScratchFree(b.apCell);
for(i=0; i<nOld; i++){
releasePage(apOld[i]);
}
@@ -6900,9 +7717,6 @@ balance_cleanup:
return rc;
}
-#if defined(_MSC_VER) && _MSC_VER >= 1700 && defined(_M_ARM)
-#pragma optimize("", on)
-#endif
/*
@@ -7063,7 +7877,8 @@ static int balance(BtCursor *pCur){
** pSpace buffer passed to the latter call to balance_nonroot().
*/
u8 *pSpace = sqlite3PageMalloc(pCur->pBt->pageSize);
- rc = balance_nonroot(pParent, iIdx, pSpace, iPage==1, pCur->hints);
+ rc = balance_nonroot(pParent, iIdx, pSpace, iPage==1,
+ pCur->hints&BTREE_BULKLOAD);
if( pFree ){
/* If pFree is not NULL, it points to the pSpace buffer used
** by a previous call to balance_nonroot(). Its contents are
@@ -7084,6 +7899,7 @@ static int balance(BtCursor *pCur){
/* The next iteration of the do-loop balances the parent page. */
releasePage(pPage);
pCur->iPage--;
+ assert( pCur->iPage>=0 );
}
}while( rc==SQLITE_OK );
@@ -7163,24 +7979,28 @@ int sqlite3BtreeInsert(
** doing any work. To avoid thwarting these optimizations, it is important
** not to clear the cursor here.
*/
- rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
- if( rc ) return rc;
+ if( pCur->curFlags & BTCF_Multiple ){
+ rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
+ if( rc ) return rc;
+ }
if( pCur->pKeyInfo==0 ){
+ assert( pKey==0 );
/* If this is an insert into a table b-tree, invalidate any incrblob
** cursors open on the row being replaced */
invalidateIncrblobCursors(p, nKey, 0);
/* If the cursor is currently on the last row and we are appending a
- ** new row onto the end, set the "loc" to avoid an unnecessary btreeMoveto()
- ** call */
+ ** new row onto the end, set the "loc" to avoid an unnecessary
+ ** btreeMoveto() call */
if( (pCur->curFlags&BTCF_ValidNKey)!=0 && nKey>0
&& pCur->info.nKey==nKey-1 ){
- loc = -1;
+ loc = -1;
+ }else if( loc==0 ){
+ rc = sqlite3BtreeMovetoUnpacked(pCur, 0, nKey, appendBias, &loc);
+ if( rc ) return rc;
}
- }
-
- if( !loc ){
+ }else if( loc==0 ){
rc = btreeMoveto(pCur, pKey, nKey, appendBias, &loc);
if( rc ) return rc;
}
@@ -7198,7 +8018,7 @@ int sqlite3BtreeInsert(
assert( newCell!=0 );
rc = fillInCell(pPage, newCell, pKey, nKey, pData, nData, nZero, &szNew);
if( rc ) goto end_insert;
- assert( szNew==cellSizePtr(pPage, newCell) );
+ assert( szNew==pPage->xCellSize(pPage, newCell) );
assert( szNew <= MX_CELL_SIZE(pBt) );
idx = pCur->aiIdx[pCur->iPage];
if( loc==0 ){
@@ -7263,10 +8083,15 @@ end_insert:
}
/*
-** Delete the entry that the cursor is pointing to. The cursor
-** is left pointing at an arbitrary location.
+** Delete the entry that the cursor is pointing to.
+**
+** If the second parameter is zero, then the cursor is left pointing at an
+** arbitrary location after the delete. If it is non-zero, then the cursor
+** is left in a state such that the next call to BtreeNext() or BtreePrev()
+** moves it to the same row as it would if the call to BtreeDelete() had
+** been omitted.
*/
-int sqlite3BtreeDelete(BtCursor *pCur){
+int sqlite3BtreeDelete(BtCursor *pCur, int bPreserve){
Btree *p = pCur->pBtree;
BtShared *pBt = p->pBt;
int rc; /* Return code */
@@ -7275,6 +8100,7 @@ int sqlite3BtreeDelete(BtCursor *pCur){
int iCellIdx; /* Index of cell to delete */
int iCellDepth; /* Depth of node containing pCell */
u16 szCell; /* Size of the cell being deleted */
+ int bSkipnext = 0; /* Leaf cursor in SKIPNEXT state */
assert( cursorHoldsMutex(pCur) );
assert( pBt->inTransaction==TRANS_WRITE );
@@ -7282,12 +8108,8 @@ int sqlite3BtreeDelete(BtCursor *pCur){
assert( pCur->curFlags & BTCF_WriteFlag );
assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );
assert( !hasReadConflicts(p, pCur->pgnoRoot) );
-
- if( NEVER(pCur->aiIdx[pCur->iPage]>=pCur->apPage[pCur->iPage]->nCell)
- || NEVER(pCur->eState!=CURSOR_VALID)
- ){
- return SQLITE_ERROR; /* Something has gone awry. */
- }
+ assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
+ assert( pCur->eState==CURSOR_VALID );
iCellDepth = pCur->iPage;
iCellIdx = pCur->aiIdx[iCellDepth];
@@ -7308,12 +8130,11 @@ int sqlite3BtreeDelete(BtCursor *pCur){
}
/* Save the positions of any other cursors open on this table before
- ** making any modifications. Make the page containing the entry to be
- ** deleted writable. Then free any overflow pages associated with the
- ** entry and finally remove the cell itself from within the page.
- */
- rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
- if( rc ) return rc;
+ ** making any modifications. */
+ if( pCur->curFlags & BTCF_Multiple ){
+ rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);
+ if( rc ) return rc;
+ }
/* If this is a delete operation to remove a row from a table b-tree,
** invalidate any incrblob cursors open on the row being deleted. */
@@ -7321,6 +8142,31 @@ int sqlite3BtreeDelete(BtCursor *pCur){
invalidateIncrblobCursors(p, pCur->info.nKey, 0);
}
+ /* If the bPreserve flag is set to true, then the cursor position must
+ ** be preserved following this delete operation. If the current delete
+ ** will cause a b-tree rebalance, then this is done by saving the cursor
+ ** key and leaving the cursor in CURSOR_REQUIRESEEK state before
+ ** returning.
+ **
+ ** Or, if the current delete will not cause a rebalance, then the cursor
+ ** will be left in CURSOR_SKIPNEXT state pointing to the entry immediately
+ ** before or after the deleted entry. In this case set bSkipnext to true. */
+ if( bPreserve ){
+ if( !pPage->leaf
+ || (pPage->nFree+cellSizePtr(pPage,pCell)+2)>(int)(pBt->usableSize*2/3)
+ ){
+ /* A b-tree rebalance will be required after deleting this entry.
+ ** Save the cursor key. */
+ rc = saveCursorKey(pCur);
+ if( rc ) return rc;
+ }else{
+ bSkipnext = 1;
+ }
+ }
+
+ /* Make the page containing the entry to be deleted writable. Then free any
+ ** overflow pages associated with the entry and finally remove the cell
+ ** itself from within the page. */
rc = sqlite3PagerWrite(pPage->pDbPage);
if( rc ) return rc;
rc = clearCell(pPage, pCell, &szCell);
@@ -7339,7 +8185,8 @@ int sqlite3BtreeDelete(BtCursor *pCur){
unsigned char *pTmp;
pCell = findCell(pLeaf, pLeaf->nCell-1);
- nCell = cellSizePtr(pLeaf, pCell);
+ if( pCell<&pLeaf->aData[4] ) return SQLITE_CORRUPT_BKPT;
+ nCell = pLeaf->xCellSize(pLeaf, pCell);
assert( MX_CELL_SIZE(pBt) >= nCell );
pTmp = pBt->pTmpSpace;
assert( pTmp!=0 );
@@ -7373,7 +8220,23 @@ int sqlite3BtreeDelete(BtCursor *pCur){
}
if( rc==SQLITE_OK ){
- moveToRoot(pCur);
+ if( bSkipnext ){
+ assert( bPreserve && (pCur->iPage==iCellDepth || CORRUPT_DB) );
+ assert( pPage==pCur->apPage[pCur->iPage] );
+ assert( (pPage->nCell>0 || CORRUPT_DB) && iCellIdx<=pPage->nCell );
+ pCur->eState = CURSOR_SKIPNEXT;
+ if( iCellIdx>=pPage->nCell ){
+ pCur->skipNext = -1;
+ pCur->aiIdx[iCellDepth] = pPage->nCell-1;
+ }else{
+ pCur->skipNext = 1;
+ }
+ }else{
+ rc = moveToRoot(pCur);
+ if( bPreserve ){
+ pCur->eState = CURSOR_REQUIRESEEK;
+ }
+ }
}
return rc;
}
@@ -7431,7 +8294,8 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
pgnoRoot==PENDING_BYTE_PAGE(pBt) ){
pgnoRoot++;
}
- assert( pgnoRoot>=3 );
+ assert( pgnoRoot>=3 || CORRUPT_DB );
+ testcase( pgnoRoot<3 );
/* Allocate a page. The page that currently resides at pgnoRoot will
** be moved to the allocated page (unless the allocated page happens
@@ -7560,9 +8424,13 @@ static int clearDatabasePage(
if( pgno>btreePagecount(pBt) ){
return SQLITE_CORRUPT_BKPT;
}
-
- rc = getAndInitPage(pBt, pgno, &pPage, 0);
+ rc = getAndInitPage(pBt, pgno, &pPage, 0, 0);
if( rc ) return rc;
+ if( pPage->bBusy ){
+ rc = SQLITE_CORRUPT_BKPT;
+ goto cleardatabasepage_out;
+ }
+ pPage->bBusy = 1;
hdr = pPage->hdrOffset;
for(i=0; i<pPage->nCell; i++){
pCell = findCell(pPage, i);
@@ -7577,7 +8445,8 @@ static int clearDatabasePage(
rc = clearDatabasePage(pBt, get4byte(&pPage->aData[hdr+8]), 1, pnChange);
if( rc ) goto cleardatabasepage_out;
}else if( pnChange ){
- assert( pPage->intKey );
+ assert( pPage->intKey || CORRUPT_DB );
+ testcase( !pPage->intKey );
*pnChange += pPage->nCell;
}
if( freePageFlag ){
@@ -7587,6 +8456,7 @@ static int clearDatabasePage(
}
cleardatabasepage_out:
+ pPage->bBusy = 0;
releasePage(pPage);
return rc;
}
@@ -7776,6 +8646,13 @@ int sqlite3BtreeDropTable(Btree *p, int iTable, int *piMoved){
** The schema layer numbers meta values differently. At the schema
** layer (and the SetCookie and ReadCookie opcodes) the number of
** free pages is not visible. So Cookie[0] is the same as Meta[1].
+**
+** This routine treats Meta[BTREE_DATA_VERSION] as a special case. Instead
+** of reading the value out of the header, it instead loads the "DataVersion"
+** from the pager. The BTREE_DATA_VERSION value is not actually stored in the
+** database file. It is a number computed by the pager. But its access
+** pattern is the same as header meta values, and so it is convenient to
+** read it from this routine.
*/
void sqlite3BtreeGetMeta(Btree *p, int idx, u32 *pMeta){
BtShared *pBt = p->pBt;
@@ -7786,7 +8663,11 @@ void sqlite3BtreeGetMeta(Btree *p, int idx, u32 *pMeta){
assert( pBt->pPage1 );
assert( idx>=0 && idx<=15 );
- *pMeta = get4byte(&pBt->pPage1->aData[36 + idx*4]);
+ if( idx==BTREE_DATA_VERSION ){
+ *pMeta = sqlite3PagerDataVersion(pBt->pPager) + p->iDataVersion;
+ }else{
+ *pMeta = get4byte(&pBt->pPage1->aData[36 + idx*4]);
+ }
/* If auto-vacuum is disabled in this build and this is an auto-vacuum
** database, mark the database as read-only. */
@@ -7877,7 +8758,7 @@ int sqlite3BtreeCount(BtCursor *pCur, i64 *pnEntry){
if( pCur->iPage==0 ){
/* All pages of the b-tree have been visited. Return successfully. */
*pnEntry = nEntry;
- return SQLITE_OK;
+ return moveToRoot(pCur);
}
moveToParent(pCur);
}while ( pCur->aiIdx[pCur->iPage]>=pCur->apPage[pCur->iPage]->nCell );
@@ -7920,7 +8801,6 @@ static void checkAppendMsg(
...
){
va_list ap;
- char zBuf[200];
if( !pCheck->mxErr ) return;
pCheck->mxErr--;
pCheck->nErr++;
@@ -7929,8 +8809,7 @@ static void checkAppendMsg(
sqlite3StrAccumAppend(&pCheck->errMsg, "\n", 1);
}
if( pCheck->zPfx ){
- sqlite3_snprintf(sizeof(zBuf), zBuf, pCheck->zPfx, pCheck->v1, pCheck->v2);
- sqlite3StrAccumAppendAll(&pCheck->errMsg, zBuf);
+ sqlite3XPrintf(&pCheck->errMsg, 0, pCheck->zPfx, pCheck->v1, pCheck->v2);
}
sqlite3VXPrintf(&pCheck->errMsg, 1, zFormat, ap);
va_end(ap);
@@ -8036,7 +8915,7 @@ static void checkList(
break;
}
if( checkRef(pCheck, iPage) ) break;
- if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage) ){
+ if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage, 0) ){
checkAppendMsg(pCheck, "failed to get page %d", iPage);
break;
}
@@ -8079,10 +8958,65 @@ static void checkList(
#endif
iPage = get4byte(pOvflData);
sqlite3PagerUnref(pOvflPage);
+
+ if( isFreeList && N<(iPage!=0) ){
+ checkAppendMsg(pCheck, "free-page count in header is too small");
+ }
}
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
+/*
+** An implementation of a min-heap.
+**
+** aHeap[0] is the number of elements on the heap. aHeap[1] is the
+** root element. The daughter nodes of aHeap[N] are aHeap[N*2]
+** and aHeap[N*2+1].
+**
+** The heap property is this: Every node is less than or equal to both
+** of its daughter nodes. A consequence of the heap property is that the
+** root node aHeap[1] is always the minimum value currently in the heap.
+**
+** The btreeHeapInsert() routine inserts an unsigned 32-bit number onto
+** the heap, preserving the heap property. The btreeHeapPull() routine
+** removes the root element from the heap (the minimum value in the heap)
+** and then moves other nodes around as necessary to preserve the heap
+** property.
+**
+** This heap is used for cell overlap and coverage testing. Each u32
+** entry represents the span of a cell or freeblock on a btree page.
+** The upper 16 bits are the index of the first byte of a range and the
+** lower 16 bits are the index of the last byte of that range.
+*/
+static void btreeHeapInsert(u32 *aHeap, u32 x){
+ u32 j, i = ++aHeap[0];
+ aHeap[i] = x;
+ while( (j = i/2)>0 && aHeap[j]>aHeap[i] ){
+ x = aHeap[j];
+ aHeap[j] = aHeap[i];
+ aHeap[i] = x;
+ i = j;
+ }
+}
+static int btreeHeapPull(u32 *aHeap, u32 *pOut){
+ u32 j, i, x;
+ if( (x = aHeap[0])==0 ) return 0;
+ *pOut = aHeap[1];
+ aHeap[1] = aHeap[x];
+ aHeap[x] = 0xffffffff;
+ aHeap[0]--;
+ i = 1;
+ while( (j = i*2)<=aHeap[0] ){
+ if( aHeap[j]>aHeap[j+1] ) j++;
+ if( aHeap[i]<aHeap[j] ) break;
+ x = aHeap[i];
+ aHeap[i] = aHeap[j];
+ aHeap[j] = x;
+ i = j;
+ }
+ return 1;
+}
+
#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/*
** Do various sanity checks on a single page of a tree. Return
@@ -8093,34 +9027,42 @@ static void checkList(
**
** 1. Make sure that cells and freeblocks do not overlap
** but combine to completely cover the page.
-** NO 2. Make sure cell keys are in order.
-** NO 3. Make sure no key is less than or equal to zLowerBound.
-** NO 4. Make sure no key is greater than or equal to zUpperBound.
-** 5. Check the integrity of overflow pages.
-** 6. Recursively call checkTreePage on all children.
-** 7. Verify that the depth of all children is the same.
-** 8. Make sure this page is at least 33% full or else it is
-** the root of the tree.
+** 2. Make sure integer cell keys are in order.
+** 3. Check the integrity of overflow pages.
+** 4. Recursively call checkTreePage on all children.
+** 5. Verify that the depth of all children is the same.
*/
static int checkTreePage(
IntegrityCk *pCheck, /* Context for the sanity check */
int iPage, /* Page number of the page to check */
- i64 *pnParentMinKey,
- i64 *pnParentMaxKey
+ i64 *piMinKey, /* Write minimum integer primary key here */
+ i64 maxKey /* Error if integer primary key greater than this */
){
- MemPage *pPage;
- int i, rc, depth, d2, pgno, cnt;
- int hdr, cellStart;
- int nCell;
- u8 *data;
- BtShared *pBt;
- int usableSize;
- char *hit = 0;
- i64 nMinKey = 0;
- i64 nMaxKey = 0;
+ MemPage *pPage = 0; /* The page being analyzed */
+ int i; /* Loop counter */
+ int rc; /* Result code from subroutine call */
+ int depth = -1, d2; /* Depth of a subtree */
+ int pgno; /* Page number */
+ int nFrag; /* Number of fragmented bytes on the page */
+ int hdr; /* Offset to the page header */
+ int cellStart; /* Offset to the start of the cell pointer array */
+ int nCell; /* Number of cells */
+ int doCoverageCheck = 1; /* True if cell coverage checking should be done */
+ int keyCanBeEqual = 1; /* True if IPK can be equal to maxKey
+ ** False if IPK must be strictly less than maxKey */
+ u8 *data; /* Page content */
+ u8 *pCell; /* Cell content */
+ u8 *pCellIdx; /* Next element of the cell pointer array */
+ BtShared *pBt; /* The BtShared object that owns pPage */
+ u32 pc; /* Address of a cell */
+ u32 usableSize; /* Usable size of the page */
+ u32 contentOffset; /* Offset to the start of the cell content area */
+ u32 *heap = 0; /* Min-heap used for checking cell coverage */
+ u32 x, prev = 0; /* Next and previous entry on the min-heap */
const char *saved_zPfx = pCheck->zPfx;
int saved_v1 = pCheck->v1;
int saved_v2 = pCheck->v2;
+ u8 savedIsInit = 0;
/* Check that the page exists
*/
@@ -8133,54 +9075,95 @@ static int checkTreePage(
if( (rc = btreeGetPage(pBt, (Pgno)iPage, &pPage, 0))!=0 ){
checkAppendMsg(pCheck,
"unable to get the page. error code=%d", rc);
- depth = -1;
goto end_of_check;
}
/* Clear MemPage.isInit to make sure the corruption detection code in
** btreeInitPage() is executed. */
+ savedIsInit = pPage->isInit;
pPage->isInit = 0;
if( (rc = btreeInitPage(pPage))!=0 ){
assert( rc==SQLITE_CORRUPT ); /* The only possible error from InitPage */
checkAppendMsg(pCheck,
"btreeInitPage() returns error code %d", rc);
- releasePage(pPage);
- depth = -1;
goto end_of_check;
}
+ data = pPage->aData;
+ hdr = pPage->hdrOffset;
- /* Check out all the cells.
- */
- depth = 0;
- for(i=0; i<pPage->nCell && pCheck->mxErr; i++){
- u8 *pCell;
- u32 sz;
+ /* Set up for cell analysis */
+ pCheck->zPfx = "On tree page %d cell %d: ";
+ contentOffset = get2byteNotZero(&data[hdr+5]);
+ assert( contentOffset<=usableSize ); /* Enforced by btreeInitPage() */
+
+ /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
+ ** number of cells on the page. */
+ nCell = get2byte(&data[hdr+3]);
+ assert( pPage->nCell==nCell );
+
+ /* EVIDENCE-OF: R-23882-45353 The cell pointer array of a b-tree page
+ ** immediately follows the b-tree page header. */
+ cellStart = hdr + 12 - 4*pPage->leaf;
+ assert( pPage->aCellIdx==&data[cellStart] );
+ pCellIdx = &data[cellStart + 2*(nCell-1)];
+
+ if( !pPage->leaf ){
+ /* Analyze the right-child page of internal pages */
+ pgno = get4byte(&data[hdr+8]);
+#ifndef SQLITE_OMIT_AUTOVACUUM
+ if( pBt->autoVacuum ){
+ pCheck->zPfx = "On page %d at right child: ";
+ checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage);
+ }
+#endif
+ depth = checkTreePage(pCheck, pgno, &maxKey, maxKey);
+ keyCanBeEqual = 0;
+ }else{
+ /* For leaf pages, the coverage check will occur in the same loop
+ ** as the other cell checks, so initialize the heap. */
+ heap = pCheck->heap;
+ heap[0] = 0;
+ }
+
+ /* EVIDENCE-OF: R-02776-14802 The cell pointer array consists of K 2-byte
+ ** integer offsets to the cell contents. */
+ for(i=nCell-1; i>=0 && pCheck->mxErr; i--){
CellInfo info;
- /* Check payload overflow pages
- */
- pCheck->zPfx = "On tree page %d cell %d: ";
- pCheck->v1 = iPage;
+ /* Check cell size */
pCheck->v2 = i;
- pCell = findCell(pPage,i);
- btreeParseCellPtr(pPage, pCell, &info);
- sz = info.nPayload;
- /* For intKey pages, check that the keys are in order.
- */
+ assert( pCellIdx==&data[cellStart + i*2] );
+ pc = get2byteAligned(pCellIdx);
+ pCellIdx -= 2;
+ if( pc<contentOffset || pc>usableSize-4 ){
+ checkAppendMsg(pCheck, "Offset %d out of range %d..%d",
+ pc, contentOffset, usableSize-4);
+ doCoverageCheck = 0;
+ continue;
+ }
+ pCell = &data[pc];
+ pPage->xParseCell(pPage, pCell, &info);
+ if( pc+info.nSize>usableSize ){
+ checkAppendMsg(pCheck, "Extends off end of page");
+ doCoverageCheck = 0;
+ continue;
+ }
+
+ /* Check for integer primary key out of range */
if( pPage->intKey ){
- if( i==0 ){
- nMinKey = nMaxKey = info.nKey;
- }else if( info.nKey <= nMaxKey ){
- checkAppendMsg(pCheck,
- "Rowid %lld out of order (previous was %lld)", info.nKey, nMaxKey);
+ if( keyCanBeEqual ? (info.nKey > maxKey) : (info.nKey >= maxKey) ){
+ checkAppendMsg(pCheck, "Rowid %lld out of order", info.nKey);
}
- nMaxKey = info.nKey;
+ maxKey = info.nKey;
}
- if( (sz>info.nLocal)
- && (&pCell[info.iOverflow]<=&pPage->aData[pBt->usableSize])
- ){
- int nPage = (sz - info.nLocal + usableSize - 5)/(usableSize - 4);
- Pgno pgnoOvfl = get4byte(&pCell[info.iOverflow]);
+
+ /* Check the content overflow list */
+ if( info.nPayload>info.nLocal ){
+ int nPage; /* Number of pages on the overflow chain */
+ Pgno pgnoOvfl; /* First page of the overflow chain */
+ assert( pc + info.nSize - 4 <= usableSize );
+ nPage = (info.nPayload - info.nLocal + usableSize - 5)/(usableSize - 4);
+ pgnoOvfl = get4byte(&pCell[info.nSize - 4]);
#ifndef SQLITE_OMIT_AUTOVACUUM
if( pBt->autoVacuum ){
checkPtrmap(pCheck, pgnoOvfl, PTRMAP_OVERFLOW1, iPage);
@@ -8189,134 +9172,109 @@ static int checkTreePage(
checkList(pCheck, 0, pgnoOvfl, nPage);
}
- /* Check sanity of left child page.
- */
if( !pPage->leaf ){
+ /* Check sanity of left child page for internal pages */
pgno = get4byte(pCell);
#ifndef SQLITE_OMIT_AUTOVACUUM
if( pBt->autoVacuum ){
checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage);
}
#endif
- d2 = checkTreePage(pCheck, pgno, &nMinKey, i==0?NULL:&nMaxKey);
- if( i>0 && d2!=depth ){
+ d2 = checkTreePage(pCheck, pgno, &maxKey, maxKey);
+ keyCanBeEqual = 0;
+ if( d2!=depth ){
checkAppendMsg(pCheck, "Child page depth differs");
+ depth = d2;
}
- depth = d2;
- }
- }
-
- if( !pPage->leaf ){
- pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);
- pCheck->zPfx = "On page %d at right child: ";
- pCheck->v1 = iPage;
-#ifndef SQLITE_OMIT_AUTOVACUUM
- if( pBt->autoVacuum ){
- checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage);
- }
-#endif
- checkTreePage(pCheck, pgno, NULL, !pPage->nCell?NULL:&nMaxKey);
- }
-
- /* For intKey leaf pages, check that the min/max keys are in order
- ** with any left/parent/right pages.
- */
- pCheck->zPfx = "Page %d: ";
- pCheck->v1 = iPage;
- if( pPage->leaf && pPage->intKey ){
- /* if we are a left child page */
- if( pnParentMinKey ){
- /* if we are the left most child page */
- if( !pnParentMaxKey ){
- if( nMaxKey > *pnParentMinKey ){
- checkAppendMsg(pCheck,
- "Rowid %lld out of order (max larger than parent min of %lld)",
- nMaxKey, *pnParentMinKey);
- }
- }else{
- if( nMinKey <= *pnParentMinKey ){
- checkAppendMsg(pCheck,
- "Rowid %lld out of order (min less than parent min of %lld)",
- nMinKey, *pnParentMinKey);
- }
- if( nMaxKey > *pnParentMaxKey ){
- checkAppendMsg(pCheck,
- "Rowid %lld out of order (max larger than parent max of %lld)",
- nMaxKey, *pnParentMaxKey);
- }
- *pnParentMinKey = nMaxKey;
- }
- /* else if we're a right child page */
- } else if( pnParentMaxKey ){
- if( nMinKey <= *pnParentMaxKey ){
- checkAppendMsg(pCheck,
- "Rowid %lld out of order (min less than parent max of %lld)",
- nMinKey, *pnParentMaxKey);
- }
+ }else{
+ /* Populate the coverage-checking heap for leaf pages */
+ btreeHeapInsert(heap, (pc<<16)|(pc+info.nSize-1));
}
}
+ *piMinKey = maxKey;
/* Check for complete coverage of the page
*/
- data = pPage->aData;
- hdr = pPage->hdrOffset;
- hit = sqlite3PageMalloc( pBt->pageSize );
pCheck->zPfx = 0;
- if( hit==0 ){
- pCheck->mallocFailed = 1;
- }else{
- int contentOffset = get2byteNotZero(&data[hdr+5]);
- assert( contentOffset<=usableSize ); /* Enforced by btreeInitPage() */
- memset(hit+contentOffset, 0, usableSize-contentOffset);
- memset(hit, 1, contentOffset);
- nCell = get2byte(&data[hdr+3]);
- cellStart = hdr + 12 - 4*pPage->leaf;
- for(i=0; i<nCell; i++){
- int pc = get2byte(&data[cellStart+i*2]);
- u32 size = 65536;
- int j;
- if( pc<=usableSize-4 ){
- size = cellSizePtr(pPage, &data[pc]);
- }
- if( (int)(pc+size-1)>=usableSize ){
- pCheck->zPfx = 0;
- checkAppendMsg(pCheck,
- "Corruption detected in cell %d on page %d",i,iPage);
- }else{
- for(j=pc+size-1; j>=pc; j--) hit[j]++;
+ if( doCoverageCheck && pCheck->mxErr>0 ){
+ /* For leaf pages, the min-heap has already been initialized and the
+ ** cells have already been inserted. But for internal pages, that has
+ ** not yet been done, so do it now */
+ if( !pPage->leaf ){
+ heap = pCheck->heap;
+ heap[0] = 0;
+ for(i=nCell-1; i>=0; i--){
+ u32 size;
+ pc = get2byteAligned(&data[cellStart+i*2]);
+ size = pPage->xCellSize(pPage, &data[pc]);
+ btreeHeapInsert(heap, (pc<<16)|(pc+size-1));
}
}
+ /* Add the freeblocks to the min-heap
+ **
+ ** EVIDENCE-OF: R-20690-50594 The second field of the b-tree page header
+ ** is the offset of the first freeblock, or zero if there are no
+ ** freeblocks on the page.
+ */
i = get2byte(&data[hdr+1]);
while( i>0 ){
int size, j;
- assert( i<=usableSize-4 ); /* Enforced by btreeInitPage() */
+ assert( (u32)i<=usableSize-4 ); /* Enforced by btreeInitPage() */
size = get2byte(&data[i+2]);
- assert( i+size<=usableSize ); /* Enforced by btreeInitPage() */
- for(j=i+size-1; j>=i; j--) hit[j]++;
+ assert( (u32)(i+size)<=usableSize ); /* Enforced by btreeInitPage() */
+ btreeHeapInsert(heap, (((u32)i)<<16)|(i+size-1));
+ /* EVIDENCE-OF: R-58208-19414 The first 2 bytes of a freeblock are a
+ ** big-endian integer which is the offset in the b-tree page of the next
+ ** freeblock in the chain, or zero if the freeblock is the last on the
+ ** chain. */
j = get2byte(&data[i]);
+ /* EVIDENCE-OF: R-06866-39125 Freeblocks are always connected in order of
+ ** increasing offset. */
assert( j==0 || j>i+size ); /* Enforced by btreeInitPage() */
- assert( j<=usableSize-4 ); /* Enforced by btreeInitPage() */
+ assert( (u32)j<=usableSize-4 ); /* Enforced by btreeInitPage() */
i = j;
}
- for(i=cnt=0; i<usableSize; i++){
- if( hit[i]==0 ){
- cnt++;
- }else if( hit[i]>1 ){
+ /* Analyze the min-heap looking for overlap between cells and/or
+ ** freeblocks, and counting the number of untracked bytes in nFrag.
+ **
+ ** Each min-heap entry is of the form: (start_address<<16)|end_address.
+ ** There is an implied first entry the covers the page header, the cell
+ ** pointer index, and the gap between the cell pointer index and the start
+ ** of cell content.
+ **
+ ** The loop below pulls entries from the min-heap in order and compares
+ ** the start_address against the previous end_address. If there is an
+ ** overlap, that means bytes are used multiple times. If there is a gap,
+ ** that gap is added to the fragmentation count.
+ */
+ nFrag = 0;
+ prev = contentOffset - 1; /* Implied first min-heap entry */
+ while( btreeHeapPull(heap,&x) ){
+ if( (prev&0xffff)>=(x>>16) ){
checkAppendMsg(pCheck,
- "Multiple uses for byte %d of page %d", i, iPage);
+ "Multiple uses for byte %u of page %d", x>>16, iPage);
break;
+ }else{
+ nFrag += (x>>16) - (prev&0xffff) - 1;
+ prev = x;
}
}
- if( cnt!=data[hdr+7] ){
+ nFrag += usableSize - (prev&0xffff) - 1;
+ /* EVIDENCE-OF: R-43263-13491 The total number of bytes in all fragments
+ ** is stored in the fifth field of the b-tree page header.
+ ** EVIDENCE-OF: R-07161-27322 The one-byte integer at offset 7 gives the
+ ** number of fragmented free bytes within the cell content area.
+ */
+ if( heap[0]==0 && nFrag!=data[hdr+7] ){
checkAppendMsg(pCheck,
"Fragmentation of %d bytes reported as %d on page %d",
- cnt, data[hdr+7], iPage);
+ nFrag, data[hdr+7], iPage);
}
}
- sqlite3PageFree(hit);
- releasePage(pPage);
end_of_check:
+ if( !doCoverageCheck ) pPage->isInit = savedIsInit;
+ releasePage(pPage);
pCheck->zPfx = saved_zPfx;
pCheck->v1 = saved_v1;
pCheck->v2 = saved_v2;
@@ -8346,14 +9304,15 @@ char *sqlite3BtreeIntegrityCheck(
int *pnErr /* Write number of errors seen to this variable */
){
Pgno i;
- int nRef;
IntegrityCk sCheck;
BtShared *pBt = p->pBt;
+ int savedDbFlags = pBt->db->flags;
char zErr[100];
+ VVA_ONLY( int nRef );
sqlite3BtreeEnter(p);
assert( p->inTrans>TRANS_NONE && pBt->inTransaction>TRANS_NONE );
- nRef = sqlite3PagerRefcount(pBt->pPager);
+ assert( (nRef = sqlite3PagerRefcount(pBt->pPager))>=0 );
sCheck.pBt = pBt;
sCheck.pPager = pBt->pPager;
sCheck.nPage = btreePagecount(sCheck.pBt);
@@ -8363,22 +9322,26 @@ char *sqlite3BtreeIntegrityCheck(
sCheck.zPfx = 0;
sCheck.v1 = 0;
sCheck.v2 = 0;
- *pnErr = 0;
+ sCheck.aPgRef = 0;
+ sCheck.heap = 0;
+ sqlite3StrAccumInit(&sCheck.errMsg, 0, zErr, sizeof(zErr), SQLITE_MAX_LENGTH);
if( sCheck.nPage==0 ){
- sqlite3BtreeLeave(p);
- return 0;
+ goto integrity_ck_cleanup;
}
sCheck.aPgRef = sqlite3MallocZero((sCheck.nPage / 8)+ 1);
if( !sCheck.aPgRef ){
- *pnErr = 1;
- sqlite3BtreeLeave(p);
- return 0;
+ sCheck.mallocFailed = 1;
+ goto integrity_ck_cleanup;
+ }
+ sCheck.heap = (u32*)sqlite3PageMalloc( pBt->pageSize );
+ if( sCheck.heap==0 ){
+ sCheck.mallocFailed = 1;
+ goto integrity_ck_cleanup;
}
+
i = PENDING_BYTE_PAGE(pBt);
if( i<=sCheck.nPage ) setPageReferenced(&sCheck, i);
- sqlite3StrAccumInit(&sCheck.errMsg, zErr, sizeof(zErr), SQLITE_MAX_LENGTH);
- sCheck.errMsg.useMalloc = 2;
/* Check the integrity of the freelist
*/
@@ -8389,17 +9352,19 @@ char *sqlite3BtreeIntegrityCheck(
/* Check all the tables.
*/
+ testcase( pBt->db->flags & SQLITE_CellSizeCk );
+ pBt->db->flags &= ~SQLITE_CellSizeCk;
for(i=0; (int)i<nRoot && sCheck.mxErr; i++){
+ i64 notUsed;
if( aRoot[i]==0 ) continue;
#ifndef SQLITE_OMIT_AUTOVACUUM
if( pBt->autoVacuum && aRoot[i]>1 ){
checkPtrmap(&sCheck, aRoot[i], PTRMAP_ROOTPAGE, 0);
}
#endif
- sCheck.zPfx = "List of tree roots: ";
- checkTreePage(&sCheck, aRoot[i], NULL, NULL);
- sCheck.zPfx = 0;
+ checkTreePage(&sCheck, aRoot[i], &notUsed, LARGEST_INT64);
}
+ pBt->db->flags = savedDbFlags;
/* Make sure every page in the file is referenced
*/
@@ -8423,28 +9388,20 @@ char *sqlite3BtreeIntegrityCheck(
#endif
}
- /* Make sure this analysis did not leave any unref() pages.
- ** This is an internal consistency check; an integrity check
- ** of the integrity check.
- */
- if( NEVER(nRef != sqlite3PagerRefcount(pBt->pPager)) ){
- checkAppendMsg(&sCheck,
- "Outstanding page count goes from %d to %d during this analysis",
- nRef, sqlite3PagerRefcount(pBt->pPager)
- );
- }
-
/* Clean up and report errors.
*/
- sqlite3BtreeLeave(p);
+integrity_ck_cleanup:
+ sqlite3PageFree(sCheck.heap);
sqlite3_free(sCheck.aPgRef);
if( sCheck.mallocFailed ){
sqlite3StrAccumReset(&sCheck.errMsg);
- *pnErr = sCheck.nErr+1;
- return 0;
+ sCheck.nErr++;
}
*pnErr = sCheck.nErr;
if( sCheck.nErr==0 ) sqlite3StrAccumReset(&sCheck.errMsg);
+ /* Make sure this analysis did not leave any unref() pages. */
+ assert( nRef==sqlite3PagerRefcount(pBt->pPager) );
+ sqlite3BtreeLeave(p);
return sqlite3StrAccumFinish(&sCheck.errMsg);
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
@@ -8655,6 +9612,7 @@ int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void *z){
*/
void sqlite3BtreeIncrblobCursor(BtCursor *pCur){
pCur->curFlags |= BTCF_Incrblob;
+ pCur->pBtree->hasIncrblobCur = 1;
}
#endif
@@ -8695,12 +9653,11 @@ int sqlite3BtreeSetVersion(Btree *pBtree, int iVersion){
}
/*
-** set the mask of hint flags for cursor pCsr. Currently the only valid
-** values are 0 and BTREE_BULKLOAD.
+** Return true if the cursor has a hint specified. This routine is
+** only used from within assert() statements
*/
-void sqlite3BtreeCursorHints(BtCursor *pCsr, unsigned int mask){
- assert( mask==BTREE_BULKLOAD || mask==0 );
- pCsr->hints = mask;
+int sqlite3BtreeCursorHasHint(BtCursor *pCsr, unsigned int mask){
+ return (pCsr->hints & mask)!=0;
}
/*
@@ -8709,3 +9666,8 @@ void sqlite3BtreeCursorHints(BtCursor *pCsr, unsigned int mask){
int sqlite3BtreeIsReadonly(Btree *p){
return (p->pBt->btsFlags & BTS_READ_ONLY)!=0;
}
+
+/*
+** Return the size of the header added to each page by this module.
+*/
+int sqlite3HeaderSizeBtree(void){ return ROUND8(sizeof(MemPage)); }
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