}
/*
-** 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.
+** 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 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;
+ }
+ pInfo->iOverflow = (u16)(&pInfo->pPayload[pInfo->nLocal] - pCell);
+ pInfo->nSize = pInfo->iOverflow + 4;
+}
+
+/*
+** 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 );
+ pInfo->nSize = 4 + getVarint(&pCell[4], (u64*)&pInfo->nKey);
+ pInfo->nPayload = 0;
+ pInfo->nLocal = 0;
+ pInfo->iOverflow = 0;
+ pInfo->pPayload = 0;
+ return;
+}
static void btreeParseCellPtr(
MemPage *pPage, /* Page containing the cell */
u8 *pCell, /* Pointer to the cell text. */
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;
+ assert( pPage->intKeyLeaf || pPage->noPayload );
+ assert( pPage->noPayload==0 );
+ assert( pPage->intKeyLeaf );
+ assert( pPage->childPtrSize==0 );
+ pIter = pCell + getVarint32(pCell, nPayload);
+ pIter += getVarint(pIter, (u64*)&pInfo->nKey);
+ 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.
+ */
+ pInfo->nSize = nPayload + (u16)(pIter - pCell);
+ if( pInfo->nSize<4 ) pInfo->nSize = 4;
+ pInfo->nLocal = (u16)nPayload;
pInfo->iOverflow = 0;
- pInfo->pPayload = 0;
- return;
}else{
- pIter = pCell + pPage->childPtrSize;
- pIter += getVarint32(pIter, nPayload);
- pInfo->nKey = nPayload;
+ 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[9];
+ 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 );
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.
- */
- 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;
+ btreeParseCellAdjustSizeForOverflow(pPage, pCell, pInfo);
}
}
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.
**
-** The first implementation, cellSizePtr(), handles pages that contain
-** payload, which is to say all index pages and left table pages. The
-** second cellSizePtrNoPayload() implemention is a high-speed version
-** for pages that contain no payload - internal table pages.
+** 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 */
** 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
assert( pPage->noPayload==0 );
** 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
assert( pPage->childPtrSize==4 );
CellInfo info;
if( *pRC ) return;
assert( pCell!=0 );
- btreeParseCellPtr(pPage, pCell, &info);
+ pPage->xParseCell(pPage, pCell, &info);
if( info.iOverflow ){
Pgno ovfl = get4byte(&pCell[info.iOverflow]);
ptrmapPut(pPage->pBt, ovfl, PTRMAP_OVERFLOW1, pPage->pgno, pRC);
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;
pPage->intKey = 0;
pPage->intKeyLeaf = 0;
pPage->noPayload = 0;
+ pPage->xParseCell = btreeParseCellPtrIndex;
pPage->maxLocal = pBt->maxLocal;
pPage->minLocal = pBt->minLocal;
}else{
u8 *pCell = findCell(pPage, i);
if( eType==PTRMAP_OVERFLOW1 ){
CellInfo info;
- btreeParseCellPtr(pPage, pCell, &info);
+ pPage->xParseCell(pPage, pCell, &info);
if( info.iOverflow
&& pCell+info.iOverflow+3<=pPage->aData+pPage->maskPage
&& iFrom==get4byte(&pCell[info.iOverflow])
** 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;
testcase( nCell<0 ); /* True if key size is 2^32 or more */
testcase( nCell==0 ); /* Invalid key size: 0x80 0x80 0x00 */
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 ){
return SQLITE_OK; /* No overflow pages. Return without doing anything */
#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 );
u8 *z;
z = findCell(pPage, j);
- btreeParseCellPtr(pPage, z, &info);
+ pPage->xParseCell(pPage, z, &info);
if( info.iOverflow ){
Pgno ovfl = get4byte(&z[info.iOverflow]);
ptrmapGet(pBt, ovfl, &e, &n);
*/
CellInfo info;
j--;
- btreeParseCellPtr(pNew, apCell[j], &info);
+ pNew->xParseCell(pNew, apCell[j], &info);
pCell = pTemp;
sz = 4 + putVarint(&pCell[4], info.nKey);
pTemp = 0;
pCheck->v1 = iPage;
pCheck->v2 = i;
pCell = findCell(pPage,i);
- btreeParseCellPtr(pPage, pCell, &info);
+ pPage->xParseCell(pPage, pCell, &info);
sz = info.nPayload;
/* For intKey pages, check that the keys are in order.
*/
projects / thirdparty / sqlite.git / commitdiff
