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Overview
| Comment: | Size reduction and substantial performance increase for cellSizePtr(). |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
bc8bbf3207288d160287519c3b712399 |
| User & Date: | drh 2014-09-22 19:51:35 |
Context
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2014-09-22
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| 20:38 | Fix to payload size overflow detection in the cellSizePtr() change of the previous check-in. check-in: 76097440 user: drh tags: trunk | |
| 19:51 | Size reduction and substantial performance increase for cellSizePtr(). check-in: bc8bbf32 user: drh tags: trunk | |
| 14:30 | Tune the query planner to be more aggressive about using automatic indexes on views and subqueries for which there is not opportunity to declare a persistent schema index. check-in: 41de1643 user: drh tags: trunk | |
Changes
Changes to src/btree.c.
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** 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.
*/
static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
u8 *pIter = &pCell[pPage->childPtrSize];
u32 nSize;
#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;
btreeParseCellPtr(pPage, pCell, &debuginfo);
#endif
if( pPage->intKey ){
u8 *pEnd;
if( pPage->hasData ){
pIter += getVarint32(pIter, nSize);
}else{
nSize = 0;
}
/* pIter now points at the 64-bit integer key value, a variable length
** integer. The following block moves pIter to point at the first byte
** past the end of the key value. */
pEnd = &pIter[9];
while( (*pIter++)&0x80 && pIter<pEnd );
}else{
pIter += getVarint32(pIter, nSize);
}
testcase( nSize==pPage->maxLocal );
testcase( nSize==pPage->maxLocal+1 );
if( nSize>pPage->maxLocal ){
int minLocal = pPage->minLocal;
nSize = minLocal + (nSize - minLocal) % (pPage->pBt->usableSize - 4);
................................................................................
nSize += (u32)(pIter - pCell);
/* The minimum size of any cell is 4 bytes. */
if( nSize<4 ){
nSize = 4;
}
assert( nSize==debuginfo.nSize );
return (u16)nSize;
}
#ifdef SQLITE_DEBUG
/* This variation on cellSizePtr() is used inside of assert() statements
** only. */
static u16 cellSize(MemPage *pPage, int iCell){
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** 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.
*/
static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
u8 *pIter = &pCell[pPage->childPtrSize];
u8 *pEnd;
u32 nSize;
#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;
btreeParseCellPtr(pPage, pCell, &debuginfo);
#endif
if( pPage->intKey==0 || pPage->hasData ){
nSize = *pIter;
if( nSize>=0x80 ){
pEnd = &pIter[9];
nSize &= 0x7f;
do{
nSize = (nSize<<7) | (*++pIter & 0x7f);
}while( *(pIter)>=0x80 && pIter<&pCell[6] );
}
pIter++;
}else{
nSize = 0;
}
if( pPage->intKey ){
/* pIter now points at the 64-bit integer key value, a variable length
** integer. The following block moves pIter to point at the first byte
** past the end of the key value. */
pEnd = &pIter[9];
while( (*pIter++)&0x80 && pIter<pEnd );
}
testcase( nSize==pPage->maxLocal );
testcase( nSize==pPage->maxLocal+1 );
if( nSize>pPage->maxLocal ){
int minLocal = pPage->minLocal;
nSize = minLocal + (nSize - minLocal) % (pPage->pBt->usableSize - 4);
................................................................................
nSize += (u32)(pIter - pCell);
/* The minimum size of any cell is 4 bytes. */
if( nSize<4 ){
nSize = 4;
}
assert( nSize==debuginfo.nSize || CORRUPT_DB );
return (u16)nSize;
}
#ifdef SQLITE_DEBUG
/* This variation on cellSizePtr() is used inside of assert() statements
** only. */
static u16 cellSize(MemPage *pPage, int iCell){
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