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Changes In Branch deadend Excluding Merge-Ins
This is equivalent to a diff from 27c59f1ea7 to 5d7e833f25
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2023-04-07
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| 13:21 | Small performance improvement in freeSpace(). (check-in: 8dc5292ee5 user: drh tags: btree-freespace-opt) | |
| 11:55 | Try to use a heap to make coalescence of adjacent free slots faster when freeing space on a btree page. Turns out that the overhead of managing the heap overwhelms any performance gain and the result is slower. (Closed-Leaf check-in: 5d7e833f25 user: drh tags: deadend) | |
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2023-04-06
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| 20:14 | Increase the size of the cache of free blocks inside of pageFreeArray() to reduce the number of calls to freeSpace(). (check-in: 27c59f1ea7 user: drh tags: btree-freespace-opt) | |
| 17:29 | Work around a harmless assertion fault associated with sqlite3VdbeMemAboutToChange() such that the detection of stale values in registers is preserved in debugging builds, but we avoid a false-positive assertion fault in cases involving a virtual table with a LIMIT clause in an IN-operator loop. dbsqlfuzz 3fd70d4ab4950acf1deb8f610a7a7c67cd38713b (check-in: 56ea2c2fe6 user: drh tags: trunk) | |
Changes to src/btree.c.
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pPayload = &pOvfl->aData[4];
spaceLeft = pBt->usableSize - 4;
}
}
releasePage(pToRelease);
return SQLITE_OK;
}
/*
** Remove the i-th cell from pPage. This routine effects pPage only.
** The cell content is not freed or deallocated. It is assumed that
** the cell content has been copied someplace else. This routine just
** removes the reference to the cell from pPage.
**
| > | 7028 7029 7030 7031 7032 7033 7034 7035 7036 7037 7038 7039 7040 7041 7042 |
pPayload = &pOvfl->aData[4];
spaceLeft = pBt->usableSize - 4;
}
}
releasePage(pToRelease);
return SQLITE_OK;
}
/*
** Remove the i-th cell from pPage. This routine effects pPage only.
** The cell content is not freed or deallocated. It is assumed that
** the cell content has been copied someplace else. This routine just
** removes the reference to the cell from pPage.
**
|
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k++;
pEnd = pCArray->apEnd[k];
}
}
*ppData = pData;
return 0;
}
/*
** The pCArray object contains pointers to b-tree cells and their sizes.
**
** 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;
| > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | < | < > | < | > | < | < < < < < < < < < < < < < < < < < < | < < | 7473 7474 7475 7476 7477 7478 7479 7480 7481 7482 7483 7484 7485 7486 7487 7488 7489 7490 7491 7492 7493 7494 7495 7496 7497 7498 7499 7500 7501 7502 7503 7504 7505 7506 7507 7508 7509 7510 7511 7512 7513 7514 7515 7516 7517 7518 7519 7520 7521 7522 7523 7524 7525 7526 7527 7528 7529 7530 7531 7532 7533 7534 7535 7536 7537 7538 7539 7540 7541 7542 7543 7544 7545 7546 7547 7548 7549 7550 7551 7552 7553 7554 7555 7556 7557 7558 7559 7560 |
k++;
pEnd = pCArray->apEnd[k];
}
}
*ppData = pData;
return 0;
}
static void btreeHeapInsert(u32 *aHeap, u32 x);
static int btreeHeapPull(u32 *aHeap, u32 *pOut);
/*
** Add all of the cells on aHep to the freelist for a page.
*/
static void btreeFreeCellsOnHeap(MemPage *pPg, u32 *aHeap){
u32 x;
int iOfst;
int iSize;
assert( aHeap[0] );
btreeHeapPull(aHeap, &x);
iSize = x & 0xffff;
iOfst = x>>16;
while( aHeap[0] ){
int iNxOfst;
int iNxSize;
btreeHeapPull(aHeap, &x);
iNxSize = x & 0xffff;
iNxOfst = x>>16;
if( iSize+iOfst==iNxOfst ){
iSize += iNxSize;
}else{
freeSpace(pPg, iOfst, iSize);
iOfst = iNxOfst;
iSize = iNxSize;
}
}
freeSpace(pPg, iOfst, iSize);
}
/*
** The pCArray object contains pointers to b-tree cells and their sizes.
**
** 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;
u32 aHeap[100];
aHeap[0] = 0;
for(i=iFirst; i<iEnd; i++){
u8 *pCell = pCArray->apCell[i];
if( SQLITE_WITHIN(pCell, pStart, pEnd) ){
u16 sz;
u16 iOfst;
/* 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 );
iOfst = (u16)(pCell - aData);
btreeHeapInsert(aHeap, (iOfst<<16)|sz);
if( aHeap[0]>=90 ) btreeFreeCellsOnHeap(pPg, aHeap);
nRet++;
}
}
if( aHeap[0] ) btreeFreeCellsOnHeap(pPg, aHeap);
return nRet;
}
/*
** pCArray contains pointers to and sizes of all cells in the page being
** balanced. The current page, pPg, has pPg->nCell cells starting with
** pCArray->apCell[iOld]. After balancing, this page should hold nNew cells
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