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Small performance optimization and size reduction in sqlite3BtreeDelete().

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FossilOrigin-Name: da0af4dd9ba4180a16543fac1549fd4ccecdc66dcf6d275f77de21fd80708882
This commit is contained in:
drh 2022-01-02 14:55:43 +00:00
parent 44a5c0257f
commit 7e17a3abbe
3 changed files with 31 additions and 24 deletions
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12
manifest
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@ -1,5 +1,5 @@
C Clear\sthe\scache\sof\striggers\sused\sto\simplement\sCASCADE\sforeign\skey\sconstraints\nwhenever\sthe\sschema\schanges.\s\sFix\sfor\sthe\sproblem\sidentified\sby\n[forum:/forumpost/2831335356|forum\spost\s2831335356].
D 2022-01-02T12:01:03.636
C Small\sperformance\soptimization\sand\ssize\sreduction\sin\ssqlite3BtreeDelete().
D 2022-01-02T14:55:43.095
F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@ -491,7 +491,7 @@ F src/auth.c f4fa91b6a90bbc8e0d0f738aa284551739c9543a367071f55574681e0f24f8cf
F src/backup.c 3014889fa06e20e6adfa0d07b60097eec1f6e5b06671625f476a714d2356513d
F src/bitvec.c 7c849aac407230278445cb069bebc5f89bf2ddd87c5ed9459b070a9175707b3d
F src/btmutex.c 8acc2f464ee76324bf13310df5692a262b801808984c1b79defb2503bbafadb6
F src/btree.c fab3d2a9e2a187373c393b9f35e68e996010a1aae1354763f7c5846915a99b83
F src/btree.c d4b6e026d85b47018dd4c31b42dd490ed22d4320917e705d6502e589d1a8227d
F src/btree.h 74d64b8f28cfa4a894d14d4ed64fa432cd697b98b61708d4351482ae15913e22
F src/btreeInt.h ee9348c4cb9077243b049edc93a82c1f32ca48baeabf2140d41362b9f9139ff7
F src/build.c 6e16f7b539bfc55149a039bf0cda26b089640339df6147070b072df2d1c4f771
@ -1936,8 +1936,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
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R aa110e7b5297811807e4f693fefdef54
U drh
Z 356b59ab85226987dbc745e5cdcb40e4
Z a31d2467491c7884583c9d9e2a7c5425
# Remove this line to create a well-formed Fossil manifest.

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manifest.uuid
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@ -1 +1 @@
5232c9777fe4fb13e1ecfe5b5d644e2c45d0514f95884dbed49a03fb9b67304c
da0af4dd9ba4180a16543fac1549fd4ccecdc66dcf6d275f77de21fd80708882

41
src/btree.c
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@ -9229,14 +9229,13 @@ int sqlite3BtreeTransferRow(BtCursor *pDest, BtCursor *pSrc, i64 iKey){
int sqlite3BtreeDelete(BtCursor *pCur, u8 flags){
Btree *p = pCur->pBtree;
BtShared *pBt = p->pBt;
int rc; /* Return code */
MemPage *pPage; /* Page to delete cell from */
unsigned char *pCell; /* Pointer to cell to delete */
int iCellIdx; /* Index of cell to delete */
int iCellDepth; /* Depth of node containing pCell */
CellInfo info; /* Size of the cell being deleted */
int bSkipnext = 0; /* Leaf cursor in SKIPNEXT state */
u8 bPreserve = flags & BTREE_SAVEPOSITION; /* Keep cursor valid */
int rc; /* Return code */
MemPage *pPage; /* Page to delete cell from */
unsigned char *pCell; /* Pointer to cell to delete */
int iCellIdx; /* Index of cell to delete */
int iCellDepth; /* Depth of node containing pCell */
CellInfo info; /* Size of the cell being deleted */
u8 bPreserve; /* Keep cursor valid. 2 for CURSOR_SKIPNEXT */
assert( cursorOwnsBtShared(pCur) );
assert( pBt->inTransaction==TRANS_WRITE );
@ -9255,23 +9254,31 @@ int sqlite3BtreeDelete(BtCursor *pCur, u8 flags){
iCellDepth = pCur->iPage;
iCellIdx = pCur->ix;
pPage = pCur->pPage;
if( pPage->nCell<=iCellIdx ){
return SQLITE_CORRUPT_BKPT;
}
pCell = findCell(pPage, iCellIdx);
if( pPage->nFree<0 && btreeComputeFreeSpace(pPage) ){
return SQLITE_CORRUPT_BKPT;
}
if( pPage->nCell<=iCellIdx ){
return SQLITE_CORRUPT_BKPT;
}
/* If the bPreserve flag is set to true, then the cursor position must
/* If the BTREE_SAVEPOSITION bit is on, 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
** 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. */
** before or after the deleted entry.
**
** The bPreserve value records which path is required:
**
** bPreserve==0 Not necessary to save the cursor position
** bPreserve==1 Use CURSOR_REQUIRESEEK to save the cursor position
** bPreserve==2 Cursor won't move. Set CURSOR_SKIPNEXT.
*/
bPreserve = (flags & BTREE_SAVEPOSITION)!=0;
if( bPreserve ){
if( !pPage->leaf
|| (pPage->nFree+cellSizePtr(pPage,pCell)+2)>(int)(pBt->usableSize*2/3)
@ -9282,7 +9289,7 @@ int sqlite3BtreeDelete(BtCursor *pCur, u8 flags){
rc = saveCursorKey(pCur);
if( rc ) return rc;
}else{
bSkipnext = 1;
bPreserve = 2;
}
}
@ -9382,8 +9389,8 @@ int sqlite3BtreeDelete(BtCursor *pCur, u8 flags){
}
if( rc==SQLITE_OK ){
if( bSkipnext ){
assert( bPreserve && (pCur->iPage==iCellDepth || CORRUPT_DB) );
if( bPreserve>1 ){
assert( (pCur->iPage==iCellDepth || CORRUPT_DB) );
assert( pPage==pCur->pPage || CORRUPT_DB );
assert( (pPage->nCell>0 || CORRUPT_DB) && iCellIdx<=pPage->nCell );
pCur->eState = CURSOR_SKIPNEXT;