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Small performance improvement in the btreeOverwriteCell() routine.

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FossilOrigin-Name: df5ea47130d275e9fa1bd6aa8d55f1d5e136cba30ba13b7ede22224aa7f78919
This commit is contained in:
drh
2023-01-03 15:11:01 +00:00
parent e364a9da72
commit 1eb88d6e5a
3 changed files with 39 additions and 16 deletions
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39
src/btree.c
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@@ -8914,9 +8914,13 @@ static int btreeOverwriteContent(
/*
** Overwrite the cell that cursor pCur is pointing to with fresh content
** contained in pX.
** contained in pX. In this variant, pCur is pointing to an overflow
** cell.
*/
static int btreeOverwriteCell(BtCursor *pCur, const BtreePayload *pX){
static SQLITE_NOINLINE int btreeOverwriteOverflowCell(
BtCursor *pCur, /* Cursor pointing to cell to ovewrite */
const BtreePayload *pX /* Content to write into the cell */
){
int iOffset; /* Next byte of pX->pData to write */
int nTotal = pX->nData + pX->nZero; /* Total bytes of to write */
int rc; /* Return code */
@@ -8925,16 +8929,12 @@ static int btreeOverwriteCell(BtCursor *pCur, const BtreePayload *pX){
Pgno ovflPgno; /* Next overflow page to write */
u32 ovflPageSize; /* Size to write on overflow page */
if( pCur->info.pPayload + pCur->info.nLocal > pPage->aDataEnd
|| pCur->info.pPayload < pPage->aData + pPage->cellOffset
){
return SQLITE_CORRUPT_BKPT;
}
assert( pCur->info.nLocal<nTotal ); /* pCur is an overflow cell */
/* Overwrite the local portion first */
rc = btreeOverwriteContent(pPage, pCur->info.pPayload, pX,
0, pCur->info.nLocal);
if( rc ) return rc;
if( pCur->info.nLocal==nTotal ) return SQLITE_OK;
/* Now overwrite the overflow pages */
iOffset = pCur->info.nLocal;
@@ -8964,6 +8964,29 @@ static int btreeOverwriteCell(BtCursor *pCur, const BtreePayload *pX){
return SQLITE_OK;
}
/*
** Overwrite the cell that cursor pCur is pointing to with fresh content
** contained in pX.
*/
static int btreeOverwriteCell(BtCursor *pCur, const BtreePayload *pX){
int nTotal = pX->nData + pX->nZero; /* Total bytes of to write */
MemPage *pPage = pCur->pPage; /* Page being written */
if( pCur->info.pPayload + pCur->info.nLocal > pPage->aDataEnd
|| pCur->info.pPayload < pPage->aData + pPage->cellOffset
){
return SQLITE_CORRUPT_BKPT;
}
if( pCur->info.nLocal==nTotal ){
/* The entire cell is local */
return btreeOverwriteContent(pPage, pCur->info.pPayload, pX,
0, pCur->info.nLocal);
}else{
/* The cell contains overflow content */
return btreeOverwriteOverflowCell(pCur, pX);
}
}
/*
** Insert a new record into the BTree. The content of the new record