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More speed improvements to btree. (CVS 1384)

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FossilOrigin-Name: aab4b794b4238bad5c4a6aee7d4443732921127d
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drh
2004-05-15 00:29:24 +00:00
parent d7556d209e
commit 3add367f2f
3 changed files with 23 additions and 28 deletions
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37
src/btree.c
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@@ -9,7 +9,7 @@
** May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btree.c,v 1.139 2004/05/14 21:12:23 drh Exp $
** $Id: btree.c,v 1.140 2004/05/15 00:29:24 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
@@ -709,7 +709,8 @@ static int initPage(
int c, pc, i, hdr;
unsigned char *data;
int usableSize;
/* int sumCell = 0; // Total size of all cells */
int nCell, nFree;
u8 *aCell[MX_PAGE_SIZE/2];
assert( pPage->pBt!=0 );
@@ -739,43 +740,37 @@ static int initPage(
usableSize = pPage->pBt->usableSize;
/* Initialize the cell count and cell pointers */
i = 0;
pc = get2byte(&data[hdr+3]);
nCell = 0;
while( pc>0 ){
if( pc>=usableSize ) return SQLITE_CORRUPT;
if( pPage->nCell>usableSize ) return SQLITE_CORRUPT;
pPage->nCell++;
if( nCell>sizeof(aCell)/sizeof(aCell[0]) ) return SQLITE_CORRUPT;
aCell[nCell++] = &data[pc];
pc = get2byte(&data[pc]);
}
if( resizeCellArray(pPage, pPage->nCell) ){
if( resizeCellArray(pPage, nCell) ){
return SQLITE_NOMEM;
}
pc = get2byte(&data[hdr+3]);
for(i=0; pc>0; i++){
pPage->aCell[i] = &data[pc];
/* sumCell += cellSize(pPage, &data[pc]); */
pc = get2byte(&data[pc]);
}
pPage->nCell = nCell;
memcpy(pPage->aCell, aCell, nCell*sizeof(aCell[0]));
/* Compute the total free space on the page */
pPage->nFree = data[hdr+5];
pc = get2byte(&data[hdr+1]);
nFree = data[hdr+5];
i = 0;
while( pc>0 ){
int next, size;
if( pc>=usableSize ) return SQLITE_CORRUPT;
if( i++>MX_PAGE_SIZE ) return SQLITE_CORRUPT;
next = get2byte(&data[pc]);
size = get2byte(&data[pc+2]);
if( next>0 && next<=pc+size+3 ) return SQLITE_CORRUPT;
pPage->nFree += size;
nFree += size;
pc = next;
}
if( pPage->nFree>=usableSize ) return SQLITE_CORRUPT;
/* Sanity check: Cells and freespace and header must sum to the size
** a page.
if( sumCell+pPage->nFree+hdr+10-pPage->leaf*4 != usableSize ){
return SQLITE_CORRUPT;
}
*/
pPage->nFree = nFree;
if( nFree>=usableSize ) return SQLITE_CORRUPT;
pPage->isInit = 1;
pageIntegrity(pPage);