Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Use memmove() rather than a home-made copy loop in dropCell() of btree.c, for a size reduction and performance improvement. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
78e1706804e88a0dd5dc40bee838a3a5 |
| User & Date: | drh 2013-12-09 01:58:11 |
Context
|
2013-12-09
| ||
| 02:32 | Use memmove() rather than a home-made copy loop in insertCell() too. check-in: a3d796b1 user: drh tags: trunk | |
| 01:58 | Use memmove() rather than a home-made copy loop in dropCell() of btree.c, for a size reduction and performance improvement. check-in: 78e17068 user: drh tags: trunk | |
| 01:04 | Avoid unnecessary no-op calls from getAndInitPage() to btreeInitPage() in the btree.c logic. check-in: 81f5ae13 user: drh tags: trunk | |
Changes
Changes to src/btree.c.
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
....
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
|
**
** "sz" must be the number of bytes in the cell.
*/
static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
u32 pc; /* Offset to cell content of cell being deleted */
u8 *data; /* pPage->aData */
u8 *ptr; /* Used to move bytes around within data[] */
u8 *endPtr; /* End of loop */
int rc; /* The return code */
int hdr; /* Beginning of the header. 0 most pages. 100 page 1 */
if( *pRC ) return;
assert( idx>=0 && idx<pPage->nCell );
assert( sz==cellSize(pPage, idx) );
................................................................................
return;
}
rc = freeSpace(pPage, pc, sz);
if( rc ){
*pRC = rc;
return;
}
endPtr = &pPage->aCellIdx[2*pPage->nCell - 2];
assert( (SQLITE_PTR_TO_INT(ptr)&1)==0 ); /* ptr is always 2-byte aligned */
while( ptr<endPtr ){
*(u16*)ptr = *(u16*)&ptr[2];
ptr += 2;
}
pPage->nCell--;
put2byte(&data[hdr+3], pPage->nCell);
pPage->nFree += 2;
}
/*
** Insert a new cell on pPage at cell index "i". pCell points to the
** content of the cell.
|
<
<
<
<
<
<
<
>
|
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
....
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
|
**
** "sz" must be the number of bytes in the cell.
*/
static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
u32 pc; /* Offset to cell content of cell being deleted */
u8 *data; /* pPage->aData */
u8 *ptr; /* Used to move bytes around within data[] */
int rc; /* The return code */
int hdr; /* Beginning of the header. 0 most pages. 100 page 1 */
if( *pRC ) return;
assert( idx>=0 && idx<pPage->nCell );
assert( sz==cellSize(pPage, idx) );
................................................................................
return;
}
rc = freeSpace(pPage, pc, sz);
if( rc ){
*pRC = rc;
return;
}
pPage->nCell--;
memmove(ptr, ptr+2, 2*(pPage->nCell - idx));
put2byte(&data[hdr+3], pPage->nCell);
pPage->nFree += 2;
}
/*
** Insert a new cell on pPage at cell index "i". pCell points to the
** content of the cell.
|