Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Performance optimization to the moveToRoot() subroutine in btree.c. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
b5842a70f8e26456a8f0d39539bc266f |
| User & Date: | drh 2013-12-06 23:25:27 |
Context
|
2013-12-07
| ||
| 16:56 | At the start of each journaled write transaction, check to see if the database file has been moved, and if it has refuse to start the transaction, returning an SQLITE_READONLY_DBMOVED error code. Writing to a moved or renamed database is still allowed when journal_mode is OFF or MEMORY. (check-in: 369a23e0 user: drh tags: trunk) | |
|
2013-12-06
| ||
| 23:25 | Performance optimization to the moveToRoot() subroutine in btree.c. (check-in: b5842a70 user: drh tags: trunk) | |
| 22:45 | Use memcmp() instead of the BINARY collating function where possible, for a performance boost. (check-in: c5a3a1af user: drh tags: trunk) | |
Changes
Changes to src/btree.c.
4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 .... 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 .... 4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468 4469 4470 |
** indicating a table b-tree, or if the caller did specify a KeyInfo
** structure the flags byte is set to 0x02 or 0x0A, indicating an index
** b-tree).
*/
static int moveToRoot(BtCursor *pCur){
MemPage *pRoot;
int rc = SQLITE_OK;
Btree *p = pCur->pBtree;
BtShared *pBt = p->pBt;
assert( cursorHoldsMutex(pCur) );
assert( CURSOR_INVALID < CURSOR_REQUIRESEEK );
assert( CURSOR_VALID < CURSOR_REQUIRESEEK );
assert( CURSOR_FAULT > CURSOR_REQUIRESEEK );
if( pCur->eState>=CURSOR_REQUIRESEEK ){
if( pCur->eState==CURSOR_FAULT ){
................................................................................
assert( pCur->skipNext!=SQLITE_OK );
return pCur->skipNext;
}
sqlite3BtreeClearCursor(pCur);
}
if( pCur->iPage>=0 ){
int i;
for(i=1; i<=pCur->iPage; i++){
releasePage(pCur->apPage[i]);
}
pCur->iPage = 0;
}else if( pCur->pgnoRoot==0 ){
pCur->eState = CURSOR_INVALID;
return SQLITE_OK;
}else{
rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0],
pCur->wrFlag==0 ? PAGER_GET_READONLY : 0);
if( rc!=SQLITE_OK ){
pCur->eState = CURSOR_INVALID;
return rc;
}
pCur->iPage = 0;
................................................................................
assert( pRoot->isInit && (pCur->pKeyInfo==0)==pRoot->intKey );
pCur->aiIdx[0] = 0;
pCur->info.nSize = 0;
pCur->atLast = 0;
pCur->validNKey = 0;
if( pRoot->nCell==0 && !pRoot->leaf ){
Pgno subpage;
if( pRoot->pgno!=1 ) return SQLITE_CORRUPT_BKPT;
subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]);
pCur->eState = CURSOR_VALID;
rc = moveToChild(pCur, subpage);
}else{
pCur->eState = ((pRoot->nCell>0)?CURSOR_VALID:CURSOR_INVALID);
}
return rc;
}
/*
** Move the cursor down to the left-most leaf entry beneath the
** entry to which it is currently pointing.
|
< < < < | < < | | > > | |
4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 .... 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 .... 4443 4444 4445 4446 4447 4448 4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 |
** indicating a table b-tree, or if the caller did specify a KeyInfo
** structure the flags byte is set to 0x02 or 0x0A, indicating an index
** b-tree).
*/
static int moveToRoot(BtCursor *pCur){
MemPage *pRoot;
int rc = SQLITE_OK;
assert( cursorHoldsMutex(pCur) );
assert( CURSOR_INVALID < CURSOR_REQUIRESEEK );
assert( CURSOR_VALID < CURSOR_REQUIRESEEK );
assert( CURSOR_FAULT > CURSOR_REQUIRESEEK );
if( pCur->eState>=CURSOR_REQUIRESEEK ){
if( pCur->eState==CURSOR_FAULT ){
................................................................................
assert( pCur->skipNext!=SQLITE_OK );
return pCur->skipNext;
}
sqlite3BtreeClearCursor(pCur);
}
if( pCur->iPage>=0 ){
while( pCur->iPage ) releasePage(pCur->apPage[pCur->iPage--]);
}else if( pCur->pgnoRoot==0 ){
pCur->eState = CURSOR_INVALID;
return SQLITE_OK;
}else{
rc = getAndInitPage(pCur->pBtree->pBt, pCur->pgnoRoot, &pCur->apPage[0],
pCur->wrFlag==0 ? PAGER_GET_READONLY : 0);
if( rc!=SQLITE_OK ){
pCur->eState = CURSOR_INVALID;
return rc;
}
pCur->iPage = 0;
................................................................................
assert( pRoot->isInit && (pCur->pKeyInfo==0)==pRoot->intKey );
pCur->aiIdx[0] = 0;
pCur->info.nSize = 0;
pCur->atLast = 0;
pCur->validNKey = 0;
if( pRoot->nCell>0 ){
pCur->eState = CURSOR_VALID;
}else if( !pRoot->leaf ){
Pgno subpage;
if( pRoot->pgno!=1 ) return SQLITE_CORRUPT_BKPT;
subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]);
pCur->eState = CURSOR_VALID;
rc = moveToChild(pCur, subpage);
}else{
pCur->eState = CURSOR_INVALID;
}
return rc;
}
/*
** Move the cursor down to the left-most leaf entry beneath the
** entry to which it is currently pointing.
|