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Overview
| Comment: | Add releasePageNotNull() as an alternative to releasePage() when the argument is guaranteed to be non-NULL, and use it for a small performance gain. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
9383a688701ac2c366a308efc287c9c0 |
| User & Date: | drh 2015-06-27 14:59:26 |
Context
|
2015-06-27
| ||
| 15:51 | Manually inline the call from getAndInitPage() to btreeGetPage() for a savings of 2.5 million cycles at a cost of less than 100 bytes. (check-in: 7f65b96b user: drh tags: trunk) | |
| 14:59 | Add releasePageNotNull() as an alternative to releasePage() when the argument is guaranteed to be non-NULL, and use it for a small performance gain. (check-in: 9383a688 user: drh tags: trunk) | |
| 03:58 | Add the Mempage.aDataOfst field and use it in sqlite3BtreeMovetoUnpacked() for about a 2 million cycle gain. (check-in: bee94dc3 user: drh tags: trunk) | |
Changes
Changes to src/btree.c.
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return rc;
}
/*
** Release a MemPage. This should be called once for each prior
** call to btreeGetPage.
*/
static void releasePage(MemPage *pPage){
if( pPage ){
assert( pPage->aData );
assert( pPage->pBt );
assert( pPage->pDbPage!=0 );
assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
assert( sqlite3_mutex_held(pPage->pBt->mutex) );
sqlite3PagerUnrefNotNull(pPage->pDbPage);
}
}
/*
** Get an unused page.
**
** This works just like btreeGetPage() with the addition:
**
................................................................................
assert( sqlite3_mutex_held(pBt->mutex) );
assert( countValidCursors(pBt,0)==0 || pBt->inTransaction>TRANS_NONE );
if( pBt->inTransaction==TRANS_NONE && pBt->pPage1!=0 ){
MemPage *pPage1 = pBt->pPage1;
assert( pPage1->aData );
assert( sqlite3PagerRefcount(pBt->pPager)==1 );
pBt->pPage1 = 0;
releasePage(pPage1);
}
}
/*
** If pBt points to an empty file then convert that empty file
** into a new empty database by initializing the first page of
** the database.
................................................................................
assert( pCur->apPage[pCur->iPage] );
assertParentIndex(
pCur->apPage[pCur->iPage-1],
pCur->aiIdx[pCur->iPage-1],
pCur->apPage[pCur->iPage]->pgno
);
testcase( pCur->aiIdx[pCur->iPage-1] > pCur->apPage[pCur->iPage-1]->nCell );
releasePage(pCur->apPage[pCur->iPage]);
pCur->iPage--;
pCur->info.nSize = 0;
pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
}
/*
** Move the cursor to point to the root page of its b-tree structure.
**
** If the table has a virtual root page, then the cursor is moved to point
** to the virtual root page instead of the actual root page. A table has a
................................................................................
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->curFlags & BTCF_WriteFlag)==0 ? PAGER_GET_READONLY : 0);
if( rc!=SQLITE_OK ){
|
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return rc; } /* ** Release a MemPage. This should be called once for each prior ** call to btreeGetPage. */ static void releasePageNotNull(MemPage *pPage){ assert( pPage->aData ); assert( pPage->pBt ); assert( pPage->pDbPage!=0 ); assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage ); assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData ); assert( sqlite3_mutex_held(pPage->pBt->mutex) ); sqlite3PagerUnrefNotNull(pPage->pDbPage); } static void releasePage(MemPage *pPage){ if( pPage ) releasePageNotNull(pPage); } /* ** Get an unused page. ** ** This works just like btreeGetPage() with the addition: ** ................................................................................ assert( sqlite3_mutex_held(pBt->mutex) ); assert( countValidCursors(pBt,0)==0 || pBt->inTransaction>TRANS_NONE ); if( pBt->inTransaction==TRANS_NONE && pBt->pPage1!=0 ){ MemPage *pPage1 = pBt->pPage1; assert( pPage1->aData ); assert( sqlite3PagerRefcount(pBt->pPager)==1 ); pBt->pPage1 = 0; releasePageNotNull(pPage1); } } /* ** If pBt points to an empty file then convert that empty file ** into a new empty database by initializing the first page of ** the database. ................................................................................ assert( pCur->apPage[pCur->iPage] ); assertParentIndex( pCur->apPage[pCur->iPage-1], pCur->aiIdx[pCur->iPage-1], pCur->apPage[pCur->iPage]->pgno ); testcase( pCur->aiIdx[pCur->iPage-1] > pCur->apPage[pCur->iPage-1]->nCell ); pCur->info.nSize = 0; pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl); releasePageNotNull(pCur->apPage[pCur->iPage--]); } /* ** Move the cursor to point to the root page of its b-tree structure. ** ** If the table has a virtual root page, then the cursor is moved to point ** to the virtual root page instead of the actual root page. A table has a ................................................................................ assert( pCur->skipNext!=SQLITE_OK ); return pCur->skipNext; } sqlite3BtreeClearCursor(pCur); } if( pCur->iPage>=0 ){ while( pCur->iPage ){ assert( pCur->apPage[pCur->iPage]!=0 ); releasePageNotNull(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->curFlags & BTCF_WriteFlag)==0 ? PAGER_GET_READONLY : 0); if( rc!=SQLITE_OK ){ |