database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-08-07 02:42:48 +03:00
Code Activity

Another size and performance optimization to readDbPage(). This time we

Browse Source 
eliminate some unnecessary local variables.

FossilOrigin-Name: 745bc8decd18d4dc00589474fd3928a3a9f4156d09e05e6f5b8623de6491795a
This commit is contained in:
drh
2017-08-18 22:30:20 +00:00
parent 56520ab848
commit 251866d07c
3 changed files with 15 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
src/pager.c
View File

@@ -2995,29 +2995,27 @@ end_playback:
*/
static int readDbPage(PgHdr *pPg){
Pager *pPager = pPg->pPager; /* Pager object associated with page pPg */
Pgno pgno = pPg->pgno; /* Page number to read */
int rc = SQLITE_OK; /* Return code */
int pgsz = pPager->pageSize; /* Number of bytes to read */
u32 iFrame = 0; /* Frame of WAL containing pgno */
assert( pPager->eState>=PAGER_READER && !MEMDB );
assert( isOpen(pPager->fd) );
if( pagerUseWal(pPager) ){
rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);
rc = sqlite3WalFindFrame(pPager->pWal, pPg->pgno, &iFrame);
if( rc ) return rc;
}
if( iFrame ){
rc = sqlite3WalReadFrame(pPager->pWal, iFrame, pgsz, pPg->pData);
rc = sqlite3WalReadFrame(pPager->pWal, iFrame,pPager->pageSize,pPg->pData);
}else{
i64 iOffset = (pgno-1)*(i64)pPager->pageSize;
rc = sqlite3OsRead(pPager->fd, pPg->pData, pgsz, iOffset);
i64 iOffset = (pPg->pgno-1)*(i64)pPager->pageSize;
rc = sqlite3OsRead(pPager->fd, pPg->pData, pPager->pageSize, iOffset);
if( rc==SQLITE_IOERR_SHORT_READ ){
rc = SQLITE_OK;
}
}
if( pgno==1 ){
if( pPg->pgno==1 ){
if( rc ){
/* If the read is unsuccessful, set the dbFileVers[] to something
** that will never be a valid file version. dbFileVers[] is a copy
@@ -3037,13 +3035,13 @@ static int readDbPage(PgHdr *pPg){
memcpy(&pPager->dbFileVers, dbFileVers, sizeof(pPager->dbFileVers));
}
}
CODEC1(pPager, pPg->pData, pgno, 3, rc = SQLITE_NOMEM_BKPT);
CODEC1(pPager, pPg->pData, pPg->pgno, 3, rc = SQLITE_NOMEM_BKPT);
PAGER_INCR(sqlite3_pager_readdb_count);
PAGER_INCR(pPager->nRead);
IOTRACE(("PGIN %p %d\n", pPager, pgno));
IOTRACE(("PGIN %p %d\n", pPager, pPg->pgno));
PAGERTRACE(("FETCH %d page %d hash(%08x)\n",
PAGERID(pPager), pgno, pager_pagehash(pPg)));
PAGERID(pPager), pPg->pgno, pager_pagehash(pPg)));
return rc;
}