database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-08-05 15:55:57 +03:00
Code Activity

Optimize the obscure case of running a checkpoint against a very large wal

Browse Source 
file for which a large percentage of the frames have already been checkpointed.

FossilOrigin-Name: 0f5057dffa9be1bccab04894709d25bf1f066c4b1aef50d67ee635d46d300a4d
This commit is contained in:
dan
2018-03-02 15:42:20 +00:00
parent 5e9825ecc4
commit 302ce47519
3 changed files with 14 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
src/wal.c
View File

@@ -1585,8 +1585,9 @@ static void walIteratorFree(WalIterator *p){
/*
** Construct a WalInterator object that can be used to loop over all
** pages in the WAL in ascending order. The caller must hold the checkpoint
** lock.
** pages in the WAL following frame nBackfill in ascending order. Frames
** nBackfill or earlier may be included - excluding them is an optimization
** only. The caller must hold the checkpoint lock.
**
** On success, make *pp point to the newly allocated WalInterator object
** return SQLITE_OK. Otherwise, return an error code. If this routine
@@ -1595,7 +1596,7 @@ static void walIteratorFree(WalIterator *p){
** The calling routine should invoke walIteratorFree() to destroy the
** WalIterator object when it has finished with it.
*/
static int walIteratorInit(Wal *pWal, WalIterator **pp){
static int walIteratorInit(Wal *pWal, u32 nBackfill, WalIterator **pp){
WalIterator *p; /* Return value */
int nSegment; /* Number of segments to merge */
u32 iLast; /* Last frame in log */
@@ -1632,7 +1633,7 @@ static int walIteratorInit(Wal *pWal, WalIterator **pp){
rc = SQLITE_NOMEM_BKPT;
}
for(i=0; rc==SQLITE_OK && i<nSegment; i++){
for(i=walFramePage(nBackfill+1); rc==SQLITE_OK && i<nSegment; i++){
volatile ht_slot *aHash;
u32 iZero;
volatile u32 *aPgno;
@@ -1789,7 +1790,7 @@ static int walCheckpoint(
if( pInfo->nBackfill<pWal->hdr.mxFrame ){
/* Allocate the iterator */
rc = walIteratorInit(pWal, &pIter);
rc = walIteratorInit(pWal, pInfo->nBackfill, &pIter);
if( rc!=SQLITE_OK ){
return rc;
}