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

Enhance WAL mode so that the WAL file honors the journal size limit set

Browse Source 
by PRAGMA journal_size_limit.

FossilOrigin-Name: db7e500f69faf1906a84991ba67d26a195f02ae5
This commit is contained in:
drh
2011-05-16 21:00:27 +00:00
parent 99a66928c2
commit 85a8375580
6 changed files with 162 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
src/wal.c
View File

@@ -412,6 +412,7 @@ struct Wal {
sqlite3_file *pDbFd; /* File handle for the database file */
sqlite3_file *pWalFd; /* File handle for WAL file */
u32 iCallback; /* Value to pass to log callback (or 0) */
i64 mxWalSize; /* Truncate WAL to this size upon reset */
int nWiData; /* Size of array apWiData */
volatile u32 **apWiData; /* Pointer to wal-index content in memory */
u32 szPage; /* Database page size */
@@ -1234,6 +1235,7 @@ int sqlite3WalOpen(
sqlite3_file *pDbFd, /* The open database file */
const char *zWalName, /* Name of the WAL file */
int bNoShm, /* True to run in heap-memory mode */
i64 mxWalSize, /* Truncate WAL to this size on reset */
Wal **ppWal /* OUT: Allocated Wal handle */
){
int rc; /* Return Code */
@@ -1266,6 +1268,7 @@ int sqlite3WalOpen(
pRet->pWalFd = (sqlite3_file *)&pRet[1];
pRet->pDbFd = pDbFd;
pRet->readLock = -1;
pRet->mxWalSize = mxWalSize;
pRet->zWalName = zWalName;
pRet->exclusiveMode = (bNoShm ? WAL_HEAPMEMORY_MODE: WAL_NORMAL_MODE);
@@ -1287,6 +1290,13 @@ int sqlite3WalOpen(
return rc;
}
/*
** Change the size to which the WAL file is trucated on each reset.
*/
void sqlite3WalLimit(Wal *pWal, i64 iLimit){
if( pWal ) pWal->mxWalSize = iLimit;
}
/*
** Find the smallest page number out of all pages held in the WAL that
** has not been returned by any prior invocation of this method on the
@@ -2522,6 +2532,22 @@ static int walRestartLog(Wal *pWal){
*/
int i; /* Loop counter */
u32 *aSalt = pWal->hdr.aSalt; /* Big-endian salt values */
/* Limit the size of WAL file if the journal_size_limit PRAGMA is
** set to a non-negative value. Log errors encountered
** during the truncation attempt. */
if( pWal->mxWalSize>=0 ){
i64 sz;
int rx;
rx = sqlite3OsFileSize(pWal->pWalFd, &sz);
if( rx==SQLITE_OK && (sz > pWal->mxWalSize) ){
rx = sqlite3OsTruncate(pWal->pWalFd, pWal->mxWalSize);
}
if( rx ){
sqlite3_log(rx, "cannot limit WAL size: %s", pWal->zWalName);
}
}
pWal->nCkpt++;
pWal->hdr.mxFrame = 0;
sqlite3Put4byte((u8*)&aSalt[0], 1 + sqlite3Get4byte((u8*)&aSalt[0]));