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Simplifications to the pager_delmaster() implementation.

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FossilOrigin-Name: 8bfbdec647d29f0eb103ba7deb9116c44193f2e1
This commit is contained in:
drh
2010-06-23 15:04:27 +00:00
parent a715211820
commit a64febe1d2
3 changed files with 53 additions and 56 deletions
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src/pager.c
+43 -46
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@@ -1796,6 +1796,9 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
sqlite3_file *pJournal; /* Malloc'd child-journal file descriptor */
char *zMasterJournal = 0; /* Contents of master journal file */
i64 nMasterJournal; /* Size of master journal file */
char *zJournal; /* Pointer to one journal within MJ file */
char *zMasterPtr; /* Space to hold MJ filename from a journal file */
int nMasterPtr; /* Amount of space allocated to zMasterPtr[] */
/* Allocate space for both the pJournal and pMaster file descriptors.
** If successful, open the master journal file for reading.
@@ -1810,69 +1813,63 @@ static int pager_delmaster(Pager *pPager, const char *zMaster){
}
if( rc!=SQLITE_OK ) goto delmaster_out;
/* Load the entire master journal file into space obtained from
** sqlite3_malloc() and pointed to by zMasterJournal. Also obtain
** sufficient space (in zMasterPtr) to hold the names of master
** journal files extracted from regular rollback-journals.
*/
rc = sqlite3OsFileSize(pMaster, &nMasterJournal);
if( rc!=SQLITE_OK ) goto delmaster_out;
nMasterPtr = pVfs->mxPathname+1;
zMasterJournal = sqlite3Malloc((int)nMasterJournal + nMasterPtr + 1);
if( !zMasterJournal ){
rc = SQLITE_NOMEM;
goto delmaster_out;
}
zMasterPtr = &zMasterJournal[nMasterJournal+1];
rc = sqlite3OsRead(pMaster, zMasterJournal, (int)nMasterJournal, 0);
if( rc!=SQLITE_OK ) goto delmaster_out;
zMasterJournal[nMasterJournal] = 0;
if( nMasterJournal>0 ){
char *zJournal;
char *zMasterPtr = 0;
int nMasterPtr = pVfs->mxPathname+1;
/* Load the entire master journal file into space obtained from
** sqlite3_malloc() and pointed to by zMasterJournal.
*/
zMasterJournal = sqlite3Malloc((int)nMasterJournal + nMasterPtr + 1);
if( !zMasterJournal ){
rc = SQLITE_NOMEM;
zJournal = zMasterJournal;
while( (zJournal-zMasterJournal)<nMasterJournal ){
int exists;
rc = sqlite3OsAccess(pVfs, zJournal, SQLITE_ACCESS_EXISTS, &exists);
if( rc!=SQLITE_OK ){
goto delmaster_out;
}
zMasterPtr = &zMasterJournal[nMasterJournal+1];
rc = sqlite3OsRead(pMaster, zMasterJournal, (int)nMasterJournal, 0);
if( rc!=SQLITE_OK ) goto delmaster_out;
zMasterJournal[nMasterJournal] = 0;
zJournal = zMasterJournal;
while( (zJournal-zMasterJournal)<nMasterJournal ){
int exists;
rc = sqlite3OsAccess(pVfs, zJournal, SQLITE_ACCESS_EXISTS, &exists);
if( exists ){
/* One of the journals pointed to by the master journal exists.
** Open it and check if it points at the master journal. If
** so, return without deleting the master journal file.
*/
int c;
int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL);
rc = sqlite3OsOpen(pVfs, zJournal, pJournal, flags, 0);
if( rc!=SQLITE_OK ){
goto delmaster_out;
}
if( exists ){
/* One of the journals pointed to by the master journal exists.
** Open it and check if it points at the master journal. If
** so, return without deleting the master journal file.
*/
int c;
int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL);
rc = sqlite3OsOpen(pVfs, zJournal, pJournal, flags, 0);
if( rc!=SQLITE_OK ){
goto delmaster_out;
}
rc = readMasterJournal(pJournal, zMasterPtr, nMasterPtr);
sqlite3OsClose(pJournal);
if( rc!=SQLITE_OK ){
goto delmaster_out;
}
c = zMasterPtr[0]!=0 && strcmp(zMasterPtr, zMaster)==0;
if( c ){
/* We have a match. Do not delete the master journal file. */
goto delmaster_out;
}
rc = readMasterJournal(pJournal, zMasterPtr, nMasterPtr);
sqlite3OsClose(pJournal);
if( rc!=SQLITE_OK ){
goto delmaster_out;
}
c = zMasterPtr[0]!=0 && strcmp(zMasterPtr, zMaster)==0;
if( c ){
/* We have a match. Do not delete the master journal file. */
goto delmaster_out;
}
zJournal += (sqlite3Strlen30(zJournal)+1);
}
zJournal += (sqlite3Strlen30(zJournal)+1);
}
sqlite3OsClose(pMaster);
rc = sqlite3OsDelete(pVfs, zMaster, 0);
delmaster_out:
if( zMasterJournal ){
sqlite3_free(zMasterJournal);
}
sqlite3_free(zMasterJournal);
if( pMaster ){
sqlite3OsClose(pMaster);
assert( !isOpen(pJournal) );