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Fix for ticket #9 (again). The rollback journal files should now also be

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byte-order independent. (CVS 705)

FossilOrigin-Name: 2fb3fdcdf06c1206bf14da640c2f9e599455f0eb
This commit is contained in:
drh
2002-08-12 12:29:56 +00:00
parent 0d316a40cc
commit 94f3331a0b
7 changed files with 106 additions and 30 deletions
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94
src/pager.c
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@@ -18,7 +18,7 @@
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.49 2002/07/07 16:52:47 drh Exp $
** @(#) $Id: pager.c,v 1.50 2002/08/12 12:29:57 drh Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
@@ -124,6 +124,7 @@ struct Pager {
u8 needSync; /* True if an fsync() is needed on the journal */
u8 dirtyFile; /* True if database file has changed in any way */
u8 alwaysRollback; /* Disable dont_rollback() for all pages */
u8 journalFormat; /* Version number of the journal file */
u8 *aInJournal; /* One bit for each page in the database file */
u8 *aInCkpt; /* One bit for each page in the database */
PgHdr *pFirst, *pLast; /* List of free pages */
@@ -153,10 +154,30 @@ struct PageRecord {
/*
** Journal files begin with the following magic string. The data
** was obtained from /dev/random. It is used only as a sanity check.
**
** There are two journal formats. The older journal format writes
** 32-bit integers in the byte-order of the host machine. The new
** format writes integers as big-endian. All new journals use the
** new format, but we have to be able to read an older journal in order
** to roll it back.
*/
static const unsigned char aJournalMagic[] = {
static const unsigned char aOldJournalMagic[] = {
0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd4,
};
static const unsigned char aJournalMagic[] = {
0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd5,
};
#define SQLITE_NEW_JOURNAL_FORMAT 1
#define SQLITE_OLD_JOURNAL_FORMAT 0
/*
** The following integer, if set, causes journals to be written in the
** old format. This is used for testing purposes only - to make sure
** the code is able to rollback an old journal.
*/
#ifdef SQLITE_TEST
int pager_old_format = 0;
#endif
/*
** Hash a page number
@@ -182,6 +203,41 @@ static const unsigned char aJournalMagic[] = {
# define REFINFO(X)
#endif
/*
** Read a 32-bit integer from the given file descriptor
*/
static int read32bits(Pager *pPager, OsFile *fd, u32 *pRes){
u32 res;
int rc;
rc = sqliteOsRead(fd, &res, sizeof(res));
if( rc==SQLITE_OK && pPager->journalFormat==SQLITE_NEW_JOURNAL_FORMAT ){
unsigned char ac[4];
memcpy(ac, &res, 4);
res = (ac[0]<<24) | (ac[1]<<16) | (ac[2]<<8) | ac[3];
}
*pRes = res;
return rc;
}
/*
** Write a 32-bit integer into the given file descriptor. Writing
** is always done using the new journal format.
*/
static int write32bits(OsFile *fd, u32 val){
unsigned char ac[4];
#ifdef SQLITE_TEST
if( pager_old_format ){
return sqliteOsWrite(fd, &val, 4);
}
#endif
ac[0] = (val>>24) & 0xff;
ac[1] = (val>>16) & 0xff;
ac[2] = (val>>8) & 0xff;
ac[3] = val & 0xff;
return sqliteOsWrite(fd, ac, 4);
}
/*
** Convert the bits in the pPager->errMask into an approprate
** return code.
@@ -281,7 +337,9 @@ static int pager_playback_one_page(Pager *pPager, OsFile *jfd){
PgHdr *pPg; /* An existing page in the cache */
PageRecord pgRec;
rc = sqliteOsRead(jfd, &pgRec, sizeof(pgRec));
rc = read32bits(pPager, jfd, &pgRec.pgno);
if( rc!=SQLITE_OK ) return rc;
rc = sqliteOsRead(jfd, &pgRec.aData, sizeof(pgRec.aData));
if( rc!=SQLITE_OK ) return rc;
/* Sanity checking on the page */
@@ -347,11 +405,19 @@ static int pager_playback(Pager *pPager){
** database file back to its original size.
*/
rc = sqliteOsRead(&pPager->jfd, aMagic, sizeof(aMagic));
if( rc!=SQLITE_OK || memcmp(aMagic,aJournalMagic,sizeof(aMagic))!=0 ){
if( rc!=SQLITE_OK ){
rc = SQLITE_PROTOCOL;
goto end_playback;
}
rc = sqliteOsRead(&pPager->jfd, &mxPg, sizeof(mxPg));
if( memcmp(aMagic, aOldJournalMagic, sizeof(aMagic))==0 ){
pPager->journalFormat = SQLITE_OLD_JOURNAL_FORMAT;
}else if( memcmp(aMagic, aJournalMagic, sizeof(aMagic))==0 ){
pPager->journalFormat = SQLITE_NEW_JOURNAL_FORMAT;
}else{
rc = SQLITE_PROTOCOL;
goto end_playback;
}
rc = read32bits(pPager, &pPager->jfd, &mxPg);
if( rc!=SQLITE_OK ){
goto end_playback;
}
@@ -416,6 +482,7 @@ static int pager_ckpt_playback(Pager *pPager){
/* Copy original pages out of the checkpoint journal and back into the
** database file.
*/
pPager->journalFormat = SQLITE_NEW_JOURNAL_FORMAT;
for(i=nRec-1; i>=0; i--){
rc = pager_playback_one_page(pPager, &pPager->cpfd);
if( rc!=SQLITE_OK ) goto end_ckpt_playback;
@@ -847,7 +914,7 @@ int sqlitepager_get(Pager *pPager, Pgno pgno, void **ppPage){
** database. But syncing is a very slow operation. So after a
** sync, it is best to write everything we can back to the main
** database to minimize the risk of having to sync again in the
** near future. That is way we write all dirty pages after a
** near future. That is why we write all dirty pages after a
** sync.
*/
if( pPg==0 ){
@@ -1073,9 +1140,18 @@ int sqlitepager_begin(void *pData){
pPager->state = SQLITE_WRITELOCK;
sqlitepager_pagecount(pPager);
pPager->origDbSize = pPager->dbSize;
#ifdef SQLITE_TEST
if( pager_old_format ){
rc = sqliteOsWrite(&pPager->jfd, aOldJournalMagic,
sizeof(aOldJournalMagic));
}else{
rc = sqliteOsWrite(&pPager->jfd, aJournalMagic, sizeof(aJournalMagic));
}
#else
rc = sqliteOsWrite(&pPager->jfd, aJournalMagic, sizeof(aJournalMagic));
#endif
if( rc==SQLITE_OK ){
rc = sqliteOsWrite(&pPager->jfd, &pPager->dbSize, sizeof(Pgno));
rc = write32bits(&pPager->jfd, pPager->dbSize);
}
if( rc!=SQLITE_OK ){
rc = pager_unwritelock(pPager);
@@ -1144,7 +1220,7 @@ int sqlitepager_write(void *pData){
** journal if it is not there already.
*/
if( !pPg->inJournal && (int)pPg->pgno <= pPager->origDbSize ){
rc = sqliteOsWrite(&pPager->jfd, &pPg->pgno, sizeof(Pgno));
rc = write32bits(&pPager->jfd, pPg->pgno);
if( rc==SQLITE_OK ){
rc = sqliteOsWrite(&pPager->jfd, pData, SQLITE_PAGE_SIZE);
}
@@ -1168,7 +1244,7 @@ int sqlitepager_write(void *pData){
*/
if( pPager->ckptInUse && !pPg->inCkpt && (int)pPg->pgno<=pPager->ckptSize ){
assert( pPg->inJournal || (int)pPg->pgno>pPager->origDbSize );
rc = sqliteOsWrite(&pPager->cpfd, &pPg->pgno, sizeof(Pgno));
rc = write32bits(&pPager->cpfd, pPg->pgno);
if( rc==SQLITE_OK ){
rc = sqliteOsWrite(&pPager->cpfd, pData, SQLITE_PAGE_SIZE);
}