** file simultaneously, or one process from reading the database while
** another is writing.
**
-** @(#) $Id: pager.c,v 1.115 2004/06/09 17:37:28 drh Exp $
+** @(#) $Id: pager.c,v 1.116 2004/06/09 19:03:55 drh Exp $
*/
#include "os.h" /* Must be first to enable large file support */
#include "sqliteInt.h"
#define PAGER_ERR_CORRUPT 0x08 /* database or journal corruption */
#define PAGER_ERR_DISK 0x10 /* general disk I/O error - bad hard drive? */
-/*
-** The journal file contains page records in the following
-** format.
-**
-** Actually, this structure is the complete page record for pager
-** formats less than 3. Beginning with format 3, this record is surrounded
-** by two checksums.
-*/
-typedef struct PageRecord PageRecord;
-struct PageRecord {
- Pgno pgno; /* The page number */
- char aData[SQLITE_PAGE_SIZE]; /* Original data for page pgno */
-};
-
/*
** 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 three journal formats (so far). The 1st journal format writes
-** 32-bit integers in the byte-order of the host machine. New
-** formats 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 rollback journals created by older versions of the library.
-**
-** The 3rd journal format (added for 2.8.0) adds additional sanity
-** checking information to the journal. If the power fails while the
-** journal is being written, semi-random garbage data might appear in
-** the journal file after power is restored. If an attempt is then made
+** Since version 2.8.0, the journal format contains additional sanity
+** checking information. If the power fails while the journal is begin
+** written, semi-random garbage data might appear in the journal
+** file after power is restored. If an attempt is then made
** to roll the journal back, the database could be corrupted. The additional
** sanity checking data is an attempt to discover the garbage in the
** journal and ignore it.
**
-** The sanity checking information for the 3rd journal format consists
+** The sanity checking information for the new journal format consists
** of a 32-bit checksum on each page of data. The checksum covers both
** the page number and the SQLITE_PAGE_SIZE bytes of data for the page.
** This cksum is initialized to a 32-bit random value that appears in the
** be correct. But by initializing the checksum to random value which
** is different for every journal, we minimize that risk.
*/
-static const unsigned char aJournalMagic1[] = {
- 0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd4,
-};
-static const unsigned char aJournalMagic2[] = {
- 0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd5,
+static const unsigned char aJournalMagic[] = {
+ 0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd7,
};
-static const unsigned char aJournalMagic3[] = {
- 0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd6,
-};
-#define JOURNAL_FORMAT_1 1
-#define JOURNAL_FORMAT_2 2
-#define JOURNAL_FORMAT_3 3
-
-/*
-** The following integer determines what format to use when creating
-** new primary journal files. By default we always use format 3.
-** When testing, we can set this value to older journal formats in order to
-** make sure that newer versions of the library are able to rollback older
-** journal files.
-**
-** Note that statement journals always use format 2 and omit the header.
-*/
-#ifdef SQLITE_TEST
-int journal_format = 3;
-#else
-# define journal_format 3
-#endif
/*
** The size of the header and of each page in the journal varies according
** to which journal format is being used. The following macros figure out
** the sizes based on format numbers.
*/
-/*
-#define JOURNAL_HDR_SZ(X) \
- (sizeof(aJournalMagic1) + sizeof(Pgno) + ((X)>=3)*2*sizeof(u32))
-*/
-#define JOURNAL_HDR_SZ(pPager, X) (\
- sizeof(aJournalMagic1) + \
- sizeof(Pgno) + \
- ((X)>=3?3*sizeof(u32)+(pPager)->nMaster:0) )
-#define JOURNAL_PG_SZ(X) \
- (SQLITE_PAGE_SIZE + sizeof(Pgno) + ((X)>=3)*sizeof(u32))
+#define JOURNAL_HDR_SZ(pPager) (24 + (pPager)->nMaster)
+#define JOURNAL_PG_SZ(pPager) ((pPager->pageSize) + 8)
/*
** Read a 32-bit integer from the given file descriptor. Store the integer
** that is read in *pRes. Return SQLITE_OK if everything worked, or an
** error code is something goes wrong.
-**
-** If the journal format is 2 or 3, read a big-endian integer. If the
-** journal format is 1, read an integer in the native byte-order of the
-** host machine.
*/
-static int read32bits(int format, OsFile *fd, u32 *pRes){
+static int read32bits(OsFile *fd, u32 *pRes){
u32 res;
int rc;
rc = sqlite3OsRead(fd, &res, sizeof(res));
- if( rc==SQLITE_OK && format>JOURNAL_FORMAT_1 ){
+ if( rc==SQLITE_OK ){
unsigned char ac[4];
memcpy(ac, &res, 4);
res = (ac[0]<<24) | (ac[1]<<16) | (ac[2]<<8) | ac[3];
/*
** Write a 32-bit integer into the given file descriptor. Return SQLITE_OK
** on success or an error code is something goes wrong.
-**
-** If the journal format is 2 or 3, write the integer as 4 big-endian
-** bytes. If the journal format is 1, write the integer in the native
-** byte order. In normal operation, only formats 2 and 3 are used.
-** Journal format 1 is only used for testing.
*/
static int write32bits(OsFile *fd, u32 val){
unsigned char ac[4];
- if( journal_format<=1 ){
- return sqlite3OsWrite(fd, &val, 4);
- }
ac[0] = (val>>24) & 0xff;
ac[1] = (val>>16) & 0xff;
ac[2] = (val>>8) & 0xff;
/*
** Write a 32-bit integer into a page header right before the
** page data. This will overwrite the PgHdr.pDirty pointer.
-**
-** The integer is big-endian for formats 2 and 3 and native byte order
-** for journal format 1.
*/
static void store32bits(u32 val, PgHdr *p, int offset){
unsigned char *ac;
ac = &((unsigned char*)PGHDR_TO_DATA(p))[offset];
- if( journal_format<=1 ){
- memcpy(ac, &val, 4);
- }else{
- ac[0] = (val>>24) & 0xff;
- ac[1] = (val>>16) & 0xff;
- ac[2] = (val>>8) & 0xff;
- ac[3] = val & 0xff;
- }
+ ac[0] = (val>>24) & 0xff;
+ ac[1] = (val>>16) & 0xff;
+ ac[2] = (val>>8) & 0xff;
+ ac[3] = val & 0xff;
}
** Read a single page from the journal file opened on file descriptor
** jfd. Playback this one page.
**
+**
+**
** There are three different journal formats. The format parameter determines
** which format is used by the journal that is played back.
*/
-static int pager_playback_one_page(Pager *pPager, OsFile *jfd, int format){
+static int pager_playback_one_page(Pager *pPager, OsFile *jfd, int useCksum){
int rc;
- PgHdr *pPg; /* An existing page in the cache */
- PageRecord pgRec;
- u32 cksum;
+ PgHdr *pPg; /* An existing page in the cache */
+ Pgno pgno; /* The page number of a page in journal */
+ u32 cksum; /* Checksum used for sanity checking */
+ u8 aData[SQLITE_PAGE_SIZE]; /* Store data here */
- rc = read32bits(format, jfd, &pgRec.pgno);
+ rc = read32bits(jfd, &pgno);
if( rc!=SQLITE_OK ) return rc;
- rc = sqlite3OsRead(jfd, &pgRec.aData, sizeof(pgRec.aData));
+ rc = sqlite3OsRead(jfd, &aData, pPager->pageSize);
if( rc!=SQLITE_OK ) return rc;
/* Sanity checking on the page. This is more important that I originally
** it could cause invalid data to be written into the journal. We need to
** detect this invalid data (with high probability) and ignore it.
*/
- if( pgRec.pgno==0 ){
+ if( pgno==0 ){
return SQLITE_DONE;
}
- if( pgRec.pgno>(unsigned)pPager->dbSize ){
+ if( pgno>(unsigned)pPager->dbSize ){
return SQLITE_OK;
}
- if( format>=JOURNAL_FORMAT_3 ){
- rc = read32bits(format, jfd, &cksum);
+ if( useCksum ){
+ rc = read32bits(jfd, &cksum);
if( rc ) return rc;
- if( pager_cksum(pPager, pgRec.pgno, pgRec.aData)!=cksum ){
+ if( pager_cksum(pPager, pgno, aData)!=cksum ){
return SQLITE_DONE;
}
}
/* Playback the page. Update the in-memory copy of the page
** at the same time, if there is one.
*/
- pPg = pager_lookup(pPager, pgRec.pgno);
- TRACE2("PLAYBACK page %d\n", pgRec.pgno);
- sqlite3OsSeek(&pPager->fd, (pgRec.pgno-1)*(off_t)SQLITE_PAGE_SIZE);
- rc = sqlite3OsWrite(&pPager->fd, pgRec.aData, SQLITE_PAGE_SIZE);
+ pPg = pager_lookup(pPager, pgno);
+ TRACE2("PLAYBACK page %d\n", pgno);
+ sqlite3OsSeek(&pPager->fd, (pgno-1)*(off_t)SQLITE_PAGE_SIZE);
+ rc = sqlite3OsWrite(&pPager->fd, aData, SQLITE_PAGE_SIZE);
if( pPg ){
/* No page should ever be rolled back that is in use, except for page
** 1 which is held in use in order to keep the lock on the database
void *pData;
assert( pPg->nRef==0 || pPg->pgno==1 );
pData = PGHDR_TO_DATA(pPg);
- memcpy(pData, pgRec.aData, pPager->pageSize);
+ memcpy(pData, aData, pPager->pageSize);
if( pPager->xDestructor ){
pPager->xDestructor(pData, pPager->pageSize);
}
goto delmaster_out;
}
- /* Check if the file is big enough to be a format 3 journal file
+ /* Check if the file is big enough to be a journal file
** with the required master journal name. If not, ignore it.
*/
rc = sqlite3OsFileSize(&journal, &jsz);
sqlite3OsClose(&journal);
goto delmaster_out;
}
- if( jsz<(sizeof(aJournalMagic3)+4*sizeof(u32)+strlen(zMaster)+1) ){
+ if( jsz<(25+strlen(zMaster)) ){
sqlite3OsClose(&journal);
continue;
}
** is stored. Read the master journal name into memory obtained
** from malloc.
*/
- rc = sqlite3OsSeek(&journal, sizeof(aJournalMagic3)+2*sizeof(u32));
+ rc = sqlite3OsSeek(&journal, 20);
if( rc!=SQLITE_OK ) goto delmaster_out;
- rc = read32bits(3, &journal, (u32 *)&nMaster);
+ rc = read32bits(&journal, (u32*)&nMaster);
if( rc!=SQLITE_OK ) goto delmaster_out;
- if( nMaster>0 && nMaster==strlen(zMaster)+1 ){
+ if( nMaster>0 && nMaster>=strlen(zMaster)+1 ){
char *zMasterPtr = (char *)sqliteMalloc(nMaster);
if( !zMasterPtr ){
rc = SQLITE_NOMEM;
**
** The journal file format is as follows:
**
-** * 8 byte prefix. One of the aJournalMagic123 vectors defined
-** above. The format of the journal file is determined by which
-** of the three prefix vectors is seen.
-** * 4 byte big-endian integer which is the number of valid page records
+** (1) 8 byte prefix. A copy of aJournalMagic[].
+** (2) 4 byte big-endian integer which is the number of valid page records
** in the journal. If this value is 0xffffffff, then compute the
-** number of page records from the journal size. This field appears
-** in format 3 only.
-** * 4 byte big-endian integer which is the initial value for the
-** sanity checksum. This field appears in format 3 only.
-** * 4 byte integer which is the number of pages to truncate the
+** number of page records from the journal size.
+** (3) 4 byte big-endian integer which is the initial value for the
+** sanity checksum.
+** (4) 4 byte integer which is the number of pages to truncate the
** database to during a rollback.
-** * Zero or more pages instances, each as follows:
+** (5) 4 byte integer which is the number of bytes in the master journal
+** name. The value may be zero (indicate that there is no master
+** journal.)
+** (6) N bytes of the master journal name. The name will be nul-terminated
+** and might be shorter than the value read from (5). If the first byte
+** of the name is \000 then there is no master journal. The master
+** journal name is stored in UTF-8.
+** (7) Zero or more pages instances, each as follows:
** + 4 byte page number.
-** + SQLITE_PAGE_SIZE bytes of data.
-** + 4 byte checksum (format 3 only)
+** + pPager->pageSize bytes of data.
+** + 4 byte checksum
**
-** When we speak of the journal header, we mean the first 4 bullets above.
-** Each entry in the journal is an instance of the 5th bullet. Note that
-** bullets 2 and 3 only appear in format-3 journals.
+** When we speak of the journal header, we mean the first 6 items above.
+** Each entry in the journal is an instance of the 7th item.
**
** Call the value from the second bullet "nRec". nRec is the number of
** valid page entries in the journal. In most cases, you can compute the
** in this case. But for things like temporary table (which will be
** deleted when the power is restored) we don't care.
**
-** Journal formats 1 and 2 do not have an nRec value in the header so we
-** have to compute nRec from the file size. This has risks (as described
-** above) which is why all persistent tables have been changed to use
-** format 3.
-**
** If the file opened as the journal file is not a well-formed
** journal file then the database will likely already be
** corrupted, so the PAGER_ERR_CORRUPT bit is set in pPager->errMask
int nRec; /* Number of Records in the journal */
int i; /* Loop counter */
Pgno mxPg = 0; /* Size of the original file in pages */
- int format; /* Format of the journal file. */
- unsigned char aMagic[sizeof(aJournalMagic1)];
- int rc;
+ unsigned char aMagic[8]; /* A buffer to hold the magic header */
+ int rc; /* Result code of a subroutine */
+ int nMaster; /* Number of bytes in the name of master journal */
char *zMaster = 0; /* Name of master journal file if any */
/* Figure out how many records are in the journal. Abort early if
** the database file should have still been completely unchanged.
** Nothing needs to be rolled back. We can safely ignore this journal.
*/
- if( szJ < sizeof(aMagic)+sizeof(Pgno) ){
+ if( szJ < 24 ){
goto end_playback;
}
- /* Read the beginning of the journal and truncate the
- ** database file back to its original size.
- */
+ /* (1) Read the beginning of the journal and verify the magic string
+ ** at the beginning of the journal. */
rc = sqlite3OsRead(&pPager->jfd, aMagic, sizeof(aMagic));
- if( rc!=SQLITE_OK ){
+ if( rc!=SQLITE_OK || memcmp(aMagic, aJournalMagic, sizeof(aMagic))!=0 ){
rc = SQLITE_PROTOCOL;
goto end_playback;
}
- if( memcmp(aMagic, aJournalMagic3, sizeof(aMagic))==0 ){
- format = JOURNAL_FORMAT_3;
- }else if( memcmp(aMagic, aJournalMagic2, sizeof(aMagic))==0 ){
- format = JOURNAL_FORMAT_2;
- }else if( memcmp(aMagic, aJournalMagic1, sizeof(aMagic))==0 ){
- format = JOURNAL_FORMAT_1;
- }else{
- rc = SQLITE_PROTOCOL;
+
+ /* (2) Read the number of pages stored in the journal. */
+ rc = read32bits(&pPager->jfd, (u32*)&nRec);
+ if( rc ) goto end_playback;
+ if( nRec==0xffffffff || useJournalSize ){
+ nRec = (szJ - JOURNAL_HDR_SZ(pPager))/JOURNAL_PG_SZ(pPager);
+ }
+
+ /* (3) Read the initial value for the sanity checksum */
+ rc = read32bits(&pPager->jfd, &pPager->cksumInit);
+ if( rc ) goto end_playback;
+
+ /* (4) Read the number of pages in the database file prior to the
+ ** start of the transaction */
+ rc = read32bits(&pPager->jfd, &mxPg);
+ if( rc!=SQLITE_OK ){
goto end_playback;
}
- if( format>=JOURNAL_FORMAT_3 ){
- if( szJ < sizeof(aMagic) + 4*sizeof(u32) ){
- /* Ignore the journal if it is too small to contain a complete
- ** header. We already did this test once above, but at the prior
- ** test, we did not know the journal format and so we had to assume
- ** the smallest possible header. Now we know the header is bigger
- ** than the minimum so we test again.
- */
+
+ /* (5) and (6): Check if a master journal file is specified. If one is
+ ** specified, only proceed with the playback if it still exists. */
+ rc = read32bits(&pPager->jfd, &nMaster);
+ if( rc ) goto end_playback;
+ if( nMaster>0 ){
+ zMaster = sqliteMalloc(nMaster);
+ if( !zMaster ){
+ rc = SQLITE_NOMEM;
goto end_playback;
}
- rc = read32bits(format, &pPager->jfd, (u32*)&nRec);
- if( rc ) goto end_playback;
- rc = read32bits(format, &pPager->jfd, &pPager->cksumInit);
- if( rc ) goto end_playback;
- if( nRec==0xffffffff || useJournalSize ){
- nRec = (szJ - JOURNAL_HDR_SZ(pPager, 3))/JOURNAL_PG_SZ(3);
- }
-
- /* Check if a master journal file is specified. If one is specified,
- ** only proceed with the playback if it still exists.
- */
- rc = read32bits(format, &pPager->jfd, &pPager->nMaster);
- if( rc ) goto end_playback;
- if( pPager->nMaster>0 ){
- zMaster = sqliteMalloc(pPager->nMaster);
- if( !zMaster ){
- rc = SQLITE_NOMEM;
- goto end_playback;
- }
- rc = sqlite3OsRead(&pPager->jfd, zMaster, pPager->nMaster);
- if( rc!=SQLITE_OK || (strlen(zMaster) && !sqlite3OsFileExists(zMaster)) ){
- goto end_playback;
- }
+ rc = sqlite3OsRead(&pPager->jfd, zMaster, pPager->nMaster);
+ if( rc!=SQLITE_OK || (zMaster[0] && !sqlite3OsFileExists(zMaster)) ){
+ goto end_playback;
}
- }else{
- nRec = (szJ - JOURNAL_HDR_SZ(pPager, 2))/JOURNAL_PG_SZ(2);
- assert( nRec*JOURNAL_PG_SZ(2)+JOURNAL_HDR_SZ(pPager, 2)==szJ );
- }
- rc = read32bits(format, &pPager->jfd, &mxPg);
- if( rc!=SQLITE_OK ){
- goto end_playback;
}
+
+ /* Truncate the database file back to it's original size */
assert( pPager->origDbSize==0 || pPager->origDbSize==mxPg );
rc = sqlite3OsTruncate(&pPager->fd, SQLITE_PAGE_SIZE*(off_t)mxPg);
if( rc!=SQLITE_OK ){
/* Copy original pages out of the journal and back into the database file.
*/
for(i=0; i<nRec; i++){
- rc = pager_playback_one_page(pPager, &pPager->jfd, format);
+ rc = pager_playback_one_page(pPager, &pPager->jfd, 1);
if( rc!=SQLITE_OK ){
if( rc==SQLITE_DONE ){
rc = SQLITE_OK;
nRec = pPager->stmtNRec;
/* Copy original pages out of the statement journal and back into the
- ** database file. Note that the statement journal always uses format
- ** 2 instead of format 3 since it does not need to be concerned with
- ** power failures corrupting the journal and can thus omit the checksums.
+ ** database file. Note that the statement journal omits checksums from
+ ** each record since power-failure recovery is not important to statement
+ ** journals.
*/
for(i=nRec-1; i>=0; i--){
- rc = pager_playback_one_page(pPager, &pPager->stfd, 2);
+ rc = pager_playback_one_page(pPager, &pPager->stfd, 0);
assert( rc!=SQLITE_DONE );
if( rc!=SQLITE_OK ) goto end_stmt_playback;
}
if( rc!=SQLITE_OK ){
goto end_stmt_playback;
}
- nRec = (szJ - pPager->stmtJSize)/JOURNAL_PG_SZ(journal_format);
+ nRec = (szJ - pPager->stmtJSize)/JOURNAL_PG_SZ(pPager);
for(i=nRec-1; i>=0; i--){
- rc = pager_playback_one_page(pPager, &pPager->jfd, journal_format);
+ rc = pager_playback_one_page(pPager, &pPager->jfd, 1);
if( rc!=SQLITE_OK ){
assert( rc!=SQLITE_DONE );
goto end_stmt_playback;
if( strcmp(zFilename,":memory:")==0 ){
memDb = 1;
zFullPathname = sqliteMalloc(4);
- if( zFullPathname ) strcpy(zFullPathname, "nil");
+ if( zFullPathname ) strcpy(zFullPathname, "");
rc = SQLITE_OK;
}else{
zFullPathname = sqlite3OsFullPathname(zFilename);
** with the nRec computed from the size of the journal file.
*/
off_t hdrSz, pgSz, jSz;
- hdrSz = JOURNAL_HDR_SZ(pPager, journal_format);
- pgSz = JOURNAL_PG_SZ(journal_format);
+ hdrSz = JOURNAL_HDR_SZ(pPager);
+ pgSz = JOURNAL_PG_SZ(pPager);
rc = sqlite3OsFileSize(&pPager->jfd, &jSz);
if( rc!=0 ) return rc;
assert( pPager->nRec*pgSz+hdrSz==jSz );
}
#endif
- if( journal_format>=3 ){
+ {
/* Write the nRec value into the journal file header */
off_t szJ;
if( pPager->fullSync ){
rc = sqlite3OsSync(&pPager->jfd);
if( rc!=0 ) return rc;
}
- sqlite3OsSeek(&pPager->jfd, sizeof(aJournalMagic1));
+ sqlite3OsSeek(&pPager->jfd, sizeof(aJournalMagic));
rc = write32bits(&pPager->jfd, pPager->nRec);
if( rc ) return rc;
/* Write the name of the master journal file if one is specified */
if( zMaster ){
assert( strlen(zMaster)<pPager->nMaster );
- rc = sqlite3OsSeek(&pPager->jfd, sizeof(aJournalMagic3) + 3*4);
+ rc = sqlite3OsSeek(&pPager->jfd, 20);
if( rc ) return rc;
rc = sqlite3OsWrite(&pPager->jfd, zMaster, strlen(zMaster)+1);
if( rc ) return rc;
}
- szJ = JOURNAL_HDR_SZ(pPager, journal_format) +
- pPager->nRec*JOURNAL_PG_SZ(journal_format);
+ szJ = JOURNAL_HDR_SZ(pPager) + pPager->nRec*JOURNAL_PG_SZ(pPager);
sqlite3OsSeek(&pPager->jfd, szJ);
}
TRACE2("SYNC journal of %d\n", pPager->fd.h);
return rc;
}
pPager->origDbSize = pPager->dbSize;
- if( journal_format==JOURNAL_FORMAT_3 ){
- /* Create the header for a format 3 journal:
- ** - 8 bytes: Magic identifying journal format 3.
- ** - 4 bytes: Number of records in journal, or -1 no-sync mode is on.
- ** - 4 bytes: Magic used for page checksums.
- ** - 4 bytes: Number of bytes reserved for master journal ptr (nMaster)
- ** - nMaster bytes: Space for a master journal pointer.
- ** - 4 bytes: Initial database page count.
- */
- rc = sqlite3OsWrite(&pPager->jfd, aJournalMagic3, sizeof(aJournalMagic3));
- if( rc==SQLITE_OK ){
- rc = write32bits(&pPager->jfd, pPager->noSync ? 0xffffffff : 0);
- }
- if( rc==SQLITE_OK ){
- sqlite3Randomness(sizeof(pPager->cksumInit), &pPager->cksumInit);
- rc = write32bits(&pPager->jfd, pPager->cksumInit);
- }
- if( rc==SQLITE_OK ){
- rc = write32bits(&pPager->jfd, pPager->nMaster);
- }
-
- /* Unless the size reserved for the master-journal pointer is 0, set
- ** the first byte of the master journal pointer to 0x00. Either way,
- ** this is interpreted as 'no master journal' in the event of a
- ** rollback after a crash.
- */
- if( rc==SQLITE_OK && pPager->nMaster>0 ){
- rc = sqlite3OsWrite(&pPager->jfd, "", 1);
- }
- if( rc==SQLITE_OK ){
- rc = sqlite3OsSeek(&pPager->jfd,
- sizeof(aJournalMagic3) + 3*4 + pPager->nMaster);
- }
- }else if( journal_format==JOURNAL_FORMAT_2 ){
- rc = sqlite3OsWrite(&pPager->jfd, aJournalMagic2, sizeof(aJournalMagic2));
- }else{
- assert( journal_format==JOURNAL_FORMAT_1 );
- rc = sqlite3OsWrite(&pPager->jfd, aJournalMagic1, sizeof(aJournalMagic1));
+
+ /* Create the header for the journal:
+ ** - 8 bytes: Magic identifying journal format.
+ ** - 4 bytes: Number of records in journal, or -1 no-sync mode is on.
+ ** - 4 bytes: Magic used for page checksums.
+ ** - 4 bytes: Initial database page count.
+ ** - 4 bytes: Number of bytes reserved for master journal ptr (nMaster)
+ ** - nMaster bytes: Space for a master journal pointer.
+ */
+ rc = sqlite3OsWrite(&pPager->jfd, aJournalMagic, sizeof(aJournalMagic));
+ if( rc==SQLITE_OK ){
+ rc = write32bits(&pPager->jfd, pPager->noSync ? 0xffffffff : 0);
+ }
+ if( rc==SQLITE_OK ){
+ sqlite3Randomness(sizeof(pPager->cksumInit), &pPager->cksumInit);
+ rc = write32bits(&pPager->jfd, pPager->cksumInit);
}
if( rc==SQLITE_OK ){
rc = write32bits(&pPager->jfd, pPager->dbSize);
}
+ if( rc==SQLITE_OK ){
+ rc = write32bits(&pPager->jfd, pPager->nMaster);
+ }
+ if( rc==SQLITE_OK ){
+ rc = sqlite3OsSeek(&pPager->jfd, 24 + pPager->nMaster);
+ }
if( pPager->stmtAutoopen && rc==SQLITE_OK ){
rc = sqlite3pager_stmt_begin(pPager);
}
}
pPg->inJournal = 1;
}else{
- if( journal_format>=JOURNAL_FORMAT_3 ){
- u32 cksum = pager_cksum(pPager, pPg->pgno, pData);
- saved = *(u32*)PGHDR_TO_EXTRA(pPg);
- store32bits(cksum, pPg, SQLITE_PAGE_SIZE);
- szPg = SQLITE_PAGE_SIZE+8;
- }else{
- szPg = SQLITE_PAGE_SIZE+4;
- }
+ u32 cksum = pager_cksum(pPager, pPg->pgno, pData);
+ saved = *(u32*)PGHDR_TO_EXTRA(pPg);
+ store32bits(cksum, pPg, SQLITE_PAGE_SIZE);
+ szPg = SQLITE_PAGE_SIZE+8;
store32bits(pPg->pgno, pPg, -4);
CODEC(pPager, pData, pPg->pgno, 7);
rc = sqlite3OsWrite(&pPager->jfd, &((char*)pData)[-4], szPg);
TRACE3("JOURNAL page %d needSync=%d\n", pPg->pgno, pPg->needSync);
CODEC(pPager, pData, pPg->pgno, 0);
- if( journal_format>=JOURNAL_FORMAT_3 ){
- *(u32*)PGHDR_TO_EXTRA(pPg) = saved;
- }
+ *(u32*)PGHDR_TO_EXTRA(pPg) = saved;
if( rc!=SQLITE_OK ){
sqlite3pager_rollback(pPager);
pPager->errMask |= PAGER_ERR_FULL;
/* If the statement journal is open and the page is not in it,
** then write the current page to the statement journal. Note that
- ** the statement journal always uses the simplier format 2 that lacks
- ** checksums. The header is also omitted from the statement journal.
+ ** the statement journal format differs from the standard journal format
+ ** in that it omits the checksums and the header.
*/
if( pPager->stmtInUse && !pPg->inStmt && (int)pPg->pgno<=pPager->stmtSize ){
assert( pPg->inJournal || (int)pPg->pgno>pPager->origDbSize );
rc = sqlite3OsFileSize(&pPager->jfd, &pPager->stmtJSize);
if( rc ) goto stmt_begin_failed;
assert( pPager->stmtJSize ==
- pPager->nRec*JOURNAL_PG_SZ(journal_format) +
- JOURNAL_HDR_SZ(pPager, journal_format) );
+ pPager->nRec*JOURNAL_PG_SZ(pPager) + JOURNAL_HDR_SZ(pPager) );
#endif
- pPager->stmtJSize = pPager->nRec*JOURNAL_PG_SZ(journal_format)
- + JOURNAL_HDR_SZ(pPager, journal_format);
+ pPager->stmtJSize =
+ pPager->nRec*JOURNAL_PG_SZ(pPager) + JOURNAL_HDR_SZ(pPager);
pPager->stmtSize = pPager->dbSize;
if( !pPager->stmtOpen ){
rc = sqlite3pager_opentemp(zTemp, &pPager->stfd);
projects / thirdparty / sqlite.git / commitdiff
