/*
** Write data to an jt-file.
*/
static int jtWrite(
sqlite3_file *pFile,
const void *zBuf,
int iAmt,
sqlite_int64 iOfst
){
int rc;
jt_file *p = (jt_file *)pFile;
if( p->flags&SQLITE_OPEN_MAIN_JOURNAL ){
if( iOfst==0 ){
jt_file *pMain = locateDatabaseHandle(p->zName);
assert( pMain );
if( iAmt==28 ){
/* Zeroing the first journal-file header. This is the end of a
** transaction. */
closeTransaction(pMain);
}else if( iAmt!=12 ){
/* Writing the first journal header to a journal file. This happens
** when a transaction is first started. */
u8 *z = (u8 *)zBuf;
pMain->nPage = decodeUint32(&z[16]);
pMain->nPagesize = decodeUint32(&z[24]);
if( SQLITE_OK!=(rc=openTransaction(pMain, p)) ){
return rc;
}
}
}
if( p->iMaxOff<(iOfst + iAmt) ){
p->iMaxOff = iOfst + iAmt;
}
}
if( p->flags&SQLITE_OPEN_MAIN_DB && p->pWritable ){
if( iAmt<p->nPagesize
&& p->nPagesize%iAmt==0
&& iOfst>=(PENDING_BYTE+512)
&& iOfst+iAmt<=PENDING_BYTE+p->nPagesize
){
/* No-op. This special case is hit when the backup code is copying a
** to a database with a larger page-size than the source database and
** it needs to fill in the non-locking-region part of the original
** pending-byte page.
*/
}else{
u32 pgno = iOfst/p->nPagesize + 1;
assert( (iAmt==1||iAmt==p->nPagesize) && ((iOfst+iAmt)%p->nPagesize)==0 );
assert( pgno<=p->nPage || p->nSync>0 );
assert( pgno>p->nPage || sqlite3BitvecTest(p->pWritable, pgno) );
}
}
rc = sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
if( (p->flags&SQLITE_OPEN_MAIN_JOURNAL) && iAmt==12 ){
jt_file *pMain = locateDatabaseHandle(p->zName);
int rc2 = readJournalFile(p, pMain);
if( rc==SQLITE_OK ) rc = rc2;
}
return rc;
}
static int jtWrite(
sqlite3_file *pFile,
const void *zBuf,
int iAmt,
sqlite_int64 iOfst
){
int rc;
jt_file *p = (jt_file *)pFile;
if( p->flags&SQLITE_OPEN_MAIN_JOURNAL ){
if( iOfst==0 ){
jt_file *pMain = locateDatabaseHandle(p->zName);
assert( pMain );
if( iAmt==28 ){
closeTransaction(pMain);
}else if( iAmt!=12 ){
u8 *z = (u8 *)zBuf;
pMain->nPage = decodeUint32(&z[16]);
pMain->nPagesize = decodeUint32(&z[24]);
if( SQLITE_OK!=(rc=openTransaction(pMain, p)) ){
return rc;
}
}
}
if( p->iMaxOff<(iOfst + iAmt) ){
p->iMaxOff = iOfst + iAmt;
}
}
if( p->flags&SQLITE_OPEN_MAIN_DB && p->pWritable ){
if( iAmt<p->nPagesize
&& p->nPagesize%iAmt==0
&& iOfst>=(PENDING_BYTE+512)
&& iOfst+iAmt<=PENDING_BYTE+p->nPagesize
){
}else{
u32 pgno = iOfst/p->nPagesize + 1;
assert( (iAmt==1||iAmt==p->nPagesize) && ((iOfst+iAmt)%p->nPagesize)==0 );
assert( pgno<=p->nPage || p->nSync>0 );
assert( pgno>p->nPage || sqlite3BitvecTest(p->pWritable, pgno) );
}
}
rc = sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
if( (p->flags&SQLITE_OPEN_MAIN_JOURNAL) && iAmt==12 ){
jt_file *pMain = locateDatabaseHandle(p->zName);
int rc2 = readJournalFile(p, pMain);
if( rc==SQLITE_OK ) rc = rc2;
}
return rc;
}
/*
** The first argument, zBuf, points to a buffer containing a 28 byte
** serialized journal header. This function deserializes four of the
** integer fields contained in the journal header and writes their
** values to the output variables.
**
** SQLITE_OK is returned if the journal-header is successfully
** decoded. Otherwise, SQLITE_ERROR.
*/
static int decodeJournalHdr(
const unsigned char *zBuf, /* Input: 28 byte journal header */
u32 *pnRec, /* Out: Number of journalled records */
u32 *pnPage, /* Out: Original database page count */
u32 *pnSector, /* Out: Sector size in bytes */
u32 *pnPagesize /* Out: Page size in bytes */
){
unsigned char aMagic[] = { 0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd7 };
if( memcmp(aMagic, zBuf, 8) ) return SQLITE_ERROR;
if( pnRec ) *pnRec = decodeUint32(&zBuf[8]);
if( pnPage ) *pnPage = decodeUint32(&zBuf[16]);
if( pnSector ) *pnSector = decodeUint32(&zBuf[20]);
if( pnPagesize ) *pnPagesize = decodeUint32(&zBuf[24]);
return SQLITE_OK;
}
static int decodeJournalHdr(
const unsigned char *zBuf,
u32 *pnRec,
u32 *pnPage,
u32 *pnSector,
u32 *pnPagesize
){
unsigned char aMagic[] = { 0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd7 };
if( memcmp(aMagic, zBuf, 8) ) return SQLITE_ERROR;
if( pnRec ) *pnRec = decodeUint32(&zBuf[8]);
if( pnPage ) *pnPage = decodeUint32(&zBuf[16]);
if( pnSector ) *pnSector = decodeUint32(&zBuf[20]);
if( pnPagesize ) *pnPagesize = decodeUint32(&zBuf[24]);
return SQLITE_OK;
}
/*
** The first argument to this function is a handle open on a journal file.
** This function reads the journal file and adds the page number for each
** page in the journal to the Bitvec object passed as the second argument.
*/
static int readJournalFile(jt_file *p, jt_file *pMain){
int rc = SQLITE_OK;
unsigned char zBuf[28];
sqlite3_file *pReal = p->pReal;
sqlite3_int64 iOff = 0;
sqlite3_int64 iSize = p->iMaxOff;
unsigned char *aPage;
int iSave;
int iSave2;
aPage = sqlite3_malloc(pMain->nPagesize);
if( !aPage ){
return SQLITE_IOERR_NOMEM;
}
stop_ioerr_simulation(&iSave, &iSave2);
while( rc==SQLITE_OK && iOff<iSize ){
u32 nRec, nPage, nSector, nPagesize;
u32 ii;
/* Read and decode the next journal-header from the journal file. */
rc = sqlite3OsRead(pReal, zBuf, 28, iOff);
if( rc!=SQLITE_OK
|| decodeJournalHdr(zBuf, &nRec, &nPage, &nSector, &nPagesize)
){
goto finish_rjf;
}
iOff += nSector;
if( nRec==0 ){
/* A trick. There might be another journal-header immediately
** following this one. In this case, 0 records means 0 records,
** not "read until the end of the file". See also ticket #2565.
*/
if( iSize>=(iOff+nSector) ){
rc = sqlite3OsRead(pReal, zBuf, 28, iOff);
if( rc!=SQLITE_OK || 0==decodeJournalHdr(zBuf, 0, 0, 0, 0) ){
continue;
}
}
nRec = (iSize-iOff) / (pMain->nPagesize+8);
}
/* Read all the records that follow the journal-header just read. */
for(ii=0; rc==SQLITE_OK && ii<nRec && iOff<iSize; ii++){
u32 pgno;
rc = sqlite3OsRead(pReal, zBuf, 4, iOff);
if( rc==SQLITE_OK ){
pgno = decodeUint32(zBuf);
if( pgno>0 && pgno<=pMain->nPage ){
if( 0==sqlite3BitvecTest(pMain->pWritable, pgno) ){
rc = sqlite3OsRead(pReal, aPage, pMain->nPagesize, iOff+4);
if( rc==SQLITE_OK ){
u32 cksum = genCksum(aPage, pMain->nPagesize);
assert( cksum==pMain->aCksum[pgno-1] );
}
}
sqlite3BitvecSet(pMain->pWritable, pgno);
}
iOff += (8 + pMain->nPagesize);
}
}
iOff = ((iOff + (nSector-1)) / nSector) * nSector;
}
finish_rjf:
start_ioerr_simulation(iSave, iSave2);
sqlite3_free(aPage);
if( rc==SQLITE_IOERR_SHORT_READ ){
rc = SQLITE_OK;
}
return rc;
}
/*
** This function is called when a new transaction is opened, just after
** the first journal-header is written to the journal file.
*/
static int openTransaction(jt_file *pMain, jt_file *pJournal){
unsigned char *aData;
sqlite3_file *p = pMain->pReal;
int rc = SQLITE_OK;
closeTransaction(pMain);
aData = sqlite3_malloc(pMain->nPagesize);
pMain->pWritable = sqlite3BitvecCreate(pMain->nPage);
pMain->aCksum = sqlite3_malloc(sizeof(u32) * (pMain->nPage + 1));
pJournal->iMaxOff = 0;
if( !pMain->pWritable || !pMain->aCksum || !aData ){
rc = SQLITE_IOERR_NOMEM;
}else if( pMain->nPage>0 ){
u32 iTrunk;
int iSave;
int iSave2;
stop_ioerr_simulation(&iSave, &iSave2);
/* Read the database free-list. Add the page-number for each free-list
** leaf to the jt_file.pWritable bitvec.
*/
rc = sqlite3OsRead(p, aData, pMain->nPagesize, 0);
if( rc==SQLITE_OK ){
u32 nDbsize = decodeUint32(&aData[28]);
if( nDbsize>0 && memcmp(&aData[24], &aData[92], 4)==0 ){
u32 iPg;
for(iPg=nDbsize+1; iPg<=pMain->nPage; iPg++){
sqlite3BitvecSet(pMain->pWritable, iPg);
}
}
}
iTrunk = decodeUint32(&aData[32]);
while( rc==SQLITE_OK && iTrunk>0 ){
u32 nLeaf;
u32 iLeaf;
sqlite3_int64 iOff = (iTrunk-1)*pMain->nPagesize;
rc = sqlite3OsRead(p, aData, pMain->nPagesize, iOff);
nLeaf = decodeUint32(&aData[4]);
for(iLeaf=0; rc==SQLITE_OK && iLeaf<nLeaf; iLeaf++){
u32 pgno = decodeUint32(&aData[8+4*iLeaf]);
sqlite3BitvecSet(pMain->pWritable, pgno);
}
iTrunk = decodeUint32(aData);
}
/* Calculate and store a checksum for each page in the database file. */
if( rc==SQLITE_OK ){
int ii;
for(ii=0; rc==SQLITE_OK && ii<pMain->nPage; ii++){
i64 iOff = (i64)(pMain->nPagesize) * (i64)ii;
if( iOff==PENDING_BYTE ) continue;
rc = sqlite3OsRead(pMain->pReal, aData, pMain->nPagesize, iOff);
pMain->aCksum[ii] = genCksum(aData, pMain->nPagesize);
}
}
start_ioerr_simulation(iSave, iSave2);
}
sqlite3_free(aData);
return rc;
}
static int readJournalFile(jt_file *p, jt_file *pMain){
int rc = SQLITE_OK;
unsigned char zBuf[28];
sqlite3_file *pReal = p->pReal;
sqlite3_int64 iOff = 0;
sqlite3_int64 iSize = p->iMaxOff;
unsigned char *aPage;
int iSave;
int iSave2;
aPage = sqlite3_malloc(pMain->nPagesize);
if( !aPage ){
return SQLITE_IOERR_NOMEM;
}
stop_ioerr_simulation(&iSave, &iSave2);
while( rc==SQLITE_OK && iOff<iSize ){
u32 nRec, nPage, nSector, nPagesize;
u32 ii;
rc = sqlite3OsRead(pReal, zBuf, 28, iOff);
if( rc!=SQLITE_OK
|| decodeJournalHdr(zBuf, &nRec, &nPage, &nSector, &nPagesize)
){
goto finish_rjf;
}
iOff += nSector;
if( nRec==0 ){
if( iSize>=(iOff+nSector) ){
rc = sqlite3OsRead(pReal, zBuf, 28, iOff);
if( rc!=SQLITE_OK || 0==decodeJournalHdr(zBuf, 0, 0, 0, 0) ){
continue;
}
}
nRec = (iSize-iOff) / (pMain->nPagesize+8);
}
for(ii=0; rc==SQLITE_OK && ii<nRec && iOff<iSize; ii++){
u32 pgno;
rc = sqlite3OsRead(pReal, zBuf, 4, iOff);
if( rc==SQLITE_OK ){
pgno = decodeUint32(zBuf);
if( pgno>0 && pgno<=pMain->nPage ){
if( 0==sqlite3BitvecTest(pMain->pWritable, pgno) ){
rc = sqlite3OsRead(pReal, aPage, pMain->nPagesize, iOff+4);
if( rc==SQLITE_OK ){
u32 cksum = genCksum(aPage, pMain->nPagesize);
assert( cksum==pMain->aCksum[pgno-1] );
}
}
sqlite3BitvecSet(pMain->pWritable, pgno);
}
iOff += (8 + pMain->nPagesize);
}
}
iOff = ((iOff + (nSector-1)) / nSector) * nSector;
}
finish_rjf:
start_ioerr_simulation(iSave, iSave2);
sqlite3_free(aPage);
if( rc==SQLITE_IOERR_SHORT_READ ){
rc = SQLITE_OK;
}
return rc;
}
