/*
** Create a temporary file name in zBuf. zBuf must be big enough to
** hold at least SQLITE_TEMPNAME_SIZE characters.
*/
int sqlite3Os2TempFileName( char *zBuf ){
static const unsigned char zChars[] =
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789";
int i, j;
PSZ zTempPath = 0;
if( DosScanEnv( (PSZ)"TEMP", &zTempPath ) ){
if( DosScanEnv( (PSZ)"TMP", &zTempPath ) ){
if( DosScanEnv( (PSZ)"TMPDIR", &zTempPath ) ){
ULONG ulDriveNum = 0, ulDriveMap = 0;
DosQueryCurrentDisk( &ulDriveNum, &ulDriveMap );
sprintf( (char*)zTempPath, "%c:", (char)( 'A' + ulDriveNum - 1 ) );
}
}
}
for(;;){
sprintf( zBuf, "%s\\"TEMP_FILE_PREFIX, zTempPath );
j = strlen( zBuf );
sqlite3Randomness( 15, &zBuf[j] );
for( i = 0; i < 15; i++, j++ ){
zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
}
zBuf[j] = 0;
if( !sqlite3OsFileExists( zBuf ) ) break;
}
OSTRACE2( "TEMP FILENAME: %s\n", zBuf );
return SQLITE_OK;
}
/*
** Create a temporary file name in zBuf. zBuf must be big enough to
** hold at least SQLITE_TEMPNAME_SIZE characters.
*/
int sqlite3WinTempFileName(char *zBuf){
static char zChars[] =
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789";
int i, j;
char zTempPath[SQLITE_TEMPNAME_SIZE];
if( sqlite3_temp_directory ){
strncpy(zTempPath, sqlite3_temp_directory, SQLITE_TEMPNAME_SIZE-30);
zTempPath[SQLITE_TEMPNAME_SIZE-30] = 0;
}else if( isNT() ){
char *zMulti;
WCHAR zWidePath[SQLITE_TEMPNAME_SIZE];
GetTempPathW(SQLITE_TEMPNAME_SIZE-30, zWidePath);
zMulti = unicodeToUtf8(zWidePath);
if( zMulti ){
strncpy(zTempPath, zMulti, SQLITE_TEMPNAME_SIZE-30);
zTempPath[SQLITE_TEMPNAME_SIZE-30] = 0;
sqliteFree(zMulti);
}else{
return SQLITE_NOMEM;
}
}else{
char *zUtf8;
char zMbcsPath[SQLITE_TEMPNAME_SIZE];
GetTempPathA(SQLITE_TEMPNAME_SIZE-30, zMbcsPath);
zUtf8 = mbcsToUtf8(zMbcsPath);
if( zUtf8 ){
strncpy(zTempPath, zUtf8, SQLITE_TEMPNAME_SIZE-30);
zTempPath[SQLITE_TEMPNAME_SIZE-30] = 0;
sqliteFree(zUtf8);
}else{
return SQLITE_NOMEM;
}
}
for(i=strlen(zTempPath); i>0 && zTempPath[i-1]=='\\'; i--){}
zTempPath[i] = 0;
for(;;){
sprintf(zBuf, "%s\\"TEMP_FILE_PREFIX, zTempPath);
j = strlen(zBuf);
sqlite3Randomness(15, &zBuf[j]);
for(i=0; i<15; i++, j++){
zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
}
zBuf[j] = 0;
if( !sqlite3OsFileExists(zBuf) ) break;
}
TRACE2("TEMP FILENAME: %s\n", zBuf);
return SQLITE_OK;
}
/*
** Create a temporary file name in zBuf. zBuf must be big enough to
** hold at least SQLITE_TEMPNAME_SIZE characters.
*/
int sqlite3Os2TempFileName( char *zBuf ){
static const unsigned char zChars[] =
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789";
int i, j;
PSZ zTempPath = 0;
if( DosScanEnv( (PSZ)"TEMP", &zTempPath ) ){
if( DosScanEnv( (PSZ)"TMP", &zTempPath ) ){
if( DosScanEnv( (PSZ)"TMPDIR", &zTempPath ) ){
ULONG ulDriveNum = 0, ulDriveMap = 0;
DosQueryCurrentDisk( &ulDriveNum, &ulDriveMap );
sprintf( (char*)zTempPath, "%c:", (char)( 'A' + ulDriveNum - 1 ) );
}
}
}
/* strip off a trailing slashes or backslashes, otherwise we would get *
* multiple (back)slashes which causes DosOpen() to fail */
j = strlen(zTempPath);
while( j > 0 && zTempPath[j-1] == '\\' || zTempPath[j-1] == '/' ){
j--;
}
zTempPath[j] = '\0';
for(;;){
sprintf( zBuf, "%s\\"TEMP_FILE_PREFIX, zTempPath );
j = strlen( zBuf );
sqlite3Randomness( 15, &zBuf[j] );
for( i = 0; i < 15; i++, j++ ){
zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
}
zBuf[j] = 0;
if( !sqlite3OsFileExists( zBuf ) ) break;
}
OSTRACE2( "TEMP FILENAME: %s\n", zBuf );
return SQLITE_OK;
}
/*
** This routine implements the OP_Vacuum opcode of the VDBE.
*/
int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
int rc = SQLITE_OK; /* Return code from service routines */
const char *zFilename; /* full pathname of the database file */
int nFilename; /* number of characters in zFilename[] */
char *zTemp = 0; /* a temporary file in same directory as zFilename */
Btree *pMain; /* The database being vacuumed */
Btree *pTemp;
char *zSql = 0;
int saved_flags; /* Saved value of the db->flags */
Db *pDb = 0; /* Database to detach at end of vacuum */
/* Save the current value of the write-schema flag before setting it. */
saved_flags = db->flags;
db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;
if( !db->autoCommit ){
sqlite3SetString(pzErrMsg, "cannot VACUUM from within a transaction",
(char*)0);
rc = SQLITE_ERROR;
goto end_of_vacuum;
}
/* Get the full pathname of the database file and create a
** temporary filename in the same directory as the original file.
*/
pMain = db->aDb[0].pBt;
zFilename = sqlite3BtreeGetFilename(pMain);
assert( zFilename );
if( zFilename[0]=='\0' ){
/* The in-memory database. Do nothing. Return directly to avoid causing
** an error trying to DETACH the vacuum_db (which never got attached)
** in the exit-handler.
*/
return SQLITE_OK;
}
nFilename = strlen(zFilename);
zTemp = sqliteMalloc( nFilename+100 );
if( zTemp==0 ){
rc = SQLITE_NOMEM;
goto end_of_vacuum;
}
strcpy(zTemp, zFilename);
/* The randomName() procedure in the following loop uses an excellent
** source of randomness to generate a name from a space of 1.3e+31
** possibilities. So unless the directory already contains on the order
** of 1.3e+31 files, the probability that the following loop will
** run more than once or twice is vanishingly small. We are certain
** enough that this loop will always terminate (and terminate quickly)
** that we don't even bother to set a maximum loop count.
*/
do {
zTemp[nFilename] = '-';
randomName((unsigned char*)&zTemp[nFilename+1]);
} while( sqlite3OsFileExists(zTemp) );
/* Attach the temporary database as 'vacuum_db'. The synchronous pragma
** can be set to 'off' for this file, as it is not recovered if a crash
** occurs anyway. The integrity of the database is maintained by a
** (possibly synchronous) transaction opened on the main database before
** sqlite3BtreeCopyFile() is called.
**
** An optimisation would be to use a non-journaled pager.
*/
zSql = sqlite3MPrintf("ATTACH '%q' AS vacuum_db;", zTemp);
if( !zSql ){
rc = SQLITE_NOMEM;
goto end_of_vacuum;
}
rc = execSql(db, zSql);
sqliteFree(zSql);
zSql = 0;
if( rc!=SQLITE_OK ) goto end_of_vacuum;
pDb = &db->aDb[db->nDb-1];
assert( strcmp(db->aDb[db->nDb-1].zName,"vacuum_db")==0 );
pTemp = db->aDb[db->nDb-1].pBt;
sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain),
sqlite3BtreeGetReserve(pMain));
assert( sqlite3BtreeGetPageSize(pTemp)==sqlite3BtreeGetPageSize(pMain) );
rc = execSql(db, "PRAGMA vacuum_db.synchronous=OFF");
if( rc!=SQLITE_OK ){
goto end_of_vacuum;
}
#ifndef SQLITE_OMIT_AUTOVACUUM
sqlite3BtreeSetAutoVacuum(pTemp, sqlite3BtreeGetAutoVacuum(pMain));
#endif
/* Begin a transaction */
rc = execSql(db, "BEGIN EXCLUSIVE;");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Query the schema of the main database. Create a mirror schema
** in the temporary database.
*/
rc = execExecSql(db,
"SELECT 'CREATE TABLE vacuum_db.' || substr(sql,14,100000000) "
" FROM sqlite_master WHERE type='table' AND name!='sqlite_sequence'"
" AND rootpage>0"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = execExecSql(db,
"SELECT 'CREATE INDEX vacuum_db.' || substr(sql,14,100000000)"
" FROM sqlite_master WHERE sql LIKE 'CREATE INDEX %' ");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = execExecSql(db,
"SELECT 'CREATE UNIQUE INDEX vacuum_db.' || substr(sql,21,100000000) "
" FROM sqlite_master WHERE sql LIKE 'CREATE UNIQUE INDEX %'");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Loop through the tables in the main database. For each, do
** an "INSERT INTO vacuum_db.xxx SELECT * FROM xxx;" to copy
** the contents to the temporary database.
*/
rc = execExecSql(db,
"SELECT 'INSERT INTO vacuum_db.' || quote(name) "
"|| ' SELECT * FROM ' || quote(name) || ';'"
"FROM sqlite_master "
"WHERE type = 'table' AND name!='sqlite_sequence' "
" AND rootpage>0"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy over the sequence table
*/
rc = execExecSql(db,
"SELECT 'DELETE FROM vacuum_db.' || quote(name) || ';' "
"FROM vacuum_db.sqlite_master WHERE name='sqlite_sequence' "
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = execExecSql(db,
"SELECT 'INSERT INTO vacuum_db.' || quote(name) "
"|| ' SELECT * FROM ' || quote(name) || ';' "
"FROM vacuum_db.sqlite_master WHERE name=='sqlite_sequence';"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy the triggers, views, and virtual tables from the main database
** over to the temporary database. None of these objects has any
** associated storage, so all we have to do is copy their entries
** from the SQLITE_MASTER table.
*/
rc = execSql(db,
"INSERT INTO vacuum_db.sqlite_master "
" SELECT type, name, tbl_name, rootpage, sql"
" FROM sqlite_master"
" WHERE type='view' OR type='trigger'"
" OR (type='table' AND rootpage=0)"
);
if( rc ) goto end_of_vacuum;
/* At this point, unless the main db was completely empty, there is now a
** transaction open on the vacuum database, but not on the main database.
** Open a btree level transaction on the main database. This allows a
** call to sqlite3BtreeCopyFile(). The main database btree level
** transaction is then committed, so the SQL level never knows it was
** opened for writing. This way, the SQL transaction used to create the
** temporary database never needs to be committed.
*/
if( rc==SQLITE_OK ){
u32 meta;
int i;
/* This array determines which meta meta values are preserved in the
** vacuum. Even entries are the meta value number and odd entries
** are an increment to apply to the meta value after the vacuum.
** The increment is used to increase the schema cookie so that other
** connections to the same database will know to reread the schema.
*/
static const unsigned char aCopy[] = {
1, 1, /* Add one to the old schema cookie */
3, 0, /* Preserve the default page cache size */
5, 0, /* Preserve the default text encoding */
6, 0, /* Preserve the user version */
};
assert( 1==sqlite3BtreeIsInTrans(pTemp) );
assert( 1==sqlite3BtreeIsInTrans(pMain) );
/* Copy Btree meta values */
for(i=0; i<sizeof(aCopy)/sizeof(aCopy[0]); i+=2){
rc = sqlite3BtreeGetMeta(pMain, aCopy[i], &meta);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeUpdateMeta(pTemp, aCopy[i], meta+aCopy[i+1]);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
}
rc = sqlite3BtreeCopyFile(pMain, pTemp);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeCommit(pTemp);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeCommit(pMain);
}
end_of_vacuum:
/* Restore the original value of db->flags */
db->flags = saved_flags;
/* Currently there is an SQL level transaction open on the vacuum
** database. No locks are held on any other files (since the main file
** was committed at the btree level). So it safe to end the transaction
** by manually setting the autoCommit flag to true and detaching the
** vacuum database. The vacuum_db journal file is deleted when the pager
** is closed by the DETACH.
*/
db->autoCommit = 1;
if( pDb ){
sqlite3MallocDisallow();
sqlite3BtreeClose(pDb->pBt);
sqlite3MallocAllow();
pDb->pBt = 0;
pDb->pSchema = 0;
}
if( zTemp ){
sqlite3OsDelete(zTemp);
sqliteFree(zTemp);
}
sqliteFree( zSql );
sqlite3ResetInternalSchema(db, 0);
return rc;
}
/*
** A read or write transaction may or may not be active on database handle
** db. If a transaction is active, commit it. If there is a
** write-transaction spanning more than one database file, this routine
** takes care of the master journal trickery.
*/
static int vdbeCommit(sqlite3 *db){
int i;
int nTrans = 0; /* Number of databases with an active write-transaction */
int rc = SQLITE_OK;
int needXcommit = 0;
for(i=0; i<db->nDb; i++){
Btree *pBt = db->aDb[i].pBt;
if( pBt && sqlite3BtreeIsInTrans(pBt) ){
needXcommit = 1;
if( i!=1 ) nTrans++;
}
}
/* If there are any write-transactions at all, invoke the commit hook */
if( needXcommit && db->xCommitCallback ){
int rc;
sqlite3SafetyOff(db);
rc = db->xCommitCallback(db->pCommitArg);
sqlite3SafetyOn(db);
if( rc ){
return SQLITE_CONSTRAINT;
}
}
/* The simple case - no more than one database file (not counting the
** TEMP database) has a transaction active. There is no need for the
** master-journal.
**
** If the return value of sqlite3BtreeGetFilename() is a zero length
** string, it means the main database is :memory:. In that case we do
** not support atomic multi-file commits, so use the simple case then
** too.
*/
if( 0==strlen(sqlite3BtreeGetFilename(db->aDb[0].pBt)) || nTrans<=1 ){
for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
Btree *pBt = db->aDb[i].pBt;
if( pBt ){
rc = sqlite3BtreeSync(pBt, 0);
}
}
/* Do the commit only if all databases successfully synced */
if( rc==SQLITE_OK ){
for(i=0; i<db->nDb; i++){
Btree *pBt = db->aDb[i].pBt;
if( pBt ){
sqlite3BtreeCommit(pBt);
}
}
}
}
/* The complex case - There is a multi-file write-transaction active.
** This requires a master journal file to ensure the transaction is
** committed atomicly.
*/
else{
char *zMaster = 0; /* File-name for the master journal */
char const *zMainFile = sqlite3BtreeGetFilename(db->aDb[0].pBt);
OsFile master;
/* Select a master journal file name */
do {
u32 random;
sqliteFree(zMaster);
sqlite3Randomness(sizeof(random), &random);
zMaster = sqlite3MPrintf("%s-mj%08X", zMainFile, random&0x7fffffff);
if( !zMaster ){
return SQLITE_NOMEM;
}
}while( sqlite3OsFileExists(zMaster) );
/* Open the master journal. */
memset(&master, 0, sizeof(master));
rc = sqlite3OsOpenExclusive(zMaster, &master, 0);
if( rc!=SQLITE_OK ){
sqliteFree(zMaster);
return rc;
}
/* Write the name of each database file in the transaction into the new
** master journal file. If an error occurs at this point close
** and delete the master journal file. All the individual journal files
** still have 'null' as the master journal pointer, so they will roll
** back independantly if a failure occurs.
*/
for(i=0; i<db->nDb; i++){
Btree *pBt = db->aDb[i].pBt;
if( i==1 ) continue; /* Ignore the TEMP database */
if( pBt && sqlite3BtreeIsInTrans(pBt) ){
char const *zFile = sqlite3BtreeGetJournalname(pBt);
if( zFile[0]==0 ) continue; /* Ignore :memory: databases */
rc = sqlite3OsWrite(&master, zFile, strlen(zFile)+1);
if( rc!=SQLITE_OK ){
sqlite3OsClose(&master);
sqlite3OsDelete(zMaster);
sqliteFree(zMaster);
return rc;
}
}
}
/* Sync the master journal file. Before doing this, open the directory
** the master journal file is store in so that it gets synced too.
*/
zMainFile = sqlite3BtreeGetDirname(db->aDb[0].pBt);
rc = sqlite3OsOpenDirectory(zMainFile, &master);
if( rc!=SQLITE_OK ){
sqlite3OsClose(&master);
sqlite3OsDelete(zMaster);
sqliteFree(zMaster);
return rc;
}
rc = sqlite3OsSync(&master);
if( rc!=SQLITE_OK ){
sqlite3OsClose(&master);
sqliteFree(zMaster);
return rc;
}
/* Sync all the db files involved in the transaction. The same call
** sets the master journal pointer in each individual journal. If
** an error occurs here, do not delete the master journal file.
**
** If the error occurs during the first call to sqlite3BtreeSync(),
** then there is a chance that the master journal file will be
** orphaned. But we cannot delete it, in case the master journal
** file name was written into the journal file before the failure
** occured.
*/
for(i=0; i<db->nDb; i++){
Btree *pBt = db->aDb[i].pBt;
if( pBt && sqlite3BtreeIsInTrans(pBt) ){
rc = sqlite3BtreeSync(pBt, zMaster);
if( rc!=SQLITE_OK ){
sqlite3OsClose(&master);
sqliteFree(zMaster);
return rc;
}
}
}
sqlite3OsClose(&master);
/* Delete the master journal file. This commits the transaction. After
** doing this the directory is synced again before any individual
** transaction files are deleted.
*/
rc = sqlite3OsDelete(zMaster);
assert( rc==SQLITE_OK );
sqliteFree(zMaster);
zMaster = 0;
rc = sqlite3OsSyncDirectory(zMainFile);
if( rc!=SQLITE_OK ){
/* This is not good. The master journal file has been deleted, but
** the directory sync failed. There is no completely safe course of
** action from here. The individual journals contain the name of the
** master journal file, but there is no way of knowing if that
** master journal exists now or if it will exist after the operating
** system crash that may follow the fsync() failure.
*/
assert(0);
sqliteFree(zMaster);
return rc;
}
/* All files and directories have already been synced, so the following
** calls to sqlite3BtreeCommit() are only closing files and deleting
** journals. If something goes wrong while this is happening we don't
** really care. The integrity of the transaction is already guaranteed,
** but some stray 'cold' journals may be lying around. Returning an
** error code won't help matters.
*/
for(i=0; i<db->nDb; i++){
Btree *pBt = db->aDb[i].pBt;
if( pBt ){
sqlite3BtreeCommit(pBt);
}
}
}
return rc;
}
/*
** Prepare a virtual machine for execution. This involves things such
** as allocating stack space and initializing the program counter.
** After the VDBE has be prepped, it can be executed by one or more
** calls to sqlite3VdbeExec().
**
** This is the only way to move a VDBE from VDBE_MAGIC_INIT to
** VDBE_MAGIC_RUN.
*/
void sqlite3VdbeMakeReady(
Vdbe *p, /* The VDBE */
int nVar, /* Number of '?' see in the SQL statement */
int nMem, /* Number of memory cells to allocate */
int nCursor, /* Number of cursors to allocate */
int isExplain /* True if the EXPLAIN keywords is present */
){
int n;
assert( p!=0 );
assert( p->magic==VDBE_MAGIC_INIT );
/* There should be at least one opcode.
*/
assert( p->nOp>0 );
/* No instruction ever pushes more than a single element onto the
** stack. And the stack never grows on successive executions of the
** same loop. So the total number of instructions is an upper bound
** on the maximum stack depth required.
**
** Allocation all the stack space we will ever need.
*/
if( p->aStack==0 ){
resolveP2Values(p);
assert( nVar>=0 );
n = isExplain ? 10 : p->nOp;
p->aStack = sqliteMalloc(
n*sizeof(p->aStack[0]) /* aStack */
+ n*sizeof(Mem*) /* apArg */
+ nVar*sizeof(Mem) /* aVar */
+ nVar*sizeof(char*) /* azVar */
+ nMem*sizeof(Mem) /* aMem */
+ nCursor*sizeof(Cursor*) /* apCsr */
);
if( !sqlite3_malloc_failed ){
p->aMem = &p->aStack[n];
p->nMem = nMem;
p->aVar = &p->aMem[nMem];
p->nVar = nVar;
p->okVar = 0;
p->apArg = (Mem**)&p->aVar[nVar];
p->azVar = (char**)&p->apArg[n];
p->apCsr = (Cursor**)&p->azVar[nVar];
p->nCursor = nCursor;
for(n=0; n<nVar; n++){
p->aVar[n].flags = MEM_Null;
}
for(n=0; n<nMem; n++){
p->aMem[n].flags = MEM_Null;
}
}
}
#ifdef SQLITE_DEBUG
if( (p->db->flags & SQLITE_VdbeListing)!=0
|| sqlite3OsFileExists("vdbe_explain")
){
int i;
printf("VDBE Program Listing:\n");
sqlite3VdbePrintSql(p);
for(i=0; i<p->nOp; i++){
sqlite3VdbePrintOp(stdout, i, &p->aOp[i]);
}
}
if( sqlite3OsFileExists("vdbe_trace") ){
p->trace = stdout;
}
#endif
p->pTos = &p->aStack[-1];
p->pc = -1;
p->rc = SQLITE_OK;
p->uniqueCnt = 0;
p->returnDepth = 0;
p->errorAction = OE_Abort;
p->popStack = 0;
p->explain |= isExplain;
p->magic = VDBE_MAGIC_RUN;
p->nChange = 0;
#ifdef VDBE_PROFILE
{
int i;
for(i=0; i<p->nOp; i++){
p->aOp[i].cnt = 0;
p->aOp[i].cycles = 0;
}
}
#endif
}
/*
** This routine implements the OP_Vacuum opcode of the VDBE.
*/
int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
int rc = SQLITE_OK; /* Return code from service routines */
#if !defined(SQLITE_OMIT_VACUUM) || SQLITE_OMIT_VACUUM
const char *zFilename; /* full pathname of the database file */
int nFilename; /* number of characters in zFilename[] */
char *zTemp = 0; /* a temporary file in same directory as zFilename */
int i; /* Loop counter */
Btree *pMain; /* The database being vacuumed */
Btree *pTemp;
char *zSql = 0;
if( !db->autoCommit ){
sqlite3SetString(pzErrMsg, "cannot VACUUM from within a transaction",
(char*)0);
rc = SQLITE_ERROR;
goto end_of_vacuum;
}
/* Get the full pathname of the database file and create a
** temporary filename in the same directory as the original file.
*/
pMain = db->aDb[0].pBt;
zFilename = sqlite3BtreeGetFilename(pMain);
assert( zFilename );
if( zFilename[0]=='\0' ){
/* The in-memory database. Do nothing. Return directly to avoid causing
** an error trying to DETACH the vacuum_db (which never got attached)
** in the exit-handler.
*/
return SQLITE_OK;
}
nFilename = strlen(zFilename);
zTemp = sqliteMalloc( nFilename+100 );
if( zTemp==0 ){
rc = SQLITE_NOMEM;
goto end_of_vacuum;
}
strcpy(zTemp, zFilename);
i = 0;
do {
zTemp[nFilename] = '-';
randomName((unsigned char*)&zTemp[nFilename+1]);
} while( i<10 && sqlite3OsFileExists(zTemp) );
/* Attach the temporary database as 'vacuum_db'. The synchronous pragma
** can be set to 'off' for this file, as it is not recovered if a crash
** occurs anyway. The integrity of the database is maintained by a
** (possibly synchronous) transaction opened on the main database before
** sqlite3BtreeCopyFile() is called.
**
** An optimisation would be to use a non-journaled pager.
*/
zSql = sqlite3MPrintf("ATTACH '%q' AS vacuum_db;", zTemp);
if( !zSql ){
rc = SQLITE_NOMEM;
goto end_of_vacuum;
}
rc = execSql(db, zSql);
sqliteFree(zSql);
zSql = 0;
if( rc!=SQLITE_OK ) goto end_of_vacuum;
assert( strcmp(db->aDb[db->nDb-1].zName,"vacuum_db")==0 );
pTemp = db->aDb[db->nDb-1].pBt;
sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain),
sqlite3BtreeGetReserve(pMain));
assert( sqlite3BtreeGetPageSize(pTemp)==sqlite3BtreeGetPageSize(pMain) );
execSql(db, "PRAGMA vacuum_db.synchronous=OFF");
/* Begin a transaction */
rc = execSql(db, "BEGIN;");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Query the schema of the main database. Create a mirror schema
** in the temporary database.
*/
rc = execExecSql(db,
"SELECT 'CREATE TABLE vacuum_db.' || substr(sql,14,100000000) "
" FROM sqlite_master WHERE type='table' "
"UNION ALL "
"SELECT 'CREATE INDEX vacuum_db.' || substr(sql,14,100000000) "
" FROM sqlite_master WHERE sql LIKE 'CREATE INDEX %' "
"UNION ALL "
"SELECT 'CREATE UNIQUE INDEX vacuum_db.' || substr(sql,21,100000000) "
" FROM sqlite_master WHERE sql LIKE 'CREATE UNIQUE INDEX %'"
"UNION ALL "
"SELECT 'CREATE VIEW vacuum_db.' || substr(sql,13,100000000) "
" FROM sqlite_master WHERE type='view'"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Loop through the tables in the main database. For each, do
** an "INSERT INTO vacuum_db.xxx SELECT * FROM xxx;" to copy
** the contents to the temporary database.
*/
rc = execExecSql(db,
"SELECT 'INSERT INTO vacuum_db.' || quote(name) "
"|| ' SELECT * FROM ' || quote(name) || ';'"
"FROM sqlite_master "
"WHERE type = 'table';"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy the triggers from the main database to the temporary database.
** This was deferred before in case the triggers interfered with copying
** the data. It's possible the indices should be deferred until this
** point also.
*/
rc = execExecSql(db,
"SELECT 'CREATE TRIGGER vacuum_db.' || substr(sql, 16, 1000000) "
"FROM sqlite_master WHERE type='trigger'"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* At this point, unless the main db was completely empty, there is now a
** transaction open on the vacuum database, but not on the main database.
** Open a btree level transaction on the main database. This allows a
** call to sqlite3BtreeCopyFile(). The main database btree level
** transaction is then committed, so the SQL level never knows it was
** opened for writing. This way, the SQL transaction used to create the
** temporary database never needs to be committed.
*/
if( sqlite3BtreeIsInTrans(pTemp) ){
u32 meta;
assert( 0==sqlite3BtreeIsInTrans(pMain) );
rc = sqlite3BtreeBeginTrans(pMain, 1);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy Btree meta values 3 and 4. These correspond to SQL layer meta
** values 2 and 3, the default values of a couple of pragmas.
*/
rc = sqlite3BtreeGetMeta(pMain, 3, &meta);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeUpdateMeta(pTemp, 3, meta);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeGetMeta(pMain, 4, &meta);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeUpdateMeta(pTemp, 4, meta);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeCopyFile(pMain, pTemp);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeCommit(pMain);
}
end_of_vacuum:
/* Currently there is an SQL level transaction open on the vacuum
** database. No locks are held on any other files (since the main file
** was committed at the btree level). So it safe to end the transaction
** by manually setting the autoCommit flag to true and detaching the
** vacuum database. The vacuum_db journal file is deleted when the pager
** is closed by the DETACH.
*/
db->autoCommit = 1;
if( rc==SQLITE_OK ){
rc = execSql(db, "DETACH vacuum_db;");
}else{
execSql(db, "DETACH vacuum_db;");
}
if( zTemp ){
sqlite3OsDelete(zTemp);
sqliteFree(zTemp);
}
if( zSql ) sqliteFree( zSql );
sqlite3ResetInternalSchema(db, 0);
#endif
return rc;
}
/*
** Create a temporary file name in zBuf. zBuf must be big enough to
** hold at least SQLITE_TEMPNAME_SIZE characters.
*/
int sqlite3OsTempFileName(char *zBuf){
static char zChars[] =
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789";
int i, j;
char zTempPath[SQLITE_TEMPNAME_SIZE];
if( sqlite3_temp_directory ){
strncpy(zTempPath, sqlite3_temp_directory, SQLITE_TEMPNAME_SIZE-30);
zTempPath[SQLITE_TEMPNAME_SIZE-30] = 0;
}else{
GetTempPathA(SQLITE_TEMPNAME_SIZE-30, zTempPath);
}
for(i=strlen(zTempPath); i>0 && zTempPath[i-1]=='\\'; i--){}
zTempPath[i] = 0;
for(;;){
sprintf(zBuf, "%s\\"TEMP_FILE_PREFIX, zTempPath);
j = strlen(zBuf);
sqlite3Randomness(15, &zBuf[j]);
for(i=0; i<15; i++, j++){
zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
}
zBuf[j] = 0;
if( !sqlite3OsFileExists(zBuf) ) break;
}
TRACE2("TEMP FILENAME: %s\n", zBuf);
return SQLITE_OK;
}
