/**************************** sqlite3_column_ ******************************* ** The following routines are used to access elements of the current row ** in the result set. */ const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){ const void *val; sqlite3MallocDisallow(); val = sqlite3_value_blob( columnMem(pStmt,i) ); sqlite3MallocAllow(); return val; }
/* ** Transfer all bindings from the first statement over to the second. ** If the two statements contain a different number of bindings, then ** an SQLITE_ERROR is returned. */ int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){ Vdbe *pFrom = (Vdbe*)pFromStmt; Vdbe *pTo = (Vdbe*)pToStmt; int i, rc = SQLITE_OK; if( (pFrom->magic!=VDBE_MAGIC_RUN && pFrom->magic!=VDBE_MAGIC_HALT) || (pTo->magic!=VDBE_MAGIC_RUN && pTo->magic!=VDBE_MAGIC_HALT) ){ return SQLITE_MISUSE; } if( pFrom->nVar!=pTo->nVar ){ return SQLITE_ERROR; } for(i=0; rc==SQLITE_OK && i<pFrom->nVar; i++){ sqlite3MallocDisallow(); rc = sqlite3VdbeMemMove(&pTo->aVar[i], &pFrom->aVar[i]); sqlite3MallocAllow(); } return rc; }
/* ** 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; }