/*
** Initialize all database files - the main database file, the file
** used to store temporary tables, and any additional database files
** created using ATTACH statements. Return a success code. If an
** error occurs, write an error message into *pzErrMsg.
**
** After the database is initialized, the SQLITE_Initialized
** bit is set in the flags field of the sqlite structure. An
** attempt is made to initialize the database as soon as it
** is opened. If that fails (perhaps because another process
** has the sqlite_master table locked) than another attempt
** is made the first time the database is accessed.
*/
int sqliteInit(sqlite *db, char **pzErrMsg){
int i, rc;
if( db->init.busy ) return SQLITE_OK;
assert( (db->flags & SQLITE_Initialized)==0 );
rc = SQLITE_OK;
db->init.busy = 1;
for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
if( DbHasProperty(db, i, DB_SchemaLoaded) ) continue;
assert( i!=1 ); /* Should have been initialized together with 0 */
rc = sqliteInitOne(db, i, pzErrMsg);
if( rc ){
sqliteResetInternalSchema(db, i);
}
}
db->init.busy = 0;
if( rc==SQLITE_OK ){
db->flags |= SQLITE_Initialized;
sqliteCommitInternalChanges(db);
}
/* If the database is in formats 1 or 2, then upgrade it to
** version 3. This will reconstruct all indices. If the
** upgrade fails for any reason (ex: out of disk space, database
** is read only, interrupt received, etc.) then fail the init.
*/
if( rc==SQLITE_OK && db->file_format<3 ){
char *zErr = 0;
InitData initData;
int meta[SQLITE_N_BTREE_META];
db->magic = SQLITE_MAGIC_OPEN;
initData.db = db;
initData.pzErrMsg = &zErr;
db->file_format = 3;
rc = sqlite_exec(db,
"BEGIN; SELECT name FROM sqlite_master WHERE type='table';",
upgrade_3_callback,
&initData,
&zErr);
if( rc==SQLITE_OK ){
sqliteBtreeGetMeta(db->aDb[0].pBt, meta);
meta[2] = 4;
sqliteBtreeUpdateMeta(db->aDb[0].pBt, meta);
sqlite_exec(db, "COMMIT", 0, 0, 0);
}
if( rc!=SQLITE_OK ){
sqliteSetString(pzErrMsg,
"unable to upgrade database to the version 2.6 format",
zErr ? ": " : 0, zErr, (char*)0);
}
sqlite_freemem(zErr);
}
if( rc!=SQLITE_OK ){
db->flags &= ~SQLITE_Initialized;
}
return rc;
}
/*
** Attempt to read the database schema and initialize internal
** data structures for a single database file. The index of the
** database file is given by iDb. iDb==0 is used for the main
** database. iDb==1 should never be used. iDb>=2 is used for
** auxiliary databases. Return one of the SQLITE_ error codes to
** indicate success or failure.
*/
static int sqliteInitOne(sqlite *db, int iDb, char **pzErrMsg){
int rc;
BtCursor *curMain;
int size;
Table *pTab;
char const *azArg[6];
char zDbNum[30];
int meta[SQLITE_N_BTREE_META];
InitData initData;
char const *zMasterSchema;
char const *zMasterName;
char *zSql = 0;
/*
** The master database table has a structure like this
*/
static char master_schema[] =
"CREATE TABLE sqlite_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
static char temp_master_schema[] =
"CREATE TEMP TABLE sqlite_temp_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
assert( iDb>=0 && iDb<db->nDb );
/* zMasterSchema and zInitScript are set to point at the master schema
** and initialisation script appropriate for the database being
** initialised. zMasterName is the name of the master table.
*/
if( iDb==1 ){
zMasterSchema = temp_master_schema;
zMasterName = TEMP_MASTER_NAME;
}else{
zMasterSchema = master_schema;
zMasterName = MASTER_NAME;
}
/* Construct the schema table.
*/
sqliteSafetyOff(db);
azArg[0] = "table";
azArg[1] = zMasterName;
azArg[2] = "2";
azArg[3] = zMasterSchema;
sprintf(zDbNum, "%d", iDb);
azArg[4] = zDbNum;
azArg[5] = 0;
initData.db = db;
initData.pzErrMsg = pzErrMsg;
sqliteInitCallback(&initData, 5, (char **)azArg, 0);
pTab = sqliteFindTable(db, zMasterName, db->aDb[iDb].zName);
if( pTab ){
pTab->readOnly = 1;
}else{
return SQLITE_NOMEM;
}
sqliteSafetyOn(db);
/* Create a cursor to hold the database open
*/
if( db->aDb[iDb].pBt==0 ) return SQLITE_OK;
rc = sqliteBtreeCursor(db->aDb[iDb].pBt, 2, 0, &curMain);
if( rc ){
sqliteSetString(pzErrMsg, sqlite_error_string(rc), (char*)0);
return rc;
}
/* Get the database meta information
*/
rc = sqliteBtreeGetMeta(db->aDb[iDb].pBt, meta);
if( rc ){
sqliteSetString(pzErrMsg, sqlite_error_string(rc), (char*)0);
sqliteBtreeCloseCursor(curMain);
return rc;
}
db->aDb[iDb].schema_cookie = meta[1];
if( iDb==0 ){
db->next_cookie = meta[1];
db->file_format = meta[2];
size = meta[3];
if( size==0 ){ size = MAX_PAGES; }
db->cache_size = size;
db->safety_level = meta[4];
if( meta[6]>0 && meta[6]<=2 && db->temp_store==0 ){
db->temp_store = meta[6];
}
if( db->safety_level==0 ) db->safety_level = 2;
/*
** file_format==1 Version 2.1.0.
** file_format==2 Version 2.2.0. Add support for INTEGER PRIMARY KEY.
** file_format==3 Version 2.6.0. Fix empty-string index bug.
** file_format==4 Version 2.7.0. Add support for separate numeric and
** text datatypes.
*/
if( db->file_format==0 ){
/* This happens if the database was initially empty */
db->file_format = 4;
}else if( db->file_format>4 ){
sqliteBtreeCloseCursor(curMain);
sqliteSetString(pzErrMsg, "unsupported file format", (char*)0);
return SQLITE_ERROR;
}
}else if( iDb!=1 && (db->file_format!=meta[2] || db->file_format<4) ){
assert( db->file_format>=4 );
if( meta[2]==0 ){
sqliteSetString(pzErrMsg, "cannot attach empty database: ",
db->aDb[iDb].zName, (char*)0);
}else{
sqliteSetString(pzErrMsg, "incompatible file format in auxiliary "
"database: ", db->aDb[iDb].zName, (char*)0);
}
sqliteBtreeClose(db->aDb[iDb].pBt);
db->aDb[iDb].pBt = 0;
return SQLITE_FORMAT;
}
sqliteBtreeSetCacheSize(db->aDb[iDb].pBt, db->cache_size);
sqliteBtreeSetSafetyLevel(db->aDb[iDb].pBt, meta[4]==0 ? 2 : meta[4]);
/* Read the schema information out of the schema tables
*/
assert( db->init.busy );
sqliteSafetyOff(db);
/* The following SQL will read the schema from the master tables.
** The first version works with SQLite file formats 2 or greater.
** The second version is for format 1 files.
**
** Beginning with file format 2, the rowid for new table entries
** (including entries in sqlite_master) is an increasing integer.
** So for file format 2 and later, we can play back sqlite_master
** and all the CREATE statements will appear in the right order.
** But with file format 1, table entries were random and so we
** have to make sure the CREATE TABLEs occur before their corresponding
** CREATE INDEXs. (We don't have to deal with CREATE VIEW or
** CREATE TRIGGER in file format 1 because those constructs did
** not exist then.)
*/
if( db->file_format>=2 ){
sqliteSetString(&zSql,
"SELECT type, name, rootpage, sql, ", zDbNum, " FROM \"",
db->aDb[iDb].zName, "\".", zMasterName, (char*)0);
}else{
sqliteSetString(&zSql,
"SELECT type, name, rootpage, sql, ", zDbNum, " FROM \"",
db->aDb[iDb].zName, "\".", zMasterName,
" WHERE type IN ('table', 'index')"
" ORDER BY CASE type WHEN 'table' THEN 0 ELSE 1 END", (char*)0);
}
rc = sqlite_exec(db, zSql, sqliteInitCallback, &initData, 0);
sqliteFree(zSql);
sqliteSafetyOn(db);
sqliteBtreeCloseCursor(curMain);
if( sqlite_malloc_failed ){
sqliteSetString(pzErrMsg, "out of memory", (char*)0);
rc = SQLITE_NOMEM;
sqliteResetInternalSchema(db, 0);
}
if( rc==SQLITE_OK ){
DbSetProperty(db, iDb, DB_SchemaLoaded);
}else{
sqliteResetInternalSchema(db, iDb);
}
return rc;
}
