/*
** 2005 May 25
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
**
** $Id: prepare.c,v 1.3 2005/08/19 00:14:42 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
*/
static void corruptSchema(InitData *pData, const char *zExtra){
if( !sqlite3_malloc_failed ){
sqlite3SetString(pData->pzErrMsg, "malformed database schema",
zExtra!=0 && zExtra[0]!=0 ? " - " : (char*)0, zExtra, (char*)0);
}
}
/*
** This is the callback routine for the code that initializes the
** database. See sqlite3Init() below for additional information.
** This routine is also called from the OP_ParseSchema opcode of the VDBE.
**
** Each callback contains the following information:
**
** argv[0] = name of thing being created
** argv[1] = root page number for table or index. NULL for trigger or view.
** argv[2] = SQL text for the CREATE statement.
** argv[3] = "1" for temporary files, "0" for main database, "2" or more
** for auxiliary database files.
**
*/
int sqlite3InitCallback(void *pInit, int argc, char **argv, char **azColName){
InitData *pData = (InitData*)pInit;
sqlite3 *db = pData->db;
int iDb;
assert( argc==4 );
if( argv==0 ) return 0; /* Might happen if EMPTY_RESULT_CALLBACKS are on */
if( argv[1]==0 || argv[3]==0 ){
corruptSchema(pData, 0);
return 1;
}
iDb = atoi(argv[3]);
assert( iDb>=0 && iDb<db->nDb );
if( argv[2] && argv[2][0] ){
/* Call the parser to process a CREATE TABLE, INDEX or VIEW.
** But because db->init.busy is set to 1, no VDBE code is generated
** or executed. All the parser does is build the internal data
** structures that describe the table, index, or view.
*/
char *zErr;
int rc;
assert( db->init.busy );
db->init.iDb = iDb;
db->init.newTnum = atoi(argv[1]);
rc = sqlite3_exec(db, argv[2], 0, 0, &zErr);
db->init.iDb = 0;
if( SQLITE_OK!=rc ){
corruptSchema(pData, zErr);
sqlite3_free(zErr);
return rc;
}
}else{
/* If the SQL column is blank it means this is an index that
** was created to be the PRIMARY KEY or to fulfill a UNIQUE
** constraint for a CREATE TABLE. The index should have already
** been created when we processed the CREATE TABLE. All we have
** to do here is record the root page number for that index.
*/
Index *pIndex;
pIndex = sqlite3FindIndex(db, argv[0], db->aDb[iDb].zName);
if( pIndex==0 || pIndex->tnum!=0 ){
/* This can occur if there exists an index on a TEMP table which
** has the same name as another index on a permanent index. Since
** the permanent table is hidden by the TEMP table, we can also
** safely ignore the index on the permanent table.
*/
/* Do Nothing */;
}else{
pIndex->tnum = atoi(argv[1]);
}
}
return 0;
}
/*
** 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 sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
int rc;
BtCursor *curMain;
int size;
Table *pTab;
char const *azArg[5];
char zDbNum[30];
int meta[10];
InitData initData;
char const *zMasterSchema;
char const *zMasterName = SCHEMA_TABLE(iDb);
/*
** The master database table has a structure like this
*/
static const char master_schema[] =
"CREATE TABLE sqlite_master(\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" rootpage integer,\n"
" sql text\n"
")"
;
#ifndef SQLITE_OMIT_TEMPDB
static const 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"
")"
;
#else
#define temp_master_schema 0
#endif
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( !OMIT_TEMPDB && iDb==1 ){
zMasterSchema = temp_master_schema;
}else{
zMasterSchema = master_schema;
}
zMasterName = SCHEMA_TABLE(iDb);
/* Construct the schema tables. */
sqlite3SafetyOff(db);
azArg[0] = zMasterName;
azArg[1] = "1";
azArg[2] = zMasterSchema;
sprintf(zDbNum, "%d", iDb);
azArg[3] = zDbNum;
azArg[4] = 0;
initData.db = db;
initData.pzErrMsg = pzErrMsg;
rc = sqlite3InitCallback(&initData, 4, (char **)azArg, 0);
if( rc!=SQLITE_OK ){
sqlite3SafetyOn(db);
return rc;
}
pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
if( pTab ){
pTab->readOnly = 1;
}
sqlite3SafetyOn(db);
/* Create a cursor to hold the database open
*/
if( db->aDb[iDb].pBt==0 ){
if( !OMIT_TEMPDB && iDb==1 ) DbSetProperty(db, 1, DB_SchemaLoaded);
return SQLITE_OK;
}
rc = sqlite3BtreeCursor(db->aDb[iDb].pBt, MASTER_ROOT, 0, 0, 0, &curMain);
if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
return rc;
}
/* Get the database meta information.
**
** Meta values are as follows:
** meta[0] Schema cookie. Changes with each schema change.
** meta[1] File format of schema layer.
** meta[2] Size of the page cache.
** meta[3] Use freelist if 0. Autovacuum if greater than zero.
** meta[4] Db text encoding. 1:UTF-8 3:UTF-16 LE 4:UTF-16 BE
** meta[5] The user cookie. Used by the application.
** meta[6]
** meta[7]
** meta[8]
** meta[9]
**
** Note: The hash defined SQLITE_UTF* symbols in sqliteInt.h correspond to
** the possible values of meta[4].
*/
if( rc==SQLITE_OK ){
int i;
for(i=0; rc==SQLITE_OK && i<sizeof(meta)/sizeof(meta[0]); i++){
rc = sqlite3BtreeGetMeta(db->aDb[iDb].pBt, i+1, (u32 *)&meta[i]);
}
if( rc ){
sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
sqlite3BtreeCloseCursor(curMain);
return rc;
}
}else{
memset(meta, 0, sizeof(meta));
}
db->aDb[iDb].schema_cookie = meta[0];
/* If opening a non-empty database, check the text encoding. For the
** main database, set sqlite3.enc to the encoding of the main database.
** For an attached db, it is an error if the encoding is not the same
** as sqlite3.enc.
*/
if( meta[4] ){ /* text encoding */
if( iDb==0 ){
/* If opening the main database, set db->enc. */
db->enc = (u8)meta[4];
db->pDfltColl = sqlite3FindCollSeq(db, db->enc, "BINARY", 6, 0);
}else{
/* If opening an attached database, the encoding much match db->enc */
if( meta[4]!=db->enc ){
sqlite3BtreeCloseCursor(curMain);
sqlite3SetString(pzErrMsg, "attached databases must use the same"
" text encoding as main database", (char*)0);
return SQLITE_ERROR;
}
}
}
size = meta[2];
if( size==0 ){ size = MAX_PAGES; }
db->aDb[iDb].cache_size = size;
if( iDb==0 ){
db->file_format = meta[1];
if( db->file_format==0 ){
/* This happens if the database was initially empty */
db->file_format = 1;
}
if( db->file_format==2 || db->file_format==3 ){
/* File format 2 is treated exactly as file format 1. New
** databases are created with file format 1.
*/
db->file_format = 1;
}
}
/*
** file_format==1 Version 3.0.0.
** file_format==2 Version 3.1.3.
** file_format==3 Version 3.1.4.
**
** Version 3.0 can only use files with file_format==1. Version 3.1.3
** can read and write files with file_format==1 or file_format==2.
** Version 3.1.4 can read and write file formats 1, 2 and 3.
*/
if( meta[1]>3 ){
sqlite3BtreeCloseCursor(curMain);
sqlite3SetString(pzErrMsg, "unsupported file format", (char*)0);
return SQLITE_ERROR;
}
sqlite3BtreeSetCacheSize(db->aDb[iDb].pBt, db->aDb[iDb].cache_size);
/* Read the schema information out of the schema tables
*/
assert( db->init.busy );
if( rc==SQLITE_EMPTY ){
/* For an empty database, there is nothing to read */
rc = SQLITE_OK;
}else{
char *zSql;
zSql = sqlite3MPrintf(
"SELECT name, rootpage, sql, '%s' FROM '%q'.%s",
zDbNum, db->aDb[iDb].zName, zMasterName);
sqlite3SafetyOff(db);
rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
sqlite3SafetyOn(db);
sqliteFree(zSql);
#ifndef SQLITE_OMIT_ANALYZE
if( rc==SQLITE_OK ){
sqlite3AnalysisLoad(db, iDb);
}
#endif
sqlite3BtreeCloseCursor(curMain);
}
if( sqlite3_malloc_failed ){
sqlite3SetString(pzErrMsg, "out of memory", (char*)0);
rc = SQLITE_NOMEM;
sqlite3ResetInternalSchema(db, 0);
}
if( rc==SQLITE_OK ){
DbSetProperty(db, iDb, DB_SchemaLoaded);
}else{
sqlite3ResetInternalSchema(db, iDb);
}
return rc;
}
/*
** 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.
*/
int sqlite3Init(sqlite3 *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) || i==1 ) continue;
rc = sqlite3InitOne(db, i, pzErrMsg);
if( rc ){
sqlite3ResetInternalSchema(db, i);
}
}
/* Once all the other databases have been initialised, load the schema
** for the TEMP database. This is loaded last, as the TEMP database
** schema may contain references to objects in other databases.
*/
#ifndef SQLITE_OMIT_TEMPDB
if( rc==SQLITE_OK && db->nDb>1 && !DbHasProperty(db, 1, DB_SchemaLoaded) ){
rc = sqlite3InitOne(db, 1, pzErrMsg);
if( rc ){
sqlite3ResetInternalSchema(db, 1);
}
}
#endif
db->init.busy = 0;
if( rc==SQLITE_OK ){
db->flags |= SQLITE_Initialized;
sqlite3CommitInternalChanges(db);
}
if( rc!=SQLITE_OK ){
db->flags &= ~SQLITE_Initialized;
}
return rc;
}
/*
** This routine is a no-op if the database schema is already initialised.
** Otherwise, the schema is loaded. An error code is returned.
*/
int sqlite3ReadSchema(Parse *pParse){
int rc = SQLITE_OK;
sqlite3 *db = pParse->db;
if( !db->init.busy ){
if( (db->flags & SQLITE_Initialized)==0 ){
rc = sqlite3Init(db, &pParse->zErrMsg);
}
}
assert( rc!=SQLITE_OK || (db->flags & SQLITE_Initialized) || db->init.busy );
if( rc!=SQLITE_OK ){
pParse->rc = rc;
pParse->nErr++;
}
return rc;
}
/*
** Check schema cookies in all databases. If any cookie is out
** of date, return 0. If all schema cookies are current, return 1.
*/
static int schemaIsValid(sqlite3 *db){
int iDb;
int rc;
BtCursor *curTemp;
int cookie;
int allOk = 1;
for(iDb=0; allOk && iDb<db->nDb; iDb++){
Btree *pBt;
pBt = db->aDb[iDb].pBt;
if( pBt==0 ) continue;
rc = sqlite3BtreeCursor(pBt, MASTER_ROOT, 0, 0, 0, &curTemp);
if( rc==SQLITE_OK ){
rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&cookie);
if( rc==SQLITE_OK && cookie!=db->aDb[iDb].schema_cookie ){
allOk = 0;
}
sqlite3BtreeCloseCursor(curTemp);
}
}
return allOk;
}
/*
** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
*/
int sqlite3_prepare(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char** pzTail /* OUT: End of parsed string */
){
Parse sParse;
char *zErrMsg = 0;
int rc = SQLITE_OK;
if( sqlite3_malloc_failed ){
return SQLITE_NOMEM;
}
assert( ppStmt );
*ppStmt = 0;
if( sqlite3SafetyOn(db) ){
return SQLITE_MISUSE;
}
memset(&sParse, 0, sizeof(sParse));
sParse.db = db;
sqlite3RunParser(&sParse, zSql, &zErrMsg);
if( sqlite3_malloc_failed ){
rc = SQLITE_NOMEM;
sqlite3RollbackAll(db);
sqlite3ResetInternalSchema(db, 0);
db->flags &= ~SQLITE_InTrans;
goto prepare_out;
}
if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;
if( sParse.rc!=SQLITE_OK && sParse.checkSchema && !schemaIsValid(db) ){
sParse.rc = SQLITE_SCHEMA;
}
if( sParse.rc==SQLITE_SCHEMA ){
sqlite3ResetInternalSchema(db, 0);
}
if( pzTail ) *pzTail = sParse.zTail;
rc = sParse.rc;
#ifndef SQLITE_OMIT_EXPLAIN
if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){
sqlite3VdbeSetNumCols(sParse.pVdbe, 5);
sqlite3VdbeSetColName(sParse.pVdbe, 0, "addr", P3_STATIC);
sqlite3VdbeSetColName(sParse.pVdbe, 1, "opcode", P3_STATIC);
sqlite3VdbeSetColName(sParse.pVdbe, 2, "p1", P3_STATIC);
sqlite3VdbeSetColName(sParse.pVdbe, 3, "p2", P3_STATIC);
sqlite3VdbeSetColName(sParse.pVdbe, 4, "p3", P3_STATIC);
}
#endif
prepare_out:
if( sqlite3SafetyOff(db) ){
rc = SQLITE_MISUSE;
}
if( rc==SQLITE_OK ){
*ppStmt = (sqlite3_stmt*)sParse.pVdbe;
}else if( sParse.pVdbe ){
sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe);
}
if( zErrMsg ){
sqlite3Error(db, rc, "%s", zErrMsg);
sqliteFree(zErrMsg);
}else{
sqlite3Error(db, rc, 0);
}
return rc;
}
#ifndef SQLITE_OMIT_UTF16
/*
** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
*/
int sqlite3_prepare16(
sqlite3 *db, /* Database handle. */
const void *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const void **pzTail /* OUT: End of parsed string */
){
/* This function currently works by first transforming the UTF-16
** encoded string to UTF-8, then invoking sqlite3_prepare(). The
** tricky bit is figuring out the pointer to return in *pzTail.
*/
char const *zSql8 = 0;
char const *zTail8 = 0;
int rc;
sqlite3_value *pTmp;
if( sqlite3SafetyCheck(db) ){
return SQLITE_MISUSE;
}
pTmp = sqlite3GetTransientValue(db);
sqlite3ValueSetStr(pTmp, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC);
zSql8 = sqlite3ValueText(pTmp, SQLITE_UTF8);
if( !zSql8 ){
sqlite3Error(db, SQLITE_NOMEM, 0);
return SQLITE_NOMEM;
}
rc = sqlite3_prepare(db, zSql8, -1, ppStmt, &zTail8);
if( zTail8 && pzTail ){
/* If sqlite3_prepare returns a tail pointer, we calculate the
** equivalent pointer into the UTF-16 string by counting the unicode
** characters between zSql8 and zTail8, and then returning a pointer
** the same number of characters into the UTF-16 string.
*/
int chars_parsed = sqlite3utf8CharLen(zSql8, zTail8-zSql8);
*pzTail = (u8 *)zSql + sqlite3utf16ByteLen(zSql, chars_parsed);
}
return rc;
}
#endif /* SQLITE_OMIT_UTF16 */