--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/engine/sqlite/src/prepare.cpp Thu Feb 25 14:29:19 2010 +0000
@@ -0,0 +1,763 @@
+/*
+** 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.cpp 1282 2008-11-13 09:31:33Z LarsPson $
+*/
+#include "sqliteInt.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( !pData->db->mallocFailed ){
+ sqlite3SetString(pData->pzErrMsg, "malformed database schema",
+ zExtra!=0 && zExtra[0]!=0 ? " - " : (char*)0, zExtra, (char*)0);
+ }
+ pData->rc = SQLITE_CORRUPT;
+}
+
+/*
+** 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. 0 for trigger or view.
+** argv[2] = SQL text for the CREATE statement.
+**
+*/
+int sqlite3InitCallback(void *pInit, int argc, char **argv, char **azColName){
+ InitData *pData = (InitData*)pInit;
+ sqlite3 *db = pData->db;
+ int iDb = pData->iDb;
+
+ assert( sqlite3_mutex_held(db->mutex) );
+ pData->rc = SQLITE_OK;
+ DbClearProperty(db, iDb, DB_Empty);
+ if( db->mallocFailed ){
+ corruptSchema(pData, 0);
+ return SQLITE_NOMEM;
+ }
+
+ assert( argc==3 );
+ if( argv==0 ) return 0; /* Might happen if EMPTY_RESULT_CALLBACKS are on */
+ if( argv[1]==0 ){
+ corruptSchema(pData, 0);
+ return 1;
+ }
+ 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;
+ assert( rc!=SQLITE_OK || zErr==0 );
+ if( SQLITE_OK!=rc ){
+ pData->rc = rc;
+ if( rc==SQLITE_NOMEM ){
+ db->mallocFailed = 1;
+ }else if( rc!=SQLITE_INTERRUPT ){
+ corruptSchema(pData, zErr);
+ }
+ sqlite3_free(zErr);
+ return 1;
+ }
+ }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;
+ Db *pDb;
+ char const *azArg[4];
+ 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 );
+ assert( db->aDb[iDb].pSchema );
+ assert( sqlite3_mutex_held(db->mutex) );
+
+ /* 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;
+ azArg[3] = 0;
+ initData.db = db;
+ initData.iDb = iDb;
+ initData.pzErrMsg = pzErrMsg;
+ rc = sqlite3InitCallback(&initData, 3, (char **)azArg, 0);
+ if( rc ){
+ sqlite3SafetyOn(db);
+ rc = initData.rc;
+ goto error_out;
+ }
+ pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
+ if( pTab ){
+ pTab->readOnly = 1;
+ }
+ sqlite3SafetyOn(db);
+
+ /* Create a cursor to hold the database open
+ */
+ pDb = &db->aDb[iDb];
+ if( pDb->pBt==0 ){
+ if( !OMIT_TEMPDB && iDb==1 ){
+ DbSetProperty(db, 1, DB_SchemaLoaded);
+ }
+ return SQLITE_OK;
+ }
+ sqlite3BtreeEnter(pDb->pBt);
+ rc = sqlite3BtreeCursor(pDb->pBt, MASTER_ROOT, 0, 0, 0, &curMain);
+ if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){
+ sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
+ sqlite3BtreeLeave(pDb->pBt);
+ goto error_out;
+ }
+
+ /* 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 2:UTF-16LE 3:UTF-16BE
+ ** meta[5] The user cookie. Used by the application.
+ ** meta[6] Incremental-vacuum flag.
+ ** meta[7]
+ ** meta[8]
+ ** meta[9]
+ **
+ ** Note: The #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(pDb->pBt, i+1, (u32 *)&meta[i]);
+ }
+ if( rc ){
+ sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0);
+ sqlite3BtreeCloseCursor(curMain);
+ sqlite3BtreeLeave(pDb->pBt);
+ goto error_out;
+ }
+ }else{
+ memset(meta, 0, sizeof(meta));
+ }
+ pDb->pSchema->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 ENC(db). */
+ ENC(db) = (u8)meta[4];
+ db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0);
+ }else{
+ /* If opening an attached database, the encoding much match ENC(db) */
+ if( meta[4]!=ENC(db) ){
+ sqlite3BtreeCloseCursor(curMain);
+ sqlite3SetString(pzErrMsg, "attached databases must use the same"
+ " text encoding as main database", (char*)0);
+ sqlite3BtreeLeave(pDb->pBt);
+ return SQLITE_ERROR;
+ }
+ }
+ }else{
+ DbSetProperty(db, iDb, DB_Empty);
+ }
+ pDb->pSchema->enc = ENC(db);
+
+ size = meta[2];
+ if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; }
+ pDb->pSchema->cache_size = size;
+ sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
+
+ /*
+ ** file_format==1 Version 3.0.0.
+ ** file_format==2 Version 3.1.3. // ALTER TABLE ADD COLUMN
+ ** file_format==3 Version 3.1.4. // ditto but with non-NULL defaults
+ ** file_format==4 Version 3.3.0. // DESC indices. Boolean constants
+ */
+ pDb->pSchema->file_format = meta[1];
+ if( pDb->pSchema->file_format==0 ){
+ pDb->pSchema->file_format = 1;
+ }
+ if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){
+ sqlite3BtreeCloseCursor(curMain);
+ sqlite3SetString(pzErrMsg, "unsupported file format", (char*)0);
+ sqlite3BtreeLeave(pDb->pBt);
+ return SQLITE_ERROR;
+ }
+
+ /* Ticket #2804: When we open a database in the newer file format,
+ ** clear the legacy_file_format pragma flag so that a VACUUM will
+ ** not downgrade the database and thus invalidate any descending
+ ** indices that the user might have created.
+ */
+ if( iDb==0 && meta[1]>=4 ){
+ db->flags &= ~SQLITE_LegacyFileFmt;
+ }
+
+ /* 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(db,
+ "SELECT name, rootpage, sql FROM '%q'.%s",
+ db->aDb[iDb].zName, zMasterName);
+ sqlite3SafetyOff(db);
+#ifndef SQLITE_OMIT_AUTHORIZATION
+ {
+ int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
+ xAuth = db->xAuth;
+ db->xAuth = 0;
+#endif
+ rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
+#ifndef SQLITE_OMIT_AUTHORIZATION
+ db->xAuth = xAuth;
+ }
+#endif
+ if( rc==SQLITE_ABORT ) rc = initData.rc;
+ sqlite3SafetyOn(db);
+ sqlite3_free(zSql);
+#ifndef SQLITE_OMIT_ANALYZE
+ if( rc==SQLITE_OK ){
+ sqlite3AnalysisLoad(db, iDb);
+ }
+#endif
+ sqlite3BtreeCloseCursor(curMain);
+ }
+ if( db->mallocFailed ){
+ /* sqlite3SetString(pzErrMsg, "out of memory", (char*)0); */
+ rc = SQLITE_NOMEM;
+ sqlite3ResetInternalSchema(db, 0);
+ }
+ if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){
+ /* Black magic: If the SQLITE_RecoveryMode flag is set, then consider
+ ** the schema loaded, even if errors occured. In this situation the
+ ** current sqlite3_prepare() operation will fail, but the following one
+ ** will attempt to compile the supplied statement against whatever subset
+ ** of the schema was loaded before the error occured. The primary
+ ** purpose of this is to allow access to the sqlite_master table
+ ** even when its contents have been corrupted.
+ */
+ DbSetProperty(db, iDb, DB_SchemaLoaded);
+ rc = SQLITE_OK;
+ }
+ sqlite3BtreeLeave(pDb->pBt);
+
+error_out:
+ if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
+ db->mallocFailed = 1;
+ }
+ 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 a database is initialized, the DB_SchemaLoaded bit is set
+** bit is set in the flags field of the Db structure. If the database
+** file was of zero-length, then the DB_Empty flag is also set.
+*/
+int sqlite3Init(sqlite3 *db, char **pzErrMsg){
+ int i, rc;
+ int commit_internal = !(db->flags&SQLITE_InternChanges);
+
+ assert( sqlite3_mutex_held(db->mutex) );
+ if( db->init.busy ) return SQLITE_OK;
+ 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 && commit_internal ){
+ sqlite3CommitInternalChanges(db);
+ }
+
+ 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;
+ assert( sqlite3_mutex_held(db->mutex) );
+ if( !db->init.busy ){
+ rc = sqlite3Init(db, &pParse->zErrMsg);
+ }
+ 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;
+
+ assert( sqlite3_mutex_held(db->mutex) );
+ 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].pSchema->schema_cookie ){
+ allOk = 0;
+ }
+ sqlite3BtreeCloseCursor(curTemp);
+ }
+ if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
+ db->mallocFailed = 1;
+ }
+ }
+ return allOk;
+}
+
+/*
+** Convert a schema pointer into the iDb index that indicates
+** which database file in db->aDb[] the schema refers to.
+**
+** If the same database is attached more than once, the first
+** attached database is returned.
+*/
+int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){
+ int i = -1000000;
+
+ /* If pSchema is NULL, then return -1000000. This happens when code in
+ ** expr.c is trying to resolve a reference to a transient table (i.e. one
+ ** created by a sub-select). In this case the return value of this
+ ** function should never be used.
+ **
+ ** We return -1000000 instead of the more usual -1 simply because using
+ ** -1000000 as incorrectly using -1000000 index into db->aDb[] is much
+ ** more likely to cause a segfault than -1 (of course there are assert()
+ ** statements too, but it never hurts to play the odds).
+ */
+ assert( sqlite3_mutex_held(db->mutex) );
+ if( pSchema ){
+ for(i=0; i<db->nDb; i++){
+ if( db->aDb[i].pSchema==pSchema ){
+ break;
+ }
+ }
+ assert( i>=0 &&i>=0 && i<db->nDb );
+ }
+ return i;
+}
+
+/*
+** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
+*/
+int sqlite3Prepare(
+ sqlite3 *db, /* Database handle. */
+ const char *zSql, /* UTF-8 encoded SQL statement. */
+ int nBytes, /* Length of zSql in bytes. */
+ int saveSqlFlag, /* True to copy SQL text into the sqlite3_stmt */
+ 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;
+ int i;
+
+ assert( ppStmt );
+ *ppStmt = 0;
+ if( sqlite3SafetyOn(db) ){
+ return SQLITE_MISUSE;
+ }
+ assert( !db->mallocFailed );
+ assert( sqlite3_mutex_held(db->mutex) );
+
+ /* If any attached database schemas are locked, do not proceed with
+ ** compilation. Instead return SQLITE_LOCKED immediately.
+ */
+ for(i=0; i<db->nDb; i++) {
+ Btree *pBt = db->aDb[i].pBt;
+ if( pBt ){
+ int rc;
+ rc = sqlite3BtreeSchemaLocked(pBt);
+ if( rc ){
+ const char *zDb = db->aDb[i].zName;
+ sqlite3Error(db, SQLITE_LOCKED, "database schema is locked: %s", zDb);
+ sqlite3SafetyOff(db);
+ return SQLITE_LOCKED;
+ }
+ }
+ }
+
+ memset(&sParse, 0, sizeof(sParse));
+ sParse.db = db;
+ if( nBytes>=0 && zSql[nBytes]!=0 ){
+ char *zSqlCopy;
+ if( nBytes>SQLITE_MAX_SQL_LENGTH ){
+ return SQLITE_TOOBIG;
+ }
+ zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
+ if( zSqlCopy ){
+ sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg);
+ sqlite3_free(zSqlCopy);
+ }
+ sParse.zTail = &zSql[nBytes];
+ }else{
+ sqlite3RunParser(&sParse, zSql, &zErrMsg);
+ }
+
+ if( db->mallocFailed ){
+ sParse.rc = SQLITE_NOMEM;
+ }
+ if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;
+ if( sParse.checkSchema && !schemaIsValid(db) ){
+ sParse.rc = SQLITE_SCHEMA;
+ }
+ if( sParse.rc==SQLITE_SCHEMA ){
+ sqlite3ResetInternalSchema(db, 0);
+ }
+ if( db->mallocFailed ){
+ sParse.rc = SQLITE_NOMEM;
+ }
+ if( pzTail ){
+ *pzTail = sParse.zTail;
+ }
+ rc = sParse.rc;
+
+#ifndef SQLITE_OMIT_EXPLAIN
+ if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){
+ if( sParse.explain==2 ){
+ sqlite3VdbeSetNumCols(sParse.pVdbe, 3);
+ sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "order", P3_STATIC);
+ sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "from", P3_STATIC);
+ sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "detail", P3_STATIC);
+ }else{
+ sqlite3VdbeSetNumCols(sParse.pVdbe, 5);
+ sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "addr", P3_STATIC);
+ sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "opcode", P3_STATIC);
+ sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "p1", P3_STATIC);
+ sqlite3VdbeSetColName(sParse.pVdbe, 3, COLNAME_NAME, "p2", P3_STATIC);
+ sqlite3VdbeSetColName(sParse.pVdbe, 4, COLNAME_NAME, "p3", P3_STATIC);
+ }
+ }
+#endif
+
+ if( sqlite3SafetyOff(db) ){
+ rc = SQLITE_MISUSE;
+ }
+
+ if( saveSqlFlag ){
+ sqlite3VdbeSetSql(sParse.pVdbe, zSql, sParse.zTail - zSql);
+ }
+ if( rc!=SQLITE_OK || db->mallocFailed ){
+ sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe);
+ assert(!(*ppStmt));
+ }else{
+ *ppStmt = (sqlite3_stmt*)sParse.pVdbe;
+ }
+
+ if( zErrMsg ){
+ sqlite3Error(db, rc, "%s", zErrMsg);
+ sqlite3_free(zErrMsg);
+ }else{
+ sqlite3Error(db, rc, 0);
+ }
+
+ rc = sqlite3ApiExit(db, rc);
+ /* sqlite3ReleaseThreadData(); */
+ assert( (rc&db->errMask)==rc );
+ return rc;
+}
+static int sqlite3LockAndPrepare(
+ sqlite3 *db, /* Database handle. */
+ const char *zSql, /* UTF-8 encoded SQL statement. */
+ int nBytes, /* Length of zSql in bytes. */
+ int saveSqlFlag, /* True to copy SQL text into the sqlite3_stmt */
+ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
+ const char **pzTail /* OUT: End of parsed string */
+){
+ int rc;
+ if( sqlite3SafetyCheck(db) ){
+ return SQLITE_MISUSE;
+ }
+ sqlite3_mutex_enter(db->mutex);
+ sqlite3BtreeEnterAll(db);
+ rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, ppStmt, pzTail);
+ sqlite3BtreeLeaveAll(db);
+ sqlite3_mutex_leave(db->mutex);
+ return rc;
+}
+
+/*
+** Rerun the compilation of a statement after a schema change.
+** Return true if the statement was recompiled successfully.
+** Return false if there is an error of some kind.
+*/
+int sqlite3Reprepare(Vdbe *p){
+ int rc;
+ sqlite3_stmt *pNew;
+ const char *zSql;
+ sqlite3 *db;
+
+ assert( sqlite3_mutex_held(sqlite3VdbeDb(p)->mutex) );
+ zSql = sqlite3_sql((sqlite3_stmt *)p);
+ if( zSql==0 ){
+ return 0;
+ }
+ db = sqlite3VdbeDb(p);
+ assert( sqlite3_mutex_held(db->mutex) );
+ rc = sqlite3LockAndPrepare(db, zSql, -1, 0, &pNew, 0);
+ if( rc ){
+ if( rc==SQLITE_NOMEM ){
+ db->mallocFailed = 1;
+ }
+ assert( pNew==0 );
+ return 0;
+ }else{
+ assert( pNew!=0 );
+ }
+ sqlite3VdbeSwap((Vdbe*)pNew, p);
+ sqlite3_transfer_bindings(pNew, (sqlite3_stmt*)p);
+ sqlite3VdbeResetStepResult((Vdbe*)pNew);
+ sqlite3VdbeFinalize((Vdbe*)pNew);
+ return 1;
+}
+
+
+/*
+** Two versions of the official API. Legacy and new use. In the legacy
+** version, the original SQL text is not saved in the prepared statement
+** and so if a schema change occurs, SQLITE_SCHEMA is returned by
+** sqlite3_step(). In the new version, the original SQL text is retained
+** and the statement is automatically recompiled if an schema change
+** occurs.
+*/
+EXPORT_C 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 */
+){
+ return sqlite3LockAndPrepare(db,zSql,nBytes,0,ppStmt,pzTail);
+}
+EXPORT_C int sqlite3_prepare_v2(
+ 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 */
+){
+ return sqlite3LockAndPrepare(db,zSql,nBytes,1,ppStmt,pzTail);
+}
+
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
+*/
+static int sqlite3Prepare16(
+ sqlite3 *db, /* Database handle. */
+ const void *zSql, /* UTF-8 encoded SQL statement. */
+ int nBytes, /* Length of zSql in bytes. */
+ int saveSqlFlag, /* True to save SQL text into the sqlite3_stmt */
+ 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 *zSql8;
+ const char *zTail8 = 0;
+ int rc = SQLITE_OK;
+
+ if( sqlite3SafetyCheck(db) ){
+ return SQLITE_MISUSE;
+ }
+ sqlite3_mutex_enter(db->mutex);
+ zSql8 = sqlite3Utf16to8(db, zSql, nBytes);
+ if( zSql8 ){
+ rc = sqlite3LockAndPrepare(db, zSql8, -1, saveSqlFlag, 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);
+ }
+ sqlite3_free(zSql8);
+ rc = sqlite3ApiExit(db, rc);
+ sqlite3_mutex_leave(db->mutex);
+ return rc;
+}
+
+/*
+** Two versions of the official API. Legacy and new use. In the legacy
+** version, the original SQL text is not saved in the prepared statement
+** and so if a schema change occurs, SQLITE_SCHEMA is returned by
+** sqlite3_step(). In the new version, the original SQL text is retained
+** and the statement is automatically recompiled if an schema change
+** occurs.
+*/
+EXPORT_C 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 */
+){
+ return sqlite3Prepare16(db,zSql,nBytes,0,ppStmt,pzTail);
+}
+EXPORT_C int sqlite3_prepare16_v2(
+ 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 */
+){
+ return sqlite3Prepare16(db,zSql,nBytes,1,ppStmt,pzTail);
+}
+
+#endif /* SQLITE_OMIT_UTF16 */