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Diffstat (limited to 'src/sqlite/prepare.c')
| -rw-r--r-- | src/sqlite/prepare.c | 529 |
1 files changed, 529 insertions, 0 deletions
diff --git a/src/sqlite/prepare.c b/src/sqlite/prepare.c new file mode 100644 index 0000000..0892fab --- /dev/null +++ b/src/sqlite/prepare.c @@ -0,0 +1,529 @@ +/* +** 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 1.1.1.1 2006/02/03 20:35:11 hoganrobert 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); + 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 */ + |