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Diffstat (limited to 'src/attach.c')
-rw-r--r-- | src/attach.c | 557 |
1 files changed, 557 insertions, 0 deletions
diff --git a/src/attach.c b/src/attach.c new file mode 100644 index 0000000..18f8823 --- /dev/null +++ b/src/attach.c @@ -0,0 +1,557 @@ +/* +** 2003 April 6 +** +** 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 code used to implement the ATTACH and DETACH commands. +*/ +#include "sqliteInt.h" + +#ifndef SQLITE_OMIT_ATTACH +/* +** Resolve an expression that was part of an ATTACH or DETACH statement. This +** is slightly different from resolving a normal SQL expression, because simple +** identifiers are treated as strings, not possible column names or aliases. +** +** i.e. if the parser sees: +** +** ATTACH DATABASE abc AS def +** +** it treats the two expressions as literal strings 'abc' and 'def' instead of +** looking for columns of the same name. +** +** This only applies to the root node of pExpr, so the statement: +** +** ATTACH DATABASE abc||def AS 'db2' +** +** will fail because neither abc or def can be resolved. +*/ +static int resolveAttachExpr(NameContext *pName, Expr *pExpr) +{ + int rc = SQLITE_OK; + if( pExpr ){ + if( pExpr->op!=TK_ID ){ + rc = sqlite3ResolveExprNames(pName, pExpr); + if( rc==SQLITE_OK && !sqlite3ExprIsConstant(pExpr) ){ + sqlite3ErrorMsg(pName->pParse, "invalid name: \"%s\"", pExpr->u.zToken); + return SQLITE_ERROR; + } + }else{ + pExpr->op = TK_STRING; + } + } + return rc; +} + +/* +** An SQL user-function registered to do the work of an ATTACH statement. The +** three arguments to the function come directly from an attach statement: +** +** ATTACH DATABASE x AS y KEY z +** +** SELECT sqlite_attach(x, y, z) +** +** If the optional "KEY z" syntax is omitted, an SQL NULL is passed as the +** third argument. +*/ +static void attachFunc( + sqlite3_context *context, + int NotUsed, + sqlite3_value **argv +){ + int i; + int rc = 0; + sqlite3 *db = sqlite3_context_db_handle(context); + const char *zName; + const char *zFile; + char *zPath = 0; + char *zErr = 0; + unsigned int flags; + Db *aNew; + char *zErrDyn = 0; + sqlite3_vfs *pVfs; + + UNUSED_PARAMETER(NotUsed); + + zFile = (const char *)sqlite3_value_text(argv[0]); + zName = (const char *)sqlite3_value_text(argv[1]); + if( zFile==0 ) zFile = ""; + if( zName==0 ) zName = ""; + + /* Check for the following errors: + ** + ** * Too many attached databases, + ** * Transaction currently open + ** * Specified database name already being used. + */ + if( db->nDb>=db->aLimit[SQLITE_LIMIT_ATTACHED]+2 ){ + zErrDyn = sqlite3MPrintf(db, "too many attached databases - max %d", + db->aLimit[SQLITE_LIMIT_ATTACHED] + ); + goto attach_error; + } + if( !db->autoCommit ){ + zErrDyn = sqlite3MPrintf(db, "cannot ATTACH database within transaction"); + goto attach_error; + } + for(i=0; i<db->nDb; i++){ + char *z = db->aDb[i].zName; + assert( z && zName ); + if( sqlite3StrICmp(z, zName)==0 ){ + zErrDyn = sqlite3MPrintf(db, "database %s is already in use", zName); + goto attach_error; + } + } + + /* Allocate the new entry in the db->aDb[] array and initialise the schema + ** hash tables. + */ + if( db->aDb==db->aDbStatic ){ + aNew = sqlite3DbMallocRaw(db, sizeof(db->aDb[0])*3 ); + if( aNew==0 ) return; + memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2); + }else{ + aNew = sqlite3DbRealloc(db, db->aDb, sizeof(db->aDb[0])*(db->nDb+1) ); + if( aNew==0 ) return; + } + db->aDb = aNew; + aNew = &db->aDb[db->nDb]; + memset(aNew, 0, sizeof(*aNew)); + + /* Open the database file. If the btree is successfully opened, use + ** it to obtain the database schema. At this point the schema may + ** or may not be initialised. + */ + flags = db->openFlags; + rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr); + if( rc!=SQLITE_OK ){ + if( rc==SQLITE_NOMEM ) db->mallocFailed = 1; + sqlite3_result_error(context, zErr, -1); + sqlite3_free(zErr); + return; + } + assert( pVfs ); + flags |= SQLITE_OPEN_MAIN_DB; + rc = sqlite3BtreeOpen(pVfs, zPath, db, &aNew->pBt, 0, flags); + sqlite3_free( zPath ); + db->nDb++; + if( rc==SQLITE_CONSTRAINT ){ + rc = SQLITE_ERROR; + zErrDyn = sqlite3MPrintf(db, "database is already attached"); + }else if( rc==SQLITE_OK ){ + Pager *pPager; + aNew->pSchema = sqlite3SchemaGet(db, aNew->pBt); + if( !aNew->pSchema ){ + rc = SQLITE_NOMEM; + }else if( aNew->pSchema->file_format && aNew->pSchema->enc!=ENC(db) ){ + zErrDyn = sqlite3MPrintf(db, + "attached databases must use the same text encoding as main database"); + rc = SQLITE_ERROR; + } + pPager = sqlite3BtreePager(aNew->pBt); + sqlite3PagerLockingMode(pPager, db->dfltLockMode); + sqlite3BtreeSecureDelete(aNew->pBt, + sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) ); + } + aNew->safety_level = 3; + aNew->zName = sqlite3DbStrDup(db, zName); + if( rc==SQLITE_OK && aNew->zName==0 ){ + rc = SQLITE_NOMEM; + } + + +#ifdef SQLITE_HAS_CODEC + if( rc==SQLITE_OK ){ + extern int sqlite3CodecAttach(sqlite3*, int, const void*, int); + extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*); + int nKey; + char *zKey; + int t = sqlite3_value_type(argv[2]); + switch( t ){ + case SQLITE_INTEGER: + case SQLITE_FLOAT: + zErrDyn = sqlite3DbStrDup(db, "Invalid key value"); + rc = SQLITE_ERROR; + break; + + case SQLITE_TEXT: + case SQLITE_BLOB: + nKey = sqlite3_value_bytes(argv[2]); + zKey = (char *)sqlite3_value_blob(argv[2]); + rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey); + break; + + case SQLITE_NULL: + /* No key specified. Use the key from the main database */ + sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey); + if( nKey>0 || sqlite3BtreeGetReserve(db->aDb[0].pBt)>0 ){ + rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey); + } + break; + } + } +#endif + + /* If the file was opened successfully, read the schema for the new database. + ** If this fails, or if opening the file failed, then close the file and + ** remove the entry from the db->aDb[] array. i.e. put everything back the way + ** we found it. + */ + if( rc==SQLITE_OK ){ + sqlite3BtreeEnterAll(db); + rc = sqlite3Init(db, &zErrDyn); + sqlite3BtreeLeaveAll(db); + } + if( rc ){ + int iDb = db->nDb - 1; + assert( iDb>=2 ); + if( db->aDb[iDb].pBt ){ + sqlite3BtreeClose(db->aDb[iDb].pBt); + db->aDb[iDb].pBt = 0; + db->aDb[iDb].pSchema = 0; + } + sqlite3ResetInternalSchema(db, -1); + db->nDb = iDb; + if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){ + db->mallocFailed = 1; + sqlite3DbFree(db, zErrDyn); + zErrDyn = sqlite3MPrintf(db, "out of memory"); + }else if( zErrDyn==0 ){ + zErrDyn = sqlite3MPrintf(db, "unable to open database: %s", zFile); + } + goto attach_error; + } + + return; + +attach_error: + /* Return an error if we get here */ + if( zErrDyn ){ + sqlite3_result_error(context, zErrDyn, -1); + sqlite3DbFree(db, zErrDyn); + } + if( rc ) sqlite3_result_error_code(context, rc); +} + +/* +** An SQL user-function registered to do the work of an DETACH statement. The +** three arguments to the function come directly from a detach statement: +** +** DETACH DATABASE x +** +** SELECT sqlite_detach(x) +*/ +static void detachFunc( + sqlite3_context *context, + int NotUsed, + sqlite3_value **argv +){ + const char *zName = (const char *)sqlite3_value_text(argv[0]); + sqlite3 *db = sqlite3_context_db_handle(context); + int i; + Db *pDb = 0; + char zErr[128]; + + UNUSED_PARAMETER(NotUsed); + + if( zName==0 ) zName = ""; + for(i=0; i<db->nDb; i++){ + pDb = &db->aDb[i]; + if( pDb->pBt==0 ) continue; + if( sqlite3StrICmp(pDb->zName, zName)==0 ) break; + } + + if( i>=db->nDb ){ + sqlite3_snprintf(sizeof(zErr),zErr, "no such database: %s", zName); + goto detach_error; + } + if( i<2 ){ + sqlite3_snprintf(sizeof(zErr),zErr, "cannot detach database %s", zName); + goto detach_error; + } + if( !db->autoCommit ){ + sqlite3_snprintf(sizeof(zErr), zErr, + "cannot DETACH database within transaction"); + goto detach_error; + } + if( sqlite3BtreeIsInReadTrans(pDb->pBt) || sqlite3BtreeIsInBackup(pDb->pBt) ){ + sqlite3_snprintf(sizeof(zErr),zErr, "database %s is locked", zName); + goto detach_error; + } + + sqlite3BtreeClose(pDb->pBt); + pDb->pBt = 0; + pDb->pSchema = 0; + sqlite3ResetInternalSchema(db, -1); + return; + +detach_error: + sqlite3_result_error(context, zErr, -1); +} + +/* +** This procedure generates VDBE code for a single invocation of either the +** sqlite_detach() or sqlite_attach() SQL user functions. +*/ +static void codeAttach( + Parse *pParse, /* The parser context */ + int type, /* Either SQLITE_ATTACH or SQLITE_DETACH */ + FuncDef const *pFunc,/* FuncDef wrapper for detachFunc() or attachFunc() */ + Expr *pAuthArg, /* Expression to pass to authorization callback */ + Expr *pFilename, /* Name of database file */ + Expr *pDbname, /* Name of the database to use internally */ + Expr *pKey /* Database key for encryption extension */ +){ + int rc; + NameContext sName; + Vdbe *v; + sqlite3* db = pParse->db; + int regArgs; + + memset(&sName, 0, sizeof(NameContext)); + sName.pParse = pParse; + + if( + SQLITE_OK!=(rc = resolveAttachExpr(&sName, pFilename)) || + SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) || + SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey)) + ){ + pParse->nErr++; + goto attach_end; + } + +#ifndef SQLITE_OMIT_AUTHORIZATION + if( pAuthArg ){ + char *zAuthArg; + if( pAuthArg->op==TK_STRING ){ + zAuthArg = pAuthArg->u.zToken; + }else{ + zAuthArg = 0; + } + rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0); + if(rc!=SQLITE_OK ){ + goto attach_end; + } + } +#endif /* SQLITE_OMIT_AUTHORIZATION */ + + + v = sqlite3GetVdbe(pParse); + regArgs = sqlite3GetTempRange(pParse, 4); + sqlite3ExprCode(pParse, pFilename, regArgs); + sqlite3ExprCode(pParse, pDbname, regArgs+1); + sqlite3ExprCode(pParse, pKey, regArgs+2); + + assert( v || db->mallocFailed ); + if( v ){ + sqlite3VdbeAddOp3(v, OP_Function, 0, regArgs+3-pFunc->nArg, regArgs+3); + assert( pFunc->nArg==-1 || (pFunc->nArg&0xff)==pFunc->nArg ); + sqlite3VdbeChangeP5(v, (u8)(pFunc->nArg)); + sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF); + + /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this + ** statement only). For DETACH, set it to false (expire all existing + ** statements). + */ + sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH)); + } + +attach_end: + sqlite3ExprDelete(db, pFilename); + sqlite3ExprDelete(db, pDbname); + sqlite3ExprDelete(db, pKey); +} + +/* +** Called by the parser to compile a DETACH statement. +** +** DETACH pDbname +*/ +void sqlite3Detach(Parse *pParse, Expr *pDbname){ + static const FuncDef detach_func = { + 1, /* nArg */ + SQLITE_UTF8, /* iPrefEnc */ + 0, /* flags */ + 0, /* pUserData */ + 0, /* pNext */ + detachFunc, /* xFunc */ + 0, /* xStep */ + 0, /* xFinalize */ + "sqlite_detach", /* zName */ + 0, /* pHash */ + 0 /* pDestructor */ + }; + codeAttach(pParse, SQLITE_DETACH, &detach_func, pDbname, 0, 0, pDbname); +} + +/* +** Called by the parser to compile an ATTACH statement. +** +** ATTACH p AS pDbname KEY pKey +*/ +void sqlite3Attach(Parse *pParse, Expr *p, Expr *pDbname, Expr *pKey){ + static const FuncDef attach_func = { + 3, /* nArg */ + SQLITE_UTF8, /* iPrefEnc */ + 0, /* flags */ + 0, /* pUserData */ + 0, /* pNext */ + attachFunc, /* xFunc */ + 0, /* xStep */ + 0, /* xFinalize */ + "sqlite_attach", /* zName */ + 0, /* pHash */ + 0 /* pDestructor */ + }; + codeAttach(pParse, SQLITE_ATTACH, &attach_func, p, p, pDbname, pKey); +} +#endif /* SQLITE_OMIT_ATTACH */ + +/* +** Initialize a DbFixer structure. This routine must be called prior +** to passing the structure to one of the sqliteFixAAAA() routines below. +** +** The return value indicates whether or not fixation is required. TRUE +** means we do need to fix the database references, FALSE means we do not. +*/ +int sqlite3FixInit( + DbFixer *pFix, /* The fixer to be initialized */ + Parse *pParse, /* Error messages will be written here */ + int iDb, /* This is the database that must be used */ + const char *zType, /* "view", "trigger", or "index" */ + const Token *pName /* Name of the view, trigger, or index */ +){ + sqlite3 *db; + + if( NEVER(iDb<0) || iDb==1 ) return 0; + db = pParse->db; + assert( db->nDb>iDb ); + pFix->pParse = pParse; + pFix->zDb = db->aDb[iDb].zName; + pFix->zType = zType; + pFix->pName = pName; + return 1; +} + +/* +** The following set of routines walk through the parse tree and assign +** a specific database to all table references where the database name +** was left unspecified in the original SQL statement. The pFix structure +** must have been initialized by a prior call to sqlite3FixInit(). +** +** These routines are used to make sure that an index, trigger, or +** view in one database does not refer to objects in a different database. +** (Exception: indices, triggers, and views in the TEMP database are +** allowed to refer to anything.) If a reference is explicitly made +** to an object in a different database, an error message is added to +** pParse->zErrMsg and these routines return non-zero. If everything +** checks out, these routines return 0. +*/ +int sqlite3FixSrcList( + DbFixer *pFix, /* Context of the fixation */ + SrcList *pList /* The Source list to check and modify */ +){ + int i; + const char *zDb; + struct SrcList_item *pItem; + + if( NEVER(pList==0) ) return 0; + zDb = pFix->zDb; + for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){ + if( pItem->zDatabase==0 ){ + pItem->zDatabase = sqlite3DbStrDup(pFix->pParse->db, zDb); + }else if( sqlite3StrICmp(pItem->zDatabase,zDb)!=0 ){ + sqlite3ErrorMsg(pFix->pParse, + "%s %T cannot reference objects in database %s", + pFix->zType, pFix->pName, pItem->zDatabase); + return 1; + } +#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) + if( sqlite3FixSelect(pFix, pItem->pSelect) ) return 1; + if( sqlite3FixExpr(pFix, pItem->pOn) ) return 1; +#endif + } + return 0; +} +#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) +int sqlite3FixSelect( + DbFixer *pFix, /* Context of the fixation */ + Select *pSelect /* The SELECT statement to be fixed to one database */ +){ + while( pSelect ){ + if( sqlite3FixExprList(pFix, pSelect->pEList) ){ + return 1; + } + if( sqlite3FixSrcList(pFix, pSelect->pSrc) ){ + return 1; + } + if( sqlite3FixExpr(pFix, pSelect->pWhere) ){ + return 1; + } + if( sqlite3FixExpr(pFix, pSelect->pHaving) ){ + return 1; + } + pSelect = pSelect->pPrior; + } + return 0; +} +int sqlite3FixExpr( + DbFixer *pFix, /* Context of the fixation */ + Expr *pExpr /* The expression to be fixed to one database */ +){ + while( pExpr ){ + if( ExprHasAnyProperty(pExpr, EP_TokenOnly) ) break; + if( ExprHasProperty(pExpr, EP_xIsSelect) ){ + if( sqlite3FixSelect(pFix, pExpr->x.pSelect) ) return 1; + }else{ + if( sqlite3FixExprList(pFix, pExpr->x.pList) ) return 1; + } + if( sqlite3FixExpr(pFix, pExpr->pRight) ){ + return 1; + } + pExpr = pExpr->pLeft; + } + return 0; +} +int sqlite3FixExprList( + DbFixer *pFix, /* Context of the fixation */ + ExprList *pList /* The expression to be fixed to one database */ +){ + int i; + struct ExprList_item *pItem; + if( pList==0 ) return 0; + for(i=0, pItem=pList->a; i<pList->nExpr; i++, pItem++){ + if( sqlite3FixExpr(pFix, pItem->pExpr) ){ + return 1; + } + } + return 0; +} +#endif + +#ifndef SQLITE_OMIT_TRIGGER +int sqlite3FixTriggerStep( + DbFixer *pFix, /* Context of the fixation */ + TriggerStep *pStep /* The trigger step be fixed to one database */ +){ + while( pStep ){ + if( sqlite3FixSelect(pFix, pStep->pSelect) ){ + return 1; + } + if( sqlite3FixExpr(pFix, pStep->pWhere) ){ + return 1; + } + if( sqlite3FixExprList(pFix, pStep->pExprList) ){ + return 1; + } + pStep = pStep->pNext; + } + return 0; +} +#endif |