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Diffstat (limited to 'src/attach.c')
| -rw-r--r-- | src/attach.c | 617 |
1 files changed, 617 insertions, 0 deletions
diff --git a/src/attach.c b/src/attach.c new file mode 100644 index 0000000..4a6a25b --- /dev/null +++ b/src/attach.c @@ -0,0 +1,617 @@ +/* +** 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); + }else{ + pExpr->op = TK_STRING; + } + } + return rc; +} + +/* +** Return true if zName points to a name that may be used to refer to +** database iDb attached to handle db. +*/ +int sqlite3DbIsNamed(sqlite3 *db, int iDb, const char *zName){ + return ( + sqlite3StrICmp(db->aDb[iDb].zDbSName, zName)==0 + || (iDb==0 && sqlite3StrICmp("main", zName)==0) + ); +} + +/* +** 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. +** +** If the db->init.reopenMemdb flags is set, then instead of attaching a +** new database, close the database on db->init.iDb and reopen it as an +** empty MemDB. +*/ +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; /* New array of Db pointers */ + Db *pNew = 0; /* Db object for the newly attached database */ + 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 = ""; + +#ifndef SQLITE_OMIT_DESERIALIZE +# define REOPEN_AS_MEMDB(db) (db->init.reopenMemdb) +#else +# define REOPEN_AS_MEMDB(db) (0) +#endif + + if( REOPEN_AS_MEMDB(db) ){ + /* This is not a real ATTACH. Instead, this routine is being called + ** from sqlite3_deserialize() to close database db->init.iDb and + ** reopen it as a MemDB */ + Btree *pNewBt = 0; + pVfs = sqlite3_vfs_find("memdb"); + if( pVfs==0 ) return; + rc = sqlite3BtreeOpen(pVfs, "x\0", db, &pNewBt, 0, SQLITE_OPEN_MAIN_DB); + if( rc==SQLITE_OK ){ + Schema *pNewSchema = sqlite3SchemaGet(db, pNewBt); + if( pNewSchema ){ + /* Both the Btree and the new Schema were allocated successfully. + ** Close the old db and update the aDb[] slot with the new memdb + ** values. */ + pNew = &db->aDb[db->init.iDb]; + if( ALWAYS(pNew->pBt) ) sqlite3BtreeClose(pNew->pBt); + pNew->pBt = pNewBt; + pNew->pSchema = pNewSchema; + }else{ + sqlite3BtreeClose(pNewBt); + rc = SQLITE_NOMEM; + } + } + if( rc ) goto attach_error; + }else{ + /* This is a real ATTACH + ** + ** 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; + } + for(i=0; i<db->nDb; i++){ + assert( zName ); + if( sqlite3DbIsNamed(db, i, zName) ){ + zErrDyn = sqlite3MPrintf(db, "database %s is already in use", zName); + goto attach_error; + } + } + + /* Allocate the new entry in the db->aDb[] array and initialize the schema + ** hash tables. + */ + if( db->aDb==db->aDbStatic ){ + aNew = sqlite3DbMallocRawNN(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; + pNew = &db->aDb[db->nDb]; + memset(pNew, 0, sizeof(*pNew)); + + /* 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 initialized. + */ + flags = db->openFlags; + rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr); + if( rc!=SQLITE_OK ){ + if( rc==SQLITE_NOMEM ) sqlite3OomFault(db); + sqlite3_result_error(context, zErr, -1); + sqlite3_free(zErr); + return; + } + assert( pVfs ); + flags |= SQLITE_OPEN_MAIN_DB; + rc = sqlite3BtreeOpen(pVfs, zPath, db, &pNew->pBt, 0, flags); + db->nDb++; + pNew->zDbSName = sqlite3DbStrDup(db, zName); + } + db->noSharedCache = 0; + if( rc==SQLITE_CONSTRAINT ){ + rc = SQLITE_ERROR; + zErrDyn = sqlite3MPrintf(db, "database is already attached"); + }else if( rc==SQLITE_OK ){ + Pager *pPager; + pNew->pSchema = sqlite3SchemaGet(db, pNew->pBt); + if( !pNew->pSchema ){ + rc = SQLITE_NOMEM_BKPT; + }else if( pNew->pSchema->file_format && pNew->pSchema->enc!=ENC(db) ){ + zErrDyn = sqlite3MPrintf(db, + "attached databases must use the same text encoding as main database"); + rc = SQLITE_ERROR; + } + sqlite3BtreeEnter(pNew->pBt); + pPager = sqlite3BtreePager(pNew->pBt); + sqlite3PagerLockingMode(pPager, db->dfltLockMode); + sqlite3BtreeSecureDelete(pNew->pBt, + sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) ); +#ifndef SQLITE_OMIT_PAGER_PRAGMAS + sqlite3BtreeSetPagerFlags(pNew->pBt, + PAGER_SYNCHRONOUS_FULL | (db->flags & PAGER_FLAGS_MASK)); +#endif + sqlite3BtreeLeave(pNew->pBt); + } + pNew->safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1; + if( rc==SQLITE_OK && pNew->zDbSName==0 ){ + rc = SQLITE_NOMEM_BKPT; + } + sqlite3_free_filename( zPath ); + + /* 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); + db->init.iDb = 0; + db->mDbFlags &= ~(DBFLAG_SchemaKnownOk); + if( !REOPEN_AS_MEMDB(db) ){ + rc = sqlite3Init(db, &zErrDyn); + } + sqlite3BtreeLeaveAll(db); + assert( zErrDyn==0 || rc!=SQLITE_OK ); + } +#ifdef SQLITE_USER_AUTHENTICATION + if( rc==SQLITE_OK && !REOPEN_AS_MEMDB(db) ){ + u8 newAuth = 0; + rc = sqlite3UserAuthCheckLogin(db, zName, &newAuth); + if( newAuth<db->auth.authLevel ){ + rc = SQLITE_AUTH_USER; + } + } +#endif + if( rc ){ + if( ALWAYS(!REOPEN_AS_MEMDB(db)) ){ + 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; + } + sqlite3ResetAllSchemasOfConnection(db); + db->nDb = iDb; + if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){ + sqlite3OomFault(db); + 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; + HashElem *pEntry; + 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( sqlite3DbIsNamed(db, i, zName) ) 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( sqlite3BtreeTxnState(pDb->pBt)!=SQLITE_TXN_NONE + || sqlite3BtreeIsInBackup(pDb->pBt) + ){ + sqlite3_snprintf(sizeof(zErr),zErr, "database %s is locked", zName); + goto detach_error; + } + + /* If any TEMP triggers reference the schema being detached, move those + ** triggers to reference the TEMP schema itself. */ + assert( db->aDb[1].pSchema ); + pEntry = sqliteHashFirst(&db->aDb[1].pSchema->trigHash); + while( pEntry ){ + Trigger *pTrig = (Trigger*)sqliteHashData(pEntry); + if( pTrig->pTabSchema==pDb->pSchema ){ + pTrig->pTabSchema = pTrig->pSchema; + } + pEntry = sqliteHashNext(pEntry); + } + + sqlite3BtreeClose(pDb->pBt); + pDb->pBt = 0; + pDb->pSchema = 0; + sqlite3CollapseDatabaseArray(db); + 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; + + if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) goto attach_end; + + if( pParse->nErr ) goto attach_end; + memset(&sName, 0, sizeof(NameContext)); + sName.pParse = pParse; + + if( + SQLITE_OK!=resolveAttachExpr(&sName, pFilename) || + SQLITE_OK!=resolveAttachExpr(&sName, pDbname) || + SQLITE_OK!=resolveAttachExpr(&sName, pKey) + ){ + goto attach_end; + } + +#ifndef SQLITE_OMIT_AUTHORIZATION + if( ALWAYS(pAuthArg) ){ + char *zAuthArg; + if( pAuthArg->op==TK_STRING ){ + assert( !ExprHasProperty(pAuthArg, EP_IntValue) ); + 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 ){ + sqlite3VdbeAddFunctionCall(pParse, 0, regArgs+3-pFunc->nArg, regArgs+3, + pFunc->nArg, pFunc, 0); + /* 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, /* funcFlags */ + 0, /* pUserData */ + 0, /* pNext */ + detachFunc, /* xSFunc */ + 0, /* xFinalize */ + 0, 0, /* xValue, xInverse */ + "sqlite_detach", /* zName */ + {0} + }; + 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, /* funcFlags */ + 0, /* pUserData */ + 0, /* pNext */ + attachFunc, /* xSFunc */ + 0, /* xFinalize */ + 0, 0, /* xValue, xInverse */ + "sqlite_attach", /* zName */ + {0} + }; + codeAttach(pParse, SQLITE_ATTACH, &attach_func, p, p, pDbname, pKey); +} +#endif /* SQLITE_OMIT_ATTACH */ + +/* +** Expression callback used by sqlite3FixAAAA() routines. +*/ +static int fixExprCb(Walker *p, Expr *pExpr){ + DbFixer *pFix = p->u.pFix; + if( !pFix->bTemp ) ExprSetProperty(pExpr, EP_FromDDL); + if( pExpr->op==TK_VARIABLE ){ + if( pFix->pParse->db->init.busy ){ + pExpr->op = TK_NULL; + }else{ + sqlite3ErrorMsg(pFix->pParse, "%s cannot use variables", pFix->zType); + return WRC_Abort; + } + } + return WRC_Continue; +} + +/* +** Select callback used by sqlite3FixAAAA() routines. +*/ +static int fixSelectCb(Walker *p, Select *pSelect){ + DbFixer *pFix = p->u.pFix; + int i; + SrcItem *pItem; + sqlite3 *db = pFix->pParse->db; + int iDb = sqlite3FindDbName(db, pFix->zDb); + SrcList *pList = pSelect->pSrc; + + if( NEVER(pList==0) ) return WRC_Continue; + for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){ + if( pFix->bTemp==0 ){ + if( pItem->zDatabase ){ + if( iDb!=sqlite3FindDbName(db, pItem->zDatabase) ){ + sqlite3ErrorMsg(pFix->pParse, + "%s %T cannot reference objects in database %s", + pFix->zType, pFix->pName, pItem->zDatabase); + return WRC_Abort; + } + sqlite3DbFree(db, pItem->zDatabase); + pItem->zDatabase = 0; + pItem->fg.notCte = 1; + } + pItem->pSchema = pFix->pSchema; + pItem->fg.fromDDL = 1; + } +#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) + if( pList->a[i].fg.isUsing==0 + && sqlite3WalkExpr(&pFix->w, pList->a[i].u3.pOn) + ){ + return WRC_Abort; + } +#endif + } + if( pSelect->pWith ){ + for(i=0; i<pSelect->pWith->nCte; i++){ + if( sqlite3WalkSelect(p, pSelect->pWith->a[i].pSelect) ){ + return WRC_Abort; + } + } + } + return WRC_Continue; +} + +/* +** Initialize a DbFixer structure. This routine must be called prior +** to passing the structure to one of the sqliteFixAAAA() routines below. +*/ +void 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 = pParse->db; + assert( db->nDb>iDb ); + pFix->pParse = pParse; + pFix->zDb = db->aDb[iDb].zDbSName; + pFix->pSchema = db->aDb[iDb].pSchema; + pFix->zType = zType; + pFix->pName = pName; + pFix->bTemp = (iDb==1); + pFix->w.pParse = pParse; + pFix->w.xExprCallback = fixExprCb; + pFix->w.xSelectCallback = fixSelectCb; + pFix->w.xSelectCallback2 = sqlite3WalkWinDefnDummyCallback; + pFix->w.walkerDepth = 0; + pFix->w.eCode = 0; + pFix->w.u.pFix = pFix; +} + +/* +** 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 res = 0; + if( pList ){ + Select s; + memset(&s, 0, sizeof(s)); + s.pSrc = pList; + res = sqlite3WalkSelect(&pFix->w, &s); + } + return res; +} +#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 */ +){ + return sqlite3WalkSelect(&pFix->w, pSelect); +} +int sqlite3FixExpr( + DbFixer *pFix, /* Context of the fixation */ + Expr *pExpr /* The expression to be fixed to one database */ +){ + return sqlite3WalkExpr(&pFix->w, pExpr); +} +#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( sqlite3WalkSelect(&pFix->w, pStep->pSelect) + || sqlite3WalkExpr(&pFix->w, pStep->pWhere) + || sqlite3WalkExprList(&pFix->w, pStep->pExprList) + || sqlite3FixSrcList(pFix, pStep->pFrom) + ){ + return 1; + } +#ifndef SQLITE_OMIT_UPSERT + { + Upsert *pUp; + for(pUp=pStep->pUpsert; pUp; pUp=pUp->pNextUpsert){ + if( sqlite3WalkExprList(&pFix->w, pUp->pUpsertTarget) + || sqlite3WalkExpr(&pFix->w, pUp->pUpsertTargetWhere) + || sqlite3WalkExprList(&pFix->w, pUp->pUpsertSet) + || sqlite3WalkExpr(&pFix->w, pUp->pUpsertWhere) + ){ + return 1; + } + } + } +#endif + pStep = pStep->pNext; + } + + return 0; +} +#endif |