attach.c.svn-base
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- /*
- ** 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.
- **
- ** $Id: attach.c,v 1.74 2008/03/20 14:03:29 drh Exp $
- */
- #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 = sqlite3ExprResolveNames(pName, pExpr);
- if( rc==SQLITE_OK && !sqlite3ExprIsConstant(pExpr) ){
- sqlite3ErrorMsg(pName->pParse, "invalid name: "%T"", &pExpr->span);
- 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 argc,
- sqlite3_value **argv
- ){
- int i;
- int rc = 0;
- sqlite3 *db = sqlite3_context_db_handle(context);
- const char *zName;
- const char *zFile;
- Db *aNew;
- char *zErrDyn = 0;
- char zErr[128];
- 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 ){
- sqlite3_snprintf(
- sizeof(zErr), zErr, "too many attached databases - max %d",
- db->aLimit[SQLITE_LIMIT_ATTACHED]
- );
- goto attach_error;
- }
- if( !db->autoCommit ){
- sqlite3_snprintf(sizeof(zErr), zErr,
- "cannot ATTACH database within transaction");
- goto attach_error;
- }
- for(i=0; i<db->nDb; i++){
- char *z = db->aDb[i].zName;
- if( z && zName && sqlite3StrICmp(z, zName)==0 ){
- sqlite3_snprintf(sizeof(zErr), zErr,
- "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 = sqlite3_malloc( sizeof(db->aDb[0])*3 );
- if( aNew==0 ){
- db->mallocFailed = 1;
- return;
- }
- memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
- }else{
- aNew = sqlite3_realloc(db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );
- if( aNew==0 ){
- db->mallocFailed = 1;
- 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.
- */
- rc = sqlite3BtreeFactory(db, zFile, 0, SQLITE_DEFAULT_CACHE_SIZE,
- db->openFlags | SQLITE_OPEN_MAIN_DB,
- &aNew->pBt);
- if( rc==SQLITE_OK ){
- aNew->pSchema = sqlite3SchemaGet(db, aNew->pBt);
- if( !aNew->pSchema ){
- rc = SQLITE_NOMEM;
- }else if( aNew->pSchema->file_format && aNew->pSchema->enc!=ENC(db) ){
- sqlite3_snprintf(sizeof(zErr), zErr,
- "attached databases must use the same text encoding as main database");
- goto attach_error;
- }
- sqlite3PagerLockingMode(sqlite3BtreePager(aNew->pBt), db->dfltLockMode);
- }
- aNew->zName = sqlite3DbStrDup(db, zName);
- aNew->safety_level = 3;
- #if SQLITE_HAS_CODEC
- {
- 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]);
- 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);
- 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 ){
- (void)sqlite3SafetyOn(db);
- sqlite3BtreeEnterAll(db);
- rc = sqlite3Init(db, &zErrDyn);
- sqlite3BtreeLeaveAll(db);
- (void)sqlite3SafetyOff(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, 0);
- db->nDb = iDb;
- if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
- db->mallocFailed = 1;
- sqlite3_snprintf(sizeof(zErr),zErr, "out of memory");
- }else{
- sqlite3_snprintf(sizeof(zErr),zErr, "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);
- sqlite3_free(zErrDyn);
- }else{
- zErr[sizeof(zErr)-1] = 0;
- sqlite3_result_error(context, zErr, -1);
- }
- 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 argc,
- 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];
- 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) ){
- sqlite3_snprintf(sizeof(zErr),zErr, "database %s is locked", zName);
- goto detach_error;
- }
- sqlite3BtreeClose(pDb->pBt);
- pDb->pBt = 0;
- pDb->pSchema = 0;
- sqlite3ResetInternalSchema(db, 0);
- 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 */
- const char *zFunc, /* Either "sqlite_attach" or "sqlite_detach */
- int nFunc, /* Number of args to pass to zFunc */
- 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;
- FuncDef *pFunc;
- sqlite3* db = pParse->db;
- int regArgs;
- #ifndef SQLITE_OMIT_AUTHORIZATION
- assert( db->mallocFailed || pAuthArg );
- if( pAuthArg ){
- char *zAuthArg = sqlite3NameFromToken(db, &pAuthArg->span);
- if( !zAuthArg ){
- goto attach_end;
- }
- rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0);
- sqlite3_free(zAuthArg);
- if(rc!=SQLITE_OK ){
- goto attach_end;
- }
- }
- #endif /* SQLITE_OMIT_AUTHORIZATION */
- 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;
- }
- 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-nFunc, regArgs+3);
- sqlite3VdbeChangeP5(v, nFunc);
- pFunc = sqlite3FindFunction(db, zFunc, strlen(zFunc), nFunc, SQLITE_UTF8,0);
- 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(pFilename);
- sqlite3ExprDelete(pDbname);
- sqlite3ExprDelete(pKey);
- }
- /*
- ** Called by the parser to compile a DETACH statement.
- **
- ** DETACH pDbname
- */
- void sqlite3Detach(Parse *pParse, Expr *pDbname){
- codeAttach(pParse, SQLITE_DETACH, "sqlite_detach", 1, 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){
- codeAttach(pParse, SQLITE_ATTACH, "sqlite_attach", 3, p, p, pDbname, pKey);
- }
- #endif /* SQLITE_OMIT_ATTACH */
- /*
- ** Register the functions sqlite_attach and sqlite_detach.
- */
- void sqlite3AttachFunctions(sqlite3 *db){
- #ifndef SQLITE_OMIT_ATTACH
- static const int enc = SQLITE_UTF8;
- sqlite3CreateFunc(db, "sqlite_attach", 3, enc, 0, attachFunc, 0, 0);
- sqlite3CreateFunc(db, "sqlite_detach", 1, enc, 0, detachFunc, 0, 0);
- #endif
- }
- /*
- ** 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( 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( 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( sqlite3FixSelect(pFix, pExpr->pSelect) ){
- return 1;
- }
- if( sqlite3FixExprList(pFix, pExpr->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