/*+
−
** 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.cpp 1282 2008-11-13 09:31:33Z LarsPson $+
−
*/+
−
#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 *)sqlite3_user_data(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>=SQLITE_MAX_ATTACHED+2 ){+
−
    sqlite3_snprintf(+
−
      sizeof(zErr), zErr, "too many attached databases - max %d", +
−
      SQLITE_MAX_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 = (Db*)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 = (Db*)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 ){+
−
    sqlite3SafetyOn(db);+
−
    rc = sqlite3Init(db, &zErrDyn);+
−
    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);+
−
  }+
−
}+
−
+
−
/*+
−
** 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 *)sqlite3_user_data(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;+
−
+
−
#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);+
−
  sqlite3ExprCode(pParse, pFilename);+
−
  sqlite3ExprCode(pParse, pDbname);+
−
  sqlite3ExprCode(pParse, pKey);+
−
+
−
  assert( v || db->mallocFailed );+
−
  if( v ){+
−
    sqlite3VdbeAddOp(v, OP_Function, 0, nFunc);+
−
    pFunc = sqlite3FindFunction(db, zFunc, strlen(zFunc), nFunc, SQLITE_UTF8,0);+
−
    sqlite3VdbeChangeP3(v, -1, (char *)pFunc, P3_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).+
−
    */+
−
    sqlite3VdbeAddOp(v, OP_Expire, (type==SQLITE_ATTACH), 0);+
−
  }+
−
  +
−
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, db, attachFunc, 0, 0);+
−
  sqlite3CreateFunc(db, "sqlite_detach", 1, enc, db, 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;+
−
  SrcList::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;+
−
  ExprList::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+
−