Bug 416173 - BackupDB is completely useless. r=vlad, a=damons

git-svn-id: svn://10.0.0.236/trunk@245317 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/storage/public/mozIStorageConnection.idl

@@ -67,7 +67,10 @@ interface mozIStorageConnection : nsISupports {
    void close();
 
   /**
-   * whether the database is open or not
+   * Indicates if the connection is open and ready to use.  This will be false
+   * if the connection failed to open, or it has been closed.  It is strongly
+   * recommended that the database be backed up before removing the file by
+   * calling backupDB.
    */
   readonly attribute boolean connectionReady;
 

mozilla/storage/public/mozIStorageService.idl

@@ -70,6 +70,11 @@ interface mozIStorageService : nsISupports {
   /**
    * Open a connection to the specified file.
    *
+   * Consumers should check mozIStorageConnection::connectionReady to ensure
+   * that they can use the database.  If this value is false, it is strongly
+   * recommended that the database be backed up with
+   * mozIStorageConnection::backupDB so user data is not lost.
+   *
    * ==========
    *   DANGER
    * ==========
@@ -88,11 +93,13 @@ interface mozIStorageService : nsISupports {
    * containing virtual tables, it will think the database is corrupted and
    * throw NS_ERROR_FILE_CORRUPTED.
    *
-   * @param aDatabaseFile a nsIFile of the database to open.
+   * @param aDatabaseFile
+   *        A nsIFile that represents the database that is to be opened..
    *
    * @returns a mozIStorageConnection for the requested database file.
    *
-   * @throws NS_ERROR_FAILURE if any operation fails while opening the database.
+   * @throws NS_ERROR_OUT_OF_MEMORY
+   *         If allocating a new storage object fails.
    */
   mozIStorageConnection openDatabase(in nsIFile aDatabaseFile);
 
@@ -104,6 +111,11 @@ interface mozIStorageService : nsISupports {
    * of SQLite that is incompatible with a shared cache, like virtual table
    * and full text indexing support.
    *
+   * Consumers should check mozIStorageConnection::connectionReady to ensure
+   * that they can use the database.  If this value is false, it is strongly
+   * recommended that the database be backed up with
+   * mozIStorageConnection::backupDB so user data is not lost.
+   *
    * ==========
    *   DANGER
    * ==========
@@ -116,11 +128,13 @@ interface mozIStorageService : nsISupports {
    * The connection object returned by this function is not threadsafe. You must
    * use it only from the thread you created it from.
    *
-   * @param aDatabaseFile a nsIFile of the database to open.
+   * @param aDatabaseFile
+   *        A nsIFile that represents the database that is to be opened..
    *
    * @returns a mozIStorageConnection for the requested database file.
    *
-   * @throws NS_ERROR_FAILURE if any operation fails while opening the database.
+   * @throws NS_ERROR_OUT_OF_MEMORY
+   *         If allocating a new storage object fails.
    */
   mozIStorageConnection openUnsharedDatabase(in nsIFile aDatabaseFile);
 

mozilla/storage/src/mozStorageService.cpp

@@ -135,10 +135,11 @@ mozStorageService::OpenDatabase(nsIFile *aDatabaseFile, mozIStorageConnection **
     if (!msc)
         return NS_ERROR_OUT_OF_MEMORY;
 
-    rv = msc->Initialize (aDatabaseFile);
-    NS_ENSURE_SUCCESS(rv, rv);
-
+    // We want to return a valid connection regardless if it succeeded or not so
+    // that consumers can backup the database if it failed.
+    (void)msc->Initialize(aDatabaseFile);
     NS_ADDREF(*_retval = msc);
+
     return NS_OK;
 }
 
@@ -158,11 +159,12 @@ mozStorageService::OpenUnsharedDatabase(nsIFile *aDatabaseFile, mozIStorageConne
     // lifetimes, unaffected by changes to the shared caches setting, so we can
     // disable shared caches temporarily while we initialize the new connection
     // without affecting the caches currently in use by other connections.
+    // We want to return a valid connection regardless if it succeeded or not so
+    // that consumers can backup the database if it failed.
     sqlite3_enable_shared_cache(0);
-    rv = msc->Initialize (aDatabaseFile);
+    (void)msc->Initialize(aDatabaseFile);
     sqlite3_enable_shared_cache(1);
-    NS_ENSURE_SUCCESS(rv, rv);
-
     NS_ADDREF(*_retval = msc);
+
     return NS_OK;
 }

mozilla/storage/test/unit/head_storage.js

@@ -81,6 +81,7 @@ var gDBConn = null;
  *        whether or not to open a connection to the database that doesn't share
  *        its cache; if true, we use mozIStorageService::openUnsharedDatabase
  *        to create the connection; otherwise we use openDatabase.
+ * @returns the mozIStorageConnection for the file.
  */
 function getOpenedDatabase(unshared)
 {
@@ -92,6 +93,18 @@ function getOpenedDatabase(unshared)
   return gDBConn;
 }
 
+/**
+ * Obtains a specific database to use.
+ *
+ * @param aFile
+ *        The nsIFile representing the db file to open.
+ * @returns the mozIStorageConnection for the file.
+ */
+function getDatabase(aFile)
+{
+  return getService().openDatabase(aFile);
+}
+
 function createStatement(aSQL)
 {
   return getOpenedDatabase().createStatement(aSQL);

mozilla/storage/test/unit/test_bug-416173.js

@@ -0,0 +1,68 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Storage Test Code.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2008
+ * the Initial Developer. All Rights Reserved.
+ *
+ * This code is based off of like.test from the sqlite code
+ *
+ * Contributor(s):
+ *   Shawn Wilsher <me@shawnwilsher.com> (Original Author)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+// Tests to make sure that mozIStorageConnection::backupDB works when trying to
+// open a corrupted database.
+
+const BACKUP_FILE_NAME = "test_storage.sqlite.backup";
+
+function test_backup_bad_connection()
+{
+  var msc = getDatabase(do_get_file("storage/test/unit/corruptDB.sqlite"));
+  do_check_false(msc.connectionReady);
+
+  var backup = msc.backupDB(BACKUP_FILE_NAME);
+  do_check_eq(BACKUP_FILE_NAME, backup.leafName);
+  do_check_true(backup.exists());
+  
+  backup.remove(false);
+}
+
+var tests = [test_backup_bad_connection];
+
+function run_test()
+{
+  cleanup();
+
+  for (var i = 0; i < tests.length; i++)
+    tests[i]();
+    
+  cleanup();
+}
+