1 // Copyright (c) 2010 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CHROME_BROWSER_SYNC_ENGINE_CLEANUP_DISABLED_TYPES_COMMAND_H_ 6 #define CHROME_BROWSER_SYNC_ENGINE_CLEANUP_DISABLED_TYPES_COMMAND_H_ 7 #pragma once 8 9 #include "chrome/browser/sync/engine/syncer_command.h" 10 11 namespace browser_sync { 12 13 // A syncer command that purges (from memory and disk) entries belonging to 14 // a ModelType or ServerModelType that the user has not elected to sync. 15 // 16 // This is done as part of a session to 1) ensure it does not block the UI, 17 // and 2) avoid complicated races that could arise between a) deleting 18 // things b) a sync session trying to use these things c) and the potential 19 // re-enabling of the data type by the user before some scheduled deletion 20 // took place. Here, we are safe to perform I/O synchronously and we know it 21 // is a safe time to delete as we are in the only active session. 22 // 23 // The removal from memory is done synchronously, while the disk purge is left 24 // to an asynchronous SaveChanges operation. However, all the updates for 25 // meta data fields (such as initial_sync_ended) as well as the actual entry 26 // deletions will be committed in a single sqlite transaction. Thus it is 27 // possible that disabled types re-appear (in the sync db) after a reboot, 28 // but things will remain in a consistent state. This kind of error case is 29 // cared for in this command by retrying; see ExecuteImpl. 30 class CleanupDisabledTypesCommand : public SyncerCommand { 31 public: 32 CleanupDisabledTypesCommand(); 33 virtual ~CleanupDisabledTypesCommand(); 34 35 // SyncerCommand implementation. 36 virtual void ExecuteImpl(sessions::SyncSession* session); 37 38 private: 39 DISALLOW_COPY_AND_ASSIGN(CleanupDisabledTypesCommand); 40 }; 41 42 } // namespace browser_sync 43 44 #endif // CHROME_BROWSER_SYNC_ENGINE_CLEANUP_DISABLED_TYPES_COMMAND_H_ 45 46
