1// Copyright (c) 2011 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_BACKEND_MIGRATOR_H_
6#define CHROME_BROWSER_SYNC_BACKEND_MIGRATOR_H_
7
8#include "base/task.h"
9#include "chrome/browser/sync/profile_sync_service_observer.h"
10#include "chrome/browser/sync/syncable/model_type.h"
11#include "content/common/notification_observer.h"
12#include "content/common/notification_registrar.h"
13
14class ProfileSyncService;
15
16namespace browser_sync {
17
18class DataTypeManager;
19
20// A class to perform migration of a datatype pursuant to the 'MIGRATION_DONE'
21// code in the sync protocol definition (protocol/sync.proto).
22class BackendMigrator : public NotificationObserver,
23                        public ProfileSyncServiceObserver {
24 public:
25  enum State {
26    IDLE,
27    WAITING_TO_START,   // Waiting for previous configuration to finish.
28    DISABLING_TYPES,    // Exit criteria: SYNC_CONFIGURE_DONE for enabled
29                        // types _excluding_ |to_migrate_|.
30    WAITING_FOR_PURGE,  // Exit criteria: SyncCycleEnded for enabled types
31                        // excluding |to_migrate|
32    REENABLING_TYPES,   // Exit criteria: SYNC_CONFIGURE_DONE for enabled
33                        // types.
34  };
35
36  BackendMigrator(ProfileSyncService* service, DataTypeManager* manager);
37  virtual ~BackendMigrator();
38
39  // Starts a sequence of events that will disable and reenable |types|.
40  void MigrateTypes(const syncable::ModelTypeSet& types);
41
42  // ProfileSyncServiceObserver implementation.
43  virtual void OnStateChanged();
44
45  // NotificationObserver implementation.
46  virtual void Observe(NotificationType type,
47                       const NotificationSource& source,
48                       const NotificationDetails& details);
49
50  State state() const;
51
52 private:
53  bool HasStartedMigrating() const;
54
55  State state_;
56  ProfileSyncService* service_;
57  DataTypeManager* manager_;
58  NotificationRegistrar registrar_;
59
60  syncable::ModelTypeSet to_migrate_;
61  bool restart_migration_;
62
63  // We use this to gracefully re-start migrations.
64  ScopedRunnableMethodFactory<BackendMigrator> method_factory_;
65
66  DISALLOW_COPY_AND_ASSIGN(BackendMigrator);
67};
68
69}  // namespace browser_sync
70
71#endif  // CHROME_BROWSER_SYNC_BACKEND_MIGRATOR_H_
72