chrome/browser/sync/backend_migrator.h

   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
  14 class ProfileSyncService;
  15
  16 namespace browser_sync {
  17
  18 class 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).
  22 class 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_