[Sync] Initial USS service implementation for DeviceInfo.

components/sync_driver/device_info_service.h

Index: components/sync_driver/device_info_service.h
diff --git a/components/sync_driver/device_info_service.h b/components/sync_driver/device_info_service.h
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index 0000000000000000000000000000000000000000..47d334a9230651ca3bed55cbb6e902bb6a4c41f0
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+++ b/components/sync_driver/device_info_service.h
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+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_SYNC_DRIVER_DEVICE_INFO_SERVICE_H_
+#define COMPONENTS_SYNC_DRIVER_DEVICE_INFO_SERVICE_H_
+
+#include <string>
+
+#include "base/containers/scoped_ptr_map.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+#include "base/observer_list.h"
+#include "components/sync_driver/device_info_tracker.h"
+#include "components/sync_driver/local_device_info_provider.h"
+#include "sync/api/model_type_service.h"
+
+namespace syncer {
+class SyncError;
+}  // namespace syncer
+
+namespace syncer_v2 {
+class ModelTypeChangeProcessor;
+}  // namespace syncer_v2
+
+namespace sync_pb {
+class DeviceInfoSpecifics;
+}  // namespace sync_pb
+
+namespace sync_driver_v2 {
+
+class ModelTypeChangeProcessor;
+
+// USS service implementation for DEVICE_INFO model type. Handles storage of
+// device info and associated sync metadata, applying/merging foreign changes,
+// and allows public read access.
+class DeviceInfoService : public syncer_v2::ModelTypeService,
+                          public sync_driver::DeviceInfoTracker {
+ public:
+  explicit DeviceInfoService(
+      sync_driver::LocalDeviceInfoProvider* local_device_info_provider);
+  ~DeviceInfoService() override;
+
+  // TODO(skym): Update once these are added to ModelTypeService interface.
+  // ModelTypeService implementation.
+  syncer::SyncError ApplySyncChanges();
+  syncer::SyncError LoadMetadata();
+  syncer::SyncError UpdateMetadata();
+  syncer::SyncError GetData();
+  syncer::SyncError GetAllData();
+  syncer::SyncError ClearMetadata();
+  // TODO(skym): See crbug/547087, do we need all these accessors?
+  syncer_v2::ModelTypeChangeProcessor* get_change_processor();
+  void set_change_processor(
+      scoped_ptr<syncer_v2::ModelTypeChangeProcessor> change_processor);
+  void clear_change_processor();
+
+  // DeviceInfoTracker implementation.
+  bool IsSyncing() const override;
+  scoped_ptr<sync_driver::DeviceInfo> GetDeviceInfo(
+      const std::string& client_id) const override;
+  ScopedVector<sync_driver::DeviceInfo> GetAllDeviceInfo() const override;
+  void AddObserver(Observer* observer) override;
+  void RemoveObserver(Observer* observer) override;
+
+  // Called to update local device backup time.
+  void UpdateLocalDeviceBackupTime(base::Time backup_time);
+  // Gets the most recently set local device backup time.
+  base::Time GetLocalDeviceBackupTime() const;
+
+ private:
+  friend class DeviceInfoServiceTest;
+
+  scoped_ptr<sync_pb::DeviceInfoSpecifics> CreateLocalSpecifics();
+  static scoped_ptr<sync_pb::DeviceInfoSpecifics> CreateSpecifics(
+      const sync_driver::DeviceInfo& info);
+
+  // Allocate new DeviceInfo from SyncData.
+  static scoped_ptr<sync_driver::DeviceInfo> CreateDeviceInfo(
+      const sync_pb::DeviceInfoSpecifics& specifics);
+
+  // Store SyncData in the cache.
+  void StoreSpecifics(scoped_ptr<sync_pb::DeviceInfoSpecifics> specifics);
+  // Delete SyncData from the cache.
+  void DeleteSpecifics(const std::string& client_id);
+  // Notify all registered observers.
+  void NotifyObservers();
+
+  void OnProviderInitialized();
+
+  // |local_device_backup_time_| accessors.
+  int64 local_device_backup_time() const { return local_device_backup_time_; }
+  bool has_local_device_backup_time() const {
+    return local_device_backup_time_ >= 0;
+  }
+  void set_local_device_backup_time(int64 value) {
+    local_device_backup_time_ = value;
+  }
+  void clear_local_device_backup_time() { local_device_backup_time_ = -1; }
+
+  // TODO(skym): Remove once we remove local provider.
+  // Local device last set backup time (in proto format).
+  // -1 if the value hasn't been specified
+  int64 local_device_backup_time_;
+
+  // |local_device_info_provider_| isn't owned.
+  const sync_driver::LocalDeviceInfoProvider* const local_device_info_provider_;
+
+  // Recieves ownership in set_change_processor(...).
+  scoped_ptr<syncer_v2::ModelTypeChangeProcessor> change_processor_;
+
+  // TODO(skym): Switch to use client tag hash instead of cache guid as key.
+  // Cache of all syncable and local data, stored by device cache guid.
+  typedef base::ScopedPtrMap<std::string,
+                             scoped_ptr<sync_pb::DeviceInfoSpecifics>>
+      ClientIdToSpecifics;
+  ClientIdToSpecifics all_data_;
+
+  // Registered observers, not owned.
+  base::ObserverList<Observer, true> observers_;
+
+  scoped_ptr<sync_driver::LocalDeviceInfoProvider::Subscription> subscription_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeviceInfoService);
+};
+
+}  // namespace sync_driver_v2
+
+#endif  // COMPONENTS_SYNC_DRIVER_DEVICE_INFO_SERVICE_H_