components/sync/engine/model_type_connector.h

// Copyright 2014 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_ENGINE_MODEL_TYPE_CONNECTOR_H_
#define COMPONENTS_SYNC_ENGINE_MODEL_TYPE_CONNECTOR_H_

#include <memory>

#include "components/sync/base/model_type.h"
#include "components/sync/engine/model_safe_worker.h"

namespace syncer {
struct DataTypeActivationResponse;

// An interface into the core parts of sync for model types. By adding/removing
// types through methods of this interface consumer controls which types will be
// syncing (receiving updates and committing local changes).
// In addition it handles creating the connection between the ModelTypeWorker
// (CommitQueue) on the sync side and the (Shared)ModelTypeProcessor on the
// model type side for non-blocking types.
class ModelTypeConnector {
 public:
  ModelTypeConnector();
  virtual ~ModelTypeConnector();

  // Connect a worker on the sync thread and |type|'s processor on the model
  // thread. Note that in production |activation_response| actually
  // owns a processor proxy that forwards calls to the model thread and is safe
  // to call from the sync thread.
  virtual void ConnectNonBlockingType(
      ModelType type,
      std::unique_ptr<DataTypeActivationResponse> activation_response) = 0;

  // Disconnects the worker from |type|'s processor and stop syncing the type.
  //
  // This is the sync thread's chance to clear state associated with the type.
  // It also causes the syncer to stop requesting updates for this type, and to
  // abort any in-progress commit requests.
  virtual void DisconnectNonBlockingType(ModelType type) = 0;

  // Registers directory based type with sync engine. Sync engine will create
  // update handler and commit contributor objects for this type. It will start
  // including the type in GetUpdates and commit requests.
  virtual void RegisterDirectoryType(ModelType type, ModelSafeGroup group) = 0;

  // Unregisters directory based type from sync engine. Type will no longer be
  // included in communications with server.
  virtual void UnregisterDirectoryType(ModelType type) = 0;
};

}  // namespace syncer

#endif  // COMPONENTS_SYNC_ENGINE_MODEL_TYPE_CONNECTOR_H_