// Copyright 2012 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 SYNC_API_SYNC_CHANGE_PROCESSOR_H_ #define SYNC_API_SYNC_CHANGE_PROCESSOR_H_ #include <vector> #include "sync/api/sync_data.h" #include "sync/api/sync_error.h" #include "sync/base/sync_export.h" #include "sync/internal_api/public/base/model_type.h" namespace tracked_objects { class Location; } // namespace tracked_objects namespace syncer { class SyncChange; typedef std::vector<SyncChange> SyncChangeList; // An interface for services that handle receiving SyncChanges. class SYNC_EXPORT SyncChangeProcessor { public: // Whether a context change should force a datatype refresh or not. enum ContextRefreshStatus { NO_REFRESH, REFRESH_NEEDED }; typedef base::Callback<void(const SyncData&)> GetSyncDataCallback; SyncChangeProcessor(); virtual ~SyncChangeProcessor(); // Process a list of SyncChanges. // Returns: A default SyncError (IsSet() == false) if no errors were // encountered, and a filled SyncError (IsSet() == true) // otherwise. // Inputs: // |from_here|: allows tracking of where sync changes originate. // |change_list|: is the list of sync changes in need of processing. virtual SyncError ProcessSyncChanges( const tracked_objects::Location& from_here, const SyncChangeList& change_list) = 0; // Fills a list of SyncData. This should create an up to date representation // of all the data known to the ChangeProcessor for |datatype|, and // should match/be a subset of the server's view of that datatype. // // WARNING: This can be a potentially slow & memory intensive operation and // should only be used when absolutely necessary / sparingly. virtual SyncDataList GetAllSyncData(ModelType type) const = 0; // Retrieves the SyncData identified by |type| and |sync_tag| and invokes // |callback| asynchronously. If no such SyncData exists locally, IsValid on // the SyncData passed to |callback| will return false. // // This is an asynchronous local operation that may result in disk IO. // // Refer to sync_data.h for a description of |sync_tag|. // // TODO:(maniscalco): N.B. this method should really be pure virtual. An // implentation is provided here just to verify that everything compiles. // Update this method to be pure virtual (bug 353300). virtual void GetSyncData(const ModelType& type, const std::string& sync_tag, const GetSyncDataCallback& callback) const {} // Updates the context for |type|, triggering an optional context refresh. // Default implementation does nothing. A type's context is a per-client blob // that can affect all SyncData sent to/from the server, much like a cookie. // TODO(zea): consider pulling the refresh logic into a separate method // unrelated to datatype implementations. virtual syncer::SyncError UpdateDataTypeContext( ModelType type, ContextRefreshStatus refresh_status, const std::string& context); }; } // namespace syncer #endif // SYNC_API_SYNC_CHANGE_PROCESSOR_H_