1// Copyright 2012 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 SYNC_API_SYNC_CHANGE_PROCESSOR_H_ 6#define SYNC_API_SYNC_CHANGE_PROCESSOR_H_ 7 8#include <vector> 9 10#include "sync/api/sync_data.h" 11#include "sync/api/sync_error.h" 12#include "sync/base/sync_export.h" 13#include "sync/internal_api/public/base/model_type.h" 14 15namespace tracked_objects { 16class Location; 17} // namespace tracked_objects 18 19namespace syncer { 20 21class SyncChange; 22 23typedef std::vector<SyncChange> SyncChangeList; 24 25// An interface for services that handle receiving SyncChanges. 26class SYNC_EXPORT SyncChangeProcessor { 27 public: 28 // Whether a context change should force a datatype refresh or not. 29 enum ContextRefreshStatus { NO_REFRESH, REFRESH_NEEDED }; 30 typedef base::Callback<void(const SyncData&)> GetSyncDataCallback; 31 32 SyncChangeProcessor(); 33 virtual ~SyncChangeProcessor(); 34 35 // Process a list of SyncChanges. 36 // Returns: A default SyncError (IsSet() == false) if no errors were 37 // encountered, and a filled SyncError (IsSet() == true) 38 // otherwise. 39 // Inputs: 40 // |from_here|: allows tracking of where sync changes originate. 41 // |change_list|: is the list of sync changes in need of processing. 42 virtual SyncError ProcessSyncChanges( 43 const tracked_objects::Location& from_here, 44 const SyncChangeList& change_list) = 0; 45 46 // Fills a list of SyncData. This should create an up to date representation 47 // of all the data known to the ChangeProcessor for |datatype|, and 48 // should match/be a subset of the server's view of that datatype. 49 // 50 // WARNING: This can be a potentially slow & memory intensive operation and 51 // should only be used when absolutely necessary / sparingly. 52 virtual SyncDataList GetAllSyncData(ModelType type) const = 0; 53 54 // Retrieves the SyncData identified by |type| and |sync_tag| and invokes 55 // |callback| asynchronously. If no such SyncData exists locally, IsValid on 56 // the SyncData passed to |callback| will return false. 57 // 58 // This is an asynchronous local operation that may result in disk IO. 59 // 60 // Refer to sync_data.h for a description of |sync_tag|. 61 // 62 // TODO:(maniscalco): N.B. this method should really be pure virtual. An 63 // implentation is provided here just to verify that everything compiles. 64 // Update this method to be pure virtual (bug 353300). 65 virtual void GetSyncData(const ModelType& type, 66 const std::string& sync_tag, 67 const GetSyncDataCallback& callback) const {} 68 69 // Updates the context for |type|, triggering an optional context refresh. 70 // Default implementation does nothing. A type's context is a per-client blob 71 // that can affect all SyncData sent to/from the server, much like a cookie. 72 // TODO(zea): consider pulling the refresh logic into a separate method 73 // unrelated to datatype implementations. 74 virtual syncer::SyncError UpdateDataTypeContext( 75 ModelType type, 76 ContextRefreshStatus refresh_status, 77 const std::string& context); 78}; 79 80} // namespace syncer 81 82#endif // SYNC_API_SYNC_CHANGE_PROCESSOR_H_ 83