// Copyright (c) 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 CHROME_BROWSER_SYNC_GLUE_GENERIC_CHANGE_PROCESSOR_H_
#define CHROME_BROWSER_SYNC_GLUE_GENERIC_CHANGE_PROCESSOR_H_
#include <vector>
#include "base/compiler_specific.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/non_thread_safe.h"
#include "chrome/browser/sync/glue/change_processor.h"
#include "components/sync_driver/data_type_controller.h"
#include "components/sync_driver/data_type_error_handler.h"
#include "sync/api/attachments/attachment_service.h"
#include "sync/api/attachments/attachment_service_proxy.h"
#include "sync/api/sync_change_processor.h"
#include "sync/api/sync_merge_result.h"
namespace syncer {
class SyncData;
class SyncableService;
class WriteNode;
class WriteTransaction;
typedef std::vector<syncer::SyncData> SyncDataList;
} // namespace syncer
namespace browser_sync {
// TODO(sync): deprecate all change processors and have them replaced by
// instances of this.
// Datatype agnostic change processor. One instance of GenericChangeProcessor
// is created for each datatype and lives on the datatype's thread. It then
// handles all interaction with the sync api, both translating pushes from the
// local service into transactions and receiving changes from the sync model,
// which then get converted into SyncChange's and sent to the local service.
//
// As a rule, the GenericChangeProcessor is not thread safe, and should only
// be used on the same thread in which it was created.
class GenericChangeProcessor : public ChangeProcessor,
public syncer::SyncChangeProcessor,
public base::NonThreadSafe {
public:
// Create a change processor and connect it to the syncer.
GenericChangeProcessor(
DataTypeErrorHandler* error_handler,
const base::WeakPtr<syncer::SyncableService>& local_service,
const base::WeakPtr<syncer::SyncMergeResult>& merge_result,
syncer::UserShare* user_share,
scoped_ptr<syncer::AttachmentService> attachment_service);
virtual ~GenericChangeProcessor();
// ChangeProcessor interface.
// Build and store a list of all changes into |syncer_changes_|.
virtual void ApplyChangesFromSyncModel(
const syncer::BaseTransaction* trans,
int64 version,
const syncer::ImmutableChangeRecordList& changes) OVERRIDE;
// Passes |syncer_changes_|, built in ApplyChangesFromSyncModel, onto
// |local_service_| by way of its ProcessSyncChanges method.
virtual void CommitChangesFromSyncModel() OVERRIDE;
// syncer::SyncChangeProcessor implementation.
virtual syncer::SyncError ProcessSyncChanges(
const tracked_objects::Location& from_here,
const syncer::SyncChangeList& change_list) OVERRIDE;
virtual syncer::SyncDataList GetAllSyncData(syncer::ModelType type)
const OVERRIDE;
virtual syncer::SyncError UpdateDataTypeContext(
syncer::ModelType type,
const std::string& context) OVERRIDE;
// Similar to above, but returns a SyncError for use by direct clients
// of GenericChangeProcessor that may need more error visibility.
virtual syncer::SyncError GetAllSyncDataReturnError(
syncer::ModelType type,
syncer::SyncDataList* data) const;
// Returns the number of items for this type.
virtual int GetSyncCountForType(syncer::ModelType type);
// Generic versions of AssociatorInterface methods. Called by
// syncer::SyncableServiceAdapter or the DataTypeController.
virtual bool SyncModelHasUserCreatedNodes(syncer::ModelType type,
bool* has_nodes);
virtual bool CryptoReadyIfNecessary(syncer::ModelType type);
protected:
// ChangeProcessor interface.
virtual void StartImpl(Profile* profile) OVERRIDE; // Does nothing.
virtual syncer::UserShare* share_handle() const OVERRIDE;
private:
// Helper methods for acting on changes coming from the datatype. These are
// logically part of ProcessSyncChanges.
syncer::SyncError HandleActionAdd(const syncer::SyncChange& change,
const std::string& type_str,
const syncer::ModelType& type,
const syncer::WriteTransaction& trans,
syncer::WriteNode* sync_node);
syncer::SyncError HandleActionUpdate(const syncer::SyncChange& change,
const std::string& type_str,
const syncer::ModelType& type,
const syncer::WriteTransaction& trans,
syncer::WriteNode* sync_node);
// The SyncableService this change processor will forward changes on to.
const base::WeakPtr<syncer::SyncableService> local_service_;
// A SyncMergeResult used to track the changes made during association. The
// owner will invalidate the weak pointer when association is complete. While
// the pointer is valid though, we increment it with any changes received
// via ProcessSyncChanges.
const base::WeakPtr<syncer::SyncMergeResult> merge_result_;
// The current list of changes received from the syncer. We buffer because
// we must ensure no syncapi transaction is held when we pass it on to
// |local_service_|.
// Set in ApplyChangesFromSyncModel, consumed in CommitChangesFromSyncModel.
syncer::SyncChangeList syncer_changes_;
// Our handle to the sync model. Unlike normal ChangeProcessors, we need to
// be able to access the sync model before the change processor begins
// listening to changes (the local_service_ will be interacting with us
// when it starts up). As such we can't wait until Start(_) has been called,
// and have to keep a local pointer to the user_share.
syncer::UserShare* const share_handle_;
scoped_ptr<syncer::AttachmentService> attachment_service_;
// Must be destroyed before attachment_service_ to ensure WeakPtrs are
// invalidated before attachment_service_ is destroyed.
base::WeakPtrFactory<syncer::AttachmentService>
attachment_service_weak_ptr_factory_;
syncer::AttachmentServiceProxy attachment_service_proxy_;
DISALLOW_COPY_AND_ASSIGN(GenericChangeProcessor);
};
} // namespace browser_sync
#endif // CHROME_BROWSER_SYNC_GLUE_GENERIC_CHANGE_PROCESSOR_H_