| // 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_DRIVER_GENERIC_CHANGE_PROCESSOR_H_ |
| #define COMPONENTS_SYNC_DRIVER_GENERIC_CHANGE_PROCESSOR_H_ |
| |
| #include <stdint.h> |
| |
| #include <memory> |
| #include <string> |
| #include <vector> |
| |
| #include "base/compiler_specific.h" |
| #include "base/macros.h" |
| #include "base/memory/weak_ptr.h" |
| #include "base/observer_list.h" |
| #include "base/sequence_checker.h" |
| #include "components/sync/model/change_processor.h" |
| #include "components/sync/model/data_type_error_handler.h" |
| #include "components/sync/model/sync_change_processor.h" |
| #include "components/sync/model/sync_merge_result.h" |
| |
| namespace syncer { |
| |
| class SyncClient; |
| class SyncData; |
| class SyncableService; |
| class WriteNode; |
| class WriteTransaction; |
| |
| namespace syncable { |
| class Entry; |
| } // namespace syncable |
| |
| using SyncDataList = std::vector<SyncData>; |
| |
| // Datatype agnostic change processor. One instance of GenericChangeProcessor |
| // is created for each datatype and lives on the datatype's sequence. 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 sequence in which it was created. |
| class GenericChangeProcessor : public ChangeProcessor, |
| public SyncChangeProcessor { |
| public: |
| // Create a change processor for |type| and connect it to the syncer. |
| GenericChangeProcessor(ModelType type, |
| std::unique_ptr<DataTypeErrorHandler> error_handler, |
| const base::WeakPtr<SyncableService>& local_service, |
| const base::WeakPtr<SyncMergeResult>& merge_result, |
| UserShare* user_share, |
| SyncClient* sync_client); |
| ~GenericChangeProcessor() override; |
| |
| // ChangeProcessor interface. |
| // Build and store a list of all changes into |syncer_changes_|. |
| void ApplyChangesFromSyncModel( |
| const BaseTransaction* trans, |
| int64_t version, |
| const ImmutableChangeRecordList& changes) override; |
| // Passes |syncer_changes_|, built in ApplyChangesFromSyncModel, onto |
| // |local_service_| by way of its ProcessSyncChanges method. |
| void CommitChangesFromSyncModel() override; |
| |
| // SyncChangeProcessor implementation. |
| SyncError ProcessSyncChanges(const base::Location& from_here, |
| const SyncChangeList& change_list) override; |
| SyncDataList GetAllSyncData(ModelType type) const override; |
| SyncError UpdateDataTypeContext( |
| ModelType type, |
| SyncChangeProcessor::ContextRefreshStatus refresh_status, |
| const std::string& context) override; |
| void AddLocalChangeObserver(LocalChangeObserver* observer) override; |
| void RemoveLocalChangeObserver(LocalChangeObserver* observer) override; |
| |
| // Similar to above, but returns a SyncError for use by direct clients |
| // of GenericChangeProcessor that may need more error visibility. |
| virtual SyncError GetAllSyncDataReturnError(SyncDataList* data) const; |
| |
| // If a datatype context associated with this GenericChangeProcessor's type |
| // exists, fills |context| and returns true. Otheriwse, if there has not been |
| // a context set, returns false. |
| virtual bool GetDataTypeContext(std::string* context) const; |
| |
| // Returns the number of items for this type. |
| virtual int GetSyncCount(); |
| |
| // Generic versions of AssociatorInterface methods. Called by |
| // SyncableServiceAdapter or the DataTypeController. |
| virtual bool SyncModelHasUserCreatedNodes(bool* has_nodes); |
| virtual bool CryptoReadyIfNecessary(); |
| |
| protected: |
| // ChangeProcessor interface. |
| void StartImpl() override; // Does nothing. |
| UserShare* share_handle() const override; |
| |
| private: |
| SyncError AttemptDelete(const SyncChange& change, |
| ModelType type, |
| const std::string& type_str, |
| WriteNode* node, |
| DataTypeErrorHandler* error_handler); |
| // Logically part of ProcessSyncChanges. |
| SyncError HandleActionAdd(const SyncChange& change, |
| const std::string& type_str, |
| const WriteTransaction& trans, |
| WriteNode* sync_node); |
| |
| // Logically part of ProcessSyncChanges. |
| SyncError HandleActionUpdate(const SyncChange& change, |
| const std::string& type_str, |
| const WriteTransaction& trans, |
| WriteNode* sync_node); |
| |
| // Notify every registered local change observer that |change| is about to be |
| // applied to |current_entry|. |
| void NotifyLocalChangeObservers(const syncable::Entry* current_entry, |
| const SyncChange& change); |
| |
| base::SequenceChecker sequence_checker_; |
| |
| const ModelType type_; |
| |
| // The SyncableService this change processor will forward changes on to. |
| const base::WeakPtr<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<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. |
| 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. |
| UserShare* const share_handle_; |
| |
| // List of observers that want to be notified of local changes being written. |
| base::ObserverList<LocalChangeObserver>::Unchecked local_change_observers_; |
| |
| base::WeakPtrFactory<GenericChangeProcessor> weak_ptr_factory_; |
| |
| DISALLOW_COPY_AND_ASSIGN(GenericChangeProcessor); |
| }; |
| |
| } // namespace syncer |
| |
| #endif // COMPONENTS_SYNC_DRIVER_GENERIC_CHANGE_PROCESSOR_H_ |