with sync

ios/chrome/browser/reading_list/reading_list_store.h

 // Copyright 2016 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 IOS_CHROME_BROWSER_READING_LIST_READING_LIST_STORE_H_
 #define IOS_CHROME_BROWSER_READING_LIST_READING_LIST_STORE_H_
 
-#include "base/memory/weak_ptr.h"
 #include "components/leveldb_proto/proto_database.h"
+#include "components/sync/api/model_type_service.h"
+#include "components/sync/api/model_type_store.h"
 #include "ios/chrome/browser/reading_list/reading_list_model_storage.h"
 
 using ReadingListDB =
     leveldb_proto::ProtoDatabase<reading_list::ReadingListLocal>;
 
+namespace syncer {
+class ModelTypeService;
+}
+
+typedef base::Callback<void(
+    const syncer::ModelTypeStore::InitCallback& callback)>
+    StoreFactoryFunction;
+
 // A ReadingListModelStorage storing data in protobufs.
-class ReadingListStore : public ReadingListModelStorage {
+class ReadingListStore : public ReadingListModelStorage,
+                         public syncer::ModelTypeService {
   using EntryVector = std::vector<reading_list::ReadingListLocal>;
 
  public:
   ReadingListStore(std::unique_ptr<ReadingListDB> database,
-                   const base::FilePath& database_dir);
-  virtual ~ReadingListStore();
+                   const base::FilePath& database_dir,
+                   StoreFactoryFunction create_store_callback);
+  ~ReadingListStore() override;
 
   // ReadingListModelStorage implementation
   void SetReadingListModel(ReadingListModelImpl* model) override;
   void BeginTransaction() override;
   void CommitTransaction() override;
   void LoadPersistentLists() override;
   void SaveEntry(const ReadingListEntry& entry, bool read) override;
   void RemoveEntry(const ReadingListEntry& entry) override;
 
+  // ReadingListModelStorage implementation.
+  syncer::ModelTypeService* GetModelTypeService() override;
+
+  // Creates an object used to communicate changes in the sync metadata to the
+  // model type store.
+  std::unique_ptr<syncer::MetadataChangeList> CreateMetadataChangeList()
+      override;
+
+  // Perform the initial merge between local and sync data. This should only be
+  // called when a data type is first enabled to start syncing, and there is no
+  // sync metadata. Best effort should be made to match local and sync data. The
+  // keys in the |entity_data_map| will have been created via GetClientTag(...),
+  // and if a local and sync data should match/merge but disagree on tags, the
+  // service should use the sync data's tag. Any local pieces of data that are
+  // not present in sync should immediately be Put(...) to the processor before
+  // returning. The same MetadataChangeList that was passed into this function
+  // can be passed to Put(...) calls. Delete(...) can also be called but should
+  // not be needed for most model types. Durable storage writes, if not able to
+  // combine all change atomically, should save the metadata after the data
+  // changes, so that this merge will be re-driven by sync if is not completely
+  // saved during the current run.
+  syncer::SyncError MergeSyncData(
+      std::unique_ptr<syncer::MetadataChangeList> metadata_change_list,
+      syncer::EntityDataMap entity_data_map) override;
+
+  // Apply changes from the sync server locally.
+  // Please note that |entity_changes| might have fewer entries than
+  // |metadata_change_list| in case when some of the data changes are filtered
+  // out, or even be empty in case when a commit confirmation is processed and
+  // only the metadata needs to persisted.
+  syncer::SyncError ApplySyncChanges(
+      std::unique_ptr<syncer::MetadataChangeList> metadata_change_list,
+      syncer::EntityChangeList entity_changes) override;
+
+  // Asynchronously retrieve the corresponding sync data for |storage_keys|.
+  void GetData(StorageKeyList storage_keys, DataCallback callback) override;
+
+  // Asynchronously retrieve all of the local sync data.
+  void GetAllData(DataCallback callback) override;
+
+  // Get or generate a client tag for |entity_data|. This must be the same tag
+  // that was/would have been generated in the SyncableService/Directory world
+  // for backward compatibility with pre-USS clients. The only time this
+  // theoretically needs to be called is on the creation of local data, however
+  // it is also used to verify the hash of remote data. If a data type was never
+  // launched pre-USS, then method does not need to be different from
+  // GetStorageKey().
+  std::string GetClientTag(const syncer::EntityData& entity_data) override;
+
+  // Get or generate a storage key for |entity_data|. This will only ever be
+  // called once when first encountering a remote entity. Local changes will
+  // provide their storage keys directly to Put instead of using this method.
+  // Theoretically this function doesn't need to be stable across multiple calls
+  // on the same or different clients, but to keep things simple, it probably
+  // should be.
+  std::string GetStorageKey(const syncer::EntityData& entity_data) override;
+
+  // Overridable notification for when the processor is set. This is typically
+  // when the service should start loading metadata and then subsequently giving
+  // it to the processor.
+  void OnChangeProcessorSet() override;
+
+  // Methods used as callbacks given to DataTypeStore.
+  void OnStoreCreated(syncer::ModelTypeStore::Result result,
+                      std::unique_ptr<syncer::ModelTypeStore> store);
+
  private:
   void OnDatabaseInit(bool success);
-  void OnDatabaseLoad(bool success, std::unique_ptr<EntryVector> entries);
-  void OnDatabaseSave(bool success);
+  void OnDatabaseLoad(
+      syncer::ModelTypeStore::Result result,
+      std::unique_ptr<syncer::ModelTypeStore::RecordList> entries);
+  void OnDatabaseSave(syncer::ModelTypeStore::Result result);
+  void OnReadAllMetadata(
+      syncer::ModelTypeStore::Result result,
+      std::unique_ptr<syncer::ModelTypeStore::RecordList> metadata_records,
+      const std::string& global_metadata);
 
-  std::unique_ptr<ReadingListDB> database_;
+  void NoopEntry(const ReadingListEntry&);
+
+  std::unique_ptr<syncer::ModelTypeStore> store_;
   bool database_loaded_;
   ReadingListModelImpl* model_;
+  StoreFactoryFunction create_store_callback_;
+  bool has_metadata_loaded_ = false;
 
   int pending_transaction_;
   std::unique_ptr<ReadingListDB::KeyEntryVector> pending_keys_to_save_;
   std::unique_ptr<std::vector<std::string>> pending_keys_to_remove_;
 
-  base::WeakPtrFactory<ReadingListStore> weak_ptr_factory_;
 };
 
 #endif  // IOS_CHROME_BROWSER_READING_LIST_READING_LIST_STORE_H_