Move ReadingList model to components/reading_list/core

components/reading_list/ios/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 COMPONENTS_READING_LIST_IOS_READING_LIST_STORE_H_
-#define COMPONENTS_READING_LIST_IOS_READING_LIST_STORE_H_
-
-#include <memory>
-#include <string>
-
-#include "base/threading/non_thread_safe.h"
-#include "components/reading_list/ios/reading_list_model_storage.h"
-#include "components/reading_list/ios/reading_list_store_delegate.h"
-#include "components/sync/model/model_error.h"
-#include "components/sync/model/model_type_store.h"
-
-namespace syncer {
-class MutableDataBatch;
-}
-
-class ReadingListModel;
-
-// A ReadingListModelStorage storing and syncing data in protobufs.
-class ReadingListStore : public ReadingListModelStorage,
-                         public base::NonThreadSafe {
-  using StoreFactoryFunction = base::Callback<void(
-      const syncer::ModelTypeStore::InitCallback& callback)>;
-
- public:
-  ReadingListStore(StoreFactoryFunction create_store_callback,
-                   const ChangeProcessorFactory& change_processor_factory);
-  ~ReadingListStore() override;
-
-  std::unique_ptr<ScopedBatchUpdate> EnsureBatchCreated() override;
-
-  // ReadingListModelStorage implementation
-  void SetReadingListModel(ReadingListModel* model,
-                           ReadingListStoreDelegate* delegate,
-                           base::Clock* clock) override;
-
-  void SaveEntry(const ReadingListEntry& entry) override;
-  void RemoveEntry(const ReadingListEntry& entry) 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.
-  base::Optional<syncer::ModelError> 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.
-  base::Optional<syncer::ModelError> ApplySyncChanges(
-      std::unique_ptr<syncer::MetadataChangeList> metadata_change_list,
-      syncer::EntityChangeList entity_changes) override;
-
-  // Returns whether entries respect a strict order for sync and if |rhs| can be
-  // submitted to sync after |lhs| has been received.
-  // The order should ensure that there is no sync loop in sync and should be
-  // submitted to sync in strictly increasing order.
-  // Entries are in increasing order if all the fields respect increasing order.
-  // - URL must be the same.
-  // - update_title_time_us:
-  //       rhs.update_title_time_us >= lhs.update_title_time_us
-  // - title:
-  //       if rhs.update_title_time_us > lhs.update_title_time_us
-  //         title can be anything
-  //       if rhs.update_title_time_us == lhs.update_title_time_us
-  //         title must verify rhs.title.compare(lhs.title) >= 0
-  // - creation_time_us:
-  //       rhs.creation_time_us >= lhs.creation_time_us
-  // - rhs.first_read_time_us:
-  //       if rhs.creation_time_us > lhs.creation_time_us,
-  //         rhs.first_read_time_us can be anything.
-  //       if rhs.creation_time_us == lhs.creation_time_us
-  //           and rhs.first_read_time_us == 0
-  //         rhs.first_read_time_us can be anything.
-  //       if rhs.creation_time_us == lhs.creation_time_us,
-  //         rhs.first_read_time_us <= lhs.first_read_time_us
-  // - update_time_us:
-  //       rhs.update_time_us >= lhs.update_time_us
-  // - state:
-  //       if rhs.update_time_us > lhs.update_time_us
-  //         rhs.state can be anything.
-  //       if rhs.update_time_us == lhs.update_time_us
-  //         rhs.state >= lhs.state in the order UNSEEN, UNREAD, READ.
-  static bool CompareEntriesForSync(const sync_pb::ReadingListSpecifics& lhs,
-                                    const sync_pb::ReadingListSpecifics& rhs);
-
-  // 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;
-
-  // Methods used as callbacks given to DataTypeStore.
-  void OnStoreCreated(syncer::ModelTypeStore::Result result,
-                      std::unique_ptr<syncer::ModelTypeStore> store);
-
-  class ScopedBatchUpdate : public ReadingListModelStorage::ScopedBatchUpdate {
-   public:
-    explicit ScopedBatchUpdate(ReadingListStore* store);
-
-    ~ScopedBatchUpdate() override;
-
-   private:
-    ReadingListStore* store_;
-
-    DISALLOW_COPY_AND_ASSIGN(ScopedBatchUpdate);
-  };
-
- private:
-  void BeginTransaction();
-  void CommitTransaction();
-  // Callbacks needed for the database handling.
-  void OnDatabaseLoad(
-      syncer::ModelTypeStore::Result result,
-      std::unique_ptr<syncer::ModelTypeStore::RecordList> entries);
-  void OnDatabaseSave(syncer::ModelTypeStore::Result result);
-  void OnReadAllMetadata(base::Optional<syncer::ModelError> error,
-                         std::unique_ptr<syncer::MetadataBatch> metadata_batch);
-
-  void AddEntryToBatch(syncer::MutableDataBatch* batch,
-                       const ReadingListEntry& entry);
-
-  std::unique_ptr<syncer::ModelTypeStore> store_;
-  ReadingListModel* model_;
-  ReadingListStoreDelegate* delegate_;
-  StoreFactoryFunction create_store_callback_;
-
-  int pending_transaction_count_;
-  std::unique_ptr<syncer::ModelTypeStore::WriteBatch> batch_;
-
-  base::Clock* clock_;
-
-  DISALLOW_COPY_AND_ASSIGN(ReadingListStore);
-};
-
-#endif  // COMPONENTS_READING_LIST_IOS_READING_LIST_STORE_H_