[Offline pages] OPM SQL store: moving load to constructor, updating read to GetOfflinePages

components/offline_pages/offline_page_metadata_store_sql.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_OFFLINE_PAGES_OFFLINE_PAGE_METADATA_STORE_SQL_H_
 #define COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_METADATA_STORE_SQL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 16 matching lines @@
 // OfflinePageMetadataStoreSQL is an instance of OfflinePageMetadataStore
 // which is implemented using a SQLite database.
 class OfflinePageMetadataStoreSQL : public OfflinePageMetadataStore {
  public:
   OfflinePageMetadataStoreSQL(
       scoped_refptr<base::SequencedTaskRunner> background_task_runner,
       const base::FilePath& database_dir);
   ~OfflinePageMetadataStoreSQL() override;
 
   // Implementation methods.
-  void Load(const LoadCallback& callback) override;
+  void GetOfflinePages(const LoadCallback& callback) override;
   void AddOrUpdateOfflinePage(const OfflinePageItem& offline_page,
                               const UpdateCallback& callback) override;
   void RemoveOfflinePages(const std::vector<int64_t>& offline_ids,
                           const UpdateCallback& callback) override;
   void Reset(const ResetCallback& callback) override;
+  StoreState state() const override;
 
  private:
   // Synchronous implementations, these are run on the background thread
   // and actually do the work to access SQL.  The implementations above
   // simply dispatch to the corresponding *Sync method on the background thread.
   // 'runner' is where to run the callback.
-  static void LoadSync(sql::Connection* db,
-                       const base::FilePath& path,
-                       scoped_refptr<base::SingleThreadTaskRunner> runner,
-                       const LoadCallback& callback);
   static void AddOrUpdateOfflinePageSync(
       const OfflinePageItem& offline_page,
       sql::Connection* db,
       scoped_refptr<base::SingleThreadTaskRunner> runner,
       const UpdateCallback& callback);
   static void RemoveOfflinePagesSync(
       const std::vector<int64_t>& offline_ids,
       sql::Connection* db,
       scoped_refptr<base::SingleThreadTaskRunner> runner,
       const UpdateCallback& callback);
-  static void ResetSync(std::unique_ptr<sql::Connection> db,
-                        scoped_refptr<base::SingleThreadTaskRunner> runner,
-                        const ResetCallback& callback);
 
-  static void NotifyLoadResult(
-      scoped_refptr<base::SingleThreadTaskRunner> runner,
-      const LoadCallback& callback,
-      LoadStatus status,
-      const std::vector<OfflinePageItem>& result);
+  // Used to initialize DB connection.
+  void OpenConnection();
+  void OnOpenConnectionDone(StoreState state);
+
+  // Used to reset DB connection.
+  void OnResetDone(const ResetCallback& callback, StoreState state);
+
+  // Helper function that checks whether a valid DB connection is present.
+  // Returns true if valid connection is present, otherwise it returns false and
+  // calls the provided callback as a shortcut.
+  bool CheckDb(const base::Closure& callback);
 
   // Background thread where all SQL access should be run.
   scoped_refptr<base::SequencedTaskRunner> background_task_runner_;
 
   // Path to the database on disk.
   base::FilePath db_file_path_;
   std::unique_ptr<sql::Connection> db_;
 
+  StoreState state_;
+  base::WeakPtrFactory<OfflinePageMetadataStoreSQL> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(OfflinePageMetadataStoreSQL);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_METADATA_STORE_SQL_H_