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

components/offline_pages/offline_page_metadata_store_sql.h

Index: components/offline_pages/offline_page_metadata_store_sql.h
diff --git a/components/offline_pages/offline_page_metadata_store_sql.h b/components/offline_pages/offline_page_metadata_store_sql.h
index 8a480293f90bb5f2007b36c79b93d8a606cfc805..d5e2a0c0eb308835abe10c6a1e126aed4729ee13 100644
--- a/components/offline_pages/offline_page_metadata_store_sql.h
+++ b/components/offline_pages/offline_page_metadata_store_sql.h
@@ -34,22 +34,19 @@ class OfflinePageMetadataStoreSQL : public OfflinePageMetadataStore {
   ~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,
@@ -60,15 +57,18 @@ class OfflinePageMetadataStoreSQL : public OfflinePageMetadataStore {
       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_;
@@ -77,6 +77,9 @@ class OfflinePageMetadataStoreSQL : public OfflinePageMetadataStore {
   base::FilePath db_file_path_;
   std::unique_ptr<sql::Connection> db_;
 
+  StoreState state_;
+  base::WeakPtrFactory<OfflinePageMetadataStoreSQL> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(OfflinePageMetadataStoreSQL);
 };