[Offline pages] Adding persistent request queue based on SQLite

components/offline_pages/background/request_queue_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_
+#ifndef COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_QUEUE_STORE_SQL_H_
+#define COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_QUEUE_STORE_SQL_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "base/memory/weak_ptr.h"
-#include "components/offline_pages/offline_page_metadata_store.h"
+#include "components/offline_pages/background/request_queue_store.h"
 
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace sql {
 class Connection;
 }
 
 namespace offline_pages {
 
-// OfflinePageMetadataStoreSQL is an instance of OfflinePageMetadataStore
-// which is implemented using a SQLite database.
-class OfflinePageMetadataStoreSQL : public OfflinePageMetadataStore {
+// SQLite implementation of RequestQueueStore.
+class RequestQueueStoreSQL : public RequestQueueStore {
  public:
-  OfflinePageMetadataStoreSQL(
+  RequestQueueStoreSQL(
       scoped_refptr<base::SequencedTaskRunner> background_task_runner,
       const base::FilePath& database_dir);
-  ~OfflinePageMetadataStoreSQL() override;
+  ~RequestQueueStoreSQL() override;
 
-  // Implementation methods.
-  void Load(const LoadCallback& callback) override;
-  void AddOrUpdateOfflinePage(const OfflinePageItem& offline_page,
-                              const UpdateCallback& callback) override;
-  void RemoveOfflinePages(const std::vector<int64_t>& offline_ids,
+  // RequestQueueStore implementation.
+  void GetRequests(const GetRequestsCallback& callback) override;
+  void AddOrUpdateRequest(const SavePageRequest& offline_page,
                           const UpdateCallback& callback) override;
+  void RemoveRequests(const std::vector<int64_t>& request_ids,
+                      const RemoveCallback& callback) override;
   void Reset(const ResetCallback& callback) 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,
+  static void GetRequestsSync(
       sql::Connection* db,
       scoped_refptr<base::SingleThreadTaskRunner> runner,
-      const UpdateCallback& callback);
-  static void RemoveOfflinePagesSync(
-      const std::vector<int64_t>& offline_ids,
+      const GetRequestsCallback& callback);
+  static void AddOrUpdateRequestSync(
       sql::Connection* db,
       scoped_refptr<base::SingleThreadTaskRunner> runner,
+      const SavePageRequest& offline_page,
       const UpdateCallback& callback);
+  static void RemoveRequestsSync(
+      sql::Connection* db,
+      scoped_refptr<base::SingleThreadTaskRunner> runner,
+      const std::vector<int64_t>& request_ids,
+      const RemoveCallback& callback);
   static void ResetSync(std::unique_ptr<sql::Connection> db,
                         scoped_refptr<base::SingleThreadTaskRunner> runner,
                         const ResetCallback& callback);
 
-  static void NotifyLoadResult(
+  // Used to initialize DB connection.
+  static void OpenConnectionSync(
+      sql::Connection* db,
       scoped_refptr<base::SingleThreadTaskRunner> runner,
-      const LoadCallback& callback,
-      LoadStatus status,
-      const std::vector<OfflinePageItem>& result);
+      const base::FilePath& path,
+      const base::Callback<void(bool)>& callback);
+  void OpenConnection();
+  void OnOpenConnectionDone(bool success);
 
   // 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_;
+
+  // Database connection.
   std::unique_ptr<sql::Connection> db_;
 
-  DISALLOW_COPY_AND_ASSIGN(OfflinePageMetadataStoreSQL);
+  base::WeakPtrFactory<RequestQueueStoreSQL> weak_ptr_factory_;
+  DISALLOW_COPY_AND_ASSIGN(RequestQueueStoreSQL);
 };
 
 }  // namespace offline_pages
 
-#endif  // COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_METADATA_STORE_SQL_H_
+#endif  // COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_QUEUE_STORE_SQL_H_