Quota: Implement QuotaBackendImpl

webkit/browser/fileapi/quota/quota_reservation_manager.h

 // Copyright 2013 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 WEBKIT_BROWSER_FILEAPI_QUOTA_QUOTA_RESERVATION_MANAGER_H_
 #define WEBKIT_BROWSER_FILEAPI_QUOTA_QUOTA_RESERVATION_MANAGER_H_
 
 #include <map>
+#include <utility>
 
 #include "base/basictypes.h"
 #include "base/callback_forward.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/platform_file.h"
 #include "url/gurl.h"
 #include "webkit/browser/webkit_storage_browser_export.h"
 #include "webkit/common/fileapi/file_system_types.h"
 
 namespace fileapi {
 
 class QuotaReservation;
 class QuotaReservationBuffer;
 class OpenFileHandle;
 class OpenFileHandleContext;
 
 class WEBKIT_STORAGE_BROWSER_EXPORT QuotaReservationManager {
  public:
   typedef base::Callback<void(base::PlatformFileError error)> StatusCallback;
+
+  // Callback for ReserveQuota. When this callback returns false, ReserveQuota
+  // operation should be reverted.
   typedef base::Callback<bool(base::PlatformFileError error)>
       ReserveQuotaCallback;
 
   // An abstraction of backing quota system.
-  class QuotaBackend {
+  class WEBKIT_STORAGE_BROWSER_EXPORT QuotaBackend {
    public:
+    QuotaBackend() {}
+    virtual ~QuotaBackend() {}
+
     // Reserves or reclaims |delta| of quota for |origin| and |type| pair.
     // Reserved quota should be counted as usage, but it should be on-memory
     // and be cleared by a browser restart.
     // Invokes |callback| upon completion with an error code.
     // |callback| should return false if it can't accept the reservation, in
     // that case, the backend should roll back the reservation.
     virtual void ReserveQuota(const GURL& origin,
                               FileSystemType type,
                               int64 delta,
                               const ReserveQuotaCallback& callback) = 0;
 
     // Reclaims |size| of quota for |origin| and |type|.
     virtual void ReleaseReservedQuota(const GURL& origin,
                                       FileSystemType type,
                                       int64 size) = 0;
 
     // Updates disk usage of |origin| and |type|.
     // Invokes |callback| upon completion with an error code.
     virtual void CommitQuotaUsage(const GURL& origin,
                                   FileSystemType type,
                                   int64 delta,
                                   const StatusCallback& callback) = 0;
 
-    virtual void IncreaseDirtyCount(const GURL& origin,
+    virtual void IncrementDirtyCount(const GURL& origin,
                                     FileSystemType type) = 0;
-    virtual void DecreaseDirtyCount(const GURL& origin,
+    virtual void DecrementDirtyCount(const GURL& origin,
                                     FileSystemType type) = 0;
 
-   protected:
-    QuotaBackend() {}
-    virtual ~QuotaBackend() {}
-
    private:
     DISALLOW_COPY_AND_ASSIGN(QuotaBackend);
   };
 
   explicit QuotaReservationManager(QuotaBackend* backend);

[tzik, 2013/11/07 07:34:13]

Could you also replace this with scoped_ptr<QuotaBackend>?

[nhiroki, 2013/11/08 00:12:05]

Done.

   ~QuotaReservationManager();
 
   // The entry point of the quota reservation.  Creates new reservation object
   // for |origin| and |type|.
   scoped_refptr<QuotaReservation> CreateReservation(
       const GURL& origin,
       FileSystemType type);
 
  private:
   typedef std::map<std::pair<GURL, FileSystemType>, QuotaReservationBuffer*>
       ReservationBufferByOriginAndType;
 
   friend class QuotaReservation;
   friend class QuotaReservationBuffer;
 
   void ReserveQuota(const GURL& origin,
                     FileSystemType type,
                     int64 delta,
                     const ReserveQuotaCallback& callback);
 
   void ReleaseReservedQuota(const GURL& origin,
                             FileSystemType type,
                             int64 size);
 
   void CommitQuotaUsage(const GURL& origin,
                         FileSystemType type,
                         int64 delta,
                         const StatusCallback& callback);
 
-  void IncreaseDirtyCount(const GURL& origin, FileSystemType type);
-  void DecreaseDirtyCount(const GURL& origin, FileSystemType type);
+  void IncrementDirtyCount(const GURL& origin, FileSystemType type);
+  void DecrementDirtyCount(const GURL& origin, FileSystemType type);
 
   scoped_refptr<QuotaReservationBuffer> GetReservationBuffer(
       const GURL& origin,
       FileSystemType type);
   void ReleaseReservationBuffer(QuotaReservationBuffer* reservation_pool);
 
-
-  // Not owned.  |backend_| should outlive QuotaReservationManager
-  QuotaBackend* backend_;
+  scoped_ptr<QuotaBackend> backend_;
 
   // Not owned.  The destructor of ReservationBuffer should erase itself from
   // |reservation_buffers_| by calling ReleaseReservationBuffer.
   ReservationBufferByOriginAndType reservation_buffers_;
 
   base::SequenceChecker sequence_checker_;
   base::WeakPtrFactory<QuotaReservationManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(QuotaReservationManager);
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_BROWSER_FILEAPI_QUOTA_QUOTA_RESERVATION_MANAGER_H_