ppapi/shared_impl/scoped_pp_resource.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef PPAPI_SHARED_IMPL_SCOPED_RESOURCE_H_
   6 #define PPAPI_SHARED_IMPL_SCOPED_RESOURCE_H_
   7
   8 #include "ppapi/c/pp_resource.h"
   9 #include "ppapi/shared_impl/ppapi_shared_export.h"
  10
  11 namespace ppapi {
  12
  13 class Resource;
  14
  15 // This is a version of scoped_refptr but for PP_Resources.
  16 class PPAPI_SHARED_EXPORT ScopedPPResource {
  17  public:
  18   struct PassRef {};
  19
  20   ScopedPPResource();
  21
  22   // Takes one reference to the given resource.
  23   explicit ScopedPPResource(PP_Resource resource);
  24
  25   // Assumes responsibility for one ref that the resource already has.
  26   explicit ScopedPPResource(const PassRef&, PP_Resource resource);
  27
  28   // Helper to get the PP_Resource out of the given object and take a reference
  29   // to it.
  30   explicit ScopedPPResource(Resource* resource);
  31
  32   // Implicit copy constructor allowed.
  33   ScopedPPResource(const ScopedPPResource& other);
  34
  35   ~ScopedPPResource();
  36
  37   ScopedPPResource& operator=(PP_Resource resource);
  38   ScopedPPResource& operator=(const ScopedPPResource& resource);
  39
  40   // Returns the PP_Resource without affecting the refcounting.
  41   PP_Resource get() const { return id_; }
  42   operator PP_Resource() const { return id_; }
  43
  44   // Returns the PP_Resource, passing the reference to the caller. This class
  45   // will no longer hold the resource.
  46   PP_Resource Release();
  47
  48  private:
  49   // Helpers to addref or release the id_ if it's non-NULL. The id_ value will
  50   // be unchanged.
  51   void CallAddRef();
  52   void CallRelease();
  53
  54   PP_Resource id_;
  55 };
  56
  57 }  // namespace ppapi
  58
  59 #endif  // PPAPI_SHARED_IMPL_SCOPED_RESOURCE_H_