ppapi/shared_impl/host_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_HOST_RESOURCE_H_
   6 #define PPAPI_SHARED_IMPL_HOST_RESOURCE_H_
   7
   8 #include "ppapi/c/pp_instance.h"
   9 #include "ppapi/c/pp_resource.h"
  10 #include "ppapi/shared_impl/ppapi_shared_export.h"
  11
  12 namespace ppapi {
  13
  14 // Represents a PP_Resource sent over the wire. This just wraps a PP_Resource.
  15 // The point is to prevent mistakes where the wrong resource value is sent.
  16 // Resource values are remapped in the plugin so that it can talk to multiple
  17 // hosts. If all values were PP_Resource, it would be easy to forget to do
  18 // this transformation.
  19 //
  20 // To get the corresponding plugin PP_Resource for a HostResource, use
  21 // PluginResourceTracker::PluginResourceForHostResource().
  22 //
  23 // All HostResources respresent IDs valid in the host.
  24 class PPAPI_SHARED_EXPORT HostResource {
  25  public:
  26   HostResource();
  27
  28   bool is_null() const {
  29     return !host_resource_;
  30   }
  31
  32   // Some resources are plugin-side only and don't have a corresponding
  33   // resource in the host. Yet these resources still need an instance to be
  34   // associated with. This function creates a HostResource with the given
  35   // instances and a 0 host resource ID for these cases.
  36   static HostResource MakeInstanceOnly(PP_Instance instance);
  37
  38   // Sets and retrieves the internal PP_Resource which is valid for the host
  39   // (a.k.a. renderer, as opposed to the plugin) process.
  40   //
  41   // DO NOT CALL THESE FUNCTIONS IN THE PLUGIN SIDE OF THE PROXY. The values
  42   // will be invalid. See the class comment above.
  43   void SetHostResource(PP_Instance instance, PP_Resource resource);
  44   PP_Resource host_resource() const {
  45     return host_resource_;
  46   }
  47
  48   PP_Instance instance() const { return instance_; }
  49
  50   // This object is used in maps so we need to provide this sorting operator.
  51   bool operator<(const HostResource& other) const {
  52     if (instance_ != other.instance_)
  53       return instance_ < other.instance_;
  54     return host_resource_ < other.host_resource_;
  55   }
  56
  57  private:
  58   PP_Instance instance_;
  59   PP_Resource host_resource_;
  60 };
  61
  62 }  // namespace ppapi
  63
  64 #endif  // PPAPI_SHARED_IMPL_HOST_RESOURCE_H_