src/content/renderer/pepper/host_var_tracker.h

   1 // Copyright (c) 2012 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 CONTENT_RENDERER_PEPPER_HOST_VAR_TRACKER_H_
   6 #define CONTENT_RENDERER_PEPPER_HOST_VAR_TRACKER_H_
   7
   8 #include <map>
   9
  10 #include "base/basictypes.h"
  11 #include "base/compiler_specific.h"
  12 #include "base/containers/hash_tables.h"
  13 #include "base/gtest_prod_util.h"
  14 #include "base/memory/linked_ptr.h"
  15 #include "base/memory/ref_counted.h"
  16 #include "content/common/content_export.h"
  17 #include "ppapi/c/pp_instance.h"
  18 #include "ppapi/shared_impl/host_resource.h"
  19 #include "ppapi/shared_impl/resource_tracker.h"
  20 #include "ppapi/shared_impl/var_tracker.h"
  21
  22 typedef struct NPObject NPObject;
  23
  24 namespace ppapi {
  25 class ArrayBufferVar;
  26 class NPObjectVar;
  27 class Var;
  28 }
  29
  30 namespace content {
  31
  32 // Adds NPObject var tracking to the standard PPAPI VarTracker for use in the
  33 // renderer.
  34 class HostVarTracker : public ppapi::VarTracker {
  35  public:
  36   HostVarTracker();
  37   virtual ~HostVarTracker();
  38
  39   // Tracks all live NPObjectVar. This is so we can map between instance +
  40   // NPObject and get the NPObjectVar corresponding to it. This Add/Remove
  41   // function is called by the NPObjectVar when it is created and
  42   // destroyed.
  43   void AddNPObjectVar(ppapi::NPObjectVar* object_var);
  44   void RemoveNPObjectVar(ppapi::NPObjectVar* object_var);
  45
  46   // Looks up a previously registered NPObjectVar for the given NPObject and
  47   // instance. Returns NULL if there is no NPObjectVar corresponding to the
  48   // given NPObject for the given instance. See AddNPObjectVar above.
  49   ppapi::NPObjectVar* NPObjectVarForNPObject(PP_Instance instance,
  50                                              NPObject* np_object);
  51
  52   // Returns the number of NPObjectVar's associated with the given instance.
  53   // Returns 0 if the instance isn't known.
  54   CONTENT_EXPORT int GetLiveNPObjectVarsForInstance(
  55       PP_Instance instance) const;
  56
  57   // VarTracker public implementation.
  58   virtual PP_Var MakeResourcePPVarFromMessage(
  59       PP_Instance instance,
  60       const IPC::Message& creation_message,
  61       int pending_renderer_id,
  62       int pending_browser_id) OVERRIDE;
  63   virtual ppapi::ResourceVar* MakeResourceVar(PP_Resource pp_resource) OVERRIDE;
  64   virtual void DidDeleteInstance(PP_Instance instance) OVERRIDE;
  65
  66   virtual int TrackSharedMemoryHandle(PP_Instance instance,
  67                                       base::SharedMemoryHandle file,
  68                                       uint32 size_in_bytes) OVERRIDE;
  69   virtual bool StopTrackingSharedMemoryHandle(int id,
  70                                               PP_Instance instance,
  71                                               base::SharedMemoryHandle* handle,
  72                                               uint32* size_in_bytes) OVERRIDE;
  73
  74  private:
  75   // VarTracker private implementation.
  76   virtual ppapi::ArrayBufferVar* CreateArrayBuffer(
  77       uint32 size_in_bytes) OVERRIDE;
  78   virtual ppapi::ArrayBufferVar* CreateShmArrayBuffer(
  79       uint32 size_in_bytes, base::SharedMemoryHandle handle) OVERRIDE;
  80
  81   // Clear the reference count of the given object and remove it from
  82   // live_vars_.
  83   void ForceReleaseNPObject(ppapi::NPObjectVar* object_var);
  84
  85   typedef std::map<NPObject*, ppapi::NPObjectVar*> NPObjectToNPObjectVarMap;
  86
  87   // Lists all known NPObjects, first indexed by the corresponding instance,
  88   // then by the NPObject*. This allows us to look up an NPObjectVar given
  89   // these two pieces of information.
  90   //
  91   // The instance map is lazily managed, so we'll add the
  92   // NPObjectToNPObjectVarMap lazily when the first NPObject var is created,
  93   // and delete it when it's empty.
  94   typedef std::map<PP_Instance, linked_ptr<NPObjectToNPObjectVarMap> >
  95       InstanceMap;
  96   InstanceMap instance_map_;
  97
  98   // Tracks all shared memory handles used for transmitting array buffers.
  99   struct SharedMemoryMapEntry {
 100     PP_Instance instance;
 101     base::SharedMemoryHandle handle;
 102     uint32 size_in_bytes;
 103   };
 104   typedef std::map<int, SharedMemoryMapEntry> SharedMemoryMap;
 105   SharedMemoryMap shared_memory_map_;
 106   uint32_t last_shared_memory_map_id_;
 107
 108   DISALLOW_COPY_AND_ASSIGN(HostVarTracker);
 109 };
 110
 111 }  // namespace content
 112
 113 #endif  // CONTENT_RENDERER_PEPPER_HOST_VAR_TRACKER_H_