content/renderer/pepper/pepper_in_process_router.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 #include "base/callback.h"
   6 #include "base/basictypes.h"
   7 #include "base/memory/scoped_ptr.h"
   8 #include "base/memory/weak_ptr.h"
   9 #include "ppapi/c/pp_instance.h"
  10 #include "ppapi/proxy/connection.h"
  11 #include "ppapi/proxy/resource_message_params.h"
  12
  13 namespace IPC {
  14 class Message;
  15 class MessageReplyDeserializer;
  16 }  // namespace
  17
  18 namespace content {
  19
  20 class RendererPpapiHostImpl;
  21
  22 // This class fakes an IPC channel so that we can take the new resources with
  23 // IPC backends and run them in-process.
  24 //
  25 // (See pepper_in_process_resource_creation.h for more background.)
  26 //
  27 // This class just provides the fake routing for in-process plugins.
  28 // Asynchronous messages are converted into an asynchronous execution of the
  29 // message receiver on the opposite end. Synchronous messages just call right
  30 // through.
  31 //
  32 // The resources in ppapi/proxy assume that there is an IPC connection to
  33 // both the renderer and the browser processes. They take a connection object
  34 // that includes both of these channels. However, in-process plugins don't
  35 // have a BrowserPpapiHost on the browser side to receive these messages.
  36 //
  37 // As a result, we can't support resources that rely on sending messages to the
  38 // browser process. Since this class is a stopgap until all interfaces are
  39 // converted and all plugins are run out-of-procss, we just choose not to
  40 // support faking IPC channels for resources that send messages directly to the
  41 // browser process. These resources will just have to use the "old" in-process
  42 // implementation until the conversion is complete and all this code can be
  43 // deleted.
  44 //
  45 // To keep things consistent, we provide an IPC::Sender for the browser channel
  46 // in the connection object supplied to resources. This dummy browser channel
  47 // will just assert and delete the message if anything is ever sent over it.
  48 //
  49 // There are two restrictions for in-process resource calls:
  50 // Sync messages can only be sent from the plugin to the host.
  51 // The host must handle sync messages synchronously.
  52 class PepperInProcessRouter {
  53  public:
  54   // The given host parameter owns this class and must outlive us.
  55   PepperInProcessRouter(RendererPpapiHostImpl* host_impl);
  56   ~PepperInProcessRouter();
  57
  58   // Returns the dummy sender for the cooresponding end of the in-process
  59   // emulated channel.
  60   IPC::Sender* GetPluginToRendererSender();
  61   IPC::Sender* GetRendererToPluginSender();
  62
  63   // Returns a connection pair for use by a resource proxy. This includes
  64   // the plugin->renderer sender as well as a dummy sender to the browser
  65   // process. See the class comment above about the dummy sender.
  66   ppapi::proxy::Connection GetPluginConnection(PP_Instance instance);
  67
  68   // Handles resource reply messages from the host.
  69   static bool OnPluginMsgReceived(const IPC::Message& msg);
  70
  71  private:
  72   bool SendToHost(IPC::Message* msg);
  73   bool SendToPlugin(IPC::Message* msg);
  74   void DispatchHostMsg(IPC::Message* msg);
  75   void DispatchPluginMsg(IPC::Message* msg);
  76   bool SendToBrowser(IPC::Message* msg);
  77
  78   RendererPpapiHostImpl* host_impl_;
  79
  80   class Channel;
  81   scoped_ptr<Channel> browser_channel_;
  82
  83   // Renderer -> plugin channel.
  84   scoped_ptr<Channel> host_to_plugin_router_;
  85
  86   // Plugin -> renderer channel.
  87   scoped_ptr<Channel> plugin_to_host_router_;
  88
  89   // Pending sync message id.
  90   int pending_message_id_;
  91
  92   // Reply deserializer of the pending sync message.
  93   scoped_ptr<IPC::MessageReplyDeserializer> reply_deserializer_;
  94
  95   // Reply result of the pending sync message.
  96   bool reply_result_;
  97
  98   base::WeakPtrFactory<PepperInProcessRouter> weak_factory_;
  99
 100   DISALLOW_COPY_AND_ASSIGN(PepperInProcessRouter);
 101 };
 102
 103 }  // namespace content