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