ppapi/proxy/message_handler.h

   1 // Copyright 2014 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_PROXY_MESSAGE_HANDLER_H_
   6 #define PPAPI_PROXY_MESSAGE_HANDLER_H_
   7
   8 #include "base/memory/ref_counted.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "ppapi/c/dev/ppb_messaging_deprecated.h"
  11 #include "ppapi/c/pp_resource.h"
  12 #include "ppapi/c/ppp_message_handler.h"
  13 #include "ppapi/proxy/ppapi_proxy_export.h"
  14
  15 namespace IPC {
  16 class Message;
  17 }
  18
  19 namespace ppapi {
  20
  21 class ScopedPPVar;
  22
  23 namespace proxy {
  24
  25 class MessageLoopResource;
  26
  27 // MessageHandler wraps a PPP_MessageHandler to encapsulate calling methods
  28 // on the right thread and calling the Destroy function when this
  29 // MessageHandler is destroyed.
  30 class PPAPI_PROXY_EXPORT MessageHandler {
  31  public:
  32   // Create a MessageHandler. If any parameters are invalid, it will return a
  33   // null scoped_ptr and set |*error| appropriately.
  34   // |handler_if| is the struct of function pointers we will invoke. All of
  35   //              the function pointers within must be valid, or we fail
  36   //              with PP_ERROR_BADARGUMENT.
  37   // |user_data| is a pointer provided by the plugin that we pass back when we
  38   //             call functions in |handler_if|.
  39   // |message_loop| is the message loop where we will invoke functions in
  40   //                |handler_if|. Must not be the main thread message loop,
  41   //                to try to force the plugin to not over-subscribe the main
  42   //                thread. If it's the main thread loop, |error| will be set
  43   //                to PP_ERROR_WRONGTHREAD.
  44   // |error| is an out-param that will be set on failure.
  45   static scoped_ptr<MessageHandler> Create(
  46       PP_Instance instance,
  47       const PPP_MessageHandler_0_2* handler_if,
  48       void* user_data,
  49       PP_Resource message_loop,
  50       int32_t* error);
  51   // Provide temporary backwards compatibility. TODO(dmichael): Remove all
  52   // references to PPB_Messaging_1_1 and PPP_MessageHandler_0_1.
  53   // crbug.com/414398
  54   static scoped_ptr<MessageHandler> CreateDeprecated(
  55       PP_Instance instance,
  56       const PPP_MessageHandler_0_1_Deprecated* handler_if,
  57       void* user_data,
  58       PP_Resource message_loop,
  59       int32_t* error);
  60   ~MessageHandler();
  61
  62   bool LoopIsValid() const;
  63
  64   void HandleMessage(ScopedPPVar var);
  65   void HandleBlockingMessage(ScopedPPVar var,
  66                              scoped_ptr<IPC::Message> reply_msg);
  67
  68  private:
  69   MessageHandler(PP_Instance instance,
  70                  const PPP_MessageHandler_0_2* handler_if,
  71                  void* user_data,
  72                  scoped_refptr<MessageLoopResource> message_loop);
  73   MessageHandler(PP_Instance instance,
  74                  const PPP_MessageHandler_0_1_Deprecated* handler_if,
  75                  void* user_data,
  76                  scoped_refptr<MessageLoopResource> message_loop);
  77
  78
  79   PP_Instance instance_;
  80   const PPP_MessageHandler_0_2* handler_if_;
  81   const PPP_MessageHandler_0_1_Deprecated* handler_if_0_1_;
  82   void* user_data_;
  83   scoped_refptr<MessageLoopResource> message_loop_;
  84
  85   DISALLOW_COPY_AND_ASSIGN(MessageHandler);
  86 };
  87
  88 }  // namespace proxy
  89 }  // namespace ppapi
  90
  91 #endif  // PPAPI_PROXY_MESSAGE_HANDLER_H_