Prevent an extra copy of data types that get passed into IPC messages when...

chrome/common/ipc_message_utils.h

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_COMMON_IPC_MESSAGE_UTILS_H_
 #define CHROME_COMMON_IPC_MESSAGE_UTILS_H_
 
 #include <string>
 #include <vector>
 #include <map>
@@ skipping 1043 matching lines @@
 
 
 //-----------------------------------------------------------------------------
 // Generic message subclasses
 
 // Used for asynchronous messages.
 template <class ParamType>
 class MessageWithTuple : public Message {
  public:
   typedef ParamType Param;
+  typedef typename ParamType::ParamTuple RefParam;
 
-  MessageWithTuple(int32 routing_id, uint16 type, const Param& p)
+  MessageWithTuple(int32 routing_id, uint16 type, const RefParam& p)
       : Message(routing_id, type, PRIORITY_NORMAL) {
     WriteParam(this, p);
   }
 
   static bool Read(const Message* msg, Param* p) {
     void* iter = NULL;
     bool rv = ReadParam(msg, &iter, p);
     DCHECK(rv) << "Error deserializing message " << msg->type();
     return rv;
   }
@@ skipping 10 matching lines @@
   }
 
   // The following dispatchers exist for the case where the callback function
   // needs the message as well.  They assume that "Param" is a type of Tuple
   // (except the one arg case, as there is no Tuple1).
   template<class T, typename TA>
   static bool Dispatch(const Message* msg, T* obj,
                        void (T::*func)(const Message&, TA)) {
     Param p;
     if (Read(msg, &p)) {
-      (obj->*func)(*msg, p);
+      (obj->*func)(*msg, p.a);
       return true;
     }
     return false;
   }
 
   template<class T, typename TA, typename TB>
   static bool Dispatch(const Message* msg, T* obj,
                        void (T::*func)(const Message&, TA, TB)) {
     Param p;
     if (Read(msg, &p)) {
@@ skipping 108 matching lines @@
 
 // defined in ipc_logging.cc
 void GenerateLogData(const std::wstring& channel, const Message& message,
                      LogData* data);
 
 // Used for synchronous messages.
 template <class SendParamType, class ReplyParamType>
 class MessageWithReply : public SyncMessage {
  public:
   typedef SendParamType SendParam;
+  typedef typename SendParam::ParamTuple RefSendParam;
   typedef ReplyParamType ReplyParam;
 
   MessageWithReply(int32 routing_id, uint16 type,
-                   const SendParam& send, const ReplyParam& reply)
+                   const RefSendParam& send, const ReplyParam& reply)
       : SyncMessage(routing_id, type, PRIORITY_NORMAL,
                     new ParamDeserializer<ReplyParam>(reply)) {
     WriteParam(this, send);
   }
 
   static void Log(const Message* msg, std::wstring* l) {
     if (msg->is_sync()) {
       SendParam p;
       void* iter = SyncMessage::GetDataIterator(msg);
       if (ReadParam(msg, &iter, &p))
@@ skipping 104 matching lines @@
     ReplyParam p(a, b, c, d, e);
     WriteParam(reply, p);
   }
 };
 
 //-----------------------------------------------------------------------------
 
 }  // namespace IPC
 
 #endif  // CHROME_COMMON_IPC_MESSAGE_UTILS_H_