Refactor ChildProcess and related classes to create a framework outside of br...

chrome/common/message_router.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_MESSAGE_ROUTER_H__
-#define CHROME_COMMON_MESSAGE_ROUTER_H__
-
-#include "base/id_map.h"
-#include "ipc/ipc_channel.h"
-
-// The MessageRouter handles all incoming messages sent to it by routing them
-// to the correct listener.  Routing is based on the Message's routing ID.
-// Since routing IDs are typically assigned asynchronously by the browser
-// process, the MessageRouter has the notion of pending IDs for listeners that
-// have not yet been assigned a routing ID.
-//
-// When a message arrives, the routing ID is used to index the set of routes to
-// find a listener.  If a listener is found, then the message is passed to it.
-// Otherwise, the message is ignored if its routing ID is not equal to
-// MSG_ROUTING_CONTROL.
-//
-// The MessageRouter supports the IPC::Message::Sender interface for outgoing
-// messages, but does not define a meaningful implementation of it.  The
-// subclass of MessageRouter is intended to provide that if appropriate.
-//
-// The MessageRouter can be used as a concrete class provided its Send method
-// is not called and it does not receive any control messages.
-
-class MessageRouter : public IPC::Channel::Listener,
-                      public IPC::Message::Sender {
- public:
-  MessageRouter() {}
-  virtual ~MessageRouter() {}
-
-  // Implemented by subclasses to handle control messages
-  virtual void OnControlMessageReceived(const IPC::Message& msg);
-
-  // IPC::Channel::Listener implementation:
-  virtual void OnMessageReceived(const IPC::Message& msg);
-
-  // Like OnMessageReceived, except it only handles routed messages.  Returns
-  // true if the message was dispatched, or false if there was no listener for
-  // that route id.
-  virtual bool RouteMessage(const IPC::Message& msg);
-
-  // IPC::Message::Sender implementation:
-  virtual bool Send(IPC::Message* msg);
-
-  // Called to add/remove a listener for a particular message routing ID.
-  void AddRoute(int32 routing_id, IPC::Channel::Listener* listener);
-  void RemoveRoute(int32 routing_id);
-
-  IPC::Channel::Listener* ResolveRoute(int32 routing_id);
-
- private:
-  // A list of all listeners with assigned routing IDs.
-  IDMap<IPC::Channel::Listener> routes_;
-
-  DISALLOW_COPY_AND_ASSIGN(MessageRouter);
-};
-
-#endif  // CHROME_COMMON_MESSAGE_ROUTER_H__