content/browser/message_port_message_filter.h

// Copyright 2013 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 CONTENT_BROWSER_MESSAGE_PORT_MESSAGE_FILTER_H_
#define CONTENT_BROWSER_MESSAGE_PORT_MESSAGE_FILTER_H_

#include "base/callback.h"
#include "content/common/content_export.h"
#include "content/public/browser/browser_message_filter.h"

namespace content {

// Filter for MessagePort related IPC messages (creating and destroying a
// MessagePort, sending a message via a MessagePort etc).
class CONTENT_EXPORT MessagePortMessageFilter : public BrowserMessageFilter {
 public:
  typedef base::Callback<int(void)> NextRoutingIDCallback;

  // |next_routing_id| is owned by this object.  It can be used up until
  // OnChannelClosing.
  explicit MessagePortMessageFilter(const NextRoutingIDCallback& callback);

  // BrowserMessageFilter implementation.
  virtual void OnChannelClosing() OVERRIDE;
  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
  virtual void OnDestruct() const OVERRIDE;

  int GetNextRoutingID();

  // Updates message ports registered for |message_port_ids| and returns
  // new routing IDs for the updated ports via |new_routing_ids|.
  void UpdateMessagePortsWithNewRoutes(
      const std::vector<int>& message_port_ids,
      std::vector<int>* new_routing_ids);

 protected:
  // This is protected, so we can define sub classes for testing.
  virtual ~MessagePortMessageFilter();

 private:
  friend class BrowserThread;
  friend class base::DeleteHelper<MessagePortMessageFilter>;

  // Message handlers.
  void OnCreateMessagePort(int* route_id, int* message_port_id);

  // This is guaranteed to be valid until OnChannelClosing is invoked, and it's
  // not used after.
  NextRoutingIDCallback next_routing_id_;

  DISALLOW_IMPLICIT_CONSTRUCTORS(MessagePortMessageFilter);
};

}  // namespace content

#endif  // CONTENT_BROWSER_WORKER_MESSAGE_FILTER_H_