base/asyncsocket.h

/*
 * libjingle
 * Copyright 2004--2010, Google Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef TALK_BASE_ASYNCSOCKET_H_
#define TALK_BASE_ASYNCSOCKET_H_

#include "talk/base/common.h"
#include "talk/base/sigslot.h"
#include "talk/base/socket.h"

namespace talk_base {

// TODO: Remove Socket and rename AsyncSocket to Socket.

// Provides the ability to perform socket I/O asynchronously.
class AsyncSocket : public Socket {
 public:
  AsyncSocket();
  virtual ~AsyncSocket();

  virtual AsyncSocket* Accept(SocketAddress* paddr) = 0;

  // SignalReadEvent and SignalWriteEvent use multi_threaded_local to allow
  // access concurrently from different thread.
  // For example SignalReadEvent::connect will be called in AsyncUDPSocket ctor
  // but at the same time the SocketDispatcher maybe signaling the read event.
  // ready to read
  sigslot::signal1<AsyncSocket*,
                   sigslot::multi_threaded_local> SignalReadEvent;
  // ready to write
  sigslot::signal1<AsyncSocket*,
                   sigslot::multi_threaded_local> SignalWriteEvent;
  sigslot::signal1<AsyncSocket*> SignalConnectEvent;     // connected
  sigslot::signal2<AsyncSocket*, int> SignalCloseEvent;  // closed
};

class AsyncSocketAdapter : public AsyncSocket, public sigslot::has_slots<> {
 public:
  // The adapted socket may explicitly be NULL, and later assigned using Attach.
  // However, subclasses which support detached mode must override any methods
  // that will be called during the detached period (usually GetState()), to
  // avoid dereferencing a null pointer.
  explicit AsyncSocketAdapter(AsyncSocket* socket);
  virtual ~AsyncSocketAdapter();
  void Attach(AsyncSocket* socket);
  virtual SocketAddress GetLocalAddress() const {
    return socket_->GetLocalAddress();
  }
  virtual SocketAddress GetRemoteAddress() const {
    return socket_->GetRemoteAddress();
  }
  virtual int Bind(const SocketAddress& addr) {
    return socket_->Bind(addr);
  }
  virtual int Connect(const SocketAddress& addr) {
    return socket_->Connect(addr);
  }
  virtual int Send(const void* pv, size_t cb) {
    return socket_->Send(pv, cb);
  }
  virtual int SendTo(const void* pv, size_t cb, const SocketAddress& addr) {
    return socket_->SendTo(pv, cb, addr);
  }
  virtual int Recv(void* pv, size_t cb) {
    return socket_->Recv(pv, cb);
  }
  virtual int RecvFrom(void* pv, size_t cb, SocketAddress* paddr) {
    return socket_->RecvFrom(pv, cb, paddr);
  }
  virtual int Listen(int backlog) {
    return socket_->Listen(backlog);
  }
  virtual AsyncSocket* Accept(SocketAddress* paddr) {
    return socket_->Accept(paddr);
  }
  virtual int Close() {
    return socket_->Close();
  }
  virtual int GetError() const {
    return socket_->GetError();
  }
  virtual void SetError(int error) {
    return socket_->SetError(error);
  }
  virtual ConnState GetState() const {
    return socket_->GetState();
  }
  virtual int EstimateMTU(uint16* mtu) {
    return socket_->EstimateMTU(mtu);
  }
  virtual int GetOption(Option opt, int* value) {
    return socket_->GetOption(opt, value);
  }
  virtual int SetOption(Option opt, int value) {
    return socket_->SetOption(opt, value);
  }

 protected:
  virtual void OnConnectEvent(AsyncSocket* socket) {
    SignalConnectEvent(this);
  }
  virtual void OnReadEvent(AsyncSocket* socket) {
    SignalReadEvent(this);
  }
  virtual void OnWriteEvent(AsyncSocket* socket) {
    SignalWriteEvent(this);
  }
  virtual void OnCloseEvent(AsyncSocket* socket, int err) {
    SignalCloseEvent(this, err);
  }

  AsyncSocket* socket_;
};

}  // namespace talk_base

#endif  // TALK_BASE_ASYNCSOCKET_H_