// 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 NET_SOCKET_SOCKET_H_
#define NET_SOCKET_SOCKET_H_
#pragma once

#include "net/base/completion_callback.h"

namespace net {

class IOBuffer;

// Represents a read/write socket.
class Socket {
 public:
  virtual ~Socket() {}

  // Reads data, up to buf_len bytes, from the socket.  The number of bytes read
  // is returned, or an error is returned upon failure.  Zero is returned once
  // to indicate end-of-file; subsequent calls return ERR_CONNECTION_CLOSED.
  // ERR_IO_PENDING is returned if the operation could not be completed
  // synchronously, in which case the result will be passed to the callback when
  // available. If the operation is not completed immediately, the socket
  // acquires a reference to the provided buffer until the callback is invoked
  // or the socket is destroyed.  If the socket is closed before the read
  // completes, the callback will not be invoked.
  virtual int Read(IOBuffer* buf, int buf_len,
                   CompletionCallback* callback) = 0;

  // Writes data, up to buf_len bytes, to the socket.  Note: only part of the
  // data may be written!  The number of bytes written is returned, or an error
  // is returned upon failure.  ERR_CONNECTION_CLOSED is returned if the
  // operation is attempted on a closed socket.  ERR_IO_PENDING is returned if
  // the operation could not be completed synchronously, in which case the
  // result will be passed to the callback when available. If the operation is
  // not completed immediately, the socket acquires a reference to the provided
  // buffer until the callback is invoked or the socket is destroyed.
  // Implementations of this method should not modify the contents of the actual
  // buffer that is written to the socket.  If the socket is closed before the
  // write completes, the callback will not be invoked.
  virtual int Write(IOBuffer* buf, int buf_len,
                    CompletionCallback* callback) = 0;

  // Set the receive buffer size (in bytes) for the socket.
  // Note: changing this value can effect the TCP window size on some platforms.
  // Returns true on success, or false on failure.
  virtual bool SetReceiveBufferSize(int32 size) = 0;

  // Set the send buffer size (in bytes) for the socket.
  // Note: changing this value can effect the TCP window size on some platforms.
  // Returns true on success, or false on failure.
  virtual bool SetSendBufferSize(int32 size) = 0;
};

}  // namespace net

#endif  // NET_SOCKET_SOCKET_H_