/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2011 Tatsuhiro Tsujikawa
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 * You must obey the GNU General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
 * version of the file(s), but you are not obligated to do so.  If you
 * do not wish to do so, delete this exception statement from your
 * version.  If you delete this exception statement from all source
 * files in the program, then also delete it here.
 */
/* copyright --> */
#ifndef D_SOCKET_RECV_BUFFER_H
#define D_SOCKET_RECV_BUFFER_H

#include "common.h"

#include <memory>
#include <array>

#include "a2functional.h"

namespace aria2 {

class SocketCore;

class SocketRecvBuffer {
public:
  SocketRecvBuffer(std::shared_ptr<SocketCore> socket);
  ~SocketRecvBuffer();
  // Reads data from socket as much as capacity allows. Returns the
  // number of bytes read.
  ssize_t recv();
  // Truncates the contents of buffer to 0.
  void truncateBuffer();
  // Drains first n bytes of data from buffer.  It is an programmer's
  // responsibility to ensure that n is smaller or equal to the
  // buffered data.
  void drain(size_t n);

  const std::shared_ptr<SocketCore>& getSocket() const { return socket_; }

  const unsigned char* getBuffer() const { return pos_; }

  size_t getBufferLength() const { return last_ - pos_; }

  bool bufferEmpty() const { return pos_ == last_; }

private:
  std::array<unsigned char, 16_k> buf_;
  std::shared_ptr<SocketCore> socket_;
  unsigned char* pos_;
  unsigned char* last_;
};

} // namespace aria2

#endif // D_SOCKET_RECV_BUFFER_H