BtBitfieldMessage.cc

/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2006 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 --> */
#include "BtBitfieldMessage.h"

#include <cstring>

#include "bittorrent_helper.h"
#include "util.h"
#include "DlAbortEx.h"
#include "message.h"
#include "Peer.h"
#include "PieceStorage.h"
#include "a2functional.h"

namespace aria2 {

const char BtBitfieldMessage::NAME[] = "bitfield";

BtBitfieldMessage::BtBitfieldMessage()
    : SimpleBtMessage(ID, NAME), bitfieldLength_(0)
{
}

BtBitfieldMessage::BtBitfieldMessage(const unsigned char* bitfield,
                                     size_t bitfieldLength)
    : SimpleBtMessage(ID, NAME), bitfieldLength_(0)
{
  setBitfield(bitfield, bitfieldLength);
}

BtBitfieldMessage::~BtBitfieldMessage() {}

void BtBitfieldMessage::setBitfield(const unsigned char* bitfield,
                                    size_t bitfieldLength)
{
  if (bitfield_.get() == bitfield) {
    return;
  }

  bitfieldLength_ = bitfieldLength;
  bitfield_ = make_unique<unsigned char[]>(bitfieldLength_);
  memcpy(bitfield_.get(), bitfield, bitfieldLength_);
}

std::unique_ptr<BtBitfieldMessage>
BtBitfieldMessage::create(const unsigned char* data, size_t dataLength)
{
  bittorrent::assertPayloadLengthGreater(1, dataLength, NAME);
  bittorrent::assertID(ID, data, NAME);
  auto message = make_unique<BtBitfieldMessage>();
  message->setBitfield(data + 1, dataLength - 1);
  return message;
}

void BtBitfieldMessage::doReceivedAction()
{
  if (isMetadataGetMode()) {
    return;
  }
  getPieceStorage()->updatePieceStats(bitfield_.get(), bitfieldLength_,
                                      getPeer()->getBitfield());
  getPeer()->setBitfield(bitfield_.get(), bitfieldLength_);
  if (getPeer()->isSeeder() && getPieceStorage()->downloadFinished()) {
    throw DL_ABORT_EX(MSG_GOOD_BYE_SEEDER);
  }
}

unsigned char* BtBitfieldMessage::createMessage()
{
  /**
   * len --- 1+bitfieldLength, 4bytes
   * id --- 5, 1byte
   * bitfield --- bitfield, bitfieldLength bytes
   * total: 5+bitfieldLength bytes
   */
  const size_t msgLength = 5 + bitfieldLength_;
  auto msg = new unsigned char[msgLength];
  bittorrent::createPeerMessageString(msg, msgLength, 1 + bitfieldLength_, ID);
  memcpy(msg + 5, bitfield_.get(), bitfieldLength_);
  return msg;
}

size_t BtBitfieldMessage::getMessageLength() { return 5 + bitfieldLength_; }

std::string BtBitfieldMessage::toString() const
{
  std::string s = NAME;
  s += " ";
  s += util::toHex(bitfield_.get(), bitfieldLength_);
  return s;
}

} // namespace aria2