aria2/src/PieceStatMan.h

/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2009 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_PIECE_STAT_MAN_H
#define D_PIECE_STAT_MAN_H

#include "common.h"

#include <vector>

#include "SharedHandle.h"

namespace aria2 {

class PieceStat {
private:
  size_t order_;
  size_t index_;
  size_t count_;
public:
  PieceStat(size_t index);

  bool operator<(const PieceStat& pieceStat) const
  {
    if(count_ == pieceStat.count_) {
      return order_ < pieceStat.order_;
    } else {
      return count_ < pieceStat.count_;
    }
  }

  void addCount();
  void subCount();

  size_t getOrder() const
  {
    return order_;
  }

  void setOrder(size_t order)
  {
    order_ = order;
  }

  size_t getIndex() const
  {
    return index_;
  }

  size_t getCount() const
  {
    return count_;
  }

};

class PieceStatMan {
private:
  std::vector<SharedHandle<PieceStat> > pieceStats_;

  std::vector<size_t> sortedPieceStatIndexes_;
public:
  PieceStatMan(size_t pieceNum, bool randomShuffle);

  ~PieceStatMan();

  void addPieceStats(size_t index);

  void addPieceStats(const unsigned char* bitfield,
                     size_t bitfieldLength);
  
  void subtractPieceStats(const unsigned char* bitfield,
                          size_t bitfieldLength);

  void updatePieceStats(const unsigned char* newBitfield,
                        size_t newBitfieldLength,
                        const unsigned char* oldBitfield);

  // Returns piece index in rarest first order.
  const std::vector<size_t>& getRarerPieceIndexes() const
  {
    return sortedPieceStatIndexes_;
  }

  const std::vector<SharedHandle<PieceStat> >& getPieceStats() const
  {
    return pieceStats_;
  }

};

} // namespace aria2

#endif // D_PIECE_STAT_MAN_H