aria2/src/StreamPieceSelector.h

72 lines
2.7 KiB
C++

/* <!-- 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_STREAM_PIECE_SELECTOR_H
#define D_STREAM_PIECE_SELECTOR_H
#include "common.h"
#include <cstdlib>
namespace aria2 {
// Select piece for HTTP/FTP download. For BitTorrent downloads, use
// PieceSelector interface.
class StreamPieceSelector {
public:
virtual ~StreamPieceSelector() {}
// Selected piece index will be stored in index. To ignore some
// piece indexes from selection, use ignoreBitfield and set
// corresponding bit. length is the number of byte of
// ignoreBitfield. The number of bits in ignoreBitfield must be
// equal to the number of blocks in BitfieldMan. If piece index is
// selected, returns true. Otherwise, returns false. minSplitSize
// is a advice to derived class not to select piece such which the
// distance between it and already selected piece is less than
// minSplitSize.
virtual bool select
(size_t& index,
size_t minSplitSize,
const unsigned char* ignoreBitfield,
size_t length) = 0;
// Called when initial bitfield was fixed. Optimize
// StreamPieceSelector to take advantages of the initial bitfield.
virtual void onBitfieldInit() = 0;
};
} // namespace aria2
#endif // D_STREAM_PIECE_SELECTOR_H