aria2/src/PieceStatMan.cc

122 lines
3.4 KiB
C++

/* <!-- 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 --> */
#include "PieceStatMan.h"
#include <limits>
#include <algorithm>
#include "SimpleRandomizer.h"
#include "bitfield.h"
namespace aria2 {
PieceStatMan::PieceStatMan(size_t pieceNum, bool randomShuffle):
order_(pieceNum),
counts_(pieceNum)
{
for(size_t i = 0; i < pieceNum; ++i) {
order_[i] = i;
}
// we need some randomness in ordering.
if(randomShuffle) {
std::random_shuffle(order_.begin(), order_.end(),
*(SimpleRandomizer::getInstance().get()));
}
}
PieceStatMan::~PieceStatMan() {}
namespace {
void inc(int& x)
{
if(x < std::numeric_limits<int>::max()) {
++x;
}
}
} // namespace
namespace {
void sub(int& x)
{
if(x > 0) {
--x;
}
}
} // namespace
void PieceStatMan::addPieceStats(const unsigned char* bitfield,
size_t bitfieldLength)
{
for(size_t i = 0, nbits = counts_.size(); i < nbits; ++i) {
if(bitfield::test(bitfield, nbits, i)) {
inc(counts_[i]);
}
}
}
void PieceStatMan::subtractPieceStats(const unsigned char* bitfield,
size_t bitfieldLength)
{
for(size_t i = 0, nbits = counts_.size(); i < nbits; ++i) {
if(bitfield::test(bitfield, nbits, i)) {
sub(counts_[i]);
}
}
}
void PieceStatMan::updatePieceStats(const unsigned char* newBitfield,
size_t newBitfieldLength,
const unsigned char* oldBitfield)
{
for(size_t i = 0, nbits = counts_.size(); i < nbits; ++i) {
bool inNew = bitfield::test(newBitfield, nbits, i);
bool inOld = bitfield::test(oldBitfield, nbits, i);
if(inNew) {
if(!inOld) {
inc(counts_[i]);
}
} else if(inOld) {
sub(counts_[i]);
}
}
}
void PieceStatMan::addPieceStats(size_t index)
{
inc(counts_[index]);
}
} // namespace aria2