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/* <!-- 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 "SpeedCalc.h"
#include <algorithm>
#include <functional>
#include "wallclock.h"
namespace aria2 {
namespace {
constexpr auto WINDOW_TIME = 15_s;
} // namespace
SpeedCalc::SpeedCalc()
: accumulatedLength_(0),
bytesWindow_(0),
maxSpeed_(0)
{}
void SpeedCalc::reset()
{
timeSlots_.clear();
start_ = global::wallclock();
accumulatedLength_ = 0;
bytesWindow_ = 0;
maxSpeed_ = 0;
}
void SpeedCalc::removeStaleTimeSlot(const Timer& now)
{
while(!timeSlots_.empty()) {
if(timeSlots_[0].first.difference(now) <= WINDOW_TIME) {
break;
}
bytesWindow_ -= timeSlots_[0].second;
timeSlots_.pop_front();
}
}
int SpeedCalc::calculateSpeed()
{
const auto& now = global::wallclock();
removeStaleTimeSlot(now);
if(timeSlots_.empty()) {
return 0;
}
auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(
timeSlots_[0].first.difference(now)).count();
if(elapsed <= 0) {
elapsed = 1;
}
int speed = bytesWindow_*1000/elapsed;
maxSpeed_ = std::max(speed, maxSpeed_);
return speed;
}
void SpeedCalc::update(size_t bytes)
{
const auto& now = global::wallclock();
removeStaleTimeSlot(now);
if(timeSlots_.empty() ||
std::chrono::duration_cast<std::chrono::seconds>(
timeSlots_.back().first.difference(now)) >= 1_s) {
timeSlots_.push_back(std::make_pair(now, bytes));
} else {
timeSlots_.back().second += bytes;
}
bytesWindow_ += bytes;
accumulatedLength_ += bytes;
}
int SpeedCalc::calculateAvgSpeed() const
{
auto milliElapsed = std::chrono::duration_cast<std::chrono::milliseconds>(
start_.difference(global::wallclock())).count();
// if milliElapsed is too small, the average speed is rubbish, better
// return 0
if(milliElapsed > 4) {
int speed = accumulatedLength_*1000/milliElapsed;
return speed;
} else {
return 0;
}
}
} // namespace aria2
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