Files
pilotclient/src/blackmisc/tokenbucket.cpp
Mathew Sutcliffe 2f54e00d65 Ref T184 Minor optimization in CTokenBucket: avoid converting interval to seconds
every time a token is consumed, by doing the conversion once in the constructor.
2017-11-12 13:48:05 +00:00

62 lines
2.0 KiB
C++

/* Copyright (C) 2014
* swift project Community / Contributors
*
* This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
* directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
* including this file, may be copied, modified, propagated, or distributed except according to the terms
* contained in the LICENSE file.
*/
#include "blackmisc/tokenbucket.h"
#include "blackmisc/pq/units.h"
#include <QtGlobal>
using namespace BlackMisc::PhysicalQuantities;
namespace BlackMisc
{
CTokenBucket::CTokenBucket(int capacity, const CTime &interval, int numTokensToRefill)
: m_capacity(capacity), m_intervalSecs(interval.value(CTimeUnit::s())), m_numTokensToRefill(numTokensToRefill) {}
bool CTokenBucket::tryConsume(int numTokens)
{
Q_ASSERT(numTokens > 0 && numTokens < m_capacity);
// Replenish maximal up to capacity
int replenishedTokens = qMin(m_capacity, getTokens());
// Take care of overflows
m_availableTokens = qMin(m_availableTokens + replenishedTokens, m_capacity);
if (numTokens <= m_availableTokens)
{
m_availableTokens -= numTokens;
return true;
}
return false;
}
void CTokenBucket::setNumberOfTokensToRefill(int noTokens)
{
m_numTokensToRefill = noTokens;
}
void CTokenBucket::setCapacity(int capacity)
{
m_capacity = capacity;
}
int CTokenBucket::getTokens()
{
const auto now = QDateTime::currentDateTime();
const auto deltaSeconds = m_lastReplenishmentTime.secsTo(now);
const int numberOfTokens = static_cast<int>(m_numTokensToRefill * deltaSeconds / m_intervalSecs);
// Update the time only when replenishment actually took place. We will end up in a infinite loop otherwise.
if (numberOfTokens > 0) { m_lastReplenishmentTime = now; }
return numberOfTokens;
}
} // namespace