Files
pilotclient/src/blackcore/token_bucket.h
2015-05-05 21:34:28 +02:00

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2.4 KiB
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/* 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.
*/
#ifndef BLACKCORE_TOKENBUCKET_H
#define BLACKCORE_TOKENBUCKET_H
#include "blackcoreexport.h"
#include "blackmisc/pq/time.h"
#include <QtGlobal>
#include <QDateTime>
namespace BlackCore
{
/*!
* Token bucket algorithm
*
* This class implements the token bucket algorithm. Tokens as arbitrary unit are added to the bucket at a defined rate.
* Token can be consumsed as long as there are enough available. This class can be used to throttle traffic and packet
* generation. Each time a packet needs to be generated and sent a token is consumed. If no token is available, consumption
* will fail the the packet cannot be sent.
*/
class BLACKCORE_EXPORT CTokenBucket
{
public:
//! Constructor
//! \tparam Replenishment policy
CTokenBucket(int capacity, BlackMisc::PhysicalQuantities::CTime interval, int numTokensToRefill)
: m_capacity(capacity), m_interval(interval), m_numTokensToRefill(numTokensToRefill) {}
//! Try to consume a token
bool tryConsume()
{
return tryConsume(1);
}
//! Try to consume a number of tokens
bool tryConsume(int numTokens);
private:
//! Get available tokens since last replenishment.
// Note that replenishment is implemented lazy. This means, tokens will not replenished
// on regular basis via a running timer, but they will be replenished while trying to consume
// them.
int getTokens();
int m_capacity = 10; //!< Maximum capacity of tokens
int m_availableTokens = 10; //!< Currently available tokens. The initial value is 10
BlackMisc::PhysicalQuantities::CTime m_interval; //!< Refill interval, e.g. every 5 secs
int m_numTokensToRefill; //!< Number of tokens to be refilled each interval
QDateTime m_lastReplenishmentTime = QDateTime::currentDateTime(); //!< Last time
};
}
#endif