syndilights/open-lighting-architecture/ola-0.8.4/common/utils/TokenBucket.cpp

55 lines
1.6 KiB
C++

/*
* 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 Library 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* TokenBucket.cpp
* Token Bucket implementation.
* Copyright (C) 2010 Simon Newton
*/
#include <algorithm>
#include "olad/TokenBucket.h"
namespace ola {
/*
* Check if we have enough tokens for an operation. Assuming there is enough
* tokens, the count is decremented by one.
* @param now the current time
* @returns true if there is enough tokens, false otherwise
*/
bool TokenBucket::GetToken(const TimeStamp &now) {
Count(now);
if (m_count > 0) {
m_count--;
return true;
}
return false;
}
/*
* Get the number of tokens in the bucket
*/
unsigned int TokenBucket::Count(const TimeStamp &now) {
int64_t delta = (now - m_last).AsInt();
unsigned int tokens = delta * m_rate / USEC_IN_SECONDS;
m_count = std::min(m_max, m_count + tokens);
if (tokens)
m_last += ola::TimeInterval(tokens * USEC_IN_SECONDS / m_rate);
return m_count;
}
} // ola