icinga2/lib/base/ringbuffer.cpp

90 lines
2.5 KiB
C++

/******************************************************************************
* Icinga 2 *
* Copyright (C) 2012 Icinga Development Team (http://www.icinga.org/) *
* *
* 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 St, Fifth Floor, Boston, MA 02110-1301, USA. *
******************************************************************************/
#include "i2-base.h"
using namespace icinga;
RingBuffer::RingBuffer(RingBuffer::SizeType slots)
: Object(), m_Slots(slots, 0), m_TimeValue(0)
{ }
/**
* @threadsafety Always.
*/
RingBuffer::SizeType RingBuffer::GetLength(void) const
{
ObjectLock olock(this);
return m_Slots.size();
}
/**
* @threadsafety Always.
*/
void RingBuffer::InsertValue(RingBuffer::SizeType tv, int num)
{
ObjectLock olock(this);
RingBuffer::SizeType offsetTarget = tv % m_Slots.size();
if (tv > m_TimeValue) {
RingBuffer::SizeType offset = m_TimeValue % m_Slots.size();
/* walk towards the target offset, resetting slots to 0 */
while (offset != offsetTarget) {
offset++;
if (offset >= m_Slots.size())
offset = 0;
m_Slots[offset] = 0;
}
m_TimeValue = tv;
}
m_Slots[offsetTarget] += num;
}
/**
* @threadsafety Always.
*/
int RingBuffer::GetValues(RingBuffer::SizeType span) const
{
ObjectLock olock(this);
if (span > m_Slots.size())
span = m_Slots.size();
int off = m_TimeValue % m_Slots.size();;
int sum = 0;
while (span > 0) {
sum += m_Slots[off];
if (off == 0)
off = m_Slots.size();
off--;
span--;
}
return sum;
}