/**
* Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information regarding copyright ownership. Apereo
* licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use
* this file except in compliance with the License. You may obtain a copy of the License at the
* following location:
*
* <p>http://www.apache.org/licenses/LICENSE-2.0
*
* <p>Unless required by applicable law or agreed to in writing, software distributed under the
* License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apereo.portal.utils;
/**
* @since 2.5
*/
public class MovingAverage {
public static final int SAMPLESIZE = 100;
private long[] samples;
private int ent = -1;
private long sum = 0;
private long totalSamples = 0;
private long highMax = 0;
public MovingAverage() {
samples = new long[SAMPLESIZE];
}
public synchronized MovingAverageSample add(final long sample) {
final long lastSample = sample;
final int first = ++ent % samples.length;
if (totalSamples >= samples.length) {
sum -= samples[first]; // We've wrapped, so we can remove the 'first' entry
}
sum += sample;
samples[first] = sample;
if (sample > highMax) {
highMax = sample;
}
totalSamples++;
long max = 0;
long min = Long.MAX_VALUE;
final long arraySize = Math.min(totalSamples, samples.length);
for (int i = 0; i < arraySize; i++) {
if (samples[i] > max) {
max = samples[i];
}
if (samples[i] < min) {
min = samples[i];
}
}
return new MovingAverageSample(
sum / arraySize, highMax, lastSample, max, min, totalSamples);
}
}