JMeter example source code file (SamplingStatCalculator.java)

This example JMeter source code file (SamplingStatCalculator.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - JMeter tags/keywords

long, no, number, number, rate, sample, sample, samples, samplingstatcalculator, samplingstatcalculator, statcalculatorlong, string, string, stringbuilder, util

The JMeter SamplingStatCalculator.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.apache.jmeter.visualizers;

import java.util.Map;

import org.apache.jmeter.samplers.SampleResult;
import org.apache.jorphan.math.StatCalculatorLong;

/**
 * Aggegate sample data container. Just instantiate a new instance of this
 * class, and then call {@link #addSample(SampleResult)} a few times, and pull
 * the stats out with whatever methods you prefer.
 *
 */
public class SamplingStatCalculator {
    private final StatCalculatorLong calculator = new StatCalculatorLong();

    private double maxThroughput;

    private long firstTime;

    private String label;

    private Sample currentSample;

    public SamplingStatCalculator(){ // Only for use by test code
        this("");
    }

    public SamplingStatCalculator(String label) {
        this.label = label;
        init();
    }

    private void init() {
        firstTime = Long.MAX_VALUE;
        calculator.clear();
        maxThroughput = Double.MIN_VALUE;
        currentSample = new Sample();
    }

    /**
     * Clear the counters (useful for differential stats)
     *
     */
    public synchronized void clear() {
        init();
    }

    public Sample getCurrentSample() {
        return currentSample;
    }

    /**
     * Get the elapsed time for the samples
     *
     * @return how long the samples took
     */
    public long getElapsed() {
        if (getCurrentSample().getEndTime() == 0) {
            return 0;// No samples collected ...
        }
        return getCurrentSample().getEndTime() - firstTime;
    }

    /**
     * Returns the throughput associated to this sampler in requests per second.
     * May be slightly skewed because it takes the timestamps of the first and
     * last samples as the total time passed, and the test may actually have
     * started before that start time and ended after that end time.
     */
    public double getRate() {
        if (calculator.getCount() == 0) {
            return 0.0; // Better behaviour when howLong=0 or lastTime=0
        }

        return getCurrentSample().getThroughput();
    }

    /**
     * Throughput in bytes / second
     *
     * @return throughput in bytes/second
     */
    public double getBytesPerSecond() {
        // Code duplicated from getPageSize()
        double rate = 0;
        if (this.getElapsed() > 0 && calculator.getTotalBytes() > 0) {
            rate = calculator.getTotalBytes() / ((double) this.getElapsed() / 1000);
        }
        if (rate < 0) {
            rate = 0;
        }
        return rate;
    }

    /**
     * Throughput in kilobytes / second
     *
     * @return Throughput in kilobytes / second
     */
    public double getKBPerSecond() {
        return getBytesPerSecond() / 1024; // 1024=bytes per kb
    }

    /**
     * calculates the average page size, which means divide the bytes by number
     * of samples.
     *
     * @return average page size in bytes
     */
    public double getAvgPageBytes() {
        double rate = 0;
        if (this.getElapsed() > 0 && calculator.getTotalBytes() > 0) {
            rate = calculator.getTotalBytes() / ((double) this.getElapsed() / 1000);
        }
        if (rate < 0) {
            rate = 0;
        }
        return rate;
    }

    public String getLabel() {
        return label;
    }

    /**
     * Records a sample.
     *
     */
    public Sample addSample(SampleResult res) {
        long rtime, cmean, cstdv, cmedian, cpercent, eCount, endTime;
        double throughput;
        boolean rbool;
        synchronized (calculator) {
            calculator.addValue(res.getTime(), res.getSampleCount());
            calculator.addBytes(res.getBytes());
            setStartTime(res);
            eCount = getCurrentSample().getErrorCount();
            if (!res.isSuccessful()) {
                eCount++;
            }
            endTime = getEndTime(res);
            long howLongRunning = endTime - firstTime;
            throughput = ((double) calculator.getCount() / (double) howLongRunning) * 1000.0;
            if (throughput > maxThroughput) {
                maxThroughput = throughput;
            }

            rtime = res.getTime();
            cmean = (long)calculator.getMean();
            cstdv = (long)calculator.getStandardDeviation();
            cmedian = calculator.getMedian().longValue();
            cpercent = calculator.getPercentPoint( 0.500 ).longValue();
// TODO cpercent is the same as cmedian here - why? and why pass it to "distributionLine"?
            rbool = res.isSuccessful();
        }

        int count = calculator.getCount();
        Sample s =
            new Sample( null, rtime, cmean, cstdv, cmedian, cpercent, throughput, eCount, rbool, count, endTime );
        currentSample = s;
        return s;
    }

    private long getEndTime(SampleResult res) {
        long endTime = res.getEndTime();
        long lastTime = getCurrentSample().getEndTime();
        if (lastTime < endTime) {
            lastTime = endTime;
        }
        return lastTime;
    }

    /**
     * @param res
     */
    private void setStartTime(SampleResult res) {
        long startTime = res.getStartTime();
        if (firstTime > startTime) {
            // this is our first sample, set the start time to current timestamp
            firstTime = startTime;
        }
    }

    /**
     * Returns the raw double value of the percentage of samples with errors
     * that were recorded. (Between 0.0 and 1.0)
     *
     * @return the raw double value of the percentage of samples with errors
     *         that were recorded.
     */
    public double getErrorPercentage() {
        double rval = 0.0;

        if (calculator.getCount() == 0) {
            return (rval);
        }
        rval = (double) getCurrentSample().getErrorCount() / (double) calculator.getCount();
        return (rval);
    }

    /**
     * For debugging purposes, only.
     */
    @Override
    public String toString() {
        StringBuilder mySB = new StringBuilder();

        mySB.append("Samples: " + this.getCount() + "  ");
        mySB.append("Avg: " + this.getMean() + "  ");
        mySB.append("Min: " + this.getMin() + "  ");
        mySB.append("Max: " + this.getMax() + "  ");
        mySB.append("Error Rate: " + this.getErrorPercentage() + "  ");
        mySB.append("Sample Rate: " + this.getRate());
        return (mySB.toString());
    }

    /**
     * @return errorCount
     */
    public long getErrorCount() {
        return getCurrentSample().getErrorCount();
    }

    /**
     * @return Returns the maxThroughput.
     */
    public double getMaxThroughput() {
        return maxThroughput;
    }

    public Map<Number, Number[]> getDistribution() {
        return calculator.getDistribution();
    }

    public Number getPercentPoint(double percent) {
        return calculator.getPercentPoint(percent);
    }

    public int getCount() {
        return calculator.getCount();
    }

    public Number getMax() {
        return calculator.getMax();
    }

    public double getMean() {
        return calculator.getMean();
    }

    public Number getMeanAsNumber() {
        return new Long((long) calculator.getMean());
    }

    public Number getMedian() {
        return calculator.getMedian();
    }

    public Number getMin() {
        if (calculator.getMin().longValue() < 0) {
            return new Long(0);
        }
        return calculator.getMin();
    }

    public Number getPercentPoint(float percent) {
        return calculator.getPercentPoint(percent);
    }

    public double getStandardDeviation() {
        return calculator.getStandardDeviation();
    }
}