slf4j-jdk14/src/test/java/org/slf4j/impl/PerfTest.java

/**
 * Copyright (c) 2004-2011 QOS.ch
 * All rights reserved.
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 * "Software"), to  deal in  the Software without  restriction, including
 * without limitation  the rights to  use, copy, modify,  merge, publish,
 * distribute,  sublicense, and/or sell  copies of  the Software,  and to
 * permit persons to whom the Software  is furnished to do so, subject to
 * the following conditions:
 *
 * The  above  copyright  notice  and  this permission  notice  shall  be
 * included in all copies or substantial portions of the Software.
 *
 * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
 * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
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package org.slf4j.impl;

import junit.framework.TestCase;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.helpers.BogoPerf;

public class PerfTest extends TestCase {

    static long REFERENCE_BIPS = 9000;

    public PerfTest(String name) {
        super(name);
    }

    protected void setUp() throws Exception {
        super.setUp();
    }

    protected void tearDown() throws Exception {
        super.tearDown();
    }

    public void testBug72() {

        int LEN = 1000 * 1000 * 10;
        debugLoop(LEN); // warm up
        double avg = debugLoop(LEN);
        long referencePerf = 93;
        BogoPerf.assertDuration(avg, referencePerf, REFERENCE_BIPS);

        // when the code is guarded by a logger.isLoggable condition,
        // duration is about 16 *micro*seconds for 1000 iterations
        // when it is not guarded the figure is 90 milliseconds,
        // i.e a ration of 1 to 5000
    }

    double debugLoop(int len) {
        Logger logger = LoggerFactory.getLogger(PerfTest.class);
        long start = System.currentTimeMillis();
        for (int i = 0; i < len; i++) {
            logger.debug("hello");
        }

        long end = System.currentTimeMillis();

        long duration = end - start;
        return duration;
    }

}