com.zavakid.mushroom.lib.MetricMutableStat.java Source code

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Here is the source code for com.zavakid.mushroom.lib.MetricMutableStat.java

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/**
   Copyright [2013] [Mushroom]
    
   Licensed 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.
 */
/**
 Notice : this source is extracted from Hadoop metric2 package
 and some source code may changed by zavakid
 */
package com.zavakid.mushroom.lib;

import org.apache.commons.lang.StringUtils;

import com.zavakid.mushroom.MetricsRecordBuilder;
import com.zavakid.mushroom.util.SampleStat;

/**
 * A mutable metric with stats
 * <p>
 * Useful for keep throughput/latency stats.
 * </p>
 * <p>
 * e.g., new MetricMutableStat("rpcName", "rpcName stats", "ops", "time");
 * 
 * @author Hadoop metric2 package's authors
 * @since 0.1
 */
public class MetricMutableStat extends MetricMutable {

    private final String numSamplesName, numSamplesDesc;
    private final String avgValueName, avgValueDesc;
    private final String stdevValueName, stdevValueDesc;
    private final String iMinValueName, iMinValueDesc;
    private final String iMaxValueName, iMaxValueDesc;
    private final String minValueName, minValueDesc;
    private final String maxValueName, maxValueDesc;

    private final SampleStat intervalStat = new SampleStat();
    private final SampleStat prevStat = new SampleStat();
    private final SampleStat.MinMax minMax = new SampleStat.MinMax();
    private long numSamples = 0;
    private boolean extended = false;

    /**
     * Construct a sample statistics metric
     * 
     * @param name of the metric
     * @param description of the metric
     * @param sampleName of the metric (e.g. "ops")
     * @param valueName of the metric (e.g. "time", "latency")
     * @param extended create extended stats (stdev, min/max etc.) by default.
     */
    public MetricMutableStat(String name, String description, String sampleName, String valueName,
            boolean extended) {
        super(name, description);
        String desc = StringUtils.uncapitalize(description);
        numSamplesName = name + "_num_" + sampleName;
        numSamplesDesc = "Number of " + sampleName + " for " + desc;
        avgValueName = name + "_avg_" + valueName;
        avgValueDesc = "Average " + valueName + " for " + desc;
        stdevValueName = name + "_stdev_" + valueName;
        stdevValueDesc = "Standard deviation of " + valueName + " for " + desc;
        iMinValueName = name + "_imin_" + valueName;
        iMinValueDesc = "Interval min " + valueName + " for " + desc;
        iMaxValueName = name + "_imax_" + valueName;
        iMaxValueDesc = "Interval max " + valueName + " for " + desc;
        minValueName = name + "_min_" + valueName;
        minValueDesc = "Min " + valueName + " for " + desc;
        maxValueName = name + "_max_" + valueName;
        maxValueDesc = "Max " + valueName + " for " + desc;
        this.extended = extended;
    }

    /**
     * Construct a snapshot stat metric with extended stat off by default
     * 
     * @param name of the metric
     * @param description of the metric
     * @param sampleName of the metric (e.g. "ops")
     * @param valueName of the metric (e.g. "time", "latency")
     */
    public MetricMutableStat(String name, String description, String sampleName, String valueName) {
        this(name, description, sampleName, valueName, false);
    }

    /**
     * Add a number of samples and their sum to the running stat
     * 
     * @param numSamples number of samples
     * @param sum of the samples
     */
    public synchronized void add(long numSamples, long sum) {
        intervalStat.add(numSamples, sum);
        setChanged();
    }

    /**
     * Add a snapshot to the metric
     * 
     * @param value of the metric
     */
    public synchronized void add(long value) {
        intervalStat.add(value);
        minMax.add(value);
        setChanged();
    }

    public synchronized void snapshot(MetricsRecordBuilder builder, boolean all) {
        if (all || changed()) {
            numSamples += intervalStat.numSamples();
            builder.addCounter(numSamplesName, numSamplesDesc, numSamples);
            builder.addGauge(avgValueName, avgValueDesc, lastStat().mean());
            if (extended) {
                builder.addGauge(stdevValueName, stdevValueDesc, lastStat().stddev());
                builder.addGauge(iMinValueName, iMinValueDesc, lastStat().min());
                builder.addGauge(iMaxValueName, iMaxValueDesc, lastStat().max());
                builder.addGauge(minValueName, minValueDesc, minMax.min());
                builder.addGauge(maxValueName, maxValueDesc, minMax.max());
            }
            if (changed()) {
                intervalStat.copyTo(prevStat);
                intervalStat.reset();
                clearChanged();
            }
        }
    }

    private SampleStat lastStat() {
        return changed() ? intervalStat : prevStat;
    }

    /**
     * Reset the all time min max of the metric
     */
    public void resetMinMax() {
        minMax.reset();
    }

}