Glassfish example source code file (MutableAverageRangeStatisticImpl.java)

This example Glassfish source code file (MutableAverageRangeStatisticImpl.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 - Glassfish tags/keywords

averagerangestatistic, averagerangestatisticimpl, default_max_bound, default_max_bound, mutableaveragerangestatisticimpl, mutableboundedrangestatisticimpl, mutableboundedrangestatisticimpl, mutablecountstatistic, statistic, statistic, string, string

The Glassfish MutableAverageRangeStatisticImpl.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package com.sun.enterprise.admin.monitor.stats;

import org.glassfish.j2ee.statistics.Statistic;
import org.glassfish.j2ee.statistics.BoundedRangeStatistic;

/** An implementation of AverageRangeStatistic that provides ways to change the state externally through mutators.
 * Convenience class that is useful for components that gather the statistical data.
 * By merely changing the count (which is a mandatory measurement), rest of the statistical
 * information could be deduced.
 * @author Larry White
 * @author Kedar Mhaswade
 * @see AverageRangeStatisticImpl for an immutable implementation
 * @since S1AS8.1
 * @version 1.0
 */

/**
 *
 * @author  lwhite
 */
public class MutableAverageRangeStatisticImpl implements AverageRangeStatistic, MutableCountStatistic {

    /** DEFAULT_UPPER_BOUND is maximum value Long can attain */
    public static final long DEFAULT_MAX_BOUND = java.lang.Long.MAX_VALUE;
        
    private MutableBoundedRangeStatisticImpl    mutableBoundedRangeStat = null;
    private long                                numberOfSamples;
    private long                                runningTotal;
    private String                              description = null;
    
    /** Constructs an instance of MutableAverageRangeStatisticImpl that encapsulates the given Statistic.
     * The only parameter denotes the initial state of this statistic. It is
     * guaranteed that the initial state is preserved internally, so that one
     * can reset to the initial state.
     * @param initial           an instance of BoundedRangeStatistic that represents initial state
     */
    public MutableAverageRangeStatisticImpl(BoundedRangeStatistic initial) {
        mutableBoundedRangeStat = new MutableBoundedRangeStatisticImpl(initial);
        numberOfSamples = 0L;
        runningTotal = 0L;
        description = initial.getDescription();        
    }
    
    public Statistic modifiableView() {        
        return this;
    }
    
    public Statistic unmodifiableView() {        
        return ( new AverageRangeStatisticImpl(
            this.getCurrent(),               // this is the actual changing statistic
            this.getHighWaterMark(),         // highWaterMark may change per current
            this.getLowWaterMark(),          // lowWaterMark may change per current
            mutableBoundedRangeStat.getUpperBound(),    // upperBound is not designed to change
            mutableBoundedRangeStat.getLowerBound(),    // lowerBound is not designed to change
            mutableBoundedRangeStat.getName(),          // name does not change
            mutableBoundedRangeStat.getUnit(),          // unit does not change
            mutableBoundedRangeStat.getDescription(),   // description does not change
            this.getLastSampleTime(),        // changes all the time!
            this.getStartTime(),             // changes if reset is called earlier
            this.numberOfSamples,       // this is the current number of samples
            this.runningTotal           // this is the current running total
        ));        
    }    

    public void reset() {
        mutableBoundedRangeStat.reset();
        this.resetAverageStats();
    }
    
    private void resetAverageStats() {
        numberOfSamples = 0L;
        runningTotal = 0L;
    }    
    
    public void setCount(long current) {
        mutableBoundedRangeStat.setCount(current);
        if(DEFAULT_MAX_BOUND - runningTotal < current) {
            this.resetAverageStats();
        }
        numberOfSamples++;
        runningTotal += current;
    }
    
    public long getAverage() {
        if(numberOfSamples == 0) {
            return -1;
        } else {
            return runningTotal / numberOfSamples;
        }
    }
    
    public long getCurrent() {
        return mutableBoundedRangeStat.getCurrent();
    }
    
    public String getDescription() {
        return description;
        //return mutableBoundedRangeStat.getDescription();
    }
    
    public long getHighWaterMark() {
        return mutableBoundedRangeStat.getHighWaterMark();
    }
    
    public long getLastSampleTime() {
        return mutableBoundedRangeStat.getLastSampleTime();
    }
    
    public long getLowWaterMark() {
        long result = mutableBoundedRangeStat.getLowWaterMark();
        if(result == DEFAULT_MAX_BOUND) {
            result = 0L;
        }
        return result;
    }
    
    public String getName() {
        return mutableBoundedRangeStat.getName();
    }
    
    public long getStartTime() {
        return mutableBoundedRangeStat.getStartTime();
    }
    
    public String getUnit() {
        return mutableBoundedRangeStat.getUnit();
    }
    
}