    001/**
    002 * Copyright (c) 2004-2011 QOS.ch
    003 * All rights reserved.
    004 *
    005 * Permission is hereby granted, free  of charge, to any person obtaining
    006 * a  copy  of this  software  and  associated  documentation files  (the
    007 * "Software"), to  deal in  the Software without  restriction, including
    008 * without limitation  the rights to  use, copy, modify,  merge, publish,
    009 * distribute,  sublicense, and/or sell  copies of  the Software,  and to
    010 * permit persons to whom the Software  is furnished to do so, subject to
    011 * the following conditions:
    012 *
    013 * The  above  copyright  notice  and  this permission  notice  shall  be
    014 * included in all copies or substantial portions of the Software.
    015 *
    016 * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
    017 * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
    018 * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
    019 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
    020 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
    021 * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
    022 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
    023 *
    024 */
    025package org.slf4j.profiler;
    026
    027/**
    028 * A very basic {@link TimeInstrument} which can be started and stopped
    029 * once and only once.
    030 *
    031 * @author Ceki G&uuml;lc&uuml;
    032 *
    033 */
    034public class StopWatch implements TimeInstrument {
    035
    036    private String name;
    037    private long startTime;
    038    private long stopTime;
    039    TimeInstrumentStatus status;
    040
    041    public StopWatch(String name) {
    042        start(name);
    043    }
    044
    045    StopWatch(StopWatch original) {
    046        this.name = original.name;
    047        this.startTime = original.startTime;
    048        this.stopTime = original.stopTime;
    049        this.status = original.status;
    050    }
    051
    052    public void start(String name) {
    053        this.name = name;
    054        startTime = System.nanoTime();
    055        status = TimeInstrumentStatus.STARTED;
    056    }
    057
    058    public String getName() {
    059        return name;
    060    }
    061
    062    public TimeInstrument stop() {
    063        if (status == TimeInstrumentStatus.STOPPED) {
    064            return this;
    065        }
    066        return stop(System.nanoTime());
    067    }
    068
    069    public StopWatch stop(long stopTime) {
    070        this.status = TimeInstrumentStatus.STOPPED;
    071        this.stopTime = stopTime;
    072        return this;
    073    }
    074
    075    @Override
    076    public String toString() {
    077        StringBuilder buf = new StringBuilder();
    078        buf.append("StopWatch [");
    079        buf.append(name);
    080        buf.append("] ");
    081
    082        switch (status) {
    083        case STARTED:
    084            buf.append("STARTED");
    085            break;
    086        case STOPPED:
    087            buf.append("elapsed time: ");
    088            buf.append(Util.durationInDurationUnitsAsStr(elapsedTime(), DurationUnit.MICROSECOND));
    089            break;
    090        default:
    091            throw new IllegalStateException("Status " + status + " is not expected");
    092        }
    093        return buf.toString();
    094    }
    095
    096    public final long elapsedTime() {
    097        if (status == TimeInstrumentStatus.STARTED) {
    098            return 0;
    099        } else {
    100            return stopTime - startTime;
    101        }
    102    }
    103
    104    public TimeInstrumentStatus getStatus() {
    105        return status;
    106    }
    107
    108    public void print() {
    109        System.out.println(toString());
    110    }
    111
    112    public void log() {
    113        throw new UnsupportedOperationException("A stopwatch instance does not know how to log");
    114    }
    115
    116}