Mega Code Archive
Some simple stop watch
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/*
* Copyright 2000,2005 wingS development team.
*
* This file is part of wingS (http://wingsframework.org).
*
* wingS is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* Please see COPYING for the complete licence.
*/
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Iterator;
/*
* Ein Klasse, die Zeitmessungen aufnimmt und diese in Relation zueineander
* setzt. Zum Start der Zeitmessung Methode start kurzer Beschreibung was
* gemessen wird als Parameter aufrufen. Das Ende der Zeitmessung wird durch
* stop angezeigt. Es kann nur eine Zeitmessung gleichzeitig stattfinden. Die
* Ausgabe ist nicht sortiert, gibt aber die relativen Unterschiede in der
* Dauer der einzelnen Messungen an. Die Messung mit der laengsten Dauer ist
* der Referenzwert (1.0).
*/
/**
* Some simple stop watch. It allows to measure multiple time periods
* and prints them. Usage: call start(comment) and stop() for
* each period of time.
*
* @author <a href="mailto:haaf@mercatis.de">Armin Haaf</a>
*/
public class TimeMeasure {
protected final static double RESOLUTION = 100.0;
/**
* List of measurements.
*/
protected final ArrayList measures;
/**
* Message formatter
*/
protected final MessageFormat formatter;
/**
* the current time measurement.
*/
protected Measure current;
/**
* Simple TimeMesaure with default format.
*/
public TimeMeasure() {
this(new MessageFormat("{0}\t: {1}\t {2}x\n"));
}
/**
* A new TimeMeasure which reports in a specific format. The
* format is a standard MessageFormat with the following variables:
* <ul>
* <li><code>{0}</code> the measurement comment</li>
* <li><code>{1}</code> the time it took</li>
* <li><code>{2}</code> how many times this is faster than the
* slowest measurement</li>
* </ul>
*/
public TimeMeasure(MessageFormat formatter) {
this.measures = new ArrayList();
this.formatter = formatter;
}
/**
* Reset of all Measurements.
*/
public void reset() {
measures.clear();
}
/*
* Startet eine neue Messsung.
* @param comment Die Beschreibung der Messung.
*/
public void start(String comment) {
current = new Measure(comment);
}
/*
* Startet eine neue Messsung.
* @param comment Die Beschreibung der Messung.
public Object generate(String comment) {
current = new Measure();
actual.comment = comment;
measures.add(actual);
return actual;
}
*/
/*
* Addiert eine Messsung zu einer bestehenden.
* @param comment Die Beschreibung der Messung.
public void addToMeasure(Object measure) {
int index = measures.indexOf(measure);
if ( index<0 ) {
System.err.println("Measure does not exists " + measure);
actual = null;
return;
}
actual = (Measure)measures.get(index);
measures.remove(index);
actual.start = System.currentTimeMillis();
}
*/
/**
* stop current time measurement and store it.
*/
public void stop() {
if (current != null) {
current.stop();
measures.add(current);
current = null;
}
}
/**
* determines the time duration of the longest or shortest time interval.
*
* @param findShortest boolean 'true', if we are looking for the shortest
* time interval; 'false' if we are looking for the
* longest.
*/
private long findReferenceValue(boolean findShortest) {
long result = findShortest ? Long.MAX_VALUE : -1;
Iterator it = measures.iterator();
while (it.hasNext()) {
Measure m = (Measure) it.next();
result = (findShortest
? Math.min(result, m.getDuration())
: Math.max(result, m.getDuration()));
}
return result;
}
public String print() {
return print(false);
}
/**
* creates a formatted output (using the MessageFormat) of all
* results. The output is sorted in the in the sequence the time
* measurements took place.
* Writes the relative time to either the shortest or the longest
* time interval.
*
* @param shortestIsReference boolean true, if the shortest time interval
* is the reference value (1.0). False, if the
* longest is the reference.
*/
public String print(boolean shortestIsReference) {
StringBuilder result = new StringBuilder();
long reference = findReferenceValue(shortestIsReference);
Iterator it = measures.iterator();
while (it.hasNext()) {
Measure m = (Measure) it.next();
String factor = " -- ";
long duration = m.getDuration();
if (reference > 0) {
long tmp = (long) ((duration * RESOLUTION) / reference);
factor = String.valueOf(tmp / RESOLUTION);
}
Object[] args = {m.getComment(), (duration + "ms"), factor};
result.append(formatter.format(args));
}
return result.toString();
}
public String toString() {
return print();
}
/**
* A class to store one period of time.
*/
private final static class Measure {
/**
* start time.
*/
private final long start;
/**
* stop time.
*/
private long stop;
/**
* Die Gesamtdauer der Messung
*/
private long duration;
/**
* Description.
*/
private String comment;
public Measure(String comment) {
start = System.currentTimeMillis();
this.comment = comment;
}
public void stop() {
stop = System.currentTimeMillis();
duration = stop - start;
}
public long getDuration() { return duration; }
public String getComment() { return comment; }
}
}
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