StopWatch.java

/**
 * Mad-Advertisement
 * Copyright (C) 2011 Thorsten Marx <thmarx@gmx.net>
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package net.mad.ads.common.benchmark;

public class StopWatch {

	private long startTime = -1;
	private long stopTime = -1;
	private boolean running = false;

	public StopWatch start() {
		startTime = System.currentTimeMillis();
		running = true;
		return this;
	}

	public StopWatch stop() {
		stopTime = System.currentTimeMillis();
		running = false;
		return this;
	}

	/**
	 * returns elapsed time in milliseconds if the watch has never been started
	 * then return zero
	 */
	public long getElapsedTime() {
		if (startTime == -1) {
			return 0;
		}
		if (running) {
			return System.currentTimeMillis() - startTime;
		} else {
			return stopTime - startTime;
		}
	}

	public StopWatch reset() {
		startTime = -1;
		stopTime = -1;
		running = false;
		return this;
	}
}