event.java

DTNSim2 is a simulator for Delay-Tolerant Networks (DTNs) written in Java. It is based on Sushant Ja

/**
 * simulator/Event.java
 */
package simulator;

import java.util.Comparator;

/**
 * Represents events that occur at specific times. When this event occurs, the
 * fire() method will be called.
 */
public class Event
{
	protected long seq = 0;

	protected double time = 0;

	protected EventReceiver receiver = null;

	public Event(double t, EventReceiver r)
	{
		time = t;
		receiver = r;
	}

	/** Returns the time that this event will fire. */
	public double getTime()
	{
		return time;
	}

	public EventReceiver getReceiver()
	{
		return receiver;
	}

	public void setSeq(long s)
	{
		seq = s;
	}

	public long getSeq()
	{
		return seq;
	}

	public String toString()
	{
		return "EVENT: Time: " + time + "; Seq: " + seq + "; Receiver: " + receiver;
	}

	/**
	 * Called when this event occurs.
	 * 
	 * @param forNetwork
	 *            the {@link Simulator} triggering this event.
	 */
	public void fire(Simulator net)
	{
		if (receiver == null)
			return;

		receiver.receiveEvent(this);
	}

	public int compareWith(Event e1)
	{
		double e0Time = this.getTime();
		double e1Time = e1.getTime();

		if (e0Time < e1Time)
			return -1;
		else if (e0Time > e1Time)
			return 1;

		assert e0Time == e1Time : "Event times should be equal and are different!";

		long e0Seq = this.getSeq();
		long e1Seq = e1.getSeq();

		// For BOTH negative seq numbers their order is reversed.
		if (e0Seq < 0 && e1Seq < 0)
		{
			if (e0Seq < e1Seq)
				return 1;
			else if (e0Seq > e1Seq)
				return -1;
		}
		else
		{
			if (e0Seq < e1Seq)
				return -1;
			else if (e0Seq > e1Seq)
				return 1;
		}

		assert e0Seq == e1Seq : "Event seqs should be equal and are different!";

		return 0;
	}

	public static class EventComparator implements Comparator<Event>
	{
		public int compare(Event e0, Event e1)
		{
			return e0.compareWith(e1);
		}
	}
}