eventqueue.java

发布/订阅系统路由重配算法,可应用于ad hoc环境

/*
 * project: RebecaSim
 * package: sim
 * file:    EventQueue.java
 * 
 * version: 0.1
 * date:    03.05.2005
 * 
 * This software is part of the diploma thesis "Ein adaptives Brokernetz 
 * für Publish/Subscribe Systeme".
 */
package sim;

import broker.*;

import java.util.*;

import com.Broadcast;
import com.Notification;
/**
 * TODO Insert class description here.
 *
 * @version 03.05.2005
 * @author  parzy
 */
public class EventQueue {

	private TreeSet queue;
	
	public EventQueue(){
		queue = new TreeSet();
	}
	
	public void enqueue(Event e){
		if(!queue.add(e)){
			throw new IllegalStateException("Unable to enqueue event.");
		}
	}
	
	public Event dequeue(){
		Event e = (Event)queue.first();
		if(!queue.remove(e)){
			throw new IllegalStateException("Unable to remove dequeued event.");		
		}
		return e;			
	}
	
	public boolean remove(Event e){
		return queue.remove(e);
	}
	
	public boolean isEmpty(){
		return queue.isEmpty();
	}
	
	public int size() {
		return queue.size();
	}
	
	public void clear() {
		queue.clear();
	}
	
	// TODO remove
	public void stats(){
		int b = 0;
		int n = 0;
		for(Iterator it = queue.iterator(); it.hasNext();){
			Event e = (Event)it.next();
			if(e instanceof ReceiveEvent){
				ReceiveEvent r = (ReceiveEvent)e;
				if(r.message instanceof Broadcast){
					b++;
				}
				if(r.message instanceof Notification){
					n++;
				}
			}
		}
		System.out.println("Broadcasts: "+b+" Notification: "+n);
	}
}