EventStream.java

package hu.bme.mit.incquery.cep.streams;

import hu.bme.mit.incquery.cep.api.runtime.EventQueue;
import hu.bme.mit.incquery.cep.metamodels.cep.Event;

import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;

import org.eclipse.emf.common.notify.Notification;
import org.eclipse.emf.ecore.impl.ENotificationImpl;
import org.eclipse.emf.ecore.impl.EObjectImpl;

public class EventStream extends EObjectImpl {
    private Queue<Event> queue = new ConcurrentLinkedQueue<Event>();

    public EventStream() {
        super();
    }

    /**
     * Adds an {@link Event} to the {@link EventQueue}. Every new Event is published to the interested adapters via
     * EMF's notification mechanism. For example see {@link EventPatternRegistry}.
     * 
     * @param event
     *            the {@link Event} to be added
     */
    public void push(Event event) {
        if (event == null) {
            return;
        }
        Queue<Event> oldQueue = this.queue;
        this.queue.add(event);
        if (eNotificationRequired()) {
            eNotify(new ENotificationImpl(this, Notification.ADD, null, oldQueue, event));
            queue.remove(event);
        }
    }

    /**
     * Returns the whole queue of {@link Event}s.
     * 
     * @return the queue containing yet unprocessed {@link Event}s
     */
    public Queue<Event> getQueue() {
        return this.queue;
    }
}