virtualsubscription.java

The source code for this package is located in src/gov/nist/sip/proxy. The proxy is a pure JAIN-SIP

/**
 * VirtualSubscription.java
 */

package gov.nist.sip.proxy.presenceserver;

import gov.nist.sip.proxy.*;
import java.util.*;
import javax.sip.Dialog;

/**
 * A virtual subscription is a subscription that the Resource List Server
 * (colocated with the Presence Server in this implementation) issues if someone
 * subscribes to a resource list containing external references.
 * <p />
 * VirtualSubscriptions are sent to one PA, and thus what we receive is the full
 * pidf for all the PA's PUAs (in other words, if the notifier we are
 * subscribing to has a presenceServer like this one, the presenceServer will
 * compose a full state for us).
 * <p />
 * A VirtualSubscription has Subscribers, just like the Notifier object.
 * 
 * 
 * @author Henrik Leion
 * @version 0.1
 * @see draft-ietf-simple-event-list-04
 */
public class VirtualSubscription {

	private Dialog dialog;

	private HashMap subscribers;

	/**
	 * Collects the extra time that the subscribers require. Used when
	 * resubscribing to th virtualSubscription *
	 */
	private int extraTime;

	private int expiresTime;

	private long creationTime;

	private String subscriptionState;

	private String fullState; // File instead?

	private String subscriberURI;

	protected VirtualSubscription(String subscriberURI, Dialog d, int e) {
		this.dialog = d;
		this.expiresTime = e;
		this.subscribers = new HashMap();
		this.creationTime = System.currentTimeMillis();
		this.fullState = new String();
		this.extraTime = 0;
		this.subscriptionState = javax.sip.header.SubscriptionStateHeader.PENDING;
	}

	/**
	 * Todo:
	 * <ul>
	 * <li>Could support partial presence</li>
	 * </ul>
	 */
	protected int processNotify(String newBody) {
		fullState = newBody;
		return 200;
	}

	/**
	 * Adds a new subscriber and sets the extraTime field to this subscribers
	 * expires-time if larger. This means that the newExpires field will contain
	 * a sufficiently large number when resubscribing to the notifier.
	 * 
	 */
	protected void addSubscriber(Subscriber subscriber, String subscriberKey,
			int subscribeExpires) {

		// Does this subscription need more time than what we have subscribed
		// for?
		int temp = subscribeExpires - getExpiresTime();
		if (temp > 0) {
			extraTime = temp;
		}

	}

	/**
	 * If we have added subscribers that need this subscription to stay alive
	 * longer than what is negotiated, the extraTime field is larger than zero.
	 */
	protected boolean needToResubscribe() {
		return extraTime > 0;
	}

	// ***********************
	// Getters & Setters
	// ***********************

	protected Dialog getDialog() {
		return dialog;
	}

	public String getURI() {
		return subscriberURI;
	}

	/**
	 * Returns remaining time of subscription
	 * 
	 * @author Henrik Leion
	 */
	public int getExpiresTime() {
		long temp = creationTime + expiresTime * 1000
				- System.currentTimeMillis();
		return (int) temp / 1000;
	}

	public void setExpiresTime(int newExpires) {
		creationTime = System.currentTimeMillis();
		expiresTime = newExpires;
		extraTime = extraTime - newExpires;
		if (extraTime < newExpires)
			extraTime = 0;
		else
			extraTime = extraTime - newExpires;
	}

	/**
	 * Returns an expires time that is as large as the current subscribers
	 * require
	 */
	public int getRequiredExpiresTime() {
		return extraTime;
	}

	protected boolean hasExpired() {
		return ((creationTime + expiresTime * 1000) < System
				.currentTimeMillis());
	}

	protected boolean hasNoSubscribers() {
		return subscribers.isEmpty();
	}

	protected String getSubscriptionState() {
		return subscriptionState;
	}

	protected void setSubscriptionState(String newState) {
		subscriptionState = newState;
	}

	protected Collection getSubscribers() {
		return subscribers.values();
	}

}