finger.java

High performance DB query

/*
 * @(#)$Id: Finger.java,v 1.6 2004/07/02 23:59:20 huebsch Exp $
 *
 * Copyright (c) 2001-2004 Regents of the University of California.
 * All rights reserved.
 *
 * This file is distributed under the terms in the attached BERKELEY-LICENSE
 * file. If you do not find these files, copies can be found by writing to:
 * Computer Science Division, Database Group, Universite of California,
 * 617 Soda Hall #1776, Berkeley, CA 94720-1776. Attention: Berkeley License
 *
 * Copyright (c) 2003-2004 Intel Corporation. All rights reserved.
 *
 * This file is distributed under the terms in the attached INTEL-LICENSE file.
 * If you do not find these files, copies can be found by writing to:
 * Intel Research Berkeley, 2150 Shattuck Avenue, Suite 1300,
 * Berkeley, CA, 94704.  Attention:  Intel License Inquiry.
 */


package overlay.location.chord;

import java.net.InetSocketAddress;
import services.network.Payload;
import util.BitID;

/** This class represents an entry in a chord fingertable. */
public class Finger {

    private InetSocketAddress node;
    private BitID id;
    private double lastUpdate, expiration;
    private double latency;

    /**
     * Creates a new instance of Finger
     *
     * @param node
     * @param id
     * @param now
     * @param lifetime
     * @param latency
     */
    public Finger(InetSocketAddress node, BitID id, double now,
                  double lifetime, double latency) {
        this.node = node;
        this.id = id;
        this.lastUpdate = now;
        this.expiration = now + lifetime;
        this.latency = latency;
    }

    /**
     * Method getAddress
     * @return
     */
    public InetSocketAddress getAddress() {
        return node;
    }

    /**
     * Method getID
     * @return
     */
    public BitID getID() {
        return id;
    }

    /**
     * Method getLastUpdate
     * @return
     */
    public double getLastUpdate() {
        return lastUpdate;
    }

    /**
     * Method setLastUpdate
     *
     * @param time
     */
    public void setLastUpdate(double time) {
        this.lastUpdate = time;
    }

    /**
     * Method getExpiration
     * @return
     */
    public double getExpiration() {
        return expiration;
    }

    /**
     * Method setExpiration
     *
     * @param time
     */
    public void setExpiration(double time) {
        this.expiration = time;
    }

    /**
     * Method extendLifetime
     *
     * @param lifetime
     */
    public void extendLifetime(double lifetime) {
        this.expiration += lifetime;
    }

    /**
     * Method getLatency
     * @return
     */
    public double getLatency() {
        return latency;
    }

    /**
     * Method setLatency
     *
     * @param latency
     */
    public void setLatency(double latency) {
        this.latency = latency;
    }

    /**
     * Method getSize
     * @return
     */
    public int getSize() {
        return Payload.INET_SOCKET_SIZE + id.getSize() + Payload.DOUBLE_SIZE
               + Payload.DOUBLE_SIZE + Payload.LONG_SIZE;
    }

    /**
     * Method clone
     * @return
     */
    public Object clone() {
        return new Finger(node, id, expiration, expiration - lastUpdate,
                          latency);
    }

    /**
     * Method toString
     * @return
     */
    public String toString() {
        return new String("[F: " + node + ", " + id.toNumString() + "]");
    }
}