/*
 * The contents of this file are subject to the terms of the Common Development and
 * Distribution License (the License). You may not use this file except in compliance with the
 * License.
 *
 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
 * specific language governing permission and limitations under the License.
 *
 * When distributing Covered Software, include this CDDL Header Notice in each file and include
 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
 * Header, with the fields enclosed by brackets [] replaced by your own identifying
 * information: "Portions Copyright [year] [name of copyright owner]".
 *
 * Copyright 2006-2010 Sun Microsystems, Inc.
 * Portions copyright 2014 ForgeRock AS.
 */
package org.opends.server.replication.protocol;



/**
 * This is an abstract class of messages of the replication protocol for message
 * that needs to contain information about the server that send them and the
 * destination servers to which they should be sent.
 * <p>
 * Routable messages are used when initializing a new replica from an existing
 * replica: the total update messages are sent across the topology from the
 * source replica to the target replica, possibly traversing one or two
 * replication servers in the process (e.g. DS1 -&gt; RS1 -&gt; RS2 -&gt; DS2).
 */
public abstract class RoutableMsg extends ReplicationMsg
{

  /**
   *  Special values for the server ids fields contained in the routable
   *  messages.
   **/

  /**
   *  Specifies that no server is identified.
   */
  public static final int UNKNOWN_SERVER      = -1;
  /**
   * Specifies all servers in the replication domain.
   */
  public static final int ALL_SERVERS         = -2;
  /**
   * Inside a topology of servers in the same domain, it specifies
   * the server that is the "closest" to the sender.
   */
  public static final int THE_CLOSEST_SERVER  = -3;

  /**
   * The destination server or servers of this message.
   */
  protected int destination = UNKNOWN_SERVER;
  /**
   * The serverID of the server that sends this message.
   */
  protected int senderID = UNKNOWN_SERVER;

  /**
   * Creates a routable message.
   * @param serverID replication server id
   * @param destination replication server id
   */
  public RoutableMsg(int serverID, int destination)
  {
    this.senderID = serverID;
    this.destination = destination;
  }

  /**
   * Creates a routable message.
   */
  public RoutableMsg()
  {
  }

  /**
   * Get the destination. The value is a serverId, or ALL_SERVERS dedicated
   * value.
   * @return the destination
   */
  public int getDestination()
  {
    return this.destination;
  }

  /**
   * Get the server ID of the server that sent this message.
   * @return the server id
   */
  public int getSenderID()
  {
    return this.senderID;
  }

  /**
   * Returns a string representation of the message.
   *
   * @return the string representation of this message.
   */
  public String toString()
  {
    return "[" + getClass().getCanonicalName() +
      " sender=" + this.senderID +
      " destination=" + this.destination + "]";
  }
}