/*************************************************************************

"FreePastry" Peer-to-Peer Application Development Substrate 

Copyright 2002, Rice University. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.

- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.

- Neither  the name  of Rice  University (RICE) nor  the names  of its
contributors may be  used to endorse or promote  products derived from
this software without specific prior written permission.

This software is provided by RICE and the contributors on an "as is"
basis, without any representations or warranties of any kind, express
or implied including, but not limited to, representations or
warranties of non-infringement, merchantability or fitness for a
particular purpose. In no event shall RICE or contributors be liable
for any direct, indirect, incidental, special, exemplary, or
consequential damages (including, but not limited to, procurement of
substitute goods or services; loss of use, data, or profits; or
business interruption) however caused and on any theory of liability,
whether in contract, strict liability, or tort (including negligence
or otherwise) arising in any way out of the use of this software, even
if advised of the possibility of such damage.

********************************************************************************/

package rice.p2p.scribe;

import java.io.*;

import rice.*;
import rice.p2p.commonapi.*;
import rice.p2p.commonapi.rawserialization.*;

/**
 * @(#) Topic.java This class represents a specific topic in the Scribe system.
 *
 * @version $Id: Topic.java 3274 2006-05-15 16:17:47Z jeffh $
 * @author Alan Mislove
 */
public class Topic implements Serializable {

  /**
   * The Id to which this topic is mapped
   */
  protected Id id;

  /**
   * Constructor which takes an Id for this topic
   *
   * @param id The Id for this topic
   */
  public Topic(Id id) {
    this.id = id;
  }

  /**
   * Constructor which takes a name for this topic
   *
   * @param factory The factory to use when creating the id
   * @param name The name for this topic
   */
  public Topic(IdFactory factory, String name) {
    this.id = getId(factory, name);
  }

  /**
   * Constructor for Topic.
   *
   * @param buf DESCRIBE THE PARAMETER
   * @param endpoint DESCRIBE THE PARAMETER
   * @exception IOException DESCRIBE THE EXCEPTION
   */
  public Topic(InputBuffer buf, Endpoint endpoint) throws IOException {
    id = endpoint.readId(buf, buf.readShort());
  }

  /**
   * Returns the Id to which this topic is mapped
   *
   * @return The id to which this topic is mapped
   */
  public Id getId() {
    return id;
  }

  /**
   * Returns whether this is equal to o or not
   *
   * @param o The object to compare to
   * @return Whether or not they are equal
   */
  public boolean equals(Object o) {
    if (o instanceof Topic) {
      return ((Topic) o).id.equals(id);
    }

    return false;
  }

  /**
   * Returns the hashCode for this topic
   *
   * @return The hashcode for this topic
   */
  public int hashCode() {
    return id.hashCode();
  }

  /**
   * Returns a String representation of this topic
   *
   * @return A String representation of this topic
   */
  public String toString() {
    return "[TOPIC " + id + "]";
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @param buf DESCRIBE THE PARAMETER
   * @exception IOException DESCRIBE THE EXCEPTION
   */
  public void serialize(OutputBuffer buf) throws IOException {
    buf.writeShort(id.getType());
    id.serialize(buf);
  }

  /**
   * Returns the Id to which the string is mapped
   *
   * @param factory The factory to use when creating the id
   * @param name The string to map
   * @return The id to which this string is mapped
   */
  public static Id getId(IdFactory factory, String name) {
    return factory.buildId(name);
  }
}

