fragmentmetadata.java

pastry的java实现的2.0b版

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

"FreePastry" Peer-to-Peer Application Development Substrate 

Copyright 2002, Rice University. All rights reserved.

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- Redistributions of source code must retain the above copyright
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- Redistributions in binary form must reproduce the above copyright
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- 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"
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********************************************************************************/
package rice.p2p.glacier.v2;

import java.io.Serializable;

/**
 * DESCRIBE THE CLASS
 *
 * @version $Id: pretty.settings 2305 2005-03-11 20:22:33Z jeffh $
 * @author jeffh
 */
public class FragmentMetadata implements Serializable, Comparable {

  /**
   * DESCRIBE THE FIELD
   */
  protected long currentExpirationDate;
  /**
   * DESCRIBE THE FIELD
   */
  protected long previousExpirationDate;
  /**
   * DESCRIBE THE FIELD
   */
  protected long storedSince;

  private final static long serialVersionUID = 3380538644355999384L;

  /**
   * Constructor for FragmentMetadata.
   *
   * @param currentExpirationDate DESCRIBE THE PARAMETER
   * @param previousExpirationDate DESCRIBE THE PARAMETER
   * @param storedSince DESCRIBE THE PARAMETER
   */
  public FragmentMetadata(long currentExpirationDate, long previousExpirationDate, long storedSince) {
    this.currentExpirationDate = currentExpirationDate;
    this.previousExpirationDate = previousExpirationDate;
    this.storedSince = storedSince;
  }

  /**
   * Gets the CurrentExpiration attribute of the FragmentMetadata object
   *
   * @return The CurrentExpiration value
   */
  long getCurrentExpiration() {
    return currentExpirationDate;
  }

  /**
   * Gets the PreviousExpiration attribute of the FragmentMetadata object
   *
   * @return The PreviousExpiration value
   */
  long getPreviousExpiration() {
    return previousExpirationDate;
  }

  /**
   * Gets the StoredSince attribute of the FragmentMetadata object
   *
   * @return The StoredSince value
   */
  long getStoredSince() {
    return storedSince;
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @param object DESCRIBE THE PARAMETER
   * @return DESCRIBE THE RETURN VALUE
   */
  public int compareTo(Object object) {
    FragmentMetadata metadata = (FragmentMetadata) object;

    if (metadata.currentExpirationDate > currentExpirationDate) {
      return -1;
    } else if (metadata.currentExpirationDate < currentExpirationDate) {
      return 1;
    } else if (metadata.previousExpirationDate < previousExpirationDate) {
      return -1;
    } else if (metadata.previousExpirationDate > previousExpirationDate) {
      return 1;
    } else if (metadata.storedSince < storedSince) {
      return -1;
    } else if (metadata.storedSince > storedSince) {
      return 1;
    } else {
      return 0;
    }
  }
}