aggregatedescriptor.java

pastry的java实现的2.0b版

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

"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.aggregation;

import rice.p2p.commonapi.Id;

/**
 * DESCRIBE THE CLASS
 *
 * @version $Id: pretty.settings 2305 2005-03-11 20:22:33Z jeffh $
 * @author jeffh
 */
class AggregateDescriptor {

  /**
   * DESCRIBE THE FIELD
   */
  public Id key;
  /**
   * DESCRIBE THE FIELD
   */
  public long currentLifetime;
  /**
   * DESCRIBE THE FIELD
   */
  public ObjectDescriptor[] objects;
  /**
   * DESCRIBE THE FIELD
   */
  public Id[] pointers;
  /**
   * DESCRIBE THE FIELD
   */
  public boolean marker;
  /**
   * DESCRIBE THE FIELD
   */
  public int referenceCount;

  /**
   * Constructor for AggregateDescriptor.
   *
   * @param key DESCRIBE THE PARAMETER
   * @param currentLifetime DESCRIBE THE PARAMETER
   * @param objects DESCRIBE THE PARAMETER
   * @param pointers DESCRIBE THE PARAMETER
   */
  public AggregateDescriptor(Id key, long currentLifetime, ObjectDescriptor[] objects, Id[] pointers) {
    this.key = key;
    this.currentLifetime = currentLifetime;
    this.objects = objects;
    this.pointers = pointers;
    this.marker = false;
    this.referenceCount = 0;
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @param id DESCRIBE THE PARAMETER
   * @return DESCRIBE THE RETURN VALUE
   */
  public int lookupNewest(Id id) {
    int result = -1;
    for (int i = 0; i < objects.length; i++) {
      if (objects[i].key.equals(id)) {
        if ((result == -1) || (objects[i].version > objects[result].version)) {
          result = i;
        }
      }
    }
    return result;
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @param id DESCRIBE THE PARAMETER
   * @param version DESCRIBE THE PARAMETER
   * @return DESCRIBE THE RETURN VALUE
   */
  public int lookupSpecific(Id id, long version) {
    for (int i = 0; i < objects.length; i++) {
      if (objects[i].key.equals(id) && (objects[i].version == version)) {
        return i;
      }
    }

    return -1;
  }

  /**
   * Adds a feature to the Reference attribute of the AggregateDescriptor object
   */
  public void addReference() {
    referenceCount++;
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @param pointInTime DESCRIBE THE PARAMETER
   * @return DESCRIBE THE RETURN VALUE
   */
  public int objectsAliveAt(long pointInTime) {
    int result = 0;
    for (int i = 0; i < objects.length; i++) {
      if (objects[i].isAliveAt(pointInTime)) {
        result++;
      }
    }
    return result;
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @param pointInTime DESCRIBE THE PARAMETER
   * @return DESCRIBE THE RETURN VALUE
   */
  public int bytesAliveAt(long pointInTime) {
    int result = 0;
    for (int i = 0; i < objects.length; i++) {
      if (objects[i].isAliveAt(pointInTime)) {
        result += objects[i].size;
      }
    }
    return result;
  }
}