broadcastleafset.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
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This software is provided by RICE and the contributors on an "as is"
basis, without any representations or warranties of any kind, express
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********************************************************************************/
package rice.pastry.leafset;

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

import java.io.*;
import java.util.*;

/**
 * Broadcast a leaf set to another node.
 *
 * @version $Id: BroadcastLeafSet.java 3274 2006-05-15 16:17:47Z jeffh $
 * @author Andrew Ladd
 */

public class BroadcastLeafSet extends PRawMessage {

  private NodeHandle fromNode;

  private LeafSet theLeafSet;

  private int theType;
  /**
   * DESCRIBE THE FIELD
   */
  public final static short TYPE = 2;

  /**
   * DESCRIBE THE FIELD
   */
  public final static int Update = 0;

  /**
   * DESCRIBE THE FIELD
   */
  public final static int JoinInitial = 1;

  /**
   * DESCRIBE THE FIELD
   */
  public final static int JoinAdvertise = 2;

  /**
   * DESCRIBE THE FIELD
   */
  public final static int Correction = 3;

  /**
   * Constructor.
   *
   * @param from DESCRIBE THE PARAMETER
   * @param leafSet DESCRIBE THE PARAMETER
   * @param type DESCRIBE THE PARAMETER
   */

  public BroadcastLeafSet(NodeHandle from, LeafSet leafSet, int type) {
    this(null, from, leafSet, type);
  }

  /**
   * Constructor.
   *
   * @param stamp the timestamp
   * @param from DESCRIBE THE PARAMETER
   * @param leafSet DESCRIBE THE PARAMETER
   * @param type DESCRIBE THE PARAMETER
   */

  public BroadcastLeafSet(Date stamp, NodeHandle from, LeafSet leafSet, int type) {
    super(LeafSetProtocolAddress.getCode(), stamp);

    fromNode = from;
    theLeafSet = leafSet;
    theType = type;
    setPriority(MAX_PRIORITY);
  }

  /**
   * Constructor for BroadcastLeafSet.
   *
   * @param buf DESCRIBE THE PARAMETER
   * @param nhf DESCRIBE THE PARAMETER
   * @exception IOException DESCRIBE THE EXCEPTION
   */
  public BroadcastLeafSet(InputBuffer buf, NodeHandleFactory nhf) throws IOException {
    super(LeafSetProtocolAddress.getCode());

    byte version = buf.readByte();
    switch (version) {
      case 0:
        fromNode = nhf.readNodeHandle(buf);
        theLeafSet = LeafSet.build(buf, nhf);
        theType = buf.readByte();
        break;
      default:
        throw new IOException("Unknown Version: " + version);
    }
  }

  /**
   * Raw Serialization **************************************
   *
   * @return The Type value
   */
  public short getType() {
    return TYPE;
  }

  /**
   * Returns the node id of the node that broadcast its leaf set.
   *
   * @return the node id.
   */

  public NodeHandle from() {
    return fromNode;
  }

  /**
   * Returns the leaf set that was broadcast.
   *
   * @return the leaf set.
   */

  public LeafSet leafSet() {
    return theLeafSet;
  }

  /**
   * Returns the type of leaf set.
   *
   * @return the type.
   */

  public int type() {
    return theType;
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @return DESCRIBE THE RETURN VALUE
   */
  public String toString() {
    String s = "BroadcastLeafSet(of " + fromNode.getNodeId() + ":" + theLeafSet + ")";
    return s;
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @param buf DESCRIBE THE PARAMETER
   * @exception IOException DESCRIBE THE EXCEPTION
   */
  public void serialize(OutputBuffer buf) throws IOException {
    buf.writeByte((byte) 0);
    // version
    fromNode.serialize(buf);
    theLeafSet.serialize(buf);
    buf.writeByte((byte) theType);
  }
}