joinrequest.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.pastry.join;

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

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

/**
 * Request to join this network.
 *
 * @version $Id: JoinRequest.java 3274 2006-05-15 16:17:47Z jeffh $
 * @author Jeff Hoye, Andrew Ladd
 */
public class JoinRequest extends PRawMessage {

  private NodeHandle handle;

  private NodeHandle joinHandle;

  private byte rowCount;

  private RouteSet rows[][];

  private LeafSet leafSet;

  private byte rtBaseBitLength;

  /**
   * DESCRIBE THE FIELD
   */
  public final static byte HAS_HANDLE = 0x01;
  /**
   * DESCRIBE THE FIELD
   */
  public final static byte HAS_JOIN_HANDLE = 0x02;
  /**
   * DESCRIBE THE FIELD
   */
  public final static byte HAS_LEAFSET = 0x02;

  final static long serialVersionUID = 231671018732832563L;

  /**
   * DESCRIBE THE FIELD
   */
  public final static short TYPE = 1;

  /**
   * Constructor.
   *
   * @param nh a handle of the node trying to join the network.
   * @param rtBaseBitLength DESCRIBE THE PARAMETER
   */
  public JoinRequest(NodeHandle nh, byte rtBaseBitLength) {
    this(nh, null, rtBaseBitLength);
  }

  /**
   * Constructor.
   *
   * @param nh a handle of the node trying to join the network.
   * @param stamp the timestamp
   * @param rtBaseBitLength DESCRIBE THE PARAMETER
   */
  public JoinRequest(NodeHandle nh, Date stamp, byte rtBaseBitLength) {
    super(JoinAddress.getCode(), stamp);
    handle = nh;
    initialize(rtBaseBitLength);
    setPriority(MAX_PRIORITY);
  }

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

    byte version = buf.readByte();
    switch (version) {
      case 0:
        setSender(sender);
        rtBaseBitLength = buf.readByte();
        initialize(rtBaseBitLength);

        handle = nhf.readNodeHandle(buf);
        if (buf.readBoolean()) {
          joinHandle = nhf.readNodeHandle(buf);
        }

        rowCount = buf.readByte();
        int numRows = Id.IdBitLength / rtBaseBitLength;
        int numCols = 1 << rtBaseBitLength;
        for (int i = 0; i < numRows; i++) {
          RouteSet[] thisRow;
          if (buf.readBoolean()) {
            thisRow = new RouteSet[numCols];
            for (int j = 0; j < numCols; j++) {
              if (buf.readBoolean()) {
                thisRow[j] = new RouteSet(buf, nhf);
              } else {
                thisRow[j] = null;
              }
            }
          } else {
            thisRow = null;
          }
          rows[i] = thisRow;
        }

        if (buf.readBoolean()) {
          leafSet = LeafSet.build(buf, nhf);
        }
        break;
      default:
        throw new IOException("Unknown Version: " + version);
    }
  }

  /**
   * Gets the handle of the node trying to join.
   *
   * @return the handle.
   */

  public NodeHandle getHandle() {
    return handle;
  }

  /**
   * Gets the handle of the node that accepted the join request;
   *
   * @return the handle.
   */

  public NodeHandle getJoinHandle() {
    return joinHandle;
  }

  /**
   * Gets the leafset of the node that accepted the join request;
   *
   * @return the leafset.
   */

  public LeafSet getLeafSet() {
    return leafSet;
  }

  /**
   * Get row.
   *
   * @param i the row to get.
   * @return the row.
   */

  public RouteSet[] getRow(int i) {
    return rows[i];
  }

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

  /**
   * Returns true if the request was accepted, false if it hasn't yet.
   *
   * @return DESCRIBE THE RETURN VALUE
   */

  public boolean accepted() {
    return joinHandle != null;
  }

  /**
   * Accept join request.
   *
   * @param nh the node handle that accepts the join request.
   * @param ls DESCRIBE THE PARAMETER
   */

  public void acceptJoin(NodeHandle nh, LeafSet ls) {
    joinHandle = nh;
    leafSet = ls;
  }

  /**
   * Returns the number of rows left to determine (in order).
   *
   * @return the number of rows left.
   */

  public int lastRow() {
    return rowCount;
  }

  /**
   * Push row.
   *
   * @param row the row to push.
   */

  public void pushRow(RouteSet row[]) {
    rows[--rowCount] = row;
  }

  /**
   * Get the number of rows.
   *
   * @return the number of rows.
   */

  public int numRows() {
    return rows.length;
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @param rtBaseBitLength DESCRIBE THE PARAMETER
   */
  private void initialize(byte rtBaseBitLength) {
    joinHandle = null;
    this.rtBaseBitLength = rtBaseBitLength;
    rowCount = (byte) (Id.IdBitLength / rtBaseBitLength);

    rows = new RouteSet[rowCount][];
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @return DESCRIBE THE RETURN VALUE
   */
  public String toString() {
    return "JoinRequest(" + (handle != null ? handle.getNodeId() : null) + ","
      + (joinHandle != null ? joinHandle.getNodeId() : null) + ")";
  }

  /**
   * 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
    buf.writeByte((byte) rtBaseBitLength);
    handle.serialize(buf);
    if (joinHandle != null) {
      buf.writeBoolean(true);
      joinHandle.serialize(buf);
    } else {
      buf.writeBoolean(false);
    }

    // encode the table
    buf.writeByte((byte) rowCount);
    int maxIndex = Id.IdBitLength / rtBaseBitLength;
    for (int i = 0; i < maxIndex; i++) {
      RouteSet[] thisRow = rows[i];
      if (thisRow != null) {
        buf.writeBoolean(true);
        for (int j = 0; j < thisRow.length; j++) {
          if (thisRow[j] != null) {
            buf.writeBoolean(true);
            thisRow[j].serialize(buf);
          } else {
            buf.writeBoolean(false);
          }
        }
      } else {
        buf.writeBoolean(false);
      }
    }

    if (leafSet != null) {
      buf.writeBoolean(true);
      leafSet.serialize(buf);
    } else {
      buf.writeBoolean(false);
    }

  }
}