glacierquerymessage.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 in binary form must reproduce the above copyright
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- Neither  the name  of Rice  University (RICE) nor  the names  of its
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This software is provided by RICE and the contributors on an "as is"
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********************************************************************************/
package rice.p2p.glacier.v2.messaging;

import java.io.IOException;

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

/**
 * DESCRIBE THE CLASS
 *
 * @version $Id: GlacierQueryMessage.java 3274 2006-05-15 16:17:47Z jeffh $
 * @author ahae
 */
public class GlacierQueryMessage extends GlacierMessage {

  /**
   * DESCRIBE THE FIELD
   */
  protected FragmentKey keys[];
  /**
   * DESCRIBE THE FIELD
   */
  public final static short TYPE = 5;

  /**
   * Constructor for GlacierQueryMessage.
   *
   * @param uid DESCRIBE THE PARAMETER
   * @param keys DESCRIBE THE PARAMETER
   * @param source DESCRIBE THE PARAMETER
   * @param dest DESCRIBE THE PARAMETER
   * @param tag DESCRIBE THE PARAMETER
   */
  public GlacierQueryMessage(int uid, FragmentKey keys[], NodeHandle source, Id dest, char tag) {
    super(uid, source, dest, false, tag);

    this.keys = keys;
  }

  /**
   * Constructor for GlacierQueryMessage.
   *
   * @param buf DESCRIBE THE PARAMETER
   * @param endpoint DESCRIBE THE PARAMETER
   * @exception IOException DESCRIBE THE EXCEPTION
   */
  private GlacierQueryMessage(InputBuffer buf, Endpoint endpoint) throws IOException {
    super(buf, endpoint);
    keys = new FragmentKey[buf.readInt()];
    for (int i = 0; i < keys.length; i++) {
      keys[i] = new FragmentKey(buf, endpoint);
    }
  }

  /**
   * Gets the Key attribute of the GlacierQueryMessage object
   *
   * @param index DESCRIBE THE PARAMETER
   * @return The Key value
   */
  public FragmentKey getKey(int index) {
    return keys[index];
  }

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

  /**
   * DESCRIBE THE METHOD
   *
   * @return DESCRIBE THE RETURN VALUE
   */
  public int numKeys() {
    return keys.length;
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @return DESCRIBE THE RETURN VALUE
   */
  public String toString() {
    return "[GlacierQuery for " + keys[0] + " (" + (numKeys() - 1) + " more keys)]";
  }

  /**
   * 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
    super.serialize(buf);
    buf.writeInt(keys.length);
    for (int i = 0; i < keys.length; i++) {
      keys[i].serialize(buf);
    }
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @param buf DESCRIBE THE PARAMETER
   * @param endpoint DESCRIBE THE PARAMETER
   * @return DESCRIBE THE RETURN VALUE
   * @exception IOException DESCRIBE THE EXCEPTION
   */
  public static GlacierQueryMessage build(InputBuffer buf, Endpoint endpoint) throws IOException {
    byte version = buf.readByte();
    switch (version) {
      case 0:
        return new GlacierQueryMessage(buf, endpoint);
      default:
        throw new IOException("Unknown Version: " + version);
    }
  }
}