/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hdfs.protocol;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

/**
 * The header for the OP_COPY_BLOCK datanode operation.
 */
public class CopyBlockHeader extends DataTransferHeader {

  private int namespaceId;
  private long blockId;
  private long genStamp;
  
  public CopyBlockHeader(final VersionAndOpcode versionAndOpcode) {
    super(versionAndOpcode);
  }
  
  public CopyBlockHeader(final int dataTransferVersion,
      final int namespaceId, final long blockId, final long genStamp) {
    super(dataTransferVersion, DataTransferProtocol.OP_COPY_BLOCK);
    set(namespaceId, blockId, genStamp);
  }

  public void set(int namespaceId, long blockId, long genStamp) {
    this.namespaceId = namespaceId;
    this.blockId = blockId;
    this.genStamp = genStamp;
  }

  public int getNamespaceId() {
    return namespaceId;
  }

  public long getBlockId() {
    return blockId;
  }

  public long getGenStamp() {
    return genStamp;
  }

  public void write(DataOutput out) throws IOException {
    if (getDataTransferVersion() >= DataTransferProtocol.FEDERATION_VERSION) {
      out.writeInt(namespaceId);
    }
    out.writeLong(blockId);
    out.writeLong(genStamp);
  }

  public void readFields(DataInput in) throws IOException {
    namespaceId = in.readInt();
    blockId = in.readLong();
    genStamp = in.readLong();
  }
}