001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.hdfs.server.datanode;
020
021/**
022 * holder class that holds checksum bytes and the length in a block at which
023 * the checksum bytes end
024 * 
025 * ex: length = 1023 and checksum is 4 bytes which is for 512 bytes, then
026 *     the checksum applies for the last chunk, or bytes 512 - 1023
027 */
028
029public class ChunkChecksum {
030  private final long dataLength;
031  // can be null if not available
032  private final byte[] checksum;
033
034  public ChunkChecksum(long dataLength, byte[] checksum) {
035    this.dataLength = dataLength;
036    this.checksum = checksum;
037  }
038
039  public long getDataLength() {
040    return dataLength;
041  }
042
043  public byte[] getChecksum() {
044    return checksum;
045  }
046}