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 package org.apache.hadoop.fs;
019
020 import java.util.Arrays;
021
022 import org.apache.hadoop.classification.InterfaceAudience;
023 import org.apache.hadoop.classification.InterfaceStability;
024 import org.apache.hadoop.io.Writable;
025
026 /** An abstract class representing file checksums for files. */
027 @InterfaceAudience.Public
028 @InterfaceStability.Stable
029 public abstract class FileChecksum implements Writable {
030 /** The checksum algorithm name */
031 public abstract String getAlgorithmName();
032
033 /** The length of the checksum in bytes */
034 public abstract int getLength();
035
036 /** The value of the checksum in bytes */
037 public abstract byte[] getBytes();
038
039 /** Return true if both the algorithms and the values are the same. */
040 public boolean equals(Object other) {
041 if (other == this) {
042 return true;
043 }
044 if (other == null || !(other instanceof FileChecksum)) {
045 return false;
046 }
047
048 final FileChecksum that = (FileChecksum)other;
049 return this.getAlgorithmName().equals(that.getAlgorithmName())
050 && Arrays.equals(this.getBytes(), that.getBytes());
051 }
052
053 /** {@inheritDoc} */
054 public int hashCode() {
055 return getAlgorithmName().hashCode() ^ Arrays.hashCode(getBytes());
056 }
057 }