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.yarn.sharedcache;
020
021import java.io.IOException;
022import java.io.InputStream;
023
024import org.apache.hadoop.classification.InterfaceAudience.Public;
025import org.apache.hadoop.classification.InterfaceStability.Evolving;
026
027@Public
028@Evolving
029/**
030 * An interface to calculate a checksum for a resource in the shared cache. The
031 * checksum implementation should be thread safe.
032 */
033public interface SharedCacheChecksum {
034
035  /**
036   * Calculate the checksum of the passed input stream.
037   *
038   * @param in <code>InputStream</code> to be checksumed
039   * @return the message digest of the input stream
040   * @throws IOException
041   */
042  public String computeChecksum(InputStream in) throws IOException;
043}