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.util;
020
021import org.apache.hadoop.classification.InterfaceAudience;
022import org.apache.hadoop.classification.InterfaceStability;
023
024/**
025 * A facility for reporting progress.
026 * 
027 * <p>Clients and/or applications can use the provided <code>Progressable</code>
028 * to explicitly report progress to the Hadoop framework. This is especially
029 * important for operations which take significant amount of time since,
030 * in-lieu of the reported progress, the framework has to assume that an error
031 * has occured and time-out the operation.</p>
032 */
033@InterfaceAudience.Public
034@InterfaceStability.Stable
035public interface Progressable {
036  /**
037   * Report progress to the Hadoop framework.
038   */
039  public void progress();
040}