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    
019    package org.apache.hadoop.util;
020    
021    import org.apache.hadoop.classification.InterfaceAudience;
022    import 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
035    public interface Progressable {
036      /**
037       * Report progress to the Hadoop framework.
038       */
039      public void progress();
040    }