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.mapreduce;
020
021 import java.io.IOException;
022
023 import org.apache.hadoop.classification.InterfaceAudience;
024 import org.apache.hadoop.classification.InterfaceStability;
025 import org.apache.hadoop.mapreduce.InputFormat;
026 import org.apache.hadoop.mapreduce.Mapper;
027 import org.apache.hadoop.mapreduce.RecordReader;
028
029 /**
030 * <code>InputSplit</code> represents the data to be processed by an
031 * individual {@link Mapper}.
032 *
033 * <p>Typically, it presents a byte-oriented view on the input and is the
034 * responsibility of {@link RecordReader} of the job to process this and present
035 * a record-oriented view.
036 *
037 * @see InputFormat
038 * @see RecordReader
039 */
040 @InterfaceAudience.Public
041 @InterfaceStability.Stable
042 public abstract class InputSplit {
043 /**
044 * Get the size of the split, so that the input splits can be sorted by size.
045 * @return the number of bytes in the split
046 * @throws IOException
047 * @throws InterruptedException
048 */
049 public abstract long getLength() throws IOException, InterruptedException;
050
051 /**
052 * Get the list of nodes by name where the data for the split would be local.
053 * The locations do not need to be serialized.
054 * @return a new array of the node nodes.
055 * @throws IOException
056 * @throws InterruptedException
057 */
058 public abstract
059 String[] getLocations() throws IOException, InterruptedException;
060 }