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.mapred; 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.io.Writable; 026 027 /** 028 * <code>InputSplit</code> represents the data to be processed by an 029 * individual {@link Mapper}. 030 * 031 * <p>Typically, it presents a byte-oriented view on the input and is the 032 * responsibility of {@link RecordReader} of the job to process this and present 033 * a record-oriented view. 034 * 035 * @see InputFormat 036 * @see RecordReader 037 */ 038 @InterfaceAudience.Public 039 @InterfaceStability.Stable 040 public interface InputSplit extends Writable { 041 042 /** 043 * Get the total number of bytes in the data of the <code>InputSplit</code>. 044 * 045 * @return the number of bytes in the input split. 046 * @throws IOException 047 */ 048 long getLength() throws IOException; 049 050 /** 051 * Get the list of hostnames where the input split is located. 052 * 053 * @return list of hostnames where data of the <code>InputSplit</code> is 054 * located as an array of <code>String</code>s. 055 * @throws IOException 056 */ 057 String[] getLocations() throws IOException; 058 }