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.mapred; 020 021import java.io.IOException; 022import java.io.DataInput; 023import java.io.DataOutput; 024 025import org.apache.hadoop.classification.InterfaceAudience; 026import org.apache.hadoop.classification.InterfaceStability; 027import org.apache.hadoop.classification.InterfaceStability.Evolving; 028import org.apache.hadoop.fs.Path; 029 030/** A section of an input file. Returned by {@link 031 * InputFormat#getSplits(JobConf, int)} and passed to 032 * {@link InputFormat#getRecordReader(InputSplit,JobConf,Reporter)}. 033 */ 034@InterfaceAudience.Public 035@InterfaceStability.Stable 036public class FileSplit extends org.apache.hadoop.mapreduce.InputSplit 037 implements InputSplitWithLocationInfo { 038 org.apache.hadoop.mapreduce.lib.input.FileSplit fs; 039 protected FileSplit() { 040 fs = new org.apache.hadoop.mapreduce.lib.input.FileSplit(); 041 } 042 043 /** Constructs a split. 044 * @deprecated 045 * @param file the file name 046 * @param start the position of the first byte in the file to process 047 * @param length the number of bytes in the file to process 048 */ 049 @Deprecated 050 public FileSplit(Path file, long start, long length, JobConf conf) { 051 this(file, start, length, (String[])null); 052 } 053 054 /** Constructs a split with host information 055 * 056 * @param file the file name 057 * @param start the position of the first byte in the file to process 058 * @param length the number of bytes in the file to process 059 * @param hosts the list of hosts containing the block, possibly null 060 */ 061 public FileSplit(Path file, long start, long length, String[] hosts) { 062 fs = new org.apache.hadoop.mapreduce.lib.input.FileSplit(file, start, 063 length, hosts); 064 } 065 066 /** Constructs a split with host information 067 * 068 * @param file the file name 069 * @param start the position of the first byte in the file to process 070 * @param length the number of bytes in the file to process 071 * @param hosts the list of hosts containing the block, possibly null 072 * @param inMemoryHosts the list of hosts containing the block in memory 073 */ 074 public FileSplit(Path file, long start, long length, String[] hosts, 075 String[] inMemoryHosts) { 076 fs = new org.apache.hadoop.mapreduce.lib.input.FileSplit(file, start, 077 length, hosts, inMemoryHosts); 078 } 079 080 public FileSplit(org.apache.hadoop.mapreduce.lib.input.FileSplit fs) { 081 this.fs = fs; 082 } 083 084 /** The file containing this split's data. */ 085 public Path getPath() { return fs.getPath(); } 086 087 /** The position of the first byte in the file to process. */ 088 public long getStart() { return fs.getStart(); } 089 090 /** The number of bytes in the file to process. */ 091 public long getLength() { return fs.getLength(); } 092 093 public String toString() { return fs.toString(); } 094 095 //////////////////////////////////////////// 096 // Writable methods 097 //////////////////////////////////////////// 098 099 public void write(DataOutput out) throws IOException { 100 fs.write(out); 101 } 102 public void readFields(DataInput in) throws IOException { 103 fs.readFields(in); 104 } 105 106 public String[] getLocations() throws IOException { 107 return fs.getLocations(); 108 } 109 110 @Override 111 @Evolving 112 public SplitLocationInfo[] getLocationInfo() throws IOException { 113 return fs.getLocationInfo(); 114 } 115}