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 import java.io.DataInput;
023 import java.io.DataOutput;
024
025 import org.apache.hadoop.classification.InterfaceAudience;
026 import org.apache.hadoop.classification.InterfaceStability;
027 import org.apache.hadoop.classification.InterfaceStability.Evolving;
028 import 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
036 public 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 }