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    }