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