hadoop PipesNonJavaInputFormat 源码

  • 2022-10-20
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haddop PipesNonJavaInputFormat 代码


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 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
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 *     http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.hadoop.mapred.pipes;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.FloatWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapred.InputFormat;
import org.apache.hadoop.mapred.InputSplit;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.RecordReader;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.TextInputFormat;
import org.apache.hadoop.util.ReflectionUtils;

 * Dummy input format used when non-Java a {@link RecordReader} is used by
 * the Pipes' application.
 * The only useful thing this does is set up the Map-Reduce job to get the
 * {@link PipesDummyRecordReader}, everything else left for the 'actual'
 * InputFormat specified by the user which is given by 
 * <i>mapreduce.pipes.inputformat</i>.
class PipesNonJavaInputFormat 
implements InputFormat<FloatWritable, NullWritable> {

  public RecordReader<FloatWritable, NullWritable> getRecordReader(
      InputSplit genericSplit, JobConf job, Reporter reporter)
      throws IOException {
    return new PipesDummyRecordReader(job, genericSplit);
  public InputSplit[] getSplits(JobConf job, int numSplits) throws IOException {
    // Delegate the generation of input splits to the 'original' InputFormat
    return ReflectionUtils.newInstance(
                     InputFormat.class), job).getSplits(job, numSplits);

   * A dummy {@link org.apache.hadoop.mapred.RecordReader} to help track the
   * progress of Hadoop Pipes' applications when they are using a non-Java
   * <code>RecordReader</code>.
   * The <code>PipesDummyRecordReader</code> is informed of the 'progress' of
   * the task by the {@link OutputHandler#progress(float)} which calls the
   * {@link #next(FloatWritable, NullWritable)} with the progress as the
   * <code>key</code>.
  static class PipesDummyRecordReader implements RecordReader<FloatWritable, NullWritable> {
    float progress = 0.0f;
    public PipesDummyRecordReader(Configuration job, InputSplit split)
    throws IOException{

    public FloatWritable createKey() {
      return null;

    public NullWritable createValue() {
      return null;

    public synchronized void close() throws IOException {}

    public synchronized long getPos() throws IOException {
      return 0;

    public float getProgress() {
      return progress;

    public synchronized boolean next(FloatWritable key, NullWritable value)
        throws IOException {
      progress = key.get();
      return true;


hadoop 源码目录


hadoop Application 源码

hadoop BinaryProtocol 源码

hadoop DownwardProtocol 源码

hadoop OutputHandler 源码

hadoop PipesMapRunner 源码

hadoop PipesPartitioner 源码

hadoop PipesReducer 源码

hadoop Submitter 源码

hadoop UpwardProtocol 源码

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