org.apache.hadoop.examples.terasort

Class TeraInputFormatWithCRC

java.lang.Object

org.apache.hadoop.mapred.FileInputFormat<org.apache.hadoop.io.Text,org.apache.hadoop.io.Text>

org.apache.hadoop.examples.terasort.TeraInputFormatWithCRC

All Implemented Interfaces:

org.apache.hadoop.mapred.InputFormat<org.apache.hadoop.io.Text,org.apache.hadoop.io.Text>

public class TeraInputFormatWithCRC
extends org.apache.hadoop.mapred.FileInputFormat<org.apache.hadoop.io.Text,org.apache.hadoop.io.Text>

An input format that reads the first 10 characters of each line as the key and the rest of the line as the value. Both key and value are represented as Text.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapred.FileInputFormat

org.apache.hadoop.mapred.FileInputFormat.Counter

Field Summary

Fields inherited from class org.apache.hadoop.mapred.FileInputFormat

INPUT_DIR_RECURSIVE, LOG, NUM_INPUT_FILES

Constructor Summary

Constructors

Constructor and Description
TeraInputFormatWithCRC()

Method Summary

Methods

Modifier and Type	Method and Description
org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.Text,org.apache.hadoop.io.Text>	getRecordReader(org.apache.hadoop.mapred.InputSplit split, org.apache.hadoop.mapred.JobConf job, org.apache.hadoop.mapred.Reporter reporter)
org.apache.hadoop.mapred.InputSplit[]	getSplits(org.apache.hadoop.mapred.JobConf conf, int splits)
static void	writePartitionFile(org.apache.hadoop.mapred.JobConf conf, org.apache.hadoop.fs.Path partFile) Use the input splits to take samples of the input and generate sample keys.

Methods inherited from class org.apache.hadoop.mapred.FileInputFormat

addInputPath, addInputPathRecursively, addInputPaths, computeSplitSize, getBlockIndex, getInputPathFilter, getInputPaths, getSplitHosts, isSplitable, listStatus, makeSplit, setInputPathFilter, setInputPaths, setInputPaths, setMinSplitSize

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TeraInputFormatWithCRC

public TeraInputFormatWithCRC()

Method Detail

writePartitionFile

public static void writePartitionFile(org.apache.hadoop.mapred.JobConf conf,
                      org.apache.hadoop.fs.Path partFile)
                               throws IOException

Use the input splits to take samples of the input and generate sample keys. By default reads 100,000 keys from 10 locations in the input, sorts them and picks N-1 keys to generate N equally sized partitions.

Parameters:

conf - the job to sample

partFile - where to write the output file to

Throws:

IOException - if something goes wrong

getRecordReader

public org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.Text,org.apache.hadoop.io.Text> getRecordReader(org.apache.hadoop.mapred.InputSplit split,
                                                                                                         org.apache.hadoop.mapred.JobConf job,
                                                                                                         org.apache.hadoop.mapred.Reporter reporter)
                                                                                                           throws IOException

Specified by:

getRecordReader in interface org.apache.hadoop.mapred.InputFormat<org.apache.hadoop.io.Text,org.apache.hadoop.io.Text>

Specified by:

getRecordReader in class org.apache.hadoop.mapred.FileInputFormat<org.apache.hadoop.io.Text,org.apache.hadoop.io.Text>

Throws:

IOException

getSplits

public org.apache.hadoop.mapred.InputSplit[] getSplits(org.apache.hadoop.mapred.JobConf conf,
                                              int splits)
                                                throws IOException

Specified by:

getSplits in interface org.apache.hadoop.mapred.InputFormat<org.apache.hadoop.io.Text,org.apache.hadoop.io.Text>

Overrides:

getSplits in class org.apache.hadoop.mapred.FileInputFormat<org.apache.hadoop.io.Text,org.apache.hadoop.io.Text>

Throws:

IOException