org.apache.hadoop.examples

Class SecondarySort.FirstGroupingComparator

java.lang.Object

org.apache.hadoop.examples.SecondarySort.FirstGroupingComparator

All Implemented Interfaces:

Comparator<SecondarySort.IntPair>, RawComparator<SecondarySort.IntPair>

Enclosing class:

SecondarySort

public static class SecondarySort.FirstGroupingComparator
extends Object
implements RawComparator<SecondarySort.IntPair>

Compare only the first part of the pair, so that reduce is called once for each value of the first part.

Constructor Summary

Constructors

Constructor and Description
SecondarySort.FirstGroupingComparator()

Method Summary

Methods

Modifier and Type	Method and Description
int	compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) Compare two objects in binary.
int	compare(SecondarySort.IntPair o1, SecondarySort.IntPair o2)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals

Constructor Detail

SecondarySort.FirstGroupingComparator

public SecondarySort.FirstGroupingComparator()

Method Detail

compare

public int compare(byte[] b1,
          int s1,
          int l1,
          byte[] b2,
          int s2,
          int l2)

Description copied from interface: RawComparator

Compare two objects in binary. b1[s1:l1] is the first object, and b2[s2:l2] is the second object.

Specified by:

compare in interface RawComparator<SecondarySort.IntPair>

Parameters:

b1 - The first byte array.

s1 - The position index in b1. The object under comparison's starting index.

l1 - The length of the object in b1.

b2 - The second byte array.

s2 - The position index in b2. The object under comparison's starting index.

l2 - The length of the object under comparison in b2.

Returns:

An integer result of the comparison.

compare

public int compare(SecondarySort.IntPair o1,
          SecondarySort.IntPair o2)

Specified by:

compare in interface Comparator<SecondarySort.IntPair>