Package org.apache.hadoop.io

Class LongWritable.DecreasingComparator

java.lang.Object

org.apache.hadoop.io.WritableComparator

org.apache.hadoop.io.LongWritable.Comparator

org.apache.hadoop.io.LongWritable.DecreasingComparator

All Implemented Interfaces:

Comparator, Configurable, RawComparator

Enclosing class:

LongWritable

public static class LongWritable.DecreasingComparator
extends LongWritable.Comparator

A decreasing Comparator optimized for LongWritable.

Constructor Summary

Constructors

Constructor	Description
DecreasingComparator()

Method Summary

Modifier and Type	Method	Description
int	compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2)	Optimization hook.
int	compare(WritableComparable a, WritableComparable b)	Compare two WritableComparables.

Methods inherited from class org.apache.hadoop.io.WritableComparator

compare, compareBytes, define, get, get, getConf, getKeyClass, hashBytes, hashBytes, newKey, readDouble, readFloat, readInt, readLong, readUnsignedShort, readVInt, readVLong, setConf

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, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Details

DecreasingComparator

public DecreasingComparator()

Method Details

compare

public int compare(WritableComparable a,
 WritableComparable b)

Description copied from class: WritableComparator

Compare two WritableComparables. The default implementation uses the natural ordering, calling Comparable.compareTo(Object).

Overrides:

compare in class WritableComparator

Parameters:

a - the first object to be compared.

b - the second object to be compared.

Returns:

compare result.

compare

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

Description copied from class: WritableComparator

Optimization hook. Override this to make SequenceFile.Sorter's scream.

The default implementation reads the data into two WritableComparables (using Writable.readFields(DataInput), then calls WritableComparator.compare(WritableComparable,WritableComparable).

Specified by:

compare in interface RawComparator

Overrides:

compare in class LongWritable.Comparator

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.