Package org.apache.commons.collections4.bloomfilter

Class IndexFilter

java.lang.Object

org.apache.commons.collections4.bloomfilter.IndexFilter

public final class IndexFilter
extends Object

A convenience class for Hasher implementations to filter out duplicate indices.

If the index is negative the behavior is not defined.

This is conceptually a unique filter implemented as an IntPredicate.

Since:

4.5.0-M1

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	IndexFilter.ArrayTracker	An IndexTracker implementation that uses an array of integers to track whether or not a number has been seen.
(package private) static class	IndexFilter.BitMapTracker	An IndexTracker implementation that uses an array of bit maps to track whether or not a number has been seen.

Field Summary

Fields

Modifier and Type	Field	Description
private final IntPredicate	consumer
private final int	size
private final IntPredicate	tracker

Constructor Summary

Constructors

Modifier	Constructor	Description
private	IndexFilter(Shape shape, IntPredicate consumer)	Creates an instance optimized for the specified shape.

Method Summary

Modifier and Type	Method	Description
static IntPredicate	create(Shape shape, IntPredicate consumer)	Creates an instance optimized for the specified shape.
boolean	test(int number)	Test if the number should be processed by the consumer.

Methods inherited from class java.lang.Object

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

Field Details

tracker

private final IntPredicate tracker

size

private final int size

consumer

private final IntPredicate consumer

Constructor Details

IndexFilter

private IndexFilter(Shape shape,
 IntPredicate consumer)

Creates an instance optimized for the specified shape.

Parameters:

shape - The shape that is being generated.

consumer - The consumer to accept the values.

Method Details

create

public static IntPredicate create(Shape shape,
 IntPredicate consumer)

Creates an instance optimized for the specified shape.

Parameters:

shape - The shape that is being generated.

consumer - The consumer to accept the values.

Returns:

an IndexFilter optimized for the specified shape.

test

public boolean test(int number)

Test if the number should be processed by the consumer.

If the number has not been seen before it is passed to the consumer and the result returned. If the number has been seen before the consumer is not called and true returned.

If the input is not in the range [0,size) an IndexOutOfBoundsException exception is thrown.

Parameters:

number - the number to check.

Returns:

true if processing should continue, false otherwise.