com.github.lovasoa.bloomfilter

Class BloomFilter

java.lang.Object

com.github.lovasoa.bloomfilter.BloomFilter

All Implemented Interfaces:

Cloneable

public class BloomFilter
extends Object
implements Cloneable

Constructor Summary

Constructors

Constructor and Description
BloomFilter(int n) Create a bloom filter of 1Mib.
BloomFilter(int n, int m) Create a new bloom filter.

Method Summary

Modifier and Type	Method and Description
void	add(Object o) Add an element to the container
void	clear() Removes all of the elements from this filter.
BloomFilter	clone() Create a copy of the current filter
boolean	contains(Object o) Returns true if the element is in the container.
boolean	equals(BloomFilter other) Test if the filters have equal bitsets.
int	hashCode() Generate a unique hash representing the filter
void	merge(BloomFilter other) Merge another bloom filter into the current one.

Methods inherited from class java.lang.Object

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

Constructor Detail

BloomFilter

public BloomFilter(int n,
                   int m)

Create a new bloom filter.

Parameters:

n - Expected number of elements

m - Desired size of the container in bits

BloomFilter

public BloomFilter(int n)

Create a bloom filter of 1Mib.

Parameters:

n - Expected number of elements

Method Detail

add

public void add(Object o)

Add an element to the container

contains

public boolean contains(Object o)

Returns true if the element is in the container. Returns false with a probability ≈ 1-e^(-ln(2)² * m/n) if the element is not in the container.

clear

public void clear()

Removes all of the elements from this filter.

clone

public BloomFilter clone()
                  throws CloneNotSupportedException

Create a copy of the current filter

Overrides:

clone in class Object

Throws:

CloneNotSupportedException

hashCode

public int hashCode()

Generate a unique hash representing the filter

Overrides:

hashCode in class Object

equals

public boolean equals(BloomFilter other)

Test if the filters have equal bitsets. WARNING: two filters may contain the same elements, but not be equal (if the filters have different size for example).

merge

public void merge(BloomFilter other)

Merge another bloom filter into the current one. After this operation, the current bloom filter contains all elements in other.