org.apache.pig.impl.bloom

Class HashFunction

java.lang.Object

org.apache.pig.impl.bloom.HashFunction

public class HashFunction
extends java.lang.Object

Field Summary

Fields

Modifier and Type	Field and Description
protected Hash	hashAlgorithm Hashing algorithm to use.
protected int	maxValue The maximum highest returned value.
protected int	nbHash The number of hashed values.

Constructor Summary

Constructors

Constructor and Description
HashFunction(int maxValue, int nbHash, int hashAlgorithm) Constructor.

Method Summary

Modifier and Type	Method and Description
void	clear() Clears this hash function.
int[]	hash(org.apache.hadoop.util.bloom.Key k) Hashes a specified key into several integers.

Methods inherited from class java.lang.Object

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

Field Detail

nbHash

protected int nbHash

The number of hashed values.

maxValue

protected int maxValue

The maximum highest returned value.

hashAlgorithm

protected Hash hashAlgorithm

Hashing algorithm to use.

Constructor Detail

HashFunction

public HashFunction(int maxValue,
                    int nbHash,
                    int hashAlgorithm)

Constructor.

Builds a hash function that must obey to a given maximum number of returned values and a highest value.

Parameters:

maxValue - The maximum highest returned value.

nbHash - The number of resulting hashed values.

hashAlgorithm - type of the hashing algorithm (see Hash).

Method Detail

clear

public void clear()

Clears this hash function. A NOOP

hash

public int[] hash(org.apache.hadoop.util.bloom.Key k)

Hashes a specified key into several integers.

Parameters:

k - The specified key.

Returns:

The array of hashed values.