Package org.hibernate.search.util.common.data.impl

Class Murmur3HashFunction

java.lang.Object

org.hibernate.search.util.common.data.impl.Murmur3HashFunction

All Implemented Interfaces:

HashFunction, RangeCompatibleHashFunction

public final class Murmur3HashFunction
extends Object
implements RangeCompatibleHashFunction

A fast, but cryptographically insecure hash function, implementing Murmur3.

See MurmurHash3_x86_32 in the C++ implementation.

This function is more complex than SimpleHashFunction, but is suitable for use in RangeHashTable, because it produces a more uniform hash distribution, even for datasets with very similar strings (same length, small character set, ...).

MurmurHash3 was written by Austin Appleby, and is placed in the public domain. The author hereby disclaims copyright to this source code.

Original source code: http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp (Modified to adapt to Guava coding conventions and to use Guava's HashFunction interface, then modified again to adapt to Hibernate Search's coding conventions and to remove code that is unnecessary in Hibernate Search).

Author:

Austin Appleby, Dimitris Andreou, Kurt Alfred Kluever

Field Summary

Fields

Modifier and Type	Field	Description
static Murmur3HashFunction	INSTANCE

Method Summary

Modifier and Type	Method	Description
int	hash(CharSequence input)	Hashes a key, i.e.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final Murmur3HashFunction INSTANCE

Method Detail

toString

public String toString()

Overrides:

toString in class Object

hash

public int hash(CharSequence input)

Description copied from interface: HashFunction

Hashes a key, i.e. turns it into an integer for use in a HashTable.

Specified by:

hash in interface HashFunction

Parameters:

input - A key to hash.

Returns:

A hash.