Package org.elasticsearch.common.hash

Enum Class MurmurHash3

java.lang.Object

java.lang.Enum<MurmurHash3>

org.elasticsearch.common.hash.MurmurHash3

All Implemented Interfaces:

Serializable, Comparable<MurmurHash3>, Constable

public enum MurmurHash3
extends Enum<MurmurHash3>

MurmurHash3 hashing functions.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MurmurHash3.Hash128	A 128-bits hash.

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Method Summary

Modifier and Type	Method	Description
protected static long	fmix(long k)
protected static long	getblock(byte[] key, int offset, int index)
static MurmurHash3.Hash128	hash128(byte[] key, int offset, int length, long seed, MurmurHash3.Hash128 hash)	Compute the hash of the MurmurHash3_x64_128 hashing function.
static long	murmur64(long h)	A 64-bit variant which accepts a long to hash, and returns the 64bit long hash.
static MurmurHash3	valueOf(String name)	Returns the enum constant of this class with the specified name.
static MurmurHash3[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Method Details

values

public static MurmurHash3[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static MurmurHash3 valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum class has no constant with the specified name

NullPointerException - if the argument is null

getblock

protected static long getblock(byte[] key,
 int offset,
 int index)

fmix

protected static long fmix(long k)

hash128

public static MurmurHash3.Hash128 hash128(byte[] key,
 int offset,
 int length,
 long seed,
 MurmurHash3.Hash128 hash)

Compute the hash of the MurmurHash3_x64_128 hashing function. Note, this hashing function might be used to persist hashes, so if the way hashes are computed changes for some reason, it needs to be addressed (like in BloomFilter and MurmurHashField).

murmur64

public static long murmur64(long h)

A 64-bit variant which accepts a long to hash, and returns the 64bit long hash. This is useful if the input is already in long (or smaller) format and you don't need the full 128b width and flexibility of hash128(byte[], int, int, long, Hash128) Given the limited nature of this variant, it should be faster than the 128b version when you only need 128b (many fewer instructions)