Package net.spy.memcached

Enum DefaultHashAlgorithm

java.lang.Object

java.lang.Enum<DefaultHashAlgorithm>

net.spy.memcached.DefaultHashAlgorithm

All Implemented Interfaces:

Serializable, Comparable<DefaultHashAlgorithm>, java.lang.constant.Constable, HashAlgorithm

public enum DefaultHashAlgorithm
extends Enum<DefaultHashAlgorithm>
implements HashAlgorithm

Known hashing algorithms for locating a server for a key. Note that all hash algorithms return 64-bits of hash, but only the lower 32-bits are significant. This allows a positive 32-bit number to be returned for all cases.

Nested Class Summary

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

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
CRC_HASH	CRC_HASH as used by the perl API.
FNV1_32_HASH	32-bit FNV1.
FNV1_64_HASH	FNV hashes are designed to be fast while maintaining a low collision rate.
FNV1A_32_HASH	32-bit FNV1a.
FNV1A_64_HASH	Variation of FNV.
KETAMA_HASH	SHA-384 based hash algorithm used by ketama.
NATIVE_HASH	Native hash (String.hashCode()).

Method Summary

Modifier and Type	Method	Description
static byte[]	computeHashDigest(String k)	Get the hash digest of the given key.
long	hash(String k)	Compute the hash for the given key.
static DefaultHashAlgorithm	valueOf(String name)	Returns the enum constant of this type with the specified name.
static DefaultHashAlgorithm[]	values()	Returns an array containing the constants of this enum type, 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

Enum Constant Details

NATIVE_HASH

public static final DefaultHashAlgorithm NATIVE_HASH

Native hash (String.hashCode()).

CRC_HASH

public static final DefaultHashAlgorithm CRC_HASH

CRC_HASH as used by the perl API. This will be more consistent both across multiple API users as well as java versions, but is mostly likely significantly slower.

FNV1_64_HASH

public static final DefaultHashAlgorithm FNV1_64_HASH

FNV hashes are designed to be fast while maintaining a low collision rate. The FNV speed allows one to quickly hash lots of data while maintaining a reasonable collision rate.

See Also:

• fnv comparisons
• fnv at wikipedia

FNV1A_64_HASH

public static final DefaultHashAlgorithm FNV1A_64_HASH

Variation of FNV.

FNV1_32_HASH

public static final DefaultHashAlgorithm FNV1_32_HASH

32-bit FNV1.

FNV1A_32_HASH

public static final DefaultHashAlgorithm FNV1A_32_HASH

32-bit FNV1a.

KETAMA_HASH

public static final DefaultHashAlgorithm KETAMA_HASH

SHA-384 based hash algorithm used by ketama.

Method Details

values

public static DefaultHashAlgorithm[] values()

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

Returns:

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

valueOf

public static DefaultHashAlgorithm valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (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 type has no constant with the specified name

NullPointerException - if the argument is null

hash

public long hash(String k)

Compute the hash for the given key.

Specified by:

hash in interface HashAlgorithm

Returns:

a positive integer hash

computeHashDigest

public static byte[] computeHashDigest(String k)

Get the hash digest of the given key.