SpookyV2.h File Reference

SpookyHash: a 128-bit noncryptographic hash function. More...

#include <stddef.h>
#include <stdint.h>

Go to the source code of this file.

Classes
class	SpookyHash

Macros
#define	INLINE   inline

Typedefs
typedef uint64_t	uint64
typedef uint32_t	uint32
typedef uint16_t	uint16
typedef uint8_t	uint8

Detailed Description

SpookyHash: a 128-bit noncryptographic hash function.

Author

Bob Jenkins

LICENSE

public domain

DESCRIPTION

SpookyHash: a 128-bit noncryptographic hash function By Bob Jenkins, public domain Oct 31 2010: alpha, framework + SpookyHash::Mix appears right Oct 31 2011: alpha again, Mix only good to 2^^69 but rest appears right Dec 31 2011: beta, improved Mix, tested it for 2-bit deltas Feb 2 2012: production, same bits as beta Feb 5 2012: adjusted definitions of uint* to be more portable Mar 30 2012: 3 bytes/cycle, not 4. Alpha was 4 but wasn't thorough enough. August 5 2012: SpookyV2 (different results)

Up to 3 bytes/cycle for long messages. Reasonably fast for short messages. All 1 or 2 bit deltas achieve avalanche within 1% bias per output bit.

This was developed for and tested on 64-bit x86-compatible processors. It assumes the processor is little-endian. There is a macro controlling whether unaligned reads are allowed (by default they are). This should be an equally good hash on big-endian machines, but it will compute different results on them than on little-endian machines.

Google's CityHash has similar specs to SpookyHash, and CityHash is faster on new Intel boxes. MD4 and MD5 also have similar specs, but they are orders of magnitude slower. CRCs are two or more times slower, but unlike SpookyHash, they have nice math for combining the CRCs of pieces to form the CRCs of wholes. There are also cryptographic hashes, but those are even slower than MD5.

Macro Definition Documentation

#define INLINE   inline

Typedef Documentation

typedef uint16_t uint16

typedef uint32_t uint32

typedef uint64_t uint64

typedef uint8_t uint8