murmur3

README

MurmurHash3

A Golang Implementation of MurmurHash3.

Overview

Murmur3 is the 3rd version of MurmurHash by Austin Appleby. As described in wiki, it serves as a general hash-table lookup algorithm. When it comes to need of a cryptographic hash function, this should be definitely out of your choice.

Requirement

• go-1.11

Installation

go get -u -v github.com/sammyne/murmur3

References

• MurmurHash Wiki
• MurmurHash3

Documentation

Overview

Package murmur3 implements Austin Appleby's non-cryptographic MurmurHash3

Index

• Constants
• func FinalizeMix64(h uint64) uint64
• func FinalizeMix86(h uint32) uint32
• func Sum32(data []byte, seed uint32) [4]byte
• func Sum128(data []byte, seed uint32) [16]byte
• func SumUint32(key []byte, seed uint32) uint32

Constants

const (
	C1 = 0xcc9e2d51
	C2 = 0x1b873593
	R1 = 15
	R2 = 13
	M  = 5
	N  = 0xe6546b64

	// extra constants
	D1 = 0x85ebca6b
	D2 = 0xc2b2ae35
)

configuration contants for 32-bit hashing

const (
	CC1 uint64 = 0x87c37b91114253d5
	CC2 uint64 = 0x4cf5ad432745937f

	RR11 = 31
	RR12 = 33
	RR21 = 27
	RR22 = 31

	NN1 = 0x52dce729
	NN2 = 0x38495ab5

	DD1 uint64 = 0xff51afd7ed558ccd
	DD2 uint64 = 0xc4ceb9fe1a85ec53
)

constants enumeration for x64-128bit

Functions

func FinalizeMix64

func FinalizeMix64(h uint64) uint64

FinalizeMix64 is a bit finalizer obfuscating a 64-bit integer

func FinalizeMix86

func FinalizeMix86(h uint32) uint32

FinalizeMix86 is a bit finalizer obfuscating a 32-bit integer

func Sum32

func Sum32(data []byte, seed uint32) [4]byte

Sum32 serves an alias as SumUint32 but with the hashed data encoded as a 4-byte little-endian byte sequences

func Sum128

func Sum128(data []byte, seed uint32) [16]byte

Sum128 calculates the MurmurHash3 sum of data

func SumUint32

func SumUint32(key []byte, seed uint32) uint32

SumUint32 hashes the given 32-bit seed with the key block into a new 32-bit integer, based on the snippet as

key *= C1
key = rotl(key, R1)
key *= C2

hash ^= k

hash = rotl(hash, R1)
hash = hash*M+N