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  1. 66b1409 feat: add ristretto to the Projects using this package on by rfyiamcool · 9 weeks ago main
  2. fe2f6e8 Update Go versions for GH action by Caleb Spare · 6 months ago
  3. a76eb16 Fix staticcheck failure by Caleb Spare · 6 months ago v2.2.0
  4. 3c87ff8 Update README for arm64 asm; latest benchmarks by Caleb Spare · 6 months ago
  5. ced83c3 Rename register aliases by Caleb Spare · 6 months ago


Go Reference Test

xxhash is a Go implementation of the 64-bit xxHash algorithm, XXH64. This is a high-quality hashing algorithm that is much faster than anything in the Go standard library.

This package provides a straightforward API:

func Sum64(b []byte) uint64
func Sum64String(s string) uint64
type Digest struct{ ... }
    func New() *Digest

The Digest type implements hash.Hash64. Its key methods are:

func (*Digest) Write([]byte) (int, error)
func (*Digest) WriteString(string) (int, error)
func (*Digest) Sum64() uint64

The package is written with optimized pure Go and also contains even faster assembly implementations for amd64 and arm64. If desired, the purego build tag opts into using the Go code even on those architectures.


This package is in a module and the latest code is in version 2 of the module. You need a version of Go with at least “minimal module compatibility” to use

  • 1.9.7+ for Go 1.9
  • 1.10.3+ for Go 1.10
  • Go 1.11 or later

I recommend using the latest release of Go.


Here are some quick benchmarks comparing the pure-Go and assembly implementations of Sum64.

input sizepuregoasm
4 B1.3 GB/s1.2 GB/s
16 B2.9 GB/s3.5 GB/s
100 B6.9 GB/s8.1 GB/s
4 KB11.7 GB/s16.7 GB/s
10 MB12.0 GB/s17.3 GB/s

These numbers were generated on Ubuntu 20.04 with an Intel Xeon Platinum 8252C CPU using the following commands under Go 1.19.2:

benchstat <(go test -tags purego -benchtime 500ms -count 15 -bench 'Sum64$')
benchstat <(go test -benchtime 500ms -count 15 -bench 'Sum64$')

Projects using this package