xxh3

README

XXH3

This package is a port of the xxh3 library to Go.

Upstream has fixed the output as of v0.8.0, and this package matches that.

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Benchmarks

Run on my i7-8850H CPU @ 2.60GHz

Small Sizes

Bytes	Rate
0	0.74 ns/op
1-3	4.19 ns/op (0.24 GB/s - 0.71 GB/s)
4-8	4.16 ns/op (0.97 GB/s - 1.98 GB/s)
9-16	4.46 ns/op (2.02 GB/s - 3.58 GB/s)
17-32	6.22 ns/op (2.76 GB/s - 5.15 GB/s)
33-64	8.00 ns/op (4.13 GB/s - 8.13 GB/s)
65-96	11.0 ns/op (5.91 GB/s - 8.84 GB/s)
97-128	12.8 ns/op (7.68 GB/s - 10.0 GB/s)

Large Sizes

Bytes	Rate	SSE2 Rate	AVX2 Rate
129	13.6 ns/op (9.45 GB/s)
240	23.8 ns/op (10.1 GB/s)
241	40.5 ns/op (5.97 GB/s)	23.3 ns/op (10.4 GB/s)	20.1 ns/op (12.0 GB/s)
512	69.8 ns/op (7.34 GB/s)	30.4 ns/op (16.9 GB/s)	24.7 ns/op (20.7 GB/s)
1024	132 ns/op (7.77 GB/s)	48.9 ns/op (20.9 GB/s)	37.7 ns/op (27.2 GB/s)
100KB	13.0 us/op (7.88 GB/s)	4.05 us/op (25.3 GB/s)	2.31 us/op (44.3 GB/s)

Documentation

Index

• func Hash(b []byte) uint64
• func HashString(s string) uint64
• type Hasher
  • func New() *Hasher
  • func (h *Hasher) BlockSize() int
  • func (h *Hasher) Reset()
  • func (h *Hasher) Size() int
  • func (h *Hasher) Sum(b []byte) []byte
  • func (h *Hasher) Sum64() uint64
  • func (h *Hasher) Sum128() Uint128
  • func (h *Hasher) Write(buf []byte) (int, error)
  • func (h *Hasher) WriteString(buf string) (int, error)
• type Uint128
  • func Hash128(b []byte) Uint128
  • func HashString128(s string) Uint128
  • func (u Uint128) Bytes() [16]byte

Functions

func Hash

func Hash(b []byte) uint64

Hash returns the hash of the byte slice.

func HashString

func HashString(s string) uint64

Hash returns the hash of the string slice.

Types

type Hasher

type Hasher struct {
	// contains filtered or unexported fields
}

Hasher implements the hash.Hash interface

func New

func New() *Hasher

New returns a new Hasher that implements the hash.Hash interface.

func (*Hasher) BlockSize

func (h *Hasher) BlockSize() int

BlockSize returns the hash's underlying block size. The Write method will accept any amount of data, but it may operate more efficiently if all writes are a multiple of the block size.

func (*Hasher) Reset

func (h *Hasher) Reset()

Reset resets the Hash to its initial state.

func (*Hasher) Size

func (h *Hasher) Size() int

Size returns the number of bytes Sum will return.

func (*Hasher) Sum

func (h *Hasher) Sum(b []byte) []byte

Sum appends the current hash to b and returns the resulting slice. It does not change the underlying hash state.

func (*Hasher) Sum64

func (h *Hasher) Sum64() uint64

Sum64 returns the 64-bit hash of the written data.

func (*Hasher) Sum128

func (h *Hasher) Sum128() Uint128

Sum64 returns the 128-bit hash of the written data.

func (*Hasher) Write

func (h *Hasher) Write(buf []byte) (int, error)

Write adds more data to the running hash. It never returns an error.

func (*Hasher) WriteString

func (h *Hasher) WriteString(buf string) (int, error)

WriteString adds more data to the running hash. It never returns an error.

type Uint128

type Uint128 struct {
	Hi, Lo uint64
}

Uint128 is a 128 bit value. The actual value can be thought of as u.Hi<<64 | u.Lo.

func Hash128

func Hash128(b []byte) Uint128

Hash128 returns the 128-bit hash of the byte slice.

func HashString128

func HashString128(s string) Uint128

HashString128 returns the 128-bit hash of the string slice.

func (Uint128) Bytes

func (u Uint128) Bytes() [16]byte

Bytes returns the uint128 as an array of bytes in canonical form (big-endian encoded).