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 HashSeed(b []byte, seed uint64) uint64
• func HashString(s string) uint64
• func HashStringSeed(s string, seed uint64) uint64
• type Hasher
  • func New() *Hasher
  • func NewSeed(seed uint64) *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) Sum128() Uint128
  • func (h *Hasher) Sum64() uint64
  • func (h *Hasher) Write(buf []byte) (int, error)
  • func (h *Hasher) WriteString(buf string) (int, error)
• type Uint128
  • func Hash128(b []byte) Uint128
  • func Hash128Seed(b []byte, seed uint64) Uint128
  • func HashString128(s string) Uint128
  • func HashString128Seed(s string, seed uint64) Uint128
  • func (u Uint128) Bytes() [16]byte

Functions

func Hash

func Hash(b []byte) uint64

Hash returns the hash of the byte slice.

func HashSeed

func HashSeed(b []byte, seed uint64) uint64

HashSeed returns the hash of the byte slice with given seed.

func HashString

func HashString(s string) uint64

Hash returns the hash of the string slice.

func HashStringSeed

func HashStringSeed(s string, seed uint64) uint64

HashStringSeed returns the hash of the string slice with given seed.

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 NewSeed

func NewSeed(seed uint64) *Hasher

NewSeed 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) Sum128

func (h *Hasher) Sum128() Uint128

Sum128 returns the 128-bit hash of the written data.

func (*Hasher) Sum64

func (h *Hasher) Sum64() uint64

Sum64 returns the 64-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 Hash128Seed

func Hash128Seed(b []byte, seed uint64) Uint128

Hash128Seed 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 HashString128Seed

func HashString128Seed(s string, seed uint64) Uint128

HashString128Seed 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).