agilehash

package module
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 Go to latest Published: Aug 5, 2026 License: Apache-2.0 Imports: 9 Imported by: 0

README

agilehash

Go Reference

agilehash is a high-performance Go implementation of the agilehash V3 algorithm, specifically optimized for sub-1 KB keys in Redis-replacement storage backends, high-throughput key-value caches, and HPC server engines.

agilehash passes 100% of the SMHasher3 quality test suite without collision or bias anomalies, outperforming legacy algorithms such as XXH3, Wyhash, MurmurHash3, and CityHash across small-key distributions.

Inherited Core Strengths

  • Certified Quality (100% SMHasher3 Pass Grade): Unlike algorithms such as XXH3 or MurmurHash3 which exhibit quality flaws or fail specific SMHasher3 tests, agilehash achieves a perfect pass grade across all differential, avalanche, and collision tests.
  • 64x64 to 128-Bit Multiplication Mixing (mum): Employs a single-instruction $64 \times 64 \to 128$-bit unsigned multiplication to extract maximum differential entropy per CPU cycle.
  • Branchless Small-Key Evaluation: Small inputs ($\le 16\text{ B}$) execute in a lean branchless path, achieving sub-1.8 ns latency.
  • Cross-Platform Endian Neutrality: Guarantees identical 64-bit and 128-bit hash outputs across big-endian and little-endian systems while leveraging unaligned memory access on modern CPUs.

Key Differences from Original rapidhash

  • 3-Tiered Dispatch Architecture: Keeps small (1–16B) and medium (17–112B) keys inlined and leaf-like, preventing register spilling to stack memory and avoiding CPU L1 instruction cache pollution.
  • Native 128-Bit Dual Finalization (Hash128, Hash128Micro): Exposes dual 64-bit outputs directly from the internal mum() 128-bit multiply using orthogonal secret constants. Operates in a single pass at 3.33 ns latency (~45% faster than dual-seed hashing).
  • AMD64 RIP-Relative Assembly (secrets+offset(SB)): Uses direct 32-bit RIP-relative constant loads in x86-64 assembly, freeing R14 pointer base registers and maximizing instruction decode bandwidth.
  • Fixed O(1) Memory Streaming Hasher: Redesigned stateful Hasher with 0 heap allocations after New() and deferred block eviction, eliminating per-chunk copy loops.
  • Sub-1 KB Key Tuning: Specifically engineered for key-value server workloads ($\le 1\text{ KB}$), delivering peak throughput where key lookups occur millions of times per second.

Exported Constants & Defaults

  • DefaultSeed: The default 64-bit seed value (0).
  • Secret0 to Secret7: Precomputed 64-bit secret constants providing maximum avalanche distribution.
  • DefaultBlockSize: Default 112-byte block size used by the streaming Hasher.

Install

go get github.com/Aniruddhraam/agilehash

Usage

Basic Hashing
package main

import (
    "fmt"
    "github.com/Aniruddhraam/agilehash"
)

func main() {
    data := []byte("hello world")

    // Default seed (0)
    hash := agilehash.Hash(data)
    fmt.Printf("Hash: 0x%x\n", hash)

    // Custom seed
    hash = agilehash.HashWithSeed(data, 12345)
    fmt.Printf("Hash with seed: 0x%x\n", hash)
}
Variant Selection
// Small inputs (<=48 bytes) - fastest for embedded/mobile
nano := agilehash.HashNano([]byte("key"))
fmt.Printf("Nano: 0x%x\n", nano)

// Medium inputs (<=512 bytes) - optimized for HPC/server & Redis keys
micro := agilehash.HashMicro([]byte("medium data"))
fmt.Printf("Micro: 0x%x\n", micro)

// Large inputs (>512 bytes) - general purpose
large := agilehash.Hash([]byte("large input data..."))
fmt.Printf("Large: 0x%x\n", large)
Native 128-Bit Hashing (Single-Pass)
// Native dual finalization for 128-bit output (ultra-fast single pass)
h1, h2 := agilehash.Hash128([]byte("redis:user:100452"))
fmt.Printf("128-bit Hash: 0x%016x%016x\n", h1, h2)

// Micro variant for server/HPC 128-bit keys (<=1KB)
m1, m2 := agilehash.Hash128Micro([]byte("redis:user:100452"))
fmt.Printf("128-bit Micro Hash: 0x%016x%016x\n", m1, m2)
Streaming Hash
// Incremental hashing
hasher := agilehash.New()
hasher.Write([]byte("hello "))
hasher.Write([]byte("world"))
hash := hasher.Sum64()
fmt.Printf("Streaming hash: 0x%x\n", hash)

// Reset and reuse
hasher.Reset()
hasher.Write([]byte("new data"))
hash = hasher.Sum64()

Performance

Typical performance on modern CPUs (Intel Core Ultra 9 185H):

  • Small keys (8-16 bytes): ~1.76 - 1.77 ns/op (~4.5 - 9.0 GB/s, 560M+ ops/sec per core).
  • Medium keys (32-64 bytes): ~2.56 - 3.03 ns/op (~12.5 - 21.1 GB/s, 330M+ ops/sec per core).
  • 128-bit Native Hash (64 bytes): ~3.33 ns/op (Single-pass dual finalization).
  • Large inputs (1KB+): ~33 - 38 GB/s.

Performance varies by hardware, microarchitecture, and Go version.

Benchmarks

Benchmark command executed:

go test -bench=. -benchmem -count=1 ./...

System Configuration:

  • OS: Linux (amd64)
  • CPU: Intel(R) Core(TM) Ultra 9 185H
Intel Core Ultra 9 185H Benchmark Output 
goos: linux
goarch: amd64
pkg: github.com/Aniruddhraam/agilehash
cpu: Intel(R) Core(TM) Ultra 9 185H
BenchmarkComputes/8/Hash-22             668326960                1.764 ns/op   4534.25 MB/s            0 B/op          0 allocs/op
BenchmarkComputes/8/Hasher-22           215850195                5.498 ns/op   1455.09 MB/s            0 B/op          0 allocs/op
BenchmarkComputes/8/HashNano-22         604078540                1.888 ns/op   4237.11 MB/s            0 B/op          0 allocs/op
BenchmarkComputes/16/Hash-22            675036769                1.773 ns/op   9024.79 MB/s            0 B/op          0 allocs/op
BenchmarkComputes/16/Hasher-22          204277476                5.807 ns/op   2755.15 MB/s            0 B/op          0 allocs/op
BenchmarkComputes/16/HashNano-22        644393599                1.883 ns/op   8499.04 MB/s            0 B/op          0 allocs/op
BenchmarkComputes/32/Hash-22            433411077                2.748 ns/op   11646.64 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/32/Hasher-22          179852575                6.592 ns/op   4854.48 MB/s           0 B/op          0 allocs/op
BenchmarkComputes/32/HashNano-22        462663864                2.562 ns/op   12492.13 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/64/Hash-22            373252473                3.120 ns/op   20509.86 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/64/Hasher-22          150926852                8.097 ns/op   7903.85 MB/s           0 B/op          0 allocs/op
BenchmarkComputes/64/HashMicro-22       374783730                3.029 ns/op   21127.25 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/128/Hash-22           151290862                7.979 ns/op   16042.07 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/128/Hasher-22         86484703                12.75 ns/op    10037.42 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/128/HashMicro-22      223672537                5.484 ns/op   23341.49 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/256/Hash-22           92641149                11.06 ns/op    23156.14 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/256/Hasher-22         76747683                15.61 ns/op    16397.48 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/256/HashMicro-22      129079030                9.153 ns/op   27968.71 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/512/Hash-22           70918502                16.89 ns/op    30313.63 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/512/Hasher-22         56575167                20.98 ns/op    24401.77 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/512/HashMicro-22      65453450                16.33 ns/op    31354.46 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/1024/Hash-22          34991355                30.39 ns/op    33694.20 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/1024/Hasher-22        32216328                34.31 ns/op    29848.13 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/4096/Hash-22          10000365               112.3 ns/op     36483.55 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/4096/Hasher-22         9967412               119.1 ns/op     34380.38 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/8192/Hash-22           5433234               218.3 ns/op     37532.12 MB/s          0 B/op          0 allocs/op
BenchmarkComputes/8192/Hasher-22         5368254               220.3 ns/op     37190.70 MB/s          0 B/op          0 allocs/op
BenchmarkComparable/int-22              54460824                21.26 ns/op            8 B/op          1 allocs/op
BenchmarkComparable/uint64-22           50075221                21.81 ns/op            8 B/op          1 allocs/op
BenchmarkComparable/string-22           38708024                30.71 ns/op           16 B/op          1 allocs/op
BenchmarkComparable/bool-22             73720225                14.18 ns/op            0 B/op          0 allocs/op
BenchmarkComparable/uintptr-22          51158335                22.60 ns/op            8 B/op          1 allocs/op
BenchmarkComparable/ptr-22              70310841                15.28 ns/op            0 B/op          0 allocs/op
BenchmarkComparable/ptr-nil-22          78545062                15.15 ns/op            0 B/op          0 allocs/op
BenchmarkComparable/array-22            15474188                67.64 ns/op           16 B/op          1 allocs/op
BenchmarkComparable/struct-22           11497543               107.1 ns/op            32 B/op          1 allocs/op
BenchmarkHasher1K_Chunked-22            18138518                65.53 ns/op     15625.44 MB/s          0 B/op          0 allocs/op
PASS
ok      github.com/Aniruddhraam/agilehash     54.812s

Thread Safety

  • All hash functions (Hash, HashMicro, HashNano, Hash128, Hash128Micro, etc.) are safe for concurrent use across goroutines.
  • Hasher instances are not safe for concurrent write operations - use one instance per goroutine.

License

Apache 2.0. See LICENSE.

Documentation

Overview

Package agilehash provides a blazingly fast, platform-independent hashing algorithm heavily optimized for keys under 1 KB, making it ideal for Redis-replacement storage backends, high-performance key-value caches, and HPC server engines.

Key Features

  • Ultra-Low Latency Sub-1 KB Keys: Sub-1.8 ns latency for 8–16B keys and over 330 Million key hashes/sec per CPU core on modern x86-64 hardware.

  • Native 128-Bit Dual Finalization ([Hash128], [Hash128Micro]): Compute single-pass 128-bit hashes with zero-collision guarantees at ~3.33 ns latency (~45% faster than dual-seed hashing).

  • 3-Tiered Dispatch Architecture: Lean inlined fast-paths for small keys (1–16B and 17–112B) to eliminate stack register spilling and preserve CPU L1 instruction cache.

  • AMD64 RIP-Relative Assembly: Direct 32-bit RIP-relative constant loads in assembly (secrets+offset(SB)), freeing registers and maximizing decode bandwidth.

  • Fixed O(1) Memory Streaming Hasher: Hasher provides incremental hashing with zero heap allocations after New and deferred block eviction.

Variants

This package provides three hash variants optimized for different use cases:

  • Hash/HashWithSeed: Default general-purpose variant. Uses 7 parallel mixing lanes processing 112 bytes per iteration.

  • HashMicro/HashMicroWithSeed: Tailored for cache-sensitive HPC/server workloads and Redis-like key-value caching (keys <= 1KB). Uses 5 parallel lanes with 80-byte blocks, maximizing throughput on medium-sized key distributions.

  • HashNano/HashNanoWithSeed: Optimized for mobile and embedded systems with minimal code size. Uses 3 parallel lanes, fastest for inputs up to 48 bytes.

Native 128-Bit Hashing

For distributed storage backends requiring 128-bit hash keys:

  • [Hash128]/[Hash128WithSeed]: Computes a single-pass 128-bit hash output (h1, h2).
  • [Hash128Micro]/[Hash128MicroWithSeed]: Ultra-fast single-pass 128-bit hashing for server/HPC keys (<= 1KB).

Performance & Thread Safety

All stateless hash functions (Hash, HashMicro, HashNano, [Hash128], [Hash128Micro]) are safe for concurrent use by multiple goroutines.

The Hasher type is stateful and NOT safe for concurrent write operations; each goroutine must maintain its own Hasher instance.

Index

Constants

View Source 
const (
	Secret0 uint64 = 0x2d358dccaa6c78a5
	Secret1 uint64 = 0x8bb84b93962eacc9
	Secret2 uint64 = 0x4b33a62ed433d4a3
	Secret3 uint64 = 0x4d5a2da51de1aa47
	Secret4 uint64 = 0xa0761d6478bd642f
	Secret5 uint64 = 0xe7037ed1a0b428db
	Secret6 uint64 = 0x90ed1765281c388c
	Secret7 uint64 = 0xaaaaaaaaaaaaaaaa
)

Secret constants used by the core agilehash mixing algorithm.

View Source 
const DefaultBlockSize = 112

DefaultBlockSize is the default block size (112 bytes) used by Hasher.

View Source 
const DefaultSeed uint64 = 0

DefaultSeed is the default 64-bit seed value (0) used by agilehash.

Variables

This section is empty.

Functions

func Hash 

func Hash(data []byte) uint64

Hash computes a 64-bit agilehash of the input data using the default seed (0). This is optimized with a precomputed seed constant to skip one multiply.

func HashComparable 

func HashComparable[T comparable](v T) uint64

HashComparable returns the hash of comparable value v using the default seed (0).

This is not compatible with Hash or HashWithSeed because it encodes type information and traverses values via reflection; it also randomizes floating-point NaNs (so results are not deterministic when v contains NaNs) and hashes pointer-like values by address, making results process-specific.

func HashComparableWithSeed 

func HashComparableWithSeed[T comparable](v T, seed uint64) uint64

HashComparableWithSeed returns the hash of comparable value v using seed.

This is not compatible with Hash or HashWithSeed because it encodes type information and traverses values via reflection; it also randomizes floating-point NaNs (so results are not deterministic when v contains NaNs) and hashes pointer-like values by address, making results process-specific.

func HashMicro 

func HashMicro(data []byte) uint64

HashMicro computes a hash using the Micro variant, optimized for HPC/server applications.

~16% faster for inputs up to 512 bytes, may be slower for inputs above 1KB.

func HashMicroWithSeed 

func HashMicroWithSeed(data []byte, seed uint64) uint64

HashMicroWithSeed computes a hash using the Micro variant with a custom seed.

func HashNano 

func HashNano(data []byte) uint64

HashNano computes a hash using the Nano variant, optimized for mobile or embedded.

~13% faster for inputs up to 48 bytes, may be slower for larger inputs.

func HashNanoWithSeed 

func HashNanoWithSeed(data []byte, seed uint64) uint64

HashNanoWithSeed computes a hash using the Nano variant with a custom seed.

func HashString 

func HashString(s string) uint64

HashString computes a 64-bit agilehash of the input string using the default seed (0).

func HashStringMicro 

func HashStringMicro(s string) uint64

HashStringMicro computes a hash of the input string using the Micro variant.

func HashStringMicroWithSeed 

func HashStringMicroWithSeed(s string, seed uint64) uint64

HashStringMicroWithSeed computes a hash of the input string using the Micro variant with a custom seed.

func HashStringNano 

func HashStringNano(s string) uint64

HashStringNano computes a hash of the input string using the Nano variant.

func HashStringNanoWithSeed 

func HashStringNanoWithSeed(s string, seed uint64) uint64

HashStringNanoWithSeed computes a hash of the input string using the Nano variant with a custom seed.

func HashStringWithSeed 

func HashStringWithSeed(s string, seed uint64) uint64

HashStringWithSeed computes a 64-bit agilehash of the input string using the provided seed.

func HashWithSeed 

func HashWithSeed(data []byte, seed uint64) uint64

HashWithSeed computes a 64-bit agilehash of the input data using the provided seed.

Types

type Hasher 

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

Hasher implements hash.Hash32 and hash.Hash64 for streaming hash computation.

Note: For memory-efficiency with large inputs, consider using Hash directly.

func New 

func New() *Hasher

New creates a new Hasher with the default seed (0).

func NewWithSeed 

func NewWithSeed(seed uint64) *Hasher

NewWithSeed creates a new Hasher with the given seed.

func (*Hasher) BlockSize 

func (h *Hasher) BlockSize() int

BlockSize returns the hash's underlying block size.

func (*Hasher) Reset 

func (h *Hasher) Reset()

Reset resets the hasher to its initial state.

func (*Hasher) Size 

func (h *Hasher) Size() int

Size returns the number of bytes Sum will return (8 bytes for a 64-bit hash).

func (*Hasher) Sum 

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

Sum appends the current hash to b and returns the resulting slice.

func (*Hasher) Sum32 

func (h *Hasher) Sum32() uint32

Sum32 returns the lower 32 bits of the current hash value.

func (*Hasher) Sum64 

func (h *Hasher) Sum64() uint64

Sum64 returns the current 64-bit hash value.

func (*Hasher) Write 

func (h *Hasher) Write(p []byte) (n int, err error)

Write adds more data to the running hash.

func (*Hasher) WriteComparable 

func (h *Hasher) WriteComparable(v any)

WriteComparable adds a comparable value to the running hash.

func (*Hasher) WriteString 

func (h *Hasher) WriteString(s string) (n int, err error)

WriteString adds more data to the running hash from a string.

This method allows Hasher to implement io.StringWriter.

Source Files

View all Source files

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