MurmurHash.Net

Extremely fast MurmurHash3 implementation with zero heap allocations

This is a fork of the System.Data.HashFunction.MurmurHash.

Differences

• Faster (zero heap allocations via Spans, reduced class inheritance, bytes to uint conversion optimisations)
• Only 32-bit output hash value. Maybe 128-bit will be supported in the future. But you can implement it by yourself and send me PR :)

Installation

This project is available as a NuGet package

Example

Some code 1. You can use traditional byte[]

uint hash = MurmurHash3.Hash32(bytes: new byte[]{1,2,3}, seed: 123456U);
Console.WriteLine(hash);

Output 1

3800434721

Some code 2. State-of-the-art Span<byte> and ReadOnlySpan<byte> also supported

ReadOnlySpan<byte> span = ...
uint hash = MurmurHash3.Hash32(bytes: span, seed: 123456U);

Benchmarks

// * Summary *

BenchmarkDotNet=v0.12.0, OS=macOS Mojave 10.14.6 (18G103) [Darwin 18.7.0]
Intel Core i7-7660U CPU 2.50GHz (Kaby Lake), 1 CPU, 4 logical and 2 physical cores
.NET Core SDK=3.1.100
  [Host]     : .NET Core 3.1.0 (CoreCLR 4.700.19.56402, CoreFX 4.700.19.56404), X64 RyuJIT
  DefaultJob : .NET Core 3.1.0 (CoreCLR 4.700.19.56402, CoreFX 4.700.19.56404), X64 RyuJIT

Byte[] to uint

Method	Mean	StdDev	Ratio	RatioSD	Gen 0	Allocated
CRC32	40.73 us	0.696 us	3.32	0.06	-	-
XxHash	197.13 us	10.995 us	15.65	0.62	87.8906	184000 B
MurMurHashByDarrenkopp	51.46 us	3.469 us	4.04	0.16	15.3198	32000 B
Blake2B	91.83 us	3.949 us	7.57	0.41	7.5684	16000 B
MurMurHashNet	12.28 us	0.122 us	1.00	0.00	-	-

String to uint

Method	Mean	StdDev	Ratio	RatioSD	Gen 0	Allocated
CRC32	65.63 us	1.385 us	3.00	0.08	15.2588	32000 B
XxHash	228.36 us	21.086 us	9.52	0.28	103.2715	216000 B
MurMurHashByDarrenkopp	77.14 us	2.490 us	3.53	0.15	30.6396	64000 B
Blake2B	119.69 us	2.443 us	5.46	0.18	22.9492	48000 B
MurMurHashNet	21.91 us	0.364 us	1.00	0.00	-	-

Legend

• CRC32 - https://www.nuget.org/packages/Crc32/1.1.0
• XxHash - https://www.nuget.org/packages/System.Data.HashFunction.xxHash/2.0.0
• MurMurHashByDarrenkopp - https://www.nuget.org/packages/murmurhash/1.0.3
• Blake2B - https://www.nuget.org/packages/SauceControl.Blake2Fast/1.0.0
• MurMurHashNet - https://www.nuget.org/packages/MurmurHash.Net/0.0.1 (this repo)