Murmur3

Murmur3 hash algorithm in C#

This small project is an implementation of the Murmur3 hash algorithm for 32-bit x86, 128-bit x86, and 128-bit x64 variants. All implemented classes descend from System.IO.Hashing's NonCryptographicHashAlgorithm, which should make for easy adoption.

Example:

namespace Murmur3Test
{
    using System;
    using System.Globalization;
    using System.IO.Hashing;
    using System.Text;
    
    using Murmur3;
    
    public static class Program
    {
        public static void Main()
        {
            NonCryptographicHashAlgorithm alg = new Murmur3F();

            alg.Append(Encoding.UTF8.GetBytes("foobar"));
            Console.WriteLine(((ulong)BitConverter.ToInt64(alg.GetCurrentHash(), 0)).ToString("X8", CultureInfo.InvariantCulture));
        }
    }
}

This will output BDD2AE7116C85A45 as the Murmur3 128-bit x64 hash of the string "foobar".

Benchmark Results

BenchmarkDotNet v0.15.6, Linux Ubuntu 24.04.3 LTS (Noble Numbat)
AMD EPYC 7763 3.21GHz, 1 CPU, 4 logical and 2 physical cores
.NET SDK 10.0.101
  [Host]     : .NET 10.0.1 (10.0.1, 10.0.125.57005), X64 RyuJIT x86-64-v3
  DefaultJob : .NET 10.0.1 (10.0.1, 10.0.125.57005), X64 RyuJIT x86-64-v3

Method	Mean	Error	StdDev
Murmur3A	33.33 μs	0.079 μs	0.066 μs
Murmur3C	31.57 μs	0.057 μs	0.050 μs
Murmur3F	18.58 μs	0.035 μs	0.031 μs