A pure C# implementation of xxhash algorithm
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README.md

xxHash.st

Extremely fast non-cryptographic hash algorithm xxhash


build coverage nuget platform license

xxHash is an Extremely fast Hash algorithm, running at RAM speed limits. It successfully completes the SMHasher test suite which evaluates collision, dispersion and randomness qualities of hash functions.

Instalation

PM> Install-Package Standart.Hash.xxHash

Benchmarks

This benchmark was launched on a Windows 10 (10.0.16299.309). The reference system uses a Intel Core i7-4700MQ CPU 2.40GHz (Haswell)

Method x64
Hash32 Array 5.05 GB/s
Hash64 Array 8.92 GB/s
Hash32 Span 5.05 GB/s
Hash64 Span 8.92 GB/s
Hash32 Stream 3.22 GB/s
Hash64 Stream 4.81 GB/s

Comparison between С# and C implementation

Method Platform Language 1KB Time 1MB Time 1GB Time Speed Difference
Hash32 x64 C# 185.1 ns 170.6 us 193.6 ms 5.16 GB/s 1.4 %
Hash32 x64 C 183.5 ns 170.1 us 190.8 ms 5.24 GB/s 1.4 %
Hash64 x64 C# 117.3 ns 87.1 us 116.9 ms 8.55 GB/s 2.4 %
Hash64 x64 C 104.8 ns 85.3 us 114.1 ms 8.76 GB/s 2.4 %

Api

public static uint ComputeHash(byte[] data, int length, uint seed = 0) { throw null; }
public static uint ComputeHash(Span<byte> data, int length, uint seed = 0) { throw null; }
public static uint ComputeHash(Stream stream, int bufferSize = 4096, uint seed = 0) { throw null; }
public static async ValueTask<uint> ComputeHashAsync(Stream stream, int bufferSize = 4096, uint seed = 0) { throw null; }

public static ulong ComputeHash(byte[] data, int length, ulong seed = 0) { throw null; }
public static ulong ComputeHash(Span<byte> data, int length, ulong seed = 0) { throw null; }
public static ulong ComputeHash(Stream stream, int bufferSize = 8192, ulong seed = 0) { throw null; }
public static async ValueTask<ulong> ComputeHashAsync(Stream stream, int bufferSize = 8192, ulong seed = 0) { throw null; }

Examples

A few examples of how to use api

byte[] data = Encoding.UTF8.GetBytes("veni vidi vici");

ulong h64_1 = xxHash64.ComputeHash(data, data.Length);
ulong h64_2 = xxHash64.ComputeHash(new Span<byte>(data), data.Length);
ulong h64_3 = xxHash64.ComputeHash(new ReadOnlySpan<byte>(data), data.Length);
ulong h64_4 = xxHash64.ComputeHash(new MemoryStream(data));
ulong h64_5 = await xxHash64.ComputeHashAsync(new MemoryStream(data));

uint h32_1 = xxHash32.ComputeHash(data, data.Length);
uint h32_2 = xxHash32.ComputeHash(new Span<byte>(data), data.Length);
uint h32_3 = xxHash32.ComputeHash(new ReadOnlySpan<byte>(data), data.Length);
uint h32_4 = xxHash32.ComputeHash(new MemoryStream(data));
uint h32_5 = await xxHash32.ComputeHashAsync(new MemoryStream(data));

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