DTLib.XXHash/src/Standart.Hash.xxHash/xxHash3.XXH.cs
Oleksandr Melnyk cb6236f476 Add xxHash3
2022-06-12 22:36:31 +03:00

86 lines
3.0 KiB
C#

// ReSharper disable InconsistentNaming
using System.Runtime.CompilerServices;
namespace Standart.Hash.xxHash
{
public static partial class xxHash3
{
private const ulong XXH_PRIME64_1 = 11400714785074694791UL;
private const ulong XXH_PRIME64_2 = 14029467366897019727UL;
private const ulong XXH_PRIME64_3 = 1609587929392839161UL;
private const ulong XXH_PRIME64_4 = 9650029242287828579UL;
private const ulong XXH_PRIME64_5 = 2870177450012600261UL;
private const uint XXH_PRIME32_1 = 2654435761U;
private const uint XXH_PRIME32_2 = 2246822519U;
private const uint XXH_PRIME32_3 = 3266489917U;
private const uint XXH_PRIME32_4 = 668265263U;
private const uint XXH_PRIME32_5 = 374761393U;
private const int XXH_STRIPE_LEN = 64;
private const int XXH_ACC_NB = XXH_STRIPE_LEN / 8;
private const int XXH_SECRET_CONSUME_RATE = 8;
private const int XXH_SECRET_DEFAULT_SIZE = 192;
private const int XXH_SECRET_MERGEACCS_START = 11;
private const int XXH_SECRET_LASTACC_START = 7;
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static unsafe ulong XXH_readLE64(byte* ptr)
{
return *(ulong*) ptr;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static unsafe uint XXH_readLE32(byte* ptr)
{
return *(uint*) ptr;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static ulong XXH_swap64(ulong x)
{
return ((x << 56) & 0xff00000000000000UL) |
((x << 40) & 0x00ff000000000000UL) |
((x << 24) & 0x0000ff0000000000UL) |
((x << 8) & 0x000000ff00000000UL) |
((x >> 8) & 0x00000000ff000000UL) |
((x >> 24) & 0x0000000000ff0000UL) |
((x >> 40) & 0x000000000000ff00UL) |
((x >> 56) & 0x00000000000000ffUL);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static ulong XXH_mult32to64(ulong x, ulong y)
{
return (ulong) (uint) (x) * (ulong) (uint) (y);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static ulong XXH_xorshift64(ulong v64, int shift)
{
return v64 ^ (v64 >> shift);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static uint XXH_swap32(uint x)
{
return ((x << 24) & 0xff000000) |
((x << 8) & 0x00ff0000) |
((x >> 8) & 0x0000ff00) |
((x >> 24) & 0x000000ff);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static ulong XXH_rotl64(ulong x, int r)
{
return (x << r) | (x >> (64 - r));
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static unsafe void XXH_writeLE64(byte* dst, ulong v64)
{
*(ulong*) dst = v64;
}
}
}