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| author | TSR Berry <20988865+TSRBerry@users.noreply.github.com> | 2023-04-08 01:22:00 +0200 |
|---|---|---|
| committer | Mary <thog@protonmail.com> | 2023-04-27 23:51:14 +0200 |
| commit | cee712105850ac3385cd0091a923438167433f9f (patch) | |
| tree | 4a5274b21d8b7f938c0d0ce18736d3f2993b11b1 /Ryujinx.Graphics.Gpu/Shader/HashTable/HashState.cs | |
| parent | cd124bda587ef09668a971fa1cac1c3f0cfc9f21 (diff) | |
Move solution and projects to src
Diffstat (limited to 'Ryujinx.Graphics.Gpu/Shader/HashTable/HashState.cs')
| -rw-r--r-- | Ryujinx.Graphics.Gpu/Shader/HashTable/HashState.cs | 113 |
1 files changed, 0 insertions, 113 deletions
diff --git a/Ryujinx.Graphics.Gpu/Shader/HashTable/HashState.cs b/Ryujinx.Graphics.Gpu/Shader/HashTable/HashState.cs deleted file mode 100644 index 584eefdc..00000000 --- a/Ryujinx.Graphics.Gpu/Shader/HashTable/HashState.cs +++ /dev/null @@ -1,113 +0,0 @@ -using System; -using System.Runtime.InteropServices; - -namespace Ryujinx.Graphics.Gpu.Shader.HashTable -{ - /// <summary> - /// State of a hash calculation. - /// </summary> - struct HashState - { - // This is using a slightly modified implementation of FastHash64. - // Reference: https://github.com/ztanml/fast-hash/blob/master/fasthash.c - private const ulong M = 0x880355f21e6d1965UL; - private ulong _hash; - private int _start; - - /// <summary> - /// One shot hash calculation for a given data. - /// </summary> - /// <param name="data">Data to be hashed</param> - /// <returns>Hash of the given data</returns> - public static uint CalcHash(ReadOnlySpan<byte> data) - { - HashState state = new HashState(); - - state.Initialize(); - state.Continue(data); - return state.Finalize(data); - } - - /// <summary> - /// Initializes the hash state. - /// </summary> - public void Initialize() - { - _hash = 23; - } - - /// <summary> - /// Calculates the hash of the given data. - /// </summary> - /// <remarks> - /// The full data must be passed on <paramref name="data"/>. - /// If this is not the first time the method is called, then <paramref name="data"/> must start with the data passed on the last call. - /// If a smaller slice of the data was already hashed before, only the additional data will be hashed. - /// This can be used for additive hashing of data in chuncks. - /// </remarks> - /// <param name="data">Data to be hashed</param> - public void Continue(ReadOnlySpan<byte> data) - { - ulong h = _hash; - - ReadOnlySpan<ulong> dataAsUlong = MemoryMarshal.Cast<byte, ulong>(data.Slice(_start)); - - for (int i = 0; i < dataAsUlong.Length; i++) - { - ulong value = dataAsUlong[i]; - - h ^= Mix(value); - h *= M; - } - - _hash = h; - _start = data.Length & ~7; - } - - /// <summary> - /// Performs the hash finalization step, and returns the calculated hash. - /// </summary> - /// <remarks> - /// The full data must be passed on <paramref name="data"/>. - /// <paramref name="data"/> must start with the data passed on the last call to <see cref="Continue"/>. - /// No internal state is changed, so one can still continue hashing data with <see cref="Continue"/> - /// after calling this method. - /// </remarks> - /// <param name="data">Data to be hashed</param> - /// <returns>Hash of all the data hashed with this <see cref="HashState"/></returns> - public uint Finalize(ReadOnlySpan<byte> data) - { - ulong h = _hash; - - int remainder = data.Length & 7; - if (remainder != 0) - { - ulong v = 0; - - for (int i = data.Length - remainder; i < data.Length; i++) - { - v |= (ulong)data[i] << ((i - remainder) * 8); - } - - h ^= Mix(v); - h *= M; - } - - h = Mix(h); - return (uint)(h - (h >> 32)); - } - - /// <summary> - /// Hash mix function. - /// </summary> - /// <param name="h">Hash to mix</param> - /// <returns>Mixed hash</returns> - private static ulong Mix(ulong h) - { - h ^= h >> 23; - h *= 0x2127599bf4325c37UL; - h ^= h >> 47; - return h; - } - } -} |
