diff options
| 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 /Spv.Generator/DeterministicHashCode.cs | |
| parent | cd124bda587ef09668a971fa1cac1c3f0cfc9f21 (diff) | |
Move solution and projects to src
Diffstat (limited to 'Spv.Generator/DeterministicHashCode.cs')
| -rw-r--r-- | Spv.Generator/DeterministicHashCode.cs | 109 |
1 files changed, 0 insertions, 109 deletions
diff --git a/Spv.Generator/DeterministicHashCode.cs b/Spv.Generator/DeterministicHashCode.cs deleted file mode 100644 index 1bf0b468..00000000 --- a/Spv.Generator/DeterministicHashCode.cs +++ /dev/null @@ -1,109 +0,0 @@ -using System; -using System.Numerics; -using System.Runtime.CompilerServices; - -namespace Spv.Generator -{ - /// <summary> - /// Similar to System.HashCode, but without introducing random values. - /// The same primes and shifts are used. - /// </summary> - internal static class DeterministicHashCode - { - private const uint Prime1 = 2654435761U; - private const uint Prime2 = 2246822519U; - private const uint Prime3 = 3266489917U; - private const uint Prime4 = 668265263U; - - public static int GetHashCode(string value) - { - uint hash = (uint)value.Length + Prime1; - - for (int i = 0; i < value.Length; i++) - { - hash += (hash << 7) ^ value[i]; - } - - return (int)MixFinal(hash); - } - - public static int Combine<T>(ReadOnlySpan<T> values) - { - uint hashCode = Prime2; - hashCode += 4 * (uint)values.Length; - - foreach (T value in values) - { - uint hc = (uint)(value?.GetHashCode() ?? 0); - hashCode = MixStep(hashCode, hc); - } - - return (int)MixFinal(hashCode); - } - - public static int Combine<T1, T2>(T1 value1, T2 value2) - { - uint hc1 = (uint)(value1?.GetHashCode() ?? 0); - uint hc2 = (uint)(value2?.GetHashCode() ?? 0); - - uint hash = Prime2; - hash += 8; - - hash = MixStep(hash, hc1); - hash = MixStep(hash, hc2); - - return (int)MixFinal(hash); - } - - public static int Combine<T1, T2, T3>(T1 value1, T2 value2, T3 value3) - { - uint hc1 = (uint)(value1?.GetHashCode() ?? 0); - uint hc2 = (uint)(value2?.GetHashCode() ?? 0); - uint hc3 = (uint)(value3?.GetHashCode() ?? 0); - - uint hash = Prime2; - hash += 12; - - hash = MixStep(hash, hc1); - hash = MixStep(hash, hc2); - hash = MixStep(hash, hc3); - - return (int)MixFinal(hash); - } - - public static int Combine<T1, T2, T3, T4>(T1 value1, T2 value2, T3 value3, T4 value4) - { - uint hc1 = (uint)(value1?.GetHashCode() ?? 0); - uint hc2 = (uint)(value2?.GetHashCode() ?? 0); - uint hc3 = (uint)(value3?.GetHashCode() ?? 0); - uint hc4 = (uint)(value4?.GetHashCode() ?? 0); - - uint hash = Prime2; - hash += 16; - - hash = MixStep(hash, hc1); - hash = MixStep(hash, hc2); - hash = MixStep(hash, hc3); - hash = MixStep(hash, hc4); - - return (int)MixFinal(hash); - } - - [MethodImpl(MethodImplOptions.AggressiveInlining)] - private static uint MixStep(uint hashCode, uint mixValue) - { - return BitOperations.RotateLeft(hashCode + mixValue * Prime3, 17) * Prime4; - } - - [MethodImpl(MethodImplOptions.AggressiveInlining)] - private static uint MixFinal(uint hash) - { - hash ^= hash >> 15; - hash *= Prime2; - hash ^= hash >> 13; - hash *= Prime3; - hash ^= hash >> 16; - return hash; - } - } -} |