bbradson
106 lines
3.3 KiB
C#
106 lines
3.3 KiB
C#
// Copyright (c) 2022 bradson
|
|
// This Source Code Form is subject to the terms of the Mozilla Public
|
|
// License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
// file, You can obtain one at https://mozilla.org/MPL/2.0/.
|
|
|
|
using System.Linq;
|
|
using System.Runtime.CompilerServices;
|
|
|
|
namespace FisheryLib.FunctionPointers;
|
|
public static class GetHashCode<T>
|
|
{
|
|
public static readonly unsafe delegate*<T, int> Default = (delegate*<T, int>)FunctionPointers.GetHashCode.MakeDelegate(typeof(T));
|
|
}
|
|
|
|
public static class GetHashCode
|
|
{
|
|
public static class Methods
|
|
{
|
|
public static int Byte(byte obj)
|
|
=> obj;
|
|
|
|
public static int Int(int obj)
|
|
=> obj;
|
|
|
|
public static int Uint(uint obj)
|
|
=> (int)obj;
|
|
|
|
public static int Ushort(ushort obj)
|
|
=> obj;
|
|
|
|
public static unsafe int VoidPtr(void* obj)
|
|
=> (int)obj;
|
|
|
|
public static int Enum<T>(T obj) where T : struct
|
|
=> JitHelpers.UnsafeEnumCast(obj).GetHashCode();
|
|
|
|
public static int SbyteEnum<T>(T obj) where T : struct
|
|
=> ((sbyte)JitHelpers.UnsafeEnumCast(obj)).GetHashCode();
|
|
|
|
public static int ShortEnum<T>(T obj) where T : struct
|
|
=> ((short)JitHelpers.UnsafeEnumCast(obj)).GetHashCode();
|
|
|
|
public static int LongEnum<T>(T obj) where T : struct
|
|
=> JitHelpers.UnsafeEnumCastLong(obj).GetHashCode();
|
|
|
|
public static int ValueType<T>(T obj) where T : struct
|
|
=> obj.GetHashCode();
|
|
|
|
public static int Nullable<T>(T? obj) where T : struct
|
|
=> obj.GetHashCode();
|
|
|
|
public static int Reference<T>(T obj) where T : class
|
|
=> RuntimeHelpers.GetHashCode(obj);
|
|
|
|
public static int Object<T>(T obj)
|
|
=> obj?.GetHashCode() ?? 0;
|
|
}
|
|
|
|
internal static unsafe IntPtr MakeDelegate(Type type)
|
|
=> _getHashCodeMethods.Where(m => !m.IsGenericMethod)
|
|
.FirstOrDefault(m
|
|
=> m.GetParameters().First().ParameterType == type)
|
|
is { } specializedMethod
|
|
? specializedMethod.GetFunctionPointer()
|
|
: type.IsNullable(out var genericArgument)
|
|
&& genericArgument.IsAssignableTo(typeof(IEquatable<>), genericArgument)
|
|
? GetMethod(nameof(Methods.Nullable)).MakeGenericMethod(genericArgument).GetFunctionPointer()
|
|
: GetMethod(
|
|
type.IsEnum
|
|
? Type.GetTypeCode(Enum.GetUnderlyingType(type))
|
|
switch
|
|
{
|
|
TypeCode.Int16 => nameof(Methods.ShortEnum),
|
|
TypeCode.SByte => nameof(Methods.SbyteEnum),
|
|
TypeCode.Byte
|
|
or TypeCode.UInt16
|
|
or TypeCode.Int32
|
|
or TypeCode.UInt32 => nameof(Methods.Enum),
|
|
TypeCode.Int64
|
|
or TypeCode.UInt64 => nameof(Methods.LongEnum),
|
|
_ => ThrowHelper.ThrowNotSupportedException<string>()
|
|
}
|
|
: type.IsValueType
|
|
? nameof(Methods.ValueType)
|
|
: nameof(Methods.Object)
|
|
).MakeGenericMethod(type).GetFunctionPointer();
|
|
|
|
private static MethodInfo GetMethod(string name)
|
|
=> Array.Find(_getHashCodeMethods, m => m.Name == name);
|
|
|
|
private static MethodInfo[] _getHashCodeMethods
|
|
= typeof(Methods)
|
|
.GetMethods(BindingFlags.Static | BindingFlags.Public | BindingFlags.DeclaredOnly)
|
|
.Where(m
|
|
=> m.ReturnType == typeof(int)
|
|
&& m.GetParameters().Length == 1)
|
|
.ToArray();
|
|
|
|
[MethodImpl(MethodImplOptions.AggressiveInlining)]
|
|
private static unsafe delegate*<V, int> Cast<T,V>(delegate*<T, int> @delegate)
|
|
=> (delegate*<V, int>)@delegate;
|
|
|
|
[MethodImpl(MethodImplOptions.AggressiveInlining)]
|
|
private static unsafe delegate*<T, int> CastVoid<T>(delegate*<void*, int> @delegate)
|
|
=> (delegate*<T, int>)@delegate;
|
|
} |