GhostEngine/Ghost.Core/Utilities/Win32Utility.cs

using Misaki.HighPerformance.LowLevel;
using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.CompilerServices;
using System.Runtime.Versioning;
using TerraFX.Interop.Windows;

namespace Ghost.Core.Utilities;

[SupportedOSPlatform("windows10.0.19041.0")]
internal static unsafe partial class Win32Utility
{
    [EditorBrowsable(EditorBrowsableState.Never)]
    public readonly ref struct IID_PPV
    {
        public readonly Guid* iid;
        public readonly void** ppv;

        public IID_PPV(Guid* iid, void** ppv)
        {
            this.iid = iid;
            this.ppv = ppv;
        }

        public void Deconstruct(out Guid* iid, out void** ppv)
        {
            iid = this.iid;
            ppv = this.ppv;
        }
    }

    public static Guid* IID_NULL
    {
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        get => (Guid*)Unsafe.AsPointer(ref Unsafe.AsRef(in IID.IID_NULL));
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static IID_PPV IID_PPV_ARGS<T>(ComPtr<T>* comPtr)
        where T : unmanaged, IUnknown.Interface
    {
        return new IID_PPV(Windows.__uuidof<T>(), (void**)comPtr);
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static void Attach<T>(ref this UniquePtr<T> uPtr, T* other)
        where T : unmanaged, IUnknown.Interface
    {
        var ptr = uPtr.Get();
        if (ptr != null)
        {
            var refCount = ptr->Release();
            Debug.Assert((refCount != 0) || (ptr != other));
        }

        uPtr = new UniquePtr<T>(other);
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static void Dispose<T>(ref this UniquePtr<T> uPtr)
        where T : unmanaged, IUnknown.Interface
    {
        T* ptr = uPtr.Get();
        if (ptr != null)
        {
            uPtr = default;
            ptr->Release();
            //MemoryLeakException.ThrowIfRefCountNonZero(ptr->Release());
        }
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static Result ToResult(this HRESULT hr, [CallerArgumentExpression(nameof(hr))] string? op = null)
    {
        if (hr.SUCCEEDED)
        {
            return Result.Success();
        }
        
        return Result.Failure($"{op} failed with code {hr}");
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static void** ReleaseAndGetVoidAddressOf<T>(ref this ComPtr<T> comPtr)
        where T : unmanaged, IUnknown.Interface
    {
        return (void**)comPtr.ReleaseAndGetAddressOf();
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static ComPtr<T> Move<T>(ref this ComPtr<T> comPtr)
        where T : unmanaged, IUnknown.Interface
    {
        var copy = default(ComPtr<T>);
        comPtr.Swap(ref copy);
        return copy;
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static bool HasFlag<T>(this uint flags, T flag)
        where T : Enum
    {
        return (flags & Unsafe.As<T, uint>(ref flag)) != 0;
    }

    extension(MemoryLeakException)
    {
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static void ThrowIfRefCountNonZero(uint count)
        {
            if (count != 0)
            {
                throw new MemoryLeakException($"Reference count is not zero: {count}");
            }
        }
    }
}