Ryujinx/Ryujinx.Common/Memory/ArrayPtr.cs

124 lines
4.1 KiB
C#
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using System;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
namespace Ryujinx.Common.Memory
{
/// <summary>
/// Represents an array of unmanaged resources.
/// </summary>
/// <typeparam name="T">Array element type</typeparam>
public unsafe struct ArrayPtr<T> : IEquatable<ArrayPtr<T>>, IArray<T> where T : unmanaged
{
private IntPtr _ptr;
/// <summary>
/// Null pointer.
/// </summary>
public static ArrayPtr<T> Null => new ArrayPtr<T>() { _ptr = IntPtr.Zero };
/// <summary>
/// True if the pointer is null, false otherwise.
/// </summary>
public bool IsNull => _ptr == IntPtr.Zero;
/// <summary>
/// Number of elements on the array.
/// </summary>
public int Length { get; }
/// <summary>
/// Gets a reference to the item at the given index.
/// </summary>
/// <remarks>
/// No bounds checks are performed, this allows negative indexing,
/// but care must be taken if the index may be out of bounds.
/// </remarks>
/// <param name="index">Index of the element</param>
/// <returns>Reference to the element at the given index</returns>
public ref T this[int index] => ref Unsafe.AsRef<T>((T*)_ptr + index);
/// <summary>
/// Creates a new array from a given reference.
/// </summary>
/// <remarks>
/// For data on the heap, proper pinning is necessary during
/// use. Failure to do so will result in memory corruption and crashes.
/// </remarks>
/// <param name="value">Reference of the first array element</param>
/// <param name="length">Number of elements on the array</param>
public ArrayPtr(ref T value, int length)
{
_ptr = (IntPtr)Unsafe.AsPointer(ref value);
Length = length;
}
/// <summary>
/// Creates a new array from a given pointer.
/// </summary>
/// <param name="ptr">Array base pointer</param>
/// <param name="length">Number of elements on the array</param>
public ArrayPtr(T* ptr, int length)
{
_ptr = (IntPtr)ptr;
Length = length;
}
/// <summary>
/// Creates a new array from a given pointer.
/// </summary>
/// <param name="ptr">Array base pointer</param>
/// <param name="length">Number of elements on the array</param>
public ArrayPtr(IntPtr ptr, int length)
{
_ptr = ptr;
Length = length;
}
/// <summary>
/// Splits the array starting at the specified position.
/// </summary>
/// <param name="start">Index where the new array should start</param>
/// <returns>New array starting at the specified position</returns>
public ArrayPtr<T> Slice(int start) => new ArrayPtr<T>(ref this[start], Length - start);
/// <summary>
/// Gets a span from the array.
/// </summary>
/// <returns>Span of the array</returns>
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public Span<T> AsSpan() => Length == 0 ? Span<T>.Empty : MemoryMarshal.CreateSpan(ref this[0], Length);
/// <summary>
/// Gets the array base pointer.
/// </summary>
/// <returns>Base pointer</returns>
public T* ToPointer() => (T*)_ptr;
public override bool Equals(object obj)
{
return obj is ArrayPtr<T> other && Equals(other);
}
public bool Equals([AllowNull] ArrayPtr<T> other)
{
return _ptr == other._ptr && Length == other.Length;
}
public override int GetHashCode()
{
return HashCode.Combine(_ptr, Length);
}
public static bool operator ==(ArrayPtr<T> left, ArrayPtr<T> right)
{
return left.Equals(right);
}
public static bool operator !=(ArrayPtr<T> left, ArrayPtr<T> right)
{
return !(left == right);
}
}
}