blob: 5e567ab8d6a9ddbdec57190ce9541304a45648e2 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
#nullable enable
using System;
using System.Buffers;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Threading;
namespace Ryujinx.Common.Memory
{
/// <summary>
/// An <see cref="IMemoryOwner{T}"/> implementation with an embedded length and fast <see cref="Span{T}"/>
/// accessor, with memory allocated from <seealso cref="ArrayPool{T}.Shared"/>.
/// </summary>
/// <typeparam name="T">The type of item to store.</typeparam>
public sealed class MemoryOwner<T> : IMemoryOwner<T>
{
private readonly int _length;
private T[]? _array;
/// <summary>
/// Initializes a new instance of the <see cref="MemoryOwner{T}"/> class with the specified parameters.
/// </summary>
/// <param name="length">The length of the new memory buffer to use</param>
private MemoryOwner(int length)
{
_length = length;
_array = ArrayPool<T>.Shared.Rent(length);
}
/// <summary>
/// Creates a new <see cref="MemoryOwner{T}"/> instance with the specified length.
/// </summary>
/// <param name="length">The length of the new memory buffer to use</param>
/// <returns>A <see cref="MemoryOwner{T}"/> instance of the requested length</returns>
/// <exception cref="ArgumentOutOfRangeException">Thrown when <paramref name="length"/> is not valid</exception>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static MemoryOwner<T> Rent(int length) => new(length);
/// <summary>
/// Creates a new <see cref="MemoryOwner{T}"/> instance with the specified length and the content cleared.
/// </summary>
/// <param name="length">The length of the new memory buffer to use</param>
/// <returns>A <see cref="MemoryOwner{T}"/> instance of the requested length and the content cleared</returns>
/// <exception cref="ArgumentOutOfRangeException">Thrown when <paramref name="length"/> is not valid</exception>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static MemoryOwner<T> RentCleared(int length)
{
MemoryOwner<T> result = new(length);
result._array.AsSpan(0, length).Clear();
return result;
}
/// <summary>
/// Creates a new <see cref="MemoryOwner{T}"/> instance with the content copied from the specified buffer.
/// </summary>
/// <param name="buffer">The buffer to copy</param>
/// <returns>A <see cref="MemoryOwner{T}"/> instance with the same length and content as <paramref name="buffer"/></returns>
public static MemoryOwner<T> RentCopy(ReadOnlySpan<T> buffer)
{
MemoryOwner<T> result = new(buffer.Length);
buffer.CopyTo(result._array);
return result;
}
/// <summary>
/// Gets the number of items in the current instance.
/// </summary>
public int Length
{
[MethodImpl(MethodImplOptions.AggressiveInlining)]
get => _length;
}
/// <inheritdoc/>
public Memory<T> Memory
{
[MethodImpl(MethodImplOptions.AggressiveInlining)]
get
{
T[]? array = _array;
if (array is null)
{
ThrowObjectDisposedException();
}
return new(array, 0, _length);
}
}
/// <summary>
/// Gets a <see cref="Span{T}"/> wrapping the memory belonging to the current instance.
/// </summary>
/// <remarks>
/// Uses a trick made possible by the .NET 6+ runtime array layout.
/// </remarks>
public Span<T> Span
{
[MethodImpl(MethodImplOptions.AggressiveInlining)]
get
{
T[]? array = _array;
if (array is null)
{
ThrowObjectDisposedException();
}
ref T firstElementRef = ref MemoryMarshal.GetArrayDataReference(array);
return MemoryMarshal.CreateSpan(ref firstElementRef, _length);
}
}
/// <inheritdoc/>
public void Dispose()
{
T[]? array = Interlocked.Exchange(ref _array, null);
if (array is not null)
{
ArrayPool<T>.Shared.Return(array);
}
}
/// <summary>
/// Throws an <see cref="ObjectDisposedException"/> when <see cref="_array"/> is <see langword="null"/>.
/// </summary>
[DoesNotReturn]
private static void ThrowObjectDisposedException()
{
throw new ObjectDisposedException(nameof(MemoryOwner<T>), "The buffer has already been disposed.");
}
}
}
|
