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| /* | ||
| Copyright (c) 2009-2010 Mikko Mononen [email protected] | ||
| recast4j copyright (c) 2015-2019 Piotr Piastucki [email protected] | ||
| DotRecast Copyright (c) 2023-2024 Choi Ikpil [email protected] | ||
| This software is provided 'as-is', without any express or implied | ||
| warranty. In no event will the authors be held liable for any damages | ||
| arising from the use of this software. | ||
| Permission is granted to anyone to use this software for any purpose, | ||
| including commercial applications, and to alter it and redistribute it | ||
| freely, subject to the following restrictions: | ||
| 1. The origin of this software must not be misrepresented; you must not | ||
| claim that you wrote the original software. If you use this software | ||
| in a product, an acknowledgment in the product documentation would be | ||
| appreciated but is not required. | ||
| 2. Altered source versions must be plainly marked as such, and must not be | ||
| misrepresented as being the original software. | ||
| 3. This notice may not be removed or altered from any source distribution. | ||
| */ | ||
|
|
||
| using System; | ||
| using System.Collections.Generic; | ||
| using System.Runtime.CompilerServices; | ||
| using System.Runtime.InteropServices; | ||
|
|
||
| namespace DotRecast.Core | ||
| { | ||
| public static class FCollectionsMarshal | ||
| { | ||
| /// <summary> | ||
| /// similar as AsSpan but modify size to create fixed-size span. | ||
| /// </summary> | ||
| [MethodImpl(MethodImplOptions.AggressiveInlining)] | ||
| public static Span<T> CreateSpan<T>(List<T> list, int count) | ||
| { | ||
| #if NET8_0_OR_GREATER | ||
| CollectionsMarshal.SetCount(list, count); | ||
| return CollectionsMarshal.AsSpan(list); | ||
| #else | ||
| // TODO 有一些差异，CollectionsMarshal.SetCount 会清掉引用类型的对象 | ||
| if (list.Capacity < count) | ||
| list.Capacity = count; | ||
|
|
||
| ref var view = ref Unsafe.As<List<T>, ListView<T>>(ref list); // 0 gc | ||
| view._size = count; | ||
| return view._items.AsSpan(0, count); | ||
| #endif | ||
| } | ||
|
|
||
| /// <summary> | ||
| /// similar as AsSpan but modify size to create fixed-size span. | ||
| /// </summary> | ||
| [MethodImpl(MethodImplOptions.AggressiveInlining)] | ||
| public static Span<T> AsSpan<T>(List<T> list) | ||
| { | ||
| #if NET6_0_OR_GREATER | ||
| return CollectionsMarshal.AsSpan(list); | ||
| #else | ||
| ref var view = ref Unsafe.As<List<T>, ListView<T>>(ref list); | ||
| return view._items.AsSpan(0, view._size); | ||
| #endif | ||
| } | ||
|
|
||
| #if !NET8_0_OR_GREATER | ||
| // NOTE: These structure depndent on .NET 7, if changed, require to keep same structure. | ||
| internal class ListView<T> | ||
| { | ||
| public T[] _items; | ||
|
Check warning on line 68 in src/DotRecast.Core/FCollectionsMarshal.cs
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| public int _size; | ||
| public int _version; | ||
|
Check warning on line 70 in src/DotRecast.Core/FCollectionsMarshal.cs
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||
| } | ||
| #endif | ||
| } | ||
| } | ||
