sean-m
/
Vanara
mirror of https://github.com/dahall/Vanara.git
1
0
Fork 0
Code Issues Releases Wiki Activity

Added IntPtr.AsSpan and IntPtr.AsReadOnlySpan extension methods

pull/133/head
dahall 2020-05-15 11:40:11 -06:00
parent 30aabcaaed
commit 5c726943b3
1 changed files with 38 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
Core/Extensions/InteropExtensions.cs
View File

@ -15,6 +15,44 @@ namespace Vanara.Extensions
/// <summary>Extension methods for System.Runtime.InteropServices.</summary>
public static partial class InteropExtensions
{
#if ALLOWSPAN
/// <summary>Returns the pointer as a <see cref="ReadOnlySpan{T}"/>.</summary>
/// <typeparam name="T">The type of items in the <see cref="ReadOnlySpan{T}"/>.</typeparam>
/// <param name="ptr">A pointer to the starting address of a specified number of <typeparamref name="T"/> elements in memory.</param>
/// <param name="length">The number of <typeparamref name="T"/> elements to be included in the <see cref="ReadOnlySpan{T}"/>.</param>
/// <param name="prefixBytes">Bytes to skip before starting the span.</param>
/// <param name="allocatedBytes">If known, the total number of bytes allocated to the native memory in <paramref name="ptr"/>.</param>
/// <returns>A <see cref="ReadOnlySpan{T}"/> that represents the memory.</returns>
/// <exception cref="System.InsufficientMemoryException"></exception>
public static unsafe ReadOnlySpan<T> AsReadOnlySpan<T>(this IntPtr ptr, int length, int prefixBytes = 0, SizeT allocatedBytes = default)
{
if (ptr == IntPtr.Zero) return null;
if (length < 0) throw new ArgumentOutOfRangeException(nameof(length));
if (allocatedBytes > 0 && SizeOf<T>() * length + prefixBytes > allocatedBytes)
throw new InsufficientMemoryException();
return new ReadOnlySpan<T>((ptr + prefixBytes).ToPointer(), length);
}
/// <summary>Returns the pointer as a <see cref="Span{T}"/>.</summary>
/// <typeparam name="T">The type of items in the <see cref="Span{T}"/>.</typeparam>
/// <param name="ptr">A pointer to the starting address of a specified number of <typeparamref name="T"/> elements in memory.</param>
/// <param name="length">The number of <typeparamref name="T"/> elements to be included in the <see cref="Span{T}"/>.</param>
/// <param name="prefixBytes">Bytes to skip before starting the span.</param>
/// <param name="allocatedBytes">If known, the total number of bytes allocated to the native memory in <paramref name="ptr"/>.</param>
/// <returns>A <see cref="Span{T}"/> that represents the memory.</returns>
/// <exception cref="System.InsufficientMemoryException"></exception>
public static unsafe Span<T> AsSpan<T>(this IntPtr ptr, int length, int prefixBytes = 0, SizeT allocatedBytes = default)
{
if (ptr == IntPtr.Zero) return null;
if (length < 0) throw new ArgumentOutOfRangeException(nameof(length));
if (allocatedBytes > 0 && SizeOf<T>() * length + prefixBytes > allocatedBytes)
throw new InsufficientMemoryException();
return new Span<T>((ptr + prefixBytes).ToPointer(), length);
}
#endif
/// <summary>Copies the number of specified bytes from one unmanaged memory block to another.</summary>
/// <param name="ptr">The allocated memory pointer.</param>
/// <param name="dest">The allocated memory pointer to copy to.</param>