Plug System.IO.UnmanagedMemoryStream

source/Cosmos.System2_Plugs/Cosmos.System2_Plugs.csproj

@@ -6,6 +6,7 @@
         <RootNamespace>Cosmos.System_Plugs</RootNamespace>
         <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
         <Configurations>Debug;Release;TEST</Configurations>
+        <ImplicitUsings>enable</ImplicitUsings>
     </PropertyGroup>
 
     <ItemGroup>

source/Cosmos.System2_Plugs/System/IO/UnmanagedMemoryStreamImpl.cs

@@ -0,0 +1,66 @@
+using IL2CPU.API.Attribs;
+using System.IO;
+
+namespace Cosmos.System_Plugs.System.IO
+{
+    [Plug(Target = typeof(UnmanagedMemoryStream))]
+    public unsafe static class UnmanagedMemoryStreamImpl
+    {
+        public static void WriteCore(this UnmanagedMemoryStream aStream, ReadOnlySpan<byte> aSpan)
+        {
+            for (int I = 0; I < aSpan.Length; I++)
+            {
+                aStream.WriteByte(aSpan[I]);
+            }
+        }
+        public static int ReadCore(this UnmanagedMemoryStream aStream, Span<byte> aSpan)
+        {
+            long n = Math.Min(aStream.Length - aStream.Position, aSpan.Length);
+            if (n <= 0)
+            {
+                return 0;
+            }
+
+            int nInt = (int)n; // Safe because n <= count, which is an Int32
+            if (nInt < 0)
+            {
+                return 0;  // _position could be beyond EOF
+            }
+
+            unsafe
+            {
+                if (aSpan != null)
+                {
+                    byte* pointer = null;
+
+                    try
+                    {
+                        for (int I = 0; I < nInt; I++)
+                        {
+                            aSpan[I] = *(pointer + aStream.Position + aStream.Capacity);
+                        }
+                    }
+                    catch { }
+                }
+                else
+                {
+                    for (int I = 0; I < nInt; I++)
+                    {
+                        aSpan[I] = *(aStream.PositionPointer + aStream.Position);
+                    }
+                }
+            }
+
+            aStream.Position += n;
+            return nInt;
+        }
+        public static void WriteByte(this UnmanagedMemoryStream aStream, byte aValue)
+        {
+            aStream.PositionPointer[aStream.Position++] = aValue;
+        }
+        public static int ReadByte(this UnmanagedMemoryStream aStream)
+        {
+            return aStream.PositionPointer[aStream.Position++];
+        }
+    }
+}