From dad928df02b23da86f956906af286cb4bd7023fe Mon Sep 17 00:00:00 2001
From: timyhac <timyhac@gmail.com>
Date: Sun, 17 May 2026 09:03:55 +1000
Subject: [PATCH] Add `Span<byte>` overloads for `get/set_raw_bytes`

This is anticipated to be part 1 of a series of performance-oriented changes around the native interop.
---
 src/libplctag.NativeImport/NativeMethods.cs   |  4 +--
 .../libplctag.NativeImport.csproj             |  2 ++
 src/libplctag.NativeImport/plctag.cs          | 26 +++++++++++++++++--
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/src/libplctag.NativeImport/NativeMethods.cs b/src/libplctag.NativeImport/NativeMethods.cs
index 7076d38..37d2ee2 100644
--- a/src/libplctag.NativeImport/NativeMethods.cs
+++ b/src/libplctag.NativeImport/NativeMethods.cs
@@ -257,9 +257,9 @@ static NativeMethods()
 
 
         [DllImport(DLL_NAME, EntryPoint = nameof(plc_tag_get_raw_bytes), CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-        public static extern int plc_tag_get_raw_bytes(Int32 tag_id, int start_offset, [Out] byte[] buffer, int buffer_length);
+        public unsafe static extern int plc_tag_get_raw_bytes(Int32 tag_id, int start_offset, byte* buffer, int buffer_length);
 
         [DllImport(DLL_NAME, EntryPoint = nameof(plc_tag_set_raw_bytes), CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-        public static extern int plc_tag_set_raw_bytes(Int32 tag_id, int start_offset, [In] byte[] buffer, int buffer_length);
+        public unsafe static extern int plc_tag_set_raw_bytes(Int32 tag_id, int start_offset, byte* buffer, int buffer_length);
     }
 }
diff --git a/src/libplctag.NativeImport/libplctag.NativeImport.csproj b/src/libplctag.NativeImport/libplctag.NativeImport.csproj
index 6dd8ce8..9141956 100644
--- a/src/libplctag.NativeImport/libplctag.NativeImport.csproj
+++ b/src/libplctag.NativeImport/libplctag.NativeImport.csproj
@@ -33,10 +33,12 @@
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <EmbedUntrackedSources>true</EmbedUntrackedSources>
     <DebugType>embedded</DebugType>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
 
   <ItemGroup>
 	  <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All"/>
+	  <PackageReference Include="System.Memory" Version="4.6.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/libplctag.NativeImport/plctag.cs b/src/libplctag.NativeImport/plctag.cs
index 0da0f80..07eb31d 100644
--- a/src/libplctag.NativeImport/plctag.cs
+++ b/src/libplctag.NativeImport/plctag.cs
@@ -295,12 +295,34 @@ public static int plc_tag_get_string_total_length(Int32 tag_id, int string_start
 
         public static int plc_tag_get_raw_bytes(Int32 tag_id, int start_offset, byte[] buffer, int buffer_length)
         {
-            return NativeMethods.plc_tag_get_raw_bytes(tag_id, start_offset, buffer, buffer_length);
+            return plc_tag_get_raw_bytes(tag_id, start_offset, buffer.AsSpan(0, buffer_length));
+        }
+
+        public static int plc_tag_get_raw_bytes(Int32 tag_id, int start_offset, Span<byte> buffer)
+        {
+            unsafe
+            {
+                fixed (byte* ptr = buffer)
+                {
+                    return NativeMethods.plc_tag_get_raw_bytes(tag_id, start_offset, ptr, buffer.Length);
+                }
+            }
         }
 
         public static int plc_tag_set_raw_bytes(Int32 tag_id, int start_offset, byte[] buffer, int buffer_length)
         {
-            return NativeMethods.plc_tag_set_raw_bytes(tag_id, start_offset, buffer, buffer_length);
+            return plc_tag_set_raw_bytes(tag_id, start_offset, new ReadOnlySpan<byte>(buffer, 0, buffer_length));
+        }
+
+        public static int plc_tag_set_raw_bytes(Int32 tag_id, int start_offset, ReadOnlySpan<byte> buffer)
+        {
+            unsafe
+            {
+                fixed (byte* ptr = buffer)
+                {
+                    return NativeMethods.plc_tag_set_raw_bytes(tag_id, start_offset, ptr, buffer.Length);
+                }
+            }
         }