Apply performance optimizations using MemoryMarshal.TryGetArray

Copilot · stephentoub · Tyler-IN · commit 87145655329d · 2025-12-24T02:52:09.000-05:00
Co-authored-by: stephentoub &lt;2642209+stephentoub@users.noreply.github.com&gt;
diff --git a/src/ModelContextProtocol.Core/Protocol/BlobResourceContents.cs b/src/ModelContextProtocol.Core/Protocol/BlobResourceContents.cs
@@ -1,4 +1,5 @@
 using System.Diagnostics;
+using System.Runtime.InteropServices;
 using System.Text.Json.Serialization;
 
 namespace ModelContextProtocol.Protocol;
@@ -58,10 +59,11 @@ public ReadOnlyMemory<byte> Data
         {
             if (_decodedData is null)
             {
-#if NET6_0_OR_GREATER
+#if NET
                 _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Blob.Span));
 #else
-                _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Blob.ToArray()));
+                byte[] array = MemoryMarshal.TryGetArray(Blob, out ArraySegment<byte> segment) && segment.Offset == 0 && segment.Count == segment.Array!.Length ? segment.Array : Blob.ToArray();
+                _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(array));
 #endif
             }
             return _decodedData;
diff --git a/src/ModelContextProtocol.Core/Protocol/ContentBlock.cs b/src/ModelContextProtocol.Core/Protocol/ContentBlock.cs
@@ -2,6 +2,7 @@
 using System.ComponentModel;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.Runtime.InteropServices;
 using System.Text.Json;
 using System.Text.Json.Nodes;
 using System.Text.Json.Serialization;
@@ -424,10 +425,11 @@ public ReadOnlyMemory<byte> DecodedData
         {
             if (_decodedData is null)
             {
-#if NET6_0_OR_GREATER
+#if NET
                 _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Data.Span));
 #else
-                _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Data.ToArray()));
+                byte[] array = MemoryMarshal.TryGetArray(Data, out ArraySegment<byte> segment) && segment.Offset == 0 && segment.Count == segment.Array!.Length ? segment.Array : Data.ToArray();
+                _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(array));
 #endif
             }
             return _decodedData;
@@ -488,10 +490,11 @@ public ReadOnlyMemory<byte> DecodedData
         {
             if (_decodedData is null)
             {
-#if NET6_0_OR_GREATER
+#if NET
                 _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Data.Span));
 #else
-                _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Data.ToArray()));
+                byte[] array = MemoryMarshal.TryGetArray(Data, out ArraySegment<byte> segment) && segment.Offset == 0 && segment.Count == segment.Array!.Length ? segment.Array : Data.ToArray();
+                _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(array));
 #endif
             }
             return _decodedData;
diff --git a/src/ModelContextProtocol.Core/Server/AIFunctionMcpServerResource.cs b/src/ModelContextProtocol.Core/Server/AIFunctionMcpServerResource.cs
@@ -7,6 +7,7 @@
 using System.Globalization;
 using System.Reflection;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using System.Text;
 using System.Text.Json;
 using System.Text.Json.Nodes;
@@ -391,7 +392,14 @@ public override async ValueTask<ReadResourceResult> ReadAsync(
 
             DataContent dc => new()
             {
-                Contents = [new BlobResourceContents { Uri = request.Params!.Uri, MimeType = dc.MediaType, Blob = System.Text.Encoding.UTF8.GetBytes(dc.Base64Data.ToString()) }],
+                Contents = [new BlobResourceContents 
+                { 
+                    Uri = request.Params!.Uri, 
+                    MimeType = dc.MediaType, 
+                    Blob = MemoryMarshal.TryGetArray(dc.Base64Data, out ArraySegment<char> segment) && segment.Offset == 0 && segment.Count == segment.Array!.Length 
+                        ? System.Text.Encoding.UTF8.GetBytes(segment.Array) 
+                        : System.Text.Encoding.UTF8.GetBytes(dc.Base64Data.ToString()) 
+                }],
             },
 
             string text => new()
@@ -420,7 +428,9 @@ public override async ValueTask<ReadResourceResult> ReadAsync(
                         {
                             Uri = request.Params!.Uri,
                             MimeType = dc.MediaType,
-                            Blob = System.Text.Encoding.UTF8.GetBytes(dc.Base64Data.ToString())
+                            Blob = MemoryMarshal.TryGetArray(dc.Base64Data, out ArraySegment<char> segment) && segment.Offset == 0 && segment.Count == segment.Array!.Length 
+                                ? System.Text.Encoding.UTF8.GetBytes(segment.Array) 
+                                : System.Text.Encoding.UTF8.GetBytes(dc.Base64Data.ToString())
                         },
 
                         _ => throw new InvalidOperationException($"Unsupported AIContent type '{ac.GetType()}' returned from resource function."),

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,5 @@`
`1`	`1`	`using System.Diagnostics;`
	`2`	`+using System.Runtime.InteropServices;`
`2`	`3`	`using System.Text.Json.Serialization;`
`3`	`4`
`4`	`5`	`namespace ModelContextProtocol.Protocol;`
`@@ -58,10 +59,11 @@ public ReadOnlyMemory<byte> Data`
`58`	`59`	`{`
`59`	`60`	`if (_decodedData is null)`
`60`	`61`	`{`
`61`		`-#if NET6_0_OR_GREATER`
	`62`	`+#if NET`
`62`	`63`	`_decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Blob.Span));`
`63`	`64`	`#else`
`64`		`- _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Blob.ToArray()));`
	`65`	`+ byte[] array = MemoryMarshal.TryGetArray(Blob, out ArraySegment<byte> segment) && segment.Offset == 0 && segment.Count == segment.Array!.Length ? segment.Array : Blob.ToArray();`
	`66`	`+ _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(array));`
`65`	`67`	`#endif`
`66`	`68`	`}`
`67`	`69`	`return _decodedData;`
Original file line number	Diff line number	Diff line change
`@@ -2,6 +2,7 @@`
`2`	`2`	`using System.ComponentModel;`
`3`	`3`	`using System.Diagnostics;`
`4`	`4`	`using System.Diagnostics.CodeAnalysis;`
	`5`	`+using System.Runtime.InteropServices;`
`5`	`6`	`using System.Text.Json;`
`6`	`7`	`using System.Text.Json.Nodes;`
`7`	`8`	`using System.Text.Json.Serialization;`
`@@ -424,10 +425,11 @@ public ReadOnlyMemory<byte> DecodedData`
`424`	`425`	`{`
`425`	`426`	`if (_decodedData is null)`
`426`	`427`	`{`
`427`		`-#if NET6_0_OR_GREATER`
	`428`	`+#if NET`
`428`	`429`	`_decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Data.Span));`
`429`	`430`	`#else`
`430`		`- _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Data.ToArray()));`
	`431`	`+ byte[] array = MemoryMarshal.TryGetArray(Data, out ArraySegment<byte> segment) && segment.Offset == 0 && segment.Count == segment.Array!.Length ? segment.Array : Data.ToArray();`
	`432`	`+ _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(array));`
`431`	`433`	`#endif`
`432`	`434`	`}`
`433`	`435`	`return _decodedData;`
`@@ -488,10 +490,11 @@ public ReadOnlyMemory<byte> DecodedData`
`488`	`490`	`{`
`489`	`491`	`if (_decodedData is null)`
`490`	`492`	`{`
`491`		`-#if NET6_0_OR_GREATER`
	`493`	`+#if NET`
`492`	`494`	`_decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Data.Span));`
`493`	`495`	`#else`
`494`		`- _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(Data.ToArray()));`
	`496`	`+ byte[] array = MemoryMarshal.TryGetArray(Data, out ArraySegment<byte> segment) && segment.Offset == 0 && segment.Count == segment.Array!.Length ? segment.Array : Data.ToArray();`
	`497`	`+ _decodedData = Convert.FromBase64String(System.Text.Encoding.UTF8.GetString(array));`
`495`	`498`	`#endif`
`496`	`499`	`}`
`497`	`500`	`return _decodedData;`