Remove internal GetBase64Data helper (#422)

This can now just use DataContent.Base64Data.

Author: stephentoub

src/ModelContextProtocol/AIContentExtensions.cs

@@ -178,18 +178,6 @@ public static IList<AIContent> ToAIContents(this IEnumerable<ResourceContents> c
         return [.. contents.Select(ToAIContent)];
     }
 
-    /// <summary>Extracts the data from a <see cref="DataContent"/> as a Base64 string.</summary>
-    internal static string GetBase64Data(this DataContent dataContent)
-    {
-#if NET
-        return Convert.ToBase64String(dataContent.Data.Span);
-#else
-        return MemoryMarshal.TryGetArray(dataContent.Data, out ArraySegment<byte> segment) ?
-            Convert.ToBase64String(segment.Array!, segment.Offset, segment.Count) :
-            Convert.ToBase64String(dataContent.Data.ToArray());
-#endif
-    }
-
     internal static Content ToContent(this AIContent content) =>
         content switch
         {
@@ -201,7 +189,7 @@ internal static Content ToContent(this AIContent content) =>
 
             DataContent dataContent => new()
             {
-                Data = dataContent.GetBase64Data(),
+                Data = dataContent.Base64Data.ToString(),
                 MimeType = dataContent.MediaType,
                 Type =
                     dataContent.HasTopLevelMediaType("image") ? "image" :

src/ModelContextProtocol/Client/McpClientExtensions.cs

@@ -976,7 +976,7 @@ internal static CreateMessageResult ToCreateMessageResult(this ChatResponse chat
                     {
                         Type = dc.HasTopLevelMediaType("image") ? "image" : "audio",
                         MimeType = dc.MediaType,
-                        Data = dc.GetBase64Data(),
+                        Data = dc.Base64Data.ToString(),
                     };
                 }
             }

src/ModelContextProtocol/Server/AIFunctionMcpServerResource.cs

@@ -400,7 +400,7 @@ private AIFunctionMcpServerResource(AIFunction function, ResourceTemplate resour
 
             DataContent dc => new()
             {
-                Contents = [new BlobResourceContents() { Uri = request.Params!.Uri, MimeType = dc.MediaType, Blob = dc.GetBase64Data() }],
+                Contents = [new BlobResourceContents() { Uri = request.Params!.Uri, MimeType = dc.MediaType, Blob = dc.Base64Data.ToString() }],
             },
 
             string text => new()
@@ -429,7 +429,7 @@ private AIFunctionMcpServerResource(AIFunction function, ResourceTemplate resour
                         {
                             Uri = request.Params!.Uri,
                             MimeType = dc.MediaType,
-                            Blob = dc.GetBase64Data()
+                            Blob = dc.Base64Data.ToString()
                         },
 
                         _ => throw new InvalidOperationException($"Unsupported AIContent type '{ac.GetType()}' returned from resource function."),

src/ModelContextProtocol/Server/McpServerExtensions.cs

@@ -110,7 +110,7 @@ public static async Task<ChatResponse> RequestSamplingAsync(
                                 {
                                     Type = dataContent.HasTopLevelMediaType("image") ? "image" : "audio",
                                     MimeType = dataContent.MediaType,
-                                    Data = dataContent.GetBase64Data(),
+                                    Data = dataContent.Base64Data.ToString(),
                                 },
                             });
                             break;