GSF.Web: Introduce a media type formatter for byte arrays

Author: StephenCWills

Source/Libraries/GSF.Web/GSF.Web.csproj

@@ -329,6 +329,7 @@
     <Reference Include="WindowsBase" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Hosting\OctetStreamMediaTypeFormatter.cs" />
     <Compile Include="Model\ModelController.cs" />
     <Compile Include="ModuleInitializer.cs" />
     <Compile Include="Security\AntiForgery.cs" />

Source/Libraries/GSF.Web/Hosting/OctetStreamMediaTypeFormatter.cs

@@ -0,0 +1,121 @@
+//******************************************************************************************************
+//  OctetStreamMediaTypeFormatter.cs - Gbtc
+//
+//  Copyright © 2026, Grid Protection Alliance.  All Rights Reserved.
+//
+//  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See
+//  the NOTICE file distributed with this work for additional information regarding copyright ownership.
+//  The GPA licenses this file to you under the MIT License (MIT), the "License"; you may not use this
+//  file except in compliance with the License. You may obtain a copy of the License at:
+//
+//      http://opensource.org/licenses/MIT
+//
+//  Unless agreed to in writing, the subject software distributed under the License is distributed on an
+//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the
+//  License for the specific language governing permissions and limitations.
+//
+//  Code Modification History:
+//  ----------------------------------------------------------------------------------------------------
+//  04/08/2026 - Stephen C. Wills
+//       Generated original version of source code.
+//
+//******************************************************************************************************
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Net;
+using System.Net.Http;
+using System.Net.Http.Formatting;
+using System.Net.Http.Headers;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace GSF.Web.Hosting;
+
+/// <summary>
+/// A <see cref="MediaTypeFormatter"/> for HTTP data as a byte array.
+/// </summary>
+public class OctetStreamMediaTypeFormatter : MediaTypeFormatter
+{
+    /// <summary>
+    /// Creates a new instance of the <see cref="OctetStreamMediaTypeFormatter"/> class.
+    /// </summary>
+    public OctetStreamMediaTypeFormatter()
+    {
+        const string ApplicationOctetStream = "application/octet-stream";
+        MediaTypeHeaderValue mediaType = new MediaTypeHeaderValue(ApplicationOctetStream);
+        SupportedMediaTypes.Add(mediaType);
+    }
+
+    /// <inheritdoc/>
+    public override bool CanReadType(Type type)
+    {
+        return type == typeof(byte[]);
+    }
+
+    /// <inheritdoc/>
+    public override bool CanWriteType(Type type)
+    {
+        return type == typeof(byte[]);
+    }
+
+    /// <inheritdoc/>
+    public override Task<object> ReadFromStreamAsync(Type type, Stream readStream, HttpContent content, IFormatterLogger formatterLogger)
+    {
+        return ReadFromStreamAsync(type, readStream, content, formatterLogger, default);
+    }
+
+    /// <inheritdoc/>
+    public override async Task<object> ReadFromStreamAsync(Type type, Stream readStream, HttpContent content, IFormatterLogger formatterLogger, CancellationToken cancellationToken)
+    {
+        long length = content.Headers.ContentLength.GetValueOrDefault();
+
+        return (length > 0L && length <= int.MaxValue)
+            ? await ReadFromAsync(readStream, (int)length, cancellationToken)
+            : await ReadFromAsync(readStream, cancellationToken);
+    }
+
+    /// <inheritdoc/>
+    public override Task WriteToStreamAsync(Type type, object value, Stream writeStream, HttpContent content, TransportContext transportContext)
+    {
+        return WriteToStreamAsync(type, value, writeStream, content, transportContext, default);
+    }
+
+    /// <inheritdoc/>
+    public override async Task WriteToStreamAsync(Type type, object value, Stream writeStream, HttpContent content, TransportContext transportContext, CancellationToken cancellationToken)
+    {
+        if (!(value is byte[] bytes))
+            throw new InvalidOperationException("Value is not a byte array");
+
+        await writeStream.WriteAsync(bytes, 0, bytes.Length, cancellationToken);
+    }
+
+    private async Task<byte[]> ReadFromAsync(Stream stream, int length, CancellationToken cancellationToken)
+    {
+        byte[] bytes = new byte[length];
+        int offset = 0;
+        int remaining = length;
+
+        while (offset < length)
+        {
+            int bytesRead = await stream.ReadAsync(bytes, offset, remaining, cancellationToken);
+            if (bytesRead == 0) throw new EndOfStreamException();
+            offset += bytesRead;
+            remaining -= bytesRead;
+        }
+
+        return bytes;
+    }
+
+    private async Task<byte[]> ReadFromAsync(Stream stream, CancellationToken cancellationToken)
+    {
+        using (MemoryStream memoryStream = new MemoryStream())
+        {
+            await stream.CopyToAsync(memoryStream, 81920, cancellationToken);
+            return memoryStream.ToArray();
+        }
+    }
+}