Replace WebClient with HttpClient

OpenRA.Game/HttpExtension.cs

@@ -0,0 +1,63 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.IO;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace OpenRA
+{
+	public delegate void OnProgress(long total, long totalRead, int progressPercentage);
+
+	public static class HttpExtension
+	{
+		public static async Task ReadAsStreamWithProgress(this HttpResponseMessage response, Stream outputStream, OnProgress onProgress, CancellationToken token)
+		{
+			var total = response.Content.Headers.ContentLength ?? -1;
+			var canReportProgress = total > 0;
+
+#if !MONO
+			using (var contentStream = await response.Content.ReadAsStreamAsync(token))
+#else
+			using (var contentStream = await response.Content.ReadAsStreamAsync())
+#endif
+			{
+				var totalRead = 0L;
+				var buffer = new byte[8192];
+				var hasMoreToRead = true;
+
+				do
+				{
+					var read = await contentStream.ReadAsync(buffer.AsMemory(0, buffer.Length), token);
+					if (read == 0)
+						hasMoreToRead = false;
+					else
+					{
+						await outputStream.WriteAsync(buffer.AsMemory(0, read), token);
+
+						totalRead += read;
+
+						if (canReportProgress)
+						{
+							var progressPercentage = (int)((double)totalRead / total * 100);
+							onProgress?.Invoke(total, totalRead, progressPercentage);
+						}
+					}
+				}
+				while (hasMoreToRead && !token.IsCancellationRequested);
+
+				onProgress?.Invoke(total, totalRead, 100);
+			}
+		}
+	}
+}