Retry API call once on error -503 Timeout

EXAMPLES.md

@@ -371,10 +371,7 @@ If you are not in a Console app or don't want the logs on screen, you can redire
 // • Log to VS Output debugging pane in addition to default Console screen logging:
 WTelegram.Helpers.Log += (lvl, str) => System.Diagnostics.Debug.WriteLine(str);
 
-// • Log to file in replacement of default Console screen logging:
-WTelegram.Helpers.Log = (lvl, str) => File.AppendAllText("WTelegram.log", str + Environment.NewLine);
-
-// • More efficient example with a static variable and detailed logging to file:
+// • Log to file in replacement of default Console screen logging, using this static variable:
 static StreamWriter WTelegramLogs = new StreamWriter("WTelegram.log", true, Encoding.UTF8) { AutoFlush = true };
 ...
 WTelegram.Helpers.Log = (lvl, str) => WTelegramLogs.WriteLine($"{DateTime.Now:yyyy-MM-dd HH:mm:ss} [{"TDIWE!"[lvl]}] {str}");

src/Client.cs

@@ -40,6 +40,8 @@ namespace WTelegram
 		public int FloodRetryThreshold { get; set; } = 60;
 		/// <summary>Number of seconds between each keep-alive ping. Increase this if you have a slow connection or you're debugging your code</summary>
 		public int PingInterval { get; set; } = 60;
+		/// <summary>Size of chunks when uploading/downloading files. Reduce this if you don't have much memory</summary>
+		public int FilePartSize { get; set; } = 512 * 1024;
 		/// <summary>Is this Client instance the main or a secondary DC session</summary>
 		public bool IsMainDC => (_dcSession?.DataCenter?.id ?? 0) == _session.MainDC;
 		/// <summary>Has this Client established connection been disconnected?</summary>
@@ -68,7 +70,6 @@ namespace WTelegram
 		private Task _connecting;
 		private CancellationTokenSource _cts;
 		private int _reactorReconnects = 0;
-		private const int FilePartSize = 512 * 1024;
 		private const string ConnectionShutDown = "Could not read payload length : Connection shut down";
 		private readonly SemaphoreSlim _parallelTransfers = new(10); // max parallel part uploads/downloads
 		private readonly SHA256 _sha256 = SHA256.Create();
@@ -840,6 +841,7 @@ namespace WTelegram
 			var tcs = new TaskCompletionSource<object>(TaskCreationOptions.RunContinuationsAsynchronously);
 			lock (_pendingRequests)
 				_pendingRequests[msgId] = (typeof(X), tcs);
+			bool got503 = false;
 			var result = await tcs.Task;
 			switch (result)
 			{
@@ -873,6 +875,11 @@ namespace WTelegram
 							goto retry;
 						}
 					}
+					else if (rpcError.error_code == -503 && !got503)
+					{
+						got503 = true;
+						goto retry;
+					}
 					else if (rpcError.error_code == 500 && rpcError.error_message == "AUTH_RESTART")
 					{
 						_session.UserId = 0; // force a full login authorization flow, next time

src/Session.cs

@@ -120,7 +120,7 @@ namespace WTelegram
 		private int _nextPosition = 8;
 
 		public SessionStore(string pathname)
-			: base(pathname, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.None, 1) // no buffering
+			: base(pathname, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.None, 1) // no in-app buffering
 		{
 			if (base.Read(_header, 0, 8) == 8)
 			{

src/TL.Schema.cs

@@ -15527,7 +15527,7 @@ namespace TL
 		/// <param name="peer">Peer</param>
 		/// <param name="id">Message ID</param>
 		/// <param name="reaction">Get only reactions of this type (UTF8 emoji)</param>
-		/// <param name="offset">Offset (typically taken from the <c>next_offset</c> field of the returned <see cref="MessageReactionsList"/>)</param>
+		/// <param name="offset">Offset (typically taken from the <c>next_offset</c> field of the returned <see cref="Messages_MessageReactionsList"/>)</param>
 		/// <param name="limit">Maximum number of results to return, <a href="https://corefork.telegram.org/api/offsets">see pagination</a></param>
 		public static Task<Messages_MessageReactionsList> Messages_GetMessageReactionsList(this Client client, InputPeer peer, int id, int limit = int.MaxValue, string reaction = null, string offset = null)
 			=> client.Invoke(new Messages_GetMessageReactionsList