Initial Commit

Library/PackageCache/com.unity.ide.visualstudio@2.0.7/Editor/Messaging/Messenger.cs

@@ -0,0 +1,220 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+using System;
+using System.Net;
+using System.Net.Sockets;
+
+namespace Microsoft.Unity.VisualStudio.Editor.Messaging
+{
+	internal class Messager : IDisposable
+	{
+		public event EventHandler<MessageEventArgs> ReceiveMessage;
+		public event EventHandler<ExceptionEventArgs> MessagerException;
+
+		private readonly UdpSocket _socket;
+		private readonly object _disposeLock = new object();
+		private bool _disposed;
+
+		protected Messager(int port)
+		{
+			_socket = new UdpSocket();
+			_socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ExclusiveAddressUse, false);
+			_socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
+			_socket.Bind(IPAddress.Any, port);
+
+			BeginReceiveMessage();
+		}
+
+		private void BeginReceiveMessage()
+		{
+			var buffer = new byte[UdpSocket.BufferSize];
+			var any = UdpSocket.Any();
+
+			try
+			{
+				lock (_disposeLock)
+				{
+					if (_disposed)
+						return;
+
+					_socket.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref any, ReceiveMessageCallback, buffer);
+				}
+			}
+			catch (SocketException se)
+			{
+				MessagerException?.Invoke(this, new ExceptionEventArgs(se));
+
+				BeginReceiveMessage();
+			}
+			catch (ObjectDisposedException)
+			{
+			}
+		}
+
+		private void ReceiveMessageCallback(IAsyncResult result)
+		{
+			try
+			{
+				var endPoint = UdpSocket.Any();
+
+				lock (_disposeLock)
+				{
+					if (_disposed)
+						return;
+
+					_socket.EndReceiveFrom(result, ref endPoint);
+				}
+
+				var message = DeserializeMessage(UdpSocket.BufferFor(result));
+				if (message != null)
+				{
+					message.Origin = (IPEndPoint)endPoint;
+
+					int port;
+					int bufferSize;
+					if (IsValidTcpMessage(message, out port, out bufferSize))
+					{
+						// switch to TCP mode to handle big messages
+						TcpClient.Queue(message.Origin.Address, port, bufferSize, buffer =>
+						{
+							var originalMessage = DeserializeMessage(buffer);
+							originalMessage.Origin = message.Origin;
+							ReceiveMessage?.Invoke(this, new MessageEventArgs(originalMessage));
+						});
+					}
+					else
+					{
+						ReceiveMessage?.Invoke(this, new MessageEventArgs(message));
+					}
+				}
+			}
+			catch (ObjectDisposedException)
+			{
+				return;
+			}
+			catch (Exception e)
+			{
+				RaiseMessagerException(e);
+			}
+
+			BeginReceiveMessage();
+		}
+
+		private static bool IsValidTcpMessage(Message message, out int port, out int bufferSize)
+		{
+			port = 0;
+			bufferSize = 0;
+			if (message.Value == null)
+				return false;
+			if (message.Type != MessageType.Tcp)
+				return false;
+			var parts = message.Value.Split(':');
+			if (parts.Length != 2)
+				return false;
+			if (!int.TryParse(parts[0], out port))
+				return false;
+			return int.TryParse(parts[1], out bufferSize);
+		}
+
+		private void RaiseMessagerException(Exception e)
+		{
+			MessagerException?.Invoke(this, new ExceptionEventArgs(e));
+		}
+
+		private static Message MessageFor(MessageType type, string value)
+		{
+			return new Message { Type = type, Value = value };
+		}
+
+		public void SendMessage(IPEndPoint target, MessageType type, string value = "")
+		{
+			var message = MessageFor(type, value);
+			var buffer = SerializeMessage(message);
+
+			try
+			{
+				lock (_disposeLock)
+				{
+					if (_disposed)
+						return;
+
+					if (buffer.Length >= UdpSocket.BufferSize)
+					{
+						// switch to TCP mode to handle big messages
+						var port = TcpListener.Queue(buffer);
+						if (port > 0)
+						{
+							// success, replace original message with "switch to tcp" marker + port information + buffer length
+							message = MessageFor(MessageType.Tcp, string.Concat(port, ':', buffer.Length));
+							buffer = SerializeMessage(message);
+						}
+					}
+
+					_socket.BeginSendTo(buffer, 0, Math.Min(buffer.Length, UdpSocket.BufferSize), SocketFlags.None, target, SendMessageCallback, null);
+				}
+			}
+			catch (SocketException se)
+			{
+				MessagerException?.Invoke(this, new ExceptionEventArgs(se));
+			}
+		}
+
+		private void SendMessageCallback(IAsyncResult result)
+		{
+			try
+			{
+				lock (_disposeLock)
+				{
+					if (_disposed)
+						return;
+
+					_socket.EndSendTo(result);
+				}
+			}
+			catch (SocketException se)
+			{
+				MessagerException?.Invoke(this, new ExceptionEventArgs(se));
+			}
+			catch (ObjectDisposedException)
+			{
+			}
+		}
+
+		private static byte[] SerializeMessage(Message message)
+		{
+			var serializer = new Serializer();
+			serializer.WriteInt32((int)message.Type);
+			serializer.WriteString(message.Value);
+
+			return serializer.Buffer();
+		}
+
+		private static Message DeserializeMessage(byte[] buffer)
+		{
+			if (buffer.Length < 4)
+				return null;
+
+			var deserializer = new Deserializer(buffer);
+			var type = (MessageType)deserializer.ReadInt32();
+			var value = deserializer.ReadString();
+
+			return new Message { Type = type, Value = value };
+		}
+
+		public static Messager BindTo(int port)
+		{
+			return new Messager(port);
+		}
+
+		public void Dispose()
+		{
+			lock (_disposeLock)
+			{
+				_disposed = true;
+				_socket.Close();
+			}
+		}
+	}
+}