feat: Simple implementation of heartbeats

arstomp/src/StompClient.cs

@@ -16,12 +16,15 @@ namespace ArStomp
 	/// </summary>
 	public class StompClient
 	{
+		private int heartBeatInMillis;
 		public static bool Debug { get; set; } = false;
 		private WebSocket ws;
 		private volatile bool stompConnected = false;
 		public CancellationTokenSource Token { get; } = new CancellationTokenSource();
 		private readonly X509Certificate2Collection certCollection;
 		private readonly Dictionary<string, Subscription> subs = new Dictionary<string, Subscription>();
+		private DateTime lastSend = DateTime.UtcNow;
+		private DateTime lastRcvd = DateTime.UtcNow;
 		/// <summary>
 		/// Handler of incoming messages.
 		/// Used only for RPC. <see cref="Subscription">Subsscriptions</see> have own handlers.
@@ -33,14 +36,12 @@ namespace ArStomp
 		/// Works with binary frames.
 		/// </summary>
 		/// <param name="certCollection">collection of root ca certificates (if TLS is used)</param>
-		public StompClient(X509Certificate2Collection certCollection = null)
+		public StompClient(X509Certificate2Collection certCollection = null, int heartBeatSec = 20)
 		{
+			this.heartBeatInMillis = heartBeatSec * 1000;
 			if (certCollection != null && certCollection.Count > 0)
 			{
-			 	this.certCollection = certCollection;
+				this.certCollection = certCollection;
-
-			 	// In .netstandard2.0 - setup validator globally
-			 	// System.Net.ServicePointManager.ServerCertificateValidationCallback = RemoteCertificateValidationCallback;
 			}
 		}
 
@@ -67,10 +68,10 @@ namespace ArStomp
 		private bool RemoteCertificateValidationCallback(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
 		{
 			if (Debug)
-            {
+			{
 				System.Console.WriteLine("Subject: {0}", certificate.Subject.ToString());
 				System.Console.WriteLine("Cert: {0}", certificate.ToString());
-            }
+			}
 			// if there is no detected problems we can say OK
 			if ((sslPolicyErrors & (SslPolicyErrors.None)) > 0)
 			{
@@ -88,20 +89,20 @@ namespace ArStomp
 				return false;
 			}
 			if (Debug)
-            {
+			{
 				System.Console.WriteLine("Chain:");
 				foreach (var ce in chain.ChainElements)
-                {
+				{
 					System.Console.WriteLine("Element: {0}", ce.Certificate);
-                }
+				}
-            }
+			}
 			// last certificate in chain should be one of our trust anchors
 			X509Certificate2 projectedRootCert = chain.ChainElements[chain.ChainElements.Count - 1].Certificate;
 			// check if server's root ca is one of our trusted
 			bool anytrusted = false;
 			foreach (var cert in certCollection)
 			{
-				if (Debug) System.Console.WriteLine("Anytrust: {0}, {1} =? {2}", projectedRootCert.Thumbprint.ToString(),cert.Thumbprint.ToString(), (projectedRootCert.Thumbprint == cert.Thumbprint));
+				if (Debug) System.Console.WriteLine("Anytrust: {0}, {1} =? {2}", projectedRootCert.Thumbprint.ToString(), cert.Thumbprint.ToString(), (projectedRootCert.Thumbprint == cert.Thumbprint));
 				anytrusted = anytrusted || (projectedRootCert.Thumbprint == cert.Thumbprint);
 			}
 			if (!anytrusted)
@@ -145,7 +146,7 @@ namespace ArStomp
 		public async Task Connect(Uri uri, string login, string password)
 		{
 			if (ws != null) throw new Exception("Cannot connect in this state. Should close before");
-			ws = new WebSocket( uri.ToString(), "v12.stomp");
+			ws = new WebSocket(uri.ToString(), "v12.stomp");
 			if (uri.Scheme == "wss")
 			{
 				if (certCollection != null)
@@ -172,12 +173,14 @@ namespace ArStomp
 			ws.OnOpen += (sender, o) =>
 			{
 				if (Debug) System.Console.WriteLine("OnOpen");
-				StompFrm connect = new StompFrm(login, password);
+				StompFrm connect = new StompFrm(login, password, heartBeatInMillis);
+				lastSend = DateTime.UtcNow;
 				Task.Run(() => { return connect.Serialize(ws, ct); });
 			};
 
 			ws.OnMessage += (sender, o) =>
 			{
+				lastRcvd = DateTime.UtcNow;
 				try
 				{
 					if (Debug)
@@ -195,7 +198,8 @@ namespace ArStomp
 							ExpectFrame(fr, FrameType.Connected);
 							openTask.TrySetResult(true);
 							if (Debug) System.Console.WriteLine("Logon done");
-						} catch (Exception e)
+						}
+						catch (Exception e)
 						{
 							openTask.TrySetException(e);
 						}
@@ -224,7 +228,7 @@ namespace ArStomp
 		/// <returns>true if it looks like we have proper connection to server</returns>
 		public bool IsConnected()
 		{
-			return ws != null && ws.IsAlive;
+			return ws != null && ws.IsAlive && (DateTime.UtcNow - lastRcvd) < TimeSpan.FromMilliseconds(3 * heartBeatInMillis);
 		}
 		/// <summary>
 		/// Send message
@@ -238,6 +242,7 @@ namespace ArStomp
 
 			SendFrm send = new SendFrm(destination, correlationId, body);
 			await send.Serialize(ws, ct);
+			lastSend = DateTime.UtcNow;
 		}
 
 		private int SubId = 0;
@@ -308,6 +313,12 @@ namespace ArStomp
 						}
 					}
 				}
+				if (fr.Type == FrameType.Heartbeat || DateTime.UtcNow - lastSend > TimeSpan.FromSeconds(20))
+				{
+					lastSend = DateTime.UtcNow;
+					ws.Send(new byte[] { 10 }); // send heartbeat
+				}
+
 
 			}
 			catch (Exception e)

arstomp/src/StompFrame.cs

@@ -103,18 +103,18 @@ namespace ArStomp
 			stream.Position = 0;
 			ws.Send(stream, (int) stream.Length);
 			return Task.CompletedTask;
-			//return ws.SendAsync(new ArraySegment<byte>(array, 0, (int)stream.Position), WebSocketMessageType.Binary, true, cancellationToken);
 		}
 	}
 
 	internal class StompFrm : Frame
 	{
-		public StompFrm(string login, string passwd)
+		public StompFrm(string login, string passwd, int hbmilis)
 		{
 			Type = FrameType.Stomp;
 			Headers["login"] = login;
 			Headers["passcode"] = passwd;
 			Headers["accept-version"] = "1.2";
+			if (hbmilis > 0) Headers["heart-beat"] = $"{hbmilis},{hbmilis}";
 		}
 	}