Add a callback when an Ack message is received from the client

src/MagicOnion.Server/Diagnostics/MagicOnionMetrics.cs

@@ -63,7 +63,7 @@ public void StreamingHubMethodCompleted(in MetricsContext context, StreamingHubH
             var tags = InitializeTagListForStreamingHub(handler.HubName);
             tags.Add("rpc.method", handler.MethodInfo.Name);
             tags.Add("magiconion.streaminghub.is_error", isErrorOrInterrupted ? BoxedTrue : BoxedFalse);
-            streamingHubMethodDuration.Record((long)StopwatchHelper.GetElapsedTime(startingTimestamp, endingTimestamp).TotalMilliseconds, tags);
+            streamingHubMethodDuration.Record((long)TimeProvider.System.GetElapsedTime(startingTimestamp, endingTimestamp).TotalMilliseconds, tags);
             streamingHubMethodCompletedCounter.Add(1, tags);
         }
     }

src/MagicOnion.Server/Features/IMagicOnionHeartbeatFeature.cs

@@ -22,6 +22,12 @@ public interface IMagicOnionHeartbeatFeature
     /// </summary>
     CancellationToken TimeoutToken { get; }
 
+    /// <summary>
+    /// Sets the callback action to be performed when an Ack message is received from the client.
+    /// </summary>
+    /// <param name="callbackAction"></param>
+    void SetAckCallback(Action<TimeSpan>? callbackAction);
+
     /// <summary>
     /// Unregister the current StreamingHub connection from the HeartbeatManager.
     /// </summary>
@@ -37,4 +43,6 @@ internal sealed class MagicOnionHeartbeatFeature(StreamingHubHeartbeatHandle han
     public CancellationToken TimeoutToken => handle.TimeoutToken;
 
     public void Unregister() => handle.Unregister();
+
+    public void SetAckCallback(Action<TimeSpan>? callbackAction) => handle.SetAckCallback(callbackAction);
 }

src/MagicOnion.Server/Hubs/StreamingHub.cs

@@ -1,8 +1,6 @@
 using System.Buffers;
-using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using System.Threading.Channels;
-using Cysharp.Runtime.Multicast;
 using Cysharp.Runtime.Multicast.Remoting;
 using Grpc.Core;
 using MagicOnion.Internal;
@@ -23,6 +21,7 @@ public abstract class StreamingHubBase<THubInterface, TReceiver> : ServiceBase<T
 {
     IRemoteClientResultPendingTaskRegistry remoteClientResultPendingTasks = default!;
     StreamingHubHeartbeatHandle heartbeatHandle = default!;
+    TimeProvider timeProvider = default!;
 
     protected static readonly Task<Nil> NilTask = Task.FromResult(Nil.Default);
     protected static readonly ValueTask CompletedTask = new ValueTask();
@@ -88,10 +87,11 @@ internal async Task<DuplexStreamingResult<StreamingHubPayload, StreamingHubPaylo
 
         var features = this.Context.CallContext.GetHttpContext().Features;
         var magicOnionOptions = serviceProvider.GetRequiredService<IOptions<MagicOnionOptions>>().Value;
+        timeProvider = magicOnionOptions.TimeProvider ?? TimeProvider.System;
 
         var remoteProxyFactory = serviceProvider.GetRequiredService<IRemoteProxyFactory>();
         var remoteSerializer = serviceProvider.GetRequiredService<IRemoteSerializer>();
-        this.remoteClientResultPendingTasks = new RemoteClientResultPendingTaskRegistry(magicOnionOptions.ClientResultsDefaultTimeout, magicOnionOptions.TimeProvider ?? TimeProvider.System);
+        this.remoteClientResultPendingTasks = new RemoteClientResultPendingTaskRegistry(magicOnionOptions.ClientResultsDefaultTimeout, timeProvider);
         this.Client = remoteProxyFactory.CreateDirect<TReceiver>(new MagicOnionRemoteReceiverWriter(StreamingServiceContext), remoteSerializer, remoteClientResultPendingTasks);
 
         var handlerRepository = serviceProvider.GetRequiredService<StreamingHubHandlerRepository>();
@@ -134,10 +134,13 @@ internal async Task<DuplexStreamingResult<StreamingHubPayload, StreamingHubPaylo
         {
             Metrics.StreamingHubConnectionDecrement(Context.Metrics, Context.MethodHandler.ServiceName);
 
-            heartbeatHandle.Dispose();
             StreamingServiceContext.CompleteStreamingHub();
+            heartbeatHandle.Unregister(); // NOTE: To be able to use CancellationToken within OnDisconnected event, separate the calls to Dispose and Unregister.
+
             await OnDisconnected();
+
             await this.Group.DisposeAsync();
+            heartbeatHandle.Dispose();
             remoteClientResultPendingTasks.Dispose();
         }
 
@@ -267,10 +270,10 @@ async ValueTask ProcessRequestAsync(UniqueHashDictionary<StreamingHubHandler> ha
                 hubInstance: this,
                 request: body,
                 messageId: messageId,
-                timestamp: DateTime.UtcNow
+                timestamp: timeProvider.GetUtcNow().UtcDateTime
             );
 
-            var methodStartingTimestamp = Stopwatch.GetTimestamp();
+            var methodStartingTimestamp = timeProvider.GetTimestamp();
             var isErrorOrInterrupted = false;
             MagicOnionServerLog.BeginInvokeHubMethod(Context.MethodHandler.Logger, context, context.Request, handler.RequestType);
             try
@@ -297,8 +300,8 @@ async ValueTask ProcessRequestAsync(UniqueHashDictionary<StreamingHubHandler> ha
             }
             finally
             {
-                var methodEndingTimestamp = Stopwatch.GetTimestamp();
-                MagicOnionServerLog.EndInvokeHubMethod(Context.MethodHandler.Logger, context, context.ResponseSize, context.ResponseType, StopwatchHelper.GetElapsedTime(methodStartingTimestamp, methodEndingTimestamp).TotalMilliseconds, isErrorOrInterrupted);
+                var methodEndingTimestamp = timeProvider.GetTimestamp();
+                MagicOnionServerLog.EndInvokeHubMethod(Context.MethodHandler.Logger, context, context.ResponseSize, context.ResponseType, timeProvider.GetElapsedTime(methodStartingTimestamp, methodEndingTimestamp).TotalMilliseconds, isErrorOrInterrupted);
                 Metrics.StreamingHubMethodCompleted(Context.Metrics, handler, methodStartingTimestamp, methodEndingTimestamp, isErrorOrInterrupted);
 
                 StreamingHubContextPool.Shared.Return(context);

src/MagicOnion.Server/Hubs/StreamingHubHeartbeatManager.cs

@@ -3,6 +3,7 @@
 using System.Diagnostics;
 using MagicOnion.Internal;
 using MagicOnion.Server.Diagnostics;
+using MagicOnion.Server.Internal;
 using Microsoft.Extensions.Logging;
 
 namespace MagicOnion.Server.Hubs;
@@ -17,26 +18,27 @@ internal interface IStreamingHubHeartbeatManager : IDisposable
 
 internal class StreamingHubHeartbeatHandle : IDisposable
 {
+    readonly object gate = new();
     readonly IStreamingHubHeartbeatManager manager;
     readonly CancellationTokenSource timeoutToken;
     readonly TimeSpan timeoutDuration;
     bool disposed;
-    short waitingSequence;
+    bool unregistered;
+    short waitingSequence = -1;
     bool timeoutTimerIsRunning;
     DateTimeOffset lastSentAt;
-    DateTimeOffset lastReceivedAt;
+    long lastSentAtTimestamp;
+    Action<TimeSpan>? onAckCallback;
 
     /// <summary>
     /// Gets the last received time.
     /// </summary>
-    public DateTimeOffset LastReceivedAt => lastReceivedAt;
+    public DateTimeOffset LastReceivedAt { get; private set; }
 
     /// <summary>
     /// Gets the latency between client and server. Returns <see cref="TimeSpan.Zero"/> if not sent or received.
     /// </summary>
-    public TimeSpan Latency => (lastSentAt == default || lastReceivedAt == default)
-        ? TimeSpan.Zero
-        : lastReceivedAt - lastSentAt;
+    public TimeSpan Latency { get; private set; }
 
     public IStreamingServiceContext<StreamingHubPayload, StreamingHubPayload> ServiceContext { get; }
     public CancellationToken TimeoutToken => timeoutToken.Token;
@@ -53,16 +55,21 @@ public StreamingHubHeartbeatHandle(IStreamingHubHeartbeatManager manager, IStrea
         );
     }
 
-    public void RestartTimeoutTimer(short sequence, DateTimeOffset sentAt)
+    public void RestartTimeoutTimer(short sequence, DateTimeOffset sentAt, long sentAtTimestamp)
     {
         if (disposed || timeoutDuration == Timeout.InfiniteTimeSpan) return;
-        waitingSequence = sequence;
-        lastSentAt = sentAt;
 
-        if (!timeoutTimerIsRunning)
+        lock (gate)
         {
-            timeoutToken.CancelAfter(timeoutDuration);
-            timeoutTimerIsRunning = true;
+            waitingSequence = sequence;
+            lastSentAt = sentAt;
+            lastSentAtTimestamp = sentAtTimestamp;
+
+            if (!timeoutTimerIsRunning)
+            {
+                timeoutToken.CancelAfter(timeoutDuration);
+                timeoutTimerIsRunning = true;
+            }
         }
     }
 
@@ -71,23 +78,46 @@ public void Ack(short sequence)
         if (disposed || timeoutDuration == Timeout.InfiniteTimeSpan) return;
 
         if (waitingSequence != sequence) return;
-        lastReceivedAt = manager.TimeProvider.GetUtcNow();
-        timeoutToken.CancelAfter(Timeout.InfiniteTimeSpan);
-        timeoutTimerIsRunning = false;
+
+        lock (gate)
+        {
+            var receivedAtTimestamp = manager.TimeProvider.GetTimestamp();
+            var elapsed = manager.TimeProvider.GetElapsedTime(lastSentAtTimestamp, receivedAtTimestamp);
+
+            LastReceivedAt = lastSentAt.Add(elapsed);
+            Latency = elapsed;
+            timeoutToken.CancelAfter(Timeout.InfiniteTimeSpan);
+            timeoutTimerIsRunning = false;
+
+            onAckCallback?.Invoke(Latency);
+        }
+    }
+
+    public void SetAckCallback(Action<TimeSpan>? callbackAction)
+    {
+        this.onAckCallback = callbackAction;
     }
 
     public void Unregister()
     {
+        if (unregistered) return;
+
         manager.Unregister(ServiceContext);
         timeoutToken.CancelAfter(Timeout.InfiniteTimeSpan);
         timeoutTimerIsRunning = false;
+        unregistered = true;
     }
 
     public void Dispose()
     {
         if (disposed) return;
+
         disposed = true;
-        manager.Unregister(ServiceContext);
+        onAckCallback = null;
+        if (!unregistered)
+        {
+            manager.Unregister(ServiceContext);
+        }
         timeoutToken.Dispose();
     }
 }
@@ -172,6 +202,7 @@ async Task StartHeartbeatAsync(PeriodicTimer runningTimer, string method)
         while (await runningTimer.WaitForNextTickAsync())
         {
             var now = TimeProvider.GetUtcNow();
+            var timestamp = TimeProvider.GetTimestamp();
             StreamingHubMessageWriter.WriteServerHeartbeatMessageHeader(writer, sequence, now);
             if (!(heartbeatMetadataProvider?.TryWriteMetadata(writer) ?? false))
             {
@@ -183,7 +214,7 @@ async Task StartHeartbeatAsync(PeriodicTimer runningTimer, string method)
             {
                 foreach (var (contextId, handle) in contexts)
                 {
-                    handle.RestartTimeoutTimer(sequence, now);
+                    handle.RestartTimeoutTimer(sequence, now, timestamp);
                     handle.ServiceContext.QueueResponseStreamWrite(StreamingHubPayloadPool.Shared.RentOrCreate(writer.WrittenSpan));
                 }
             }