feat: serve planning snapshots on loopback

2026-08-06 09:38:12 +08:00
parent 106201e87b
commit fa1a2666d3
6 changed files with 955 additions and 0 deletions
@@ -0,0 +1,115 @@
+using System;
+using System.Net.Sockets;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace TrajectoryPlanningVisualization;
+
+internal sealed class SseClientConnection : IDisposable
+{
+    private readonly TcpClient client;
+    private readonly CancellationToken cancellationToken;
+    private readonly AutoResetEvent pendingSignal = new AutoResetEvent(false);
+    private readonly Task writerTask;
+    private string pendingPayload;
+    private int completeAfterWrite;
+    private int disposed;
+
+    public SseClientConnection(TcpClient client, CancellationToken cancellationToken)
+    {
+        this.client = client ?? throw new ArgumentNullException(nameof(client));
+        this.cancellationToken = cancellationToken;
+        writerTask = Task.Run((Action)WriteLoop);
+    }
+
+    public Task Completion => writerTask;
+
+    public void Offer(string payload)
+    {
+        if (payload == null || Volatile.Read(ref disposed) != 0)
+        {
+            return;
+        }
+
+        Interlocked.Exchange(ref pendingPayload, payload);
+        pendingSignal.Set();
+    }
+
+    public void OfferTerminal(string payload)
+    {
+        if (payload == null || Volatile.Read(ref disposed) != 0)
+        {
+            return;
+        }
+
+        Interlocked.Exchange(ref pendingPayload, payload);
+        Interlocked.Exchange(ref completeAfterWrite, 1);
+        pendingSignal.Set();
+    }
+
+    public bool WaitForCompletion(TimeSpan timeout)
+    {
+        try
+        {
+            return writerTask.Wait(timeout);
+        }
+        catch (AggregateException)
+        {
+            return true;
+        }
+    }
+
+    public void Dispose()
+    {
+        if (Interlocked.Exchange(ref disposed, 1) != 0)
+        {
+            return;
+        }
+
+        pendingSignal.Set();
+        try
+        {
+            client.Close();
+        }
+        finally
+        {
+            pendingSignal.Dispose();
+        }
+    }
+
+    private void WriteLoop()
+    {
+        try
+        {
+            NetworkStream stream = client.GetStream();
+            stream.WriteTimeout = 1000;
+            while (!cancellationToken.IsCancellationRequested && Volatile.Read(ref disposed) == 0)
+            {
+                string payload = Interlocked.Exchange(ref pendingPayload, null);
+                if (payload == null)
+                {
+                    pendingSignal.WaitOne(50);
+                    continue;
+                }
+
+                byte[] bytes = Encoding.UTF8.GetBytes(payload);
+                stream.Write(bytes, 0, bytes.Length);
+                stream.Flush();
+                if (Interlocked.Exchange(ref completeAfterWrite, 0) != 0)
+                {
+                    return;
+                }
+            }
+        }
+        catch (SocketException)
+        {
+        }
+        catch (System.IO.IOException)
+        {
+        }
+        catch (ObjectDisposedException)
+        {
+        }
+    }
+}