proper web socket close

TanksServer/ClientScreenServer.cs

@@ -1,52 +1,60 @@
 using System.Net.WebSockets;
+using System.Threading;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
 
 namespace TanksServer;
 
-internal sealed class ClientScreenServer
+internal sealed class ClientScreenServer(
+    ILogger<ClientScreenServer> logger,
+    ILoggerFactory loggerFactory
+) : IHostedLifecycleService
 {
     private readonly List<ClientScreenServerConnection> _connections = new();
 
-    public ClientScreenServerConnection AddClient(WebSocket socket)
+    public Task HandleClient(WebSocket socket)
     {
-        var connection = new ClientScreenServerConnection(socket);
+        logger.LogDebug("HandleClient");
+        var connection =
+            new ClientScreenServerConnection(socket, loggerFactory.CreateLogger<ClientScreenServerConnection>());
         _connections.Add(connection);
-        return connection;
+        return connection.Done;
     }
 
     public Task Send(DisplayPixelBuffer buf)
     {
+        logger.LogDebug("Sending buffer to {} clients", _connections.Count);
         return Task.WhenAll(_connections.Select(c => c.Send(buf)));
     }
+
+    public Task StoppingAsync(CancellationToken cancellationToken)
+    {
+        logger.LogInformation("closing connections");
+        return Task.WhenAll(_connections.Select(c => c.CloseAsync()));
+    }
+
+    public Task StartAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+    public Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+    public Task StartedAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+    public Task StartingAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+    public Task StoppedAsync(CancellationToken cancellationToken) => Task.CompletedTask;
 }
 
-internal sealed class ClientScreenServerConnection
+internal sealed class ClientScreenServerConnection(WebSocket webSocket, ILogger<ClientScreenServerConnection> logger)
+    : EasyWebSocket(webSocket, logger, ArraySegment<byte>.Empty)
 {
-    private readonly WebSocket _socket;
-    private readonly Task _readTask;
-    private readonly TaskCompletionSource _completionSource = new();
     private bool _wantsNewFrame = true;
 
-    public ClientScreenServerConnection(WebSocket webSocket)
-    {
-        _socket = webSocket;
-        _readTask = Read();
-    }
-
-    public Task Done => _completionSource.Task;
-
-    private async Task Read()
-    {
-        while (true)
-        {
-            await _socket.ReceiveAsync(ArraySegment<byte>.Empty, default);
-            _wantsNewFrame = true;
-        }
-    }
-
     public Task Send(DisplayPixelBuffer buf)
     {
         if (!_wantsNewFrame)
             return Task.CompletedTask;
-        return _socket.SendAsync(buf.Data, WebSocketMessageType.Binary, true, default);
+        return SendAsync(buf.Data);
+    }
+
+    protected override Task ReceiveAsync(ArraySegment<byte> buffer)
+    {
+        _wantsNewFrame = true;
+        return Task.CompletedTask;
     }
 }

TanksServer/DisplayPixelBuffer.cs

@@ -1,6 +1,6 @@
 namespace TanksServer;
 
-public sealed class DisplayPixelBuffer(byte[] data)
+internal sealed class DisplayPixelBuffer(byte[] data)
 {
     public byte[] Data => data;
 

TanksServer/EasyWebSocket.cs

@@ -0,0 +1,53 @@
+using System.Net.WebSockets;
+using System.Threading;
+using Microsoft.Extensions.Logging;
+
+namespace TanksServer;
+
+internal abstract class EasyWebSocket
+{
+    private readonly TaskCompletionSource _completionSource = new();
+
+    private readonly ILogger _logger;
+    private readonly WebSocket _socket;
+    private readonly Task _readLoop;
+    private readonly ArraySegment<byte> _buffer;
+
+    protected EasyWebSocket(WebSocket socket, ILogger logger, ArraySegment<byte> buffer)
+    {
+        _socket = socket;
+        _logger = logger;
+        _buffer = buffer;
+        _readLoop = ReadLoopAsync();
+    }
+
+    public Task Done => _completionSource.Task;
+
+    private async Task ReadLoopAsync()
+    {
+        do
+        {
+            var response = await _socket.ReceiveAsync(_buffer, CancellationToken.None);
+            if (response.CloseStatus.HasValue)
+                break;
+
+            await ReceiveAsync(_buffer[..response.Count]);
+        } while (_socket.State == WebSocketState.Open);
+    }
+
+    protected abstract Task ReceiveAsync(ArraySegment<byte> buffer);
+
+    protected Task SendAsync(byte[] data)
+    {
+        _logger.LogTrace("sending {} bytes of data", _buffer.Count);
+        return _socket.SendAsync(data, WebSocketMessageType.Binary, true, CancellationToken.None);
+    }
+
+    public async Task CloseAsync()
+    {
+        _logger.LogDebug("closing socket");
+        await _socket.CloseAsync(WebSocketCloseStatus.NormalClosure, null, CancellationToken.None);
+        await _readLoop;
+        _completionSource.SetResult();
+    }
+}

TanksServer/FixedSizeBitFieldView.cs

@@ -2,7 +2,7 @@ using System.Collections;
 
 namespace TanksServer;
 
-public sealed class FixedSizeBitFieldView(Memory<byte> data) : IList<bool>
+internal sealed class FixedSizeBitFieldView(Memory<byte> data) : IList<bool>
 {
     public int Count => data.Length * 8;
     public bool IsReadOnly => false;

TanksServer/MapDrawer.cs

@@ -1,6 +1,6 @@
 namespace TanksServer;
 
-public class MapDrawer(MapService map)
+internal class MapDrawer(MapService map)
 {
     private const uint GameFieldPixelCount = MapService.PixelsPerRow * MapService.PixelsPerColumn;
 

TanksServer/MapService.cs

@@ -1,6 +1,6 @@
 namespace TanksServer;
 
-public class MapService
+internal class MapService
 {
     public const int TilesPerRow = 44;
     public const int TilesPerColumn = 20;
@@ -8,7 +8,8 @@ public class MapService
     public const int PixelsPerRow = TilesPerRow * TileSize;
     public const int PixelsPerColumn = TilesPerColumn * TileSize;
 
-    private string _map = """
+    private readonly string _map =
+        """
             ############################################
             #...................##.....................#
             #...................##.....................#

TanksServer/Program.cs

@@ -1,5 +1,6 @@
 using System.IO;
 using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.FileProviders;
 
@@ -27,11 +28,13 @@ internal static class Program
         app.Map("/screen", async context =>
         {
             if (!context.WebSockets.IsWebSocketRequest)
+            {
+                context.Response.StatusCode = StatusCodes.Status400BadRequest;
                 return;
-            var ws = await context.WebSockets.AcceptWebSocketAsync();
+            }
-            var client = clientScreenServer.AddClient(ws);
+
-            await client.Send(buffer);
+            using var ws = await context.WebSockets.AcceptWebSocketAsync();
-            await client.Done;
+            await clientScreenServer.HandleClient(ws);
         });
 
         await app.RunAsync();
@@ -45,6 +48,7 @@ internal static class Program
         builder.Services.AddSingleton<MapService>();
         builder.Services.AddSingleton<MapDrawer>();
         builder.Services.AddSingleton<ClientScreenServer>();
+        builder.Services.AddHostedService<ClientScreenServer>(sp => sp.GetRequiredService<ClientScreenServer>());
 
         return builder.Build();
     }

TanksServer/ServicePointDisplay.cs

@@ -3,7 +3,7 @@ using Microsoft.Extensions.Options;
 
 namespace TanksServer;
 
-public class ServicePointDisplay(IOptions<ServicePointDisplayConfiguration> options)
+internal class ServicePointDisplay(IOptions<ServicePointDisplayConfiguration> options)
 {
     private readonly UdpClient _udpClient = new(options.Value.Hostname, options.Value.Port);
 
@@ -12,3 +12,9 @@ public class ServicePointDisplay(IOptions<ServicePointDisplayConfiguration> opti
         return _udpClient.SendAsync(buffer.Data);
     }
 }
+
+internal class ServicePointDisplayConfiguration
+{
+    public string Hostname { get; set; } = string.Empty;
+    public int Port { get; set; }
+}

TanksServer/ServicePointDisplayConfiguration.cs

@@ -1,7 +0,0 @@
-namespace TanksServer;
-
-public class ServicePointDisplayConfiguration
-{
-    public string Hostname { get; set; } = string.Empty;
-    public int Port { get; set; }
-}