sse: improve reliability

Streetwriters.Messenger/Helpers/SSEHelper.cs

@@ -18,28 +18,49 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 using System.Linq;
+using System;
+using System.Threading;
 using System.Threading.Tasks;
 using Lib.AspNetCore.ServerSentEvents;
 using System.Security.Claims;
+using System.Collections.Generic;
 
 namespace Streetwriters.Messenger.Helpers
 {
     public class SSEHelper
     {
-        public static async Task SendEventToUserAsync(string data, IServerSentEventsService sseService, string userId, string? originTokenId = null)
+        public static async Task SendEventToUserAsync(string data, IServerSentEventsService sseService, string userId, string? originTokenId = null, CancellationToken cancellationToken = default)
         {
-            var clients = sseService.GetClients().Where(c => c.User.FindFirstValue("sub") == userId);
-            foreach (var client in clients)
-            {
-                if (originTokenId != null && client.User.FindFirstValue("jti") == originTokenId) continue;
-                if (!client.IsConnected) continue;
-                await client.SendEventAsync(data);
-            }
+            var clients = sseService.GetClients()
+                .Where(c => c.User?.FindFirstValue("sub") == userId)
+                .Where(c => originTokenId == null || c.User?.FindFirstValue("jti") != originTokenId);
+
+            await SendEventToClientsAsync(clients, data, cancellationToken);
         }
 
-        public static async Task SendEventToAllUsersAsync(string data, IServerSentEventsService sseService)
+        public static async Task SendEventToAllUsersAsync(string data, IServerSentEventsService sseService, CancellationToken cancellationToken = default)
         {
-            await sseService.SendEventAsync(data);
+            await SendEventToClientsAsync(sseService.GetClients(), data, cancellationToken);
+        }
+
+        private static async Task SendEventToClientsAsync(IEnumerable<IServerSentEventsClient> clients, string data, CancellationToken cancellationToken)
+        {
+            foreach (var client in clients)
+            {
+                if (!client.IsConnected) continue;
+
+                try
+                {
+                    await client.SendEventAsync(data, cancellationToken);
+                }
+                catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+                {
+                    break;
+                }
+                catch
+                {
+                }
+            }
         }
     }
 }

Streetwriters.Messenger/Services/HeartbeatService.cs

@@ -21,6 +21,7 @@ using System;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
 using Lib.AspNetCore.ServerSentEvents;
 using Streetwriters.Messenger.Helpers;
 using System.Text.Json;
@@ -33,12 +34,14 @@ namespace Streetwriters.Messenger.Services
         private const string HEARTBEAT_MESSAGE_FORMAT = "Streetwriters Heartbeat ({0} UTC)";
 
         private readonly IServerSentEventsService _serverSentEventsService;
+        private readonly ILogger<HeartbeatService> _logger;
         #endregion
 
         #region Constructor
-        public HeartbeatService(IServerSentEventsService serverSentEventsService)
+        public HeartbeatService(IServerSentEventsService serverSentEventsService, ILogger<HeartbeatService> logger)
         {
             _serverSentEventsService = serverSentEventsService;
+            _logger = logger;
         }
         #endregion
 
@@ -47,15 +50,28 @@ namespace Streetwriters.Messenger.Services
         {
             while (!stoppingToken.IsCancellationRequested)
             {
-                var message = JsonSerializer.Serialize(new
+                try
                 {
-                    type = "heartbeat",
-                    data = JsonSerializer.Serialize(new
+                    var message = JsonSerializer.Serialize(new
                     {
-                        t = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds()
-                    })
-                });
-                await SSEHelper.SendEventToAllUsersAsync(message, _serverSentEventsService);
+                        type = "heartbeat",
+                        data = JsonSerializer.Serialize(new
+                        {
+                            t = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds()
+                        })
+                    });
+
+                    await SSEHelper.SendEventToAllUsersAsync(message, _serverSentEventsService, stoppingToken);
+                }
+                catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+                {
+                    break;
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogWarning(ex, "Failed to send SSE heartbeat to one or more clients.");
+                }
+
                 await Task.Delay(TimeSpan.FromSeconds(5), stoppingToken);
             }
         }

Streetwriters.Messenger/Streetwriters.Messenger.csproj

@@ -8,7 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="DotNetEnv" Version="2.3.0" />
-    <PackageReference Include="Lib.AspNetCore.ServerSentEvents" Version="6.0.0" />
+    <PackageReference Include="Lib.AspNetCore.ServerSentEvents" Version="9.1.0" />
     <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="5.0.0"
       NoWarn="NU1605" />
     <PackageReference Include="Microsoft.AspNetCore.Authentication.OpenIdConnect" Version="5.0.0"