Update Dockerfile to use .NET 10.0 stable and Alpine 3.23, refactor SSE implementation

HoolIt.sln.DotSettings.user

@@ -1,2 +1,3 @@
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+	<s:String x:Key="/Default/CodeInspection/ExcludedFiles/FilesAndFoldersToSkip2/=7020124F_002D9FFC_002D4AC3_002D8F3D_002DAAB8E0240759_002Ff_003ADebugger_002Ecs_002Fl_003A_002E_002E_003F_002E_002E_003F_002Econfig_003FJetBrains_003FRider2025_002E3_003Fresharper_002Dhost_003FSourcesCache_003Ff9d2f95d72fa884d8b6ddefc717c56da3657fbb2d5fb683656c3589eb6587_003FDebugger_002Ecs/@EntryIndexedValue">ForceIncluded</s:String>
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HoolIt/Dockerfile

@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/dotnet/sdk:10.0.100-preview.7-alpine3.22-aot AS build
+FROM mcr.microsoft.com/dotnet/dotnet/sdk:10.0-alpine3.23-aot AS build
 
 # Install NativeAOT build prerequisites
 RUN apk update \
@@ -10,7 +10,7 @@ WORKDIR /source
 COPY . .
 RUN dotnet publish -r linux-musl-x64 -o /app 'HoolIt.csproj'
 
-FROM mcr.microsoft.com/dotnet/runtime-deps:10.0.0-preview.7-alpine3.22
+FROM mcr.microsoft.com/dotnet/runtime-deps:10.0-alpine3.23
 WORKDIR /app
 COPY --from=build /app .
 ENTRYPOINT ["/app/HoolIt"]

HoolIt/Program.cs

@@ -1,7 +1,9 @@
 using System.Collections.Concurrent;
+using System.Runtime.CompilerServices;
 using System.Text;
 using System.Text.Json;
 using System.Text.Json.Serialization;
+using System.Threading.Channels;
 using HoolIt.Models;
 
 var builder = WebApplication.CreateSlimBuilder(args);
@@ -15,7 +17,7 @@ var app = builder.Build();
 app.Urls.Clear();
 app.Urls.Add("http://0.0.0.0:5030");
 
-var subscribers = new ConcurrentDictionary<string, List<StreamWriter>>();
+var subscribers = new ConcurrentDictionary<string, List<ChannelWriter<string>>>();
 var cancellationSources =
     new ConcurrentDictionary<string, CancellationTokenSource>(); // To manage cancellation per feedId
 
@@ -36,18 +38,15 @@ createApi.MapGet("/{feedId}", async (HttpContext context, string feedId) =>
 
     try
     {
-        var chunkedQueryData = JsonSerializer.Serialize(dweet, AppJsonSerializerContext.Default.Dweet);
+        var jsonQueryData = JsonSerializer.Serialize(dweet, AppJsonSerializerContext.Default.Dweet);
 
         if (subscribers.TryGetValue(feedId, out var subscribersList))
             foreach (var writer in subscribersList)
-            {
+                await writer.WriteAsync(jsonQueryData);
-                await writer.WriteLineAsync(chunkedQueryData);
-                await writer.FlushAsync();
-            }
     }
     catch (Exception e)
     {
-        var faultResponse = new AddDweetFailedResponse()
+        var faultResponse = new AddDweetFailedResponse
         {
             This = "failed",
             With = "WeMessedUp",
@@ -59,7 +58,6 @@ createApi.MapGet("/{feedId}", async (HttpContext context, string feedId) =>
         context.Response.ContentType = "application/json";
         await context.Response.WriteAsync(addFailedResponse);
         await context.Response.CompleteAsync();
-
     }
 
     var addSuccessResponse = new AddDweetSucceededResponse
@@ -77,54 +75,44 @@ getLiveDataApi.MapGet("/{feedId}",
     async (HttpContext context, string feedId, IHostApplicationLifetime appLifetime,
         CancellationToken reqCancellationToken) =>
     {
-        context.Response.Headers.ContentType = "text/event-stream";
+        context.Response.StatusCode = 200;
+        context.Response.Headers.ContentType = "text/plain";
+        context.Response.Headers.CacheControl = "no-cache";
+        context.Response.Headers["X-Content-Type-Options"] = "nosniff";
 
-        var writer = new StreamWriter(context.Response.Body, Encoding.UTF8);
+        // Disable response buffering
-        subscribers.GetOrAdd(feedId, _ => new List<StreamWriter>()).Add(writer);
+        context.Features.Get<Microsoft.AspNetCore.Http.Features.IHttpResponseBodyFeature>()?
+            .DisableBuffering();
 
-        // How this cancellation token mess works:
+        var channel = Channel.CreateUnbounded<string>();
-        // - reqCancellationToken is the cancellation token from the client request, it is used when a client closes the request.
+        var writer = channel.Writer;
-        // - feedCts is the cancellation token from the feedId, it is used when the app is shutting down.
-        // - linkedCts is a linked token source that combines both reqCancellationToken and feedCts and gets canceled when either of them does.
-        // When the app is shutting down, the feedCts token source is canceled which means everything gets canceled altogether (Even that date you have been planning for the past few months; c'mon, you are probably a computer science student with no friends who barely touches grass).
 
-        var feedCts = cancellationSources.GetOrAdd(feedId, _ => new CancellationTokenSource());
+        subscribers.GetOrAdd(feedId, _ => new List<ChannelWriter<string>>()).Add(writer);
-        using var linkedCts = CancellationTokenSource.CreateLinkedTokenSource(reqCancellationToken, feedCts.Token);
+        Console.WriteLine($"Added subscriber to feed {feedId}");
-        var linkedToken = linkedCts.Token;
-
-        appLifetime.ApplicationStopping.Register(() =>
-        {
-            if (cancellationSources.TryGetValue(feedId, out var existingFeedCts) &&
-                !existingFeedCts.IsCancellationRequested)
-            {
-                // It cancels 
-                existingFeedCts.Cancel();
-                Console.WriteLine($"Cancellation signaled for feedId: {feedId} due to app shutdown.");
-            }
-        });
 
         try
         {
-            while (!linkedToken.IsCancellationRequested) await Task.Delay(Timeout.Infinite, linkedToken);
+            var reader = channel.Reader;
+
+            while (!reqCancellationToken.IsCancellationRequested &&
+                   await reader.WaitToReadAsync(reqCancellationToken))
+            while (reader.TryRead(out var msg))
+            {
+                await context.Response.WriteAsync(msg + "\n", reqCancellationToken);
+                await context.Response.Body.FlushAsync(reqCancellationToken);
+            }
         }
         catch (OperationCanceledException)
         {
-            Console.WriteLine($"SSE connection for feedId: {feedId} canceled.");
+            Console.WriteLine($"Cancellation requested for feed {feedId}");
         }
         finally
         {
-            if (subscribers.TryGetValue(feedId, out var subscribersList))
+            if (subscribers.TryGetValue(feedId, out var list))
             {
-                subscribersList.Remove(writer);
+                list.Remove(writer);
-                if (subscribersList.Count == 0)
+                Console.WriteLine($"Removed subscriber from feed {feedId}");
-                {
+                if (list.Count == 0) subscribers.TryRemove(feedId, out _);
-                    subscribers.TryRemove(feedId, out _);
-                    cancellationSources.TryRemove(feedId, out _);
-                    Console.WriteLine($"No more subscribers for feedId: {feedId}. CTS removed.");
-                }
-
-                await writer.DisposeAsync();
-                Console.WriteLine("Removed subscriber from feed " + feedId);
             }
         }
     });