Move to SSE from websocket

2024-08-24 16:49:56 +02:00
parent 5e93732183
commit c9be7c9c2c
9 changed files with 133 additions and 111 deletions
@@ -0,0 +1,78 @@
+using System.Text;
+using ChatTwo.Http.MessageProtocol;
+using Newtonsoft.Json;
+using WatsonWebserver.Core;
+
+namespace ChatTwo.Http;
+
+public class EventServer
+{
+    private bool Stopping;
+    private bool Finished;
+    private readonly CancellationToken Token;
+
+    public readonly Stack<BaseMessage> OutboundStack = new();
+
+    private long Index;
+
+    public EventServer(CancellationToken token)
+    {
+        Token = token;
+    }
+
+    public async Task HandleEventLoop(HttpContextBase ctx)
+    {
+        try
+        {
+            ctx.Response.Headers.Add("Content-Type", "text/event-stream");
+            ctx.Response.Headers.Add("Cache-Control", "no-cache");
+            ctx.Response.Headers.Add("Connection", "keep-alive");
+
+            ctx.Response.ChunkedTransfer = true;
+            while (!Token.IsCancellationRequested && !Stopping)
+            {
+                await Task.Delay(10, Token);
+                if (Token.IsCancellationRequested)
+                    return;
+
+                if (!OutboundStack.TryPop(out var message))
+                    continue;
+
+                var data = JsonConvert.SerializeObject(message);
+                await ctx.Response.SendChunk(Encoding.UTF8.GetBytes($"id: {Index}\ndata: {data}\n\n"), Token);
+                Index++;
+            }
+        }
+        catch (TaskCanceledException)
+        {
+            // Ignore
+        }
+        catch (Exception ex)
+        {
+            Plugin.Log.Error(ex, "Event queued failed to continue");
+        }
+        finally
+        {
+            // No Content (204) didn't work for Firefox, so manually closing the connection on client side
+            await ctx.Response.SendFinalChunk("data: closing\nevent: close\n\n"u8.ToArray());
+
+            Finished = true;
+        }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        Stopping = true;
+
+        var timeout = 1000; // 1000ms
+        while (timeout > 0)
+        {
+            if (Finished)
+                break;
+
+            timeout -= 100;
+            await Task.Delay(100);
+            Plugin.Log.Debug("Sleeping because EventServer still alive");
+        }
+    }
+}