Publish LumaOps source

lumaops/backend/src/lumaops_backend/events.py

@@ -0,0 +1,35 @@
+"""In-process event fan-out for Server-Sent Events clients."""
+
+from __future__ import annotations
+
+import asyncio
+from collections.abc import AsyncIterator
+from typing import Any
+
+
+class EventBus:
+    def __init__(self) -> None:
+        self._subscribers: set[asyncio.Queue[dict[str, Any]]] = set()
+
+    async def publish(self, event_type: str, data: dict[str, Any]) -> None:
+        event = {"type": event_type, "data": data}
+        dead: list[asyncio.Queue[dict[str, Any]]] = []
+        for queue in self._subscribers:
+            try:
+                queue.put_nowait(event)
+            except asyncio.QueueFull:
+                dead.append(queue)
+        for queue in dead:
+            self._subscribers.discard(queue)
+
+    async def subscribe(self) -> AsyncIterator[dict[str, Any]]:
+        queue: asyncio.Queue[dict[str, Any]] = asyncio.Queue(maxsize=100)
+        self._subscribers.add(queue)
+        try:
+            while True:
+                try:
+                    yield await asyncio.wait_for(queue.get(), timeout=20)
+                except TimeoutError:
+                    yield {"type": "heartbeat", "data": {}}
+        finally:
+            self._subscribers.discard(queue)