Первый коммит

app/modules/shared/event_bus.py

@@ -0,0 +1,57 @@
+import asyncio
+import json
+import time
+from collections import defaultdict
+from dataclasses import dataclass
+
+
+@dataclass
+class Event:
+    name: str
+    payload: dict
+
+
+class EventBus:
+    def __init__(self) -> None:
+        self._channels: dict[str, list[asyncio.Queue[Event]]] = defaultdict(list)
+        self._history: dict[str, list[Event]] = defaultdict(list)
+        self._lock = asyncio.Lock()
+        self._history_limit = 5000
+
+    async def subscribe(self, channel_id: str, replay: bool = True) -> asyncio.Queue[Event]:
+        queue: asyncio.Queue[Event] = asyncio.Queue()
+        snapshot: list[Event] = []
+        async with self._lock:
+            self._channels[channel_id].append(queue)
+            if replay:
+                snapshot = list(self._history.get(channel_id, []))
+        for event in snapshot:
+            await queue.put(event)
+        return queue
+
+    async def unsubscribe(self, channel_id: str, queue: asyncio.Queue[Event]) -> None:
+        async with self._lock:
+            if channel_id not in self._channels:
+                return
+            items = self._channels[channel_id]
+            if queue in items:
+                items.remove(queue)
+            if not items:
+                del self._channels[channel_id]
+
+    async def publish(self, channel_id: str, name: str, payload: dict) -> None:
+        event_payload = dict(payload)
+        event_payload.setdefault("published_at_ms", int(time.time() * 1000))
+        event = Event(name=name, payload=event_payload)
+        async with self._lock:
+            queues = list(self._channels.get(channel_id, []))
+            history = self._history[channel_id]
+            history.append(event)
+            if len(history) > self._history_limit:
+                del history[: len(history) - self._history_limit]
+        for queue in queues:
+            await queue.put(event)
+
+    @staticmethod
+    def as_sse(event: Event) -> str:
+        return f"event: {event.name}\ndata: {json.dumps(event.payload, ensure_ascii=False)}\n\n"