Разработана первая версия приложений

codebase/backend/api-backend/app/realtime.py

@@ -0,0 +1,65 @@
+import asyncio
+import json
+import uuid
+from collections.abc import AsyncIterator
+from contextlib import suppress
+from typing import Any
+
+from redis.asyncio import Redis
+
+CHANNEL_PREFIX = "han:realtime:dialog:"
+
+
+class LocalFanout:
+    def __init__(self) -> None:
+        self._queues: set[asyncio.Queue[dict[str, Any]]] = set()
+
+    async def publish(self, event: dict[str, Any]) -> None:
+        for queue in tuple(self._queues):
+            with suppress(asyncio.QueueFull):
+                queue.put_nowait(event)
+
+    async def subscribe(self) -> AsyncIterator[dict[str, Any]]:
+        queue: asyncio.Queue[dict[str, Any]] = asyncio.Queue(maxsize=256)
+        self._queues.add(queue)
+        try:
+            while True:
+                yield await queue.get()
+        finally:
+            self._queues.discard(queue)
+
+
+class RealtimeFanout:
+    def __init__(self, redis: Redis, local: LocalFanout | None = None) -> None:
+        self.redis = redis
+        self.local = local or LocalFanout()
+
+    async def publish(self, event: dict[str, Any]) -> None:
+        event = {"event_id": str(uuid.uuid4()), **event}
+        channel = CHANNEL_PREFIX + str(event["dialog_id"])
+        try:
+            await self.redis.publish(channel, json.dumps(event, default=str, separators=(",", ":")))
+        except Exception:
+            await self.local.publish(event)
+
+    async def events(self, dialog_ids: set[uuid.UUID]) -> AsyncIterator[dict[str, Any]]:
+        channels = [CHANNEL_PREFIX + str(dialog_id) for dialog_id in dialog_ids]
+        pubsub = self.redis.pubsub()
+        try:
+            await pubsub.subscribe(*channels)
+        except Exception:
+            await pubsub.aclose()
+            async for event in self.local.subscribe():
+                if uuid.UUID(str(event["dialog_id"])) in dialog_ids:
+                    yield event
+            return
+        try:
+            while True:
+                message = await pubsub.get_message(ignore_subscribe_messages=True, timeout=1)
+                if message:
+                    yield json.loads(message["data"])
+                else:
+                    await asyncio.sleep(0)
+        finally:
+            await pubsub.unsubscribe(*channels)
+            await pubsub.aclose()