dify

dify/api/libs/broadcast_channel/redis/channel.py

@@ -0,0 +1,67 @@
+from libs.broadcast_channel.channel import Producer, Subscriber, Subscription
+from redis import Redis
+
+from ._subscription import RedisSubscriptionBase
+
+
+class BroadcastChannel:
+    """
+    Redis Pub/Sub based broadcast channel implementation (regular, non-sharded).
+
+    Provides "at most once" delivery semantics for messages published to channels
+    using Redis PUBLISH/SUBSCRIBE commands for real-time message delivery.
+
+    The `redis_client` used to construct BroadcastChannel should have `decode_responses` set to `False`.
+    """
+
+    def __init__(
+        self,
+        redis_client: Redis,
+    ):
+        self._client = redis_client
+
+    def topic(self, topic: str) -> "Topic":
+        return Topic(self._client, topic)
+
+
+class Topic:
+    def __init__(self, redis_client: Redis, topic: str):
+        self._client = redis_client
+        self._topic = topic
+
+    def as_producer(self) -> Producer:
+        return self
+
+    def publish(self, payload: bytes) -> None:
+        self._client.publish(self._topic, payload)
+
+    def as_subscriber(self) -> Subscriber:
+        return self
+
+    def subscribe(self) -> Subscription:
+        return _RedisSubscription(
+            pubsub=self._client.pubsub(),
+            topic=self._topic,
+        )
+
+
+class _RedisSubscription(RedisSubscriptionBase):
+    """Regular Redis pub/sub subscription implementation."""
+
+    def _get_subscription_type(self) -> str:
+        return "regular"
+
+    def _subscribe(self) -> None:
+        assert self._pubsub is not None
+        self._pubsub.subscribe(self._topic)
+
+    def _unsubscribe(self) -> None:
+        assert self._pubsub is not None
+        self._pubsub.unsubscribe(self._topic)
+
+    def _get_message(self) -> dict | None:
+        assert self._pubsub is not None
+        return self._pubsub.get_message(ignore_subscribe_messages=True, timeout=0.1)
+
+    def _get_message_type(self) -> str:
+        return "message"