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2025-12-01 17:21:38 +08:00
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"