psycopg# class litestar.channels.backends.psycopg.PsycoPgChannelsBackend# Bases: ChannelsBackend __init__(pg_dsn: str) → None# async on_startup() → None# Called by the plugin on application startup async on_shutdown() → None# Called by the plugin on application shutdown async publish(data: bytes, channels: Iterable[str]) → None# Publish the message data to all channels async subscribe(channels: Iterable[str]) → None# Start listening for events on channels async unsubscribe(channels: Iterable[str]) → None# Stop listening for events on channels async stream_events() → AsyncGenerator[tuple[str, bytes], None]# Return a generator, iterating over events of subscribed channels as they become available async get_history(channel: str, limit: int | None = None) → list[bytes]# Return the event history of channel, at most limit entries