Struct PgNotifyBackplane 

pub struct PgNotifyBackplane { /* private fields */ }

Subscription backplanes (docs/design/subscriptions-websocket.md §4): PgNotifyBackplane is the default; InProcessBackplane serves a single replica. Swap with Cratestack::builder(pool).with_backplane(..).

Implementations

impl PgNotifyBackplane

pub fn new(pool: Pool<Postgres>) -> PgNotifyBackplane

The listener takes one connection from pool’s settings (not from the pool itself). It needs a session that keeps LISTEN state, so not a PgBouncer in transaction mode.

Trait Implementations

impl SubscriptionBackplane for PgNotifyBackplane

fn publish<'a>( &'a self, channel: &'a str, payload: &'a str, ) -> Pin<Box<dyn Future<Output = Result<(), CratestackError>> + Send + 'a>>

Publishes payload on channel, fire and forget.

fn subscribe<'a>( &'a self, channel: &'a str, ) -> Pin<Box<dyn Future<Output = Result<Pin<Box<dyn Stream<Item = BackplaneMessage> + Send>>, CratestackError>> + Send + 'a>>

Receives everything published on channel from now on. The future resolves only once the subscription is live, so a caller that then tells its client “ready” has not missed anything published after.

fn publishes_model_events_in_tx(&self) -> bool

Whether model events reach this backplane from inside the writing transaction (Postgres NOTIFY, delivered at commit). When false, the runtime publishes each model event after commit, from its outbox drain, and a topic’s publish_in_tx is refused.