Operations

A receive operation reports its queue group in the nats binding, the one field that binding has.

The binding is {"queue": "<group>", "bindingVersion": "0.1.0"}. The group is the one queue_group names on a CoreSubject or a CoreWildcard. A subscription outside a queue group carries no binding. A JetStream consumer carries none either: its durable name and its other settings are on the channel.

Example

The operation receive_orders_created reports the queue group workers.

Macros

examples/nats_asyncapi.rs

#[subscriber(CoreSubject::new("orders.created").queue_group("workers"))]
async fn confirm(order: &Order) -> HandlerOutcome {
    tracing::info!(order.id, "order confirmed");
    HandlerOutcome::ack()
}

Manual

examples/manual/nats_asyncapi.rs

struct Confirm;

impl Handle<Order> for Confirm {
    fn handle(
        &self,
        order: &Order,
        _outs: &(),
        _ctx: &mut Context<'_>,
    ) -> impl Future<Output = Result<(), HandlerOutcome>> {
        tracing::info!(order.id, "order confirmed");
        ready(Ok(()))
    }
}

/// Core NATS subject `orders.created`, shared by the queue group `workers`.
fn created() -> CoreSubject {
    CoreSubject::new("orders.created").queue_group("workers")
}