Struct LapinSubscriber 

pub struct LapinSubscriber { /* private fields */ }

A consumer on one queue, yielding LapinMessage deliveries.

Created by subscribing a RabbitQueue descriptor (or a bare queue name) through LapinBroker. The subscriber owns a dedicated channel; dropping it closes that channel and the broker redelivers whatever was unacknowledged.

Back-pressure: the broker stops pushing once prefetch unacknowledged deliveries are in flight, so consuming slower slows the producer side down instead of buffering without bound.

It is a BatchSubscriber as well as a Subscriber: AMQP has no wire batch, so a batch handler’s size is honoured by collecting the deliveries here (see the impl).

Implementations

impl LapinSubscriber

pub fn queue(&self) -> &str

The queue this subscriber consumes from.

Trait Implementations

impl BatchSubscriber for LapinSubscriber

Batches are assembled on the client: AMQP delivers one basic.deliver at a time, so there is no wire batch to ask the broker for, and a batch closes on the registration’s size or on the descriptor’s batch_wait, whichever comes first.

A batch can only hold what the broker has already pushed, so a subscription whose prefetch window is narrower than the registration’s batch size yields batches capped by the window rather than by the size.

fn batches( &mut self, size: NonZeroUsize, ) -> impl Stream<Item = Result<Self::Batch, <Self as Subscriber>::Error>> + Send + '_

Cancel safety

As cancel safe as stream between polls; dropping the returned stream abandons the batch being assembled, and the broker redelivers those deliveries when the channel closes.

type Batch = Vec<LapinMessage>

Container yielded by batches. Implementations choose between Vec, custom iterators, or anything else that yields the underlying Subscriber::Message.

impl Debug for LapinSubscriber

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Subscriber for LapinSubscriber

fn stream( &mut self, ) -> impl Stream<Item = Result<Self::Message, Self::Error>> + Send + '_

Streams deliveries as they arrive; the stream ends when the consumer is cancelled or the connection closes.

Cancel safety

Polling is cancel safe (no delivery is lost by dropping the stream between polls), and the stream can be re-created by calling stream again: deliveries buffer in the consumer, not in the returned stream.

type Message = LapinMessage

The message type yielded by this subscriber.

type Error = AmqpError

The error type yielded by the stream when delivery fails.