SNS topics

A fan-out position reports its topic through an sns binding, with a FIFO ordering object on a .fifo topic.

A channel the service publishes to through SnsPublish carries the sns binding instead of the sqs one. name is the topic the mount site resolved, from a reply clause, a reply type's #[outgoing(name)] or a slot entry. A topic whose name ends in .fifo adds ordering, with type set to FIFO. Its contentBasedDeduplication is false: every FIFO send this crate makes carries a deduplication id of its own, which wins over one derived from the body. A standard topic carries no ordering object, which the specification reads as a standard topic.

Example

The reply of settle fans out from the FIFO topic payment-events.fifo.

Macros
Manual

examples/sqs_asyncapi.rs
/// The reply names a FIFO topic.
#[subscriber(SqsQueue::new("payments"), reply("payment-events.fifo"))]
async fn settle(payment: &Payment) -> PaymentSettled {
    PaymentSettled { id: payment.id }
}

fn service(broker: SqsBroker) -> impl App<State = ()> {
    RustStream::new(AppInfo::new("orders", "1.0.0")).with_broker_labeled("sqs", broker, |b| {
        b.include(confirm);
        b.include(ship);
        // The reply fans out from the topic its clause names.
        b.include(settle).out_reply(SnsPublish::default());
    })
}

examples/manual/sqs_asyncapi.rs
fn service(broker: SqsBroker) -> impl App<State = ()> {
    RustStream::new(AppInfo::new("orders", "1.0.0")).with_broker_labeled("sqs", broker, |b| {
        let confirm = subscriber("orders", Confirm).map_source(|_| orders());
        b.include(confirm.reply().to("confirmations").build());
        b.include(
            subscriber("shipments.fifo", Ship)
                .map_source(|_| shipments())
                .build(),
        );
        // The reply fans out from a FIFO topic.
        let settle = subscriber("payments", Settle);
        b.include(settle.reply().to("payment-events.fifo").build())
            .out_reply(SnsPublish::default());
    })
}

The binding of payment-events.fifo in the document:

{
  "sns": {
    "bindingVersion": "1.0.0",
    "name": "payment-events.fifo",
    "ordering": {
      "type": "FIFO",
      "contentBasedDeduplication": false
    }
  }
}

Example​

Example