InRound

The InRound transform on the reply position puts a handler's reply into its delivery's round, after the commands it queued.

The transform chains after the reply policy: .out_reply(Publish).transform(InRound). The reply then leaves with the delivery's settle, in the window's pipeline, and only when the delivery is acknowledged. It follows what the handler queued and published through a bound slot, so a reader sees the handler's writes in the order the handler made them. Without the transform a reply is an ordinary publish: it leaves as the handler returns, before the window sends what the handler queued. The transform writes the crate's per-message options, so it mounts only where this crate's policies publish.

Example

The reply confirms the order on the same log the bound slot wrote to; with InRound the log reads accepted, then confirmed.

Macros
Manual

examples/redis_pipelining_round.rs
#[ruststream::app]
fn app() -> impl App {
    RustStream::new(AppInfo::new("orders", "0.1.0")).with_broker(
        RedisBroker::standalone("redis://localhost:6379"),
        |b| {
            // The reply joins the delivery's round after the bound entry, so the log keeps the
            // order the handler wrote them in.
            b.include(accept.pipeline())
                .out_reply(Publish)
                .transform(InRound)
                .out(DefaultSlot, Publish)
                .build();
        },
    )
}

examples/manual/redis_pipelining_round.rs
fn app() -> impl App {
    RustStream::new(AppInfo::new("orders", "0.1.0")).with_broker(
        RedisBroker::standalone("redis://localhost:6379"),
        |b| {
            let accept = subscriber(RedisStream::new("orders").group("workers"), Accept);
            // The reply joins the delivery's round after the bound entry, so the log keeps the
            // order the handler wrote them in.
            b.include(accept.pipeline().reply().build())
                .out_reply(Publish)
                .transform(InRound)
                .out(DefaultSlot, Publish)
                .build();
        },
    )
}

Example​

Example