Struct PubSubPublishOptions 

pub struct PubSubPublishOptions {
    pub ordering_key: Option<String>,
}

The settings one Pub/Sub message may differ from the next by.

Pub/Sub gives a message exactly one such field, its ordering key, so that is the whole type. The field is optional, because a publish carries only what its call site adjusted: what a call leaves unset keeps what the PubSubPublish policy fixed at the mount site.

A handler body that names the ordering_key step bounds its slot on this type, and a test reads the value back with tb.out::<Marker>().with_options(..).

Examples

use std::error::Error;

use ruststream::testing::TestApp;
use ruststream_gcp_pubsub::prelude::*;
use serde::{Deserialize, Serialize};

#[derive(Debug, Deserialize, Serialize, Outgoing)]
struct Order {
    id: u64,
}

#[subscriber("orders-workers")]
async fn confirm(
    order: &Order,
    Out(out): Out<impl Publisher<Options = PubSubPublishOptions>>,
) -> HandlerOutcome {
    let sent = out
        .message(order)
        .to("confirmations")
        .ordering_key(format!("order-{}", order.id))
        .publish()
        .await;
    if sent.is_err() {
        return HandlerOutcome::retry();
    }
    HandlerOutcome::ack()
}

/// The app `main` runs, and the one the test hands the harness.
pub fn app() -> impl App {
    RustStream::new(AppInfo::new("orders", "0.1.0"))
        .with_broker(PubSubBroker::new("my-project"), |b| {
            b.include(confirm).out(DefaultSlot, Publish::default()).build();
        })
}

pub async fn each_confirmation_carries_its_orders_key() -> Result<(), Box<dyn Error>> {
    let tb = TestApp::start(app()).await?;

    // A subscription the service only names is attached to the topic of its own name.
    tb.broker::<PubSubBroker>()
        .message(&Order { id: 42 })
        .to("orders-workers")
        .publish()
        .await?;
    tb.settle().await?;

    tb.out::<DefaultSlot>()
        .assert_called(1)
        .with_options(&PubSubPublishOptions {
            ordering_key: Some("order-42".to_owned()),
        });
    tb.shutdown().await?;
    Ok(())
}

Fields

ordering_key: Option<String>

The message’s ordering key. Messages sharing a key reach one subscriber in publish order, on a subscription that enables message ordering; None leaves the publish unordered unless the policy fixed a key.

Trait Implementations

impl Clone for PubSubPublishOptions

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for PubSubPublishOptions

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

Formats the value using the given formatter.

impl Default for PubSubPublishOptions

fn default() -> Self

Returns the “default value” for a type.

impl Eq for PubSubPublishOptions

impl PartialEq for PubSubPublishOptions

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for PubSubPublishOptions