Trait SubscriptionBackplane 

pub trait SubscriptionBackplane:
    Send
    + Sync
    + 'static {
    // Required methods
    fn publish<'a>(
        &'a self,
        channel: &'a str,
        payload: &'a str,
    ) -> Pin<Box<dyn Future<Output = Result<(), CratestackError>> + Send + 'a>>;
    fn subscribe<'a>(
        &'a self,
        channel: &'a str,
    ) -> Pin<Box<dyn Future<Output = Result<Pin<Box<dyn Stream<Item = BackplaneMessage> + Send>>, CratestackError>> + Send + 'a>>;

    // Provided method
    fn publishes_model_events_in_tx(&self) -> bool { ... }
}

Fans a published message out to every replica, this one included.

Required Methods

fn publish<'a>( &'a self, channel: &'a str, payload: &'a str, ) -> Pin<Box<dyn Future<Output = Result<(), CratestackError>> + Send + 'a>>

Publishes payload on channel, fire and forget.

fn subscribe<'a>( &'a self, channel: &'a str, ) -> Pin<Box<dyn Future<Output = Result<Pin<Box<dyn Stream<Item = BackplaneMessage> + Send>>, CratestackError>> + Send + 'a>>

Receives everything published on channel from now on. The future resolves only once the subscription is live, so a caller that then tells its client “ready” has not missed anything published after.

Provided Methods

fn publishes_model_events_in_tx(&self) -> bool

Whether model events reach this backplane from inside the writing transaction (Postgres NOTIFY, delivered at commit). When false, the runtime publishes each model event after commit, from its outbox drain, and a topic’s publish_in_tx is refused.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl SubscriptionBackplane for InProcessBackplane

impl SubscriptionBackplane for PgNotifyBackplane