Struct SubscriptionEventLoopState 

pub struct SubscriptionEventLoopState<T, R, S> { /* private fields */ }

The state machine for the subscription event loop.

This is made generic and removed from the subscription event loop to make it possible for users to implement their own event loop that doesn’t depend on the Session, which can allow for several useful features that we are unlikely to implement in the Session itself, such as:

• Backpressure, letting users replace the publish implementation with one that waits for the consumer to be ready before passing the publish response to the event loop.
• Custom subscription caches, for example for persisting subscription state.

Implementations

impl<T: Future<Output = Result<bool, StatusCode>>, R: Fn() -> T, S: SubscriptionCache> SubscriptionEventLoopState<T, R, S>

pub fn new( session_id: u32, trigger_publish_recv: Receiver<Instant>, publish_limits_rx: Receiver<PublishLimits>, publish_source: R, subscription_cache: S, ) -> Self

Construct a new subscription cache.

Arguments

• session_id - The session id for logging purposes.
• trigger_publish_recv - A channel used to transmit external publish triggers. This is used to trigger publish outside of the normal schedule, for example when a new subscription is created.
• publish_limits_rx - A channel used to receive updates to publish limits.
• publish_source - A function that produces a future that performs a publish operation.
• subscription_cache - An implementation of the SubscriptionCache trait.

pub async fn iter_loop(&mut self) -> SubscriptionActivity

Run an iteration of the event loop, returning each time a publish message is received.