Struct SubscriptionEngine 

pub struct SubscriptionEngine { /* private fields */ }

The subscription engine orchestrates the entire subscription pipeline.

It is designed to be invoked asynchronously after resource writes (fire-and-forget via tokio::spawn), mirroring the audit middleware pattern.

Implementations

impl SubscriptionEngine

pub fn new(config: SubscriptionConfig, base_url: String) -> Self

Creates a new subscription engine with a no-op outbound auth provider.

pub fn with_outbound_auth( config: SubscriptionConfig, base_url: String, outbound_auth: Arc<dyn OutboundAuthProvider>, ) -> Self

Creates a new subscription engine with a custom outbound auth provider.

The provider is used by channels that initiate outbound HTTP requests (currently the FHIR Messaging channel) to attach server-side credentials when the subscription does not supply its own Authorization header.

pub fn topic_registry(&self) -> &Arc<InMemoryTopicRegistry>

Returns a reference to the topic registry.

pub fn manager(&self) -> &Arc<SubscriptionManager>

Returns a reference to the subscription manager.

pub fn ws_manager(&self) -> &Arc<WebSocketManager>

Returns a reference to the WebSocket manager.

pub fn ws_token_manager(&self) -> &Arc<WsBindingTokenManager>

Returns a reference to the WebSocket binding token manager.

pub async fn on_resource_event(&self, event: ResourceEvent)

Called after a resource write has been committed.

This method:

1. Handles subscription/topic lifecycle events (if the written resource is a Subscription, SubscriptionTopic, or an R4 backport Basic topic).
2. Evaluates the event against all active subscriptions.
3. Builds and dispatches notifications.