Struct WaitEngine 

pub struct WaitEngine { /* private fields */ }

Drives Waiting flows back into Running (or Cancelled) based on their WaitCondition.

The engine is intentionally minimal — no broker, no internal scheduler. tick() is pull-based and idempotent; the host (or Phase 7 heartbeat) invokes it on whatever cadence is appropriate. run(interval, shutdown) is provided as a convenience for the common case.

Implementations

impl WaitEngine

pub fn new(manager: FlowManager) -> Self

pub fn manager(&self) -> &FlowManager

pub async fn tick_at(&self, now: DateTime<Utc>) -> TickReport

Single pass over all Waiting flows. Returns counters for telemetry. now is injected for deterministic testing — callers in production should pass Utc::now().

pub async fn tick(&self) -> TickReport

pub async fn try_resume_external( &self, flow_id: Uuid, topic: &str, correlation_id: &str, payload: Option<Value>, ) -> Result<Option<Flow>, FlowError>

Host-driven resume for ExternalEvent waits. Invoked when (e.g.) a NATS subscriber receives a message and resolves it to a flow. Returns:

• Ok(Some(flow)) when the flow matched and was resumed
• Ok(None) when no flow matched (no-op for caller)
• Err(_) for store/manager errors that the caller should log

pub async fn run(&self, interval: Duration, shutdown: CancellationToken)

Long-running tick loop. Stops cleanly when shutdown.cancelled() fires. Logs each tick at debug level.

Trait Implementations

impl Clone for WaitEngine

fn clone(&self) -> WaitEngine

Returns a duplicate of the value.

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

Performs copy-assignment from source.