Struct OriginBreaker 

pub struct OriginBreaker { /* private fields */ }

Per-origin circuit-breaker. One instance fronts each origin’s pull-through retry loop in crate::CacheEngine.

Cheap to construct and Send + Sync; the engine holds one per origin in a parallel Vec. A disabled policy (!policy.is_active()) makes every Self::acquire return Admission::Proceed with an inert guard whose TrialGuard::record is a no-op, so an opted-out operator pays nothing but a mutex-free is_active check on the hot path.

Implementations

impl OriginBreaker

pub fn new( policy: CircuitBreakerPolicy, clock: Arc<dyn Clock>, metrics: Option<Arc<CacheMetrics>>, ) -> Self

Construct a breaker for one origin under policy, using clock for cooldown timekeeping and bumping transition counters on metrics when present.

pub fn state(&self) -> BreakerState

Current state, for tests and observability. Note this may run the lazy OPEN→HALF-OPEN cooldown check is not applied here — it reports the raw stored phase. Use Self::acquire to drive transitions.

pub fn acquire(&self) -> Admission<'_>

Decide whether to admit a pull-through attempt for this origin now, applying the lazy OPEN→HALF-OPEN cooldown transition.

Returns Admission::ShortCircuit when the breaker is OPEN (cooldown not yet elapsed) or HALF-OPEN with no remaining trial budget — the caller must fast-fail the miss without running the retry loop. Otherwise returns Admission::Proceed carrying a TrialGuard; if that admission was a HALF-OPEN trial, the guard owns the reserved trial slot and MUST be resolved — either by TrialGuard::record (which drives the transition) or by being dropped on cancellation (which reclaims the slot). Either way the slot is never leaked.

A disabled policy always returns Proceed(Closed, _) with an inert guard.

Trait Implementations

impl Debug for OriginBreaker

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

Formats the value using the given formatter.