CircuitBreaker class

Wraps an unreliable operation with the circuit-breaker resilience pattern: after failureThreshold consecutive failures the breaker "opens" and fast-fails calls for resetTimeout; one probe call is then admitted, and its outcome decides whether the breaker closes or reopens.

final breaker = CircuitBreaker(failureThreshold: 3);

final result = await breaker.execute(() => api.fetchUser(id));
// If the breaker is open, `result` is an Error with
// FailureKind.circuitOpen — the underlying call was not made.

Constructors

CircuitBreaker({int failureThreshold = 5, Duration resetTimeout = const Duration(seconds: 30), bool shouldTrip(Failure failure)?, void onStateChange(CircuitBreakerState from, CircuitBreakerState to)?, DateTime clock()?})
Creates a breaker.

Properties

consecutiveFailures → int
Number of consecutive failures observed in the current closed window. Resets on every Success and on a successful probe in half-open.
no setter
failureThreshold → int
Number of consecutive trip-eligible failures that move the breaker to CircuitBreakerState.open.
final
hashCode → int
The hash code for this object.
no setterinherited
resetTimeout → Duration
How long the breaker stays in CircuitBreakerState.open before admitting a single probe call.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
state → CircuitBreakerState
The current state of the breaker.
no setter

Methods

execute<T>(Future<Result<T>> operation()) → Future<Result<T>>
Runs operation subject to the breaker's state machine. Returns Error(Failure(kind: FailureKind.circuitOpen)) if the breaker is open (or if a half-open probe is already in flight) without calling operation.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
reset() → void
Force the breaker back to CircuitBreakerState.closed, clearing failure counters. Useful after an out-of-band recovery (e.g. operator resets the dependency manually).
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited