Encapsulate Circuit Breaker Success Condition in a Half-Open State

[empire]

In the current implementation of the CircuitBreaker library, the logic for determining whether the circuit should transition from StateHalfOpen to StateClosed is directly embedded within the onSuccess method. Specifically, the condition cb.counts.ConsecutiveSuccesses >= cb.maxRequests is checked to decide if the circuit should close.

The current approach tightly couples the condition with the onSuccess method, making the code less modular and harder to maintain. It might be helpful to adjust or extend the logic for transitioning states.

Proposed Solution

To improve code modularity and maintainability, I propose encapsulating the condition cb.counts.ConsecutiveSuccesses >= cb.maxRequests into a dedicated method, such as shouldCloseCircuit(). This change would make the onSuccess method cleaner and the success condition easier to manage and modify.

Suggested Implementation

Here's how the refactored onSuccess method would look:

func (cb *CircuitBreaker) onSuccess(state State, now time.Time) {
    switch state {
    case StateClosed:
        cb.counts.onSuccess()
    case StateHalfOpen:
        cb.counts.onSuccess()
        if cb.shouldCloseCircuit(cb.counts) {
            cb.setState(StateClosed, now)
        }
    }
}

I'll be okay to send a pull request.