with_circuit.go

func (c *Circuit) WithCircuit(call func() error, fallback func()) error {
	if !c.isOpen() {
		wait := make(chan error, 1)

		// run function with timeout
		go func() { wait <- call() }()

		select {
		case err := <-wait:
			if err != nil {
				break
			}
			return nil
		case <-time.After(time.Second * c.TimeOut):
			break
		}
	}
	
	fallback()
	return ErrorCircuitTripped
}