class ObservableCallback

final class ObservableCallback implements ObservableCallbackInterface {
    public function __construct(MetricWriterInterface $writer, ReferenceCounterInterface $referenceCounter, ?int $callbackId, ?ObservableCallbackDestructor $callbackDestructor, ?object $target) {
    }
    public function detach() : void {
        if ($this->callbackId === null) {
            return;
        }
        $this->writer
            ->unregisterCallback($this->callbackId);
        $this->referenceCounter
            ->release();
        if ($this->callbackDestructor !== null) {
            unset($this->callbackDestructor->callbackIds[$this->callbackId]);
            if (!$this->callbackDestructor->callbackIds) {
                assert($this->target !== null);
                unset($this->callbackDestructor->destructors[$this->target]);
            }
        }
        $this->callbackId = null;
        $this->target = null;
    }
    public function __destruct() {
        if ($this->callbackDestructor !== null) {
            return;
        }
        if ($this->callbackId === null) {
            return;
        }
        $this->referenceCounter
            ->acquire(true);
        $this->referenceCounter
            ->release();
    }

}