class PerformanceTestRecorder

class PerformanceTestRecorder implements EventSubscriberInterface {
    
    /**
     * The state service for persistent storage if necessary.
     */
    protected $state;
    
    /**
     * @var array
     */
    protected static $record = [];
    
    /**
     * PerformanceTestRecorder constructor.
     *
     * @param bool $persistent
     *   Whether to save the record to state.
     * @param \Drupal\Core\State\StateInterface|null $state
     *   (optional) The state service for persistent storage. Required if
     *   $persistent is TRUE.
     */
    public function __construct(bool $persistent, ?StateInterface $state) {
        if ($persistent && !$state) {
            throw new \InvalidArgumentException('If $persistent is TRUE then $state must be set');
        }
        $this->state = $state;
    }
    public function getCount(string $type, string $name) : int {
        $count = 0;
        if ($this->state) {
            $record = $this->state
                ->get('drupal.performance_test_recorder', []);
            $count += $record[$type][$name] ?? 0;
        }
        $count += self::$record[$type][$name] ?? 0;
        return $count;
    }
    
    /**
     * Records the occurrence of an event.
     *
     * @param string $type
     *   The type of event to record.
     * @param string $name
     *   The name of the event to record.
     */
    public function record(string $type, string $name) : void {
        if ($this->state) {
            $record = $this->state
                ->get('drupal.performance_test_recorder', []);
            isset($record[$type][$name]) ? $record[$type][$name]++ : ($record[$type][$name] = 1);
            $this->state
                ->set('drupal.performance_test_recorder', $record);
        }
        else {
            isset(self::$record[$type][$name]) ? self::$record[$type][$name]++ : (self::$record[$type][$name] = 1);
        }
    }
    
    /**
     * Records a router rebuild.
     */
    public function onRouteBuilderFinish() {
        $this->record('event', RoutingEvents::FINISHED);
    }
    
    /**
     * {@inheritdoc}
     */
    public static function getSubscribedEvents() {
        $events = [];
        $events[RoutingEvents::FINISHED][] = [
            'onRouteBuilderFinish',
            -9999999,
        ];
        return $events;
    }
    
    /**
     * Registers core.performance.test.recorder service.
     *
     * @param string $services_file
     *   Path to the services file to register the service in.
     * @param bool $persistent
     *   Whether the recorder should be in persistent mode. The persistent mode
     *   records using the state service so that the recorder will work on the
     *   site under test when requests are made. However, if we want to measure
     *   something used by the state system then this will be recursive. Also in
     *   kernel tests using state is unnecessary.
     */
    public static function registerService(string $services_file, bool $persistent) : void {
        $services = Yaml::parse(file_get_contents($services_file));
        if (isset($services['services']['core.performance.test.recorder'])) {
            // Once the service has been marked as persistent don't change that.
            $persistent = $persistent || $services['services']['core.performance.test.recorder']['arguments'][0];
        }
        $services['services']['core.performance.test.recorder'] = [
            'class' => PerformanceTestRecorder::class,
            'arguments' => [
                $persistent,
                $persistent ? '@state' : NULL,
            ],
            'tags' => [
                [
                    'name' => 'event_subscriber',
                ],
            ],
        ];
        file_put_contents($services_file, Yaml::dump($services));
    }

}