class StopwatchEvent

StopwatchEventTest.php in drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Tests/Debug/StopwatchEventTest.php

class StopwatchEvent {
  private $periods;
  private $origin;
  private $category;
  private $started;

  /**
   * Constructor.
   *
   * @param float  $origin   The origin time in milliseconds
   * @param string $category The event category
   *
   * @throws \InvalidArgumentException When the raw time is not valid
   */
  public function __construct($origin, $category = null) {
    $this->origin = $this
      ->formatTime($origin);
    $this->category = is_string($category) ? $category : 'default';
    $this->started = array();
    $this->periods = array();
  }

  /**
   * Gets the category.
   *
   * @return string The category
   */
  public function getCategory() {
    return $this->category;
  }

  /**
   * Gets the origin.
   *
   * @return integer The origin in milliseconds
   */
  public function getOrigin() {
    return $this->origin;
  }

  /**
   * Starts a new event period.
   *
   * @return StopwatchEvent The event
   */
  public function start() {
    $this->started[] = $this
      ->getNow();
    return $this;
  }

  /**
   * Stops the last started event period.
   *
   * @return StopwatchEvent The event
   */
  public function stop() {
    if (!count($this->started)) {
      throw new \LogicException('stop() called but start() has not been called before.');
    }
    $this->periods[] = array(
      array_pop($this->started),
      $this
        ->getNow(),
    );
    return $this;
  }

  /**
   * Stops the current period and then starts a new one.
   *
   * @return StopwatchEvent The event
   */
  public function lap() {
    return $this
      ->stop()
      ->start();
  }

  /**
   * Stops all non already stopped periods.
   */
  public function ensureStopped() {
    while (count($this->started)) {
      $this
        ->stop();
    }
  }

  /**
   * Gets all event periods.
   *
   * @return array An array of periods
   */
  public function getPeriods() {
    return $this->periods;
  }

  /**
   * Gets the relative time of the start of the first period.
   *
   * @return integer The time (in milliseconds)
   */
  public function getStartTime() {
    return isset($this->periods[0]) ? $this->periods[0][0] : 0;
  }

  /**
   * Gets the relative time of the end of the last period.
   *
   * @return integer The time (in milliseconds)
   */
  public function getEndTime() {
    return ($count = count($this->periods)) ? $this->periods[$count - 1][1] : 0;
  }

  /**
   * Gets the total time of all periods.
   *
   * @return integer The time (in milliseconds)
   */
  public function getTotalTime() {
    $total = 0;
    foreach ($this->periods as $period) {
      $total += $period[1] - $period[0];
    }
    return $this
      ->formatTime($total);
  }

  /**
   * Return the current time relative to origin.
   *
   * @return float Time in ms
   */
  protected function getNow() {
    return $this
      ->formatTime(microtime(true) * 1000 - $this->origin);
  }

  /**
   * Formats a time.
   *
   * @param numerical $time A raw time
   *
   * @return float The formatted time
   *
   * @throws \InvalidArgumentException When the raw time is not valid
   */
  private function formatTime($time) {
    if (!is_numeric($time)) {
      throw new \InvalidArgumentException('The time must be a numerical value');
    }
    return round($time, 1);
  }

}