Stopwatch.php

<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace Symfony\Component\HttpKernel\Debug;


/**
 * Stopwatch provides a way to profile code.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class Stopwatch {
  private $sections;
  private $activeSections;
  public function __construct() {
    $this->sections = $this->activeSections = array(
      '__root__' => new Section('__root__'),
    );
  }

  /**
   * Creates a new section or re-opens an existing section.
   *
   * @param string|null $id The id of the session to re-open, null to create a new one
   *
   * @throws \LogicException When the section to re-open is not reachable
   */
  public function openSection($id = null) {
    $current = end($this->activeSections);
    if (null !== $id && null === $current
      ->get($id)) {
      throw new \LogicException(sprintf('The section "%s" has been started at an other level and can not be opened.', $id));
    }
    $this
      ->start('__section__.child', 'section');
    $this->activeSections[] = $current
      ->open($id);
    $this
      ->start('__section__');
  }

  /**
   * Stops the last started section.
   *
   * The id parameter is used to retrieve the events from this section.
   *
   * @see getSectionEvents
   *
   * @param string $id The identifier of the section
   */
  public function stopSection($id) {
    $this
      ->stop('__section__');
    if (1 == count($this->activeSections)) {
      throw new \LogicException('There is no started section to stop.');
    }
    $this->sections[$id] = array_pop($this->activeSections)
      ->setId($id);
    $this
      ->stop('__section__.child');
  }

  /**
   * Starts an event.
   *
   * @param string $name     The event name
   * @param string $category The event category
   *
   * @return StopwatchEvent A StopwatchEvent instance
   */
  public function start($name, $category = null) {
    return end($this->activeSections)
      ->startEvent($name, $category);
  }

  /**
   * Stops an event.
   *
   * @param string $name The event name
   *
   * @return StopwatchEvent A StopwatchEvent instance
   */
  public function stop($name) {
    return end($this->activeSections)
      ->stopEvent($name);
  }

  /**
   * Stops then restarts an event.
   *
   * @param string $name The event name
   *
   * @return StopwatchEvent A StopwatchEvent instance
   */
  public function lap($name) {
    return end($this->activeSections)
      ->stopEvent($name)
      ->start();
  }

  /**
   * Gets all events for a given section.
   *
   * @param string $id A section identifier
   *
   * @return StopwatchEvent[] An array of StopwatchEvent instances
   */
  public function getSectionEvents($id) {
    return isset($this->sections[$id]) ? $this->sections[$id]
      ->getEvents() : array();
  }

}
class Section {
  private $events = array();
  private $origin;
  private $id;
  private $children = array();

  /**
   * Constructor.
   *
   * @param float|null $origin Set the origin of the events in this section, use null to set their origin to their start time
   */
  public function __construct($origin = null) {
    $this->origin = is_numeric($origin) ? $origin : null;
  }

  /**
   * Returns the child section.
   *
   * @param string $id The child section identifier
   *
   * @return Section|null The child section or null when none found
   */
  public function get($id) {
    foreach ($this->children as $child) {
      if ($id === $child
        ->getId()) {
        return $child;
      }
    }
    return null;
  }

  /**
   * Creates or re-opens a child section.
   *
   * @param string|null $id null to create a new section, the identifier to re-open an existing one.
   *
   * @return Section A child section
   */
  public function open($id) {
    if (null === ($session = $this
      ->get($id))) {
      $session = $this->children[] = new self(microtime(true) * 1000);
    }
    return $session;
  }

  /**
   * @return string The identifier of the section
   */
  public function getId() {
    return $this->id;
  }

  /**
   * Sets the session identifier.
   *
   * @param string $id The session identifier
   *
   * @return Section The current section
   */
  public function setId($id) {
    $this->id = $id;
    return $this;
  }

  /**
   * Starts an event.
   *
   * @param string $name     The event name
   * @param string $category The event category
   *
   * @return StopwatchEvent The event
   */
  public function startEvent($name, $category) {
    if (!isset($this->events[$name])) {
      $this->events[$name] = new StopwatchEvent($this->origin ?: microtime(true) * 1000, $category);
    }
    return $this->events[$name]
      ->start();
  }

  /**
   * Stops an event.
   *
   * @param string $name The event name
   *
   * @return StopwatchEvent The event
   *
   * @throws \LogicException When the event has not been started
   */
  public function stopEvent($name) {
    if (!isset($this->events[$name])) {
      throw new \LogicException(sprintf('Event "%s" is not started.', $name));
    }
    return $this->events[$name]
      ->stop();
  }

  /**
   * Stops then restarts an event.
   *
   * @param string $name The event name
   *
   * @return StopwatchEvent The event
   *
   * @throws \LogicException When the event has not been started
   */
  public function lap($name) {
    return $this
      ->stop($name)
      ->start();
  }

  /**
   * Returns the events from this section.
   *
   * @return StopwatchEvent[] An array of StopwatchEvent instances
   */
  public function getEvents() {
    return $this->events;
  }

}