Timer.php

<?php

namespace Drupal\Component\Utility;


/**
 * Provides helpers to use timers throughout a request.
 *
 * @ingroup utility
 */
class Timer {
    protected static $timers = [];
    
    /**
     * Starts the timer with the specified name.
     *
     * If you start and stop the same timer multiple times, the measured intervals
     * will be accumulated.
     *
     * @param $name
     *   The name of the timer.
     */
    public static function start($name) {
        static::$timers[$name]['start'] = microtime(TRUE);
        static::$timers[$name]['count'] = isset(static::$timers[$name]['count']) ? ++static::$timers[$name]['count'] : 1;
    }
    
    /**
     * Reads the current timer value without stopping the timer.
     *
     * @param string $name
     *   The name of the timer.
     *
     * @return int
     *   The current timer value in ms.
     */
    public static function read($name) {
        if (isset(static::$timers[$name]['start'])) {
            $stop = microtime(TRUE);
            $diff = round(($stop - static::$timers[$name]['start']) * 1000, 2);
            if (isset(static::$timers[$name]['time'])) {
                $diff += static::$timers[$name]['time'];
            }
            return $diff;
        }
        return static::$timers[$name]['time'];
    }
    
    /**
     * Stops the timer with the specified name.
     *
     * @param string $name
     *   The name of the timer.
     *
     * @return array
     *   A timer array. The array contains the number of times the timer has been
     *   started and stopped (count) and the accumulated timer value in ms (time).
     */
    public static function stop($name) {
        if (isset(static::$timers[$name]['start'])) {
            $stop = microtime(TRUE);
            $diff = round(($stop - static::$timers[$name]['start']) * 1000, 2);
            if (isset(static::$timers[$name]['time'])) {
                static::$timers[$name]['time'] += $diff;
            }
            else {
                static::$timers[$name]['time'] = $diff;
            }
            unset(static::$timers[$name]['start']);
        }
        return static::$timers[$name];
    }

}