Profiler PHP class

<?php namespace MightyPork\Wrack;

/**
 * Utility for profiling.
 */
class Profiler
{

    /**
     * Get current time
     *
     * @return float time with microsecond precision
     */
    public static function now()
    {
        list($usec, $sec) = explode(" ", microtime());
        return ((float) $usec + (float) $sec);
    }


    /**
     * Start profiling
     *
     * @return float current time (profiling token)
     */
    public static function start()
    {
        return self::now();
    }


    /**
     * Measure time elapsed since start
     *
     * @param float $start time obtained with "start()"
     * @return string time elapsed (s)
     */
    public static function end($start)
    {
        return sprintf('%0.3f', self::now() - $start);
    }
}