Simple PHP timer class

timer.php

<?php

/**
 * Utility class to enable very simplistic timing.
 *
 * Usage example:
 *
 *     $t = new Timer();
 *     // do something here
 *     echo $t;
 *
 * You can also mark positions:
 *
 *     $t->mark('Step 1');
 *     sleep(2.24);
 *     $t->mark();
 *     usleep(327);
 *     $t->stop();
 *     echo $t;
 */
class Timer
{
    protected $times = [];
    protected $started = false;
    protected $stopped = false;

    /**
     * Timer constructor
     */
    public function __construct()
    {
        $this->times = [$this->getTimestamp('Start timer')];
        $this->started = true;
        $this->stopped = false;
    }

    /**
     * Create a timestamp object
     *
     * @param null|string $message
     * @return object
     */
    protected function getTimestamp($message = null)
    {
        if (phpversion() < 7) {
            return (object)[
                'time' => microtime(true),
                'message' => $message
            ];
        }

        return (object)[
            'time' => date_create_immutable_from_format('U.u', microtime(true)),
            'message' => $message
        ];
    }

    /**
     * Mark the next timer spot
     *
     * @param null|string $message
     * @return $this
     */
    public function mark($message = null)
    {
        if ($this->stopped) {
            return $this;
        }
        if ($this->started !== true) {
            throw new \RuntimeException('You have not started a timer');
        }
        $this->times[] = $this->getTimestamp($message);
        return $this;
    }

    /**
     * Stop the timer
     *
     * @return $this
     */
    public function stop()
    {
        if ($this->stopped) {
            return $this;
        }
        if ($this->started !== true) {
            throw new \RuntimeException('You have not started a timer');
        }
        $this->times[] = $this->getTimestamp('End timer');
        $this->stopped = true;
        return $this;
    }

    /**
     * Output the timer details.
     *
     * If the timer has not been stopped it will just give the output with the
     * start time and the delta since then.  If the timer has been stopped it
     * will give a fully summary with any marked positions.
     *
     * @return string
     */
    public function __toString()
    {
        if ($this->started !== true) {
            return 'You have not started a timer';
        }
        try {
            if (!$this->stopped) {
                $current = $this->getTimestamp('So far');
                return sprintf("Started %s, current delta %s\n",
                    $this->getFormatted($this->times[0]->time),
                    $this->getDiff($current->time, $this->times[0]->time)
                );
            } else {
                $output = '';
                $total = count($this->times);
                for ($i = 0; $i < $total; $i++) {
                    if (!$i) {
                        $output .= sprintf("Started %s\n", $this->getFormatted($this->times[$i]->time));
                    } else if ($i == ($total - 1)) {
                        $output .= sprintf("Ended %s, total time %s\n",
                            $this->getFormatted($this->times[$i]->time),
                            $this->getDiff($this->times[0]->time, $this->times[$i]->time)
                        );
                    } else {
                        $output .= sprintf("\tΔ %s%s\n",
                            $this->getDiff($this->times[$i-1]->time, $this->times[$i]->time),
                            $this->times[$i]->message ? " ({$this->times[$i]->message})" : ''
                        );
                    }
                }
                return $output;
            }
        } catch (\Exception $e) {
            return 'Cannot determine timer: ' . $e->getMessage();
        }
    }

    /**
     * Represent the delta between the start and end times.
     *
     * @param \DateTimeInterface|float $start
     * @param \DateTimeInterface|float $end
     * @return string
     */
    protected function getDiff($start, $end)
    {
        if ($start instanceof \DateTimeInterface) {
            $diff = $end->diff($start, true);
            return $diff->format('%dd %hh %im %s.%Fs');
        }

        $diff = $end - $start;
        return sprintf('%0dd %0dh %0dm %0.04fs',
            floor($diff / 86400),
            ($diff / 3600) % 24,
            ($diff / 60) % 60,
            ($diff % 60) + fmod($diff, 1)
        );
    }

    /**
     * Get formatted date/time.
     *
     * @param \DateTimeInterface|float $datetime
     * @return false|string
     */
    protected function getFormatted($datetime)
    {
        if ($datetime instanceof \DateTimeInterface) {
            return $datetime->format('Y-m-d H:i:s');
        }
        return date_format(
            date_create_from_format('U.u', $datetime),
            'Y-m-d H:i:s'
        );
    }
}