Stopwatch

Another useful tool is the debugger stopwatch with a precision of microseconds:

Debugger::timer();

// sweet dreams my cherrie
sleep(2);

$elapsed = Debugger::timer();
// $elapsed = 2

Multiple measurements at once can be achieved by an optional parameter.

Debugger::timer('page-generating');
// some code

Debugger::timer('rss-generating');
// some code

$rssElapsed = Debugger::timer('rss-generating');
$pageElapsed = Debugger::timer('page-generating');
Debugger::timer(); // runs the timer

... // some time-consuming operation

echo Debugger::timer(); // elapsed time in seconds