time_elapsed() - function to track php script execution time. To find where the code is slow.

time_elapsed.php

function time_elapsed() {
	$backtrace = debug_backtrace();
	$calling_file = $backtrace[0]['file'];
	$calling_line = $backtrace[0]['line'];

	$call_string = $calling_file . ' line ' . $calling_line . '<br/>';

    static $last = null;

    $now = microtime(true);

    if ($last == null) {
    	$outstring = $call_string . 'Starting timer...<br/>';
    } else {
    	$elapsed = ($now - $last);
    	$outstring = $call_string . 'Elapsed: ' . round($elapsed, 4) . ' seconds';
    }
    echo $outstring;

    $last = $now;
}

Use once to start the timer. Each use thereafter within the same script will output how long it took to get to it from the previous use. The $last variable resets to null at each new script execution.

Example use:

time_elapsed();
sleep(2);
time_elapsed();

will output

\calling_file.php line 3
Starting timer...
\calling_file.php line 5
Elapsed: 2.0009 seconds

Looks nicer if you replace echo with debug from my other gist, debug.