Memory and time usage for PHP function

gistfile1.php

<?php

function formatBytes($bytes, $precision = 2) {
  $units = array('B', 'KB', 'MB', 'GB', 'TB');

  $bytes = max($bytes, 0);
  $pow = floor(($bytes ? log($bytes) : 0) / log(1024));
  $pow = min($pow, count($units) - 1);
  $bytes /= pow(1024, $pow);

  return round($bytes, $precision) . ' ' . $units[$pow];
}

function formatTime($seconds) {
  $seconds = max(1, (int)$seconds);
  if ($seconds > 60) {
    $minutes = (int)($seconds / 60);
    $seconds = $seconds % 60;
    return "$minutes mins, $seconds seconds";
  }
  return $seconds . ' seconds';
}

// start loggedin memory and time
$time_start = microtime_float();
$global_memory_start = memory_get_usage();

// *Magic happens here*

// Show timing end
$time_end    = microtime_float();
$memory_end  = memory_get_usage();
$runtime     = formatTime($time_end - $time_start);
$memory_used = formatBytes($memory_end - $global_memory_start, 3);

print "#    Finished in: $runtime\n";
print "#    Memory used: $memory_used\n";