1. public function fileSizeFilter($size)
    2.     {
    3.         $currentValue = $currentUnit = null;
    4.         $unitExps     = array('B' => 0, 'KB' => 1, 'MB' => 2, 'GB' => 3);
    6.         foreach ($unitExps as $unit => $exp) {
    7.             $divisor      = pow(1000, $exp);
    8.             $currentUnit  = $unit;
    9.             $currentValue = $size / $divisor;
    11.             if ($currentValue < 1000) {
    12.                 break;
    13.             }
    14.         }
    16.         return sprintf('%.1f', $currentValue).$currentUnit;
    17.     }