This is simpler method of checking for too much POST data (alternative to that by v3 from sonic-world.ru).

<?php
    if ($_SERVER['REQUEST_METHOD'] == 'POST' && empty($_POST) && $_SERVER['CONTENT_LENGTH'] > 0) {
        throw new Exception(sprintf('The server was unable to handle that much POST data (%s bytes) due to its current configuration', $_SERVER['CONTENT_LENGTH']));
    }
?>