PHP セキュリティ 現在のページのURLを安全に作る方法

<?php
function get_current_url_unsafe(){
	$uri = getenv('REQUEST_URI');
	$https = getenv('HTTPS');
	$host = getenv('HTTP_HOST');
	$protocol = ($https == 'on') ? 'https':'http';
	$url = "{$protocol}://{$host}{$uri}";
	return $url;
}
$url = get_current_url_unsafe();
echo $url;
?>

<?php
function get_current_url(){
	$uri = filter_input(INPUT_SERVER, 'REQUEST_URI', FILTER_SANITIZE_STRING);
	$https = filter_input(INPUT_SERVER, 'HTTPS', FILTER_SANITIZE_STRING);
	$host = filter_input(INPUT_SERVER, 'HTTP_HOST', FILTER_SANITIZE_STRING);
	$protocol = ($https == 'on') ? 'https':'http';
	$url = "{$protocol}://{$host}{$uri}";
	return $url;
}
$url = get_current_url();
echo $url;
?>