Кэширование на WP

<?php
$filename = 'cache/'.md5($_SERVER['REQUEST_URI']).'.html';

$cached = false;

if (file_exists($filename)) {
if ((time()-filemtime($filename))<6160) {
$cached = true;
} else {
unlink($filename);
$cached = false;
}
}

if ($cached) {
readfile($filename);
} else {
ob_start();

// WP
define('WP_USE_THEMES', true);
require('./wp-blog-header.php');
//

$text = ob_get_clean();

$fh = fopen($filename, 'w+');
fwrite($fh, $text);
fclose($fh);

echo $text;
}
?>