2025-08-06 18:11:51 +02:00

113 lines
3.3 KiB
PHP

<?php
// phpcs:disable PSR1.Classes.ClassDeclaration.MissingNamespace
// phpcs:disable PSR1.Files.SideEffects
defined('SYSPATH') or die('No direct access allowed.');
// phpcs:enable PSR1.Files.SideEffects
// phpcs:disable Squiz.Classes.ValidClassName.NotCamelCaps
/**
* Controls headers that effect client caching of pages
*
* $Id: expires.php 4272 2009-04-25 21:47:26Z zombor $
*
* @package Core
* @author Kohana Team
* @copyright (c) 2007-2008 Kohana Team
* @license http://kohanaphp.com/license.html
*/
class expires_Core
{
/**
* Sets the amount of time before a page expires
*
* @param integer Seconds before the page expires
* @return boolean
*/
public static function set($seconds = 60)
{
if (expires::check_headers()) {
$now = $expires = time();
// Set the expiration timestamp
$expires += $seconds;
// Send headers
header('Last-Modified: ' . gmdate('D, d M Y H:i:s T', $now));
header('Expires: ' . gmdate('D, d M Y H:i:s T', $expires));
header('Cache-Control: max-age=' . $seconds);
return $expires;
}
return false;
}
/**
* Checks to see if a page should be updated or send Not Modified status
*
* @param integer Seconds added to the modified time received to calculate what should be sent
* @return bool FALSE when the request needs to be updated
*/
public static function check($seconds = 60)
{
if (! empty($_SERVER['HTTP_IF_MODIFIED_SINCE']) and expires::check_headers()) {
if (($strpos = strpos($_SERVER['HTTP_IF_MODIFIED_SINCE'], ';')) !== false) {
// IE6 and perhaps other IE versions send length too, compensate here
$mod_time = substr($_SERVER['HTTP_IF_MODIFIED_SINCE'], 0, $strpos);
} else {
$mod_time = $_SERVER['HTTP_IF_MODIFIED_SINCE'];
}
$mod_time = strtotime($mod_time);
$mod_time_diff = $mod_time + $seconds - time();
if ($mod_time_diff > 0) {
// Re-send headers
header('Last-Modified: ' . gmdate('D, d M Y H:i:s T', $mod_time));
header('Expires: ' . gmdate('D, d M Y H:i:s T', time() + $mod_time_diff));
header('Cache-Control: max-age=' . $mod_time_diff);
header('Status: 304 Not Modified', true, 304);
// Prevent any output
Event::add('system.display', array('expires', 'prevent_output'));
// Exit to prevent other output
exit;
}
}
return false;
}
/**
* Check headers already created to not step on download or Img_lib's feet
*
* @return boolean
*/
public static function check_headers()
{
foreach (headers_list() as $header) {
if (
(session_cache_limiter() == '' and stripos($header, 'Last-Modified:') === 0)
or stripos($header, 'Expires:') === 0
) {
return false;
}
}
return true;
}
/**
* Prevent any output from being displayed. Executed during system.display.
*
* @return void
*/
public static function prevent_output()
{
Kohana::$output = '';
}
}
// End expires