diff options
Diffstat (limited to 'system/helpers/expires.php')
| -rw-r--r-- | system/helpers/expires.php | 115 |
1 files changed, 62 insertions, 53 deletions
diff --git a/system/helpers/expires.php b/system/helpers/expires.php index c43cc0cc..ce0482c8 100644 --- a/system/helpers/expires.php +++ b/system/helpers/expires.php @@ -2,54 +2,49 @@ /** * Controls headers that effect client caching of pages * - * $Id: expires.php 4272 2009-04-25 21:47:26Z zombor $ + * $Id: expires.php 4679 2009-11-10 01:45:52Z isaiah $ * * @package Core * @author Kohana Team - * @copyright (c) 2007-2008 Kohana Team - * @license http://kohanaphp.com/license.html + * @copyright (c) 2007-2009 Kohana Team + * @license http://kohanaphp.com/license */ class expires_Core { /** - * Sets the amount of time before a page expires + * Sets the amount of time before content expires * - * @param integer Seconds before the page expires - * @return boolean + * @param integer Seconds before the content expires + * @return integer Timestamp when the content expires */ public static function set($seconds = 60) { - if (expires::check_headers()) - { - $now = $expires = time(); + $now = time(); + $expires = $now + $seconds; - // Set the expiration timestamp - $expires += $seconds; + header('Last-Modified: '.gmdate('D, d M Y H:i:s T', $now)); - // 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); + // HTTP 1.0 + header('Expires: '.gmdate('D, d M Y H:i:s T', $expires)); - return $expires; - } + // HTTP 1.1 + header('Cache-Control: max-age='.$seconds); - return FALSE; + return $expires; } /** - * Checks to see if a page should be updated or send Not Modified status + * Parses the If-Modified-Since header * - * @param integer Seconds added to the modified time received to calculate what should be sent - * @return bool FALSE when the request needs to be updated + * @return integer|boolean Timestamp or FALSE when header is lacking or malformed */ - public static function check($seconds = 60) + public static function get() { - if ( ! empty($_SERVER['HTTP_IF_MODIFIED_SINCE']) AND expires::check_headers()) + if ( ! empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) { + // Some versions of IE6 append "; length=####" 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 @@ -57,55 +52,69 @@ class expires_Core { $mod_time = $_SERVER['HTTP_IF_MODIFIED_SINCE']; } - $mod_time = strtotime($mod_time); - $mod_time_diff = $mod_time + $seconds - time(); + return strtotime($mod_time); + } + + return FALSE; + } - if ($mod_time_diff > 0) + /** + * Checks to see if content should be updated otherwise sends Not Modified status + * and exits. + * + * @uses exit() + * @uses expires::get() + * + * @param integer Maximum age of the content in seconds + * @return integer|boolean Timestamp of the If-Modified-Since header or FALSE when header is lacking or malformed + */ + public static function check($seconds = 60) + { + if ($last_modified = expires::get()) + { + $expires = $last_modified + $seconds; + $max_age = $expires - time(); + + if ($max_age > 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); + // Content has not expired + header($_SERVER['SERVER_PROTOCOL'].' 304 Not Modified'); + header('Last-Modified: '.gmdate('D, d M Y H:i:s T', $last_modified)); + + // HTTP 1.0 + header('Expires: '.gmdate('D, d M Y H:i:s T', $expires)); - // Prevent any output - Event::add('system.display', array('expires', 'prevent_output')); + // HTTP 1.1 + header('Cache-Control: max-age='.$max_age); + + // Clear any output + Event::add('system.display', create_function('', 'Kohana::$output = "";')); - // Exit to prevent other output exit; } } - return FALSE; + return $last_modified; } /** - * Check headers already created to not step on download or Img_lib's feet + * Check if expiration headers are already set * * @return boolean */ - public static function check_headers() + public static function headers_set() { foreach (headers_list() as $header) { - if ((session_cache_limiter() == '' AND stripos($header, 'Last-Modified:') === 0) - OR stripos($header, 'Expires:') === 0) + if (strncasecmp($header, 'Expires:', 8) === 0 + OR strncasecmp($header, 'Cache-Control:', 14) === 0 + OR strncasecmp($header, 'Last-Modified:', 14) === 0) { - return FALSE; + return TRUE; } } - return TRUE; - } - - /** - * Prevent any output from being displayed. Executed during system.display. - * - * @return void - */ - public static function prevent_output() - { - Kohana::$output = ''; + return FALSE; } -} // End expires
\ No newline at end of file +} // End expires |