diff options
| -rwxr-xr-x | system/core/Output.php | 45 |
1 files changed, 43 insertions, 2 deletions
diff --git a/system/core/Output.php b/system/core/Output.php index abd8a0ea9..1f214a0b3 100755 --- a/system/core/Output.php +++ b/system/core/Output.php @@ -466,6 +466,9 @@ class CI_Output { @chmod($cache_path, FILE_WRITE_MODE); log_message('debug', 'Cache file written: '.$cache_path); + + // Send HTTP cache-control headers to browser to match file cache settings. + $this->set_cache_header($_SERVER['REQUEST_TIME'],$expire); } // -------------------------------------------------------------------- @@ -503,13 +506,22 @@ class CI_Output { return FALSE; } - // Has the file expired? If so we'll delete it. - if (time() >= trim(str_replace('TS--->', '', $match[1])) && is_really_writable($cache_path)) + $last_modified = filemtime($cache_path); + $expire = trim(str_replace('TS--->', '', $match[1])); + + // Has the file expired? + if ($_SERVER['REQUEST_TIME'] >= $expire && is_really_writable($cache_path)) { + // If so we'll delete it. @unlink($filepath); log_message('debug', 'Cache file has expired. File deleted.'); return FALSE; } + else + { + // Or else send the HTTP cache control headers. + $this->set_cache_header($last_modified,$expire); + } // Display the cache $this->_display(str_replace($match[0], '', $cache)); @@ -517,6 +529,35 @@ class CI_Output { return TRUE; } + + // -------------------------------------------------------------------- + /** + * Set the HTTP headers to match the server-side file cache settings + * in order to reduce bandwidth. + * + * @param int timestamp of when the page was last modified + * @param int timestamp of when should the requested page expire from cache + * @return void + */ + public function set_cache_header($last_modified,$expiration) + { + $max_age = $expiration - $_SERVER['REQUEST_TIME']; + + if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && ($last_modified <= strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']))) + { + $this->set_status_header(304); + exit; + } + else + { + header('Pragma: public'); + header('Cache-Control: max-age=' . $max_age . ', public'); + header('Expires: '.gmdate('D, d M Y H:i:s', $expiration).' GMT'); + header('Last-modified: '.gmdate('D, d M Y H:i:s', $last_modified).' GMT'); + } + } + + } /* End of file Output.php */ |