| 1 | <?php |
| 2 | /* |
| 3 | +--------------------------------------------------------------------+ |
| 4 | | Copyright CiviCRM LLC. All rights reserved. | |
| 5 | | | |
| 6 | | This work is published under the GNU AGPLv3 license with some | |
| 7 | | permitted exceptions and without any warranty. For full license | |
| 8 | | and copyright information, see https://civicrm.org/licensing | |
| 9 | +--------------------------------------------------------------------+ |
| 10 | */ |
| 11 | |
| 12 | /** |
| 13 | * |
| 14 | * @package CiviCRM_Hook |
| 15 | * @copyright CiviCRM LLC https://civicrm.org/licensing |
| 16 | */ |
| 17 | class CRM_Utils_Http { |
| 18 | |
| 19 | /** |
| 20 | * Parse the expiration time from a series of HTTP headers. |
| 21 | * |
| 22 | * @param array $headers |
| 23 | * @return int|null |
| 24 | * Expiration tme as seconds since epoch, or NULL if not cacheable. |
| 25 | */ |
| 26 | public static function parseExpiration($headers) { |
| 27 | $headers = CRM_Utils_Array::rekey($headers, function ($k, $v) { |
| 28 | return strtolower($k); |
| 29 | }); |
| 30 | |
| 31 | if (!empty($headers['cache-control'])) { |
| 32 | $cc = self::parseCacheControl($headers['cache-control']); |
| 33 | if ($cc['max-age'] && is_numeric($cc['max-age'])) { |
| 34 | return CRM_Utils_Time::getTimeRaw() + $cc['max-age']; |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | return NULL; |
| 39 | } |
| 40 | |
| 41 | /** |
| 42 | * @param string $value |
| 43 | * Ex: "max-age=86400, public". |
| 44 | * @return array |
| 45 | * Ex: Array("max-age"=>86400, "public"=>1). |
| 46 | */ |
| 47 | public static function parseCacheControl($value) { |
| 48 | $result = []; |
| 49 | |
| 50 | $parts = preg_split('/, */', $value); |
| 51 | foreach ($parts as $part) { |
| 52 | if (strpos($part, '=') !== FALSE) { |
| 53 | list ($key, $value) = explode('=', $part, 2); |
| 54 | $result[$key] = $value; |
| 55 | } |
| 56 | else { |
| 57 | $result[$part] = TRUE; |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | return $result; |
| 62 | } |
| 63 | |
| 64 | } |