crm.fsf.org/20131203/files/sites/all/modules-new/civicrm/CRM/Utils/Http.php

   1 <?php
   2
   3 class CRM_Utils_Http {
   4
   5   /**
   6    * Parse the expiration time from a series of HTTP headers.
   7    *
   8    * @param array $headers
   9    * @return int|NULL
  10    *   Expiration tme as seconds since epoch, or NULL if not cacheable.
  11    */
  12   public static function parseExpiration($headers) {
  13     $headers = CRM_Utils_Array::rekey($headers, function ($k, $v) {
  14       return strtolower($k);
  15     });
  16
  17     if (!empty($headers['cache-control'])) {
  18       $cc = self::parseCacheControl($headers['cache-control']);
  19       if ($cc['max-age'] && is_numeric($cc['max-age'])) {
  20         return CRM_Utils_Time::getTimeRaw() + $cc['max-age'];
  21       }
  22     }
  23
  24     return NULL;
  25   }
  26
  27   /**
  28    * @param string $value
  29    *   Ex: "max-age=86400, public".
  30    * @return array
  31    *   Ex: Array("max-age"=>86400, "public"=>1).
  32    */
  33   public static function parseCacheControl($value) {
  34     $result = array();
  35
  36     $parts = preg_split('/, */', $value);
  37     foreach ($parts as $part) {
  38       if (strpos($part, '=') !== FALSE) {
  39         list ($key, $value) = explode('=', $part, 2);
  40         $result[$key] = $value;
  41       }
  42       else {
  43         $result[$part] = TRUE;
  44       }
  45     }
  46
  47     return $result;
  48   }
  49
  50 }