function page_cache_fastpath in Authenticated User Page Caching (Authcache) 6

Main callback from DRUPAL_BOOTSTRAP_EARLY_PAGE_CACHE phase. Sends cached page to browser, if found.

Return value

boolean for bootstrap (if TRUE, PHP will exit)

File

./authcache.inc, line 80

Code

function page_cache_fastpath() {
  global $base_root, $cache, $conf;

  // User is logged in but their role should not receive any cached pages
  // (i.e., cached anonymous pages, since they have no authcache key)
  if (isset($_COOKIE['drupal_user']) && !isset($_COOKIE['authcache'])) {
    return FALSE;
  }

  // Caching for browser session was temporarily disabled (most likely from drupal_set_message()/drupal_goto() redirect)
  if (isset($_COOKIE['nocache_temp'])) {
    setcookie('nocache', '', time() - 36000, ini_get('session.cookie_path'), ini_get('session.cookie_domain'), ini_get('session.cookie_secure') == '1');
    setcookie('nocache_temp', '', time() - 36000, ini_get('session.cookie_path'), ini_get('session.cookie_domain'), ini_get('session.cookie_secure') == '1');
    return FALSE;
  }

  // Caching disabled for browser session
  if (isset($_COOKIE['nocache'])) {
    return FALSE;
  }

  // Attempt to retrieve page from cache
  if (empty($_POST)) {

    // Connect to database if 'db' engine selected
    if ($conf['authcache_is_db']) {
      require_once './includes/database.inc';
      db_set_active();
    }

    // Memcache module's cache_get function requires variables to be loaded
    if ($conf['authcache_handler'] == 'memcache.inc' && ($vars_exist = cache_get('variables', 'cache'))) {
      $conf = variable_init($conf);
    }

    // Authenticated cache role(s) key
    $key = isset($_COOKIE['authcache']) && $_COOKIE['authcache'] ? $_COOKIE['authcache'] : '';
    $cache_key = $key . $base_root . request_uri();
    $page = cache_get($cache_key, 'cache_page');

    // Cached page found
    if (!empty($page)) {

      // Set HTTP headers in preparation for a cached page response.
      // The following headers force validation of cache:
      header("Expires: Sun, 19 Nov 1978 05:00:00 GMT");
      header("Cache-Control: must-revalidate");

      // Visitors can keep a local cache of the page, but must revalidate
      // it on every request.  Then, they are given a '304 Not Modified'
      // response with no body as long as they say page has not been modified.
      $last_modified = gmdate('D, d M Y H:i:s', $page->created) . ' GMT';

      // See if the client has provided the required HTTP caching header
      // ETag used instead of Last-Modifed header, since browsers won't update
      // cookie if Last-Modifed is used? - http://us.php.net/manual/en/function.setcookie.php#90616
      $etag = isset($_SERVER['HTTP_IF_NONE_MATCH']) ? stripslashes($_SERVER['HTTP_IF_NONE_MATCH']) : FALSE;
      if ($etag == $page->created) {

        // Save cache benchmark
        if (isset($_COOKIE['authcache_debug'])) {
          setcookie('cache_render', timer_read('page'));
        }
        header('HTTP/1.1 304 Not Modified');
        return TRUE;
      }

      // Time from when page was saved to cache
      header("ETag: {$page->created}");

      // Send the original request headers.
      $headers = explode("\n", $page->headers);
      foreach ($headers as $header) {
        header($header);
      }

      // Checking if first chars are compressed (always the same pattern for every header)
      if (substr($page->data, 0, 3) == "") {

        // Determine if the browser accepts gzipped data.
        if (@strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') === FALSE && function_exists('gzencode')) {

          // Strip the gzip header and run uncompress.
          $page->data = gzinflate(substr(substr($page->data, 10), 0, -8));
        }
        elseif (function_exists('gzencode')) {

          // Send gzip header to the browser
          header('Content-Encoding: gzip');
        }
      }

      // Save cache benchmark
      if (isset($_COOKIE['authcache_debug'])) {
        setcookie('cache_render', timer_read('page'));
      }
      print $page->data;
      return TRUE;
    }
  }
  return FALSE;
}