Trong file bootstrap.inc
<?php
function _drupal_bootstrap($phase) {
global $conf;
switch ($phase) {
case DRUPAL_BOOTSTRAP_CONFIGURATION:
drupal_unset_globals();
// Start a page timer:
timer_start('page');
// Initialize the configuration
conf_init();
break;
case DRUPAL_BOOTSTRAP_EARLY_PAGE_CACHE:
// Allow specifying special cache handlers in settings.php, like
// using memcached or files for storing cache information.
require_once variable_get('cache_inc', './includes/cache.inc');
// If the page_cache_fastpath is set to TRUE in settings.php and
// page_cache_fastpath (implemented in the special implementation of
// cache.inc) printed the page and indicated this with a returned TRUE
// then we are done.
if (variable_get('page_cache_fastpath', FALSE) && page_cache_fastpath()) {
exit;
}
break;
?>
