authcache.inc in Authenticated User Page Caching (Authcache) 7

Attempt to deliver a cached version of a page depending on the users role.

This file gets included by _drupal_bootstrap_page_cache in bootstrap.inc during the drupal bootstrap stage DRUPAL_BOOTSTRAP_PAGE_CACHE. This script serves two purposes:

• Delegate the request to the underlying cache handler and deliver a cached version of a page for this request. Then exit.
• Execute Ajax callbacks necessary for customizing a page delivered before and then exit.

In the event of a cache-miss or if a page is not cachable, execution is passed back to _drupal_bootstrap_page_cache and the cache will be served using a full bootstrap.

See also

_drupal_bootstrap_page_cache in boostrap.inc

File

authcache.inc

<?php

/**
 * @file
 * Attempt to deliver a cached version of a page depending on the users role.
 *
 * This file gets included by _drupal_bootstrap_page_cache in bootstrap.inc
 * during the drupal bootstrap stage DRUPAL_BOOTSTRAP_PAGE_CACHE. This script
 * serves two purposes:
 * - Delegate the request to the underlying cache handler and deliver a cached
 *   version of a page for this request. Then exit.
 * - Execute Ajax callbacks necessary for customizing a page delivered before
 *   and then exit.
 *
 * In the event of a cache-miss or if a page is not cachable, execution is
 * passed back to _drupal_bootstrap_page_cache and the cache will be served
 * using a full bootstrap.
 *
 * @see _drupal_bootstrap_page_cache in boostrap.inc
 */

// Check if in Ajax phase and return JSON.
// This is a custom HTTP header defined by the authcache.js XHR
if (isset($_SERVER['HTTP_AUTHCACHE'])) {
  require_once dirname(__FILE__) . '/ajax/authcache.php';
  exit;
}

// Attempt to deliver the page from cache
$delivered = authcache_retrieve_cache_page();
if ($delivered) {
  exit;
}

/**
 * Send cached page to browser, if found.
 *
 * @return boolean TRUE if page was delivered, FALSE otherwise
 */
function authcache_retrieve_cache_page() {
  global $base_root;

  // Do not attempt to serve page from cache, when invoked by drush.
  if (drupal_is_cli()) {
    return FALSE;
  }

  // User is logged in but their role should not receive any cached pages
  // (i.e., cached anonymous pages, since they have no authcache key)

  /* simg: this logic doesn't work, because a visitor can have the drupal_user cookie set whilst not logged in */

  /*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', '', REQUEST_TIME - 36000, ini_get('session.cookie_path'), ini_get('session.cookie_domain'), ini_get('session.cookie_secure') == '1');
    setcookie('nocache_temp', '', REQUEST_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 and initialzie configuration if not
    // disabled from within settings.php
    if (!variable_get('page_cache_without_database')) {
      drupal_bootstrap(DRUPAL_BOOTSTRAP_VARIABLES, FALSE);
    }

    // Authenticated cache role(s) key
    if ($authcache_keygen = variable_get('authcache_key_generator', FALSE)) {
      $key = isset($_COOKIE['authcache']) && $_COOKIE['authcache'] ? $_COOKIE['authcache'] : $authcache_keygen();
    }
    else {
      $key = isset($_COOKIE['authcache']) && $_COOKIE['authcache'] ? $_COOKIE['authcache'] : '';
    }
    $cache_key = $key . $base_root . request_uri();
    $cache = cache_get($cache_key, 'cache_page');
    if (!empty($cache)) {

      // Cached page found
      header('X-Drupal-Cache: HIT');

      // render cache benchmark
      if (isset($_COOKIE['authcache_debug'])) {
        setcookie('cache_render', timer_read('page'));
      }
      drupal_serve_page_from_cache($cache);
      return TRUE;
    }
    else {

      //cache miss
      header('X-Drupal-Cache: MISS');
    }
  }
  else {

    //form post detected so allow normal page processing
  }
}

Functions

Name	Description
authcache_retrieve_cache_page	Send cached page to browser, if found.