function _registry_update

Does the work for registry_update().

Related topics

File

includes/registry.inc, line 21

Code

function _registry_update() {
    // The registry serves as a central autoloader for all classes, including
    // the database query builders. However, the registry rebuild process
    // requires write ability to the database, which means having access to the
    // query builders that require the registry in order to be loaded. That
    // causes a fatal race condition. Therefore we manually include the
    // appropriate query builders for the currently active database before the
    // registry rebuild process runs.
    $connection_info = Database::getConnectionInfo();
    $driver = $connection_info['default']['driver'];
    require_once DRUPAL_ROOT . '/includes/database/query.inc';
    require_once DRUPAL_ROOT . '/includes/database/select.inc';
    require_once DRUPAL_ROOT . '/includes/database/' . $driver . '/query.inc';
    // During the first registry rebuild in a request, we check all the files.
    // During subsequent rebuilds, we only add new files. It makes the rebuilding
    // process faster during installation of modules.
    static $check_existing_files = TRUE;
    // Get current list of modules and their files.
    $modules = db_query("SELECT * FROM {system} WHERE type = 'module'")->fetchAll();
    // Get the list of files we are going to parse.
    $files = array();
    foreach ($modules as &$module) {
        $module->info = unserialize($module->info);
        $dir = dirname($module->filename);
        // Store the module directory for use in hook_registry_files_alter().
        $module->dir = $dir;
        if ($module->status) {
            // Add files for enabled modules to the registry.
            foreach ($module->info['files'] as $file) {
                $files["{$dir}/{$file}"] = array(
                    'module' => $module->name,
                    'weight' => $module->weight,
                );
            }
        }
    }
    foreach (file_scan_directory('includes', '/\\.inc$/') as $filename => $file) {
        $files["{$filename}"] = array(
            'module' => '',
            'weight' => 0,
        );
    }
    // Initialize an empty array for the unchanged files.
    $unchanged_files = array();
    $transaction = db_transaction();
    try {
        // Allow modules to manually modify the list of files before the registry
        // parses them. The $modules array provides the .info file information, which
        // includes the list of files registered to each module. Any files in the
        // list can then be added to the list of files that the registry will parse,
        // or modify attributes of a file.
        drupal_alter('registry_files', $files, $modules);
        foreach (registry_get_parsed_files() as $filename => $file) {
            // Add the hash for those files we have already parsed.
            if (isset($files[$filename])) {
                if ($check_existing_files === TRUE) {
                    $files[$filename]['hash'] = $file['hash'];
                }
                else {
                    // Ignore that file for this request, it has been parsed previously
                    // and it is unlikely it has changed.
                    unset($files[$filename]);
                    $unchanged_files[$filename] = $file;
                }
            }
            else {
                // Flush the registry of resources in files that are no longer on disc
                // or are in files that no installed modules require to be parsed.
                db_delete('registry')->condition('filename', $filename)
                    ->execute();
                db_delete('registry_file')->condition('filename', $filename)
                    ->execute();
            }
        }
        $parsed_files = _registry_parse_files($files);
        // Add unchanged files to the files.
        $files += $unchanged_files;
        $unchanged_resources = array();
        $lookup_cache = array();
        if ($cache = cache_get('lookup_cache', 'cache_bootstrap')) {
            $lookup_cache = $cache->data;
        }
        foreach ($lookup_cache as $key => $file) {
            // If the file for this cached resource is carried over unchanged from
            // the last registry build, then we can safely re-cache it.
            if ($file && isset($files[$file]) && !in_array($file, $parsed_files, TRUE)) {
                $unchanged_resources[$key] = $file;
            }
        }
    } catch (Exception $e) {
        $transaction->rollback();
        watchdog_exception('registry', $e);
        throw $e;
    }
    module_implements('', FALSE, TRUE);
    _registry_check_code(REGISTRY_RESET_LOOKUP_CACHE);
    // During the next run in this request, don't bother re-checking existing
    // files.
    $check_existing_files = FALSE;
    // We have some unchanged resources, warm up the cache - no need to pay
    // for looking them up again.
    if (count($unchanged_resources) > 0) {
        cache_set('lookup_cache', $unchanged_resources, 'cache_bootstrap');
    }
}