function _registry_check_code

Checks for a resource in the registry.

Parameters

$type: The type of resource we are looking up, or one of the constants REGISTRY_RESET_LOOKUP_CACHE or REGISTRY_WRITE_LOOKUP_CACHE, which signal that we should reset or write the cache, respectively.

$name: The name of the resource, or NULL if either of the REGISTRY_* constants is passed in.

Return value

TRUE if the resource was found, FALSE if not. NULL if either of the REGISTRY_* constants is passed in as $type.

Related topics

File

includes/bootstrap.inc, line 3524

Code

function _registry_check_code($type, $name = NULL) {
    static $lookup_cache, $cache_update_needed;
    if ($type == 'class' && class_exists($name) || $type == 'interface' && interface_exists($name) || $type == 'trait' && trait_exists($name)) {
        return TRUE;
    }
    if (!isset($lookup_cache)) {
        $lookup_cache = array();
        if ($cache = cache_get('lookup_cache', 'cache_bootstrap')) {
            $lookup_cache = $cache->data;
        }
    }
    // When we rebuild the registry, we need to reset this cache so
    // we don't keep lookups for resources that changed during the rebuild.
    if ($type == REGISTRY_RESET_LOOKUP_CACHE) {
        $cache_update_needed = TRUE;
        $lookup_cache = NULL;
        return;
    }
    // Called from drupal_page_footer, we write to permanent storage if there
    // changes to the lookup cache for this request.
    if ($type == REGISTRY_WRITE_LOOKUP_CACHE) {
        if ($cache_update_needed) {
            cache_set('lookup_cache', $lookup_cache, 'cache_bootstrap');
        }
        return;
    }
    // $type is either 'interface' or 'class', so we only need the first letter to
    // keep the cache key unique.
    $cache_key = $type[0] . $name;
    if (isset($lookup_cache[$cache_key])) {
        if ($lookup_cache[$cache_key]) {
            include_once DRUPAL_ROOT . '/' . $lookup_cache[$cache_key];
        }
        return (bool) $lookup_cache[$cache_key];
    }
    // This function may get called when the default database is not active, but
    // there is no reason we'd ever want to not use the default database for
    // this query.
    $file = Database::getConnection('default', 'default')->select('registry', 'r', array(
        'target' => 'default',
    ))
        ->fields('r', array(
        'filename',
    ))
        ->condition('r.name', db_like($name), 'LIKE')
        ->condition('r.type', $type)
        ->execute()
        ->fetchField();
    // Flag that we've run a lookup query and need to update the cache.
    $cache_update_needed = TRUE;
    // Misses are valuable information worth caching, so cache even if
    // $file is FALSE.
    $lookup_cache[$cache_key] = $file;
    if ($file) {
        include_once DRUPAL_ROOT . '/' . $file;
        return TRUE;
    }
    else {
        return FALSE;
    }
}