diff options
| -rw-r--r-- | includes/common.inc | 1 | ||||
| -rw-r--r-- | includes/module.inc | 71 | ||||
| -rw-r--r-- | update.php | 4 |
3 files changed, 69 insertions, 7 deletions
diff --git a/includes/common.inc b/includes/common.inc index 06b42e0f9..0c09f7087 100644 --- a/includes/common.inc +++ b/includes/common.inc @@ -2405,6 +2405,7 @@ function drupal_page_footer() { _registry_check_code(REGISTRY_WRITE_LOOKUP_CACHE); drupal_cache_system_paths(); + module_implements_write_cache(); } /** diff --git a/includes/module.inc b/includes/module.inc index 3a5609a00..1b6d04cf7 100644 --- a/includes/module.inc +++ b/includes/module.inc @@ -14,7 +14,6 @@ function module_load_all($bootstrap = FALSE) { foreach (module_list(TRUE, $bootstrap) as $module) { drupal_load('module', $module); } - module_implements('', FALSE, TRUE); } /** @@ -336,27 +335,67 @@ function module_hook($module, $hook) { * @param $sort * By default, modules are ordered by weight and filename, settings this option * to TRUE, module list will be ordered by module name. - * @param $refresh + * @param $reset * For internal use only: Whether to force the stored list of hook * implementations to be regenerated (such as after enabling a new module, * before processing hook_enable). + * * @return * An array with the names of the modules which are implementing this hook. + * + * @see module_implements_write_cache(). */ -function module_implements($hook, $sort = FALSE, $refresh = FALSE) { - static $implementations; - - if ($refresh) { +function module_implements($hook, $sort = FALSE, $reset = FALSE) { + $implementations = &drupal_static(__FUNCTION__, array()); + + // We maintain a persistent cache of hook implementations in addition to the + // static cache to avoid looping through every module and every hook on each + // request. Benchmarks show that the benefit of this caching outweighs the + // additional database hit even when using the default database caching + // backend and only a small number of modules are enabled. The cost of the + // cache_get() is more or less constant and reduced further when non-database + // caching backends are used, so there will be more significant gains when a + // large number of modules are installed or hooks invoked, since this can + // quickly lead to module_hook() being called several thousand times + // per request. + if ($reset) { $implementations = array(); + cache_set('module_implements', array()); return; } + // Fetch implementations from cache. + if (empty($implementations)) { + $implementations = cache_get('module_implements'); + if ($implementations === FALSE) { + $implementations = array(); + } + else { + $implementations = $implementations->data; + } + } + if (!isset($implementations[$hook])) { $implementations[$hook] = array(); $list = module_list(FALSE, FALSE, $sort); foreach ($list as $module) { if (module_hook($module, $hook)) { - $implementations[$hook][] = $module; + $implementations[$hook][$module] = $module; + // We added something to the cache, so write it when we are done. + $implementations['#write_cache'] = TRUE; + } + } + } + else { + foreach ($implementations[$hook] as $module) { + // It is possible that a module removed a hook implementation without the + // implementations cache being rebuilt yet, so we check module_hook() on + // each request to avoid undefined function errors. + if (!module_hook($module, $hook)) { + // Clear out the stale implementation from the cache and force a cache + // refresh to forget about no longer existing hook implementations. + unset($implementations[$hook][$module]); + $implementations['#write_cache'] = TRUE; } } } @@ -371,6 +410,24 @@ function module_implements($hook, $sort = FALSE, $refresh = FALSE) { } /** + * Writes the hook implementation cache. + * + * @see module_implements() + */ +function module_implements_write_cache() { + $implementations = &drupal_static('module_implements'); + // Check whether we need to write the cache. We do not want to cache hooks, + // which are only invoked on HTTP POST requests. Maybe the page is not + // cacheable for other reasons than the HTTP request type as well, but this + // does not matter for the hook implementation cache, because nothing breaks + // if hook implementations are not cached. + if (isset($implementations['#write_cache']) && drupal_page_is_cacheable()) { + unset($implementations['#write_cache']); + cache_set('module_implements', $implementations); + } +} + +/** * Invoke a hook in a particular module. * * @param $module diff --git a/update.php b/update.php index 2c8fbb14b..20a9caf45 100644 --- a/update.php +++ b/update.php @@ -292,6 +292,10 @@ if (empty($op) && $update_access_allowed) { drupal_load('module', 'system'); drupal_load('module', 'filter'); + // Reset the module_implements() cache so that any new hook implementations + // in updated code are picked up. + module_implements('', FALSE, TRUE); + // Set up $language, since the installer components require it. drupal_language_initialize(); |