From b14349889e9e51fb44934694030e95306918e3bd Mon Sep 17 00:00:00 2001
From: Angie Byron <webchick@24967.no-reply.drupal.org>
Date: Fri, 20 Nov 2009 06:12:45 +0000
Subject: [PATCH] #619666 by effulgentsia, casey, and catch: Changed Introduce
new pattern for drupal_static() in performance-critical functions.
---
includes/bootstrap.inc | 79 ++++++++++++++++++++++++++++++++++++++++
includes/common.inc | 22 ++++++++---
includes/module.inc | 5 ++-
includes/path.inc | 37 ++++++++++++++-----
modules/user/user.module | 5 ++-
5 files changed, 131 insertions(+), 17 deletions(-)
diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index 803212c14606..f0a5ec12a5d2 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -2086,6 +2086,83 @@ function registry_rebuild() {
/**
* Central static variable storage.
*
+ * All functions requiring a static variable to persist or cache data within
+ * a single page request are encouraged to use this function unless it is
+ * absolutely certain that the static variable will not need to be reset during
+ * the page request. By centralizing static variable storage through this
+ * function, other functions can rely on a consistent API for resetting any
+ * other function's static variables.
+ *
+ * Example:
+ * @code
+ * function language_list($field = 'language') {
+ * $languages = &drupal_static(__FUNCTION__);
+ * if (!isset($languages)) {
+ * // If this function is being called for the first time after a reset,
+ * // query the database and execute any other code needed to retrieve
+ * // information about the supported languages.
+ * ...
+ * }
+ * if (!isset($languages[$field])) {
+ * // If this function is being called for the first time for a particular
+ * // index field, then execute code needed to index the information already
+ * // available in $languages by the desired field.
+ * ...
+ * }
+ * // Subsequent invocations of this function for a particular index field
+ * // skip the above two code blocks and quickly return the already indexed
+ * // information.
+ * return $languages[$field];
+ * }
+ * function locale_translate_overview_screen() {
+ * // When building the content for the translations overview page, make
+ * // sure to get completely fresh information about the supported languages.
+ * drupal_static_reset('language_list');
+ * ...
+ * }
+ * @endcode
+ *
+ * In a few cases, a function can have certainty that there is no legitimate
+ * use-case for resetting that function's static variable. This is rare,
+ * because when writing a function, it's hard to forecast all the situations in
+ * which it will be used. A guideline is that if a function's static variable
+ * does not depend on any information outside of the function that might change
+ * during a single page request, then it's ok to use the "static" keyword
+ * instead of the drupal_static() function.
+ *
+ * Example:
+ * @code
+ * function actions_do(...) {
+ * // $stack tracks the number of recursive calls.
+ * static $stack;
+ * $stack++;
+ * if ($stack > variable_get('actions_max_stack', 35)) {
+ * ...
+ * return;
+ * }
+ * ...
+ * $stack--;
+ * }
+ * @endcode
+ *
+ * In a few cases, a function needs a resettable static variable, but the
+ * function is called many times (100+) during a single page request, so
+ * every microsecond of execution time that can be removed from the function
+ * counts. These functions can use a more cumbersome, but faster variant of
+ * calling drupal_static(). For benchmarks and background on this variant,
+ * please see http://drupal.org/node/619666.
+ *
+ * Example:
+ * @code
+ * function user_access($string, $account = NULL) {
+ * // Use the advanced drupal_static() pattern, since this is called very often.
+ * static $drupal_static = array();
+ * isset($drupal_static[__FUNCTION__]) || ($drupal_static[__FUNCTION__] = &drupal_static(__FUNCTION__));
+ * $perm = &$drupal_static[__FUNCTION__];
+ * ...
+ * }
+ * @endcode
+ *
* @param $name
* Globally unique name for the variable. For a function with only one static,
* variable, the function name (e.g. via the PHP magic __FUNCTION__ constant)
@@ -2102,6 +2179,8 @@ function registry_rebuild() {
*
* @return
* Returns a variable by reference.
+ *
+ * @see drupal_static_reset()
*/
function &drupal_static($name, $default_value = NULL, $reset = FALSE) {
static $data = array(), $default = array();
diff --git a/includes/common.inc b/includes/common.inc
index 197124868e45..be8f2a974f1d 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -2275,7 +2275,11 @@ function format_interval($timestamp, $granularity = 2, $langcode = NULL) {
* A translated date string in the requested format.
*/
function format_date($timestamp, $type = 'medium', $format = '', $timezone = NULL, $langcode = NULL) {
- $timezones = &drupal_static(__FUNCTION__, array());
+ // Use the advanced drupal_static() pattern, since this is called very often.
+ static $drupal_static = array();
+ isset($drupal_static[__FUNCTION__]) || ($drupal_static[__FUNCTION__] = &drupal_static(__FUNCTION__));
+ $timezones = &$drupal_static[__FUNCTION__];
+
if (!isset($timezone)) {
global $user;
if (variable_get('configurable_timezones', 1) && $user->uid && $user->timezone) {
@@ -2512,7 +2516,10 @@ function url($path = NULL, array $options = array()) {
}
global $base_url, $base_secure_url, $base_insecure_url;
- $script = &drupal_static(__FUNCTION__);
+ // Use the advanced drupal_static() pattern, since this is called very often.
+ static $drupal_static = array();
+ isset($drupal_static[__FUNCTION__]) || ($drupal_static[__FUNCTION__] = &drupal_static(__FUNCTION__));
+ $script = &$drupal_static[__FUNCTION__];
if (!isset($script)) {
// On some web servers, such as IIS, we can't omit "index.php". So, we
@@ -4728,7 +4735,10 @@ function drupal_system_listing($mask, $directory, $key = 'name', $min_depth = 1)
* keyed array as described above.
*/
function drupal_alter($type, &$data, &$context1 = NULL, &$context2 = NULL) {
- $functions = &drupal_static(__FUNCTION__, array());
+ // Use the advanced drupal_static() pattern, since this is called very often.
+ static $drupal_static = array();
+ isset($drupal_static[__FUNCTION__]) || ($drupal_static[__FUNCTION__] = &drupal_static(__FUNCTION__));
+ $functions = &$drupal_static[__FUNCTION__];
// Some alter hooks are invoked many times per page request, so statically
// cache the list of functions to call, and on subsequent calls, iterate
@@ -6214,8 +6224,10 @@ function drupal_check_incompatibility($v, $current_version) {
* to return an array with info about all types.
*/
function entity_get_info($entity_type = NULL) {
- // We statically cache the information returned by hook_entity_info().
- $entity_info = &drupal_static(__FUNCTION__, array());
+ // Use the advanced drupal_static() pattern, since this is called very often.
+ static $drupal_static = array();
+ isset($drupal_static[__FUNCTION__]) || ($drupal_static[__FUNCTION__] = &drupal_static(__FUNCTION__));
+ $entity_info = &$drupal_static[__FUNCTION__];
if (empty($entity_info)) {
if ($cache = cache_get('entity_info')) {
diff --git a/includes/module.inc b/includes/module.inc
index 8df91dd5ca01..a3d6c8b458d1 100644
--- a/includes/module.inc
+++ b/includes/module.inc
@@ -438,7 +438,10 @@ function module_hook($module, $hook) {
* @see module_implements_write_cache().
*/
function module_implements($hook, $sort = FALSE, $reset = FALSE) {
- $implementations = &drupal_static(__FUNCTION__, array());
+ // Use the advanced drupal_static() pattern, since this is called very often.
+ static $drupal_static = array();
+ isset($drupal_static[__FUNCTION__]) || ($drupal_static[__FUNCTION__] = &drupal_static(__FUNCTION__));
+ $implementations = &$drupal_static[__FUNCTION__];
// 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
diff --git a/includes/path.inc b/includes/path.inc
index 19d52df38d7b..4a9faa373b7e 100644
--- a/includes/path.inc
+++ b/includes/path.inc
@@ -45,14 +45,21 @@ function drupal_path_initialize() {
*/
function drupal_lookup_path($action, $path = '', $path_language = '') {
global $language;
- $cache = &drupal_static(__FUNCTION__, array(
- 'map' => array(),
- 'no_source' => array(),
- 'whitelist' => NULL,
- 'system_paths' => array(),
- 'no_aliases' => array(),
- 'first_call' => TRUE,
- ));
+ // Use the advanced drupal_static() pattern, since this is called very often.
+ static $drupal_static = array();
+ isset($drupal_static[__FUNCTION__]) || ($drupal_static[__FUNCTION__] = &drupal_static(__FUNCTION__));
+ $cache = &$drupal_static[__FUNCTION__];
+
+ if (!isset($cache)) {
+ $cache = array(
+ 'map' => array(),
+ 'no_source' => array(),
+ 'whitelist' => NULL,
+ 'system_paths' => array(),
+ 'no_aliases' => array(),
+ 'first_call' => TRUE,
+ );
+ }
// Retrieve the path alias whitelist.
if (!isset($cache['whitelist'])) {
@@ -245,7 +252,14 @@ function drupal_get_normal_path($path, $path_language = '') {
* not found.
*/
function arg($index = NULL, $path = NULL) {
- $arguments = &drupal_static(__FUNCTION__);
+ // Even though $arguments doesn't need to be resettable for any functional
+ // reasons (the result of explode() does not depend on any run-time
+ // information), it should be resettable anyway in case a module needs to
+ // free up the memory used by it.
+ // Use the advanced drupal_static() pattern, since this is called very often.
+ static $drupal_static = array();
+ isset($drupal_static[__FUNCTION__]) || ($drupal_static[__FUNCTION__] = &drupal_static(__FUNCTION__));
+ $arguments = &$drupal_static[__FUNCTION__];
if (!isset($path)) {
$path = $_GET['q'];
@@ -310,7 +324,10 @@ function drupal_set_title($title = NULL, $output = CHECK_PLAIN) {
* Boolean value: TRUE if the current page is the front page; FALSE if otherwise.
*/
function drupal_is_front_page() {
- $is_front_page = &drupal_static(__FUNCTION__);
+ // Use the advanced drupal_static() pattern, since this is called very often.
+ static $drupal_static = array();
+ isset($drupal_static[__FUNCTION__]) || ($drupal_static[__FUNCTION__] = &drupal_static(__FUNCTION__));
+ $is_front_page = &$drupal_static[__FUNCTION__];
if (!isset($is_front_page)) {
// As drupal_path_initialize updates $_GET['q'] with the 'site_frontpage' path,
diff --git a/modules/user/user.module b/modules/user/user.module
index 2772b5ffb836..a244ea88740e 100644
--- a/modules/user/user.module
+++ b/modules/user/user.module
@@ -679,7 +679,10 @@ function user_role_permissions($roles = array()) {
*/
function user_access($string, $account = NULL) {
global $user;
- $perm = &drupal_static(__FUNCTION__, array());
+ // Use the advanced drupal_static() pattern, since this is called very often.
+ static $drupal_static = array();
+ isset($drupal_static[__FUNCTION__]) || ($drupal_static[__FUNCTION__] = &drupal_static(__FUNCTION__));
+ $perm = &$drupal_static[__FUNCTION__];
if (!isset($account)) {
$account = $user;
--
GitLab