/**
* Object Cache API
*
+ * @link http://codex.wordpress.org/Function_Reference/WP_Cache
+ *
* @package WordPress
* @subpackage Cache
*/
/**
- * wp_cache_add() - Adds data to the cache, if the cache key doesn't aleady exist
+ * Adds data to the cache, if the cache key doesn't already exist.
*
- * @since 2.0
+ * @since 2.0.0
* @uses $wp_object_cache Object Cache Class
* @see WP_Object_Cache::add()
*
- * @param int|string $key The cache ID to use for retrieval later
+ * @param int|string $key The cache key to use for retrieval later
* @param mixed $data The data to add to the cache store
- * @param string $flag The group to add the cache to
+ * @param string $group The group to add the cache to
* @param int $expire When the cache data should be expired
- * @return unknown
+ * @return bool False if cache key and group already exist, true on success
*/
-function wp_cache_add($key, $data, $flag = '', $expire = 0) {
+function wp_cache_add( $key, $data, $group = '', $expire = 0 ) {
global $wp_object_cache;
- return $wp_object_cache->add($key, $data, $flag, $expire);
+ return $wp_object_cache->add( $key, $data, $group, (int) $expire );
}
/**
- * wp_cache_close() - Closes the cache
+ * Closes the cache.
*
- * This function has ceased to do anything since WordPress 2.5.
- * The functionality was removed along with the rest of the
- * persistant cache.
+ * This function has ceased to do anything since WordPress 2.5. The
+ * functionality was removed along with the rest of the persistent cache. This
+ * does not mean that plugins can't implement this function when they need to
+ * make sure that the cache is cleaned up after WordPress no longer needs it.
*
- * @since 2.0
+ * @since 2.0.0
*
* @return bool Always returns True
*/
}
/**
- * wp_cache_delete() - Removes the cache contents matching ID and flag
+ * Decrement numeric cache item's value
*
- * @since 2.0
+ * @since 3.3.0
+ * @uses $wp_object_cache Object Cache Class
+ * @see WP_Object_Cache::decr()
+ *
+ * @param int|string $key The cache key to increment
+ * @param int $offset The amount by which to decrement the item's value. Default is 1.
+ * @param string $group The group the key is in.
+ * @return false|int False on failure, the item's new value on success.
+ */
+function wp_cache_decr( $key, $offset = 1, $group = '' ) {
+ global $wp_object_cache;
+
+ return $wp_object_cache->decr( $key, $offset, $group );
+}
+
+/**
+ * Removes the cache contents matching key and group.
+ *
+ * @since 2.0.0
* @uses $wp_object_cache Object Cache Class
* @see WP_Object_Cache::delete()
*
- * @param int|string $id What the contents in the cache are called
- * @param string $flag Where the cache contents are grouped
+ * @param int|string $key What the contents in the cache are called
+ * @param string $group Where the cache contents are grouped
* @return bool True on successful removal, false on failure
*/
-function wp_cache_delete($id, $flag = '') {
+function wp_cache_delete($key, $group = '') {
global $wp_object_cache;
- return $wp_object_cache->delete($id, $flag);
+ return $wp_object_cache->delete($key, $group);
}
/**
- * wp_cache_flush() - Removes all cache items
+ * Removes all cache items.
*
- * @since 2.0
+ * @since 2.0.0
* @uses $wp_object_cache Object Cache Class
* @see WP_Object_Cache::flush()
*
- * @return bool Always returns true
+ * @return bool False on failure, true on success
*/
function wp_cache_flush() {
global $wp_object_cache;
}
/**
- * wp_cache_get() - Retrieves the cache contents from the cache by ID and flag
+ * Retrieves the cache contents from the cache by key and group.
*
- * @since 2.0
+ * @since 2.0.0
* @uses $wp_object_cache Object Cache Class
* @see WP_Object_Cache::get()
*
- * @param int|string $id What the contents in the cache are called
- * @param string $flag Where the cache contents are grouped
- * @return bool|mixed False on failure to retrieve contents or the cache contents on success
+ * @param int|string $key What the contents in the cache are called
+ * @param string $group Where the cache contents are grouped
+ * @param bool $force Whether to force an update of the local cache from the persistent cache (default is false)
+ * @param &bool $found Whether key was found in the cache. Disambiguates a return of false, a storable value.
+ * @return bool|mixed False on failure to retrieve contents or the cache
+ * contents on success
*/
-function wp_cache_get($id, $flag = '') {
+function wp_cache_get( $key, $group = '', $force = false, &$found = null ) {
global $wp_object_cache;
- return $wp_object_cache->get($id, $flag);
+ return $wp_object_cache->get( $key, $group, $force, $found );
}
/**
- * wp_cache_init() - Sets up Object Cache Global and assigns it
+ * Increment numeric cache item's value
*
- * @since 2.0
+ * @since 3.3.0
+ * @uses $wp_object_cache Object Cache Class
+ * @see WP_Object_Cache::incr()
+ *
+ * @param int|string $key The cache key to increment
+ * @param int $offset The amount by which to increment the item's value. Default is 1.
+ * @param string $group The group the key is in.
+ * @return false|int False on failure, the item's new value on success.
+ */
+function wp_cache_incr( $key, $offset = 1, $group = '' ) {
+ global $wp_object_cache;
+
+ return $wp_object_cache->incr( $key, $offset, $group );
+}
+
+/**
+ * Sets up Object Cache Global and assigns it.
+ *
+ * @since 2.0.0
* @global WP_Object_Cache $wp_object_cache WordPress Object Cache
*/
function wp_cache_init() {
- $GLOBALS['wp_object_cache'] =& new WP_Object_Cache();
+ $GLOBALS['wp_object_cache'] = new WP_Object_Cache();
}
/**
- * wp_cache_replace() - Replaces the contents of the cache with new data
+ * Replaces the contents of the cache with new data.
*
- * @since 2.0
+ * @since 2.0.0
* @uses $wp_object_cache Object Cache Class
* @see WP_Object_Cache::replace()
*
- * @param int|string $id What to call the contents in the cache
+ * @param int|string $key What to call the contents in the cache
* @param mixed $data The contents to store in the cache
- * @param string $flag Where to group the cache contents
+ * @param string $group Where to group the cache contents
* @param int $expire When to expire the cache contents
- * @return bool False if cache ID and group already exists, true on success
+ * @return bool False if not exists, true if contents were replaced
*/
-function wp_cache_replace($key, $data, $flag = '', $expire = 0) {
+function wp_cache_replace( $key, $data, $group = '', $expire = 0 ) {
global $wp_object_cache;
- return $wp_object_cache->replace($key, $data, $flag, $expire);
+ return $wp_object_cache->replace( $key, $data, $group, (int) $expire );
}
/**
- * wp_cache_set() - Saves the data to the cache
+ * Saves the data to the cache.
*
* @since 2.0
* @uses $wp_object_cache Object Cache Class
* @see WP_Object_Cache::set()
*
- * @param int|string $id What to call the contents in the cache
+ * @param int|string $key What to call the contents in the cache
* @param mixed $data The contents to store in the cache
- * @param string $flag Where to group the cache contents
+ * @param string $group Where to group the cache contents
* @param int $expire When to expire the cache contents
- * @return bool False if cache ID and group already exists, true on success
+ * @return bool False on failure, true on success
+ */
+function wp_cache_set( $key, $data, $group = '', $expire = 0 ) {
+ global $wp_object_cache;
+
+ return $wp_object_cache->set( $key, $data, $group, (int) $expire );
+}
+
+/**
+ * Switch the interal blog id.
+ *
+ * This changes the blog id used to create keys in blog specific groups.
+ *
+ * @since 3.5.0
+ *
+ * @param int $blog_id Blog ID
*/
-function wp_cache_set($key, $data, $flag = '', $expire = 0) {
+function wp_cache_switch_to_blog( $blog_id ) {
global $wp_object_cache;
- return $wp_object_cache->set($key, $data, $flag, $expire);
+ return $wp_object_cache->switch_to_blog( $blog_id );
+}
+
+/**
+ * Adds a group or set of groups to the list of global groups.
+ *
+ * @since 2.6.0
+ *
+ * @param string|array $groups A group or an array of groups to add
+ */
+function wp_cache_add_global_groups( $groups ) {
+ global $wp_object_cache;
+
+ return $wp_object_cache->add_global_groups( $groups );
+}
+
+/**
+ * Adds a group or set of groups to the list of non-persistent groups.
+ *
+ * @since 2.6.0
+ *
+ * @param string|array $groups A group or an array of groups to add
+ */
+function wp_cache_add_non_persistent_groups( $groups ) {
+ // Default cache doesn't persist so nothing to do here.
+ return;
+}
+
+/**
+ * Reset internal cache keys and structures. If the cache backend uses global
+ * blog or site IDs as part of its cache keys, this function instructs the
+ * backend to reset those keys and perform any cleanup since blog or site IDs
+ * have changed since cache init.
+ *
+ * This function is deprecated. Use wp_cache_switch_to_blog() instead of this
+ * function when preparing the cache for a blog switch. For clearing the cache
+ * during unit tests, consider using wp_cache_init(). wp_cache_init() is not
+ * recommended outside of unit tests as the performance penality for using it is
+ * high.
+ *
+ * @since 2.6.0
+ * @deprecated 3.5.0
+ */
+function wp_cache_reset() {
+ _deprecated_function( __FUNCTION__, '3.5' );
+
+ global $wp_object_cache;
+
+ return $wp_object_cache->reset();
}
/**
* WordPress Object Cache
*
- * The WordPress Object Cache is used to save on trips to the database.
- * The Object Cache stores all of the cache data to memory and makes the
- * cache contents available by using a key, which is used to name and
- * later retrieve the cache contents.
+ * The WordPress Object Cache is used to save on trips to the database. The
+ * Object Cache stores all of the cache data to memory and makes the cache
+ * contents available by using a key, which is used to name and later retrieve
+ * the cache contents.
*
- * The Object Cache can be replaced by other caching mechanisms by placing
- * files in the wp-content folder which is looked at in wp-settings. If
- * that file exists, then this file will not be included.
+ * The Object Cache can be replaced by other caching mechanisms by placing files
+ * in the wp-content folder which is looked at in wp-settings. If that file
+ * exists, then this file will not be included.
*
* @package WordPress
* @subpackage Cache
*
* @var array
* @access private
- * @since 2.0
+ * @since 2.0.0
*/
var $cache = array ();
/**
- * Cache objects that do not exist in the cache
+ * The amount of times the cache data was already stored in the cache.
*
- * @var array
+ * @since 2.5.0
* @access private
- * @since 2.0
+ * @var int
*/
- var $non_existant_objects = array ();
+ var $cache_hits = 0;
/**
- * Object caches that are global
+ * Amount of times the cache did not have the request in cache
*
- * @var array
- * @access private
- * @since 2.0
+ * @var int
+ * @access public
+ * @since 2.0.0
*/
- var $global_groups = array ('users', 'userlogins', 'usermeta');
+ var $cache_misses = 0;
/**
- * The amount of times the cache data was already stored in the cache.
+ * List of global groups
*
- * @since 2.5
- * @access private
- * @var int
+ * @var array
+ * @access protected
+ * @since 3.0.0
*/
- var $cache_hits = 0;
+ var $global_groups = array();
/**
- * Amount of times the cache did not have the request in cache
+ * The blog prefix to prepend to keys in non-global groups.
*
* @var int
- * @access public
- * @since 2.0
+ * @access private
+ * @since 3.5.0
*/
- var $cache_misses = 0;
+ var $blog_prefix;
/**
* Adds data to the cache if it doesn't already exist.
*
- * @uses WP_Object_Cache::get Checks to see if the cache already has data.
- * @uses WP_Object_Cache::set Sets the data after the checking the cache contents existance.
+ * @uses WP_Object_Cache::_exists Checks to see if the cache already has data.
+ * @uses WP_Object_Cache::set Sets the data after the checking the cache
+ * contents existence.
*
- * @since 2.0
+ * @since 2.0.0
*
- * @param int|string $id What to call the contents in the cache
+ * @param int|string $key What to call the contents in the cache
* @param mixed $data The contents to store in the cache
* @param string $group Where to group the cache contents
* @param int $expire When to expire the cache contents
- * @return bool False if cache ID and group already exists, true on success
+ * @return bool False if cache key and group already exist, true on success
*/
- function add($id, $data, $group = 'default', $expire = '') {
- if (empty ($group))
+ function add( $key, $data, $group = 'default', $expire = 0 ) {
+ if ( wp_suspend_cache_addition() )
+ return false;
+
+ if ( empty( $group ) )
$group = 'default';
- if (false !== $this->get($id, $group, false))
+ $id = $key;
+ if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+ $id = $this->blog_prefix . $key;
+
+ if ( $this->_exists( $id, $group ) )
return false;
- return $this->set($id, $data, $group, $expire);
+ return $this->set( $key, $data, $group, (int) $expire );
}
/**
- * Remove the contents of the cache ID in the group
+ * Sets the list of global groups.
*
- * If the cache ID does not exist in the group and $force parameter
- * is set to false, then nothing will happen. The $force parameter
- * is set to false by default.
+ * @since 3.0.0
*
- * On success the group and the id will be added to the
- * $non_existant_objects property in the class.
+ * @param array $groups List of groups that are global.
+ */
+ function add_global_groups( $groups ) {
+ $groups = (array) $groups;
+
+ $groups = array_fill_keys( $groups, true );
+ $this->global_groups = array_merge( $this->global_groups, $groups );
+ }
+
+ /**
+ * Decrement numeric cache item's value
*
- * @since 2.0
+ * @since 3.3.0
*
- * @param int|string $id What the contents in the cache are called
+ * @param int|string $key The cache key to increment
+ * @param int $offset The amount by which to decrement the item's value. Default is 1.
+ * @param string $group The group the key is in.
+ * @return false|int False on failure, the item's new value on success.
+ */
+ function decr( $key, $offset = 1, $group = 'default' ) {
+ if ( empty( $group ) )
+ $group = 'default';
+
+ if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+ $key = $this->blog_prefix . $key;
+
+ if ( ! $this->_exists( $key, $group ) )
+ return false;
+
+ if ( ! is_numeric( $this->cache[ $group ][ $key ] ) )
+ $this->cache[ $group ][ $key ] = 0;
+
+ $offset = (int) $offset;
+
+ $this->cache[ $group ][ $key ] -= $offset;
+
+ if ( $this->cache[ $group ][ $key ] < 0 )
+ $this->cache[ $group ][ $key ] = 0;
+
+ return $this->cache[ $group ][ $key ];
+ }
+
+ /**
+ * Remove the contents of the cache key in the group
+ *
+ * If the cache key does not exist in the group and $force parameter is set
+ * to false, then nothing will happen. The $force parameter is set to false
+ * by default.
+ *
+ * @since 2.0.0
+ *
+ * @param int|string $key What the contents in the cache are called
* @param string $group Where the cache contents are grouped
- * @param bool $force Optional. Whether to force the unsetting of the cache ID in the group
+ * @param bool $force Optional. Whether to force the unsetting of the cache
+ * key in the group
* @return bool False if the contents weren't deleted and true on success
*/
- function delete($id, $group = 'default', $force = false) {
- if (empty ($group))
+ function delete($key, $group = 'default', $force = false) {
+ if ( empty( $group ) )
$group = 'default';
- if (!$force && false === $this->get($id, $group, false))
+ if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+ $key = $this->blog_prefix . $key;
+
+ if ( ! $force && ! $this->_exists( $key, $group ) )
return false;
- unset ($this->cache[$group][$id]);
- $this->non_existant_objects[$group][$id] = true;
+ unset( $this->cache[$group][$key] );
return true;
}
/**
* Clears the object cache of all data
*
- * @since 2.0
+ * @since 2.0.0
*
* @return bool Always returns true
*/
/**
* Retrieves the cache contents, if it exists
*
- * The contents will be first attempted to be retrieved by searching
- * by the ID in the cache group. If the cache is hit (success) then
- * the contents are returned.
+ * The contents will be first attempted to be retrieved by searching by the
+ * key in the cache group. If the cache is hit (success) then the contents
+ * are returned.
*
- * On failure, the $non_existant_objects property is checked and if
- * the cache group and ID exist in there the cache misses will not be
- * incremented. If not in the nonexistant objects property, then the
- * cache misses will be incremented and the cache group and ID will
- * be added to the nonexistant objects.
+ * On failure, the number of cache misses will be incremented.
*
- * @since 2.0
+ * @since 2.0.0
*
- * @param int|string $id What the contents in the cache are called
+ * @param int|string $key What the contents in the cache are called
* @param string $group Where the cache contents are grouped
- * @return bool|mixed False on failure to retrieve contents or the cache contents on success
+ * @param string $force Whether to force a refetch rather than relying on the local cache (default is false)
+ * @return bool|mixed False on failure to retrieve contents or the cache
+ * contents on success
*/
- function get($id, $group = 'default') {
- if (empty ($group))
+ function get( $key, $group = 'default', $force = false, &$found = null ) {
+ if ( empty( $group ) )
$group = 'default';
- if (isset ($this->cache[$group][$id])) {
+ if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+ $key = $this->blog_prefix . $key;
+
+ if ( $this->_exists( $key, $group ) ) {
+ $found = true;
$this->cache_hits += 1;
- return $this->cache[$group][$id];
+ if ( is_object($this->cache[$group][$key]) )
+ return clone $this->cache[$group][$key];
+ else
+ return $this->cache[$group][$key];
}
- if ( isset ($this->non_existant_objects[$group][$id]) )
- return false;
-
- $this->non_existant_objects[$group][$id] = true;
+ $found = false;
$this->cache_misses += 1;
return false;
}
+ /**
+ * Increment numeric cache item's value
+ *
+ * @since 3.3.0
+ *
+ * @param int|string $key The cache key to increment
+ * @param int $offset The amount by which to increment the item's value. Default is 1.
+ * @param string $group The group the key is in.
+ * @return false|int False on failure, the item's new value on success.
+ */
+ function incr( $key, $offset = 1, $group = 'default' ) {
+ if ( empty( $group ) )
+ $group = 'default';
+
+ if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+ $key = $this->blog_prefix . $key;
+
+ if ( ! $this->_exists( $key, $group ) )
+ return false;
+
+ if ( ! is_numeric( $this->cache[ $group ][ $key ] ) )
+ $this->cache[ $group ][ $key ] = 0;
+
+ $offset = (int) $offset;
+
+ $this->cache[ $group ][ $key ] += $offset;
+
+ if ( $this->cache[ $group ][ $key ] < 0 )
+ $this->cache[ $group ][ $key ] = 0;
+
+ return $this->cache[ $group ][ $key ];
+ }
+
/**
* Replace the contents in the cache, if contents already exist
*
- * @since 2.0
+ * @since 2.0.0
* @see WP_Object_Cache::set()
*
- * @param int|string $id What to call the contents in the cache
+ * @param int|string $key What to call the contents in the cache
* @param mixed $data The contents to store in the cache
* @param string $group Where to group the cache contents
* @param int $expire When to expire the cache contents
* @return bool False if not exists, true if contents were replaced
*/
- function replace($id, $data, $group = 'default', $expire = '') {
- if (empty ($group))
+ function replace( $key, $data, $group = 'default', $expire = 0 ) {
+ if ( empty( $group ) )
$group = 'default';
- if (false === $this->get($id, $group, false))
+ $id = $key;
+ if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+ $id = $this->blog_prefix . $key;
+
+ if ( ! $this->_exists( $id, $group ) )
return false;
- return $this->set($id, $data, $group, $expire);
+ return $this->set( $key, $data, $group, (int) $expire );
+ }
+
+ /**
+ * Reset keys
+ *
+ * @since 3.0.0
+ * @deprecated 3.5.0
+ */
+ function reset() {
+ _deprecated_function( __FUNCTION__, '3.5', 'switch_to_blog()' );
+
+ // Clear out non-global caches since the blog ID has changed.
+ foreach ( array_keys( $this->cache ) as $group ) {
+ if ( ! isset( $this->global_groups[ $group ] ) )
+ unset( $this->cache[ $group ] );
+ }
}
/**
* Sets the data contents into the cache
*
- * The cache contents is grouped by the $group parameter followed
- * by the $id. This allows for duplicate ids in unique groups.
- * Therefore, naming of the group should be used with care and
- * should follow normal function naming guidelines outside of
- * core WordPress usage.
+ * The cache contents is grouped by the $group parameter followed by the
+ * $key. This allows for duplicate ids in unique groups. Therefore, naming of
+ * the group should be used with care and should follow normal function
+ * naming guidelines outside of core WordPress usage.
*
- * The $expire parameter is not used, because the cache will
- * automatically expire for each time a page is accessed and PHP
- * finishes. The method is more for cache plugins which use files.
+ * The $expire parameter is not used, because the cache will automatically
+ * expire for each time a page is accessed and PHP finishes. The method is
+ * more for cache plugins which use files.
*
- * @since 2.0
+ * @since 2.0.0
*
- * @param int|string $id What to call the contents in the cache
+ * @param int|string $key What to call the contents in the cache
* @param mixed $data The contents to store in the cache
* @param string $group Where to group the cache contents
* @param int $expire Not Used
* @return bool Always returns true
*/
- function set($id, $data, $group = 'default', $expire = '') {
- if (empty ($group))
+ function set( $key, $data, $group = 'default', $expire = 0 ) {
+ if ( empty( $group ) )
$group = 'default';
- if (NULL === $data)
- $data = '';
+ if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+ $key = $this->blog_prefix . $key;
- $this->cache[$group][$id] = $data;
-
- if(isset($this->non_existant_objects[$group][$id]))
- unset ($this->non_existant_objects[$group][$id]);
+ if ( is_object( $data ) )
+ $data = clone $data;
+ $this->cache[$group][$key] = $data;
return true;
}
/**
- * Echos the stats of the caching.
+ * Echoes the stats of the caching.
*
- * Gives the cache hits, and cache misses. Also prints every cached
- * group, key and the data.
+ * Gives the cache hits, and cache misses. Also prints every cached group,
+ * key and the data.
*
- * @since 2.0
+ * @since 2.0.0
*/
function stats() {
echo "<p>";
echo "<strong>Cache Hits:</strong> {$this->cache_hits}<br />";
echo "<strong>Cache Misses:</strong> {$this->cache_misses}<br />";
echo "</p>";
-
+ echo '<ul>';
foreach ($this->cache as $group => $cache) {
- echo "<p>";
- echo "<strong>Group:</strong> $group<br />";
- echo "<strong>Cache:</strong>";
- echo "<pre>";
- print_r($cache);
- echo "</pre>";
+ echo "<li><strong>Group:</strong> $group - ( " . number_format( strlen( serialize( $cache ) ) / 1024, 2 ) . 'k )</li>';
}
+ echo '</ul>';
}
/**
- * PHP4 constructor; Calls PHP 5 style constructor
+ * Switch the interal blog id.
*
- * @since 2.0
+ * This changes the blog id used to create keys in blog specific groups.
*
- * @return WP_Object_Cache
+ * @since 3.5.0
+ *
+ * @param int $blog_id Blog ID
*/
- function WP_Object_Cache() {
- return $this->__construct();
+ function switch_to_blog( $blog_id ) {
+ $blog_id = (int) $blog_id;
+ $this->blog_prefix = $this->multisite ? $blog_id . ':' : '';
+ }
+
+ /**
+ * Utility function to determine whether a key exists in the cache.
+ *
+ * @since 3.4.0
+ *
+ * @access protected
+ */
+ protected function _exists( $key, $group ) {
+ return isset( $this->cache[ $group ] ) && ( isset( $this->cache[ $group ][ $key ] ) || array_key_exists( $key, $this->cache[ $group ] ) );
}
/**
* @return null|WP_Object_Cache If cache is disabled, returns null.
*/
function __construct() {
- register_shutdown_function(array(&$this, "__destruct")); /** @todo This should be moved to the PHP4 style constructor, PHP5 already calls __destruct() */
+ global $blog_id;
+
+ $this->multisite = is_multisite();
+ $this->blog_prefix = $this->multisite ? $blog_id . ':' : '';
+
+
+ /**
+ * @todo This should be moved to the PHP4 style constructor, PHP5
+ * already calls __destruct()
+ */
+ register_shutdown_function( array( $this, '__destruct' ) );
}
/**
return true;
}
}
-?>