";
- echo "Cache Hits: {$this->cache_hits}
";
- echo "Cache Misses: {$this->cache_misses}
";
- echo "
";
- echo "Group: $group
";
- echo "Cache:";
- echo "
"; - print_r($cache); - echo ""; - } - } - - /** - * PHP4 constructor; Calls PHP 5 style constructor - * - * @since 2.0.0 - * - * @return WP_Object_Cache - */ - function WP_Object_Cache() { - return $this->__construct(); - } - - /** - * Sets up object properties; PHP 5 style constructor - * - * @since 2.0.8 - * @return null|WP_Object_Cache If cache is disabled, returns null. - */ - function __construct() { - /** - * @todo This should be moved to the PHP4 style constructor, PHP5 - * already calls __destruct() - */ - register_shutdown_function(array(&$this, "__destruct")); - } - - /** - * Will save the object cache before object is completely destroyed. - * - * Called upon object destruction, which should be when PHP ends. - * - * @since 2.0.8 - * - * @return bool True value. Won't be used by PHP - */ - function __destruct() { - return true; - } -} -?> +add($key, $data, $flag, $expire); +} + +/** + * 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 + * 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 2.0.0 + * + * @return bool Always returns True + */ +function wp_cache_close() { + return true; +} + +/** + * Removes the cache contents matching ID and flag. + * + * @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 $flag Where the cache contents are grouped + * @return bool True on successful removal, false on failure + */ +function wp_cache_delete($id, $flag = '') { + global $wp_object_cache; + + return $wp_object_cache->delete($id, $flag); +} + +/** + * Removes all cache items. + * + * @since 2.0.0 + * @uses $wp_object_cache Object Cache Class + * @see WP_Object_Cache::flush() + * + * @return bool Always returns true + */ +function wp_cache_flush() { + global $wp_object_cache; + + return $wp_object_cache->flush(); +} + +/** + * Retrieves the cache contents from the cache by ID and flag. + * + * @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 $flag Where the cache contents are grouped + * @return bool|mixed False on failure to retrieve contents or the cache + * contents on success + */ +function wp_cache_get($id, $flag = '') { + global $wp_object_cache; + + return $wp_object_cache->get($id, $flag); +} + +/** + * 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(); +} + +/** + * Replaces the contents of the cache with new data. + * + * @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 mixed $data The contents to store in the cache + * @param string $flag Where to group the cache contents + * @param int $expire When to expire the cache contents + * @return bool False if cache ID and group already exists, true on success + */ +function wp_cache_replace($key, $data, $flag = '', $expire = 0) { + global $wp_object_cache; + + return $wp_object_cache->replace($key, $data, $flag, $expire); +} + +/** + * 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 mixed $data The contents to store in the cache + * @param string $flag Where to group the cache contents + * @param int $expire When to expire the cache contents + * @return bool False if cache ID and group already exists, true on success + */ +function wp_cache_set($key, $data, $flag = '', $expire = 0) { + global $wp_object_cache; + + return $wp_object_cache->set($key, $data, $flag, $expire); +} + +/** + * 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 ) { + // Default cache doesn't persist so nothing to do here. + return; +} + +/** + * 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; +} + +/** + * 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 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 + * @since 2.0 + */ +class WP_Object_Cache { + + /** + * Holds the cached objects + * + * @var array + * @access private + * @since 2.0.0 + */ + var $cache = array (); + + /** + * Cache objects that do not exist in the cache + * + * @var array + * @access private + * @since 2.0.0 + */ + var $non_existant_objects = array (); + + /** + * The amount of times the cache data was already stored in the cache. + * + * @since 2.5.0 + * @access private + * @var int + */ + var $cache_hits = 0; + + /** + * Amount of times the cache did not have the request in cache + * + * @var int + * @access public + * @since 2.0.0 + */ + var $cache_misses = 0; + + /** + * 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. + * + * @since 2.0.0 + * + * @param int|string $id 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 $expire When to expire the cache contents + * @return bool False if cache ID and group already exists, true on success + */ + function add($id, $data, $group = 'default', $expire = '') { + if (empty ($group)) + $group = 'default'; + + if (false !== $this->get($id, $group, false)) + return false; + + return $this->set($id, $data, $group, $expire); + } + + /** + * Remove the contents of the cache ID in the group + * + * 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. + * + * On success the group and the id will be added to the + * $non_existant_objects property in the class. + * + * @since 2.0.0 + * + * @param int|string $id What the contents in the cache are called + * @param string $group Where the cache contents are grouped + * @param bool $force Optional. Whether to force the unsetting of the cache + * ID in the group + * @return bool False if the contents weren't deleted and true on success + */ + function delete($id, $group = 'default', $force = false) { + if (empty ($group)) + $group = 'default'; + + if (!$force && false === $this->get($id, $group, false)) + return false; + + unset ($this->cache[$group][$id]); + $this->non_existant_objects[$group][$id] = true; + return true; + } + + /** + * Clears the object cache of all data + * + * @since 2.0.0 + * + * @return bool Always returns true + */ + function flush() { + $this->cache = array (); + + return 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. + * + * 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. + * + * @since 2.0.0 + * + * @param int|string $id What the contents in the cache are called + * @param string $group Where the cache contents are grouped + * @return bool|mixed False on failure to retrieve contents or the cache + * contents on success + */ + function get($id, $group = 'default') { + if (empty ($group)) + $group = 'default'; + + if (isset ($this->cache[$group][$id])) { + $this->cache_hits += 1; + if ( is_object($this->cache[$group][$id]) ) + return wp_clone($this->cache[$group][$id]); + else + return $this->cache[$group][$id]; + } + + if ( isset ($this->non_existant_objects[$group][$id]) ) + return false; + + $this->non_existant_objects[$group][$id] = true; + $this->cache_misses += 1; + return false; + } + + /** + * Replace the contents in the cache, if contents already exist + * + * @since 2.0.0 + * @see WP_Object_Cache::set() + * + * @param int|string $id 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)) + $group = 'default'; + + if (false === $this->get($id, $group, false)) + return false; + + return $this->set($id, $data, $group, $expire); + } + + /** + * 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 $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 2.0.0 + * + * @param int|string $id 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)) + $group = 'default'; + + if (NULL === $data) + $data = ''; + + if ( is_object($data) ) + $data = wp_clone($data); + + $this->cache[$group][$id] = $data; + + if(isset($this->non_existant_objects[$group][$id])) + unset ($this->non_existant_objects[$group][$id]); + + return true; + } + + /** + * Echos the stats of the caching. + * + * Gives the cache hits, and cache misses. Also prints every cached group, + * key and the data. + * + * @since 2.0.0 + */ + function stats() { + echo "
";
+ echo "Cache Hits: {$this->cache_hits}
";
+ echo "Cache Misses: {$this->cache_misses}
";
+ echo "
";
+ echo "Group: $group
";
+ echo "Cache:";
+ echo "
"; + print_r($cache); + echo ""; + } + } + + /** + * PHP4 constructor; Calls PHP 5 style constructor + * + * @since 2.0.0 + * + * @return WP_Object_Cache + */ + function WP_Object_Cache() { + return $this->__construct(); + } + + /** + * Sets up object properties; PHP 5 style constructor + * + * @since 2.0.8 + * @return null|WP_Object_Cache If cache is disabled, returns null. + */ + function __construct() { + /** + * @todo This should be moved to the PHP4 style constructor, PHP5 + * already calls __destruct() + */ + register_shutdown_function(array(&$this, "__destruct")); + } + + /** + * Will save the object cache before object is completely destroyed. + * + * Called upon object destruction, which should be when PHP ends. + * + * @since 2.0.8 + * + * @return bool True value. Won't be used by PHP + */ + function __destruct() { + return true; + } +} +?>