<?php /** * Object Cache API * * @link http://codex.wordpress.org/Function_Reference/WP_Cache * * @package WordPress * @subpackage Cache */ /** * Adds data to the cache, if the cache key doesn't already exist. * * @since 2.0.0 * @uses $wp_object_cache Object Cache Class * @see WP_Object_Cache::add() * * @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 $group The group to add the cache to * @param int $expire When the cache data should be expired * @return bool False if cache key and group already exist, true on success */ function wp_cache_add( $key, $data, $group = '', $expire = 0 ) { global $wp_object_cache; return $wp_object_cache->add( $key, $data, $group, (int) $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 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 2.0.0 * * @return bool Always returns True */ function wp_cache_close() { return true; } /** * Decrement numeric cache item's value * * @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 $key What the contents in the cache are called * @param string $group Where the cache contents are grouped * @return bool True on successful removal, false on failure */ function wp_cache_delete($key, $group = '') { global $wp_object_cache; return $wp_object_cache->delete($key, $group); } /** * Removes all cache items. * * @since 2.0.0 * @uses $wp_object_cache Object Cache Class * @see WP_Object_Cache::flush() * * @return bool False on failure, true on success */ function wp_cache_flush() { global $wp_object_cache; return $wp_object_cache->flush(); } /** * Retrieves the cache contents from the cache by key and group. * * @since 2.0.0 * @uses $wp_object_cache Object Cache Class * @see WP_Object_Cache::get() * * @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( $key, $group = '', $force = false, &$found = null ) { global $wp_object_cache; return $wp_object_cache->get( $key, $group, $force, $found ); } /** * Increment numeric cache item's value * * @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(); } /** * 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 $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 wp_cache_replace( $key, $data, $group = '', $expire = 0 ) { global $wp_object_cache; return $wp_object_cache->replace( $key, $data, $group, (int) $expire ); } /** * Saves the data to the cache. * * @since 2.0.0 * * @uses $wp_object_cache Object Cache Class * @see WP_Object_Cache::set() * * @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 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_switch_to_blog( $blog_id ) { global $wp_object_cache; 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 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 2.0.0 */ class WP_Object_Cache { /** * Holds the cached objects * * @var array * @access private * @since 2.0.0 */ var $cache = 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; /** * List of global groups * * @var array * @access protected * @since 3.0.0 */ var $global_groups = array(); /** * The blog prefix to prepend to keys in non-global groups. * * @var int * @access private * @since 3.5.0 */ var $blog_prefix; /** * Adds data to the cache if it doesn't already exist. * * @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 2.0.0 * * @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 key and group already exist, true on success */ function add( $key, $data, $group = 'default', $expire = 0 ) { if ( wp_suspend_cache_addition() ) return false; if ( empty( $group ) ) $group = 'default'; $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( $key, $data, $group, (int) $expire ); } /** * Sets the list of global groups. * * @since 3.0.0 * * @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 3.3.0 * * @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, then nothing will happen. * * @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 $deprecated Deprecated. * * @return bool False if the contents weren't deleted and true on success */ function delete( $key, $group = 'default', $deprecated = false ) { 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; unset( $this->cache[$group][$key] ); 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 * key in the cache group. If the cache is hit (success) then the contents * are returned. * * On failure, the number of cache misses will be incremented. * * @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 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( $key, $group = 'default', $force = false, &$found = null ) { if ( empty( $group ) ) $group = 'default'; if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) ) $key = $this->blog_prefix . $key; if ( $this->_exists( $key, $group ) ) { $found = true; $this->cache_hits += 1; if ( is_object($this->cache[$group][$key]) ) return clone $this->cache[$group][$key]; else return $this->cache[$group][$key]; } $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 2.0.0 * @see WP_Object_Cache::set() * * @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( $key, $data, $group = 'default', $expire = 0 ) { if ( empty( $group ) ) $group = 'default'; $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( $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 * $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. * * @since 2.0.0 * * @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( $key, $data, $group = 'default', $expire = 0 ) { if ( empty( $group ) ) $group = 'default'; if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) ) $key = $this->blog_prefix . $key; if ( is_object( $data ) ) $data = clone $data; $this->cache[$group][$key] = $data; return true; } /** * Echoes the stats of the caching. * * Gives the cache hits, and cache misses. Also prints every cached group, * key and the data. * * @since 2.0.0 */ function stats() { echo "<p>"; echo "<strong>Cache Hits:</strong> {$this->cache_hits}<br />"; echo "<strong>Cache Misses:</strong> {$this->cache_misses}<br />"; echo "</p>"; echo '<ul>'; foreach ($this->cache as $group => $cache) { echo "<li><strong>Group:</strong> $group - ( " . number_format( strlen( serialize( $cache ) ) / 1024, 2 ) . 'k )</li>'; } echo '</ul>'; } /** * 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 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 ] ) ); } /** * 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() { 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' ) ); } /** * 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; } }