File Content: cache.php <?php /** * Object Cache API * * @link https://codex.wordpress.org/Class_Reference/WP_Object_Cache * * @package WordPress * @subpackage Cache */ /** * Adds data to the cache, if the cache key doesn't already exist. * * @since 2.0.0 * * @see WP_Object_Cache::add() * @global WP_Object_Cache $wp_object_cache Object cache global instance. * * @param int|string $key The cache key to use for retrieval later. * @param mixed $data The data to add to the cache. * @param string $group Optional. The group to add the cache to. Enables the same key * to be used across groups. Default empty. * @param int $expire Optional. When the cache data should expire, in seconds. * Default 0 (no expiration). * @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 true Always returns true. */ function wp_cache_close() { return true; } /** * Decrements numeric cache item's value. * * @since 3.3.0 * * @see WP_Object_Cache::decr() * @global WP_Object_Cache $wp_object_cache Object cache global instance. * * @param int|string $key The cache key to decrement. * @param int $offset Optional. The amount by which to decrement the item's value. Default 1. * @param string $group Optional. The group the key is in. Default empty. * @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 * * @see WP_Object_Cache::delete() * @global WP_Object_Cache $wp_object_cache Object cache global instance. * * @param int|string $key What the contents in the cache are called. * @param string $group Optional. Where the cache contents are grouped. Default empty. * @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 * * @see WP_Object_Cache::flush() * @global WP_Object_Cache $wp_object_cache Object cache global instance. * * @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 * * @see WP_Object_Cache::get() * @global WP_Object_Cache $wp_object_cache Object cache global instance. * * @param int|string $key The key under which the cache contents are stored. * @param string $group Optional. Where the cache contents are grouped. Default empty. * @param bool $force Optional. Whether to force an update of the local cache from the persistent * cache. Default false. * @param bool $found Optional. Whether the key was found in the cache (passed by reference). * Disambiguates a return of false, a storable value. Default null. * @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 * * @see WP_Object_Cache::incr() * @global WP_Object_Cache $wp_object_cache Object cache global instance. * * @param int|string $key The key for the cache contents that should be incremented. * @param int $offset Optional. The amount by which to increment the item's value. Default 1. * @param string $group Optional. The group the key is in. Default empty. * @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 */ 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 * * @see WP_Object_Cache::replace() * @global WP_Object_Cache $wp_object_cache Object cache global instance. * * @param int|string $key The key for the cache data that should be replaced. * @param mixed $data The new data to store in the cache. * @param string $group Optional. The group for the cache data that should be replaced. * Default empty. * @param int $expire Optional. When to expire the cache contents, in seconds. * Default 0 (no expiration). * @return bool False if original value does not exist, 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. * * Differs from wp_cache_add() and wp_cache_replace() in that it will always write data. * * @since 2.0.0 * * @see WP_Object_Cache::set() * @global WP_Object_Cache $wp_object_cache Object cache global instance. * * @param int|string $key The cache key to use for retrieval later. * @param mixed $data The contents to store in the cache. * @param string $group Optional. Where to group the cache contents. Enables the same key * to be used across groups. Default empty. * @param int $expire Optional. When to expire the cache contents, in seconds. * Default 0 (no expiration). * @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 ); } /** * Switches the internal blog ID. * * This changes the blog id used to create keys in blog specific groups. * * @since 3.5.0 * * @see WP_Object_Cache::switch_to_blog() * @global WP_Object_Cache $wp_object_cache Object cache global instance. * * @param int $blog_id Site ID. */ function wp_cache_switch_to_blog( $blog_id ) { global $wp_object_cache; $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 * * @see WP_Object_Cache::add_global_groups() * @global WP_Object_Cache $wp_object_cache Object cache global instance. * * @param string|array $groups A group or an array of groups to add. */ function wp_cache_add_global_groups( $groups ) { global $wp_object_cache; $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. } /** * Reset internal cache keys and structures. * * If the cache back end uses global blog or site IDs as part of its cache keys, * this function instructs the back end 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 penalty for using it is * high. * * @since 2.6.0 * @deprecated 3.5.0 WP_Object_Cache::reset() * @see WP_Object_Cache::reset() * * @global WP_Object_Cache $wp_object_cache Object cache global instance. */ function wp_cache_reset() { _deprecated_function( __FUNCTION__, '3.5.0', 'WP_Object_Cache::reset()' ); global $wp_object_cache; $wp_object_cache->reset(); } /** * Core class that implements an 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. * * @since 2.0.0 */ class WP_Object_Cache { /** * Holds the cached objects. * * @since 2.0.0 * @var array */ private $cache = array(); /** * The amount of times the cache data was already stored in the cache. * * @since 2.5.0 * @var int */ public $cache_hits = 0; /** * Amount of times the cache did not have the request in cache. * * @since 2.0.0 * @var int */ public $cache_misses = 0; /** * List of global cache groups. * * @since 3.0.0 * @var array */ protected $global_groups = array(); /** * The blog prefix to prepend to keys in non-global groups. * * @since 3.5.0 * @var int */ private $blog_prefix; /** * Holds the value of is_multisite(). * * @since 3.5.0 * @var bool */ private $multisite; /** * Makes private properties readable for backward compatibility. * * @since 4.0.0 * * @param string $name Property to get. * @return mixed Property. */ public function __get( $name ) { return $this->$name; } /** * Makes private properties settable for backward compatibility. * * @since 4.0.0 * * @param string $name Property to set. * @param mixed $value Property value. * @return mixed Newly-set property. */ public function __set( $name, $value ) { return $this->$name = $value; } /** * Makes private properties checkable for backward compatibility. * * @since 4.0.0 * * @param string $name Property to check if set. * @return bool Whether the property is set. */ public function __isset( $name ) { return isset( $this->$name ); } /** * Makes private properties un-settable for backward compatibility. * * @since 4.0.0 * * @param string $name Property to unset. */ public function __unset( $name ) { unset( $this->$name ); } /** * Adds data to the cache if it doesn't already exist. * * @since 2.0.0 * * @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. * * @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 Optional. Where to group the cache contents. Default 'default'. * @param int $expire Optional. When to expire the cache contents. Default 0 (no expiration). * @return bool False if cache key and group already exist, true on success */ public 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 cache groups. * * @since 3.0.0 * * @param array $groups List of groups that are global. */ public function add_global_groups( $groups ) { $groups = (array) $groups; $groups = array_fill_keys( $groups, true ); $this->global_groups = array_merge( $this->global_groups, $groups ); } /** * Decrements numeric cache item's value. * * @since 3.3.0 * * @param int|string $key The cache key to decrement. * @param int $offset Optional. The amount by which to decrement the item's value. Default 1. * @param string $group Optional. The group the key is in. Default 'default'. * @return false|int False on failure, the item's new value on success. */ public 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 ]; } /** * Removes 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 Optional. Where the cache contents are grouped. Default 'default'. * @param bool $deprecated Optional. Unused. Default false. * @return bool False if the contents weren't deleted and true on success. */ public 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 true Always returns true. */ public 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 Optional. Where the cache contents are grouped. Default 'default'. * @param string $force Optional. Unused. Whether to force a refetch rather than relying on the local * cache. Default false. * @param bool $found Optional. Whether the key was found in the cache (passed by reference). * Disambiguates a return of false, a storable value. Default null. * @return false|mixed False on failure to retrieve contents or the cache contents on success. */ public 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; } /** * Increments numeric cache item's value. * * @since 3.3.0 * * @param int|string $key The cache key to increment * @param int $offset Optional. The amount by which to increment the item's value. Default 1. * @param string $group Optional. The group the key is in. Default 'default'. * @return false|int False on failure, the item's new value on success. */ public 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 ]; } /** * Replaces 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 Optional. Where to group the cache contents. Default 'default'. * @param int $expire Optional. When to expire the cache contents. Default 0 (no expiration). * @return bool False if not exists, true if contents were replaced. */ public 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 ); } /** * Resets cache keys. * * @since 3.0.0 * * @deprecated 3.5.0 Use switch_to_blog() * @see switch_to_blog() */ public function reset() { _deprecated_function( __FUNCTION__, '3.5.0', '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 Optional. Where to group the cache contents. Default 'default'. * @param int $expire Not Used. * @return true Always returns true. */ public 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] = $data; return true; } /** * Echoes the stats of the caching. * * Gives the cache hits, and cache misses. Also prints every cached group, * key and the data. * * @since 2.0.0 */ public function stats() { echo "<p>"; echo "<strong>Cache Hits:</strong> {$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> ' . esc_html( $group ) . ' - ( ' . number_format( strlen( serialize( $cache ) ) / KB_IN_BYTES, 2 ) . 'k )</li>'; } echo '</ul>'; } /** * Switches the internal 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. */ public function switch_to_blog( $blog_id ) { $blog_id = (int) $blog_id; $this->blog_prefix = $this->multisite ? $blog_id . ':' : ''; } /** * Serves as a utility function to determine whether a key exists in the cache. * * @since 3.4.0 * * @param int|string $key Cache key to check for existence. * @param string $group Cache group for the key existence check. * @return bool Whether the key exists in the cache for the given group. */ 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 */ public function __construct() { $this->multisite = is_multisite(); $this->blog_prefix = $this->multisite ? get_current_blog_id() . ':' : ''; /** * @todo This should be moved to the PHP4 style constructor, PHP5 * already calls __destruct() */ register_shutdown_function( array( $this, '__destruct' ) ); } /** * Saves the object cache before object is completely destroyed. * * Called upon object destruction, which should be when PHP ends. * * @since 2.0.8 * * @return true Always returns true. */ public function __destruct() { return true; } } Submit