name : class-wp-object-cache.php <?php /** * Object Cache API: WP_Object_Cache class * * @package WordPress * @subpackage Cache * @since 5.4.0 */ /** * 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 */ #[AllowDynamicProperties] 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 string[] */ protected $global_groups = array(); /** * The blog prefix to prepend to keys in non-global groups. * * @since 3.5.0 * @var string */ private $blog_prefix; /** * Holds the value of is_multisite(). * * @since 3.5.0 * @var bool */ private $multisite; /** * Sets up object properties. * * @since 2.0.8 */ public function __construct() { $this->multisite = is_multisite(); $this->blog_prefix = $this->multisite ? get_current_blog_id() . ':' : ''; } /** * 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. */ public function __set( $name, $value ) { $this->$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 ); } /** * Serves as a utility function to determine whether a key is valid. * * @since 6.1.0 * * @param int|string $key Cache key to check for validity. * @return bool Whether the key is valid. */ protected function is_valid_key( $key ) { if ( is_int( $key ) ) { return true; } if ( is_string( $key ) && trim( $key ) !== '' ) { return true; } $type = gettype( $key ); if ( ! function_exists( '__' ) ) { wp_load_translations_early(); } $message = is_string( $key ) ? __( 'Cache key must not be an empty string.' ) /* translators: %s: The type of the given cache key. */ : sprintf( __( 'Cache key must be an integer or a non-empty string, %s given.' ), $type ); _doing_it_wrong( sprintf( '%s::%s', __CLASS__, debug_backtrace( DEBUG_BACKTRACE_IGNORE_ARGS, 2 )[1]['function'] ), $message, '6.1.0' ); return false; } /** * 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 ] ) ); } /** * 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, in seconds. * Default 0 (no expiration). * @return bool True on success, false if cache key and group already exist. */ public function add( $key, $data, $group = 'default', $expire = 0 ) { if ( wp_suspend_cache_addition() ) { return false; } if ( ! $this->is_valid_key( $key ) ) { 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 ); } /** * Adds multiple values to the cache in one call. * * @since 6.0.0 * * @param array $data Array of keys and values to be added. * @param string $group Optional. Where the cache contents are grouped. Default empty. * @param int $expire Optional. When to expire the cache contents, in seconds. * Default 0 (no expiration). * @return bool[] Array of return values, grouped by key. Each value is either * true on success, or false if cache key and group already exist. */ public function add_multiple( array $data, $group = '', $expire = 0 ) { $values = array(); foreach ( $data as $key => $value ) { $values[ $key ] = $this->add( $key, $value, $group, $expire ); } return $values; } /** * 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, in seconds. * Default 0 (no expiration). * @return bool True if contents were replaced, false if original value does not exist. */ public function replace( $key, $data, $group = 'default', $expire = 0 ) { if ( ! $this->is_valid_key( $key ) ) { 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 data contents into the cache. * * The cache contents are 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 * @since 6.1.0 Returns false if cache key is invalid. * * @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. Not used. * @return bool True if contents were set, false if key is invalid. */ public function set( $key, $data, $group = 'default', $expire = 0 ) { if ( ! $this->is_valid_key( $key ) ) { return false; } 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; } /** * Sets multiple values to the cache in one call. * * @since 6.0.0 * * @param array $data Array of key and value to be set. * @param string $group Optional. Where the cache contents are grouped. Default empty. * @param int $expire Optional. When to expire the cache contents, in seconds. * Default 0 (no expiration). * @return bool[] Array of return values, grouped by key. Each value is always true. */ public function set_multiple( array $data, $group = '', $expire = 0 ) { $values = array(); foreach ( $data as $key => $value ) { $values[ $key ] = $this->set( $key, $value, $group, $expire ); } return $values; } /** * 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 The key under which the cache contents are stored. * @param string $group Optional. Where the cache contents are grouped. Default 'default'. * @param bool $force Optional. Unused. 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 mixed|false The cache contents on success, false on failure to retrieve contents. */ public function get( $key, $group = 'default', $force = false, &$found = null ) { if ( ! $this->is_valid_key( $key ) ) { return false; } 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; } /** * Retrieves multiple values from the cache in one call. * * @since 5.5.0 * * @param array $keys Array of keys under which the cache contents are stored. * @param string $group Optional. Where the cache contents are grouped. Default 'default'. * @param bool $force Optional. Whether to force an update of the local cache * from the persistent cache. Default false. * @return array Array of return values, grouped by key. Each value is either * the cache contents on success, or false on failure. */ public function get_multiple( $keys, $group = 'default', $force = false ) { $values = array(); foreach ( $keys as $key ) { $values[ $key ] = $this->get( $key, $group, $force ); } return $values; } /** * 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 True on success, false if the contents were not deleted. */ public function delete( $key, $group = 'default', $deprecated = false ) { if ( ! $this->is_valid_key( $key ) ) { return 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; } /** * Deletes multiple values from the cache in one call. * * @since 6.0.0 * * @param array $keys Array of keys to be deleted. * @param string $group Optional. Where the cache contents are grouped. Default empty. * @return bool[] Array of return values, grouped by key. Each value is either * true on success, or false if the contents were not deleted. */ public function delete_multiple( array $keys, $group = '' ) { $values = array(); foreach ( $keys as $key ) { $values[ $key ] = $this->delete( $key, $group ); } return $values; } /** * 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 int|false The item's new value on success, false on failure. */ public function incr( $key, $offset = 1, $group = 'default' ) { if ( ! $this->is_valid_key( $key ) ) { return 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; } 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 ]; } /** * 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 int|false The item's new value on success, false on failure. */ public function decr( $key, $offset = 1, $group = 'default' ) { if ( ! $this->is_valid_key( $key ) ) { return 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; } 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 ]; } /** * Clears the object cache of all data. * * @since 2.0.0 * * @return true Always returns true. */ public function flush() { $this->cache = array(); return true; } /** * Removes all cache items in a group. * * @since 6.1.0 * * @param string $group Name of group to remove from cache. * @return true Always returns true. */ public function flush_group( $group ) { unset( $this->cache[ $group ] ); return true; } /** * Sets the list of global cache groups. * * @since 3.0.0 * * @param string|string[] $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 ); } /** * 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 . ':' : ''; } /** * Resets cache keys. * * @since 3.0.0 * * @deprecated 3.5.0 Use WP_Object_Cache::switch_to_blog() * @see switch_to_blog() */ public function reset() { _deprecated_function( __FUNCTION__, '3.5.0', 'WP_Object_Cache::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[ $group ] ); } } } /** * Echoes the stats of the caching. * * Gives the cache hits, and cache misses. Also prints every cached group, * key and the data. * * @since 2.0.0 */ public function stats() { echo '<p>'; echo "<strong>Cache Hits:</strong> {$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>'; } }