/wp-includes/class-wp-object-cache.php
PHP | 496 lines | 182 code | 61 blank | 253 comment | 38 complexity | cd6ecca924a6b3b89b9695a6082f5617 MD5 | raw file
- <?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
- */
- 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 string
- */
- private $blog_prefix;
- /**
- * Holds the value of is_multisite().
- *
- * @since 3.5.0
- * @var bool
- */
- private $multisite;
- /**
- * 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() . ':' : '';
- }
- /**
- * 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 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 ( 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 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 );
- }
- /**
- * 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 ( 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 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 ( 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 values organized into groups.
- */
- public function get_multiple( $keys, $group = 'default', $force = false ) {
- $values = array();
- foreach ( $keys as $key ) {
- $values[ $key ] = $this->get( $key, $group, $force );
- }
- 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 ( 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 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
- *
- * @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 ] ) );
- }
- }