<?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;

}

/**

 * 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

 */

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

	 */

	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

	 *

	 * @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 ) {

			return false;

			$group = 'default';

		$id = $key;

			$id = $this->blog_prefix . $key;

			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;

		$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' ) {