enmi-conf.org: comparison wp/wp-includes/cache.php

equal deleted inserted replaced

-:490d5cc509ed
+:cf61fcea0001
 <?php
 /**
 * Object Cache API
 *
-* @link https://codex.wordpress.org/Function_Reference/WP_Cache
+* @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
-* @uses $wp_object_cache Object Cache Class
+*
 * @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 store
+* @param int|string $key    The cache key to use for retrieval later.
-* @param string $group The group to add the cache to
+* @param mixed      $data   The data to add to the cache.
-* @param int $expire When the cache data should be expired
+* @param string     $group  Optional. The group to add the cache to. Enables the same key
-* @return bool False if cache key and group already exist, true on success
+*                           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
+* functionality was removed along with the rest of the persistent cache.
-* 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.
+* 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
+*
-*
+* @since 2.0.0
-* @return bool Always returns True
+*
+* @return true Always returns true.
 */
 function wp_cache_close() {
 	return true;
 }
 /**
-* Decrement numeric cache item's value
+* Decrements numeric cache item's value.
 *
 * @since 3.3.0
-* @uses $wp_object_cache Object Cache Class
+*
 * @see WP_Object_Cache::decr()
-*
+* @global WP_Object_Cache $wp_object_cache Object cache global instance.
-* @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 int|string $key    The cache key to decrement.
-* @param string $group The group the key is in.
+* @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;
 /**
 * Removes the cache contents matching key and group.
 *
 * @since 2.0.0
-* @uses $wp_object_cache Object Cache Class
+*
 * @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 Where the cache contents are grouped
+* @param int|string $key   What the contents in the cache are called.
-* @return bool True on successful removal, false on failure
+* @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 = '') {
+*/
+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()
+* @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;
 /**
 * 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()
-*
+* @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 Where the cache contents are grouped
+* @param int|string  $key    The key under which the cache contents are stored.
-* @param bool $force Whether to force an update of the local cache from the persistent cache (default is false)
+* @param string      $group  Optional. Where the cache contents are grouped. Default empty.
-* @param bool &$found Whether key was found in the cache. Disambiguates a return of false, a storable value.
+* @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
+*		              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()
-*
+* @global WP_Object_Cache $wp_object_cache Object cache global instance.
-* @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 int|string $key    The key for the cache contents that should be incremented.
-* @param string $group The group the key is in.
+* @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;
 /**
 * Sets up Object Cache Global and assigns it.
 *
 * @since 2.0.0
-* @global WP_Object_Cache $wp_object_cache WordPress Object Cache
+*
+* @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
-* @uses $wp_object_cache Object Cache Class
+*
 * @see WP_Object_Cache::replace()
-*
+* @global WP_Object_Cache $wp_object_cache Object cache global instance.
-* @param int|string $key What to call the contents in the cache
+*
-* @param mixed $data The contents to store in the cache
+* @param int|string $key    The key for the cache data that should be replaced.
-* @param string $group Where to group the cache contents
+* @param mixed      $data   The new data to store in the cache.
-* @param int $expire When to expire the cache contents
+* @param string     $group  Optional. The group for the cache data that should be replaced.
-* @return bool False if not exists, true if contents were 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.
 *
-* @since 2.0.0
+* Differs from wp_cache_add() and wp_cache_replace() in that it will always write data.
 *
-* @uses $wp_object_cache Object Cache Class
+* @since 2.0.0
+*
 * @see WP_Object_Cache::set()
-*
+* @global WP_Object_Cache $wp_object_cache Object cache global instance.
-* @param int|string $key What to call the contents in the cache
+*
-* @param mixed $data The contents to store in the cache
+* @param int|string $key    The cache key to use for retrieval later.
-* @param string $group Where to group the cache contents
+* @param mixed      $data   The contents to store in the cache.
-* @param int $expire When to expire the cache contents
+* @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 );
 }
 /**
-* Switch the interal blog id.
+* 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
+* @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;
-	return $wp_object_cache->switch_to_blog( $blog_id );
+	$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
+* @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;
-	return $wp_object_cache->add_global_groups( $groups );
+	$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
+* @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 backend uses global
+* Reset internal cache keys and structures.
-* 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
+* If the cache back end uses global blog or site IDs as part of its cache keys,
-* have changed since cache init.
+* 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 penality for using it is
+* recommended outside of unit tests as the performance penalty for using it is
 * high.
 *
 * @since 2.6.0
-* @deprecated 3.5.0
+* @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' );
+	_deprecated_function( __FUNCTION__, '3.5.0', 'WP_Object_Cache::reset()' );
 	global $wp_object_cache;
-	return $wp_object_cache->reset();
+	$wp_object_cache->reset();
 }
 /**
-* WordPress Object Cache
+* 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.
 *
-* @package WordPress
-* @subpackage Cache
 * @since 2.0.0
 */
 class WP_Object_Cache {
 	/**
-	 * Holds the cached objects
+	 * Holds the cached objects.
 	 *
+	 * @since 2.0.0
 	 * @var array
-	 * @access private
-	 * @since 2.0.0
 	 */
 	private $cache = array();
 	/**
 	 * The amount of times the cache data was already stored in the cache.
 	 *
 	 * @since 2.5.0
-	 * @access private
 	 * @var int
 	 */
-	private $cache_hits = 0;
+	public $cache_hits = 0;
 	/**
-	 * Amount of times the cache did not have the request in cache
+	 * Amount of times the cache did not have the request in cache.
 	 *
+	 * @since 2.0.0
 	 * @var int
-	 * @access public
-	 * @since 2.0.0
 	 */
 	public $cache_misses = 0;
 	/**
-	 * List of global groups
+	 * List of global cache groups.
 	 *
+	 * @since 3.0.0
 	 * @var array
-	 * @access protected
-	 * @since 3.0.0
 	 */
 	protected $global_groups = array();
 	/**
 	 * The blog prefix to prepend to keys in non-global groups.
 	 *
+	 * @since 3.5.0
 	 * @var int
-	 * @access private
+	 */
+	private $blog_prefix;
+	/**
+	 * Holds the value of is_multisite().
+	 *
 	 * @since 3.5.0
-	 */
-	private $blog_prefix;
-	/**
-	 * Holds the value of `is_multisite()`
-	 *
 	 * @var bool
-	 * @access private
-	 * @since 3.5.0
 	 */
 	private $multisite;
 	/**
-	 * Make private properties readable for backwards compatibility.
+	 * Makes private properties readable for backward compatibility.
 	 *
 	 * @since 4.0.0
-	 * @access public
 	 *
 	 * @param string $name Property to get.
 	 * @return mixed Property.
 	 */
 	public function __get( $name ) {
 		return $this->$name;
 	}
 	/**
-	 * Make private properties settable for backwards compatibility.
+	 * Makes private properties settable for backward compatibility.
 	 *
 	 * @since 4.0.0
-	 * @access public
 	 *
 	 * @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;
 	}
 	/**
-	 * Make private properties checkable for backwards compatibility.
+	 * Makes private properties checkable for backward compatibility.
 	 *
 	 * @since 4.0.0
-	 * @access public
 	 *
 	 * @param string $name Property to check if set.
 	 * @return bool Whether the property is set.
 	 */
 	public function __isset( $name ) {
 		return isset( $this->$name );
 	}
 	/**
-	 * Make private properties un-settable for backwards compatibility.
+	 * Makes private properties un-settable for backward compatibility.
 	 *
 	 * @since 4.0.0
-	 * @access public
 	 *
 	 * @param string $name Property to unset.
 	 */
 	public function __unset( $name ) {
 		unset( $this->$name );
 	}
 	/**
 	 * 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.
+	 * @since 2.0.0
-	 * @uses WP_Object_Cache::set Sets the data after the checking the cache
+	 *
-	 *		contents existence.
+	 * @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
-	 * @since 2.0.0
+	 *		                            contents existence.
 	 *
-	 * @param int|string $key What to call the contents in 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 mixed      $data   The contents to store in the cache.
-	 * @param string $group Where to group the cache contents
+	 * @param string     $group  Optional. Where to group the cache contents. Default 'default'.
-	 * @param int $expire When to expire the cache contents
+	 * @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;
 		return $this->set( $key, $data, $group, (int) $expire );
 	}
 	/**
-	 * Sets the list of global groups.
+	 * Sets the list of global cache groups.
 	 *
 	 * @since 3.0.0
 	 *
 	 * @param array $groups List of groups that are global.
 	 */
 		$groups = array_fill_keys( $groups, true );
 		$this->global_groups = array_merge( $this->global_groups, $groups );
 	}
 	/**
-	 * Decrement numeric cache item's value
+	 * Decrements numeric cache item's value.
 	 *
 	 * @since 3.3.0
 	 *
-	 * @param int|string $key The cache key to increment
+	 * @param int|string $key    The cache key to decrement.
-	 * @param int $offset The amount by which to decrement the item's value. Default is 1.
+	 * @param int        $offset Optional. The amount by which to decrement the item's value. Default 1.
-	 * @param string $group The group the key is in.
+	 * @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';
 		return $this->cache[ $group ][ $key ];
 	}
 	/**
-	 * Remove the contents of the cache key in the group
+	 * 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 int|string $key        What the contents in the cache are called.
-	 * @param string $group Where the cache contents are grouped
+	 * @param string     $group      Optional. Where the cache contents are grouped. Default 'default'.
-	 * @param bool $deprecated Deprecated.
+	 * @param bool       $deprecated Optional. Unused. Default false.
-	 *
+	 * @return bool False if the contents weren't deleted and true on success.
-	 * @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';
 		unset( $this->cache[$group][$key] );
 		return true;
 	}
 	/**
-	 * Clears the object cache of all data
+	 * Clears the object cache of all data.
 	 *
 	 * @since 2.0.0
 	 *
-	 * @return bool Always returns true
+	 * @return true Always returns true.
 	 */
 	public function flush() {
-		$this->cache = array ();
+		$this->cache = array();
 		return true;
 	}
 	/**
-	 * Retrieves the cache contents, if it exists
+	 * 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 int|string $key    What the contents in the cache are called.
-	 * @param string $group Where the cache contents are grouped
+	 * @param string     $group  Optional. Where the cache contents are grouped. Default 'default'.
-	 * @param string $force Whether to force a refetch rather than relying on the local cache (default is false)
+	 * @param string     $force  Optional. Unused. Whether to force a refetch rather than relying on the local
-	 * @return bool|mixed False on failure to retrieve contents or the cache
+	 *                           cache. Default false.
-	 *		contents on success
+	 * @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';
 		$this->cache_misses += 1;
 		return false;
 	}
 	/**
-	 * Increment numeric cache item's value
+	 * Increments numeric cache item's value.
 	 *
 	 * @since 3.3.0
 	 *
-	 * @param int|string $key The cache key to increment
+	 * @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 int        $offset Optional. The amount by which to increment the item's value. Default 1.
-	 * @param string $group The group the key is in.
+	 * @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';
 		return $this->cache[ $group ][ $key ];
 	}
 	/**
-	 * Replace the contents in the cache, if contents already exist
+	 * 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 int|string $key    What to call the contents in the cache.
-	 * @param mixed $data The contents to store in the cache
+	 * @param mixed      $data   The contents to store in the cache.
-	 * @param string $group Where to group the cache contents
+	 * @param string     $group  Optional. Where to group the cache contents. Default 'default'.
-	 * @param int $expire When to expire the cache contents
+	 * @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
+	 * @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';
 		return $this->set( $key, $data, $group, (int) $expire );
 	}
 	/**
-	 * Reset keys
+	 * Resets cache keys.
 	 *
 	 * @since 3.0.0
-	 * @deprecated 3.5.0
+	 *
+	 * @deprecated 3.5.0 Use switch_to_blog()
+	 * @see switch_to_blog()
 	 */
 	public function reset() {
-		_deprecated_function( __FUNCTION__, '3.5', 'switch_to_blog()' );
+		_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
+	 * 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.
 	 * 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 int|string $key    What to call the contents in the cache.
-	 * @param mixed $data The contents to store in the cache
+	 * @param mixed      $data   The contents to store in the cache.
-	 * @param string $group Where to group the cache contents
+	 * @param string     $group  Optional. Where to group the cache contents. Default 'default'.
-	 * @param int $expire Not Used
+	 * @param int        $expire Not Used.
-	 * @return bool Always returns true
+	 * @return true Always returns true.
 	 */
 	public function set( $key, $data, $group = 'default', $expire = 0 ) {
 		if ( empty( $group ) )
 			$group = 'default';
 		echo "<strong>Cache Hits:</strong> {$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 "<li><strong>Group:</strong> $group - ( " . number_format( strlen( serialize( $cache ) ) / KB_IN_BYTES, 2 ) . 'k )</li>';
 		}
 		echo '</ul>';
 	}
 	/**
-	 * Switch the interal blog id.
+	 * Switches the internal blog ID.
 	 *
-	 * This changes the blog id used to create keys in blog specific groups.
+	 * This changes the blog ID used to create keys in blog specific groups.
 	 *
 	 * @since 3.5.0
 	 *
-	 * @param int $blog_id Blog ID
+	 * @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 . ':' : '';
 	}
 	/**
-	 * Utility function to determine whether a key exists in the cache.
+	 * Serves as a utility function to determine whether a key exists in the cache.
 	 *
 	 * @since 3.4.0
 	 *
-	 * @access protected
+	 * @param int|string $key   Cache key to check for existence.
-	 * @param string $key
+	 * @param string     $group Cache group for the key existence check.
-	 * @param string $group
+	 * @return bool Whether the key exists in the cache for the given group.
-	 * @return bool
 	 */
 	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
+	 * Sets up object properties; PHP 5 style constructor.
 	 *
 	 * @since 2.0.8
 	 */
 	public function __construct() {
-		global $blog_id;
 		$this->multisite = is_multisite();
-		$this->blog_prefix =  $this->multisite ? $blog_id . ':' : '';
+		$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' ) );
 	}
 	/**
-	 * Will save the object cache before object is completely destroyed.
+	 * Saves the object cache before object is completely destroyed.
 	 *
 	 * Called upon object destruction, which should be when PHP ends.
 	 *
-	 * @since  2.0.8
+	 * @since 2.0.8
 	 *
-	 * @return bool True value. Won't be used by PHP
+	 * @return true Always returns true.
 	 */
 	public function __destruct() {
 		return true;
 	}
 }

changeset 7	cf61fcea0001
parent 5	5e2f62d02dcd
child 9	177826044cd9