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/wp-includes/ -> cache.php (summary)

Object Cache API

File Size: 758 lines (22 kb)
Included or required: 1 time
Referenced: 0 times
Includes or requires: 0 files

Defines 1 class

WP_Object_Cache:: (19 methods):
  __get()
  __set()
  __isset()
  __unset()
  add()
  add_global_groups()
  decr()
  delete()
  flush()
  get()
  incr()
  replace()
  reset()
  set()
  stats()
  switch_to_blog()
  _exists()
  __construct()
  __destruct()

Defines 19 functions

  wp_cache_add()
  wp_cache_close()
  wp_cache_decr()
  wp_cache_delete()
  wp_cache_flush()
  wp_cache_get()
  wp_cache_incr()
  wp_cache_init()
  wp_cache_replace()
  wp_cache_set()
  wp_cache_switch_to_blog()
  wp_cache_add_global_groups()
  wp_cache_add_non_persistent_groups()
  wp_cache_reset()

Class: WP_Object_Cache  - X-Ref

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.

__get( $name )   X-Ref
Makes private properties readable for backward compatibility.

param: string $name Property to get.
return: mixed Property.

__set( $name, $value )   X-Ref
Makes private properties settable for backward compatibility.

param: string $name  Property to set.
param: mixed  $value Property value.
return: mixed Newly-set property.

__isset( $name )   X-Ref
Makes private properties checkable for backward compatibility.

param: string $name Property to check if set.
return: bool Whether the property is set.

__unset( $name )   X-Ref
Makes private properties un-settable for backward compatibility.

param: string $name Property to unset.

add( $key, $data, $group = 'default', $expire = 0 )   X-Ref
Adds data to the cache if it doesn't already exist.

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

add_global_groups( $groups )   X-Ref
Sets the list of global cache groups.

param: array $groups List of groups that are global.

decr( $key, $offset = 1, $group = 'default' )   X-Ref
Decrements numeric cache item's value.

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.

delete( $key, $group = 'default', $deprecated = false )   X-Ref
Removes the contents of the cache key in the group.

If the cache key does not exist in the group, then nothing will happen.

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.

flush()   X-Ref
Clears the object cache of all data.

return: true Always returns true.

get( $key, $group = 'default', $force = false, &$found = null )   X-Ref
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.

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
param: bool        $found  Optional. Whether the key was found in the cache (passed by reference).
return: false|mixed False on failure to retrieve contents or the cache contents on success.

incr( $key, $offset = 1, $group = 'default' )   X-Ref
Increments numeric cache item's value.

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.

replace( $key, $data, $group = 'default', $expire = 0 )   X-Ref
Replaces the contents in the cache, if contents already exist.

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.

reset()   X-Ref
Resets cache keys.


set( $key, $data, $group = 'default', $expire = 0 )   X-Ref
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.

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.

stats()   X-Ref
Echoes the stats of the caching.

Gives the cache hits, and cache misses. Also prints every cached group,
key and the data.


switch_to_blog( $blog_id )   X-Ref
Switches the internal blog ID.

This changes the blog ID used to create keys in blog specific groups.

param: int $blog_id Blog ID.

_exists( $key, $group )   X-Ref
Serves as a utility function to determine whether a key exists in the cache.

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.

__construct()   X-Ref
Sets up object properties; PHP 5 style constructor.


__destruct()   X-Ref
Saves the object cache before object is completely destroyed.

Called upon object destruction, which should be when PHP ends.

return: true Always returns true.

Functions
Functions that are not part of a class:

wp_cache_add( $key, $data, $group = '', $expire = 0 )   X-Ref
Adds data to the cache, if the cache key doesn't already exist.

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
param: int        $expire Optional. When the cache data should expire, in seconds.
return: bool False if cache key and group already exist, true on success.

wp_cache_close()   X-Ref
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.

return: true Always returns true.

wp_cache_decr( $key, $offset = 1, $group = '' )   X-Ref
Decrements numeric cache item's value.

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.

wp_cache_delete( $key, $group = '' )   X-Ref
Removes the cache contents matching key and group.

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.

wp_cache_flush()   X-Ref
Removes all cache items.

return: bool False on failure, true on success

wp_cache_get( $key, $group = '', $force = false, &$found = null )   X-Ref
Retrieves the cache contents from the cache by key and group.

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
param: bool        $found  Optional. Whether the key was found in the cache (passed by reference).
return: bool|mixed False on failure to retrieve contents or the cache

wp_cache_incr( $key, $offset = 1, $group = '' )   X-Ref
Increment numeric cache item's value

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.

wp_cache_init()   X-Ref
Sets up Object Cache Global and assigns it.


wp_cache_replace( $key, $data, $group = '', $expire = 0 )   X-Ref
Replaces the contents of the cache with new data.

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.
param: int        $expire Optional. When to expire the cache contents, in seconds.
return: bool False if original value does not exist, true if contents were replaced

wp_cache_set( $key, $data, $group = '', $expire = 0 )   X-Ref
Saves the data to the cache.

Differs from wp_cache_add() and wp_cache_replace() in that it will always write data.

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
param: int        $expire Optional. When to expire the cache contents, in seconds.
return: bool False on failure, true on success

wp_cache_switch_to_blog( $blog_id )   X-Ref
Switches the internal blog ID.

This changes the blog id used to create keys in blog specific groups.

param: int $blog_id Site ID.

wp_cache_add_global_groups( $groups )   X-Ref
Adds a group or set of groups to the list of global groups.

param: string|array $groups A group or an array of groups to add.

wp_cache_add_non_persistent_groups( $groups )   X-Ref
Adds a group or set of groups to the list of non-persistent groups.

param: string|array $groups A group or an array of groups to add.

wp_cache_reset()   X-Ref
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.




Generated: Sun Oct 21 08:20:01 2018 Cross-referenced by PHPXref 0.7