5
* @link http://codex.wordpress.org/Function_Reference/WP_Cache
12
* Adds data to the cache, if the cache key doesn't already exist.
15
* @uses $wp_object_cache Object Cache Class
16
* @see WP_Object_Cache::add()
18
* @param int|string $key The cache key to use for retrieval later
19
* @param mixed $data The data to add to the cache store
20
* @param string $group The group to add the cache to
21
* @param int $expire When the cache data should be expired
22
* @return bool False if cache key and group already exist, true on success
24
function wp_cache_add( $key, $data, $group = '', $expire = 0 ) {
25
global $wp_object_cache;
27
return $wp_object_cache->add( $key, $data, $group, (int) $expire );
33
* This function has ceased to do anything since WordPress 2.5. The
34
* functionality was removed along with the rest of the persistent cache. This
35
* does not mean that plugins can't implement this function when they need to
36
* make sure that the cache is cleaned up after WordPress no longer needs it.
40
* @return bool Always returns True
42
function wp_cache_close() {
47
* Decrement numeric cache item's value
50
* @uses $wp_object_cache Object Cache Class
51
* @see WP_Object_Cache::decr()
53
* @param int|string $key The cache key to increment
54
* @param int $offset The amount by which to decrement the item's value. Default is 1.
55
* @param string $group The group the key is in.
56
* @return false|int False on failure, the item's new value on success.
58
function wp_cache_decr( $key, $offset = 1, $group = '' ) {
59
global $wp_object_cache;
61
return $wp_object_cache->decr( $key, $offset, $group );
65
* Removes the cache contents matching key and group.
68
* @uses $wp_object_cache Object Cache Class
69
* @see WP_Object_Cache::delete()
71
* @param int|string $key What the contents in the cache are called
72
* @param string $group Where the cache contents are grouped
73
* @return bool True on successful removal, false on failure
75
function wp_cache_delete($key, $group = '') {
76
global $wp_object_cache;
78
return $wp_object_cache->delete($key, $group);
82
* Removes all cache items.
85
* @uses $wp_object_cache Object Cache Class
86
* @see WP_Object_Cache::flush()
88
* @return bool False on failure, true on success
90
function wp_cache_flush() {
91
global $wp_object_cache;
93
return $wp_object_cache->flush();
97
* Retrieves the cache contents from the cache by key and group.
100
* @uses $wp_object_cache Object Cache Class
101
* @see WP_Object_Cache::get()
103
* @param int|string $key What the contents in the cache are called
104
* @param string $group Where the cache contents are grouped
105
* @param bool $force Whether to force an update of the local cache from the persistent cache (default is false)
106
* @param &bool $found Whether key was found in the cache. Disambiguates a return of false, a storable value.
107
* @return bool|mixed False on failure to retrieve contents or the cache
108
* contents on success
110
function wp_cache_get( $key, $group = '', $force = false, &$found = null ) {
111
global $wp_object_cache;
113
return $wp_object_cache->get( $key, $group, $force, $found );
117
* Increment numeric cache item's value
120
* @uses $wp_object_cache Object Cache Class
121
* @see WP_Object_Cache::incr()
123
* @param int|string $key The cache key to increment
124
* @param int $offset The amount by which to increment the item's value. Default is 1.
125
* @param string $group The group the key is in.
126
* @return false|int False on failure, the item's new value on success.
128
function wp_cache_incr( $key, $offset = 1, $group = '' ) {
129
global $wp_object_cache;
131
return $wp_object_cache->incr( $key, $offset, $group );
135
* Sets up Object Cache Global and assigns it.
138
* @global WP_Object_Cache $wp_object_cache WordPress Object Cache
140
function wp_cache_init() {
141
$GLOBALS['wp_object_cache'] = new WP_Object_Cache();
145
* Replaces the contents of the cache with new data.
148
* @uses $wp_object_cache Object Cache Class
149
* @see WP_Object_Cache::replace()
151
* @param int|string $key What to call the contents in the cache
152
* @param mixed $data The contents to store in the cache
153
* @param string $group Where to group the cache contents
154
* @param int $expire When to expire the cache contents
155
* @return bool False if not exists, true if contents were replaced
157
function wp_cache_replace( $key, $data, $group = '', $expire = 0 ) {
158
global $wp_object_cache;
160
return $wp_object_cache->replace( $key, $data, $group, (int) $expire );
164
* Saves the data to the cache.
168
* @uses $wp_object_cache Object Cache Class
169
* @see WP_Object_Cache::set()
171
* @param int|string $key What to call the contents in the cache
172
* @param mixed $data The contents to store in the cache
173
* @param string $group Where to group the cache contents
174
* @param int $expire When to expire the cache contents
175
* @return bool False on failure, true on success
177
function wp_cache_set( $key, $data, $group = '', $expire = 0 ) {
178
global $wp_object_cache;
180
return $wp_object_cache->set( $key, $data, $group, (int) $expire );
184
* Switch the interal blog id.
186
* This changes the blog id used to create keys in blog specific groups.
190
* @param int $blog_id Blog ID
192
function wp_cache_switch_to_blog( $blog_id ) {
193
global $wp_object_cache;
195
return $wp_object_cache->switch_to_blog( $blog_id );
199
* Adds a group or set of groups to the list of global groups.
203
* @param string|array $groups A group or an array of groups to add
205
function wp_cache_add_global_groups( $groups ) {
206
global $wp_object_cache;
208
return $wp_object_cache->add_global_groups( $groups );
212
* Adds a group or set of groups to the list of non-persistent groups.
216
* @param string|array $groups A group or an array of groups to add
218
function wp_cache_add_non_persistent_groups( $groups ) {
219
// Default cache doesn't persist so nothing to do here.
224
* Reset internal cache keys and structures. If the cache backend uses global
225
* blog or site IDs as part of its cache keys, this function instructs the
226
* backend to reset those keys and perform any cleanup since blog or site IDs
227
* have changed since cache init.
229
* This function is deprecated. Use wp_cache_switch_to_blog() instead of this
230
* function when preparing the cache for a blog switch. For clearing the cache
231
* during unit tests, consider using wp_cache_init(). wp_cache_init() is not
232
* recommended outside of unit tests as the performance penality for using it is
238
function wp_cache_reset() {
239
_deprecated_function( __FUNCTION__, '3.5' );
241
global $wp_object_cache;
243
return $wp_object_cache->reset();
247
* WordPress Object Cache
249
* The WordPress Object Cache is used to save on trips to the database. The
250
* Object Cache stores all of the cache data to memory and makes the cache
251
* contents available by using a key, which is used to name and later retrieve
252
* the cache contents.
254
* The Object Cache can be replaced by other caching mechanisms by placing files
255
* in the wp-content folder which is looked at in wp-settings. If that file
256
* exists, then this file will not be included.
262
class WP_Object_Cache {
265
* Holds the cached objects
271
private $cache = array();
274
* The amount of times the cache data was already stored in the cache.
280
private $cache_hits = 0;
283
* Amount of times the cache did not have the request in cache
289
public $cache_misses = 0;
292
* List of global groups
298
protected $global_groups = array();
301
* The blog prefix to prepend to keys in non-global groups.
307
private $blog_prefix;
310
* Make private properties readable for backwards compatibility.
315
* @param string $name Property to get.
316
* @return mixed Property.
318
public function __get( $name ) {
323
* Make private properties settable for backwards compatibility.
328
* @param string $name Property to set.
329
* @param mixed $value Property value.
330
* @return mixed Newly-set property.
332
public function __set( $name, $value ) {
333
return $this->$name = $value;
337
* Make private properties checkable for backwards compatibility.
342
* @param string $name Property to check if set.
343
* @return bool Whether the property is set.
345
public function __isset( $name ) {
346
return isset( $this->$name );
350
* Make private properties un-settable for backwards compatibility.
355
* @param string $name Property to unset.
357
public function __unset( $name ) {
358
unset( $this->$name );
362
* Adds data to the cache if it doesn't already exist.
364
* @uses WP_Object_Cache::_exists Checks to see if the cache already has data.
365
* @uses WP_Object_Cache::set Sets the data after the checking the cache
366
* contents existence.
370
* @param int|string $key What to call the contents in the cache
371
* @param mixed $data The contents to store in the cache
372
* @param string $group Where to group the cache contents
373
* @param int $expire When to expire the cache contents
374
* @return bool False if cache key and group already exist, true on success
376
public function add( $key, $data, $group = 'default', $expire = 0 ) {
377
if ( wp_suspend_cache_addition() )
380
if ( empty( $group ) )
384
if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
385
$id = $this->blog_prefix . $key;
387
if ( $this->_exists( $id, $group ) )
390
return $this->set( $key, $data, $group, (int) $expire );
394
* Sets the list of global groups.
398
* @param array $groups List of groups that are global.
400
public function add_global_groups( $groups ) {
401
$groups = (array) $groups;
403
$groups = array_fill_keys( $groups, true );
404
$this->global_groups = array_merge( $this->global_groups, $groups );
408
* Decrement numeric cache item's value
412
* @param int|string $key The cache key to increment
413
* @param int $offset The amount by which to decrement the item's value. Default is 1.
414
* @param string $group The group the key is in.
415
* @return false|int False on failure, the item's new value on success.
417
public function decr( $key, $offset = 1, $group = 'default' ) {
418
if ( empty( $group ) )
421
if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
422
$key = $this->blog_prefix . $key;
424
if ( ! $this->_exists( $key, $group ) )
427
if ( ! is_numeric( $this->cache[ $group ][ $key ] ) )
428
$this->cache[ $group ][ $key ] = 0;
430
$offset = (int) $offset;
432
$this->cache[ $group ][ $key ] -= $offset;
434
if ( $this->cache[ $group ][ $key ] < 0 )
435
$this->cache[ $group ][ $key ] = 0;
437
return $this->cache[ $group ][ $key ];
441
* Remove the contents of the cache key in the group
443
* If the cache key does not exist in the group, then nothing will happen.
447
* @param int|string $key What the contents in the cache are called
448
* @param string $group Where the cache contents are grouped
449
* @param bool $deprecated Deprecated.
451
* @return bool False if the contents weren't deleted and true on success
453
public function delete( $key, $group = 'default', $deprecated = false ) {
454
if ( empty( $group ) )
457
if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
458
$key = $this->blog_prefix . $key;
460
if ( ! $this->_exists( $key, $group ) )
463
unset( $this->cache[$group][$key] );
468
* Clears the object cache of all data
472
* @return bool Always returns true
474
public function flush() {
475
$this->cache = array ();
481
* Retrieves the cache contents, if it exists
483
* The contents will be first attempted to be retrieved by searching by the
484
* key in the cache group. If the cache is hit (success) then the contents
487
* On failure, the number of cache misses will be incremented.
491
* @param int|string $key What the contents in the cache are called
492
* @param string $group Where the cache contents are grouped
493
* @param string $force Whether to force a refetch rather than relying on the local cache (default is false)
494
* @return bool|mixed False on failure to retrieve contents or the cache
495
* contents on success
497
public function get( $key, $group = 'default', $force = false, &$found = null ) {
498
if ( empty( $group ) )
501
if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
502
$key = $this->blog_prefix . $key;
504
if ( $this->_exists( $key, $group ) ) {
506
$this->cache_hits += 1;
507
if ( is_object($this->cache[$group][$key]) )
508
return clone $this->cache[$group][$key];
510
return $this->cache[$group][$key];
514
$this->cache_misses += 1;
519
* Increment numeric cache item's value
523
* @param int|string $key The cache key to increment
524
* @param int $offset The amount by which to increment the item's value. Default is 1.
525
* @param string $group The group the key is in.
526
* @return false|int False on failure, the item's new value on success.
528
public function incr( $key, $offset = 1, $group = 'default' ) {
529
if ( empty( $group ) )
532
if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
533
$key = $this->blog_prefix . $key;
535
if ( ! $this->_exists( $key, $group ) )
538
if ( ! is_numeric( $this->cache[ $group ][ $key ] ) )
539
$this->cache[ $group ][ $key ] = 0;
541
$offset = (int) $offset;
543
$this->cache[ $group ][ $key ] += $offset;
545
if ( $this->cache[ $group ][ $key ] < 0 )
546
$this->cache[ $group ][ $key ] = 0;
548
return $this->cache[ $group ][ $key ];
552
* Replace the contents in the cache, if contents already exist
555
* @see WP_Object_Cache::set()
557
* @param int|string $key What to call the contents in the cache
558
* @param mixed $data The contents to store in the cache
559
* @param string $group Where to group the cache contents
560
* @param int $expire When to expire the cache contents
561
* @return bool False if not exists, true if contents were replaced
563
public function replace( $key, $data, $group = 'default', $expire = 0 ) {
564
if ( empty( $group ) )
568
if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
569
$id = $this->blog_prefix . $key;
571
if ( ! $this->_exists( $id, $group ) )
574
return $this->set( $key, $data, $group, (int) $expire );
583
public function reset() {
584
_deprecated_function( __FUNCTION__, '3.5', 'switch_to_blog()' );
586
// Clear out non-global caches since the blog ID has changed.
587
foreach ( array_keys( $this->cache ) as $group ) {
588
if ( ! isset( $this->global_groups[ $group ] ) )
589
unset( $this->cache[ $group ] );
594
* Sets the data contents into the cache
596
* The cache contents is grouped by the $group parameter followed by the
597
* $key. This allows for duplicate ids in unique groups. Therefore, naming of
598
* the group should be used with care and should follow normal function
599
* naming guidelines outside of core WordPress usage.
601
* The $expire parameter is not used, because the cache will automatically
602
* expire for each time a page is accessed and PHP finishes. The method is
603
* more for cache plugins which use files.
607
* @param int|string $key What to call the contents in the cache
608
* @param mixed $data The contents to store in the cache
609
* @param string $group Where to group the cache contents
610
* @param int $expire Not Used
611
* @return bool Always returns true
613
public function set( $key, $data, $group = 'default', $expire = 0 ) {
614
if ( empty( $group ) )
617
if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
618
$key = $this->blog_prefix . $key;
620
if ( is_object( $data ) )
623
$this->cache[$group][$key] = $data;
628
* Echoes the stats of the caching.
630
* Gives the cache hits, and cache misses. Also prints every cached group,
635
public function stats() {
637
echo "<strong>Cache Hits:</strong> {$this->cache_hits}<br />";
638
echo "<strong>Cache Misses:</strong> {$this->cache_misses}<br />";
641
foreach ($this->cache as $group => $cache) {
642
echo "<li><strong>Group:</strong> $group - ( " . number_format( strlen( serialize( $cache ) ) / 1024, 2 ) . 'k )</li>';
648
* Switch the interal blog id.
650
* This changes the blog id used to create keys in blog specific groups.
654
* @param int $blog_id Blog ID
656
public function switch_to_blog( $blog_id ) {
657
$blog_id = (int) $blog_id;
658
$this->blog_prefix = $this->multisite ? $blog_id . ':' : '';
662
* Utility function to determine whether a key exists in the cache.
668
protected function _exists( $key, $group ) {
669
return isset( $this->cache[ $group ] ) && ( isset( $this->cache[ $group ][ $key ] ) || array_key_exists( $key, $this->cache[ $group ] ) );
673
* Sets up object properties; PHP 5 style constructor
676
* @return null|WP_Object_Cache If cache is disabled, returns null.
678
public function __construct() {
681
$this->multisite = is_multisite();
682
$this->blog_prefix = $this->multisite ? $blog_id . ':' : '';
686
* @todo This should be moved to the PHP4 style constructor, PHP5
687
* already calls __destruct()
689
register_shutdown_function( array( $this, '__destruct' ) );
693
* Will save the object cache before object is completely destroyed.
695
* Called upon object destruction, which should be when PHP ends.
699
* @return bool True value. Won't be used by PHP
701
public function __destruct() {
added
removed
wp-includes/cache.php
