Projects : mp-wp : mp-wp_genesis
1 | <?php |
2 | /** |
3 | * Object Cache API |
4 | * |
5 | * @link http://codex.wordpress.org/Function_Reference/WP_Cache |
6 | * |
7 | * @package WordPress |
8 | * @subpackage Cache |
9 | */ |
10 | |
11 | /** |
12 | * Adds data to the cache, if the cache key doesn't aleady exist. |
13 | * |
14 | * @since 2.0.0 |
15 | * @uses $wp_object_cache Object Cache Class |
16 | * @see WP_Object_Cache::add() |
17 | * |
18 | * @param int|string $key The cache ID to use for retrieval later |
19 | * @param mixed $data The data to add to the cache store |
20 | * @param string $flag The group to add the cache to |
21 | * @param int $expire When the cache data should be expired |
22 | * @return unknown |
23 | */ |
24 | function wp_cache_add($key, $data, $flag = '', $expire = 0) { |
25 | global $wp_object_cache; |
26 | |
27 | return $wp_object_cache->add($key, $data, $flag, $expire); |
28 | } |
29 | |
30 | /** |
31 | * Closes the cache. |
32 | * |
33 | * This function has ceased to do anything since WordPress 2.5. The |
34 | * functionality was removed along with the rest of the persistant 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. |
37 | * |
38 | * @since 2.0.0 |
39 | * |
40 | * @return bool Always returns True |
41 | */ |
42 | function wp_cache_close() { |
43 | return true; |
44 | } |
45 | |
46 | /** |
47 | * Removes the cache contents matching ID and flag. |
48 | * |
49 | * @since 2.0.0 |
50 | * @uses $wp_object_cache Object Cache Class |
51 | * @see WP_Object_Cache::delete() |
52 | * |
53 | * @param int|string $id What the contents in the cache are called |
54 | * @param string $flag Where the cache contents are grouped |
55 | * @return bool True on successful removal, false on failure |
56 | */ |
57 | function wp_cache_delete($id, $flag = '') { |
58 | global $wp_object_cache; |
59 | |
60 | return $wp_object_cache->delete($id, $flag); |
61 | } |
62 | |
63 | /** |
64 | * Removes all cache items. |
65 | * |
66 | * @since 2.0.0 |
67 | * @uses $wp_object_cache Object Cache Class |
68 | * @see WP_Object_Cache::flush() |
69 | * |
70 | * @return bool Always returns true |
71 | */ |
72 | function wp_cache_flush() { |
73 | global $wp_object_cache; |
74 | |
75 | return $wp_object_cache->flush(); |
76 | } |
77 | |
78 | /** |
79 | * Retrieves the cache contents from the cache by ID and flag. |
80 | * |
81 | * @since 2.0.0 |
82 | * @uses $wp_object_cache Object Cache Class |
83 | * @see WP_Object_Cache::get() |
84 | * |
85 | * @param int|string $id What the contents in the cache are called |
86 | * @param string $flag Where the cache contents are grouped |
87 | * @return bool|mixed False on failure to retrieve contents or the cache |
88 | * contents on success |
89 | */ |
90 | function wp_cache_get($id, $flag = '') { |
91 | global $wp_object_cache; |
92 | |
93 | return $wp_object_cache->get($id, $flag); |
94 | } |
95 | |
96 | /** |
97 | * Sets up Object Cache Global and assigns it. |
98 | * |
99 | * @since 2.0.0 |
100 | * @global WP_Object_Cache $wp_object_cache WordPress Object Cache |
101 | */ |
102 | function wp_cache_init() { |
103 | $GLOBALS['wp_object_cache'] = new WP_Object_Cache(); |
104 | } |
105 | |
106 | /** |
107 | * Replaces the contents of the cache with new data. |
108 | * |
109 | * @since 2.0.0 |
110 | * @uses $wp_object_cache Object Cache Class |
111 | * @see WP_Object_Cache::replace() |
112 | * |
113 | * @param int|string $id What to call the contents in the cache |
114 | * @param mixed $data The contents to store in the cache |
115 | * @param string $flag Where to group the cache contents |
116 | * @param int $expire When to expire the cache contents |
117 | * @return bool False if cache ID and group already exists, true on success |
118 | */ |
119 | function wp_cache_replace($key, $data, $flag = '', $expire = 0) { |
120 | global $wp_object_cache; |
121 | |
122 | return $wp_object_cache->replace($key, $data, $flag, $expire); |
123 | } |
124 | |
125 | /** |
126 | * Saves the data to the cache. |
127 | * |
128 | * @since 2.0 |
129 | * @uses $wp_object_cache Object Cache Class |
130 | * @see WP_Object_Cache::set() |
131 | * |
132 | * @param int|string $id What to call the contents in the cache |
133 | * @param mixed $data The contents to store in the cache |
134 | * @param string $flag Where to group the cache contents |
135 | * @param int $expire When to expire the cache contents |
136 | * @return bool False if cache ID and group already exists, true on success |
137 | */ |
138 | function wp_cache_set($key, $data, $flag = '', $expire = 0) { |
139 | global $wp_object_cache; |
140 | |
141 | return $wp_object_cache->set($key, $data, $flag, $expire); |
142 | } |
143 | |
144 | /** |
145 | * Adds a group or set of groups to the list of global groups. |
146 | * |
147 | * @since 2.6.0 |
148 | * |
149 | * @param string|array $groups A group or an array of groups to add |
150 | */ |
151 | function wp_cache_add_global_groups( $groups ) { |
152 | // Default cache doesn't persist so nothing to do here. |
153 | return; |
154 | } |
155 | |
156 | /** |
157 | * Adds a group or set of groups to the list of non-persistent groups. |
158 | * |
159 | * @since 2.6.0 |
160 | * |
161 | * @param string|array $groups A group or an array of groups to add |
162 | */ |
163 | function wp_cache_add_non_persistent_groups( $groups ) { |
164 | // Default cache doesn't persist so nothing to do here. |
165 | return; |
166 | } |
167 | |
168 | /** |
169 | * WordPress Object Cache |
170 | * |
171 | * The WordPress Object Cache is used to save on trips to the database. The |
172 | * Object Cache stores all of the cache data to memory and makes the cache |
173 | * contents available by using a key, which is used to name and later retrieve |
174 | * the cache contents. |
175 | * |
176 | * The Object Cache can be replaced by other caching mechanisms by placing files |
177 | * in the wp-content folder which is looked at in wp-settings. If that file |
178 | * exists, then this file will not be included. |
179 | * |
180 | * @package WordPress |
181 | * @subpackage Cache |
182 | * @since 2.0 |
183 | */ |
184 | class WP_Object_Cache { |
185 | |
186 | /** |
187 | * Holds the cached objects |
188 | * |
189 | * @var array |
190 | * @access private |
191 | * @since 2.0.0 |
192 | */ |
193 | var $cache = array (); |
194 | |
195 | /** |
196 | * Cache objects that do not exist in the cache |
197 | * |
198 | * @var array |
199 | * @access private |
200 | * @since 2.0.0 |
201 | */ |
202 | var $non_existant_objects = array (); |
203 | |
204 | /** |
205 | * The amount of times the cache data was already stored in the cache. |
206 | * |
207 | * @since 2.5.0 |
208 | * @access private |
209 | * @var int |
210 | */ |
211 | var $cache_hits = 0; |
212 | |
213 | /** |
214 | * Amount of times the cache did not have the request in cache |
215 | * |
216 | * @var int |
217 | * @access public |
218 | * @since 2.0.0 |
219 | */ |
220 | var $cache_misses = 0; |
221 | |
222 | /** |
223 | * Adds data to the cache if it doesn't already exist. |
224 | * |
225 | * @uses WP_Object_Cache::get Checks to see if the cache already has data. |
226 | * @uses WP_Object_Cache::set Sets the data after the checking the cache |
227 | * contents existance. |
228 | * |
229 | * @since 2.0.0 |
230 | * |
231 | * @param int|string $id What to call the contents in the cache |
232 | * @param mixed $data The contents to store in the cache |
233 | * @param string $group Where to group the cache contents |
234 | * @param int $expire When to expire the cache contents |
235 | * @return bool False if cache ID and group already exists, true on success |
236 | */ |
237 | function add($id, $data, $group = 'default', $expire = '') { |
238 | if (empty ($group)) |
239 | $group = 'default'; |
240 | |
241 | if (false !== $this->get($id, $group, false)) |
242 | return false; |
243 | |
244 | return $this->set($id, $data, $group, $expire); |
245 | } |
246 | |
247 | /** |
248 | * Remove the contents of the cache ID in the group |
249 | * |
250 | * If the cache ID does not exist in the group and $force parameter is set |
251 | * to false, then nothing will happen. The $force parameter is set to false |
252 | * by default. |
253 | * |
254 | * On success the group and the id will be added to the |
255 | * $non_existant_objects property in the class. |
256 | * |
257 | * @since 2.0.0 |
258 | * |
259 | * @param int|string $id What the contents in the cache are called |
260 | * @param string $group Where the cache contents are grouped |
261 | * @param bool $force Optional. Whether to force the unsetting of the cache |
262 | * ID in the group |
263 | * @return bool False if the contents weren't deleted and true on success |
264 | */ |
265 | function delete($id, $group = 'default', $force = false) { |
266 | if (empty ($group)) |
267 | $group = 'default'; |
268 | |
269 | if (!$force && false === $this->get($id, $group, false)) |
270 | return false; |
271 | |
272 | unset ($this->cache[$group][$id]); |
273 | $this->non_existant_objects[$group][$id] = true; |
274 | return true; |
275 | } |
276 | |
277 | /** |
278 | * Clears the object cache of all data |
279 | * |
280 | * @since 2.0.0 |
281 | * |
282 | * @return bool Always returns true |
283 | */ |
284 | function flush() { |
285 | $this->cache = array (); |
286 | |
287 | return true; |
288 | } |
289 | |
290 | /** |
291 | * Retrieves the cache contents, if it exists |
292 | * |
293 | * The contents will be first attempted to be retrieved by searching by the |
294 | * ID in the cache group. If the cache is hit (success) then the contents |
295 | * are returned. |
296 | * |
297 | * On failure, the $non_existant_objects property is checked and if the |
298 | * cache group and ID exist in there the cache misses will not be |
299 | * incremented. If not in the nonexistant objects property, then the cache |
300 | * misses will be incremented and the cache group and ID will be added to |
301 | * the nonexistant objects. |
302 | * |
303 | * @since 2.0.0 |
304 | * |
305 | * @param int|string $id What the contents in the cache are called |
306 | * @param string $group Where the cache contents are grouped |
307 | * @return bool|mixed False on failure to retrieve contents or the cache |
308 | * contents on success |
309 | */ |
310 | function get($id, $group = 'default') { |
311 | if (empty ($group)) |
312 | $group = 'default'; |
313 | |
314 | if (isset ($this->cache[$group][$id])) { |
315 | $this->cache_hits += 1; |
316 | if ( is_object($this->cache[$group][$id]) ) |
317 | return wp_clone($this->cache[$group][$id]); |
318 | else |
319 | return $this->cache[$group][$id]; |
320 | } |
321 | |
322 | if ( isset ($this->non_existant_objects[$group][$id]) ) |
323 | return false; |
324 | |
325 | $this->non_existant_objects[$group][$id] = true; |
326 | $this->cache_misses += 1; |
327 | return false; |
328 | } |
329 | |
330 | /** |
331 | * Replace the contents in the cache, if contents already exist |
332 | * |
333 | * @since 2.0.0 |
334 | * @see WP_Object_Cache::set() |
335 | * |
336 | * @param int|string $id What to call the contents in the cache |
337 | * @param mixed $data The contents to store in the cache |
338 | * @param string $group Where to group the cache contents |
339 | * @param int $expire When to expire the cache contents |
340 | * @return bool False if not exists, true if contents were replaced |
341 | */ |
342 | function replace($id, $data, $group = 'default', $expire = '') { |
343 | if (empty ($group)) |
344 | $group = 'default'; |
345 | |
346 | if (false === $this->get($id, $group, false)) |
347 | return false; |
348 | |
349 | return $this->set($id, $data, $group, $expire); |
350 | } |
351 | |
352 | /** |
353 | * Sets the data contents into the cache |
354 | * |
355 | * The cache contents is grouped by the $group parameter followed by the |
356 | * $id. This allows for duplicate ids in unique groups. Therefore, naming of |
357 | * the group should be used with care and should follow normal function |
358 | * naming guidelines outside of core WordPress usage. |
359 | * |
360 | * The $expire parameter is not used, because the cache will automatically |
361 | * expire for each time a page is accessed and PHP finishes. The method is |
362 | * more for cache plugins which use files. |
363 | * |
364 | * @since 2.0.0 |
365 | * |
366 | * @param int|string $id What to call the contents in the cache |
367 | * @param mixed $data The contents to store in the cache |
368 | * @param string $group Where to group the cache contents |
369 | * @param int $expire Not Used |
370 | * @return bool Always returns true |
371 | */ |
372 | function set($id, $data, $group = 'default', $expire = '') { |
373 | if (empty ($group)) |
374 | $group = 'default'; |
375 | |
376 | if (NULL === $data) |
377 | $data = ''; |
378 | |
379 | if ( is_object($data) ) |
380 | $data = wp_clone($data); |
381 | |
382 | $this->cache[$group][$id] = $data; |
383 | |
384 | if(isset($this->non_existant_objects[$group][$id])) |
385 | unset ($this->non_existant_objects[$group][$id]); |
386 | |
387 | return true; |
388 | } |
389 | |
390 | /** |
391 | * Echos the stats of the caching. |
392 | * |
393 | * Gives the cache hits, and cache misses. Also prints every cached group, |
394 | * key and the data. |
395 | * |
396 | * @since 2.0.0 |
397 | */ |
398 | function stats() { |
399 | echo "<p>"; |
400 | echo "<strong>Cache Hits:</strong> {$this->cache_hits}<br />"; |
401 | echo "<strong>Cache Misses:</strong> {$this->cache_misses}<br />"; |
402 | echo "</p>"; |
403 | |
404 | foreach ($this->cache as $group => $cache) { |
405 | echo "<p>"; |
406 | echo "<strong>Group:</strong> $group<br />"; |
407 | echo "<strong>Cache:</strong>"; |
408 | echo "<pre>"; |
409 | print_r($cache); |
410 | echo "</pre>"; |
411 | } |
412 | } |
413 | |
414 | /** |
415 | * PHP4 constructor; Calls PHP 5 style constructor |
416 | * |
417 | * @since 2.0.0 |
418 | * |
419 | * @return WP_Object_Cache |
420 | */ |
421 | function WP_Object_Cache() { |
422 | return $this->__construct(); |
423 | } |
424 | |
425 | /** |
426 | * Sets up object properties; PHP 5 style constructor |
427 | * |
428 | * @since 2.0.8 |
429 | * @return null|WP_Object_Cache If cache is disabled, returns null. |
430 | */ |
431 | function __construct() { |
432 | /** |
433 | * @todo This should be moved to the PHP4 style constructor, PHP5 |
434 | * already calls __destruct() |
435 | */ |
436 | register_shutdown_function(array(&$this, "__destruct")); |
437 | } |
438 | |
439 | /** |
440 | * Will save the object cache before object is completely destroyed. |
441 | * |
442 | * Called upon object destruction, which should be when PHP ends. |
443 | * |
444 | * @since 2.0.8 |
445 | * |
446 | * @return bool True value. Won't be used by PHP |
447 | */ |
448 | function __destruct() { |
449 | return true; |
450 | } |
451 | } |
452 | ?> |