Wordpress 2.0.4
[autoinstalls/wordpress.git] / wp-includes / cache.php
1 <?php
2 function wp_cache_add($key, $data, $flag = '', $expire = 0) {
3         global $wp_object_cache;
4
5         return $wp_object_cache->add($key, $data, $flag, $expire);
6 }
7
8 function wp_cache_close() {
9         global $wp_object_cache;
10
11         return $wp_object_cache->save();
12 }
13
14 function wp_cache_delete($id, $flag = '') {
15         global $wp_object_cache;
16
17         return $wp_object_cache->delete($id, $flag);
18 }
19
20 function wp_cache_flush() {
21         global $wp_object_cache;
22
23         return $wp_object_cache->flush();
24 }
25
26 function wp_cache_get($id, $flag = '') {
27         global $wp_object_cache;
28
29         return $wp_object_cache->get($id, $flag);
30 }
31
32 function wp_cache_init() {
33         global $wp_object_cache;
34
35         $wp_object_cache = new WP_Object_Cache();
36 }
37
38 function wp_cache_replace($key, $data, $flag = '', $expire = 0) {
39         global $wp_object_cache;
40
41         return $wp_object_cache->replace($key, $data, $flag, $expire);
42 }
43
44 function wp_cache_set($key, $data, $flag = '', $expire = 0) {
45         global $wp_object_cache;
46
47         return $wp_object_cache->set($key, $data, $flag, $expire);
48 }
49
50 define('CACHE_SERIAL_HEADER', "<?php\n/*");
51 define('CACHE_SERIAL_FOOTER', "*/\n?".">");
52
53 class WP_Object_Cache {
54         var $cache_dir;
55         var $cache_enabled = false;
56         var $expiration_time = 900;
57         var $flock_filename = 'wp_object_cache.lock';
58         var $mutex;
59         var $cache = array ();
60         var $dirty_objects = array ();
61         var $non_existant_objects = array ();
62         var $global_groups = array ('users', 'userlogins', 'usermeta');
63         var $blog_id;
64         var $cold_cache_hits = 0;
65         var $warm_cache_hits = 0;
66         var $cache_misses = 0;
67         var $secret = '';
68
69         function acquire_lock() {
70                 // Acquire a write lock. 
71                 $this->mutex = @fopen($this->cache_dir.$this->flock_filename, 'w');
72                 if ( false == $this->mutex)
73                         return false;
74                 flock($this->mutex, LOCK_EX);
75                 return true;
76         }
77
78         function add($id, $data, $group = 'default', $expire = '') {
79                 if (empty ($group))
80                         $group = 'default';
81
82                 if (false !== $this->get($id, $group, false))
83                         return false;
84
85                 return $this->set($id, $data, $group, $expire);
86         }
87
88         function delete($id, $group = 'default', $force = false) {
89                 if (empty ($group))
90                         $group = 'default';
91
92                 if (!$force && false === $this->get($id, $group, false))
93                         return false;
94
95                 unset ($this->cache[$group][$id]);
96                 $this->non_existant_objects[$group][$id] = true;
97                 $this->dirty_objects[$group][] = $id;
98                 return true;
99         }
100
101         function flush() {
102                 if ( !$this->cache_enabled )
103                         return true;
104
105                 if ( ! $this->acquire_lock() )
106                         return false;
107
108                 $this->rm_cache_dir();
109                 $this->cache = array ();
110                 $this->dirty_objects = array ();
111                 $this->non_existant_objects = array ();
112                 
113                 $this->release_lock();
114
115                 return true;
116         }
117
118         function get($id, $group = 'default', $count_hits = true) {
119                 if (empty ($group))
120                         $group = 'default';
121
122                 if (isset ($this->cache[$group][$id])) {
123                         if ($count_hits)
124                                 $this->warm_cache_hits += 1;
125                         return $this->cache[$group][$id];
126                 }
127
128                 if (isset ($this->non_existant_objects[$group][$id]))
129                         return false;
130
131                 //  If caching is not enabled, we have to fall back to pulling from the DB.
132                 if (!$this->cache_enabled) {
133                         if (!isset ($this->cache[$group]))
134                                 $this->load_group_from_db($group);
135
136                         if (isset ($this->cache[$group][$id])) {
137                                 $this->cold_cache_hits += 1;
138                                 return $this->cache[$group][$id];
139                         }
140
141                         $this->non_existant_objects[$group][$id] = true;
142                         $this->cache_misses += 1;
143                         return false;
144                 }
145
146                 $cache_file = $this->cache_dir.$this->get_group_dir($group)."/".$this->hash($id).'.php';
147                 if (!file_exists($cache_file)) {
148                         $this->non_existant_objects[$group][$id] = true;
149                         $this->cache_misses += 1;
150                         return false;
151                 }
152
153                 // If the object has expired, remove it from the cache and return false to force
154                 // a refresh.
155                 $now = time();
156                 if ((filemtime($cache_file) + $this->expiration_time) <= $now) {
157                         $this->cache_misses += 1;
158                         $this->delete($id, $group, true);
159                         return false;
160                 }
161
162                 $this->cache[$group][$id] = unserialize(base64_decode(substr(@ file_get_contents($cache_file), strlen(CACHE_SERIAL_HEADER), -strlen(CACHE_SERIAL_FOOTER))));
163                 if (false === $this->cache[$group][$id])
164                         $this->cache[$group][$id] = '';
165
166                 $this->cold_cache_hits += 1;
167                 return $this->cache[$group][$id];
168         }
169
170         function get_group_dir($group) {
171                 if (false !== array_search($group, $this->global_groups))
172                         return $group;
173
174                 return "{$this->blog_id}/$group";
175         }
176
177         function hash($data) {
178                 if ( function_exists('hash_hmac') ) {
179                         return hash_hmac('md5', $data, $this->secret);
180                 } else {
181                         return md5($data . $this->secret);
182                 }
183         }
184
185         function load_group_from_db($group) {
186                 global $wpdb;
187
188                 if ('category' == $group) {
189                         $this->cache['category'] = array ();
190                         if ($dogs = $wpdb->get_results("SELECT * FROM $wpdb->categories")) {
191                                 foreach ($dogs as $catt)
192                                         $this->cache['category'][$catt->cat_ID] = $catt;
193
194                                 foreach ($this->cache['category'] as $catt) {
195                                         $curcat = $catt->cat_ID;
196                                         $fullpath = '/'.$this->cache['category'][$catt->cat_ID]->category_nicename;
197                                         while ($this->cache['category'][$curcat]->category_parent != 0) {
198                                                 $curcat = $this->cache['category'][$curcat]->category_parent;
199                                                 $fullpath = '/'.$this->cache['category'][$curcat]->category_nicename.$fullpath;
200                                         }
201                                         $this->cache['category'][$catt->cat_ID]->fullpath = $fullpath;
202                                 }
203                         }
204                 } else
205                         if ('options' == $group) {
206                                 $wpdb->hide_errors();
207                                 if (!$options = $wpdb->get_results("SELECT option_name, option_value FROM $wpdb->options WHERE autoload = 'yes'")) {
208                                         $options = $wpdb->get_results("SELECT option_name, option_value FROM $wpdb->options");
209                                 }
210                                 $wpdb->show_errors();
211
212                                 if ( ! $options )
213                                         return;
214
215                                 foreach ($options as $option) {
216                                         $this->cache['options'][$option->option_name] = $option->option_value;
217                                 }
218                         }
219         }
220
221         function make_group_dir($group, $perms) {
222                 $group_dir = $this->get_group_dir($group);
223                 $make_dir = '';
224                 foreach (split('/', $group_dir) as $subdir) {
225                         $make_dir .= "$subdir/";
226                         if (!file_exists($this->cache_dir.$make_dir)) {
227                                 if (! @ mkdir($this->cache_dir.$make_dir))
228                                         break;
229                                 @ chmod($this->cache_dir.$make_dir, $perms);
230                         }
231
232                         if (!file_exists($this->cache_dir.$make_dir."index.php")) {
233                                 $file_perms = $perms & 0000666;
234                                 @ touch($this->cache_dir.$make_dir."index.php");
235                                 @ chmod($this->cache_dir.$make_dir."index.php", $file_perms);
236                         }
237                 }
238
239                 return $this->cache_dir."$group_dir/";
240         }
241
242         function rm_cache_dir() {
243                 $dir = $this->cache_dir;
244                 $dir = rtrim($dir, DIRECTORY_SEPARATOR);
245                 $top_dir = $dir;
246                 $stack = array($dir);
247                 $index = 0;
248
249                 while ($index < count($stack)) {
250                         # Get indexed directory from stack
251                         $dir = $stack[$index];
252       
253                         $dh = @ opendir($dir);
254                         if (!$dh)
255                                 return false;
256       
257                         while (($file = @ readdir($dh)) !== false) {
258                                 if ($file == '.' or $file == '..')
259                                         continue;
260                                         
261                                 if (@ is_dir($dir . DIRECTORY_SEPARATOR . $file))
262                                         $stack[] = $dir . DIRECTORY_SEPARATOR . $file;
263                                 else if (@ is_file($dir . DIRECTORY_SEPARATOR . $file))
264                                         @ unlink($dir . DIRECTORY_SEPARATOR . $file);
265                         }
266
267                         $index++;
268                 }
269
270                 $stack = array_reverse($stack);  // Last added dirs are deepest
271                 foreach($stack as $dir) {
272                         if ( $dir != $top_dir)
273                                 @ rmdir($dir);
274                 }
275
276         }
277
278         function release_lock() {
279                 // Release write lock.
280                 flock($this->mutex, LOCK_UN);
281                 fclose($this->mutex);
282         }
283
284         function replace($id, $data, $group = 'default', $expire = '') {
285                 if (empty ($group))
286                         $group = 'default';
287
288                 if (false === $this->get($id, $group, false))
289                         return false;
290
291                 return $this->set($id, $data, $group, $expire);
292         }
293
294         function set($id, $data, $group = 'default', $expire = '') {
295                 if (empty ($group))
296                         $group = 'default';
297
298                 if (NULL == $data)
299                         $data = '';
300
301                 $this->cache[$group][$id] = $data;
302                 unset ($this->non_existant_objects[$group][$id]);
303                 $this->dirty_objects[$group][] = $id;
304
305                 return true;
306         }
307
308         function save() {
309                 //$this->stats();
310
311                 if (!$this->cache_enabled)
312                         return true;
313
314                 if (empty ($this->dirty_objects))
315                         return true;
316
317                 // Give the new dirs the same perms as wp-content.
318                 $stat = stat(ABSPATH.'wp-content');
319                 $dir_perms = $stat['mode'] & 0007777; // Get the permission bits.
320                 $file_perms = $dir_perms & 0000666; // Remove execute bits for files.
321
322                 // Make the base cache dir.
323                 if (!file_exists($this->cache_dir)) {
324                         if (! @ mkdir($this->cache_dir))
325                                 return false;
326                         @ chmod($this->cache_dir, $dir_perms);
327                 }
328
329                 if (!file_exists($this->cache_dir."index.php")) {
330                         @ touch($this->cache_dir."index.php");
331                         @ chmod($this->cache_dir."index.php", $file_perms);
332                 }
333
334                 if ( ! $this->acquire_lock() )
335                         return false;
336
337                 // Loop over dirty objects and save them.
338                 $errors = 0;
339                 foreach ($this->dirty_objects as $group => $ids) {
340                         $group_dir = $this->make_group_dir($group, $dir_perms);
341
342                         $ids = array_unique($ids);
343                         foreach ($ids as $id) {
344                                 $cache_file = $group_dir.$this->hash($id).'.php';
345
346                                 // Remove the cache file if the key is not set.
347                                 if (!isset ($this->cache[$group][$id])) {
348                                         if (file_exists($cache_file))
349                                                 @ unlink($cache_file);
350                                         continue;
351                                 }
352
353                                 $temp_file = tempnam($group_dir, 'tmp');
354                                 $serial = CACHE_SERIAL_HEADER.base64_encode(serialize($this->cache[$group][$id])).CACHE_SERIAL_FOOTER;
355                                 $fd = @fopen($temp_file, 'w');
356                                 if ( false === $fd ) {
357                                         $errors++;
358                                         continue;
359                                 }
360                                 fputs($fd, $serial);
361                                 fclose($fd);
362                                 if (!@ rename($temp_file, $cache_file)) {
363                                         if (@ copy($temp_file, $cache_file))
364                                                 @ unlink($temp_file);
365                                         else
366                                                 $errors++;      
367                                 }
368                                 @ chmod($cache_file, $file_perms);
369                         }
370                 }
371
372                 $this->dirty_objects = array();
373
374                 $this->release_lock();
375                 
376                 if ( $errors )
377                         return false;
378
379                 return true;
380         }
381
382         function stats() {
383                 echo "<p>";
384                 echo "<strong>Cold Cache Hits:</strong> {$this->cold_cache_hits}<br/>";
385                 echo "<strong>Warm Cache Hits:</strong> {$this->warm_cache_hits}<br/>";
386                 echo "<strong>Cache Misses:</strong> {$this->cache_misses}<br/>";
387                 echo "</p>";
388
389                 foreach ($this->cache as $group => $cache) {
390                         echo "<p>";
391                         echo "<strong>Group:</strong> $group<br/>";
392                         echo "<strong>Cache:</strong>";
393                         echo "<pre>";
394                         print_r($cache);
395                         echo "</pre>";
396                         if (isset ($this->dirty_objects[$group])) {
397                                 echo "<strong>Dirty Objects:</strong>";
398                                 echo "<pre>";
399                                 print_r(array_unique($this->dirty_objects[$group]));
400                                 echo "</pre>";
401                                 echo "</p>";
402                         }
403                 }
404         }
405
406         function WP_Object_Cache() {
407                 global $blog_id;
408
409                 if (defined('DISABLE_CACHE'))
410                         return;
411
412                 if ( ! defined('ENABLE_CACHE') )
413                         return;
414
415                 // Disable the persistent cache if safe_mode is on.
416                 if ( ini_get('safe_mode') && ! defined('ENABLE_CACHE') )
417                         return;
418
419                 if (defined('CACHE_PATH'))
420                         $this->cache_dir = CACHE_PATH;
421                 else
422                         // Using the correct separator eliminates some cache flush errors on Windows
423                         $this->cache_dir = ABSPATH.'wp-content'.DIRECTORY_SEPARATOR.'cache'.DIRECTORY_SEPARATOR;
424
425                 if (is_writable($this->cache_dir) && is_dir($this->cache_dir)) {
426                                 $this->cache_enabled = true;
427                 } else {
428                         if (is_writable(ABSPATH.'wp-content')) {
429                                 $this->cache_enabled = true;
430                         }
431                 }
432
433                 if (defined('CACHE_EXPIRATION_TIME'))
434                         $this->expiration_time = CACHE_EXPIRATION_TIME;
435
436                 if ( defined('WP_SECRET') )
437                         $this->secret = WP_SECRET;
438                 else
439                         $this->secret = DB_PASSWORD . DB_USER . DB_NAME . DB_HOST . ABSPATH;
440
441                 $this->blog_id = $this->hash($blog_id);
442         }
443 }
444 ?>