Wordpress 2.0.2
[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
68         function acquire_lock() {
69                 // Acquire a write lock. 
70                 $this->mutex = @fopen($this->cache_dir.$this->flock_filename, 'w');
71                 if ( false == $this->mutex)
72                         return false;
73                 flock($this->mutex, LOCK_EX);
74                 return true;
75         }
76
77         function add($id, $data, $group = 'default', $expire = '') {
78                 if (empty ($group))
79                         $group = 'default';
80
81                 if (false !== $this->get($id, $group, false))
82                         return false;
83
84                 return $this->set($id, $data, $group, $expire);
85         }
86
87         function delete($id, $group = 'default', $force = false) {
88                 if (empty ($group))
89                         $group = 'default';
90
91                 if (!$force && false === $this->get($id, $group, false))
92                         return false;
93
94                 unset ($this->cache[$group][$id]);
95                 $this->non_existant_objects[$group][$id] = true;
96                 $this->dirty_objects[$group][] = $id;
97                 return true;
98         }
99
100         function flush() {
101                 if ( !$this->cache_enabled )
102                         return true;
103
104                 if ( ! $this->acquire_lock() )
105                         return false;
106                 
107                 $this->rm_cache_dir();
108                 $this->cache = array ();
109                 $this->dirty_objects = array ();
110                 $this->non_existant_objects = array ();
111                 
112                 $this->release_lock();
113
114                 return true;
115         }
116
117         function get($id, $group = 'default', $count_hits = true) {
118                 if (empty ($group))
119                         $group = 'default';
120
121                 if (isset ($this->cache[$group][$id])) {
122                         if ($count_hits)
123                                 $this->warm_cache_hits += 1;
124                         return $this->cache[$group][$id];
125                 }
126
127                 if (isset ($this->non_existant_objects[$group][$id]))
128                         return false;
129
130                 //  If caching is not enabled, we have to fall back to pulling from the DB.
131                 if (!$this->cache_enabled) {
132                         if (!isset ($this->cache[$group]))
133                                 $this->load_group_from_db($group);
134
135                         if (isset ($this->cache[$group][$id])) {
136                                 $this->cold_cache_hits += 1;
137                                 return $this->cache[$group][$id];
138                         }
139
140                         $this->non_existant_objects[$group][$id] = true;
141                         $this->cache_misses += 1;
142                         return false;
143                 }
144
145                 $cache_file = $this->cache_dir.$this->get_group_dir($group)."/".md5($id.DB_PASSWORD).'.php';
146                 if (!file_exists($cache_file)) {
147                         $this->non_existant_objects[$group][$id] = true;
148                         $this->cache_misses += 1;
149                         return false;
150                 }
151
152                 // If the object has expired, remove it from the cache and return false to force
153                 // a refresh.
154                 $now = time();
155                 if ((filemtime($cache_file) + $this->expiration_time) <= $now) {
156                         $this->cache_misses += 1;
157                         $this->delete($id, $group, true);
158                         return false;
159                 }
160
161                 $this->cache[$group][$id] = unserialize(substr(@ file_get_contents($cache_file), strlen(CACHE_SERIAL_HEADER), -strlen(CACHE_SERIAL_FOOTER)));
162                 if (false === $this->cache[$group][$id])
163                         $this->cache[$group][$id] = '';
164
165                 $this->cold_cache_hits += 1;
166                 return $this->cache[$group][$id];
167         }
168
169         function get_group_dir($group) {
170                 if (false !== array_search($group, $this->global_groups))
171                         return $group;
172
173                 return "{$this->blog_id}/$group";
174         }
175
176         function load_group_from_db($group) {
177                 global $wpdb;
178
179                 if ('category' == $group) {
180                         $this->cache['category'] = array ();
181                         if ($dogs = $wpdb->get_results("SELECT * FROM $wpdb->categories")) {
182                                 foreach ($dogs as $catt)
183                                         $this->cache['category'][$catt->cat_ID] = $catt;
184
185                                 foreach ($this->cache['category'] as $catt) {
186                                         $curcat = $catt->cat_ID;
187                                         $fullpath = '/'.$this->cache['category'][$catt->cat_ID]->category_nicename;
188                                         while ($this->cache['category'][$curcat]->category_parent != 0) {
189                                                 $curcat = $this->cache['category'][$curcat]->category_parent;
190                                                 $fullpath = '/'.$this->cache['category'][$curcat]->category_nicename.$fullpath;
191                                         }
192                                         $this->cache['category'][$catt->cat_ID]->fullpath = $fullpath;
193                                 }
194                         }
195                 } else
196                         if ('options' == $group) {
197                                 $wpdb->hide_errors();
198                                 if (!$options = $wpdb->get_results("SELECT option_name, option_value FROM $wpdb->options WHERE autoload = 'yes'")) {
199                                         $options = $wpdb->get_results("SELECT option_name, option_value FROM $wpdb->options");
200                                 }
201                                 $wpdb->show_errors();
202
203                                 if ( ! $options )
204                                         return;
205
206                                 foreach ($options as $option) {
207                                         $this->cache['options'][$option->option_name] = $option->option_value;
208                                 }
209                         }
210         }
211
212         function make_group_dir($group, $perms) {
213                 $group_dir = $this->get_group_dir($group);
214                 $make_dir = '';
215                 foreach (split('/', $group_dir) as $subdir) {
216                         $make_dir .= "$subdir/";
217                         if (!file_exists($this->cache_dir.$make_dir)) {
218                                 if (! @ mkdir($this->cache_dir.$make_dir))
219                                         break;
220                                 @ chmod($this->cache_dir.$make_dir, $perms);
221                         }
222
223                         if (!file_exists($this->cache_dir.$make_dir."index.php")) {
224                                 $file_perms = $perms & 0000666;
225                                 @ touch($this->cache_dir.$make_dir."index.php");
226                                 @ chmod($this->cache_dir.$make_dir."index.php", $file_perms);
227                         }
228                 }
229
230                 return $this->cache_dir."$group_dir/";
231         }
232
233         function rm_cache_dir() {
234                 $dir = $this->cache_dir;
235                 $dir = rtrim($dir, DIRECTORY_SEPARATOR);
236                 $top_dir = $dir;
237                 $stack = array($dir);
238                 $index = 0;
239
240                 while ($index < count($stack)) {
241                         # Get indexed directory from stack
242                         $dir = $stack[$index];
243       
244                         $dh = @ opendir($dir);
245                         if (!$dh)
246                                 return false;
247       
248                         while (($file = @ readdir($dh)) !== false) {
249                                 if ($file == '.' or $file == '..')
250                                         continue;
251                                         
252                                 if (@ is_dir($dir . DIRECTORY_SEPARATOR . $file))
253                                         $stack[] = $dir . DIRECTORY_SEPARATOR . $file;
254                                 else if (@ is_file($dir . DIRECTORY_SEPARATOR . $file))
255                                         @ unlink($dir . DIRECTORY_SEPARATOR . $file);
256                         }
257
258                         $index++;
259                 }
260
261                 $stack = array_reverse($stack);  // Last added dirs are deepest
262                 foreach($stack as $dir) {
263                         if ( $dir != $top_dir)
264                                 @ rmdir($dir);
265                 }
266
267         }
268
269         function release_lock() {
270                 // Release write lock.
271                 flock($this->mutex, LOCK_UN);
272                 fclose($this->mutex);
273         }
274
275         function replace($id, $data, $group = 'default', $expire = '') {
276                 if (empty ($group))
277                         $group = 'default';
278
279                 if (false === $this->get($id, $group, false))
280                         return false;
281
282                 return $this->set($id, $data, $group, $expire);
283         }
284
285         function set($id, $data, $group = 'default', $expire = '') {
286                 if (empty ($group))
287                         $group = 'default';
288
289                 if (NULL == $data)
290                         $data = '';
291
292                 $this->cache[$group][$id] = $data;
293                 unset ($this->non_existant_objects[$group][$id]);
294                 $this->dirty_objects[$group][] = $id;
295
296                 return true;
297         }
298
299         function save() {
300                 //$this->stats();
301
302                 if (!$this->cache_enabled)
303                         return true;
304
305                 if (empty ($this->dirty_objects))
306                         return true;
307
308                 // Give the new dirs the same perms as wp-content.
309                 $stat = stat(ABSPATH.'wp-content');
310                 $dir_perms = $stat['mode'] & 0007777; // Get the permission bits.
311                 $file_perms = $dir_perms & 0000666; // Remove execute bits for files.
312
313                 // Make the base cache dir.
314                 if (!file_exists($this->cache_dir)) {
315                         if (! @ mkdir($this->cache_dir))
316                                 return false;
317                         @ chmod($this->cache_dir, $dir_perms);
318                 }
319
320                 if (!file_exists($this->cache_dir."index.php")) {
321                         @ touch($this->cache_dir."index.php");
322                         @ chmod($this->cache_dir."index.php", $file_perms);
323                 }
324
325                 if ( ! $this->acquire_lock() )
326                         return false;
327
328                 // Loop over dirty objects and save them.
329                 $errors = 0;
330                 foreach ($this->dirty_objects as $group => $ids) {
331                         $group_dir = $this->make_group_dir($group, $dir_perms);
332
333                         $ids = array_unique($ids);
334                         foreach ($ids as $id) {
335                                 $cache_file = $group_dir.md5($id.DB_PASSWORD).'.php';
336
337                                 // Remove the cache file if the key is not set.
338                                 if (!isset ($this->cache[$group][$id])) {
339                                         if (file_exists($cache_file))
340                                                 @ unlink($cache_file);
341                                         continue;
342                                 }
343
344                                 $temp_file = tempnam($group_dir, 'tmp');
345                                 $serial = CACHE_SERIAL_HEADER.serialize($this->cache[$group][$id]).CACHE_SERIAL_FOOTER;
346                                 $fd = @fopen($temp_file, 'w');
347                                 if ( false === $fd ) {
348                                         $errors++;
349                                         continue;
350                                 }
351                                 fputs($fd, $serial);
352                                 fclose($fd);
353                                 if (!@ rename($temp_file, $cache_file)) {
354                                         if (@ copy($temp_file, $cache_file))
355                                                 @ unlink($temp_file);
356                                         else
357                                                 $errors++;      
358                                 }
359                                 @ chmod($cache_file, $file_perms);
360                         }
361                 }
362
363                 $this->dirty_objects = array();
364
365                 $this->release_lock();
366                 
367                 if ( $errors )
368                         return false;
369
370                 return true;
371         }
372
373         function stats() {
374                 echo "<p>";
375                 echo "<strong>Cold Cache Hits:</strong> {$this->cold_cache_hits}<br/>";
376                 echo "<strong>Warm Cache Hits:</strong> {$this->warm_cache_hits}<br/>";
377                 echo "<strong>Cache Misses:</strong> {$this->cache_misses}<br/>";
378                 echo "</p>";
379
380                 foreach ($this->cache as $group => $cache) {
381                         echo "<p>";
382                         echo "<strong>Group:</strong> $group<br/>";
383                         echo "<strong>Cache:</strong>";
384                         echo "<pre>";
385                         print_r($cache);
386                         echo "</pre>";
387                         if (isset ($this->dirty_objects[$group])) {
388                                 echo "<strong>Dirty Objects:</strong>";
389                                 echo "<pre>";
390                                 print_r(array_unique($this->dirty_objects[$group]));
391                                 echo "</pre>";
392                                 echo "</p>";
393                         }
394                 }
395         }
396
397         function WP_Object_Cache() {
398                 global $blog_id;
399
400                 if (defined('DISABLE_CACHE'))
401                         return;
402
403                 // Disable the persistent cache if safe_mode is on.
404                 if ( ini_get('safe_mode') && ! defined('ENABLE_CACHE') )
405                         return;
406
407                 if (defined('CACHE_PATH'))
408                         $this->cache_dir = CACHE_PATH;
409                 else
410                         // Using the correct separator eliminates some cache flush errors on Windows
411                         $this->cache_dir = ABSPATH.'wp-content'.DIRECTORY_SEPARATOR.'cache'.DIRECTORY_SEPARATOR;
412
413                 if (is_writable($this->cache_dir) && is_dir($this->cache_dir)) {
414                                 $this->cache_enabled = true;
415                 } else {
416                         if (is_writable(ABSPATH.'wp-content')) {
417                                 $this->cache_enabled = true;
418                         }
419                 }
420
421                 if (defined('CACHE_EXPIRATION_TIME'))
422                         $this->expiration_time = CACHE_EXPIRATION_TIME;
423
424                 $this->blog_id = md5($blog_id);
425         }
426 }
427 ?>