1: <?php
2: /**
3: * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
4: * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
5: *
6: * Licensed under The MIT License
7: * For full copyright and license information, please see the LICENSE.txt
8: * Redistributions of files must retain the above copyright notice.
9: *
10: * @copyright Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
11: * @link http://cakephp.org CakePHP(tm) Project
12: * @package Cake.Cache
13: * @since CakePHP(tm) v 1.2.0.4933
14: * @license http://www.opensource.org/licenses/mit-license.php MIT License
15: */
16:
17: App::uses('Inflector', 'Utility');
18: App::uses('CacheEngine', 'Cache');
19:
20: /**
21: * Cache provides a consistent interface to Caching in your application. It allows you
22: * to use several different Cache engines, without coupling your application to a specific
23: * implementation. It also allows you to change out cache storage or configuration without effecting
24: * the rest of your application.
25: *
26: * You can configure Cache engines in your application's `bootstrap.php` file. A sample configuration would
27: * be
28: *
29: * {{{
30: * Cache::config('shared', array(
31: * 'engine' => 'Apc',
32: * 'prefix' => 'my_app_'
33: * ));
34: * }}}
35: *
36: * This would configure an APC cache engine to the 'shared' alias. You could then read and write
37: * to that cache alias by using it for the `$config` parameter in the various Cache methods. In
38: * general all Cache operations are supported by all cache engines. However, Cache::increment() and
39: * Cache::decrement() are not supported by File caching.
40: *
41: * @package Cake.Cache
42: */
43: class Cache {
44:
45: /**
46: * Cache configuration stack
47: * Keeps the permanent/default settings for each cache engine.
48: * These settings are used to reset the engines after temporary modification.
49: *
50: * @var array
51: */
52: protected static $_config = array();
53:
54: /**
55: * Group to Config mapping
56: *
57: * @var array
58: */
59: protected static $_groups = array();
60:
61: /**
62: * Whether to reset the settings with the next call to Cache::set();
63: *
64: * @var array
65: */
66: protected static $_reset = false;
67:
68: /**
69: * Engine instances keyed by configuration name.
70: *
71: * @var array
72: */
73: protected static $_engines = array();
74:
75: /**
76: * Set the cache configuration to use. config() can
77: * both create new configurations, return the settings for already configured
78: * configurations.
79: *
80: * To create a new configuration, or to modify an existing configuration permanently:
81: *
82: * `Cache::config('my_config', array('engine' => 'File', 'path' => TMP));`
83: *
84: * If you need to modify a configuration temporarily, use Cache::set().
85: * To get the settings for a configuration:
86: *
87: * `Cache::config('default');`
88: *
89: * There are 5 built-in caching engines:
90: *
91: * - `FileEngine` - Uses simple files to store content. Poor performance, but good for
92: * storing large objects, or things that are not IO sensitive.
93: * - `ApcEngine` - Uses the APC object cache, one of the fastest caching engines.
94: * - `MemcacheEngine` - Uses the PECL::Memcache extension and Memcached for storage.
95: * Fast reads/writes, and benefits from memcache being distributed.
96: * - `XcacheEngine` - Uses the Xcache extension, an alternative to APC.
97: * - `WincacheEngine` - Uses Windows Cache Extension for PHP. Supports wincache 1.1.0 and higher.
98: *
99: * The following keys are used in core cache engines:
100: *
101: * - `duration` Specify how long items in this cache configuration last.
102: * - `groups` List of groups or 'tags' associated to every key stored in this config.
103: * handy for deleting a complete group from cache.
104: * - `prefix` Prefix appended to all entries. Good for when you need to share a keyspace
105: * with either another cache config or another application.
106: * - `probability` Probability of hitting a cache gc cleanup. Setting to 0 will disable
107: * cache::gc from ever being called automatically.
108: * - `servers' Used by memcache. Give the address of the memcached servers to use.
109: * - `compress` Used by memcache. Enables memcache's compressed format.
110: * - `serialize` Used by FileCache. Should cache objects be serialized first.
111: * - `path` Used by FileCache. Path to where cachefiles should be saved.
112: * - `lock` Used by FileCache. Should files be locked before writing to them?
113: * - `user` Used by Xcache. Username for XCache
114: * - `password` Used by Xcache/Redis. Password for XCache/Redis
115: *
116: * @param string $name Name of the configuration
117: * @param array $settings Optional associative array of settings passed to the engine
118: * @return array array(engine, settings) on success, false on failure
119: * @throws CacheException
120: * @see app/Config/core.php for configuration settings
121: */
122: public static function config($name = null, $settings = array()) {
123: if (is_array($name)) {
124: $settings = $name;
125: }
126:
127: $current = array();
128: if (isset(self::$_config[$name])) {
129: $current = self::$_config[$name];
130: }
131:
132: if (!empty($settings)) {
133: self::$_config[$name] = $settings + $current;
134: }
135:
136: if (empty(self::$_config[$name]['engine'])) {
137: return false;
138: }
139:
140: if (!empty(self::$_config[$name]['groups'])) {
141: foreach (self::$_config[$name]['groups'] as $group) {
142: self::$_groups[$group][] = $name;
143: sort(self::$_groups[$group]);
144: self::$_groups[$group] = array_unique(self::$_groups[$group]);
145: }
146: }
147:
148: $engine = self::$_config[$name]['engine'];
149:
150: if (!isset(self::$_engines[$name])) {
151: self::_buildEngine($name);
152: $settings = self::$_config[$name] = self::settings($name);
153: } elseif ($settings = self::set(self::$_config[$name], null, $name)) {
154: self::$_config[$name] = $settings;
155: }
156: return compact('engine', 'settings');
157: }
158:
159: /**
160: * Finds and builds the instance of the required engine class.
161: *
162: * @param string $name Name of the config array that needs an engine instance built
163: * @return bool
164: * @throws CacheException
165: */
166: protected static function _buildEngine($name) {
167: $config = self::$_config[$name];
168:
169: list($plugin, $class) = pluginSplit($config['engine'], true);
170: $cacheClass = $class . 'Engine';
171: App::uses($cacheClass, $plugin . 'Cache/Engine');
172: if (!class_exists($cacheClass)) {
173: throw new CacheException(__d('cake_dev', 'Cache engine %s is not available.', $name));
174: }
175: $cacheClass = $class . 'Engine';
176: if (!is_subclass_of($cacheClass, 'CacheEngine')) {
177: throw new CacheException(__d('cake_dev', 'Cache engines must use %s as a base class.', 'CacheEngine'));
178: }
179: self::$_engines[$name] = new $cacheClass();
180: if (!self::$_engines[$name]->init($config)) {
181: throw new CacheException(__d('cake_dev', 'Cache engine %s is not properly configured.', $name));
182: }
183: if (self::$_engines[$name]->settings['probability'] && time() % self::$_engines[$name]->settings['probability'] === 0) {
184: self::$_engines[$name]->gc();
185: }
186: return true;
187: }
188:
189: /**
190: * Returns an array containing the currently configured Cache settings.
191: *
192: * @return array Array of configured Cache config names.
193: */
194: public static function configured() {
195: return array_keys(self::$_config);
196: }
197:
198: /**
199: * Drops a cache engine. Deletes the cache configuration information
200: * If the deleted configuration is the last configuration using a certain engine,
201: * the Engine instance is also unset.
202: *
203: * @param string $name A currently configured cache config you wish to remove.
204: * @return bool success of the removal, returns false when the config does not exist.
205: */
206: public static function drop($name) {
207: if (!isset(self::$_config[$name])) {
208: return false;
209: }
210: unset(self::$_config[$name], self::$_engines[$name]);
211: return true;
212: }
213:
214: /**
215: * Temporarily change the settings on a cache config. The settings will persist for the next write
216: * operation (write, decrement, increment, clear). Any reads that are done before the write, will
217: * use the modified settings. If `$settings` is empty, the settings will be reset to the
218: * original configuration.
219: *
220: * Can be called with 2 or 3 parameters. To set multiple values at once.
221: *
222: * `Cache::set(array('duration' => '+30 minutes'), 'my_config');`
223: *
224: * Or to set one value.
225: *
226: * `Cache::set('duration', '+30 minutes', 'my_config');`
227: *
228: * To reset a config back to the originally configured values.
229: *
230: * `Cache::set(null, 'my_config');`
231: *
232: * @param string|array $settings Optional string for simple name-value pair or array
233: * @param string $value Optional for a simple name-value pair
234: * @param string $config The configuration name you are changing. Defaults to 'default'
235: * @return array Array of settings.
236: */
237: public static function set($settings = array(), $value = null, $config = 'default') {
238: if (is_array($settings) && $value !== null) {
239: $config = $value;
240: }
241: if (!isset(self::$_config[$config]) || !isset(self::$_engines[$config])) {
242: return false;
243: }
244: if (!empty($settings)) {
245: self::$_reset = true;
246: }
247:
248: if (self::$_reset === true) {
249: if (empty($settings)) {
250: self::$_reset = false;
251: $settings = self::$_config[$config];
252: } else {
253: if (is_string($settings) && $value !== null) {
254: $settings = array($settings => $value);
255: }
256: $settings += self::$_config[$config];
257: if (isset($settings['duration']) && !is_numeric($settings['duration'])) {
258: $settings['duration'] = strtotime($settings['duration']) - time();
259: }
260: }
261: self::$_engines[$config]->settings = $settings;
262: }
263: return self::settings($config);
264: }
265:
266: /**
267: * Garbage collection
268: *
269: * Permanently remove all expired and deleted data
270: *
271: * @param string $config [optional] The config name you wish to have garbage collected. Defaults to 'default'
272: * @param int $expires [optional] An expires timestamp. Defaults to NULL
273: * @return void
274: */
275: public static function gc($config = 'default', $expires = null) {
276: self::$_engines[$config]->gc($expires);
277: }
278:
279: /**
280: * Write data for key into a cache engine.
281: *
282: * ### Usage:
283: *
284: * Writing to the active cache config:
285: *
286: * `Cache::write('cached_data', $data);`
287: *
288: * Writing to a specific cache config:
289: *
290: * `Cache::write('cached_data', $data, 'long_term');`
291: *
292: * @param string $key Identifier for the data
293: * @param mixed $value Data to be cached - anything except a resource
294: * @param string $config Optional string configuration name to write to. Defaults to 'default'
295: * @return bool True if the data was successfully cached, false on failure
296: */
297: public static function write($key, $value, $config = 'default') {
298: $settings = self::settings($config);
299:
300: if (empty($settings)) {
301: return false;
302: }
303: if (!self::isInitialized($config)) {
304: return false;
305: }
306: $key = self::$_engines[$config]->key($key);
307:
308: if (!$key || is_resource($value)) {
309: return false;
310: }
311:
312: $success = self::$_engines[$config]->write($settings['prefix'] . $key, $value, $settings['duration']);
313: self::set(null, $config);
314: if ($success === false && $value !== '') {
315: trigger_error(
316: __d('cake_dev',
317: "%s cache was unable to write '%s' to %s cache",
318: $config,
319: $key,
320: self::$_engines[$config]->settings['engine']
321: ),
322: E_USER_WARNING
323: );
324: }
325: return $success;
326: }
327:
328: /**
329: * Read a key from a cache config.
330: *
331: * ### Usage:
332: *
333: * Reading from the active cache configuration.
334: *
335: * `Cache::read('my_data');`
336: *
337: * Reading from a specific cache configuration.
338: *
339: * `Cache::read('my_data', 'long_term');`
340: *
341: * @param string $key Identifier for the data
342: * @param string $config optional name of the configuration to use. Defaults to 'default'
343: * @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it
344: */
345: public static function read($key, $config = 'default') {
346: $settings = self::settings($config);
347:
348: if (empty($settings)) {
349: return false;
350: }
351: if (!self::isInitialized($config)) {
352: return false;
353: }
354: $key = self::$_engines[$config]->key($key);
355: if (!$key) {
356: return false;
357: }
358: return self::$_engines[$config]->read($settings['prefix'] . $key);
359: }
360:
361: /**
362: * Increment a number under the key and return incremented value.
363: *
364: * @param string $key Identifier for the data
365: * @param int $offset How much to add
366: * @param string $config Optional string configuration name. Defaults to 'default'
367: * @return mixed new value, or false if the data doesn't exist, is not integer,
368: * or if there was an error fetching it.
369: */
370: public static function increment($key, $offset = 1, $config = 'default') {
371: $settings = self::settings($config);
372:
373: if (empty($settings)) {
374: return false;
375: }
376: if (!self::isInitialized($config)) {
377: return false;
378: }
379: $key = self::$_engines[$config]->key($key);
380:
381: if (!$key || !is_int($offset) || $offset < 0) {
382: return false;
383: }
384: $success = self::$_engines[$config]->increment($settings['prefix'] . $key, $offset);
385: self::set(null, $config);
386: return $success;
387: }
388:
389: /**
390: * Decrement a number under the key and return decremented value.
391: *
392: * @param string $key Identifier for the data
393: * @param int $offset How much to subtract
394: * @param string $config Optional string configuration name. Defaults to 'default'
395: * @return mixed new value, or false if the data doesn't exist, is not integer,
396: * or if there was an error fetching it
397: */
398: public static function decrement($key, $offset = 1, $config = 'default') {
399: $settings = self::settings($config);
400:
401: if (empty($settings)) {
402: return false;
403: }
404: if (!self::isInitialized($config)) {
405: return false;
406: }
407: $key = self::$_engines[$config]->key($key);
408:
409: if (!$key || !is_int($offset) || $offset < 0) {
410: return false;
411: }
412: $success = self::$_engines[$config]->decrement($settings['prefix'] . $key, $offset);
413: self::set(null, $config);
414: return $success;
415: }
416:
417: /**
418: * Delete a key from the cache.
419: *
420: * ### Usage:
421: *
422: * Deleting from the active cache configuration.
423: *
424: * `Cache::delete('my_data');`
425: *
426: * Deleting from a specific cache configuration.
427: *
428: * `Cache::delete('my_data', 'long_term');`
429: *
430: * @param string $key Identifier for the data
431: * @param string $config name of the configuration to use. Defaults to 'default'
432: * @return bool True if the value was successfully deleted, false if it didn't exist or couldn't be removed
433: */
434: public static function delete($key, $config = 'default') {
435: $settings = self::settings($config);
436:
437: if (empty($settings)) {
438: return false;
439: }
440: if (!self::isInitialized($config)) {
441: return false;
442: }
443: $key = self::$_engines[$config]->key($key);
444: if (!$key) {
445: return false;
446: }
447:
448: $success = self::$_engines[$config]->delete($settings['prefix'] . $key);
449: self::set(null, $config);
450: return $success;
451: }
452:
453: /**
454: * Delete all keys from the cache.
455: *
456: * @param bool $check if true will check expiration, otherwise delete all
457: * @param string $config name of the configuration to use. Defaults to 'default'
458: * @return bool True if the cache was successfully cleared, false otherwise
459: */
460: public static function clear($check = false, $config = 'default') {
461: if (!self::isInitialized($config)) {
462: return false;
463: }
464: $success = self::$_engines[$config]->clear($check);
465: self::set(null, $config);
466: return $success;
467: }
468:
469: /**
470: * Delete all keys from the cache belonging to the same group.
471: *
472: * @param string $group name of the group to be cleared
473: * @param string $config name of the configuration to use. Defaults to 'default'
474: * @return bool True if the cache group was successfully cleared, false otherwise
475: */
476: public static function clearGroup($group, $config = 'default') {
477: if (!self::isInitialized($config)) {
478: return false;
479: }
480: $success = self::$_engines[$config]->clearGroup($group);
481: self::set(null, $config);
482: return $success;
483: }
484:
485: /**
486: * Check if Cache has initialized a working config for the given name.
487: *
488: * @param string $config name of the configuration to use. Defaults to 'default'
489: * @return bool Whether or not the config name has been initialized.
490: */
491: public static function isInitialized($config = 'default') {
492: if (Configure::read('Cache.disable')) {
493: return false;
494: }
495: return isset(self::$_engines[$config]);
496: }
497:
498: /**
499: * Return the settings for the named cache engine.
500: *
501: * @param string $name Name of the configuration to get settings for. Defaults to 'default'
502: * @return array list of settings for this engine
503: * @see Cache::config()
504: */
505: public static function settings($name = 'default') {
506: if (!empty(self::$_engines[$name])) {
507: return self::$_engines[$name]->settings();
508: }
509: return array();
510: }
511:
512: /**
513: * Retrieve group names to config mapping.
514: *
515: * {{{
516: * Cache::config('daily', array(
517: * 'duration' => '1 day', 'groups' => array('posts')
518: * ));
519: * Cache::config('weekly', array(
520: * 'duration' => '1 week', 'groups' => array('posts', 'archive')
521: * ));
522: * $configs = Cache::groupConfigs('posts');
523: * }}}
524: *
525: * $config will equal to `array('posts' => array('daily', 'weekly'))`
526: *
527: * @param string $group group name or null to retrieve all group mappings
528: * @return array map of group and all configuration that has the same group
529: * @throws CacheException
530: */
531: public static function groupConfigs($group = null) {
532: if ($group === null) {
533: return self::$_groups;
534: }
535: if (isset(self::$_groups[$group])) {
536: return array($group => self::$_groups[$group]);
537: }
538: throw new CacheException(__d('cake_dev', 'Invalid cache group %s', $group));
539: }
540:
541: /**
542: * Provides the ability to easily do read-through caching.
543: *
544: * When called if the $key is not set in $config, the $callable function
545: * will be invoked. The results will then be stored into the cache config
546: * at key.
547: *
548: * Examples:
549: *
550: * Using a Closure to provide data, assume $this is a Model:
551: *
552: * {{{
553: * $model = $this;
554: * $results = Cache::remember('all_articles', function() use ($model) {
555: * return $model->find('all');
556: * });
557: * }}}
558: *
559: * @param string $key The cache key to read/store data at.
560: * @param callable $callable The callable that provides data in the case when
561: * the cache key is empty. Can be any callable type supported by your PHP.
562: * @param string $config The cache configuration to use for this operation.
563: * Defaults to default.
564: * @return mixed The results of the callable or unserialized results.
565: */
566: public static function remember($key, $callable, $config = 'default') {
567: $existing = self::read($key, $config);
568: if ($existing !== false) {
569: return $existing;
570: }
571: $results = call_user_func($callable);
572: self::write($key, $results, $config);
573: return $results;
574: }
575:
576: }
577: