/
cache.php
599 lines (553 loc) · 17.2 KB
/
cache.php
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
<?php
/**
* Caching for CakePHP.
*
*
* PHP 5
*
* CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
* Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
*
* Licensed under The MIT License
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
* @link http://cakephp.org CakePHP(tm) Project
* @package cake.libs
* @since CakePHP(tm) v 1.2.0.4933
* @license MIT License (http://www.opensource.org/licenses/mit-license.php)
*/
/**
* Cache provides a consistent interface to Caching in your application. It allows you
* to use several different Cache engines, without coupling your application to a specific
* implementation. It also allows you to change out cache storage or configuration without effecting
* the rest of your application.
*
* You can configure Cache engines in your application's `bootstrap.php` file. A sample configuration would
* be
*
* {{{
* Cache::config('shared', array(
* 'engine' => 'Apc',
* 'prefix' => 'my_app_'
* ));
* }}}
*
* This would configure an APC cache engine to the 'shared' alias. You could then read and write
* to that cache alias by using it for the `$config` parameter in the various Cache methods. In
* general all Cache operations are supported by all cache engines. However, Cache::increment() and
* Cache::decrement() are not supported by File caching.
*
* @package cake.libs
*/
class Cache {
/**
* Cache configuration stack
* Keeps the permanent/default settings for each cache engine.
* These settings are used to reset the engines after temporary modification.
*
* @var array
*/
protected static $_config = array();
/**
* Whether to reset the settings with the next call to Cache::set();
*
* @var array
*/
protected static $_reset = false;
/**
* Engine instances keyed by configuration name.
*
* @var array
*/
protected static $_engines = array();
/**
* Set the cache configuration to use. config() can
* both create new configurations, return the settings for already configured
* configurations.
*
* To create a new configuration, or to modify an existing configuration permanently:
*
* `Cache::config('my_config', array('engine' => 'File', 'path' => TMP));`
*
* If you need to modify a configuration temporarily, use Cache::set().
* To get the settings for a configuration:
*
* `Cache::config('default');`
*
* There are 4 built-in caching engines:
*
* - `FileEngine` - Uses simple files to store content. Poor performance, but good for
* storing large objects, or things that are not IO sensitive.
* - `ApcEngine` - Uses the APC object cache, one of the fastest caching engines.
* - `MemcacheEngine` - Uses the PECL::Memcache extension and Memcached for storage.
* Fast reads/writes, and benefits from memcache being distributed.
* - `XcacheEngine` - Uses the Xcache extension, an alternative to APC.
*
* @see app/config/core.php for configuration settings
* @param string $name Name of the configuration
* @param array $settings Optional associative array of settings passed to the engine
* @return array(engine, settings) on success, false on failure
* @throws CacheException
*/
public static function config($name = null, $settings = array()) {
if (is_array($name)) {
$settings = $name;
}
$current = array();
if (isset(self::$_config[$name])) {
$current = self::$_config[$name];
}
if (!empty($settings)) {
self::$_config[$name] = array_merge($current, $settings);
}
if (empty(self::$_config[$name]['engine'])) {
return false;
}
$engine = self::$_config[$name]['engine'];
if (!isset(self::$_engines[$name])) {
self::_buildEngine($name);
$settings = self::$_config[$name] = self::settings($name);
} elseif ($settings = self::set(self::$_config[$name], null, $name)) {
self::$_config[$name] = $settings;
}
return compact('engine', 'settings');
}
/**
* Finds and builds the instance of the required engine class.
*
* @param string $name Name of the config array that needs an engine instance built
* @return void
*/
protected static function _buildEngine($name) {
$config = self::$_config[$name];
list($plugin, $class) = pluginSplit($config['engine']);
$cacheClass = $class . 'Engine';
if (!class_exists($cacheClass) && self::_loadEngine($class, $plugin) === false) {
return false;
}
$cacheClass = $class . 'Engine';
if (!is_subclass_of($cacheClass, 'CacheEngine')) {
throw new CacheException(__('Cache engines must use CacheEngine as a base class.'));
}
self::$_engines[$name] = new $cacheClass();
if (self::$_engines[$name]->init($config)) {
if (time() % self::$_engines[$name]->settings['probability'] === 0) {
self::$_engines[$name]->gc();
}
return true;
}
return false;
}
/**
* Returns an array containing the currently configured Cache settings.
*
* @return array Array of configured Cache config names.
*/
public static function configured() {
return array_keys(self::$_config);
}
/**
* Drops a cache engine. Deletes the cache configuration information
* If the deleted configuration is the last configuration using an certain engine,
* the Engine instance is also unset.
*
* @param string $name A currently configured cache config you wish to remove.
* @return boolen success of the removal, returns false when the config does not exist.
*/
public static function drop($name) {
if (!isset(self::$_config[$name])) {
return false;
}
unset(self::$_config[$name], self::$_engines[$name]);
return true;
}
/**
* Tries to find and include a file for a cache engine and returns object instance
*
* @param $name Name of the engine (without 'Engine')
* @return mixed $engine object or null
*/
protected static function _loadEngine($name, $plugin = null) {
if ($plugin) {
return App::import('Lib', $plugin . '.cache' . DS . $name, false);
} else {
$core = App::core();
$path = $core['libs'][0] . 'cache' . DS . strtolower($name) . '.php';
if (file_exists($path)) {
require $path;
return true;
}
return App::import('Lib', 'cache' . DS . $name, false);
}
}
/**
* Temporarily change the settings on a cache config. The settings will persist for the next write
* operation (write, decrement, increment, clear). Any reads that are done before the write, will
* use the modified settings. If `$settings` is empty, the settings will be reset to the
* original configuration.
*
* Can be called with 2 or 3 parameters. To set multiple values at once.
*
* `Cache::set(array('duration' => '+30 minutes'), 'my_config');`
*
* Or to set one value.
*
* `Cache::set('duration', '+30 minutes', 'my_config');`
*
* To reset a config back to the originally configured values.
*
* `Cache::set(null, 'my_config');`
*
* @param mixed $settings Optional string for simple name-value pair or array
* @param string $value Optional for a simple name-value pair
* @param string $config The configuration name you are changing. Defaults to 'default'
* @return array Array of settings.
*/
public static function set($settings = array(), $value = null, $config = 'default') {
if (is_array($settings) && $value !== null) {
$config = $value;
}
if (!isset(self::$_config[$config]) || !isset(self::$_engines[$config])) {
return false;
}
if (!empty($settings)) {
self::$_reset = true;
}
if (self::$_reset === true) {
if (empty($settings)) {
self::$_reset = false;
$settings = self::$_config[$config];
} else {
if (is_string($settings) && $value !== null) {
$settings = array($settings => $value);
}
$settings = array_merge(self::$_config[$config], $settings);
if (isset($settings['duration']) && !is_numeric($settings['duration'])) {
$settings['duration'] = strtotime($settings['duration']) - time();
}
}
self::$_engines[$config]->settings = $settings;
}
return self::settings($config);
}
/**
* Garbage collection
*
* Permanently remove all expired and deleted data
*
* @param string $config The config name you wish to have garbage collected. Defaults to 'default'
* @return void
*/
public static function gc($config = 'default') {
self::$_engines[$config]->gc();
}
/**
* Write data for key into cache. Will automatically use the currently
* active cache configuration. To set the currently active configuration use
* Cache::config()
*
* ### Usage:
*
* Writing to the active cache config:
*
* `Cache::write('cached_data', $data);`
*
* Writing to a specific cache config:
*
* `Cache::write('cached_data', $data, 'long_term');`
*
* @param string $key Identifier for the data
* @param mixed $value Data to be cached - anything except a resource
* @param string $config Optional string configuration name to write to. Defaults to 'default'
* @return boolean True if the data was successfully cached, false on failure
*/
public static function write($key, $value, $config = 'default') {
$settings = self::settings($config);
if (empty($settings)) {
return null;
}
if (!self::isInitialized($config)) {
return false;
}
$key = self::$_engines[$config]->key($key);
if (!$key || is_resource($value)) {
return false;
}
$success = self::$_engines[$config]->write($settings['prefix'] . $key, $value, $settings['duration']);
self::set(null, $config);
if ($success === false && $value !== '') {
trigger_error(
__("%s cache was unable to write '%s' to cache", $config, $key),
E_USER_WARNING
);
}
return $success;
}
/**
* Read a key from the cache. Will automatically use the currently
* active cache configuration. To set the currently active configuration use
* Cache::config()
*
* ### Usage:
*
* Reading from the active cache configuration.
*
* `Cache::read('my_data');`
*
* Reading from a specific cache configuration.
*
* `Cache::read('my_data', 'long_term');`
*
* @param string $key Identifier for the data
* @param string $config optional name of the configuration to use. Defaults to 'default'
* @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it
*/
public static function read($key, $config = 'default') {
$settings = self::settings($config);
if (empty($settings)) {
return null;
}
if (!self::isInitialized($config)) {
return false;
}
$key = self::$_engines[$config]->key($key);
if (!$key) {
return false;
}
return self::$_engines[$config]->read($settings['prefix'] . $key);
}
/**
* Increment a number under the key and return incremented value.
*
* @param string $key Identifier for the data
* @param integer $offset How much to add
* @param string $config Optional string configuration name. Defaults to 'default'
* @return mixed new value, or false if the data doesn't exist, is not integer,
* or if there was an error fetching it.
*/
public static function increment($key, $offset = 1, $config = 'default') {
$settings = self::settings($config);
if (empty($settings)) {
return null;
}
if (!self::isInitialized($config)) {
return false;
}
$key = self::$_engines[$config]->key($key);
if (!$key || !is_integer($offset) || $offset < 0) {
return false;
}
$success = self::$_engines[$config]->increment($settings['prefix'] . $key, $offset);
self::set(null, $config);
return $success;
}
/**
* Decrement a number under the key and return decremented value.
*
* @param string $key Identifier for the data
* @param integer $offset How much to substract
* @param string $config Optional string configuration name. Defaults to 'default'
* @return mixed new value, or false if the data doesn't exist, is not integer,
* or if there was an error fetching it
*/
public static function decrement($key, $offset = 1, $config = 'default') {
$settings = self::settings($config);
if (empty($settings)) {
return null;
}
if (!self::isInitialized($config)) {
return false;
}
$key = self::$_engines[$config]->key($key);
if (!$key || !is_integer($offset) || $offset < 0) {
return false;
}
$success = self::$_engines[$config]->decrement($settings['prefix'] . $key, $offset);
self::set(null, $config);
return $success;
}
/**
* Delete a key from the cache.
*
* ### Usage:
*
* Deleting from the active cache configuration.
*
* `Cache::delete('my_data');`
*
* Deleting from a specific cache configuration.
*
* `Cache::delete('my_data', 'long_term');`
*
* @param string $key Identifier for the data
* @param string $config name of the configuration to use. Defaults to 'default'
* @return boolean True if the value was succesfully deleted, false if it didn't exist or couldn't be removed
*/
public static function delete($key, $config = 'default') {
$settings = self::settings($config);
if (empty($settings)) {
return null;
}
if (!self::isInitialized($config)) {
return false;
}
$key = self::$_engines[$config]->key($key);
if (!$key) {
return false;
}
$success = self::$_engines[$config]->delete($settings['prefix'] . $key);
self::set(null, $config);
return $success;
}
/**
* Delete all keys from the cache.
*
* @param boolean $check if true will check expiration, otherwise delete all
* @param string $config name of the configuration to use. Defaults to 'default'
* @return boolean True if the cache was succesfully cleared, false otherwise
*/
public static function clear($check = false, $config = 'default') {
if (!self::isInitialized($config)) {
return false;
}
$success = self::$_engines[$config]->clear($check);
self::set(null, $config);
return $success;
}
/**
* Check if Cache has initialized a working config for the given name.
*
* @param string $engine Name of the engine, Defaults to default
* @param string $config Name of the configuration setting
* @return bool Whether or not the config name has been initialized.
*/
public static function isInitialized($name = 'default') {
if (Configure::read('Cache.disable')) {
return false;
}
return isset(self::$_engines[$name]);
}
/**
* Return the settings for the named cache engine.
*
* @param string $engine Name of the configuration to get settings for. Defaults to 'default'
* @return array list of settings for this engine
* @see Cache::config()
* @access public
* @static
*/
public static function settings($name = 'default') {
if (!empty(self::$_engines[$name])) {
return self::$_engines[$name]->settings();
}
return array();
}
}
/**
* Storage engine for CakePHP caching
*
* @package cake.libs
*/
abstract class CacheEngine {
/**
* Settings of current engine instance
*
* @var int
* @access public
*/
public $settings = array();
/**
* Initialize the cache engine
*
* Called automatically by the cache frontend
*
* @param array $params Associative array of parameters for the engine
* @return boolean True if the engine has been succesfully initialized, false if not
*/
public function init($settings = array()) {
$this->settings = array_merge(
array('prefix' => 'cake_', 'duration'=> 3600, 'probability'=> 100),
$this->settings,
$settings
);
if (!is_numeric($this->settings['duration'])) {
$this->settings['duration'] = strtotime($this->settings['duration']) - time();
}
return true;
}
/**
* Garbage collection
*
* Permanently remove all expired and deleted data
* @return void
*/
public function gc() { }
/**
* Write value for a key into cache
*
* @param string $key Identifier for the data
* @param mixed $value Data to be cached
* @param mixed $duration How long to cache for.
* @return boolean True if the data was succesfully cached, false on failure
*/
abstract public function write($key, $value, $duration);
/**
* Read a key from the cache
*
* @param string $key Identifier for the data
* @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it
*/
abstract public function read($key);
/**
* Increment a number under the key and return incremented value
*
* @param string $key Identifier for the data
* @param integer $offset How much to add
* @return New incremented value, false otherwise
*/
abstract public function increment($key, $offset = 1);
/**
* Decrement a number under the key and return decremented value
*
* @param string $key Identifier for the data
* @param integer $value How much to substract
* @return New incremented value, false otherwise
*/
abstract public function decrement($key, $offset = 1);
/**
* Delete a key from the cache
*
* @param string $key Identifier for the data
* @return boolean True if the value was succesfully deleted, false if it didn't exist or couldn't be removed
*/
abstract public function delete($key);
/**
* Delete all keys from the cache
*
* @param boolean $check if true will check expiration, otherwise delete all
* @return boolean True if the cache was succesfully cleared, false otherwise
*/
abstract public function clear($check);
/**
* Cache Engine settings
*
* @return array settings
*/
public function settings() {
return $this->settings;
}
/**
* Generates a safe key for use with cache engine storage engines.
*
* @param string $key the key passed over
* @return mixed string $key or false
*/
public function key($key) {
if (empty($key)) {
return false;
}
$key = Inflector::underscore(str_replace(array(DS, '/', '.'), '_', strval($key)));
return $key;
}
}