1: <?php
  2: /**
  3:  * File Storage engine for cache. Filestorage is the slowest cache storage
  4:  * to read and write. However, it is good for servers that don't have other storage
  5:  * engine available, or have content which is not performance sensitive.
  6:  *
  7:  * You can configure a FileEngine cache, using Cache::config()
  8:  *
  9:  * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 10:  * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 11:  *
 12:  * Licensed under The MIT License
 13:  * For full copyright and license information, please see the LICENSE.txt
 14:  * Redistributions of files must retain the above copyright notice.
 15:  *
 16:  * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 17:  * @link          http://cakephp.org CakePHP(tm) Project
 18:  * @since         CakePHP(tm) v 1.2.0.4933
 19:  * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 20:  */
 21: 
 22: /**
 23:  * File Storage engine for cache. Filestorage is the slowest cache storage
 24:  * to read and write. However, it is good for servers that don't have other storage
 25:  * engine available, or have content which is not performance sensitive.
 26:  *
 27:  * You can configure a FileEngine cache, using Cache::config()
 28:  *
 29:  * @package       Cake.Cache.Engine
 30:  */
 31: class FileEngine extends CacheEngine {
 32: 
 33: /**
 34:  * Instance of SplFileObject class
 35:  *
 36:  * @var File
 37:  */
 38:     protected $_File = null;
 39: 
 40: /**
 41:  * Settings
 42:  *
 43:  * - path = absolute path to cache directory, default => CACHE
 44:  * - prefix = string prefix for filename, default => cake_
 45:  * - lock = enable file locking on write, default => true
 46:  * - serialize = serialize the data, default => true
 47:  *
 48:  * @var array
 49:  * @see CacheEngine::__defaults
 50:  */
 51:     public $settings = array();
 52: 
 53: /**
 54:  * True unless FileEngine::__active(); fails
 55:  *
 56:  * @var bool
 57:  */
 58:     protected $_init = true;
 59: 
 60: /**
 61:  * Initialize the Cache Engine
 62:  *
 63:  * Called automatically by the cache frontend
 64:  * To reinitialize the settings call Cache::engine('EngineName', [optional] settings = array());
 65:  *
 66:  * @param array $settings array of setting for the engine
 67:  * @return bool True if the engine has been successfully initialized, false if not
 68:  */
 69:     public function init($settings = array()) {
 70:         $settings += array(
 71:             'engine' => 'File',
 72:             'path' => CACHE,
 73:             'prefix' => 'cake_',
 74:             'lock' => true,
 75:             'serialize' => true,
 76:             'isWindows' => false,
 77:             'mask' => 0664
 78:         );
 79:         parent::init($settings);
 80: 
 81:         if (DS === '\\') {
 82:             $this->settings['isWindows'] = true;
 83:         }
 84:         if (substr($this->settings['path'], -1) !== DS) {
 85:             $this->settings['path'] .= DS;
 86:         }
 87:         if (!empty($this->_groupPrefix)) {
 88:             $this->_groupPrefix = str_replace('_', DS, $this->_groupPrefix);
 89:         }
 90:         return $this->_active();
 91:     }
 92: 
 93: /**
 94:  * Garbage collection. Permanently remove all expired and deleted data
 95:  *
 96:  * @param int $expires [optional] An expires timestamp, invalidating all data before.
 97:  * @return bool True if garbage collection was successful, false on failure
 98:  */
 99:     public function gc($expires = null) {
100:         return $this->clear(true);
101:     }
102: 
103: /**
104:  * Write data for key into cache
105:  *
106:  * @param string $key Identifier for the data
107:  * @param mixed $data Data to be cached
108:  * @param int $duration How long to cache the data, in seconds
109:  * @return bool True if the data was successfully cached, false on failure
110:  */
111:     public function write($key, $data, $duration) {
112:         if (!$this->_init) {
113:             return false;
114:         }
115: 
116:         if ($this->_setKey($key, true) === false) {
117:             return false;
118:         }
119: 
120:         $lineBreak = "\n";
121: 
122:         if ($this->settings['isWindows']) {
123:             $lineBreak = "\r\n";
124:         }
125: 
126:         if (!empty($this->settings['serialize'])) {
127:             if ($this->settings['isWindows']) {
128:                 $data = str_replace('\\', '\\\\\\\\', serialize($data));
129:             } else {
130:                 $data = serialize($data);
131:             }
132:         }
133: 
134:         $expires = time() + $duration;
135:         $contents = implode(array($expires, $lineBreak, $data, $lineBreak));
136: 
137:         if ($this->settings['lock']) {
138:             $this->_File->flock(LOCK_EX);
139:         }
140: 
141:         $this->_File->rewind();
142:         $success = $this->_File->ftruncate(0) && $this->_File->fwrite($contents) && $this->_File->fflush();
143: 
144:         if ($this->settings['lock']) {
145:             $this->_File->flock(LOCK_UN);
146:         }
147: 
148:         return $success;
149:     }
150: 
151: /**
152:  * Read a key from the cache
153:  *
154:  * @param string $key Identifier for the data
155:  * @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it
156:  */
157:     public function read($key) {
158:         if (!$this->_init || $this->_setKey($key) === false) {
159:             return false;
160:         }
161: 
162:         if ($this->settings['lock']) {
163:             $this->_File->flock(LOCK_SH);
164:         }
165: 
166:         $this->_File->rewind();
167:         $time = time();
168:         $cachetime = (int)$this->_File->current();
169: 
170:         if ($cachetime !== false && ($cachetime < $time || ($time + $this->settings['duration']) < $cachetime)) {
171:             if ($this->settings['lock']) {
172:                 $this->_File->flock(LOCK_UN);
173:             }
174:             return false;
175:         }
176: 
177:         $data = '';
178:         $this->_File->next();
179:         while ($this->_File->valid()) {
180:             $data .= $this->_File->current();
181:             $this->_File->next();
182:         }
183: 
184:         if ($this->settings['lock']) {
185:             $this->_File->flock(LOCK_UN);
186:         }
187: 
188:         $data = trim($data);
189: 
190:         if ($data !== '' && !empty($this->settings['serialize'])) {
191:             if ($this->settings['isWindows']) {
192:                 $data = str_replace('\\\\\\\\', '\\', $data);
193:             }
194:             $data = unserialize((string)$data);
195:         }
196:         return $data;
197:     }
198: 
199: /**
200:  * Delete a key from the cache
201:  *
202:  * @param string $key Identifier for the data
203:  * @return bool True if the value was successfully deleted, false if it didn't exist or couldn't be removed
204:  */
205:     public function delete($key) {
206:         if ($this->_setKey($key) === false || !$this->_init) {
207:             return false;
208:         }
209:         $path = $this->_File->getRealPath();
210:         $this->_File = null;
211: 
212:         //@codingStandardsIgnoreStart
213:         return @unlink($path);
214:         //@codingStandardsIgnoreEnd
215:     }
216: 
217: /**
218:  * Delete all values from the cache
219:  *
220:  * @param bool $check Optional - only delete expired cache items
221:  * @return bool True if the cache was successfully cleared, false otherwise
222:  */
223:     public function clear($check) {
224:         if (!$this->_init) {
225:             return false;
226:         }
227:         $this->_File = null;
228: 
229:         $threshold = $now = false;
230:         if ($check) {
231:             $now = time();
232:             $threshold = $now - $this->settings['duration'];
233:         }
234: 
235:         $this->_clearDirectory($this->settings['path'], $now, $threshold);
236: 
237:         $directory = new RecursiveDirectoryIterator($this->settings['path']);
238:         $contents = new RecursiveIteratorIterator($directory, RecursiveIteratorIterator::SELF_FIRST);
239:         $cleared = array();
240:         foreach ($contents as $path) {
241:             if ($path->isFile()) {
242:                 continue;
243:             }
244: 
245:             $path = $path->getRealPath() . DS;
246:             if (!in_array($path, $cleared)) {
247:                 $this->_clearDirectory($path, $now, $threshold);
248:                 $cleared[] = $path;
249:             }
250:         }
251:         return true;
252:     }
253: 
254: /**
255:  * Used to clear a directory of matching files.
256:  *
257:  * @param string $path The path to search.
258:  * @param int $now The current timestamp
259:  * @param int $threshold Any file not modified after this value will be deleted.
260:  * @return void
261:  */
262:     protected function _clearDirectory($path, $now, $threshold) {
263:         $prefixLength = strlen($this->settings['prefix']);
264: 
265:         if (!is_dir($path)) {
266:             return;
267:         }
268: 
269:         $dir = dir($path);
270:         while (($entry = $dir->read()) !== false) {
271:             if (substr($entry, 0, $prefixLength) !== $this->settings['prefix']) {
272:                 continue;
273:             }
274: 
275:             try {
276:                 $file = new SplFileObject($path . $entry, 'r');
277:             } catch (Exception $e) {
278:                 continue;
279:             }
280: 
281:             if ($threshold) {
282:                 $mtime = $file->getMTime();
283: 
284:                 if ($mtime > $threshold) {
285:                     continue;
286:                 }
287:                 $expires = (int)$file->current();
288: 
289:                 if ($expires > $now) {
290:                     continue;
291:                 }
292:             }
293:             if ($file->isFile()) {
294:                 $filePath = $file->getRealPath();
295:                 $file = null;
296: 
297:                 //@codingStandardsIgnoreStart
298:                 @unlink($filePath);
299:                 //@codingStandardsIgnoreEnd
300:             }
301:         }
302:     }
303: 
304: /**
305:  * Not implemented
306:  *
307:  * @param string $key The key to decrement
308:  * @param int $offset The number to offset
309:  * @return void
310:  * @throws CacheException
311:  */
312:     public function decrement($key, $offset = 1) {
313:         throw new CacheException(__d('cake_dev', 'Files cannot be atomically decremented.'));
314:     }
315: 
316: /**
317:  * Not implemented
318:  *
319:  * @param string $key The key to decrement
320:  * @param int $offset The number to offset
321:  * @return void
322:  * @throws CacheException
323:  */
324:     public function increment($key, $offset = 1) {
325:         throw new CacheException(__d('cake_dev', 'Files cannot be atomically incremented.'));
326:     }
327: 
328: /**
329:  * Sets the current cache key this class is managing, and creates a writable SplFileObject
330:  * for the cache file the key is referring to.
331:  *
332:  * @param string $key The key
333:  * @param bool $createKey Whether the key should be created if it doesn't exists, or not
334:  * @return bool true if the cache key could be set, false otherwise
335:  */
336:     protected function _setKey($key, $createKey = false) {
337:         $groups = null;
338:         if (!empty($this->_groupPrefix)) {
339:             $groups = vsprintf($this->_groupPrefix, $this->groups());
340:         }
341:         $dir = $this->settings['path'] . $groups;
342: 
343:         if (!is_dir($dir)) {
344:             mkdir($dir, 0775, true);
345:         }
346:         $path = new SplFileInfo($dir . $key);
347: 
348:         if (!$createKey && !$path->isFile()) {
349:             return false;
350:         }
351:         if (empty($this->_File) || $this->_File->getBaseName() !== $key) {
352:             $exists = file_exists($path->getPathname());
353:             try {
354:                 $this->_File = $path->openFile('c+');
355:             } catch (Exception $e) {
356:                 trigger_error($e->getMessage(), E_USER_WARNING);
357:                 return false;
358:             }
359:             unset($path);
360: 
361:             if (!$exists && !chmod($this->_File->getPathname(), (int)$this->settings['mask'])) {
362:                 trigger_error(__d(
363:                     'cake_dev', 'Could not apply permission mask "%s" on cache file "%s"',
364:                     array($this->_File->getPathname(), $this->settings['mask'])), E_USER_WARNING);
365:             }
366:         }
367:         return true;
368:     }
369: 
370: /**
371:  * Determine is cache directory is writable
372:  *
373:  * @return bool
374:  */
375:     protected function _active() {
376:         $dir = new SplFileInfo($this->settings['path']);
377:         if (Configure::read('debug')) {
378:             $path = $dir->getPathname();
379:             if (!is_dir($path)) {
380:                 mkdir($path, 0775, true);
381:             }
382:         }
383:         if ($this->_init && !($dir->isDir() && $dir->isWritable())) {
384:             $this->_init = false;
385:             trigger_error(__d('cake_dev', '%s is not writable', $this->settings['path']), E_USER_WARNING);
386:             return false;
387:         }
388:         return true;
389:     }
390: 
391: /**
392:  * Generates a safe key for use with cache engine storage engines.
393:  *
394:  * @param string $key the key passed over
395:  * @return mixed string $key or false
396:  */
397:     public function key($key) {
398:         if (empty($key)) {
399:             return false;
400:         }
401: 
402:         $key = Inflector::underscore(str_replace(array(DS, '/', '.', '<', '>', '?', ':', '|', '*', '"'), '_', strval($key)));
403:         return $key;
404:     }
405: 
406: /**
407:  * Recursively deletes all files under any directory named as $group
408:  *
409:  * @param string $group The group to clear.
410:  * @return bool success
411:  */
412:     public function clearGroup($group) {
413:         $this->_File = null;
414:         $directoryIterator = new RecursiveDirectoryIterator($this->settings['path']);
415:         $contents = new RecursiveIteratorIterator($directoryIterator, RecursiveIteratorIterator::CHILD_FIRST);
416:         foreach ($contents as $object) {
417:             $containsGroup = strpos($object->getPathName(), DS . $group . DS) !== false;
418:             $hasPrefix = true;
419:             if (strlen($this->settings['prefix']) !== 0) {
420:                 $hasPrefix = strpos($object->getBaseName(), $this->settings['prefix']) === 0;
421:             }
422:             if ($object->isFile() && $containsGroup && $hasPrefix) {
423:                 $path = $object->getPathName();
424:                 $object = null;
425:                 //@codingStandardsIgnoreStart
426:                 @unlink($path);
427:                 //@codingStandardsIgnoreEnd
428:             }
429:         }
430:         return true;
431:     }
432: 
433: /**
434:  * Write data for key into cache if it doesn't exist already.
435:  * If it already exists, it fails and returns false.
436:  *
437:  * @param string $key Identifier for the data.
438:  * @param mixed $value Data to be cached.
439:  * @param int $duration How long to cache the data, in seconds.
440:  * @return bool True if the data was successfully cached, false on failure.
441:  */
442:     public function add($key, $value, $duration) {
443:         $cachedValue = $this->read($key);
444:         if ($cachedValue === false) {
445:             return $this->write($key, $value, $duration);
446:         }
447:         return false;
448:     }
449: }
450: