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 (https://cakephp.org)
10 * Copyright (c) Cake Software Foundation, Inc. (https://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. (https://cakefoundation.org)
17 * @link          https://cakephp.org CakePHP(tm) Project
18 * @since         CakePHP(tm) v 1.2.0.4933
19 * @license       https://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 */
31class 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		if ($dir === false) {
271			return;
272		}
273
274		while (($entry = $dir->read()) !== false) {
275			if (substr($entry, 0, $prefixLength) !== $this->settings['prefix']) {
276				continue;
277			}
278
279			try {
280				$file = new SplFileObject($path . $entry, 'r');
281			} catch (Exception $e) {
282				continue;
283			}
284
285			if ($threshold) {
286				$mtime = $file->getMTime();
287
288				if ($mtime > $threshold) {
289					continue;
290				}
291				$expires = (int)$file->current();
292
293				if ($expires > $now) {
294					continue;
295				}
296			}
297			if ($file->isFile()) {
298				$filePath = $file->getRealPath();
299				$file = null;
300
301				//@codingStandardsIgnoreStart
302				@unlink($filePath);
303				//@codingStandardsIgnoreEnd
304			}
305		}
306	}
307
308/**
309 * Not implemented
310 *
311 * @param string $key The key to decrement
312 * @param int $offset The number to offset
313 * @return void
314 * @throws CacheException
315 */
316	public function decrement($key, $offset = 1) {
317		throw new CacheException(__d('cake_dev', 'Files cannot be atomically decremented.'));
318	}
319
320/**
321 * Not implemented
322 *
323 * @param string $key The key to decrement
324 * @param int $offset The number to offset
325 * @return void
326 * @throws CacheException
327 */
328	public function increment($key, $offset = 1) {
329		throw new CacheException(__d('cake_dev', 'Files cannot be atomically incremented.'));
330	}
331
332/**
333 * Sets the current cache key this class is managing, and creates a writable SplFileObject
334 * for the cache file the key is referring to.
335 *
336 * @param string $key The key
337 * @param bool $createKey Whether the key should be created if it doesn't exists, or not
338 * @return bool true if the cache key could be set, false otherwise
339 */
340	protected function _setKey($key, $createKey = false) {
341		$groups = null;
342		if (!empty($this->_groupPrefix)) {
343			$groups = vsprintf($this->_groupPrefix, $this->groups());
344		}
345		$dir = $this->settings['path'] . $groups;
346
347		if (!is_dir($dir)) {
348			mkdir($dir, 0775, true);
349		}
350		$path = new SplFileInfo($dir . $key);
351
352		if (!$createKey && !$path->isFile()) {
353			return false;
354		}
355		if (
356			empty($this->_File) ||
357			$this->_File->getBaseName() !== $key ||
358			$this->_File->valid() === false
359		) {
360			$exists = file_exists($path->getPathname());
361			try {
362				$this->_File = $path->openFile('c+');
363			} catch (Exception $e) {
364				trigger_error($e->getMessage(), E_USER_WARNING);
365				return false;
366			}
367			unset($path);
368
369			if (!$exists && !chmod($this->_File->getPathname(), (int)$this->settings['mask'])) {
370				trigger_error(__d(
371					'cake_dev', 'Could not apply permission mask "%s" on cache file "%s"',
372					array($this->_File->getPathname(), $this->settings['mask'])), E_USER_WARNING);
373			}
374		}
375		return true;
376	}
377
378/**
379 * Determine is cache directory is writable
380 *
381 * @return bool
382 */
383	protected function _active() {
384		$dir = new SplFileInfo($this->settings['path']);
385		if (Configure::read('debug')) {
386			$path = $dir->getPathname();
387			if (!is_dir($path)) {
388				mkdir($path, 0775, true);
389			}
390		}
391		if ($this->_init && !($dir->isDir() && $dir->isWritable())) {
392			$this->_init = false;
393			trigger_error(__d('cake_dev', '%s is not writable', $this->settings['path']), E_USER_WARNING);
394			return false;
395		}
396		return true;
397	}
398
399/**
400 * Generates a safe key for use with cache engine storage engines.
401 *
402 * @param string $key the key passed over
403 * @return mixed string $key or false
404 */
405	public function key($key) {
406		if (empty($key)) {
407			return false;
408		}
409
410		$key = Inflector::underscore(str_replace(array(DS, '/', '.', '<', '>', '?', ':', '|', '*', '"'), '_', strval($key)));
411		return $key;
412	}
413
414/**
415 * Recursively deletes all files under any directory named as $group
416 *
417 * @param string $group The group to clear.
418 * @return bool success
419 */
420	public function clearGroup($group) {
421		$this->_File = null;
422		$directoryIterator = new RecursiveDirectoryIterator($this->settings['path']);
423		$contents = new RecursiveIteratorIterator($directoryIterator, RecursiveIteratorIterator::CHILD_FIRST);
424		foreach ($contents as $object) {
425			$containsGroup = strpos($object->getPathName(), DS . $group . DS) !== false;
426			$hasPrefix = true;
427			if (strlen($this->settings['prefix']) !== 0) {
428				$hasPrefix = strpos($object->getBaseName(), $this->settings['prefix']) === 0;
429			}
430			if ($object->isFile() && $containsGroup && $hasPrefix) {
431				$path = $object->getPathName();
432				$object = null;
433				//@codingStandardsIgnoreStart
434				@unlink($path);
435				//@codingStandardsIgnoreEnd
436			}
437		}
438		return true;
439	}
440
441/**
442 * Write data for key into cache if it doesn't exist already.
443 * If it already exists, it fails and returns false.
444 *
445 * @param string $key Identifier for the data.
446 * @param mixed $value Data to be cached.
447 * @param int $duration How long to cache the data, in seconds.
448 * @return bool True if the data was successfully cached, false on failure.
449 */
450	public function add($key, $value, $duration) {
451		$cachedValue = $this->read($key);
452		if ($cachedValue === false) {
453			return $this->write($key, $value, $duration);
454		}
455		return false;
456	}
457}
458