Cake/Cache/Engine/FileEngine.php
| 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 | * PHP 5 |
| 10 | * |
| 11 | * CakePHP(tm) : Rapid Development Framework (http://cakephp.org) |
| 12 | * Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org) |
| 13 | * |
| 14 | * Licensed under The MIT License |
| 15 | * Redistributions of files must retain the above copyright notice. |
| 16 | * |
| 17 | * @copyright Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org) |
| 18 | * @link http://cakephp.org CakePHP(tm) Project |
| 19 | * @since CakePHP(tm) v 1.2.0.4933 |
| 20 | * @license MIT License (http://www.opensource.org/licenses/mit-license.php) |
| 21 | */ |
| 22 | |
| 23 | /** |
| 24 | * File Storage engine for cache. Filestorage is the slowest cache storage |
| 25 | * to read and write. However, it is good for servers that don't have other storage |
| 26 | * engine available, or have content which is not performance sensitive. |
| 27 | * |
| 28 | * You can configure a FileEngine cache, using Cache::config() |
| 29 | * |
| 30 | * @package Cake.Cache.Engine |
| 31 | */ |
| 32 | class FileEngine extends CacheEngine { |
| 33 | |
| 34 | /** |
| 35 | * Instance of SplFileObject class |
| 36 | * |
| 37 | * @var File |
| 38 | */ |
| 39 | protected $_File = null; |
| 40 | |
| 41 | /** |
| 42 | * Settings |
| 43 | * |
| 44 | * - path = absolute path to cache directory, default => CACHE |
| 45 | * - prefix = string prefix for filename, default => cake_ |
| 46 | * - lock = enable file locking on write, default => false |
| 47 | * - serialize = serialize the data, default => true |
| 48 | * |
| 49 | * @var array |
| 50 | * @see CacheEngine::__defaults |
| 51 | */ |
| 52 | public $settings = array(); |
| 53 | |
| 54 | /** |
| 55 | * True unless FileEngine::__active(); fails |
| 56 | * |
| 57 | * @var boolean |
| 58 | */ |
| 59 | protected $_init = true; |
| 60 | |
| 61 | /** |
| 62 | * Initialize the Cache Engine |
| 63 | * |
| 64 | * Called automatically by the cache frontend |
| 65 | * To reinitialize the settings call Cache::engine('EngineName', [optional] settings = array()); |
| 66 | * |
| 67 | * @param array $settings array of setting for the engine |
| 68 | * @return boolean True if the engine has been successfully initialized, false if not |
| 69 | */ |
| 70 | public function init($settings = array()) { |
| 71 | parent::init(array_merge( |
| 72 | array( |
| 73 | 'engine' => 'File', 'path' => CACHE, 'prefix' => 'cake_', 'lock' => true, |
| 74 | 'serialize' => true, 'isWindows' => false, 'mask' => 0664 |
| 75 | ), |
| 76 | $settings |
| 77 | )); |
| 78 | |
| 79 | if (DS === '\\') { |
| 80 | $this->settings['isWindows'] = true; |
| 81 | } |
| 82 | if (substr($this->settings['path'], -1) !== DS) { |
| 83 | $this->settings['path'] .= DS; |
| 84 | } |
| 85 | return $this->_active(); |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * Garbage collection. Permanently remove all expired and deleted data |
| 90 | * |
| 91 | * @return boolean True if garbage collection was successful, false on failure |
| 92 | */ |
| 93 | public function gc() { |
| 94 | return $this->clear(true); |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * Write data for key into cache |
| 99 | * |
| 100 | * @param string $key Identifier for the data |
| 101 | * @param mixed $data Data to be cached |
| 102 | * @param mixed $duration How long to cache the data, in seconds |
| 103 | * @return boolean True if the data was successfully cached, false on failure |
| 104 | */ |
| 105 | public function write($key, $data, $duration) { |
| 106 | if ($data === '' || !$this->_init) { |
| 107 | return false; |
| 108 | } |
| 109 | |
| 110 | if ($this->_setKey($key, true) === false) { |
| 111 | return false; |
| 112 | } |
| 113 | |
| 114 | $lineBreak = "\n"; |
| 115 | |
| 116 | if ($this->settings['isWindows']) { |
| 117 | $lineBreak = "\r\n"; |
| 118 | } |
| 119 | |
| 120 | if (!empty($this->settings['serialize'])) { |
| 121 | if ($this->settings['isWindows']) { |
| 122 | $data = str_replace('\\', '\\\\\\\\', serialize($data)); |
| 123 | } else { |
| 124 | $data = serialize($data); |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | $expires = time() + $duration; |
| 129 | $contents = $expires . $lineBreak . $data . $lineBreak; |
| 130 | |
| 131 | if ($this->settings['lock']) { |
| 132 | $this->_File->flock(LOCK_EX); |
| 133 | } |
| 134 | |
| 135 | $this->_File->rewind(); |
| 136 | $success = $this->_File->ftruncate(0) && $this->_File->fwrite($contents) && $this->_File->fflush(); |
| 137 | |
| 138 | if ($this->settings['lock']) { |
| 139 | $this->_File->flock(LOCK_UN); |
| 140 | } |
| 141 | |
| 142 | return $success; |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * Read a key from the cache |
| 147 | * |
| 148 | * @param string $key Identifier for the data |
| 149 | * @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it |
| 150 | */ |
| 151 | public function read($key) { |
| 152 | if (!$this->_init || $this->_setKey($key) === false) { |
| 153 | return false; |
| 154 | } |
| 155 | |
| 156 | if ($this->settings['lock']) { |
| 157 | $this->_File->flock(LOCK_SH); |
| 158 | } |
| 159 | |
| 160 | $this->_File->rewind(); |
| 161 | $time = time(); |
| 162 | $cachetime = intval($this->_File->current()); |
| 163 | |
| 164 | if ($cachetime !== false && ($cachetime < $time || ($time + $this->settings['duration']) < $cachetime)) { |
| 165 | if ($this->settings['lock']) { |
| 166 | $this->_File->flock(LOCK_UN); |
| 167 | } |
| 168 | return false; |
| 169 | } |
| 170 | |
| 171 | $data = ''; |
| 172 | $this->_File->next(); |
| 173 | while ($this->_File->valid()) { |
| 174 | $data .= $this->_File->current(); |
| 175 | $this->_File->next(); |
| 176 | } |
| 177 | |
| 178 | if ($this->settings['lock']) { |
| 179 | $this->_File->flock(LOCK_UN); |
| 180 | } |
| 181 | |
| 182 | $data = trim($data); |
| 183 | |
| 184 | if ($data !== '' && !empty($this->settings['serialize'])) { |
| 185 | if ($this->settings['isWindows']) { |
| 186 | $data = str_replace('\\\\\\\\', '\\', $data); |
| 187 | } |
| 188 | $data = unserialize((string)$data); |
| 189 | } |
| 190 | return $data; |
| 191 | } |
| 192 | |
| 193 | /** |
| 194 | * Delete a key from the cache |
| 195 | * |
| 196 | * @param string $key Identifier for the data |
| 197 | * @return boolean True if the value was successfully deleted, false if it didn't exist or couldn't be removed |
| 198 | */ |
| 199 | public function delete($key) { |
| 200 | if ($this->_setKey($key) === false || !$this->_init) { |
| 201 | return false; |
| 202 | } |
| 203 | $path = $this->_File->getRealPath(); |
| 204 | $this->_File = null; |
| 205 | return unlink($path); |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * Delete all values from the cache |
| 210 | * |
| 211 | * @param boolean $check Optional - only delete expired cache items |
| 212 | * @return boolean True if the cache was successfully cleared, false otherwise |
| 213 | */ |
| 214 | public function clear($check) { |
| 215 | if (!$this->_init) { |
| 216 | return false; |
| 217 | } |
| 218 | $dir = dir($this->settings['path']); |
| 219 | if ($check) { |
| 220 | $now = time(); |
| 221 | $threshold = $now - $this->settings['duration']; |
| 222 | } |
| 223 | $prefixLength = strlen($this->settings['prefix']); |
| 224 | while (($entry = $dir->read()) !== false) { |
| 225 | if (substr($entry, 0, $prefixLength) !== $this->settings['prefix']) { |
| 226 | continue; |
| 227 | } |
| 228 | if ($this->_setKey($entry) === false) { |
| 229 | continue; |
| 230 | } |
| 231 | if ($check) { |
| 232 | $mtime = $this->_File->getMTime(); |
| 233 | |
| 234 | if ($mtime > $threshold) { |
| 235 | continue; |
| 236 | } |
| 237 | |
| 238 | $expires = (int)$this->_File->current(); |
| 239 | |
| 240 | if ($expires > $now) { |
| 241 | continue; |
| 242 | } |
| 243 | } |
| 244 | $path = $this->_File->getRealPath(); |
| 245 | $this->_File = null; |
| 246 | if (file_exists($path)) { |
| 247 | unlink($path); |
| 248 | } |
| 249 | } |
| 250 | $dir->close(); |
| 251 | return true; |
| 252 | } |
| 253 | |
| 254 | /** |
| 255 | * Not implemented |
| 256 | * |
| 257 | * @param string $key |
| 258 | * @param integer $offset |
| 259 | * @return void |
| 260 | * @throws CacheException |
| 261 | */ |
| 262 | public function decrement($key, $offset = 1) { |
| 263 | throw new CacheException(__d('cake_dev', 'Files cannot be atomically decremented.')); |
| 264 | } |
| 265 | |
| 266 | /** |
| 267 | * Not implemented |
| 268 | * |
| 269 | * @param string $key |
| 270 | * @param integer $offset |
| 271 | * @return void |
| 272 | * @throws CacheException |
| 273 | */ |
| 274 | public function increment($key, $offset = 1) { |
| 275 | throw new CacheException(__d('cake_dev', 'Files cannot be atomically incremented.')); |
| 276 | } |
| 277 | |
| 278 | /** |
| 279 | * Sets the current cache key this class is managing, and creates a writable SplFileObject |
| 280 | * for the cache file the key is referring to. |
| 281 | * |
| 282 | * @param string $key The key |
| 283 | * @param boolean $createKey Whether the key should be created if it doesn't exists, or not |
| 284 | * @return boolean true if the cache key could be set, false otherwise |
| 285 | */ |
| 286 | protected function _setKey($key, $createKey = false) { |
| 287 | $path = new SplFileInfo($this->settings['path'] . $key); |
| 288 | |
| 289 | if (!$createKey && !$path->isFile()) { |
| 290 | return false; |
| 291 | } |
| 292 | if (empty($this->_File) || $this->_File->getBaseName() !== $key) { |
| 293 | $exists = file_exists($path->getPathname()); |
| 294 | try { |
| 295 | $this->_File = $path->openFile('c+'); |
| 296 | } catch (Exception $e) { |
| 297 | trigger_error($e->getMessage(), E_USER_WARNING); |
| 298 | return false; |
| 299 | } |
| 300 | unset($path); |
| 301 | |
| 302 | if (!$exists && !chmod($this->_File->getPathname(), (int)$this->settings['mask'])) { |
| 303 | trigger_error(__d( |
| 304 | 'cake_dev', 'Could not apply permission mask "%s" on cache file "%s"', |
| 305 | array($this->_File->getPathname(), $this->settings['mask'])), E_USER_WARNING); |
| 306 | } |
| 307 | } |
| 308 | return true; |
| 309 | } |
| 310 | |
| 311 | /** |
| 312 | * Determine is cache directory is writable |
| 313 | * |
| 314 | * @return boolean |
| 315 | */ |
| 316 | protected function _active() { |
| 317 | $dir = new SplFileInfo($this->settings['path']); |
| 318 | if ($this->_init && !($dir->isDir() && $dir->isWritable())) { |
| 319 | $this->_init = false; |
| 320 | trigger_error(__d('cake_dev', '%s is not writable', $this->settings['path']), E_USER_WARNING); |
| 321 | return false; |
| 322 | } |
| 323 | return true; |
| 324 | } |
| 325 | |
| 326 | } |
| 327 | |
| 328 |