diff options
Diffstat (limited to 'lib/classes/cache/FileCache.php')
| -rw-r--r-- | lib/classes/cache/FileCache.php | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/lib/classes/cache/FileCache.php b/lib/classes/cache/FileCache.php new file mode 100644 index 0000000..d760f08 --- /dev/null +++ b/lib/classes/cache/FileCache.php @@ -0,0 +1,278 @@ +<?php + +namespace Studip\Cache; + +use Config; +use Exception; +use Psr\Cache\CacheItemInterface; + +/** + * Cache implementation using files + * + * @author André Noack <noack@data-quest.de> + * @copyright 2007 André Noack <noack@data-quest.de> + * @license GPL2 or any later version + */ +class FileCache extends Cache +{ + use KeyTrait; + + /** + * full path to cache directory + * + * @var string + */ + private string $dir; + + /** + * @return string A translateable display name for this cache class. + */ + public static function getDisplayName(): string + { + return _('Dateisystem'); + } + + /** + * without the 'dir' argument the cache path is taken from + * $CACHING_FILECACHE_PATH or is set to + * $TMP_PATH/studip_cache + * + * @param string $path the path to use + * @throws Exception if the directory does not exist or could not be + * created + */ + public function __construct(string $path = '') + { + $this->dir = $path + ?: ( + Config::get()->SYSTEMCACHE['type'] === self::class + ? Config::get()->SYSTEMCACHE['config']['path'] + : '' + ) + ?: $GLOBALS['CACHING_FILECACHE_PATH'] + ?: ($GLOBALS['TMP_PATH'] . '/' . 'studip_cache'); + $this->dir = rtrim($this->dir, '\\/') . '/'; + + if (!is_dir($this->dir) && !@mkdir($this->dir, 0700)) { + throw new \Exception('Could not create directory: ' . $this->dir); + } + + if (!is_writable($this->dir)) { + throw new \Exception('Can not write to directory: ' . $this->dir); + } + } + + /** + * get path to cache directory + * + * @return string + */ + public function getCacheDir() + { + return $this->dir; + } + + /** + * expire cache item + * + * @param string $arg + * + * @return void + * @throws Exception + * @see Cache::expire() + */ + public function expire($arg) + { + $key = $this->getCacheKey($arg); + + if ($file = $this->getPathAndFile($key)){ + @unlink($file); + } + } + + /** + * Expire all items from the cache. + */ + public function flush() + { + rmdirr($this->dir); + } + + /** + * checks if specified cache item is expired + * if expired the cache file is deleted + * + * @param string $key a cache key to check + * + * @return array|bool the path to the cache file or false if expired + * @throws Exception + */ + private function check($key) + { + if ($file = $this->getPathAndFile($key)){ + [$id, $expire] = explode('-', basename($file)); + if (time() < $expire) { + return [$file, $expire]; + } else { + @unlink($file); + } + } + return false; + } + + /** + * get the full path to a cache file + * + * the cache files are organized in sub-folders named by + * the first two characters of the hashed cache key. + * the filename is constructed from the hashed cache key + * and the timestamp of expiration + * + * @param string $key a cache key + * @param int|null $expire expiry time in seconds + * + * @return string|bool full path to cache item or false on failure + * @throws Exception + */ + private function getPathAndFile(string $key, ?int $expire = null): bool|string + { + $id = hash('md5', $key); + $path = $this->dir . mb_substr($id, 0, 2); + if (!is_dir($path) && !@mkdir($path, 0700)) { + throw new \Exception('Could not create directory: ' . $path); + } + if (!is_null($expire)){ + return $path . '/' . $id . '-' . (time() + $expire); + } else { + $files = @glob("{$path}/{$id}*"); + if (count($files) > 0) { + return $files[0]; + } + } + return false; + } + + /** + * purges expired entries from the cache directory + * + * @param bool $be_quiet echo messages if set to false + * + * @return int the number of deleted files + */ + public function purge(bool $be_quiet = true): int + { + $now = time(); + $deleted = 0; + foreach (@glob($this->dir . '*', GLOB_ONLYDIR) as $current_dir){ + foreach (@glob("{$current_dir}/*") as $file){ + [$id, $expire] = explode('-', basename($file)); + if ($expire < $now) { + if (@unlink($file)) { + ++$deleted; + if (!$be_quiet) { + echo "File: {$file} deleted.\n"; + } + } + } else if (!$be_quiet) { + echo "File: {$file} expires on " . date('Y-m-d H:i:s', $expire) . "\n"; + } + } + } + return $deleted; + } + + /** + * Return statistics. + * + * @return array|array[] + */ + public function getStats(): array + { + return [ + __CLASS__ => [ + 'name' => _('Anzahl Einträge'), + 'value' => \DBManager::get()->fetchColumn("SELECT COUNT(*) FROM `cache`") + ] + ]; + } + + /** + * Return the Vue component name and props that handle configuration. + * + * @return array + */ + public static function getConfig(): array + { + $currentCache = Config::get()->SYSTEMCACHE; + + // Set default config for this cache + $currentConfig = [ + 'path' => $GLOBALS['TMP_PATH'] . '/studip_cache' + ]; + + // If this cache is set as system cache, use config from global settings. + if ($currentCache['type'] == __CLASS__) { + $currentConfig = $currentCache['config']; + } + + return [ + 'component' => 'FileCacheConfig', + 'props' => $currentConfig + ]; + } + + /** + * @inheritDoc + */ + public function getItem(string $key): CacheItemInterface + { + $real_key = $this->getCacheKey($key); + + $item = new \Studip\Cache\Item($key); + + $file_data = $this->check($real_key); + if ($file_data) { + $file = $file_data[0]; + $expire = $file_data[1]; + $f = @fopen($file, 'rb'); + if ($f) { + @flock($f, LOCK_SH); + $result = stream_get_contents($f); + @fclose($f); + } + $item->setHit(); + $item->set(unserialize($result)); + $expiration = new \DateTime(); + $expiration->setTimestamp($expire); + $item->expiresAt($expiration); + } + return $item; + } + + /** + * @inheritDoc + */ + public function hasItem(string $key): bool + { + $real_key = $this->getCacheKey($key); + $file_data = $this->check($real_key); + return $file_data !== false; + } + + /** + * @inheritDoc + */ + public function save(CacheItemInterface $item): bool + { + $expiration = $this->getExpiration($item); + if ($expiration < 1) { + //The item would expire immediately. + return false; + } + + $real_key = $this->getCacheKey($item->getKey()); + $this->expire($real_key); + $file = $this->getPathAndFile($real_key, $expiration); + return @file_put_contents($file, serialize($item->get()), LOCK_EX); + } +} |