umask = $umask; if (! $this->createPathIfNeeded($directory)) { throw new InvalidArgumentException(sprintf( 'The directory "%s" does not exist and could not be created.', $directory )); } if (! is_writable($directory)) { throw new InvalidArgumentException(sprintf( 'The directory "%s" is not writable.', $directory )); } // YES, this needs to be *after* createPathIfNeeded() $this->directory = realpath($directory); $this->extension = (string) $extension; $this->directoryStringLength = strlen($this->directory); $this->extensionStringLength = strlen($this->extension); $this->isRunningOnWindows = defined('PHP_WINDOWS_VERSION_BUILD'); } /** * Gets the cache directory. * * @return string */ public function getDirectory() { return $this->directory; } /** * Gets the cache file extension. * * @return string */ public function getExtension() { return $this->extension; } /** * @param string $id * * @return string */ protected function getFilename($id) { $hash = hash('sha256', $id); // This ensures that the filename is unique and that there are no invalid chars in it. if ( $id === '' || ((strlen($id) * 2 + $this->extensionStringLength) > 255) || ($this->isRunningOnWindows && ($this->directoryStringLength + 4 + strlen($id) * 2 + $this->extensionStringLength) > 258) ) { // Most filesystems have a limit of 255 chars for each path component. On Windows the the whole path is limited // to 260 chars (including terminating null char). Using long UNC ("\\?\" prefix) does not work with the PHP API. // And there is a bug in PHP (https://bugs.php.net/bug.php?id=70943) with path lengths of 259. // So if the id in hex representation would surpass the limit, we use the hash instead. The prefix prevents // collisions between the hash and bin2hex. $filename = '_' . $hash; } else { $filename = bin2hex($id); } return $this->directory . DIRECTORY_SEPARATOR . substr($hash, 0, 2) . DIRECTORY_SEPARATOR . $filename . $this->extension; } /** * {@inheritdoc} */ protected function doDelete($id) { $filename = $this->getFilename($id); return @unlink($filename) || ! file_exists($filename); } /** * {@inheritdoc} */ protected function doFlush() { foreach ($this->getIterator() as $name => $file) { if ($file->isDir()) { // Remove the intermediate directories which have been created to balance the tree. It only takes effect // if the directory is empty. If several caches share the same directory but with different file extensions, // the other ones are not removed. @rmdir($name); } elseif ($this->isFilenameEndingWithExtension($name)) { // If an extension is set, only remove files which end with the given extension. // If no extension is set, we have no other choice than removing everything. @unlink($name); } } return true; } /** * {@inheritdoc} */ protected function doGetStats() { $usage = 0; foreach ($this->getIterator() as $name => $file) { if ($file->isDir() || ! $this->isFilenameEndingWithExtension($name)) { continue; } $usage += $file->getSize(); } $free = disk_free_space($this->directory); return [ Cache::STATS_HITS => null, Cache::STATS_MISSES => null, Cache::STATS_UPTIME => null, Cache::STATS_MEMORY_USAGE => $usage, Cache::STATS_MEMORY_AVAILABLE => $free, ]; } /** * Create path if needed. * * @return bool TRUE on success or if path already exists, FALSE if path cannot be created. */ private function createPathIfNeeded(string $path): bool { if (! is_dir($path)) { if (@mkdir($path, 0777 & (~$this->umask), true) === false && ! is_dir($path)) { return false; } } return true; } /** * Writes a string content to file in an atomic way. * * @param string $filename Path to the file where to write the data. * @param string $content The content to write * * @return bool TRUE on success, FALSE if path cannot be created, if path is not writable or an any other error. */ protected function writeFile(string $filename, string $content): bool { $filepath = pathinfo($filename, PATHINFO_DIRNAME); if (! $this->createPathIfNeeded($filepath)) { return false; } if (! is_writable($filepath)) { return false; } $tmpFile = tempnam($filepath, 'swap'); @chmod($tmpFile, 0666 & (~$this->umask)); if (file_put_contents($tmpFile, $content) !== false) { @chmod($tmpFile, 0666 & (~$this->umask)); if (@rename($tmpFile, $filename)) { return true; } @unlink($tmpFile); } return false; } /** * @return Iterator */ private function getIterator(): Iterator { return new RecursiveIteratorIterator( new RecursiveDirectoryIterator($this->directory, FilesystemIterator::SKIP_DOTS), RecursiveIteratorIterator::CHILD_FIRST ); } /** * @param string $name The filename */ private function isFilenameEndingWithExtension(string $name): bool { return $this->extension === '' || strrpos($name, $this->extension) === strlen($name) - $this->extensionStringLength; } }