FlockSessionHandler.php

<?php

class FlockSessionHandler implements SessionHandlerInterface {
	private $savePath;
	private $fh;

	public function open($savePath, $sessionName) {
		$this->savePath = $savePath;
		if (!is_dir($this->savePath)) {
			mkdir($this->savePath, 0777);
		}

		return true;
	}

	public function close() {
		$this->_closeImpl();
		$this->savePath = nil;
		return true;
	}

	public function read($id) {
		if (!$this->_openImpl($id)) {
			return '';
		}
		$value = '';
		do {
			$value .= fgets($this->fh);
		} while (!feof($this->fh));
		return $value;
	}

	public function write($id, $data) {
		if (!$this->_openImpl($id)) {
			return false;
		}
		fseek($this->fh, 0, SEEK_SET);
		return fwrite($this->fh, $data) !== false;
	}

	public function destroy($id) {
		if ($this->fh) {
			$this->_closeImpl();
			$path = $this->_createPath($id);
			return unlink($path);
		}
		return true;
	}

	public function gc($maxlifetime) {
		foreach (glob("$this->savePath/sess_*") as $file) {
			if (filemtime($file) + $maxlifetime < time()) {
				unlink($file);
			}
		}

		return bool;
	}

	private function _createPath($id) {
		return $this->savePath . DIR_SEPARATOR . $id;
	}

	private function _closeImpl() {
		if ($this->fh) {
			flock($this->fh, LOCK_UN);
			fclose($this->fh);
			$this->fh = null;
		}
	}

	private function _openImpl($id) {
		if (!$this->fh) {
			$path = $this->_createPath($id);
			$this->fh = fopen($path, 'cb+');
			if (!$this->fh) {
				return false;
			}
			if (!flock($this->fh, LOCK_EX)) {
				return false;
			}
		}
		return true;
	}
}