<?php
namespace Zeedhi\Framework\Session\Fallback;

/**
 * Interface SessionHandlerInterface
 *
 * SessionHandlerInterface for PHP < 5.4.
 * The order in which these methods are invoked by PHP are:
 * 1. open [session_start]
 * 2. read
 * 3. gc [optional depending on probability settings: gc_probability / gc_divisor]
 * 4. destroy [optional when session_regenerate_id(true) is used]
 * 5. write [session_write_close] or destroy [session_destroy]
 * 6. close
 *
 * Extensive documentation can be found at php.net, see links:
 *
 * @see     http://php.net/sessionhandlerinterface
 * @see     http://php.net/session.customhandler
 * @see     http://php.net/session-set-save-handler
 *
 * @package Zeedhi\Framework\Session\Fallback
 */
interface SessionHandlerInterface {

	/**
	 * Re-initializes existing session, or creates a new one.
	 *
	 * @see http://php.net/sessionhandlerinterface.open
	 *
	 * @param string $savePath    Save path
	 * @param string $sessionName Session name, see http://php.net/function.session-name.php
	 *
	 * @return bool true on success, false on failure
	 */
	public function open($savePath, $sessionName);

	/**
	 * Closes the current session.
	 *
	 * @see http://php.net/sessionhandlerinterface.close
	 *
	 * @return bool true on success, false on failure
	 */
	public function close();

	/**
	 * Reads the session data.
	 *
	 * @see http://php.net/sessionhandlerinterface.read
	 *
	 * @param string $sessionId Session ID, see http://php.net/function.session-id
	 *
	 * @return string Same session data as passed in write() or empty string when non-existent or on failure
	 */
	public function read($sessionId);

	/**
	 * Writes the session data to the storage.
	 *
	 * Care, the session ID passed to write() can be different from the one previously
	 * received in read() when the session ID changed due to session_regenerate_id().
	 *
	 * @see http://php.net/sessionhandlerinterface.write
	 *
	 * @param string $sessionId Session ID , see http://php.net/function.session-id
	 * @param string $data      Serialized session data to save
	 *
	 * @return bool true on success, false on failure
	 */
	public function write($sessionId, $data);

	/**
	 * Destroys a session.
	 *
	 * @see http://php.net/sessionhandlerinterface.destroy
	 *
	 * @param string $sessionId Session ID, see http://php.net/function.session-id
	 *
	 * @return bool true on success, false on failure
	 */
	public function destroy($sessionId);

	/**
	 * Cleans up expired sessions (garbage collection).
	 *
	 * @see http://php.net/sessionhandlerinterface.gc
	 *
	 * @param string|int $maxlifetime Sessions that have not updated for the last maxlifetime seconds will be removed
	 *
	 * @return bool true on success, false on failure
	 */
	public function gc($maxlifetime);
}