Class HttpHandler

pywebio/platform/adaptor/http.py:147–380

基于HTTP的后端Handler实现 .. note:: Don't need a lock when access HttpHandler._webio_sessions, See： https://stackoverflow.com/questions/1312331/using-a-global-dictionary-with-threads-in-python

# todo: use lock to avoid thread race condition
class HttpHandler:
    """基于HTTP的后端Handler实现

    .. note::
        Don't need a lock when access HttpHandler._webio_sessions, See：
        https://stackoverflow.com/questions/1312331/using-a-global-dictionary-with-threads-in-python

    """
    _webio_sessions = {}  # WebIOSessionID -> WebIOSession()
    _webio_transports = {}  # WebIOSessionID -> ReliableTransport(), type: Dict[str, ReliableTransport]
    _webio_expire = LRUDict()  # WebIOSessionID -> last active timestamp. In increasing order of last active time
    _webio_expire_lock = threading.Lock()

    _last_check_session_expire_ts = 0  # Timestamp of the last check session validation

    # After processing the POST request, wait for WAIT_MS_ON_POST milliseconds before generate response
    WAIT_MS_ON_POST = 100

    DEFAULT_SESSION_EXPIRE_SECONDS = 600  # Default session expiration time
    DEFAULT_SESSIONS_CLEANUP_INTERVAL = 300  # Default interval for clearing expired sessions (in seconds)

    @classmethod
    def _remove_expired_sessions(cls, session_expire_seconds):
        """清除当前会话列表中的过期会话"""
        logger.debug("removing expired sessions")
        while cls._webio_expire:
            sid, active_ts = cls._webio_expire.popitem(last=False)  # 弹出最不活跃的session info

            if time.time() - active_ts < session_expire_seconds:
                # this session is not expired
                cls._webio_expire[sid] = active_ts
                cls._webio_expire.move_to_end(sid, last=False)
                break

            # clean this session
            logger.debug("session %s expired" % sid)
            session = cls._webio_sessions.get(sid)
            if session:
                session.close(nonblock=True)
                del cls._webio_sessions[sid]
                del cls._webio_transports[sid]

    @classmethod
    def _remove_webio_session(cls, sid):
        cls._webio_sessions.pop(sid, None)
        cls._webio_expire.pop(sid, None)

    def _process_cors(self, context: HttpContext):
        """Handling cross-domain requests: check the source of the request and set headers"""
        origin = context.request_headers().get('Origin', '')
        if self.check_origin(origin):
            context.set_header('Access-Control-Allow-Origin', origin)
            context.set_header('Access-Control-Allow-Methods', 'GET, POST')
            context.set_header('Access-Control-Allow-Headers', 'content-type, webio-session-id')
            context.set_header('Access-Control-Expose-Headers', 'webio-session-id')
            context.set_header('Access-Control-Max-Age', str(1440 * 60))

    def interval_cleaning(self):