flask源碼淺析——session機制

看了flask的session源碼，知道了flask的session

flask的open_session源碼

class SecureCookieSessionInterface(SessionInterface):
.....
    def open_session(self, app, request):
        s = self.get_signing_serializer(app)
        if s is None:
            return None
        val = request.cookies.get(app.session_cookie_name)
        if not val:
            return self.session_class()
        max_age = total_seconds(app.permanent_session_lifetime)
        try:
            data = s.loads(val, max_age=max_age)
            return self.session_class(data)
        except BadSignature:
            return self.session_class()
.....

能夠從源碼中看出，session中存放了 life_time 因此能夠根據這個存活時間進行session過濾。