Update atst to atat

atat/utils/session_limiter.py

@@ -0,0 +1,20 @@
+from atat.domain.users import Users
+
+
+class SessionLimiter(object):
+    def __init__(self, config, session, redis):
+        self.limit_logins = config["LIMIT_CONCURRENT_SESSIONS"]
+        self.session_prefix = config.get("SESSION_KEY_PREFIX", "session:")
+        self.session = session
+        self.redis = redis
+
+    def on_login(self, user):
+        if not self.limit_logins:
+            return
+
+        session_id = self.session.sid
+        self._delete_session(user.last_session_id)
+        Users.update_last_session_id(user, session_id)
+
+    def _delete_session(self, session_id):
+        self.redis.delete(f"{self.session_prefix}{session_id}")