[M]HuanXinClient singleton

hx/client.py

 # -*- coding: utf-8 -*-
 import json
 from typing import Optional
+from threading import Lock
 
 from django.conf import settings
 import requests
@@ -39,6 +40,9 @@ def handle_huanxin_response_error(response: requests.models.Response, client=Non
     return result
 
 
+_instance = None
+_lock = Lock()
+
 class HuanXinClient(object):
     BASE_URL = getattr(settings, 'HX_BASE_URL', None)
     ORG_NAME = getattr(settings, 'HX_ORG_NAME', None)
@@ -54,6 +58,14 @@ class HuanXinClient(object):
         'huanxin config error'
         self.session = requests.Session()
 
+    @staticmethod
+    def __new__(cls, *args, **kwargs):
+        global _lock, _instance
+        _lock.acquire()
+        _instance = _instance or super(HuanXinClient, cls).__new__(cls)
+        _lock.release()
+        return _instance
+
     def _get_auth_token(self):
         GET_TOKEN_URL = '{base_url}/{org_name}/{app_name}/token'.format(
             base_url=self.BASE_URL,