[Feature] 添加signals 解耦代码

apps/terminal/tasks.py

@@ -1,19 +1,15 @@
 # -*- coding: utf-8 -*-
 #
-import threading
 import time
 
 from celery import shared_task
 from django.core.cache import cache
-from django.db.utils import ProgrammingError
+from django.db.utils import ProgrammingError, OperationalError
 
 from .models import Session
 
 
 
-ASSETS_CACHE_KEY = "terminal__session__assets"
-USERS_CACHE_KEY = "terminal__session__users"
-SYSTEM_USER_CACHE_KEY = "terminal__session__system_users"
 CACHE_REFRESH_INTERVAL = 10
 RUNNING = False
 
@@ -24,46 +20,7 @@ def clean_terminal_history():
     pass
 
 
-def get_session_asset_list():
-    return set(list(Session.objects.values_list('asset', flat=True)))
 
 
-def get_session_user_list():
-    return set(list(Session.objects.values_list('user', flat=True)))
 
 
-def get_session_system_user_list():
-    return set(list(Session.objects.values_list('system_user', flat=True)))
-
-
-def set_cache():
-    while True:
-        try:
-            assets = get_session_asset_list()
-            users = get_session_user_list()
-            system_users = get_session_system_user_list()
-
-            cache.set(ASSETS_CACHE_KEY, assets)
-            cache.set(USERS_CACHE_KEY, users)
-            cache.set(SYSTEM_USER_CACHE_KEY, system_users)
-        except ProgrammingError:
-            pass
-        finally:
-            time.sleep(10)
-
-
-def main():
-    global RUNNING
-    if RUNNING:
-        return
-    threads = []
-    thread = threading.Thread(target=set_cache)
-    threads.append(thread)
-
-    for t in threads:
-        t.daemon = True
-        t.start()
-        RUNNING = True
-
-# Todo: 不能migrations了
-main()