feat: add online status int

Author: FGadvancer

constant/constant.go

@@ -151,6 +151,9 @@ const (
 	Registered    = "registered"
 	UnRegistered  = "unregistered"
 
+	Online  = 1
+	Offline = 0
+
 	// MsgReceiveOpt.
 	ReceiveMessage          = 0
 	NotReceiveMessage       = 1
@@ -362,7 +365,7 @@ const CallbackCommand = "command"
 
 const BatchNum = 100
 
-//Subscribe to user constants
+// Subscribe to user constants
 const (
 	SubscriberUser = 1
 	Unsubscribe    = 2