feat: add user request limit config (#98)

pkg/cache/user_mode.go

@@ -0,0 +1,22 @@
+package cache
+
+import "github.com/patrickmn/go-cache"
+
+// GetUserMode 获取当前对话模式
+func (s *UserService) GetUserMode(userId string) string {
+	sessionContext, ok := s.cache.Get(userId + "_mode")
+	if !ok {
+		return ""
+	}
+	return sessionContext.(string)
+}
+
+// SetUserMode 设置用户对话模式
+func (s *UserService) SetUserMode(userId string, mode string) {
+	s.cache.Set(userId+"_mode", mode, cache.DefaultExpiration)
+}
+
+// ClearUserMode 重置用户对话模式
+func (s *UserService) ClearUserMode(userId string) {
+	s.cache.Delete(userId + "_mode")
+}