medium / singleflight

sf_2.go

type App struct {
   g singleflight.Group
}

func (a *App) GetNodeStat(nodeID string) (*NodeStat, error) {
   f := func() (interface{}, error){
      return a.GetNodeStatSync(nodeID)
   }
   result, err, _ := a.g.Do(nodeID, f)
   if err != nil {
      return nil, err
   }
   stat, ok := result.(*NodeStat)
   if !ok {
      return nil, errors.New("unable to cast interface to NodeStat")
   }
   return stat, nil
}