caching idea go

caching_example.go

func Cache(key string, expirationTime int, f func() (interface{}, error)) (interface{}, error) {
	logger.Info("Check caching if exist return the result immediately")
	q, e := f()
	logger.Info("Set result to cache")
	return q, e
}

func (r *repository) ResolveQuestionSetBySerials(serials []string) (*[]RubelQuestionSet, error) {
	questionSets, err := Cache("Test", 100, func() (interface{}, error) {
		
		// this part used to resolve the records
		session := r.session.Clone()

		c := session.DB("xxx").C("xxxxx")

		questionSets := []RubelQuestionSet{}

		err := c.Find(bson.M{"serial": bson.M{"$in": serials}}).All(&questionSets)

		if err != nil {
			return nil, err
		}

		return &questionSets, err
	})

	if err != nil {
		// handle error
		return nil, err
	}
	
	// however still need to do casting
	return questionSets.(*[]RubelQuestionSet), err
}