Appengine: Comparing existing GetMulti() to proposed Query.ByKey()

getbykey.go

// Comparing existing GetMulti() to proposed Query.ByKey()
//
// https://groups.google.com/d/topic/google-appengine-go/R7jRPz0frlE/discussion

type Thingy struct {
	A, B string
}

const N = 3

func GetThingyMulti(w http.ResponseWriter, r *http.Request) {
	c := appengine.NewContext(r)

	var keys = make([]*ds.Key, N)
	var entities = make([]interface{}, N)

	for i := 0; i < N; i++ {
		keys[i] = ds.NewKey(c, "Thingy", "", int64(i+1), nil)
		thingies[i] = &Thingy{}
	}

	if err := ds.GetMulti(c, keys, entities); err != nil {
		fmt.Fprintf(w, "error: %#v\n", err)
		return
	}

	for _, e := range entities {
		e, ok := e.(*Thingy)
		if !ok {
			fmt.Fprintf(w, "error: %#v\n")
			return
		}
		fmt.Fprintf(w, "%#v: %#v\n", e.A, e.B)
	}
}

func GetThingyQuery(w http.ResponseWriter, r *http.Request) {
	c := appengine.NewContext(r)
	q := ds.NewQuery("Thingy")

	for i := 0; i< N; i++ {
		q.ByKey(ds.NewKey(c, "Thingy", "", int64(i+1), nil))
	}
	iter := q.Run(c)

	var t Thingy

	for _, err := iter.Next(&t); err != ds.Done; _, err = iter.Next() {
		if err != nil {
			fmt.Fprintf(w, "error: %#v\n", err)
			return
		}
		fmt.Fprintf(w, "%#v: %#v\n", t.A, t.B)
	}
}