func (q *queryImpl) Ancestor(k ds.Key) ds.Query {
return q.checkMutateClone(
func() error {
if k == nil {
// SDK has an explicit nil-check
return errors.New("datastore: nil query ancestor")
}
if k.Namespace() != q.ns {
return fmt.Errorf("bad namespace: %q (expected %q)", k.Namespace(), q.ns)
}
if !k.Valid(false, globalAppID, q.ns) {
// technically the SDK implementation does a Weird Thing (tm) if both the
// stringID and intID are set on a key; it only serializes the stringID in
// the proto. This means that if you set the Ancestor to an invalid key,
// you'll never actually hear about it. Instead of doing that insanity, we
// just swap to an error here.
return ds.ErrInvalidKey
}
if q.eqFilters["__ancestor__"] != nil {
return errors.New("cannot have more than one ancestor")
}
return nil
},
func(q *queryImpl) {
q.addEqFilt("__ancestor__", ds.MkProperty(k))
})
}