Add "MkKeyContext" KeyContext generation function.

impl/prod/datastore_key.go

 // Copyright 2015 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package prod
 
 import (
         ds "github.com/luci/gae/service/datastore"
         "github.com/luci/luci-go/common/errors"
         "golang.org/x/net/context"
         "google.golang.org/appengine"
         "google.golang.org/appengine/datastore"
 )
 
 type dsKeyImpl struct {
         *datastore.Key
 }
 
 // dsR2F (DS real-to-fake) converts an SDK Key to a ds.Key
 func dsR2F(k *datastore.Key) *ds.Key {
         if k == nil {
                 return nil
         }
-        kc := ds.KeyContext{k.AppID(), k.Namespace()}
+        kc := ds.MkKeyContext(k.AppID(), k.Namespace())
 
         count := 0
         for nk := k; nk != nil; nk = nk.Parent() {
                 count++
         }
 
         toks := make([]ds.KeyTok, count)
 
         for ; k != nil; k = k.Parent() {
                 count--
@@ skipping 30 matching lines @@
 func dsMF2R(aeCtx context.Context, ks []*ds.Key) ([]*datastore.Key, error) {
         lme := errors.NewLazyMultiError(len(ks))
         ret := make([]*datastore.Key, len(ks))
         err := error(nil)
         for i, k := range ks {
                 ret[i], err = dsF2R(aeCtx, k)
                 lme.Assign(i, err)
         }
         return ret, lme.Get()
 }