Refactor a bit.

impl/prod/datastore_key.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package prod
 
 import (
-        "github.com/luci/gae"
-        "github.com/luci/gae/helper"
+        rds "github.com/luci/gae/service/rawdatastore"
         "google.golang.org/appengine/datastore"
 )
 
 type dsKeyImpl struct {
         *datastore.Key
 }
 
-var _ gae.DSKey = dsKeyImpl{}
+var _ rds.Key = dsKeyImpl{}
 
-func (k dsKeyImpl) Parent() gae.DSKey { return dsR2F(k.Key.Parent()) }
+func (k dsKeyImpl) Parent() rds.Key { return dsR2F(k.Key.Parent()) }
 
-// dsR2F (DS real-to-fake) converts an SDK Key to a gae.DSKey
-func dsR2F(k *datastore.Key) gae.DSKey {
+// dsR2F (DS real-to-fake) converts an SDK Key to a rds.Key
+func dsR2F(k *datastore.Key) rds.Key {
         return dsKeyImpl{k}
 }
 
 // dsR2FErr (DS real-to-fake with error) acts like dsR2F, but is for wrapping function
 // invocations which return (*Key, error). e.g.
 //
 //   return dsR2FErr(datastore.Put(...))
 //
 // instead of:
 //
 //   k, err := datastore.Put(...)
 //   if err != nil {
 //     return nil, err
 //   }
 //   return dsR2F(k), nil
-func dsR2FErr(k *datastore.Key, err error) (gae.DSKey, error) {
+func dsR2FErr(k *datastore.Key, err error) (rds.Key, error) {
         if err != nil {
                 return nil, err
         }
         return dsR2F(k), nil
 }
 
 // dsF2R (DS fake-to-real) converts a DSKey back to an SDK *Key.
-func dsF2R(k gae.DSKey) *datastore.Key {
+func dsF2R(k rds.Key) *datastore.Key {
         if rkey, ok := k.(dsKeyImpl); ok {
                 return rkey.Key
         }
         // we should always hit the fast case above, but just in case, safely round
         // trip through the proto encoding.
-        rkey, err := datastore.DecodeKey(helper.DSKeyEncode(k))
+        rkey, err := datastore.DecodeKey(rds.KeyEncode(k))
         if err != nil {
                 // should never happen in a good program, but it's not ignorable, and
                 // passing an error back makes this function too cumbersome (and it causes
                 // this `if err != nil { panic(err) }` logic to show up in a bunch of
                 // places. Realistically, everything should hit the early exit clause above.
                 panic(err)
         }
         return rkey
 }
 
 // dsMR2F (DS multi-real-to-fake) converts a slice of SDK keys to their wrapped
 // types.
-func dsMR2F(ks []*datastore.Key) []gae.DSKey {
-        ret := make([]gae.DSKey, len(ks))
+func dsMR2F(ks []*datastore.Key) []rds.Key {
+        ret := make([]rds.Key, len(ks))
         for i, k := range ks {
                 ret[i] = dsR2F(k)
         }
         return ret
 }
 
 // dsMF2R (DS multi-fake-to-fake) converts a slice of wrapped keys to SDK keys.
-func dsMF2R(ks []gae.DSKey) []*datastore.Key {
+func dsMF2R(ks []rds.Key) []*datastore.Key {
         ret := make([]*datastore.Key, len(ks))
         for i, k := range ks {
                 ret[i] = dsF2R(k)
         }
         return ret
 }