Make rawdatastore API safer for writing filters.

impl/prod/datastore_key.go

Index: impl/prod/datastore_key.go
diff --git a/impl/prod/datastore_key.go b/impl/prod/datastore_key.go
index ac1980a97644f289e8a31f9cbfb4301c7ff079ac..b2e93937147ee70209db6a0c6dc6b9e98889bd35 100644
--- a/impl/prod/datastore_key.go
+++ b/impl/prod/datastore_key.go
@@ -22,25 +22,6 @@ 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) (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 rds.Key) *datastore.Key {
 	if rkey, ok := k.(dsKeyImpl); ok {
@@ -59,16 +40,6 @@ func dsF2R(k rds.Key) *datastore.Key {
 	return rkey
 }
 
-// dsMR2F (DS multi-real-to-fake) converts a slice of SDK keys to their wrapped
-// types.
-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 []rds.Key) []*datastore.Key {
 	ret := make([]*datastore.Key, len(ks))