impl/memory: Disallow empty namespace.

impl/prod/info.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 (
         "time"
 
         "github.com/luci/gae/service/info"
@@ skipping 22 matching lines @@
 
 func (g giImpl) AccessToken(scopes ...string) (token string, expiry time.Time, err error) {
         return appengine.AccessToken(g.aeCtx, scopes...)
 }
 func (g giImpl) AppID() string {
         return appengine.AppID(g.aeCtx)
 }
 func (g giImpl) FullyQualifiedAppID() string {
         return getProbeCache(g.usrCtx).fqaid
 }
-func (g giImpl) GetNamespace() string {
-        return getProbeCache(g.usrCtx).namespace
+func (g giImpl) GetNamespace() (string, bool) {
+        pc := getProbeCache(g.usrCtx)
+        if ns := pc.namespace; ns != nil {
+                return *ns, true
+        }
+        return "", false
 }
 func (g giImpl) Datacenter() string {
         return appengine.Datacenter(g.aeCtx)
 }
 func (g giImpl) DefaultVersionHostname() string {
         return appengine.DefaultVersionHostname(g.aeCtx)
 }
 func (g giImpl) InstanceID() string {
         return appengine.InstanceID()
 }
@@ skipping 12 matching lines @@
 func (g giImpl) ModuleName() (name string) {
         return appengine.ModuleName(g.aeCtx)
 }
 func (g giImpl) Namespace(namespace string) (context.Context, error) {
         aeCtx, err := appengine.Namespace(g.aeCtx, namespace)
         if err != nil {
                 return g.usrCtx, err
         }
         usrCtx := context.WithValue(g.usrCtx, prodContextKey, aeCtx)
         pc := *getProbeCache(usrCtx)
-        pc.namespace = namespace
+        pc.namespace = &namespace
         return withProbeCache(usrCtx, &pc), nil
 }
 func (g giImpl) MustNamespace(ns string) context.Context {
         ret, err := g.Namespace(ns)
         if err != nil {
                 panic(err)
         }
         return ret
 }
 func (g giImpl) PublicCertificates() ([]info.Certificate, error) {
@@ skipping 21 matching lines @@
 }
 func (g giImpl) VersionID() string {
         return appengine.VersionID(g.aeCtx)
 }
 
 func (g giImpl) Testable() info.Testable {
         return nil
 }
 
 type infoProbeCache struct {
-        namespace string
+        namespace *string
         fqaid     string
 }
 
 func probe(aeCtx context.Context) *infoProbeCache {
         probeKey := datastore.NewKey(aeCtx, "Kind", "id", 0, nil)
-        return &infoProbeCache{
-                namespace: probeKey.Namespace(),
-                fqaid:     probeKey.AppID(),
+        namespace := probeKey.Namespace()
+        ipb := infoProbeCache{
+                fqaid: probeKey.AppID(),
         }
+        if namespace != "" {
+                ipb.namespace = &namespace
+        }
+        return &ipb
 }
 
 func getProbeCache(c context.Context) *infoProbeCache {
         if pc, ok := c.Value(probeCacheKey).(*infoProbeCache); ok {
                 return pc
         }
         return nil
 }
 
 func withProbeCache(c context.Context, pc *infoProbeCache) context.Context {
         return context.WithValue(c, probeCacheKey, pc)
 }