Add API to allow you to get the non-transactional datastore or taskqueue.

impl/prod/context.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 (
         "net/http"
 
+        "github.com/luci/gae/service/info"
         "golang.org/x/net/context"
         "google.golang.org/appengine"
 )
 
 type key int
 
 var (
-        prodContextKey key
-        probeCacheKey  key = 1
+        prodContextKey      key
+        prodContextNoTxnKey key = 1
+        probeCacheKey       key = 2
 )
 
 // AEContext retrieves the raw "google.golang.org/appengine" compatible Context.
 func AEContext(c context.Context) context.Context {
         aeCtx, _ := c.Value(prodContextKey).(context.Context)
         return aeCtx
 }
 
+// AEContextNoTxn retrieves the raw "google.golang.org/appengine" compatible
+// Context that's not part of a transaction.
+func AEContextNoTxn(c context.Context) context.Context {
+        aeCtx, _ := c.Value(prodContextNoTxnKey).(context.Context)
+        aeCtx, err := appengine.Namespace(aeCtx, info.Get(c).GetNamespace())
+        if err != nil {
+                panic(err)
+        }
+        return aeCtx
+}
+
 // Use adds production implementations for all the gae services to the
 // context.
 //
 // The services added are:
 //   - github.com/luci/gae/service/datastore
 //   - github.com/luci/gae/service/taskqueue
 //   - github.com/luci/gae/service/memcache
 //   - github.com/luci/gae/service/info
 //   - github.com/luci/gae/service/urlfetch
 //
 // These can be retrieved with the <service>.Get functions.
 //
 // The implementations are all backed by the real appengine SDK functionality,
 func Use(c context.Context, r *http.Request) context.Context {
         aeCtx := appengine.NewContext(r)
         c = context.WithValue(c, prodContextKey, aeCtx)
+        c = context.WithValue(c, prodContextNoTxnKey, aeCtx)
         return useUser(useURLFetch(useRDS(useMC(useTQ(useGI(c))))))
 }