| // Copyright 2012 Google Inc. All rights reserved. |
| // Use of this source code is governed by the Apache 2.0 |
| // license that can be found in the LICENSE file. |
| |
| package appengine |
| |
| import ( |
| "fmt" |
| "regexp" |
| |
| "github.com/golang/protobuf/proto" |
| "golang.org/x/net/context" |
| |
| "google.golang.org/appengine/internal" |
| ) |
| |
| // Namespace returns a replacement context that operates within the given namespace. |
| func Namespace(c context.Context, namespace string) (context.Context, error) { |
| if !validNamespace.MatchString(namespace) { |
| return nil, fmt.Errorf("appengine: namespace %q does not match /%s/", namespace, validNamespace) |
| } |
| n := &namespacedContext{ |
| ctx: c, |
| namespace: namespace, |
| } |
| return internal.WithNamespace(internal.WithCallOverride(c, n.call), namespace), nil |
| } |
| |
| // validNamespace matches valid namespace names. |
| var validNamespace = regexp.MustCompile(`^[0-9A-Za-z._-]{0,100}$`) |
| |
| // namespacedContext wraps a Context to support namespaces. |
| type namespacedContext struct { |
| ctx context.Context |
| namespace string |
| } |
| |
| func (n *namespacedContext) call(_ context.Context, service, method string, in, out proto.Message) error { |
| // Apply any namespace mods. |
| if mod, ok := internal.NamespaceMods[service]; ok { |
| mod(in, n.namespace) |
| } |
| return internal.Call(n.ctx, service, method, in, out) |
| } |