| // 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" |
| |
| "google.golang.org/appengine/internal" |
| basepb "google.golang.org/appengine/internal/base" |
| ) |
| |
| // Namespace returns a replacement context that operates within the given namespace. |
| func Namespace(c Context, namespace string) (Context, error) { |
| if !validNamespace.MatchString(namespace) { |
| return nil, fmt.Errorf("appengine: namespace %q does not match /%s/", namespace, validNamespace) |
| } |
| return &namespacedContext{ |
| Context: c, |
| namespace: 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 { |
| Context |
| namespace string |
| } |
| |
| func (n *namespacedContext) Call(service, method string, in, out proto.Message, opts *internal.CallOptions) error { |
| // Apply any namespace mods. |
| if mod, ok := internal.NamespaceMods[service]; ok { |
| mod(in, n.namespace) |
| } |
| if service == "__go__" && method == "GetNamespace" { |
| out.(*basepb.StringProto).Value = proto.String(n.namespace) |
| return nil |
| } |
| |
| return n.Context.Call(service, method, in, out, opts) |
| } |