Interface update, per-method Contexts.

service/info/support/namespace.go

+// Copyright 2015 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+// Package support provides Info-related support functionality. It is designed
+// to be used by implementing packages.
+package support
+
+import (
+        "fmt"
+        "regexp"
+)
+
+// validNamespace matches valid namespace names.
+var validNamespace = regexp.MustCompile(`^[0-9A-Za-z._-]{0,100}$`)
+
+// ValidNamespace will return an error if the supplied string is not a valid
+// namespace.
+func ValidNamespace(ns string) error {
+        if validNamespace.MatchString(ns) {
+                return nil
+        }
+        return fmt.Errorf("appengine: namespace %q does not match /%s/", ns, validNamespace)
+}