Add filters for user service.

filter/featureBreaker/user.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 featureBreaker
+
+import (
+        "github.com/luci/gae/service/user"
+        "golang.org/x/net/context"
+)
+
+type userState struct {
+        *state
+
+        user.Interface
+}
+
+var _ user.Interface = (*userState)(nil)
+
+func (u *userState) CurrentOAuth(scopes ...string) (ret *user.User, err error) {
+        err = u.run(func() (err error) {
+                ret, err = u.Interface.CurrentOAuth(scopes...)
+                return
+        })
+        return
+}
+
+func (u *userState) LoginURL(dest string) (ret string, err error) {
+        err = u.run(func() (err error) {
+                ret, err = u.Interface.LoginURL(dest)
+                return
+        })
+        return
+}
+
+func (u *userState) LoginURLFederated(dest, identity string) (ret string, err error) {
+        err = u.run(func() (err error) {
+                ret, err = u.Interface.LoginURLFederated(dest, identity)
+                return
+        })
+        return
+}
+
+func (u *userState) LogoutURL(dest string) (ret string, err error) {
+        err = u.run(func() (err error) {
+                ret, err = u.Interface.LogoutURL(dest)
+                return
+        })
+        return
+}
+
+func (u *userState) OAuthConsumerKey() (ret string, err error) {
+        err = u.run(func() (err error) {
+                ret, err = u.Interface.OAuthConsumerKey()
+                return
+        })
+        return
+}
+
+// FilterUser installs a counter user filter in the context.
+func FilterUser(c context.Context, defaultError error) (context.Context, FeatureBreaker) {
+        state := newState(defaultError)
+        return user.AddFilters(c, func(ic context.Context, i user.Interface) user.Interface {
+                return &userState{state, i}
+        }), state
+}