Add wrappers for the module module

filter/count/mod.go

Index: filter/count/mod.go
diff --git a/filter/count/mod.go b/filter/count/mod.go
new file mode 100644
index 0000000000000000000000000000000000000000..8551dc23e4551f189ed1e6294192d6b3a301a64b
--- /dev/null
+++ b/filter/count/mod.go
@@ -0,0 +1,70 @@
+// 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 count
+
+import (
+	"golang.org/x/net/context"
+
+	"github.com/luci/gae/service/module"
+)
+
+// ModuleCounter is the counter object for the Module service.
+type ModuleCounter struct {
+	List            Entry
+	NumInstances    Entry
+	SetNumInstances Entry
+	Versions        Entry
+	DefaultVersion  Entry
+	Start           Entry
+	Stop            Entry
+}
+
+type modCounter struct {
+	c *ModuleCounter
+
+	mod module.Interface
+}
+
+var _ module.Interface = (*modCounter)(nil)
+
+func (m *modCounter) List() ([]string, error) {
+	ret, err := m.mod.List()
+	return ret, m.c.List.up(err)
+}
+
+func (m *modCounter) NumInstances(mod, ver string) (int, error) {
+	ret, err := m.mod.NumInstances(mod, ver)
+	return ret, m.c.NumInstances.up(err)
+}
+
+func (m *modCounter) SetNumInstances(mod, ver string, instances int) error {
+	return m.c.SetNumInstances.up(m.mod.SetNumInstances(mod, ver, instances))
+}
+
+func (m *modCounter) Versions(mod string) ([]string, error) {
+	ret, err := m.mod.Versions(mod)
+	return ret, m.c.Versions.up(err)
+}
+
+func (m *modCounter) DefaultVersion(mod string) (string, error) {
+	ret, err := m.mod.DefaultVersion(mod)
+	return ret, m.c.DefaultVersion.up(err)
+}
+
+func (m *modCounter) Start(mod, ver string) error {
+	return m.c.Start.up(m.mod.Start(mod, ver))
+}
+
+func (m *modCounter) Stop(mod, ver string) error {
+	return m.c.Stop.up(m.mod.Stop(mod, ver))
+}
+
+// FilterModule installs a counter Module filter in the context.
+func FilterModule(c context.Context) (context.Context, *ModuleCounter) {
+	state := &ModuleCounter{}
+	return module.AddFilters(c, func(ic context.Context, mod module.Interface) module.Interface {
+		return &modCounter{state, mod}
+	}), state
+}