Add wrappers for the module module

impl/memory/module.go

+// Copyright 2016 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 memory
+
+import (
+        "github.com/luci/gae/service/module"
+        "golang.org/x/net/context"
+)
+
+type modContextKeyType int
+
+var modContextKey modContextKeyType
+
+type moduleVersion struct {
+        module, version string
+}
+
+type modImpl struct {
+        c            context.Context
+        numInstances map[moduleVersion]int
+}
+
+// useMod adds a Module interface to the context
+func useMod(c context.Context) context.Context {
+        return module.SetFactory(c, func(ic context.Context) module.Interface {
+                return &modImpl{ic, map[moduleVersion]int{}}
+        })
+}
+
+var _ = module.Interface((*modImpl)(nil))
+
+func (mod *modImpl) List() ([]string, error) {
+        return []string{"testModule1", "testModule2"}, nil
+}
+
+func (mod *modImpl) NumInstances(module, version string) (int, error) {
+        if ret, ok := mod.numInstances[moduleVersion{module, version}]; ok {
+                return ret, nil
+        }
+        return 1, nil
+}
+
+func (mod *modImpl) SetNumInstances(module, version string, instances int) error {
+        mod.numInstances[moduleVersion{module, version}] = instances
+        return nil
+}
+
+func (mod *modImpl) Versions(module string) ([]string, error) {
+        return []string{"testVersion1", "testVersion2"}, nil
+}
+
+func (mod *modImpl) DefaultVersion(module string) (string, error) {
+        return "testVersion1", nil
+}
+
+func (mod *modImpl) Start(module, version string) error {
+        return nil
+}
+
+func (mod *modImpl) Stop(module, version string) error {
+        return nil
+}