Better attempt at an appengine wrapper.

go/src/infra/gae/libs/wrapper/gae/memcache.go

Index: go/src/infra/gae/libs/wrapper/gae/memcache.go
diff --git a/go/src/infra/gae/libs/wrapper/gae/memcache.go b/go/src/infra/gae/libs/wrapper/gae/memcache.go
new file mode 100644
index 0000000000000000000000000000000000000000..f7054d64af1becd7fdd0c1eecc1be0359b34ffee
--- /dev/null
+++ b/go/src/infra/gae/libs/wrapper/gae/memcache.go
@@ -0,0 +1,87 @@
+// 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 gae
+
+import (
+	"golang.org/x/net/context"
+
+	"appengine"
+	"appengine/memcache"
+
+	"infra/gae/libs/wrapper"
+)
+
+// UseMC adds a wrapper.Memcache implementation to context, accessible
+// by wrapper.GetMC(c)
+func UseMC(c context.Context) context.Context {
+	return wrapper.SetMCFactory(c, func(ci context.Context) wrapper.Memcache {
+		return mcImpl{ctx(c).Context}
+	})
+}
+
+type mcImpl struct{ appengine.Context }
+
+//////// MCSingleReadWriter
+func (m mcImpl) Add(item *memcache.Item) error          { return memcache.Add(m.Context, item) }
+func (m mcImpl) Set(item *memcache.Item) error          { return memcache.Set(m.Context, item) }
+func (m mcImpl) Delete(key string) error                { return memcache.Delete(m.Context, key) }
+func (m mcImpl) Get(key string) (*memcache.Item, error) { return memcache.Get(m.Context, key) }
+func (m mcImpl) CompareAndSwap(item *memcache.Item) error {
+	return memcache.CompareAndSwap(m.Context, item)
+}
+
+//////// MCMultiReadWriter
+func (m mcImpl) DeleteMulti(keys []string) error       { return memcache.DeleteMulti(m.Context, keys) }
+func (m mcImpl) AddMulti(items []*memcache.Item) error { return memcache.AddMulti(m.Context, items) }
+func (m mcImpl) SetMulti(items []*memcache.Item) error { return memcache.SetMulti(m.Context, items) }
+func (m mcImpl) GetMulti(keys []string) (map[string]*memcache.Item, error) {
+	return memcache.GetMulti(m.Context, keys)
+}
+func (m mcImpl) CompareAndSwapMulti(items []*memcache.Item) error {
+	return memcache.CompareAndSwapMulti(m.Context, items)
+}
+
+//////// MCIncrementer
+func (m mcImpl) Increment(key string, delta int64, initialValue uint64) (uint64, error) {
+	return memcache.Increment(m.Context, key, delta, initialValue)
+}
+func (m mcImpl) IncrementExisting(key string, delta int64) (uint64, error) {
+	return memcache.IncrementExisting(m.Context, key, delta)
+}
+
+//////// MCFlusher
+func (m mcImpl) Flush() error { return memcache.Flush(m.Context) }
+
+//////// MCStatter
+func (m mcImpl) Stats() (*memcache.Statistics, error) { return memcache.Stats(m.Context) }
+
+//////// MCInflateCodecer
+type mcCodecCombiner struct {
+	appengine.Context
+	codec memcache.Codec
+}
+
+//////// MCInflateCodecer.logger
+func (cc mcCodecCombiner) Set(item *memcache.Item) error { return cc.codec.Set(cc.Context, item) }
+func (cc mcCodecCombiner) Add(item *memcache.Item) error { return cc.codec.Add(cc.Context, item) }
+func (cc mcCodecCombiner) Get(key string, v interface{}) (*memcache.Item, error) {
+	return cc.codec.Get(cc.Context, key, v)
+}
+func (cc mcCodecCombiner) SetMulti(items []*memcache.Item) error {
+	return cc.codec.SetMulti(cc.Context, items)
+}
+func (cc mcCodecCombiner) AddMulti(items []*memcache.Item) error {
+	return cc.codec.AddMulti(cc.Context, items)
+}
+func (cc mcCodecCombiner) CompareAndSwap(item *memcache.Item) error {
+	return cc.codec.CompareAndSwap(cc.Context, item)
+}
+func (cc mcCodecCombiner) CompareAndSwapMulti(items []*memcache.Item) error {
+	return cc.codec.CompareAndSwapMulti(cc.Context, items)
+}
+
+func (m mcImpl) InflateCodec(codec memcache.Codec) wrapper.MCCodec {
+	return mcCodecCombiner{m.Context, codec}
+}