Refactor current GAE abstraction library to be free of the SDK*

go/src/infra/gae/libs/wrapper/doc.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 wrapper provides a fakable wrapped interface for the appengine SDK's
-// APIs. This means that it's possible to mock all of the supported appengine
-// APIs for testing (or potentially implement a different backend for them,
-// though you would still need to provide enough of the appengine SDK for a
-// few key types).
-//
-// wrapper currently provides interfaces for:
-//   * Datastore
-//   * Memcache
-//   * TaskQueue
-//   * GlobalInfo (e.g. Namespace, AppID, etc.)
-//
-// A package which implements the wrapper is expected to provide the following:
-//   * A package function `Enable(c context.Context, ...) context.Context`
-//     This function is expected to add any information to c which is necessary
-//     for the rest of its implementations to work. This may be something like
-//     an `appengine.Context` or some connection information for an external
-//     server. The `...` in the function signature may be any additional data
-//     needed.
-//   * Any of the package functions:
-//
-//       UseDS(context.Context) context.Context
-//       UseMC(context.Context) context.Context
-//                 UseTQ(context.Context) context.Context
-//       UseGI(context.Context) context.Context
-//
-//         each of which would call wrapper.Set<service>Factory with the factory
-//         function for that interface type.
-//       * A `Use(context.Context) context.Context` function which calls all of the
-//         `Use*` package functions implemented by the package.
-//   * Partially-implemented interfaces should embed one of the Dummy* structs
-//     which will panic with an appropriate error for unimplemented
-//     methods.
-//
-// see "infra/gae/libs/wrapper/gae" for an appengine-backed implementation.
-package wrapper