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

go/src/infra/gae/libs/gae/memory/raw_datstore.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 memory
+
+import (
+        "errors"
+        "fmt"
+        "golang.org/x/net/context"
+
+        "infra/gae/libs/gae"
+        "infra/gae/libs/gae/helper"
+)
+
+//////////////////////////////////// public ////////////////////////////////////
+
+// useDS adds a gae.Datastore implementation to context, accessible
+// by gae.GetDS(c)
+func useDS(c context.Context) context.Context {
+        return gae.SetRDSFactory(c, func(ic context.Context) gae.RawDatastore {
+                dsd := cur(ic).Get(memContextDSIdx)
+
+                switch x := dsd.(type) {
+                case *dataStoreData:
+                        return &dsImpl{gae.DummyRDS(), x, curGID(ic).namespace, ic}
+                case *txnDataStoreData:
+                        return &txnDsImpl{gae.DummyRDS(), x, curGID(ic).namespace}
+                default:
+                        panic(fmt.Errorf("DS: bad type: %v in context %v", dsd, ic))
+                }
+        })
+}
+
+//////////////////////////////////// dsImpl ////////////////////////////////////
+
+// dsImpl exists solely to bind the current c to the datastore data.
+type dsImpl struct {
+        gae.RawDatastore
+
+        data *dataStoreData
+        ns   string
+        c    context.Context
+}
+
+var _ interface {
+        gae.RawDatastore
+        gae.Testable
+} = (*dsImpl)(nil)
+
+func (d *dsImpl) BreakFeatures(err error, features ...string) {
+        d.data.BreakFeatures(err, features...)
+}
+func (d *dsImpl) UnbreakFeatures(features ...string) {
+        d.data.UnbreakFeatures(features...)
+}
+
+func (d *dsImpl) NewKey(kind, stringID string, intID int64, parent gae.DSKey) gae.DSKey {
+        return helper.NewDSKey(globalAppID, d.ns, kind, stringID, intID, parent)
+}
+
+func (d *dsImpl) Put(key gae.DSKey, src interface{}) (retKey gae.DSKey, err error) {
+        err = d.data.RunIfNotBroken(func() (err error) {
+                retKey, err = d.data.put(d.ns, key, src)
+                return
+        })
+        return
+}
+
+func (d *dsImpl) Get(key gae.DSKey, dst interface{}) error {
+        return d.data.RunIfNotBroken(func() error {
+                return d.data.get(d.ns, key, dst)
+        })
+}
+
+func (d *dsImpl) Delete(key gae.DSKey) error {
+        return d.data.RunIfNotBroken(func() error {
+                return d.data.del(d.ns, key)
+        })
+}
+
+////////////////////////////////// txnDsImpl ///////////////////////////////////
+
+type txnDsImpl struct {
+        gae.RawDatastore
+
+        data *txnDataStoreData
+        ns   string
+}
+
+var (
+        _ = gae.RawDatastore((*txnDsImpl)(nil))
+        _ = gae.Testable((*txnDsImpl)(nil))
+)
+
+func (d *dsImpl) NewQuery(kind string) gae.DSQuery {
+        return &queryImpl{DSQuery: gae.DummyQY(), ns: d.ns, kind: kind}
+}
+
+func (d *dsImpl) Run(q gae.DSQuery) gae.DSIterator {
+        rq := q.(*queryImpl)
+        rq = rq.normalize().checkCorrectness(d.ns, false)
+        return &queryIterImpl{rq}
+}
+
+func (d *dsImpl) GetAll(q gae.DSQuery, dst interface{}) ([]gae.DSKey, error) {
+        // TODO(riannucci): assert that dst is a slice of structs
+        return nil, nil
+}
+
+func (d *dsImpl) Count(q gae.DSQuery) (ret int, err error) {
+        itr := d.Run(q.KeysOnly())
+        for _, err = itr.Next(nil); err != nil; _, err = itr.Next(nil) {
+                ret++
+        }
+        if err == gae.ErrDSQueryDone {
+                err = nil
+        }
+        return
+}
+
+func (d *txnDsImpl) BreakFeatures(err error, features ...string) {
+        d.data.BreakFeatures(err, features...)
+}
+func (d *txnDsImpl) UnbreakFeatures(features ...string) {
+        d.data.UnbreakFeatures(features...)
+}
+
+func (d *txnDsImpl) NewKey(kind, stringID string, intID int64, parent gae.DSKey) gae.DSKey {
+        return helper.NewDSKey(globalAppID, d.ns, kind, stringID, intID, parent)
+}
+
+func (d *txnDsImpl) Put(key gae.DSKey, src interface{}) (retKey gae.DSKey, err error) {
+        err = d.data.RunIfNotBroken(func() (err error) {
+                retKey, err = d.data.put(d.ns, key, src)
+                return
+        })
+        return
+}
+
+func (d *txnDsImpl) Get(key gae.DSKey, dst interface{}) error {
+        return d.data.RunIfNotBroken(func() error {
+                return d.data.get(d.ns, key, dst)
+        })
+}
+
+func (d *txnDsImpl) Delete(key gae.DSKey) error {
+        return d.data.RunIfNotBroken(func() error {
+                return d.data.del(d.ns, key)
+        })
+}
+
+func (*txnDsImpl) RunInTransaction(func(c context.Context) error, *gae.DSTransactionOptions) error {
+        return errors.New("datastore: nested transactions are not supported")
+}