impl/memory: Disallow empty namespace.

impl/memory/datastore.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"
 
         ds "github.com/luci/gae/service/datastore"
         "github.com/luci/gae/service/info"
 )
 
 //////////////////////////////////// public ////////////////////////////////////
 
 // useRDS adds a gae.Datastore implementation to context, accessible
 // by gae.GetDS(c)
 func useRDS(c context.Context) context.Context {
         return ds.SetRawFactory(c, func(ic context.Context, wantTxn bool) ds.RawInterface {
-                ns := curGID(ic).namespace
+                ns, hasNS := curGID(ic).getNamespace()
                 maybeTxnCtx := cur(ic)
 
                 needResetCtx := false
                 if !wantTxn {
                         rootctx := curNoTxn(ic)
                         if rootctx != maybeTxnCtx {
                                 needResetCtx = true
                                 maybeTxnCtx = rootctx
                         }
                 }
 
                 dsd := maybeTxnCtx.Get(memContextDSIdx)
                 if x, ok := dsd.(*dataStoreData); ok {
                         if needResetCtx {
                                 ic = context.WithValue(ic, memContextKey, maybeTxnCtx)
                         }
-                        return &dsImpl{x, ns, ic}
+                        return &dsImpl{x, ns, hasNS, ic}
                 }
-                return &txnDsImpl{dsd.(*txnDataStoreData), ns}
+                return &txnDsImpl{dsd.(*txnDataStoreData), ns, hasNS}
         })
 }
 
 // NewDatastore creates a new standalone memory implementation of the datastore,
 // suitable for embedding for doing in-memory data organization.
 //
 // It's configured by default with the following settings:
 //   * AutoIndex(true)
 //   * Consistent(true)
 //   * DisableSpecialEntities(true)
 //
 // These settings can of course be changed by using the Testable() interface.
 func NewDatastore(aid, ns string) (ds.Interface, error) {
         ctx := UseWithAppID(context.Background(), aid)
-        ctx, err := info.Get(ctx).Namespace(ns)
-        if err != nil {
-                return nil, err
+
+        if ns != "" {
+                var err error
+                ctx, err = info.Get(ctx).Namespace(ns)
+                if err != nil {
+                        return nil, err
+                }
         }
+
         ret := ds.Get(ctx)
         t := ret.Testable()
         t.AutoIndex(true)
         t.Consistent(true)
         t.DisableSpecialEntities(true)
         return ret, nil
 }
 
 //////////////////////////////////// dsImpl ////////////////////////////////////
 
 // dsImpl exists solely to bind the current c to the datastore data.
 type dsImpl struct {
-        data *dataStoreData
-        ns   string
-        c    context.Context
+        data  *dataStoreData
+        ns    string
+        hasNS bool
+        c     context.Context
 }
 
 var _ ds.RawInterface = (*dsImpl)(nil)
 
 func (d *dsImpl) AllocateIDs(incomplete *ds.Key, n int) (int64, error) {
         return d.data.allocateIDs(incomplete, n)
 }
 
 func (d *dsImpl) PutMulti(keys []*ds.Key, vals []ds.PropertyMap, cb ds.PutMultiCB) error {
         d.data.putMulti(keys, vals, cb)
         return nil
 }
 
 func (d *dsImpl) GetMulti(keys []*ds.Key, _meta ds.MultiMetaGetter, cb ds.GetMultiCB) error {
         return d.data.getMulti(keys, cb)
 }
 
 func (d *dsImpl) DeleteMulti(keys []*ds.Key, cb ds.DeleteMultiCB) error {
         d.data.delMulti(keys, cb)
         return nil
 }
 
 func (d *dsImpl) DecodeCursor(s string) (ds.Cursor, error) {
         return newCursor(s)
 }
 
 func (d *dsImpl) Run(fq *ds.FinalizedQuery, cb ds.RawRunCB) error {
+        if err := assertQueryNamespace(d.ns, d.hasNS); err != nil {
+                return err
+        }
+
         idx, head := d.data.getQuerySnaps(!fq.EventuallyConsistent())
         err := executeQuery(fq, d.data.aid, d.ns, false, idx, head, cb)
         if d.data.maybeAutoIndex(err) {
                 idx, head = d.data.getQuerySnaps(!fq.EventuallyConsistent())
                 err = executeQuery(fq, d.data.aid, d.ns, false, idx, head, cb)
         }
         return err
 }
 
 func (d *dsImpl) Count(fq *ds.FinalizedQuery) (ret int64, err error) {
+        if err := assertQueryNamespace(d.ns, d.hasNS); err != nil {
+                return 0, err
+        }
+
         idx, head := d.data.getQuerySnaps(!fq.EventuallyConsistent())
         ret, err = countQuery(fq, d.data.aid, d.ns, false, idx, head)
         if d.data.maybeAutoIndex(err) {
                 idx, head := d.data.getQuerySnaps(!fq.EventuallyConsistent())
                 ret, err = countQuery(fq, d.data.aid, d.ns, false, idx, head)
         }
         return
 }
 
 func (d *dsImpl) AddIndexes(idxs ...*ds.IndexDefinition) {
@@ skipping 38 matching lines @@
         d.data.setDisableSpecialEntities(enabled)
 }
 
 func (d *dsImpl) Testable() ds.Testable {
         return d
 }
 
 ////////////////////////////////// txnDsImpl ///////////////////////////////////
 
 type txnDsImpl struct {
-        data *txnDataStoreData
-        ns   string
+        data  *txnDataStoreData
+        ns    string
+        hasNS bool
 }
 
 var _ ds.RawInterface = (*txnDsImpl)(nil)
 
 func (d *txnDsImpl) AllocateIDs(incomplete *ds.Key, n int) (int64, error) {
         return d.data.parent.allocateIDs(incomplete, n)
 }
 
 func (d *txnDsImpl) PutMulti(keys []*ds.Key, vals []ds.PropertyMap, cb ds.PutMultiCB) error {
         return d.data.run(func() error {
@@ skipping 12 matching lines @@
         return d.data.run(func() error {
                 return d.data.delMulti(keys, cb)
         })
 }
 
 func (d *txnDsImpl) DecodeCursor(s string) (ds.Cursor, error) {
         return newCursor(s)
 }
 
 func (d *txnDsImpl) Run(q *ds.FinalizedQuery, cb ds.RawRunCB) error {
+        if err := assertQueryNamespace(d.ns, d.hasNS); err != nil {
+                return err
+        }
+
         // note that autoIndex has no effect inside transactions. This is because
         // the transaction guarantees a consistent view of head at the time that the
         // transaction opens. At best, we could add the index on head, but then return
         // the error anyway, but adding the index then re-snapping at head would
         // potentially reveal other entities not in the original transaction snapshot.
         //
         // It's possible that if you have full-consistency and also auto index enabled
         // that this would make sense... but at that point you should probably just
         // add the index up front.
         return executeQuery(q, d.data.parent.aid, d.ns, true, d.data.snap, d.data.snap, cb)
 }
 
 func (d *txnDsImpl) Count(fq *ds.FinalizedQuery) (ret int64, err error) {
+        if err := assertQueryNamespace(d.ns, d.hasNS); err != nil {
+                return 0, err
+        }
+
         return countQuery(fq, d.data.parent.aid, d.ns, true, d.data.snap, d.data.snap)
 }
 
 func (*txnDsImpl) RunInTransaction(func(c context.Context) error, *ds.TransactionOptions) error {
         return errors.New("datastore: nested transactions are not supported")
 }
 
 func (*txnDsImpl) Testable() ds.Testable {
         return nil
 }
+
+func assertQueryNamespace(ns string, hasNS bool) error {
+        if ns == "" && hasNS {
+                // The user has set an empty namespace. Datastore does not support this
+                // for queries.
+                //
+                // Bug on file is:
+                // https://code.google.com/p/googleappengine/issues/detail?id=12914
+                return errors.New("namespace may not be present and empty")
+        }
+        return nil
+}