datastore: Add DecodeCursor to [Raw]Interface.

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"
 
@@ skipping 50 matching lines @@
 
 func (d *dsImpl) DeleteMulti(keys []ds.Key, cb ds.DeleteMultiCB) error {
         d.data.delMulti(keys, cb)
         return nil
 }
 
 func (d *dsImpl) NewQuery(kind string) ds.Query {
         return &queryImpl{ns: d.ns, kind: kind}
 }
 
+func (d *dsImpl) DecodeCursor(s string) (ds.Cursor, error) {
+        return decodeCursor(s)
+}
+
 func (d *dsImpl) Run(q ds.Query, cb ds.RawRunCB) error {
         rq := q.(*queryImpl)
         done, err := rq.valid(d.ns, true)
         if done || err != nil {
                 return err // will be nil if done
         }
         return nil
 }
 
 func (d *dsImpl) AddIndexes(idxs ...*ds.IndexDefinition) {
@@ skipping 53 matching lines @@
                 return d.data.getMulti(keys, cb)
         })
 }
 
 func (d *txnDsImpl) DeleteMulti(keys []ds.Key, cb ds.DeleteMultiCB) error {
         return d.data.run(func() error {
                 return d.data.delMulti(keys, cb)
         })
 }
 
+func (d *txnDsImpl) DecodeCursor(s string) (ds.Cursor, error) {
+        return decodeCursor(s)
+}
+
 func (d *txnDsImpl) Run(q ds.Query, cb ds.RawRunCB) error {
         rq := q.(*queryImpl)
         done, err := rq.valid(d.ns, true)
         if done || err != nil {
                 return err // will be nil if done
         }
         if rq.eventualConsistency {
                 rq = rq.checkMutateClone(nil, nil)
                 rq.eventualConsistency = false
         }
         // TODO(riannucci): use head instead of snap for indexes
         panic("NOT IMPLEMENTED")
 }
 
 func (*txnDsImpl) RunInTransaction(func(c context.Context) error, *ds.TransactionOptions) error {
         return errors.New("datastore: nested transactions are not supported")
 }
 
 func (d *txnDsImpl) NewQuery(kind string) ds.Query {
         return &queryImpl{ns: d.ns, kind: kind}
 }
 
 func (*txnDsImpl) Testable() ds.Testable {
         return nil
 }