Make SetTransactionRetryCount actually work.

impl/memory/datastore_data.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 (
         "bytes"
         "fmt"
         "sync"
         "sync/atomic"
 
         ds "github.com/luci/gae/service/datastore"
         "github.com/luci/gae/service/datastore/dskey"
         "github.com/luci/gae/service/datastore/serialize"
         "github.com/luci/luci-go/common/errors"
         "golang.org/x/net/context"
 )
 
 //////////////////////////////// dataStoreData /////////////////////////////////
 
 type dataStoreData struct {
         rwlock sync.RWMutex
         // See README.md for head schema.
         head *memStore
         snap *memStore
+        // For testing, see SetTransactionRetryCount.
+        txnFakeRetry int
 }
 
 var (
         _ = memContextObj((*dataStoreData)(nil))
         _ = sync.Locker((*dataStoreData)(nil))
 )
 
 func newDataStoreData() *dataStoreData {
         head := newMemStore()
         return &dataStoreData{
@@ skipping 393 matching lines @@
 }
 
 func rpm(data []byte) (ds.PropertyMap, error) {
         return serialize.ReadPropertyMap(bytes.NewBuffer(data),
                 serialize.WithContext, "", "")
 }
 
 type keyitem interface {
         Key() ds.Key
 }