impl/memory: Fix time serialization encoding.

service/datastore/properties.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 datastore
 
 import (
         "encoding/base64"
         "errors"
         "fmt"
@@ skipping 227 matching lines @@
                 err := error(nil)
                 if checkValid && !x.Valid() {
                         err = errors.New("invalid GeoPoint value")
                 }
                 return PTGeoPoint, err
         default:
                 return PTUnknown, fmt.Errorf("gae: Property has bad type %T", v)
         }
 }
 
+// RoundTime rounds a time.Time to microseconds, which is the (undocumented)
+// way that the AppEngine SDK stores it.
+func RoundTime(t time.Time) time.Time {

[dnj, 2015/12/29 21:40:47]

I'm adding this and exporting it b/c this is something generally useful to
datastore consumers. For example, if I generate a struct w/ a time.Time, copy it
to datastore, load it, and confirm that it matches, this must be applied to the
initial struct's time field.

+        return t.Round(time.Microsecond)
+}
+
 // timeLocationIsUTC tests if two time.Location are equal.
 //
 // This is tricky using the standard time API, as time is implicitly normalized
 // to UTC and all equality checks are performed relative to that normalized
 // time. To compensate, we instantiate two new time.Time using the respective
 // Locations.
 func timeLocationIsUTC(l *time.Location) bool {
         return time.Date(1970, 1, 1, 0, 0, 0, 0, l).Equal(utcTestTime)
 }
 
@@ skipping 563 matching lines @@
 // Example:
 //   pls.GetMetaDefault("foo", 100).(int64)
 func GetMetaDefault(getter MetaGetter, key string, dflt interface{}) interface{} {
         dflt = UpconvertUnderlyingType(dflt)
         cur, ok := getter.GetMeta(key)
         if !ok || (dflt != nil && reflect.TypeOf(cur) != reflect.TypeOf(dflt)) {
                 return dflt
         }
         return cur
 }