A transparent cache for datastore, backed by memcache.

impl/prod/memcache.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 prod
 
 import (
         "time"
 
         mc "github.com/luci/gae/service/memcache"
@@ skipping 34 matching lines @@
 func (i mcItem) SetFlags(f uint32) mc.Item {
         i.i.Flags = f
         return i
 }
 func (i mcItem) SetExpiration(d time.Duration) mc.Item {
         i.i.Expiration = d
         return i
 }
 
 func (i mcItem) SetAll(other mc.Item) {
-        o := other.(mcItem)
-        *i.i = *o.i
-        val := i.i.Value
-        i.i.Value = make([]byte, len(val))
-        copy(i.i.Value, val)
+        if other == nil {
+                i.i = &memcache.Item{Key: i.i.Key}
+        } else {
+                k := i.i.Key
+                *i.i = *other.(mcItem).i
+                i.i.Key = k
+        }
 }
 
 // mcR2FErr (MC real-to-fake w/ error) converts a *memcache.Item to a mc.Item,
 // and passes along an error.
 func mcR2FErr(i *memcache.Item, err error) (mc.Item, error) {
         if err != nil {
                 return nil, err
         }
         return mcItem{i}, nil
 }
@@ skipping 78 matching lines @@
         return memcache.Flush(m.Context)
 }
 
 func (m mcImpl) Stats() (*mc.Statistics, error) {
         stats, err := memcache.Stats(m.Context)
         if err != nil {
                 return nil, err
         }
         return (*mc.Statistics)(stats), nil
 }