A transparent cache for datastore, backed by memcache.

impl/memory/memcache.go

Index: impl/memory/memcache.go
diff --git a/impl/memory/memcache.go b/impl/memory/memcache.go
index 4a38c026a0fc3a06d9859e2d431f86fb8c5fea09..1892129f024c5b2da307fc99e90c41cd5b43b3e6 100644
--- a/impl/memory/memcache.go
+++ b/impl/memory/memcache.go
@@ -50,7 +50,13 @@ func (m *mcItem) SetExpiration(exp time.Duration) mc.Item {
 }
 
 func (m *mcItem) SetAll(other mc.Item) {
-	*m = *other.(*mcItem)
+	if other == nil {
+		*m = mcItem{key: m.key}
+	} else {
+		k := m.key
+		*m = *other.(*mcItem)
+		m.key = k
+	}
 }
 
 type mcDataItem struct {
@@ -200,7 +206,7 @@ func (m *memcacheImpl) AddMulti(items []mc.Item, cb mc.RawCB) error {
 			m.data.setItemLocked(now, itm)
 			return nil
 		} else {
-			return (mc.ErrNotStored)
+			return mc.ErrNotStored
 		}
 	})
 	return nil