Store maps in new subdir "maps"

backend/local.go

@@ -17,6 +17,7 @@ const (
 	dataPath        = "data"
 	snapshotPath    = "snapshots"
 	treePath        = "trees"
+	mapPath         = "maps"
 	lockPath        = "locks"
 	keyPath         = "keys"
 	tempPath        = "tmp"
@@ -86,6 +87,7 @@ func CreateLocal(dir string) (*Local, error) {
 		filepath.Join(dir, dataPath),
 		filepath.Join(dir, snapshotPath),
 		filepath.Join(dir, treePath),
+		filepath.Join(dir, mapPath),
 		filepath.Join(dir, lockPath),
 		filepath.Join(dir, keyPath),
 		filepath.Join(dir, tempPath),
@@ -158,6 +160,8 @@ func (b *Local) dir(t Type) string {
 		n = snapshotPath
 	case Tree:
 		n = treePath
+	case Map:
+		n = mapPath
 	case Lock:
 		n = lockPath
 	case Key: