8191142: More refactoring for naming deserialization cases

Reviewed-by: chegar, rriggs

src/share/classes/javax/naming/directory/BasicAttributes.java

 /*
- * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -302,8 +302,8 @@ public class BasicAttributes implements Attributes {
         s.defaultReadObject();  // read in the ignoreCase flag
         int n = s.readInt();    // number of attributes
         attrs = (n >= 1)
-            ? new Hashtable<String,Attribute>(n * 2)
-            : new Hashtable<String,Attribute>(2); // can't have initial size of 0 (grrr...)
+                ? new Hashtable<>(1 + (int) (Math.min(768, n) / .75f))
+                : new Hashtable<>(2); // can't have initial size of 0 (grrr...)
         while (--n >= 0) {
             put((Attribute)s.readObject());
         }