test/jdk/lib/testlibrary/jdk/testlibrary/OptimalCapacity.java

rev 49518 : [mq]: 8200696-Optimal-initial-capacity-of-java-lang-Class-enumConstantDirectory

*** 1,7 ****
  /*
!  * Copyright (c) 2015, 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
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 2015, 2018, 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
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 100,113 ****
       * </pre>
       */
      public static void ofHashMap(Class<?> clazz, String fieldName,
              int initialCapacity)
      {
          try {
              Field field = clazz.getDeclaredField(fieldName);
              field.setAccessible(true);
!             Object obj = field.get(null);
              if (!HashMap.class.equals(obj.getClass())) {
                  throw new RuntimeException(field +
                      " expected to be of type HashMap");
              }
              HashMap<?,?> map = (HashMap<?,?>)obj;
--- 100,137 ----
       * </pre>
       */
      public static void ofHashMap(Class<?> clazz, String fieldName,
              int initialCapacity)
      {
+         ofHashMap(clazz, null, fieldName, initialCapacity);
+     }
+ 
+     /**
+      * Checks adequacy of the initial capacity of a non-static field
+      * of type {@code HashMap}.
+      *
+      * Having
+      * <pre>
+      * class XClass {
+      *     HashMap theMap = new HashMap(N);
+      * }
+      * XClass instance = ...
+      * </pre>
+      *
+      * you should call from the test
+      *
+      * <pre>
+      * OptimalCapacity.ofHashMap(XClass.class, instance, "theMap", N);
+      * </pre>
+      */
+     public static void ofHashMap(Class<?> clazz, Object instance,
+             String fieldName, int initialCapacity)
+     {
          try {
              Field field = clazz.getDeclaredField(fieldName);
              field.setAccessible(true);
!             Object obj = field.get(instance);
              if (!HashMap.class.equals(obj.getClass())) {
                  throw new RuntimeException(field +
                      " expected to be of type HashMap");
              }
              HashMap<?,?> map = (HashMap<?,?>)obj;