1 /*
   2  * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 
  25 package org.graalvm.util.test;
  26 
  27 import static org.junit.Assert.assertEquals;
  28 
  29 import jdk.internal.vm.compiler.collections.EconomicMap;
  30 import jdk.internal.vm.compiler.collections.Equivalence;
  31 import org.graalvm.compiler.serviceprovider.JavaVersionUtil;
  32 import org.graalvm.util.ObjectSizeEstimate;
  33 import org.junit.Assume;
  34 import org.junit.Test;
  35 
  36 public class CollectionSizeTest {
  37 
  38     /**
  39      * Tests the memory size of an empty map and a map with only one or two entries.
  40      */
  41     @Test
  42     public void testSize() {
  43         Assume.assumeTrue("Not working in JDK9 due to module visibility.", JavaVersionUtil.JAVA_SPEC <= 8);
  44         EconomicMap<Object, Object> map = EconomicMap.create(Equivalence.IDENTITY);
  45         assertEquals(49, ObjectSizeEstimate.forObject(map).getTotalBytes());
  46 
  47         Integer value = 1;
  48         map.put(value, value);
  49         assertEquals(153, ObjectSizeEstimate.forObject(map).getTotalBytes());
  50 
  51         Integer secondValue = 2;
  52         map.put(secondValue, secondValue);
  53         assertEquals(153 + 20, ObjectSizeEstimate.forObject(map).getTotalBytes());
  54     }
  55 
  56     /**
  57      * Tests whether the map actually compresses the entries array when a large number of entries
  58      * are deleted.
  59      */
  60     @Test
  61     public void testCompress() {
  62         Assume.assumeTrue("Not working in JDK9 due to module visibility.", JavaVersionUtil.JAVA_SPEC <= 8);
  63         EconomicMap<Object, Object> map = EconomicMap.create();
  64 
  65         // Measuring size of map with one entry.
  66         Object firstValue = 0;
  67         map.put(firstValue, firstValue);
  68         ObjectSizeEstimate afterFirstValue = ObjectSizeEstimate.forObject(map);
  69 
  70         // Add 999 more entries.
  71         for (int i = 1; i < 1000; ++i) {
  72             Object value = i;
  73             map.put(value, value);
  74         }
  75         ObjectSizeEstimate beforeRemove = ObjectSizeEstimate.forObject(map);
  76 
  77         // Remove 999 first entries.
  78         for (int i = 0; i < 999; ++i) {
  79             map.removeKey(i);
  80         }
  81         ObjectSizeEstimate afterRemove = ObjectSizeEstimate.forObject(map);
  82 
  83         // Check that size is same size as with one entry.
  84         assertEquals(afterFirstValue, afterRemove);
  85 
  86         // Add 999 new entries.
  87         for (int i = 0; i < 999; ++i) {
  88             Object value = i;
  89             map.put(value, value);
  90         }
  91         ObjectSizeEstimate afterAdd = ObjectSizeEstimate.forObject(map);
  92 
  93         // Check that entries array is same size again.
  94         assertEquals(beforeRemove.getPointerCount(), afterAdd.getPointerCount());
  95     }
  96 
  97 }