1 /*

     2  * Copyright (c) 2017, 2017, 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 package org.graalvm.util.test;

    24 

    25 import static org.junit.Assert.assertEquals;

    26 

    27 import org.graalvm.collections.EconomicMap;

    28 import org.graalvm.collections.Equivalence;

    29 import org.graalvm.compiler.test.GraalTest;

    30 import org.graalvm.util.ObjectSizeEstimate;

    31 import org.junit.Assume;

    32 import org.junit.Test;

    33 

    34 public class CollectionSizeTest {

    35 

    36     /**

    37      * Tests the memory size of an empty map and a map with only one or two entries.

    38      */

    39     @Test

    40     public void testSize() {

    41         Assume.assumeTrue("Not working in JDK9 due to module visibility.", GraalTest.Java8OrEarlier);

    42         EconomicMap<Object, Object> map = EconomicMap.create(Equivalence.IDENTITY);

    43         assertEquals(49, ObjectSizeEstimate.forObject(map).getTotalBytes());

    44 

    45         Integer value = 1;

    46         map.put(value, value);

    47         assertEquals(153, ObjectSizeEstimate.forObject(map).getTotalBytes());

    48 

    49         Integer secondValue = 2;

    50         map.put(secondValue, secondValue);

    51         assertEquals(153 + 20, ObjectSizeEstimate.forObject(map).getTotalBytes());

    52     }

    53 

    54     /**

    55      * Tests whether the map actually compresses the entries array when a large number of entries

    56      * are deleted.

    57      */

    58     @Test

    59     public void testCompress() {

    60         Assume.assumeTrue("Not working in JDK9 due to module visibility.", GraalTest.Java8OrEarlier);

    61         EconomicMap<Object, Object> map = EconomicMap.create();

    62 

    63         // Measuring size of map with one entry.

    64         Object firstValue = 0;

    65         map.put(firstValue, firstValue);

    66         ObjectSizeEstimate afterFirstValue = ObjectSizeEstimate.forObject(map);

    67 

    68         // Add 999 more entries.

    69         for (int i = 1; i < 1000; ++i) {

    70             Object value = i;

    71             map.put(value, value);

    72         }

    73         ObjectSizeEstimate beforeRemove = ObjectSizeEstimate.forObject(map);

    74 

    75         // Remove 999 first entries.

    76         for (int i = 0; i < 999; ++i) {

    77             map.removeKey(i);

    78         }

    79         ObjectSizeEstimate afterRemove = ObjectSizeEstimate.forObject(map);

    80 

    81         // Check that size is same size as with one entry.

    82         assertEquals(afterFirstValue, afterRemove);

    83 

    84         // Add 999 new entries.

    85         for (int i = 0; i < 999; ++i) {

    86             Object value = i;

    87             map.put(value, value);

    88         }

    89         ObjectSizeEstimate afterAdd = ObjectSizeEstimate.forObject(map);

    90 

    91         // Check that entries array is same size again.

    92         assertEquals(beforeRemove.getPointerCount(), afterAdd.getPointerCount());

    93     }

    94 

    95 }