geode-core/src/test/java/org/apache/geode/internal/size/WellKnownClassSizerJUnitTest.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional information regarding
 * copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License. You may obtain a
 * copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
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package org.apache.geode.internal.size;

import static org.apache.geode.internal.size.SizeTestUtil.OBJECT_SIZE;
import static org.apache.geode.internal.size.SizeTestUtil.roundup;
import static org.junit.Assert.assertEquals;

import org.junit.Test;

import org.apache.geode.cache.util.ObjectSizer;

public class WellKnownClassSizerJUnitTest {

  @Test
  public void testByteArrays() {
    byte[] test1 = new byte[5];
    byte[] test2 = new byte[8];

    ReflectionSingleObjectSizer referenceSizer = new ReflectionSingleObjectSizer();

    assertEquals(referenceSizer.sizeof(test1), WellKnownClassSizer.sizeof(test1));
    assertEquals(referenceSizer.sizeof(test2), WellKnownClassSizer.sizeof(test2));

    assertEquals(0, WellKnownClassSizer.sizeof(new Object()));
  }

  @Test
  public void testStrings() {
    String test1 = "123";
    String test2 = "012345678";

    ReflectionSingleObjectSizer referenceSizer = new ReflectionSingleObjectSizer();
    test1.toCharArray();

    // The size of a string varies based on the JDK version. With 1.7.0_06
    // a couple of fields were removed. So just measure the size of an empty string.
    String emptyString = "";
    int emptySize = ObjectSizer.SIZE_CLASS_ONCE.sizeof(emptyString)
        - ObjectSizer.SIZE_CLASS_ONCE.sizeof(new char[0]);

    assertEquals(emptySize + roundup(OBJECT_SIZE + 4 + 3 * 2), WellKnownClassSizer.sizeof(test1));
    assertEquals(emptySize + roundup(OBJECT_SIZE + 4 + 9 * 2), WellKnownClassSizer.sizeof(test2));
  }

}