org.apache.hudi.org.openjdk.jol.datamodel.ModelVM Maven / Gradle / Ivy

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 * 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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package org.openjdk.jol.datamodel;

import org.openjdk.jol.vm.VM;

/**
 * Current data model as detected by JVM.
 *
 * @author Aleksey Shipilev
 */
public class ModelVM implements DataModel {

    @Override
    public int markHeaderSize() {
        return VM.current().addressSize();
    }

    @Override
    public int classHeaderSize() {
        return VM.current().classPointerSize();
    }

    @Override
    public int arrayLengthHeaderSize() {
        return 4;
    }

    @Override
    public int headerSize() {
        return markHeaderSize() + classHeaderSize();
    }

    @Override
    public int arrayHeaderSize() {
        return headerSize() + arrayLengthHeaderSize();
    }

    @Override
    public int sizeOf(String klass) {
        return (int) VM.current().sizeOfField(klass);
    }

    @Override
    public int objectAlignment() {
        return VM.current().objectAlignment();
    }

    @Override
    public String toString() {
        return "Current VM";
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        return true;
    }

    @Override
    public int hashCode() {
        return 0;
    }
}