/*
 * Copyright (c) 2014, 2015, Dynatrace and/or its affiliates. All rights reserved.
 * 
 * This file is part of the Lock Contention Tracing Subsystem for the HotSpot
 * Virtual Machine, which is developed at Christian Doppler Laboratory on
 * Monitoring and Evolution of Very-Large-Scale Software Systems. Please
 * contact us at <http://mevss.jku.at/> if you need additional information
 * or have any questions.
 *
 * 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.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 *
 */ 
package sun.evtracing.processing.statistics.metadata;

import java.util.Arrays;

public abstract class JavaObjectStack {

	public static final JavaObjectStack HIDDEN = new JavaObjectArrayStack(0) {
		@Override
		public boolean equals(Object obj) {
			return (this == obj);
		}
	};

	public abstract JavaObject top();

	public abstract JavaObject[] objects();

	public abstract void setObject(int number, JavaObject obj);

	public abstract JavaClassStack getClassStack();

	@Override
	public int hashCode() {
		return Arrays.hashCode(objects());
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj) {
			return true;
		}
		if (obj instanceof JavaObjectStack) {
			JavaObjectStack other = (JavaObjectStack) obj;
			return Arrays.equals(objects(), other.objects());
		}
		return false;
	}
}