/*
 * Copyright IBM Corp. and others 1991
 *
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which accompanies this
 * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
 * or the Apache License, Version 2.0 which accompanies this distribution and
 * is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following
 * Secondary Licenses when the conditions for such availability set
 * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
 * General Public License, version 2 with the GNU Classpath
 * Exception [1] and GNU General Public License, version 2 with the
 * OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] https://openjdk.org/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0 OR GPL-2.0-only WITH OpenJDK-assembly-exception-1.0
 */
package com.ibm.j9ddr.vm29.j9.gc;

import static com.ibm.j9ddr.vm29.events.EventManager.raiseCorruptDataEvent;

import java.util.NoSuchElementException;

import com.ibm.j9ddr.CorruptDataException;
import com.ibm.j9ddr.vm29.j9.ObjectModel;
import com.ibm.j9ddr.vm29.pointer.ObjectReferencePointer;
import com.ibm.j9ddr.vm29.pointer.VoidPointer;
import com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer;
import com.ibm.j9ddr.vm29.pointer.generated.J9ObjectPointer;
import com.ibm.j9ddr.vm29.pointer.helper.J9ObjectHelper;

class GCPointerArrayletIterator_V1 extends GCObjectIterator
{
	protected int scanIndex;
	protected int scanLimit;
	protected GCArrayObjectModel indexableObjectModel;
	
	protected GCPointerArrayletIterator_V1(J9ObjectPointer object, boolean includeClassSlot) throws CorruptDataException
	{
		super(object, includeClassSlot);
		scanIndex = 0;
		scanLimit = ObjectModel.getSizeInElements(object).intValue();
		indexableObjectModel = GCArrayObjectModel.from();
	}
	
	public boolean hasNext()
	{
		if (includeClassSlot) {
			return true;
		}
		return (scanIndex < scanLimit);
	}
	
	@Override
	public J9ObjectPointer next()
	{
		J9ObjectPointer next = null;
		try {
			if (hasNext()) {
				if (includeClassSlot) {
					includeClassSlot = false;
					next = J9ObjectHelper.clazz(object).classObject();
				} else {
					VoidPointer elementAddress = indexableObjectModel.getElementAddress(J9IndexableObjectPointer.cast(object), scanIndex, (int)ObjectReferencePointer.SIZEOF);
					next = ObjectReferencePointer.cast(elementAddress).at(0);
					scanIndex++;
				}
			} else {
				throw new NoSuchElementException("There are no more items available through this iterator");
			}
		} catch (CorruptDataException e) {
			raiseCorruptDataEvent("Error getting next item", e, false);		//can try to recover from this
		}
		return next;
	}

	public VoidPointer nextAddress()
	{
		VoidPointer next = null;
		try {
			if (hasNext()) {
				if (includeClassSlot) {
					includeClassSlot = false;
					next = VoidPointer.cast(J9ObjectHelper.clazz(object).classObjectEA());
				} else {
					next = indexableObjectModel.getElementAddress(J9IndexableObjectPointer.cast(object), scanIndex, (int)ObjectReferencePointer.SIZEOF);
					scanIndex++;
				}
			} else {
				throw new NoSuchElementException("There are no more items available through this iterator");
			}
		} catch (CorruptDataException e) {
			raiseCorruptDataEvent("Error getting next item", e, false);		//can try to recover from this
		}
		return next;
	}
}
