/*
* Copyright (c) 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017 David Berkman
*
* This file is part of the SmallMind Code Project.
*
* The SmallMind Code Project is free software, you can redistribute
* it and/or modify it under either, at your discretion...
*
* 1) The terms of GNU Affero General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
* ...or...
*
* 2) The terms of the Apache License, Version 2.0.
*
* The SmallMind Code Project 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 or Apache License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* and the Apache License along with the SmallMind Code Project. If not, see
* <http://www.gnu.org/licenses/> or <http://www.apache.org/licenses/LICENSE-2.0>.
*
* Additional permission under the GNU Affero GPL version 3 section 7
* ------------------------------------------------------------------
* If you modify this Program, or any covered work, by linking or
* combining it with other code, such other code is not for that reason
* alone subject to any of the requirements of the GNU Affero GPL
* version 3.
*/
package org.smallmind.persistence.cache.praxis.intrinsic;
import java.util.ListIterator;
import java.util.NoSuchElementException;
public class IntrinsicRosterIterator<T> implements ListIterator<T> {
private IntrinsicRoster<T> concurrentList;
private IntrinsicRosterNode<T> next;
private IntrinsicRosterNode<T> prev;
private IntrinsicRosterNode<T> current;
private int index;
public IntrinsicRosterIterator (IntrinsicRoster<T> concurrentList, IntrinsicRosterNode<T> prev, IntrinsicRosterNode<T> next, int index) {
this.concurrentList = concurrentList;
this.next = next;
this.prev = prev;
this.index = index;
}
public boolean hasNext () {
return next != null;
}
public T next () {
if (!hasNext()) {
throw new NoSuchElementException();
}
try {
return next.getObj();
}
finally {
current = next;
prev = next;
next = concurrentList.getNextInView(next);
index++;
}
}
public boolean hasPrevious () {
return prev != null;
}
public T previous () {
if (!hasPrevious()) {
throw new NoSuchElementException();
}
try {
return prev.getObj();
}
finally {
current = prev;
next = prev;
prev = concurrentList.getPrevInView(prev);
index--;
}
}
public int nextIndex () {
return index;
}
public int previousIndex () {
return index - 1;
}
public void set (T obj) {
if (current == null) {
throw new IllegalStateException();
}
current.setObj(obj);
}
public void remove () {
if (current == null) {
throw new IllegalStateException();
}
concurrentList.getLock().writeLock().lock();
try {
concurrentList.removeNode(current);
}
finally {
concurrentList.getLock().writeLock().unlock();
}
current = null;
}
public void add (T t) {
if (current == null) {
throw new IllegalStateException();
}
concurrentList.getLock().writeLock().lock();
try {
concurrentList.add(current, t);
}
finally {
concurrentList.getLock().writeLock().unlock();
}
current = null;
}
}