/*
* Javolution - Java(TM) Solution for Real-Time and Embedded Systems
* Copyright (C) 2006 - Javolution (http://javolution.org/)
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software is
* freely granted, provided that this notice is preserved.
*/
package javolution.util.stripped;
import javolution.util.stripped.FastCollection.Record;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* <p> This class represents an iterator over a FastCollection
* Iterations are thread-safe if the collections records are not removed
* or inserted at arbitrary position (appending/prepending is fine).</p>
*
* <p> Iterators are allocated on the stack when executing in a
*
* @author <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a>
* @version 3.7, March 17, 2005
*/
final class FastIterator implements Iterator {
private FastCollection _collection;
private Record _current;
private Record _next;
private Record _tail;
public static FastIterator valueOf(FastCollection collection) {
FastIterator iterator = new FastIterator();
iterator._collection = collection;
iterator._next = collection.head().getNext();
iterator._tail = collection.tail();
return iterator;
}
private FastIterator() {
}
public boolean hasNext() {
return (_next != _tail);
}
public Object next() {
if (_next == _tail)
throw new NoSuchElementException();
_current = _next;
_next = _next.getNext();
return _collection.valueOf(_current);
}
public void remove() {
if (_current != null) {
// Uses the previous record (not affected by the remove)
// to set the next record.
final Record previous = _current.getPrevious();
_collection.delete(_current);
_current = null;
_next = previous.getNext();
} else {
throw new IllegalStateException();
}
}
}