001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.kaha.impl.container;
018
019import java.util.Iterator;
020import org.apache.activemq.kaha.impl.index.IndexItem;
021import org.apache.activemq.kaha.impl.index.IndexLinkedList;
022
023/**
024 * Iterator for the set of keys for a container
025 * 
026 * 
027 */
028public class ContainerKeySetIterator implements Iterator {
029    
030    protected IndexItem nextItem;
031    protected IndexItem currentItem;
032
033    private MapContainerImpl container;
034    private IndexLinkedList list;
035
036    ContainerKeySetIterator(MapContainerImpl container) {
037        this.container = container;
038        this.list = container.getInternalList();
039        this.currentItem = list.getRoot();
040        this.nextItem = list.getNextEntry(currentItem);
041    }
042
043    public boolean hasNext() {
044        return nextItem != null;
045    }
046
047    public Object next() {
048        currentItem = nextItem;
049        Object result = container.getKey(nextItem);
050        nextItem = list.getNextEntry(nextItem);
051        return result;
052    }
053
054    public void remove() {
055        if (currentItem != null) {
056            container.remove(currentItem);
057            if (nextItem != null) {
058                list.refreshEntry(nextItem);
059            }
060        }
061    }
062}