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 */ 017 package org.apache.activemq.kaha.impl.container; 018 019 import java.util.ListIterator; 020 import org.apache.activemq.kaha.StoreEntry; 021 import org.apache.activemq.kaha.impl.index.IndexItem; 022 import org.apache.activemq.kaha.impl.index.IndexLinkedList; 023 024 /** 025 * 026 */ 027 public class ContainerListIterator extends ContainerValueCollectionIterator implements ListIterator { 028 029 protected ContainerListIterator(ListContainerImpl container, IndexLinkedList list, IndexItem start) { 030 super(container, list, start); 031 } 032 033 /* 034 * (non-Javadoc) 035 * 036 * @see java.util.ListIterator#hasPrevious() 037 */ 038 public boolean hasPrevious() { 039 synchronized (container) { 040 nextItem = (IndexItem)list.refreshEntry(nextItem); 041 return list.getPrevEntry(nextItem) != null; 042 } 043 } 044 045 /* 046 * (non-Javadoc) 047 * 048 * @see java.util.ListIterator#previous() 049 */ 050 public Object previous() { 051 synchronized (container) { 052 nextItem = (IndexItem)list.refreshEntry(nextItem); 053 nextItem = list.getPrevEntry(nextItem); 054 return nextItem != null ? container.getValue(nextItem) : null; 055 } 056 } 057 058 /* 059 * (non-Javadoc) 060 * 061 * @see java.util.ListIterator#nextIndex() 062 */ 063 public int nextIndex() { 064 int result = -1; 065 if (nextItem != null) { 066 synchronized (container) { 067 nextItem = (IndexItem)list.refreshEntry(nextItem); 068 StoreEntry next = list.getNextEntry(nextItem); 069 if (next != null) { 070 result = container.getInternalList().indexOf(next); 071 } 072 } 073 } 074 return result; 075 } 076 077 /* 078 * (non-Javadoc) 079 * 080 * @see java.util.ListIterator#previousIndex() 081 */ 082 public int previousIndex() { 083 int result = -1; 084 if (nextItem != null) { 085 synchronized (container) { 086 nextItem = (IndexItem)list.refreshEntry(nextItem); 087 StoreEntry prev = list.getPrevEntry(nextItem); 088 if (prev != null) { 089 result = container.getInternalList().indexOf(prev); 090 } 091 } 092 } 093 return result; 094 } 095 096 /* 097 * (non-Javadoc) 098 * 099 * @see java.util.ListIterator#set(E) 100 */ 101 public void set(Object o) { 102 IndexItem item = ((ListContainerImpl)container).internalSet(previousIndex() + 1, o); 103 nextItem = item; 104 } 105 106 /* 107 * (non-Javadoc) 108 * 109 * @see java.util.ListIterator#add(E) 110 */ 111 public void add(Object o) { 112 IndexItem item = ((ListContainerImpl)container).internalAdd(previousIndex() + 1, o); 113 nextItem = item; 114 } 115 }