001 /*
002 * CDDL HEADER START
003 *
004 * The contents of this file are subject to the terms of the
005 * Common Development and Distribution License, Version 1.0 only
006 * (the "License"). You may not use this file except in compliance
007 * with the License.
008 *
009 * You can obtain a copy of the license at
010 * trunk/opends/resource/legal-notices/OpenDS.LICENSE
011 * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
012 * See the License for the specific language governing permissions
013 * and limitations under the License.
014 *
015 * When distributing Covered Code, include this CDDL HEADER in each
016 * file and include the License file at
017 * trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
018 * add the following below this CDDL HEADER, with the fields enclosed
019 * by brackets "[]" replaced with your own identifying information:
020 * Portions Copyright [yyyy] [name of copyright owner]
021 *
022 * CDDL HEADER END
023 *
024 *
025 * Copyright 2006-2008 Sun Microsystems, Inc.
026 */
027 package org.opends.server.backends.jeb;
028
029 import java.util.Iterator;
030 import java.util.NoSuchElementException;
031
032 /**
033 * Iterator for a set of Entry IDs. It must return values in order of ID.
034 */
035 public class IDSetIterator implements Iterator<EntryID>
036 {
037 /**
038 * An array of ID values in order of ID.
039 */
040 private long[] entryIDList;
041
042 /**
043 * Current position of the iterator as an index into the array of IDs.
044 */
045 private int i;
046
047 /**
048 * Create a new iterator for a given array of entry IDs.
049 * @param entryIDList An array of IDs in order or ID.
050 */
051 public IDSetIterator(long[] entryIDList)
052 {
053 this.entryIDList = entryIDList;
054 }
055
056 /**
057 * Create a new iterator for a given array of entry IDs.
058 * @param entryIDList An array of IDs in order or ID.
059 * @param begin The entry ID of the first entry that should be returned, or
060 * {@code null} if it should start at the beginning of the list.
061 */
062 public IDSetIterator(long[] entryIDList, EntryID begin)
063 {
064 this.entryIDList = entryIDList;
065
066 if (begin == null)
067 {
068 i = 0;
069 }
070 else
071 {
072 for (i=0; i < entryIDList.length; i++)
073 {
074 if (entryIDList[i] == begin.longValue())
075 {
076 break;
077 }
078 }
079
080 if (i >= entryIDList.length)
081 {
082 i = 0;
083 }
084 }
085 }
086
087 /**
088 * Returns <tt>true</tt> if the iteration has more elements. (In other
089 * words, returns <tt>true</tt> if <tt>next</tt> would return an element
090 * rather than throwing an exception.)
091 *
092 * @return <tt>true</tt> if the iterator has more elements.
093 */
094 public boolean hasNext()
095 {
096 return i < entryIDList.length;
097 }
098
099 /**
100 * Returns the next element in the iteration. Calling this method
101 * repeatedly until the {@link #hasNext()} method returns false will
102 * return each element in the underlying collection exactly once.
103 *
104 * @return the next element in the iteration.
105 * @throws java.util.NoSuchElementException
106 * iteration has no more elements.
107 */
108 public EntryID next()
109 throws NoSuchElementException
110 {
111 if (i < entryIDList.length)
112 {
113 return new EntryID(entryIDList[i++]);
114 }
115 throw new NoSuchElementException();
116 }
117
118 /**
119 *
120 * Removes from the underlying collection the last element returned by the
121 * iterator (optional operation). This method can be called only once per
122 * call to <tt>next</tt>. The behavior of an iterator is unspecified if
123 * the underlying collection is modified while the iteration is in
124 * progress in any way other than by calling this method.
125 *
126 * @exception UnsupportedOperationException if the <tt>remove</tt>
127 * operation is not supported by this Iterator.
128 */
129 public void remove() throws UnsupportedOperationException
130 {
131 throw new UnsupportedOperationException();
132 }
133 }