1 //******************************************************************************
2 //
3 // File: IteratorItemGenerator.java
4 // Package: edu.rit.pj
5 // Unit: Class edu.rit.pj.IteratorItemGenerator
6 //
7 // This Java source file is copyright (C) 2007 by Alan Kaminsky. All rights
8 // reserved. For further information, contact the author, Alan Kaminsky, at
9 // ark@cs.rit.edu.
10 //
11 // This Java source file is part of the Parallel Java Library ("PJ"). PJ is free
12 // software; you can redistribute it and/or modify it under the terms of the GNU
13 // General Public License as published by the Free Software Foundation; either
14 // version 3 of the License, or (at your option) any later version.
15 //
16 // PJ is distributed in the hope that it will be useful, but WITHOUT ANY
17 // WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
18 // A PARTICULAR PURPOSE. See the GNU General Public License for more details.
19 //
20 // Linking this library statically or dynamically with other modules is making a
21 // combined work based on this library. Thus, the terms and conditions of the GNU
22 // General Public License cover the whole combination.
23 //
24 // As a special exception, the copyright holders of this library give you
25 // permission to link this library with independent modules to produce an
26 // executable, regardless of the license terms of these independent modules, and
27 // to copy and distribute the resulting executable under terms of your choice,
28 // provided that you also meet, for each linked independent module, the terms
29 // and conditions of the license of that module. An independent module is a module
30 // which is not derived from or based on this library. If you modify this library,
31 // you may extend this exception to your version of the library, but you are not
32 // obligated to do so. If you do not wish to do so, delete this exception
33 // statement from your version.
34 //
35 // A copy of the GNU General Public License is provided in the file gpl.txt. You
36 // may also obtain a copy of the GNU General Public License on the World Wide
37 // Web at http://www.gnu.org/licenses/gpl.html.
38 //
39 //******************************************************************************
40 package edu.rit.pj;
41
42 import java.util.Iterator;
43
44 /**
45 * Class IteratorItemGenerator provides an object that generates items for a
46 * {@linkplain ParallelIteration}; the items come from an iterator.
47 *
48 * @param <T> Data type of the items iterated over.
49 *
50 * @author Alan Kaminsky
51 * @version 04-Jun-2007
52 */
53 class IteratorItemGenerator<T>
54 extends ItemGenerator<T> {
55
56 // Hidden data members.
57 // Iterator over the items.
58 private Iterator<T> myIterator;
59
60 // Exported constructors.
61 /**
62 * Construct a new iterator item generator.
63 *
64 * @param theIterator Iterator over the items.
65 */
66 public IteratorItemGenerator(Iterator<T> theIterator) {
67 super();
68 myIterator = theIterator;
69 }
70
71 // Exported operations.
72 /**
73 * Return an item holder containing the next item to be processed plus
74 * associated information.
75 *
76 * @return Item holder, or null if no more items.
77 */
78 public synchronized ItemHolder<T> nextItem() {
79 ItemHolder<T> itemholder = null;
80 if (myIterator.hasNext() && !myBreak) {
81 itemholder = new ItemHolder<T>();
82 itemholder.myItem = myIterator.next();
83 itemholder.mySequenceNumber = myCurrentSequenceNumber;
84 ++myCurrentSequenceNumber;
85 }
86 return itemholder;
87 }
88
89 }