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 }