1 //****************************************************************************** 2 // 3 // File: CharacterArrayBuf_1.java 4 // Package: edu.rit.mp.buf 5 // Unit: Class edu.rit.mp.buf.CharacterArrayBuf_1 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.mp.buf; 41 42 import java.nio.ByteBuffer; 43 import java.nio.CharBuffer; 44 45 import edu.rit.mp.Buf; 46 import edu.rit.pj.reduction.CharacterOp; 47 import edu.rit.pj.reduction.Op; 48 import edu.rit.util.Range; 49 50 /** 51 * Class CharacterArrayBuf_1 provides a buffer for an array of character items 52 * sent or received using the Message Protocol (MP). The array element stride 53 * must be 1. While an instance of class CharacterArrayBuf may be constructed 54 * directly, normally you will use a factory method in class {@linkplain 55 * edu.rit.mp.CharacterBuf CharacterBuf}. See that class for further 56 * information. 57 * 58 * @author Alan Kaminsky 59 * @version 25-Oct-2007 60 */ 61 public class CharacterArrayBuf_1 62 extends CharacterArrayBuf { 63 64 // Exported constructors. 65 /** 66 * Construct a new character array buffer. 67 * 68 * @param theArray Array. 69 * @param theRange Range of array elements to include in the buffer. The 70 * stride is assumed to be 1. 71 */ 72 public CharacterArrayBuf_1(char[] theArray, 73 Range theRange) { 74 super(theArray, theRange); 75 } 76 77 // Exported operations. 78 /** 79 * {@inheritDoc} 80 * 81 * Obtain the given item from this buffer. 82 * <P> 83 * The <code>get()</code> method must not block the calling thread; if it does, 84 * all message I/O in MP will be blocked. 85 */ 86 public char get(int i) { 87 return myArray[myArrayOffset + i]; 88 } 89 90 /** 91 * {@inheritDoc} 92 * 93 * Store the given item in this buffer. 94 * <P> 95 * The <code>put()</code> method must not block the calling thread; if it does, 96 * all message I/O in MP will be blocked. 97 */ 98 public void put(int i, 99 char item) { 100 myArray[myArrayOffset + i] = item; 101 } 102 103 /** 104 * {@inheritDoc} 105 * 106 * Create a buffer for performing parallel reduction using the given binary 107 * operation. The results of the reduction are placed into this buffer. 108 * @exception ClassCastException (unchecked exception) Thrown if this 109 * buffer's element data type and the given binary operation's argument data 110 * type are not the same. 111 */ 112 public Buf getReductionBuf(Op op) { 113 return new CharacterArrayReductionBuf_1(myArray, myRange, (CharacterOp) op); 114 } 115 116 // Hidden operations. 117 /** 118 * {@inheritDoc} 119 * 120 * Send as many items as possible from this buffer to the given byte buffer. 121 * <P> 122 * The <code>sendItems()</code> method must not block the calling thread; if it 123 * does, all message I/O in MP will be blocked. 124 */ 125 protected int sendItems(int i, 126 ByteBuffer buffer) { 127 CharBuffer charbuffer = buffer.asCharBuffer(); 128 int n = Math.min(myLength - i, charbuffer.remaining()); 129 charbuffer.put(myArray, myArrayOffset + i, n); 130 buffer.position(buffer.position() + 2 * n); 131 return n; 132 } 133 134 /** 135 * {@inheritDoc} 136 * 137 * Receive as many items as possible from the given byte buffer to this 138 * buffer. 139 * <P> 140 * The <code>receiveItems()</code> method must not block the calling thread; if 141 * it does, all message I/O in MP will be blocked. 142 */ 143 protected int receiveItems(int i, 144 int num, 145 ByteBuffer buffer) { 146 CharBuffer charbuffer = buffer.asCharBuffer(); 147 int n = Math.min(num, Math.min(myLength - i, charbuffer.remaining())); 148 charbuffer.get(myArray, myArrayOffset + i, n); 149 buffer.position(buffer.position() + 2 * n); 150 return n; 151 } 152 153 }