1 //****************************************************************************** 2 // 3 // File: Unsigned16BitIntegerArrayBuf.java 4 // Package: edu.rit.mp.buf 5 // Unit: Class edu.rit.mp.buf.Unsigned16BitIntegerArrayBuf 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 44 import edu.rit.mp.Buf; 45 import edu.rit.mp.Unsigned16BitIntegerBuf; 46 import edu.rit.pj.reduction.IntegerOp; 47 import edu.rit.pj.reduction.Op; 48 import edu.rit.util.Arrays; 49 import edu.rit.util.Range; 50 51 /** 52 * Class Unsigned16BitIntegerArrayBuf provides a buffer for an array of unsigned 53 * 16-bit integer items sent or received using the Message Protocol (MP). The 54 * array element stride may be 1 or greater than 1. While an instance of class 55 * Unsigned16BitIntegerArrayBuf may be constructed directly, normally you will 56 * use a factory method in class {@linkplain edu.rit.mp.Unsigned16BitIntegerBuf 57 * Unsigned16BitIntegerBuf}. See that class for further information. 58 * 59 * @author Alan Kaminsky 60 * @version 26-Oct-2007 61 */ 62 public class Unsigned16BitIntegerArrayBuf 63 extends Unsigned16BitIntegerBuf { 64 65 // Hidden data members. 66 int[] myArray; 67 Range myRange; 68 int myArrayOffset; 69 int myStride; 70 71 // Exported constructors. 72 /** 73 * Construct a new unsigned 16-bit integer array buffer. 74 * 75 * @param theArray Array. 76 * @param theRange Range of array elements to include in the buffer. 77 */ 78 public Unsigned16BitIntegerArrayBuf(int[] theArray, 79 Range theRange) { 80 super(theRange.length()); 81 myArray = theArray; 82 myRange = theRange; 83 myArrayOffset = theRange.lb(); 84 myStride = theRange.stride(); 85 } 86 87 // Exported operations. 88 /** 89 * {@inheritDoc} 90 * 91 * Obtain the given item from this buffer. 92 * <P> 93 * The <code>get()</code> method must not block the calling thread; if it does, 94 * all message I/O in MP will be blocked. 95 */ 96 public int get(int i) { 97 return myArray[myArrayOffset + i * myStride]; 98 } 99 100 /** 101 * {@inheritDoc} 102 * 103 * Store the given item in this buffer. 104 * <P> 105 * The <code>put()</code> method must not block the calling thread; if it does, 106 * all message I/O in MP will be blocked. 107 */ 108 public void put(int i, 109 int item) { 110 myArray[myArrayOffset + i * myStride] = item; 111 } 112 113 /** 114 * {@inheritDoc} 115 * 116 * Copy items from the given buffer to this buffer. The number of items 117 * copied is this buffer's length or <code>theSrc</code>'s length, whichever is 118 * smaller. If <code>theSrc</code> is this buffer, the <code>copy()</code> method 119 * does nothing. 120 * @exception ClassCastException (unchecked exception) Thrown if 121 * <code>theSrc</code>'s item data type is not the same as this buffer's item 122 * data type. 123 */ 124 public void copy(Buf theSrc) { 125 if (theSrc == this) { 126 } else if (theSrc instanceof Unsigned16BitIntegerArrayBuf) { 127 Unsigned16BitIntegerArrayBuf src 128 = (Unsigned16BitIntegerArrayBuf) theSrc; 129 Arrays.copy(src.myArray, src.myRange, this.myArray, this.myRange); 130 } else { 131 Unsigned16BitIntegerBuf.defaultCopy((Unsigned16BitIntegerBuf) theSrc, this); 132 } 133 } 134 135 /** 136 * {@inheritDoc} 137 * 138 * Create a buffer for performing parallel reduction using the given binary 139 * operation. The results of the reduction are placed into this buffer. 140 * @exception ClassCastException (unchecked exception) Thrown if this 141 * buffer's element data type and the given binary operation's argument data 142 * type are not the same. 143 */ 144 public Buf getReductionBuf(Op op) { 145 return new Unsigned16BitIntegerArrayReductionBuf(myArray, myRange, (IntegerOp) op); 146 } 147 148 // Hidden operations. 149 /** 150 * {@inheritDoc} 151 * 152 * Send as many items as possible from this buffer to the given byte buffer. 153 * <P> 154 * The <code>sendItems()</code> method must not block the calling thread; if it 155 * does, all message I/O in MP will be blocked. 156 */ 157 protected int sendItems(int i, 158 ByteBuffer buffer) { 159 int index = i; 160 int off = myArrayOffset + i * myStride; 161 while (index < myLength && buffer.remaining() >= 2) { 162 buffer.putShort((short) myArray[off]); 163 ++index; 164 off += myStride; 165 } 166 return index - i; 167 } 168 169 /** 170 * {@inheritDoc} 171 * 172 * Receive as many items as possible from the given byte buffer to this 173 * buffer. 174 * <P> 175 * The <code>receiveItems()</code> method must not block the calling thread; if 176 * it does, all message I/O in MP will be blocked. 177 */ 178 protected int receiveItems(int i, 179 int num, 180 ByteBuffer buffer) { 181 int index = i; 182 int off = myArrayOffset + i * myStride; 183 int max = Math.min(i + num, myLength); 184 while (index < max && buffer.remaining() >= 2) { 185 myArray[off] = buffer.getShort() & 0xFFFF; 186 ++index; 187 off += myStride; 188 } 189 return index - i; 190 } 191 192 }