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1   //******************************************************************************
2   //
3   // File:    BooleanArrayBuf_1.java
4   // Package: edu.rit.mp.buf
5   // Unit:    Class edu.rit.mp.buf.BooleanArrayBuf_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
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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.pj.reduction.BooleanOp;
46  import edu.rit.pj.reduction.Op;
47  import edu.rit.util.Range;
48  
49  /**
50   * Class BooleanArrayBuf_1 provides a buffer for an array of Boolean items sent
51   * or received using the Message Protocol (MP). The array element stride must be
52   * 1. While an instance of class BooleanArrayBuf_1 may be constructed directly,
53   * normally you will use a factory method in class {@linkplain
54   * edu.rit.mp.BooleanBuf BooleanBuf}. See that class for further information.
55   *
56   * @author Alan Kaminsky
57   * @version 25-Oct-2007
58   */
59  public class BooleanArrayBuf_1
60          extends BooleanArrayBuf {
61  
62  // Exported constructors.
63      /**
64       * Construct a new Boolean array buffer.
65       *
66       * @param theArray Array.
67       * @param theRange Range of array elements to include in the buffer. The
68       * stride is assumed to be 1.
69       */
70      public BooleanArrayBuf_1(boolean[] theArray,
71              Range theRange) {
72          super(theArray, theRange);
73      }
74  
75  // Exported operations.
76      /**
77       * {@inheritDoc}
78       *
79       * Obtain the given item from this buffer.
80       * <P>
81       * The <code>get()</code> method must not block the calling thread; if it does,
82       * all message I/O in MP will be blocked.
83       */
84      public boolean get(int i) {
85          return myArray[myArrayOffset + i];
86      }
87  
88      /**
89       * {@inheritDoc}
90       *
91       * Store the given item in this buffer.
92       * <P>
93       * The <code>put()</code> method must not block the calling thread; if it does,
94       * all message I/O in MP will be blocked.
95       */
96      public void put(int i,
97              boolean item) {
98          myArray[myArrayOffset + i] = item;
99      }
100 
101     /**
102      * {@inheritDoc}
103      *
104      * Create a buffer for performing parallel reduction using the given binary
105      * operation. The results of the reduction are placed into this buffer.
106      * @exception ClassCastException (unchecked exception) Thrown if this
107      * buffer's element data type and the given binary operation's argument data
108      * type are not the same.
109      */
110     public Buf getReductionBuf(Op op) {
111         return new BooleanArrayReductionBuf_1(myArray, myRange, (BooleanOp) op);
112     }
113 
114 // Hidden operations.
115     /**
116      * {@inheritDoc}
117      *
118      * Send as many items as possible from this buffer to the given byte buffer.
119      * <P>
120      * The <code>sendItems()</code> method must not block the calling thread; if it
121      * does, all message I/O in MP will be blocked.
122      */
123     protected int sendItems(int i,
124             ByteBuffer buffer) {
125         int index = i;
126         int off = myArrayOffset + i;
127         while (index < myLength && buffer.remaining() >= 1) {
128             buffer.put(myArray[off] ? (byte) 1 : (byte) 0);
129             ++index;
130             ++off;
131         }
132         return index - i;
133     }
134 
135     /**
136      * {@inheritDoc}
137      *
138      * Receive as many items as possible from the given byte buffer to this
139      * buffer.
140      * <P>
141      * The <code>receiveItems()</code> method must not block the calling thread; if
142      * it does, all message I/O in MP will be blocked.
143      */
144     protected int receiveItems(int i,
145             int num,
146             ByteBuffer buffer) {
147         int index = i;
148         int off = myArrayOffset + i;
149         int max = Math.min(i + num, myLength);
150         while (index < max && buffer.remaining() >= 1) {
151             myArray[off] = buffer.get() != 0;
152             ++index;
153             ++off;
154         }
155         return index - i;
156     }
157 
158 }