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Breadcrumbs go here --> </ul> </div> <div class="toolbuttons toolblock"> <ul> <li id="smallA" class="t_button">A</li> <li id="medA" class="t_button active">A</li> <li id="bigA" class="t_button">A</li> <li id="print" class="t_button"><a href="javascript:this.print();"> <span>Print</span></a></li> </ul> </div> </div> <div class="content mainContent"> <h1 class="title">main.cpp Example File</h1> <span class="small-subtitle">qtconcurrent/wordcount/main.cpp</span> <!-- $$$qtconcurrent/wordcount/main.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2015 The Qt Company Ltd. ** Contact: http://www.qt.io/licensing/ ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** You may use this file under the terms of the BSD license as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/</span> <span class="preprocessor">#include <QList></span> <span class="preprocessor">#include <QMap></span> <span class="preprocessor">#include <QTextStream></span> <span class="preprocessor">#include <QString></span> <span class="preprocessor">#include <QStringList></span> <span class="preprocessor">#include <QDir></span> <span class="preprocessor">#include <QTime></span> <span class="preprocessor">#include <QApplication></span> <span class="preprocessor">#include <QDebug></span> <span class="preprocessor">#include <qtconcurrentmap.h></span> <span class="preprocessor">#ifndef QT_NO_CONCURRENT</span> <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="type"><a href="qtconcurrent.html">QtConcurrent</a></span>; <span class="comment">/* Utility function that recursivily searches for files. */</span> <span class="type"><a href="qstringlist.html">QStringList</a></span> findFiles(<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>startDir<span class="operator">,</span> <span class="type"><a href="qstringlist.html">QStringList</a></span> filters) { <span class="type"><a href="qstringlist.html">QStringList</a></span> names; <span class="type"><a href="qdir.html">QDir</a></span> dir(startDir); foreach (<span class="type"><a href="qstring.html">QString</a></span> file<span class="operator">,</span> dir<span class="operator">.</span>entryList(filters<span class="operator">,</span> <span class="type"><a href="qdir.html">QDir</a></span><span class="operator">::</span>Files)) names <span class="operator">+</span><span class="operator">=</span> startDir <span class="operator">+</span> <span class="string">"/"</span> <span class="operator">+</span> file; foreach (<span class="type"><a href="qstring.html">QString</a></span> subdir<span class="operator">,</span> dir<span class="operator">.</span>entryList(<span class="type"><a href="qdir.html">QDir</a></span><span class="operator">::</span>AllDirs <span class="operator">|</span> <span class="type"><a href="qdir.html">QDir</a></span><span class="operator">::</span>NoDotAndDotDot)) names <span class="operator">+</span><span class="operator">=</span> findFiles(startDir <span class="operator">+</span> <span class="string">"/"</span> <span class="operator">+</span> subdir<span class="operator">,</span> filters); <span class="keyword">return</span> names; } <span class="keyword">typedef</span> <span class="type"><a href="qmap.html">QMap</a></span><span class="operator"><</span><span class="type"><a href="qstring.html">QString</a></span><span class="operator">,</span> <span class="type">int</span><span class="operator">></span> WordCount; <span class="comment">/* Single threaded word counter function. */</span> WordCount singleThreadedWordCount(<span class="type"><a href="qstringlist.html">QStringList</a></span> files) { WordCount wordCount; foreach (<span class="type"><a href="qstring.html">QString</a></span> file<span class="operator">,</span> files) { <span class="type"><a href="qfile.html">QFile</a></span> f(file); f<span class="operator">.</span>open(<span class="type"><a href="qiodevice.html">QIODevice</a></span><span class="operator">::</span>ReadOnly); <span class="type"><a href="qtextstream.html">QTextStream</a></span> textStream(<span class="operator">&</span>f); <span class="keyword">while</span> (textStream<span class="operator">.</span>atEnd() <span class="operator">=</span><span class="operator">=</span> <span class="keyword">false</span>) foreach(<span class="type"><a href="qstring.html">QString</a></span> word<span class="operator">,</span> textStream<span class="operator">.</span>readLine()<span class="operator">.</span>split(<span class="string">" "</span>)) wordCount<span class="operator">[</span>word<span class="operator">]</span> <span class="operator">+</span><span class="operator">=</span> <span class="number">1</span>; } <span class="keyword">return</span> wordCount; } <span class="comment">// countWords counts the words in a single file. This function is</span> <span class="comment">// called in parallel by several threads and must be thread</span> <span class="comment">// safe.</span> WordCount countWords(<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>file) { <span class="type"><a href="qfile.html">QFile</a></span> f(file); f<span class="operator">.</span>open(<span class="type"><a href="qiodevice.html">QIODevice</a></span><span class="operator">::</span>ReadOnly); <span class="type"><a href="qtextstream.html">QTextStream</a></span> textStream(<span class="operator">&</span>f); WordCount wordCount; <span class="keyword">while</span> (textStream<span class="operator">.</span>atEnd() <span class="operator">=</span><span class="operator">=</span> <span class="keyword">false</span>) foreach (<span class="type"><a href="qstring.html">QString</a></span> word<span class="operator">,</span> textStream<span class="operator">.</span>readLine()<span class="operator">.</span>split(<span class="string">" "</span>)) wordCount<span class="operator">[</span>word<span class="operator">]</span> <span class="operator">+</span><span class="operator">=</span> <span class="number">1</span>; <span class="keyword">return</span> wordCount; } <span class="comment">// reduce adds the results from map to the final</span> <span class="comment">// result. This functor will only be called by one thread</span> <span class="comment">// at a time.</span> <span class="type">void</span> reduce(WordCount <span class="operator">&</span>result<span class="operator">,</span> <span class="keyword">const</span> WordCount <span class="operator">&</span>w) { <span class="type"><a href="qmapiterator.html">QMapIterator</a></span><span class="operator"><</span><span class="type"><a href="qstring.html">QString</a></span><span class="operator">,</span> <span class="type">int</span><span class="operator">></span> i(w); <span class="keyword">while</span> (i<span class="operator">.</span>hasNext()) { i<span class="operator">.</span>next(); result<span class="operator">[</span>i<span class="operator">.</span>key()<span class="operator">]</span> <span class="operator">+</span><span class="operator">=</span> i<span class="operator">.</span>value(); } } <span class="type">int</span> main(<span class="type">int</span> argc<span class="operator">,</span> <span class="type">char</span><span class="operator">*</span><span class="operator">*</span> argv) { <span class="type"><a href="qapplication.html">QApplication</a></span> app(argc<span class="operator">,</span> argv); <a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"finding files..."</span>; <span class="preprocessor">#ifdef Q_WS_MAEMO_5</span> <span class="type"><a href="qstringlist.html">QStringList</a></span> files <span class="operator">=</span> findFiles(<span class="string">"/usr/"</span><span class="operator">,</span> <span class="type"><a href="qstringlist.html">QStringList</a></span>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"*.sh"</span>); <span class="preprocessor">#else</span> <span class="type"><a href="qstringlist.html">QStringList</a></span> files <span class="operator">=</span> findFiles(<span class="string">"../../"</span><span class="operator">,</span> <span class="type"><a href="qstringlist.html">QStringList</a></span>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"*.cpp"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"*.h"</span>); <span class="preprocessor">#endif</span> <a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> files<span class="operator">.</span>count() <span class="operator"><</span><span class="operator"><</span> <span class="string">"files"</span>; <a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"warmup"</span>; { <span class="type"><a href="qtime.html">QTime</a></span> time; time<span class="operator">.</span>start(); WordCount total <span class="operator">=</span> singleThreadedWordCount(files); } <a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"warmup done"</span>; <span class="type">int</span> singleThreadTime <span class="operator">=</span> <span class="number">0</span>; { <span class="type"><a href="qtime.html">QTime</a></span> time; time<span class="operator">.</span>start(); WordCount total <span class="operator">=</span> singleThreadedWordCount(files); singleThreadTime <span class="operator">=</span> time<span class="operator">.</span>elapsed(); <a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"single thread"</span> <span class="operator"><</span><span class="operator"><</span> singleThreadTime; } <span class="type">int</span> mapReduceTime <span class="operator">=</span> <span class="number">0</span>; { <span class="type"><a href="qtime.html">QTime</a></span> time; time<span class="operator">.</span>start(); WordCount total <span class="operator">=</span> mappedReduced(files<span class="operator">,</span> countWords<span class="operator">,</span> reduce); mapReduceTime <span class="operator">=</span> time<span class="operator">.</span>elapsed(); <a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"MapReduce"</span> <span class="operator"><</span><span class="operator"><</span> mapReduceTime; } <a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"MapReduce speedup x"</span> <span class="operator"><</span><span class="operator"><</span> ((<span class="type">double</span>)singleThreadTime <span class="operator">-</span> (<span class="type">double</span>)mapReduceTime) <span class="operator">/</span> (<span class="type">double</span>)mapReduceTime <span class="operator">+</span> <span class="number">1</span>; } <span class="preprocessor">#else</span> <span class="preprocessor">#include <QLabel></span> <span class="type">int</span> main(<span class="type">int</span> argc<span class="operator">,</span> <span class="type">char</span> <span class="operator">*</span>argv<span class="operator">[</span><span class="operator">]</span>) { <span class="type"><a href="qapplication.html">QApplication</a></span> app(argc<span class="operator">,</span> argv); <span class="type"><a href="qstring.html">QString</a></span> text(<span class="string">"Qt Concurrent is not yet supported on this platform"</span>); <span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>label <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(text); label<span class="operator">-</span><span class="operator">></span>setWordWrap(<span class="keyword">true</span>); <span class="preprocessor">#if defined(Q_WS_S60) || defined(Q_WS_MAEMO_5)</span> label<span class="operator">-</span><span class="operator">></span>showMaximized(); <span class="preprocessor">#else</span> label<span class="operator">-</span><span class="operator">></span>show(); <span class="preprocessor">#endif</span> <a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> text; app<span class="operator">.</span>exec(); } <span class="preprocessor">#endif</span></pre> </div> <!-- @@@qtconcurrent/wordcount/main.cpp --> </div> </div> </div> <div class="ft"> <span></span> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2015 The Qt Company Ltd. 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