<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>connection.cpp Example File | Qt Network 5.12.2</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.12</td><td ><a href="qtnetwork-index.html">Qt Network</a></td><td ><a href="qtnetwork-network-chat-example.html">Network Chat Example</a></td><td >connection.cpp Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtnetwork-index.html">Qt 5.12.2 Reference Documentation</a></td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"><div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">connection.cpp Example File</h1> <span class="subtitle">network-chat/connection.cpp</span> <!-- $$$network-chat/connection.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Copyright (C) 2018 Intel Corporation. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** BSD License Usage ** Alternatively, 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 "connection.h"</span> <span class="preprocessor">#include <QtNetwork></span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="type">int</span> TransferTimeout <span class="operator">=</span> <span class="number">30</span> <span class="operator">*</span> <span class="number">1000</span>; <span class="keyword">static</span> <span class="keyword">const</span> <span class="type">int</span> PongTimeout <span class="operator">=</span> <span class="number">60</span> <span class="operator">*</span> <span class="number">1000</span>; <span class="keyword">static</span> <span class="keyword">const</span> <span class="type">int</span> PingInterval <span class="operator">=</span> <span class="number">5</span> <span class="operator">*</span> <span class="number">1000</span>; <span class="comment">/* * Protocol is defined as follows, using the CBOR Data Definition Language: * * protocol = [ * greeting, ; must start with a greeting command * * command ; zero or more regular commands after * ] * command = plaintext / ping / pong / greeting * plaintext = { 0 => text } * ping = { 1 => null } * pong = { 2 => null } * greeting = { 3 => text } */</span> Connection<span class="operator">::</span>Connection(<span class="type"><a href="../qtcore/qobject.html">QObject</a></span> <span class="operator">*</span>parent) : <span class="type"><a href="qtcpsocket.html">QTcpSocket</a></span>(parent)<span class="operator">,</span> writer(<span class="keyword">this</span>) { greetingMessage <span class="operator">=</span> tr(<span class="string">"undefined"</span>); username <span class="operator">=</span> tr(<span class="string">"unknown"</span>); state <span class="operator">=</span> WaitingForGreeting; currentDataType <span class="operator">=</span> Undefined; transferTimerId <span class="operator">=</span> <span class="operator">-</span><span class="number">1</span>; isGreetingMessageSent <span class="operator">=</span> <span class="keyword">false</span>; pingTimer<span class="operator">.</span>setInterval(PingInterval); <span class="type"><a href="../qtcore/qobject.html">QObject</a></span><span class="operator">::</span>connect(<span class="keyword">this</span><span class="operator">,</span> SIGNAL(readyRead())<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(processReadyRead())); <span class="type"><a href="../qtcore/qobject.html">QObject</a></span><span class="operator">::</span>connect(<span class="keyword">this</span><span class="operator">,</span> SIGNAL(disconnected())<span class="operator">,</span> <span class="operator">&</span>pingTimer<span class="operator">,</span> SLOT(stop())); <span class="type"><a href="../qtcore/qobject.html">QObject</a></span><span class="operator">::</span>connect(<span class="operator">&</span>pingTimer<span class="operator">,</span> SIGNAL(timeout())<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(sendPing())); <span class="type"><a href="../qtcore/qobject.html">QObject</a></span><span class="operator">::</span>connect(<span class="keyword">this</span><span class="operator">,</span> SIGNAL(connected())<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(sendGreetingMessage())); } Connection<span class="operator">::</span>Connection(qintptr socketDescriptor<span class="operator">,</span> <span class="type"><a href="../qtcore/qobject.html">QObject</a></span> <span class="operator">*</span>parent) : Connection(parent) { setSocketDescriptor(socketDescriptor); reader<span class="operator">.</span>setDevice(<span class="keyword">this</span>); } Connection<span class="operator">::</span><span class="operator">~</span>Connection() { <span class="keyword">if</span> (isGreetingMessageSent) { <span class="comment">// Indicate clean shutdown.</span> writer<span class="operator">.</span>endArray(); waitForBytesWritten(<span class="number">2000</span>); } } <span class="type"><a href="../qtcore/qstring.html">QString</a></span> Connection<span class="operator">::</span>name() <span class="keyword">const</span> { <span class="keyword">return</span> username; } <span class="type">void</span> Connection<span class="operator">::</span>setGreetingMessage(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&</span>message) { greetingMessage <span class="operator">=</span> message; } bool Connection<span class="operator">::</span>sendMessage(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&</span>message) { <span class="keyword">if</span> (message<span class="operator">.</span>isEmpty()) <span class="keyword">return</span> <span class="keyword">false</span>; writer<span class="operator">.</span>startMap(<span class="number">1</span>); writer<span class="operator">.</span>append(PlainText); writer<span class="operator">.</span>append(message); writer<span class="operator">.</span>endMap(); <span class="keyword">return</span> <span class="keyword">true</span>; } <span class="type">void</span> Connection<span class="operator">::</span>timerEvent(<span class="type"><a href="../qtcore/qtimerevent.html">QTimerEvent</a></span> <span class="operator">*</span>timerEvent) { <span class="keyword">if</span> (timerEvent<span class="operator">-</span><span class="operator">></span>timerId() <span class="operator">=</span><span class="operator">=</span> transferTimerId) { abort(); killTimer(transferTimerId); transferTimerId <span class="operator">=</span> <span class="operator">-</span><span class="number">1</span>; } } <span class="type">void</span> Connection<span class="operator">::</span>processReadyRead() { <span class="comment">// we've got more data, let's parse</span> reader<span class="operator">.</span>reparse(); <span class="keyword">while</span> (reader<span class="operator">.</span>lastError() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qtcborcommon.html">QCborError</a></span><span class="operator">::</span>NoError) { <span class="keyword">if</span> (state <span class="operator">=</span><span class="operator">=</span> WaitingForGreeting) { <span class="keyword">if</span> (<span class="operator">!</span>reader<span class="operator">.</span>isArray()) <span class="keyword">break</span>; <span class="comment">// protocol error</span> reader<span class="operator">.</span>enterContainer(); <span class="comment">// we'll be in this array forever</span> state <span class="operator">=</span> ReadingGreeting; } <span class="keyword">else</span> <span class="keyword">if</span> (reader<span class="operator">.</span>containerDepth() <span class="operator">=</span><span class="operator">=</span> <span class="number">1</span>) { <span class="comment">// Current state: no command read</span> <span class="comment">// Next state: read command ID</span> <span class="keyword">if</span> (<span class="operator">!</span>reader<span class="operator">.</span>hasNext()) { reader<span class="operator">.</span>leaveContainer(); disconnectFromHost(); <span class="keyword">return</span>; } <span class="keyword">if</span> (<span class="operator">!</span>reader<span class="operator">.</span>isMap() <span class="operator">|</span><span class="operator">|</span> <span class="operator">!</span>reader<span class="operator">.</span>isLengthKnown() <span class="operator">|</span><span class="operator">|</span> reader<span class="operator">.</span>length() <span class="operator">!</span><span class="operator">=</span> <span class="number">1</span>) <span class="keyword">break</span>; <span class="comment">// protocol error</span> reader<span class="operator">.</span>enterContainer(); } <span class="keyword">else</span> <span class="keyword">if</span> (currentDataType <span class="operator">=</span><span class="operator">=</span> Undefined) { <span class="comment">// Current state: read command ID</span> <span class="comment">// Next state: read command payload</span> <span class="keyword">if</span> (<span class="operator">!</span>reader<span class="operator">.</span>isInteger()) <span class="keyword">break</span>; <span class="comment">// protocol error</span> currentDataType <span class="operator">=</span> DataType(reader<span class="operator">.</span>toInteger()); reader<span class="operator">.</span>next(); } <span class="keyword">else</span> { <span class="comment">// Current state: read command payload</span> <span class="keyword">if</span> (reader<span class="operator">.</span>isString()) { <span class="keyword">auto</span> r <span class="operator">=</span> reader<span class="operator">.</span>readString(); buffer <span class="operator">+</span><span class="operator">=</span> r<span class="operator">.</span>data; <span class="keyword">if</span> (r<span class="operator">.</span>status <span class="operator">!</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qcborstreamreader.html">QCborStreamReader</a></span><span class="operator">::</span>EndOfString) <span class="keyword">continue</span>; } <span class="keyword">else</span> <span class="keyword">if</span> (reader<span class="operator">.</span>isNull()) { reader<span class="operator">.</span>next(); } <span class="keyword">else</span> { <span class="keyword">break</span>; <span class="comment">// protocol error</span> } <span class="comment">// Next state: no command read</span> reader<span class="operator">.</span>leaveContainer(); <span class="keyword">if</span> (transferTimerId <span class="operator">!</span><span class="operator">=</span> <span class="operator">-</span><span class="number">1</span>) { killTimer(transferTimerId); transferTimerId <span class="operator">=</span> <span class="operator">-</span><span class="number">1</span>; } <span class="keyword">if</span> (state <span class="operator">=</span><span class="operator">=</span> ReadingGreeting) { <span class="keyword">if</span> (currentDataType <span class="operator">!</span><span class="operator">=</span> Greeting) <span class="keyword">break</span>; <span class="comment">// protocol error</span> processGreeting(); } <span class="keyword">else</span> { processData(); } } } <span class="keyword">if</span> (reader<span class="operator">.</span>lastError() <span class="operator">!</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qtcborcommon.html">QCborError</a></span><span class="operator">::</span>EndOfFile) abort(); <span class="comment">// parse error</span> <span class="keyword">if</span> (transferTimerId <span class="operator">!</span><span class="operator">=</span> <span class="operator">-</span><span class="number">1</span> <span class="operator">&</span><span class="operator">&</span> reader<span class="operator">.</span>containerDepth() <span class="operator">></span> <span class="number">1</span>) transferTimerId <span class="operator">=</span> startTimer(TransferTimeout); } <span class="type">void</span> Connection<span class="operator">::</span>sendPing() { <span class="keyword">if</span> (pongTime<span class="operator">.</span>elapsed() <span class="operator">></span> PongTimeout) { abort(); <span class="keyword">return</span>; } writer<span class="operator">.</span>startMap(<span class="number">1</span>); writer<span class="operator">.</span>append(Ping); writer<span class="operator">.</span>append(nullptr); <span class="comment">// no payload</span> writer<span class="operator">.</span>endMap(); } <span class="type">void</span> Connection<span class="operator">::</span>sendGreetingMessage() { writer<span class="operator">.</span>startArray(); <span class="comment">// this array never ends</span> writer<span class="operator">.</span>startMap(<span class="number">1</span>); writer<span class="operator">.</span>append(Greeting); writer<span class="operator">.</span>append(greetingMessage); writer<span class="operator">.</span>endMap(); isGreetingMessageSent <span class="operator">=</span> <span class="keyword">true</span>; <span class="keyword">if</span> (<span class="operator">!</span>reader<span class="operator">.</span>device()) reader<span class="operator">.</span>setDevice(<span class="keyword">this</span>); } <span class="type">void</span> Connection<span class="operator">::</span>processGreeting() { username <span class="operator">=</span> buffer <span class="operator">+</span> <span class="char">'@'</span> <span class="operator">+</span> peerAddress()<span class="operator">.</span>toString() <span class="operator">+</span> <span class="char">':'</span> <span class="operator">+</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span><span class="operator">::</span>number(peerPort()); currentDataType <span class="operator">=</span> Undefined; buffer<span class="operator">.</span>clear(); <span class="keyword">if</span> (<span class="operator">!</span>isValid()) { abort(); <span class="keyword">return</span>; } <span class="keyword">if</span> (<span class="operator">!</span>isGreetingMessageSent) sendGreetingMessage(); pingTimer<span class="operator">.</span>start(); pongTime<span class="operator">.</span>start(); state <span class="operator">=</span> ReadyForUse; <span class="keyword">emit</span> readyForUse(); } <span class="type">void</span> Connection<span class="operator">::</span>processData() { <span class="keyword">switch</span> (currentDataType) { <span class="keyword">case</span> PlainText: <span class="keyword">emit</span> newMessage(username<span class="operator">,</span> buffer); <span class="keyword">break</span>; <span class="keyword">case</span> Ping: writer<span class="operator">.</span>startMap(<span class="number">1</span>); writer<span class="operator">.</span>append(Pong); writer<span class="operator">.</span>append(nullptr); <span class="comment">// no payload</span> writer<span class="operator">.</span>endMap(); <span class="keyword">break</span>; <span class="keyword">case</span> Pong: pongTime<span class="operator">.</span>restart(); <span class="keyword">break</span>; <span class="keyword">default</span>: <span class="keyword">break</span>; } currentDataType <span class="operator">=</span> Undefined; buffer<span class="operator">.</span>clear(); } </pre> </div> <!-- @@@network-chat/connection.cpp --> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2019 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br/> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br/> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>