用qt写一个tcp服务器与客户端之间如何计算延时率的示例

以下是一个简单的示例，演示如何使用Qt编写TCP服务器和客户端，并计算延迟率。

服务端（server.cpp）：

#include <QTcpServer>
#include <QTcpSocket>
#include <QDateTime>

class Server : public QTcpServer
{
    Q_OBJECT
public:
    explicit Server(QObject *parent = nullptr) : QTcpServer(parent) {}

protected:
    void incomingConnection(qintptr socketDescriptor) override
    {
        QTcpSocket *socket = new QTcpSocket(this);
        if (socket->setSocketDescriptor(socketDescriptor))
        {
            connect(socket, &QTcpSocket::readyRead, this, &Server::onReadyRead);
            connect(socket, &QTcpSocket::disconnected, socket, &QTcpSocket::deleteLater);
            m_clients.append(socket);
        }
        else
        {
            delete socket;
        }
    }

signals:
    void latencyCalculated(qint64);

private slots:
    void onReadyRead()
    {
        QTcpSocket *socket = qobject_cast<QTcpSocket*>(sender());
        if (socket)
        {
            QByteArray request = socket->readAll();
            if (request == "ping")
            {
                qint64 timestamp = QDateTime::currentMSecsSinceEpoch();
                socket->write("pong");
                socket->flush();
                qint64 latency = QDateTime::currentMSecsSinceEpoch() - timestamp;
                emit latencyCalculated(latency);
            }
        }
    }

private:
    QList<QTcpSocket*> m_clients;
};

客户端（client.cpp）：

#include <QTcpSocket>
#include <QDateTime>

class Client : public QObject
{
    Q_OBJECT
public:
    explicit Client(QObject *parent = nullptr) : QObject(parent) {}

    void connectToServer(const QString &host, quint16 port)
    {
        m_socket.connectToHost(host, port);
        connect(&m_socket, &QTcpSocket::connected, this, &Client::onConnected);
        connect(&m_socket, &QTcpSocket::disconnected, this, &Client::onDisconnected);
        connect(&m_socket, &QTcpSocket::readyRead, this, &Client::onReadyRead);
    }

signals:
    void latencyCalculated(qint64);

private slots:
    void onConnected()
    {
        m_socket.write("ping");
        m_socket.flush();
        m_timestamp = QDateTime::currentMSecsSinceEpoch();
    }

    void onDisconnected()
    {
        m_socket.deleteLater();
    }

    void onReadyRead()
    {
        QByteArray response = m_socket.readAll();
        if (response == "pong")
        {
            qint64 latency = QDateTime::currentMSecsSinceEpoch() - m_timestamp;
            emit latencyCalculated(latency);
        }
    }

private:
    QTcpSocket m_socket;
    qint64 m_timestamp;
};

主函数（main.cpp）：

#include <QCoreApplication>
#include "server.h"
#include "client.h"

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    Server server;
    QObject::connect(&server, &Server::latencyCalculated, [&](qint64 latency) {
        qDebug() << "Server latency:" << latency << "ms";
    });
    server.listen(QHostAddress::Any, 12345);

    Client client;
    QObject::connect(&client, &Client::latencyCalculated, [&](qint64 latency) {
        qDebug() << "Client latency:" << latency << "ms";
    });
    client.connectToServer("localhost", 12345);

    return a.exec();
}

上述代码演示了一个TCP服务器和客户端之间的简单通信，并计算了延迟率。当客户端连接到服务器时，客户端会发送一个"ping"请求，服务器收到请求后会记录时间戳并发送一个"pong"响应，客户端收到响应后也会记录时间戳并计算延迟率。服务器和客户端的延迟率分别通过信号和槽进行传递和处理。