Qt实现TFTP Server和 TFTP Client(四)

3.3 Server

Server包括下面3个类：

ServerSocket
TFtpServer
TFtpServerWidget

3.3.1 ServerSocket

ServerSocket从BaseUdp派生实现write接口.

3.3.1.1 ServerSocket定义

class QUdpSocket;
class ServerSocket : public BaseUdp
{
public:ServerSocket(QUdpSocket* socket, QHostAddress const& host,uint16_t port): socket_(socket), host_(host), port_(port){}uint32_t write(const char* data, size_t size) override;
private:QUdpSocket* socket_;QHostAddress host_;uint16_t port_;
};

成员函数说明:

write 重载函数，实现父类BaseUdp中定义的write接口。

3.3.1.2 ServerSocket实现

uint32_t ServerSocket::write(const char* data, size_t size)
{return socket_->writeDatagram(data, size, host_, port_);
}

函数实现说明:

直接调用QUdpSocket对象的writeDatagram接口。

3.3.2 TFtpServer

TFtpServer类通过TFtpServerFile类实现一个TFTP服务端，接受上下载文件请求。

3.3.2.1 TFtpServer定义

class QUdpSocket;
class TFtpServer:  public QObject
{
Q_OBJECT
public:TFtpServer(QObject *parent = nullptr);void setFilePath(QString const& filePath);void start();void stop();
signals:void bindError();void startFile(QString const&transferId, QString const& fileName);void progress(QString const&transferId, quint64 bytes, quint64 total);void statusText(QString const& text);void stopFile(QString const&transferId);private slots:void readPendingDatagrams();
private:private:QUdpSocket* socket;QString filePath_;TFtpFileManager::Ptr fileManager_;const uint16_t TFTP_PORT = 69;
};

成员函数说明:

setFilePath 配置TFTP服务器的下载文件路径.
start 启动TFTP服务.
stop 停止TFTP服务.

信号说明:

bindError 绑定UDP端口错误信号
startFile 文件开始传输信号
progress 文件传输进度信号
statusText 状态文本变化信号
stopFile 停止文件传输信号
槽函数说明:
readPendingDatagrams 从TFTP客户端读数据处理函数

3.3.2.1 TFtpServer实现

构造函数

TFtpServer::TFtpServer(QObject *parent): QObject(parent), socket(new QUdpSocket(this)), fileManager_(new TFtpFileManager())
{connect(socket, &QUdpSocket::readyRead,this, &TFtpServer::readPendingDatagrams);
}

函数说明:

创建QUdpSocket对象socket
连接socket的信号和对应槽函数。
setFilePath/start/stop/readPendingDatagrams

void TFtpServer::setFilePath(QString const& filePath)
{if(!filePath.endsWith("/"))filePath_ = filePath + "/";
}void TFtpServer::start()
{if(!socket->bind(TFTP_PORT))emit bindError();
}void TFtpServer::stop()
{socket->close();
}void TFtpServer::readPendingDatagrams()
{while (socket->hasPendingDatagrams()) {QNetworkDatagram datagram = socket->receiveDatagram();QByteArray d = datagram.data();QString  transferId = QString("%1:%2").arg(datagram.senderAddress().toString()).arg(datagram.senderPort());TFtpServerFile::Ptr file = fileManager_->find(transferId.toStdString());if(file)file->process((uint8_t *)d.data(), d.size());else{ServerSocket* udp = new ServerSocket(socket, datagram.senderAddress(), datagram.senderPort());file = TFtpServerFile::Ptr(new TFtpServerFile(udp, filePath_.toStdString(), transferId.toStdString()));fileManager_->add(file);file->process((uint8_t *)d.data(), d.size());emit startFile(transferId, QString::fromStdString(file->filename()));}if(!file->is_finished()){if(file->type() == TFtpServerFile::Read)emit statusText(QString("Downloding file: %1, progress: %4% blockNumber(%2/%3)").arg(QString::fromStdString(file->filename())).arg(file->block_number()).arg(file->block_numbers()).arg(file->block_number() * 100 / file->block_numbers()));elseemit statusText(QString("Uploading file: %1, blockNumber(%2)").arg(QString::fromStdString(file->filename())).arg(file->block_number()));emit progress(transferId, file->file_bytes(), file->filesize());}else{if(file->is_error())emit statusText(QString("%1:%2").arg((int)file->error()).arg(QString::fromStdString(file->error_msg())));elseemit statusText(QString());emit progress(transferId, file->file_bytes(), file->filesize());emit stopFile(transferId);fileManager_->remove(file->transfer_id());}}
}

函数说明:

setFilePath 保存文件路径地址
start 绑定TFTP端口,启动服务，绑定失败发送bindError信号。
stop 关闭socket，停止服务
readPendingDatagrams 从socket读取数据包，构造transferId，根据transferId判断是新连接还是旧连接，旧连接则找到对应TFtpServerFile对象处理文件上下载；新连接则TFtpServerFile对象处理文件上下载，并保存TFtpServerFile对象；处理数据完毕后，根据结束与否进行相应的处理。

3.3.3 TFtpServerWidget

TFtpServerWidget从QWidget派生一个窗口类，负责设置下载文件路径，并显示文件传输进度等界面操作。

3.3.3.1 TFtpServerWidget定义

class TFtpServer;
class TFtpServerWidget : public QWidget
{Q_OBJECTpublic:TFtpServerWidget(QWidget *parent = nullptr);~TFtpServerWidget();private slots:void selectTFtpDir();void setCurrentDir(QString const& path);void onBindError();void onStartFile(QString const&transferId, QString const& fileName);void onProgress(QString const&transferId, quint64 bytes, quint64 total);void onStopFile(QString const&transferId);
private:void saveSettinggs();void loadSettings();
private:Ui::TFtpServerWidget *ui;TFtpServer* tftpServer;int MAX_PATH_SIZE = 5;};

3.3.3.2 TFtpServerWidget实现

TFtpServerWidget::TFtpServerWidget(QWidget *parent): QWidget(parent), ui(new Ui::TFtpServerWidget), tftpServer(new TFtpServer(this))
{ui->setupUi(this);loadSettings();connect(ui->btnBrowse, SIGNAL(clicked()), this, SLOT(selectTFtpDir()));connect(ui->currentDir, SIGNAL(currentIndexChanged(QString)), this, SLOT(setCurrentDir(QString)));connect(tftpServer, SIGNAL(startFile(QString,QString)), this, SLOT(onStartFile(QString,QString)));connect(tftpServer, SIGNAL(progress(QString,quint64,quint64)), this, SLOT(onProgress(QString,quint64,quint64)));connect(tftpServer, SIGNAL(stopFile(QString)), this, SLOT(onStopFile(QString)));connect(tftpServer, SIGNAL(bindError()), this, SLOT(onBindError()));tftpServer->start();
}TFtpServerWidget::~TFtpServerWidget()
{saveSettinggs();tftpServer->stop();delete ui;
}void TFtpServerWidget::selectTFtpDir()
{QString filePath = QFileDialog::getExistingDirectory(this,"Select Dir", ui->currentDir->currentText());if(filePath.isEmpty())return;int index  = ui->currentDir->findText(filePath);if(index != -1)ui->currentDir->setCurrentIndex(index);else{if(ui->currentDir->count() >= MAX_PATH_SIZE)ui->currentDir->removeItem(0);ui->currentDir->addItem(filePath);ui->currentDir->setCurrentIndex(ui->currentDir->count()  - 1);}
}void TFtpServerWidget::setCurrentDir(QString const& path)
{tftpServer->setFilePath(path);
}void TFtpServerWidget::onStartFile(QString const&transferId, QString const& fileName)
{ui->clientTables->addTopLevelItem(new QTreeWidgetItem(QStringList()<< transferId << fileName << QTime::currentTime().toString("hh:mm:ss")));
}void TFtpServerWidget::onProgress(QString const&transferId, quint64 bytes, quint64 total)
{QList<QTreeWidgetItem*> items = ui->clientTables->findItems(transferId, Qt::MatchCaseSensitive);for(int i = 0; i < items.size(); i++){if(total == 0)items[i]->setText(5, QString::number(bytes));else{   items[i]->setText(3, QString("%1%").arg(bytes * 100 / total));items[i]->setText(5, QString::number(total));}items[i]->setText(4, QString::number(bytes));}
}void TFtpServerWidget::onStopFile(QString const&transferId)
{QList<QTreeWidgetItem*> items = ui->clientTables->findItems(transferId, Qt::MatchCaseSensitive);for(int i = 0; i < items.size(); i++){int index = ui->clientTables->indexOfTopLevelItem(items[i]);ui->clientTables->takeTopLevelItem(index);}
}void TFtpServerWidget::saveSettinggs()
{QSettings settings(QCoreApplication::applicationName(), QCoreApplication::applicationVersion());QStringList dirs;for(int i = 0; i < ui->currentDir->count(); i++)dirs << ui->currentDir->itemText(i);settings.setValue("dirs", dirs);settings.setValue("currentDir", ui->currentDir->currentText());
}void TFtpServerWidget::loadSettings()
{QSettings settings(QCoreApplication::applicationName(), QCoreApplication::applicationVersion());QStringList dirs = settings.value("dirs", QStringList()).toStringList();QString currentDir = settings.value("currentDir", QString()).toString();ui->currentDir->addItems(dirs);int index  = ui->currentDir->findText(currentDir);if(index != -1){tftpServer->setFilePath(currentDir);ui->currentDir->setCurrentIndex(index);}else{tftpServer->setFilePath(QApplication::applicationDirPath());ui->currentDir->addItem(QApplication::applicationDirPath());}
}void TFtpServerWidget::onBindError()
{QMessageBox::critical(this, "TFtpServer", "Port(69) is already occupied!");ui->btnBrowse->setDisabled(true);ui->currentDir->setDisabled(true);setWindowTitle("TFtpServer is not running");
}