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add progress bar for QCryptographicHash::MD5 for files

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  • S saeid0034

    i get what i need to do
    only one problem
    i have Md5_gen code in main.cpp
    how can i emit in main.cpp and get it in mainwindow2.cpp?

    main.cpp

    
    QString Md5_gen(QString const &s)
    {
        QString pakchunk_Md5;
        QCryptographicHash crypto(QCryptographicHash::Md5);
        QFile pakchunk(s);
        if (pakchunk.open(QIODevice::ReadOnly))
        {
            while(!pakchunk.atEnd()){
            crypto.addData(pakchunk.read(8192));
            }
        } else
        {
            qDebug() << "Can't open file.";
            pakchunk_Md5 = "nofile";
            return pakchunk_Md5;
        }
        pakchunk_Md5 = crypto.result().toHex();
        return pakchunk_Md5;
    }
    
    int main(int argc, char *argv[])
    {
        QApplication a(argc, argv);
        mainwindow w;
        w.show();
        return a.exec();
    }
    

    Also i do this for get progressbar value

    QString Md5_gen(QString const &s)
    {
        QString pakchunk_Md5;
        QCryptographicHash crypto(QCryptographicHash::Md5);
        QFile pakchunk(s);
        if (pakchunk.open(QIODevice::ReadOnly))
        {
            const auto size = pakchunk.size();
            while(!pakchunk.atEnd()){
            crypto.addData(pakchunk.read(8192));
    
            auto remains = pakchunk.bytesAvailable();
            auto progress = ((size - remains) * 100) / size;
            }
        } else
        {
            qDebug() << "Can't open file.";
            pakchunk_Md5 = "nofile";
            return pakchunk_Md5;
        }
        pakchunk_Md5 = crypto.result().toHex();
        return pakchunk_Md5;
    }
    

    in case someone need it

    jsulmJ Offline
    jsulmJ Offline
    jsulm
    Lifetime Qt Champion
    wrote on last edited by
    #11

    @saeid0034 said in add progress bar for QCryptographicHash::MD5 for files:

    how can i emit in main.cpp and get it in mainwindow2.cpp?

    I don't understand your code: who calls Md5_gen and where? Just add Md5_gen to the class where you calculate the checksum...

    https://forum.qt.io/topic/113070/qt-code-of-conduct

    1 Reply Last reply
    1
    • S saeid0034

      i get what i need to do
      only one problem
      i have Md5_gen code in main.cpp
      how can i emit in main.cpp and get it in mainwindow2.cpp?

      main.cpp

      
      QString Md5_gen(QString const &s)
      {
          QString pakchunk_Md5;
          QCryptographicHash crypto(QCryptographicHash::Md5);
          QFile pakchunk(s);
          if (pakchunk.open(QIODevice::ReadOnly))
          {
              while(!pakchunk.atEnd()){
              crypto.addData(pakchunk.read(8192));
              }
          } else
          {
              qDebug() << "Can't open file.";
              pakchunk_Md5 = "nofile";
              return pakchunk_Md5;
          }
          pakchunk_Md5 = crypto.result().toHex();
          return pakchunk_Md5;
      }
      
      int main(int argc, char *argv[])
      {
          QApplication a(argc, argv);
          mainwindow w;
          w.show();
          return a.exec();
      }
      

      Also i do this for get progressbar value

      QString Md5_gen(QString const &s)
      {
          QString pakchunk_Md5;
          QCryptographicHash crypto(QCryptographicHash::Md5);
          QFile pakchunk(s);
          if (pakchunk.open(QIODevice::ReadOnly))
          {
              const auto size = pakchunk.size();
              while(!pakchunk.atEnd()){
              crypto.addData(pakchunk.read(8192));
      
              auto remains = pakchunk.bytesAvailable();
              auto progress = ((size - remains) * 100) / size;
              }
          } else
          {
              qDebug() << "Can't open file.";
              pakchunk_Md5 = "nofile";
              return pakchunk_Md5;
          }
          pakchunk_Md5 = crypto.result().toHex();
          return pakchunk_Md5;
      }
      

      in case someone need it

      JonBJ Offline
      JonBJ Offline
      JonB
      wrote on last edited by JonB
      #12

      @saeid0034 said in add progress bar for QCryptographicHash::MD5 for files:

          auto remains = pakchunk.bytesAvailable();
          auto progress = ((size - remains) * 100) / size;
      

      This just sets two local variables, which are thrown away. Come on, you need to do a bit more than that! Algorithmically (no, I'm not going to type in the exact C++ statements)

      // In Md5_gen
      SIGNAL  fileReadProgress(int percentProgress)
      const chunkSize = 8192
      file = QFile(filename)
      fileSize = file.fileSize()
      readSoFar = 0
      while ((readNow = file.read(buffer, chunkSize)) > 0)
          crypto.addData(buffer, readNow)
          readSofar += readNow
          percentProgress = readSoFar * 100 / fileSize
          emit fileReadProgress(percentProgress)
      
      // In outside world, where you know about the progressbar widget/dialog
      connect(Md5_genObject, &Md5_gen::fileReadProgress,
              progressbarObject, &Progressbar::setValue)
      

      Until you define some signal and have your file reading loop emit that signal, with a parameter to say how far it has reached, and have that signal connected to a slot which accepts that parameter and updates the progressbar value, you won't be getting anywhere toward your progress goal.

      P.S.
      BTW, your QString Md5_gen(QString const &s) looks like a global function. You must move this into/write a wrapper class --- derived from QObject --- before you can define any Qt signals and emit them from it.

      S 1 Reply Last reply
      3
      • JonBJ JonB

        @saeid0034 said in add progress bar for QCryptographicHash::MD5 for files:

            auto remains = pakchunk.bytesAvailable();
            auto progress = ((size - remains) * 100) / size;
        

        This just sets two local variables, which are thrown away. Come on, you need to do a bit more than that! Algorithmically (no, I'm not going to type in the exact C++ statements)

        // In Md5_gen
        SIGNAL  fileReadProgress(int percentProgress)
        const chunkSize = 8192
        file = QFile(filename)
        fileSize = file.fileSize()
        readSoFar = 0
        while ((readNow = file.read(buffer, chunkSize)) > 0)
            crypto.addData(buffer, readNow)
            readSofar += readNow
            percentProgress = readSoFar * 100 / fileSize
            emit fileReadProgress(percentProgress)
        
        // In outside world, where you know about the progressbar widget/dialog
        connect(Md5_genObject, &Md5_gen::fileReadProgress,
                progressbarObject, &Progressbar::setValue)
        

        Until you define some signal and have your file reading loop emit that signal, with a parameter to say how far it has reached, and have that signal connected to a slot which accepts that parameter and updates the progressbar value, you won't be getting anywhere toward your progress goal.

        P.S.
        BTW, your QString Md5_gen(QString const &s) looks like a global function. You must move this into/write a wrapper class --- derived from QObject --- before you can define any Qt signals and emit them from it.

        S Offline
        S Offline
        saeid0034
        wrote on last edited by saeid0034
        #13

        @JonB
        i write this code based of your code .
        its work without problem
        do you think it better then the code i post in above?

        QString Md5_gen(QString const &fname, QString const &hash)
            {
                QString pakchunk_Md5;
                QCryptographicHash crypto(QCryptographicHash::Md5);
                QFile pakchunk(fname);
                qint64 fSize = pakchunk.size();
                if (pakchunk.open(QIODevice::ReadOnly))
                {
                    char buf[8192];
                    int bytesRead;
                    qint64 overallBytesRead = 0;
                    qint64 percentProgress = 0;
                    while((bytesRead = pakchunk.read(buf, 8192)) > 0){
                    crypto.addData(buf, bytesRead);
        
                    overallBytesRead += bytesRead;
                    percentProgress = overallBytesRead * 100 / fSize;
                    }
                    pakchunk_Md5 = crypto.result().toHex();
                } else
                {
                    qDebug() << "Can't open file.";
                    pakchunk_Md5 = "nofile";
                    return pakchunk_Md5;
                }
        		return pakchunk_Md5
            }
        

        using this code my cpu usage jump to 12% (from ~3%)
        there is anyway to reduce cpu usage?

        JonBJ 1 Reply Last reply
        0
        • S saeid0034

          @JonB
          i write this code based of your code .
          its work without problem
          do you think it better then the code i post in above?

          QString Md5_gen(QString const &fname, QString const &hash)
              {
                  QString pakchunk_Md5;
                  QCryptographicHash crypto(QCryptographicHash::Md5);
                  QFile pakchunk(fname);
                  qint64 fSize = pakchunk.size();
                  if (pakchunk.open(QIODevice::ReadOnly))
                  {
                      char buf[8192];
                      int bytesRead;
                      qint64 overallBytesRead = 0;
                      qint64 percentProgress = 0;
                      while((bytesRead = pakchunk.read(buf, 8192)) > 0){
                      crypto.addData(buf, bytesRead);
          
                      overallBytesRead += bytesRead;
                      percentProgress = overallBytesRead * 100 / fSize;
                      }
                      pakchunk_Md5 = crypto.result().toHex();
                  } else
                  {
                      qDebug() << "Can't open file.";
                      pakchunk_Md5 = "nofile";
                      return pakchunk_Md5;
                  }
          		return pakchunk_Md5
              }
          

          using this code my cpu usage jump to 12% (from ~3%)
          there is anyway to reduce cpu usage?

          JonBJ Offline
          JonBJ Offline
          JonB
          wrote on last edited by
          #14

          @saeid0034
          The code is closer to what I wrote, but

          Until you define some signal and have your file reading loop emit that signal, with a parameter to say how far it has reached, and have that signal connected to a slot which accepts that parameter and updates the progressbar value, you won't be getting anywhere toward your progress goal.

          You wrote

          there is anyway to reduce cpu usage?

          Concentrate on one question at a time. You wanted a progressbar.

          S 1 Reply Last reply
          1
          • JonBJ JonB

            @saeid0034
            The code is closer to what I wrote, but

            Until you define some signal and have your file reading loop emit that signal, with a parameter to say how far it has reached, and have that signal connected to a slot which accepts that parameter and updates the progressbar value, you won't be getting anywhere toward your progress goal.

            You wrote

            there is anyway to reduce cpu usage?

            Concentrate on one question at a time. You wanted a progressbar.

            S Offline
            S Offline
            saeid0034
            wrote on last edited by saeid0034
            #15

            @JonB

                QThread *t = new QThread(this);
                HashChecker *hc = new HashChecker();
                hc->moveToThread(t);
                QObject::connect(t, &QThread::started, hc, &HashChecker::check_sequential);
                QObject::connect(hc, &HashChecker::doneFile, this, &MainWindow2::onHashCalculated);
                QObject::connect(hc, &HashChecker::finished, t, &QThread::quit);
                QObject::connect(hc, &HashChecker::fileReadProgress, ui->progressBar, &QProgressBar::setValue);
                t->start();
            

            i move all my Md5 process to another thread, then start it
            after that im getting fileReadProgress
            and Ok, i create another Question for my other question

            1 Reply Last reply
            1
            • Christian EhrlicherC Online
              Christian EhrlicherC Online
              Christian Ehrlicher
              Lifetime Qt Champion
              wrote on last edited by
              #16

              You leak the HashChecker instance.

              Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
              Visit the Qt Academy at https://academy.qt.io/catalog

              S 1 Reply Last reply
              2
              • Christian EhrlicherC Christian Ehrlicher

                You leak the HashChecker instance.

                S Offline
                S Offline
                saeid0034
                wrote on last edited by
                #17

                @Christian-Ehrlicher said in add progress bar for QCryptographicHash::MD5 for files:

                You leak the HashChecker instance.

                what can i do about this?

                1 Reply Last reply
                0
                • Christian EhrlicherC Online
                  Christian EhrlicherC Online
                  Christian Ehrlicher
                  Lifetime Qt Champion
                  wrote on last edited by
                  #18

                  @saeid0034 said in add progress bar for QCryptographicHash::MD5 for files:

                  what can i do about this?

                  Properly clean it up after you finished the calculation maybe?

                  Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
                  Visit the Qt Academy at https://academy.qt.io/catalog

                  S 1 Reply Last reply
                  1
                  • Christian EhrlicherC Christian Ehrlicher

                    @saeid0034 said in add progress bar for QCryptographicHash::MD5 for files:

                    what can i do about this?

                    Properly clean it up after you finished the calculation maybe?

                    S Offline
                    S Offline
                    saeid0034
                    wrote on last edited by
                    #19
                    This post is deleted!
                    1 Reply Last reply
                    0
                    • S Offline
                      S Offline
                      saeid0034
                      wrote on last edited by
                      #20

                      ok i delete progressbar value after emit

                      JonBJ 1 Reply Last reply
                      0
                      • S saeid0034

                        ok i delete progressbar value after emit

                        JonBJ Offline
                        JonBJ Offline
                        JonB
                        wrote on last edited by
                        #21

                        @saeid0034
                        That doesn't sound right, @Christian-Ehrlicher is referring to your HashChecker *hc = new HashChecker(); heap allocation needing to be deleted.

                        1 Reply Last reply
                        3
                        • S Offline
                          S Offline
                          saeid0034
                          wrote on last edited by
                          #22

                          thanks, i get it

                          1 Reply Last reply
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