La taille du fichier est erronée dans Qt 5.6

Question

J'ai utilisé une classe DownloadManager comme ça, mais le problème est que pour les fichiers volumineux, j'ai une mauvaise taille de 65536 Ko au lieu de 51328022 octets. Il y a quelque chose qui ne va pas dans la méthode saveDisk.

ps: J'utilise Qt 5.6 cuz je dois exécuter l'application sous Windows Vista & XP

bool DownloadManager::saveToDisk(const QString &filename, QIODevice *data) 
{ 
    LogManager* logmgr = LogManager::GetInstance(); 
    FileManager* filemgr = FileManager::GetInstance(); 

    QFileInfo fileinfo(filename); 
    QString dirpath = fileinfo.absoluteDir().absolutePath(); 

    if (!filemgr->DirectoryIsPresent(dirpath)) 
    { 
     if (!filemgr->CreateDirectory(dirpath)) { 
      logmgr->Log(LOG_LEVEL_ERROR, QString("cannot create directory (") + dirpath + ")"); 
     } 
    } 

    QFile file(filename); 
    if (!file.open(QIODevice::WriteOnly)) { 
     const QString errorText = QString("Could not open ") + filename + QString(" for writing:") + file.errorString(); 
     logmgr->Log(LOG_LEVEL_ERROR, errorText); 
     return false; 
    } 

    file.write(data->readAll()); 
    file.close(); 

    return true; 
} 

void DownloadManager::downloadFinished(QNetworkReply *reply) 
{ 
    LogManager* logmgr = LogManager::GetInstance(); 

    if (m_currentDownloads.contains(reply)) 
    { 
     QUrl url = reply->url(); 
     if (reply->error() != QNetworkReply::NoError) { 
      m_nbFailedDownload++; 
      const QString errorText = QString("Download of ")+ url.toString() +" failed: " + reply->errorString() + " (" + QString::number(reply->error()) + ")"; 
      logmgr->Log(LOG_LEVEL_ERROR, errorText); 
     } else { 
      m_nbSucceededDownload++; 
      QString filename = saveFileName(url); 
      if (saveToDisk(filename, reply)) 
      { 
       const QString infoText = QString("Download of ") + url.toString() + " succeeded (saved to " + filename + ")"; 
       logmgr->Log(LOG_LEVEL_INFO, infoText); 
      } 
     } 

     m_currentDownloads.removeAll(reply); 
     reply->deleteLater(); 
    } 

    int total = m_nbTotalDownload == 0? 1:m_nbTotalDownload; 
    emit onProgress((m_nbFailedDownload + m_nbSucceededDownload) * 100/total); 


    if (m_currentDownloads.isEmpty()){ 
     logmgr->Log(LOG_LEVEL_INFO, "DownloadManager downloads finished"); 
     emit onFinished(); 
    } 
} 

Answer 1

Il est D'accord. Je l'ai remplacé cette ligne:

file.write(data->readAll()); 
file.close(); 
return true; 

par

ByteArray ba = data->readAll(); 
int nbTries = 99; 
int n = ba.size(); 
int idx = 0; 

while (n > 0 && nbTries > 0) 
{ 
    int ret = file.write(ba.data() + idx, std::min(16*1024, n)); 
    if (ret > 0) 
    { 
     n -= ret; 
     idx += ret; 
    } 
    else 
    { 
    nbTries --; 
    } 
} 

file.close(); 
return nbTries > 0; 

je l'ai écrit plusieurs morceaux au lieu d'un grand

Answer 2

Vous devez appeler DownloadManager :: SaveToDisk par le signal QNetworkReply :: readyRead

void DownloadManager::onDownloadReadyRead(QNetworkReply *reply) 
{ 
    ... 
    saveToDisk(filename, reply); 
    ... 
} 

void DownloadManager::saveToDisk(QNetworkReply* reply) 
{ 
    ... 
    file.write(reply->read(reply_->bytesAvailable())); 
    ... 
}