Issue with download from url

[ejoshva]

Now I am able to download and write all the content using the readyRead()

m_reply =  m_manager->get(m_request);
 
connect(m_reply,SIGNAL(readyRead()),this,SLOT(readingReadyBytes()));
 
 
void zoushoFtpTransfer::readingReadyBytes()
{
    QFile file(m_localPath);
    file.open(QIODevice::writeOnly);
    file.write(m_reply->read(m_reply->bytesAvailable()));
    file.close();
    qDebug()<<"size : "<<file.size();
    m_isDownloadSccess = true;
}

m_reply =  m_manager->get(m_request);
 
connect(m_reply,SIGNAL(readyRead()),this,SLOT(readingReadyBytes()));
 
 
void zoushoFtpTransfer::readingReadyBytes()
{
    QFile file(m_localPath);
    file.open(QIODevice::writeOnly);
    file.write(m_reply->read(m_reply->bytesAvailable()));
    file.close();
    qDebug()<<"size : "<<file.size();
    m_isDownloadSccess = true;
}

To copy to clipboard, switch view to plain text mode 

Again there is one more issue, after writing onto file, I am storing all the data for that file in QByteArray.
Its storing in QBytearray till 134459022 of data, after which bad_alloc error is thrown.

Let me know what data type can be used to store all the 318459022 size of data

[anda_skoa]

Let me know what data type can be used to store all the 318459022 size of data

It is not a matter of data type. QByteArray can easily handle that, your system can't.

Cheers,
_

[yeye_olive]

This last snippet of code you posted is exactly the same as the previous one, and suffers from exactly the same problems that were pointed to you. Since you claim to have now solved these problems, I suppose that this code is irrelevant to your new question.

If you have understood that you could not keep the whole file in memory before writing it to disk in one go, it should come as no surprise that attempting to completely load it in memory fails for the same reason.

[wysota]

Now I am able to download and write all the content using the readyRead()

m_reply =  m_manager->get(m_request);
 
connect(m_reply,SIGNAL(readyRead()),this,SLOT(readingReadyBytes()));
 
 
void zoushoFtpTransfer::readingReadyBytes()
{
    QFile file(m_localPath);
    file.open(QIODevice::writeOnly);
    file.write(m_reply->read(m_reply->bytesAvailable()));
    file.close();
    qDebug()<<"size : "<<file.size();
    m_isDownloadSccess = true;
}

m_reply =  m_manager->get(m_request);
 
connect(m_reply,SIGNAL(readyRead()),this,SLOT(readingReadyBytes()));
 
 
void zoushoFtpTransfer::readingReadyBytes()
{
    QFile file(m_localPath);
    file.open(QIODevice::writeOnly);
    file.write(m_reply->read(m_reply->bytesAvailable()));
    file.close();
    qDebug()<<"size : "<<file.size();
    m_isDownloadSccess = true;
}

To copy to clipboard, switch view to plain text mode 

Again there is one more issue, after writing onto file, I am storing all the data for that file in QByteArray.
Its storing in QBytearray till 134459022 of data, after which bad_alloc error is thrown.

Let me know what data type can be used to store all the 318459022 size of data

I'll give you a hint:

7 = 4+3 // to read 7MB, read 4MB and then 3
10 = 4+4+2 // to read 10MB read 4MB, then again 4MB and then 2 MB
445 = 4+...+4+1 // to read 445MB read 4MB as long as there is more than 4MB to read and then read whatever remains

And another hint:

If you tell read() to read 4MB but there is only 1MB available, it will read 1MB

Question:

How much memory is needed to read 445MB of data this way?

Now go and carve an algorithm out of it.

[ejoshva]

Thanks for your replies.

@wysota - will try out an algorithm based on your hints

I'll give you a hint:

7 = 4+3 // to read 7MB, read 4MB and then 3
10 = 4+4+2 // to read 10MB read 4MB, then again 4MB and then 2 MB
445 = 4+...+4+1 // to read 445MB read 4MB as long as there is more than 4MB to read and then read whatever remains

And another hint:

If you tell read() to read 4MB but there is only 1MB available, it will read 1MB

Question:

How much memory is needed to read 445MB of data this way?

Now go and carve an algorithm out of it.

ans : 4 MB