How to manage zip file

mrdebug

Sorry. I have missed the required dlls.
Is there a way to unzip a zip stream, from a QByteArray without to store it to a file before?

VRonin

yes with http://quazip.sourceforge.net/classQuaZip.html#ae52ebadd5ce64cdb49d7e198904b0b8c
create a QDataStream operating on the QByteArary and then pass QDataStream::device() to that constructor.

On the other hand, I'm not sure what you are trying to do but you might not need QuaZip at all, have a look at http://doc.qt.io/qt-5/qbytearray.html#qCompress and below

mrdebug

Someting like this?

                    QDataStream BufferIn(&Source, QIODevice::ReadOnly);
                    QuaZipFile quaZip(BufferIn.device());
                    qDebug() << quaZip.open(QIODevice::ReadOnly);

returns false...

VRonin

QuaZipFile represents a file inside a zip file, not a zip file in itself. the constructor you are calling is this one: http://quazip.sourceforge.net/classQuaZipFile.html#a1349ad27f1947bc3e346d83dbf9586c4 use QuaZip instead.

P.S.
QDataStream BufferIn(&Source, QIODevice::ReadOnly); is the same as QDataStream BufferIn(Source);

mrdebug

After many tries I can't unzip something without to use a file.
These lines of code

                        QDataStream BufferIn(&QBABufferOut, QIODevice::ReadOnly);
                        QuaZip quaZip(BufferIn.device());

does not seem to work.

SGaist

Hi,

What do you have in QBABufferOut ?
Are you sure it's opened correctly ?
Why do you need BufferIn for ?

And most important, what do you mean by does not seem to work? That's to vague to help you.

mrdebug

Please have a look at this sequence:

                            QuaZipFile quaZip(QBABufferOut);                // (rapresents a zip archivie in ram).
                            if (quaZip.open(QIODevice::ReadOnly)) {         // QIODevice::ReadOnly or someting else
                                qDebug() << "ok";
                            } else qDebug() << "error";                     // always error!!!!!!!!!!!!

VRonin

You have to open the QuaZip for decompression first:

    QBuffer storageBuff(&QBABufferOut);
    QuaZip zip(&storageBuff);
    if (!zip.open(QuaZip::mdUnzip))
        qDebug() << "error";
    QuaZipFile file(&zip);
    for (bool f = zip.goToFirstFile(); f; f = zip.goToNextFile()) {
        QuaZipFileInfo fileInfo;
        file.getFileInfo(&fileInfo);
        qDebug() << fileInfo.name;
        file.open(QIODevice::ReadOnly);
        
        qDebug() << "Content: " << file.readAll().toBase64();
        file.close();
    }
    zip.close();

P.S.

// (rapresents a zip archivie in ram).

No it doesn't. As mentioned before QuaZipFile represent a file inside a zip archive, not the archive itself

mrdebug

It works perfectly.
Many thanks.

SPlatten

@VRonin said in How to manage zip file:

QuaZIP

Is there a license associated with the use of this? As I have a need for compressing large amounts of binary data that I need to transmit to remote clients.

jsulm

@SPlatten said in How to manage zip file:

Is there a license associated with the use of this?

https://github.com/stachenov/quazip

SPlatten

Thank you,

artwaw

@SPlatten if both ends are in your software I'd suggest agains using 3rd party library. qCompress and qUncompress work just fine in that regard. My usual approach is to supply a header (using QDataStream) with checksum and whatever else is needed, then stream to it output from compression routine. Works sufficiently well, eliminates the need for another dependency.

SPlatten

@artwaw , Thank you, I will have a look.

Ramkumar Mohan

@mrdebug Which file works properly in this?

mrdebug

Hi, I'm working with zip files.