Announcing QArchive v2.1.x

June 19, 2021

QArchive has come a long road. I would say that I never expected that it would actually live this long. In this release QArchive gets a very big upgrade.

When this library was first created the only scope was hard drive based extraction and compression and libarchive seems to have a lot of optimization like zero-copy. But for a long time I've wished to have in-memory extraction and compression but was too lazy(sorry folks).

In this release, I present you with new classes to handle in-memory extraction and compression with ease. Down below are the new classes which are added to the QArchive namespace.

Pleae see the documentation for detailed information on these classes.

Bugfixes

Fixed memory leaks.
Fix pause/resume in extractor and compressor classes.
Fix addFiles for directory

A Little Demo

Let me demonstrate you a small example where we compress and extract a 7Zip archive in-memory and read the first file contents if it's text document.

#include <QCoreApplication>
#include <QDebug>
#include <QBuffer>
#include <QArchive/QArchive>
/* #include <QArchive> // if you use add_subdirectory with cmake */

int main(int argc, char **argv) {
   QCoreApplication app(argc, argv);

   // Let's write our text document.
   QString text = QString::fromUtf8("Thanks for using QArchive.");

   QBuffer document;
   document.open(QIODevice::WriteOnly);
   document.write(text.toLocal8Bit().constData());
   document.close();

   QArchive::MemoryCompressor compressor(QArchive::SevenZipFormat);
   compressor.addFiles("Readme.txt", (QIODevice*)&document);

   QIODevice *archive = nullptr;
   QArchive::MemoryExtractor extractor;

   QObject::connect(&compressor, &QArchive::MemoryCompressor::finished,
   [&](QBuffer *a) {
    archive = (QIODevice*)a;
    extractor.setArchive(archive);
    extractor.start();
   });

   QObject::connect(&extractor, &QArchive::MemoryExtractor::finished,
   [&](QArchive::MemoryExtractorOutput *output) {
    QVector<QArchive::MemoryFile> files = output->getFiles();

    for(auto iter = files.begin(),
         end = files.end();
         iter != end;
         ++iter) {
        QJsonObject fileInfo = (*iter).fileInformation();
        QBuffer *buffer = (*iter).buffer();

        // By default buffer is closed.
        buffer->open(QIODevice::ReadOnly);

        qDebug() << "Filename:: " << fileInfo.value("FileName").toString();
        qDebug() << "Contents:: " << QString(buffer->readAll());
        
        buffer->close();
    }

    // Only delete the output object and 
    // any other buffer you allocated.  
    output->deleteLater();
    archive->deleteLater();
    app.quit();
   });

   compressor.start(); 
   return app.exec();
}