How QT uses quazip to compress and decompress files

One 、QuaZIP What is it?

QuaZIP is a simple C++ wrapper over Gilles Vollant’s ZIP/UNZIP package that can be used to access ZIP archives. It uses the Qt toolkit.

• Official homepage ：http://quazip.sourceforge.net/
• github Address ：https://github.com/stachenov/quazip
• souceforge Download address ：https://sourceforge.net/projects/quazip/

Two 、 How to compile

2.1、 Use CMake compile

The first thing to know ：quazip It's right zlib Encapsulation , Need to rely on zlib Library . Use it directly CMake If you compile, you will encounter zlib Library path problem ：

Have a problem ：

CMake Tips ：Could NOT find ZLIB (missing: ZLIB_LIBRARY ZLIB_INCLUDE_DIR)

Solution ：

be aware https://github.com/stachenov/quazip In the downloaded compressed package , There's a file NEWS.txt：

QuaZip changes

* 2021-11-13 1.2
        * Add CMake option to disable installation (Sebastian Rettenberger)
        * Qt's internal zlib can be used now (QUAZIP_USE_QT_ZLIB, OFF by
          default)
        * Make tests optional (QUAZIP_ENABLE_TESTS, OFF by default)
          (Gleb Ignatev)
        * Fix: QuaZip::close() can be safely called multiple times now
        * Fix: -lz added to pkgconfig

among Qt’s internal zlib can be used now (QUAZIP_USE_QT_ZLIB, OFF bydefault), mean , Support direct use QT Built in zlib.

• A、 modify CMakeLists.txt Medium option(QUAZIP_USE_QT_ZLIB “” OFF), by option(QUAZIP_USE_QT_ZLIB “” ON)
• B、 Reuse CMake（ belt gui Interface ） Configure as needed , After the configuration is completed, a QuaZip.sln
• C、 compile QuaZip.sln, After that, you can get quazip1-qt5.dll

2.2、 Manually create new quazip engineering

A、 download zlib, Address ：http://www.zlib.net/
B、 compile zlib, direct cmake Recompile,
C、 newly build quazip Of vs engineering （qt）, hold quazip The files in the compressed package are moved to the new project , And then put zlib Configure to in the form of a third-party library quazip engineering ,

• C/C++ > routine > Attach include directory ：./zlib-1.2.11/include/
• C/C++ > Preprocessing > Preprocessing definition ：QUAZIP_BUILD
• The linker > routine > Additional Library Directory ： ./zlib-1.2.11/lib/x86/
• The linker > Input > Additional dependency ：zlibd.lib

D、 compile quazip.sln engineering , Finally get quazip.dll
It should be noted that ,quazip.dll Need to rely on zlib.dll, So you need to put... Where you need it zlib.dll Take it with you , While using quazip1-qt5.dll, You don't need to .

3、 ... and 、 Sample code

#include <QtCore/QCoreApplication>
#include <QDir>
#include <QFile>
#include <QFileInfo>
#include <QDateTime>
#include <QDebug>
#include <QElapsedTimer>
#include <QJsonDocument>
#include <QJsonObject>
#include "JlCompress.h"

int main(int argc, char* argv[])
{
    
	QCoreApplication a(argc, argv);

	QString zipName = QString("%1%2").arg("./download/").arg("package.zip");
	QString unzipDir = "./unzip_dir";
	QDir dir(unzipDir);
	if (!dir.exists())
	{
    
		bool okey = dir.mkdir(unzipDir);
		//bool okey = dir.mkpath(unzipDir);
		QString tip = QString("mkpath %1,%2").arg(unzipDir).arg(okey);
		qDebug() << tip;
	}

	QElapsedTimer timer;
	timer.start();
	QStringList files = {
    };
	QFileInfo fileInfo(zipName);
	if (fileInfo.exists())
	{
    
		files = JlCompress::extractDir(zipName, unzipDir);
	}
	qDebug() << "files count:" << files.size();
	qDebug() << "the operation(JlCompress::extractDir) took" << timer.elapsed() << "ms";

	QVariantMap NameAndPathMap;
	//  The extracted files here are sorted by file name 
	foreach(QString fileItem, files)
	{
    
		QString fileName = QFileInfo(fileItem).fileName();
		qint64 fileSize = QFileInfo(fileItem).size();
		qDebug() << "Name:" << fileName << "Size:" << fileSize << "\tPath:" << fileItem;
		//
		NameAndPathMap.insert(fileName, fileItem);
	}

	//save to file
	QJsonObject root = QJsonObject::fromVariantMap(NameAndPathMap);
	QString content = QString(QJsonDocument(root).toJson(QJsonDocument::Indented/*Compact*/));
	//
	QFile writer("./content.json");
	if (writer.open(QIODevice::WriteOnly))
	{
    
		writer.write(content.toUtf8());
		writer.close();
	}
	qDebug() << "over!!!";
	return a.exec();
}

Four 、 The pit of tread

Compile the zlib after , Added to the environment variables ZLIB_LIBRARY and ZLIB_INCLUDE_DIR, But in CMake To configure quazip when , It didn't work .
As for some online use cmake Command build , I haven't tried , for example ：

cmake .. -DZLIB_INCLUDE_DIR=E:\zlib\zlib-1.2.11 -DZLIB_LIBRARY=E:\zlib\zlib-1.2.11\zlibstaticd.lib

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