Method fileInfoString

src/backend/datasources/filters/ROOTFilter.cpp:1496–1539

// needs to be after ROOTDataHelpers namespace declaration

QString ROOTFilter::fileInfoString(const QString& fileName) {
	DEBUG(Q_FUNC_INFO);
	QString info;

	// The file structure is described in root/io/io/src/TFile.cxx
	std::ifstream is(fileName.toStdString(), std::ifstream::binary);
	std::string root(4, 0);
	is.read(const_cast<char*>(root.data()), 4);
	if (root != "root") {
		DEBUG(Q_FUNC_INFO << ", Not a ROOT file. root = " << root);
		return i18n("Not a ROOT file");
	}

	int version = read<int>(is);

	info += i18n("File format version: %1", QString::number(version));
	info += QLatin1String("<br>");

	is.seekg(20);
	int freeBytes = read<int>(is);
	int freeRecords = read<int>(is);
	int namedBytes = read<int>(is);
	char pointerBytes = read<char>(is);
	info += i18n("FREE data record size: %1 bytes", QString::number(freeBytes));
	info += QLatin1String("<br>");
	info += i18n("Number of free data records: %1", QString::number(freeRecords));
	info += QLatin1String("<br>");
	info += i18n("TNamed size: %1 bytes", QString::number(namedBytes));
	info += QLatin1String("<br>");
	info += i18n("Size of file pointers: %1 bytes", QString::number(pointerBytes));
	info += QLatin1String("<br>");

	int compression = read<int>(is);
	compression = compression > 0 ? compression : 0;
	info += i18n("Compression level and algorithm: %1", QString::number(compression));
	info += QLatin1String("<br>");

	is.seekg(41);
	int infoBytes = read<int>(is);
	info += i18n("Size of TStreamerInfo record: %1 bytes", QString::number(infoBytes));
	info += QLatin1String("<br>");

	return info;
}