NOISSUE Various changes from multiauth that are unrelated to it

logic/FileSystem.cpp

@@ -0,0 +1,56 @@
+// Licensed under the Apache-2.0 license. See README.md for details.
+
+#include "FileSystem.h"
+
+#include <QDir>
+#include <QSaveFile>
+#include <QFileInfo>
+
+void ensureExists(const QDir &dir)
+{
+	if (!QDir().mkpath(dir.absolutePath()))
+	{
+		throw FS::FileSystemException("Unable to create directory " + dir.dirName() + " (" +
+									  dir.absolutePath() + ")");
+	}
+}
+
+void FS::write(const QString &filename, const QByteArray &data)
+{
+	ensureExists(QFileInfo(filename).dir());
+	QSaveFile file(filename);
+	if (!file.open(QSaveFile::WriteOnly))
+	{
+		throw FileSystemException("Couldn't open " + filename + " for writing: " +
+								  file.errorString());
+	}
+	if (data.size() != file.write(data))
+	{
+		throw FileSystemException("Error writing data to " + filename + ": " +
+								  file.errorString());
+	}
+	if (!file.commit())
+	{
+		throw FileSystemException("Error while committing data to " + filename + ": " +
+								  file.errorString());
+	}
+}
+
+QByteArray FS::read(const QString &filename)
+{
+	QFile file(filename);
+	if (!file.open(QFile::ReadOnly))
+	{
+		throw FileSystemException("Unable to open " + filename + " for reading: " +
+								  file.errorString());
+	}
+	const qint64 size = file.size();
+	QByteArray data(int(size), 0);
+	const qint64 ret = file.read(data.data(), size);
+	if (ret == -1 || ret != size)
+	{
+		throw FileSystemException("Error reading data from " + filename + ": " +
+								  file.errorString());
+	}
+	return data;
+}