fileutils.cpp

//------------------------------------------------------------------------------
// fileutils.cpp
//------------------------------------------------------------------------------
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
// 02110-1301  USA
//
//------------------------------------------------------------------------------
// Copyright (C) 2012 "Zalewa" <zalewapl@gmail.com>
//------------------------------------------------------------------------------
#include "fileutils.h"

#include "ntfsperm.h"
#include "log.h"
#include <QCryptographicHash>
#include <QDirIterator>
#include <QFileInfo>

class FileUtilsTr : public QObject
{
        Q_OBJECT

public:
        static QString cannotCreateDirectory()
        {
                return tr("cannot create directory");
        }

        static QString parentPathIsNotADirectory(const QString &path)
        {
                return tr("the parent path is not a directory: %1").arg(path);
        }

        static QString lackOfParentDirectoryPermissions(const QString &to)
        {
                return tr("lack of necessary permissions to the parent directory: %1")
                        .arg(to);
        }

private:
        FileUtilsTr() = delete;
};

QByteArray FileUtils::md5(const QString &path)
{
        QFile f(path);
        if (f.open(QIODevice::ReadOnly))
        {
                QCryptographicHash hash(QCryptographicHash::Md5);
                QByteArray chunk = f.read(1024 * 1024);
                for (; !chunk.isEmpty(); chunk = f.read(1024 * 1024))
                        hash.addData(chunk);
                f.close();
                return hash.result();
        }
        return QByteArray();
}

QString FileUtils::cdUpUntilExists(QString path)
{
        static const int SANITY_LOOP_LIMIT = 1000;
        QFileInfo fileInfo(QDir::cleanPath(path));
        for (int i = 0; i < SANITY_LOOP_LIMIT; ++i)
        {
                if (fileInfo.filePath().endsWith("/.."))
                        return QString();
                if (fileInfo.exists() || fileInfo.isRoot())
                        return fileInfo.filePath();
                fileInfo = QFileInfo(QDir::cleanPath(fileInfo.filePath() + "/.."));
        }
        return QString();
}

Qt::CaseSensitivity FileUtils::comparisonSensitivity()
{
        #if defined(Q_OS_WIN32)
        return Qt::CaseInsensitive;
        #else
        return Qt::CaseSensitive;
        #endif
}

bool FileUtils::containsPath(const QStringList &candidates, const QString &path)
{
        for (const QString &candidate : candidates)
        {
                if (QFileInfo(candidate) == QFileInfo(path))
                        return true;
        }
        return false;
}

QDir FileUtils::dirOrDir(const QString &preferred, const QString &fallback)
{
        if (!preferred.isEmpty())
        {
                QDir dir(preferred);
                if (dir.exists())
                        return dir;
        }
        return QDir(fallback);
}

DirErrno FileUtils::mkpath(const QDir &dir)
{
        // We need to reset errno to prevent false positives
        errno = 0;
        if (!dir.mkpath("."))
        {
                int errnoval = errno;
                if (errnoval != 0)
                {
                        return DirErrno(dir.path(), errnoval, strerror(errnoval));
                }
                else
                {
                        // Try to decipher if we have permissions.
                        // First we must find the bottom-most directory that does actually exist.
                        QString pathToBottomMostExisting = FileUtils::cdUpUntilExists(dir.path());
                        // If we've found a bottom-most directory that exists, we can check its permissions.
                        if (!pathToBottomMostExisting.isEmpty())
                        {
                                QFileInfo parentDir(pathToBottomMostExisting);
                                if (parentDir.exists() && !parentDir.isDir())
                                {
                                        return DirErrno(dir.path(), DirErrno::CUSTOM_ERROR,
                                                FileUtilsTr::parentPathIsNotADirectory(parentDir.filePath()));
                                }

                                // BLOCK - keep this to absolute minimum
                                ++qt_ntfs_permission_lookup;
                                bool permissions = parentDir.isReadable()
                                        && parentDir.isWritable()
                                        && parentDir.isExecutable();
                                --qt_ntfs_permission_lookup;
                                // END OF BLOCK
                                if (!permissions)
                                {
                                        return DirErrno(dir.path(), DirErrno::CUSTOM_ERROR,
                                                FileUtilsTr::lackOfParentDirectoryPermissions(parentDir.filePath()));
                                }
                        }
                        // Just give up trying to deduce a correct error.
                        return DirErrno(dir.path(), DirErrno::CUSTOM_ERROR,
                                FileUtilsTr::cannotCreateDirectory());
                }
        }
        return DirErrno();
}

bool FileUtils::rmAllFiles(const QString &dirPath,
        const QStringList &nameFilters)
{
        QDirIterator it(dirPath, nameFilters, QDir::Files);
        bool bAllSuccess = true;
        while (it.hasNext())
        {
                QString path = it.next();
                QFile f(path);
                if (!f.remove())
                {
                        bAllSuccess = false;
                        gLog << Log::tr("Failed to remove: %1").arg(path);
                }
        }
        return bAllSuccess;
}

#include "fileutils.moc"