karchive.cpp

/* This file is part of the KDE libraries
   SPDX-FileCopyrightText: 2000-2005 David Faure <[email protected]>
   SPDX-FileCopyrightText: 2003 Leo Savernik <[email protected]>
 
   Moved from ktar.cpp by Roberto Teixeira <[email protected]>
 
   SPDX-License-Identifier: LGPL-2.0-or-later
*/
 
#include "karchive.h"
#include "karchive_p.h"
#include "klimitediodevice_p.h"
#include "loggingcategory.h"
 
#include <qplatformdefs.h> // QT_STATBUF, QT_LSTAT
 
#include <QDebug>
#include <QDir>
#include <QFile>
#include <QMap>
#include <QStack>
 
#include <cerrno>
#include <stdio.h>
#include <stdlib.h>
 
#include <assert.h>
 
#ifdef Q_OS_UNIX
#include <grp.h>
#include <limits.h> // PATH_MAX
#include <pwd.h>
#include <unistd.h>
#endif
#ifdef Q_OS_WIN
#include <windows.h> // DWORD, GetUserNameW
#endif // Q_OS_WIN
 
#if defined(Q_OS_UNIX)
#define STAT_METHOD QT_LSTAT
#else
#define STAT_METHOD QT_STAT
#endif
 
////////////////////////////////////////////////////////////////////////
/////////////////// KArchiveDirectoryPrivate ///////////////////////////
////////////////////////////////////////////////////////////////////////
 
class KArchiveDirectoryPrivate
{
public:
    KArchiveDirectoryPrivate(KArchiveDirectory *parent)
        : q(parent)
    {
    }
 
    ~KArchiveDirectoryPrivate()
    {
        qDeleteAll(entries);
    }
 
    KArchiveDirectoryPrivate(const KArchiveDirectoryPrivate &) = delete;
    KArchiveDirectoryPrivate &operator=(const KArchiveDirectoryPrivate &) = delete;
 
    static KArchiveDirectoryPrivate *get(KArchiveDirectory *directory)
    {
        return directory->d;
    }
 
    // Returns in containingDirectory the directory that actually contains the returned entry
    const KArchiveEntry *entry(const QString &_name, KArchiveDirectory **containingDirectory) const
    {
        *containingDirectory = q;
 
        QString name = QDir::cleanPath(_name);
        int pos = name.indexOf(QLatin1Char('/'));
        if (pos == 0) { // ouch absolute path (see also KArchive::findOrCreate)
            if (name.length() > 1) {
                name = name.mid(1); // remove leading slash
                pos = name.indexOf(QLatin1Char('/')); // look again
            } else { // "/"
                return q;
            }
        }
        // trailing slash ? -> remove
        if (pos != -1 && pos == name.length() - 1) {
            name = name.left(pos);
            pos = name.indexOf(QLatin1Char('/')); // look again
        }
        if (pos != -1) {
            const QString left = name.left(pos);
            const QString right = name.mid(pos + 1);
 
            // qCDebug(KArchiveLog) << "left=" << left << "right=" << right;
 
            KArchiveEntry *e = entries.value(left);
            if (!e || !e->isDirectory()) {
                return nullptr;
            }
            *containingDirectory = static_cast<KArchiveDirectory *>(e);
            return (*containingDirectory)->d->entry(right, containingDirectory);
        }
 
        return entries.value(name);
    }
 
    KArchiveDirectory *q;
    QHash<QString, KArchiveEntry *> entries;
};
 
////////////////////////////////////////////////////////////////////////
/////////////////////////// KArchive ///////////////////////////////////
////////////////////////////////////////////////////////////////////////
 
KArchive::KArchive(const QString &fileName)
    : d(new KArchivePrivate(this))
{
    if (fileName.isEmpty()) {
        qCWarning(KArchiveLog) << "KArchive: No file name specified";
    }
    d->fileName = fileName;
    // This constructor leaves the device set to 0.
    // This is for the use of QSaveFile, see open().
}
 
KArchive::KArchive(QIODevice *dev)
    : d(new KArchivePrivate(this))
{
    if (!dev) {
        qCWarning(KArchiveLog) << "KArchive: Null device specified";
    }
    d->dev = dev;
}
 
KArchive::~KArchive()
{
    Q_ASSERT(!isOpen()); // the derived class destructor must have closed already
    delete d;
}
 
bool KArchive::open(QIODevice::OpenMode mode)
{
    Q_ASSERT(mode != QIODevice::NotOpen);
 
    if (isOpen()) {
        close();
    }
 
    if (!d->fileName.isEmpty()) {
        Q_ASSERT(!d->dev);
        if (!createDevice(mode)) {
            return false;
        }
    }
 
    if (!d->dev) {
        setErrorString(tr("No filename or device was specified"));
        return false;
    }
 
    if (!d->dev->isOpen() && !d->dev->open(mode)) {
        setErrorString(tr("Could not open device in mode %1").arg(mode));
        return false;
    }
 
    d->mode = mode;
 
    Q_ASSERT(!d->rootDir);
    d->rootDir = nullptr;
 
    return openArchive(mode);
}
 
bool KArchive::createDevice(QIODevice::OpenMode mode)
{
    switch (mode) {
    case QIODevice::WriteOnly:
        if (!d->fileName.isEmpty()) {
            // The use of QSaveFile can't be done in the ctor (no mode known yet)
            // qCDebug(KArchiveLog) << "Writing to a file using QSaveFile";
            d->saveFile = new QSaveFile(d->fileName);
#ifdef Q_OS_ANDROID
            // we cannot rename on to Android content: URLs
            if (d->fileName.startsWith(QLatin1String("content://"))) {
                d->saveFile->setDirectWriteFallback(true);
            }
#endif
            if (!d->saveFile->open(QIODevice::WriteOnly)) {
                setErrorString(tr("QSaveFile creation for %1 failed: %2").arg(d->fileName, d->saveFile->errorString()));
 
                delete d->saveFile;
                d->saveFile = nullptr;
                return false;
            }
            d->dev = d->saveFile;
            Q_ASSERT(d->dev);
        }
        break;
    case QIODevice::ReadOnly:
    case QIODevice::ReadWrite:
        // ReadWrite mode still uses QFile for now; we'd need to copy to the tempfile, in fact.
        if (!d->fileName.isEmpty()) {
            d->dev = new QFile(d->fileName);
            d->deviceOwned = true;
        }
        break; // continued below
    default:
        setErrorString(tr("Unsupported mode %1").arg(d->mode));
        return false;
    }
    return true;
}
 
bool KArchive::close()
{
    if (!isOpen()) {
        setErrorString(tr("Archive already closed"));
        return false; // already closed (return false or true? arguable...)
    }
 
    // moved by holger to allow kzip to write the zip central dir
    // to the file in closeArchive()
    // DF: added d->dev so that we skip closeArchive if saving aborted.
    bool closeSucceeded = true;
    if (d->dev) {
        closeSucceeded = closeArchive();
        if (d->mode == QIODevice::WriteOnly && !closeSucceeded) {
            d->abortWriting();
        }
    }
 
    if (d->dev && d->dev != d->saveFile) {
        d->dev->close();
    }
 
    // if d->saveFile is not null then it is equal to d->dev.
    if (d->saveFile) {
        closeSucceeded = d->saveFile->commit();
        delete d->saveFile;
        d->saveFile = nullptr;
    }
    if (d->deviceOwned) {
        delete d->dev; // we created it ourselves in open()
    }
 
    delete d->rootDir;
    d->rootDir = nullptr;
    d->mode = QIODevice::NotOpen;
    d->dev = nullptr;
    return closeSucceeded;
}
 
QString KArchive::errorString() const
{
    return d->errorStr;
}
 
const KArchiveDirectory *KArchive::directory() const
{
    // rootDir isn't const so that parsing-on-demand is possible
    return const_cast<KArchive *>(this)->rootDir();
}
 
bool KArchive::addLocalFile(const QString &fileName, const QString &destName)
{
    QFileInfo fileInfo(fileName);
    if (!fileInfo.isFile() && !fileInfo.isSymLink()) {
        setErrorString(tr("%1 doesn't exist or is not a regular file.").arg(fileName));
        return false;
    }
 
    QT_STATBUF fi;
    if (STAT_METHOD(QFile::encodeName(fileName).constData(), &fi) == -1) {
        setErrorString(tr("Failed accessing the file %1 for adding to the archive. The error was: %2").arg(fileName).arg(QLatin1String{strerror(errno)}));
        return false;
    }
 
    if (fileInfo.isSymLink()) {
        QString symLinkTarget;
        // Do NOT use fileInfo.symLinkTarget() for unix symlinks!
        // It returns the -full- path to the target, while we want the target string "as is".
#if defined(Q_OS_UNIX) && !defined(Q_OS_OS2EMX)
        const QByteArray encodedFileName = QFile::encodeName(fileName);
        QByteArray s;
#if defined(PATH_MAX)
        s.resize(PATH_MAX + 1);
#else
        int path_max = pathconf(encodedFileName.data(), _PC_PATH_MAX);
        if (path_max <= 0) {
            path_max = 4096;
        }
        s.resize(path_max);
#endif
        int len = readlink(encodedFileName.data(), s.data(), s.size() - 1);
        if (len >= 0) {
            s[len] = '\0';
            symLinkTarget = QFile::decodeName(s.constData());
        }
#endif
        if (symLinkTarget.isEmpty()) { // Mac or Windows
            symLinkTarget = fileInfo.symLinkTarget();
        }
        return writeSymLink(destName,
                            symLinkTarget,
                            fileInfo.owner(),
                            fileInfo.group(),
                            fi.st_mode,
                            fileInfo.lastRead(),
                            fileInfo.lastModified(),
                            fileInfo.birthTime());
    } /*end if*/
 
    qint64 size = fileInfo.size();
 
    // the file must be opened before prepareWriting is called, otherwise
    // if the opening fails, no content will follow the already written
    // header and the tar file is effectively f*cked up
    QFile file(fileName);
    if (!file.open(QIODevice::ReadOnly)) {
        setErrorString(tr("Couldn't open file %1: %2").arg(fileName, file.errorString()));
        return false;
    }
 
    if (!prepareWriting(destName, fileInfo.owner(), fileInfo.group(), size, fi.st_mode, fileInfo.lastRead(), fileInfo.lastModified(), fileInfo.birthTime())) {
        // qCWarning(KArchiveLog) << " prepareWriting" << destName << "failed";
        return false;
    }
 
    // Read and write data in chunks to minimize memory usage
    QByteArray array;
    array.resize(int(qMin(qint64(1024 * 1024), size)));
    qint64 n;
    qint64 total = 0;
    while ((n = file.read(array.data(), array.size())) > 0) {
        if (!writeData(array.data(), n)) {
            // qCWarning(KArchiveLog) << "writeData failed";
            return false;
        }
        total += n;
    }
    Q_ASSERT(total == size);
 
    if (!finishWriting(size)) {
        // qCWarning(KArchiveLog) << "finishWriting failed";
        return false;
    }
    return true;
}
 
bool KArchive::addLocalDirectory(const QString &path, const QString &destName)
{
    QDir dir(path);
    if (!dir.exists()) {
        setErrorString(tr("Directory %1 does not exist").arg(path));
        return false;
    }
    dir.setFilter(dir.filter() | QDir::Hidden);
    const QStringList files = dir.entryList();
    for (const QString &file : files) {
        if (file != QLatin1String(".") && file != QLatin1String("..")) {
            const QString fileName = path + QLatin1Char('/') + file;
            //            qCDebug(KArchiveLog) << "storing " << fileName;
            const QString dest = destName.isEmpty() ? file : (destName + QLatin1Char('/') + file);
            QFileInfo fileInfo(fileName);
 
            if (fileInfo.isFile() || fileInfo.isSymLink()) {
                addLocalFile(fileName, dest);
            } else if (fileInfo.isDir()) {
                // Write directory, so that empty dirs are preserved (and permissions written out, etc.)
                int perms = 0;
                QT_STATBUF fi;
                if (STAT_METHOD(QFile::encodeName(fileName).constData(), &fi) != -1) {
                    perms = fi.st_mode;
                }
                writeDir(dest, fileInfo.owner(), fileInfo.group(), perms, fileInfo.lastRead(), fileInfo.lastModified(), fileInfo.birthTime());
                // Recurse
                addLocalDirectory(fileName, dest);
            }
            // We omit sockets
        }
    }
    return true;
}
 
bool KArchive::writeFile(const QString &name,
                         const QByteArray &data,
                         mode_t perm,
                         const QString &user,
                         const QString &group,
                         const QDateTime &atime,
                         const QDateTime &mtime,
                         const QDateTime &ctime)
{
    const qint64 size = data.size();
    if (!prepareWriting(name, user, group, size, perm, atime, mtime, ctime)) {
        // qCWarning(KArchiveLog) << "prepareWriting failed";
        return false;
    }
 
    // Write data
    // Note: if data is null, don't call write, it would terminate the KCompressionDevice
    if (data.constData() && size && !writeData(data.constData(), size)) {
        // qCWarning(KArchiveLog) << "writeData failed";
        return false;
    }
 
    if (!finishWriting(size)) {
        // qCWarning(KArchiveLog) << "finishWriting failed";
        return false;
    }
    return true;
}
 
bool KArchive::writeData(const char *data, qint64 size)
{
    bool ok = device()->write(data, size) == size;
    if (!ok) {
        setErrorString(tr("Writing failed: %1").arg(device()->errorString()));
        d->abortWriting();
    }
    return ok;
}
 
// The writeDir -> doWriteDir pattern allows to avoid propagating the default
// values into all virtual methods of subclasses, and it allows more extensibility:
// if a new argument is needed, we can add a writeDir overload which stores the
// additional argument in the d pointer, and doWriteDir reimplementations can fetch
// it from there.
 
bool KArchive::writeDir(const QString &name,
                        const QString &user,
                        const QString &group,
                        mode_t perm,
                        const QDateTime &atime,
                        const QDateTime &mtime,
                        const QDateTime &ctime)
{
    return doWriteDir(name, user, group, perm | 040000, atime, mtime, ctime);
}
 
bool KArchive::writeSymLink(const QString &name,
                            const QString &target,
                            const QString &user,
                            const QString &group,
                            mode_t perm,
                            const QDateTime &atime,
                            const QDateTime &mtime,
                            const QDateTime &ctime)
{
    return doWriteSymLink(name, target, user, group, perm, atime, mtime, ctime);
}
 
bool KArchive::prepareWriting(const QString &name,
                              const QString &user,
                              const QString &group,
                              qint64 size,
                              mode_t perm,
                              const QDateTime &atime,
                              const QDateTime &mtime,
                              const QDateTime &ctime)
{
    bool ok = doPrepareWriting(name, user, group, size, perm, atime, mtime, ctime);
    if (!ok) {
        d->abortWriting();
    }
    return ok;
}
 
bool KArchive::finishWriting(qint64 size)
{
    return doFinishWriting(size);
}
 
void KArchive::setErrorString(const QString &errorStr)
{
    d->errorStr = errorStr;
}
 
static QString getCurrentUserName()
{
#if defined(Q_OS_UNIX)
    struct passwd *pw = getpwuid(getuid());
    return pw ? QFile::decodeName(pw->pw_name) : QString::number(getuid());
#elif defined(Q_OS_WIN)
    wchar_t buffer[255];
    DWORD size = 255;
    bool ok = GetUserNameW(buffer, &size);
    if (!ok) {
        return QString();
    }
    return QString::fromWCharArray(buffer);
#else
    return QString();
#endif
}
 
static QString getCurrentGroupName()
{
#if defined(Q_OS_UNIX)
    struct group *grp = getgrgid(getgid());
    return grp ? QFile::decodeName(grp->gr_name) : QString::number(getgid());
#elif defined(Q_OS_WIN)
    return QString();
#else
    return QString();
#endif
}
 
KArchiveDirectory *KArchive::rootDir()
{
    if (!d->rootDir) {
        // qCDebug(KArchiveLog) << "Making root dir ";
        QString username = ::getCurrentUserName();
        QString groupname = ::getCurrentGroupName();
 
        d->rootDir = new KArchiveDirectory(this, QStringLiteral("/"), int(0777 + S_IFDIR), QDateTime(), username, groupname, QString());
    }
    return d->rootDir;
}
 
KArchiveDirectory *KArchive::findOrCreate(const QString &path)
{
    return d->findOrCreate(path, 0 /*recursionCounter*/);
}
 
KArchiveDirectory *KArchivePrivate::findOrCreate(const QString &path, int recursionCounter)
{
    // Check we're not in a path that is ultra deep, this is most probably fine since PATH_MAX on Linux
    // is defined as 4096, so even on /a/a/a/a/a/a 2500 recursions puts us over that limit
    // an ultra deep recursion will makes us crash due to not enough stack. Tests show that 1MB stack
    // (default on Linux seems to be 8MB) gives us up to around 4000 recursions
    if (recursionCounter > 2500) {
        qCWarning(KArchiveLog) << "path recursion limit exceeded, bailing out";
        return nullptr;
    }
    // qCDebug(KArchiveLog) << path;
    if (path.isEmpty() || path == QLatin1String("/") || path == QLatin1String(".")) { // root dir => found
        // qCDebug(KArchiveLog) << "returning rootdir";
        return q->rootDir();
    }
    // Important note : for tar files containing absolute paths
    // (i.e. beginning with "/"), this means the leading "/" will
    // be removed (no KDirectory for it), which is exactly the way
    // the "tar" program works (though it displays a warning about it)
    // See also KArchiveDirectory::entry().
 
    // Already created ? => found
    KArchiveDirectory *existingEntryParentDirectory;
    const KArchiveEntry *existingEntry = KArchiveDirectoryPrivate::get(q->rootDir())->entry(path, &existingEntryParentDirectory);
    if (existingEntry) {
        if (existingEntry->isDirectory())
        // qCDebug(KArchiveLog) << "found it";
        {
            const KArchiveDirectory *dir = static_cast<const KArchiveDirectory *>(existingEntry);
            return const_cast<KArchiveDirectory *>(dir);
        } else {
            const KArchiveFile *file = static_cast<const KArchiveFile *>(existingEntry);
            if (file->size() > 0) {
                qCWarning(KArchiveLog) << path << "is normal file, but there are file paths in the archive assuming it is a directory, bailing out";
                return nullptr;
            }
 
            qCDebug(KArchiveLog) << path << " is an empty file, assuming it is actually a directory and replacing";
            KArchiveEntry *myEntry = const_cast<KArchiveEntry *>(existingEntry);
            existingEntryParentDirectory->removeEntry(myEntry);
            delete myEntry;
        }
    }
 
    // Otherwise go up and try again
    int pos = path.lastIndexOf(QLatin1Char('/'));
    KArchiveDirectory *parent;
    QString dirname;
    if (pos == -1) { // no more slash => create in root dir
        parent = q->rootDir();
        dirname = path;
    } else {
        QString left = path.left(pos);
        dirname = path.mid(pos + 1);
        parent = findOrCreate(left, recursionCounter + 1); // recursive call... until we find an existing dir.
    }
 
    if (!parent) {
        return nullptr;
    }
 
    // qCDebug(KArchiveLog) << "found parent " << parent->name() << " adding " << dirname << " to ensure " << path;
    // Found -> add the missing piece
    KArchiveDirectory *e = new KArchiveDirectory(q, dirname, rootDir->permissions(), rootDir->date(), rootDir->user(), rootDir->group(), QString());
    if (parent->addEntryV2(e)) {
        return e; // now a directory to <path> exists
    } else {
        return nullptr;
    }
}
 
void KArchive::setDevice(QIODevice *dev)
{
    if (d->deviceOwned) {
        delete d->dev;
    }
    d->dev = dev;
    d->deviceOwned = false;
}
 
void KArchive::setRootDir(KArchiveDirectory *rootDir)
{
    Q_ASSERT(!d->rootDir); // Call setRootDir only once during parsing please ;)
    delete d->rootDir; // but if it happens, don't leak
    d->rootDir = rootDir;
}
 
QIODevice::OpenMode KArchive::mode() const
{
    return d->mode;
}
 
QIODevice *KArchive::device() const
{
    return d->dev;
}
 
bool KArchive::isOpen() const
{
    return d->mode != QIODevice::NotOpen;
}
 
QString KArchive::fileName() const
{
    return d->fileName;
}
 
void KArchivePrivate::abortWriting()
{
    if (saveFile) {
        saveFile->cancelWriting();
        delete saveFile;
        saveFile = nullptr;
        dev = nullptr;
    }
}
 
// this is a hacky wrapper to check if time_t value is invalid
QDateTime KArchivePrivate::time_tToDateTime(uint time_t)
{
    if (time_t == uint(-1)) {
        return QDateTime();
    }
    return QDateTime::fromSecsSinceEpoch(time_t);
}
 
////////////////////////////////////////////////////////////////////////
/////////////////////// KArchiveEntry //////////////////////////////////
////////////////////////////////////////////////////////////////////////
 
class KArchiveEntryPrivate
{
public:
    KArchiveEntryPrivate(KArchive *_archive,
                         const QString &_name,
                         int _access,
                         const QDateTime &_date,
                         const QString &_user,
                         const QString &_group,
                         const QString &_symlink)
        : name(_name)
        , date(_date)
        , access(_access)
        , user(_user)
        , group(_group)
        , symlink(_symlink)
        , archive(_archive)
    {
    }
    QString name;
    QDateTime date;
    mode_t access;
    QString user;
    QString group;
    QString symlink;
    KArchive *archive;
};
 
KArchiveEntry::KArchiveEntry(KArchive *t,
                             const QString &name,
                             int access,
                             const QDateTime &date,
                             const QString &user,
                             const QString &group,
                             const QString &symlink)
    : d(new KArchiveEntryPrivate(t, name, access, date, user, group, symlink))
{
}
 
KArchiveEntry::~KArchiveEntry()
{
    delete d;
}
 
QDateTime KArchiveEntry::date() const
{
    return d->date;
}
 
QString KArchiveEntry::name() const
{
    return d->name;
}
 
mode_t KArchiveEntry::permissions() const
{
    return d->access;
}
 
QString KArchiveEntry::user() const
{
    return d->user;
}
 
QString KArchiveEntry::group() const
{
    return d->group;
}
 
QString KArchiveEntry::symLinkTarget() const
{
    return d->symlink;
}
 
bool KArchiveEntry::isFile() const
{
    return false;
}
 
bool KArchiveEntry::isDirectory() const
{
    return false;
}
 
KArchive *KArchiveEntry::archive() const
{
    return d->archive;
}
 
////////////////////////////////////////////////////////////////////////
/////////////////////// KArchiveFile ///////////////////////////////////
////////////////////////////////////////////////////////////////////////
 
class KArchiveFilePrivate
{
public:
    KArchiveFilePrivate(qint64 _pos, qint64 _size)
        : pos(_pos)
        , size(_size)
    {
    }
    qint64 pos;
    qint64 size;
};
 
KArchiveFile::KArchiveFile(KArchive *t,
                           const QString &name,
                           int access,
                           const QDateTime &date,
                           const QString &user,
                           const QString &group,
                           const QString &symlink,
                           qint64 pos,
                           qint64 size)
    : KArchiveEntry(t, name, access, date, user, group, symlink)
    , d(new KArchiveFilePrivate(pos, size))
{
}
 
KArchiveFile::~KArchiveFile()
{
    delete d;
}
 
qint64 KArchiveFile::position() const
{
    return d->pos;
}
 
qint64 KArchiveFile::size() const
{
    return d->size;
}
 
void KArchiveFile::setSize(qint64 s)
{
    d->size = s;
}
 
QByteArray KArchiveFile::data() const
{
    bool ok = archive()->device()->seek(d->pos);
    if (!ok) {
        // qCWarning(KArchiveLog) << "Failed to sync to" << d->pos << "to read" << name();
    }
 
    // Read content
    QByteArray arr;
    if (d->size) {
        arr = archive()->device()->read(d->size);
        Q_ASSERT(arr.size() == d->size);
    }
    return arr;
}
 
QIODevice *KArchiveFile::createDevice() const
{
    return new KLimitedIODevice(archive()->device(), d->pos, d->size);
}
 
bool KArchiveFile::isFile() const
{
    return true;
}
 
static QFileDevice::Permissions withExecutablePerms(QFileDevice::Permissions filePerms, mode_t perms)
{
    if (perms & 01) {
        filePerms |= QFileDevice::ExeOther;
    }
 
    if (perms & 010) {
        filePerms |= QFileDevice::ExeGroup;
    }
 
    if (perms & 0100) {
        filePerms |= QFileDevice::ExeOwner;
    }
 
    return filePerms;
}
 
bool KArchiveFile::copyTo(const QString &dest) const
{
    QFile f(dest + QLatin1Char('/') + name());
    if (f.open(QIODevice::ReadWrite | QIODevice::Truncate)) {
        QIODevice *inputDev = createDevice();
        if (!inputDev) {
            f.remove();
            return false;
        }
 
        // Read and write data in chunks to minimize memory usage
        const qint64 chunkSize = 1024 * 1024;
        qint64 remainingSize = d->size;
        QByteArray array;
        array.resize(int(qMin(chunkSize, remainingSize)));
 
        while (remainingSize > 0) {
            const qint64 currentChunkSize = qMin(chunkSize, remainingSize);
            const qint64 n = inputDev->read(array.data(), currentChunkSize);
            Q_UNUSED(n) // except in Q_ASSERT
            Q_ASSERT(n == currentChunkSize);
            f.write(array.data(), currentChunkSize);
            remainingSize -= currentChunkSize;
        }
        f.setPermissions(withExecutablePerms(f.permissions(), permissions()));
        f.close();
 
        delete inputDev;
        return true;
    }
    return false;
}
 
////////////////////////////////////////////////////////////////////////
//////////////////////// KArchiveDirectory /////////////////////////////////
////////////////////////////////////////////////////////////////////////
 
KArchiveDirectory::KArchiveDirectory(KArchive *t,
                                     const QString &name,
                                     int access,
                                     const QDateTime &date,
                                     const QString &user,
                                     const QString &group,
                                     const QString &symlink)
    : KArchiveEntry(t, name, access, date, user, group, symlink)
    , d(new KArchiveDirectoryPrivate(this))
{
}
 
KArchiveDirectory::~KArchiveDirectory()
{
    delete d;
}
 
QStringList KArchiveDirectory::entries() const
{
    return d->entries.keys();
}
 
const KArchiveEntry *KArchiveDirectory::entry(const QString &_name) const
{
    KArchiveDirectory *dummy;
    return d->entry(_name, &dummy);
}
 
const KArchiveFile *KArchiveDirectory::file(const QString &name) const
{
    const KArchiveEntry *e = entry(name);
    if (e && e->isFile()) {
        return static_cast<const KArchiveFile *>(e);
    }
    return nullptr;
}
 
void KArchiveDirectory::addEntry(KArchiveEntry *entry)
{
    addEntryV2(entry);
}
 
bool KArchiveDirectory::addEntryV2(KArchiveEntry *entry)
{
    if (d->entries.value(entry->name())) {
        qCWarning(KArchiveLog) << "directory " << name() << "has entry" << entry->name() << "already";
        delete entry;
        return false;
    }
    d->entries.insert(entry->name(), entry);
    return true;
}
 
void KArchiveDirectory::removeEntry(KArchiveEntry *entry)
{
    if (!entry) {
        return;
    }
 
    QHash<QString, KArchiveEntry *>::Iterator it = d->entries.find(entry->name());
    // nothing removed?
    if (it == d->entries.end()) {
        qCWarning(KArchiveLog) << "directory " << name() << "has no entry with name " << entry->name();
        return;
    }
    if (it.value() != entry) {
        qCWarning(KArchiveLog) << "directory " << name() << "has another entry for name " << entry->name();
        return;
    }
    d->entries.erase(it);
}
 
bool KArchiveDirectory::isDirectory() const
{
    return true;
}
 
static bool sortByPosition(const KArchiveFile *file1, const KArchiveFile *file2)
{
    return file1->position() < file2->position();
}
 
bool KArchiveDirectory::copyTo(const QString &dest, bool recursiveCopy) const
{
    QDir root;
    const QString destDir(QDir(dest).absolutePath()); // get directory path without any "." or ".."
 
    QList<const KArchiveFile *> fileList;
    QMap<qint64, QString> fileToDir;
 
    // placeholders for iterated items
    QStack<const KArchiveDirectory *> dirStack;
    QStack<QString> dirNameStack;
 
    dirStack.push(this); // init stack at current directory
    dirNameStack.push(destDir); // ... with given path
    do {
        const KArchiveDirectory *curDir = dirStack.pop();
 
        // extract only to specified folder if it is located within archive's extraction folder
        // otherwise put file under root position in extraction folder
        QString curDirName = dirNameStack.pop();
        if (!QDir(curDirName).absolutePath().startsWith(destDir)) {
            qCWarning(KArchiveLog) << "Attempted export into folder" << curDirName << "which is outside of the extraction root folder" << destDir << "."
                                   << "Changing export of contained files to extraction root folder.";
            curDirName = destDir;
        }
 
        if (!root.mkpath(curDirName)) {
            return false;
        }
 
        const QStringList dirEntries = curDir->entries();
        for (QStringList::const_iterator it = dirEntries.begin(); it != dirEntries.end(); ++it) {
            const KArchiveEntry *curEntry = curDir->entry(*it);
            if (!curEntry->symLinkTarget().isEmpty()) {
                QString linkName = curDirName + QLatin1Char('/') + curEntry->name();
                // To create a valid link on Windows, linkName must have a .lnk file extension.
#ifdef Q_OS_WIN
                if (!linkName.endsWith(QLatin1String(".lnk"))) {
                    linkName += QLatin1String(".lnk");
                }
#endif
                QFile symLinkTarget(curEntry->symLinkTarget());
                if (!symLinkTarget.link(linkName)) {
                    // qCDebug(KArchiveLog) << "symlink(" << curEntry->symLinkTarget() << ',' << linkName << ") failed:" << strerror(errno);
                }
            } else {
                if (curEntry->isFile()) {
                    const KArchiveFile *curFile = dynamic_cast<const KArchiveFile *>(curEntry);
                    if (curFile) {
                        fileList.append(curFile);
                        fileToDir.insert(curFile->position(), curDirName);
                    }
                }
 
                if (curEntry->isDirectory() && recursiveCopy) {
                    const KArchiveDirectory *ad = dynamic_cast<const KArchiveDirectory *>(curEntry);
                    if (ad) {
                        dirStack.push(ad);
                        dirNameStack.push(curDirName + QLatin1Char('/') + curEntry->name());
                    }
                }
            }
        }
    } while (!dirStack.isEmpty());
 
    std::sort(fileList.begin(), fileList.end(), sortByPosition); // sort on d->pos, so we have a linear access
 
    for (QList<const KArchiveFile *>::const_iterator it = fileList.constBegin(), end = fileList.constEnd(); it != end; ++it) {
        const KArchiveFile *f = *it;
        qint64 pos = f->position();
        if (!f->copyTo(fileToDir[pos])) {
            return false;
        }
    }
    return true;
}
 
void KArchive::virtual_hook(int, void *)
{
    /*BASE::virtual_hook( id, data )*/;
}
 
void KArchiveEntry::virtual_hook(int, void *)
{
    /*BASE::virtual_hook( id, data );*/
}
 
void KArchiveFile::virtual_hook(int id, void *data)
{
    KArchiveEntry::virtual_hook(id, data);
}
 
void KArchiveDirectory::virtual_hook(int id, void *data)
{
    KArchiveEntry::virtual_hook(id, data);
}