qversionnumber.cpp

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// Copyright (C) 2021 The Qt Company Ltd.
// Copyright (C) 2016 Intel Corporation.
// Copyright (C) 2014 Keith Gardner <kreios4004@gmail.com>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include <QtCore/qversionnumber.h>
#include <QtCore/qhash.h>
#include <QtCore/private/qlocale_tools_p.h>
#include <QtCore/qcollator.h>
 
#ifndef QT_NO_DATASTREAM
#  include <QtCore/qdatastream.h>
#endif
 
#ifndef QT_NO_DEBUG_STREAM
#  include <QtCore/qdebug.h>
#endif
 
#include <algorithm>
#include <limits>
 
QT_BEGIN_NAMESPACE
 
QT_IMPL_METATYPE_EXTERN(QVersionNumber)
 
 
QList<int> QVersionNumber::segments() const
{
    if (m_segments.isUsingPointer())
        return *m_segments.pointer_segments;
 
    QList<int> result;
    result.resize(segmentCount());
    for (qsizetype i = 0; i < segmentCount(); ++i)
        result[i] = segmentAt(i);
    return result;
}
 
QVersionNumber QVersionNumber::normalized() const
{
    qsizetype i;
    for (i = m_segments.size(); i; --i)
        if (m_segments.at(i - 1) != 0)
            break;
 
    QVersionNumber result(*this);
    result.m_segments.resize(i);
    return result;
}
 
bool QVersionNumber::isPrefixOf(const QVersionNumber &other) const noexcept
{
    if (segmentCount() > other.segmentCount())
        return false;
    for (qsizetype i = 0; i < segmentCount(); ++i) {
        if (segmentAt(i) != other.segmentAt(i))
            return false;
    }
    return true;
}
 
int QVersionNumber::compare(const QVersionNumber &v1, const QVersionNumber &v2) noexcept
{
    qsizetype commonlen;
 
    if (Q_LIKELY(!v1.m_segments.isUsingPointer() && !v2.m_segments.isUsingPointer())) {
        // we can't use memcmp because it interprets the data as unsigned bytes
        const qint8 *ptr1 = v1.m_segments.inline_segments + InlineSegmentStartIdx;
        const qint8 *ptr2 = v2.m_segments.inline_segments + InlineSegmentStartIdx;
        commonlen = qMin(v1.m_segments.size(),
                         v2.m_segments.size());
        for (qsizetype i = 0; i < commonlen; ++i)
            if (int x = ptr1[i] - ptr2[i])
                return x;
    } else {
        commonlen = qMin(v1.segmentCount(), v2.segmentCount());
        for (qsizetype i = 0; i < commonlen; ++i) {
            if (v1.segmentAt(i) != v2.segmentAt(i))
                return v1.segmentAt(i) - v2.segmentAt(i);
        }
    }
 
    // ran out of segments in v1 and/or v2 and need to check the first trailing
    // segment to finish the compare
    if (v1.segmentCount() > commonlen) {
        // v1 is longer
        if (v1.segmentAt(commonlen) != 0)
            return v1.segmentAt(commonlen);
        else
            return 1;
    } else if (v2.segmentCount() > commonlen) {
        // v2 is longer
        if (v2.segmentAt(commonlen) != 0)
            return -v2.segmentAt(commonlen);
        else
            return -1;
    }
 
    // the two version numbers are the same
    return 0;
}
 
QVersionNumber QVersionNumber::commonPrefix(const QVersionNumber &v1,
                                            const QVersionNumber &v2)
{
    qsizetype commonlen = qMin(v1.segmentCount(), v2.segmentCount());
    qsizetype i;
    for (i = 0; i < commonlen; ++i) {
        if (v1.segmentAt(i) != v2.segmentAt(i))
            break;
    }
 
    if (i == 0)
        return QVersionNumber();
 
    // try to use the one with inline segments, if there's one
    QVersionNumber result(!v1.m_segments.isUsingPointer() ? v1 : v2);
    result.m_segments.resize(i);
    return result;
}
 
QString QVersionNumber::toString() const
{
    QString version;
    version.reserve(qMax(segmentCount() * 2 - 1, 0));
    bool first = true;
    for (qsizetype i = 0; i < segmentCount(); ++i) {
        if (!first)
            version += u'.';
        version += QString::number(segmentAt(i));
        first = false;
    }
    return version;
}
 
static QVersionNumber from_string(QLatin1StringView string, qsizetype *suffixIndex)
{
    // 32 should be more than enough, and, crucially, it means we're allocating
    // not more (and often less) often when compared with direct QList usage
    // for all possible segment counts (under the constraint that we don't want
    // to keep more capacity around for the lifetime of the resulting
    // QVersionNumber than required), esp. in the common case where the inline
    // storage can be used.
    QVarLengthArray<int, 32> seg;
 
    const char *start = string.begin();
    const char *lastGoodEnd = start;
    const char *endOfString = string.end();
 
    do {
        // parsing as unsigned so a minus sign is rejected
        auto [value, used] = qstrntoull(start, endOfString - start, 10);
        if (used <= 0 || value > qulonglong(std::numeric_limits<int>::max()))
            break;
        seg.append(int(value));
        start += used + 1;
        lastGoodEnd = start - 1;
    } while (start < endOfString && *lastGoodEnd == '.');
 
    if (suffixIndex)
        *suffixIndex = lastGoodEnd - string.begin();
 
    return QVersionNumber(seg);
}
 
static QVersionNumber from_string(q_no_char8_t::QUtf8StringView string, qsizetype *suffixIndex)
{
    return from_string(QLatin1StringView(string.data(), string.size()), suffixIndex);
}
 
// in qstring.cpp
extern void qt_to_latin1(uchar *dst, const char16_t *uc, qsizetype len);
 
static QVersionNumber from_string(QStringView string, qsizetype *suffixIndex)
{
    QVarLengthArray<char> copy;
    copy.resize(string.size());
    qt_to_latin1(reinterpret_cast<uchar*>(copy.data()), string.utf16(), string.size());
    return from_string(QLatin1StringView(copy.data(), copy.size()), suffixIndex);
}
 
QVersionNumber QVersionNumber::fromString(QAnyStringView string, qsizetype *suffixIndex)
{
    return string.visit([=] (auto string) { return from_string(string, suffixIndex); });
}
 
void QVersionNumber::SegmentStorage::setListData(const QList<int> &seg)
{
    pointer_segments = new QList<int>(seg);
}
 
void QVersionNumber::SegmentStorage::setListData(QList<int> &&seg)
{
    pointer_segments = new QList<int>(std::move(seg));
}
 
void QVersionNumber::SegmentStorage::setListData(const int *first, const int *last)
{
    pointer_segments = new QList<int>(first, last);
}
 
void QVersionNumber::SegmentStorage::resize(qsizetype len)
{
    if (isUsingPointer())
        pointer_segments->resize(len);
    else
        setInlineSize(len);
}
 
void QVersionNumber::SegmentStorage::setVector(int len, int maj, int min, int mic)
{
    pointer_segments = new QList<int>;
    pointer_segments->resize(len);
    pointer_segments->data()[0] = maj;
    if (len > 1) {
        pointer_segments->data()[1] = min;
        if (len > 2) {
            pointer_segments->data()[2] = mic;
        }
    }
}
 
#ifndef QT_NO_DATASTREAM
QDataStream& operator<<(QDataStream &out, const QVersionNumber &version)
{
    out << version.segments();
    return out;
}
 
QDataStream& operator>>(QDataStream &in, QVersionNumber &version)
{
    if (!version.m_segments.isUsingPointer())
        version.m_segments.pointer_segments = new QList<int>;
    in >> *version.m_segments.pointer_segments;
    return in;
}
#endif
 
#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug debug, const QVersionNumber &version)
{
    QDebugStateSaver saver(debug);
    debug.nospace().noquote();
    debug << "QVersionNumber(" << version.toString() << ")";
    return debug;
}
#endif
 
size_t qHash(const QVersionNumber &key, size_t seed)
{
    QtPrivate::QHashCombine hash;
    for (int i = 0; i < key.segmentCount(); ++i)
        seed = hash(seed, key.segmentAt(i));
    return seed;
}
 
QT_END_NAMESPACE