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// Copyright (C) 2021 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

// Qt-Security score:critical reason:data-parser

#ifndef QBYTEARRAYVIEW_H

#define QBYTEARRAYVIEW_H

#include <QtCore/qbytearrayalgorithms.h>

#include <QtCore/qchar.h>

#include <QtCore/qcompare.h>

#include <QtCore/qcontainerfwd.h>

#include <QtCore/qstringfwd.h>

#include <QtCore/qarraydata.h>

#include <string>

#include <string_view>

#include <QtCore/q20type_traits.h>

QT_BEGIN_NAMESPACE

namespace QtPrivate {

template <typename Byte>

struct IsCompatibleByteTypeHelper : std::false_type {};

template <> struct IsCompatibleByteTypeHelper<char> : std::true_type {};

template <> struct IsCompatibleByteTypeHelper<signed char> : std::true_type {};

template <> struct IsCompatibleByteTypeHelper<unsigned char> : std::true_type {};

template <> struct IsCompatibleByteTypeHelper<std::byte> : std::true_type {};

template <typename Byte>

struct IsCompatibleByteType

    : IsCompatibleByteTypeHelper<q20::remove_cvref_t<Byte>> {};

template <typename Pointer>

struct IsCompatibleByteArrayPointerHelper : std::false_type {};

template <typename Byte>

struct IsCompatibleByteArrayPointerHelper<Byte *>

    : IsCompatibleByteType<Byte> {};

template<typename Pointer>

struct IsCompatibleByteArrayPointer

    : IsCompatibleByteArrayPointerHelper<q20::remove_cvref_t<Pointer>> {};

template <typename T, typename Enable = void>

struct IsContainerCompatibleWithQByteArrayView : std::false_type {};

template <typename T>

struct IsContainerCompatibleWithQByteArrayView<T, std::enable_if_t<

        std::conjunction_v<

                // lacking concepts and ranges, we accept any T whose std::data yields a suitable

                // pointer ...

                IsCompatibleByteArrayPointer<decltype(std::data(std::declval<const T &>()))>,

                // ... and that has a suitable size ...

                std::is_convertible<decltype(std::size(std::declval<const T &>())), qsizetype>,

                // ... and it's a range as it defines an iterator-like API

                IsCompatibleByteType<typename std::iterator_traits<decltype(

                        std::begin(std::declval<const T &>()))>::value_type>,

                std::is_convertible<decltype(std::begin(std::declval<const T &>())

                                             != std::end(std::declval<const T &>())),

                                    bool>,

                // This needs to be treated specially due to the empty vs null distinction

                std::negation<std::is_same<std::decay_t<T>, QByteArray>>,

                // We handle array literals specially for source compat reasons

                std::negation<std::is_array<T>>,

                // Don't make an accidental copy constructor

                std::negation<std::is_same<std::decay_t<T>, QByteArrayView>>>>> : std::true_type {};

// Used by QLatin1StringView too

template <typename Char>

inline constexpr qsizetype lengthHelperPointer(const Char *data) noexcept

    // std::char_traits can only be used with one of the regular char types

    // (char, char16_t, wchar_t, but not uchar or QChar), so we roll the loop

    // out by ourselves.

    qsizetype i = 0;

    if (!data)

        return i;

    while (data[i] != Char(0))

        ++i;

    return i;

} // namespace QtPrivate

class Q_CORE_EXPORT QByteArrayView

public:

    typedef char storage_type;

    typedef const char value_type;

    typedef qptrdiff difference_type;

    typedef qsizetype size_type;

    typedef value_type &reference;

    typedef value_type &const_reference;

    typedef value_type *pointer;

    typedef value_type *const_pointer;

    typedef pointer iterator;

    typedef const_pointer const_iterator;

    typedef std::reverse_iterator<iterator> reverse_iterator;

    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

private:

    template <typename Byte>

    using if_compatible_byte =

            typename std::enable_if_t<QtPrivate::IsCompatibleByteType<Byte>::value, bool>;

    template <typename Pointer>

    using if_compatible_pointer =

            typename std::enable_if_t<QtPrivate::IsCompatibleByteArrayPointer<Pointer>::value,

                                      bool>;

    template <typename T>

    using if_compatible_qbytearray_like =

            typename std::enable_if_t<std::is_same_v<T, QByteArray>, bool>;

    template <typename T>

    using if_compatible_container =

            typename std::enable_if_t<QtPrivate::IsContainerCompatibleWithQByteArrayView<T>::value,

                                      bool>;

    template <typename Container>

    static constexpr qsizetype lengthHelperContainer(const Container &c) noexcept

        return qsizetype(std::size(c));

    static constexpr qsizetype lengthHelperCharArray(const char *data, size_t size) noexcept

        const auto it = std::char_traits<char>::find(data, size, '\0');

        const auto end = it ? it : std::next(data, size);

        return qsizetype(std::distance(data, end));

    template <typename Byte>

    static const storage_type *castHelper(const Byte *data) noexcept

    { return reinterpret_cast<const storage_type*>(data); }

    static constexpr const storage_type *castHelper(const storage_type *data) noexcept

    { return data; }

public:

    constexpr QByteArrayView() = default;

    constexpr QByteArrayView(std::nullptr_t) noexcept

        : QByteArrayView() {}

    template <typename Byte, if_compatible_byte<Byte> = true>

    constexpr QByteArrayView(const Byte *data, qsizetype len)

#if QT_VERSION >= QT_VERSION_CHECK(7, 0, 0) || defined(QT_BOOTSTRAPPED)

        : m_data(castHelper(data)),

          m_size((Q_ASSERT(len >= 0), Q_ASSERT(data || !len), len)) {}

#else

        : m_size((Q_ASSERT(len >= 0), Q_ASSERT(data || !len), len)),

          m_data(castHelper(data)) {}

#endif

    template <typename Byte, if_compatible_byte<Byte> = true>

    constexpr QByteArrayView(const Byte *first, const Byte *last)

        : QByteArrayView(first, last - first) {}

#ifdef Q_QDOC

    template <typename Byte>

    constexpr QByteArrayView(const Byte *data) noexcept;

#else

    template <typename Pointer, if_compatible_pointer<Pointer> = true>

    constexpr QByteArrayView(const Pointer &data) noexcept

        : QByteArrayView(

              data, data ? QtPrivate::lengthHelperPointer(data) : 0) {}

#endif

#ifdef Q_QDOC

    QByteArrayView(const QByteArray &data) noexcept;

#else

    template <typename ByteArray, if_compatible_qbytearray_like<ByteArray> = true>

    QByteArrayView(const ByteArray &ba) noexcept

        : QByteArrayView{ba.begin(), ba.size()} {}

#endif

    template <typename Container, if_compatible_container<Container> = true>

    constexpr QByteArrayView(const Container &c) noexcept

        : QByteArrayView(std::data(c), lengthHelperContainer(c)) {}

    template <size_t Size>

    constexpr QByteArrayView(const char (&data)[Size]) noexcept

        : QByteArrayView(data, lengthHelperCharArray(data, Size)) {}

    template <typename Byte, if_compatible_byte<Byte> = true>

    constexpr QByteArrayView(const Byte (&data)[]) noexcept

        : QByteArrayView(&*data) {} // decay to pointer

#ifdef Q_QDOC

    template <typename Byte, size_t Size>

#else

    template <typename Byte, size_t Size, if_compatible_byte<Byte> = true>

#endif

    [[nodiscard]] constexpr static QByteArrayView fromArray(const Byte (&data)[Size]) noexcept

    { return QByteArrayView(data, Size); }

    [[nodiscard]] inline QByteArray toByteArray() const; // defined in qbytearray.h

    [[nodiscard]] static constexpr qsizetype maxSize() noexcept

        // -1 to deal with the pointer one-past-the-end;

        return QtPrivate::MaxAllocSize - 1;

    [[nodiscard]] constexpr qsizetype size() const noexcept

        constexpr size_t MaxSize = maxSize();

        Q_PRESUME(size_t(m_size) <= MaxSize);

        return m_size;

    [[nodiscard]] constexpr const_pointer data() const noexcept { return m_data; }

    [[nodiscard]] constexpr const_pointer constData() const noexcept { return data(); }

    [[nodiscard]] constexpr char operator[](qsizetype n) const

    { verify(n, 1); return m_data[n]; }

//

    // QByteArray API

//

    [[nodiscard]] constexpr char at(qsizetype n) const { return (*this)[n]; }

    [[nodiscard]] constexpr QByteArrayView first(qsizetype n) const

    { verify(0, n); return sliced(0, n); }

    [[nodiscard]] constexpr QByteArrayView last(qsizetype n) const

    { verify(0, n); return sliced(size() - n, n); }

    [[nodiscard]] constexpr QByteArrayView sliced(qsizetype pos) const

    { verify(pos, 0); return QByteArrayView(data() + pos, size() - pos); }

    [[nodiscard]] constexpr QByteArrayView sliced(qsizetype pos, qsizetype n) const

    { verify(pos, n); return QByteArrayView(data() + pos, n); }

     constexpr QByteArrayView &slice(qsizetype pos)

    { *this = sliced(pos); return *this; }

     constexpr QByteArrayView &slice(qsizetype pos, qsizetype n)

    { *this = sliced(pos, n); return *this; }

    [[nodiscard]] constexpr QByteArrayView chopped(qsizetype len) const

    { verify(0, len); return sliced(0, size() - len); }

    [[nodiscard]] constexpr QByteArrayView left(qsizetype n) const

    { if (n < 0 || n > size()) n = size(); return QByteArrayView(data(), n); }

    [[nodiscard]] constexpr QByteArrayView right(qsizetype n) const

    { if (n < 0 || n > size()) n = size(); if (n < 0) n = 0; return QByteArrayView(data() + size() - n, n); }

    [[nodiscard]] constexpr QByteArrayView mid(qsizetype pos, qsizetype n = -1) const

        using namespace QtPrivate;

        auto result = QContainerImplHelper::mid(size(), &pos, &n);

        return result == QContainerImplHelper::Null ? QByteArrayView()

                                                    : QByteArrayView(m_data + pos, n);

    constexpr void truncate(qsizetype n)

    { verify(0, n); m_size = n; }

    constexpr void chop(qsizetype n)

    { verify(0, n); m_size -= n; }

    // Defined in qbytearray.cpp:

    [[nodiscard]] QByteArrayView trimmed() const noexcept

    { return QtPrivate::trimmed(*this); }

    [[nodiscard]] short toShort(bool *ok = nullptr, int base = 10) const

    { return QtPrivate::toIntegral<short>(*this, ok, base); }

    [[nodiscard]] ushort toUShort(bool *ok = nullptr, int base = 10) const

    { return QtPrivate::toIntegral<ushort>(*this, ok, base); }

    [[nodiscard]] int toInt(bool *ok = nullptr, int base = 10) const

    { return QtPrivate::toIntegral<int>(*this, ok, base); }

    [[nodiscard]] uint toUInt(bool *ok = nullptr, int base = 10) const

    { return QtPrivate::toIntegral<uint>(*this, ok, base); }

    [[nodiscard]] long toLong(bool *ok = nullptr, int base = 10) const

    { return QtPrivate::toIntegral<long>(*this, ok, base); }

    [[nodiscard]] ulong toULong(bool *ok = nullptr, int base = 10) const

    { return QtPrivate::toIntegral<ulong>(*this, ok, base); }

    [[nodiscard]] qlonglong toLongLong(bool *ok = nullptr, int base = 10) const

    { return QtPrivate::toIntegral<qlonglong>(*this, ok, base); }

    [[nodiscard]] qulonglong toULongLong(bool *ok = nullptr, int base = 10) const

    { return QtPrivate::toIntegral<qulonglong>(*this, ok, base); }

    [[nodiscard]] float toFloat(bool *ok = nullptr) const

        const auto r = QtPrivate::toFloat(*this);

        if (ok)

            *ok = bool(r);

        return r.value_or(0.0f);

    [[nodiscard]] double toDouble(bool *ok = nullptr) const

        const auto r = QtPrivate::toDouble(*this);

        if (ok)

            *ok = bool(r);

        return r.value_or(0.0);

    [[nodiscard]] bool startsWith(QByteArrayView other) const noexcept

#if (!defined(Q_CC_GNU_ONLY) || Q_CC_GNU_ONLY >= 1700) && __has_builtin(__builtin_constant_p)

        if (__builtin_constant_p(other.m_size) && other.m_size == 1)

            return startsWith(other.front());

#endif

        return QtPrivate::startsWith(*this, other);

    [[nodiscard]] constexpr bool startsWith(char c) const noexcept

    { return !empty() && front() == c; }

    [[nodiscard]] bool endsWith(QByteArrayView other) const noexcept

#if (!defined(Q_CC_GNU_ONLY) || Q_CC_GNU_ONLY >= 1700) && __has_builtin(__builtin_constant_p)

        if (__builtin_constant_p(other.m_size) && other.m_size == 1)

            return endsWith(other.front());

#endif

        return QtPrivate::endsWith(*this, other);

    [[nodiscard]] constexpr bool endsWith(char c) const noexcept

    { return !empty() && back() == c; }

    [[nodiscard]] qsizetype indexOf(QByteArrayView a, qsizetype from = 0) const noexcept

#if (!defined(Q_CC_GNU_ONLY) || Q_CC_GNU_ONLY >= 1700) && __has_builtin(__builtin_constant_p)

        if (__builtin_constant_p(a.m_size) && a.m_size == 1)

            return indexOf(a.front(), from);

#endif

        return QtPrivate::findByteArray(*this, from, a);

    [[nodiscard]] qsizetype indexOf(char ch, qsizetype from = 0) const noexcept

    { return QtPrivate::findByteArray(*this, from, ch); }

    [[nodiscard]] bool contains(QByteArrayView a) const noexcept

    { return indexOf(a) != qsizetype(-1); }

    [[nodiscard]] bool contains(char c) const noexcept

    { return indexOf(c) != qsizetype(-1); }

    [[nodiscard]] qsizetype lastIndexOf(QByteArrayView a) const noexcept

    { return lastIndexOf(a, size()); }

    [[nodiscard]] qsizetype lastIndexOf(QByteArrayView a, qsizetype from) const noexcept

#if (!defined(Q_CC_GNU_ONLY) || Q_CC_GNU_ONLY >= 1700) && __has_builtin(__builtin_constant_p)

        if (__builtin_constant_p(a.m_size) && a.m_size == 1)

            return lastIndexOf(a.front(), from);

#endif

        return QtPrivate::lastIndexOf(*this, from, a);

    [[nodiscard]] qsizetype lastIndexOf(char ch, qsizetype from = -1) const noexcept

    { return QtPrivate::lastIndexOf(*this, from, ch); }

    [[nodiscard]] qsizetype count(QByteArrayView a) const noexcept

#if (!defined(Q_CC_GNU_ONLY) || Q_CC_GNU_ONLY >= 1700) && __has_builtin(__builtin_constant_p)

        if (__builtin_constant_p(a.m_size) && a.m_size == 1)

            return count(a.front());

#endif

        return QtPrivate::count(*this, a);

    [[nodiscard]] qsizetype count(char ch) const noexcept

    { return QtPrivate::count(*this, QByteArrayView(&ch, 1)); }

    inline int compare(QByteArrayView a) const noexcept;

    inline int compare(QByteArrayView a, Qt::CaseSensitivity) const noexcept;

    [[nodiscard]] inline bool isValidUtf8() const noexcept { return QtPrivate::isValidUtf8(*this); }

//

    // STL compatibility API:

//

    [[nodiscard]] constexpr const_iterator begin()   const noexcept { return data(); }

    [[nodiscard]] constexpr const_iterator end()     const noexcept { return data() + size(); }

    [[nodiscard]] constexpr const_iterator cbegin()  const noexcept { return begin(); }

    [[nodiscard]] constexpr const_iterator cend()    const noexcept { return end(); }

    [[nodiscard]] constexpr const_reverse_iterator rbegin()  const noexcept { return const_reverse_iterator(end()); }

    [[nodiscard]] constexpr const_reverse_iterator rend()    const noexcept { return const_reverse_iterator(begin()); }

    [[nodiscard]] constexpr const_reverse_iterator crbegin() const noexcept { return rbegin(); }

    [[nodiscard]] constexpr const_reverse_iterator crend()   const noexcept { return rend(); }

    [[nodiscard]] constexpr bool empty() const noexcept { return size() == 0; }

    [[nodiscard]] constexpr char front() const { Q_ASSERT(!empty()); return m_data[0]; }

    [[nodiscard]] constexpr char back()  const { Q_ASSERT(!empty()); return m_data[m_size - 1]; }

    [[nodiscard]] constexpr Q_IMPLICIT operator std::string_view() const noexcept

    { return std::string_view(m_data, size_t(m_size)); }

    [[nodiscard]] constexpr qsizetype max_size() const noexcept { return maxSize(); }

//

    // Qt compatibility API:

//

    [[nodiscard]] constexpr bool isNull() const noexcept { return !m_data; }

    [[nodiscard]] constexpr bool isEmpty() const noexcept { return empty(); }

    [[nodiscard]] constexpr qsizetype length() const noexcept

    { return size(); }

    [[nodiscard]] constexpr char first() const { return front(); }

    [[nodiscard]] constexpr char last()  const { return back(); }

private:

    Q_ALWAYS_INLINE constexpr void verify([[maybe_unused]] qsizetype pos = 0,

                                          [[maybe_unused]] qsizetype n = 1) const

        Q_ASSERT(pos >= 0);

        Q_ASSERT(pos <= size());

        Q_ASSERT(n >= 0);

        Q_ASSERT(n <= size() - pos);

    friend bool

    comparesEqual(const QByteArrayView &lhs, char rhs) noexcept

        return lhs.size() == 1 && lhs[0] == rhs;

    friend bool

    comparesEqual(const QByteArrayView &lhs, const QByteArrayView &rhs) noexcept

        return lhs.size() == rhs.size()

                && (!lhs.size() || memcmp(lhs.data(), rhs.data(), lhs.size()) == 0);

    friend Qt::strong_ordering

    compareThreeWay(const QByteArrayView &lhs, char rhs) noexcept

        if (lhs.size() >= 1) {

            if (int diff = uchar(lhs[0]) - uchar(rhs))

                return Qt::compareThreeWay(diff, 0);

        // the first char matched

        // so the longer one is lexically after the shorter one

        const int res = lhs.size() == 1 ? 0 : lhs.size() > 1 ? 1 : -1;

        return Qt::compareThreeWay(res, 0);

    friend Qt::strong_ordering

    compareThreeWay(const QByteArrayView &lhs, const QByteArrayView &rhs) noexcept

        const int res = QtPrivate::compareMemory(lhs, rhs);

        return Qt::compareThreeWay(res, 0);

    Q_DECLARE_STRONGLY_ORDERED(QByteArrayView)

    Q_DECLARE_STRONGLY_ORDERED(QByteArrayView, char)

    // defined in qstring.cpp

    friend Q_CORE_EXPORT bool

    comparesEqual(const QByteArrayView &lhs, const QChar &rhs) noexcept;

    friend Q_CORE_EXPORT Qt::strong_ordering

    compareThreeWay(const QByteArrayView &lhs, const QChar &rhs) noexcept;

    friend Q_CORE_EXPORT bool

    comparesEqual(const QByteArrayView &lhs, char16_t rhs) noexcept;

    friend Q_CORE_EXPORT Qt::strong_ordering

    compareThreeWay(const QByteArrayView &lhs, char16_t rhs) noexcept;

#if !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)

    Q_DECLARE_STRONGLY_ORDERED(QByteArrayView, QChar, QT_ASCII_CAST_WARN)

    Q_DECLARE_STRONGLY_ORDERED(QByteArrayView, char16_t, QT_ASCII_CAST_WARN)

#endif // !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)

#if QT_VERSION >= QT_VERSION_CHECK(7, 0, 0) || defined(QT_BOOTSTRAPPED)

    const storage_type *m_data = nullptr;

    qsizetype m_size = 0;

#else

    qsizetype m_size = 0;

    const storage_type *m_data = nullptr;

#endif

};

Q_DECLARE_TYPEINFO(QByteArrayView, Q_PRIMITIVE_TYPE);

template<typename QByteArrayLike,

         std::enable_if_t<std::is_same_v<QByteArrayLike, QByteArray>, bool> = true>

[[nodiscard]] inline QByteArrayView qToByteArrayViewIgnoringNull(const QByteArrayLike &b) noexcept

{ return QByteArrayView(b.begin(), b.size()); }

inline int QByteArrayView::compare(QByteArrayView a) const noexcept

#if (!defined(Q_CC_GNU_ONLY) || Q_CC_GNU_ONLY >= 1700) && __has_builtin(__builtin_constant_p)

    if (__builtin_constant_p(a.m_size) && a.m_size == 1) {

        if (isEmpty())

            return -1;

        if (int diff = uchar(front()) - uchar(a.front()))

            return diff;

        return size() > 1 ? 1 : 0;

#endif

    return QtPrivate::compareMemory(*this, a);

inline int QByteArrayView::compare(QByteArrayView a, Qt::CaseSensitivity cs) const noexcept

    return cs == Qt::CaseSensitive ? compare(a) :

                                     qstrnicmp(data(), size(), a.data(), a.size());

#if QT_DEPRECATED_SINCE(6, 0)

QT_DEPRECATED_VERSION_X_6_0("Use the QByteArrayView overload.")

inline quint16 qChecksum(const char *s, qsizetype len,

                         Qt::ChecksumType standard = Qt::ChecksumIso3309)

{ return qChecksum(QByteArrayView(s, len), standard); }

#endif

qsizetype QtPrivate::findByteArray(QByteArrayView haystack, qsizetype from, char needle) noexcept

    const qsizetype size = haystack.size();

    if (from < 0)

        from += size;

    if (size_t(from) < size_t(size)) {

        const char *const b = haystack.data();

        const auto n = static_cast<const char *>(memchr(b + from, needle, size_t(size - from)));

        if (n) {

            qsizetype ret = n - b;

            Q_PRESUME(ret >= 0);

            return ret;

    return -1;

qsizetype QtPrivate::lastIndexOf(QByteArrayView haystack, qsizetype from, uchar needle) noexcept

    if (from < 0)

        from = qMax(from + haystack.size(), qsizetype(0));

    else

        from = qMin(from, haystack.size() - 1);

    const char *const b = haystack.data();

    const void *n = b ? qmemrchr(b, needle, from + 1) : nullptr;

    if (auto ptr = static_cast<const char *>(n)) {

        qsizetype ret = ptr - b;

        Q_PRESUME(ret >= 0);

        return ret;

    return -1;

QT_END_NAMESPACE

#endif // QBYTEARRAYVIEW_H