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Diffstat (limited to 'src/corelib/text/qbytearrayview.h')
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1 files changed, 313 insertions, 0 deletions
diff --git a/src/corelib/text/qbytearrayview.h b/src/corelib/text/qbytearrayview.h new file mode 100644 index 0000000000..36764abfb4 --- /dev/null +++ b/src/corelib/text/qbytearrayview.h @@ -0,0 +1,313 @@ +/**************************************************************************** +** +** Copyright (C) 2020 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ +#ifndef QBYTEARRAYVIEW_H +#define QBYTEARRAYVIEW_H + +#include <QtCore/qbytearrayalgorithms.h> + +#include <string> + +QT_BEGIN_NAMESPACE + +class QByteArray; +class QLatin1String; + +namespace QtPrivate { + +template <typename Byte> +struct IsCompatibleByteTypeHelper + : std::integral_constant<bool, + std::is_same_v<Byte, char> || + std::is_same_v<Byte, uchar> || + std::is_same_v<Byte, signed char> || + std::is_same_v<Byte, std::byte>> {}; + +template <typename Byte> +struct IsCompatibleByteType + : IsCompatibleByteTypeHelper< + typename std::remove_cv_t<typename std::remove_reference_t<Byte>>> {}; + +template <typename Pointer> +struct IsCompatibleByteArrayPointerHelper : std::false_type {}; +template <typename Byte> +struct IsCompatibleByteArrayPointerHelper<Byte *> + : IsCompatibleByteType<Byte> {}; +template<typename Pointer> +struct IsCompatibleByteArrayPointer + : IsCompatibleByteArrayPointerHelper< + typename std::remove_cv_t<typename std::remove_reference_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>>, + + // Don't make an accidental copy constructor + std::negation<std::is_same<std::decay_t<T>, QByteArrayView>>>>> : std::true_type {}; + +} // 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 Char> + static constexpr qsizetype lengthHelperPointer(const Char *data) noexcept + { + return qsizetype(std::char_traits<Char>::length(data)); + } + + template <typename Container> + static constexpr qsizetype lengthHelperContainer(const Container &c) noexcept + { + return qsizetype(std::size(c)); + } + + template <typename Char, size_t N> + static constexpr qsizetype lengthHelperContainer(const Char (&)[N]) noexcept + { + return qsizetype(N - 1); + } + + template <typename Byte> + static const storage_type *castHelper(const Byte *data) noexcept + { return reinterpret_cast<const storage_type*>(data); } + static Q_DECL_CONSTEXPR const storage_type *castHelper(const storage_type *data) noexcept + { return data; } + +public: + constexpr QByteArrayView() noexcept + : m_size(0), m_data(nullptr) {} + constexpr QByteArrayView(std::nullptr_t) noexcept + : QByteArrayView() {} + + template <typename Byte, if_compatible_byte<Byte> = true> + constexpr QByteArrayView(const Byte *data, qsizetype len) + : m_size((Q_ASSERT(len >= 0), Q_ASSERT(data || !len), len)), + m_data(castHelper(data)) {} + + 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, size_t N> + constexpr QByteArrayView(const Byte (&array)[N]) noexcept; + + 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 ? 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.isNull() ? nullptr : ba.data(), qsizetype(ba.size())) {} +#endif + + template <typename Container, if_compatible_container<Container> = true> + constexpr QByteArrayView(const Container &c) noexcept + : QByteArrayView(std::data(c), lengthHelperContainer(c)) {} + + [[nodiscard]] inline QByteArray toByteArray() const; // defined in qbytearray.h + + [[nodiscard]] constexpr qsizetype size() const noexcept { 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 + { Q_ASSERT(n >= 0); Q_ASSERT(n < size()); return m_data[n]; } + + // + // QByteArray API + // + [[nodiscard]] constexpr char at(qsizetype n) const { return (*this)[n]; } + + [[nodiscard]] constexpr QByteArrayView first(qsizetype n) const + { Q_ASSERT(n >= 0); Q_ASSERT(n <= size()); return QByteArrayView(data(), n); } + [[nodiscard]] constexpr QByteArrayView last(qsizetype n) const + { Q_ASSERT(n >= 0); Q_ASSERT(n <= size()); return QByteArrayView(data() + size() - n, n); } + [[nodiscard]] constexpr QByteArrayView sliced(qsizetype pos) const + { Q_ASSERT(pos >= 0); Q_ASSERT(pos <= size()); return QByteArrayView(data() + pos, size() - pos); } + [[nodiscard]] constexpr QByteArrayView sliced(qsizetype pos, qsizetype n) const + { Q_ASSERT(pos >= 0); Q_ASSERT(n >= 0); Q_ASSERT(size_t(pos) + size_t(n) <= size_t(size())); return QByteArrayView(data() + pos, n); } + [[nodiscard]] constexpr QByteArrayView chopped(qsizetype len) const + { Q_ASSERT(len >= 0); Q_ASSERT(len <= size()); return first(size() - len); } + + constexpr void truncate(qsizetype n) + { Q_ASSERT(n >= 0); Q_ASSERT(n <= size()); m_size = n; } + constexpr void chop(qsizetype n) + { Q_ASSERT(n >= 0); Q_ASSERT(n <= size()); m_size -= n; } + + [[nodiscard]] bool startsWith(QByteArrayView other) const noexcept + { return QtPrivate::startsWith(*this, other); } + [[nodiscard]] bool startsWith(char c) const noexcept + { return !empty() && front() == c; } + + [[nodiscard]] bool endsWith(QByteArrayView other) const noexcept + { return QtPrivate::endsWith(*this, other); } + [[nodiscard]] bool endsWith(char c) const noexcept + { return !empty() && back() == c; } + + [[nodiscard]] qsizetype indexOf(QByteArrayView a, qsizetype from = 0) const noexcept + { return QtPrivate::findByteArray(*this, from, a); } + [[nodiscard]] qsizetype indexOf(char ch, qsizetype from = 0) const noexcept + { return QtPrivate::findByteArray(*this, from, QByteArrayView(&ch, 1)); } + + [[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, qsizetype from = -1) const noexcept + { return QtPrivate::lastIndexOf(*this, from, a); } + [[nodiscard]] qsizetype lastIndexOf(char ch, qsizetype from = -1) const noexcept + { return QtPrivate::lastIndexOf(*this, from, QByteArrayView(&ch, 1)); } + + [[nodiscard]] qsizetype count(QByteArrayView a) const noexcept + { return QtPrivate::count(*this, a); } + [[nodiscard]] qsizetype count(char ch) const noexcept + { return QtPrivate::count(*this, QByteArrayView(&ch, 1)); } + + // + // 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]; } + + // + // Qt compatibility API: + // + [[nodiscard]] constexpr bool isNull() const noexcept { return !m_data; } + [[nodiscard]] constexpr bool isEmpty() const noexcept { return empty(); } +#if QT_DEPRECATED_SINCE(6, 0) + [[nodiscard]] + Q_DECL_DEPRECATED_X("Use size() and port callers to qsizetype.") + constexpr int length() const /* not nothrow! */ + { Q_ASSERT(int(size()) == size()); return int(size()); } +#endif + [[nodiscard]] constexpr char first() const { return front(); } + [[nodiscard]] constexpr char last() const { return back(); } + +private: + qsizetype m_size; + const storage_type *m_data; +}; +Q_DECLARE_TYPEINFO(QByteArrayView, Q_PRIMITIVE_TYPE); + +// QByteArrayView <> QByteArrayView +inline bool operator==(QByteArrayView lhs, QByteArrayView rhs) noexcept { return lhs.size() == rhs.size() && QtPrivate::compareMemory(lhs, rhs) == 0; } +inline bool operator!=(QByteArrayView lhs, QByteArrayView rhs) noexcept { return !(lhs == rhs); } +inline bool operator< (QByteArrayView lhs, QByteArrayView rhs) noexcept { return QtPrivate::compareMemory(lhs, rhs) < 0; } +inline bool operator<=(QByteArrayView lhs, QByteArrayView rhs) noexcept { return QtPrivate::compareMemory(lhs, rhs) <= 0; } +inline bool operator> (QByteArrayView lhs, QByteArrayView rhs) noexcept { return !(lhs <= rhs); } +inline bool operator>=(QByteArrayView lhs, QByteArrayView rhs) noexcept { return !(lhs < rhs); } + +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.data(), b.size()); } + +QT_END_NAMESPACE + +#endif // QBYTEARRAYVIEW_H |