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qbytearrayview.h
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1// Copyright (C) 2021 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3// Qt-Security score:critical reason:data-parser
4#ifndef QBYTEARRAYVIEW_H
5#define QBYTEARRAYVIEW_H
6
7#include <QtCore/qbytearrayalgorithms.h>
8#include <QtCore/qcompare.h>
9#include <QtCore/qcontainerfwd.h>
10#include <QtCore/qstringfwd.h>
11#include <QtCore/qarraydata.h>
12
13#include <string>
14#include <string_view>
15#include <QtCore/q20type_traits.h>
16
17QT_BEGIN_NAMESPACE
18
19namespace QtPrivate {
20
21template <typename Byte>
22struct IsCompatibleByteTypeHelper : std::false_type {};
23template <> struct IsCompatibleByteTypeHelper<char> : std::true_type {};
24template <> struct IsCompatibleByteTypeHelper<signed char> : std::true_type {};
25template <> struct IsCompatibleByteTypeHelper<unsigned char> : std::true_type {};
26template <> struct IsCompatibleByteTypeHelper<std::byte> : std::true_type {};
27
28template <typename Byte>
31
32template <typename Pointer>
33struct IsCompatibleByteArrayPointerHelper : std::false_type {};
34template <typename Byte>
37template<typename Pointer>
40
41template <typename T, typename Enable = void>
42struct IsContainerCompatibleWithQByteArrayView : std::false_type {};
43
44template <typename T>
45struct IsContainerCompatibleWithQByteArrayView<T, std::enable_if_t<
46 std::conjunction_v<
47 // lacking concepts and ranges, we accept any T whose std::data yields a suitable
48 // pointer ...
49 IsCompatibleByteArrayPointer<decltype(std::data(std::declval<const T &>()))>,
50 // ... and that has a suitable size ...
51 std::is_convertible<decltype(std::size(std::declval<const T &>())), qsizetype>,
52 // ... and it's a range as it defines an iterator-like API
53 IsCompatibleByteType<typename std::iterator_traits<decltype(
54 std::begin(std::declval<const T &>()))>::value_type>,
55 std::is_convertible<decltype(std::begin(std::declval<const T &>())
56 != std::end(std::declval<const T &>())),
57 bool>,
58
59 // This needs to be treated specially due to the empty vs null distinction
60 std::negation<std::is_same<std::decay_t<T>, QByteArray>>,
61
62 // We handle array literals specially for source compat reasons
63 std::negation<std::is_array<T>>,
64
65 // Don't make an accidental copy constructor
66 std::negation<std::is_same<std::decay_t<T>, QByteArrayView>>>>> : std::true_type {};
67
68// Used by QLatin1StringView too
69template <typename Char>
70static constexpr qsizetype lengthHelperPointer(const Char *data) noexcept
71{
72 // std::char_traits can only be used with one of the regular char types
73 // (char, char16_t, wchar_t, but not uchar or QChar), so we roll the loop
74 // out by ourselves.
75 qsizetype i = 0;
76 if (!data)
77 return i;
78 while (data[i] != Char(0))
79 ++i;
80 return i;
81}
82
83} // namespace QtPrivate
84
85class Q_CORE_EXPORT QByteArrayView
86{
87public:
88 typedef char storage_type;
89 typedef const char value_type;
90 typedef qptrdiff difference_type;
91 typedef qsizetype size_type;
92 typedef value_type &reference;
93 typedef value_type &const_reference;
94 typedef value_type *pointer;
95 typedef value_type *const_pointer;
96
97 typedef pointer iterator;
98 typedef const_pointer const_iterator;
99 typedef std::reverse_iterator<iterator> reverse_iterator;
100 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
101
102private:
103 template <typename Byte>
104 using if_compatible_byte =
105 typename std::enable_if_t<QtPrivate::IsCompatibleByteType<Byte>::value, bool>;
106
107 template <typename Pointer>
108 using if_compatible_pointer =
109 typename std::enable_if_t<QtPrivate::IsCompatibleByteArrayPointer<Pointer>::value,
110 bool>;
111
112 template <typename T>
113 using if_compatible_qbytearray_like =
114 typename std::enable_if_t<std::is_same_v<T, QByteArray>, bool>;
115
116 template <typename T>
117 using if_compatible_container =
118 typename std::enable_if_t<QtPrivate::IsContainerCompatibleWithQByteArrayView<T>::value,
119 bool>;
120
121 template <typename Container>
122 static constexpr qsizetype lengthHelperContainer(const Container &c) noexcept
123 {
124 return qsizetype(std::size(c));
125 }
126
127 static constexpr qsizetype lengthHelperCharArray(const char *data, size_t size) noexcept
128 {
129 const auto it = std::char_traits<char>::find(data, size, '\0');
130 const auto end = it ? it : std::next(data, size);
131 return qsizetype(std::distance(data, end));
132 }
133
134 template <typename Byte>
135 static const storage_type *castHelper(const Byte *data) noexcept
136 { return reinterpret_cast<const storage_type*>(data); }
137 static constexpr const storage_type *castHelper(const storage_type *data) noexcept
138 { return data; }
139
140public:
141 constexpr QByteArrayView() noexcept
142 : m_size(0), m_data(nullptr) {}
143 constexpr QByteArrayView(std::nullptr_t) noexcept
144 : QByteArrayView() {}
145
146 template <typename Byte, if_compatible_byte<Byte> = true>
147 constexpr QByteArrayView(const Byte *data, qsizetype len)
148 : m_size((Q_ASSERT(len >= 0), Q_ASSERT(data || !len), len)),
149 m_data(castHelper(data)) {}
150
151 template <typename Byte, if_compatible_byte<Byte> = true>
152 constexpr QByteArrayView(const Byte *first, const Byte *last)
153 : QByteArrayView(first, last - first) {}
154
155#ifdef Q_QDOC
156 template <typename Byte>
157 constexpr QByteArrayView(const Byte *data) noexcept;
158#else
159 template <typename Pointer, if_compatible_pointer<Pointer> = true>
160 constexpr QByteArrayView(const Pointer &data) noexcept
161 : QByteArrayView(
162 data, data ? QtPrivate::lengthHelperPointer(data) : 0) {}
163#endif
164
165#ifdef Q_QDOC
166 QByteArrayView(const QByteArray &data) noexcept;
167#else
168 template <typename ByteArray, if_compatible_qbytearray_like<ByteArray> = true>
169 QByteArrayView(const ByteArray &ba) noexcept
170 : QByteArrayView{ba.begin(), ba.size()} {}
171#endif
172
173 template <typename Container, if_compatible_container<Container> = true>
174 constexpr QByteArrayView(const Container &c) noexcept
175 : QByteArrayView(std::data(c), lengthHelperContainer(c)) {}
176 template <size_t Size>
177 constexpr QByteArrayView(const char (&data)[Size]) noexcept
178 : QByteArrayView(data, lengthHelperCharArray(data, Size)) {}
179
180 template <typename Byte, if_compatible_byte<Byte> = true>
181 constexpr QByteArrayView(const Byte (&data)[]) noexcept
182 : QByteArrayView(&*data) {} // decay to pointer
183
184#ifdef Q_QDOC
185 template <typename Byte, size_t Size>
186#else
187 template <typename Byte, size_t Size, if_compatible_byte<Byte> = true>
188#endif
189 [[nodiscard]] constexpr static QByteArrayView fromArray(const Byte (&data)[Size]) noexcept
190 { return QByteArrayView(data, Size); }
191 [[nodiscard]] inline QByteArray toByteArray() const; // defined in qbytearray.h
192
193 [[nodiscard]] constexpr qsizetype size() const noexcept { return m_size; }
194 [[nodiscard]] constexpr const_pointer data() const noexcept { return m_data; }
195 [[nodiscard]] constexpr const_pointer constData() const noexcept { return data(); }
196
197 [[nodiscard]] constexpr char operator[](qsizetype n) const
198 { verify(n, 1); return m_data[n]; }
199
200 //
201 // QByteArray API
202 //
203 [[nodiscard]] constexpr char at(qsizetype n) const { return (*this)[n]; }
204
205 [[nodiscard]] constexpr QByteArrayView first(qsizetype n) const
206 { verify(0, n); return sliced(0, n); }
207 [[nodiscard]] constexpr QByteArrayView last(qsizetype n) const
208 { verify(0, n); return sliced(size() - n, n); }
209 [[nodiscard]] constexpr QByteArrayView sliced(qsizetype pos) const
210 { verify(pos, 0); return QByteArrayView(data() + pos, size() - pos); }
211 [[nodiscard]] constexpr QByteArrayView sliced(qsizetype pos, qsizetype n) const
212 { verify(pos, n); return QByteArrayView(data() + pos, n); }
213
214 constexpr QByteArrayView &slice(qsizetype pos)
215 { *this = sliced(pos); return *this; }
216 constexpr QByteArrayView &slice(qsizetype pos, qsizetype n)
217 { *this = sliced(pos, n); return *this; }
218
219 [[nodiscard]] constexpr QByteArrayView chopped(qsizetype len) const
220 { verify(0, len); return sliced(0, size() - len); }
221
222 [[nodiscard]] constexpr QByteArrayView left(qsizetype n) const
223 { if (n < 0 || n > size()) n = size(); return QByteArrayView(data(), n); }
224 [[nodiscard]] constexpr QByteArrayView right(qsizetype n) const
225 { if (n < 0 || n > size()) n = size(); if (n < 0) n = 0; return QByteArrayView(data() + size() - n, n); }
226 [[nodiscard]] constexpr QByteArrayView mid(qsizetype pos, qsizetype n = -1) const
227 {
228 using namespace QtPrivate;
229 auto result = QContainerImplHelper::mid(size(), &pos, &n);
230 return result == QContainerImplHelper::Null ? QByteArrayView()
231 : QByteArrayView(m_data + pos, n);
232 }
233
234 constexpr void truncate(qsizetype n)
235 { verify(0, n); m_size = n; }
236 constexpr void chop(qsizetype n)
237 { verify(0, n); m_size -= n; }
238
239 // Defined in qbytearray.cpp:
240 [[nodiscard]] QByteArrayView trimmed() const noexcept
241 { return QtPrivate::trimmed(*this); }
242 [[nodiscard]] short toShort(bool *ok = nullptr, int base = 10) const
243 { return QtPrivate::toIntegral<short>(*this, ok, base); }
244 [[nodiscard]] ushort toUShort(bool *ok = nullptr, int base = 10) const
245 { return QtPrivate::toIntegral<ushort>(*this, ok, base); }
246 [[nodiscard]] int toInt(bool *ok = nullptr, int base = 10) const
247 { return QtPrivate::toIntegral<int>(*this, ok, base); }
248 [[nodiscard]] uint toUInt(bool *ok = nullptr, int base = 10) const
249 { return QtPrivate::toIntegral<uint>(*this, ok, base); }
250 [[nodiscard]] long toLong(bool *ok = nullptr, int base = 10) const
251 { return QtPrivate::toIntegral<long>(*this, ok, base); }
252 [[nodiscard]] ulong toULong(bool *ok = nullptr, int base = 10) const
253 { return QtPrivate::toIntegral<ulong>(*this, ok, base); }
254 [[nodiscard]] qlonglong toLongLong(bool *ok = nullptr, int base = 10) const
255 { return QtPrivate::toIntegral<qlonglong>(*this, ok, base); }
256 [[nodiscard]] qulonglong toULongLong(bool *ok = nullptr, int base = 10) const
257 { return QtPrivate::toIntegral<qulonglong>(*this, ok, base); }
258 [[nodiscard]] float toFloat(bool *ok = nullptr) const
259 {
260 const auto r = QtPrivate::toFloat(*this);
261 if (ok)
262 *ok = bool(r);
263 return r.value_or(0.0f);
264 }
265 [[nodiscard]] double toDouble(bool *ok = nullptr) const
266 {
267 const auto r = QtPrivate::toDouble(*this);
268 if (ok)
269 *ok = bool(r);
270 return r.value_or(0.0);
271 }
272
273 [[nodiscard]] bool startsWith(QByteArrayView other) const noexcept
274 { return QtPrivate::startsWith(*this, other); }
275 [[nodiscard]] constexpr bool startsWith(char c) const noexcept
276 { return !empty() && front() == c; }
277
278 [[nodiscard]] bool endsWith(QByteArrayView other) const noexcept
279 { return QtPrivate::endsWith(*this, other); }
280 [[nodiscard]] constexpr bool endsWith(char c) const noexcept
281 { return !empty() && back() == c; }
282
283 [[nodiscard]] qsizetype indexOf(QByteArrayView a, qsizetype from = 0) const noexcept
284 { return QtPrivate::findByteArray(*this, from, a); }
285 [[nodiscard]] qsizetype indexOf(char ch, qsizetype from = 0) const noexcept
286 { return QtPrivate::findByteArray(*this, from, ch); }
287
288 [[nodiscard]] bool contains(QByteArrayView a) const noexcept
289 { return indexOf(a) != qsizetype(-1); }
290 [[nodiscard]] bool contains(char c) const noexcept
291 { return indexOf(c) != qsizetype(-1); }
292
293 [[nodiscard]] qsizetype lastIndexOf(QByteArrayView a) const noexcept
294 { return lastIndexOf(a, size()); }
295 [[nodiscard]] qsizetype lastIndexOf(QByteArrayView a, qsizetype from) const noexcept
296 { return QtPrivate::lastIndexOf(*this, from, a); }
297 [[nodiscard]] qsizetype lastIndexOf(char ch, qsizetype from = -1) const noexcept
298 { return QtPrivate::lastIndexOf(*this, from, ch); }
299
300 [[nodiscard]] qsizetype count(QByteArrayView a) const noexcept
301 { return QtPrivate::count(*this, a); }
302 [[nodiscard]] qsizetype count(char ch) const noexcept
303 { return QtPrivate::count(*this, QByteArrayView(&ch, 1)); }
304
305 inline int compare(QByteArrayView a, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
306
307 [[nodiscard]] inline bool isValidUtf8() const noexcept { return QtPrivate::isValidUtf8(*this); }
308
309 //
310 // STL compatibility API:
311 //
312 [[nodiscard]] constexpr const_iterator begin() const noexcept { return data(); }
313 [[nodiscard]] constexpr const_iterator end() const noexcept { return data() + size(); }
314 [[nodiscard]] constexpr const_iterator cbegin() const noexcept { return begin(); }
315 [[nodiscard]] constexpr const_iterator cend() const noexcept { return end(); }
316 [[nodiscard]] constexpr const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(end()); }
317 [[nodiscard]] constexpr const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
318 [[nodiscard]] constexpr const_reverse_iterator crbegin() const noexcept { return rbegin(); }
319 [[nodiscard]] constexpr const_reverse_iterator crend() const noexcept { return rend(); }
320
321 [[nodiscard]] constexpr bool empty() const noexcept { return size() == 0; }
322 [[nodiscard]] constexpr char front() const { Q_ASSERT(!empty()); return m_data[0]; }
323 [[nodiscard]] constexpr char back() const { Q_ASSERT(!empty()); return m_data[m_size - 1]; }
324
325 [[nodiscard]] constexpr Q_IMPLICIT operator std::string_view() const noexcept
326 { return std::string_view(m_data, size_t(m_size)); }
327
328 [[nodiscard]] constexpr qsizetype max_size() const noexcept { return maxSize(); }
329
330 //
331 // Qt compatibility API:
332 //
333 [[nodiscard]] constexpr bool isNull() const noexcept { return !m_data; }
334 [[nodiscard]] constexpr bool isEmpty() const noexcept { return empty(); }
335 [[nodiscard]] constexpr qsizetype length() const noexcept
336 { return size(); }
337 [[nodiscard]] constexpr char first() const { return front(); }
338 [[nodiscard]] constexpr char last() const { return back(); }
339
340 [[nodiscard]] static constexpr qsizetype maxSize() noexcept
341 {
342 // -1 to deal with the pointer one-past-the-end;
343 return QtPrivate::MaxAllocSize - 1;
344 }
345
346private:
347 Q_ALWAYS_INLINE constexpr void verify([[maybe_unused]] qsizetype pos = 0,
348 [[maybe_unused]] qsizetype n = 1) const
349 {
350 Q_ASSERT(pos >= 0);
351 Q_ASSERT(pos <= size());
352 Q_ASSERT(n >= 0);
353 Q_ASSERT(n <= size() - pos);
354 }
355
356 friend bool
357 comparesEqual(const QByteArrayView &lhs, const QByteArrayView &rhs) noexcept
358 {
359 return lhs.size() == rhs.size()
360 && (!lhs.size() || memcmp(lhs.data(), rhs.data(), lhs.size()) == 0);
361 }
362 friend Qt::strong_ordering
363 compareThreeWay(const QByteArrayView &lhs, const QByteArrayView &rhs) noexcept
364 {
365 const int res = QtPrivate::compareMemory(lhs, rhs);
366 return Qt::compareThreeWay(res, 0);
367 }
368 Q_DECLARE_STRONGLY_ORDERED(QByteArrayView)
369
370 // defined in qstring.cpp
371 friend Q_CORE_EXPORT bool
372 comparesEqual(const QByteArrayView &lhs, const QChar &rhs) noexcept;
373 friend Q_CORE_EXPORT Qt::strong_ordering
374 compareThreeWay(const QByteArrayView &lhs, const QChar &rhs) noexcept;
375 friend Q_CORE_EXPORT bool
376 comparesEqual(const QByteArrayView &lhs, char16_t rhs) noexcept;
377 friend Q_CORE_EXPORT Qt::strong_ordering
378 compareThreeWay(const QByteArrayView &lhs, char16_t rhs) noexcept;
379#if !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
380 Q_DECLARE_STRONGLY_ORDERED(QByteArrayView, QChar, QT_ASCII_CAST_WARN)
381 Q_DECLARE_STRONGLY_ORDERED(QByteArrayView, char16_t, QT_ASCII_CAST_WARN)
382#endif // !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
383
384 qsizetype m_size;
385 const storage_type *m_data;
386};
387Q_DECLARE_TYPEINFO(QByteArrayView, Q_PRIMITIVE_TYPE);
388
389template<typename QByteArrayLike,
390 std::enable_if_t<std::is_same_v<QByteArrayLike, QByteArray>, bool> = true>
391[[nodiscard]] inline QByteArrayView qToByteArrayViewIgnoringNull(const QByteArrayLike &b) noexcept
392{ return QByteArrayView(b.begin(), b.size()); }
393
394inline int QByteArrayView::compare(QByteArrayView a, Qt::CaseSensitivity cs) const noexcept
395{
396 return cs == Qt::CaseSensitive ? QtPrivate::compareMemory(*this, a) :
397 qstrnicmp(data(), size(), a.data(), a.size());
398}
399
400#if QT_DEPRECATED_SINCE(6, 0)
401QT_DEPRECATED_VERSION_X_6_0("Use the QByteArrayView overload.")
402inline quint16 qChecksum(const char *s, qsizetype len,
403 Qt::ChecksumType standard = Qt::ChecksumIso3309)
404{ return qChecksum(QByteArrayView(s, len), standard); }
405#endif
406
407qsizetype QtPrivate::findByteArray(QByteArrayView haystack, qsizetype from, char needle) noexcept
408{
409 if (from < -haystack.size()) // from < 0 && abs(from) > haystack.size(), avoiding overflow
410 return -1;
411 if (from < 0)
412 from = from + haystack.size();
413 if (from < haystack.size()) {
414 const char *const b = haystack.data();
415 if (const auto n = static_cast<const char *>(
416 memchr(b + from, needle, static_cast<size_t>(haystack.size() - from)))) {
417 return n - b;
418 }
419 }
420 return -1;
421}
422
423qsizetype QtPrivate::lastIndexOf(QByteArrayView haystack, qsizetype from, uchar needle) noexcept
424{
425 if (from < 0)
426 from = qMax(from + haystack.size(), qsizetype(0));
427 else
428 from = qMin(from, haystack.size() - 1);
429
430 const char *const b = haystack.data();
431 const void *n = b ? qmemrchr(b, needle, from + 1) : nullptr;
432 return n ? static_cast<const char *>(n) - b : -1;
433}
434
435QT_END_NAMESPACE
436
437#endif // QBYTEARRAYVIEW_H
QDataStream
\inmodule QtCore\reentrant
Definition qdatastream.h:50
QtPrivate::asString
QString && asString(QString &&s)
Definition qstring.h:1681
QtPrivate::qStringLikeToArg
constexpr QAnyStringArg qStringLikeToArg(QAnyStringView s) noexcept
Definition qstring.h:1742
QtPrivate::asString
const QString & asString(const QString &s)
Definition qstring.h:1680
QtPrivate::lengthHelperPointer
static constexpr qsizetype lengthHelperPointer(const Char *data) noexcept
Definition qbytearrayview.h:70
QtPrivate::IsCompatibleChar32TypeHelper
std::is_same< Char, char32_t > IsCompatibleChar32TypeHelper
Definition qstring.h:57
QtPrivate::isLatin1
constexpr bool isLatin1(QLatin1StringView s) noexcept
Definition qstring.h:77
Qt::Literals::StringLiterals::operator""_s
QString operator""_s(const char16_t *str, size_t size) noexcept
Definition qstring.h:1788
Qt
Definition qcompare.h:76
qToByteArrayViewIgnoringNull
QByteArrayView qToByteArrayViewIgnoringNull(const QByteArrayLike &b) noexcept
Definition qbytearrayview.h:391
Q_DECLARE_TYPEINFO
Q_DECLARE_TYPEINFO(QByteArrayView, Q_PRIMITIVE_TYPE)
__has_builtin
#define __has_builtin(x)
Definition qcompilerdetection.h:441
__has_cpp_attribute
#define __has_cpp_attribute(x)
Definition qcompilerdetection.h:453
Q_LOGGING_CATEGORY
Q_LOGGING_CATEGORY(lcEventDispatcher, "qt.eventdispatcher")
qt_int_sqrt
Q_CORE_EXPORT Q_DECL_CONST_FUNCTION unsigned int qt_int_sqrt(unsigned int n)
\inmodule QtCore \title Global Qt Declarations
Definition qglobal.cpp:99
operator+
QString operator+(const QString &s1, QChar s2)
Definition qstring.h:1562
operator+
QString operator+(QString &&lhs, const QString &rhs)
Definition qstring.h:1560
erase_if
qsizetype erase_if(QString &s, Predicate pred)
Definition qstring.h:1780
QT_UNICODE_LITERAL
#define QT_UNICODE_LITERAL(str)
Definition qstring.h:1814
operator+
QString operator+(QString &&lhs, QChar rhs)
Definition qstring.h:1564
operator+
QString operator+(QChar s1, const QString &s2)
Definition qstring.h:1566
operator+
QString operator+(const QString &s1, const QString &s2)
Definition qstring.h:1558
erase
qsizetype erase(QString &s, const T &t)
Definition qstring.h:1774
QInternal_CallBackTable
Definition qglobal.cpp:127
QInternal_CallBackTable::callbacks
QList< QList< qInternalCallback > > callbacks
Definition qglobal.cpp:128
QtPrivate::QAnyStringArg::QAnyStringArg
constexpr QAnyStringArg(QAnyStringView v) noexcept
Definition qstring.h:1726
QtPrivate::QAnyStringArg::string
QAnyStringView string
Definition qstring.h:1724
QtPrivate::QLatin1StringArg::string
QLatin1StringView string
Definition qstring.h:1718
QtPrivate::QLatin1StringArg::QLatin1StringArg
constexpr QLatin1StringArg(QLatin1StringView v) noexcept
Definition qstring.h:1720
QtPrivate::QStringViewArg::QStringViewArg
constexpr QStringViewArg(QStringView v) noexcept
Definition qstring.h:1714
QtPrivate::treat_as_integral_arg< signed char >
Definition qstring.h:68
QtPrivate::treat_as_integral_arg< signed short >
Definition qstring.h:66
QtPrivate::treat_as_integral_arg< unsigned char >
Definition qstring.h:67
QtPrivate::treat_as_integral_arg< unsigned short >
Definition qstring.h:65