1 | // Copyright (C) 2020 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 | |
4 | #include <QtCore/qstring.h> |
5 | |
6 | #ifndef QSTRINGBUILDER_H |
7 | #define QSTRINGBUILDER_H |
8 | |
9 | #if 0 |
10 | // syncqt can not handle the templates in this file, and it doesn't need to |
11 | // process them anyway because they are internal. |
12 | #pragma qt_class(QStringBuilder) |
13 | #pragma qt_sync_stop_processing |
14 | #endif |
15 | |
16 | #include <QtCore/qbytearray.h> |
17 | |
18 | #include <string.h> |
19 | |
20 | QT_BEGIN_NAMESPACE |
21 | |
22 | |
23 | struct Q_CORE_EXPORT QAbstractConcatenable |
24 | { |
25 | protected: |
26 | static void convertFromUtf8(QByteArrayView in, QChar *&out) noexcept; |
27 | static inline void convertFromAscii(char a, QChar *&out) noexcept |
28 | { |
29 | *out++ = QLatin1Char(a); |
30 | } |
31 | static void appendLatin1To(QLatin1StringView in, QChar *out) noexcept; |
32 | }; |
33 | |
34 | template <typename T> struct QConcatenable; |
35 | |
36 | template <typename T> |
37 | using QConcatenableEx = QConcatenable<q20::remove_cvref_t<T>>; |
38 | |
39 | namespace QtStringBuilder { |
40 | template <typename A, typename B> struct ConvertToTypeHelper |
41 | { typedef A ConvertTo; }; |
42 | template <typename T> struct ConvertToTypeHelper<T, QString> |
43 | { typedef QString ConvertTo; }; |
44 | |
45 | template <typename T> using HasIsNull = decltype(std::declval<const T &>().isNull()); |
46 | template <typename T> bool isNull(const T &t) |
47 | { |
48 | if constexpr (qxp::is_detected_v<HasIsNull, T>) |
49 | return t.isNull(); |
50 | else |
51 | return false; |
52 | } |
53 | } |
54 | |
55 | template<typename Builder, typename T> |
56 | struct QStringBuilderCommon |
57 | { |
58 | T toUpper() const { return resolved().toUpper(); } |
59 | T toLower() const { return resolved().toLower(); } |
60 | |
61 | protected: |
62 | T resolved() const { return *static_cast<const Builder*>(this); } |
63 | }; |
64 | |
65 | template<typename Builder, typename T> |
66 | struct QStringBuilderBase : public QStringBuilderCommon<Builder, T> |
67 | { |
68 | }; |
69 | |
70 | template<typename Builder> |
71 | struct QStringBuilderBase<Builder, QString> : public QStringBuilderCommon<Builder, QString> |
72 | { |
73 | QByteArray toLatin1() const { return this->resolved().toLatin1(); } |
74 | QByteArray toUtf8() const { return this->resolved().toUtf8(); } |
75 | QByteArray toLocal8Bit() const { return this->resolved().toLocal8Bit(); } |
76 | }; |
77 | |
78 | template <typename A, typename B> |
79 | class QStringBuilder : public QStringBuilderBase<QStringBuilder<A, B>, |
80 | typename QtStringBuilder::ConvertToTypeHelper< |
81 | typename QConcatenableEx<A>::ConvertTo, |
82 | typename QConcatenableEx<B>::ConvertTo |
83 | >::ConvertTo |
84 | > |
85 | { |
86 | public: |
87 | QStringBuilder(A &&a_, B &&b_) : a(std::forward<A>(a_)), b(std::forward<B>(b_)) {} |
88 | |
89 | QStringBuilder(QStringBuilder &&) = default; |
90 | QStringBuilder(const QStringBuilder &) = default; |
91 | ~QStringBuilder() = default; |
92 | |
93 | private: |
94 | friend class QByteArray; |
95 | friend class QString; |
96 | template <typename T> T convertTo() const |
97 | { |
98 | if (isNull()) { |
99 | // appending two null strings must give back a null string, |
100 | // so we're special casing this one out, QTBUG-114206 |
101 | return T(); |
102 | } |
103 | |
104 | const qsizetype len = Concatenable::size(*this); |
105 | T s(len, Qt::Uninitialized); |
106 | |
107 | // Using data_ptr() here (private API) so we can bypass the |
108 | // isDetached() and the replacement of a null pointer with _empty in |
109 | // both QString and QByteArray's data() and constData(). The result is |
110 | // the same if len != 0. |
111 | auto d = reinterpret_cast<typename T::iterator>(s.data_ptr().data()); |
112 | const auto start = d; |
113 | Concatenable::appendTo(*this, d); |
114 | |
115 | if constexpr (Concatenable::ExactSize) { |
116 | Q_UNUSED(start) |
117 | } else { |
118 | if (len != d - start) { |
119 | // this resize is necessary since we allocate a bit too much |
120 | // when dealing with variable sized 8-bit encodings |
121 | s.resize(d - start); |
122 | } |
123 | } |
124 | return s; |
125 | } |
126 | |
127 | typedef QConcatenable<QStringBuilder<A, B> > Concatenable; |
128 | public: |
129 | typedef typename Concatenable::ConvertTo ConvertTo; |
130 | operator ConvertTo() const { return convertTo<ConvertTo>(); } |
131 | |
132 | qsizetype size() const { return Concatenable::size(*this); } |
133 | |
134 | bool isNull() const |
135 | { |
136 | return QtStringBuilder::isNull(a) && QtStringBuilder::isNull(b); |
137 | } |
138 | |
139 | A a; |
140 | B b; |
141 | |
142 | private: |
143 | QStringBuilder &operator=(QStringBuilder &&) = delete; |
144 | QStringBuilder &operator=(const QStringBuilder &) = delete; |
145 | }; |
146 | |
147 | template <> struct QConcatenable<char> : private QAbstractConcatenable |
148 | { |
149 | typedef char type; |
150 | typedef QByteArray ConvertTo; |
151 | enum { ExactSize = true }; |
152 | static qsizetype size(const char) { return 1; } |
153 | #ifndef QT_NO_CAST_FROM_ASCII |
154 | QT_ASCII_CAST_WARN static inline void appendTo(const char c, QChar *&out) |
155 | { |
156 | QAbstractConcatenable::convertFromAscii(c, out); |
157 | } |
158 | #endif |
159 | static inline void appendTo(const char c, char *&out) |
160 | { *out++ = c; } |
161 | }; |
162 | |
163 | template <> struct QConcatenable<QByteArrayView> : private QAbstractConcatenable |
164 | { |
165 | typedef QByteArrayView type; |
166 | typedef QByteArray ConvertTo; |
167 | enum { ExactSize = true }; |
168 | static qsizetype size(QByteArrayView bav) { return bav.size(); } |
169 | #ifndef QT_NO_CAST_FROM_ASCII |
170 | QT_ASCII_CAST_WARN static inline void appendTo(QByteArrayView bav, QChar *&out) |
171 | { |
172 | QAbstractConcatenable::convertFromUtf8(bav, out); |
173 | } |
174 | #endif |
175 | static inline void appendTo(QByteArrayView bav, char *&out) |
176 | { |
177 | qsizetype n = bav.size(); |
178 | if (n) |
179 | memcpy(dest: out, src: bav.data(), n: n); |
180 | out += n; |
181 | } |
182 | }; |
183 | |
184 | template <> struct QConcatenable<char16_t> : private QAbstractConcatenable |
185 | { |
186 | typedef char16_t type; |
187 | typedef QString ConvertTo; |
188 | enum { ExactSize = true }; |
189 | static constexpr qsizetype size(char16_t) { return 1; } |
190 | static inline void appendTo(char16_t c, QChar *&out) |
191 | { *out++ = c; } |
192 | }; |
193 | |
194 | template <> struct QConcatenable<QLatin1Char> |
195 | { |
196 | typedef QLatin1Char type; |
197 | typedef QString ConvertTo; |
198 | enum { ExactSize = true }; |
199 | static qsizetype size(const QLatin1Char) { return 1; } |
200 | static inline void appendTo(const QLatin1Char c, QChar *&out) |
201 | { *out++ = c; } |
202 | static inline void appendTo(const QLatin1Char c, char *&out) |
203 | { *out++ = c.toLatin1(); } |
204 | }; |
205 | |
206 | template <> struct QConcatenable<QChar> : private QAbstractConcatenable |
207 | { |
208 | typedef QChar type; |
209 | typedef QString ConvertTo; |
210 | enum { ExactSize = true }; |
211 | static qsizetype size(const QChar) { return 1; } |
212 | static inline void appendTo(const QChar c, QChar *&out) |
213 | { *out++ = c; } |
214 | }; |
215 | |
216 | template <> struct QConcatenable<QChar::SpecialCharacter> : private QAbstractConcatenable |
217 | { |
218 | typedef QChar::SpecialCharacter type; |
219 | typedef QString ConvertTo; |
220 | enum { ExactSize = true }; |
221 | static qsizetype size(const QChar::SpecialCharacter) { return 1; } |
222 | static inline void appendTo(const QChar::SpecialCharacter c, QChar *&out) |
223 | { *out++ = c; } |
224 | }; |
225 | |
226 | template <> struct QConcatenable<QLatin1StringView> : private QAbstractConcatenable |
227 | { |
228 | typedef QLatin1StringView type; |
229 | typedef QString ConvertTo; |
230 | enum { ExactSize = true }; |
231 | static qsizetype size(const QLatin1StringView a) { return a.size(); } |
232 | static inline void appendTo(const QLatin1StringView a, QChar *&out) |
233 | { |
234 | appendLatin1To(in: a, out); |
235 | out += a.size(); |
236 | } |
237 | static inline void appendTo(const QLatin1StringView a, char *&out) |
238 | { |
239 | if (const char *data = a.data()) { |
240 | memcpy(dest: out, src: data, n: a.size()); |
241 | out += a.size(); |
242 | } |
243 | } |
244 | }; |
245 | |
246 | template <> struct QConcatenable<QString> : private QAbstractConcatenable |
247 | { |
248 | typedef QString type; |
249 | typedef QString ConvertTo; |
250 | enum { ExactSize = true }; |
251 | static qsizetype size(const QString &a) { return a.size(); } |
252 | static inline void appendTo(const QString &a, QChar *&out) |
253 | { |
254 | const qsizetype n = a.size(); |
255 | if (n) |
256 | memcpy(dest: out, src: reinterpret_cast<const char*>(a.constData()), n: sizeof(QChar) * n); |
257 | out += n; |
258 | } |
259 | }; |
260 | |
261 | template <> struct QConcatenable<QStringView> : private QAbstractConcatenable |
262 | { |
263 | typedef QStringView type; |
264 | typedef QString ConvertTo; |
265 | enum { ExactSize = true }; |
266 | static qsizetype size(QStringView a) { return a.size(); } |
267 | static inline void appendTo(QStringView a, QChar *&out) |
268 | { |
269 | const auto n = a.size(); |
270 | if (n) |
271 | memcpy(dest: out, src: a.data(), n: sizeof(QChar) * n); |
272 | out += n; |
273 | } |
274 | }; |
275 | |
276 | template <qsizetype N> struct QConcatenable<const char[N]> : private QAbstractConcatenable |
277 | { |
278 | typedef const char type[N]; |
279 | typedef QByteArray ConvertTo; |
280 | enum { ExactSize = false }; |
281 | static qsizetype size(const char[N]) { return N - 1; } |
282 | #ifndef QT_NO_CAST_FROM_ASCII |
283 | QT_ASCII_CAST_WARN static inline void appendTo(const char a[N], QChar *&out) |
284 | { |
285 | QAbstractConcatenable::convertFromUtf8(QByteArrayView(a, N - 1), out); |
286 | } |
287 | #endif |
288 | static inline void appendTo(const char a[N], char *&out) |
289 | { |
290 | while (*a) |
291 | *out++ = *a++; |
292 | } |
293 | }; |
294 | |
295 | template <qsizetype N> struct QConcatenable<char[N]> : QConcatenable<const char[N]> |
296 | { |
297 | typedef char type[N]; |
298 | }; |
299 | |
300 | template <> struct QConcatenable<const char *> : private QAbstractConcatenable |
301 | { |
302 | typedef const char *type; |
303 | typedef QByteArray ConvertTo; |
304 | enum { ExactSize = false }; |
305 | static qsizetype size(const char *a) { return qstrlen(str: a); } |
306 | #ifndef QT_NO_CAST_FROM_ASCII |
307 | QT_ASCII_CAST_WARN static inline void appendTo(const char *a, QChar *&out) |
308 | { QAbstractConcatenable::convertFromUtf8(QByteArrayView(a), out); } |
309 | #endif |
310 | static inline void appendTo(const char *a, char *&out) |
311 | { |
312 | if (!a) |
313 | return; |
314 | while (*a) |
315 | *out++ = *a++; |
316 | } |
317 | }; |
318 | |
319 | template <> struct QConcatenable<char *> : QConcatenable<const char*> |
320 | { |
321 | typedef char *type; |
322 | }; |
323 | |
324 | template <qsizetype N> struct QConcatenable<const char16_t[N]> : private QAbstractConcatenable |
325 | { |
326 | using type = const char16_t[N]; |
327 | using ConvertTo = QString; |
328 | enum { ExactSize = true }; |
329 | static qsizetype size(const char16_t[N]) { return N - 1; } |
330 | static void appendTo(const char16_t a[N], QChar *&out) |
331 | { |
332 | memcpy(static_cast<void *>(out), a, (N - 1) * sizeof(char16_t)); |
333 | out += N - 1; |
334 | } |
335 | }; |
336 | |
337 | template <qsizetype N> struct QConcatenable<char16_t[N]> : QConcatenable<const char16_t[N]> |
338 | { |
339 | using type = char16_t[N]; |
340 | }; |
341 | |
342 | template <> struct QConcatenable<const char16_t *> : private QAbstractConcatenable |
343 | { |
344 | using type = const char16_t *; |
345 | using ConvertTo = QString; |
346 | enum { ExactSize = true }; |
347 | static qsizetype size(const char16_t *a) { return QStringView(a).size(); } |
348 | QT_ASCII_CAST_WARN static inline void appendTo(const char16_t *a, QChar *&out) |
349 | { |
350 | if (!a) |
351 | return; |
352 | while (*a) |
353 | *out++ = *a++; |
354 | } |
355 | }; |
356 | |
357 | template <> struct QConcatenable<char16_t *> : QConcatenable<const char16_t*> |
358 | { |
359 | typedef char16_t *type; |
360 | }; |
361 | |
362 | template <> struct QConcatenable<QByteArray> : private QAbstractConcatenable |
363 | { |
364 | typedef QByteArray type; |
365 | typedef QByteArray ConvertTo; |
366 | enum { ExactSize = false }; |
367 | static qsizetype size(const QByteArray &ba) { return ba.size(); } |
368 | #ifndef QT_NO_CAST_FROM_ASCII |
369 | QT_ASCII_CAST_WARN static inline void appendTo(const QByteArray &ba, QChar *&out) |
370 | { |
371 | QAbstractConcatenable::convertFromUtf8(ba, out); |
372 | } |
373 | #endif |
374 | static inline void appendTo(const QByteArray &ba, char *&out) |
375 | { |
376 | const char *a = ba.constData(); |
377 | const char * const end = ba.end(); |
378 | while (a != end) |
379 | *out++ = *a++; |
380 | } |
381 | }; |
382 | |
383 | |
384 | template <typename A, typename B> |
385 | struct QConcatenable< QStringBuilder<A, B> > |
386 | { |
387 | typedef QStringBuilder<A, B> type; |
388 | using ConvertTo = typename QtStringBuilder::ConvertToTypeHelper< |
389 | typename QConcatenableEx<A>::ConvertTo, |
390 | typename QConcatenableEx<B>::ConvertTo |
391 | >::ConvertTo; |
392 | enum { ExactSize = QConcatenableEx<A>::ExactSize && QConcatenableEx<B>::ExactSize }; |
393 | static qsizetype size(const type &p) |
394 | { |
395 | return QConcatenableEx<A>::size(p.a) + QConcatenableEx<B>::size(p.b); |
396 | } |
397 | template<typename T> static inline void appendTo(const type &p, T *&out) |
398 | { |
399 | QConcatenableEx<A>::appendTo(p.a, out); |
400 | QConcatenableEx<B>::appendTo(p.b, out); |
401 | } |
402 | }; |
403 | |
404 | template <typename A, typename B, |
405 | typename = std::void_t<typename QConcatenableEx<A>::type, typename QConcatenableEx<B>::type>> |
406 | auto operator%(A &&a, B &&b) |
407 | { |
408 | return QStringBuilder<A, B>(std::forward<A>(a), std::forward<B>(b)); |
409 | } |
410 | |
411 | // QT_USE_FAST_OPERATOR_PLUS was introduced in 4.7, QT_USE_QSTRINGBUILDER is to be used from 4.8 onwards |
412 | // QT_USE_FAST_OPERATOR_PLUS does not remove the normal operator+ for QByteArray |
413 | #if defined(QT_USE_FAST_OPERATOR_PLUS) || defined(QT_USE_QSTRINGBUILDER) |
414 | template <typename A, typename B, |
415 | typename = std::void_t<typename QConcatenableEx<A>::type, typename QConcatenableEx<B>::type>> |
416 | auto operator+(A &&a, B &&b) |
417 | { |
418 | return std::forward<A>(a) % std::forward<B>(b); |
419 | } |
420 | #endif |
421 | |
422 | namespace QtStringBuilder { |
423 | template <typename A, typename B> |
424 | QByteArray &appendToByteArray(QByteArray &a, const QStringBuilder<A, B> &b, char) |
425 | { |
426 | // append 8-bit data to a byte array |
427 | qsizetype len = a.size() + QConcatenable< QStringBuilder<A, B> >::size(b); |
428 | a.detach(); // a detach() in a.data() could reset a.capacity() to a.size() |
429 | if (len > a.data_ptr().freeSpaceAtEnd()) // capacity() was broken when prepend()-optimization landed |
430 | a.reserve(asize: qMax(a: len, b: 2 * a.capacity())); |
431 | char *it = a.data() + a.size(); |
432 | QConcatenable< QStringBuilder<A, B> >::appendTo(b, it); |
433 | a.resize(size: len); //we need to resize after the appendTo for the case str+=foo+str |
434 | return a; |
435 | } |
436 | |
437 | #ifndef QT_NO_CAST_TO_ASCII |
438 | template <typename A, typename B> |
439 | QByteArray &appendToByteArray(QByteArray &a, const QStringBuilder<A, B> &b, QChar) |
440 | { |
441 | return a += QString(b).toUtf8(); |
442 | } |
443 | #endif |
444 | } |
445 | |
446 | template <typename A, typename B> |
447 | QByteArray &operator+=(QByteArray &a, const QStringBuilder<A, B> &b) |
448 | { |
449 | return QtStringBuilder::appendToByteArray(a, b, |
450 | typename QConcatenable< QStringBuilder<A, B> >::ConvertTo::value_type()); |
451 | } |
452 | |
453 | template <typename A, typename B> |
454 | QString &operator+=(QString &a, const QStringBuilder<A, B> &b) |
455 | { |
456 | qsizetype len = a.size() + QConcatenable< QStringBuilder<A, B> >::size(b); |
457 | a.detach(); // a detach() in a.data() could reset a.capacity() to a.size() |
458 | if (len > a.data_ptr().freeSpaceAtEnd()) // capacity() was broken when prepend()-optimization landed |
459 | a.reserve(asize: qMax(a: len, b: 2 * a.capacity())); |
460 | QChar *it = a.data() + a.size(); |
461 | QConcatenable< QStringBuilder<A, B> >::appendTo(b, it); |
462 | // we need to resize after the appendTo for the case str+=foo+str |
463 | a.resize(size: it - a.constData()); //may be smaller than len if there was conversion from utf8 |
464 | return a; |
465 | } |
466 | |
467 | QT_END_NAMESPACE |
468 | |
469 | #endif // QSTRINGBUILDER_H |
470 | |