1 | // Copyright (C) 2020 The Qt Company Ltd. |
---|---|
2 | // Copyright (C) 2020 Intel Corporation. |
3 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
4 | |
5 | #include <qstringconverter.h> |
6 | #include <private/qstringconverter_p.h> |
7 | #include "qendian.h" |
8 | |
9 | #include "private/qsimd_p.h" |
10 | #include "private/qstringiterator_p.h" |
11 | #include "private/qtools_p.h" |
12 | #include "qbytearraymatcher.h" |
13 | #include "qcontainertools_impl.h" |
14 | #include <QtCore/qbytearraylist.h> |
15 | |
16 | #if QT_CONFIG(icu) |
17 | #include <unicode/ucnv.h> |
18 | #include <unicode/ucnv_cb.h> |
19 | #include <unicode/ucnv_err.h> |
20 | #include <unicode/ustring.h> |
21 | #endif |
22 | |
23 | #ifdef Q_OS_WIN |
24 | #include <qt_windows.h> |
25 | #ifndef QT_BOOTSTRAPPED |
26 | #include <QtCore/qvarlengtharray.h> |
27 | #include <QtCore/q20iterator.h> |
28 | #include <QtCore/q26numeric.h> |
29 | #endif // !QT_BOOTSTRAPPED |
30 | #endif |
31 | |
32 | #include <array> |
33 | #if __has_include(<bit>) && __cplusplus > 201703L |
34 | #include <bit> |
35 | #endif |
36 | #include <string> |
37 | |
38 | QT_BEGIN_NAMESPACE |
39 | |
40 | using namespace QtMiscUtils; |
41 | |
42 | static_assert(std::is_nothrow_move_constructible_v<QStringEncoder>); |
43 | static_assert(std::is_nothrow_move_assignable_v<QStringEncoder>); |
44 | static_assert(std::is_nothrow_move_constructible_v<QStringDecoder>); |
45 | static_assert(std::is_nothrow_move_assignable_v<QStringDecoder>); |
46 | |
47 | enum { Endian = 0, Data = 1 }; |
48 | |
49 | static const uchar utf8bom[] = { 0xef, 0xbb, 0xbf }; |
50 | |
51 | #if defined(__SSE2__) || defined(__ARM_NEON__) |
52 | static Q_ALWAYS_INLINE uint qBitScanReverse(unsigned v) noexcept |
53 | { |
54 | #if defined(__cpp_lib_int_pow2) && __cpp_lib_int_pow2 >= 202002L |
55 | return std::bit_width(v) - 1; |
56 | #else |
57 | uint result = qCountLeadingZeroBits(v); |
58 | // Now Invert the result: clz will count *down* from the msb to the lsb, so the msb index is 31 |
59 | // and the lsb index is 0. The result for _bit_scan_reverse is expected to be the index when |
60 | // counting up: msb index is 0 (because it starts there), and the lsb index is 31. |
61 | result ^= sizeof(unsigned) * 8 - 1; |
62 | return result; |
63 | #endif |
64 | } |
65 | #endif |
66 | |
67 | #if defined(__SSE2__) |
68 | static inline bool simdEncodeAscii(uchar *&dst, const char16_t *&nextAscii, const char16_t *&src, const char16_t *end) |
69 | { |
70 | // do sixteen characters at a time |
71 | for ( ; end - src >= 16; src += 16, dst += 16) { |
72 | # ifdef __AVX2__ |
73 | __m256i data = _mm256_loadu_si256(reinterpret_cast<const __m256i *>(src)); |
74 | __m128i data1 = _mm256_castsi256_si128(data); |
75 | __m128i data2 = _mm256_extracti128_si256(data, 1); |
76 | # else |
77 | __m128i data1 = _mm_loadu_si128(p: (const __m128i*)src); |
78 | __m128i data2 = _mm_loadu_si128(p: 1+(const __m128i*)src); |
79 | # endif |
80 | |
81 | // check if everything is ASCII |
82 | // the highest ASCII value is U+007F |
83 | // Do the packing directly: |
84 | // The PACKUSWB instruction has packs a signed 16-bit integer to an unsigned 8-bit |
85 | // with saturation. That is, anything from 0x0100 to 0x7fff is saturated to 0xff, |
86 | // while all negatives (0x8000 to 0xffff) get saturated to 0x00. To detect non-ASCII, |
87 | // we simply do a signed greater-than comparison to 0x00. That means we detect NULs as |
88 | // "non-ASCII", but it's an acceptable compromise. |
89 | __m128i packed = _mm_packus_epi16(a: data1, b: data2); |
90 | __m128i nonAscii = _mm_cmpgt_epi8(a: packed, b: _mm_setzero_si128()); |
91 | |
92 | // store, even if there are non-ASCII characters here |
93 | _mm_storeu_si128(p: (__m128i*)dst, b: packed); |
94 | |
95 | // n will contain 1 bit set per character in [data1, data2] that is non-ASCII (or NUL) |
96 | ushort n = ~_mm_movemask_epi8(a: nonAscii); |
97 | if (n) { |
98 | // find the next probable ASCII character |
99 | // we don't want to load 32 bytes again in this loop if we know there are non-ASCII |
100 | // characters still coming |
101 | nextAscii = src + qBitScanReverse(v: n) + 1; |
102 | |
103 | n = qCountTrailingZeroBits(v: n); |
104 | dst += n; |
105 | src += n; |
106 | return false; |
107 | } |
108 | } |
109 | |
110 | if (end - src >= 8) { |
111 | // do eight characters at a time |
112 | __m128i data = _mm_loadu_si128(p: reinterpret_cast<const __m128i *>(src)); |
113 | __m128i packed = _mm_packus_epi16(a: data, b: data); |
114 | __m128i nonAscii = _mm_cmpgt_epi8(a: packed, b: _mm_setzero_si128()); |
115 | |
116 | // store even non-ASCII |
117 | _mm_storel_epi64(p: reinterpret_cast<__m128i *>(dst), a: packed); |
118 | |
119 | uchar n = ~_mm_movemask_epi8(a: nonAscii); |
120 | if (n) { |
121 | nextAscii = src + qBitScanReverse(v: n) + 1; |
122 | n = qCountTrailingZeroBits(v: n); |
123 | dst += n; |
124 | src += n; |
125 | return false; |
126 | } |
127 | } |
128 | |
129 | return src == end; |
130 | } |
131 | |
132 | static inline bool simdDecodeAscii(char16_t *&dst, const uchar *&nextAscii, const uchar *&src, const uchar *end) |
133 | { |
134 | // do sixteen characters at a time |
135 | for ( ; end - src >= 16; src += 16, dst += 16) { |
136 | __m128i data = _mm_loadu_si128(p: (const __m128i*)src); |
137 | |
138 | #ifdef __AVX2__ |
139 | const int BitSpacing = 2; |
140 | // load and zero extend to an YMM register |
141 | const __m256i extended = _mm256_cvtepu8_epi16(data); |
142 | |
143 | uint n = _mm256_movemask_epi8(extended); |
144 | if (!n) { |
145 | // store |
146 | _mm256_storeu_si256((__m256i*)dst, extended); |
147 | continue; |
148 | } |
149 | #else |
150 | const int BitSpacing = 1; |
151 | |
152 | // check if everything is ASCII |
153 | // movemask extracts the high bit of every byte, so n is non-zero if something isn't ASCII |
154 | uint n = _mm_movemask_epi8(a: data); |
155 | if (!n) { |
156 | // unpack |
157 | _mm_storeu_si128(p: (__m128i*)dst, b: _mm_unpacklo_epi8(a: data, b: _mm_setzero_si128())); |
158 | _mm_storeu_si128(p: 1+(__m128i*)dst, b: _mm_unpackhi_epi8(a: data, b: _mm_setzero_si128())); |
159 | continue; |
160 | } |
161 | #endif |
162 | |
163 | // copy the front part that is still ASCII |
164 | while (!(n & 1)) { |
165 | *dst++ = *src++; |
166 | n >>= BitSpacing; |
167 | } |
168 | |
169 | // find the next probable ASCII character |
170 | // we don't want to load 16 bytes again in this loop if we know there are non-ASCII |
171 | // characters still coming |
172 | n = qBitScanReverse(v: n); |
173 | nextAscii = src + (n / BitSpacing) + 1; |
174 | return false; |
175 | |
176 | } |
177 | |
178 | if (end - src >= 8) { |
179 | __m128i data = _mm_loadl_epi64(p: reinterpret_cast<const __m128i *>(src)); |
180 | uint n = _mm_movemask_epi8(a: data) & 0xff; |
181 | if (!n) { |
182 | // unpack and store |
183 | _mm_storeu_si128(p: reinterpret_cast<__m128i *>(dst), b: _mm_unpacklo_epi8(a: data, b: _mm_setzero_si128())); |
184 | } else { |
185 | while (!(n & 1)) { |
186 | *dst++ = *src++; |
187 | n >>= 1; |
188 | } |
189 | |
190 | n = qBitScanReverse(v: n); |
191 | nextAscii = src + n + 1; |
192 | return false; |
193 | } |
194 | } |
195 | |
196 | return src == end; |
197 | } |
198 | |
199 | static inline const uchar *simdFindNonAscii(const uchar *src, const uchar *end, const uchar *&nextAscii) |
200 | { |
201 | #ifdef __AVX2__ |
202 | // do 32 characters at a time |
203 | // (this is similar to simdTestMask in qstring.cpp) |
204 | const __m256i mask = _mm256_set1_epi8(char(0x80)); |
205 | for ( ; end - src >= 32; src += 32) { |
206 | __m256i data = _mm256_loadu_si256(reinterpret_cast<const __m256i *>(src)); |
207 | if (_mm256_testz_si256(mask, data)) |
208 | continue; |
209 | |
210 | uint n = _mm256_movemask_epi8(data); |
211 | Q_ASSERT(n); |
212 | |
213 | // find the next probable ASCII character |
214 | // we don't want to load 32 bytes again in this loop if we know there are non-ASCII |
215 | // characters still coming |
216 | nextAscii = src + qBitScanReverse(n) + 1; |
217 | |
218 | // return the non-ASCII character |
219 | return src + qCountTrailingZeroBits(n); |
220 | } |
221 | #endif |
222 | |
223 | // do sixteen characters at a time |
224 | for ( ; end - src >= 16; src += 16) { |
225 | __m128i data = _mm_loadu_si128(p: reinterpret_cast<const __m128i*>(src)); |
226 | |
227 | // check if everything is ASCII |
228 | // movemask extracts the high bit of every byte, so n is non-zero if something isn't ASCII |
229 | uint n = _mm_movemask_epi8(a: data); |
230 | if (!n) |
231 | continue; |
232 | |
233 | // find the next probable ASCII character |
234 | // we don't want to load 16 bytes again in this loop if we know there are non-ASCII |
235 | // characters still coming |
236 | nextAscii = src + qBitScanReverse(v: n) + 1; |
237 | |
238 | // return the non-ASCII character |
239 | return src + qCountTrailingZeroBits(v: n); |
240 | } |
241 | |
242 | // do four characters at a time |
243 | for ( ; end - src >= 4; src += 4) { |
244 | quint32 data = qFromUnaligned<quint32>(src); |
245 | data &= 0x80808080U; |
246 | if (!data) |
247 | continue; |
248 | |
249 | // We don't try to guess which of the three bytes is ASCII and which |
250 | // one isn't. The chance that at least two of them are non-ASCII is |
251 | // better than 75%. |
252 | nextAscii = src; |
253 | return src; |
254 | } |
255 | nextAscii = end; |
256 | return src; |
257 | } |
258 | |
259 | // Compare only the US-ASCII beginning of [src8, end8) and [src16, end16) |
260 | // and advance src8 and src16 to the first character that could not be compared |
261 | static void simdCompareAscii(const qchar8_t *&src8, const qchar8_t *end8, const char16_t *&src16, const char16_t *end16) |
262 | { |
263 | int bitSpacing = 1; |
264 | qptrdiff len = qMin(a: end8 - src8, b: end16 - src16); |
265 | qptrdiff offset = 0; |
266 | uint mask = 0; |
267 | |
268 | // do sixteen characters at a time |
269 | for ( ; offset + 16 < len; offset += 16) { |
270 | __m128i data8 = _mm_loadu_si128(p: reinterpret_cast<const __m128i *>(src8 + offset)); |
271 | #ifdef __AVX2__ |
272 | // AVX2 version, use 256-bit registers and VPMOVXZBW |
273 | __m256i data16 = _mm256_loadu_si256(reinterpret_cast<const __m256i *>(src16 + offset)); |
274 | |
275 | // expand US-ASCII as if it were Latin1 and confirm it's US-ASCII |
276 | __m256i datax8 = _mm256_cvtepu8_epi16(data8); |
277 | mask = _mm256_movemask_epi8(datax8); |
278 | if (mask) |
279 | break; |
280 | |
281 | // compare Latin1 to UTF-16 |
282 | __m256i latin1cmp = _mm256_cmpeq_epi16(datax8, data16); |
283 | mask = ~_mm256_movemask_epi8(latin1cmp); |
284 | if (mask) |
285 | break; |
286 | #else |
287 | // non-AVX2 code |
288 | __m128i datalo16 = _mm_loadu_si128(p: reinterpret_cast<const __m128i *>(src16 + offset)); |
289 | __m128i datahi16 = _mm_loadu_si128(p: reinterpret_cast<const __m128i *>(src16 + offset) + 1); |
290 | |
291 | // expand US-ASCII as if it were Latin1, we'll confirm later |
292 | __m128i datalo8 = _mm_unpacklo_epi8(a: data8, b: _mm_setzero_si128()); |
293 | __m128i datahi8 = _mm_unpackhi_epi8(a: data8, b: _mm_setzero_si128()); |
294 | |
295 | // compare Latin1 to UTF-16 |
296 | __m128i latin1cmplo = _mm_cmpeq_epi16(a: datalo8, b: datalo16); |
297 | __m128i latin1cmphi = _mm_cmpeq_epi16(a: datahi8, b: datahi16); |
298 | mask = _mm_movemask_epi8(a: latin1cmphi) << 16; |
299 | mask |= ushort(_mm_movemask_epi8(a: latin1cmplo)); |
300 | mask = ~mask; |
301 | if (mask) |
302 | break; |
303 | |
304 | // confirm it was US-ASCII |
305 | mask = _mm_movemask_epi8(a: data8); |
306 | if (mask) { |
307 | bitSpacing = 0; |
308 | break; |
309 | } |
310 | #endif |
311 | } |
312 | |
313 | // helper for comparing 4 or 8 characters |
314 | auto cmp_lt_16 = [&mask, &offset](int n, __m128i data8, __m128i data16) { |
315 | // n = 4 -> sizemask = 0xff |
316 | // n = 8 -> sizemask = 0xffff |
317 | unsigned sizemask = (1U << (2 * n)) - 1; |
318 | |
319 | // expand as if Latin1 |
320 | data8 = _mm_unpacklo_epi8(a: data8, b: _mm_setzero_si128()); |
321 | |
322 | // compare and confirm it's US-ASCII |
323 | __m128i latin1cmp = _mm_cmpeq_epi16(a: data8, b: data16); |
324 | mask = ~_mm_movemask_epi8(a: latin1cmp) & sizemask; |
325 | mask |= _mm_movemask_epi8(a: data8); |
326 | if (mask == 0) |
327 | offset += n; |
328 | }; |
329 | |
330 | // do eight characters at a time |
331 | if (mask == 0 && offset + 8 < len) { |
332 | __m128i data8 = _mm_loadl_epi64(p: reinterpret_cast<const __m128i *>(src8 + offset)); |
333 | __m128i data16 = _mm_loadu_si128(p: reinterpret_cast<const __m128i *>(src16 + offset)); |
334 | cmp_lt_16(8, data8, data16); |
335 | } |
336 | |
337 | // do four characters |
338 | if (mask == 0 && offset + 4 < len) { |
339 | __m128i data8 = _mm_cvtsi32_si128(a: qFromUnaligned<quint32>(src: src8 + offset)); |
340 | __m128i data16 = _mm_loadl_epi64(p: reinterpret_cast<const __m128i *>(src16 + offset)); |
341 | cmp_lt_16(4, data8, data16); |
342 | } |
343 | |
344 | // correct the source pointers to point to the first character we couldn't deal with |
345 | if (mask) |
346 | offset += qCountTrailingZeroBits(v: mask) >> bitSpacing; |
347 | src8 += offset; |
348 | src16 += offset; |
349 | } |
350 | #elif defined(__ARM_NEON__) |
351 | static inline bool simdEncodeAscii(uchar *&dst, const char16_t *&nextAscii, const char16_t *&src, const char16_t *end) |
352 | { |
353 | uint16x8_t maxAscii = vdupq_n_u16(0x7f); |
354 | uint16x8_t mask1 = qvsetq_n_u16(1, 1 << 2, 1 << 4, 1 << 6, 1 << 8, 1 << 10, 1 << 12, 1 << 14 ); |
355 | uint16x8_t mask2 = vshlq_n_u16(mask1, 1); |
356 | |
357 | // do sixteen characters at a time |
358 | for ( ; end - src >= 16; src += 16, dst += 16) { |
359 | // load 2 lanes (or: "load interleaved") |
360 | uint16x8x2_t in = vld2q_u16(reinterpret_cast<const uint16_t *>(src)); |
361 | |
362 | // check if any of the elements > 0x7f, select 1 bit per element (element 0 -> bit 0, element 1 -> bit 1, etc), |
363 | // add those together into a scalar, and merge the scalars. |
364 | uint16_t nonAscii = vaddvq_u16(vandq_u16(vcgtq_u16(in.val[0], maxAscii), mask1)) |
365 | | vaddvq_u16(vandq_u16(vcgtq_u16(in.val[1], maxAscii), mask2)); |
366 | |
367 | // merge the two lanes by shifting the values of the second by 8 and inserting them |
368 | uint16x8_t out = vsliq_n_u16(in.val[0], in.val[1], 8); |
369 | |
370 | // store, even if there are non-ASCII characters here |
371 | vst1q_u8(dst, vreinterpretq_u8_u16(out)); |
372 | |
373 | if (nonAscii) { |
374 | // find the next probable ASCII character |
375 | // we don't want to load 32 bytes again in this loop if we know there are non-ASCII |
376 | // characters still coming |
377 | nextAscii = src + qBitScanReverse(nonAscii) + 1; |
378 | |
379 | nonAscii = qCountTrailingZeroBits(nonAscii); |
380 | dst += nonAscii; |
381 | src += nonAscii; |
382 | return false; |
383 | } |
384 | } |
385 | return src == end; |
386 | } |
387 | |
388 | static inline bool simdDecodeAscii(char16_t *&dst, const uchar *&nextAscii, const uchar *&src, const uchar *end) |
389 | { |
390 | // do eight characters at a time |
391 | uint8x8_t msb_mask = vdup_n_u8(0x80); |
392 | uint8x8_t add_mask = qvset_n_u8(1, 1 << 1, 1 << 2, 1 << 3, 1 << 4, 1 << 5, 1 << 6, 1 << 7 ); |
393 | for ( ; end - src >= 8; src += 8, dst += 8) { |
394 | uint8x8_t c = vld1_u8(src); |
395 | uint8_t n = vaddv_u8(vand_u8(vcge_u8(c, msb_mask), add_mask)); |
396 | if (!n) { |
397 | // store |
398 | vst1q_u16(reinterpret_cast<uint16_t *>(dst), vmovl_u8(c)); |
399 | continue; |
400 | } |
401 | |
402 | // copy the front part that is still ASCII |
403 | while (!(n & 1)) { |
404 | *dst++ = *src++; |
405 | n >>= 1; |
406 | } |
407 | |
408 | // find the next probable ASCII character |
409 | // we don't want to load 16 bytes again in this loop if we know there are non-ASCII |
410 | // characters still coming |
411 | n = qBitScanReverse(n); |
412 | nextAscii = src + n + 1; |
413 | return false; |
414 | |
415 | } |
416 | return src == end; |
417 | } |
418 | |
419 | static inline const uchar *simdFindNonAscii(const uchar *src, const uchar *end, const uchar *&nextAscii) |
420 | { |
421 | // The SIMD code below is untested, so just force an early return until |
422 | // we've had the time to verify it works. |
423 | nextAscii = end; |
424 | return src; |
425 | |
426 | // do eight characters at a time |
427 | uint8x8_t msb_mask = vdup_n_u8(0x80); |
428 | uint8x8_t add_mask = qvset_n_u8(1, 1 << 1, 1 << 2, 1 << 3, 1 << 4, 1 << 5, 1 << 6, 1 << 7); |
429 | for ( ; end - src >= 8; src += 8) { |
430 | uint8x8_t c = vld1_u8(src); |
431 | uint8_t n = vaddv_u8(vand_u8(vcge_u8(c, msb_mask), add_mask)); |
432 | if (!n) |
433 | continue; |
434 | |
435 | // find the next probable ASCII character |
436 | // we don't want to load 16 bytes again in this loop if we know there are non-ASCII |
437 | // characters still coming |
438 | nextAscii = src + qBitScanReverse(n) + 1; |
439 | |
440 | // return the non-ASCII character |
441 | return src + qCountTrailingZeroBits(n); |
442 | } |
443 | nextAscii = end; |
444 | return src; |
445 | } |
446 | |
447 | static void simdCompareAscii(const qchar8_t *&, const qchar8_t *, const char16_t *&, const char16_t *) |
448 | { |
449 | } |
450 | #else |
451 | static inline bool simdEncodeAscii(uchar *, const char16_t *, const char16_t *, const char16_t *) |
452 | { |
453 | return false; |
454 | } |
455 | |
456 | static inline bool simdDecodeAscii(char16_t *, const uchar *, const uchar *, const uchar *) |
457 | { |
458 | return false; |
459 | } |
460 | |
461 | static inline const uchar *simdFindNonAscii(const uchar *src, const uchar *end, const uchar *&nextAscii) |
462 | { |
463 | nextAscii = end; |
464 | return src; |
465 | } |
466 | |
467 | static void simdCompareAscii(const qchar8_t *&, const qchar8_t *, const char16_t *&, const char16_t *) |
468 | { |
469 | } |
470 | #endif |
471 | |
472 | enum { HeaderDone = 1 }; |
473 | |
474 | QByteArray QUtf8::convertFromUnicode(QStringView in) |
475 | { |
476 | qsizetype len = in.size(); |
477 | |
478 | // create a QByteArray with the worst case scenario size |
479 | QByteArray result(len * 3, Qt::Uninitialized); |
480 | uchar *dst = reinterpret_cast<uchar *>(const_cast<char *>(result.constData())); |
481 | const char16_t *src = reinterpret_cast<const char16_t *>(in.data()); |
482 | const char16_t *const end = src + len; |
483 | |
484 | while (src != end) { |
485 | const char16_t *nextAscii = end; |
486 | if (simdEncodeAscii(dst, nextAscii, src, end)) |
487 | break; |
488 | |
489 | do { |
490 | char16_t u = *src++; |
491 | int res = QUtf8Functions::toUtf8<QUtf8BaseTraits>(u, dst, src, end); |
492 | if (res < 0) { |
493 | // encoding error - append '?' |
494 | *dst++ = '?'; |
495 | } |
496 | } while (src < nextAscii); |
497 | } |
498 | |
499 | result.truncate(pos: dst - reinterpret_cast<uchar *>(const_cast<char *>(result.constData()))); |
500 | return result; |
501 | } |
502 | |
503 | QByteArray QUtf8::convertFromUnicode(QStringView in, QStringConverterBase::State *state) |
504 | { |
505 | QByteArray ba(3*in.size() +3, Qt::Uninitialized); |
506 | char *end = convertFromUnicode(out: ba.data(), in, state); |
507 | ba.truncate(pos: end - ba.data()); |
508 | return ba; |
509 | } |
510 | |
511 | char *QUtf8::convertFromUnicode(char *out, QStringView in, QStringConverter::State *state) |
512 | { |
513 | Q_ASSERT(state); |
514 | qsizetype len = in.size(); |
515 | if (!len) |
516 | return out; |
517 | |
518 | auto appendReplacementChar = [state](uchar *cursor) -> uchar * { |
519 | if (state->flags & QStringConverter::Flag::ConvertInvalidToNull) { |
520 | *cursor++ = 0; |
521 | } else { |
522 | // QChar::replacement encoded in utf8 |
523 | *cursor++ = 0xef; |
524 | *cursor++ = 0xbf; |
525 | *cursor++ = 0xbd; |
526 | } |
527 | return cursor; |
528 | }; |
529 | |
530 | uchar *cursor = reinterpret_cast<uchar *>(out); |
531 | const char16_t *src = in.utf16(); |
532 | const char16_t *const end = src + len; |
533 | |
534 | if (!(state->flags & QStringDecoder::Flag::Stateless)) { |
535 | if (state->remainingChars) { |
536 | int res = QUtf8Functions::toUtf8<QUtf8BaseTraits>(u: state->state_data[0], dst&: cursor, src, end); |
537 | if (res < 0) |
538 | cursor = appendReplacementChar(cursor); |
539 | state->state_data[0] = 0; |
540 | state->remainingChars = 0; |
541 | } else if (!(state->internalState & HeaderDone) && state->flags & QStringConverter::Flag::WriteBom) { |
542 | // append UTF-8 BOM |
543 | *cursor++ = utf8bom[0]; |
544 | *cursor++ = utf8bom[1]; |
545 | *cursor++ = utf8bom[2]; |
546 | state->internalState |= HeaderDone; |
547 | } |
548 | } |
549 | |
550 | while (src != end) { |
551 | const char16_t *nextAscii = end; |
552 | if (simdEncodeAscii(dst&: cursor, nextAscii, src, end)) |
553 | break; |
554 | |
555 | do { |
556 | char16_t uc = *src++; |
557 | int res = QUtf8Functions::toUtf8<QUtf8BaseTraits>(u: uc, dst&: cursor, src, end); |
558 | if (Q_LIKELY(res >= 0)) |
559 | continue; |
560 | |
561 | if (res == QUtf8BaseTraits::Error) { |
562 | // encoding error |
563 | ++state->invalidChars; |
564 | cursor = appendReplacementChar(cursor); |
565 | } else if (res == QUtf8BaseTraits::EndOfString) { |
566 | if (state->flags & QStringConverter::Flag::Stateless) { |
567 | ++state->invalidChars; |
568 | cursor = appendReplacementChar(cursor); |
569 | } else { |
570 | state->remainingChars = 1; |
571 | state->state_data[0] = uc; |
572 | } |
573 | return reinterpret_cast<char *>(cursor); |
574 | } |
575 | } while (src < nextAscii); |
576 | } |
577 | |
578 | return reinterpret_cast<char *>(cursor); |
579 | } |
580 | |
581 | char *QUtf8::convertFromLatin1(char *out, QLatin1StringView in) |
582 | { |
583 | // ### SIMD-optimize: |
584 | for (uchar ch : in) { |
585 | if (ch < 128) { |
586 | *out++ = ch; |
587 | } else { |
588 | // as per https://en.wikipedia.org/wiki/UTF-8#Encoding, 2nd row |
589 | *out++ = 0b110'0'0000u | (ch >> 6); |
590 | *out++ = 0b10'00'0000u | (ch & 0b0011'1111); |
591 | } |
592 | } |
593 | return out; |
594 | } |
595 | |
596 | QString QUtf8::convertToUnicode(QByteArrayView in) |
597 | { |
598 | // UTF-8 to UTF-16 always needs the exact same number of words or less: |
599 | // UTF-8 UTF-16 |
600 | // 1 byte 1 word |
601 | // 2 bytes 1 word |
602 | // 3 bytes 1 word |
603 | // 4 bytes 2 words (one surrogate pair) |
604 | // That is, we'll use the full buffer if the input is US-ASCII (1-byte UTF-8), |
605 | // half the buffer for U+0080-U+07FF text (e.g., Greek, Cyrillic, Arabic) or |
606 | // non-BMP text, and one third of the buffer for U+0800-U+FFFF text (e.g, CJK). |
607 | // |
608 | // The table holds for invalid sequences too: we'll insert one replacement char |
609 | // per invalid byte. |
610 | QString result(in.size(), Qt::Uninitialized); |
611 | QChar *data = const_cast<QChar*>(result.constData()); // we know we're not shared |
612 | const QChar *end = convertToUnicode(buffer: data, in); |
613 | result.truncate(pos: end - data); |
614 | return result; |
615 | } |
616 | |
617 | /*! \internal |
618 | \since 6.6 |
619 | \overload |
620 | |
621 | Converts the UTF-8 sequence of bytes viewed by \a in to a sequence of |
622 | QChar starting at \a dst in the destination buffer. The buffer is expected |
623 | to be large enough to hold the result. An upper bound for the size of the |
624 | buffer is \c in.size() QChars. |
625 | |
626 | If, during decoding, an error occurs, a QChar::ReplacementCharacter is |
627 | written. |
628 | |
629 | Returns a pointer to one past the last QChar written. |
630 | |
631 | This function never throws. |
632 | |
633 | For QChar buffers, instead of casting manually, you can use the static |
634 | QUtf8::convertToUnicode(QChar *, QByteArrayView) directly. |
635 | */ |
636 | char16_t *QUtf8::convertToUnicode(char16_t *dst, QByteArrayView in) noexcept |
637 | { |
638 | const uchar *const start = reinterpret_cast<const uchar *>(in.data()); |
639 | const uchar *src = start; |
640 | const uchar *end = src + in.size(); |
641 | |
642 | // attempt to do a full decoding in SIMD |
643 | const uchar *nextAscii = end; |
644 | if (!simdDecodeAscii(dst, nextAscii, src, end)) { |
645 | // at least one non-ASCII entry |
646 | // check if we failed to decode the UTF-8 BOM; if so, skip it |
647 | if (Q_UNLIKELY(src == start) |
648 | && end - src >= 3 |
649 | && Q_UNLIKELY(src[0] == utf8bom[0] && src[1] == utf8bom[1] && src[2] == utf8bom[2])) { |
650 | src += 3; |
651 | } |
652 | |
653 | while (src < end) { |
654 | nextAscii = end; |
655 | if (simdDecodeAscii(dst, nextAscii, src, end)) |
656 | break; |
657 | |
658 | do { |
659 | uchar b = *src++; |
660 | const qsizetype res = QUtf8Functions::fromUtf8<QUtf8BaseTraits>(b, dst, src, end); |
661 | if (res < 0) { |
662 | // decoding error |
663 | *dst++ = QChar::ReplacementCharacter; |
664 | } |
665 | } while (src < nextAscii); |
666 | } |
667 | } |
668 | |
669 | return dst; |
670 | } |
671 | |
672 | QString QUtf8::convertToUnicode(QByteArrayView in, QStringConverter::State *state) |
673 | { |
674 | // See above for buffer requirements for stateless decoding. However, that |
675 | // fails if the state is not empty. The following situations can add to the |
676 | // requirements: |
677 | // state contains chars starts with requirement |
678 | // 1 of 2 bytes valid continuation 0 |
679 | // 2 of 3 bytes same 0 |
680 | // 3 bytes of 4 same +1 (need to insert surrogate pair) |
681 | // 1 of 2 bytes invalid continuation +1 (need to insert replacement and restart) |
682 | // 2 of 3 bytes same +1 (same) |
683 | // 3 of 4 bytes same +1 (same) |
684 | QString result(in.size() + 1, Qt::Uninitialized); |
685 | QChar *end = convertToUnicode(out: result.data(), in, state); |
686 | result.truncate(pos: end - result.constData()); |
687 | return result; |
688 | } |
689 | |
690 | char16_t *QUtf8::convertToUnicode(char16_t *dst, QByteArrayView in, QStringConverter::State *state) |
691 | { |
692 | qsizetype len = in.size(); |
693 | |
694 | Q_ASSERT(state); |
695 | if (!len) |
696 | return dst; |
697 | |
698 | |
699 | char16_t replacement = QChar::ReplacementCharacter; |
700 | if (state->flags & QStringConverter::Flag::ConvertInvalidToNull) |
701 | replacement = QChar::Null; |
702 | |
703 | qsizetype res; |
704 | uchar ch = 0; |
705 | |
706 | const uchar *src = reinterpret_cast<const uchar *>(in.data()); |
707 | const uchar *end = src + len; |
708 | |
709 | if (!(state->flags & QStringConverter::Flag::Stateless)) { |
710 | bool headerdone = state->internalState & HeaderDone || state->flags & QStringConverter::Flag::ConvertInitialBom; |
711 | if (state->remainingChars || !headerdone) { |
712 | // handle incoming state first |
713 | uchar remainingCharsData[4]; // longest UTF-8 sequence possible |
714 | qsizetype remainingCharsCount = state->remainingChars; |
715 | qsizetype newCharsToCopy = qMin<qsizetype>(a: sizeof(remainingCharsData) - remainingCharsCount, b: end - src); |
716 | |
717 | memset(s: remainingCharsData, c: 0, n: sizeof(remainingCharsData)); |
718 | memcpy(dest: remainingCharsData, src: &state->state_data[0], n: remainingCharsCount); |
719 | memcpy(dest: remainingCharsData + remainingCharsCount, src: src, n: newCharsToCopy); |
720 | |
721 | const uchar *begin = &remainingCharsData[1]; |
722 | res = QUtf8Functions::fromUtf8<QUtf8BaseTraits>(b: remainingCharsData[0], dst, src&: begin, |
723 | end: static_cast<const uchar *>(remainingCharsData) + remainingCharsCount + newCharsToCopy); |
724 | if (res == QUtf8BaseTraits::Error) { |
725 | ++state->invalidChars; |
726 | *dst++ = replacement; |
727 | ++src; |
728 | } else if (res == QUtf8BaseTraits::EndOfString) { |
729 | // if we got EndOfString again, then there were too few bytes in src; |
730 | // copy to our state and return |
731 | state->remainingChars = remainingCharsCount + newCharsToCopy; |
732 | memcpy(dest: &state->state_data[0], src: remainingCharsData, n: state->remainingChars); |
733 | return dst; |
734 | } else if (!headerdone) { |
735 | // eat the UTF-8 BOM |
736 | if (dst[-1] == 0xfeff) |
737 | --dst; |
738 | } |
739 | state->internalState |= HeaderDone; |
740 | |
741 | // adjust src now that we have maybe consumed a few chars |
742 | if (res >= 0) { |
743 | Q_ASSERT(res > remainingCharsCount); |
744 | src += res - remainingCharsCount; |
745 | } |
746 | } |
747 | } else if (!(state->flags & QStringConverter::Flag::ConvertInitialBom)) { |
748 | // stateless, remove initial BOM |
749 | if (len > 2 && src[0] == utf8bom[0] && src[1] == utf8bom[1] && src[2] == utf8bom[2]) |
750 | // skip BOM |
751 | src += 3; |
752 | } |
753 | |
754 | // main body, stateless decoding |
755 | res = 0; |
756 | const uchar *nextAscii = src; |
757 | while (res >= 0 && src < end) { |
758 | if (src >= nextAscii && simdDecodeAscii(dst, nextAscii, src, end)) |
759 | break; |
760 | |
761 | ch = *src++; |
762 | res = QUtf8Functions::fromUtf8<QUtf8BaseTraits>(b: ch, dst, src, end); |
763 | if (res == QUtf8BaseTraits::Error) { |
764 | res = 0; |
765 | ++state->invalidChars; |
766 | *dst++ = replacement; |
767 | } |
768 | } |
769 | |
770 | if (res == QUtf8BaseTraits::EndOfString) { |
771 | // unterminated UTF sequence |
772 | if (state->flags & QStringConverter::Flag::Stateless) { |
773 | *dst++ = QChar::ReplacementCharacter; |
774 | ++state->invalidChars; |
775 | while (src++ < end) { |
776 | *dst++ = QChar::ReplacementCharacter; |
777 | ++state->invalidChars; |
778 | } |
779 | state->remainingChars = 0; |
780 | } else { |
781 | --src; // unread the byte in ch |
782 | state->remainingChars = end - src; |
783 | memcpy(dest: &state->state_data[0], src: src, n: end - src); |
784 | } |
785 | } else { |
786 | state->remainingChars = 0; |
787 | } |
788 | |
789 | return dst; |
790 | } |
791 | |
792 | struct QUtf8NoOutputTraits : public QUtf8BaseTraitsNoAscii |
793 | { |
794 | struct NoOutput {}; |
795 | static void appendUtf16(const NoOutput &, char16_t) {} |
796 | static void appendUcs4(const NoOutput &, char32_t) {} |
797 | }; |
798 | |
799 | QUtf8::ValidUtf8Result QUtf8::isValidUtf8(QByteArrayView in) |
800 | { |
801 | const uchar *src = reinterpret_cast<const uchar *>(in.data()); |
802 | const uchar *end = src + in.size(); |
803 | const uchar *nextAscii = src; |
804 | bool isValidAscii = true; |
805 | |
806 | while (src < end) { |
807 | if (src >= nextAscii) |
808 | src = simdFindNonAscii(src, end, nextAscii); |
809 | if (src == end) |
810 | break; |
811 | |
812 | do { |
813 | uchar b = *src++; |
814 | if ((b & 0x80) == 0) |
815 | continue; |
816 | |
817 | isValidAscii = false; |
818 | QUtf8NoOutputTraits::NoOutput output; |
819 | const qsizetype res = QUtf8Functions::fromUtf8<QUtf8NoOutputTraits>(b, dst&: output, src, end); |
820 | if (res < 0) { |
821 | // decoding error |
822 | return { .isValidUtf8: false, .isValidAscii: false }; |
823 | } |
824 | } while (src < nextAscii); |
825 | } |
826 | |
827 | return { .isValidUtf8: true, .isValidAscii: isValidAscii }; |
828 | } |
829 | |
830 | int QUtf8::compareUtf8(QByteArrayView utf8, QStringView utf16, Qt::CaseSensitivity cs) noexcept |
831 | { |
832 | auto src1 = reinterpret_cast<const qchar8_t *>(utf8.data()); |
833 | auto end1 = src1 + utf8.size(); |
834 | auto src2 = reinterpret_cast<const char16_t *>(utf16.data()); |
835 | auto end2 = src2 + utf16.size(); |
836 | |
837 | do { |
838 | simdCompareAscii(src8&: src1, end8: end1, src16&: src2, end16: end2); |
839 | |
840 | if (src1 < end1 && src2 < end2) { |
841 | char32_t uc1 = *src1++; |
842 | char32_t uc2 = *src2++; |
843 | |
844 | if (uc1 >= 0x80) { |
845 | char32_t *output = &uc1; |
846 | qsizetype res = QUtf8Functions::fromUtf8<QUtf8BaseTraitsNoAscii>(b: uc1, dst&: output, src&: src1, end: end1); |
847 | if (res < 0) { |
848 | // decoding error |
849 | uc1 = QChar::ReplacementCharacter; |
850 | } |
851 | |
852 | // Only decode the UTF-16 surrogate pair if the UTF-8 code point |
853 | // wasn't US-ASCII (a surrogate cannot match US-ASCII). |
854 | if (QChar::isHighSurrogate(ucs4: uc2) && src2 < end2 && QChar::isLowSurrogate(ucs4: *src2)) |
855 | uc2 = QChar::surrogateToUcs4(high: uc2, low: *src2++); |
856 | } |
857 | if (cs == Qt::CaseInsensitive) { |
858 | uc1 = QChar::toCaseFolded(ucs4: uc1); |
859 | uc2 = QChar::toCaseFolded(ucs4: uc2); |
860 | } |
861 | if (uc1 != uc2) |
862 | return int(uc1) - int(uc2); |
863 | } |
864 | } while (src1 < end1 && src2 < end2); |
865 | |
866 | // the shorter string sorts first |
867 | return (end1 > src1) - int(end2 > src2); |
868 | } |
869 | |
870 | int QUtf8::compareUtf8(QByteArrayView utf8, QLatin1StringView s, Qt::CaseSensitivity cs) |
871 | { |
872 | char32_t uc1 = QChar::Null; |
873 | auto src1 = reinterpret_cast<const uchar *>(utf8.data()); |
874 | auto end1 = src1 + utf8.size(); |
875 | auto src2 = reinterpret_cast<const uchar *>(s.latin1()); |
876 | auto end2 = src2 + s.size(); |
877 | |
878 | while (src1 < end1 && src2 < end2) { |
879 | uchar b = *src1++; |
880 | char32_t *output = &uc1; |
881 | const qsizetype res = QUtf8Functions::fromUtf8<QUtf8BaseTraits>(b, dst&: output, src&: src1, end: end1); |
882 | if (res < 0) { |
883 | // decoding error |
884 | uc1 = QChar::ReplacementCharacter; |
885 | } |
886 | |
887 | char32_t uc2 = *src2++; |
888 | if (cs == Qt::CaseInsensitive) { |
889 | uc1 = QChar::toCaseFolded(ucs4: uc1); |
890 | uc2 = QChar::toCaseFolded(ucs4: uc2); |
891 | } |
892 | if (uc1 != uc2) |
893 | return int(uc1) - int(uc2); |
894 | } |
895 | |
896 | // the shorter string sorts first |
897 | return (end1 > src1) - (end2 > src2); |
898 | } |
899 | |
900 | int QUtf8::compareUtf8(QByteArrayView lhs, QByteArrayView rhs, Qt::CaseSensitivity cs) noexcept |
901 | { |
902 | if (lhs.isEmpty()) |
903 | return qt_lencmp(lhs: 0, rhs: rhs.size()); |
904 | |
905 | if (cs == Qt::CaseSensitive) { |
906 | const auto l = std::min(a: lhs.size(), b: rhs.size()); |
907 | int r = memcmp(s1: lhs.data(), s2: rhs.data(), n: l); |
908 | return r ? r : qt_lencmp(lhs: lhs.size(), rhs: rhs.size()); |
909 | } |
910 | |
911 | char32_t uc1 = QChar::Null; |
912 | auto src1 = reinterpret_cast<const uchar *>(lhs.data()); |
913 | auto end1 = src1 + lhs.size(); |
914 | char32_t uc2 = QChar::Null; |
915 | auto src2 = reinterpret_cast<const uchar *>(rhs.data()); |
916 | auto end2 = src2 + rhs.size(); |
917 | |
918 | while (src1 < end1 && src2 < end2) { |
919 | uchar b = *src1++; |
920 | char32_t *output = &uc1; |
921 | qsizetype res = QUtf8Functions::fromUtf8<QUtf8BaseTraits>(b, dst&: output, src&: src1, end: end1); |
922 | if (res < 0) { |
923 | // decoding error |
924 | uc1 = QChar::ReplacementCharacter; |
925 | } |
926 | |
927 | b = *src2++; |
928 | output = &uc2; |
929 | res = QUtf8Functions::fromUtf8<QUtf8BaseTraits>(b, dst&: output, src&: src2, end: end2); |
930 | if (res < 0) { |
931 | // decoding error |
932 | uc2 = QChar::ReplacementCharacter; |
933 | } |
934 | |
935 | uc1 = QChar::toCaseFolded(ucs4: uc1); |
936 | uc2 = QChar::toCaseFolded(ucs4: uc2); |
937 | if (uc1 != uc2) |
938 | return int(uc1) - int(uc2); |
939 | } |
940 | |
941 | // the shorter string sorts first |
942 | return (end1 > src1) - (end2 > src2); |
943 | } |
944 | |
945 | #ifndef QT_BOOTSTRAPPED |
946 | QByteArray QUtf16::convertFromUnicode(QStringView in, QStringConverter::State *state, DataEndianness endian) |
947 | { |
948 | bool writeBom = !(state->internalState & HeaderDone) && state->flags & QStringConverter::Flag::WriteBom; |
949 | qsizetype length = 2 * in.size(); |
950 | if (writeBom) |
951 | length += 2; |
952 | |
953 | QByteArray d(length, Qt::Uninitialized); |
954 | char *end = convertFromUnicode(out: d.data(), in, state, endian); |
955 | Q_ASSERT(end - d.constData() == d.size()); |
956 | Q_UNUSED(end); |
957 | return d; |
958 | } |
959 | |
960 | char *QUtf16::convertFromUnicode(char *out, QStringView in, QStringConverter::State *state, DataEndianness endian) |
961 | { |
962 | Q_ASSERT(state); |
963 | bool writeBom = !(state->internalState & HeaderDone) && state->flags & QStringConverter::Flag::WriteBom; |
964 | |
965 | if (endian == DetectEndianness) |
966 | endian = (QSysInfo::ByteOrder == QSysInfo::BigEndian) ? BigEndianness : LittleEndianness; |
967 | |
968 | if (writeBom) { |
969 | // set them up the BOM |
970 | QChar bom(QChar::ByteOrderMark); |
971 | if (endian == BigEndianness) |
972 | qToBigEndian(src: bom.unicode(), dest: out); |
973 | else |
974 | qToLittleEndian(src: bom.unicode(), dest: out); |
975 | out += 2; |
976 | } |
977 | if (endian == BigEndianness) |
978 | qToBigEndian<char16_t>(source: in.data(), count: in.size(), dest: out); |
979 | else |
980 | qToLittleEndian<char16_t>(source: in.data(), count: in.size(), dest: out); |
981 | |
982 | state->remainingChars = 0; |
983 | state->internalState |= HeaderDone; |
984 | return out + 2*in.size(); |
985 | } |
986 | |
987 | QString QUtf16::convertToUnicode(QByteArrayView in, QStringConverter::State *state, DataEndianness endian) |
988 | { |
989 | QString result((in.size() + 1) >> 1, Qt::Uninitialized); // worst case |
990 | QChar *qch = convertToUnicode(out: result.data(), in, state, endian); |
991 | result.truncate(pos: qch - result.constData()); |
992 | return result; |
993 | } |
994 | |
995 | QChar *QUtf16::convertToUnicode(QChar *out, QByteArrayView in, QStringConverter::State *state, DataEndianness endian) |
996 | { |
997 | qsizetype len = in.size(); |
998 | const char *chars = in.data(); |
999 | |
1000 | Q_ASSERT(state); |
1001 | |
1002 | if (endian == DetectEndianness) |
1003 | endian = (DataEndianness)state->state_data[Endian]; |
1004 | |
1005 | const char *end = chars + len; |
1006 | |
1007 | // make sure we can decode at least one char |
1008 | if (state->remainingChars + len < 2) { |
1009 | if (len) { |
1010 | Q_ASSERT(state->remainingChars == 0 && len == 1); |
1011 | state->remainingChars = 1; |
1012 | state->state_data[Data] = *chars; |
1013 | } |
1014 | return out; |
1015 | } |
1016 | |
1017 | bool headerdone = state && state->internalState & HeaderDone; |
1018 | if (state->flags & QStringConverter::Flag::ConvertInitialBom) |
1019 | headerdone = true; |
1020 | |
1021 | if (!headerdone || state->remainingChars) { |
1022 | uchar buf; |
1023 | if (state->remainingChars) |
1024 | buf = state->state_data[Data]; |
1025 | else |
1026 | buf = *chars++; |
1027 | |
1028 | // detect BOM, set endianness |
1029 | state->internalState |= HeaderDone; |
1030 | QChar ch(buf, *chars++); |
1031 | if (endian == DetectEndianness) { |
1032 | // someone set us up the BOM |
1033 | if (ch == QChar::ByteOrderSwapped) { |
1034 | endian = BigEndianness; |
1035 | } else if (ch == QChar::ByteOrderMark) { |
1036 | endian = LittleEndianness; |
1037 | } else { |
1038 | if (QSysInfo::ByteOrder == QSysInfo::BigEndian) { |
1039 | endian = BigEndianness; |
1040 | } else { |
1041 | endian = LittleEndianness; |
1042 | } |
1043 | } |
1044 | } |
1045 | if (endian == BigEndianness) |
1046 | ch = QChar::fromUcs2(c: (ch.unicode() >> 8) | ((ch.unicode() & 0xff) << 8)); |
1047 | if (headerdone || ch != QChar::ByteOrderMark) |
1048 | *out++ = ch; |
1049 | } else if (endian == DetectEndianness) { |
1050 | endian = (QSysInfo::ByteOrder == QSysInfo::BigEndian) ? BigEndianness : LittleEndianness; |
1051 | } |
1052 | |
1053 | qsizetype nPairs = (end - chars) >> 1; |
1054 | if (endian == BigEndianness) |
1055 | qFromBigEndian<char16_t>(source: chars, count: nPairs, dest: out); |
1056 | else |
1057 | qFromLittleEndian<char16_t>(source: chars, count: nPairs, dest: out); |
1058 | out += nPairs; |
1059 | |
1060 | state->state_data[Endian] = endian; |
1061 | state->remainingChars = 0; |
1062 | if ((end - chars) & 1) { |
1063 | if (state->flags & QStringConverter::Flag::Stateless) { |
1064 | *out++ = state->flags & QStringConverter::Flag::ConvertInvalidToNull ? QChar::Null : QChar::ReplacementCharacter; |
1065 | } else { |
1066 | state->remainingChars = 1; |
1067 | state->state_data[Data] = *(end - 1); |
1068 | } |
1069 | } else { |
1070 | state->state_data[Data] = 0; |
1071 | } |
1072 | |
1073 | return out; |
1074 | } |
1075 | |
1076 | QByteArray QUtf32::convertFromUnicode(QStringView in, QStringConverter::State *state, DataEndianness endian) |
1077 | { |
1078 | bool writeBom = !(state->internalState & HeaderDone) && state->flags & QStringConverter::Flag::WriteBom; |
1079 | qsizetype length = 4*in.size(); |
1080 | if (writeBom) |
1081 | length += 4; |
1082 | QByteArray ba(length, Qt::Uninitialized); |
1083 | char *end = convertFromUnicode(out: ba.data(), in, state, endian); |
1084 | ba.truncate(pos: end - ba.constData()); |
1085 | return ba; |
1086 | } |
1087 | |
1088 | char *QUtf32::convertFromUnicode(char *out, QStringView in, QStringConverter::State *state, DataEndianness endian) |
1089 | { |
1090 | Q_ASSERT(state); |
1091 | |
1092 | bool writeBom = !(state->internalState & HeaderDone) && state->flags & QStringConverter::Flag::WriteBom; |
1093 | if (endian == DetectEndianness) |
1094 | endian = (QSysInfo::ByteOrder == QSysInfo::BigEndian) ? BigEndianness : LittleEndianness; |
1095 | |
1096 | if (writeBom) { |
1097 | // set them up the BOM |
1098 | if (endian == BigEndianness) { |
1099 | out[0] = 0; |
1100 | out[1] = 0; |
1101 | out[2] = (char)0xfe; |
1102 | out[3] = (char)0xff; |
1103 | } else { |
1104 | out[0] = (char)0xff; |
1105 | out[1] = (char)0xfe; |
1106 | out[2] = 0; |
1107 | out[3] = 0; |
1108 | } |
1109 | out += 4; |
1110 | state->internalState |= HeaderDone; |
1111 | } |
1112 | |
1113 | const QChar *uc = in.data(); |
1114 | const QChar *end = in.data() + in.size(); |
1115 | QChar ch; |
1116 | char32_t ucs4; |
1117 | if (state->remainingChars == 1) { |
1118 | auto character = state->state_data[Data]; |
1119 | Q_ASSERT(character <= 0xFFFF); |
1120 | ch = QChar(character); |
1121 | // this is ugly, but shortcuts a whole lot of logic that would otherwise be required |
1122 | state->remainingChars = 0; |
1123 | goto decode_surrogate; |
1124 | } |
1125 | |
1126 | while (uc < end) { |
1127 | ch = *uc++; |
1128 | if (Q_LIKELY(!ch.isSurrogate())) { |
1129 | ucs4 = ch.unicode(); |
1130 | } else if (Q_LIKELY(ch.isHighSurrogate())) { |
1131 | decode_surrogate: |
1132 | if (uc == end) { |
1133 | if (state->flags & QStringConverter::Flag::Stateless) { |
1134 | ucs4 = state->flags & QStringConverter::Flag::ConvertInvalidToNull ? 0 : QChar::ReplacementCharacter; |
1135 | } else { |
1136 | state->remainingChars = 1; |
1137 | state->state_data[Data] = ch.unicode(); |
1138 | return out; |
1139 | } |
1140 | } else if (uc->isLowSurrogate()) { |
1141 | ucs4 = QChar::surrogateToUcs4(high: ch, low: *uc++); |
1142 | } else { |
1143 | ucs4 = state->flags & QStringConverter::Flag::ConvertInvalidToNull ? 0 : QChar::ReplacementCharacter; |
1144 | } |
1145 | } else { |
1146 | ucs4 = state->flags & QStringConverter::Flag::ConvertInvalidToNull ? 0 : QChar::ReplacementCharacter; |
1147 | } |
1148 | if (endian == BigEndianness) |
1149 | qToBigEndian(src: ucs4, dest: out); |
1150 | else |
1151 | qToLittleEndian(src: ucs4, dest: out); |
1152 | out += 4; |
1153 | } |
1154 | |
1155 | return out; |
1156 | } |
1157 | |
1158 | QString QUtf32::convertToUnicode(QByteArrayView in, QStringConverter::State *state, DataEndianness endian) |
1159 | { |
1160 | QString result; |
1161 | result.resize(size: (in.size() + 7) >> 1); // worst case |
1162 | QChar *end = convertToUnicode(out: result.data(), in, state, endian); |
1163 | result.truncate(pos: end - result.constData()); |
1164 | return result; |
1165 | } |
1166 | |
1167 | QChar *QUtf32::convertToUnicode(QChar *out, QByteArrayView in, QStringConverter::State *state, DataEndianness endian) |
1168 | { |
1169 | qsizetype len = in.size(); |
1170 | const char *chars = in.data(); |
1171 | |
1172 | Q_ASSERT(state); |
1173 | if (endian == DetectEndianness) |
1174 | endian = (DataEndianness)state->state_data[Endian]; |
1175 | |
1176 | const char *end = chars + len; |
1177 | |
1178 | uchar tuple[4]; |
1179 | memcpy(dest: tuple, src: &state->state_data[Data], n: 4); |
1180 | |
1181 | // make sure we can decode at least one char |
1182 | if (state->remainingChars + len < 4) { |
1183 | if (len) { |
1184 | while (chars < end) { |
1185 | tuple[state->remainingChars] = *chars; |
1186 | ++state->remainingChars; |
1187 | ++chars; |
1188 | } |
1189 | Q_ASSERT(state->remainingChars < 4); |
1190 | memcpy(dest: &state->state_data[Data], src: tuple, n: 4); |
1191 | } |
1192 | return out; |
1193 | } |
1194 | |
1195 | bool headerdone = state->internalState & HeaderDone; |
1196 | if (state->flags & QStringConverter::Flag::ConvertInitialBom) |
1197 | headerdone = true; |
1198 | |
1199 | qsizetype num = state->remainingChars; |
1200 | state->remainingChars = 0; |
1201 | |
1202 | if (!headerdone || endian == DetectEndianness || num) { |
1203 | while (num < 4) |
1204 | tuple[num++] = *chars++; |
1205 | if (endian == DetectEndianness) { |
1206 | // someone set us up the BOM? |
1207 | if (tuple[0] == 0xff && tuple[1] == 0xfe && tuple[2] == 0 && tuple[3] == 0) { |
1208 | endian = LittleEndianness; |
1209 | } else if (tuple[0] == 0 && tuple[1] == 0 && tuple[2] == 0xfe && tuple[3] == 0xff) { |
1210 | endian = BigEndianness; |
1211 | } else if (QSysInfo::ByteOrder == QSysInfo::BigEndian) { |
1212 | endian = BigEndianness; |
1213 | } else { |
1214 | endian = LittleEndianness; |
1215 | } |
1216 | } |
1217 | char32_t code = (endian == BigEndianness) ? qFromBigEndian<char32_t>(src: tuple) : qFromLittleEndian<char32_t>(src: tuple); |
1218 | if (headerdone || code != QChar::ByteOrderMark) { |
1219 | if (QChar::requiresSurrogates(ucs4: code)) { |
1220 | *out++ = QChar(QChar::highSurrogate(ucs4: code)); |
1221 | *out++ = QChar(QChar::lowSurrogate(ucs4: code)); |
1222 | } else { |
1223 | *out++ = QChar(code); |
1224 | } |
1225 | } |
1226 | num = 0; |
1227 | } else if (endian == DetectEndianness) { |
1228 | endian = (QSysInfo::ByteOrder == QSysInfo::BigEndian) ? BigEndianness : LittleEndianness; |
1229 | } |
1230 | state->state_data[Endian] = endian; |
1231 | state->internalState |= HeaderDone; |
1232 | |
1233 | while (chars < end) { |
1234 | tuple[num++] = *chars++; |
1235 | if (num == 4) { |
1236 | char32_t code = (endian == BigEndianness) ? qFromBigEndian<char32_t>(src: tuple) : qFromLittleEndian<char32_t>(src: tuple); |
1237 | for (char16_t c : QChar::fromUcs4(c: code)) |
1238 | *out++ = c; |
1239 | num = 0; |
1240 | } |
1241 | } |
1242 | |
1243 | if (num) { |
1244 | if (state->flags & QStringDecoder::Flag::Stateless) { |
1245 | *out++ = QChar::ReplacementCharacter; |
1246 | } else { |
1247 | state->state_data[Endian] = endian; |
1248 | state->remainingChars = num; |
1249 | memcpy(dest: &state->state_data[Data], src: tuple, n: 4); |
1250 | } |
1251 | } |
1252 | |
1253 | return out; |
1254 | } |
1255 | #endif // !QT_BOOTSTRAPPED |
1256 | |
1257 | #if defined(Q_OS_WIN) && !defined(QT_BOOTSTRAPPED) |
1258 | int QLocal8Bit::checkUtf8() |
1259 | { |
1260 | return GetACP() == CP_UTF8 ? 1 : -1; |
1261 | } |
1262 | |
1263 | QString QLocal8Bit::convertToUnicode_sys(QByteArrayView in, QStringConverter::State *state) |
1264 | { |
1265 | return convertToUnicode_sys(in, CP_ACP, state); |
1266 | } |
1267 | |
1268 | QString QLocal8Bit::convertToUnicode_sys(QByteArrayView in, quint32 codePage, |
1269 | QStringConverter::State *state) |
1270 | { |
1271 | const char *mb = in.data(); |
1272 | qsizetype mblen = in.size(); |
1273 | |
1274 | Q_ASSERT(state); |
1275 | qsizetype &invalidChars = state->invalidChars; |
1276 | using Flag = QStringConverter::Flag; |
1277 | const bool useNullForReplacement = !!(state->flags & Flag::ConvertInvalidToNull); |
1278 | const char16_t replacementCharacter = useNullForReplacement ? QChar::Null |
1279 | : QChar::ReplacementCharacter; |
1280 | if (state->flags & Flag::Stateless) { |
1281 | Q_ASSERT(state->remainingChars == 0); |
1282 | state = nullptr; |
1283 | } |
1284 | |
1285 | if (!mb || !mblen) |
1286 | return QString(); |
1287 | |
1288 | // Use a local stack-buffer at first to allow us a decently large container |
1289 | // to avoid a lot of resizing, without also returning an overallocated |
1290 | // QString to the user for small strings. |
1291 | // Then we can be fast for small strings and take the hit of extra resizes |
1292 | // and measuring how much storage is needed for large strings. |
1293 | std::array<wchar_t, 4096> buf; |
1294 | wchar_t *out = buf.data(); |
1295 | qsizetype outlen = buf.size(); |
1296 | |
1297 | QString sp; |
1298 | |
1299 | // Return a pointer to storage where we have enough space for `size` |
1300 | const auto growOut = [&](qsizetype size) -> std::tuple<wchar_t *, qsizetype> { |
1301 | if (outlen >= size) |
1302 | return {out, outlen}; |
1303 | const bool wasStackBuffer = sp.isEmpty(); |
1304 | const auto begin = wasStackBuffer ? buf.data() : reinterpret_cast<wchar_t *>(sp.data()); |
1305 | const qsizetype offset = qsizetype(std::distance(begin, out)); |
1306 | qsizetype newSize = 0; |
1307 | if (Q_UNLIKELY(qAddOverflow(offset, size, &newSize))) { |
1308 | Q_CHECK_PTR(false); |
1309 | return {nullptr, 0}; |
1310 | } |
1311 | sp.resize(newSize); |
1312 | auto it = reinterpret_cast<wchar_t *>(sp.data()); |
1313 | if (wasStackBuffer) |
1314 | it = std::copy_n(buf.data(), offset, it); |
1315 | else |
1316 | it += offset; |
1317 | return {it, size}; |
1318 | }; |
1319 | |
1320 | // Convert the pending characters (if available) |
1321 | while (state && state->remainingChars && mblen) { |
1322 | QStringConverter::State localState; |
1323 | localState.flags = state->flags; |
1324 | // Use at most 6 characters as a guess for the longest encoded character |
1325 | // in any multibyte encoding. |
1326 | // Even with a total of 2 bytes of overhead that would leave around |
1327 | // 2^(4 * 8) possible characters |
1328 | std::array<char, 6> prev = {0}; |
1329 | Q_ASSERT(state->remainingChars <= q20::ssize(state->state_data)); |
1330 | qsizetype index = 0; |
1331 | for (; index < state->remainingChars; ++index) |
1332 | prev[index] = state->state_data[index]; |
1333 | const qsizetype toCopy = std::min(q20::ssize(prev) - index, mblen); |
1334 | for (qsizetype i = 0; i < toCopy; ++i, ++index) |
1335 | prev[index] = mb[i]; |
1336 | mb += toCopy; |
1337 | mblen -= toCopy; |
1338 | |
1339 | // Recursing: |
1340 | // Since we are using a clean local state it will try to decode what was |
1341 | // stored in our state + some extra octets from input (`prev`). If some |
1342 | // part fails we will have those characters stored in the local state's |
1343 | // storage, and we can extract those. It may also output some |
1344 | // replacement characters, which we'll count in the invalidChars. |
1345 | // In the best case we only do this once, but we will loop until we have |
1346 | // resolved all the remaining characters or we have run out of new input |
1347 | // in which case we may still have remaining characters. |
1348 | const QString tmp = convertToUnicode_sys(QByteArrayView(prev.data(), index), codePage, |
1349 | &localState); |
1350 | std::tie(out, outlen) = growOut(tmp.size()); |
1351 | if (!out) |
1352 | return {}; |
1353 | out = std::copy_n(reinterpret_cast<const wchar_t *>(tmp.constData()), tmp.size(), out); |
1354 | outlen -= tmp.size(); |
1355 | const qsizetype tail = toCopy - localState.remainingChars; |
1356 | if (tail >= 0) { |
1357 | // Everything left to process comes from `in`, so we can stop |
1358 | // looping. Adjust the window for `in` and unset remainingChars to |
1359 | // signal that we're done. |
1360 | mb -= localState.remainingChars; |
1361 | mblen += localState.remainingChars; |
1362 | localState.remainingChars = 0; |
1363 | } |
1364 | state->remainingChars = localState.remainingChars; |
1365 | state->invalidChars += localState.invalidChars; |
1366 | std::copy_n(localState.state_data, state->remainingChars, state->state_data); |
1367 | } |
1368 | |
1369 | Q_ASSERT(!state || state->remainingChars == 0 || mblen == 0); |
1370 | |
1371 | // Need it in this scope, since we try to decrease our window size if we |
1372 | // encounter an error |
1373 | int nextIn = q26::saturate_cast<int>(mblen); |
1374 | while (mblen > 0) { |
1375 | std::tie(out, outlen) = growOut(1); // Need space for at least one character |
1376 | if (!out) |
1377 | return {}; |
1378 | const int nextOut = q26::saturate_cast<int>(outlen); |
1379 | int len = MultiByteToWideChar(codePage, MB_ERR_INVALID_CHARS, mb, nextIn, out, nextOut); |
1380 | if (len) { |
1381 | mb += nextIn; |
1382 | mblen -= nextIn; |
1383 | out += len; |
1384 | outlen -= len; |
1385 | } else { |
1386 | int r = GetLastError(); |
1387 | if (r == ERROR_INSUFFICIENT_BUFFER) { |
1388 | const int wclen = MultiByteToWideChar(codePage, 0, mb, nextIn, 0, 0); |
1389 | std::tie(out, outlen) = growOut(wclen); |
1390 | if (!out) |
1391 | return {}; |
1392 | } else if (r == ERROR_NO_UNICODE_TRANSLATION) { |
1393 | // Can't decode the current window, so either store the state, |
1394 | // reduce window size or output a replacement character. |
1395 | |
1396 | // Check if we can store all remaining characters in the state |
1397 | // to be used next time we're called: |
1398 | if (state && mblen <= q20::ssize(state->state_data)) { |
1399 | state->remainingChars = mblen; |
1400 | std::copy_n(mb, mblen, state->state_data); |
1401 | mb += mblen; |
1402 | mblen = 0; |
1403 | break; |
1404 | } |
1405 | |
1406 | // .. if not, try to find the last valid character in the window |
1407 | // and try again with a shrunken window: |
1408 | if (nextIn > 1) { |
1409 | // There may be some incomplete data at the end of our current |
1410 | // window, so decrease the window size and try again. |
1411 | // In the worst case scenario there is gigs of undecodable |
1412 | // garbage, but what are we supposed to do about that? |
1413 | const auto it = CharPrevExA(codePage, mb, mb + nextIn, 0); |
1414 | if (it != mb) |
1415 | nextIn = int(it - mb); |
1416 | else |
1417 | --nextIn; |
1418 | continue; |
1419 | } |
1420 | |
1421 | // Finally, we are forced to output a replacement character for |
1422 | // the first byte in the window: |
1423 | std::tie(out, outlen) = growOut(1); |
1424 | if (!out) |
1425 | return {}; |
1426 | *out = replacementCharacter; |
1427 | ++invalidChars; |
1428 | ++out; |
1429 | --outlen; |
1430 | ++mb; |
1431 | --mblen; |
1432 | } else { |
1433 | // Fail. |
1434 | qWarning("MultiByteToWideChar: Cannot convert multibyte text"); |
1435 | break; |
1436 | } |
1437 | } |
1438 | nextIn = q26::saturate_cast<int>(mblen); |
1439 | } |
1440 | |
1441 | if (sp.isEmpty()) { |
1442 | // We must have only used the stack buffer |
1443 | if (out != buf.data()) // else: we return null-string |
1444 | sp = QStringView(buf.data(), out).toString(); |
1445 | } else{ |
1446 | const auto begin = reinterpret_cast<wchar_t *>(sp.data()); |
1447 | sp.truncate(std::distance(begin, out)); |
1448 | } |
1449 | |
1450 | if (sp.size() && sp.back().isNull()) |
1451 | sp.chop(1); |
1452 | |
1453 | if (!state && mblen > 0) { |
1454 | // We have trailing character(s) that could not be converted, and |
1455 | // nowhere to cache them |
1456 | sp.resize(sp.size() + mblen, replacementCharacter); |
1457 | invalidChars += mblen; |
1458 | } |
1459 | return sp; |
1460 | } |
1461 | |
1462 | QByteArray QLocal8Bit::convertFromUnicode_sys(QStringView in, QStringConverter::State *state) |
1463 | { |
1464 | return convertFromUnicode_sys(in, CP_ACP, state); |
1465 | } |
1466 | |
1467 | QByteArray QLocal8Bit::convertFromUnicode_sys(QStringView in, quint32 codePage, |
1468 | QStringConverter::State *state) |
1469 | { |
1470 | const wchar_t *ch = reinterpret_cast<const wchar_t *>(in.data()); |
1471 | qsizetype uclen = in.size(); |
1472 | |
1473 | Q_ASSERT(state); |
1474 | // The Windows API has a *boolean* out-parameter that says if a replacement |
1475 | // character was used, but it gives us no way to know _how many_ were used. |
1476 | // Since we cannot simply scan the string for replacement characters |
1477 | // (which is potentially a question mark, and thus a valid character), |
1478 | // we simply do not track the number of invalid characters here. |
1479 | // auto &invalidChars = state->invalidChars; |
1480 | |
1481 | using Flag = QStringConverter::Flag; |
1482 | if (state->flags & Flag::Stateless) { // temporary |
1483 | Q_ASSERT(state->remainingChars == 0); |
1484 | state = nullptr; |
1485 | } |
1486 | |
1487 | if (!ch) |
1488 | return QByteArray(); |
1489 | if (uclen == 0) |
1490 | return QByteArray(""); |
1491 | |
1492 | // Use a local stack-buffer at first to allow us a decently large container |
1493 | // to avoid a lot of resizing, without also returning an overallocated |
1494 | // QByteArray to the user for small strings. |
1495 | // Then we can be fast for small strings and take the hit of extra resizes |
1496 | // and measuring how much storage is needed for large strings. |
1497 | std::array<char, 4096> buf; |
1498 | char *out = buf.data(); |
1499 | qsizetype outlen = buf.size(); |
1500 | QByteArray mb; |
1501 | |
1502 | if (state && state->remainingChars > 0) { |
1503 | Q_ASSERT(state->remainingChars == 1); |
1504 | // Let's try to decode the pending character |
1505 | wchar_t wc[2] = { wchar_t(state->state_data[0]), ch[0] }; |
1506 | // Check if the second character is a valid low surrogate, |
1507 | // otherwise we'll just decode the first character, for which windows |
1508 | // will output a replacement character. |
1509 | const bool validCodePoint = QChar::isLowSurrogate(wc[1]); |
1510 | int len = WideCharToMultiByte(codePage, 0, wc, validCodePoint ? 2 : 1, out, outlen, nullptr, |
1511 | nullptr); |
1512 | if (!len) |
1513 | return {}; // Cannot recover, and I refuse to believe it was a size limitation |
1514 | out += len; |
1515 | outlen -= len; |
1516 | if (validCodePoint) { |
1517 | ++ch; |
1518 | --uclen; |
1519 | } |
1520 | state->remainingChars = 0; |
1521 | state->state_data[0] = 0; |
1522 | if (uclen == 0) |
1523 | return QByteArrayView(buf.data(), len).toByteArray(); |
1524 | } |
1525 | |
1526 | if (state && QChar::isHighSurrogate(ch[uclen - 1])) { |
1527 | // We can handle a missing low surrogate at the end of the string, |
1528 | // so if there is one, exclude it now and store it in the state. |
1529 | state->remainingChars = 1; |
1530 | state->state_data[0] = ch[uclen - 1]; |
1531 | --uclen; |
1532 | if (uclen == 0) |
1533 | return QByteArray(); |
1534 | } |
1535 | |
1536 | Q_ASSERT(uclen > 0); |
1537 | |
1538 | // Return a pointer to storage where we have enough space for `size` |
1539 | const auto growOut = [&](qsizetype size) -> std::tuple<char *, qsizetype> { |
1540 | if (outlen >= size) |
1541 | return {out, outlen}; |
1542 | const bool wasStackBuffer = mb.isEmpty(); |
1543 | const auto begin = wasStackBuffer ? buf.data() : mb.data(); |
1544 | const qsizetype offset = qsizetype(std::distance(begin, out)); |
1545 | qsizetype newSize = 0; |
1546 | if (Q_UNLIKELY(qAddOverflow(offset, size, &newSize))) { |
1547 | Q_CHECK_PTR(false); |
1548 | return {nullptr, 0}; |
1549 | } |
1550 | mb.resize(newSize); |
1551 | auto it = mb.data(); |
1552 | if (wasStackBuffer) |
1553 | it = std::copy_n(buf.data(), offset, it); |
1554 | else |
1555 | it += offset; |
1556 | return {it, size}; |
1557 | }; |
1558 | |
1559 | const auto getNextWindowSize = [&]() { |
1560 | int nextIn = q26::saturate_cast<int>(uclen); |
1561 | // The Windows API has some issues if the current window ends in the |
1562 | // middle of a surrogate pair, so we avoid that: |
1563 | if (nextIn > 1 && QChar::isHighSurrogate(ch[nextIn - 1])) |
1564 | --nextIn; |
1565 | return nextIn; |
1566 | }; |
1567 | |
1568 | int len = 0; |
1569 | while (uclen > 0) { |
1570 | const int nextIn = getNextWindowSize(); |
1571 | std::tie(out, outlen) = growOut(1); // We need at least one byte |
1572 | if (!out) |
1573 | return {}; |
1574 | const int nextOut = q26::saturate_cast<int>(outlen); |
1575 | len = WideCharToMultiByte(codePage, 0, ch, nextIn, out, nextOut, nullptr, nullptr); |
1576 | if (len > 0) { |
1577 | ch += nextIn; |
1578 | uclen -= nextIn; |
1579 | out += len; |
1580 | outlen -= len; |
1581 | } else { |
1582 | int r = GetLastError(); |
1583 | if (r == ERROR_INSUFFICIENT_BUFFER) { |
1584 | int neededLength = WideCharToMultiByte(codePage, 0, ch, nextIn, nullptr, 0, |
1585 | nullptr, nullptr); |
1586 | if (neededLength <= 0) { |
1587 | // Fail. Observed with UTF8 where the input window was max int and ended in an |
1588 | // incomplete sequence, probably a Windows bug. We try to avoid that from |
1589 | // happening by reducing the window size in that case. But let's keep this |
1590 | // branch just in case of other bugs. |
1591 | #ifndef QT_NO_DEBUG |
1592 | r = GetLastError(); |
1593 | fprintf(stderr, |
1594 | "WideCharToMultiByte: Cannot convert multibyte text (error %d)\n", r); |
1595 | #endif // !QT_NO_DEBUG |
1596 | break; |
1597 | } |
1598 | std::tie(out, outlen) = growOut(neededLength); |
1599 | if (!out) |
1600 | return {}; |
1601 | // and try again... |
1602 | } else { |
1603 | // Fail. Probably can't happen in fact (dwFlags is 0). |
1604 | #ifndef QT_NO_DEBUG |
1605 | // Can't use qWarning(), as it'll recurse to handle %ls |
1606 | fprintf(stderr, |
1607 | "WideCharToMultiByte: Cannot convert multibyte text (error %d): %ls\n", r, |
1608 | reinterpret_cast<const wchar_t *>( |
1609 | QStringView(ch, uclen).left(100).toString().utf16())); |
1610 | #endif |
1611 | break; |
1612 | } |
1613 | } |
1614 | } |
1615 | if (mb.isEmpty()) { |
1616 | // We must have only used the stack buffer |
1617 | if (out != buf.data()) // else: we return null-array |
1618 | mb = QByteArrayView(buf.data(), out).toByteArray(); |
1619 | } else { |
1620 | mb.truncate(std::distance(mb.data(), out)); |
1621 | } |
1622 | return mb; |
1623 | } |
1624 | #endif |
1625 | |
1626 | void QStringConverter::State::clear() noexcept |
1627 | { |
1628 | if (clearFn) |
1629 | clearFn(this); |
1630 | else |
1631 | state_data[0] = state_data[1] = state_data[2] = state_data[3] = 0; |
1632 | remainingChars = 0; |
1633 | invalidChars = 0; |
1634 | internalState = 0; |
1635 | } |
1636 | |
1637 | void QStringConverter::State::reset() noexcept |
1638 | { |
1639 | if (flags & Flag::UsesIcu) { |
1640 | #if QT_CONFIG(icu) |
1641 | UConverter *converter = static_cast<UConverter *>(d[0]); |
1642 | if (converter) |
1643 | ucnv_reset(converter); |
1644 | #else |
1645 | Q_UNREACHABLE(); |
1646 | #endif |
1647 | } else { |
1648 | clear(); |
1649 | } |
1650 | } |
1651 | |
1652 | #ifndef QT_BOOTSTRAPPED |
1653 | static QChar *fromUtf16(QChar *out, QByteArrayView in, QStringConverter::State *state) |
1654 | { |
1655 | return QUtf16::convertToUnicode(out, in, state, endian: DetectEndianness); |
1656 | } |
1657 | |
1658 | static char *toUtf16(char *out, QStringView in, QStringConverter::State *state) |
1659 | { |
1660 | return QUtf16::convertFromUnicode(out, in, state, endian: DetectEndianness); |
1661 | } |
1662 | |
1663 | static QChar *fromUtf16BE(QChar *out, QByteArrayView in, QStringConverter::State *state) |
1664 | { |
1665 | return QUtf16::convertToUnicode(out, in, state, endian: BigEndianness); |
1666 | } |
1667 | |
1668 | static char *toUtf16BE(char *out, QStringView in, QStringConverter::State *state) |
1669 | { |
1670 | return QUtf16::convertFromUnicode(out, in, state, endian: BigEndianness); |
1671 | } |
1672 | |
1673 | static QChar *fromUtf16LE(QChar *out, QByteArrayView in, QStringConverter::State *state) |
1674 | { |
1675 | return QUtf16::convertToUnicode(out, in, state, endian: LittleEndianness); |
1676 | } |
1677 | |
1678 | static char *toUtf16LE(char *out, QStringView in, QStringConverter::State *state) |
1679 | { |
1680 | return QUtf16::convertFromUnicode(out, in, state, endian: LittleEndianness); |
1681 | } |
1682 | |
1683 | static QChar *fromUtf32(QChar *out, QByteArrayView in, QStringConverter::State *state) |
1684 | { |
1685 | return QUtf32::convertToUnicode(out, in, state, endian: DetectEndianness); |
1686 | } |
1687 | |
1688 | static char *toUtf32(char *out, QStringView in, QStringConverter::State *state) |
1689 | { |
1690 | return QUtf32::convertFromUnicode(out, in, state, endian: DetectEndianness); |
1691 | } |
1692 | |
1693 | static QChar *fromUtf32BE(QChar *out, QByteArrayView in, QStringConverter::State *state) |
1694 | { |
1695 | return QUtf32::convertToUnicode(out, in, state, endian: BigEndianness); |
1696 | } |
1697 | |
1698 | static char *toUtf32BE(char *out, QStringView in, QStringConverter::State *state) |
1699 | { |
1700 | return QUtf32::convertFromUnicode(out, in, state, endian: BigEndianness); |
1701 | } |
1702 | |
1703 | static QChar *fromUtf32LE(QChar *out, QByteArrayView in, QStringConverter::State *state) |
1704 | { |
1705 | return QUtf32::convertToUnicode(out, in, state, endian: LittleEndianness); |
1706 | } |
1707 | |
1708 | static char *toUtf32LE(char *out, QStringView in, QStringConverter::State *state) |
1709 | { |
1710 | return QUtf32::convertFromUnicode(out, in, state, endian: LittleEndianness); |
1711 | } |
1712 | #endif // !QT_BOOTSTRAPPED |
1713 | |
1714 | char *QLatin1::convertFromUnicode(char *out, QStringView in, QStringConverter::State *state) noexcept |
1715 | { |
1716 | Q_ASSERT(state); |
1717 | if (state->flags & QStringConverter::Flag::Stateless) // temporary |
1718 | state = nullptr; |
1719 | |
1720 | const char replacement = (state && state->flags & QStringConverter::Flag::ConvertInvalidToNull) ? 0 : '?'; |
1721 | qsizetype invalid = 0; |
1722 | for (qsizetype i = 0; i < in.size(); ++i) { |
1723 | if (in[i] > QChar(0xff)) { |
1724 | *out = replacement; |
1725 | ++invalid; |
1726 | } else { |
1727 | *out = (char)in[i].cell(); |
1728 | } |
1729 | ++out; |
1730 | } |
1731 | if (state) |
1732 | state->invalidChars += invalid; |
1733 | return out; |
1734 | } |
1735 | |
1736 | static QChar *fromLocal8Bit(QChar *out, QByteArrayView in, QStringConverter::State *state) |
1737 | { |
1738 | QString s = QLocal8Bit::convertToUnicode(in, state); |
1739 | memcpy(dest: out, src: s.constData(), n: s.size()*sizeof(QChar)); |
1740 | return out + s.size(); |
1741 | } |
1742 | |
1743 | static char *toLocal8Bit(char *out, QStringView in, QStringConverter::State *state) |
1744 | { |
1745 | QByteArray s = QLocal8Bit::convertFromUnicode(in, state); |
1746 | memcpy(dest: out, src: s.constData(), n: s.size()); |
1747 | return out + s.size(); |
1748 | } |
1749 | |
1750 | |
1751 | static qsizetype fromUtf8Len(qsizetype l) { return l + 1; } |
1752 | static qsizetype toUtf8Len(qsizetype l) { return 3*(l + 1); } |
1753 | |
1754 | #ifndef QT_BOOTSTRAPPED |
1755 | static qsizetype fromUtf16Len(qsizetype l) { return l/2 + 2; } |
1756 | static qsizetype toUtf16Len(qsizetype l) { return 2*(l + 1); } |
1757 | |
1758 | static qsizetype fromUtf32Len(qsizetype l) { return l/2 + 2; } |
1759 | static qsizetype toUtf32Len(qsizetype l) { return 4*(l + 1); } |
1760 | #endif |
1761 | |
1762 | static qsizetype fromLatin1Len(qsizetype l) { return l + 1; } |
1763 | static qsizetype toLatin1Len(qsizetype l) { return l + 1; } |
1764 | |
1765 | |
1766 | |
1767 | /*! |
1768 | \class QStringConverterBase |
1769 | \internal |
1770 | |
1771 | Just a common base class for QStringConverter and QTextCodec |
1772 | */ |
1773 | |
1774 | /*! |
1775 | \class QStringConverter |
1776 | \inmodule QtCore |
1777 | \brief The QStringConverter class provides a base class for encoding and decoding text. |
1778 | \reentrant |
1779 | \ingroup i18n |
1780 | |
1781 | Qt uses UTF-16 to store, draw and manipulate strings. In many |
1782 | situations you may wish to deal with data that uses a different |
1783 | encoding. Most text data transferred over files and network connections is encoded |
1784 | in UTF-8. |
1785 | |
1786 | The QStringConverter class is a base class for the \l {QStringEncoder} and |
1787 | \l {QStringDecoder} classes that help with converting between different |
1788 | text encodings. QStringDecoder can decode a string from an encoded representation |
1789 | into UTF-16, the format Qt uses internally. QStringEncoder does the opposite |
1790 | operation, encoding UTF-16 encoded data (usually in the form of a QString) to |
1791 | the requested encoding. |
1792 | |
1793 | The following encodings are always supported: |
1794 | |
1795 | \list |
1796 | \li UTF-8 |
1797 | \li UTF-16 |
1798 | \li UTF-16BE |
1799 | \li UTF-16LE |
1800 | \li UTF-32 |
1801 | \li UTF-32BE |
1802 | \li UTF-32LE |
1803 | \li ISO-8859-1 (Latin-1) |
1804 | \li The system encoding |
1805 | \endlist |
1806 | |
1807 | QStringConverter may support more encodings depending on how Qt was |
1808 | compiled. If more codecs are supported, they can be listed using |
1809 | availableCodecs(). |
1810 | |
1811 | \l {QStringConverter}s can be used as follows to convert some encoded |
1812 | string to and from UTF-16. |
1813 | |
1814 | Suppose you have some string encoded in UTF-8, and |
1815 | want to convert it to a QString. The simple way |
1816 | to do it is to use a \l {QStringDecoder} like this: |
1817 | |
1818 | \snippet code/src_corelib_text_qstringconverter.cpp 0 |
1819 | |
1820 | After this, \c string holds the text in decoded form. |
1821 | Converting a string from Unicode to the local encoding is just as |
1822 | easy using the \l {QStringEncoder} class: |
1823 | |
1824 | \snippet code/src_corelib_text_qstringconverter.cpp 1 |
1825 | |
1826 | To read or write text files in various encodings, use QTextStream and |
1827 | its \l{QTextStream::setEncoding()}{setEncoding()} function. |
1828 | |
1829 | Some care must be taken when trying to convert the data in chunks, |
1830 | for example, when receiving it over a network. In such cases it is |
1831 | possible that a multi-byte character will be split over two |
1832 | chunks. At best this might result in the loss of a character and |
1833 | at worst cause the entire conversion to fail. |
1834 | |
1835 | Both QStringEncoder and QStringDecoder make this easy, by tracking |
1836 | this in an internal state. So simply calling the encoder or decoder |
1837 | again with the next chunk of data will automatically continue encoding |
1838 | or decoding the data correctly: |
1839 | |
1840 | \snippet code/src_corelib_text_qstringconverter.cpp 2 |
1841 | |
1842 | The QStringDecoder object maintains state between chunks and therefore |
1843 | works correctly even if a multi-byte character is split between |
1844 | chunks. |
1845 | |
1846 | QStringConverter objects can't be copied because of their internal state, but |
1847 | can be moved. |
1848 | |
1849 | \sa QTextStream, QStringDecoder, QStringEncoder |
1850 | */ |
1851 | |
1852 | /*! |
1853 | \enum QStringConverter::Flag |
1854 | |
1855 | \value Default Default conversion rules apply. |
1856 | \value ConvertInvalidToNull If this flag is set, each invalid input |
1857 | character is output as a null character. If it is not set, |
1858 | invalid input characters are represented as QChar::ReplacementCharacter |
1859 | if the output encoding can represent that character, otherwise as a question mark. |
1860 | \value WriteBom When converting from a QString to an output encoding, write a QChar::ByteOrderMark as the first |
1861 | character if the output encoding supports this. This is the case for UTF-8, UTF-16 and UTF-32 |
1862 | encodings. |
1863 | \value ConvertInitialBom When converting from an input encoding to a QString the QStringDecoder usually skips an |
1864 | leading QChar::ByteOrderMark. When this flag is set, the byte order mark will not be |
1865 | skipped, but converted to utf-16 and inserted at the start of the created QString. |
1866 | \value Stateless Ignore possible converter states between different function calls |
1867 | to encode or decode strings. This will also cause the QStringConverter to raise an error if an incomplete |
1868 | sequence of data is encountered. |
1869 | \omitvalue UsesIcu |
1870 | */ |
1871 | |
1872 | /*! |
1873 | \enum QStringConverter::Encoding |
1874 | \value Utf8 Create a converter to or from UTF-8 |
1875 | \value Utf16 Create a converter to or from UTF-16. When decoding, the byte order will get automatically |
1876 | detected by a leading byte order mark. If none exists or when encoding, the system byte order will |
1877 | be assumed. |
1878 | \value Utf16BE Create a converter to or from big-endian UTF-16. |
1879 | \value Utf16LE Create a converter to or from little-endian UTF-16. |
1880 | \value Utf32 Create a converter to or from UTF-32. When decoding, the byte order will get automatically |
1881 | detected by a leading byte order mark. If none exists or when encoding, the system byte order will |
1882 | be assumed. |
1883 | \value Utf32BE Create a converter to or from big-endian UTF-32. |
1884 | \value Utf32LE Create a converter to or from little-endian UTF-32. |
1885 | \value Latin1 Create a converter to or from ISO-8859-1 (Latin1). |
1886 | \value System Create a converter to or from the underlying encoding of the |
1887 | operating systems locale. This is always assumed to be UTF-8 for Unix based |
1888 | systems. On Windows, this converts to and from the locale code page. |
1889 | \omitvalue LastEncoding |
1890 | */ |
1891 | |
1892 | /*! |
1893 | \struct QStringConverter::Interface |
1894 | \internal |
1895 | */ |
1896 | |
1897 | const QStringConverter::Interface QStringConverter::encodingInterfaces[QStringConverter::LastEncoding + 1] = |
1898 | { |
1899 | { .name: "UTF-8", .toUtf16: QUtf8::convertToUnicode, .toUtf16Len: fromUtf8Len, .fromUtf16: QUtf8::convertFromUnicode, .fromUtf16Len: toUtf8Len }, |
1900 | #ifndef QT_BOOTSTRAPPED |
1901 | { .name: "UTF-16", .toUtf16: fromUtf16, .toUtf16Len: fromUtf16Len, .fromUtf16: toUtf16, .fromUtf16Len: toUtf16Len }, |
1902 | { .name: "UTF-16LE", .toUtf16: fromUtf16LE, .toUtf16Len: fromUtf16Len, .fromUtf16: toUtf16LE, .fromUtf16Len: toUtf16Len }, |
1903 | { .name: "UTF-16BE", .toUtf16: fromUtf16BE, .toUtf16Len: fromUtf16Len, .fromUtf16: toUtf16BE, .fromUtf16Len: toUtf16Len }, |
1904 | { .name: "UTF-32", .toUtf16: fromUtf32, .toUtf16Len: fromUtf32Len, .fromUtf16: toUtf32, .fromUtf16Len: toUtf32Len }, |
1905 | { .name: "UTF-32LE", .toUtf16: fromUtf32LE, .toUtf16Len: fromUtf32Len, .fromUtf16: toUtf32LE, .fromUtf16Len: toUtf32Len }, |
1906 | { .name: "UTF-32BE", .toUtf16: fromUtf32BE, .toUtf16Len: fromUtf32Len, .fromUtf16: toUtf32BE, .fromUtf16Len: toUtf32Len }, |
1907 | #endif |
1908 | { .name: "ISO-8859-1", .toUtf16: QLatin1::convertToUnicode, .toUtf16Len: fromLatin1Len, .fromUtf16: QLatin1::convertFromUnicode, .fromUtf16Len: toLatin1Len }, |
1909 | { .name: "Locale", .toUtf16: fromLocal8Bit, .toUtf16Len: fromUtf8Len, .fromUtf16: toLocal8Bit, .fromUtf16Len: toUtf8Len } |
1910 | }; |
1911 | |
1912 | // match names case insensitive and skipping '-' and '_' |
1913 | template <typename Char> |
1914 | static bool nameMatch_impl_impl(const char *a, const Char *b, const Char *b_end) |
1915 | { |
1916 | do { |
1917 | while (*a == '-' || *a == '_') |
1918 | ++a; |
1919 | while (b != b_end && (*b == Char{'-'} || *b == Char{'_'})) |
1920 | ++b; |
1921 | if (!*a && b == b_end) // end of both strings |
1922 | return true; |
1923 | if (char16_t(*b) > 127) |
1924 | return false; // non-US-ASCII cannot match US-ASCII (prevents narrowing below) |
1925 | } while (QtMiscUtils::toAsciiLower(ch: *a++) == QtMiscUtils::toAsciiLower(ch: char(*b++))); |
1926 | |
1927 | return false; |
1928 | } |
1929 | |
1930 | static bool nameMatch_impl(const char *a, QLatin1StringView b) |
1931 | { |
1932 | return nameMatch_impl_impl(a, b: b.begin(), b_end: b.end()); |
1933 | } |
1934 | |
1935 | static bool nameMatch_impl(const char *a, QUtf8StringView b) |
1936 | { |
1937 | return nameMatch_impl(a, b: QLatin1StringView{QByteArrayView{b}}); |
1938 | } |
1939 | |
1940 | static bool nameMatch_impl(const char *a, QStringView b) |
1941 | { |
1942 | return nameMatch_impl_impl(a, b: b.utf16(), b_end: b.utf16() + b.size()); // uses char16_t*, not QChar* |
1943 | } |
1944 | |
1945 | static bool nameMatch(const char *a, QAnyStringView b) |
1946 | { |
1947 | return b.visit(v: [a](auto b) { return nameMatch_impl(a, b); }); |
1948 | } |
1949 | |
1950 | |
1951 | /*! |
1952 | \fn constexpr QStringConverter::QStringConverter() |
1953 | \internal |
1954 | */ |
1955 | |
1956 | /*! |
1957 | \fn constexpr QStringConverter::QStringConverter(Encoding, Flags) |
1958 | \internal |
1959 | */ |
1960 | |
1961 | |
1962 | #if QT_CONFIG(icu) |
1963 | // only derives from QStringConverter to get access to protected types |
1964 | struct QStringConverterICU : QStringConverter |
1965 | { |
1966 | static void clear_function(QStringConverterBase::State *state) noexcept |
1967 | { |
1968 | ucnv_close(converter: static_cast<UConverter *>(state->d[0])); |
1969 | state->d[0] = nullptr; |
1970 | } |
1971 | |
1972 | static void ensureConverter(QStringConverter::State *state) |
1973 | { |
1974 | // old code might reset the state via clear instead of reset |
1975 | // in that case, the converter has been closed, and we have to reopen it |
1976 | if (state->d[0] == nullptr) |
1977 | state->d[0] = createConverterForName(name: static_cast<const char *>(state->d[1]), state); |
1978 | } |
1979 | |
1980 | static QChar *toUtf16(QChar *out, QByteArrayView in, QStringConverter::State *state) |
1981 | { |
1982 | ensureConverter(state); |
1983 | |
1984 | auto icu_conv = static_cast<UConverter *>(state->d[0]); |
1985 | UErrorCode err = U_ZERO_ERROR; |
1986 | auto source = in.data(); |
1987 | auto sourceLimit = in.data() + in.size(); |
1988 | |
1989 | qsizetype length = toLen(inLength: in.size()); |
1990 | |
1991 | UChar *target = reinterpret_cast<UChar *>(out); |
1992 | auto targetLimit = target + length; |
1993 | // We explicitly clean up anyway, so no need to set flush to true, |
1994 | // which would just reset the converter. |
1995 | UBool flush = false; |
1996 | |
1997 | // If the QStringConverter was moved, the state that we used as a context is stale now. |
1998 | UConverterToUCallback action; |
1999 | const void *context; |
2000 | ucnv_getToUCallBack(converter: icu_conv, action: &action, context: &context); |
2001 | if (context != state) |
2002 | ucnv_setToUCallBack(converter: icu_conv, newAction: action, newContext: state, oldAction: nullptr, oldContext: nullptr, err: &err); |
2003 | |
2004 | ucnv_toUnicode(converter: icu_conv, target: &target, targetLimit, source: &source, sourceLimit, offsets: nullptr, flush, err: &err); |
2005 | // We did reserve enough space: |
2006 | Q_ASSERT(err != U_BUFFER_OVERFLOW_ERROR); |
2007 | if (state->flags.testFlag(flag: QStringConverter::Flag::Stateless)) { |
2008 | if (auto leftOver = ucnv_toUCountPending(cnv: icu_conv, status: &err)) { |
2009 | ucnv_reset(converter: icu_conv); |
2010 | state->invalidChars += leftOver; |
2011 | } |
2012 | } |
2013 | return reinterpret_cast<QChar *>(target); |
2014 | } |
2015 | |
2016 | static char *fromUtf16(char *out, QStringView in, QStringConverter::State *state) |
2017 | { |
2018 | ensureConverter(state); |
2019 | auto icu_conv = static_cast<UConverter *>(state->d[0]); |
2020 | UErrorCode err = U_ZERO_ERROR; |
2021 | auto source = reinterpret_cast<const UChar *>(in.data()); |
2022 | auto sourceLimit = reinterpret_cast<const UChar *>(in.data() + in.size()); |
2023 | |
2024 | qsizetype length = UCNV_GET_MAX_BYTES_FOR_STRING(in.size(), ucnv_getMaxCharSize(icu_conv)); |
2025 | |
2026 | char *target = out; |
2027 | char *targetLimit = out + length; |
2028 | UBool flush = false; |
2029 | |
2030 | // If the QStringConverter was moved, the state that we used as a context is stale now. |
2031 | UConverterFromUCallback action; |
2032 | const void *context; |
2033 | ucnv_getFromUCallBack(converter: icu_conv, action: &action, context: &context); |
2034 | if (context != state) |
2035 | ucnv_setFromUCallBack(converter: icu_conv, newAction: action, newContext: state, oldAction: nullptr, oldContext: nullptr, err: &err); |
2036 | |
2037 | ucnv_fromUnicode(converter: icu_conv, target: &target, targetLimit, source: &source, sourceLimit, offsets: nullptr, flush, err: &err); |
2038 | // We did reserve enough space: |
2039 | Q_ASSERT(err != U_BUFFER_OVERFLOW_ERROR); |
2040 | if (state->flags.testFlag(flag: QStringConverter::Flag::Stateless)) { |
2041 | if (auto leftOver = ucnv_fromUCountPending(cnv: icu_conv, status: &err)) { |
2042 | ucnv_reset(converter: icu_conv); |
2043 | state->invalidChars += leftOver; |
2044 | } |
2045 | } |
2046 | return target; |
2047 | } |
2048 | |
2049 | Q_DISABLE_COPY_MOVE(QStringConverterICU) |
2050 | |
2051 | template<qsizetype X> |
2052 | static qsizetype fromLen(qsizetype inLength) |
2053 | { |
2054 | return X * inLength * sizeof(UChar); |
2055 | } |
2056 | |
2057 | static qsizetype toLen(qsizetype inLength) |
2058 | { |
2059 | |
2060 | /* Assumption: each input char might map to a different codepoint |
2061 | Each codepoint can take up to 4 bytes == 2 QChar |
2062 | We can ignore reserving space for a BOM, as only UTF encodings use one |
2063 | and those are not handled by the ICU converter. |
2064 | */ |
2065 | return 2 * inLength; |
2066 | } |
2067 | |
2068 | static constexpr QStringConverter::Interface forLength[] = { |
2069 | {.name: "icu, recompile if you see this", .toUtf16: QStringConverterICU::toUtf16, .toUtf16Len: QStringConverterICU::toLen, .fromUtf16: QStringConverterICU::fromUtf16, .fromUtf16Len: QStringConverterICU::fromLen<1>}, |
2070 | {.name: "icu, recompile if you see this", .toUtf16: QStringConverterICU::toUtf16, .toUtf16Len: QStringConverterICU::toLen, .fromUtf16: QStringConverterICU::fromUtf16, .fromUtf16Len: QStringConverterICU::fromLen<2>}, |
2071 | {.name: "icu, recompile if you see this", .toUtf16: QStringConverterICU::toUtf16, .toUtf16Len: QStringConverterICU::toLen, .fromUtf16: QStringConverterICU::fromUtf16, .fromUtf16Len: QStringConverterICU::fromLen<3>}, |
2072 | {.name: "icu, recompile if you see this", .toUtf16: QStringConverterICU::toUtf16, .toUtf16Len: QStringConverterICU::toLen, .fromUtf16: QStringConverterICU::fromUtf16, .fromUtf16Len: QStringConverterICU::fromLen<4>}, |
2073 | {.name: "icu, recompile if you see this", .toUtf16: QStringConverterICU::toUtf16, .toUtf16Len: QStringConverterICU::toLen, .fromUtf16: QStringConverterICU::fromUtf16, .fromUtf16Len: QStringConverterICU::fromLen<5>}, |
2074 | {.name: "icu, recompile if you see this", .toUtf16: QStringConverterICU::toUtf16, .toUtf16Len: QStringConverterICU::toLen, .fromUtf16: QStringConverterICU::fromUtf16, .fromUtf16Len: QStringConverterICU::fromLen<6>}, |
2075 | {.name: "icu, recompile if you see this", .toUtf16: QStringConverterICU::toUtf16, .toUtf16Len: QStringConverterICU::toLen, .fromUtf16: QStringConverterICU::fromUtf16, .fromUtf16Len: QStringConverterICU::fromLen<7>}, |
2076 | {.name: "icu, recompile if you see this", .toUtf16: QStringConverterICU::toUtf16, .toUtf16Len: QStringConverterICU::toLen, .fromUtf16: QStringConverterICU::fromUtf16, .fromUtf16Len: QStringConverterICU::fromLen<8>} |
2077 | }; |
2078 | |
2079 | static UConverter *createConverterForName(const char *name, const State *state) |
2080 | { |
2081 | Q_ASSERT(name); |
2082 | Q_ASSERT(state); |
2083 | UErrorCode status = U_ZERO_ERROR; |
2084 | UConverter *conv = ucnv_open(converterName: name, err: &status); |
2085 | if (status != U_ZERO_ERROR && status != U_AMBIGUOUS_ALIAS_WARNING) { |
2086 | ucnv_close(converter: conv); |
2087 | return nullptr; |
2088 | } |
2089 | |
2090 | if (state->flags.testFlag(flag: Flag::ConvertInvalidToNull)) { |
2091 | UErrorCode error = U_ZERO_ERROR; |
2092 | |
2093 | auto nullToSubstituter = [](const void *context, UConverterToUnicodeArgs *toUArgs, |
2094 | const char *, int32_t length, |
2095 | UConverterCallbackReason reason, UErrorCode *err) { |
2096 | if (reason <= UCNV_IRREGULAR) { |
2097 | *err = U_ZERO_ERROR; |
2098 | UChar c = '\0'; |
2099 | ucnv_cbToUWriteUChars(args: toUArgs, source: &c, length: 1, offsetIndex: 0, err); |
2100 | // Recover outer scope's state (which isn't const) from context: |
2101 | auto state = const_cast<State *>(static_cast<const State *>(context)); |
2102 | state->invalidChars += length; |
2103 | } |
2104 | }; |
2105 | ucnv_setToUCallBack(converter: conv, newAction: nullToSubstituter, newContext: state, oldAction: nullptr, oldContext: nullptr, err: &error); |
2106 | |
2107 | auto nullFromSubstituter = [](const void *context, UConverterFromUnicodeArgs *fromUArgs, |
2108 | const UChar *, int32_t length, |
2109 | UChar32, UConverterCallbackReason reason, UErrorCode *err) { |
2110 | if (reason <= UCNV_IRREGULAR) { |
2111 | *err = U_ZERO_ERROR; |
2112 | const UChar replacement[] = { 0 }; |
2113 | const UChar *stringBegin = std::begin(arr: replacement); |
2114 | ucnv_cbFromUWriteUChars(args: fromUArgs, source: &stringBegin, sourceLimit: std::end(arr: replacement), offsetIndex: 0, err); |
2115 | // Recover outer scope's state (which isn't const) from context: |
2116 | auto state = const_cast<State *>(static_cast<const State *>(context)); |
2117 | state->invalidChars += length; |
2118 | } |
2119 | }; |
2120 | ucnv_setFromUCallBack(converter: conv, newAction: nullFromSubstituter, newContext: state, oldAction: nullptr, oldContext: nullptr, err: &error); |
2121 | } else { |
2122 | UErrorCode error = U_ZERO_ERROR; |
2123 | |
2124 | auto qmarkToSubstituter = [](const void *context, UConverterToUnicodeArgs *toUArgs, |
2125 | const char *codeUnits,int32_t length, |
2126 | UConverterCallbackReason reason, UErrorCode *err) { |
2127 | if (reason <= UCNV_IRREGULAR) { |
2128 | // Recover outer scope's state (which isn't const) from context: |
2129 | auto state = const_cast<State *>(static_cast<const State *>(context)); |
2130 | state->invalidChars += length; |
2131 | } |
2132 | // use existing ICU callback for logic |
2133 | UCNV_TO_U_CALLBACK_SUBSTITUTE(context: nullptr, toUArgs, codeUnits, length, reason, err); |
2134 | |
2135 | }; |
2136 | ucnv_setToUCallBack(converter: conv, newAction: qmarkToSubstituter, newContext: state, oldAction: nullptr, oldContext: nullptr, err: &error); |
2137 | |
2138 | auto qmarkFromSubstituter = [](const void *context, UConverterFromUnicodeArgs *fromUArgs, |
2139 | const UChar *codeUnits, int32_t length, |
2140 | UChar32 codePoint, UConverterCallbackReason reason, UErrorCode *err) { |
2141 | if (reason <= UCNV_IRREGULAR) { |
2142 | // Recover outer scope's state (which isn't const) from context: |
2143 | auto state = const_cast<State *>(static_cast<const State *>(context)); |
2144 | state->invalidChars += length; |
2145 | } |
2146 | // use existing ICU callback for logic |
2147 | UCNV_FROM_U_CALLBACK_SUBSTITUTE(context: nullptr, fromUArgs, codeUnits, length, |
2148 | codePoint, reason, err); |
2149 | }; |
2150 | ucnv_setFromUCallBack(converter: conv, newAction: qmarkFromSubstituter, newContext: state, oldAction: nullptr, oldContext: nullptr, err: &error); |
2151 | } |
2152 | return conv; |
2153 | } |
2154 | |
2155 | static std::string nul_terminate_impl(QLatin1StringView name) |
2156 | { return name.isNull() ? std::string() : std::string{name.data(), size_t(name.size())}; } |
2157 | |
2158 | static std::string nul_terminate_impl(QUtf8StringView name) |
2159 | { return nul_terminate_impl(name: QLatin1StringView{QByteArrayView{name}}); } |
2160 | |
2161 | static std::string nul_terminate_impl(QStringView name) |
2162 | { |
2163 | std::string result; |
2164 | const auto convert = [&](char *p, size_t n) { |
2165 | const auto sz = QLatin1::convertFromUnicode(out: p, in: name) - p; |
2166 | Q_ASSERT(size_t(sz) <= n); |
2167 | return sz; |
2168 | }; |
2169 | #ifdef __cpp_lib_string_resize_and_overwrite |
2170 | result.resize_and_overwrite(size_t(name.size()), convert); |
2171 | #else |
2172 | result.resize(n: size_t(name.size())); |
2173 | result.resize(n: convert(result.data(), result.size())); |
2174 | #endif // __cpp_lib_string_resize_and_overwrite |
2175 | return result; |
2176 | } |
2177 | |
2178 | static std::string nul_terminate(QAnyStringView name) |
2179 | { return name.visit(v: [](auto name) { return nul_terminate_impl(name); }); } |
2180 | |
2181 | static const QStringConverter::Interface * |
2182 | make_icu_converter(QStringConverterBase::State *state, QAnyStringView name) |
2183 | { return make_icu_converter(state, name: nul_terminate(name).data()); } |
2184 | |
2185 | static const QStringConverter::Interface *make_icu_converter( |
2186 | QStringConverterBase::State *state, |
2187 | const char *name) |
2188 | { |
2189 | UErrorCode status = U_ZERO_ERROR; |
2190 | UConverter *conv = createConverterForName(name, state); |
2191 | if (!conv) |
2192 | return nullptr; |
2193 | |
2194 | const char *icuName = ucnv_getName(converter: conv, err: &status); |
2195 | // ucnv_getStandardName returns a name which is owned by the library |
2196 | // we can thus store it in the state without worrying aobut its lifetime |
2197 | const char *persistentName = ucnv_getStandardName(name: icuName, standard: "MIME", pErrorCode: &status); |
2198 | if (U_FAILURE(code: status) || !persistentName) { |
2199 | status = U_ZERO_ERROR; |
2200 | persistentName = ucnv_getStandardName(name: icuName, standard: "IANA", pErrorCode: &status); |
2201 | } |
2202 | state->d[1] = const_cast<char *>(persistentName); |
2203 | state->d[0] = conv; |
2204 | state->flags |= QStringConverterBase::Flag::UsesIcu; |
2205 | qsizetype maxCharSize = ucnv_getMaxCharSize(converter: conv); |
2206 | state->clearFn = QStringConverterICU::clear_function; |
2207 | if (maxCharSize > 8 || maxCharSize < 1) { |
2208 | qWarning(msg: "Encountered unexpected codec \"%s\" which requires >8x space", name); |
2209 | return nullptr; |
2210 | } else { |
2211 | return &forLength[maxCharSize - 1]; |
2212 | } |
2213 | |
2214 | } |
2215 | |
2216 | }; |
2217 | #endif |
2218 | |
2219 | /*! |
2220 | \internal |
2221 | */ |
2222 | QStringConverter::QStringConverter(QAnyStringView name, Flags f) |
2223 | : iface(nullptr), state(f) |
2224 | { |
2225 | auto e = encodingForName(name); |
2226 | if (e) |
2227 | iface = encodingInterfaces + int(*e); |
2228 | #if QT_CONFIG(icu) |
2229 | else |
2230 | iface = QStringConverterICU::make_icu_converter(state: &state, name); |
2231 | #endif |
2232 | } |
2233 | |
2234 | |
2235 | const char *QStringConverter::name() const noexcept |
2236 | { |
2237 | if (!iface) |
2238 | return nullptr; |
2239 | if (state.flags & QStringConverter::Flag::UsesIcu) { |
2240 | #if QT_CONFIG(icu) |
2241 | return static_cast<const char*>(state.d[1]); |
2242 | #else |
2243 | return nullptr; |
2244 | #endif |
2245 | } else { |
2246 | return iface->name; |
2247 | } |
2248 | } |
2249 | |
2250 | /*! |
2251 | \fn bool QStringConverter::isValid() const |
2252 | |
2253 | Returns true if this is a valid string converter that can be used for encoding or |
2254 | decoding text. |
2255 | |
2256 | Default constructed string converters or converters constructed with an unsupported |
2257 | name are not valid. |
2258 | */ |
2259 | |
2260 | /*! |
2261 | \fn void QStringConverter::resetState() |
2262 | |
2263 | Resets the internal state of the converter, clearing potential errors or partial |
2264 | conversions. |
2265 | */ |
2266 | |
2267 | /*! |
2268 | \fn bool QStringConverter::hasError() const |
2269 | |
2270 | Returns true if a conversion could not correctly convert a character. This could for example |
2271 | get triggered by an invalid UTF-8 sequence or when a character can't get converted due to |
2272 | limitations in the target encoding. |
2273 | */ |
2274 | |
2275 | /*! |
2276 | \fn const char *QStringConverter::name() const |
2277 | |
2278 | Returns the canonical name of the encoding this QStringConverter can encode or decode. |
2279 | Returns a nullptr if the converter is not valid. |
2280 | The returned name is UTF-8 encoded. |
2281 | |
2282 | \sa isValid() |
2283 | */ |
2284 | |
2285 | /*! |
2286 | Convert \a name to the corresponding \l Encoding member, if there is one. |
2287 | |
2288 | If the \a name is not the name of a codec listed in the Encoding enumeration, |
2289 | \c{std::nullopt} is returned. Such a name may, none the less, be accepted by |
2290 | the QStringConverter constructor when Qt is built with ICU, if ICU provides a |
2291 | converter with the given name. |
2292 | |
2293 | \note In Qt versions prior to 6.8, this function took only a \c{const char *}, |
2294 | which was expected to be UTF-8-encoded. |
2295 | */ |
2296 | std::optional<QStringConverter::Encoding> QStringConverter::encodingForName(QAnyStringView name) noexcept |
2297 | { |
2298 | if (name.isEmpty()) |
2299 | return std::nullopt; |
2300 | for (qsizetype i = 0; i < LastEncoding + 1; ++i) { |
2301 | if (nameMatch(a: encodingInterfaces[i].name, b: name)) |
2302 | return QStringConverter::Encoding(i); |
2303 | } |
2304 | if (nameMatch(a: "latin1", b: name)) |
2305 | return QStringConverter::Latin1; |
2306 | return std::nullopt; |
2307 | } |
2308 | |
2309 | #ifndef QT_BOOTSTRAPPED |
2310 | /*! |
2311 | Returns the encoding for the content of \a data if it can be determined. |
2312 | \a expectedFirstCharacter can be passed as an additional hint to help determine |
2313 | the encoding. |
2314 | |
2315 | The returned optional is empty, if the encoding is unclear. |
2316 | */ |
2317 | std::optional<QStringConverter::Encoding> |
2318 | QStringConverter::encodingForData(QByteArrayView data, char16_t expectedFirstCharacter) noexcept |
2319 | { |
2320 | // someone set us up the BOM? |
2321 | qsizetype arraySize = data.size(); |
2322 | if (arraySize > 3) { |
2323 | char32_t uc = qFromUnaligned<char32_t>(src: data.data()); |
2324 | if (uc == qToBigEndian(source: char32_t(QChar::ByteOrderMark))) |
2325 | return QStringConverter::Utf32BE; |
2326 | if (uc == qToLittleEndian(source: char32_t(QChar::ByteOrderMark))) |
2327 | return QStringConverter::Utf32LE; |
2328 | if (expectedFirstCharacter) { |
2329 | // catch also anything starting with the expected character |
2330 | if (qToLittleEndian(source: uc) == expectedFirstCharacter) |
2331 | return QStringConverter::Utf32LE; |
2332 | else if (qToBigEndian(source: uc) == expectedFirstCharacter) |
2333 | return QStringConverter::Utf32BE; |
2334 | } |
2335 | } |
2336 | |
2337 | if (arraySize > 2) { |
2338 | if (memcmp(s1: data.data(), s2: utf8bom, n: sizeof(utf8bom)) == 0) |
2339 | return QStringConverter::Utf8; |
2340 | } |
2341 | |
2342 | if (arraySize > 1) { |
2343 | char16_t uc = qFromUnaligned<char16_t>(src: data.data()); |
2344 | if (uc == qToBigEndian(source: char16_t(QChar::ByteOrderMark))) |
2345 | return QStringConverter::Utf16BE; |
2346 | if (uc == qToLittleEndian(source: char16_t(QChar::ByteOrderMark))) |
2347 | return QStringConverter::Utf16LE; |
2348 | if (expectedFirstCharacter) { |
2349 | // catch also anything starting with the expected character |
2350 | if (qToLittleEndian(source: uc) == expectedFirstCharacter) |
2351 | return QStringConverter::Utf16LE; |
2352 | else if (qToBigEndian(source: uc) == expectedFirstCharacter) |
2353 | return QStringConverter::Utf16BE; |
2354 | } |
2355 | } |
2356 | return std::nullopt; |
2357 | } |
2358 | |
2359 | static QByteArray parseHtmlMetaForEncoding(QByteArrayView data) |
2360 | { |
2361 | static constexpr auto metaSearcher = qMakeStaticByteArrayMatcher(pattern: "meta "); |
2362 | static constexpr auto charsetSearcher = qMakeStaticByteArrayMatcher(pattern: "charset="); |
2363 | |
2364 | QByteArray header = data.first(n: qMin(a: data.size(), b: qsizetype(1024))).toByteArray().toLower(); |
2365 | qsizetype pos = metaSearcher.indexIn(haystack: header); |
2366 | if (pos != -1) { |
2367 | pos = charsetSearcher.indexIn(haystack: header, from: pos); |
2368 | if (pos != -1) { |
2369 | pos += qstrlen(str: "charset="); |
2370 | if (pos < header.size() && (header.at(i: pos) == '\"' || header.at(i: pos) == '\'')) |
2371 | ++pos; |
2372 | |
2373 | qsizetype pos2 = pos; |
2374 | // The attribute can be closed with either """, "'", ">" or "/", |
2375 | // none of which are valid charset characters. |
2376 | while (++pos2 < header.size()) { |
2377 | char ch = header.at(i: pos2); |
2378 | if (ch == '\"' || ch == '\'' || ch == '>' || ch == '/') { |
2379 | QByteArray name = header.mid(index: pos, len: pos2 - pos); |
2380 | qsizetype colon = name.indexOf(c: ':'); |
2381 | if (colon > 0) |
2382 | name = name.left(n: colon); |
2383 | name = name.simplified(); |
2384 | if (name == "unicode") // QTBUG-41998, ICU will return UTF-16. |
2385 | name = QByteArrayLiteral("UTF-8"); |
2386 | if (!name.isEmpty()) |
2387 | return name; |
2388 | } |
2389 | } |
2390 | } |
2391 | } |
2392 | return QByteArray(); |
2393 | } |
2394 | |
2395 | /*! |
2396 | Tries to determine the encoding of the HTML in \a data by looking at leading byte |
2397 | order marks or a charset specifier in the HTML meta tag. If the optional is empty, |
2398 | the encoding specified is not supported by QStringConverter. If no encoding is |
2399 | detected, the method returns Utf8. |
2400 | |
2401 | \sa QStringDecoder::decoderForHtml() |
2402 | */ |
2403 | std::optional<QStringConverter::Encoding> QStringConverter::encodingForHtml(QByteArrayView data) |
2404 | { |
2405 | // determine charset |
2406 | std::optional<QStringConverter::Encoding> encoding = encodingForData(data); |
2407 | if (encoding) |
2408 | // trust the initial BOM |
2409 | return encoding; |
2410 | |
2411 | QByteArray encodingTag = parseHtmlMetaForEncoding(data); |
2412 | if (!encodingTag.isEmpty()) |
2413 | return encodingForName(name: encodingTag); |
2414 | |
2415 | return Utf8; |
2416 | } |
2417 | |
2418 | static qsizetype availableCodecCount() |
2419 | { |
2420 | #if !QT_CONFIG(icu) |
2421 | return QStringConverter::Encoding::LastEncoding; |
2422 | #else |
2423 | /* icu contains also the names of what Qt provides |
2424 | except for the special Locale one (so add one for it) |
2425 | */ |
2426 | return 1 + ucnv_countAvailable(); |
2427 | #endif |
2428 | } |
2429 | |
2430 | /*! |
2431 | Returns a list of names of supported codecs. The names returned |
2432 | by this function can be passed to QStringEncoder's and |
2433 | QStringDecoder's constructor to create a en- or decoder for |
2434 | the given codec. |
2435 | |
2436 | This function may be used to obtain a listing of additional codecs beyond |
2437 | the standard ones. Support for additional codecs requires Qt be compiled |
2438 | with support for the ICU library. |
2439 | |
2440 | \note The order of codecs is an internal implementation detail |
2441 | and not guaranteed to be stable. |
2442 | */ |
2443 | QStringList QStringConverter::availableCodecs() |
2444 | { |
2445 | auto availableCodec = [](qsizetype index) -> QString |
2446 | { |
2447 | #if !QT_CONFIG(icu) |
2448 | return QString::fromLatin1(encodingInterfaces[index].name); |
2449 | #else |
2450 | if (index == 0) // "Locale", not provided by icu |
2451 | return QString::fromLatin1( |
2452 | ba: encodingInterfaces[QStringConverter::Encoding::System].name); |
2453 | // this mirrors the setup we do to set a converters name |
2454 | UErrorCode status = U_ZERO_ERROR; |
2455 | auto icuName = ucnv_getAvailableName(n: int32_t(index - 1)); |
2456 | const char *standardName = ucnv_getStandardName(name: icuName, standard: "MIME", pErrorCode: &status); |
2457 | if (U_FAILURE(code: status) || !standardName) { |
2458 | status = U_ZERO_ERROR; |
2459 | standardName = ucnv_getStandardName(name: icuName, standard: "IANA", pErrorCode: &status); |
2460 | } |
2461 | if (!standardName) |
2462 | standardName = icuName; |
2463 | return QString::fromLatin1(ba: standardName); |
2464 | #endif |
2465 | }; |
2466 | |
2467 | qsizetype codecCount = availableCodecCount(); |
2468 | QStringList result; |
2469 | result.reserve(asize: codecCount); |
2470 | for (qsizetype i = 0; i < codecCount; ++i) |
2471 | result.push_back(t: availableCodec(i)); |
2472 | return result; |
2473 | } |
2474 | |
2475 | /*! |
2476 | Tries to determine the encoding of the HTML in \a data by looking at leading byte |
2477 | order marks or a charset specifier in the HTML meta tag and returns a QStringDecoder |
2478 | matching the encoding. If the returned decoder is not valid, |
2479 | the encoding specified is not supported by QStringConverter. If no encoding is |
2480 | detected, the method returns a decoder for Utf8. |
2481 | |
2482 | \sa isValid() |
2483 | */ |
2484 | QStringDecoder QStringDecoder::decoderForHtml(QByteArrayView data) |
2485 | { |
2486 | // determine charset |
2487 | std::optional<QStringConverter::Encoding> encoding = encodingForData(data); |
2488 | if (encoding) |
2489 | // trust the initial BOM |
2490 | return QStringDecoder(encoding.value()); |
2491 | |
2492 | QByteArray encodingTag = parseHtmlMetaForEncoding(data); |
2493 | if (!encodingTag.isEmpty()) |
2494 | return QStringDecoder(encodingTag); |
2495 | |
2496 | return QStringDecoder(Utf8); |
2497 | } |
2498 | #endif // !QT_BOOTSTRAPPED |
2499 | |
2500 | /*! |
2501 | Returns the canonical name for encoding \a e. |
2502 | */ |
2503 | const char *QStringConverter::nameForEncoding(QStringConverter::Encoding e) |
2504 | { |
2505 | return encodingInterfaces[int(e)].name; |
2506 | } |
2507 | |
2508 | /*! |
2509 | \class QStringEncoder |
2510 | \inmodule QtCore |
2511 | \brief The QStringEncoder class provides a state-based encoder for text. |
2512 | \reentrant |
2513 | \ingroup i18n |
2514 | |
2515 | A text encoder converts text from Qt's internal representation into an encoded |
2516 | text format using a specific encoding. |
2517 | |
2518 | Converting a string from Unicode to the local encoding can be achieved |
2519 | using the following code: |
2520 | |
2521 | \snippet code/src_corelib_text_qstringconverter.cpp 1 |
2522 | |
2523 | The encoder remembers any state that is required between calls, so converting |
2524 | data received in chunks, for example, when receiving it over a network, is just as |
2525 | easy, by calling the encoder whenever new data is available: |
2526 | |
2527 | \snippet code/src_corelib_text_qstringconverter.cpp 3 |
2528 | |
2529 | The QStringEncoder object maintains state between chunks and therefore |
2530 | works correctly even if a UTF-16 surrogate character is split between |
2531 | chunks. |
2532 | |
2533 | QStringEncoder objects can't be copied because of their internal state, but |
2534 | can be moved. |
2535 | |
2536 | \sa QStringConverter, QStringDecoder |
2537 | */ |
2538 | |
2539 | /*! |
2540 | \fn constexpr QStringEncoder::QStringEncoder(const Interface *i) |
2541 | \internal |
2542 | */ |
2543 | |
2544 | /*! |
2545 | \fn constexpr QStringEncoder::QStringEncoder() |
2546 | |
2547 | Default constructs an encoder. The default encoder is not valid, |
2548 | and can't be used for converting text. |
2549 | */ |
2550 | |
2551 | /*! |
2552 | \fn constexpr QStringEncoder::QStringEncoder(Encoding encoding, Flags flags = Flag::Default) |
2553 | |
2554 | Creates an encoder object using \a encoding and \a flags. |
2555 | */ |
2556 | |
2557 | /*! |
2558 | \fn QStringEncoder::QStringEncoder(QAnyStringView name, Flags flags = Flag::Default) |
2559 | |
2560 | Creates an encoder object using \a name and \a flags. |
2561 | If \a name is not the name of a known encoding an invalid converter will get created. |
2562 | |
2563 | \note In Qt versions prior to 6.8, this function took only a \c{const char *}, |
2564 | which was expected to be UTF-8-encoded. |
2565 | |
2566 | \sa isValid() |
2567 | */ |
2568 | |
2569 | /*! |
2570 | \fn QStringEncoder::DecodedData<const QString &> QStringEncoder::encode(const QString &in) |
2571 | \fn QStringEncoder::DecodedData<QStringView> QStringEncoder::encode(QStringView in) |
2572 | \fn QStringEncoder::DecodedData<const QString &> QStringEncoder::operator()(const QString &in) |
2573 | \fn QStringEncoder::DecodedData<QStringView> QStringEncoder::operator()(QStringView in) |
2574 | |
2575 | Converts \a in and returns a struct that is implicitly convertible to QByteArray. |
2576 | |
2577 | \snippet code/src_corelib_text_qstringconverter.cpp 5 |
2578 | */ |
2579 | |
2580 | /*! |
2581 | \fn qsizetype QStringEncoder::requiredSpace(qsizetype inputLength) const |
2582 | |
2583 | Returns the maximum amount of characters required to be able to process |
2584 | \a inputLength decoded data. |
2585 | |
2586 | \sa appendToBuffer() |
2587 | */ |
2588 | |
2589 | /*! |
2590 | \fn char *QStringEncoder::appendToBuffer(char *out, QStringView in) |
2591 | |
2592 | Encodes \a in and writes the encoded result into the buffer |
2593 | starting at \a out. Returns a pointer to the end of the data written. |
2594 | |
2595 | \note \a out must be large enough to be able to hold all the decoded data. Use |
2596 | requiredSpace() to determine the maximum size requirement to be able to encode |
2597 | \a in. |
2598 | |
2599 | \sa requiredSpace() |
2600 | */ |
2601 | |
2602 | /*! |
2603 | \class QStringDecoder |
2604 | \inmodule QtCore |
2605 | \brief The QStringDecoder class provides a state-based decoder for text. |
2606 | \reentrant |
2607 | \ingroup i18n |
2608 | |
2609 | A text decoder converts text an encoded text format that uses a specific encoding |
2610 | into Qt's internal representation. |
2611 | |
2612 | Converting encoded data into a QString can be achieved |
2613 | using the following code: |
2614 | |
2615 | \snippet code/src_corelib_text_qstringconverter.cpp 0 |
2616 | |
2617 | The decoder remembers any state that is required between calls, so converting |
2618 | data received in chunks, for example, when receiving it over a network, is just as |
2619 | easy, by calling the decoder whenever new data is available: |
2620 | |
2621 | \snippet code/src_corelib_text_qstringconverter.cpp 2 |
2622 | |
2623 | The QStringDecoder object maintains state between chunks and therefore |
2624 | works correctly even if chunks are split in the middle of a multi-byte character |
2625 | sequence. |
2626 | |
2627 | QStringDecoder objects can't be copied because of their internal state, but |
2628 | can be moved. |
2629 | |
2630 | \sa QStringConverter, QStringEncoder |
2631 | */ |
2632 | |
2633 | /*! |
2634 | \fn constexpr QStringDecoder::QStringDecoder(const Interface *i) |
2635 | \internal |
2636 | */ |
2637 | |
2638 | /*! |
2639 | \fn constexpr QStringDecoder::QStringDecoder() |
2640 | |
2641 | Default constructs an decoder. The default decoder is not valid, |
2642 | and can't be used for converting text. |
2643 | */ |
2644 | |
2645 | /*! |
2646 | \fn constexpr QStringDecoder::QStringDecoder(Encoding encoding, Flags flags = Flag::Default) |
2647 | |
2648 | Creates an decoder object using \a encoding and \a flags. |
2649 | */ |
2650 | |
2651 | /*! |
2652 | \fn QStringDecoder::QStringDecoder(QAnyStringView name, Flags flags = Flag::Default) |
2653 | |
2654 | Creates an decoder object using \a name and \a flags. |
2655 | If \a name is not the name of a known encoding an invalid converter will get created. |
2656 | |
2657 | \note In Qt versions prior to 6.8, this function took only a \c{const char *}, |
2658 | which was expected to be UTF-8-encoded. |
2659 | |
2660 | \sa isValid() |
2661 | */ |
2662 | |
2663 | /*! |
2664 | \fn QStringDecoder::EncodedData<const QByteArray &> QStringDecoder::operator()(const QByteArray &ba) |
2665 | \fn QStringDecoder::EncodedData<const QByteArray &> QStringDecoder::decode(const QByteArray &ba) |
2666 | \fn QStringDecoder::EncodedData<QByteArrayView> QStringDecoder::operator()(QByteArrayView ba) |
2667 | \fn QStringDecoder::EncodedData<QByteArrayView> QStringDecoder::decode(QByteArrayView ba) |
2668 | |
2669 | Converts \a ba and returns a struct that is implicitly convertible to QString. |
2670 | |
2671 | |
2672 | \snippet code/src_corelib_text_qstringconverter.cpp 4 |
2673 | */ |
2674 | |
2675 | /*! |
2676 | \fn qsizetype QStringDecoder::requiredSpace(qsizetype inputLength) const |
2677 | |
2678 | Returns the maximum amount of UTF-16 code units required to be able to process |
2679 | \a inputLength encoded data. |
2680 | |
2681 | \sa appendToBuffer |
2682 | */ |
2683 | |
2684 | /*! |
2685 | \fn QChar *QStringDecoder::appendToBuffer(QChar *out, QByteArrayView in) |
2686 | |
2687 | Decodes the sequence of bytes viewed by \a in and writes the decoded result into |
2688 | the buffer starting at \a out. Returns a pointer to the end of data written. |
2689 | |
2690 | \a out needs to be large enough to be able to hold all the decoded data. Use |
2691 | \l{requiredSpace} to determine the maximum size requirements to decode an encoded |
2692 | data buffer of \c in.size() bytes. |
2693 | |
2694 | \sa requiredSpace |
2695 | */ |
2696 | |
2697 | /*! |
2698 | \fn char16_t *QStringDecoder::appendToBuffer(char16_t *out, QByteArrayView in) |
2699 | \since 6.6 |
2700 | \overload |
2701 | */ |
2702 | |
2703 | QT_END_NAMESPACE |
2704 |
Definitions
- utf8bom
- qBitScanReverse
- simdEncodeAscii
- simdDecodeAscii
- simdFindNonAscii
- simdCompareAscii
- convertFromUnicode
- convertFromUnicode
- convertFromUnicode
- convertFromLatin1
- convertToUnicode
- convertToUnicode
- convertToUnicode
- convertToUnicode
- QUtf8NoOutputTraits
- NoOutput
- appendUtf16
- appendUcs4
- isValidUtf8
- compareUtf8
- compareUtf8
- compareUtf8
- convertFromUnicode
- convertFromUnicode
- convertToUnicode
- convertToUnicode
- convertFromUnicode
- convertFromUnicode
- convertToUnicode
- convertToUnicode
- clear
- reset
- fromUtf16
- toUtf16
- fromUtf16BE
- toUtf16BE
- fromUtf16LE
- toUtf16LE
- fromUtf32
- toUtf32
- fromUtf32BE
- toUtf32BE
- fromUtf32LE
- toUtf32LE
- convertFromUnicode
- fromLocal8Bit
- toLocal8Bit
- fromUtf8Len
- toUtf8Len
- fromUtf16Len
- toUtf16Len
- fromUtf32Len
- toUtf32Len
- fromLatin1Len
- toLatin1Len
- encodingInterfaces
- nameMatch_impl_impl
- nameMatch_impl
- nameMatch_impl
- nameMatch_impl
- nameMatch
- QStringConverterICU
- clear_function
- ensureConverter
- toUtf16
- fromUtf16
- QStringConverterICU
- fromLen
- toLen
- forLength
- createConverterForName
- nul_terminate_impl
- nul_terminate_impl
- nul_terminate_impl
- nul_terminate
- make_icu_converter
- make_icu_converter
- QStringConverter
- name
- encodingForName
- encodingForData
- parseHtmlMetaForEncoding
- encodingForHtml
- availableCodecCount
- availableCodecs
- decoderForHtml
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