Loading...
Searching...
No Matches
encodings.h
1// Tencent is pleased to support the open source community by making RapidJSON available.
2//
3// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
4//
5// Licensed under the MIT License (the "License"); you may not use this file except
6// in compliance with the License. You may obtain a copy of the License at
7//
8// http://opensource.org/licenses/MIT
9//
10// Unless required by applicable law or agreed to in writing, software distributed
11// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
12// CONDITIONS OF ANY KIND, either express or implied. See the License for the
13// specific language governing permissions and limitations under the License.
14
15#ifndef RAPIDJSON_ENCODINGS_H_
16#define RAPIDJSON_ENCODINGS_H_
17
18#include "rapidjson.h"
19
20#ifdef _MSC_VER
21RAPIDJSON_DIAG_PUSH
22RAPIDJSON_DIAG_OFF(4244) // conversion from 'type1' to 'type2', possible loss of data
23RAPIDJSON_DIAG_OFF(4702) // unreachable code
24#elif defined(__GNUC__)
25RAPIDJSON_DIAG_PUSH
26RAPIDJSON_DIAG_OFF(effc++)
27RAPIDJSON_DIAG_OFF(overflow)
28#endif
29
30RAPIDJSON_NAMESPACE_BEGIN
31
32///////////////////////////////////////////////////////////////////////////////
33// Encoding
34
35/*! \class rapidjson::Encoding
36 \brief Concept for encoding of Unicode characters.
37
38\code
39 concept Encoding {
40 typename Ch; //! Type of character. A "character" is actually a code unit in unicode's definition.
41
42 enum { supportUnicode = 1 }; // or 0 if not supporting unicode
43
44 //! \brief Encode a Unicode codepoint to an output stream.
45 //! \param os Output stream.
46 //! \param codepoint An unicode codepoint, ranging from 0x0 to 0x10FFFF inclusively.
47 template<typename OutputStream>
48 static void Encode(OutputStream& os, unsigned codepoint);
49
50 //! \brief Decode a Unicode codepoint from an input stream.
51 //! \param is Input stream.
52 //! \param codepoint Output of the unicode codepoint.
53 //! \return true if a valid codepoint can be decoded from the stream.
54 template <typename InputStream>
55 static bool Decode(InputStream& is, unsigned* codepoint);
56
57 //! \brief Validate one Unicode codepoint from an encoded stream.
58 //! \param is Input stream to obtain codepoint.
59 //! \param os Output for copying one codepoint.
60 //! \return true if it is valid.
61 //! \note This function just validating and copying the codepoint without actually decode it.
62 template <typename InputStream, typename OutputStream>
63 static bool Validate(InputStream& is, OutputStream& os);
64
65 // The following functions are deal with byte streams.
66
67 //! Take a character from input byte stream, skip BOM if exist.
68 template <typename InputByteStream>
69 static CharType TakeBOM(InputByteStream& is);
70
71 //! Take a character from input byte stream.
72 template <typename InputByteStream>
73 static Ch Take(InputByteStream& is);
74
75 //! Put BOM to output byte stream.
76 template <typename OutputByteStream>
77 static void PutBOM(OutputByteStream& os);
78
79 //! Put a character to output byte stream.
80 template <typename OutputByteStream>
81 static void Put(OutputByteStream& os, Ch c);
82};
83\endcode
84*/
85
86///////////////////////////////////////////////////////////////////////////////
87// UTF8
88
89//! UTF-8 encoding.
90/*! http://en.wikipedia.org/wiki/UTF-8
91 http://tools.ietf.org/html/rfc3629
92 \tparam CharType Code unit for storing 8-bit UTF-8 data. Default is char.
93 \note implements Encoding concept
94*/
95 template<typename CharType = char>
96 struct UTF8 {
97 typedef CharType Ch;
98
99 enum { supportUnicode = 1 };
100
101 template<typename OutputStream>
102 static void Encode(OutputStream& os, unsigned codepoint) {
103 if (codepoint <= 0x7F)
104 os.Put(static_cast<Ch>(codepoint & 0xFF));
105 else if (codepoint <= 0x7FF) {
106 os.Put(static_cast<Ch>(0xC0 | ((codepoint >> 6) & 0xFF)));
107 os.Put(static_cast<Ch>(0x80 | ((codepoint & 0x3F))));
108 }
109 else if (codepoint <= 0xFFFF) {
110 os.Put(static_cast<Ch>(0xE0 | ((codepoint >> 12) & 0xFF)));
111 os.Put(static_cast<Ch>(0x80 | ((codepoint >> 6) & 0x3F)));
112 os.Put(static_cast<Ch>(0x80 | (codepoint & 0x3F)));
113 }
114 else {
115 RAPIDJSON_ASSERT(codepoint <= 0x10FFFF);
116 os.Put(static_cast<Ch>(0xF0 | ((codepoint >> 18) & 0xFF)));
117 os.Put(static_cast<Ch>(0x80 | ((codepoint >> 12) & 0x3F)));
118 os.Put(static_cast<Ch>(0x80 | ((codepoint >> 6) & 0x3F)));
119 os.Put(static_cast<Ch>(0x80 | (codepoint & 0x3F)));
120 }
121 }
122
123 template<typename OutputStream>
124 static void EncodeUnsafe(OutputStream& os, unsigned codepoint) {
125 if (codepoint <= 0x7F)
126 PutUnsafe(os, static_cast<Ch>(codepoint & 0xFF));
127 else if (codepoint <= 0x7FF) {
128 PutUnsafe(os, static_cast<Ch>(0xC0 | ((codepoint >> 6) & 0xFF)));
129 PutUnsafe(os, static_cast<Ch>(0x80 | ((codepoint & 0x3F))));
130 }
131 else if (codepoint <= 0xFFFF) {
132 PutUnsafe(os, static_cast<Ch>(0xE0 | ((codepoint >> 12) & 0xFF)));
133 PutUnsafe(os, static_cast<Ch>(0x80 | ((codepoint >> 6) & 0x3F)));
134 PutUnsafe(os, static_cast<Ch>(0x80 | (codepoint & 0x3F)));
135 }
136 else {
137 RAPIDJSON_ASSERT(codepoint <= 0x10FFFF);
138 PutUnsafe(os, static_cast<Ch>(0xF0 | ((codepoint >> 18) & 0xFF)));
139 PutUnsafe(os, static_cast<Ch>(0x80 | ((codepoint >> 12) & 0x3F)));
140 PutUnsafe(os, static_cast<Ch>(0x80 | ((codepoint >> 6) & 0x3F)));
141 PutUnsafe(os, static_cast<Ch>(0x80 | (codepoint & 0x3F)));
142 }
143 }
144
145 template <typename InputStream>
146 static bool Decode(InputStream& is, unsigned* codepoint) {
147#define COPY() c = is.Take(); *codepoint = (*codepoint << 6) | (static_cast<unsigned char>(c) & 0x3Fu)
148#define TRANS(mask) result &= ((GetRange(static_cast<unsigned char>(c)) & mask) != 0)
149#define TAIL() COPY(); TRANS(0x70)
150 typename InputStream::Ch c = is.Take();
151 if (!(c & 0x80)) {
152 *codepoint = static_cast<unsigned char>(c);
153 return true;
154 }
155
156 unsigned char type = GetRange(static_cast<unsigned char>(c));
157 if (type >= 32) {
158 *codepoint = 0;
159 } else {
160 *codepoint = (0xFF >> type) & static_cast<unsigned char>(c);
161 }
162 bool result = true;
163 switch (type) {
164 case 2: TAIL(); return result;
165 case 3: TAIL(); TAIL(); return result;
166 case 4: COPY(); TRANS(0x50); TAIL(); return result;
167 case 5: COPY(); TRANS(0x10); TAIL(); TAIL(); return result;
168 case 6: TAIL(); TAIL(); TAIL(); return result;
169 case 10: COPY(); TRANS(0x20); TAIL(); return result;
170 case 11: COPY(); TRANS(0x60); TAIL(); TAIL(); return result;
171 default: return false;
172 }
173#undef COPY
174#undef TRANS
175#undef TAIL
176 }
177
178 template <typename InputStream, typename OutputStream>
179 static bool Validate(InputStream& is, OutputStream& os) {
180#define COPY() os.Put(c = is.Take())
181#define TRANS(mask) result &= ((GetRange(static_cast<unsigned char>(c)) & mask) != 0)
182#define TAIL() COPY(); TRANS(0x70)
183 Ch c;
184 COPY();
185 if (!(c & 0x80))
186 return true;
187
188 bool result = true;
189 switch (GetRange(static_cast<unsigned char>(c))) {
190 case 2: TAIL(); return result;
191 case 3: TAIL(); TAIL(); return result;
192 case 4: COPY(); TRANS(0x50); TAIL(); return result;
193 case 5: COPY(); TRANS(0x10); TAIL(); TAIL(); return result;
194 case 6: TAIL(); TAIL(); TAIL(); return result;
195 case 10: COPY(); TRANS(0x20); TAIL(); return result;
196 case 11: COPY(); TRANS(0x60); TAIL(); TAIL(); return result;
197 default: return false;
198 }
199#undef COPY
200#undef TRANS
201#undef TAIL
202 }
203
204 static unsigned char GetRange(unsigned char c) {
205 // Referring to DFA of http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
206 // With new mapping 1 -> 0x10, 7 -> 0x20, 9 -> 0x40, such that AND operation can test multiple types.
207 static const unsigned char type[] = {
208 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
209 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
210 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
211 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
212 0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10,
213 0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,
214 0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,
215 0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,
216 8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
217 10,3,3,3,3,3,3,3,3,3,3,3,3,4,3,3, 11,6,6,6,5,8,8,8,8,8,8,8,8,8,8,8,
218 };
219 return type[c];
220 }
221
222 template <typename InputByteStream>
223 static CharType TakeBOM(InputByteStream& is) {
224 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
225 typename InputByteStream::Ch c = Take(is);
226 if (static_cast<unsigned char>(c) != 0xEFu) return c;
227 c = is.Take();
228 if (static_cast<unsigned char>(c) != 0xBBu) return c;
229 c = is.Take();
230 if (static_cast<unsigned char>(c) != 0xBFu) return c;
231 c = is.Take();
232 return c;
233 }
234
235 template <typename InputByteStream>
236 static Ch Take(InputByteStream& is) {
237 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
238 return static_cast<Ch>(is.Take());
239 }
240
241 template <typename OutputByteStream>
242 static void PutBOM(OutputByteStream& os) {
243 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
244 os.Put(static_cast<typename OutputByteStream::Ch>(0xEFu));
245 os.Put(static_cast<typename OutputByteStream::Ch>(0xBBu));
246 os.Put(static_cast<typename OutputByteStream::Ch>(0xBFu));
247 }
248
249 template <typename OutputByteStream>
250 static void Put(OutputByteStream& os, Ch c) {
251 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
252 os.Put(static_cast<typename OutputByteStream::Ch>(c));
253 }
254};
255
256///////////////////////////////////////////////////////////////////////////////
257// UTF16
258
259//! UTF-16 encoding.
260/*! http://en.wikipedia.org/wiki/UTF-16
261 http://tools.ietf.org/html/rfc2781
262 \tparam CharType Type for storing 16-bit UTF-16 data. Default is wchar_t. C++11 may use char16_t instead.
263 \note implements Encoding concept
264
265 \note For in-memory access, no need to concern endianness. The code units and code points are represented by CPU's endianness.
266 For streaming, use UTF16LE and UTF16BE, which handle endianness.
267*/
268 template<typename CharType = wchar_t>
269 struct UTF16 {
270 typedef CharType Ch;
271 RAPIDJSON_STATIC_ASSERT(sizeof(Ch) >= 2);
272
273 enum { supportUnicode = 1 };
274
275 template<typename OutputStream>
276 static void Encode(OutputStream& os, unsigned codepoint) {
277 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputStream::Ch) >= 2);
278 if (codepoint <= 0xFFFF) {
279 RAPIDJSON_ASSERT(codepoint < 0xD800 || codepoint > 0xDFFF); // Code point itself cannot be surrogate pair
280 os.Put(static_cast<typename OutputStream::Ch>(codepoint));
281 }
282 else {
283 RAPIDJSON_ASSERT(codepoint <= 0x10FFFF);
284 unsigned v = codepoint - 0x10000;
285 os.Put(static_cast<typename OutputStream::Ch>((v >> 10) | 0xD800));
286 os.Put((v & 0x3FF) | 0xDC00);
287 }
288 }
289
290
291 template<typename OutputStream>
292 static void EncodeUnsafe(OutputStream& os, unsigned codepoint) {
293 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputStream::Ch) >= 2);
294 if (codepoint <= 0xFFFF) {
295 RAPIDJSON_ASSERT(codepoint < 0xD800 || codepoint > 0xDFFF); // Code point itself cannot be surrogate pair
296 PutUnsafe(os, static_cast<typename OutputStream::Ch>(codepoint));
297 }
298 else {
299 RAPIDJSON_ASSERT(codepoint <= 0x10FFFF);
300 unsigned v = codepoint - 0x10000;
301 PutUnsafe(os, static_cast<typename OutputStream::Ch>((v >> 10) | 0xD800));
302 PutUnsafe(os, (v & 0x3FF) | 0xDC00);
303 }
304 }
305
306 template <typename InputStream>
307 static bool Decode(InputStream& is, unsigned* codepoint) {
308 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputStream::Ch) >= 2);
309 typename InputStream::Ch c = is.Take();
310 if (c < 0xD800 || c > 0xDFFF) {
311 *codepoint = static_cast<unsigned>(c);
312 return true;
313 }
314 else if (c <= 0xDBFF) {
315 *codepoint = (static_cast<unsigned>(c) & 0x3FF) << 10;
316 c = is.Take();
317 *codepoint |= (static_cast<unsigned>(c) & 0x3FF);
318 *codepoint += 0x10000;
319 return c >= 0xDC00 && c <= 0xDFFF;
320 }
321 return false;
322 }
323
324 template <typename InputStream, typename OutputStream>
325 static bool Validate(InputStream& is, OutputStream& os) {
326 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputStream::Ch) >= 2);
327 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputStream::Ch) >= 2);
328 typename InputStream::Ch c;
329 os.Put(static_cast<typename OutputStream::Ch>(c = is.Take()));
330 if (c < 0xD800 || c > 0xDFFF)
331 return true;
332 else if (c <= 0xDBFF) {
333 os.Put(c = is.Take());
334 return c >= 0xDC00 && c <= 0xDFFF;
335 }
336 return false;
337 }
338};
339
340//! UTF-16 little endian encoding.
341 template<typename CharType = wchar_t>
342 struct UTF16LE : UTF16<CharType> {
343 template <typename InputByteStream>
344 static CharType TakeBOM(InputByteStream& is) {
345 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
346 CharType c = Take(is);
347 return static_cast<uint16_t>(c) == 0xFEFFu ? Take(is) : c;
348 }
349
350 template <typename InputByteStream>
351 static CharType Take(InputByteStream& is) {
352 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
353 unsigned c = static_cast<uint8_t>(is.Take());
354 c |= static_cast<unsigned>(static_cast<uint8_t>(is.Take())) << 8;
355 return static_cast<CharType>(c);
356 }
357
358 template <typename OutputByteStream>
359 static void PutBOM(OutputByteStream& os) {
360 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
361 os.Put(static_cast<typename OutputByteStream::Ch>(0xFFu));
362 os.Put(static_cast<typename OutputByteStream::Ch>(0xFEu));
363 }
364
365 template <typename OutputByteStream>
366 static void Put(OutputByteStream& os, CharType c) {
367 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
368 os.Put(static_cast<typename OutputByteStream::Ch>(static_cast<unsigned>(c) & 0xFFu));
369 os.Put(static_cast<typename OutputByteStream::Ch>((static_cast<unsigned>(c) >> 8) & 0xFFu));
370 }
371};
372
373//! UTF-16 big endian encoding.
374 template<typename CharType = wchar_t>
375 struct UTF16BE : UTF16<CharType> {
376 template <typename InputByteStream>
377 static CharType TakeBOM(InputByteStream& is) {
378 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
379 CharType c = Take(is);
380 return static_cast<uint16_t>(c) == 0xFEFFu ? Take(is) : c;
381 }
382
383 template <typename InputByteStream>
384 static CharType Take(InputByteStream& is) {
385 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
386 unsigned c = static_cast<unsigned>(static_cast<uint8_t>(is.Take())) << 8;
387 c |= static_cast<uint8_t>(is.Take());
388 return static_cast<CharType>(c);
389 }
390
391 template <typename OutputByteStream>
392 static void PutBOM(OutputByteStream& os) {
393 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
394 os.Put(static_cast<typename OutputByteStream::Ch>(0xFEu));
395 os.Put(static_cast<typename OutputByteStream::Ch>(0xFFu));
396 }
397
398 template <typename OutputByteStream>
399 static void Put(OutputByteStream& os, CharType c) {
400 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
401 os.Put(static_cast<typename OutputByteStream::Ch>((static_cast<unsigned>(c) >> 8) & 0xFFu));
402 os.Put(static_cast<typename OutputByteStream::Ch>(static_cast<unsigned>(c) & 0xFFu));
403 }
404};
405
406///////////////////////////////////////////////////////////////////////////////
407// UTF32
408
409//! UTF-32 encoding.
410/*! http://en.wikipedia.org/wiki/UTF-32
411 \tparam CharType Type for storing 32-bit UTF-32 data. Default is unsigned. C++11 may use char32_t instead.
412 \note implements Encoding concept
413
414 \note For in-memory access, no need to concern endianness. The code units and code points are represented by CPU's endianness.
415 For streaming, use UTF32LE and UTF32BE, which handle endianness.
416*/
417 template<typename CharType = unsigned>
418 struct UTF32 {
419 typedef CharType Ch;
420 RAPIDJSON_STATIC_ASSERT(sizeof(Ch) >= 4);
421
422 enum { supportUnicode = 1 };
423
424 template<typename OutputStream>
425 static void Encode(OutputStream& os, unsigned codepoint) {
426 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputStream::Ch) >= 4);
427 RAPIDJSON_ASSERT(codepoint <= 0x10FFFF);
428 os.Put(codepoint);
429 }
430
431 template<typename OutputStream>
432 static void EncodeUnsafe(OutputStream& os, unsigned codepoint) {
433 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputStream::Ch) >= 4);
434 RAPIDJSON_ASSERT(codepoint <= 0x10FFFF);
435 PutUnsafe(os, codepoint);
436 }
437
438 template <typename InputStream>
439 static bool Decode(InputStream& is, unsigned* codepoint) {
440 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputStream::Ch) >= 4);
441 Ch c = is.Take();
442 *codepoint = c;
443 return c <= 0x10FFFF;
444 }
445
446 template <typename InputStream, typename OutputStream>
447 static bool Validate(InputStream& is, OutputStream& os) {
448 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputStream::Ch) >= 4);
449 Ch c;
450 os.Put(c = is.Take());
451 return c <= 0x10FFFF;
452 }
453};
454
455//! UTF-32 little endian enocoding.
456 template<typename CharType = unsigned>
457 struct UTF32LE : UTF32<CharType> {
458 template <typename InputByteStream>
459 static CharType TakeBOM(InputByteStream& is) {
460 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
461 CharType c = Take(is);
462 return static_cast<uint32_t>(c) == 0x0000FEFFu ? Take(is) : c;
463 }
464
465 template <typename InputByteStream>
466 static CharType Take(InputByteStream& is) {
467 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
468 unsigned c = static_cast<uint8_t>(is.Take());
469 c |= static_cast<unsigned>(static_cast<uint8_t>(is.Take())) << 8;
470 c |= static_cast<unsigned>(static_cast<uint8_t>(is.Take())) << 16;
471 c |= static_cast<unsigned>(static_cast<uint8_t>(is.Take())) << 24;
472 return static_cast<CharType>(c);
473 }
474
475 template <typename OutputByteStream>
476 static void PutBOM(OutputByteStream& os) {
477 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
478 os.Put(static_cast<typename OutputByteStream::Ch>(0xFFu));
479 os.Put(static_cast<typename OutputByteStream::Ch>(0xFEu));
480 os.Put(static_cast<typename OutputByteStream::Ch>(0x00u));
481 os.Put(static_cast<typename OutputByteStream::Ch>(0x00u));
482 }
483
484 template <typename OutputByteStream>
485 static void Put(OutputByteStream& os, CharType c) {
486 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
487 os.Put(static_cast<typename OutputByteStream::Ch>(c & 0xFFu));
488 os.Put(static_cast<typename OutputByteStream::Ch>((c >> 8) & 0xFFu));
489 os.Put(static_cast<typename OutputByteStream::Ch>((c >> 16) & 0xFFu));
490 os.Put(static_cast<typename OutputByteStream::Ch>((c >> 24) & 0xFFu));
491 }
492};
493
494//! UTF-32 big endian encoding.
495 template<typename CharType = unsigned>
496 struct UTF32BE : UTF32<CharType> {
497 template <typename InputByteStream>
498 static CharType TakeBOM(InputByteStream& is) {
499 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
500 CharType c = Take(is);
501 return static_cast<uint32_t>(c) == 0x0000FEFFu ? Take(is) : c;
502 }
503
504 template <typename InputByteStream>
505 static CharType Take(InputByteStream& is) {
506 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
507 unsigned c = static_cast<unsigned>(static_cast<uint8_t>(is.Take())) << 24;
508 c |= static_cast<unsigned>(static_cast<uint8_t>(is.Take())) << 16;
509 c |= static_cast<unsigned>(static_cast<uint8_t>(is.Take())) << 8;
510 c |= static_cast<unsigned>(static_cast<uint8_t>(is.Take()));
511 return static_cast<CharType>(c);
512 }
513
514 template <typename OutputByteStream>
515 static void PutBOM(OutputByteStream& os) {
516 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
517 os.Put(static_cast<typename OutputByteStream::Ch>(0x00u));
518 os.Put(static_cast<typename OutputByteStream::Ch>(0x00u));
519 os.Put(static_cast<typename OutputByteStream::Ch>(0xFEu));
520 os.Put(static_cast<typename OutputByteStream::Ch>(0xFFu));
521 }
522
523 template <typename OutputByteStream>
524 static void Put(OutputByteStream& os, CharType c) {
525 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
526 os.Put(static_cast<typename OutputByteStream::Ch>((c >> 24) & 0xFFu));
527 os.Put(static_cast<typename OutputByteStream::Ch>((c >> 16) & 0xFFu));
528 os.Put(static_cast<typename OutputByteStream::Ch>((c >> 8) & 0xFFu));
529 os.Put(static_cast<typename OutputByteStream::Ch>(c & 0xFFu));
530 }
531};
532
533///////////////////////////////////////////////////////////////////////////////
534// ASCII
535
536//! ASCII encoding.
537/*! http://en.wikipedia.org/wiki/ASCII
538 \tparam CharType Code unit for storing 7-bit ASCII data. Default is char.
539 \note implements Encoding concept
540*/
541 template<typename CharType = char>
542 struct ASCII {
543 typedef CharType Ch;
544
545 enum { supportUnicode = 0 };
546
547 template<typename OutputStream>
548 static void Encode(OutputStream& os, unsigned codepoint) {
549 RAPIDJSON_ASSERT(codepoint <= 0x7F);
550 os.Put(static_cast<Ch>(codepoint & 0xFF));
551 }
552
553 template<typename OutputStream>
554 static void EncodeUnsafe(OutputStream& os, unsigned codepoint) {
555 RAPIDJSON_ASSERT(codepoint <= 0x7F);
556 PutUnsafe(os, static_cast<Ch>(codepoint & 0xFF));
557 }
558
559 template <typename InputStream>
560 static bool Decode(InputStream& is, unsigned* codepoint) {
561 uint8_t c = static_cast<uint8_t>(is.Take());
562 *codepoint = c;
563 return c <= 0X7F;
564 }
565
566 template <typename InputStream, typename OutputStream>
567 static bool Validate(InputStream& is, OutputStream& os) {
568 uint8_t c = static_cast<uint8_t>(is.Take());
569 os.Put(static_cast<typename OutputStream::Ch>(c));
570 return c <= 0x7F;
571 }
572
573 template <typename InputByteStream>
574 static CharType TakeBOM(InputByteStream& is) {
575 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
576 uint8_t c = static_cast<uint8_t>(Take(is));
577 return static_cast<Ch>(c);
578 }
579
580 template <typename InputByteStream>
581 static Ch Take(InputByteStream& is) {
582 RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1);
583 return static_cast<Ch>(is.Take());
584 }
585
586 template <typename OutputByteStream>
587 static void PutBOM(OutputByteStream& os) {
588 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
589 (void)os;
590 }
591
592 template <typename OutputByteStream>
593 static void Put(OutputByteStream& os, Ch c) {
594 RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1);
595 os.Put(static_cast<typename OutputByteStream::Ch>(c));
596 }
597};
598
599///////////////////////////////////////////////////////////////////////////////
600// AutoUTF
601
602//! Runtime-specified UTF encoding type of a stream.
603 enum UTFType {
604 kUTF8 = 0, //!< UTF-8.
605 kUTF16LE = 1, //!< UTF-16 little endian.
606 kUTF16BE = 2, //!< UTF-16 big endian.
607 kUTF32LE = 3, //!< UTF-32 little endian.
608 kUTF32BE = 4 //!< UTF-32 big endian.
609};
610
611//! Dynamically select encoding according to stream's runtime-specified UTF encoding type.
612/*! \note This class can be used with AutoUTFInputtStream and AutoUTFOutputStream, which provides GetType().
613*/
614 template<typename CharType>
615 struct AutoUTF {
616 typedef CharType Ch;
617
618 enum { supportUnicode = 1 };
619
620#define RAPIDJSON_ENCODINGS_FUNC(x) UTF8<Ch>::x, UTF16LE<Ch>::x, UTF16BE<Ch>::x, UTF32LE<Ch>::x, UTF32BE<Ch>::x
621
622 template<typename OutputStream>
623 RAPIDJSON_FORCEINLINE static void Encode(OutputStream& os, unsigned codepoint) {
624 typedef void (*EncodeFunc)(OutputStream&, unsigned);
625 static const EncodeFunc f[] = { RAPIDJSON_ENCODINGS_FUNC(Encode) };
626 (*f[os.GetType()])(os, codepoint);
627 }
628
629 template<typename OutputStream>
630 RAPIDJSON_FORCEINLINE static void EncodeUnsafe(OutputStream& os, unsigned codepoint) {
631 typedef void (*EncodeFunc)(OutputStream&, unsigned);
632 static const EncodeFunc f[] = { RAPIDJSON_ENCODINGS_FUNC(EncodeUnsafe) };
633 (*f[os.GetType()])(os, codepoint);
634 }
635
636 template <typename InputStream>
637 RAPIDJSON_FORCEINLINE static bool Decode(InputStream& is, unsigned* codepoint) {
638 typedef bool (*DecodeFunc)(InputStream&, unsigned*);
639 static const DecodeFunc f[] = { RAPIDJSON_ENCODINGS_FUNC(Decode) };
640 return (*f[is.GetType()])(is, codepoint);
641 }
642
643 template <typename InputStream, typename OutputStream>
644 RAPIDJSON_FORCEINLINE static bool Validate(InputStream& is, OutputStream& os) {
645 typedef bool (*ValidateFunc)(InputStream&, OutputStream&);
646 static const ValidateFunc f[] = { RAPIDJSON_ENCODINGS_FUNC(Validate) };
647 return (*f[is.GetType()])(is, os);
648 }
649
650#undef RAPIDJSON_ENCODINGS_FUNC
651};
652
653///////////////////////////////////////////////////////////////////////////////
654// Transcoder
655
656//! Encoding conversion.
657 template<typename SourceEncoding, typename TargetEncoding>
658 struct Transcoder {
659 //! Take one Unicode codepoint from source encoding, convert it to target encoding and put it to the output stream.
660 template<typename InputStream, typename OutputStream>
661 RAPIDJSON_FORCEINLINE static bool Transcode(InputStream& is, OutputStream& os) {
662 unsigned codepoint;
663 if (!SourceEncoding::Decode(is, &codepoint))
664 return false;
665 TargetEncoding::Encode(os, codepoint);
666 return true;
667 }
668
669 template<typename InputStream, typename OutputStream>
670 RAPIDJSON_FORCEINLINE static bool TranscodeUnsafe(InputStream& is, OutputStream& os) {
671 unsigned codepoint;
672 if (!SourceEncoding::Decode(is, &codepoint))
673 return false;
674 TargetEncoding::EncodeUnsafe(os, codepoint);
675 return true;
676 }
677
678 //! Validate one Unicode codepoint from an encoded stream.
679 template<typename InputStream, typename OutputStream>
680 RAPIDJSON_FORCEINLINE static bool Validate(InputStream& is, OutputStream& os) {
681 return Transcode(is, os); // Since source/target encoding is different, must transcode.
682 }
683};
684
685// Forward declaration.
686 template<typename Stream>
687 inline void PutUnsafe(Stream& stream, typename Stream::Ch c);
688
689//! Specialization of Transcoder with same source and target encoding.
690 template<typename Encoding>
691 struct Transcoder<Encoding, Encoding> {
692 template<typename InputStream, typename OutputStream>
693 RAPIDJSON_FORCEINLINE static bool Transcode(InputStream& is, OutputStream& os) {
694 os.Put(is.Take()); // Just copy one code unit. This semantic is different from primary template class.
695 return true;
696 }
697
698 template<typename InputStream, typename OutputStream>
699 RAPIDJSON_FORCEINLINE static bool TranscodeUnsafe(InputStream& is, OutputStream& os) {
700 PutUnsafe(os, is.Take()); // Just copy one code unit. This semantic is different from primary template class.
701 return true;
702 }
703
704 template<typename InputStream, typename OutputStream>
705 RAPIDJSON_FORCEINLINE static bool Validate(InputStream& is, OutputStream& os) {
706 return Encoding::Validate(is, os); // source/target encoding are the same
707 }
708};
709
710RAPIDJSON_NAMESPACE_END
711
712#if defined(__GNUC__) || defined(_MSC_VER)
713RAPIDJSON_DIAG_POP
714#endif
715
716#endif // RAPIDJSON_ENCODINGS_H_
Encoding
Concept for encoding of Unicode characters.
Stream
Concept for reading and writing characters.
RAPIDJSON_ASSERT
#define RAPIDJSON_ASSERT(x)
Assertion.
Definition rapidjson.h:402
rapidjson::PutUnsafe
void PutUnsafe(Stream &stream, typename Stream::Ch c)
Write character to a stream, presuming buffer is reserved.
Definition stream.h:91
rapidjson::UTFType
UTFType
Runtime-specified UTF encoding type of a stream.
Definition encodings.h:603
rapidjson::kUTF32LE
@ kUTF32LE
UTF-32 little endian.
Definition encodings.h:607
rapidjson::kUTF8
@ kUTF8
UTF-8.
Definition encodings.h:604
rapidjson::kUTF16BE
@ kUTF16BE
UTF-16 big endian.
Definition encodings.h:606
rapidjson::kUTF16LE
@ kUTF16LE
UTF-16 little endian.
Definition encodings.h:605
rapidjson::kUTF32BE
@ kUTF32BE
UTF-32 big endian.
Definition encodings.h:608
rapidjson.h
common definitions and configuration
RAPIDJSON_STATIC_ASSERT
#define RAPIDJSON_STATIC_ASSERT(x)
(Internal) macro to check for conditions at compile-time
Definition rapidjson.h:437
rapidjson::Transcoder
Encoding conversion.
Definition fwd.h:35
rapidjson::Transcoder::Transcode
static RAPIDJSON_FORCEINLINE bool Transcode(InputStream &is, OutputStream &os)
Take one Unicode codepoint from source encoding, convert it to target encoding and put it to the outp...
Definition encodings.h:661
rapidjson::Transcoder::Validate
static RAPIDJSON_FORCEINLINE bool Validate(InputStream &is, OutputStream &os)
Validate one Unicode codepoint from an encoded stream.
Definition encodings.h:680