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_READER_H_ 16 #define RAPIDJSON_READER_H_ 17 18 /*! \file reader.h */ 19 20 #include "rapidjson.h" 21 #include "encodings.h" 22 #include "internal/meta.h" 23 #include "internal/stack.h" 24 #include "internal/strtod.h" 25 26 #if defined(RAPIDJSON_SIMD) && defined(_MSC_VER) 27 #include <intrin.h> 28 #pragma intrinsic(_BitScanForward) 29 #endif 30 #ifdef RAPIDJSON_SSE42 31 #include <nmmintrin.h> 32 #elif defined(RAPIDJSON_SSE2) 33 #include <emmintrin.h> 34 #endif 35 36 #ifdef _MSC_VER 37 RAPIDJSON_DIAG_PUSH 38 RAPIDJSON_DIAG_OFF(4127) // conditional expression is constant 39 RAPIDJSON_DIAG_OFF(4702) // unreachable code 40 #endif 41 42 #ifdef __GNUC__ 43 RAPIDJSON_DIAG_PUSH 44 RAPIDJSON_DIAG_OFF(effc++) 45 #endif 46 47 //!@cond RAPIDJSON_HIDDEN_FROM_DOXYGEN 48 #define RAPIDJSON_NOTHING /* deliberately empty */ 49 #ifndef RAPIDJSON_PARSE_ERROR_EARLY_RETURN 50 #define RAPIDJSON_PARSE_ERROR_EARLY_RETURN(value) \ 51 RAPIDJSON_MULTILINEMACRO_BEGIN \ 52 if (HasParseError()) { return value; } \ 53 RAPIDJSON_MULTILINEMACRO_END 54 #endif 55 #define RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID \ 56 RAPIDJSON_PARSE_ERROR_EARLY_RETURN(RAPIDJSON_NOTHING) 57 //!@endcond 58 59 /*! \def RAPIDJSON_PARSE_ERROR_NORETURN 60 \ingroup RAPIDJSON_ERRORS 61 \brief Macro to indicate a parse error. 62 \param parseErrorCode \ref rapidjson::ParseErrorCode of the error 63 \param offset position of the error in JSON input (\c size_t) 64 65 This macros can be used as a customization point for the internal 66 error handling mechanism of RapidJSON. 67 68 A common usage model is to throw an exception instead of requiring the 69 caller to explicitly check the \ref rapidjson::GenericReader::Parse's 70 return value: 71 72 \code 73 #define RAPIDJSON_PARSE_ERROR_NORETURN(parseErrorCode,offset) \ 74 throw ParseException(parseErrorCode, #parseErrorCode, offset) 75 76 #include <stdexcept> // std::runtime_error 77 #include "rapidjson/error/error.h" // rapidjson::ParseResult 78 79 struct ParseException : std::runtime_error, rapidjson::ParseResult { 80 ParseException(rapidjson::ParseErrorCode code, const char* msg, size_t offset) 81 : std::runtime_error(msg), ParseResult(code, offset) {} 82 }; 83 84 #include "rapidjson/reader.h" 85 \endcode 86 87 \see RAPIDJSON_PARSE_ERROR, rapidjson::GenericReader::Parse 88 */ 89 #ifndef RAPIDJSON_PARSE_ERROR_NORETURN 90 #define RAPIDJSON_PARSE_ERROR_NORETURN(parseErrorCode, offset) \ 91 RAPIDJSON_MULTILINEMACRO_BEGIN \ 92 RAPIDJSON_ASSERT(!HasParseError()); /* Error can only be assigned once */ \ 93 SetParseError(parseErrorCode, offset); \ 94 RAPIDJSON_MULTILINEMACRO_END 95 #endif 96 97 /*! \def RAPIDJSON_PARSE_ERROR 98 \ingroup RAPIDJSON_ERRORS 99 \brief (Internal) macro to indicate and handle a parse error. 100 \param parseErrorCode \ref rapidjson::ParseErrorCode of the error 101 \param offset position of the error in JSON input (\c size_t) 102 103 Invokes RAPIDJSON_PARSE_ERROR_NORETURN and stops the parsing. 104 105 \see RAPIDJSON_PARSE_ERROR_NORETURN 106 \hideinitializer 107 */ 108 #ifndef RAPIDJSON_PARSE_ERROR 109 #define RAPIDJSON_PARSE_ERROR(parseErrorCode, offset) \ 110 RAPIDJSON_MULTILINEMACRO_BEGIN \ 111 RAPIDJSON_PARSE_ERROR_NORETURN(parseErrorCode, offset); \ 112 RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID; \ 113 RAPIDJSON_MULTILINEMACRO_END 114 #endif 115 116 #include "error/error.h" // ParseErrorCode, ParseResult 117 118 RAPIDJSON_NAMESPACE_BEGIN 119 120 /////////////////////////////////////////////////////////////////////////////// 121 // ParseFlag 122 123 /*! \def RAPIDJSON_PARSE_DEFAULT_FLAGS 124 \ingroup RAPIDJSON_CONFIG 125 \brief User-defined kParseDefaultFlags definition. 126 127 User can define this as any \c ParseFlag combinations. 128 */ 129 #ifndef RAPIDJSON_PARSE_DEFAULT_FLAGS 130 #define RAPIDJSON_PARSE_DEFAULT_FLAGS kParseNoFlags 131 #endif 132 133 //! Combination of parseFlags 134 /*! \see Reader::Parse, Document::Parse, Document::ParseInsitu, Document::ParseStream 135 */ 136 enum ParseFlag { 137 kParseNoFlags = 0, //!< No flags are set. 138 kParseInsituFlag = 1, //!< In-situ(destructive) parsing. 139 kParseValidateEncodingFlag = 2, //!< Validate encoding of JSON strings. 140 kParseIterativeFlag = 4, //!< Iterative(constant complexity in terms of function call stack size) parsing. 141 kParseStopWhenDoneFlag = 8, //!< After parsing a complete JSON root from stream, stop further processing the rest of stream. When this flag is used, parser will not generate kParseErrorDocumentRootNotSingular error. 142 kParseFullPrecisionFlag = 16, //!< Parse number in full precision (but slower). 143 kParseDefaultFlags = RAPIDJSON_PARSE_DEFAULT_FLAGS //!< Default parse flags. Can be customized by defining RAPIDJSON_PARSE_DEFAULT_FLAGS 144 }; 145 146 /////////////////////////////////////////////////////////////////////////////// 147 // Handler 148 149 /*! \class rapidjson::Handler 150 \brief Concept for receiving events from GenericReader upon parsing. 151 The functions return true if no error occurs. If they return false, 152 the event publisher should terminate the process. 153 \code 154 concept Handler { 155 typename Ch; 156 157 bool Null(); 158 bool Bool(bool b); 159 bool Int(int i); 160 bool Uint(unsigned i); 161 bool Int64(int64_t i); 162 bool Uint64(uint64_t i); 163 bool Double(double d); 164 bool String(const Ch* str, SizeType length, bool copy); 165 bool StartObject(); 166 bool Key(const Ch* str, SizeType length, bool copy); 167 bool EndObject(SizeType memberCount); 168 bool StartArray(); 169 bool EndArray(SizeType elementCount); 170 }; 171 \endcode 172 */ 173 /////////////////////////////////////////////////////////////////////////////// 174 // BaseReaderHandler 175 176 //! Default implementation of Handler. 177 /*! This can be used as base class of any reader handler. 178 \note implements Handler concept 179 */ 180 template<typename Encoding = UTF8<>, typename Derived = void> 181 struct BaseReaderHandler { 182 typedef typename Encoding::Ch Ch; 183 184 typedef typename internal::SelectIf<internal::IsSame<Derived, void>, BaseReaderHandler, Derived>::Type Override; 185 186 bool Default() { return true; } 187 bool Null() { return static_cast<Override&>(*this).Default(); } 188 bool Bool(bool) { return static_cast<Override&>(*this).Default(); } 189 bool Int(int) { return static_cast<Override&>(*this).Default(); } 190 bool Uint(unsigned) { return static_cast<Override&>(*this).Default(); } 191 bool Int64(int64_t) { return static_cast<Override&>(*this).Default(); } 192 bool Uint64(uint64_t) { return static_cast<Override&>(*this).Default(); } 193 bool Double(double) { return static_cast<Override&>(*this).Default(); } 194 bool String(const Ch*, SizeType, bool) { return static_cast<Override&>(*this).Default(); } 195 bool StartObject() { return static_cast<Override&>(*this).Default(); } 196 bool Key(const Ch* str, SizeType len, bool copy) { return static_cast<Override&>(*this).String(str, len, copy); } 197 bool EndObject(SizeType) { return static_cast<Override&>(*this).Default(); } 198 bool StartArray() { return static_cast<Override&>(*this).Default(); } 199 bool EndArray(SizeType) { return static_cast<Override&>(*this).Default(); } 200 }; 201 202 /////////////////////////////////////////////////////////////////////////////// 203 // StreamLocalCopy 204 205 namespace internal { 206 207 template<typename Stream, int = StreamTraits<Stream>::copyOptimization> 208 class StreamLocalCopy; 209 210 //! Do copy optimization. 211 template<typename Stream> 212 class StreamLocalCopy<Stream, 1> { 213 public: 214 explicit StreamLocalCopy(Stream& original) : s(original), original_(original) {} 215 ~StreamLocalCopy() { original_ = s; } 216 217 Stream s; 218 219 private: 220 StreamLocalCopy& operator=(const StreamLocalCopy&) /* = delete */; 221 222 Stream& original_; 223 }; 224 225 //! Keep reference. 226 template<typename Stream> 227 class StreamLocalCopy<Stream, 0> { 228 public: 229 explicit StreamLocalCopy(Stream& original) : s(original) {} 230 231 Stream& s; 232 233 private: 234 StreamLocalCopy& operator=(const StreamLocalCopy&) /* = delete */; 235 }; 236 237 } // namespace internal 238 239 /////////////////////////////////////////////////////////////////////////////// 240 // SkipWhitespace 241 242 //! Skip the JSON white spaces in a stream. 243 /*! \param is A input stream for skipping white spaces. 244 \note This function has SSE2/SSE4.2 specialization. 245 */ 246 template<typename InputStream> 247 void SkipWhitespace(InputStream& is) { 248 internal::StreamLocalCopy<InputStream> copy(is); 249 InputStream& s(copy.s); 250 251 while (s.Peek() == ' ' || s.Peek() == '\n' || s.Peek() == '\r' || s.Peek() == '\t') 252 s.Take(); 253 } 254 255 #ifdef RAPIDJSON_SSE42 256 //! Skip whitespace with SSE 4.2 pcmpistrm instruction, testing 16 8-byte characters at once. 257 inline const char *SkipWhitespace_SIMD(const char* p) { 258 // Fast return for single non-whitespace 259 if (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t') 260 ++p; 261 else 262 return p; 263 264 // 16-byte align to the next boundary 265 const char* nextAligned = reinterpret_cast<const char*>((reinterpret_cast<size_t>(p) + 15) & ~15); 266 while (p != nextAligned) 267 if (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t') 268 ++p; 269 else 270 return p; 271 272 // The rest of string using SIMD 273 static const char whitespace[16] = " \n\r\t"; 274 const __m128i w = _mm_loadu_si128((const __m128i *)&whitespace[0]); 275 276 for (;; p += 16) { 277 const __m128i s = _mm_load_si128((const __m128i *)p); 278 const unsigned r = _mm_cvtsi128_si32(_mm_cmpistrm(w, s, _SIDD_UBYTE_OPS | _SIDD_CMP_EQUAL_ANY | _SIDD_BIT_MASK | _SIDD_NEGATIVE_POLARITY)); 279 if (r != 0) { // some of characters is non-whitespace 280 #ifdef _MSC_VER // Find the index of first non-whitespace 281 unsigned long offset; 282 _BitScanForward(&offset, r); 283 return p + offset; 284 #else 285 return p + __builtin_ffs(r) - 1; 286 #endif 287 } 288 } 289 } 290 291 #elif defined(RAPIDJSON_SSE2) 292 293 //! Skip whitespace with SSE2 instructions, testing 16 8-byte characters at once. 294 inline const char *SkipWhitespace_SIMD(const char* p) { 295 // Fast return for single non-whitespace 296 if (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t') 297 ++p; 298 else 299 return p; 300 301 // 16-byte align to the next boundary 302 const char* nextAligned = reinterpret_cast<const char*>((reinterpret_cast<size_t>(p) + 15) & ~15); 303 while (p != nextAligned) 304 if (*p == ' ' || *p == '\n' || *p == '\r' || *p == '\t') 305 ++p; 306 else 307 return p; 308 309 // The rest of string 310 static const char whitespaces[4][17] = { 311 " ", 312 "\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n", 313 "\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r\r", 314 "\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t"}; 315 316 const __m128i w0 = _mm_loadu_si128((const __m128i *)&whitespaces[0][0]); 317 const __m128i w1 = _mm_loadu_si128((const __m128i *)&whitespaces[1][0]); 318 const __m128i w2 = _mm_loadu_si128((const __m128i *)&whitespaces[2][0]); 319 const __m128i w3 = _mm_loadu_si128((const __m128i *)&whitespaces[3][0]); 320 321 for (;; p += 16) { 322 const __m128i s = _mm_load_si128((const __m128i *)p); 323 __m128i x = _mm_cmpeq_epi8(s, w0); 324 x = _mm_or_si128(x, _mm_cmpeq_epi8(s, w1)); 325 x = _mm_or_si128(x, _mm_cmpeq_epi8(s, w2)); 326 x = _mm_or_si128(x, _mm_cmpeq_epi8(s, w3)); 327 unsigned short r = (unsigned short)~_mm_movemask_epi8(x); 328 if (r != 0) { // some of characters may be non-whitespace 329 #ifdef _MSC_VER // Find the index of first non-whitespace 330 unsigned long offset; 331 _BitScanForward(&offset, r); 332 return p + offset; 333 #else 334 return p + __builtin_ffs(r) - 1; 335 #endif 336 } 337 } 338 } 339 340 #endif // RAPIDJSON_SSE2 341 342 #ifdef RAPIDJSON_SIMD 343 //! Template function specialization for InsituStringStream 344 template<> inline void SkipWhitespace(InsituStringStream& is) { 345 is.src_ = const_cast<char*>(SkipWhitespace_SIMD(is.src_)); 346 } 347 348 //! Template function specialization for StringStream 349 template<> inline void SkipWhitespace(StringStream& is) { 350 is.src_ = SkipWhitespace_SIMD(is.src_); 351 } 352 #endif // RAPIDJSON_SIMD 353 354 /////////////////////////////////////////////////////////////////////////////// 355 // GenericReader 356 357 //! SAX-style JSON parser. Use \ref Reader for UTF8 encoding and default allocator. 358 /*! GenericReader parses JSON text from a stream, and send events synchronously to an 359 object implementing Handler concept. 360 361 It needs to allocate a stack for storing a single decoded string during 362 non-destructive parsing. 363 364 For in-situ parsing, the decoded string is directly written to the source 365 text string, no temporary buffer is required. 366 367 A GenericReader object can be reused for parsing multiple JSON text. 368 369 \tparam SourceEncoding Encoding of the input stream. 370 \tparam TargetEncoding Encoding of the parse output. 371 \tparam StackAllocator Allocator type for stack. 372 */ 373 template <typename SourceEncoding, typename TargetEncoding, typename StackAllocator = CrtAllocator> 374 class GenericReader { 375 public: 376 typedef typename SourceEncoding::Ch Ch; //!< SourceEncoding character type 377 378 //! Constructor. 379 /*! \param stackAllocator Optional allocator for allocating stack memory. (Only use for non-destructive parsing) 380 \param stackCapacity stack capacity in bytes for storing a single decoded string. (Only use for non-destructive parsing) 381 */ 382 explicit GenericReader(StackAllocator* stackAllocator = 0, size_t stackCapacity = kDefaultStackCapacity) : stack_(stackAllocator, stackCapacity), parseResult_() {} 383 384 //! Parse JSON text. 385 /*! \tparam parseFlags Combination of \ref ParseFlag. 386 \tparam InputStream Type of input stream, implementing Stream concept. 387 \tparam Handler Type of handler, implementing Handler concept. 388 \param is Input stream to be parsed. 389 \param handler The handler to receive events. 390 \return Whether the parsing is successful. 391 */ 392 template <unsigned parseFlags, typename InputStream, typename Handler> 393 ParseResult Parse(InputStream& is, Handler& handler) { 394 if (parseFlags & kParseIterativeFlag) 395 return IterativeParse<parseFlags>(is, handler); 396 397 parseResult_.Clear(); 398 399 ClearStackOnExit scope(*this); 400 401 SkipWhitespace(is); 402 403 if (is.Peek() == '\0') { 404 RAPIDJSON_PARSE_ERROR_NORETURN(kParseErrorDocumentEmpty, is.Tell()); 405 RAPIDJSON_PARSE_ERROR_EARLY_RETURN(parseResult_); 406 } 407 else { 408 ParseValue<parseFlags>(is, handler); 409 RAPIDJSON_PARSE_ERROR_EARLY_RETURN(parseResult_); 410 411 if (!(parseFlags & kParseStopWhenDoneFlag)) { 412 SkipWhitespace(is); 413 414 if (is.Peek() != '\0') { 415 RAPIDJSON_PARSE_ERROR_NORETURN(kParseErrorDocumentRootNotSingular, is.Tell()); 416 RAPIDJSON_PARSE_ERROR_EARLY_RETURN(parseResult_); 417 } 418 } 419 } 420 421 return parseResult_; 422 } 423 424 //! Parse JSON text (with \ref kParseDefaultFlags) 425 /*! \tparam InputStream Type of input stream, implementing Stream concept 426 \tparam Handler Type of handler, implementing Handler concept. 427 \param is Input stream to be parsed. 428 \param handler The handler to receive events. 429 \return Whether the parsing is successful. 430 */ 431 template <typename InputStream, typename Handler> 432 ParseResult Parse(InputStream& is, Handler& handler) { 433 return Parse<kParseDefaultFlags>(is, handler); 434 } 435 436 //! Whether a parse error has occured in the last parsing. 437 bool HasParseError() const { return parseResult_.IsError(); } 438 439 //! Get the \ref ParseErrorCode of last parsing. 440 ParseErrorCode GetParseErrorCode() const { return parseResult_.Code(); } 441 442 //! Get the position of last parsing error in input, 0 otherwise. 443 size_t GetErrorOffset() const { return parseResult_.Offset(); } 444 445 protected: 446 void SetParseError(ParseErrorCode code, size_t offset) { parseResult_.Set(code, offset); } 447 448 private: 449 // Prohibit copy constructor & assignment operator. 450 GenericReader(const GenericReader&); 451 GenericReader& operator=(const GenericReader&); 452 453 void ClearStack() { stack_.Clear(); } 454 455 // clear stack on any exit from ParseStream, e.g. due to exception 456 struct ClearStackOnExit { 457 explicit ClearStackOnExit(GenericReader& r) : r_(r) {} 458 ~ClearStackOnExit() { r_.ClearStack(); } 459 private: 460 GenericReader& r_; 461 ClearStackOnExit(const ClearStackOnExit&); 462 ClearStackOnExit& operator=(const ClearStackOnExit&); 463 }; 464 465 // Parse object: { string : value, ... } 466 template<unsigned parseFlags, typename InputStream, typename Handler> 467 void ParseObject(InputStream& is, Handler& handler) { 468 RAPIDJSON_ASSERT(is.Peek() == '{'); 469 is.Take(); // Skip '{' 470 471 if (!handler.StartObject()) 472 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell()); 473 474 SkipWhitespace(is); 475 476 if (is.Peek() == '}') { 477 is.Take(); 478 if (!handler.EndObject(0)) // empty object 479 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell()); 480 return; 481 } 482 483 for (SizeType memberCount = 0;;) { 484 if (is.Peek() != '"') 485 RAPIDJSON_PARSE_ERROR(kParseErrorObjectMissName, is.Tell()); 486 487 ParseString<parseFlags>(is, handler, true); 488 RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID; 489 490 SkipWhitespace(is); 491 492 if (is.Take() != ':') 493 RAPIDJSON_PARSE_ERROR(kParseErrorObjectMissColon, is.Tell()); 494 495 SkipWhitespace(is); 496 497 ParseValue<parseFlags>(is, handler); 498 RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID; 499 500 SkipWhitespace(is); 501 502 ++memberCount; 503 504 switch (is.Take()) { 505 case ',': SkipWhitespace(is); break; 506 case '}': 507 if (!handler.EndObject(memberCount)) 508 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell()); 509 return; 510 default: RAPIDJSON_PARSE_ERROR(kParseErrorObjectMissCommaOrCurlyBracket, is.Tell()); 511 } 512 } 513 } 514 515 // Parse array: [ value, ... ] 516 template<unsigned parseFlags, typename InputStream, typename Handler> 517 void ParseArray(InputStream& is, Handler& handler) { 518 RAPIDJSON_ASSERT(is.Peek() == '['); 519 is.Take(); // Skip '[' 520 521 if (!handler.StartArray()) 522 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell()); 523 524 SkipWhitespace(is); 525 526 if (is.Peek() == ']') { 527 is.Take(); 528 if (!handler.EndArray(0)) // empty array 529 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell()); 530 return; 531 } 532 533 for (SizeType elementCount = 0;;) { 534 ParseValue<parseFlags>(is, handler); 535 RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID; 536 537 ++elementCount; 538 SkipWhitespace(is); 539 540 switch (is.Take()) { 541 case ',': SkipWhitespace(is); break; 542 case ']': 543 if (!handler.EndArray(elementCount)) 544 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell()); 545 return; 546 default: RAPIDJSON_PARSE_ERROR(kParseErrorArrayMissCommaOrSquareBracket, is.Tell()); 547 } 548 } 549 } 550 551 template<unsigned parseFlags, typename InputStream, typename Handler> 552 void ParseNull(InputStream& is, Handler& handler) { 553 RAPIDJSON_ASSERT(is.Peek() == 'n'); 554 is.Take(); 555 556 if (is.Take() == 'u' && is.Take() == 'l' && is.Take() == 'l') { 557 if (!handler.Null()) 558 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell()); 559 } 560 else 561 RAPIDJSON_PARSE_ERROR(kParseErrorValueInvalid, is.Tell() - 1); 562 } 563 564 template<unsigned parseFlags, typename InputStream, typename Handler> 565 void ParseTrue(InputStream& is, Handler& handler) { 566 RAPIDJSON_ASSERT(is.Peek() == 't'); 567 is.Take(); 568 569 if (is.Take() == 'r' && is.Take() == 'u' && is.Take() == 'e') { 570 if (!handler.Bool(true)) 571 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell()); 572 } 573 else 574 RAPIDJSON_PARSE_ERROR(kParseErrorValueInvalid, is.Tell() - 1); 575 } 576 577 template<unsigned parseFlags, typename InputStream, typename Handler> 578 void ParseFalse(InputStream& is, Handler& handler) { 579 RAPIDJSON_ASSERT(is.Peek() == 'f'); 580 is.Take(); 581 582 if (is.Take() == 'a' && is.Take() == 'l' && is.Take() == 's' && is.Take() == 'e') { 583 if (!handler.Bool(false)) 584 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, is.Tell()); 585 } 586 else 587 RAPIDJSON_PARSE_ERROR(kParseErrorValueInvalid, is.Tell() - 1); 588 } 589 590 // Helper function to parse four hexidecimal digits in \uXXXX in ParseString(). 591 template<typename InputStream> 592 unsigned ParseHex4(InputStream& is) { 593 unsigned codepoint = 0; 594 for (int i = 0; i < 4; i++) { 595 Ch c = is.Take(); 596 codepoint <<= 4; 597 codepoint += static_cast<unsigned>(c); 598 if (c >= '0' && c <= '9') 599 codepoint -= '0'; 600 else if (c >= 'A' && c <= 'F') 601 codepoint -= 'A' - 10; 602 else if (c >= 'a' && c <= 'f') 603 codepoint -= 'a' - 10; 604 else { 605 RAPIDJSON_PARSE_ERROR_NORETURN(kParseErrorStringUnicodeEscapeInvalidHex, is.Tell() - 1); 606 RAPIDJSON_PARSE_ERROR_EARLY_RETURN(0); 607 } 608 } 609 return codepoint; 610 } 611 612 template <typename CharType> 613 class StackStream { 614 public: 615 typedef CharType Ch; 616 617 explicit StackStream(internal::Stack<StackAllocator>& stack) : stack_(stack), length_(0) {} 618 RAPIDJSON_FORCEINLINE void Put(Ch c) { 619 *stack_.template Push<Ch>() = c; 620 ++length_; 621 } 622 size_t Length() const { return length_; } 623 Ch* Pop() { 624 return stack_.template Pop<Ch>(length_); 625 } 626 627 private: 628 StackStream(const StackStream&); 629 StackStream& operator=(const StackStream&); 630 631 internal::Stack<StackAllocator>& stack_; 632 SizeType length_; 633 }; 634 635 // Parse string and generate String event. Different code paths for kParseInsituFlag. 636 template<unsigned parseFlags, typename InputStream, typename Handler> 637 void ParseString(InputStream& is, Handler& handler, bool isKey = false) { 638 internal::StreamLocalCopy<InputStream> copy(is); 639 InputStream& s(copy.s); 640 641 bool success = false; 642 if (parseFlags & kParseInsituFlag) { 643 typename InputStream::Ch *head = s.PutBegin(); 644 ParseStringToStream<parseFlags, SourceEncoding, SourceEncoding>(s, s); 645 RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID; 646 size_t length = s.PutEnd(head) - 1; 647 RAPIDJSON_ASSERT(length <= 0xFFFFFFFF); 648 const typename TargetEncoding::Ch* const str = (typename TargetEncoding::Ch*)head; 649 success = (isKey ? handler.Key(str, SizeType(length), false) : handler.String(str, SizeType(length), false)); 650 } 651 else { 652 StackStream<typename TargetEncoding::Ch> stackStream(stack_); 653 ParseStringToStream<parseFlags, SourceEncoding, TargetEncoding>(s, stackStream); 654 RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID; 655 SizeType length = static_cast<SizeType>(stackStream.Length()) - 1; 656 const typename TargetEncoding::Ch* const str = stackStream.Pop(); 657 success = (isKey ? handler.Key(str, length, true) : handler.String(str, length, true)); 658 } 659 if (!success) 660 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, s.Tell()); 661 } 662 663 // Parse string to an output is 664 // This function handles the prefix/suffix double quotes, escaping, and optional encoding validation. 665 template<unsigned parseFlags, typename SEncoding, typename TEncoding, typename InputStream, typename OutputStream> 666 RAPIDJSON_FORCEINLINE void ParseStringToStream(InputStream& is, OutputStream& os) { 667 //!@cond RAPIDJSON_HIDDEN_FROM_DOXYGEN 668 #define Z16 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 669 static const char escape[256] = { 670 Z16, Z16, 0, 0,'\"', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,'/', 671 Z16, Z16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,'\\', 0, 0, 0, 672 0, 0,'\b', 0, 0, 0,'\f', 0, 0, 0, 0, 0, 0, 0,'\n', 0, 673 0, 0,'\r', 0,'\t', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 674 Z16, Z16, Z16, Z16, Z16, Z16, Z16, Z16 675 }; 676 #undef Z16 677 //!@endcond 678 679 RAPIDJSON_ASSERT(is.Peek() == '\"'); 680 is.Take(); // Skip '\"' 681 682 for (;;) { 683 Ch c = is.Peek(); 684 if (c == '\\') { // Escape 685 is.Take(); 686 Ch e = is.Take(); 687 if ((sizeof(Ch) == 1 || unsigned(e) < 256) && escape[(unsigned char)e]) { 688 os.Put(escape[(unsigned char)e]); 689 } 690 else if (e == 'u') { // Unicode 691 unsigned codepoint = ParseHex4(is); 692 RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID; 693 if (codepoint >= 0xD800 && codepoint <= 0xDBFF) { 694 // Handle UTF-16 surrogate pair 695 if (is.Take() != '\\' || is.Take() != 'u') 696 RAPIDJSON_PARSE_ERROR(kParseErrorStringUnicodeSurrogateInvalid, is.Tell() - 2); 697 unsigned codepoint2 = ParseHex4(is); 698 RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID; 699 if (codepoint2 < 0xDC00 || codepoint2 > 0xDFFF) 700 RAPIDJSON_PARSE_ERROR(kParseErrorStringUnicodeSurrogateInvalid, is.Tell() - 2); 701 codepoint = (((codepoint - 0xD800) << 10) | (codepoint2 - 0xDC00)) + 0x10000; 702 } 703 TEncoding::Encode(os, codepoint); 704 } 705 else 706 RAPIDJSON_PARSE_ERROR(kParseErrorStringEscapeInvalid, is.Tell() - 1); 707 } 708 else if (c == '"') { // Closing double quote 709 is.Take(); 710 os.Put('\0'); // null-terminate the string 711 return; 712 } 713 else if (c == '\0') 714 RAPIDJSON_PARSE_ERROR(kParseErrorStringMissQuotationMark, is.Tell() - 1); 715 else if ((unsigned)c < 0x20) // RFC 4627: unescaped = %x20-21 / %x23-5B / %x5D-10FFFF 716 RAPIDJSON_PARSE_ERROR(kParseErrorStringEscapeInvalid, is.Tell() - 1); 717 else { 718 if (parseFlags & kParseValidateEncodingFlag ? 719 !Transcoder<SEncoding, TEncoding>::Validate(is, os) : 720 !Transcoder<SEncoding, TEncoding>::Transcode(is, os)) 721 RAPIDJSON_PARSE_ERROR(kParseErrorStringInvalidEncoding, is.Tell()); 722 } 723 } 724 } 725 726 template<typename InputStream, bool backup> 727 class NumberStream; 728 729 template<typename InputStream> 730 class NumberStream<InputStream, false> { 731 public: 732 NumberStream(GenericReader& reader, InputStream& s) : is(s) { (void)reader; } 733 ~NumberStream() {} 734 735 RAPIDJSON_FORCEINLINE Ch Peek() const { return is.Peek(); } 736 RAPIDJSON_FORCEINLINE Ch TakePush() { return is.Take(); } 737 RAPIDJSON_FORCEINLINE Ch Take() { return is.Take(); } 738 size_t Tell() { return is.Tell(); } 739 size_t Length() { return 0; } 740 const char* Pop() { return 0; } 741 742 protected: 743 NumberStream& operator=(const NumberStream&); 744 745 InputStream& is; 746 }; 747 748 template<typename InputStream> 749 class NumberStream<InputStream, true> : public NumberStream<InputStream, false> { 750 typedef NumberStream<InputStream, false> Base; 751 public: 752 NumberStream(GenericReader& reader, InputStream& is) : NumberStream<InputStream, false>(reader, is), stackStream(reader.stack_) {} 753 ~NumberStream() {} 754 755 RAPIDJSON_FORCEINLINE Ch TakePush() { 756 stackStream.Put((char)Base::is.Peek()); 757 return Base::is.Take(); 758 } 759 760 size_t Length() { return stackStream.Length(); } 761 762 const char* Pop() { 763 stackStream.Put('\0'); 764 return stackStream.Pop(); 765 } 766 767 private: 768 StackStream<char> stackStream; 769 }; 770 771 template<unsigned parseFlags, typename InputStream, typename Handler> 772 void ParseNumber(InputStream& is, Handler& handler) { 773 internal::StreamLocalCopy<InputStream> copy(is); 774 NumberStream<InputStream, (parseFlags & kParseFullPrecisionFlag) != 0> s(*this, copy.s); 775 776 // Parse minus 777 bool minus = false; 778 if (s.Peek() == '-') { 779 minus = true; 780 s.Take(); 781 } 782 783 // Parse int: zero / ( digit1-9 *DIGIT ) 784 unsigned i = 0; 785 uint64_t i64 = 0; 786 bool use64bit = false; 787 int significandDigit = 0; 788 if (s.Peek() == '0') { 789 i = 0; 790 s.TakePush(); 791 } 792 else if (s.Peek() >= '1' && s.Peek() <= '9') { 793 i = static_cast<unsigned>(s.TakePush() - '0'); 794 795 if (minus) 796 while (s.Peek() >= '0' && s.Peek() <= '9') { 797 if (i >= 214748364) { // 2^31 = 2147483648 798 if (i != 214748364 || s.Peek() > '8') { 799 i64 = i; 800 use64bit = true; 801 break; 802 } 803 } 804 i = i * 10 + static_cast<unsigned>(s.TakePush() - '0'); 805 significandDigit++; 806 } 807 else 808 while (s.Peek() >= '0' && s.Peek() <= '9') { 809 if (i >= 429496729) { // 2^32 - 1 = 4294967295 810 if (i != 429496729 || s.Peek() > '5') { 811 i64 = i; 812 use64bit = true; 813 break; 814 } 815 } 816 i = i * 10 + static_cast<unsigned>(s.TakePush() - '0'); 817 significandDigit++; 818 } 819 } 820 else 821 RAPIDJSON_PARSE_ERROR(kParseErrorValueInvalid, s.Tell()); 822 823 // Parse 64bit int 824 bool useDouble = false; 825 double d = 0.0; 826 if (use64bit) { 827 if (minus) 828 while (s.Peek() >= '0' && s.Peek() <= '9') { 829 if (i64 >= RAPIDJSON_UINT64_C2(0x0CCCCCCC, 0xCCCCCCCC)) // 2^63 = 9223372036854775808 830 if (i64 != RAPIDJSON_UINT64_C2(0x0CCCCCCC, 0xCCCCCCCC) || s.Peek() > '8') { 831 d = i64; 832 useDouble = true; 833 break; 834 } 835 i64 = i64 * 10 + static_cast<unsigned>(s.TakePush() - '0'); 836 significandDigit++; 837 } 838 else 839 while (s.Peek() >= '0' && s.Peek() <= '9') { 840 if (i64 >= RAPIDJSON_UINT64_C2(0x19999999, 0x99999999)) // 2^64 - 1 = 18446744073709551615 841 if (i64 != RAPIDJSON_UINT64_C2(0x19999999, 0x99999999) || s.Peek() > '5') { 842 d = i64; 843 useDouble = true; 844 break; 845 } 846 i64 = i64 * 10 + static_cast<unsigned>(s.TakePush() - '0'); 847 significandDigit++; 848 } 849 } 850 851 // Force double for big integer 852 if (useDouble) { 853 while (s.Peek() >= '0' && s.Peek() <= '9') { 854 if (d >= 1.7976931348623157e307) // DBL_MAX / 10.0 855 RAPIDJSON_PARSE_ERROR(kParseErrorNumberTooBig, s.Tell()); 856 d = d * 10 + (s.TakePush() - '0'); 857 } 858 } 859 860 // Parse frac = decimal-point 1*DIGIT 861 int expFrac = 0; 862 size_t decimalPosition; 863 if (s.Peek() == '.') { 864 s.Take(); 865 decimalPosition = s.Length(); 866 867 if (!(s.Peek() >= '0' && s.Peek() <= '9')) 868 RAPIDJSON_PARSE_ERROR(kParseErrorNumberMissFraction, s.Tell()); 869 870 if (!useDouble) { 871 #if RAPIDJSON_64BIT 872 // Use i64 to store significand in 64-bit architecture 873 if (!use64bit) 874 i64 = i; 875 876 while (s.Peek() >= '0' && s.Peek() <= '9') { 877 if (i64 > RAPIDJSON_UINT64_C2(0x1FFFFF, 0xFFFFFFFF)) // 2^53 - 1 for fast path 878 break; 879 else { 880 i64 = i64 * 10 + static_cast<unsigned>(s.TakePush() - '0'); 881 --expFrac; 882 if (i64 != 0) 883 significandDigit++; 884 } 885 } 886 887 d = (double)i64; 888 #else 889 // Use double to store significand in 32-bit architecture 890 d = use64bit ? (double)i64 : (double)i; 891 #endif 892 useDouble = true; 893 } 894 895 while (s.Peek() >= '0' && s.Peek() <= '9') { 896 if (significandDigit < 17) { 897 d = d * 10.0 + (s.TakePush() - '0'); 898 --expFrac; 899 if (d > 0.0) 900 significandDigit++; 901 } 902 else 903 s.TakePush(); 904 } 905 } 906 else 907 decimalPosition = s.Length(); // decimal position at the end of integer. 908 909 // Parse exp = e [ minus / plus ] 1*DIGIT 910 int exp = 0; 911 if (s.Peek() == 'e' || s.Peek() == 'E') { 912 if (!useDouble) { 913 d = use64bit ? i64 : i; 914 useDouble = true; 915 } 916 s.Take(); 917 918 bool expMinus = false; 919 if (s.Peek() == '+') 920 s.Take(); 921 else if (s.Peek() == '-') { 922 s.Take(); 923 expMinus = true; 924 } 925 926 if (s.Peek() >= '0' && s.Peek() <= '9') { 927 exp = s.Take() - '0'; 928 if (expMinus) { 929 while (s.Peek() >= '0' && s.Peek() <= '9') { 930 exp = exp * 10 + (s.Take() - '0'); 931 if (exp >= 214748364) { // Issue #313: prevent overflow exponent 932 while (s.Peek() >= '0' && s.Peek() <= '9') // Consume the rest of exponent 933 s.Take(); 934 } 935 } 936 } 937 else { // positive exp 938 int maxExp = 308 - expFrac; 939 while (s.Peek() >= '0' && s.Peek() <= '9') { 940 exp = exp * 10 + (s.Take() - '0'); 941 if (exp > maxExp) 942 RAPIDJSON_PARSE_ERROR(kParseErrorNumberTooBig, s.Tell()); 943 } 944 } 945 } 946 else 947 RAPIDJSON_PARSE_ERROR(kParseErrorNumberMissExponent, s.Tell()); 948 949 if (expMinus) 950 exp = -exp; 951 } 952 953 // Finish parsing, call event according to the type of number. 954 bool cont = true; 955 size_t length = s.Length(); 956 const char* decimal = s.Pop(); // Pop stack no matter if it will be used or not. 957 958 if (useDouble) { 959 int p = exp + expFrac; 960 if (parseFlags & kParseFullPrecisionFlag) 961 d = internal::StrtodFullPrecision(d, p, decimal, length, decimalPosition, exp); 962 else 963 d = internal::StrtodNormalPrecision(d, p); 964 965 cont = handler.Double(minus ? -d : d); 966 } 967 else { 968 if (use64bit) { 969 if (minus) 970 cont = handler.Int64(static_cast<int64_t>(~i64 + 1)); 971 else 972 cont = handler.Uint64(i64); 973 } 974 else { 975 if (minus) 976 cont = handler.Int(static_cast<int32_t>(~i + 1)); 977 else 978 cont = handler.Uint(i); 979 } 980 } 981 if (!cont) 982 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, s.Tell()); 983 } 984 985 // Parse any JSON value 986 template<unsigned parseFlags, typename InputStream, typename Handler> 987 void ParseValue(InputStream& is, Handler& handler) { 988 switch (is.Peek()) { 989 case 'n': ParseNull <parseFlags>(is, handler); break; 990 case 't': ParseTrue <parseFlags>(is, handler); break; 991 case 'f': ParseFalse <parseFlags>(is, handler); break; 992 case '"': ParseString<parseFlags>(is, handler); break; 993 case '{': ParseObject<parseFlags>(is, handler); break; 994 case '[': ParseArray <parseFlags>(is, handler); break; 995 default : ParseNumber<parseFlags>(is, handler); 996 } 997 } 998 999 // Iterative Parsing 1000 1001 // States 1002 enum IterativeParsingState { 1003 IterativeParsingStartState = 0, 1004 IterativeParsingFinishState, 1005 IterativeParsingErrorState, 1006 1007 // Object states 1008 IterativeParsingObjectInitialState, 1009 IterativeParsingMemberKeyState, 1010 IterativeParsingKeyValueDelimiterState, 1011 IterativeParsingMemberValueState, 1012 IterativeParsingMemberDelimiterState, 1013 IterativeParsingObjectFinishState, 1014 1015 // Array states 1016 IterativeParsingArrayInitialState, 1017 IterativeParsingElementState, 1018 IterativeParsingElementDelimiterState, 1019 IterativeParsingArrayFinishState, 1020 1021 // Single value state 1022 IterativeParsingValueState, 1023 1024 cIterativeParsingStateCount 1025 }; 1026 1027 // Tokens 1028 enum Token { 1029 LeftBracketToken = 0, 1030 RightBracketToken, 1031 1032 LeftCurlyBracketToken, 1033 RightCurlyBracketToken, 1034 1035 CommaToken, 1036 ColonToken, 1037 1038 StringToken, 1039 FalseToken, 1040 TrueToken, 1041 NullToken, 1042 NumberToken, 1043 1044 kTokenCount 1045 }; 1046 1047 RAPIDJSON_FORCEINLINE Token Tokenize(Ch c) { 1048 1049 //!@cond RAPIDJSON_HIDDEN_FROM_DOXYGEN 1050 #define N NumberToken 1051 #define N16 N,N,N,N,N,N,N,N,N,N,N,N,N,N,N,N 1052 // Maps from ASCII to Token 1053 static const unsigned char tokenMap[256] = { 1054 N16, // 00~0F 1055 N16, // 10~1F 1056 N, N, StringToken, N, N, N, N, N, N, N, N, N, CommaToken, N, N, N, // 20~2F 1057 N, N, N, N, N, N, N, N, N, N, ColonToken, N, N, N, N, N, // 30~3F 1058 N16, // 40~4F 1059 N, N, N, N, N, N, N, N, N, N, N, LeftBracketToken, N, RightBracketToken, N, N, // 50~5F 1060 N, N, N, N, N, N, FalseToken, N, N, N, N, N, N, N, NullToken, N, // 60~6F 1061 N, N, N, N, TrueToken, N, N, N, N, N, N, LeftCurlyBracketToken, N, RightCurlyBracketToken, N, N, // 70~7F 1062 N16, N16, N16, N16, N16, N16, N16, N16 // 80~FF 1063 }; 1064 #undef N 1065 #undef N16 1066 //!@endcond 1067 1068 if (sizeof(Ch) == 1 || unsigned(c) < 256) 1069 return (Token)tokenMap[(unsigned char)c]; 1070 else 1071 return NumberToken; 1072 } 1073 1074 RAPIDJSON_FORCEINLINE IterativeParsingState Predict(IterativeParsingState state, Token token) { 1075 // current state x one lookahead token -> new state 1076 static const char G[cIterativeParsingStateCount][kTokenCount] = { 1077 // Start 1078 { 1079 IterativeParsingArrayInitialState, // Left bracket 1080 IterativeParsingErrorState, // Right bracket 1081 IterativeParsingObjectInitialState, // Left curly bracket 1082 IterativeParsingErrorState, // Right curly bracket 1083 IterativeParsingErrorState, // Comma 1084 IterativeParsingErrorState, // Colon 1085 IterativeParsingValueState, // String 1086 IterativeParsingValueState, // False 1087 IterativeParsingValueState, // True 1088 IterativeParsingValueState, // Null 1089 IterativeParsingValueState // Number 1090 }, 1091 // Finish(sink state) 1092 { 1093 IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, 1094 IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, 1095 IterativeParsingErrorState 1096 }, 1097 // Error(sink state) 1098 { 1099 IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, 1100 IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, 1101 IterativeParsingErrorState 1102 }, 1103 // ObjectInitial 1104 { 1105 IterativeParsingErrorState, // Left bracket 1106 IterativeParsingErrorState, // Right bracket 1107 IterativeParsingErrorState, // Left curly bracket 1108 IterativeParsingObjectFinishState, // Right curly bracket 1109 IterativeParsingErrorState, // Comma 1110 IterativeParsingErrorState, // Colon 1111 IterativeParsingMemberKeyState, // String 1112 IterativeParsingErrorState, // False 1113 IterativeParsingErrorState, // True 1114 IterativeParsingErrorState, // Null 1115 IterativeParsingErrorState // Number 1116 }, 1117 // MemberKey 1118 { 1119 IterativeParsingErrorState, // Left bracket 1120 IterativeParsingErrorState, // Right bracket 1121 IterativeParsingErrorState, // Left curly bracket 1122 IterativeParsingErrorState, // Right curly bracket 1123 IterativeParsingErrorState, // Comma 1124 IterativeParsingKeyValueDelimiterState, // Colon 1125 IterativeParsingErrorState, // String 1126 IterativeParsingErrorState, // False 1127 IterativeParsingErrorState, // True 1128 IterativeParsingErrorState, // Null 1129 IterativeParsingErrorState // Number 1130 }, 1131 // KeyValueDelimiter 1132 { 1133 IterativeParsingArrayInitialState, // Left bracket(push MemberValue state) 1134 IterativeParsingErrorState, // Right bracket 1135 IterativeParsingObjectInitialState, // Left curly bracket(push MemberValue state) 1136 IterativeParsingErrorState, // Right curly bracket 1137 IterativeParsingErrorState, // Comma 1138 IterativeParsingErrorState, // Colon 1139 IterativeParsingMemberValueState, // String 1140 IterativeParsingMemberValueState, // False 1141 IterativeParsingMemberValueState, // True 1142 IterativeParsingMemberValueState, // Null 1143 IterativeParsingMemberValueState // Number 1144 }, 1145 // MemberValue 1146 { 1147 IterativeParsingErrorState, // Left bracket 1148 IterativeParsingErrorState, // Right bracket 1149 IterativeParsingErrorState, // Left curly bracket 1150 IterativeParsingObjectFinishState, // Right curly bracket 1151 IterativeParsingMemberDelimiterState, // Comma 1152 IterativeParsingErrorState, // Colon 1153 IterativeParsingErrorState, // String 1154 IterativeParsingErrorState, // False 1155 IterativeParsingErrorState, // True 1156 IterativeParsingErrorState, // Null 1157 IterativeParsingErrorState // Number 1158 }, 1159 // MemberDelimiter 1160 { 1161 IterativeParsingErrorState, // Left bracket 1162 IterativeParsingErrorState, // Right bracket 1163 IterativeParsingErrorState, // Left curly bracket 1164 IterativeParsingErrorState, // Right curly bracket 1165 IterativeParsingErrorState, // Comma 1166 IterativeParsingErrorState, // Colon 1167 IterativeParsingMemberKeyState, // String 1168 IterativeParsingErrorState, // False 1169 IterativeParsingErrorState, // True 1170 IterativeParsingErrorState, // Null 1171 IterativeParsingErrorState // Number 1172 }, 1173 // ObjectFinish(sink state) 1174 { 1175 IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, 1176 IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, 1177 IterativeParsingErrorState 1178 }, 1179 // ArrayInitial 1180 { 1181 IterativeParsingArrayInitialState, // Left bracket(push Element state) 1182 IterativeParsingArrayFinishState, // Right bracket 1183 IterativeParsingObjectInitialState, // Left curly bracket(push Element state) 1184 IterativeParsingErrorState, // Right curly bracket 1185 IterativeParsingErrorState, // Comma 1186 IterativeParsingErrorState, // Colon 1187 IterativeParsingElementState, // String 1188 IterativeParsingElementState, // False 1189 IterativeParsingElementState, // True 1190 IterativeParsingElementState, // Null 1191 IterativeParsingElementState // Number 1192 }, 1193 // Element 1194 { 1195 IterativeParsingErrorState, // Left bracket 1196 IterativeParsingArrayFinishState, // Right bracket 1197 IterativeParsingErrorState, // Left curly bracket 1198 IterativeParsingErrorState, // Right curly bracket 1199 IterativeParsingElementDelimiterState, // Comma 1200 IterativeParsingErrorState, // Colon 1201 IterativeParsingErrorState, // String 1202 IterativeParsingErrorState, // False 1203 IterativeParsingErrorState, // True 1204 IterativeParsingErrorState, // Null 1205 IterativeParsingErrorState // Number 1206 }, 1207 // ElementDelimiter 1208 { 1209 IterativeParsingArrayInitialState, // Left bracket(push Element state) 1210 IterativeParsingErrorState, // Right bracket 1211 IterativeParsingObjectInitialState, // Left curly bracket(push Element state) 1212 IterativeParsingErrorState, // Right curly bracket 1213 IterativeParsingErrorState, // Comma 1214 IterativeParsingErrorState, // Colon 1215 IterativeParsingElementState, // String 1216 IterativeParsingElementState, // False 1217 IterativeParsingElementState, // True 1218 IterativeParsingElementState, // Null 1219 IterativeParsingElementState // Number 1220 }, 1221 // ArrayFinish(sink state) 1222 { 1223 IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, 1224 IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, 1225 IterativeParsingErrorState 1226 }, 1227 // Single Value (sink state) 1228 { 1229 IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, 1230 IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, IterativeParsingErrorState, 1231 IterativeParsingErrorState 1232 } 1233 }; // End of G 1234 1235 return (IterativeParsingState)G[state][token]; 1236 } 1237 1238 // Make an advance in the token stream and state based on the candidate destination state which was returned by Transit(). 1239 // May return a new state on state pop. 1240 template <unsigned parseFlags, typename InputStream, typename Handler> 1241 RAPIDJSON_FORCEINLINE IterativeParsingState Transit(IterativeParsingState src, Token token, IterativeParsingState dst, InputStream& is, Handler& handler) { 1242 (void)token; 1243 1244 switch (dst) { 1245 case IterativeParsingErrorState: 1246 return dst; 1247 1248 case IterativeParsingObjectInitialState: 1249 case IterativeParsingArrayInitialState: 1250 { 1251 // Push the state(Element or MemeberValue) if we are nested in another array or value of member. 1252 // In this way we can get the correct state on ObjectFinish or ArrayFinish by frame pop. 1253 IterativeParsingState n = src; 1254 if (src == IterativeParsingArrayInitialState || src == IterativeParsingElementDelimiterState) 1255 n = IterativeParsingElementState; 1256 else if (src == IterativeParsingKeyValueDelimiterState) 1257 n = IterativeParsingMemberValueState; 1258 // Push current state. 1259 *stack_.template Push<SizeType>(1) = n; 1260 // Initialize and push the member/element count. 1261 *stack_.template Push<SizeType>(1) = 0; 1262 // Call handler 1263 bool hr = (dst == IterativeParsingObjectInitialState) ? handler.StartObject() : handler.StartArray(); 1264 // On handler short circuits the parsing. 1265 if (!hr) { 1266 RAPIDJSON_PARSE_ERROR_NORETURN(kParseErrorTermination, is.Tell()); 1267 return IterativeParsingErrorState; 1268 } 1269 else { 1270 is.Take(); 1271 return dst; 1272 } 1273 } 1274 1275 case IterativeParsingMemberKeyState: 1276 ParseString<parseFlags>(is, handler, true); 1277 if (HasParseError()) 1278 return IterativeParsingErrorState; 1279 else 1280 return dst; 1281 1282 case IterativeParsingKeyValueDelimiterState: 1283 RAPIDJSON_ASSERT(token == ColonToken); 1284 is.Take(); 1285 return dst; 1286 1287 case IterativeParsingMemberValueState: 1288 // Must be non-compound value. Or it would be ObjectInitial or ArrayInitial state. 1289 ParseValue<parseFlags>(is, handler); 1290 if (HasParseError()) { 1291 return IterativeParsingErrorState; 1292 } 1293 return dst; 1294 1295 case IterativeParsingElementState: 1296 // Must be non-compound value. Or it would be ObjectInitial or ArrayInitial state. 1297 ParseValue<parseFlags>(is, handler); 1298 if (HasParseError()) { 1299 return IterativeParsingErrorState; 1300 } 1301 return dst; 1302 1303 case IterativeParsingMemberDelimiterState: 1304 case IterativeParsingElementDelimiterState: 1305 is.Take(); 1306 // Update member/element count. 1307 *stack_.template Top<SizeType>() = *stack_.template Top<SizeType>() + 1; 1308 return dst; 1309 1310 case IterativeParsingObjectFinishState: 1311 { 1312 // Get member count. 1313 SizeType c = *stack_.template Pop<SizeType>(1); 1314 // If the object is not empty, count the last member. 1315 if (src == IterativeParsingMemberValueState) 1316 ++c; 1317 // Restore the state. 1318 IterativeParsingState n = static_cast<IterativeParsingState>(*stack_.template Pop<SizeType>(1)); 1319 // Transit to Finish state if this is the topmost scope. 1320 if (n == IterativeParsingStartState) 1321 n = IterativeParsingFinishState; 1322 // Call handler 1323 bool hr = handler.EndObject(c); 1324 // On handler short circuits the parsing. 1325 if (!hr) { 1326 RAPIDJSON_PARSE_ERROR_NORETURN(kParseErrorTermination, is.Tell()); 1327 return IterativeParsingErrorState; 1328 } 1329 else { 1330 is.Take(); 1331 return n; 1332 } 1333 } 1334 1335 case IterativeParsingArrayFinishState: 1336 { 1337 // Get element count. 1338 SizeType c = *stack_.template Pop<SizeType>(1); 1339 // If the array is not empty, count the last element. 1340 if (src == IterativeParsingElementState) 1341 ++c; 1342 // Restore the state. 1343 IterativeParsingState n = static_cast<IterativeParsingState>(*stack_.template Pop<SizeType>(1)); 1344 // Transit to Finish state if this is the topmost scope. 1345 if (n == IterativeParsingStartState) 1346 n = IterativeParsingFinishState; 1347 // Call handler 1348 bool hr = handler.EndArray(c); 1349 // On handler short circuits the parsing. 1350 if (!hr) { 1351 RAPIDJSON_PARSE_ERROR_NORETURN(kParseErrorTermination, is.Tell()); 1352 return IterativeParsingErrorState; 1353 } 1354 else { 1355 is.Take(); 1356 return n; 1357 } 1358 } 1359 1360 default: 1361 // This branch is for IterativeParsingValueState actually. 1362 // Use `default:` rather than 1363 // `case IterativeParsingValueState:` is for code coverage. 1364 1365 // The IterativeParsingStartState is not enumerated in this switch-case. 1366 // It is impossible for that case. And it can be caught by following assertion. 1367 1368 // The IterativeParsingFinishState is not enumerated in this switch-case either. 1369 // It is a "derivative" state which cannot triggered from Predict() directly. 1370 // Therefore it cannot happen here. And it can be caught by following assertion. 1371 RAPIDJSON_ASSERT(dst == IterativeParsingValueState); 1372 1373 // Must be non-compound value. Or it would be ObjectInitial or ArrayInitial state. 1374 ParseValue<parseFlags>(is, handler); 1375 if (HasParseError()) { 1376 return IterativeParsingErrorState; 1377 } 1378 return IterativeParsingFinishState; 1379 } 1380 } 1381 1382 template <typename InputStream> 1383 void HandleError(IterativeParsingState src, InputStream& is) { 1384 if (HasParseError()) { 1385 // Error flag has been set. 1386 return; 1387 } 1388 1389 switch (src) { 1390 case IterativeParsingStartState: RAPIDJSON_PARSE_ERROR(kParseErrorDocumentEmpty, is.Tell()); return; 1391 case IterativeParsingFinishState: RAPIDJSON_PARSE_ERROR(kParseErrorDocumentRootNotSingular, is.Tell()); return; 1392 case IterativeParsingObjectInitialState: 1393 case IterativeParsingMemberDelimiterState: RAPIDJSON_PARSE_ERROR(kParseErrorObjectMissName, is.Tell()); return; 1394 case IterativeParsingMemberKeyState: RAPIDJSON_PARSE_ERROR(kParseErrorObjectMissColon, is.Tell()); return; 1395 case IterativeParsingMemberValueState: RAPIDJSON_PARSE_ERROR(kParseErrorObjectMissCommaOrCurlyBracket, is.Tell()); return; 1396 case IterativeParsingElementState: RAPIDJSON_PARSE_ERROR(kParseErrorArrayMissCommaOrSquareBracket, is.Tell()); return; 1397 default: RAPIDJSON_PARSE_ERROR(kParseErrorUnspecificSyntaxError, is.Tell()); 1398 } 1399 } 1400 1401 template <unsigned parseFlags, typename InputStream, typename Handler> 1402 ParseResult IterativeParse(InputStream& is, Handler& handler) { 1403 parseResult_.Clear(); 1404 ClearStackOnExit scope(*this); 1405 IterativeParsingState state = IterativeParsingStartState; 1406 1407 SkipWhitespace(is); 1408 while (is.Peek() != '\0') { 1409 Token t = Tokenize(is.Peek()); 1410 IterativeParsingState n = Predict(state, t); 1411 IterativeParsingState d = Transit<parseFlags>(state, t, n, is, handler); 1412 1413 if (d == IterativeParsingErrorState) { 1414 HandleError(state, is); 1415 break; 1416 } 1417 1418 state = d; 1419 1420 // Do not further consume streams if a root JSON has been parsed. 1421 if ((parseFlags & kParseStopWhenDoneFlag) && state == IterativeParsingFinishState) 1422 break; 1423 1424 SkipWhitespace(is); 1425 } 1426 1427 // Handle the end of file. 1428 if (state != IterativeParsingFinishState) 1429 HandleError(state, is); 1430 1431 return parseResult_; 1432 } 1433 1434 static const size_t kDefaultStackCapacity = 256; //!< Default stack capacity in bytes for storing a single decoded string. 1435 internal::Stack<StackAllocator> stack_; //!< A stack for storing decoded string temporarily during non-destructive parsing. 1436 ParseResult parseResult_; 1437 }; // class GenericReader 1438 1439 //! Reader with UTF8 encoding and default allocator. 1440 typedef GenericReader<UTF8<>, UTF8<> > Reader; 1441 1442 RAPIDJSON_NAMESPACE_END 1443 1444 #ifdef __GNUC__ 1445 RAPIDJSON_DIAG_POP 1446 #endif 1447 1448 #ifdef _MSC_VER 1449 RAPIDJSON_DIAG_POP 1450 #endif 1451 1452 #endif // RAPIDJSON_READER_H_ 1453
