1 // Copyright 2011 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef V8_UNICODE_H_ 6 #define V8_UNICODE_H_ 7 8 #include <sys/types.h> 9 #include "src/globals.h" 10 /** 11 * \file 12 * Definitions and convenience functions for working with unicode. 13 */ 14 15 namespace unibrow { 16 17 typedef unsigned int uchar; 18 typedef unsigned char byte; 19 20 /** 21 * The max length of the result of converting the case of a single 22 * character. 23 */ 24 const int kMaxMappingSize = 4; 25 26 template <class T, int size = 256> 27 class Predicate { 28 public: 29 inline Predicate() { } 30 inline bool get(uchar c); 31 private: 32 friend class Test; 33 bool CalculateValue(uchar c); 34 struct CacheEntry { 35 inline CacheEntry() : code_point_(0), value_(0) { } 36 inline CacheEntry(uchar code_point, bool value) 37 : code_point_(code_point), 38 value_(value) { } 39 uchar code_point_ : 21; 40 bool value_ : 1; 41 }; 42 static const int kSize = size; 43 static const int kMask = kSize - 1; 44 CacheEntry entries_[kSize]; 45 }; 46 47 // A cache used in case conversion. It caches the value for characters 48 // that either have no mapping or map to a single character independent 49 // of context. Characters that map to more than one character or that 50 // map differently depending on context are always looked up. 51 template <class T, int size = 256> 52 class Mapping { 53 public: 54 inline Mapping() { } 55 inline int get(uchar c, uchar n, uchar* result); 56 private: 57 friend class Test; 58 int CalculateValue(uchar c, uchar n, uchar* result); 59 struct CacheEntry { 60 inline CacheEntry() : code_point_(kNoChar), offset_(0) { } 61 inline CacheEntry(uchar code_point, signed offset) 62 : code_point_(code_point), 63 offset_(offset) { } 64 uchar code_point_; 65 signed offset_; 66 static const int kNoChar = (1 << 21) - 1; 67 }; 68 static const int kSize = size; 69 static const int kMask = kSize - 1; 70 CacheEntry entries_[kSize]; 71 }; 72 73 class UnicodeData { 74 private: 75 friend class Test; 76 static int GetByteCount(); 77 static const uchar kMaxCodePoint; 78 }; 79 80 class Utf16 { 81 public: 82 static inline bool IsSurrogatePair(int lead, int trail) { 83 return IsLeadSurrogate(lead) && IsTrailSurrogate(trail); 84 } 85 static inline bool IsLeadSurrogate(int code) { 86 if (code == kNoPreviousCharacter) return false; 87 return (code & 0xfc00) == 0xd800; 88 } 89 static inline bool IsTrailSurrogate(int code) { 90 if (code == kNoPreviousCharacter) return false; 91 return (code & 0xfc00) == 0xdc00; 92 } 93 94 static inline int CombineSurrogatePair(uchar lead, uchar trail) { 95 return 0x10000 + ((lead & 0x3ff) << 10) + (trail & 0x3ff); 96 } 97 static const int kNoPreviousCharacter = -1; 98 static const uchar kMaxNonSurrogateCharCode = 0xffff; 99 // Encoding a single UTF-16 code unit will produce 1, 2 or 3 bytes 100 // of UTF-8 data. The special case where the unit is a surrogate 101 // trail produces 1 byte net, because the encoding of the pair is 102 // 4 bytes and the 3 bytes that were used to encode the lead surrogate 103 // can be reclaimed. 104 static const int kMaxExtraUtf8BytesForOneUtf16CodeUnit = 3; 105 // One UTF-16 surrogate is endoded (illegally) as 3 UTF-8 bytes. 106 // The illegality stems from the surrogate not being part of a pair. 107 static const int kUtf8BytesToCodeASurrogate = 3; 108 static inline uint16_t LeadSurrogate(uint32_t char_code) { 109 return 0xd800 + (((char_code - 0x10000) >> 10) & 0x3ff); 110 } 111 static inline uint16_t TrailSurrogate(uint32_t char_code) { 112 return 0xdc00 + (char_code & 0x3ff); 113 } 114 }; 115 116 class Latin1 { 117 public: 118 static const unsigned kMaxChar = 0xff; 119 // Returns 0 if character does not convert to single latin-1 character 120 // or if the character doesn't not convert back to latin-1 via inverse 121 // operation (upper to lower, etc). 122 static inline uint16_t ConvertNonLatin1ToLatin1(uint16_t); 123 }; 124 125 class Utf8 { 126 public: 127 static inline uchar Length(uchar chr, int previous); 128 static inline unsigned EncodeOneByte(char* out, uint8_t c); 129 static inline unsigned Encode(char* out, 130 uchar c, 131 int previous, 132 bool replace_invalid = false); 133 static uchar CalculateValue(const byte* str, 134 unsigned length, 135 unsigned* cursor); 136 137 // The unicode replacement character, used to signal invalid unicode 138 // sequences (e.g. an orphan surrogate) when converting to a UTF-8 encoding. 139 static const uchar kBadChar = 0xFFFD; 140 static const unsigned kMaxEncodedSize = 4; 141 static const unsigned kMaxOneByteChar = 0x7f; 142 static const unsigned kMaxTwoByteChar = 0x7ff; 143 static const unsigned kMaxThreeByteChar = 0xffff; 144 static const unsigned kMaxFourByteChar = 0x1fffff; 145 146 // A single surrogate is coded as a 3 byte UTF-8 sequence, but two together 147 // that match are coded as a 4 byte UTF-8 sequence. 148 static const unsigned kBytesSavedByCombiningSurrogates = 2; 149 static const unsigned kSizeOfUnmatchedSurrogate = 3; 150 // The maximum size a single UTF-16 code unit may take up when encoded as 151 // UTF-8. 152 static const unsigned kMax16BitCodeUnitSize = 3; 153 static inline uchar ValueOf(const byte* str, 154 unsigned length, 155 unsigned* cursor); 156 }; 157 158 159 class Utf8DecoderBase { 160 public: 161 // Initialization done in subclass. 162 inline Utf8DecoderBase(); 163 inline Utf8DecoderBase(uint16_t* buffer, 164 unsigned buffer_length, 165 const uint8_t* stream, 166 unsigned stream_length); 167 inline unsigned Utf16Length() const { return utf16_length_; } 168 protected: 169 // This reads all characters and sets the utf16_length_. 170 // The first buffer_length utf16 chars are cached in the buffer. 171 void Reset(uint16_t* buffer, 172 unsigned buffer_length, 173 const uint8_t* stream, 174 unsigned stream_length); 175 static void WriteUtf16Slow(const uint8_t* stream, 176 uint16_t* data, 177 unsigned length); 178 const uint8_t* unbuffered_start_; 179 unsigned utf16_length_; 180 bool last_byte_of_buffer_unused_; 181 private: 182 DISALLOW_COPY_AND_ASSIGN(Utf8DecoderBase); 183 }; 184 185 template <unsigned kBufferSize> 186 class Utf8Decoder : public Utf8DecoderBase { 187 public: 188 inline Utf8Decoder() {} 189 inline Utf8Decoder(const char* stream, unsigned length); 190 inline void Reset(const char* stream, unsigned length); 191 inline unsigned WriteUtf16(uint16_t* data, unsigned length) const; 192 private: 193 uint16_t buffer_[kBufferSize]; 194 }; 195 196 197 struct Uppercase { 198 static bool Is(uchar c); 199 }; 200 struct Lowercase { 201 static bool Is(uchar c); 202 }; 203 struct Letter { 204 static bool Is(uchar c); 205 }; 206 struct Number { 207 static bool Is(uchar c); 208 }; 209 struct WhiteSpace { 210 static bool Is(uchar c); 211 }; 212 struct LineTerminator { 213 static bool Is(uchar c); 214 }; 215 struct CombiningMark { 216 static bool Is(uchar c); 217 }; 218 struct ConnectorPunctuation { 219 static bool Is(uchar c); 220 }; 221 struct ToLowercase { 222 static const int kMaxWidth = 3; 223 static const bool kIsToLower = true; 224 static int Convert(uchar c, 225 uchar n, 226 uchar* result, 227 bool* allow_caching_ptr); 228 }; 229 struct ToUppercase { 230 static const int kMaxWidth = 3; 231 static const bool kIsToLower = false; 232 static int Convert(uchar c, 233 uchar n, 234 uchar* result, 235 bool* allow_caching_ptr); 236 }; 237 struct Ecma262Canonicalize { 238 static const int kMaxWidth = 1; 239 static int Convert(uchar c, 240 uchar n, 241 uchar* result, 242 bool* allow_caching_ptr); 243 }; 244 struct Ecma262UnCanonicalize { 245 static const int kMaxWidth = 4; 246 static int Convert(uchar c, 247 uchar n, 248 uchar* result, 249 bool* allow_caching_ptr); 250 }; 251 struct CanonicalizationRange { 252 static const int kMaxWidth = 1; 253 static int Convert(uchar c, 254 uchar n, 255 uchar* result, 256 bool* allow_caching_ptr); 257 }; 258 259 } // namespace unibrow 260 261 #endif // V8_UNICODE_H_ 262
