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#include "src/utils.h"
11/**
12 * \file
13 * Definitions and convenience functions for working with unicode.
14 */
15
16namespace unibrow {
17
18typedef unsigned int uchar;
19typedef unsigned char byte;
20
21/**
22 * The max length of the result of converting the case of a single
23 * character.
24 */
25const int kMaxMappingSize = 4;
26
27template <class T, int size = 256>
28class Predicate {
29 public:
30  inline Predicate() { }
31  inline bool get(uchar c);
32
33 private:
34  friend class Test;
35  bool CalculateValue(uchar c);
36  class CacheEntry {
37   public:
38    inline CacheEntry()
39        : bit_field_(CodePointField::encode(0) | ValueField::encode(0)) {}
40    inline CacheEntry(uchar code_point, bool value)
41        : bit_field_(CodePointField::encode(code_point) |
42                     ValueField::encode(value)) {}
43
44    uchar code_point() const { return CodePointField::decode(bit_field_); }
45    bool value() const { return ValueField::decode(bit_field_); }
46
47   private:
48    class CodePointField : public v8::internal::BitField<uchar, 0, 21> {};
49    class ValueField : public v8::internal::BitField<bool, 21, 1> {};
50
51    uint32_t bit_field_;
52  };
53  static const int kSize = size;
54  static const int kMask = kSize - 1;
55  CacheEntry entries_[kSize];
56};
57
58
59// A cache used in case conversion.  It caches the value for characters
60// that either have no mapping or map to a single character independent
61// of context.  Characters that map to more than one character or that
62// map differently depending on context are always looked up.
63template <class T, int size = 256>
64class Mapping {
65 public:
66  inline Mapping() { }
67  inline int get(uchar c, uchar n, uchar* result);
68 private:
69  friend class Test;
70  int CalculateValue(uchar c, uchar n, uchar* result);
71  struct CacheEntry {
72    inline CacheEntry() : code_point_(kNoChar), offset_(0) { }
73    inline CacheEntry(uchar code_point, signed offset)
74      : code_point_(code_point),
75        offset_(offset) { }
76    uchar code_point_;
77    signed offset_;
78    static const int kNoChar = (1 << 21) - 1;
79  };
80  static const int kSize = size;
81  static const int kMask = kSize - 1;
82  CacheEntry entries_[kSize];
83};
84
85
86class UnicodeData {
87 private:
88  friend class Test;
89  static int GetByteCount();
90  static const uchar kMaxCodePoint;
91};
92
93
94class Utf16 {
95 public:
96  static inline bool IsSurrogatePair(int lead, int trail) {
97    return IsLeadSurrogate(lead) && IsTrailSurrogate(trail);
98  }
99  static inline bool IsLeadSurrogate(int code) {
100    if (code == kNoPreviousCharacter) return false;
101    return (code & 0xfc00) == 0xd800;
102  }
103  static inline bool IsTrailSurrogate(int code) {
104    if (code == kNoPreviousCharacter) return false;
105    return (code & 0xfc00) == 0xdc00;
106  }
107
108  static inline int CombineSurrogatePair(uchar lead, uchar trail) {
109    return 0x10000 + ((lead & 0x3ff) << 10) + (trail & 0x3ff);
110  }
111  static const int kNoPreviousCharacter = -1;
112  static const uchar kMaxNonSurrogateCharCode = 0xffff;
113  // Encoding a single UTF-16 code unit will produce 1, 2 or 3 bytes
114  // of UTF-8 data.  The special case where the unit is a surrogate
115  // trail produces 1 byte net, because the encoding of the pair is
116  // 4 bytes and the 3 bytes that were used to encode the lead surrogate
117  // can be reclaimed.
118  static const int kMaxExtraUtf8BytesForOneUtf16CodeUnit = 3;
119  // One UTF-16 surrogate is endoded (illegally) as 3 UTF-8 bytes.
120  // The illegality stems from the surrogate not being part of a pair.
121  static const int kUtf8BytesToCodeASurrogate = 3;
122  static inline uint16_t LeadSurrogate(uint32_t char_code) {
123    return 0xd800 + (((char_code - 0x10000) >> 10) & 0x3ff);
124  }
125  static inline uint16_t TrailSurrogate(uint32_t char_code) {
126    return 0xdc00 + (char_code & 0x3ff);
127  }
128};
129
130
131class Utf8 {
132 public:
133  static inline uchar Length(uchar chr, int previous);
134  static inline unsigned EncodeOneByte(char* out, uint8_t c);
135  static inline unsigned Encode(char* out,
136                                uchar c,
137                                int previous,
138                                bool replace_invalid = false);
139  static uchar CalculateValue(const byte* str, size_t length, size_t* cursor);
140
141  // The unicode replacement character, used to signal invalid unicode
142  // sequences (e.g. an orphan surrogate) when converting to a UTF-8 encoding.
143  static const uchar kBadChar = 0xFFFD;
144  static const uchar kBufferEmpty = 0x0;
145  static const uchar kIncomplete = 0xFFFFFFFC;  // any non-valid code point.
146  static const unsigned kMaxEncodedSize   = 4;
147  static const unsigned kMaxOneByteChar   = 0x7f;
148  static const unsigned kMaxTwoByteChar   = 0x7ff;
149  static const unsigned kMaxThreeByteChar = 0xffff;
150  static const unsigned kMaxFourByteChar  = 0x1fffff;
151
152  // A single surrogate is coded as a 3 byte UTF-8 sequence, but two together
153  // that match are coded as a 4 byte UTF-8 sequence.
154  static const unsigned kBytesSavedByCombiningSurrogates = 2;
155  static const unsigned kSizeOfUnmatchedSurrogate = 3;
156  // The maximum size a single UTF-16 code unit may take up when encoded as
157  // UTF-8.
158  static const unsigned kMax16BitCodeUnitSize  = 3;
159  static inline uchar ValueOf(const byte* str, size_t length, size_t* cursor);
160
161  typedef uint32_t Utf8IncrementalBuffer;
162  static uchar ValueOfIncremental(byte next_byte,
163                                  Utf8IncrementalBuffer* buffer);
164  static uchar ValueOfIncrementalFinish(Utf8IncrementalBuffer* buffer);
165
166  // Excludes non-characters from the set of valid code points.
167  static inline bool IsValidCharacter(uchar c);
168
169  static bool Validate(const byte* str, size_t length);
170};
171
172struct Uppercase {
173  static bool Is(uchar c);
174};
175struct Lowercase {
176  static bool Is(uchar c);
177};
178struct Letter {
179  static bool Is(uchar c);
180};
181struct V8_EXPORT_PRIVATE ID_Start {
182  static bool Is(uchar c);
183};
184struct V8_EXPORT_PRIVATE ID_Continue {
185  static bool Is(uchar c);
186};
187struct V8_EXPORT_PRIVATE WhiteSpace {
188  static bool Is(uchar c);
189};
190struct V8_EXPORT_PRIVATE LineTerminator {
191  static bool Is(uchar c);
192};
193struct ToLowercase {
194  static const int kMaxWidth = 3;
195  static const bool kIsToLower = true;
196  static int Convert(uchar c,
197                     uchar n,
198                     uchar* result,
199                     bool* allow_caching_ptr);
200};
201struct ToUppercase {
202  static const int kMaxWidth = 3;
203  static const bool kIsToLower = false;
204  static int Convert(uchar c,
205                     uchar n,
206                     uchar* result,
207                     bool* allow_caching_ptr);
208};
209struct Ecma262Canonicalize {
210  static const int kMaxWidth = 1;
211  static int Convert(uchar c,
212                     uchar n,
213                     uchar* result,
214                     bool* allow_caching_ptr);
215};
216struct Ecma262UnCanonicalize {
217  static const int kMaxWidth = 4;
218  static int Convert(uchar c,
219                     uchar n,
220                     uchar* result,
221                     bool* allow_caching_ptr);
222};
223struct CanonicalizationRange {
224  static const int kMaxWidth = 1;
225  static int Convert(uchar c,
226                     uchar n,
227                     uchar* result,
228                     bool* allow_caching_ptr);
229};
230
231}  // namespace unibrow
232
233#endif  // V8_UNICODE_H_
234