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1 // Copyright 2007-2008 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
4 // met:
5 //
6 //     * Redistributions of source code must retain the above copyright
7 //       notice, this list of conditions and the following disclaimer.
8 //     * Redistributions in binary form must reproduce the above
9 //       copyright notice, this list of conditions and the following
10 //       disclaimer in the documentation and/or other materials provided
11 //       with the distribution.
12 //     * Neither the name of Google Inc. nor the names of its
13 //       contributors may be used to endorse or promote products derived
14 //       from this software without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 
28 #ifndef V8_UNICODE_INL_H_
29 #define V8_UNICODE_INL_H_
30 
31 #include "unicode.h"
32 
33 namespace unibrow {
34 
get(uchar code_point)35 template <class T, int s> bool Predicate<T, s>::get(uchar code_point) {
36   CacheEntry entry = entries_[code_point & kMask];
37   if (entry.code_point_ == code_point) return entry.value_;
38   return CalculateValue(code_point);
39 }
40 
CalculateValue(uchar code_point)41 template <class T, int s> bool Predicate<T, s>::CalculateValue(
42     uchar code_point) {
43   bool result = T::Is(code_point);
44   entries_[code_point & kMask] = CacheEntry(code_point, result);
45   return result;
46 }
47 
get(uchar c,uchar n,uchar * result)48 template <class T, int s> int Mapping<T, s>::get(uchar c, uchar n,
49     uchar* result) {
50   CacheEntry entry = entries_[c & kMask];
51   if (entry.code_point_ == c) {
52     if (entry.offset_ == 0) {
53       return 0;
54     } else {
55       result[0] = c + entry.offset_;
56       return 1;
57     }
58   } else {
59     return CalculateValue(c, n, result);
60   }
61 }
62 
CalculateValue(uchar c,uchar n,uchar * result)63 template <class T, int s> int Mapping<T, s>::CalculateValue(uchar c, uchar n,
64     uchar* result) {
65   bool allow_caching = true;
66   int length = T::Convert(c, n, result, &allow_caching);
67   if (allow_caching) {
68     if (length == 1) {
69       entries_[c & kMask] = CacheEntry(c, result[0] - c);
70       return 1;
71     } else {
72       entries_[c & kMask] = CacheEntry(c, 0);
73       return 0;
74     }
75   } else {
76     return length;
77   }
78 }
79 
80 
Encode(char * str,uchar c)81 unsigned Utf8::Encode(char* str, uchar c) {
82   static const int kMask = ~(1 << 6);
83   if (c <= kMaxOneByteChar) {
84     str[0] = c;
85     return 1;
86   } else if (c <= kMaxTwoByteChar) {
87     str[0] = 0xC0 | (c >> 6);
88     str[1] = 0x80 | (c & kMask);
89     return 2;
90   } else if (c <= kMaxThreeByteChar) {
91     str[0] = 0xE0 | (c >> 12);
92     str[1] = 0x80 | ((c >> 6) & kMask);
93     str[2] = 0x80 | (c & kMask);
94     return 3;
95   } else {
96     str[0] = 0xF0 | (c >> 18);
97     str[1] = 0x80 | ((c >> 12) & kMask);
98     str[2] = 0x80 | ((c >> 6) & kMask);
99     str[3] = 0x80 | (c & kMask);
100     return 4;
101   }
102 }
103 
104 
ValueOf(const byte * bytes,unsigned length,unsigned * cursor)105 uchar Utf8::ValueOf(const byte* bytes, unsigned length, unsigned* cursor) {
106   if (length <= 0) return kBadChar;
107   byte first = bytes[0];
108   // Characters between 0000 and 0007F are encoded as a single character
109   if (first <= kMaxOneByteChar) {
110     *cursor += 1;
111     return first;
112   }
113   return CalculateValue(bytes, length, cursor);
114 }
115 
Length(uchar c)116 unsigned Utf8::Length(uchar c) {
117   if (c <= kMaxOneByteChar) {
118     return 1;
119   } else if (c <= kMaxTwoByteChar) {
120     return 2;
121   } else if (c <= kMaxThreeByteChar) {
122     return 3;
123   } else {
124     return 4;
125   }
126 }
127 
GetNext()128 uchar CharacterStream::GetNext() {
129   uchar result = DecodeCharacter(buffer_, &cursor_);
130   if (remaining_ == 1) {
131     cursor_ = 0;
132     FillBuffer();
133   } else {
134     remaining_--;
135   }
136   return result;
137 }
138 
139 #if __BYTE_ORDER == __LITTLE_ENDIAN
140 #define IF_LITTLE(expr) expr
141 #define IF_BIG(expr)    ((void) 0)
142 #elif __BYTE_ORDER == __BIG_ENDIAN
143 #define IF_LITTLE(expr) ((void) 0)
144 #define IF_BIG(expr)    expr
145 #else
146 #warning Unknown byte ordering
147 #endif
148 
EncodeAsciiCharacter(uchar c,byte * buffer,unsigned capacity,unsigned & offset)149 bool CharacterStream::EncodeAsciiCharacter(uchar c, byte* buffer,
150     unsigned capacity, unsigned& offset) {
151   if (offset >= capacity) return false;
152   buffer[offset] = c;
153   offset += 1;
154   return true;
155 }
156 
EncodeNonAsciiCharacter(uchar c,byte * buffer,unsigned capacity,unsigned & offset)157 bool CharacterStream::EncodeNonAsciiCharacter(uchar c, byte* buffer,
158     unsigned capacity, unsigned& offset) {
159   unsigned aligned = (offset + 0x3) & ~0x3;
160   if ((aligned + sizeof(uchar)) > capacity)
161     return false;
162   if (offset == aligned) {
163     IF_LITTLE(*reinterpret_cast<uchar*>(buffer + aligned) = (c << 8) | 0x80);
164     IF_BIG(*reinterpret_cast<uchar*>(buffer + aligned) = c | (1 << 31));
165   } else {
166     buffer[offset] = 0x80;
167     IF_LITTLE(*reinterpret_cast<uchar*>(buffer + aligned) = c << 8);
168     IF_BIG(*reinterpret_cast<uchar*>(buffer + aligned) = c);
169   }
170   offset = aligned + sizeof(uchar);
171   return true;
172 }
173 
EncodeCharacter(uchar c,byte * buffer,unsigned capacity,unsigned & offset)174 bool CharacterStream::EncodeCharacter(uchar c, byte* buffer, unsigned capacity,
175     unsigned& offset) {
176   if (c <= Utf8::kMaxOneByteChar) {
177     return EncodeAsciiCharacter(c, buffer, capacity, offset);
178   } else {
179     return EncodeNonAsciiCharacter(c, buffer, capacity, offset);
180   }
181 }
182 
DecodeCharacter(const byte * buffer,unsigned * offset)183 uchar CharacterStream::DecodeCharacter(const byte* buffer, unsigned* offset) {
184   byte b = buffer[*offset];
185   if (b <= Utf8::kMaxOneByteChar) {
186     (*offset)++;
187     return b;
188   } else {
189     unsigned aligned = (*offset + 0x3) & ~0x3;
190     *offset = aligned + sizeof(uchar);
191     IF_LITTLE(return *reinterpret_cast<const uchar*>(buffer + aligned) >> 8);
192     IF_BIG(return *reinterpret_cast<const uchar*>(buffer + aligned) &
193                     ~(1 << 31));
194   }
195 }
196 
197 #undef IF_LITTLE
198 #undef IF_BIG
199 
200 template <class R, class I, unsigned s>
FillBuffer()201 void InputBuffer<R, I, s>::FillBuffer() {
202   buffer_ = R::ReadBlock(input_, util_buffer_, s, &remaining_, &offset_);
203 }
204 
205 template <class R, class I, unsigned s>
Rewind()206 void InputBuffer<R, I, s>::Rewind() {
207   Reset(input_);
208 }
209 
210 template <class R, class I, unsigned s>
Reset(unsigned position,I input)211 void InputBuffer<R, I, s>::Reset(unsigned position, I input) {
212   input_ = input;
213   remaining_ = 0;
214   cursor_ = 0;
215   offset_ = position;
216   buffer_ = R::ReadBlock(input_, util_buffer_, s, &remaining_, &offset_);
217 }
218 
219 template <class R, class I, unsigned s>
Reset(I input)220 void InputBuffer<R, I, s>::Reset(I input) {
221   Reset(0, input);
222 }
223 
224 template <class R, class I, unsigned s>
Seek(unsigned position)225 void InputBuffer<R, I, s>::Seek(unsigned position) {
226   offset_ = position;
227   buffer_ = R::ReadBlock(input_, util_buffer_, s, &remaining_, &offset_);
228 }
229 
230 template <unsigned s>
Utf8InputBuffer(const char * data,unsigned length)231 Utf8InputBuffer<s>::Utf8InputBuffer(const char* data, unsigned length)
232     : InputBuffer<Utf8, Buffer<const char*>, s>(Buffer<const char*>(data,
233                                                                     length)) {
234 }
235 
236 }  // namespace unibrow
237 
238 #endif  // V8_UNICODE_INL_H_
239