1 | /* Copyright 2013 Google Inc. All Rights Reserved. |
2 | |
3 | Distributed under MIT license. |
4 | See file LICENSE for detail or copy at https://opensource.org/licenses/MIT |
5 | */ |
6 | |
7 | #include "./transform.h" |
8 | |
9 | #if defined(__cplusplus) || defined(c_plusplus) |
10 | extern "C" { |
11 | #endif |
12 | |
13 | /* RFC 7932 transforms string data */ |
14 | static const char kPrefixSuffix[217] = |
15 | "\1 \2, \10 of the \4 of \2s \1.\5 and \4 " |
16 | /* 0x _0 _2 __5 _E _3 _6 _8 _E */ |
17 | "in \1\"\4 to \2\">\1\n\2. \1]\5 for \3 a \6 " |
18 | /* 2x _3_ _5 _A_ _D_ _F _2 _4 _A _E */ |
19 | "that \1\'\6 with \6 from \4 by \1(\6. T" |
20 | /* 4x _5_ _7 _E _5 _A _C */ |
21 | "he \4 on \4 as \4 is \4ing \2\n\t\1:\3ed " |
22 | /* 6x _3 _8 _D _2 _7_ _ _A _C */ |
23 | "\2=\"\4 at \3ly \1,\2=\'\5.com/\7. This \5" |
24 | /* 8x _0 _ _3 _8 _C _E _ _1 _7 _F */ |
25 | " not \3er \3al \4ful \4ive \5less \4es" |
26 | /* Ax _5 _9 _D _2 _7 _D */ |
27 | "t \4ize \2\xc2\xa0\4ous \5 the \2e \0" ; |
28 | /* Cx _2 _7___ ___ _A _F _5 _8 */ |
29 | |
30 | static const uint16_t kPrefixSuffixMap[50] = { |
31 | 0x00, 0x02, 0x05, 0x0E, 0x13, 0x16, 0x18, 0x1E, 0x23, 0x25, |
32 | 0x2A, 0x2D, 0x2F, 0x32, 0x34, 0x3A, 0x3E, 0x45, 0x47, 0x4E, |
33 | 0x55, 0x5A, 0x5C, 0x63, 0x68, 0x6D, 0x72, 0x77, 0x7A, 0x7C, |
34 | 0x80, 0x83, 0x88, 0x8C, 0x8E, 0x91, 0x97, 0x9F, 0xA5, 0xA9, |
35 | 0xAD, 0xB2, 0xB7, 0xBD, 0xC2, 0xC7, 0xCA, 0xCF, 0xD5, 0xD8 |
36 | }; |
37 | |
38 | /* RFC 7932 transforms */ |
39 | static const uint8_t kTransformsData[] = { |
40 | 49, BROTLI_TRANSFORM_IDENTITY, 49, |
41 | 49, BROTLI_TRANSFORM_IDENTITY, 0, |
42 | 0, BROTLI_TRANSFORM_IDENTITY, 0, |
43 | 49, BROTLI_TRANSFORM_OMIT_FIRST_1, 49, |
44 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 0, |
45 | 49, BROTLI_TRANSFORM_IDENTITY, 47, |
46 | 0, BROTLI_TRANSFORM_IDENTITY, 49, |
47 | 4, BROTLI_TRANSFORM_IDENTITY, 0, |
48 | 49, BROTLI_TRANSFORM_IDENTITY, 3, |
49 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 49, |
50 | 49, BROTLI_TRANSFORM_IDENTITY, 6, |
51 | 49, BROTLI_TRANSFORM_OMIT_FIRST_2, 49, |
52 | 49, BROTLI_TRANSFORM_OMIT_LAST_1, 49, |
53 | 1, BROTLI_TRANSFORM_IDENTITY, 0, |
54 | 49, BROTLI_TRANSFORM_IDENTITY, 1, |
55 | 0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 0, |
56 | 49, BROTLI_TRANSFORM_IDENTITY, 7, |
57 | 49, BROTLI_TRANSFORM_IDENTITY, 9, |
58 | 48, BROTLI_TRANSFORM_IDENTITY, 0, |
59 | 49, BROTLI_TRANSFORM_IDENTITY, 8, |
60 | 49, BROTLI_TRANSFORM_IDENTITY, 5, |
61 | 49, BROTLI_TRANSFORM_IDENTITY, 10, |
62 | 49, BROTLI_TRANSFORM_IDENTITY, 11, |
63 | 49, BROTLI_TRANSFORM_OMIT_LAST_3, 49, |
64 | 49, BROTLI_TRANSFORM_IDENTITY, 13, |
65 | 49, BROTLI_TRANSFORM_IDENTITY, 14, |
66 | 49, BROTLI_TRANSFORM_OMIT_FIRST_3, 49, |
67 | 49, BROTLI_TRANSFORM_OMIT_LAST_2, 49, |
68 | 49, BROTLI_TRANSFORM_IDENTITY, 15, |
69 | 49, BROTLI_TRANSFORM_IDENTITY, 16, |
70 | 0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 49, |
71 | 49, BROTLI_TRANSFORM_IDENTITY, 12, |
72 | 5, BROTLI_TRANSFORM_IDENTITY, 49, |
73 | 0, BROTLI_TRANSFORM_IDENTITY, 1, |
74 | 49, BROTLI_TRANSFORM_OMIT_FIRST_4, 49, |
75 | 49, BROTLI_TRANSFORM_IDENTITY, 18, |
76 | 49, BROTLI_TRANSFORM_IDENTITY, 17, |
77 | 49, BROTLI_TRANSFORM_IDENTITY, 19, |
78 | 49, BROTLI_TRANSFORM_IDENTITY, 20, |
79 | 49, BROTLI_TRANSFORM_OMIT_FIRST_5, 49, |
80 | 49, BROTLI_TRANSFORM_OMIT_FIRST_6, 49, |
81 | 47, BROTLI_TRANSFORM_IDENTITY, 49, |
82 | 49, BROTLI_TRANSFORM_OMIT_LAST_4, 49, |
83 | 49, BROTLI_TRANSFORM_IDENTITY, 22, |
84 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 49, |
85 | 49, BROTLI_TRANSFORM_IDENTITY, 23, |
86 | 49, BROTLI_TRANSFORM_IDENTITY, 24, |
87 | 49, BROTLI_TRANSFORM_IDENTITY, 25, |
88 | 49, BROTLI_TRANSFORM_OMIT_LAST_7, 49, |
89 | 49, BROTLI_TRANSFORM_OMIT_LAST_1, 26, |
90 | 49, BROTLI_TRANSFORM_IDENTITY, 27, |
91 | 49, BROTLI_TRANSFORM_IDENTITY, 28, |
92 | 0, BROTLI_TRANSFORM_IDENTITY, 12, |
93 | 49, BROTLI_TRANSFORM_IDENTITY, 29, |
94 | 49, BROTLI_TRANSFORM_OMIT_FIRST_9, 49, |
95 | 49, BROTLI_TRANSFORM_OMIT_FIRST_7, 49, |
96 | 49, BROTLI_TRANSFORM_OMIT_LAST_6, 49, |
97 | 49, BROTLI_TRANSFORM_IDENTITY, 21, |
98 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 1, |
99 | 49, BROTLI_TRANSFORM_OMIT_LAST_8, 49, |
100 | 49, BROTLI_TRANSFORM_IDENTITY, 31, |
101 | 49, BROTLI_TRANSFORM_IDENTITY, 32, |
102 | 47, BROTLI_TRANSFORM_IDENTITY, 3, |
103 | 49, BROTLI_TRANSFORM_OMIT_LAST_5, 49, |
104 | 49, BROTLI_TRANSFORM_OMIT_LAST_9, 49, |
105 | 0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 1, |
106 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 8, |
107 | 5, BROTLI_TRANSFORM_IDENTITY, 21, |
108 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 0, |
109 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 10, |
110 | 49, BROTLI_TRANSFORM_IDENTITY, 30, |
111 | 0, BROTLI_TRANSFORM_IDENTITY, 5, |
112 | 35, BROTLI_TRANSFORM_IDENTITY, 49, |
113 | 47, BROTLI_TRANSFORM_IDENTITY, 2, |
114 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 17, |
115 | 49, BROTLI_TRANSFORM_IDENTITY, 36, |
116 | 49, BROTLI_TRANSFORM_IDENTITY, 33, |
117 | 5, BROTLI_TRANSFORM_IDENTITY, 0, |
118 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 21, |
119 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 5, |
120 | 49, BROTLI_TRANSFORM_IDENTITY, 37, |
121 | 0, BROTLI_TRANSFORM_IDENTITY, 30, |
122 | 49, BROTLI_TRANSFORM_IDENTITY, 38, |
123 | 0, BROTLI_TRANSFORM_UPPERCASE_ALL, 0, |
124 | 49, BROTLI_TRANSFORM_IDENTITY, 39, |
125 | 0, BROTLI_TRANSFORM_UPPERCASE_ALL, 49, |
126 | 49, BROTLI_TRANSFORM_IDENTITY, 34, |
127 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 8, |
128 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 12, |
129 | 0, BROTLI_TRANSFORM_IDENTITY, 21, |
130 | 49, BROTLI_TRANSFORM_IDENTITY, 40, |
131 | 0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 12, |
132 | 49, BROTLI_TRANSFORM_IDENTITY, 41, |
133 | 49, BROTLI_TRANSFORM_IDENTITY, 42, |
134 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 17, |
135 | 49, BROTLI_TRANSFORM_IDENTITY, 43, |
136 | 0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 5, |
137 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 10, |
138 | 0, BROTLI_TRANSFORM_IDENTITY, 34, |
139 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 33, |
140 | 49, BROTLI_TRANSFORM_IDENTITY, 44, |
141 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 5, |
142 | 45, BROTLI_TRANSFORM_IDENTITY, 49, |
143 | 0, BROTLI_TRANSFORM_IDENTITY, 33, |
144 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 30, |
145 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 30, |
146 | 49, BROTLI_TRANSFORM_IDENTITY, 46, |
147 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 1, |
148 | 49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 34, |
149 | 0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 33, |
150 | 0, BROTLI_TRANSFORM_UPPERCASE_ALL, 30, |
151 | 0, BROTLI_TRANSFORM_UPPERCASE_ALL, 1, |
152 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 33, |
153 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 21, |
154 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 12, |
155 | 0, BROTLI_TRANSFORM_UPPERCASE_ALL, 5, |
156 | 49, BROTLI_TRANSFORM_UPPERCASE_ALL, 34, |
157 | 0, BROTLI_TRANSFORM_UPPERCASE_ALL, 12, |
158 | 0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 30, |
159 | 0, BROTLI_TRANSFORM_UPPERCASE_ALL, 34, |
160 | 0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 34, |
161 | }; |
162 | |
163 | static BrotliTransforms kBrotliTransforms = { |
164 | sizeof(kPrefixSuffix), |
165 | (const uint8_t*)kPrefixSuffix, |
166 | kPrefixSuffixMap, |
167 | sizeof(kTransformsData) / (3 * sizeof(kTransformsData[0])), |
168 | kTransformsData, |
169 | NULL, /* no extra parameters */ |
170 | {0, 12, 27, 23, 42, 63, 56, 48, 59, 64} |
171 | }; |
172 | |
173 | const BrotliTransforms* BrotliGetTransforms(void) { |
174 | return &kBrotliTransforms; |
175 | } |
176 | |
177 | static int ToUpperCase(uint8_t* p) { |
178 | if (p[0] < 0xC0) { |
179 | if (p[0] >= 'a' && p[0] <= 'z') { |
180 | p[0] ^= 32; |
181 | } |
182 | return 1; |
183 | } |
184 | /* An overly simplified uppercasing model for UTF-8. */ |
185 | if (p[0] < 0xE0) { |
186 | p[1] ^= 32; |
187 | return 2; |
188 | } |
189 | /* An arbitrary transform for three byte characters. */ |
190 | p[2] ^= 5; |
191 | return 3; |
192 | } |
193 | |
194 | static int Shift(uint8_t* word, int word_len, uint16_t parameter) { |
195 | /* Limited sign extension: scalar < (1 << 24). */ |
196 | uint32_t scalar = |
197 | (parameter & 0x7FFFu) + (0x1000000u - (parameter & 0x8000u)); |
198 | if (word[0] < 0x80) { |
199 | /* 1-byte rune / 0sssssss / 7 bit scalar (ASCII). */ |
200 | scalar += (uint32_t)word[0]; |
201 | word[0] = (uint8_t)(scalar & 0x7Fu); |
202 | return 1; |
203 | } else if (word[0] < 0xC0) { |
204 | /* Continuation / 10AAAAAA. */ |
205 | return 1; |
206 | } else if (word[0] < 0xE0) { |
207 | /* 2-byte rune / 110sssss AAssssss / 11 bit scalar. */ |
208 | if (word_len < 2) return 1; |
209 | scalar += (uint32_t)((word[1] & 0x3Fu) | ((word[0] & 0x1Fu) << 6u)); |
210 | word[0] = (uint8_t)(0xC0 | ((scalar >> 6u) & 0x1F)); |
211 | word[1] = (uint8_t)((word[1] & 0xC0) | (scalar & 0x3F)); |
212 | return 2; |
213 | } else if (word[0] < 0xF0) { |
214 | /* 3-byte rune / 1110ssss AAssssss BBssssss / 16 bit scalar. */ |
215 | if (word_len < 3) return word_len; |
216 | scalar += (uint32_t)((word[2] & 0x3Fu) | ((word[1] & 0x3Fu) << 6u) | |
217 | ((word[0] & 0x0Fu) << 12u)); |
218 | word[0] = (uint8_t)(0xE0 | ((scalar >> 12u) & 0x0F)); |
219 | word[1] = (uint8_t)((word[1] & 0xC0) | ((scalar >> 6u) & 0x3F)); |
220 | word[2] = (uint8_t)((word[2] & 0xC0) | (scalar & 0x3F)); |
221 | return 3; |
222 | } else if (word[0] < 0xF8) { |
223 | /* 4-byte rune / 11110sss AAssssss BBssssss CCssssss / 21 bit scalar. */ |
224 | if (word_len < 4) return word_len; |
225 | scalar += (uint32_t)((word[3] & 0x3Fu) | ((word[2] & 0x3Fu) << 6u) | |
226 | ((word[1] & 0x3Fu) << 12u) | ((word[0] & 0x07u) << 18u)); |
227 | word[0] = (uint8_t)(0xF0 | ((scalar >> 18u) & 0x07)); |
228 | word[1] = (uint8_t)((word[1] & 0xC0) | ((scalar >> 12u) & 0x3F)); |
229 | word[2] = (uint8_t)((word[2] & 0xC0) | ((scalar >> 6u) & 0x3F)); |
230 | word[3] = (uint8_t)((word[3] & 0xC0) | (scalar & 0x3F)); |
231 | return 4; |
232 | } |
233 | return 1; |
234 | } |
235 | |
236 | int BrotliTransformDictionaryWord(uint8_t* dst, const uint8_t* word, int len, |
237 | const BrotliTransforms* transforms, int transform_idx) { |
238 | int idx = 0; |
239 | const uint8_t* prefix = BROTLI_TRANSFORM_PREFIX(transforms, transform_idx); |
240 | uint8_t type = BROTLI_TRANSFORM_TYPE(transforms, transform_idx); |
241 | const uint8_t* suffix = BROTLI_TRANSFORM_SUFFIX(transforms, transform_idx); |
242 | { |
243 | int prefix_len = *prefix++; |
244 | while (prefix_len--) { dst[idx++] = *prefix++; } |
245 | } |
246 | { |
247 | const int t = type; |
248 | int i = 0; |
249 | if (t <= BROTLI_TRANSFORM_OMIT_LAST_9) { |
250 | len -= t; |
251 | } else if (t >= BROTLI_TRANSFORM_OMIT_FIRST_1 |
252 | && t <= BROTLI_TRANSFORM_OMIT_FIRST_9) { |
253 | int skip = t - (BROTLI_TRANSFORM_OMIT_FIRST_1 - 1); |
254 | word += skip; |
255 | len -= skip; |
256 | } |
257 | while (i < len) { dst[idx++] = word[i++]; } |
258 | if (t == BROTLI_TRANSFORM_UPPERCASE_FIRST) { |
259 | ToUpperCase(&dst[idx - len]); |
260 | } else if (t == BROTLI_TRANSFORM_UPPERCASE_ALL) { |
261 | uint8_t* uppercase = &dst[idx - len]; |
262 | while (len > 0) { |
263 | int step = ToUpperCase(uppercase); |
264 | uppercase += step; |
265 | len -= step; |
266 | } |
267 | } else if (t == BROTLI_TRANSFORM_SHIFT_FIRST) { |
268 | uint16_t param = (uint16_t)(transforms->params[transform_idx * 2] |
269 | + (transforms->params[transform_idx * 2 + 1] << 8u)); |
270 | Shift(&dst[idx - len], len, param); |
271 | } else if (t == BROTLI_TRANSFORM_SHIFT_ALL) { |
272 | uint16_t param = (uint16_t)(transforms->params[transform_idx * 2] |
273 | + (transforms->params[transform_idx * 2 + 1] << 8u)); |
274 | uint8_t* shift = &dst[idx - len]; |
275 | while (len > 0) { |
276 | int step = Shift(shift, len, param); |
277 | shift += step; |
278 | len -= step; |
279 | } |
280 | } |
281 | } |
282 | { |
283 | int suffix_len = *suffix++; |
284 | while (suffix_len--) { dst[idx++] = *suffix++; } |
285 | return idx; |
286 | } |
287 | } |
288 | |
289 | #if defined(__cplusplus) || defined(c_plusplus) |
290 | } /* extern "C" */ |
291 | #endif |
292 | |