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)
10extern "C" {
11#endif
12
13/* RFC 7932 transforms string data */
14static 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
30static 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 */
39static 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
163static 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
173const BrotliTransforms* BrotliGetTransforms(void) {
174 return &kBrotliTransforms;
175}
176
177static 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
194static 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
236int 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