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 "./static_dict.h"
8
9 #include "../common/dictionary.h"
10 #include "../common/platform.h"
11 #include "../common/transform.h"
12 #include "./encoder_dict.h"
13 #include "./find_match_length.h"
14
15 #if defined(__cplusplus) || defined(c_plusplus)
16 extern "C" {
17 #endif
18
Hash(const uint8_t * data)19 static BROTLI_INLINE uint32_t Hash(const uint8_t* data) {
20 uint32_t h = BROTLI_UNALIGNED_LOAD32LE(data) * kDictHashMul32;
21 /* The higher bits contain more mixture from the multiplication,
22 so we take our results from there. */
23 return h >> (32 - kDictNumBits);
24 }
25
AddMatch(size_t distance,size_t len,size_t len_code,uint32_t * matches)26 static BROTLI_INLINE void AddMatch(size_t distance, size_t len, size_t len_code,
27 uint32_t* matches) {
28 uint32_t match = (uint32_t)((distance << 5) + len_code);
29 matches[len] = BROTLI_MIN(uint32_t, matches[len], match);
30 }
31
DictMatchLength(const BrotliDictionary * dictionary,const uint8_t * data,size_t id,size_t len,size_t maxlen)32 static BROTLI_INLINE size_t DictMatchLength(const BrotliDictionary* dictionary,
33 const uint8_t* data,
34 size_t id,
35 size_t len,
36 size_t maxlen) {
37 const size_t offset = dictionary->offsets_by_length[len] + len * id;
38 return FindMatchLengthWithLimit(&dictionary->data[offset], data,
39 BROTLI_MIN(size_t, len, maxlen));
40 }
41
IsMatch(const BrotliDictionary * dictionary,DictWord w,const uint8_t * data,size_t max_length)42 static BROTLI_INLINE BROTLI_BOOL IsMatch(const BrotliDictionary* dictionary,
43 DictWord w, const uint8_t* data, size_t max_length) {
44 if (w.len > max_length) {
45 return BROTLI_FALSE;
46 } else {
47 const size_t offset = dictionary->offsets_by_length[w.len] +
48 (size_t)w.len * (size_t)w.idx;
49 const uint8_t* dict = &dictionary->data[offset];
50 if (w.transform == 0) {
51 /* Match against base dictionary word. */
52 return
53 TO_BROTLI_BOOL(FindMatchLengthWithLimit(dict, data, w.len) == w.len);
54 } else if (w.transform == 10) {
55 /* Match against uppercase first transform.
56 Note that there are only ASCII uppercase words in the lookup table. */
57 return TO_BROTLI_BOOL(dict[0] >= 'a' && dict[0] <= 'z' &&
58 (dict[0] ^ 32) == data[0] &&
59 FindMatchLengthWithLimit(&dict[1], &data[1], w.len - 1u) ==
60 w.len - 1u);
61 } else {
62 /* Match against uppercase all transform.
63 Note that there are only ASCII uppercase words in the lookup table. */
64 size_t i;
65 for (i = 0; i < w.len; ++i) {
66 if (dict[i] >= 'a' && dict[i] <= 'z') {
67 if ((dict[i] ^ 32) != data[i]) return BROTLI_FALSE;
68 } else {
69 if (dict[i] != data[i]) return BROTLI_FALSE;
70 }
71 }
72 return BROTLI_TRUE;
73 }
74 }
75 }
76
BrotliFindAllStaticDictionaryMatches(const BrotliEncoderDictionary * dictionary,const uint8_t * data,size_t min_length,size_t max_length,uint32_t * matches)77 BROTLI_BOOL BrotliFindAllStaticDictionaryMatches(
78 const BrotliEncoderDictionary* dictionary, const uint8_t* data,
79 size_t min_length, size_t max_length, uint32_t* matches) {
80 BROTLI_BOOL has_found_match = BROTLI_FALSE;
81 {
82 size_t offset = dictionary->buckets[Hash(data)];
83 BROTLI_BOOL end = !offset;
84 while (!end) {
85 DictWord w = dictionary->dict_words[offset++];
86 const size_t l = w.len & 0x1F;
87 const size_t n = (size_t)1 << dictionary->words->size_bits_by_length[l];
88 const size_t id = w.idx;
89 end = !!(w.len & 0x80);
90 w.len = (uint8_t)l;
91 if (w.transform == 0) {
92 const size_t matchlen =
93 DictMatchLength(dictionary->words, data, id, l, max_length);
94 const uint8_t* s;
95 size_t minlen;
96 size_t maxlen;
97 size_t len;
98 /* Transform "" + BROTLI_TRANSFORM_IDENTITY + "" */
99 if (matchlen == l) {
100 AddMatch(id, l, l, matches);
101 has_found_match = BROTLI_TRUE;
102 }
103 /* Transforms "" + BROTLI_TRANSFORM_OMIT_LAST_1 + "" and
104 "" + BROTLI_TRANSFORM_OMIT_LAST_1 + "ing " */
105 if (matchlen >= l - 1) {
106 AddMatch(id + 12 * n, l - 1, l, matches);
107 if (l + 2 < max_length &&
108 data[l - 1] == 'i' && data[l] == 'n' && data[l + 1] == 'g' &&
109 data[l + 2] == ' ') {
110 AddMatch(id + 49 * n, l + 3, l, matches);
111 }
112 has_found_match = BROTLI_TRUE;
113 }
114 /* Transform "" + BROTLI_TRANSFORM_OMIT_LAST_# + "" (# = 2 .. 9) */
115 minlen = min_length;
116 if (l > 9) minlen = BROTLI_MAX(size_t, minlen, l - 9);
117 maxlen = BROTLI_MIN(size_t, matchlen, l - 2);
118 for (len = minlen; len <= maxlen; ++len) {
119 size_t cut = l - len;
120 size_t transform_id = (cut << 2) +
121 (size_t)((dictionary->cutoffTransforms >> (cut * 6)) & 0x3F);
122 AddMatch(id + transform_id * n, len, l, matches);
123 has_found_match = BROTLI_TRUE;
124 }
125 if (matchlen < l || l + 6 >= max_length) {
126 continue;
127 }
128 s = &data[l];
129 /* Transforms "" + BROTLI_TRANSFORM_IDENTITY + <suffix> */
130 if (s[0] == ' ') {
131 AddMatch(id + n, l + 1, l, matches);
132 if (s[1] == 'a') {
133 if (s[2] == ' ') {
134 AddMatch(id + 28 * n, l + 3, l, matches);
135 } else if (s[2] == 's') {
136 if (s[3] == ' ') AddMatch(id + 46 * n, l + 4, l, matches);
137 } else if (s[2] == 't') {
138 if (s[3] == ' ') AddMatch(id + 60 * n, l + 4, l, matches);
139 } else if (s[2] == 'n') {
140 if (s[3] == 'd' && s[4] == ' ') {
141 AddMatch(id + 10 * n, l + 5, l, matches);
142 }
143 }
144 } else if (s[1] == 'b') {
145 if (s[2] == 'y' && s[3] == ' ') {
146 AddMatch(id + 38 * n, l + 4, l, matches);
147 }
148 } else if (s[1] == 'i') {
149 if (s[2] == 'n') {
150 if (s[3] == ' ') AddMatch(id + 16 * n, l + 4, l, matches);
151 } else if (s[2] == 's') {
152 if (s[3] == ' ') AddMatch(id + 47 * n, l + 4, l, matches);
153 }
154 } else if (s[1] == 'f') {
155 if (s[2] == 'o') {
156 if (s[3] == 'r' && s[4] == ' ') {
157 AddMatch(id + 25 * n, l + 5, l, matches);
158 }
159 } else if (s[2] == 'r') {
160 if (s[3] == 'o' && s[4] == 'm' && s[5] == ' ') {
161 AddMatch(id + 37 * n, l + 6, l, matches);
162 }
163 }
164 } else if (s[1] == 'o') {
165 if (s[2] == 'f') {
166 if (s[3] == ' ') AddMatch(id + 8 * n, l + 4, l, matches);
167 } else if (s[2] == 'n') {
168 if (s[3] == ' ') AddMatch(id + 45 * n, l + 4, l, matches);
169 }
170 } else if (s[1] == 'n') {
171 if (s[2] == 'o' && s[3] == 't' && s[4] == ' ') {
172 AddMatch(id + 80 * n, l + 5, l, matches);
173 }
174 } else if (s[1] == 't') {
175 if (s[2] == 'h') {
176 if (s[3] == 'e') {
177 if (s[4] == ' ') AddMatch(id + 5 * n, l + 5, l, matches);
178 } else if (s[3] == 'a') {
179 if (s[4] == 't' && s[5] == ' ') {
180 AddMatch(id + 29 * n, l + 6, l, matches);
181 }
182 }
183 } else if (s[2] == 'o') {
184 if (s[3] == ' ') AddMatch(id + 17 * n, l + 4, l, matches);
185 }
186 } else if (s[1] == 'w') {
187 if (s[2] == 'i' && s[3] == 't' && s[4] == 'h' && s[5] == ' ') {
188 AddMatch(id + 35 * n, l + 6, l, matches);
189 }
190 }
191 } else if (s[0] == '"') {
192 AddMatch(id + 19 * n, l + 1, l, matches);
193 if (s[1] == '>') {
194 AddMatch(id + 21 * n, l + 2, l, matches);
195 }
196 } else if (s[0] == '.') {
197 AddMatch(id + 20 * n, l + 1, l, matches);
198 if (s[1] == ' ') {
199 AddMatch(id + 31 * n, l + 2, l, matches);
200 if (s[2] == 'T' && s[3] == 'h') {
201 if (s[4] == 'e') {
202 if (s[5] == ' ') AddMatch(id + 43 * n, l + 6, l, matches);
203 } else if (s[4] == 'i') {
204 if (s[5] == 's' && s[6] == ' ') {
205 AddMatch(id + 75 * n, l + 7, l, matches);
206 }
207 }
208 }
209 }
210 } else if (s[0] == ',') {
211 AddMatch(id + 76 * n, l + 1, l, matches);
212 if (s[1] == ' ') {
213 AddMatch(id + 14 * n, l + 2, l, matches);
214 }
215 } else if (s[0] == '\n') {
216 AddMatch(id + 22 * n, l + 1, l, matches);
217 if (s[1] == '\t') {
218 AddMatch(id + 50 * n, l + 2, l, matches);
219 }
220 } else if (s[0] == ']') {
221 AddMatch(id + 24 * n, l + 1, l, matches);
222 } else if (s[0] == '\'') {
223 AddMatch(id + 36 * n, l + 1, l, matches);
224 } else if (s[0] == ':') {
225 AddMatch(id + 51 * n, l + 1, l, matches);
226 } else if (s[0] == '(') {
227 AddMatch(id + 57 * n, l + 1, l, matches);
228 } else if (s[0] == '=') {
229 if (s[1] == '"') {
230 AddMatch(id + 70 * n, l + 2, l, matches);
231 } else if (s[1] == '\'') {
232 AddMatch(id + 86 * n, l + 2, l, matches);
233 }
234 } else if (s[0] == 'a') {
235 if (s[1] == 'l' && s[2] == ' ') {
236 AddMatch(id + 84 * n, l + 3, l, matches);
237 }
238 } else if (s[0] == 'e') {
239 if (s[1] == 'd') {
240 if (s[2] == ' ') AddMatch(id + 53 * n, l + 3, l, matches);
241 } else if (s[1] == 'r') {
242 if (s[2] == ' ') AddMatch(id + 82 * n, l + 3, l, matches);
243 } else if (s[1] == 's') {
244 if (s[2] == 't' && s[3] == ' ') {
245 AddMatch(id + 95 * n, l + 4, l, matches);
246 }
247 }
248 } else if (s[0] == 'f') {
249 if (s[1] == 'u' && s[2] == 'l' && s[3] == ' ') {
250 AddMatch(id + 90 * n, l + 4, l, matches);
251 }
252 } else if (s[0] == 'i') {
253 if (s[1] == 'v') {
254 if (s[2] == 'e' && s[3] == ' ') {
255 AddMatch(id + 92 * n, l + 4, l, matches);
256 }
257 } else if (s[1] == 'z') {
258 if (s[2] == 'e' && s[3] == ' ') {
259 AddMatch(id + 100 * n, l + 4, l, matches);
260 }
261 }
262 } else if (s[0] == 'l') {
263 if (s[1] == 'e') {
264 if (s[2] == 's' && s[3] == 's' && s[4] == ' ') {
265 AddMatch(id + 93 * n, l + 5, l, matches);
266 }
267 } else if (s[1] == 'y') {
268 if (s[2] == ' ') AddMatch(id + 61 * n, l + 3, l, matches);
269 }
270 } else if (s[0] == 'o') {
271 if (s[1] == 'u' && s[2] == 's' && s[3] == ' ') {
272 AddMatch(id + 106 * n, l + 4, l, matches);
273 }
274 }
275 } else {
276 /* Set is_all_caps=0 for BROTLI_TRANSFORM_UPPERCASE_FIRST and
277 is_all_caps=1 otherwise (BROTLI_TRANSFORM_UPPERCASE_ALL)
278 transform. */
279 const BROTLI_BOOL is_all_caps =
280 TO_BROTLI_BOOL(w.transform != BROTLI_TRANSFORM_UPPERCASE_FIRST);
281 const uint8_t* s;
282 if (!IsMatch(dictionary->words, w, data, max_length)) {
283 continue;
284 }
285 /* Transform "" + kUppercase{First,All} + "" */
286 AddMatch(id + (is_all_caps ? 44 : 9) * n, l, l, matches);
287 has_found_match = BROTLI_TRUE;
288 if (l + 1 >= max_length) {
289 continue;
290 }
291 /* Transforms "" + kUppercase{First,All} + <suffix> */
292 s = &data[l];
293 if (s[0] == ' ') {
294 AddMatch(id + (is_all_caps ? 68 : 4) * n, l + 1, l, matches);
295 } else if (s[0] == '"') {
296 AddMatch(id + (is_all_caps ? 87 : 66) * n, l + 1, l, matches);
297 if (s[1] == '>') {
298 AddMatch(id + (is_all_caps ? 97 : 69) * n, l + 2, l, matches);
299 }
300 } else if (s[0] == '.') {
301 AddMatch(id + (is_all_caps ? 101 : 79) * n, l + 1, l, matches);
302 if (s[1] == ' ') {
303 AddMatch(id + (is_all_caps ? 114 : 88) * n, l + 2, l, matches);
304 }
305 } else if (s[0] == ',') {
306 AddMatch(id + (is_all_caps ? 112 : 99) * n, l + 1, l, matches);
307 if (s[1] == ' ') {
308 AddMatch(id + (is_all_caps ? 107 : 58) * n, l + 2, l, matches);
309 }
310 } else if (s[0] == '\'') {
311 AddMatch(id + (is_all_caps ? 94 : 74) * n, l + 1, l, matches);
312 } else if (s[0] == '(') {
313 AddMatch(id + (is_all_caps ? 113 : 78) * n, l + 1, l, matches);
314 } else if (s[0] == '=') {
315 if (s[1] == '"') {
316 AddMatch(id + (is_all_caps ? 105 : 104) * n, l + 2, l, matches);
317 } else if (s[1] == '\'') {
318 AddMatch(id + (is_all_caps ? 116 : 108) * n, l + 2, l, matches);
319 }
320 }
321 }
322 }
323 }
324 /* Transforms with prefixes " " and "." */
325 if (max_length >= 5 && (data[0] == ' ' || data[0] == '.')) {
326 BROTLI_BOOL is_space = TO_BROTLI_BOOL(data[0] == ' ');
327 size_t offset = dictionary->buckets[Hash(&data[1])];
328 BROTLI_BOOL end = !offset;
329 while (!end) {
330 DictWord w = dictionary->dict_words[offset++];
331 const size_t l = w.len & 0x1F;
332 const size_t n = (size_t)1 << dictionary->words->size_bits_by_length[l];
333 const size_t id = w.idx;
334 end = !!(w.len & 0x80);
335 w.len = (uint8_t)l;
336 if (w.transform == 0) {
337 const uint8_t* s;
338 if (!IsMatch(dictionary->words, w, &data[1], max_length - 1)) {
339 continue;
340 }
341 /* Transforms " " + BROTLI_TRANSFORM_IDENTITY + "" and
342 "." + BROTLI_TRANSFORM_IDENTITY + "" */
343 AddMatch(id + (is_space ? 6 : 32) * n, l + 1, l, matches);
344 has_found_match = BROTLI_TRUE;
345 if (l + 2 >= max_length) {
346 continue;
347 }
348 /* Transforms " " + BROTLI_TRANSFORM_IDENTITY + <suffix> and
349 "." + BROTLI_TRANSFORM_IDENTITY + <suffix>
350 */
351 s = &data[l + 1];
352 if (s[0] == ' ') {
353 AddMatch(id + (is_space ? 2 : 77) * n, l + 2, l, matches);
354 } else if (s[0] == '(') {
355 AddMatch(id + (is_space ? 89 : 67) * n, l + 2, l, matches);
356 } else if (is_space) {
357 if (s[0] == ',') {
358 AddMatch(id + 103 * n, l + 2, l, matches);
359 if (s[1] == ' ') {
360 AddMatch(id + 33 * n, l + 3, l, matches);
361 }
362 } else if (s[0] == '.') {
363 AddMatch(id + 71 * n, l + 2, l, matches);
364 if (s[1] == ' ') {
365 AddMatch(id + 52 * n, l + 3, l, matches);
366 }
367 } else if (s[0] == '=') {
368 if (s[1] == '"') {
369 AddMatch(id + 81 * n, l + 3, l, matches);
370 } else if (s[1] == '\'') {
371 AddMatch(id + 98 * n, l + 3, l, matches);
372 }
373 }
374 }
375 } else if (is_space) {
376 /* Set is_all_caps=0 for BROTLI_TRANSFORM_UPPERCASE_FIRST and
377 is_all_caps=1 otherwise (BROTLI_TRANSFORM_UPPERCASE_ALL)
378 transform. */
379 const BROTLI_BOOL is_all_caps =
380 TO_BROTLI_BOOL(w.transform != BROTLI_TRANSFORM_UPPERCASE_FIRST);
381 const uint8_t* s;
382 if (!IsMatch(dictionary->words, w, &data[1], max_length - 1)) {
383 continue;
384 }
385 /* Transforms " " + kUppercase{First,All} + "" */
386 AddMatch(id + (is_all_caps ? 85 : 30) * n, l + 1, l, matches);
387 has_found_match = BROTLI_TRUE;
388 if (l + 2 >= max_length) {
389 continue;
390 }
391 /* Transforms " " + kUppercase{First,All} + <suffix> */
392 s = &data[l + 1];
393 if (s[0] == ' ') {
394 AddMatch(id + (is_all_caps ? 83 : 15) * n, l + 2, l, matches);
395 } else if (s[0] == ',') {
396 if (!is_all_caps) {
397 AddMatch(id + 109 * n, l + 2, l, matches);
398 }
399 if (s[1] == ' ') {
400 AddMatch(id + (is_all_caps ? 111 : 65) * n, l + 3, l, matches);
401 }
402 } else if (s[0] == '.') {
403 AddMatch(id + (is_all_caps ? 115 : 96) * n, l + 2, l, matches);
404 if (s[1] == ' ') {
405 AddMatch(id + (is_all_caps ? 117 : 91) * n, l + 3, l, matches);
406 }
407 } else if (s[0] == '=') {
408 if (s[1] == '"') {
409 AddMatch(id + (is_all_caps ? 110 : 118) * n, l + 3, l, matches);
410 } else if (s[1] == '\'') {
411 AddMatch(id + (is_all_caps ? 119 : 120) * n, l + 3, l, matches);
412 }
413 }
414 }
415 }
416 }
417 if (max_length >= 6) {
418 /* Transforms with prefixes "e ", "s ", ", " and "\xC2\xA0" */
419 if ((data[1] == ' ' &&
420 (data[0] == 'e' || data[0] == 's' || data[0] == ',')) ||
421 (data[0] == 0xC2 && data[1] == 0xA0)) {
422 size_t offset = dictionary->buckets[Hash(&data[2])];
423 BROTLI_BOOL end = !offset;
424 while (!end) {
425 DictWord w = dictionary->dict_words[offset++];
426 const size_t l = w.len & 0x1F;
427 const size_t n = (size_t)1 << dictionary->words->size_bits_by_length[l];
428 const size_t id = w.idx;
429 end = !!(w.len & 0x80);
430 w.len = (uint8_t)l;
431 if (w.transform == 0 &&
432 IsMatch(dictionary->words, w, &data[2], max_length - 2)) {
433 if (data[0] == 0xC2) {
434 AddMatch(id + 102 * n, l + 2, l, matches);
435 has_found_match = BROTLI_TRUE;
436 } else if (l + 2 < max_length && data[l + 2] == ' ') {
437 size_t t = data[0] == 'e' ? 18 : (data[0] == 's' ? 7 : 13);
438 AddMatch(id + t * n, l + 3, l, matches);
439 has_found_match = BROTLI_TRUE;
440 }
441 }
442 }
443 }
444 }
445 if (max_length >= 9) {
446 /* Transforms with prefixes " the " and ".com/" */
447 if ((data[0] == ' ' && data[1] == 't' && data[2] == 'h' &&
448 data[3] == 'e' && data[4] == ' ') ||
449 (data[0] == '.' && data[1] == 'c' && data[2] == 'o' &&
450 data[3] == 'm' && data[4] == '/')) {
451 size_t offset = dictionary->buckets[Hash(&data[5])];
452 BROTLI_BOOL end = !offset;
453 while (!end) {
454 DictWord w = dictionary->dict_words[offset++];
455 const size_t l = w.len & 0x1F;
456 const size_t n = (size_t)1 << dictionary->words->size_bits_by_length[l];
457 const size_t id = w.idx;
458 end = !!(w.len & 0x80);
459 w.len = (uint8_t)l;
460 if (w.transform == 0 &&
461 IsMatch(dictionary->words, w, &data[5], max_length - 5)) {
462 AddMatch(id + (data[0] == ' ' ? 41 : 72) * n, l + 5, l, matches);
463 has_found_match = BROTLI_TRUE;
464 if (l + 5 < max_length) {
465 const uint8_t* s = &data[l + 5];
466 if (data[0] == ' ') {
467 if (l + 8 < max_length &&
468 s[0] == ' ' && s[1] == 'o' && s[2] == 'f' && s[3] == ' ') {
469 AddMatch(id + 62 * n, l + 9, l, matches);
470 if (l + 12 < max_length &&
471 s[4] == 't' && s[5] == 'h' && s[6] == 'e' && s[7] == ' ') {
472 AddMatch(id + 73 * n, l + 13, l, matches);
473 }
474 }
475 }
476 }
477 }
478 }
479 }
480 }
481 return has_found_match;
482 }
483
484 #if defined(__cplusplus) || defined(c_plusplus)
485 } /* extern "C" */
486 #endif
487