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e1273106 VM |
1 | /** |
2 | * Copyright 2013, GitHub, Inc | |
3 | * Copyright 2009-2013, Daniel Lemire, Cliff Moon, | |
4 | * David McIntosh, Robert Becho, Google Inc. and Veronika Zenz | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version 2 | |
9 | * of the License, or (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
48425792 | 17 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
e1273106 VM |
18 | */ |
19 | #include "git-compat-util.h" | |
20 | #include "ewok.h" | |
21 | #include "ewok_rlw.h" | |
22 | ||
23 | static inline size_t min_size(size_t a, size_t b) | |
24 | { | |
25 | return a < b ? a : b; | |
26 | } | |
27 | ||
28 | static inline size_t max_size(size_t a, size_t b) | |
29 | { | |
30 | return a > b ? a : b; | |
31 | } | |
32 | ||
33 | static inline void buffer_grow(struct ewah_bitmap *self, size_t new_size) | |
34 | { | |
35 | size_t rlw_offset = (uint8_t *)self->rlw - (uint8_t *)self->buffer; | |
36 | ||
37 | if (self->alloc_size >= new_size) | |
38 | return; | |
39 | ||
40 | self->alloc_size = new_size; | |
08c95df8 | 41 | REALLOC_ARRAY(self->buffer, self->alloc_size); |
68f4e1fc | 42 | self->rlw = self->buffer + (rlw_offset / sizeof(eword_t)); |
e1273106 VM |
43 | } |
44 | ||
45 | static inline void buffer_push(struct ewah_bitmap *self, eword_t value) | |
46 | { | |
47 | if (self->buffer_size + 1 >= self->alloc_size) | |
48 | buffer_grow(self, self->buffer_size * 3 / 2); | |
49 | ||
50 | self->buffer[self->buffer_size++] = value; | |
51 | } | |
52 | ||
53 | static void buffer_push_rlw(struct ewah_bitmap *self, eword_t value) | |
54 | { | |
55 | buffer_push(self, value); | |
56 | self->rlw = self->buffer + self->buffer_size - 1; | |
57 | } | |
58 | ||
59 | static size_t add_empty_words(struct ewah_bitmap *self, int v, size_t number) | |
60 | { | |
61 | size_t added = 0; | |
62 | eword_t runlen, can_add; | |
63 | ||
64 | if (rlw_get_run_bit(self->rlw) != v && rlw_size(self->rlw) == 0) { | |
65 | rlw_set_run_bit(self->rlw, v); | |
66 | } else if (rlw_get_literal_words(self->rlw) != 0 || | |
67 | rlw_get_run_bit(self->rlw) != v) { | |
68 | buffer_push_rlw(self, 0); | |
69 | if (v) rlw_set_run_bit(self->rlw, v); | |
70 | added++; | |
71 | } | |
72 | ||
73 | runlen = rlw_get_running_len(self->rlw); | |
74 | can_add = min_size(number, RLW_LARGEST_RUNNING_COUNT - runlen); | |
75 | ||
76 | rlw_set_running_len(self->rlw, runlen + can_add); | |
77 | number -= can_add; | |
78 | ||
79 | while (number >= RLW_LARGEST_RUNNING_COUNT) { | |
80 | buffer_push_rlw(self, 0); | |
81 | added++; | |
82 | if (v) rlw_set_run_bit(self->rlw, v); | |
83 | rlw_set_running_len(self->rlw, RLW_LARGEST_RUNNING_COUNT); | |
84 | number -= RLW_LARGEST_RUNNING_COUNT; | |
85 | } | |
86 | ||
87 | if (number > 0) { | |
88 | buffer_push_rlw(self, 0); | |
89 | added++; | |
90 | ||
91 | if (v) rlw_set_run_bit(self->rlw, v); | |
92 | rlw_set_running_len(self->rlw, number); | |
93 | } | |
94 | ||
95 | return added; | |
96 | } | |
97 | ||
98 | size_t ewah_add_empty_words(struct ewah_bitmap *self, int v, size_t number) | |
99 | { | |
100 | if (number == 0) | |
101 | return 0; | |
102 | ||
34b935c0 | 103 | self->bit_size += number * BITS_IN_EWORD; |
e1273106 VM |
104 | return add_empty_words(self, v, number); |
105 | } | |
106 | ||
107 | static size_t add_literal(struct ewah_bitmap *self, eword_t new_data) | |
108 | { | |
109 | eword_t current_num = rlw_get_literal_words(self->rlw); | |
110 | ||
111 | if (current_num >= RLW_LARGEST_LITERAL_COUNT) { | |
112 | buffer_push_rlw(self, 0); | |
113 | ||
114 | rlw_set_literal_words(self->rlw, 1); | |
115 | buffer_push(self, new_data); | |
116 | return 2; | |
117 | } | |
118 | ||
119 | rlw_set_literal_words(self->rlw, current_num + 1); | |
120 | ||
121 | /* sanity check */ | |
122 | assert(rlw_get_literal_words(self->rlw) == current_num + 1); | |
123 | ||
124 | buffer_push(self, new_data); | |
125 | return 1; | |
126 | } | |
127 | ||
128 | void ewah_add_dirty_words( | |
129 | struct ewah_bitmap *self, const eword_t *buffer, | |
130 | size_t number, int negate) | |
131 | { | |
132 | size_t literals, can_add; | |
133 | ||
134 | while (1) { | |
135 | literals = rlw_get_literal_words(self->rlw); | |
136 | can_add = min_size(number, RLW_LARGEST_LITERAL_COUNT - literals); | |
137 | ||
138 | rlw_set_literal_words(self->rlw, literals + can_add); | |
139 | ||
140 | if (self->buffer_size + can_add >= self->alloc_size) | |
141 | buffer_grow(self, (self->buffer_size + can_add) * 3 / 2); | |
142 | ||
143 | if (negate) { | |
144 | size_t i; | |
145 | for (i = 0; i < can_add; ++i) | |
146 | self->buffer[self->buffer_size++] = ~buffer[i]; | |
147 | } else { | |
148 | memcpy(self->buffer + self->buffer_size, | |
149 | buffer, can_add * sizeof(eword_t)); | |
150 | self->buffer_size += can_add; | |
151 | } | |
152 | ||
34b935c0 | 153 | self->bit_size += can_add * BITS_IN_EWORD; |
e1273106 VM |
154 | |
155 | if (number - can_add == 0) | |
156 | break; | |
157 | ||
158 | buffer_push_rlw(self, 0); | |
159 | buffer += can_add; | |
160 | number -= can_add; | |
161 | } | |
162 | } | |
163 | ||
164 | static size_t add_empty_word(struct ewah_bitmap *self, int v) | |
165 | { | |
166 | int no_literal = (rlw_get_literal_words(self->rlw) == 0); | |
167 | eword_t run_len = rlw_get_running_len(self->rlw); | |
168 | ||
169 | if (no_literal && run_len == 0) { | |
170 | rlw_set_run_bit(self->rlw, v); | |
171 | assert(rlw_get_run_bit(self->rlw) == v); | |
172 | } | |
173 | ||
174 | if (no_literal && rlw_get_run_bit(self->rlw) == v && | |
175 | run_len < RLW_LARGEST_RUNNING_COUNT) { | |
176 | rlw_set_running_len(self->rlw, run_len + 1); | |
177 | assert(rlw_get_running_len(self->rlw) == run_len + 1); | |
178 | return 0; | |
179 | } else { | |
180 | buffer_push_rlw(self, 0); | |
181 | ||
182 | assert(rlw_get_running_len(self->rlw) == 0); | |
183 | assert(rlw_get_run_bit(self->rlw) == 0); | |
184 | assert(rlw_get_literal_words(self->rlw) == 0); | |
185 | ||
186 | rlw_set_run_bit(self->rlw, v); | |
187 | assert(rlw_get_run_bit(self->rlw) == v); | |
188 | ||
189 | rlw_set_running_len(self->rlw, 1); | |
190 | assert(rlw_get_running_len(self->rlw) == 1); | |
191 | assert(rlw_get_literal_words(self->rlw) == 0); | |
192 | return 1; | |
193 | } | |
194 | } | |
195 | ||
196 | size_t ewah_add(struct ewah_bitmap *self, eword_t word) | |
197 | { | |
34b935c0 | 198 | self->bit_size += BITS_IN_EWORD; |
e1273106 VM |
199 | |
200 | if (word == 0) | |
201 | return add_empty_word(self, 0); | |
202 | ||
203 | if (word == (eword_t)(~0)) | |
204 | return add_empty_word(self, 1); | |
205 | ||
206 | return add_literal(self, word); | |
207 | } | |
208 | ||
209 | void ewah_set(struct ewah_bitmap *self, size_t i) | |
210 | { | |
211 | const size_t dist = | |
42c78a21 RS |
212 | DIV_ROUND_UP(i + 1, BITS_IN_EWORD) - |
213 | DIV_ROUND_UP(self->bit_size, BITS_IN_EWORD); | |
e1273106 VM |
214 | |
215 | assert(i >= self->bit_size); | |
216 | ||
217 | self->bit_size = i + 1; | |
218 | ||
219 | if (dist > 0) { | |
220 | if (dist > 1) | |
221 | add_empty_words(self, 0, dist - 1); | |
222 | ||
34b935c0 | 223 | add_literal(self, (eword_t)1 << (i % BITS_IN_EWORD)); |
e1273106 VM |
224 | return; |
225 | } | |
226 | ||
227 | if (rlw_get_literal_words(self->rlw) == 0) { | |
228 | rlw_set_running_len(self->rlw, | |
229 | rlw_get_running_len(self->rlw) - 1); | |
34b935c0 | 230 | add_literal(self, (eword_t)1 << (i % BITS_IN_EWORD)); |
e1273106 VM |
231 | return; |
232 | } | |
233 | ||
234 | self->buffer[self->buffer_size - 1] |= | |
34b935c0 | 235 | ((eword_t)1 << (i % BITS_IN_EWORD)); |
e1273106 VM |
236 | |
237 | /* check if we just completed a stream of 1s */ | |
238 | if (self->buffer[self->buffer_size - 1] == (eword_t)(~0)) { | |
239 | self->buffer[--self->buffer_size] = 0; | |
240 | rlw_set_literal_words(self->rlw, | |
241 | rlw_get_literal_words(self->rlw) - 1); | |
242 | add_empty_word(self, 1); | |
243 | } | |
244 | } | |
245 | ||
246 | void ewah_each_bit(struct ewah_bitmap *self, void (*callback)(size_t, void*), void *payload) | |
247 | { | |
248 | size_t pos = 0; | |
249 | size_t pointer = 0; | |
250 | size_t k; | |
251 | ||
252 | while (pointer < self->buffer_size) { | |
253 | eword_t *word = &self->buffer[pointer]; | |
254 | ||
255 | if (rlw_get_run_bit(word)) { | |
34b935c0 | 256 | size_t len = rlw_get_running_len(word) * BITS_IN_EWORD; |
e1273106 VM |
257 | for (k = 0; k < len; ++k, ++pos) |
258 | callback(pos, payload); | |
259 | } else { | |
34b935c0 | 260 | pos += rlw_get_running_len(word) * BITS_IN_EWORD; |
e1273106 VM |
261 | } |
262 | ||
263 | ++pointer; | |
264 | ||
265 | for (k = 0; k < rlw_get_literal_words(word); ++k) { | |
266 | int c; | |
267 | ||
268 | /* todo: zero count optimization */ | |
34b935c0 | 269 | for (c = 0; c < BITS_IN_EWORD; ++c, ++pos) { |
e1273106 VM |
270 | if ((self->buffer[pointer] & ((eword_t)1 << c)) != 0) |
271 | callback(pos, payload); | |
272 | } | |
273 | ||
274 | ++pointer; | |
275 | } | |
276 | } | |
277 | } | |
278 | ||
c806278e JH |
279 | /** |
280 | * Clear all the bits in the bitmap. Does not free or resize | |
281 | * memory. | |
282 | */ | |
283 | static void ewah_clear(struct ewah_bitmap *self) | |
284 | { | |
285 | self->buffer_size = 1; | |
286 | self->buffer[0] = 0; | |
287 | self->bit_size = 0; | |
288 | self->rlw = self->buffer; | |
289 | } | |
290 | ||
e1273106 VM |
291 | struct ewah_bitmap *ewah_new(void) |
292 | { | |
293 | struct ewah_bitmap *self; | |
294 | ||
fb7dbf3e | 295 | self = xmalloc(sizeof(struct ewah_bitmap)); |
e1273106 | 296 | self->alloc_size = 32; |
08c95df8 | 297 | ALLOC_ARRAY(self->buffer, self->alloc_size); |
e1273106 VM |
298 | |
299 | ewah_clear(self); | |
300 | return self; | |
301 | } | |
302 | ||
e1273106 VM |
303 | void ewah_free(struct ewah_bitmap *self) |
304 | { | |
305 | if (!self) | |
306 | return; | |
307 | ||
308 | if (self->alloc_size) | |
309 | free(self->buffer); | |
310 | ||
311 | free(self); | |
312 | } | |
313 | ||
314 | static void read_new_rlw(struct ewah_iterator *it) | |
315 | { | |
316 | const eword_t *word = NULL; | |
317 | ||
318 | it->literals = 0; | |
319 | it->compressed = 0; | |
320 | ||
321 | while (1) { | |
322 | word = &it->buffer[it->pointer]; | |
323 | ||
324 | it->rl = rlw_get_running_len(word); | |
325 | it->lw = rlw_get_literal_words(word); | |
326 | it->b = rlw_get_run_bit(word); | |
327 | ||
328 | if (it->rl || it->lw) | |
329 | return; | |
330 | ||
331 | if (it->pointer < it->buffer_size - 1) { | |
332 | it->pointer++; | |
333 | } else { | |
334 | it->pointer = it->buffer_size; | |
335 | return; | |
336 | } | |
337 | } | |
338 | } | |
339 | ||
340 | int ewah_iterator_next(eword_t *next, struct ewah_iterator *it) | |
341 | { | |
342 | if (it->pointer >= it->buffer_size) | |
343 | return 0; | |
344 | ||
345 | if (it->compressed < it->rl) { | |
346 | it->compressed++; | |
347 | *next = it->b ? (eword_t)(~0) : 0; | |
348 | } else { | |
349 | assert(it->literals < it->lw); | |
350 | ||
351 | it->literals++; | |
352 | it->pointer++; | |
353 | ||
354 | assert(it->pointer < it->buffer_size); | |
355 | ||
356 | *next = it->buffer[it->pointer]; | |
357 | } | |
358 | ||
359 | if (it->compressed == it->rl && it->literals == it->lw) { | |
360 | if (++it->pointer < it->buffer_size) | |
361 | read_new_rlw(it); | |
362 | } | |
363 | ||
364 | return 1; | |
365 | } | |
366 | ||
367 | void ewah_iterator_init(struct ewah_iterator *it, struct ewah_bitmap *parent) | |
368 | { | |
369 | it->buffer = parent->buffer; | |
370 | it->buffer_size = parent->buffer_size; | |
371 | it->pointer = 0; | |
372 | ||
373 | it->lw = 0; | |
374 | it->rl = 0; | |
375 | it->compressed = 0; | |
376 | it->literals = 0; | |
377 | it->b = 0; | |
378 | ||
379 | if (it->pointer < it->buffer_size) | |
380 | read_new_rlw(it); | |
381 | } | |
382 | ||
e1273106 VM |
383 | void ewah_xor( |
384 | struct ewah_bitmap *ewah_i, | |
385 | struct ewah_bitmap *ewah_j, | |
386 | struct ewah_bitmap *out) | |
387 | { | |
388 | struct rlw_iterator rlw_i; | |
389 | struct rlw_iterator rlw_j; | |
390 | size_t literals; | |
391 | ||
392 | rlwit_init(&rlw_i, ewah_i); | |
393 | rlwit_init(&rlw_j, ewah_j); | |
394 | ||
395 | while (rlwit_word_size(&rlw_i) > 0 && rlwit_word_size(&rlw_j) > 0) { | |
396 | while (rlw_i.rlw.running_len > 0 || rlw_j.rlw.running_len > 0) { | |
397 | struct rlw_iterator *prey, *predator; | |
398 | size_t index; | |
399 | int negate_words; | |
400 | ||
401 | if (rlw_i.rlw.running_len < rlw_j.rlw.running_len) { | |
402 | prey = &rlw_i; | |
403 | predator = &rlw_j; | |
404 | } else { | |
405 | prey = &rlw_j; | |
406 | predator = &rlw_i; | |
407 | } | |
408 | ||
409 | negate_words = !!predator->rlw.running_bit; | |
410 | index = rlwit_discharge(prey, out, | |
411 | predator->rlw.running_len, negate_words); | |
412 | ||
413 | ewah_add_empty_words(out, negate_words, | |
414 | predator->rlw.running_len - index); | |
415 | ||
416 | rlwit_discard_first_words(predator, | |
417 | predator->rlw.running_len); | |
418 | } | |
419 | ||
420 | literals = min_size( | |
421 | rlw_i.rlw.literal_words, | |
422 | rlw_j.rlw.literal_words); | |
423 | ||
424 | if (literals) { | |
425 | size_t k; | |
426 | ||
427 | for (k = 0; k < literals; ++k) { | |
428 | ewah_add(out, | |
429 | rlw_i.buffer[rlw_i.literal_word_start + k] ^ | |
430 | rlw_j.buffer[rlw_j.literal_word_start + k] | |
431 | ); | |
432 | } | |
433 | ||
434 | rlwit_discard_first_words(&rlw_i, literals); | |
435 | rlwit_discard_first_words(&rlw_j, literals); | |
436 | } | |
437 | } | |
438 | ||
439 | if (rlwit_word_size(&rlw_i) > 0) | |
440 | rlwit_discharge(&rlw_i, out, ~0, 0); | |
441 | else | |
442 | rlwit_discharge(&rlw_j, out, ~0, 0); | |
443 | ||
444 | out->bit_size = max_size(ewah_i->bit_size, ewah_j->bit_size); | |
445 | } | |
446 | ||
e1273106 VM |
447 | #define BITMAP_POOL_MAX 16 |
448 | static struct ewah_bitmap *bitmap_pool[BITMAP_POOL_MAX]; | |
449 | static size_t bitmap_pool_size; | |
450 | ||
451 | struct ewah_bitmap *ewah_pool_new(void) | |
452 | { | |
453 | if (bitmap_pool_size) | |
454 | return bitmap_pool[--bitmap_pool_size]; | |
455 | ||
456 | return ewah_new(); | |
457 | } | |
458 | ||
459 | void ewah_pool_free(struct ewah_bitmap *self) | |
460 | { | |
461 | if (self == NULL) | |
462 | return; | |
463 | ||
464 | if (bitmap_pool_size == BITMAP_POOL_MAX || | |
465 | self->alloc_size == 0) { | |
466 | ewah_free(self); | |
467 | return; | |
468 | } | |
469 | ||
470 | ewah_clear(self); | |
471 | bitmap_pool[bitmap_pool_size++] = self; | |
472 | } | |
473 | ||
474 | uint32_t ewah_checksum(struct ewah_bitmap *self) | |
475 | { | |
476 | const uint8_t *p = (uint8_t *)self->buffer; | |
477 | uint32_t crc = (uint32_t)self->bit_size; | |
478 | size_t size = self->buffer_size * sizeof(eword_t); | |
479 | ||
480 | while (size--) | |
481 | crc = (crc << 5) - crc + (uint32_t)*p++; | |
482 | ||
483 | return crc; | |
484 | } |