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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" | |
36bf1958 | 20 | #include "alloc.h" |
e1273106 VM |
21 | #include "ewok.h" |
22 | #include "ewok_rlw.h" | |
23 | ||
24 | static inline size_t min_size(size_t a, size_t b) | |
25 | { | |
26 | return a < b ? a : b; | |
27 | } | |
28 | ||
29 | static inline size_t max_size(size_t a, size_t b) | |
30 | { | |
31 | return a > b ? a : b; | |
32 | } | |
33 | ||
34 | static inline void buffer_grow(struct ewah_bitmap *self, size_t new_size) | |
35 | { | |
36 | size_t rlw_offset = (uint8_t *)self->rlw - (uint8_t *)self->buffer; | |
3b1ca60f | 37 | ALLOC_GROW(self->buffer, new_size, self->alloc_size); |
68f4e1fc | 38 | self->rlw = self->buffer + (rlw_offset / sizeof(eword_t)); |
e1273106 VM |
39 | } |
40 | ||
41 | static inline void buffer_push(struct ewah_bitmap *self, eword_t value) | |
42 | { | |
3b1ca60f | 43 | buffer_grow(self, self->buffer_size + 1); |
e1273106 VM |
44 | self->buffer[self->buffer_size++] = value; |
45 | } | |
46 | ||
47 | static void buffer_push_rlw(struct ewah_bitmap *self, eword_t value) | |
48 | { | |
49 | buffer_push(self, value); | |
50 | self->rlw = self->buffer + self->buffer_size - 1; | |
51 | } | |
52 | ||
53 | static size_t add_empty_words(struct ewah_bitmap *self, int v, size_t number) | |
54 | { | |
55 | size_t added = 0; | |
56 | eword_t runlen, can_add; | |
57 | ||
58 | if (rlw_get_run_bit(self->rlw) != v && rlw_size(self->rlw) == 0) { | |
59 | rlw_set_run_bit(self->rlw, v); | |
60 | } else if (rlw_get_literal_words(self->rlw) != 0 || | |
61 | rlw_get_run_bit(self->rlw) != v) { | |
62 | buffer_push_rlw(self, 0); | |
63 | if (v) rlw_set_run_bit(self->rlw, v); | |
64 | added++; | |
65 | } | |
66 | ||
67 | runlen = rlw_get_running_len(self->rlw); | |
68 | can_add = min_size(number, RLW_LARGEST_RUNNING_COUNT - runlen); | |
69 | ||
70 | rlw_set_running_len(self->rlw, runlen + can_add); | |
71 | number -= can_add; | |
72 | ||
73 | while (number >= RLW_LARGEST_RUNNING_COUNT) { | |
74 | buffer_push_rlw(self, 0); | |
75 | added++; | |
76 | if (v) rlw_set_run_bit(self->rlw, v); | |
77 | rlw_set_running_len(self->rlw, RLW_LARGEST_RUNNING_COUNT); | |
78 | number -= RLW_LARGEST_RUNNING_COUNT; | |
79 | } | |
80 | ||
81 | if (number > 0) { | |
82 | buffer_push_rlw(self, 0); | |
83 | added++; | |
84 | ||
85 | if (v) rlw_set_run_bit(self->rlw, v); | |
86 | rlw_set_running_len(self->rlw, number); | |
87 | } | |
88 | ||
89 | return added; | |
90 | } | |
91 | ||
92 | size_t ewah_add_empty_words(struct ewah_bitmap *self, int v, size_t number) | |
93 | { | |
94 | if (number == 0) | |
95 | return 0; | |
96 | ||
34b935c0 | 97 | self->bit_size += number * BITS_IN_EWORD; |
e1273106 VM |
98 | return add_empty_words(self, v, number); |
99 | } | |
100 | ||
101 | static size_t add_literal(struct ewah_bitmap *self, eword_t new_data) | |
102 | { | |
103 | eword_t current_num = rlw_get_literal_words(self->rlw); | |
104 | ||
105 | if (current_num >= RLW_LARGEST_LITERAL_COUNT) { | |
106 | buffer_push_rlw(self, 0); | |
107 | ||
108 | rlw_set_literal_words(self->rlw, 1); | |
109 | buffer_push(self, new_data); | |
110 | return 2; | |
111 | } | |
112 | ||
113 | rlw_set_literal_words(self->rlw, current_num + 1); | |
114 | ||
115 | /* sanity check */ | |
116 | assert(rlw_get_literal_words(self->rlw) == current_num + 1); | |
117 | ||
118 | buffer_push(self, new_data); | |
119 | return 1; | |
120 | } | |
121 | ||
122 | void ewah_add_dirty_words( | |
123 | struct ewah_bitmap *self, const eword_t *buffer, | |
124 | size_t number, int negate) | |
125 | { | |
126 | size_t literals, can_add; | |
127 | ||
128 | while (1) { | |
129 | literals = rlw_get_literal_words(self->rlw); | |
130 | can_add = min_size(number, RLW_LARGEST_LITERAL_COUNT - literals); | |
131 | ||
132 | rlw_set_literal_words(self->rlw, literals + can_add); | |
133 | ||
3b1ca60f | 134 | buffer_grow(self, self->buffer_size + can_add); |
e1273106 VM |
135 | |
136 | if (negate) { | |
137 | size_t i; | |
138 | for (i = 0; i < can_add; ++i) | |
139 | self->buffer[self->buffer_size++] = ~buffer[i]; | |
140 | } else { | |
141 | memcpy(self->buffer + self->buffer_size, | |
142 | buffer, can_add * sizeof(eword_t)); | |
143 | self->buffer_size += can_add; | |
144 | } | |
145 | ||
34b935c0 | 146 | self->bit_size += can_add * BITS_IN_EWORD; |
e1273106 VM |
147 | |
148 | if (number - can_add == 0) | |
149 | break; | |
150 | ||
151 | buffer_push_rlw(self, 0); | |
152 | buffer += can_add; | |
153 | number -= can_add; | |
154 | } | |
155 | } | |
156 | ||
157 | static size_t add_empty_word(struct ewah_bitmap *self, int v) | |
158 | { | |
159 | int no_literal = (rlw_get_literal_words(self->rlw) == 0); | |
160 | eword_t run_len = rlw_get_running_len(self->rlw); | |
161 | ||
162 | if (no_literal && run_len == 0) { | |
163 | rlw_set_run_bit(self->rlw, v); | |
164 | assert(rlw_get_run_bit(self->rlw) == v); | |
165 | } | |
166 | ||
167 | if (no_literal && rlw_get_run_bit(self->rlw) == v && | |
168 | run_len < RLW_LARGEST_RUNNING_COUNT) { | |
169 | rlw_set_running_len(self->rlw, run_len + 1); | |
170 | assert(rlw_get_running_len(self->rlw) == run_len + 1); | |
171 | return 0; | |
172 | } else { | |
173 | buffer_push_rlw(self, 0); | |
174 | ||
175 | assert(rlw_get_running_len(self->rlw) == 0); | |
176 | assert(rlw_get_run_bit(self->rlw) == 0); | |
177 | assert(rlw_get_literal_words(self->rlw) == 0); | |
178 | ||
179 | rlw_set_run_bit(self->rlw, v); | |
180 | assert(rlw_get_run_bit(self->rlw) == v); | |
181 | ||
182 | rlw_set_running_len(self->rlw, 1); | |
183 | assert(rlw_get_running_len(self->rlw) == 1); | |
184 | assert(rlw_get_literal_words(self->rlw) == 0); | |
185 | return 1; | |
186 | } | |
187 | } | |
188 | ||
189 | size_t ewah_add(struct ewah_bitmap *self, eword_t word) | |
190 | { | |
34b935c0 | 191 | self->bit_size += BITS_IN_EWORD; |
e1273106 VM |
192 | |
193 | if (word == 0) | |
194 | return add_empty_word(self, 0); | |
195 | ||
196 | if (word == (eword_t)(~0)) | |
197 | return add_empty_word(self, 1); | |
198 | ||
199 | return add_literal(self, word); | |
200 | } | |
201 | ||
202 | void ewah_set(struct ewah_bitmap *self, size_t i) | |
203 | { | |
204 | const size_t dist = | |
42c78a21 RS |
205 | DIV_ROUND_UP(i + 1, BITS_IN_EWORD) - |
206 | DIV_ROUND_UP(self->bit_size, BITS_IN_EWORD); | |
e1273106 VM |
207 | |
208 | assert(i >= self->bit_size); | |
209 | ||
210 | self->bit_size = i + 1; | |
211 | ||
212 | if (dist > 0) { | |
213 | if (dist > 1) | |
214 | add_empty_words(self, 0, dist - 1); | |
215 | ||
34b935c0 | 216 | add_literal(self, (eword_t)1 << (i % BITS_IN_EWORD)); |
e1273106 VM |
217 | return; |
218 | } | |
219 | ||
220 | if (rlw_get_literal_words(self->rlw) == 0) { | |
221 | rlw_set_running_len(self->rlw, | |
222 | rlw_get_running_len(self->rlw) - 1); | |
34b935c0 | 223 | add_literal(self, (eword_t)1 << (i % BITS_IN_EWORD)); |
e1273106 VM |
224 | return; |
225 | } | |
226 | ||
227 | self->buffer[self->buffer_size - 1] |= | |
34b935c0 | 228 | ((eword_t)1 << (i % BITS_IN_EWORD)); |
e1273106 VM |
229 | |
230 | /* check if we just completed a stream of 1s */ | |
231 | if (self->buffer[self->buffer_size - 1] == (eword_t)(~0)) { | |
232 | self->buffer[--self->buffer_size] = 0; | |
233 | rlw_set_literal_words(self->rlw, | |
234 | rlw_get_literal_words(self->rlw) - 1); | |
235 | add_empty_word(self, 1); | |
236 | } | |
237 | } | |
238 | ||
239 | void ewah_each_bit(struct ewah_bitmap *self, void (*callback)(size_t, void*), void *payload) | |
240 | { | |
241 | size_t pos = 0; | |
242 | size_t pointer = 0; | |
243 | size_t k; | |
244 | ||
245 | while (pointer < self->buffer_size) { | |
246 | eword_t *word = &self->buffer[pointer]; | |
247 | ||
248 | if (rlw_get_run_bit(word)) { | |
34b935c0 | 249 | size_t len = rlw_get_running_len(word) * BITS_IN_EWORD; |
e1273106 VM |
250 | for (k = 0; k < len; ++k, ++pos) |
251 | callback(pos, payload); | |
252 | } else { | |
34b935c0 | 253 | pos += rlw_get_running_len(word) * BITS_IN_EWORD; |
e1273106 VM |
254 | } |
255 | ||
256 | ++pointer; | |
257 | ||
258 | for (k = 0; k < rlw_get_literal_words(word); ++k) { | |
259 | int c; | |
260 | ||
261 | /* todo: zero count optimization */ | |
34b935c0 | 262 | for (c = 0; c < BITS_IN_EWORD; ++c, ++pos) { |
e1273106 VM |
263 | if ((self->buffer[pointer] & ((eword_t)1 << c)) != 0) |
264 | callback(pos, payload); | |
265 | } | |
266 | ||
267 | ++pointer; | |
268 | } | |
269 | } | |
270 | } | |
271 | ||
c806278e JH |
272 | /** |
273 | * Clear all the bits in the bitmap. Does not free or resize | |
274 | * memory. | |
275 | */ | |
276 | static void ewah_clear(struct ewah_bitmap *self) | |
277 | { | |
278 | self->buffer_size = 1; | |
279 | self->buffer[0] = 0; | |
280 | self->bit_size = 0; | |
281 | self->rlw = self->buffer; | |
282 | } | |
283 | ||
e1273106 VM |
284 | struct ewah_bitmap *ewah_new(void) |
285 | { | |
286 | struct ewah_bitmap *self; | |
287 | ||
fb7dbf3e | 288 | self = xmalloc(sizeof(struct ewah_bitmap)); |
e1273106 | 289 | self->alloc_size = 32; |
08c95df8 | 290 | ALLOC_ARRAY(self->buffer, self->alloc_size); |
e1273106 VM |
291 | |
292 | ewah_clear(self); | |
293 | return self; | |
294 | } | |
295 | ||
e1273106 VM |
296 | void ewah_free(struct ewah_bitmap *self) |
297 | { | |
298 | if (!self) | |
299 | return; | |
300 | ||
301 | if (self->alloc_size) | |
302 | free(self->buffer); | |
303 | ||
304 | free(self); | |
305 | } | |
306 | ||
307 | static void read_new_rlw(struct ewah_iterator *it) | |
308 | { | |
309 | const eword_t *word = NULL; | |
310 | ||
311 | it->literals = 0; | |
312 | it->compressed = 0; | |
313 | ||
314 | while (1) { | |
315 | word = &it->buffer[it->pointer]; | |
316 | ||
317 | it->rl = rlw_get_running_len(word); | |
318 | it->lw = rlw_get_literal_words(word); | |
319 | it->b = rlw_get_run_bit(word); | |
320 | ||
321 | if (it->rl || it->lw) | |
322 | return; | |
323 | ||
324 | if (it->pointer < it->buffer_size - 1) { | |
325 | it->pointer++; | |
326 | } else { | |
327 | it->pointer = it->buffer_size; | |
328 | return; | |
329 | } | |
330 | } | |
331 | } | |
332 | ||
333 | int ewah_iterator_next(eword_t *next, struct ewah_iterator *it) | |
334 | { | |
335 | if (it->pointer >= it->buffer_size) | |
336 | return 0; | |
337 | ||
338 | if (it->compressed < it->rl) { | |
339 | it->compressed++; | |
340 | *next = it->b ? (eword_t)(~0) : 0; | |
341 | } else { | |
342 | assert(it->literals < it->lw); | |
343 | ||
344 | it->literals++; | |
345 | it->pointer++; | |
346 | ||
347 | assert(it->pointer < it->buffer_size); | |
348 | ||
349 | *next = it->buffer[it->pointer]; | |
350 | } | |
351 | ||
352 | if (it->compressed == it->rl && it->literals == it->lw) { | |
353 | if (++it->pointer < it->buffer_size) | |
354 | read_new_rlw(it); | |
355 | } | |
356 | ||
357 | return 1; | |
358 | } | |
359 | ||
360 | void ewah_iterator_init(struct ewah_iterator *it, struct ewah_bitmap *parent) | |
361 | { | |
362 | it->buffer = parent->buffer; | |
363 | it->buffer_size = parent->buffer_size; | |
364 | it->pointer = 0; | |
365 | ||
366 | it->lw = 0; | |
367 | it->rl = 0; | |
368 | it->compressed = 0; | |
369 | it->literals = 0; | |
370 | it->b = 0; | |
371 | ||
372 | if (it->pointer < it->buffer_size) | |
373 | read_new_rlw(it); | |
374 | } | |
375 | ||
e1273106 VM |
376 | void ewah_xor( |
377 | struct ewah_bitmap *ewah_i, | |
378 | struct ewah_bitmap *ewah_j, | |
379 | struct ewah_bitmap *out) | |
380 | { | |
381 | struct rlw_iterator rlw_i; | |
382 | struct rlw_iterator rlw_j; | |
383 | size_t literals; | |
384 | ||
385 | rlwit_init(&rlw_i, ewah_i); | |
386 | rlwit_init(&rlw_j, ewah_j); | |
387 | ||
388 | while (rlwit_word_size(&rlw_i) > 0 && rlwit_word_size(&rlw_j) > 0) { | |
389 | while (rlw_i.rlw.running_len > 0 || rlw_j.rlw.running_len > 0) { | |
390 | struct rlw_iterator *prey, *predator; | |
391 | size_t index; | |
392 | int negate_words; | |
393 | ||
394 | if (rlw_i.rlw.running_len < rlw_j.rlw.running_len) { | |
395 | prey = &rlw_i; | |
396 | predator = &rlw_j; | |
397 | } else { | |
398 | prey = &rlw_j; | |
399 | predator = &rlw_i; | |
400 | } | |
401 | ||
402 | negate_words = !!predator->rlw.running_bit; | |
403 | index = rlwit_discharge(prey, out, | |
404 | predator->rlw.running_len, negate_words); | |
405 | ||
406 | ewah_add_empty_words(out, negate_words, | |
407 | predator->rlw.running_len - index); | |
408 | ||
409 | rlwit_discard_first_words(predator, | |
410 | predator->rlw.running_len); | |
411 | } | |
412 | ||
413 | literals = min_size( | |
414 | rlw_i.rlw.literal_words, | |
415 | rlw_j.rlw.literal_words); | |
416 | ||
417 | if (literals) { | |
418 | size_t k; | |
419 | ||
420 | for (k = 0; k < literals; ++k) { | |
421 | ewah_add(out, | |
422 | rlw_i.buffer[rlw_i.literal_word_start + k] ^ | |
423 | rlw_j.buffer[rlw_j.literal_word_start + k] | |
424 | ); | |
425 | } | |
426 | ||
427 | rlwit_discard_first_words(&rlw_i, literals); | |
428 | rlwit_discard_first_words(&rlw_j, literals); | |
429 | } | |
430 | } | |
431 | ||
432 | if (rlwit_word_size(&rlw_i) > 0) | |
433 | rlwit_discharge(&rlw_i, out, ~0, 0); | |
434 | else | |
435 | rlwit_discharge(&rlw_j, out, ~0, 0); | |
436 | ||
437 | out->bit_size = max_size(ewah_i->bit_size, ewah_j->bit_size); | |
438 | } | |
439 | ||
e1273106 VM |
440 | #define BITMAP_POOL_MAX 16 |
441 | static struct ewah_bitmap *bitmap_pool[BITMAP_POOL_MAX]; | |
442 | static size_t bitmap_pool_size; | |
443 | ||
444 | struct ewah_bitmap *ewah_pool_new(void) | |
445 | { | |
446 | if (bitmap_pool_size) | |
447 | return bitmap_pool[--bitmap_pool_size]; | |
448 | ||
449 | return ewah_new(); | |
450 | } | |
451 | ||
452 | void ewah_pool_free(struct ewah_bitmap *self) | |
453 | { | |
afe8a907 | 454 | if (!self) |
e1273106 VM |
455 | return; |
456 | ||
457 | if (bitmap_pool_size == BITMAP_POOL_MAX || | |
458 | self->alloc_size == 0) { | |
459 | ewah_free(self); | |
460 | return; | |
461 | } | |
462 | ||
463 | ewah_clear(self); | |
464 | bitmap_pool[bitmap_pool_size++] = self; | |
465 | } | |
466 | ||
467 | uint32_t ewah_checksum(struct ewah_bitmap *self) | |
468 | { | |
469 | const uint8_t *p = (uint8_t *)self->buffer; | |
470 | uint32_t crc = (uint32_t)self->bit_size; | |
471 | size_t size = self->buffer_size * sizeof(eword_t); | |
472 | ||
473 | while (size--) | |
474 | crc = (crc << 5) - crc + (uint32_t)*p++; | |
475 | ||
476 | return crc; | |
477 | } |