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