Line | Count | Source |
1 | | #define USE_THE_REPOSITORY_VARIABLE |
2 | | #define DISABLE_SIGN_COMPARE_WARNINGS |
3 | | |
4 | | #include "git-compat-util.h" |
5 | | #include "pseudo-merge.h" |
6 | | #include "date.h" |
7 | | #include "oid-array.h" |
8 | | #include "strbuf.h" |
9 | | #include "config.h" |
10 | | #include "string-list.h" |
11 | | #include "refs.h" |
12 | | #include "pack-bitmap.h" |
13 | | #include "commit.h" |
14 | | #include "alloc.h" |
15 | | #include "progress.h" |
16 | | #include "hex.h" |
17 | | |
18 | 0 | #define DEFAULT_PSEUDO_MERGE_DECAY 1.0 |
19 | 0 | #define DEFAULT_PSEUDO_MERGE_MAX_MERGES 64 |
20 | 0 | #define DEFAULT_PSEUDO_MERGE_SAMPLE_RATE 1 |
21 | 0 | #define DEFAULT_PSEUDO_MERGE_THRESHOLD approxidate("1.week.ago") |
22 | 0 | #define DEFAULT_PSEUDO_MERGE_STABLE_THRESHOLD approxidate("1.month.ago") |
23 | 0 | #define DEFAULT_PSEUDO_MERGE_STABLE_SIZE 512 |
24 | | |
25 | | static double gitexp(double base, int exp) |
26 | 0 | { |
27 | 0 | double result = 1; |
28 | 0 | while (1) { |
29 | 0 | if (exp % 2) |
30 | 0 | result *= base; |
31 | 0 | exp >>= 1; |
32 | 0 | if (!exp) |
33 | 0 | break; |
34 | 0 | base *= base; |
35 | 0 | } |
36 | 0 | return result; |
37 | 0 | } |
38 | | |
39 | | static uint32_t pseudo_merge_group_size(const struct pseudo_merge_group *group, |
40 | | const struct pseudo_merge_matches *matches, |
41 | | uint32_t i) |
42 | 0 | { |
43 | 0 | double C = 0.0f; |
44 | 0 | uint32_t n; |
45 | | |
46 | | /* |
47 | | * The size of pseudo-merge groups decays according to a power series, |
48 | | * which looks like: |
49 | | * |
50 | | * f(n) = C * n^-k |
51 | | * |
52 | | * , where 'n' is the n-th pseudo-merge group, 'f(n)' is its size, 'k' |
53 | | * is the decay rate, and 'C' is a scaling value. |
54 | | * |
55 | | * The value of C depends on the number of groups, decay rate, and total |
56 | | * number of commits. It is computed such that if there are M and N |
57 | | * total groups and commits, respectively, that: |
58 | | * |
59 | | * N = f(0) + f(1) + ... f(M-1) |
60 | | * |
61 | | * Rearranging to isolate C, we get: |
62 | | * |
63 | | * N = \sum_{n=1}^M C / n^k |
64 | | * |
65 | | * N / C = \sum_{n=1}^M n^-k |
66 | | * |
67 | | * C = N / \sum_{n=1}^M n^-k |
68 | | * |
69 | | * For example, if we have a decay rate of 'k' being equal to 1.5, 'N' |
70 | | * total commits equal to 10,000, and 'M' being equal to 6 groups, then |
71 | | * the (rounded) group sizes are: |
72 | | * |
73 | | * { 5469, 1934, 1053, 684, 489, 372 } |
74 | | * |
75 | | * increasing the number of total groups, say to 10, scales the group |
76 | | * sizes appropriately: |
77 | | * |
78 | | * { 5012, 1772, 964, 626, 448, 341, 271, 221, 186, 158 } |
79 | | */ |
80 | 0 | for (n = 0; n < group->max_merges; n++) |
81 | 0 | C += 1.0 / gitexp(n + 1, group->decay); |
82 | 0 | C = matches->unstable_nr / C; |
83 | |
|
84 | 0 | return (uint32_t)((C / gitexp(i + 1, group->decay)) + 0.5); |
85 | 0 | } |
86 | | |
87 | | static void pseudo_merge_group_init(struct pseudo_merge_group *group) |
88 | 0 | { |
89 | 0 | memset(group, 0, sizeof(struct pseudo_merge_group)); |
90 | |
|
91 | 0 | strmap_init_with_options(&group->matches, NULL, 1); |
92 | |
|
93 | 0 | group->decay = DEFAULT_PSEUDO_MERGE_DECAY; |
94 | 0 | group->max_merges = DEFAULT_PSEUDO_MERGE_MAX_MERGES; |
95 | 0 | group->sample_rate = DEFAULT_PSEUDO_MERGE_SAMPLE_RATE; |
96 | 0 | group->threshold = DEFAULT_PSEUDO_MERGE_THRESHOLD; |
97 | 0 | group->stable_threshold = DEFAULT_PSEUDO_MERGE_STABLE_THRESHOLD; |
98 | 0 | group->stable_size = DEFAULT_PSEUDO_MERGE_STABLE_SIZE; |
99 | 0 | } |
100 | | |
101 | | void pseudo_merge_group_release(struct pseudo_merge_group *group) |
102 | 0 | { |
103 | 0 | struct hashmap_iter iter; |
104 | 0 | struct strmap_entry *e; |
105 | |
|
106 | 0 | regfree(group->pattern); |
107 | 0 | free(group->pattern); |
108 | |
|
109 | 0 | strmap_for_each_entry(&group->matches, &iter, e) { |
110 | 0 | struct pseudo_merge_matches *matches = e->value; |
111 | 0 | free(matches->stable); |
112 | 0 | free(matches->unstable); |
113 | 0 | free(matches); |
114 | 0 | } |
115 | 0 | strmap_clear(&group->matches, 0); |
116 | |
|
117 | 0 | free(group->merges); |
118 | 0 | } |
119 | | |
120 | | static int pseudo_merge_config(const char *var, const char *value, |
121 | | const struct config_context *ctx, |
122 | | void *cb_data) |
123 | 0 | { |
124 | 0 | struct string_list *list = cb_data; |
125 | 0 | struct string_list_item *item; |
126 | 0 | struct pseudo_merge_group *group; |
127 | 0 | struct strbuf buf = STRBUF_INIT; |
128 | 0 | const char *sub, *key; |
129 | 0 | size_t sub_len; |
130 | 0 | int ret = 0; |
131 | |
|
132 | 0 | if (parse_config_key(var, "bitmappseudomerge", &sub, &sub_len, &key)) |
133 | 0 | goto done; |
134 | | |
135 | 0 | if (!sub_len) |
136 | 0 | goto done; |
137 | | |
138 | 0 | strbuf_add(&buf, sub, sub_len); |
139 | |
|
140 | 0 | item = string_list_lookup(list, buf.buf); |
141 | 0 | if (!item) { |
142 | 0 | item = string_list_insert(list, buf.buf); |
143 | |
|
144 | 0 | item->util = xmalloc(sizeof(struct pseudo_merge_group)); |
145 | 0 | pseudo_merge_group_init(item->util); |
146 | 0 | } |
147 | |
|
148 | 0 | group = item->util; |
149 | |
|
150 | 0 | if (!strcmp(key, "pattern")) { |
151 | 0 | struct strbuf re = STRBUF_INIT; |
152 | |
|
153 | 0 | if (group->pattern) { |
154 | 0 | regfree(group->pattern); |
155 | 0 | free(group->pattern); |
156 | 0 | } |
157 | 0 | if (*value != '^') |
158 | 0 | strbuf_addch(&re, '^'); |
159 | 0 | strbuf_addstr(&re, value); |
160 | |
|
161 | 0 | group->pattern = xcalloc(1, sizeof(regex_t)); |
162 | 0 | if (regcomp(group->pattern, re.buf, REG_EXTENDED)) |
163 | 0 | die(_("failed to load pseudo-merge regex for %s: '%s'"), |
164 | 0 | sub, re.buf); |
165 | | |
166 | 0 | strbuf_release(&re); |
167 | 0 | } else if (!strcmp(key, "decay")) { |
168 | 0 | group->decay = git_config_double(var, value, ctx->kvi); |
169 | 0 | if (group->decay < 0) { |
170 | 0 | warning(_("%s must be non-negative, using default"), var); |
171 | 0 | group->decay = DEFAULT_PSEUDO_MERGE_DECAY; |
172 | 0 | } |
173 | 0 | } else if (!strcmp(key, "samplerate")) { |
174 | 0 | group->sample_rate = git_config_double(var, value, ctx->kvi); |
175 | 0 | if (!(0 < group->sample_rate && group->sample_rate <= 1)) { |
176 | 0 | warning(_("%s must be between 0 (exclusive) and 1, using default"), var); |
177 | 0 | group->sample_rate = DEFAULT_PSEUDO_MERGE_SAMPLE_RATE; |
178 | 0 | } |
179 | 0 | } else if (!strcmp(key, "threshold")) { |
180 | 0 | if (git_config_expiry_date(&group->threshold, var, value)) { |
181 | 0 | ret = -1; |
182 | 0 | goto done; |
183 | 0 | } |
184 | 0 | } else if (!strcmp(key, "maxmerges")) { |
185 | 0 | group->max_merges = git_config_int(var, value, ctx->kvi); |
186 | 0 | if (group->max_merges < 0) { |
187 | 0 | warning(_("%s must be non-negative, using default"), var); |
188 | 0 | group->max_merges = DEFAULT_PSEUDO_MERGE_MAX_MERGES; |
189 | 0 | } |
190 | 0 | } else if (!strcmp(key, "stablethreshold")) { |
191 | 0 | if (git_config_expiry_date(&group->stable_threshold, var, value)) { |
192 | 0 | ret = -1; |
193 | 0 | goto done; |
194 | 0 | } |
195 | 0 | } else if (!strcmp(key, "stablesize")) { |
196 | 0 | group->stable_size = git_config_int(var, value, ctx->kvi); |
197 | 0 | if (group->stable_size <= 0) { |
198 | 0 | warning(_("%s must be positive, using default"), var); |
199 | 0 | group->stable_size = DEFAULT_PSEUDO_MERGE_STABLE_SIZE; |
200 | 0 | } |
201 | 0 | } |
202 | | |
203 | 0 | done: |
204 | 0 | strbuf_release(&buf); |
205 | |
|
206 | 0 | return ret; |
207 | 0 | } |
208 | | |
209 | | void load_pseudo_merges_from_config(struct repository *r, |
210 | | struct string_list *list) |
211 | 0 | { |
212 | 0 | struct string_list_item *item; |
213 | |
|
214 | 0 | repo_config(r, pseudo_merge_config, list); |
215 | |
|
216 | 0 | for_each_string_list_item(item, list) { |
217 | 0 | struct pseudo_merge_group *group = item->util; |
218 | 0 | if (!group->pattern) |
219 | 0 | die(_("pseudo-merge group '%s' missing required pattern"), |
220 | 0 | item->string); |
221 | 0 | if (group->threshold < group->stable_threshold) |
222 | 0 | die(_("pseudo-merge group '%s' has unstable threshold " |
223 | 0 | "before stable one"), item->string); |
224 | 0 | } |
225 | 0 | } |
226 | | |
227 | | static int find_pseudo_merge_group_for_ref(const struct reference *ref, void *_data) |
228 | 0 | { |
229 | 0 | struct bitmap_writer *writer = _data; |
230 | 0 | const struct object_id *maybe_peeled = ref->oid; |
231 | 0 | struct object_id peeled; |
232 | 0 | struct commit *c; |
233 | 0 | uint32_t i; |
234 | 0 | int has_bitmap; |
235 | |
|
236 | 0 | if (!reference_get_peeled_oid(the_repository, ref, &peeled)) |
237 | 0 | maybe_peeled = &peeled; |
238 | |
|
239 | 0 | c = lookup_commit(the_repository, maybe_peeled); |
240 | 0 | if (!c) |
241 | 0 | return 0; |
242 | 0 | if (repo_parse_commit(the_repository, c)) |
243 | 0 | return 0; |
244 | 0 | if (!packlist_find(writer->to_pack, maybe_peeled)) |
245 | 0 | return 0; |
246 | | |
247 | 0 | has_bitmap = bitmap_writer_has_bitmapped_object_id(writer, maybe_peeled); |
248 | |
|
249 | 0 | for (i = 0; i < writer->pseudo_merge_groups.nr; i++) { |
250 | 0 | struct pseudo_merge_group *group; |
251 | 0 | struct pseudo_merge_matches *matches; |
252 | 0 | struct strbuf group_name = STRBUF_INIT; |
253 | 0 | regmatch_t captures[16]; |
254 | 0 | size_t j; |
255 | |
|
256 | 0 | group = writer->pseudo_merge_groups.items[i].util; |
257 | 0 | if (regexec(group->pattern, ref->name, ARRAY_SIZE(captures), |
258 | 0 | captures, 0)) |
259 | 0 | continue; |
260 | | |
261 | 0 | if (captures[ARRAY_SIZE(captures) - 1].rm_so != -1) |
262 | 0 | warning(_("pseudo-merge regex from config has too many capture " |
263 | 0 | "groups (max=%"PRIuMAX")"), |
264 | 0 | (uintmax_t)ARRAY_SIZE(captures) - 2); |
265 | |
|
266 | 0 | for (j = !!group->pattern->re_nsub; j < ARRAY_SIZE(captures); j++) { |
267 | 0 | regmatch_t *match = &captures[j]; |
268 | 0 | if (match->rm_so == -1) |
269 | 0 | continue; |
270 | | |
271 | 0 | if (group_name.len) |
272 | 0 | strbuf_addch(&group_name, '-'); |
273 | |
|
274 | 0 | strbuf_add(&group_name, ref->name + match->rm_so, |
275 | 0 | match->rm_eo - match->rm_so); |
276 | 0 | } |
277 | |
|
278 | 0 | matches = strmap_get(&group->matches, group_name.buf); |
279 | 0 | if (!matches) { |
280 | 0 | matches = xcalloc(1, sizeof(*matches)); |
281 | 0 | strmap_put(&group->matches, group_name.buf, |
282 | 0 | matches); |
283 | 0 | } |
284 | |
|
285 | 0 | if (c->date <= group->stable_threshold) { |
286 | 0 | ALLOC_GROW(matches->stable, matches->stable_nr + 1, |
287 | 0 | matches->stable_alloc); |
288 | 0 | matches->stable[matches->stable_nr++] = c; |
289 | 0 | } else if (c->date <= group->threshold && !has_bitmap) { |
290 | 0 | ALLOC_GROW(matches->unstable, matches->unstable_nr + 1, |
291 | 0 | matches->unstable_alloc); |
292 | 0 | matches->unstable[matches->unstable_nr++] = c; |
293 | 0 | } |
294 | |
|
295 | 0 | strbuf_release(&group_name); |
296 | 0 | } |
297 | |
|
298 | 0 | return 0; |
299 | 0 | } |
300 | | |
301 | | static struct commit *push_pseudo_merge(struct pseudo_merge_group *group) |
302 | 0 | { |
303 | 0 | struct commit *merge; |
304 | |
|
305 | 0 | ALLOC_GROW(group->merges, group->merges_nr + 1, group->merges_alloc); |
306 | |
|
307 | 0 | merge = alloc_commit_node(the_repository); |
308 | 0 | merge->object.parsed = 1; |
309 | 0 | merge->object.flags |= BITMAP_PSEUDO_MERGE; |
310 | |
|
311 | 0 | group->merges[group->merges_nr++] = merge; |
312 | |
|
313 | 0 | return merge; |
314 | 0 | } |
315 | | |
316 | | static struct pseudo_merge_commit_idx *pseudo_merge_idx(kh_oid_map_t *pseudo_merge_commits, |
317 | | const struct object_id *oid) |
318 | | |
319 | 0 | { |
320 | 0 | struct pseudo_merge_commit_idx *pmc; |
321 | 0 | int hash_ret; |
322 | 0 | khiter_t hash_pos = kh_put_oid_map(pseudo_merge_commits, *oid, |
323 | 0 | &hash_ret); |
324 | |
|
325 | 0 | if (hash_ret) { |
326 | 0 | CALLOC_ARRAY(pmc, 1); |
327 | 0 | kh_value(pseudo_merge_commits, hash_pos) = pmc; |
328 | 0 | } else { |
329 | 0 | pmc = kh_value(pseudo_merge_commits, hash_pos); |
330 | 0 | } |
331 | |
|
332 | 0 | return pmc; |
333 | 0 | } |
334 | | |
335 | 0 | #define MIN_PSEUDO_MERGE_SIZE 8 |
336 | | |
337 | | static void select_pseudo_merges_1(struct bitmap_writer *writer, |
338 | | struct pseudo_merge_group *group, |
339 | | struct pseudo_merge_matches *matches) |
340 | 0 | { |
341 | 0 | uint32_t i, j; |
342 | 0 | uint32_t stable_merges_nr; |
343 | |
|
344 | 0 | if (!matches->stable_nr && !matches->unstable_nr) |
345 | 0 | return; /* all tips in this group already have bitmaps */ |
346 | | |
347 | 0 | stable_merges_nr = matches->stable_nr / group->stable_size; |
348 | 0 | if (matches->stable_nr % group->stable_size) |
349 | 0 | stable_merges_nr++; |
350 | | |
351 | | /* make stable_merges_nr pseudo merges for stable commits */ |
352 | 0 | for (i = 0, j = 0; i < stable_merges_nr; i++) { |
353 | 0 | struct commit *merge; |
354 | 0 | struct commit_list **p; |
355 | |
|
356 | 0 | merge = push_pseudo_merge(group); |
357 | 0 | p = &merge->parents; |
358 | | |
359 | | /* |
360 | | * For each pseudo-merge created above, add parents to the |
361 | | * allocated commit node from the stable set of commits |
362 | | * (un-bitmapped, newer than the stable threshold). |
363 | | */ |
364 | 0 | do { |
365 | 0 | struct commit *c; |
366 | 0 | struct pseudo_merge_commit_idx *pmc; |
367 | |
|
368 | 0 | if (j >= matches->stable_nr) |
369 | 0 | break; |
370 | | |
371 | 0 | c = matches->stable[j++]; |
372 | | /* |
373 | | * Here and below, make sure that we keep our mapping of |
374 | | * commits -> pseudo-merge(s) which include the key'd |
375 | | * commit up-to-date. |
376 | | */ |
377 | 0 | pmc = pseudo_merge_idx(writer->pseudo_merge_commits, |
378 | 0 | &c->object.oid); |
379 | |
|
380 | 0 | ALLOC_GROW(pmc->pseudo_merge, pmc->nr + 1, pmc->alloc); |
381 | |
|
382 | 0 | pmc->pseudo_merge[pmc->nr++] = writer->pseudo_merges_nr; |
383 | 0 | p = commit_list_append(c, p); |
384 | 0 | } while (j % group->stable_size); |
385 | |
|
386 | 0 | if (merge->parents) { |
387 | 0 | bitmap_writer_push_commit(writer, merge, 1); |
388 | 0 | writer->pseudo_merges_nr++; |
389 | 0 | } |
390 | 0 | } |
391 | | |
392 | | /* make up to group->max_merges pseudo merges for unstable commits */ |
393 | 0 | for (i = 0, j = 0; i < group->max_merges; i++) { |
394 | 0 | struct commit *merge; |
395 | 0 | struct commit_list **p; |
396 | 0 | uint32_t size, end; |
397 | |
|
398 | 0 | merge = push_pseudo_merge(group); |
399 | 0 | p = &merge->parents; |
400 | |
|
401 | 0 | size = pseudo_merge_group_size(group, matches, i); |
402 | 0 | end = size < MIN_PSEUDO_MERGE_SIZE ? matches->unstable_nr : j + size; |
403 | | |
404 | | /* |
405 | | * For each pseudo-merge commit created above, add parents to |
406 | | * the allocated commit node from the unstable set of commits |
407 | | * (newer than the stable threshold). |
408 | | * |
409 | | * Account for the sample rate, since not every candidate from |
410 | | * the set of stable commits will be included as a pseudo-merge |
411 | | * parent. |
412 | | */ |
413 | 0 | for (; j < end && j < matches->unstable_nr; j++) { |
414 | 0 | struct commit *c = matches->unstable[j]; |
415 | 0 | struct pseudo_merge_commit_idx *pmc; |
416 | |
|
417 | 0 | if (j % (uint32_t)(1.0 / group->sample_rate)) |
418 | 0 | continue; |
419 | | |
420 | 0 | pmc = pseudo_merge_idx(writer->pseudo_merge_commits, |
421 | 0 | &c->object.oid); |
422 | |
|
423 | 0 | ALLOC_GROW(pmc->pseudo_merge, pmc->nr + 1, pmc->alloc); |
424 | |
|
425 | 0 | pmc->pseudo_merge[pmc->nr++] = writer->pseudo_merges_nr; |
426 | 0 | p = commit_list_append(c, p); |
427 | 0 | } |
428 | |
|
429 | 0 | if (merge->parents) { |
430 | 0 | bitmap_writer_push_commit(writer, merge, 1); |
431 | 0 | writer->pseudo_merges_nr++; } |
432 | 0 | if (end >= matches->unstable_nr) |
433 | 0 | break; |
434 | 0 | } |
435 | 0 | } |
436 | | |
437 | | static int commit_date_cmp(const void *va, const void *vb) |
438 | 0 | { |
439 | 0 | timestamp_t a = (*(const struct commit **)va)->date; |
440 | 0 | timestamp_t b = (*(const struct commit **)vb)->date; |
441 | |
|
442 | 0 | if (a < b) |
443 | 0 | return -1; |
444 | 0 | else if (a > b) |
445 | 0 | return 1; |
446 | 0 | return 0; |
447 | 0 | } |
448 | | |
449 | | static void sort_pseudo_merge_matches(struct pseudo_merge_matches *matches) |
450 | 0 | { |
451 | 0 | QSORT(matches->stable, matches->stable_nr, commit_date_cmp); |
452 | 0 | QSORT(matches->unstable, matches->unstable_nr, commit_date_cmp); |
453 | 0 | } |
454 | | |
455 | | void select_pseudo_merges(struct bitmap_writer *writer) |
456 | 0 | { |
457 | 0 | struct progress *progress = NULL; |
458 | 0 | uint32_t i; |
459 | |
|
460 | 0 | if (!writer->pseudo_merge_groups.nr) |
461 | 0 | return; |
462 | | |
463 | 0 | if (writer->show_progress) |
464 | 0 | progress = start_progress(the_repository, |
465 | 0 | "Selecting pseudo-merge commits", |
466 | 0 | writer->pseudo_merge_groups.nr); |
467 | |
|
468 | 0 | refs_for_each_ref(get_main_ref_store(the_repository), |
469 | 0 | find_pseudo_merge_group_for_ref, writer); |
470 | |
|
471 | 0 | for (i = 0; i < writer->pseudo_merge_groups.nr; i++) { |
472 | 0 | struct pseudo_merge_group *group; |
473 | 0 | struct hashmap_iter iter; |
474 | 0 | struct strmap_entry *e; |
475 | |
|
476 | 0 | group = writer->pseudo_merge_groups.items[i].util; |
477 | 0 | strmap_for_each_entry(&group->matches, &iter, e) { |
478 | 0 | struct pseudo_merge_matches *matches = e->value; |
479 | |
|
480 | 0 | sort_pseudo_merge_matches(matches); |
481 | |
|
482 | 0 | select_pseudo_merges_1(writer, group, matches); |
483 | 0 | } |
484 | |
|
485 | 0 | display_progress(progress, i + 1); |
486 | 0 | } |
487 | |
|
488 | 0 | stop_progress(&progress); |
489 | 0 | } |
490 | | |
491 | | void free_pseudo_merge_map(struct pseudo_merge_map *pm) |
492 | 0 | { |
493 | 0 | uint32_t i; |
494 | 0 | for (i = 0; i < pm->nr; i++) { |
495 | 0 | ewah_pool_free(pm->v[i].commits); |
496 | 0 | ewah_pool_free(pm->v[i].bitmap); |
497 | 0 | } |
498 | 0 | free(pm->v); |
499 | 0 | } |
500 | | |
501 | | struct pseudo_merge_commit_ext { |
502 | | uint32_t nr; |
503 | | const unsigned char *ptr; |
504 | | }; |
505 | | |
506 | | static int pseudo_merge_ext_at(const struct pseudo_merge_map *pm, |
507 | | struct pseudo_merge_commit_ext *ext, size_t at) |
508 | 0 | { |
509 | 0 | if (at >= pm->map_size) |
510 | 0 | return error(_("extended pseudo-merge read out-of-bounds " |
511 | 0 | "(%"PRIuMAX" >= %"PRIuMAX")"), |
512 | 0 | (uintmax_t)at, (uintmax_t)pm->map_size); |
513 | 0 | if (at + 4 >= pm->map_size) |
514 | 0 | return error(_("extended pseudo-merge entry is too short " |
515 | 0 | "(%"PRIuMAX" >= %"PRIuMAX")"), |
516 | 0 | (uintmax_t)(at + 4), (uintmax_t)pm->map_size); |
517 | | |
518 | 0 | ext->nr = get_be32(pm->map + at); |
519 | 0 | ext->ptr = pm->map + at + sizeof(uint32_t); |
520 | |
|
521 | 0 | return 0; |
522 | 0 | } |
523 | | |
524 | | struct ewah_bitmap *pseudo_merge_bitmap(const struct pseudo_merge_map *pm, |
525 | | struct pseudo_merge *merge) |
526 | 0 | { |
527 | 0 | if (!merge->loaded_commits) |
528 | 0 | BUG("cannot use unloaded pseudo-merge bitmap"); |
529 | | |
530 | 0 | if (!merge->loaded_bitmap) { |
531 | 0 | size_t at = merge->bitmap_at; |
532 | |
|
533 | 0 | merge->bitmap = read_bitmap(pm->map, pm->map_size, &at); |
534 | 0 | merge->loaded_bitmap = 1; |
535 | 0 | } |
536 | |
|
537 | 0 | return merge->bitmap; |
538 | 0 | } |
539 | | |
540 | | struct pseudo_merge *use_pseudo_merge(const struct pseudo_merge_map *pm, |
541 | | struct pseudo_merge *merge) |
542 | 0 | { |
543 | 0 | if (!merge->loaded_commits) { |
544 | 0 | size_t pos = merge->at; |
545 | |
|
546 | 0 | merge->commits = read_bitmap(pm->map, pm->map_size, &pos); |
547 | 0 | merge->bitmap_at = pos; |
548 | 0 | merge->loaded_commits = 1; |
549 | 0 | } |
550 | 0 | return merge; |
551 | 0 | } |
552 | | |
553 | | static struct pseudo_merge *pseudo_merge_at(const struct pseudo_merge_map *pm, |
554 | | struct object_id *oid, |
555 | | size_t want) |
556 | 0 | { |
557 | 0 | size_t lo = 0; |
558 | 0 | size_t hi = pm->nr; |
559 | |
|
560 | 0 | while (lo < hi) { |
561 | 0 | size_t mi = lo + (hi - lo) / 2; |
562 | 0 | size_t got = pm->v[mi].at; |
563 | |
|
564 | 0 | if (got == want) |
565 | 0 | return use_pseudo_merge(pm, &pm->v[mi]); |
566 | 0 | else if (got < want) |
567 | 0 | lo = mi + 1; |
568 | 0 | else |
569 | 0 | hi = mi; |
570 | 0 | } |
571 | | |
572 | 0 | warning(_("could not find pseudo-merge for commit %s at offset %"PRIuMAX), |
573 | 0 | oid_to_hex(oid), (uintmax_t)want); |
574 | |
|
575 | 0 | return NULL; |
576 | 0 | } |
577 | | |
578 | | struct pseudo_merge_commit { |
579 | | uint32_t commit_pos; |
580 | | uint64_t pseudo_merge_ofs; |
581 | | }; |
582 | | |
583 | 0 | #define PSEUDO_MERGE_COMMIT_RAWSZ (sizeof(uint32_t)+sizeof(uint64_t)) |
584 | | |
585 | | static void read_pseudo_merge_commit_at(struct pseudo_merge_commit *merge, |
586 | | const unsigned char *at) |
587 | 0 | { |
588 | 0 | merge->commit_pos = get_be32(at); |
589 | 0 | merge->pseudo_merge_ofs = get_be64(at + sizeof(uint32_t)); |
590 | 0 | } |
591 | | |
592 | | static int nth_pseudo_merge_ext(const struct pseudo_merge_map *pm, |
593 | | struct pseudo_merge_commit_ext *ext, |
594 | | struct pseudo_merge_commit *merge, |
595 | | uint32_t n) |
596 | 0 | { |
597 | 0 | size_t ofs; |
598 | |
|
599 | 0 | if (n >= ext->nr) |
600 | 0 | return error(_("extended pseudo-merge lookup out-of-bounds " |
601 | 0 | "(%"PRIu32" >= %"PRIu32")"), n, ext->nr); |
602 | | |
603 | 0 | ofs = get_be64(ext->ptr + st_mult(n, sizeof(uint64_t))); |
604 | 0 | if (ofs >= pm->map_size) |
605 | 0 | return error(_("out-of-bounds read: (%"PRIuMAX" >= %"PRIuMAX")"), |
606 | 0 | (uintmax_t)ofs, (uintmax_t)pm->map_size); |
607 | | |
608 | 0 | merge->pseudo_merge_ofs = ofs; |
609 | |
|
610 | 0 | return 0; |
611 | 0 | } |
612 | | |
613 | | static unsigned apply_pseudo_merge(const struct pseudo_merge_map *pm, |
614 | | struct pseudo_merge *merge, |
615 | | struct bitmap *result, |
616 | | struct bitmap *roots) |
617 | 0 | { |
618 | 0 | if (merge->satisfied) |
619 | 0 | return 0; |
620 | | |
621 | 0 | if (!ewah_bitmap_is_subset(merge->commits, roots ? roots : result)) |
622 | 0 | return 0; |
623 | | |
624 | 0 | bitmap_or_ewah(result, pseudo_merge_bitmap(pm, merge)); |
625 | 0 | if (roots) |
626 | 0 | bitmap_or_ewah(roots, pseudo_merge_bitmap(pm, merge)); |
627 | 0 | merge->satisfied = 1; |
628 | |
|
629 | 0 | return 1; |
630 | 0 | } |
631 | | |
632 | | static int pseudo_merge_commit_cmp(const void *va, const void *vb) |
633 | 0 | { |
634 | 0 | struct pseudo_merge_commit merge; |
635 | 0 | uint32_t key = *(uint32_t*)va; |
636 | |
|
637 | 0 | read_pseudo_merge_commit_at(&merge, vb); |
638 | |
|
639 | 0 | if (key < merge.commit_pos) |
640 | 0 | return -1; |
641 | 0 | if (key > merge.commit_pos) |
642 | 0 | return 1; |
643 | 0 | return 0; |
644 | 0 | } |
645 | | |
646 | | static int find_pseudo_merge(const struct pseudo_merge_map *pm, uint32_t pos, |
647 | | struct pseudo_merge_commit *out) |
648 | 0 | { |
649 | 0 | const unsigned char *at; |
650 | |
|
651 | 0 | if (!pm->commits_nr) |
652 | 0 | return 0; |
653 | | |
654 | 0 | at = bsearch(&pos, pm->commits, pm->commits_nr, |
655 | 0 | PSEUDO_MERGE_COMMIT_RAWSZ, pseudo_merge_commit_cmp); |
656 | 0 | if (!at) |
657 | 0 | return 0; |
658 | | |
659 | 0 | read_pseudo_merge_commit_at(out, at); |
660 | 0 | return 1; |
661 | 0 | } |
662 | | |
663 | | int apply_pseudo_merges_for_commit(const struct pseudo_merge_map *pm, |
664 | | struct bitmap *result, |
665 | | struct commit *commit, uint32_t commit_pos) |
666 | 0 | { |
667 | 0 | struct pseudo_merge *merge; |
668 | 0 | struct pseudo_merge_commit merge_commit; |
669 | 0 | int ret = 0; |
670 | |
|
671 | 0 | if (!find_pseudo_merge(pm, commit_pos, &merge_commit)) |
672 | 0 | return 0; |
673 | | |
674 | 0 | if (merge_commit.pseudo_merge_ofs & ((uint64_t)1<<63)) { |
675 | 0 | struct pseudo_merge_commit_ext ext = { 0 }; |
676 | 0 | off_t ofs = merge_commit.pseudo_merge_ofs & ~((uint64_t)1<<63); |
677 | 0 | uint32_t i; |
678 | |
|
679 | 0 | if (pseudo_merge_ext_at(pm, &ext, ofs) < 0) { |
680 | 0 | warning(_("could not read extended pseudo-merge table " |
681 | 0 | "for commit %s"), |
682 | 0 | oid_to_hex(&commit->object.oid)); |
683 | 0 | return ret; |
684 | 0 | } |
685 | | |
686 | 0 | for (i = 0; i < ext.nr; i++) { |
687 | 0 | if (nth_pseudo_merge_ext(pm, &ext, &merge_commit, i) < 0) |
688 | 0 | return ret; |
689 | | |
690 | 0 | merge = pseudo_merge_at(pm, &commit->object.oid, |
691 | 0 | merge_commit.pseudo_merge_ofs); |
692 | |
|
693 | 0 | if (!merge) |
694 | 0 | return ret; |
695 | | |
696 | 0 | if (apply_pseudo_merge(pm, merge, result, NULL)) |
697 | 0 | ret++; |
698 | 0 | } |
699 | 0 | } else { |
700 | 0 | merge = pseudo_merge_at(pm, &commit->object.oid, |
701 | 0 | merge_commit.pseudo_merge_ofs); |
702 | |
|
703 | 0 | if (!merge) |
704 | 0 | return ret; |
705 | | |
706 | 0 | if (apply_pseudo_merge(pm, merge, result, NULL)) |
707 | 0 | ret++; |
708 | 0 | } |
709 | | |
710 | 0 | if (ret) |
711 | 0 | cascade_pseudo_merges(pm, result, NULL); |
712 | |
|
713 | 0 | return ret; |
714 | 0 | } |
715 | | |
716 | | int cascade_pseudo_merges(const struct pseudo_merge_map *pm, |
717 | | struct bitmap *result, |
718 | | struct bitmap *roots) |
719 | 0 | { |
720 | 0 | unsigned any_satisfied; |
721 | 0 | int ret = 0; |
722 | |
|
723 | 0 | do { |
724 | 0 | struct pseudo_merge *merge; |
725 | 0 | uint32_t i; |
726 | |
|
727 | 0 | any_satisfied = 0; |
728 | |
|
729 | 0 | for (i = 0; i < pm->nr; i++) { |
730 | 0 | merge = use_pseudo_merge(pm, &pm->v[i]); |
731 | 0 | if (apply_pseudo_merge(pm, merge, result, roots)) { |
732 | 0 | any_satisfied |= 1; |
733 | 0 | ret++; |
734 | 0 | } |
735 | 0 | } |
736 | 0 | } while (any_satisfied); |
737 | |
|
738 | 0 | return ret; |
739 | 0 | } |
740 | | |
741 | | struct pseudo_merge *pseudo_merge_for_parents(const struct pseudo_merge_map *pm, |
742 | | struct bitmap *parents) |
743 | 0 | { |
744 | 0 | struct pseudo_merge *match = NULL; |
745 | 0 | size_t i; |
746 | |
|
747 | 0 | if (!pm->nr) |
748 | 0 | return NULL; |
749 | | |
750 | | /* |
751 | | * NOTE: this loop is quadratic in the worst-case (where no |
752 | | * matching pseudo-merge bitmaps are found), but in practice |
753 | | * this is OK for a few reasons: |
754 | | * |
755 | | * - Rejecting pseudo-merge bitmaps that do not match the |
756 | | * given commit is done quickly (i.e. `bitmap_equals_ewah()` |
757 | | * returns early when we know the two bitmaps aren't equal. |
758 | | * |
759 | | * - Already matched pseudo-merge bitmaps (which we track with |
760 | | * the `->satisfied` bit here) are skipped as potential |
761 | | * candidates. |
762 | | * |
763 | | * - The number of pseudo-merges should be small (in the |
764 | | * hundreds for most repositories). |
765 | | * |
766 | | * If in the future this semi-quadratic behavior does become a |
767 | | * problem, another approach would be to keep track of which |
768 | | * pseudo-merges are still "viable" after enumerating the |
769 | | * pseudo-merge commit's parents: |
770 | | * |
771 | | * - A pseudo-merge bitmap becomes non-viable when the bit(s) |
772 | | * corresponding to one or more parent(s) of the given |
773 | | * commit are not set in a candidate pseudo-merge's commits |
774 | | * bitmap. |
775 | | * |
776 | | * - After processing all bits, enumerate the remaining set of |
777 | | * viable pseudo-merge bitmaps, and check that their |
778 | | * popcount() matches the number of parents in the given |
779 | | * commit. |
780 | | */ |
781 | 0 | for (i = 0; i < pm->nr; i++) { |
782 | 0 | struct pseudo_merge *candidate = use_pseudo_merge(pm, &pm->v[i]); |
783 | 0 | if (!candidate || candidate->satisfied) |
784 | 0 | continue; |
785 | 0 | if (!bitmap_equals_ewah(parents, candidate->commits)) |
786 | 0 | continue; |
787 | | |
788 | 0 | match = candidate; |
789 | 0 | match->satisfied = 1; |
790 | 0 | break; |
791 | 0 | } |
792 | |
|
793 | 0 | return match; |
794 | 0 | } |