Merge branch 'bc/sha-256'
[git/git.git] / commit-graph.c
1 #include "cache.h"
2 #include "config.h"
3 #include "dir.h"
4 #include "git-compat-util.h"
5 #include "lockfile.h"
6 #include "pack.h"
7 #include "packfile.h"
8 #include "commit.h"
9 #include "object.h"
10 #include "refs.h"
11 #include "revision.h"
12 #include "sha1-lookup.h"
13 #include "commit-graph.h"
14 #include "object-store.h"
15 #include "alloc.h"
16 #include "hashmap.h"
17 #include "replace-object.h"
18 #include "progress.h"
19
20 #define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */
21 #define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
22 #define GRAPH_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
23 #define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */
24 #define GRAPH_CHUNKID_LARGEEDGES 0x45444745 /* "EDGE" */
25
26 #define GRAPH_DATA_WIDTH (the_hash_algo->rawsz + 16)
27
28 #define GRAPH_VERSION_1 0x1
29 #define GRAPH_VERSION GRAPH_VERSION_1
30
31 #define GRAPH_OCTOPUS_EDGES_NEEDED 0x80000000
32 #define GRAPH_EDGE_LAST_MASK 0x7fffffff
33 #define GRAPH_PARENT_NONE 0x70000000
34
35 #define GRAPH_LAST_EDGE 0x80000000
36
37 #define GRAPH_HEADER_SIZE 8
38 #define GRAPH_FANOUT_SIZE (4 * 256)
39 #define GRAPH_CHUNKLOOKUP_WIDTH 12
40 #define GRAPH_MIN_SIZE (GRAPH_HEADER_SIZE + 4 * GRAPH_CHUNKLOOKUP_WIDTH \
41 + GRAPH_FANOUT_SIZE + the_hash_algo->rawsz)
42
43 char *get_commit_graph_filename(const char *obj_dir)
44 {
45 return xstrfmt("%s/info/commit-graph", obj_dir);
46 }
47
48 static uint8_t oid_version(void)
49 {
50 return 1;
51 }
52
53 static struct commit_graph *alloc_commit_graph(void)
54 {
55 struct commit_graph *g = xcalloc(1, sizeof(*g));
56 g->graph_fd = -1;
57
58 return g;
59 }
60
61 extern int read_replace_refs;
62
63 static int commit_graph_compatible(struct repository *r)
64 {
65 if (!r->gitdir)
66 return 0;
67
68 if (read_replace_refs) {
69 prepare_replace_object(r);
70 if (hashmap_get_size(&r->objects->replace_map->map))
71 return 0;
72 }
73
74 prepare_commit_graft(r);
75 if (r->parsed_objects && r->parsed_objects->grafts_nr)
76 return 0;
77 if (is_repository_shallow(r))
78 return 0;
79
80 return 1;
81 }
82
83 struct commit_graph *load_commit_graph_one(const char *graph_file)
84 {
85 void *graph_map;
86 const unsigned char *data, *chunk_lookup;
87 size_t graph_size;
88 struct stat st;
89 uint32_t i;
90 struct commit_graph *graph;
91 int fd = git_open(graph_file);
92 uint64_t last_chunk_offset;
93 uint32_t last_chunk_id;
94 uint32_t graph_signature;
95 unsigned char graph_version, hash_version;
96
97 if (fd < 0)
98 return NULL;
99 if (fstat(fd, &st)) {
100 close(fd);
101 return NULL;
102 }
103 graph_size = xsize_t(st.st_size);
104
105 if (graph_size < GRAPH_MIN_SIZE) {
106 close(fd);
107 die(_("graph file %s is too small"), graph_file);
108 }
109 graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
110 data = (const unsigned char *)graph_map;
111
112 graph_signature = get_be32(data);
113 if (graph_signature != GRAPH_SIGNATURE) {
114 error(_("graph signature %X does not match signature %X"),
115 graph_signature, GRAPH_SIGNATURE);
116 goto cleanup_fail;
117 }
118
119 graph_version = *(unsigned char*)(data + 4);
120 if (graph_version != GRAPH_VERSION) {
121 error(_("graph version %X does not match version %X"),
122 graph_version, GRAPH_VERSION);
123 goto cleanup_fail;
124 }
125
126 hash_version = *(unsigned char*)(data + 5);
127 if (hash_version != oid_version()) {
128 error(_("hash version %X does not match version %X"),
129 hash_version, oid_version());
130 goto cleanup_fail;
131 }
132
133 graph = alloc_commit_graph();
134
135 graph->hash_len = the_hash_algo->rawsz;
136 graph->num_chunks = *(unsigned char*)(data + 6);
137 graph->graph_fd = fd;
138 graph->data = graph_map;
139 graph->data_len = graph_size;
140
141 last_chunk_id = 0;
142 last_chunk_offset = 8;
143 chunk_lookup = data + 8;
144 for (i = 0; i < graph->num_chunks; i++) {
145 uint32_t chunk_id = get_be32(chunk_lookup + 0);
146 uint64_t chunk_offset = get_be64(chunk_lookup + 4);
147 int chunk_repeated = 0;
148
149 chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
150
151 if (chunk_offset > graph_size - the_hash_algo->rawsz) {
152 error(_("improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),
153 (uint32_t)chunk_offset);
154 goto cleanup_fail;
155 }
156
157 switch (chunk_id) {
158 case GRAPH_CHUNKID_OIDFANOUT:
159 if (graph->chunk_oid_fanout)
160 chunk_repeated = 1;
161 else
162 graph->chunk_oid_fanout = (uint32_t*)(data + chunk_offset);
163 break;
164
165 case GRAPH_CHUNKID_OIDLOOKUP:
166 if (graph->chunk_oid_lookup)
167 chunk_repeated = 1;
168 else
169 graph->chunk_oid_lookup = data + chunk_offset;
170 break;
171
172 case GRAPH_CHUNKID_DATA:
173 if (graph->chunk_commit_data)
174 chunk_repeated = 1;
175 else
176 graph->chunk_commit_data = data + chunk_offset;
177 break;
178
179 case GRAPH_CHUNKID_LARGEEDGES:
180 if (graph->chunk_large_edges)
181 chunk_repeated = 1;
182 else
183 graph->chunk_large_edges = data + chunk_offset;
184 break;
185 }
186
187 if (chunk_repeated) {
188 error(_("chunk id %08x appears multiple times"), chunk_id);
189 goto cleanup_fail;
190 }
191
192 if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)
193 {
194 graph->num_commits = (chunk_offset - last_chunk_offset)
195 / graph->hash_len;
196 }
197
198 last_chunk_id = chunk_id;
199 last_chunk_offset = chunk_offset;
200 }
201
202 return graph;
203
204 cleanup_fail:
205 munmap(graph_map, graph_size);
206 close(fd);
207 exit(1);
208 }
209
210 static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
211 {
212 char *graph_name;
213
214 if (r->objects->commit_graph)
215 return;
216
217 graph_name = get_commit_graph_filename(obj_dir);
218 r->objects->commit_graph =
219 load_commit_graph_one(graph_name);
220
221 FREE_AND_NULL(graph_name);
222 }
223
224 /*
225 * Return 1 if commit_graph is non-NULL, and 0 otherwise.
226 *
227 * On the first invocation, this function attemps to load the commit
228 * graph if the_repository is configured to have one.
229 */
230 static int prepare_commit_graph(struct repository *r)
231 {
232 struct object_directory *odb;
233 int config_value;
234
235 if (r->objects->commit_graph_attempted)
236 return !!r->objects->commit_graph;
237 r->objects->commit_graph_attempted = 1;
238
239 if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
240 (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
241 !config_value))
242 /*
243 * This repository is not configured to use commit graphs, so
244 * do not load one. (But report commit_graph_attempted anyway
245 * so that commit graph loading is not attempted again for this
246 * repository.)
247 */
248 return 0;
249
250 if (!commit_graph_compatible(r))
251 return 0;
252
253 prepare_alt_odb(r);
254 for (odb = r->objects->odb;
255 !r->objects->commit_graph && odb;
256 odb = odb->next)
257 prepare_commit_graph_one(r, odb->path);
258 return !!r->objects->commit_graph;
259 }
260
261 int generation_numbers_enabled(struct repository *r)
262 {
263 uint32_t first_generation;
264 struct commit_graph *g;
265 if (!prepare_commit_graph(r))
266 return 0;
267
268 g = r->objects->commit_graph;
269
270 if (!g->num_commits)
271 return 0;
272
273 first_generation = get_be32(g->chunk_commit_data +
274 g->hash_len + 8) >> 2;
275
276 return !!first_generation;
277 }
278
279 void close_commit_graph(struct repository *r)
280 {
281 free_commit_graph(r->objects->commit_graph);
282 r->objects->commit_graph = NULL;
283 }
284
285 static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
286 {
287 return bsearch_hash(oid->hash, g->chunk_oid_fanout,
288 g->chunk_oid_lookup, g->hash_len, pos);
289 }
290
291 static struct commit_list **insert_parent_or_die(struct commit_graph *g,
292 uint64_t pos,
293 struct commit_list **pptr)
294 {
295 struct commit *c;
296 struct object_id oid;
297
298 if (pos >= g->num_commits)
299 die("invalid parent position %"PRIu64, pos);
300
301 hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
302 c = lookup_commit(the_repository, &oid);
303 if (!c)
304 die(_("could not find commit %s"), oid_to_hex(&oid));
305 c->graph_pos = pos;
306 return &commit_list_insert(c, pptr)->next;
307 }
308
309 static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
310 {
311 const unsigned char *commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * pos;
312 item->graph_pos = pos;
313 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
314 }
315
316 static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)
317 {
318 uint32_t edge_value;
319 uint32_t *parent_data_ptr;
320 uint64_t date_low, date_high;
321 struct commit_list **pptr;
322 const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
323
324 item->object.parsed = 1;
325 item->graph_pos = pos;
326
327 item->maybe_tree = NULL;
328
329 date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
330 date_low = get_be32(commit_data + g->hash_len + 12);
331 item->date = (timestamp_t)((date_high << 32) | date_low);
332
333 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
334
335 pptr = &item->parents;
336
337 edge_value = get_be32(commit_data + g->hash_len);
338 if (edge_value == GRAPH_PARENT_NONE)
339 return 1;
340 pptr = insert_parent_or_die(g, edge_value, pptr);
341
342 edge_value = get_be32(commit_data + g->hash_len + 4);
343 if (edge_value == GRAPH_PARENT_NONE)
344 return 1;
345 if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {
346 pptr = insert_parent_or_die(g, edge_value, pptr);
347 return 1;
348 }
349
350 parent_data_ptr = (uint32_t*)(g->chunk_large_edges +
351 4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
352 do {
353 edge_value = get_be32(parent_data_ptr);
354 pptr = insert_parent_or_die(g,
355 edge_value & GRAPH_EDGE_LAST_MASK,
356 pptr);
357 parent_data_ptr++;
358 } while (!(edge_value & GRAPH_LAST_EDGE));
359
360 return 1;
361 }
362
363 static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
364 {
365 if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
366 *pos = item->graph_pos;
367 return 1;
368 } else {
369 return bsearch_graph(g, &(item->object.oid), pos);
370 }
371 }
372
373 static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item)
374 {
375 uint32_t pos;
376
377 if (item->object.parsed)
378 return 1;
379
380 if (find_commit_in_graph(item, g, &pos))
381 return fill_commit_in_graph(item, g, pos);
382
383 return 0;
384 }
385
386 int parse_commit_in_graph(struct repository *r, struct commit *item)
387 {
388 if (!prepare_commit_graph(r))
389 return 0;
390 return parse_commit_in_graph_one(r->objects->commit_graph, item);
391 }
392
393 void load_commit_graph_info(struct repository *r, struct commit *item)
394 {
395 uint32_t pos;
396 if (!prepare_commit_graph(r))
397 return;
398 if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
399 fill_commit_graph_info(item, r->objects->commit_graph, pos);
400 }
401
402 static struct tree *load_tree_for_commit(struct commit_graph *g, struct commit *c)
403 {
404 struct object_id oid;
405 const unsigned char *commit_data = g->chunk_commit_data +
406 GRAPH_DATA_WIDTH * (c->graph_pos);
407
408 hashcpy(oid.hash, commit_data);
409 c->maybe_tree = lookup_tree(the_repository, &oid);
410
411 return c->maybe_tree;
412 }
413
414 static struct tree *get_commit_tree_in_graph_one(struct commit_graph *g,
415 const struct commit *c)
416 {
417 if (c->maybe_tree)
418 return c->maybe_tree;
419 if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
420 BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
421
422 return load_tree_for_commit(g, (struct commit *)c);
423 }
424
425 struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
426 {
427 return get_commit_tree_in_graph_one(r->objects->commit_graph, c);
428 }
429
430 static void write_graph_chunk_fanout(struct hashfile *f,
431 struct commit **commits,
432 int nr_commits)
433 {
434 int i, count = 0;
435 struct commit **list = commits;
436
437 /*
438 * Write the first-level table (the list is sorted,
439 * but we use a 256-entry lookup to be able to avoid
440 * having to do eight extra binary search iterations).
441 */
442 for (i = 0; i < 256; i++) {
443 while (count < nr_commits) {
444 if ((*list)->object.oid.hash[0] != i)
445 break;
446 count++;
447 list++;
448 }
449
450 hashwrite_be32(f, count);
451 }
452 }
453
454 static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
455 struct commit **commits, int nr_commits)
456 {
457 struct commit **list = commits;
458 int count;
459 for (count = 0; count < nr_commits; count++, list++)
460 hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
461 }
462
463 static const unsigned char *commit_to_sha1(size_t index, void *table)
464 {
465 struct commit **commits = table;
466 return commits[index]->object.oid.hash;
467 }
468
469 static void write_graph_chunk_data(struct hashfile *f, int hash_len,
470 struct commit **commits, int nr_commits)
471 {
472 struct commit **list = commits;
473 struct commit **last = commits + nr_commits;
474 uint32_t num_extra_edges = 0;
475
476 while (list < last) {
477 struct commit_list *parent;
478 int edge_value;
479 uint32_t packedDate[2];
480
481 parse_commit(*list);
482 hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
483
484 parent = (*list)->parents;
485
486 if (!parent)
487 edge_value = GRAPH_PARENT_NONE;
488 else {
489 edge_value = sha1_pos(parent->item->object.oid.hash,
490 commits,
491 nr_commits,
492 commit_to_sha1);
493
494 if (edge_value < 0)
495 BUG("missing parent %s for commit %s",
496 oid_to_hex(&parent->item->object.oid),
497 oid_to_hex(&(*list)->object.oid));
498 }
499
500 hashwrite_be32(f, edge_value);
501
502 if (parent)
503 parent = parent->next;
504
505 if (!parent)
506 edge_value = GRAPH_PARENT_NONE;
507 else if (parent->next)
508 edge_value = GRAPH_OCTOPUS_EDGES_NEEDED | num_extra_edges;
509 else {
510 edge_value = sha1_pos(parent->item->object.oid.hash,
511 commits,
512 nr_commits,
513 commit_to_sha1);
514 if (edge_value < 0)
515 BUG("missing parent %s for commit %s",
516 oid_to_hex(&parent->item->object.oid),
517 oid_to_hex(&(*list)->object.oid));
518 }
519
520 hashwrite_be32(f, edge_value);
521
522 if (edge_value & GRAPH_OCTOPUS_EDGES_NEEDED) {
523 do {
524 num_extra_edges++;
525 parent = parent->next;
526 } while (parent);
527 }
528
529 if (sizeof((*list)->date) > 4)
530 packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
531 else
532 packedDate[0] = 0;
533
534 packedDate[0] |= htonl((*list)->generation << 2);
535
536 packedDate[1] = htonl((*list)->date);
537 hashwrite(f, packedDate, 8);
538
539 list++;
540 }
541 }
542
543 static void write_graph_chunk_large_edges(struct hashfile *f,
544 struct commit **commits,
545 int nr_commits)
546 {
547 struct commit **list = commits;
548 struct commit **last = commits + nr_commits;
549 struct commit_list *parent;
550
551 while (list < last) {
552 int num_parents = 0;
553 for (parent = (*list)->parents; num_parents < 3 && parent;
554 parent = parent->next)
555 num_parents++;
556
557 if (num_parents <= 2) {
558 list++;
559 continue;
560 }
561
562 /* Since num_parents > 2, this initializer is safe. */
563 for (parent = (*list)->parents->next; parent; parent = parent->next) {
564 int edge_value = sha1_pos(parent->item->object.oid.hash,
565 commits,
566 nr_commits,
567 commit_to_sha1);
568
569 if (edge_value < 0)
570 BUG("missing parent %s for commit %s",
571 oid_to_hex(&parent->item->object.oid),
572 oid_to_hex(&(*list)->object.oid));
573 else if (!parent->next)
574 edge_value |= GRAPH_LAST_EDGE;
575
576 hashwrite_be32(f, edge_value);
577 }
578
579 list++;
580 }
581 }
582
583 static int commit_compare(const void *_a, const void *_b)
584 {
585 const struct object_id *a = (const struct object_id *)_a;
586 const struct object_id *b = (const struct object_id *)_b;
587 return oidcmp(a, b);
588 }
589
590 struct packed_commit_list {
591 struct commit **list;
592 int nr;
593 int alloc;
594 };
595
596 struct packed_oid_list {
597 struct object_id *list;
598 int nr;
599 int alloc;
600 struct progress *progress;
601 int progress_done;
602 };
603
604 static int add_packed_commits(const struct object_id *oid,
605 struct packed_git *pack,
606 uint32_t pos,
607 void *data)
608 {
609 struct packed_oid_list *list = (struct packed_oid_list*)data;
610 enum object_type type;
611 off_t offset = nth_packed_object_offset(pack, pos);
612 struct object_info oi = OBJECT_INFO_INIT;
613
614 if (list->progress)
615 display_progress(list->progress, ++list->progress_done);
616
617 oi.typep = &type;
618 if (packed_object_info(the_repository, pack, offset, &oi) < 0)
619 die(_("unable to get type of object %s"), oid_to_hex(oid));
620
621 if (type != OBJ_COMMIT)
622 return 0;
623
624 ALLOC_GROW(list->list, list->nr + 1, list->alloc);
625 oidcpy(&(list->list[list->nr]), oid);
626 list->nr++;
627
628 return 0;
629 }
630
631 static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)
632 {
633 struct commit_list *parent;
634 for (parent = commit->parents; parent; parent = parent->next) {
635 if (!(parent->item->object.flags & UNINTERESTING)) {
636 ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);
637 oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));
638 oids->nr++;
639 parent->item->object.flags |= UNINTERESTING;
640 }
641 }
642 }
643
644 static void close_reachable(struct packed_oid_list *oids, int report_progress)
645 {
646 int i, j;
647 struct commit *commit;
648 struct progress *progress = NULL;
649
650 if (report_progress)
651 progress = start_delayed_progress(
652 _("Loading known commits in commit graph"), j = 0);
653 for (i = 0; i < oids->nr; i++) {
654 display_progress(progress, ++j);
655 commit = lookup_commit(the_repository, &oids->list[i]);
656 if (commit)
657 commit->object.flags |= UNINTERESTING;
658 }
659 stop_progress(&progress);
660
661 /*
662 * As this loop runs, oids->nr may grow, but not more
663 * than the number of missing commits in the reachable
664 * closure.
665 */
666 if (report_progress)
667 progress = start_delayed_progress(
668 _("Expanding reachable commits in commit graph"), j = 0);
669 for (i = 0; i < oids->nr; i++) {
670 display_progress(progress, ++j);
671 commit = lookup_commit(the_repository, &oids->list[i]);
672
673 if (commit && !parse_commit(commit))
674 add_missing_parents(oids, commit);
675 }
676 stop_progress(&progress);
677
678 if (report_progress)
679 progress = start_delayed_progress(
680 _("Clearing commit marks in commit graph"), j = 0);
681 for (i = 0; i < oids->nr; i++) {
682 display_progress(progress, ++j);
683 commit = lookup_commit(the_repository, &oids->list[i]);
684
685 if (commit)
686 commit->object.flags &= ~UNINTERESTING;
687 }
688 stop_progress(&progress);
689 }
690
691 static void compute_generation_numbers(struct packed_commit_list* commits,
692 int report_progress)
693 {
694 int i;
695 struct commit_list *list = NULL;
696 struct progress *progress = NULL;
697
698 if (report_progress)
699 progress = start_progress(
700 _("Computing commit graph generation numbers"),
701 commits->nr);
702 for (i = 0; i < commits->nr; i++) {
703 display_progress(progress, i + 1);
704 if (commits->list[i]->generation != GENERATION_NUMBER_INFINITY &&
705 commits->list[i]->generation != GENERATION_NUMBER_ZERO)
706 continue;
707
708 commit_list_insert(commits->list[i], &list);
709 while (list) {
710 struct commit *current = list->item;
711 struct commit_list *parent;
712 int all_parents_computed = 1;
713 uint32_t max_generation = 0;
714
715 for (parent = current->parents; parent; parent = parent->next) {
716 if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
717 parent->item->generation == GENERATION_NUMBER_ZERO) {
718 all_parents_computed = 0;
719 commit_list_insert(parent->item, &list);
720 break;
721 } else if (parent->item->generation > max_generation) {
722 max_generation = parent->item->generation;
723 }
724 }
725
726 if (all_parents_computed) {
727 current->generation = max_generation + 1;
728 pop_commit(&list);
729
730 if (current->generation > GENERATION_NUMBER_MAX)
731 current->generation = GENERATION_NUMBER_MAX;
732 }
733 }
734 }
735 stop_progress(&progress);
736 }
737
738 static int add_ref_to_list(const char *refname,
739 const struct object_id *oid,
740 int flags, void *cb_data)
741 {
742 struct string_list *list = (struct string_list *)cb_data;
743
744 string_list_append(list, oid_to_hex(oid));
745 return 0;
746 }
747
748 void write_commit_graph_reachable(const char *obj_dir, int append,
749 int report_progress)
750 {
751 struct string_list list = STRING_LIST_INIT_DUP;
752
753 for_each_ref(add_ref_to_list, &list);
754 write_commit_graph(obj_dir, NULL, &list, append, report_progress);
755
756 string_list_clear(&list, 0);
757 }
758
759 void write_commit_graph(const char *obj_dir,
760 struct string_list *pack_indexes,
761 struct string_list *commit_hex,
762 int append, int report_progress)
763 {
764 struct packed_oid_list oids;
765 struct packed_commit_list commits;
766 struct hashfile *f;
767 uint32_t i, count_distinct = 0;
768 char *graph_name;
769 struct lock_file lk = LOCK_INIT;
770 uint32_t chunk_ids[5];
771 uint64_t chunk_offsets[5];
772 int num_chunks;
773 int num_extra_edges;
774 struct commit_list *parent;
775 struct progress *progress = NULL;
776 const unsigned hashsz = the_hash_algo->rawsz;
777
778 if (!commit_graph_compatible(the_repository))
779 return;
780
781 oids.nr = 0;
782 oids.alloc = approximate_object_count() / 32;
783 oids.progress = NULL;
784 oids.progress_done = 0;
785
786 if (append) {
787 prepare_commit_graph_one(the_repository, obj_dir);
788 if (the_repository->objects->commit_graph)
789 oids.alloc += the_repository->objects->commit_graph->num_commits;
790 }
791
792 if (oids.alloc < 1024)
793 oids.alloc = 1024;
794 ALLOC_ARRAY(oids.list, oids.alloc);
795
796 if (append && the_repository->objects->commit_graph) {
797 struct commit_graph *commit_graph =
798 the_repository->objects->commit_graph;
799 for (i = 0; i < commit_graph->num_commits; i++) {
800 const unsigned char *hash = commit_graph->chunk_oid_lookup +
801 commit_graph->hash_len * i;
802 hashcpy(oids.list[oids.nr++].hash, hash);
803 }
804 }
805
806 if (pack_indexes) {
807 struct strbuf packname = STRBUF_INIT;
808 int dirlen;
809 strbuf_addf(&packname, "%s/pack/", obj_dir);
810 dirlen = packname.len;
811 if (report_progress) {
812 oids.progress = start_delayed_progress(
813 _("Finding commits for commit graph"), 0);
814 oids.progress_done = 0;
815 }
816 for (i = 0; i < pack_indexes->nr; i++) {
817 struct packed_git *p;
818 strbuf_setlen(&packname, dirlen);
819 strbuf_addstr(&packname, pack_indexes->items[i].string);
820 p = add_packed_git(packname.buf, packname.len, 1);
821 if (!p)
822 die(_("error adding pack %s"), packname.buf);
823 if (open_pack_index(p))
824 die(_("error opening index for %s"), packname.buf);
825 for_each_object_in_pack(p, add_packed_commits, &oids, 0);
826 close_pack(p);
827 free(p);
828 }
829 stop_progress(&oids.progress);
830 strbuf_release(&packname);
831 }
832
833 if (commit_hex) {
834 if (report_progress)
835 progress = start_delayed_progress(
836 _("Finding commits for commit graph"),
837 commit_hex->nr);
838 for (i = 0; i < commit_hex->nr; i++) {
839 const char *end;
840 struct object_id oid;
841 struct commit *result;
842
843 display_progress(progress, i + 1);
844 if (commit_hex->items[i].string &&
845 parse_oid_hex(commit_hex->items[i].string, &oid, &end))
846 continue;
847
848 result = lookup_commit_reference_gently(the_repository, &oid, 1);
849
850 if (result) {
851 ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
852 oidcpy(&oids.list[oids.nr], &(result->object.oid));
853 oids.nr++;
854 }
855 }
856 stop_progress(&progress);
857 }
858
859 if (!pack_indexes && !commit_hex) {
860 if (report_progress)
861 oids.progress = start_delayed_progress(
862 _("Finding commits for commit graph"), 0);
863 for_each_packed_object(add_packed_commits, &oids, 0);
864 stop_progress(&oids.progress);
865 }
866
867 close_reachable(&oids, report_progress);
868
869 QSORT(oids.list, oids.nr, commit_compare);
870
871 count_distinct = 1;
872 for (i = 1; i < oids.nr; i++) {
873 if (!oideq(&oids.list[i - 1], &oids.list[i]))
874 count_distinct++;
875 }
876
877 if (count_distinct >= GRAPH_EDGE_LAST_MASK)
878 die(_("the commit graph format cannot write %d commits"), count_distinct);
879
880 commits.nr = 0;
881 commits.alloc = count_distinct;
882 ALLOC_ARRAY(commits.list, commits.alloc);
883
884 num_extra_edges = 0;
885 for (i = 0; i < oids.nr; i++) {
886 int num_parents = 0;
887 if (i > 0 && oideq(&oids.list[i - 1], &oids.list[i]))
888 continue;
889
890 commits.list[commits.nr] = lookup_commit(the_repository, &oids.list[i]);
891 parse_commit(commits.list[commits.nr]);
892
893 for (parent = commits.list[commits.nr]->parents;
894 parent; parent = parent->next)
895 num_parents++;
896
897 if (num_parents > 2)
898 num_extra_edges += num_parents - 1;
899
900 commits.nr++;
901 }
902 num_chunks = num_extra_edges ? 4 : 3;
903
904 if (commits.nr >= GRAPH_EDGE_LAST_MASK)
905 die(_("too many commits to write graph"));
906
907 compute_generation_numbers(&commits, report_progress);
908
909 graph_name = get_commit_graph_filename(obj_dir);
910 if (safe_create_leading_directories(graph_name)) {
911 UNLEAK(graph_name);
912 die_errno(_("unable to create leading directories of %s"),
913 graph_name);
914 }
915
916 hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
917 f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
918
919 hashwrite_be32(f, GRAPH_SIGNATURE);
920
921 hashwrite_u8(f, GRAPH_VERSION);
922 hashwrite_u8(f, oid_version());
923 hashwrite_u8(f, num_chunks);
924 hashwrite_u8(f, 0); /* unused padding byte */
925
926 chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
927 chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
928 chunk_ids[2] = GRAPH_CHUNKID_DATA;
929 if (num_extra_edges)
930 chunk_ids[3] = GRAPH_CHUNKID_LARGEEDGES;
931 else
932 chunk_ids[3] = 0;
933 chunk_ids[4] = 0;
934
935 chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
936 chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
937 chunk_offsets[2] = chunk_offsets[1] + hashsz * commits.nr;
938 chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * commits.nr;
939 chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
940
941 for (i = 0; i <= num_chunks; i++) {
942 uint32_t chunk_write[3];
943
944 chunk_write[0] = htonl(chunk_ids[i]);
945 chunk_write[1] = htonl(chunk_offsets[i] >> 32);
946 chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
947 hashwrite(f, chunk_write, 12);
948 }
949
950 write_graph_chunk_fanout(f, commits.list, commits.nr);
951 write_graph_chunk_oids(f, hashsz, commits.list, commits.nr);
952 write_graph_chunk_data(f, hashsz, commits.list, commits.nr);
953 write_graph_chunk_large_edges(f, commits.list, commits.nr);
954
955 close_commit_graph(the_repository);
956 finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
957 commit_lock_file(&lk);
958
959 free(graph_name);
960 free(commits.list);
961 free(oids.list);
962 }
963
964 #define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
965 static int verify_commit_graph_error;
966
967 static void graph_report(const char *fmt, ...)
968 {
969 va_list ap;
970
971 verify_commit_graph_error = 1;
972 va_start(ap, fmt);
973 vfprintf(stderr, fmt, ap);
974 fprintf(stderr, "\n");
975 va_end(ap);
976 }
977
978 #define GENERATION_ZERO_EXISTS 1
979 #define GENERATION_NUMBER_EXISTS 2
980
981 int verify_commit_graph(struct repository *r, struct commit_graph *g)
982 {
983 uint32_t i, cur_fanout_pos = 0;
984 struct object_id prev_oid, cur_oid, checksum;
985 int generation_zero = 0;
986 struct hashfile *f;
987 int devnull;
988 struct progress *progress = NULL;
989
990 if (!g) {
991 graph_report("no commit-graph file loaded");
992 return 1;
993 }
994
995 verify_commit_graph_error = 0;
996
997 if (!g->chunk_oid_fanout)
998 graph_report("commit-graph is missing the OID Fanout chunk");
999 if (!g->chunk_oid_lookup)
1000 graph_report("commit-graph is missing the OID Lookup chunk");
1001 if (!g->chunk_commit_data)
1002 graph_report("commit-graph is missing the Commit Data chunk");
1003
1004 if (verify_commit_graph_error)
1005 return verify_commit_graph_error;
1006
1007 devnull = open("/dev/null", O_WRONLY);
1008 f = hashfd(devnull, NULL);
1009 hashwrite(f, g->data, g->data_len - g->hash_len);
1010 finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
1011 if (!hasheq(checksum.hash, g->data + g->data_len - g->hash_len)) {
1012 graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
1013 verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
1014 }
1015
1016 for (i = 0; i < g->num_commits; i++) {
1017 struct commit *graph_commit;
1018
1019 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1020
1021 if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
1022 graph_report("commit-graph has incorrect OID order: %s then %s",
1023 oid_to_hex(&prev_oid),
1024 oid_to_hex(&cur_oid));
1025
1026 oidcpy(&prev_oid, &cur_oid);
1027
1028 while (cur_oid.hash[0] > cur_fanout_pos) {
1029 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1030
1031 if (i != fanout_value)
1032 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
1033 cur_fanout_pos, fanout_value, i);
1034 cur_fanout_pos++;
1035 }
1036
1037 graph_commit = lookup_commit(r, &cur_oid);
1038 if (!parse_commit_in_graph_one(g, graph_commit))
1039 graph_report("failed to parse %s from commit-graph",
1040 oid_to_hex(&cur_oid));
1041 }
1042
1043 while (cur_fanout_pos < 256) {
1044 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1045
1046 if (g->num_commits != fanout_value)
1047 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
1048 cur_fanout_pos, fanout_value, i);
1049
1050 cur_fanout_pos++;
1051 }
1052
1053 if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
1054 return verify_commit_graph_error;
1055
1056 progress = start_progress(_("Verifying commits in commit graph"),
1057 g->num_commits);
1058 for (i = 0; i < g->num_commits; i++) {
1059 struct commit *graph_commit, *odb_commit;
1060 struct commit_list *graph_parents, *odb_parents;
1061 uint32_t max_generation = 0;
1062
1063 display_progress(progress, i + 1);
1064 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1065
1066 graph_commit = lookup_commit(r, &cur_oid);
1067 odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
1068 if (parse_commit_internal(odb_commit, 0, 0)) {
1069 graph_report("failed to parse %s from object database",
1070 oid_to_hex(&cur_oid));
1071 continue;
1072 }
1073
1074 if (!oideq(&get_commit_tree_in_graph_one(g, graph_commit)->object.oid,
1075 get_commit_tree_oid(odb_commit)))
1076 graph_report("root tree OID for commit %s in commit-graph is %s != %s",
1077 oid_to_hex(&cur_oid),
1078 oid_to_hex(get_commit_tree_oid(graph_commit)),
1079 oid_to_hex(get_commit_tree_oid(odb_commit)));
1080
1081 graph_parents = graph_commit->parents;
1082 odb_parents = odb_commit->parents;
1083
1084 while (graph_parents) {
1085 if (odb_parents == NULL) {
1086 graph_report("commit-graph parent list for commit %s is too long",
1087 oid_to_hex(&cur_oid));
1088 break;
1089 }
1090
1091 if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
1092 graph_report("commit-graph parent for %s is %s != %s",
1093 oid_to_hex(&cur_oid),
1094 oid_to_hex(&graph_parents->item->object.oid),
1095 oid_to_hex(&odb_parents->item->object.oid));
1096
1097 if (graph_parents->item->generation > max_generation)
1098 max_generation = graph_parents->item->generation;
1099
1100 graph_parents = graph_parents->next;
1101 odb_parents = odb_parents->next;
1102 }
1103
1104 if (odb_parents != NULL)
1105 graph_report("commit-graph parent list for commit %s terminates early",
1106 oid_to_hex(&cur_oid));
1107
1108 if (!graph_commit->generation) {
1109 if (generation_zero == GENERATION_NUMBER_EXISTS)
1110 graph_report("commit-graph has generation number zero for commit %s, but non-zero elsewhere",
1111 oid_to_hex(&cur_oid));
1112 generation_zero = GENERATION_ZERO_EXISTS;
1113 } else if (generation_zero == GENERATION_ZERO_EXISTS)
1114 graph_report("commit-graph has non-zero generation number for commit %s, but zero elsewhere",
1115 oid_to_hex(&cur_oid));
1116
1117 if (generation_zero == GENERATION_ZERO_EXISTS)
1118 continue;
1119
1120 /*
1121 * If one of our parents has generation GENERATION_NUMBER_MAX, then
1122 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
1123 * extra logic in the following condition.
1124 */
1125 if (max_generation == GENERATION_NUMBER_MAX)
1126 max_generation--;
1127
1128 if (graph_commit->generation != max_generation + 1)
1129 graph_report("commit-graph generation for commit %s is %u != %u",
1130 oid_to_hex(&cur_oid),
1131 graph_commit->generation,
1132 max_generation + 1);
1133
1134 if (graph_commit->date != odb_commit->date)
1135 graph_report("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime,
1136 oid_to_hex(&cur_oid),
1137 graph_commit->date,
1138 odb_commit->date);
1139 }
1140 stop_progress(&progress);
1141
1142 return verify_commit_graph_error;
1143 }
1144
1145 void free_commit_graph(struct commit_graph *g)
1146 {
1147 if (!g)
1148 return;
1149 if (g->graph_fd >= 0) {
1150 munmap((void *)g->data, g->data_len);
1151 g->data = NULL;
1152 close(g->graph_fd);
1153 }
1154 free(g);
1155 }