promisor-remote: skip move_to_tail when no-op
[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_EXTRAEDGES 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_EXTRA_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 int open_commit_graph(const char *graph_file, int *fd, struct stat *st)
84 {
85 *fd = git_open(graph_file);
86 if (*fd < 0)
87 return 0;
88 if (fstat(*fd, st)) {
89 close(*fd);
90 return 0;
91 }
92 return 1;
93 }
94
95 struct commit_graph *load_commit_graph_one_fd_st(int fd, struct stat *st)
96 {
97 void *graph_map;
98 size_t graph_size;
99 struct commit_graph *ret;
100
101 graph_size = xsize_t(st->st_size);
102
103 if (graph_size < GRAPH_MIN_SIZE) {
104 close(fd);
105 error(_("commit-graph file is too small"));
106 return NULL;
107 }
108 graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
109 ret = parse_commit_graph(graph_map, fd, graph_size);
110
111 if (!ret) {
112 munmap(graph_map, graph_size);
113 close(fd);
114 }
115
116 return ret;
117 }
118
119 static int verify_commit_graph_lite(struct commit_graph *g)
120 {
121 /*
122 * Basic validation shared between parse_commit_graph()
123 * which'll be called every time the graph is used, and the
124 * much more expensive verify_commit_graph() used by
125 * "commit-graph verify".
126 *
127 * There should only be very basic checks here to ensure that
128 * we don't e.g. segfault in fill_commit_in_graph(), but
129 * because this is a very hot codepath nothing that e.g. loops
130 * over g->num_commits, or runs a checksum on the commit-graph
131 * itself.
132 */
133 if (!g->chunk_oid_fanout) {
134 error("commit-graph is missing the OID Fanout chunk");
135 return 1;
136 }
137 if (!g->chunk_oid_lookup) {
138 error("commit-graph is missing the OID Lookup chunk");
139 return 1;
140 }
141 if (!g->chunk_commit_data) {
142 error("commit-graph is missing the Commit Data chunk");
143 return 1;
144 }
145
146 return 0;
147 }
148
149 struct commit_graph *parse_commit_graph(void *graph_map, int fd,
150 size_t graph_size)
151 {
152 const unsigned char *data, *chunk_lookup;
153 uint32_t i;
154 struct commit_graph *graph;
155 uint64_t last_chunk_offset;
156 uint32_t last_chunk_id;
157 uint32_t graph_signature;
158 unsigned char graph_version, hash_version;
159
160 if (!graph_map)
161 return NULL;
162
163 if (graph_size < GRAPH_MIN_SIZE)
164 return NULL;
165
166 data = (const unsigned char *)graph_map;
167
168 graph_signature = get_be32(data);
169 if (graph_signature != GRAPH_SIGNATURE) {
170 error(_("commit-graph signature %X does not match signature %X"),
171 graph_signature, GRAPH_SIGNATURE);
172 return NULL;
173 }
174
175 graph_version = *(unsigned char*)(data + 4);
176 if (graph_version != GRAPH_VERSION) {
177 error(_("commit-graph version %X does not match version %X"),
178 graph_version, GRAPH_VERSION);
179 return NULL;
180 }
181
182 hash_version = *(unsigned char*)(data + 5);
183 if (hash_version != oid_version()) {
184 error(_("commit-graph hash version %X does not match version %X"),
185 hash_version, oid_version());
186 return NULL;
187 }
188
189 graph = alloc_commit_graph();
190
191 graph->hash_len = the_hash_algo->rawsz;
192 graph->num_chunks = *(unsigned char*)(data + 6);
193 graph->graph_fd = fd;
194 graph->data = graph_map;
195 graph->data_len = graph_size;
196
197 last_chunk_id = 0;
198 last_chunk_offset = 8;
199 chunk_lookup = data + 8;
200 for (i = 0; i < graph->num_chunks; i++) {
201 uint32_t chunk_id;
202 uint64_t chunk_offset;
203 int chunk_repeated = 0;
204
205 if (data + graph_size - chunk_lookup <
206 GRAPH_CHUNKLOOKUP_WIDTH) {
207 error(_("commit-graph chunk lookup table entry missing; file may be incomplete"));
208 free(graph);
209 return NULL;
210 }
211
212 chunk_id = get_be32(chunk_lookup + 0);
213 chunk_offset = get_be64(chunk_lookup + 4);
214
215 chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
216
217 if (chunk_offset > graph_size - the_hash_algo->rawsz) {
218 error(_("commit-graph improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),
219 (uint32_t)chunk_offset);
220 free(graph);
221 return NULL;
222 }
223
224 switch (chunk_id) {
225 case GRAPH_CHUNKID_OIDFANOUT:
226 if (graph->chunk_oid_fanout)
227 chunk_repeated = 1;
228 else
229 graph->chunk_oid_fanout = (uint32_t*)(data + chunk_offset);
230 break;
231
232 case GRAPH_CHUNKID_OIDLOOKUP:
233 if (graph->chunk_oid_lookup)
234 chunk_repeated = 1;
235 else
236 graph->chunk_oid_lookup = data + chunk_offset;
237 break;
238
239 case GRAPH_CHUNKID_DATA:
240 if (graph->chunk_commit_data)
241 chunk_repeated = 1;
242 else
243 graph->chunk_commit_data = data + chunk_offset;
244 break;
245
246 case GRAPH_CHUNKID_EXTRAEDGES:
247 if (graph->chunk_extra_edges)
248 chunk_repeated = 1;
249 else
250 graph->chunk_extra_edges = data + chunk_offset;
251 break;
252 }
253
254 if (chunk_repeated) {
255 error(_("commit-graph chunk id %08x appears multiple times"), chunk_id);
256 free(graph);
257 return NULL;
258 }
259
260 if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)
261 {
262 graph->num_commits = (chunk_offset - last_chunk_offset)
263 / graph->hash_len;
264 }
265
266 last_chunk_id = chunk_id;
267 last_chunk_offset = chunk_offset;
268 }
269
270 if (verify_commit_graph_lite(graph)) {
271 free(graph);
272 return NULL;
273 }
274
275 return graph;
276 }
277
278 static struct commit_graph *load_commit_graph_one(const char *graph_file)
279 {
280
281 struct stat st;
282 int fd;
283 int open_ok = open_commit_graph(graph_file, &fd, &st);
284
285 if (!open_ok)
286 return NULL;
287
288 return load_commit_graph_one_fd_st(fd, &st);
289 }
290
291 static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
292 {
293 char *graph_name;
294
295 if (r->objects->commit_graph)
296 return;
297
298 graph_name = get_commit_graph_filename(obj_dir);
299 r->objects->commit_graph =
300 load_commit_graph_one(graph_name);
301
302 FREE_AND_NULL(graph_name);
303 }
304
305 /*
306 * Return 1 if commit_graph is non-NULL, and 0 otherwise.
307 *
308 * On the first invocation, this function attemps to load the commit
309 * graph if the_repository is configured to have one.
310 */
311 static int prepare_commit_graph(struct repository *r)
312 {
313 struct object_directory *odb;
314 int config_value;
315
316 if (git_env_bool(GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD, 0))
317 die("dying as requested by the '%s' variable on commit-graph load!",
318 GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD);
319
320 if (r->objects->commit_graph_attempted)
321 return !!r->objects->commit_graph;
322 r->objects->commit_graph_attempted = 1;
323
324 if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
325 (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
326 !config_value))
327 /*
328 * This repository is not configured to use commit graphs, so
329 * do not load one. (But report commit_graph_attempted anyway
330 * so that commit graph loading is not attempted again for this
331 * repository.)
332 */
333 return 0;
334
335 if (!commit_graph_compatible(r))
336 return 0;
337
338 prepare_alt_odb(r);
339 for (odb = r->objects->odb;
340 !r->objects->commit_graph && odb;
341 odb = odb->next)
342 prepare_commit_graph_one(r, odb->path);
343 return !!r->objects->commit_graph;
344 }
345
346 int generation_numbers_enabled(struct repository *r)
347 {
348 uint32_t first_generation;
349 struct commit_graph *g;
350 if (!prepare_commit_graph(r))
351 return 0;
352
353 g = r->objects->commit_graph;
354
355 if (!g->num_commits)
356 return 0;
357
358 first_generation = get_be32(g->chunk_commit_data +
359 g->hash_len + 8) >> 2;
360
361 return !!first_generation;
362 }
363
364 void close_commit_graph(struct repository *r)
365 {
366 free_commit_graph(r->objects->commit_graph);
367 r->objects->commit_graph = NULL;
368 }
369
370 static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
371 {
372 return bsearch_hash(oid->hash, g->chunk_oid_fanout,
373 g->chunk_oid_lookup, g->hash_len, pos);
374 }
375
376 static struct commit_list **insert_parent_or_die(struct repository *r,
377 struct commit_graph *g,
378 uint64_t pos,
379 struct commit_list **pptr)
380 {
381 struct commit *c;
382 struct object_id oid;
383
384 if (pos >= g->num_commits)
385 die("invalid parent position %"PRIu64, pos);
386
387 hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
388 c = lookup_commit(r, &oid);
389 if (!c)
390 die(_("could not find commit %s"), oid_to_hex(&oid));
391 c->graph_pos = pos;
392 return &commit_list_insert(c, pptr)->next;
393 }
394
395 static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
396 {
397 const unsigned char *commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * pos;
398 item->graph_pos = pos;
399 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
400 }
401
402 static inline void set_commit_tree(struct commit *c, struct tree *t)
403 {
404 c->maybe_tree = t;
405 }
406
407 static int fill_commit_in_graph(struct repository *r,
408 struct commit *item,
409 struct commit_graph *g, uint32_t pos)
410 {
411 uint32_t edge_value;
412 uint32_t *parent_data_ptr;
413 uint64_t date_low, date_high;
414 struct commit_list **pptr;
415 const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
416
417 item->object.parsed = 1;
418 item->graph_pos = pos;
419
420 set_commit_tree(item, NULL);
421
422 date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
423 date_low = get_be32(commit_data + g->hash_len + 12);
424 item->date = (timestamp_t)((date_high << 32) | date_low);
425
426 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
427
428 pptr = &item->parents;
429
430 edge_value = get_be32(commit_data + g->hash_len);
431 if (edge_value == GRAPH_PARENT_NONE)
432 return 1;
433 pptr = insert_parent_or_die(r, g, edge_value, pptr);
434
435 edge_value = get_be32(commit_data + g->hash_len + 4);
436 if (edge_value == GRAPH_PARENT_NONE)
437 return 1;
438 if (!(edge_value & GRAPH_EXTRA_EDGES_NEEDED)) {
439 pptr = insert_parent_or_die(r, g, edge_value, pptr);
440 return 1;
441 }
442
443 parent_data_ptr = (uint32_t*)(g->chunk_extra_edges +
444 4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
445 do {
446 edge_value = get_be32(parent_data_ptr);
447 pptr = insert_parent_or_die(r, g,
448 edge_value & GRAPH_EDGE_LAST_MASK,
449 pptr);
450 parent_data_ptr++;
451 } while (!(edge_value & GRAPH_LAST_EDGE));
452
453 return 1;
454 }
455
456 static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
457 {
458 if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
459 *pos = item->graph_pos;
460 return 1;
461 } else {
462 return bsearch_graph(g, &(item->object.oid), pos);
463 }
464 }
465
466 static int parse_commit_in_graph_one(struct repository *r,
467 struct commit_graph *g,
468 struct commit *item)
469 {
470 uint32_t pos;
471
472 if (item->object.parsed)
473 return 1;
474
475 if (find_commit_in_graph(item, g, &pos))
476 return fill_commit_in_graph(r, item, g, pos);
477
478 return 0;
479 }
480
481 int parse_commit_in_graph(struct repository *r, struct commit *item)
482 {
483 if (!prepare_commit_graph(r))
484 return 0;
485 return parse_commit_in_graph_one(r, r->objects->commit_graph, item);
486 }
487
488 void load_commit_graph_info(struct repository *r, struct commit *item)
489 {
490 uint32_t pos;
491 if (!prepare_commit_graph(r))
492 return;
493 if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
494 fill_commit_graph_info(item, r->objects->commit_graph, pos);
495 }
496
497 static struct tree *load_tree_for_commit(struct repository *r,
498 struct commit_graph *g,
499 struct commit *c)
500 {
501 struct object_id oid;
502 const unsigned char *commit_data = g->chunk_commit_data +
503 GRAPH_DATA_WIDTH * (c->graph_pos);
504
505 hashcpy(oid.hash, commit_data);
506 set_commit_tree(c, lookup_tree(r, &oid));
507
508 return c->maybe_tree;
509 }
510
511 static struct tree *get_commit_tree_in_graph_one(struct repository *r,
512 struct commit_graph *g,
513 const struct commit *c)
514 {
515 if (c->maybe_tree)
516 return c->maybe_tree;
517 if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
518 BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
519
520 return load_tree_for_commit(r, g, (struct commit *)c);
521 }
522
523 struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
524 {
525 return get_commit_tree_in_graph_one(r, r->objects->commit_graph, c);
526 }
527
528 static void write_graph_chunk_fanout(struct hashfile *f,
529 struct commit **commits,
530 int nr_commits,
531 struct progress *progress,
532 uint64_t *progress_cnt)
533 {
534 int i, count = 0;
535 struct commit **list = commits;
536
537 /*
538 * Write the first-level table (the list is sorted,
539 * but we use a 256-entry lookup to be able to avoid
540 * having to do eight extra binary search iterations).
541 */
542 for (i = 0; i < 256; i++) {
543 while (count < nr_commits) {
544 if ((*list)->object.oid.hash[0] != i)
545 break;
546 display_progress(progress, ++*progress_cnt);
547 count++;
548 list++;
549 }
550
551 hashwrite_be32(f, count);
552 }
553 }
554
555 static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
556 struct commit **commits, int nr_commits,
557 struct progress *progress,
558 uint64_t *progress_cnt)
559 {
560 struct commit **list = commits;
561 int count;
562 for (count = 0; count < nr_commits; count++, list++) {
563 display_progress(progress, ++*progress_cnt);
564 hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
565 }
566 }
567
568 static const unsigned char *commit_to_sha1(size_t index, void *table)
569 {
570 struct commit **commits = table;
571 return commits[index]->object.oid.hash;
572 }
573
574 static void write_graph_chunk_data(struct hashfile *f, int hash_len,
575 struct commit **commits, int nr_commits,
576 struct progress *progress,
577 uint64_t *progress_cnt)
578 {
579 struct commit **list = commits;
580 struct commit **last = commits + nr_commits;
581 uint32_t num_extra_edges = 0;
582
583 while (list < last) {
584 struct commit_list *parent;
585 int edge_value;
586 uint32_t packedDate[2];
587 display_progress(progress, ++*progress_cnt);
588
589 parse_commit_no_graph(*list);
590 hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
591
592 parent = (*list)->parents;
593
594 if (!parent)
595 edge_value = GRAPH_PARENT_NONE;
596 else {
597 edge_value = sha1_pos(parent->item->object.oid.hash,
598 commits,
599 nr_commits,
600 commit_to_sha1);
601
602 if (edge_value < 0)
603 BUG("missing parent %s for commit %s",
604 oid_to_hex(&parent->item->object.oid),
605 oid_to_hex(&(*list)->object.oid));
606 }
607
608 hashwrite_be32(f, edge_value);
609
610 if (parent)
611 parent = parent->next;
612
613 if (!parent)
614 edge_value = GRAPH_PARENT_NONE;
615 else if (parent->next)
616 edge_value = GRAPH_EXTRA_EDGES_NEEDED | num_extra_edges;
617 else {
618 edge_value = sha1_pos(parent->item->object.oid.hash,
619 commits,
620 nr_commits,
621 commit_to_sha1);
622 if (edge_value < 0)
623 BUG("missing parent %s for commit %s",
624 oid_to_hex(&parent->item->object.oid),
625 oid_to_hex(&(*list)->object.oid));
626 }
627
628 hashwrite_be32(f, edge_value);
629
630 if (edge_value & GRAPH_EXTRA_EDGES_NEEDED) {
631 do {
632 num_extra_edges++;
633 parent = parent->next;
634 } while (parent);
635 }
636
637 if (sizeof((*list)->date) > 4)
638 packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
639 else
640 packedDate[0] = 0;
641
642 packedDate[0] |= htonl((*list)->generation << 2);
643
644 packedDate[1] = htonl((*list)->date);
645 hashwrite(f, packedDate, 8);
646
647 list++;
648 }
649 }
650
651 static void write_graph_chunk_extra_edges(struct hashfile *f,
652 struct commit **commits,
653 int nr_commits,
654 struct progress *progress,
655 uint64_t *progress_cnt)
656 {
657 struct commit **list = commits;
658 struct commit **last = commits + nr_commits;
659 struct commit_list *parent;
660
661 while (list < last) {
662 int num_parents = 0;
663
664 display_progress(progress, ++*progress_cnt);
665
666 for (parent = (*list)->parents; num_parents < 3 && parent;
667 parent = parent->next)
668 num_parents++;
669
670 if (num_parents <= 2) {
671 list++;
672 continue;
673 }
674
675 /* Since num_parents > 2, this initializer is safe. */
676 for (parent = (*list)->parents->next; parent; parent = parent->next) {
677 int edge_value = sha1_pos(parent->item->object.oid.hash,
678 commits,
679 nr_commits,
680 commit_to_sha1);
681
682 if (edge_value < 0)
683 BUG("missing parent %s for commit %s",
684 oid_to_hex(&parent->item->object.oid),
685 oid_to_hex(&(*list)->object.oid));
686 else if (!parent->next)
687 edge_value |= GRAPH_LAST_EDGE;
688
689 hashwrite_be32(f, edge_value);
690 }
691
692 list++;
693 }
694 }
695
696 static int commit_compare(const void *_a, const void *_b)
697 {
698 const struct object_id *a = (const struct object_id *)_a;
699 const struct object_id *b = (const struct object_id *)_b;
700 return oidcmp(a, b);
701 }
702
703 struct packed_commit_list {
704 struct commit **list;
705 int nr;
706 int alloc;
707 };
708
709 struct packed_oid_list {
710 struct object_id *list;
711 int nr;
712 int alloc;
713 struct progress *progress;
714 int progress_done;
715 };
716
717 static int add_packed_commits(const struct object_id *oid,
718 struct packed_git *pack,
719 uint32_t pos,
720 void *data)
721 {
722 struct packed_oid_list *list = (struct packed_oid_list*)data;
723 enum object_type type;
724 off_t offset = nth_packed_object_offset(pack, pos);
725 struct object_info oi = OBJECT_INFO_INIT;
726
727 if (list->progress)
728 display_progress(list->progress, ++list->progress_done);
729
730 oi.typep = &type;
731 if (packed_object_info(the_repository, pack, offset, &oi) < 0)
732 die(_("unable to get type of object %s"), oid_to_hex(oid));
733
734 if (type != OBJ_COMMIT)
735 return 0;
736
737 ALLOC_GROW(list->list, list->nr + 1, list->alloc);
738 oidcpy(&(list->list[list->nr]), oid);
739 list->nr++;
740
741 return 0;
742 }
743
744 static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)
745 {
746 struct commit_list *parent;
747 for (parent = commit->parents; parent; parent = parent->next) {
748 if (!(parent->item->object.flags & UNINTERESTING)) {
749 ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);
750 oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));
751 oids->nr++;
752 parent->item->object.flags |= UNINTERESTING;
753 }
754 }
755 }
756
757 static void close_reachable(struct packed_oid_list *oids, int report_progress)
758 {
759 int i;
760 struct commit *commit;
761 struct progress *progress = NULL;
762
763 if (report_progress)
764 progress = start_delayed_progress(
765 _("Loading known commits in commit graph"), oids->nr);
766 for (i = 0; i < oids->nr; i++) {
767 display_progress(progress, i + 1);
768 commit = lookup_commit(the_repository, &oids->list[i]);
769 if (commit)
770 commit->object.flags |= UNINTERESTING;
771 }
772 stop_progress(&progress);
773
774 /*
775 * As this loop runs, oids->nr may grow, but not more
776 * than the number of missing commits in the reachable
777 * closure.
778 */
779 if (report_progress)
780 progress = start_delayed_progress(
781 _("Expanding reachable commits in commit graph"), oids->nr);
782 for (i = 0; i < oids->nr; i++) {
783 display_progress(progress, i + 1);
784 commit = lookup_commit(the_repository, &oids->list[i]);
785
786 if (commit && !parse_commit_no_graph(commit))
787 add_missing_parents(oids, commit);
788 }
789 stop_progress(&progress);
790
791 if (report_progress)
792 progress = start_delayed_progress(
793 _("Clearing commit marks in commit graph"), oids->nr);
794 for (i = 0; i < oids->nr; i++) {
795 display_progress(progress, i + 1);
796 commit = lookup_commit(the_repository, &oids->list[i]);
797
798 if (commit)
799 commit->object.flags &= ~UNINTERESTING;
800 }
801 stop_progress(&progress);
802 }
803
804 static void compute_generation_numbers(struct packed_commit_list* commits,
805 int report_progress)
806 {
807 int i;
808 struct commit_list *list = NULL;
809 struct progress *progress = NULL;
810
811 if (report_progress)
812 progress = start_progress(
813 _("Computing commit graph generation numbers"),
814 commits->nr);
815 for (i = 0; i < commits->nr; i++) {
816 display_progress(progress, i + 1);
817 if (commits->list[i]->generation != GENERATION_NUMBER_INFINITY &&
818 commits->list[i]->generation != GENERATION_NUMBER_ZERO)
819 continue;
820
821 commit_list_insert(commits->list[i], &list);
822 while (list) {
823 struct commit *current = list->item;
824 struct commit_list *parent;
825 int all_parents_computed = 1;
826 uint32_t max_generation = 0;
827
828 for (parent = current->parents; parent; parent = parent->next) {
829 if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
830 parent->item->generation == GENERATION_NUMBER_ZERO) {
831 all_parents_computed = 0;
832 commit_list_insert(parent->item, &list);
833 break;
834 } else if (parent->item->generation > max_generation) {
835 max_generation = parent->item->generation;
836 }
837 }
838
839 if (all_parents_computed) {
840 current->generation = max_generation + 1;
841 pop_commit(&list);
842
843 if (current->generation > GENERATION_NUMBER_MAX)
844 current->generation = GENERATION_NUMBER_MAX;
845 }
846 }
847 }
848 stop_progress(&progress);
849 }
850
851 static int add_ref_to_list(const char *refname,
852 const struct object_id *oid,
853 int flags, void *cb_data)
854 {
855 struct string_list *list = (struct string_list *)cb_data;
856
857 string_list_append(list, oid_to_hex(oid));
858 return 0;
859 }
860
861 void write_commit_graph_reachable(const char *obj_dir, int append,
862 int report_progress)
863 {
864 struct string_list list = STRING_LIST_INIT_DUP;
865
866 for_each_ref(add_ref_to_list, &list);
867 write_commit_graph(obj_dir, NULL, &list, append, report_progress);
868
869 string_list_clear(&list, 0);
870 }
871
872 void write_commit_graph(const char *obj_dir,
873 struct string_list *pack_indexes,
874 struct string_list *commit_hex,
875 int append, int report_progress)
876 {
877 struct packed_oid_list oids;
878 struct packed_commit_list commits;
879 struct hashfile *f;
880 uint32_t i, count_distinct = 0;
881 char *graph_name;
882 struct lock_file lk = LOCK_INIT;
883 uint32_t chunk_ids[5];
884 uint64_t chunk_offsets[5];
885 int num_chunks;
886 int num_extra_edges;
887 struct commit_list *parent;
888 struct progress *progress = NULL;
889 const unsigned hashsz = the_hash_algo->rawsz;
890 uint64_t progress_cnt = 0;
891 struct strbuf progress_title = STRBUF_INIT;
892 unsigned long approx_nr_objects;
893
894 if (!commit_graph_compatible(the_repository))
895 return;
896
897 oids.nr = 0;
898 approx_nr_objects = approximate_object_count();
899 oids.alloc = approx_nr_objects / 32;
900 oids.progress = NULL;
901 oids.progress_done = 0;
902
903 if (append) {
904 prepare_commit_graph_one(the_repository, obj_dir);
905 if (the_repository->objects->commit_graph)
906 oids.alloc += the_repository->objects->commit_graph->num_commits;
907 }
908
909 if (oids.alloc < 1024)
910 oids.alloc = 1024;
911 ALLOC_ARRAY(oids.list, oids.alloc);
912
913 if (append && the_repository->objects->commit_graph) {
914 struct commit_graph *commit_graph =
915 the_repository->objects->commit_graph;
916 for (i = 0; i < commit_graph->num_commits; i++) {
917 const unsigned char *hash = commit_graph->chunk_oid_lookup +
918 commit_graph->hash_len * i;
919 hashcpy(oids.list[oids.nr++].hash, hash);
920 }
921 }
922
923 if (pack_indexes) {
924 struct strbuf packname = STRBUF_INIT;
925 int dirlen;
926 strbuf_addf(&packname, "%s/pack/", obj_dir);
927 dirlen = packname.len;
928 if (report_progress) {
929 strbuf_addf(&progress_title,
930 Q_("Finding commits for commit graph in %d pack",
931 "Finding commits for commit graph in %d packs",
932 pack_indexes->nr),
933 pack_indexes->nr);
934 oids.progress = start_delayed_progress(progress_title.buf, 0);
935 oids.progress_done = 0;
936 }
937 for (i = 0; i < pack_indexes->nr; i++) {
938 struct packed_git *p;
939 strbuf_setlen(&packname, dirlen);
940 strbuf_addstr(&packname, pack_indexes->items[i].string);
941 p = add_packed_git(packname.buf, packname.len, 1);
942 if (!p)
943 die(_("error adding pack %s"), packname.buf);
944 if (open_pack_index(p))
945 die(_("error opening index for %s"), packname.buf);
946 for_each_object_in_pack(p, add_packed_commits, &oids,
947 FOR_EACH_OBJECT_PACK_ORDER);
948 close_pack(p);
949 free(p);
950 }
951 stop_progress(&oids.progress);
952 strbuf_reset(&progress_title);
953 strbuf_release(&packname);
954 }
955
956 if (commit_hex) {
957 if (report_progress) {
958 strbuf_addf(&progress_title,
959 Q_("Finding commits for commit graph from %d ref",
960 "Finding commits for commit graph from %d refs",
961 commit_hex->nr),
962 commit_hex->nr);
963 progress = start_delayed_progress(progress_title.buf,
964 commit_hex->nr);
965 }
966 for (i = 0; i < commit_hex->nr; i++) {
967 const char *end;
968 struct object_id oid;
969 struct commit *result;
970
971 display_progress(progress, i + 1);
972 if (commit_hex->items[i].string &&
973 parse_oid_hex(commit_hex->items[i].string, &oid, &end))
974 continue;
975
976 result = lookup_commit_reference_gently(the_repository, &oid, 1);
977
978 if (result) {
979 ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
980 oidcpy(&oids.list[oids.nr], &(result->object.oid));
981 oids.nr++;
982 }
983 }
984 stop_progress(&progress);
985 strbuf_reset(&progress_title);
986 }
987
988 if (!pack_indexes && !commit_hex) {
989 if (report_progress)
990 oids.progress = start_delayed_progress(
991 _("Finding commits for commit graph among packed objects"),
992 approx_nr_objects);
993 for_each_packed_object(add_packed_commits, &oids,
994 FOR_EACH_OBJECT_PACK_ORDER);
995 if (oids.progress_done < approx_nr_objects)
996 display_progress(oids.progress, approx_nr_objects);
997 stop_progress(&oids.progress);
998 }
999
1000 close_reachable(&oids, report_progress);
1001
1002 if (report_progress)
1003 progress = start_delayed_progress(
1004 _("Counting distinct commits in commit graph"),
1005 oids.nr);
1006 display_progress(progress, 0); /* TODO: Measure QSORT() progress */
1007 QSORT(oids.list, oids.nr, commit_compare);
1008 count_distinct = 1;
1009 for (i = 1; i < oids.nr; i++) {
1010 display_progress(progress, i + 1);
1011 if (!oideq(&oids.list[i - 1], &oids.list[i]))
1012 count_distinct++;
1013 }
1014 stop_progress(&progress);
1015
1016 if (count_distinct >= GRAPH_EDGE_LAST_MASK)
1017 die(_("the commit graph format cannot write %d commits"), count_distinct);
1018
1019 commits.nr = 0;
1020 commits.alloc = count_distinct;
1021 ALLOC_ARRAY(commits.list, commits.alloc);
1022
1023 num_extra_edges = 0;
1024 if (report_progress)
1025 progress = start_delayed_progress(
1026 _("Finding extra edges in commit graph"),
1027 oids.nr);
1028 for (i = 0; i < oids.nr; i++) {
1029 int num_parents = 0;
1030 display_progress(progress, i + 1);
1031 if (i > 0 && oideq(&oids.list[i - 1], &oids.list[i]))
1032 continue;
1033
1034 commits.list[commits.nr] = lookup_commit(the_repository, &oids.list[i]);
1035 parse_commit_no_graph(commits.list[commits.nr]);
1036
1037 for (parent = commits.list[commits.nr]->parents;
1038 parent; parent = parent->next)
1039 num_parents++;
1040
1041 if (num_parents > 2)
1042 num_extra_edges += num_parents - 1;
1043
1044 commits.nr++;
1045 }
1046 num_chunks = num_extra_edges ? 4 : 3;
1047 stop_progress(&progress);
1048
1049 if (commits.nr >= GRAPH_EDGE_LAST_MASK)
1050 die(_("too many commits to write graph"));
1051
1052 compute_generation_numbers(&commits, report_progress);
1053
1054 graph_name = get_commit_graph_filename(obj_dir);
1055 if (safe_create_leading_directories(graph_name)) {
1056 UNLEAK(graph_name);
1057 die_errno(_("unable to create leading directories of %s"),
1058 graph_name);
1059 }
1060
1061 hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
1062 f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
1063
1064 hashwrite_be32(f, GRAPH_SIGNATURE);
1065
1066 hashwrite_u8(f, GRAPH_VERSION);
1067 hashwrite_u8(f, oid_version());
1068 hashwrite_u8(f, num_chunks);
1069 hashwrite_u8(f, 0); /* unused padding byte */
1070
1071 chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
1072 chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
1073 chunk_ids[2] = GRAPH_CHUNKID_DATA;
1074 if (num_extra_edges)
1075 chunk_ids[3] = GRAPH_CHUNKID_EXTRAEDGES;
1076 else
1077 chunk_ids[3] = 0;
1078 chunk_ids[4] = 0;
1079
1080 chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
1081 chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
1082 chunk_offsets[2] = chunk_offsets[1] + hashsz * commits.nr;
1083 chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * commits.nr;
1084 chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
1085
1086 for (i = 0; i <= num_chunks; i++) {
1087 uint32_t chunk_write[3];
1088
1089 chunk_write[0] = htonl(chunk_ids[i]);
1090 chunk_write[1] = htonl(chunk_offsets[i] >> 32);
1091 chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
1092 hashwrite(f, chunk_write, 12);
1093 }
1094
1095 if (report_progress) {
1096 strbuf_addf(&progress_title,
1097 Q_("Writing out commit graph in %d pass",
1098 "Writing out commit graph in %d passes",
1099 num_chunks),
1100 num_chunks);
1101 progress = start_delayed_progress(
1102 progress_title.buf,
1103 num_chunks * commits.nr);
1104 }
1105 write_graph_chunk_fanout(f, commits.list, commits.nr, progress, &progress_cnt);
1106 write_graph_chunk_oids(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
1107 write_graph_chunk_data(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
1108 if (num_extra_edges)
1109 write_graph_chunk_extra_edges(f, commits.list, commits.nr, progress, &progress_cnt);
1110 stop_progress(&progress);
1111 strbuf_release(&progress_title);
1112
1113 close_commit_graph(the_repository);
1114 finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
1115 commit_lock_file(&lk);
1116
1117 free(graph_name);
1118 free(commits.list);
1119 free(oids.list);
1120 }
1121
1122 #define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
1123 static int verify_commit_graph_error;
1124
1125 static void graph_report(const char *fmt, ...)
1126 {
1127 va_list ap;
1128
1129 verify_commit_graph_error = 1;
1130 va_start(ap, fmt);
1131 vfprintf(stderr, fmt, ap);
1132 fprintf(stderr, "\n");
1133 va_end(ap);
1134 }
1135
1136 #define GENERATION_ZERO_EXISTS 1
1137 #define GENERATION_NUMBER_EXISTS 2
1138
1139 int verify_commit_graph(struct repository *r, struct commit_graph *g)
1140 {
1141 uint32_t i, cur_fanout_pos = 0;
1142 struct object_id prev_oid, cur_oid, checksum;
1143 int generation_zero = 0;
1144 struct hashfile *f;
1145 int devnull;
1146 struct progress *progress = NULL;
1147
1148 if (!g) {
1149 graph_report("no commit-graph file loaded");
1150 return 1;
1151 }
1152
1153 verify_commit_graph_error = verify_commit_graph_lite(g);
1154 if (verify_commit_graph_error)
1155 return verify_commit_graph_error;
1156
1157 devnull = open("/dev/null", O_WRONLY);
1158 f = hashfd(devnull, NULL);
1159 hashwrite(f, g->data, g->data_len - g->hash_len);
1160 finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
1161 if (!hasheq(checksum.hash, g->data + g->data_len - g->hash_len)) {
1162 graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
1163 verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
1164 }
1165
1166 for (i = 0; i < g->num_commits; i++) {
1167 struct commit *graph_commit;
1168
1169 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1170
1171 if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
1172 graph_report(_("commit-graph has incorrect OID order: %s then %s"),
1173 oid_to_hex(&prev_oid),
1174 oid_to_hex(&cur_oid));
1175
1176 oidcpy(&prev_oid, &cur_oid);
1177
1178 while (cur_oid.hash[0] > cur_fanout_pos) {
1179 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1180
1181 if (i != fanout_value)
1182 graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1183 cur_fanout_pos, fanout_value, i);
1184 cur_fanout_pos++;
1185 }
1186
1187 graph_commit = lookup_commit(r, &cur_oid);
1188 if (!parse_commit_in_graph_one(r, g, graph_commit))
1189 graph_report(_("failed to parse commit %s from commit-graph"),
1190 oid_to_hex(&cur_oid));
1191 }
1192
1193 while (cur_fanout_pos < 256) {
1194 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1195
1196 if (g->num_commits != fanout_value)
1197 graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1198 cur_fanout_pos, fanout_value, i);
1199
1200 cur_fanout_pos++;
1201 }
1202
1203 if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
1204 return verify_commit_graph_error;
1205
1206 progress = start_progress(_("Verifying commits in commit graph"),
1207 g->num_commits);
1208 for (i = 0; i < g->num_commits; i++) {
1209 struct commit *graph_commit, *odb_commit;
1210 struct commit_list *graph_parents, *odb_parents;
1211 uint32_t max_generation = 0;
1212
1213 display_progress(progress, i + 1);
1214 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1215
1216 graph_commit = lookup_commit(r, &cur_oid);
1217 odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
1218 if (parse_commit_internal(odb_commit, 0, 0)) {
1219 graph_report(_("failed to parse commit %s from object database for commit-graph"),
1220 oid_to_hex(&cur_oid));
1221 continue;
1222 }
1223
1224 if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
1225 get_commit_tree_oid(odb_commit)))
1226 graph_report(_("root tree OID for commit %s in commit-graph is %s != %s"),
1227 oid_to_hex(&cur_oid),
1228 oid_to_hex(get_commit_tree_oid(graph_commit)),
1229 oid_to_hex(get_commit_tree_oid(odb_commit)));
1230
1231 graph_parents = graph_commit->parents;
1232 odb_parents = odb_commit->parents;
1233
1234 while (graph_parents) {
1235 if (odb_parents == NULL) {
1236 graph_report(_("commit-graph parent list for commit %s is too long"),
1237 oid_to_hex(&cur_oid));
1238 break;
1239 }
1240
1241 if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
1242 graph_report(_("commit-graph parent for %s is %s != %s"),
1243 oid_to_hex(&cur_oid),
1244 oid_to_hex(&graph_parents->item->object.oid),
1245 oid_to_hex(&odb_parents->item->object.oid));
1246
1247 if (graph_parents->item->generation > max_generation)
1248 max_generation = graph_parents->item->generation;
1249
1250 graph_parents = graph_parents->next;
1251 odb_parents = odb_parents->next;
1252 }
1253
1254 if (odb_parents != NULL)
1255 graph_report(_("commit-graph parent list for commit %s terminates early"),
1256 oid_to_hex(&cur_oid));
1257
1258 if (!graph_commit->generation) {
1259 if (generation_zero == GENERATION_NUMBER_EXISTS)
1260 graph_report(_("commit-graph has generation number zero for commit %s, but non-zero elsewhere"),
1261 oid_to_hex(&cur_oid));
1262 generation_zero = GENERATION_ZERO_EXISTS;
1263 } else if (generation_zero == GENERATION_ZERO_EXISTS)
1264 graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
1265 oid_to_hex(&cur_oid));
1266
1267 if (generation_zero == GENERATION_ZERO_EXISTS)
1268 continue;
1269
1270 /*
1271 * If one of our parents has generation GENERATION_NUMBER_MAX, then
1272 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
1273 * extra logic in the following condition.
1274 */
1275 if (max_generation == GENERATION_NUMBER_MAX)
1276 max_generation--;
1277
1278 if (graph_commit->generation != max_generation + 1)
1279 graph_report(_("commit-graph generation for commit %s is %u != %u"),
1280 oid_to_hex(&cur_oid),
1281 graph_commit->generation,
1282 max_generation + 1);
1283
1284 if (graph_commit->date != odb_commit->date)
1285 graph_report(_("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime),
1286 oid_to_hex(&cur_oid),
1287 graph_commit->date,
1288 odb_commit->date);
1289 }
1290 stop_progress(&progress);
1291
1292 return verify_commit_graph_error;
1293 }
1294
1295 void free_commit_graph(struct commit_graph *g)
1296 {
1297 if (!g)
1298 return;
1299 if (g->graph_fd >= 0) {
1300 munmap((void *)g->data, g->data_len);
1301 g->data = NULL;
1302 close(g->graph_fd);
1303 }
1304 free(g);
1305 }