8a1bec7b8aa420dd3d4ecadc95dee31029533c07
[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
17 #define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */
18 #define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
19 #define GRAPH_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
20 #define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */
21 #define GRAPH_CHUNKID_LARGEEDGES 0x45444745 /* "EDGE" */
22
23 #define GRAPH_DATA_WIDTH 36
24
25 #define GRAPH_VERSION_1 0x1
26 #define GRAPH_VERSION GRAPH_VERSION_1
27
28 #define GRAPH_OID_VERSION_SHA1 1
29 #define GRAPH_OID_LEN_SHA1 GIT_SHA1_RAWSZ
30 #define GRAPH_OID_VERSION GRAPH_OID_VERSION_SHA1
31 #define GRAPH_OID_LEN GRAPH_OID_LEN_SHA1
32
33 #define GRAPH_OCTOPUS_EDGES_NEEDED 0x80000000
34 #define GRAPH_PARENT_MISSING 0x7fffffff
35 #define GRAPH_EDGE_LAST_MASK 0x7fffffff
36 #define GRAPH_PARENT_NONE 0x70000000
37
38 #define GRAPH_LAST_EDGE 0x80000000
39
40 #define GRAPH_HEADER_SIZE 8
41 #define GRAPH_FANOUT_SIZE (4 * 256)
42 #define GRAPH_CHUNKLOOKUP_WIDTH 12
43 #define GRAPH_MIN_SIZE (GRAPH_HEADER_SIZE + 4 * GRAPH_CHUNKLOOKUP_WIDTH \
44 + GRAPH_FANOUT_SIZE + GRAPH_OID_LEN)
45
46 char *get_commit_graph_filename(const char *obj_dir)
47 {
48 return xstrfmt("%s/info/commit-graph", obj_dir);
49 }
50
51 static struct commit_graph *alloc_commit_graph(void)
52 {
53 struct commit_graph *g = xcalloc(1, sizeof(*g));
54 g->graph_fd = -1;
55
56 return g;
57 }
58
59 struct commit_graph *load_commit_graph_one(const char *graph_file)
60 {
61 void *graph_map;
62 const unsigned char *data, *chunk_lookup;
63 size_t graph_size;
64 struct stat st;
65 uint32_t i;
66 struct commit_graph *graph;
67 int fd = git_open(graph_file);
68 uint64_t last_chunk_offset;
69 uint32_t last_chunk_id;
70 uint32_t graph_signature;
71 unsigned char graph_version, hash_version;
72
73 if (fd < 0)
74 return NULL;
75 if (fstat(fd, &st)) {
76 close(fd);
77 return NULL;
78 }
79 graph_size = xsize_t(st.st_size);
80
81 if (graph_size < GRAPH_MIN_SIZE) {
82 close(fd);
83 die(_("graph file %s is too small"), graph_file);
84 }
85 graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
86 data = (const unsigned char *)graph_map;
87
88 graph_signature = get_be32(data);
89 if (graph_signature != GRAPH_SIGNATURE) {
90 error(_("graph signature %X does not match signature %X"),
91 graph_signature, GRAPH_SIGNATURE);
92 goto cleanup_fail;
93 }
94
95 graph_version = *(unsigned char*)(data + 4);
96 if (graph_version != GRAPH_VERSION) {
97 error(_("graph version %X does not match version %X"),
98 graph_version, GRAPH_VERSION);
99 goto cleanup_fail;
100 }
101
102 hash_version = *(unsigned char*)(data + 5);
103 if (hash_version != GRAPH_OID_VERSION) {
104 error(_("hash version %X does not match version %X"),
105 hash_version, GRAPH_OID_VERSION);
106 goto cleanup_fail;
107 }
108
109 graph = alloc_commit_graph();
110
111 graph->hash_len = GRAPH_OID_LEN;
112 graph->num_chunks = *(unsigned char*)(data + 6);
113 graph->graph_fd = fd;
114 graph->data = graph_map;
115 graph->data_len = graph_size;
116
117 last_chunk_id = 0;
118 last_chunk_offset = 8;
119 chunk_lookup = data + 8;
120 for (i = 0; i < graph->num_chunks; i++) {
121 uint32_t chunk_id = get_be32(chunk_lookup + 0);
122 uint64_t chunk_offset = get_be64(chunk_lookup + 4);
123 int chunk_repeated = 0;
124
125 chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
126
127 if (chunk_offset > graph_size - GIT_MAX_RAWSZ) {
128 error(_("improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),
129 (uint32_t)chunk_offset);
130 goto cleanup_fail;
131 }
132
133 switch (chunk_id) {
134 case GRAPH_CHUNKID_OIDFANOUT:
135 if (graph->chunk_oid_fanout)
136 chunk_repeated = 1;
137 else
138 graph->chunk_oid_fanout = (uint32_t*)(data + chunk_offset);
139 break;
140
141 case GRAPH_CHUNKID_OIDLOOKUP:
142 if (graph->chunk_oid_lookup)
143 chunk_repeated = 1;
144 else
145 graph->chunk_oid_lookup = data + chunk_offset;
146 break;
147
148 case GRAPH_CHUNKID_DATA:
149 if (graph->chunk_commit_data)
150 chunk_repeated = 1;
151 else
152 graph->chunk_commit_data = data + chunk_offset;
153 break;
154
155 case GRAPH_CHUNKID_LARGEEDGES:
156 if (graph->chunk_large_edges)
157 chunk_repeated = 1;
158 else
159 graph->chunk_large_edges = data + chunk_offset;
160 break;
161 }
162
163 if (chunk_repeated) {
164 error(_("chunk id %08x appears multiple times"), chunk_id);
165 goto cleanup_fail;
166 }
167
168 if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)
169 {
170 graph->num_commits = (chunk_offset - last_chunk_offset)
171 / graph->hash_len;
172 }
173
174 last_chunk_id = chunk_id;
175 last_chunk_offset = chunk_offset;
176 }
177
178 return graph;
179
180 cleanup_fail:
181 munmap(graph_map, graph_size);
182 close(fd);
183 exit(1);
184 }
185
186 static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
187 {
188 char *graph_name;
189
190 if (r->objects->commit_graph)
191 return;
192
193 graph_name = get_commit_graph_filename(obj_dir);
194 r->objects->commit_graph =
195 load_commit_graph_one(graph_name);
196
197 FREE_AND_NULL(graph_name);
198 }
199
200 /*
201 * Return 1 if commit_graph is non-NULL, and 0 otherwise.
202 *
203 * On the first invocation, this function attemps to load the commit
204 * graph if the_repository is configured to have one.
205 */
206 static int prepare_commit_graph(struct repository *r)
207 {
208 struct alternate_object_database *alt;
209 char *obj_dir;
210 int config_value;
211
212 if (r->objects->commit_graph_attempted)
213 return !!r->objects->commit_graph;
214 r->objects->commit_graph_attempted = 1;
215
216 if (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
217 !config_value)
218 /*
219 * This repository is not configured to use commit graphs, so
220 * do not load one. (But report commit_graph_attempted anyway
221 * so that commit graph loading is not attempted again for this
222 * repository.)
223 */
224 return 0;
225
226 obj_dir = r->objects->objectdir;
227 prepare_commit_graph_one(r, obj_dir);
228 prepare_alt_odb(r);
229 for (alt = r->objects->alt_odb_list;
230 !r->objects->commit_graph && alt;
231 alt = alt->next)
232 prepare_commit_graph_one(r, alt->path);
233 return !!r->objects->commit_graph;
234 }
235
236 static void close_commit_graph(void)
237 {
238 free_commit_graph(the_repository->objects->commit_graph);
239 the_repository->objects->commit_graph = NULL;
240 }
241
242 static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
243 {
244 return bsearch_hash(oid->hash, g->chunk_oid_fanout,
245 g->chunk_oid_lookup, g->hash_len, pos);
246 }
247
248 static struct commit_list **insert_parent_or_die(struct commit_graph *g,
249 uint64_t pos,
250 struct commit_list **pptr)
251 {
252 struct commit *c;
253 struct object_id oid;
254
255 if (pos >= g->num_commits)
256 die("invalid parent position %"PRIu64, pos);
257
258 hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
259 c = lookup_commit(the_repository, &oid);
260 if (!c)
261 die(_("could not find commit %s"), oid_to_hex(&oid));
262 c->graph_pos = pos;
263 return &commit_list_insert(c, pptr)->next;
264 }
265
266 static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
267 {
268 const unsigned char *commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * pos;
269 item->graph_pos = pos;
270 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
271 }
272
273 static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)
274 {
275 uint32_t edge_value;
276 uint32_t *parent_data_ptr;
277 uint64_t date_low, date_high;
278 struct commit_list **pptr;
279 const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
280
281 item->object.parsed = 1;
282 item->graph_pos = pos;
283
284 item->maybe_tree = NULL;
285
286 date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
287 date_low = get_be32(commit_data + g->hash_len + 12);
288 item->date = (timestamp_t)((date_high << 32) | date_low);
289
290 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
291
292 pptr = &item->parents;
293
294 edge_value = get_be32(commit_data + g->hash_len);
295 if (edge_value == GRAPH_PARENT_NONE)
296 return 1;
297 pptr = insert_parent_or_die(g, edge_value, pptr);
298
299 edge_value = get_be32(commit_data + g->hash_len + 4);
300 if (edge_value == GRAPH_PARENT_NONE)
301 return 1;
302 if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {
303 pptr = insert_parent_or_die(g, edge_value, pptr);
304 return 1;
305 }
306
307 parent_data_ptr = (uint32_t*)(g->chunk_large_edges +
308 4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
309 do {
310 edge_value = get_be32(parent_data_ptr);
311 pptr = insert_parent_or_die(g,
312 edge_value & GRAPH_EDGE_LAST_MASK,
313 pptr);
314 parent_data_ptr++;
315 } while (!(edge_value & GRAPH_LAST_EDGE));
316
317 return 1;
318 }
319
320 static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
321 {
322 if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
323 *pos = item->graph_pos;
324 return 1;
325 } else {
326 return bsearch_graph(g, &(item->object.oid), pos);
327 }
328 }
329
330 static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item)
331 {
332 uint32_t pos;
333
334 if (item->object.parsed)
335 return 1;
336
337 if (find_commit_in_graph(item, g, &pos))
338 return fill_commit_in_graph(item, g, pos);
339
340 return 0;
341 }
342
343 int parse_commit_in_graph(struct repository *r, struct commit *item)
344 {
345 if (!prepare_commit_graph(r))
346 return 0;
347 return parse_commit_in_graph_one(r->objects->commit_graph, item);
348 }
349
350 void load_commit_graph_info(struct repository *r, struct commit *item)
351 {
352 uint32_t pos;
353 if (!prepare_commit_graph(r))
354 return;
355 if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
356 fill_commit_graph_info(item, r->objects->commit_graph, pos);
357 }
358
359 static struct tree *load_tree_for_commit(struct commit_graph *g, struct commit *c)
360 {
361 struct object_id oid;
362 const unsigned char *commit_data = g->chunk_commit_data +
363 GRAPH_DATA_WIDTH * (c->graph_pos);
364
365 hashcpy(oid.hash, commit_data);
366 c->maybe_tree = lookup_tree(the_repository, &oid);
367
368 return c->maybe_tree;
369 }
370
371 static struct tree *get_commit_tree_in_graph_one(struct commit_graph *g,
372 const struct commit *c)
373 {
374 if (c->maybe_tree)
375 return c->maybe_tree;
376 if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
377 BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
378
379 return load_tree_for_commit(g, (struct commit *)c);
380 }
381
382 struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
383 {
384 return get_commit_tree_in_graph_one(r->objects->commit_graph, c);
385 }
386
387 static void write_graph_chunk_fanout(struct hashfile *f,
388 struct commit **commits,
389 int nr_commits)
390 {
391 int i, count = 0;
392 struct commit **list = commits;
393
394 /*
395 * Write the first-level table (the list is sorted,
396 * but we use a 256-entry lookup to be able to avoid
397 * having to do eight extra binary search iterations).
398 */
399 for (i = 0; i < 256; i++) {
400 while (count < nr_commits) {
401 if ((*list)->object.oid.hash[0] != i)
402 break;
403 count++;
404 list++;
405 }
406
407 hashwrite_be32(f, count);
408 }
409 }
410
411 static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
412 struct commit **commits, int nr_commits)
413 {
414 struct commit **list = commits;
415 int count;
416 for (count = 0; count < nr_commits; count++, list++)
417 hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
418 }
419
420 static const unsigned char *commit_to_sha1(size_t index, void *table)
421 {
422 struct commit **commits = table;
423 return commits[index]->object.oid.hash;
424 }
425
426 static void write_graph_chunk_data(struct hashfile *f, int hash_len,
427 struct commit **commits, int nr_commits)
428 {
429 struct commit **list = commits;
430 struct commit **last = commits + nr_commits;
431 uint32_t num_extra_edges = 0;
432
433 while (list < last) {
434 struct commit_list *parent;
435 int edge_value;
436 uint32_t packedDate[2];
437
438 parse_commit(*list);
439 hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
440
441 parent = (*list)->parents;
442
443 if (!parent)
444 edge_value = GRAPH_PARENT_NONE;
445 else {
446 edge_value = sha1_pos(parent->item->object.oid.hash,
447 commits,
448 nr_commits,
449 commit_to_sha1);
450
451 if (edge_value < 0)
452 edge_value = GRAPH_PARENT_MISSING;
453 }
454
455 hashwrite_be32(f, edge_value);
456
457 if (parent)
458 parent = parent->next;
459
460 if (!parent)
461 edge_value = GRAPH_PARENT_NONE;
462 else if (parent->next)
463 edge_value = GRAPH_OCTOPUS_EDGES_NEEDED | num_extra_edges;
464 else {
465 edge_value = sha1_pos(parent->item->object.oid.hash,
466 commits,
467 nr_commits,
468 commit_to_sha1);
469 if (edge_value < 0)
470 edge_value = GRAPH_PARENT_MISSING;
471 }
472
473 hashwrite_be32(f, edge_value);
474
475 if (edge_value & GRAPH_OCTOPUS_EDGES_NEEDED) {
476 do {
477 num_extra_edges++;
478 parent = parent->next;
479 } while (parent);
480 }
481
482 if (sizeof((*list)->date) > 4)
483 packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
484 else
485 packedDate[0] = 0;
486
487 packedDate[0] |= htonl((*list)->generation << 2);
488
489 packedDate[1] = htonl((*list)->date);
490 hashwrite(f, packedDate, 8);
491
492 list++;
493 }
494 }
495
496 static void write_graph_chunk_large_edges(struct hashfile *f,
497 struct commit **commits,
498 int nr_commits)
499 {
500 struct commit **list = commits;
501 struct commit **last = commits + nr_commits;
502 struct commit_list *parent;
503
504 while (list < last) {
505 int num_parents = 0;
506 for (parent = (*list)->parents; num_parents < 3 && parent;
507 parent = parent->next)
508 num_parents++;
509
510 if (num_parents <= 2) {
511 list++;
512 continue;
513 }
514
515 /* Since num_parents > 2, this initializer is safe. */
516 for (parent = (*list)->parents->next; parent; parent = parent->next) {
517 int edge_value = sha1_pos(parent->item->object.oid.hash,
518 commits,
519 nr_commits,
520 commit_to_sha1);
521
522 if (edge_value < 0)
523 edge_value = GRAPH_PARENT_MISSING;
524 else if (!parent->next)
525 edge_value |= GRAPH_LAST_EDGE;
526
527 hashwrite_be32(f, edge_value);
528 }
529
530 list++;
531 }
532 }
533
534 static int commit_compare(const void *_a, const void *_b)
535 {
536 const struct object_id *a = (const struct object_id *)_a;
537 const struct object_id *b = (const struct object_id *)_b;
538 return oidcmp(a, b);
539 }
540
541 struct packed_commit_list {
542 struct commit **list;
543 int nr;
544 int alloc;
545 };
546
547 struct packed_oid_list {
548 struct object_id *list;
549 int nr;
550 int alloc;
551 };
552
553 static int add_packed_commits(const struct object_id *oid,
554 struct packed_git *pack,
555 uint32_t pos,
556 void *data)
557 {
558 struct packed_oid_list *list = (struct packed_oid_list*)data;
559 enum object_type type;
560 off_t offset = nth_packed_object_offset(pack, pos);
561 struct object_info oi = OBJECT_INFO_INIT;
562
563 oi.typep = &type;
564 if (packed_object_info(the_repository, pack, offset, &oi) < 0)
565 die(_("unable to get type of object %s"), oid_to_hex(oid));
566
567 if (type != OBJ_COMMIT)
568 return 0;
569
570 ALLOC_GROW(list->list, list->nr + 1, list->alloc);
571 oidcpy(&(list->list[list->nr]), oid);
572 list->nr++;
573
574 return 0;
575 }
576
577 static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)
578 {
579 struct commit_list *parent;
580 for (parent = commit->parents; parent; parent = parent->next) {
581 if (!(parent->item->object.flags & UNINTERESTING)) {
582 ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);
583 oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));
584 oids->nr++;
585 parent->item->object.flags |= UNINTERESTING;
586 }
587 }
588 }
589
590 static void close_reachable(struct packed_oid_list *oids)
591 {
592 int i;
593 struct commit *commit;
594
595 for (i = 0; i < oids->nr; i++) {
596 commit = lookup_commit(the_repository, &oids->list[i]);
597 if (commit)
598 commit->object.flags |= UNINTERESTING;
599 }
600
601 /*
602 * As this loop runs, oids->nr may grow, but not more
603 * than the number of missing commits in the reachable
604 * closure.
605 */
606 for (i = 0; i < oids->nr; i++) {
607 commit = lookup_commit(the_repository, &oids->list[i]);
608
609 if (commit && !parse_commit(commit))
610 add_missing_parents(oids, commit);
611 }
612
613 for (i = 0; i < oids->nr; i++) {
614 commit = lookup_commit(the_repository, &oids->list[i]);
615
616 if (commit)
617 commit->object.flags &= ~UNINTERESTING;
618 }
619 }
620
621 static void compute_generation_numbers(struct packed_commit_list* commits)
622 {
623 int i;
624 struct commit_list *list = NULL;
625
626 for (i = 0; i < commits->nr; i++) {
627 if (commits->list[i]->generation != GENERATION_NUMBER_INFINITY &&
628 commits->list[i]->generation != GENERATION_NUMBER_ZERO)
629 continue;
630
631 commit_list_insert(commits->list[i], &list);
632 while (list) {
633 struct commit *current = list->item;
634 struct commit_list *parent;
635 int all_parents_computed = 1;
636 uint32_t max_generation = 0;
637
638 for (parent = current->parents; parent; parent = parent->next) {
639 if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
640 parent->item->generation == GENERATION_NUMBER_ZERO) {
641 all_parents_computed = 0;
642 commit_list_insert(parent->item, &list);
643 break;
644 } else if (parent->item->generation > max_generation) {
645 max_generation = parent->item->generation;
646 }
647 }
648
649 if (all_parents_computed) {
650 current->generation = max_generation + 1;
651 pop_commit(&list);
652
653 if (current->generation > GENERATION_NUMBER_MAX)
654 current->generation = GENERATION_NUMBER_MAX;
655 }
656 }
657 }
658 }
659
660 static int add_ref_to_list(const char *refname,
661 const struct object_id *oid,
662 int flags, void *cb_data)
663 {
664 struct string_list *list = (struct string_list *)cb_data;
665
666 string_list_append(list, oid_to_hex(oid));
667 return 0;
668 }
669
670 void write_commit_graph_reachable(const char *obj_dir, int append)
671 {
672 struct string_list list;
673
674 string_list_init(&list, 1);
675 for_each_ref(add_ref_to_list, &list);
676 write_commit_graph(obj_dir, NULL, &list, append);
677 }
678
679 void write_commit_graph(const char *obj_dir,
680 struct string_list *pack_indexes,
681 struct string_list *commit_hex,
682 int append)
683 {
684 struct packed_oid_list oids;
685 struct packed_commit_list commits;
686 struct hashfile *f;
687 uint32_t i, count_distinct = 0;
688 char *graph_name;
689 struct lock_file lk = LOCK_INIT;
690 uint32_t chunk_ids[5];
691 uint64_t chunk_offsets[5];
692 int num_chunks;
693 int num_extra_edges;
694 struct commit_list *parent;
695
696 oids.nr = 0;
697 oids.alloc = approximate_object_count() / 4;
698
699 if (append) {
700 prepare_commit_graph_one(the_repository, obj_dir);
701 if (the_repository->objects->commit_graph)
702 oids.alloc += the_repository->objects->commit_graph->num_commits;
703 }
704
705 if (oids.alloc < 1024)
706 oids.alloc = 1024;
707 ALLOC_ARRAY(oids.list, oids.alloc);
708
709 if (append && the_repository->objects->commit_graph) {
710 struct commit_graph *commit_graph =
711 the_repository->objects->commit_graph;
712 for (i = 0; i < commit_graph->num_commits; i++) {
713 const unsigned char *hash = commit_graph->chunk_oid_lookup +
714 commit_graph->hash_len * i;
715 hashcpy(oids.list[oids.nr++].hash, hash);
716 }
717 }
718
719 if (pack_indexes) {
720 struct strbuf packname = STRBUF_INIT;
721 int dirlen;
722 strbuf_addf(&packname, "%s/pack/", obj_dir);
723 dirlen = packname.len;
724 for (i = 0; i < pack_indexes->nr; i++) {
725 struct packed_git *p;
726 strbuf_setlen(&packname, dirlen);
727 strbuf_addstr(&packname, pack_indexes->items[i].string);
728 p = add_packed_git(packname.buf, packname.len, 1);
729 if (!p)
730 die(_("error adding pack %s"), packname.buf);
731 if (open_pack_index(p))
732 die(_("error opening index for %s"), packname.buf);
733 for_each_object_in_pack(p, add_packed_commits, &oids, 0);
734 close_pack(p);
735 }
736 strbuf_release(&packname);
737 }
738
739 if (commit_hex) {
740 for (i = 0; i < commit_hex->nr; i++) {
741 const char *end;
742 struct object_id oid;
743 struct commit *result;
744
745 if (commit_hex->items[i].string &&
746 parse_oid_hex(commit_hex->items[i].string, &oid, &end))
747 continue;
748
749 result = lookup_commit_reference_gently(the_repository, &oid, 1);
750
751 if (result) {
752 ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
753 oidcpy(&oids.list[oids.nr], &(result->object.oid));
754 oids.nr++;
755 }
756 }
757 }
758
759 if (!pack_indexes && !commit_hex)
760 for_each_packed_object(add_packed_commits, &oids, 0);
761
762 close_reachable(&oids);
763
764 QSORT(oids.list, oids.nr, commit_compare);
765
766 count_distinct = 1;
767 for (i = 1; i < oids.nr; i++) {
768 if (oidcmp(&oids.list[i-1], &oids.list[i]))
769 count_distinct++;
770 }
771
772 if (count_distinct >= GRAPH_PARENT_MISSING)
773 die(_("the commit graph format cannot write %d commits"), count_distinct);
774
775 commits.nr = 0;
776 commits.alloc = count_distinct;
777 ALLOC_ARRAY(commits.list, commits.alloc);
778
779 num_extra_edges = 0;
780 for (i = 0; i < oids.nr; i++) {
781 int num_parents = 0;
782 if (i > 0 && !oidcmp(&oids.list[i-1], &oids.list[i]))
783 continue;
784
785 commits.list[commits.nr] = lookup_commit(the_repository, &oids.list[i]);
786 parse_commit(commits.list[commits.nr]);
787
788 for (parent = commits.list[commits.nr]->parents;
789 parent; parent = parent->next)
790 num_parents++;
791
792 if (num_parents > 2)
793 num_extra_edges += num_parents - 1;
794
795 commits.nr++;
796 }
797 num_chunks = num_extra_edges ? 4 : 3;
798
799 if (commits.nr >= GRAPH_PARENT_MISSING)
800 die(_("too many commits to write graph"));
801
802 compute_generation_numbers(&commits);
803
804 graph_name = get_commit_graph_filename(obj_dir);
805 if (safe_create_leading_directories(graph_name))
806 die_errno(_("unable to create leading directories of %s"),
807 graph_name);
808
809 hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
810 f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
811
812 hashwrite_be32(f, GRAPH_SIGNATURE);
813
814 hashwrite_u8(f, GRAPH_VERSION);
815 hashwrite_u8(f, GRAPH_OID_VERSION);
816 hashwrite_u8(f, num_chunks);
817 hashwrite_u8(f, 0); /* unused padding byte */
818
819 chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
820 chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
821 chunk_ids[2] = GRAPH_CHUNKID_DATA;
822 if (num_extra_edges)
823 chunk_ids[3] = GRAPH_CHUNKID_LARGEEDGES;
824 else
825 chunk_ids[3] = 0;
826 chunk_ids[4] = 0;
827
828 chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
829 chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
830 chunk_offsets[2] = chunk_offsets[1] + GRAPH_OID_LEN * commits.nr;
831 chunk_offsets[3] = chunk_offsets[2] + (GRAPH_OID_LEN + 16) * commits.nr;
832 chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
833
834 for (i = 0; i <= num_chunks; i++) {
835 uint32_t chunk_write[3];
836
837 chunk_write[0] = htonl(chunk_ids[i]);
838 chunk_write[1] = htonl(chunk_offsets[i] >> 32);
839 chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
840 hashwrite(f, chunk_write, 12);
841 }
842
843 write_graph_chunk_fanout(f, commits.list, commits.nr);
844 write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr);
845 write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr);
846 write_graph_chunk_large_edges(f, commits.list, commits.nr);
847
848 close_commit_graph();
849 finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
850 commit_lock_file(&lk);
851
852 free(oids.list);
853 oids.alloc = 0;
854 oids.nr = 0;
855 }
856
857 #define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
858 static int verify_commit_graph_error;
859
860 static void graph_report(const char *fmt, ...)
861 {
862 va_list ap;
863
864 verify_commit_graph_error = 1;
865 va_start(ap, fmt);
866 vfprintf(stderr, fmt, ap);
867 fprintf(stderr, "\n");
868 va_end(ap);
869 }
870
871 #define GENERATION_ZERO_EXISTS 1
872 #define GENERATION_NUMBER_EXISTS 2
873
874 int verify_commit_graph(struct repository *r, struct commit_graph *g)
875 {
876 uint32_t i, cur_fanout_pos = 0;
877 struct object_id prev_oid, cur_oid, checksum;
878 int generation_zero = 0;
879 struct hashfile *f;
880 int devnull;
881
882 if (!g) {
883 graph_report("no commit-graph file loaded");
884 return 1;
885 }
886
887 verify_commit_graph_error = 0;
888
889 if (!g->chunk_oid_fanout)
890 graph_report("commit-graph is missing the OID Fanout chunk");
891 if (!g->chunk_oid_lookup)
892 graph_report("commit-graph is missing the OID Lookup chunk");
893 if (!g->chunk_commit_data)
894 graph_report("commit-graph is missing the Commit Data chunk");
895
896 if (verify_commit_graph_error)
897 return verify_commit_graph_error;
898
899 devnull = open("/dev/null", O_WRONLY);
900 f = hashfd(devnull, NULL);
901 hashwrite(f, g->data, g->data_len - g->hash_len);
902 finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
903 if (hashcmp(checksum.hash, g->data + g->data_len - g->hash_len)) {
904 graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
905 verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
906 }
907
908 for (i = 0; i < g->num_commits; i++) {
909 struct commit *graph_commit;
910
911 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
912
913 if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
914 graph_report("commit-graph has incorrect OID order: %s then %s",
915 oid_to_hex(&prev_oid),
916 oid_to_hex(&cur_oid));
917
918 oidcpy(&prev_oid, &cur_oid);
919
920 while (cur_oid.hash[0] > cur_fanout_pos) {
921 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
922
923 if (i != fanout_value)
924 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
925 cur_fanout_pos, fanout_value, i);
926 cur_fanout_pos++;
927 }
928
929 graph_commit = lookup_commit(r, &cur_oid);
930 if (!parse_commit_in_graph_one(g, graph_commit))
931 graph_report("failed to parse %s from commit-graph",
932 oid_to_hex(&cur_oid));
933 }
934
935 while (cur_fanout_pos < 256) {
936 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
937
938 if (g->num_commits != fanout_value)
939 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
940 cur_fanout_pos, fanout_value, i);
941
942 cur_fanout_pos++;
943 }
944
945 if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
946 return verify_commit_graph_error;
947
948 for (i = 0; i < g->num_commits; i++) {
949 struct commit *graph_commit, *odb_commit;
950 struct commit_list *graph_parents, *odb_parents;
951 uint32_t max_generation = 0;
952
953 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
954
955 graph_commit = lookup_commit(r, &cur_oid);
956 odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
957 if (parse_commit_internal(odb_commit, 0, 0)) {
958 graph_report("failed to parse %s from object database",
959 oid_to_hex(&cur_oid));
960 continue;
961 }
962
963 if (oidcmp(&get_commit_tree_in_graph_one(g, graph_commit)->object.oid,
964 get_commit_tree_oid(odb_commit)))
965 graph_report("root tree OID for commit %s in commit-graph is %s != %s",
966 oid_to_hex(&cur_oid),
967 oid_to_hex(get_commit_tree_oid(graph_commit)),
968 oid_to_hex(get_commit_tree_oid(odb_commit)));
969
970 graph_parents = graph_commit->parents;
971 odb_parents = odb_commit->parents;
972
973 while (graph_parents) {
974 if (odb_parents == NULL) {
975 graph_report("commit-graph parent list for commit %s is too long",
976 oid_to_hex(&cur_oid));
977 break;
978 }
979
980 if (oidcmp(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
981 graph_report("commit-graph parent for %s is %s != %s",
982 oid_to_hex(&cur_oid),
983 oid_to_hex(&graph_parents->item->object.oid),
984 oid_to_hex(&odb_parents->item->object.oid));
985
986 if (graph_parents->item->generation > max_generation)
987 max_generation = graph_parents->item->generation;
988
989 graph_parents = graph_parents->next;
990 odb_parents = odb_parents->next;
991 }
992
993 if (odb_parents != NULL)
994 graph_report("commit-graph parent list for commit %s terminates early",
995 oid_to_hex(&cur_oid));
996
997 if (!graph_commit->generation) {
998 if (generation_zero == GENERATION_NUMBER_EXISTS)
999 graph_report("commit-graph has generation number zero for commit %s, but non-zero elsewhere",
1000 oid_to_hex(&cur_oid));
1001 generation_zero = GENERATION_ZERO_EXISTS;
1002 } else if (generation_zero == GENERATION_ZERO_EXISTS)
1003 graph_report("commit-graph has non-zero generation number for commit %s, but zero elsewhere",
1004 oid_to_hex(&cur_oid));
1005
1006 if (generation_zero == GENERATION_ZERO_EXISTS)
1007 continue;
1008
1009 /*
1010 * If one of our parents has generation GENERATION_NUMBER_MAX, then
1011 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
1012 * extra logic in the following condition.
1013 */
1014 if (max_generation == GENERATION_NUMBER_MAX)
1015 max_generation--;
1016
1017 if (graph_commit->generation != max_generation + 1)
1018 graph_report("commit-graph generation for commit %s is %u != %u",
1019 oid_to_hex(&cur_oid),
1020 graph_commit->generation,
1021 max_generation + 1);
1022
1023 if (graph_commit->date != odb_commit->date)
1024 graph_report("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime,
1025 oid_to_hex(&cur_oid),
1026 graph_commit->date,
1027 odb_commit->date);
1028 }
1029
1030 return verify_commit_graph_error;
1031 }
1032
1033 void free_commit_graph(struct commit_graph *g)
1034 {
1035 if (!g)
1036 return;
1037 if (g->graph_fd >= 0) {
1038 munmap((void *)g->data, g->data_len);
1039 g->data = NULL;
1040 close(g->graph_fd);
1041 }
1042 free(g);
1043 }