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 "revision.h"
11#include "sha1-lookup.h"
12#include "commit-graph.h"
13#include "object-store.h"
14#include "alloc.h"
15
16#define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */
17#define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
18#define GRAPH_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
19#define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */
20#define GRAPH_CHUNKID_LARGEEDGES 0x45444745 /* "EDGE" */
21
22#define GRAPH_DATA_WIDTH 36
23
24#define GRAPH_VERSION_1 0x1
25#define GRAPH_VERSION GRAPH_VERSION_1
26
27#define GRAPH_OID_VERSION_SHA1 1
28#define GRAPH_OID_LEN_SHA1 GIT_SHA1_RAWSZ
29#define GRAPH_OID_VERSION GRAPH_OID_VERSION_SHA1
30#define GRAPH_OID_LEN GRAPH_OID_LEN_SHA1
31
32#define GRAPH_OCTOPUS_EDGES_NEEDED 0x80000000
33#define GRAPH_PARENT_MISSING 0x7fffffff
34#define GRAPH_EDGE_LAST_MASK 0x7fffffff
35#define GRAPH_PARENT_NONE 0x70000000
36
37#define GRAPH_LAST_EDGE 0x80000000
38
39#define GRAPH_HEADER_SIZE 8
40#define GRAPH_FANOUT_SIZE (4 * 256)
41#define GRAPH_CHUNKLOOKUP_WIDTH 12
42#define GRAPH_MIN_SIZE (GRAPH_HEADER_SIZE + 4 * GRAPH_CHUNKLOOKUP_WIDTH \
43 + GRAPH_FANOUT_SIZE + GRAPH_OID_LEN)
44
45char *get_commit_graph_filename(const char *obj_dir)
46{
47 return xstrfmt("%s/info/commit-graph", obj_dir);
48}
49
50static struct commit_graph *alloc_commit_graph(void)
51{
52 struct commit_graph *g = xcalloc(1, sizeof(*g));
53 g->graph_fd = -1;
54
55 return g;
56}
57
58struct commit_graph *load_commit_graph_one(const char *graph_file)
59{
60 void *graph_map;
61 const unsigned char *data, *chunk_lookup;
62 size_t graph_size;
63 struct stat st;
64 uint32_t i;
65 struct commit_graph *graph;
66 int fd = git_open(graph_file);
67 uint64_t last_chunk_offset;
68 uint32_t last_chunk_id;
69 uint32_t graph_signature;
70 unsigned char graph_version, hash_version;
71
72 if (fd < 0)
73 return NULL;
74 if (fstat(fd, &st)) {
75 close(fd);
76 return NULL;
77 }
78 graph_size = xsize_t(st.st_size);
79
80 if (graph_size < GRAPH_MIN_SIZE) {
81 close(fd);
82 die("graph file %s is too small", graph_file);
83 }
84 graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
85 data = (const unsigned char *)graph_map;
86
87 graph_signature = get_be32(data);
88 if (graph_signature != GRAPH_SIGNATURE) {
89 error("graph signature %X does not match signature %X",
90 graph_signature, GRAPH_SIGNATURE);
91 goto cleanup_fail;
92 }
93
94 graph_version = *(unsigned char*)(data + 4);
95 if (graph_version != GRAPH_VERSION) {
96 error("graph version %X does not match version %X",
97 graph_version, GRAPH_VERSION);
98 goto cleanup_fail;
99 }
100
101 hash_version = *(unsigned char*)(data + 5);
102 if (hash_version != GRAPH_OID_VERSION) {
103 error("hash version %X does not match version %X",
104 hash_version, GRAPH_OID_VERSION);
105 goto cleanup_fail;
106 }
107
108 graph = alloc_commit_graph();
109
110 graph->hash_len = GRAPH_OID_LEN;
111 graph->num_chunks = *(unsigned char*)(data + 6);
112 graph->graph_fd = fd;
113 graph->data = graph_map;
114 graph->data_len = graph_size;
115
116 last_chunk_id = 0;
117 last_chunk_offset = 8;
118 chunk_lookup = data + 8;
119 for (i = 0; i < graph->num_chunks; i++) {
120 uint32_t chunk_id = get_be32(chunk_lookup + 0);
121 uint64_t chunk_offset = get_be64(chunk_lookup + 4);
122 int chunk_repeated = 0;
123
124 chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
125
126 if (chunk_offset > graph_size - GIT_MAX_RAWSZ) {
127 error("improper chunk offset %08x%08x", (uint32_t)(chunk_offset >> 32),
128 (uint32_t)chunk_offset);
129 goto cleanup_fail;
130 }
131
132 switch (chunk_id) {
133 case GRAPH_CHUNKID_OIDFANOUT:
134 if (graph->chunk_oid_fanout)
135 chunk_repeated = 1;
136 else
137 graph->chunk_oid_fanout = (uint32_t*)(data + chunk_offset);
138 break;
139
140 case GRAPH_CHUNKID_OIDLOOKUP:
141 if (graph->chunk_oid_lookup)
142 chunk_repeated = 1;
143 else
144 graph->chunk_oid_lookup = data + chunk_offset;
145 break;
146
147 case GRAPH_CHUNKID_DATA:
148 if (graph->chunk_commit_data)
149 chunk_repeated = 1;
150 else
151 graph->chunk_commit_data = data + chunk_offset;
152 break;
153
154 case GRAPH_CHUNKID_LARGEEDGES:
155 if (graph->chunk_large_edges)
156 chunk_repeated = 1;
157 else
158 graph->chunk_large_edges = data + chunk_offset;
159 break;
160 }
161
162 if (chunk_repeated) {
163 error("chunk id %08x appears multiple times", chunk_id);
164 goto cleanup_fail;
165 }
166
167 if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)
168 {
169 graph->num_commits = (chunk_offset - last_chunk_offset)
170 / graph->hash_len;
171 }
172
173 last_chunk_id = chunk_id;
174 last_chunk_offset = chunk_offset;
175 }
176
177 return graph;
178
179cleanup_fail:
180 munmap(graph_map, graph_size);
181 close(fd);
182 exit(1);
183}
184
185/* global storage */
186static struct commit_graph *commit_graph = NULL;
187
188static void prepare_commit_graph_one(const char *obj_dir)
189{
190 char *graph_name;
191
192 if (commit_graph)
193 return;
194
195 graph_name = get_commit_graph_filename(obj_dir);
196 commit_graph = load_commit_graph_one(graph_name);
197
198 FREE_AND_NULL(graph_name);
199}
200
201static int prepare_commit_graph_run_once = 0;
202static void prepare_commit_graph(void)
203{
204 struct alternate_object_database *alt;
205 char *obj_dir;
206
207 if (prepare_commit_graph_run_once)
208 return;
209 prepare_commit_graph_run_once = 1;
210
211 obj_dir = get_object_directory();
212 prepare_commit_graph_one(obj_dir);
213 prepare_alt_odb(the_repository);
214 for (alt = the_repository->objects->alt_odb_list;
215 !commit_graph && alt;
216 alt = alt->next)
217 prepare_commit_graph_one(alt->path);
218}
219
220static void close_commit_graph(void)
221{
222 if (!commit_graph)
223 return;
224
225 if (commit_graph->graph_fd >= 0) {
226 munmap((void *)commit_graph->data, commit_graph->data_len);
227 commit_graph->data = NULL;
228 close(commit_graph->graph_fd);
229 }
230
231 FREE_AND_NULL(commit_graph);
232}
233
234static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
235{
236 return bsearch_hash(oid->hash, g->chunk_oid_fanout,
237 g->chunk_oid_lookup, g->hash_len, pos);
238}
239
240static struct commit_list **insert_parent_or_die(struct commit_graph *g,
241 uint64_t pos,
242 struct commit_list **pptr)
243{
244 struct commit *c;
245 struct object_id oid;
246
247 hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
248 c = lookup_commit(&oid);
249 if (!c)
250 die("could not find commit %s", oid_to_hex(&oid));
251 c->graph_pos = pos;
252 return &commit_list_insert(c, pptr)->next;
253}
254
255static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
256{
257 const unsigned char *commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * pos;
258 item->graph_pos = pos;
259 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
260}
261
262static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)
263{
264 uint32_t edge_value;
265 uint32_t *parent_data_ptr;
266 uint64_t date_low, date_high;
267 struct commit_list **pptr;
268 const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
269
270 item->object.parsed = 1;
271 item->graph_pos = pos;
272
273 item->maybe_tree = NULL;
274
275 date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
276 date_low = get_be32(commit_data + g->hash_len + 12);
277 item->date = (timestamp_t)((date_high << 32) | date_low);
278
279 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
280
281 pptr = &item->parents;
282
283 edge_value = get_be32(commit_data + g->hash_len);
284 if (edge_value == GRAPH_PARENT_NONE)
285 return 1;
286 pptr = insert_parent_or_die(g, edge_value, pptr);
287
288 edge_value = get_be32(commit_data + g->hash_len + 4);
289 if (edge_value == GRAPH_PARENT_NONE)
290 return 1;
291 if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {
292 pptr = insert_parent_or_die(g, edge_value, pptr);
293 return 1;
294 }
295
296 parent_data_ptr = (uint32_t*)(g->chunk_large_edges +
297 4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
298 do {
299 edge_value = get_be32(parent_data_ptr);
300 pptr = insert_parent_or_die(g,
301 edge_value & GRAPH_EDGE_LAST_MASK,
302 pptr);
303 parent_data_ptr++;
304 } while (!(edge_value & GRAPH_LAST_EDGE));
305
306 return 1;
307}
308
309static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
310{
311 if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
312 *pos = item->graph_pos;
313 return 1;
314 } else {
315 return bsearch_graph(g, &(item->object.oid), pos);
316 }
317}
318
319static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item)
320{
321 uint32_t pos;
322
323 if (!core_commit_graph)
324 return 0;
325 if (item->object.parsed)
326 return 1;
327
328 if (find_commit_in_graph(item, g, &pos))
329 return fill_commit_in_graph(item, g, pos);
330
331 return 0;
332}
333
334int parse_commit_in_graph(struct commit *item)
335{
336 if (!core_commit_graph)
337 return 0;
338
339 prepare_commit_graph();
340 if (commit_graph)
341 return parse_commit_in_graph_one(commit_graph, item);
342 return 0;
343}
344
345void load_commit_graph_info(struct commit *item)
346{
347 uint32_t pos;
348 if (!core_commit_graph)
349 return;
350 prepare_commit_graph();
351 if (commit_graph && find_commit_in_graph(item, commit_graph, &pos))
352 fill_commit_graph_info(item, commit_graph, pos);
353}
354
355static struct tree *load_tree_for_commit(struct commit_graph *g, struct commit *c)
356{
357 struct object_id oid;
358 const unsigned char *commit_data = g->chunk_commit_data +
359 GRAPH_DATA_WIDTH * (c->graph_pos);
360
361 hashcpy(oid.hash, commit_data);
362 c->maybe_tree = lookup_tree(&oid);
363
364 return c->maybe_tree;
365}
366
367static struct tree *get_commit_tree_in_graph_one(struct commit_graph *g,
368 const struct commit *c)
369{
370 if (c->maybe_tree)
371 return c->maybe_tree;
372 if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
373 BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
374
375 return load_tree_for_commit(g, (struct commit *)c);
376}
377
378struct tree *get_commit_tree_in_graph(const struct commit *c)
379{
380 return get_commit_tree_in_graph_one(commit_graph, c);
381}
382
383static void write_graph_chunk_fanout(struct hashfile *f,
384 struct commit **commits,
385 int nr_commits)
386{
387 int i, count = 0;
388 struct commit **list = commits;
389
390 /*
391 * Write the first-level table (the list is sorted,
392 * but we use a 256-entry lookup to be able to avoid
393 * having to do eight extra binary search iterations).
394 */
395 for (i = 0; i < 256; i++) {
396 while (count < nr_commits) {
397 if ((*list)->object.oid.hash[0] != i)
398 break;
399 count++;
400 list++;
401 }
402
403 hashwrite_be32(f, count);
404 }
405}
406
407static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
408 struct commit **commits, int nr_commits)
409{
410 struct commit **list = commits;
411 int count;
412 for (count = 0; count < nr_commits; count++, list++)
413 hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
414}
415
416static const unsigned char *commit_to_sha1(size_t index, void *table)
417{
418 struct commit **commits = table;
419 return commits[index]->object.oid.hash;
420}
421
422static void write_graph_chunk_data(struct hashfile *f, int hash_len,
423 struct commit **commits, int nr_commits)
424{
425 struct commit **list = commits;
426 struct commit **last = commits + nr_commits;
427 uint32_t num_extra_edges = 0;
428
429 while (list < last) {
430 struct commit_list *parent;
431 int edge_value;
432 uint32_t packedDate[2];
433
434 parse_commit(*list);
435 hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
436
437 parent = (*list)->parents;
438
439 if (!parent)
440 edge_value = GRAPH_PARENT_NONE;
441 else {
442 edge_value = sha1_pos(parent->item->object.oid.hash,
443 commits,
444 nr_commits,
445 commit_to_sha1);
446
447 if (edge_value < 0)
448 edge_value = GRAPH_PARENT_MISSING;
449 }
450
451 hashwrite_be32(f, edge_value);
452
453 if (parent)
454 parent = parent->next;
455
456 if (!parent)
457 edge_value = GRAPH_PARENT_NONE;
458 else if (parent->next)
459 edge_value = GRAPH_OCTOPUS_EDGES_NEEDED | num_extra_edges;
460 else {
461 edge_value = sha1_pos(parent->item->object.oid.hash,
462 commits,
463 nr_commits,
464 commit_to_sha1);
465 if (edge_value < 0)
466 edge_value = GRAPH_PARENT_MISSING;
467 }
468
469 hashwrite_be32(f, edge_value);
470
471 if (edge_value & GRAPH_OCTOPUS_EDGES_NEEDED) {
472 do {
473 num_extra_edges++;
474 parent = parent->next;
475 } while (parent);
476 }
477
478 if (sizeof((*list)->date) > 4)
479 packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
480 else
481 packedDate[0] = 0;
482
483 packedDate[0] |= htonl((*list)->generation << 2);
484
485 packedDate[1] = htonl((*list)->date);
486 hashwrite(f, packedDate, 8);
487
488 list++;
489 }
490}
491
492static void write_graph_chunk_large_edges(struct hashfile *f,
493 struct commit **commits,
494 int nr_commits)
495{
496 struct commit **list = commits;
497 struct commit **last = commits + nr_commits;
498 struct commit_list *parent;
499
500 while (list < last) {
501 int num_parents = 0;
502 for (parent = (*list)->parents; num_parents < 3 && parent;
503 parent = parent->next)
504 num_parents++;
505
506 if (num_parents <= 2) {
507 list++;
508 continue;
509 }
510
511 /* Since num_parents > 2, this initializer is safe. */
512 for (parent = (*list)->parents->next; parent; parent = parent->next) {
513 int edge_value = sha1_pos(parent->item->object.oid.hash,
514 commits,
515 nr_commits,
516 commit_to_sha1);
517
518 if (edge_value < 0)
519 edge_value = GRAPH_PARENT_MISSING;
520 else if (!parent->next)
521 edge_value |= GRAPH_LAST_EDGE;
522
523 hashwrite_be32(f, edge_value);
524 }
525
526 list++;
527 }
528}
529
530static int commit_compare(const void *_a, const void *_b)
531{
532 const struct object_id *a = (const struct object_id *)_a;
533 const struct object_id *b = (const struct object_id *)_b;
534 return oidcmp(a, b);
535}
536
537struct packed_commit_list {
538 struct commit **list;
539 int nr;
540 int alloc;
541};
542
543struct packed_oid_list {
544 struct object_id *list;
545 int nr;
546 int alloc;
547};
548
549static int add_packed_commits(const struct object_id *oid,
550 struct packed_git *pack,
551 uint32_t pos,
552 void *data)
553{
554 struct packed_oid_list *list = (struct packed_oid_list*)data;
555 enum object_type type;
556 off_t offset = nth_packed_object_offset(pack, pos);
557 struct object_info oi = OBJECT_INFO_INIT;
558
559 oi.typep = &type;
560 if (packed_object_info(the_repository, pack, offset, &oi) < 0)
561 die("unable to get type of object %s", oid_to_hex(oid));
562
563 if (type != OBJ_COMMIT)
564 return 0;
565
566 ALLOC_GROW(list->list, list->nr + 1, list->alloc);
567 oidcpy(&(list->list[list->nr]), oid);
568 list->nr++;
569
570 return 0;
571}
572
573static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)
574{
575 struct commit_list *parent;
576 for (parent = commit->parents; parent; parent = parent->next) {
577 if (!(parent->item->object.flags & UNINTERESTING)) {
578 ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);
579 oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));
580 oids->nr++;
581 parent->item->object.flags |= UNINTERESTING;
582 }
583 }
584}
585
586static void close_reachable(struct packed_oid_list *oids)
587{
588 int i;
589 struct commit *commit;
590
591 for (i = 0; i < oids->nr; i++) {
592 commit = lookup_commit(&oids->list[i]);
593 if (commit)
594 commit->object.flags |= UNINTERESTING;
595 }
596
597 /*
598 * As this loop runs, oids->nr may grow, but not more
599 * than the number of missing commits in the reachable
600 * closure.
601 */
602 for (i = 0; i < oids->nr; i++) {
603 commit = lookup_commit(&oids->list[i]);
604
605 if (commit && !parse_commit(commit))
606 add_missing_parents(oids, commit);
607 }
608
609 for (i = 0; i < oids->nr; i++) {
610 commit = lookup_commit(&oids->list[i]);
611
612 if (commit)
613 commit->object.flags &= ~UNINTERESTING;
614 }
615}
616
617static void compute_generation_numbers(struct packed_commit_list* commits)
618{
619 int i;
620 struct commit_list *list = NULL;
621
622 for (i = 0; i < commits->nr; i++) {
623 if (commits->list[i]->generation != GENERATION_NUMBER_INFINITY &&
624 commits->list[i]->generation != GENERATION_NUMBER_ZERO)
625 continue;
626
627 commit_list_insert(commits->list[i], &list);
628 while (list) {
629 struct commit *current = list->item;
630 struct commit_list *parent;
631 int all_parents_computed = 1;
632 uint32_t max_generation = 0;
633
634 for (parent = current->parents; parent; parent = parent->next) {
635 if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
636 parent->item->generation == GENERATION_NUMBER_ZERO) {
637 all_parents_computed = 0;
638 commit_list_insert(parent->item, &list);
639 break;
640 } else if (parent->item->generation > max_generation) {
641 max_generation = parent->item->generation;
642 }
643 }
644
645 if (all_parents_computed) {
646 current->generation = max_generation + 1;
647 pop_commit(&list);
648
649 if (current->generation > GENERATION_NUMBER_MAX)
650 current->generation = GENERATION_NUMBER_MAX;
651 }
652 }
653 }
654}
655
656void write_commit_graph(const char *obj_dir,
657 const char **pack_indexes,
658 int nr_packs,
659 const char **commit_hex,
660 int nr_commits,
661 int append)
662{
663 struct packed_oid_list oids;
664 struct packed_commit_list commits;
665 struct hashfile *f;
666 uint32_t i, count_distinct = 0;
667 char *graph_name;
668 struct lock_file lk = LOCK_INIT;
669 uint32_t chunk_ids[5];
670 uint64_t chunk_offsets[5];
671 int num_chunks;
672 int num_extra_edges;
673 struct commit_list *parent;
674
675 oids.nr = 0;
676 oids.alloc = approximate_object_count() / 4;
677
678 if (append) {
679 prepare_commit_graph_one(obj_dir);
680 if (commit_graph)
681 oids.alloc += commit_graph->num_commits;
682 }
683
684 if (oids.alloc < 1024)
685 oids.alloc = 1024;
686 ALLOC_ARRAY(oids.list, oids.alloc);
687
688 if (append && commit_graph) {
689 for (i = 0; i < commit_graph->num_commits; i++) {
690 const unsigned char *hash = commit_graph->chunk_oid_lookup +
691 commit_graph->hash_len * i;
692 hashcpy(oids.list[oids.nr++].hash, hash);
693 }
694 }
695
696 if (pack_indexes) {
697 struct strbuf packname = STRBUF_INIT;
698 int dirlen;
699 strbuf_addf(&packname, "%s/pack/", obj_dir);
700 dirlen = packname.len;
701 for (i = 0; i < nr_packs; i++) {
702 struct packed_git *p;
703 strbuf_setlen(&packname, dirlen);
704 strbuf_addstr(&packname, pack_indexes[i]);
705 p = add_packed_git(packname.buf, packname.len, 1);
706 if (!p)
707 die("error adding pack %s", packname.buf);
708 if (open_pack_index(p))
709 die("error opening index for %s", packname.buf);
710 for_each_object_in_pack(p, add_packed_commits, &oids);
711 close_pack(p);
712 }
713 strbuf_release(&packname);
714 }
715
716 if (commit_hex) {
717 for (i = 0; i < nr_commits; i++) {
718 const char *end;
719 struct object_id oid;
720 struct commit *result;
721
722 if (commit_hex[i] && parse_oid_hex(commit_hex[i], &oid, &end))
723 continue;
724
725 result = lookup_commit_reference_gently(&oid, 1);
726
727 if (result) {
728 ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
729 oidcpy(&oids.list[oids.nr], &(result->object.oid));
730 oids.nr++;
731 }
732 }
733 }
734
735 if (!pack_indexes && !commit_hex)
736 for_each_packed_object(add_packed_commits, &oids, 0);
737
738 close_reachable(&oids);
739
740 QSORT(oids.list, oids.nr, commit_compare);
741
742 count_distinct = 1;
743 for (i = 1; i < oids.nr; i++) {
744 if (oidcmp(&oids.list[i-1], &oids.list[i]))
745 count_distinct++;
746 }
747
748 if (count_distinct >= GRAPH_PARENT_MISSING)
749 die(_("the commit graph format cannot write %d commits"), count_distinct);
750
751 commits.nr = 0;
752 commits.alloc = count_distinct;
753 ALLOC_ARRAY(commits.list, commits.alloc);
754
755 num_extra_edges = 0;
756 for (i = 0; i < oids.nr; i++) {
757 int num_parents = 0;
758 if (i > 0 && !oidcmp(&oids.list[i-1], &oids.list[i]))
759 continue;
760
761 commits.list[commits.nr] = lookup_commit(&oids.list[i]);
762 parse_commit(commits.list[commits.nr]);
763
764 for (parent = commits.list[commits.nr]->parents;
765 parent; parent = parent->next)
766 num_parents++;
767
768 if (num_parents > 2)
769 num_extra_edges += num_parents - 1;
770
771 commits.nr++;
772 }
773 num_chunks = num_extra_edges ? 4 : 3;
774
775 if (commits.nr >= GRAPH_PARENT_MISSING)
776 die(_("too many commits to write graph"));
777
778 compute_generation_numbers(&commits);
779
780 graph_name = get_commit_graph_filename(obj_dir);
781 if (safe_create_leading_directories(graph_name))
782 die_errno(_("unable to create leading directories of %s"),
783 graph_name);
784
785 hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
786 f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
787
788 hashwrite_be32(f, GRAPH_SIGNATURE);
789
790 hashwrite_u8(f, GRAPH_VERSION);
791 hashwrite_u8(f, GRAPH_OID_VERSION);
792 hashwrite_u8(f, num_chunks);
793 hashwrite_u8(f, 0); /* unused padding byte */
794
795 chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
796 chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
797 chunk_ids[2] = GRAPH_CHUNKID_DATA;
798 if (num_extra_edges)
799 chunk_ids[3] = GRAPH_CHUNKID_LARGEEDGES;
800 else
801 chunk_ids[3] = 0;
802 chunk_ids[4] = 0;
803
804 chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
805 chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
806 chunk_offsets[2] = chunk_offsets[1] + GRAPH_OID_LEN * commits.nr;
807 chunk_offsets[3] = chunk_offsets[2] + (GRAPH_OID_LEN + 16) * commits.nr;
808 chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
809
810 for (i = 0; i <= num_chunks; i++) {
811 uint32_t chunk_write[3];
812
813 chunk_write[0] = htonl(chunk_ids[i]);
814 chunk_write[1] = htonl(chunk_offsets[i] >> 32);
815 chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
816 hashwrite(f, chunk_write, 12);
817 }
818
819 write_graph_chunk_fanout(f, commits.list, commits.nr);
820 write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr);
821 write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr);
822 write_graph_chunk_large_edges(f, commits.list, commits.nr);
823
824 close_commit_graph();
825 finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
826 commit_lock_file(&lk);
827
828 free(oids.list);
829 oids.alloc = 0;
830 oids.nr = 0;
831}
832
833static int verify_commit_graph_error;
834
835static void graph_report(const char *fmt, ...)
836{
837 va_list ap;
838
839 verify_commit_graph_error = 1;
840 va_start(ap, fmt);
841 vfprintf(stderr, fmt, ap);
842 fprintf(stderr, "\n");
843 va_end(ap);
844}
845
846int verify_commit_graph(struct repository *r, struct commit_graph *g)
847{
848 uint32_t i, cur_fanout_pos = 0;
849 struct object_id prev_oid, cur_oid;
850
851 if (!g) {
852 graph_report("no commit-graph file loaded");
853 return 1;
854 }
855
856 verify_commit_graph_error = 0;
857
858 if (!g->chunk_oid_fanout)
859 graph_report("commit-graph is missing the OID Fanout chunk");
860 if (!g->chunk_oid_lookup)
861 graph_report("commit-graph is missing the OID Lookup chunk");
862 if (!g->chunk_commit_data)
863 graph_report("commit-graph is missing the Commit Data chunk");
864
865 if (verify_commit_graph_error)
866 return verify_commit_graph_error;
867
868 for (i = 0; i < g->num_commits; i++) {
869 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
870
871 if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
872 graph_report("commit-graph has incorrect OID order: %s then %s",
873 oid_to_hex(&prev_oid),
874 oid_to_hex(&cur_oid));
875
876 oidcpy(&prev_oid, &cur_oid);
877
878 while (cur_oid.hash[0] > cur_fanout_pos) {
879 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
880
881 if (i != fanout_value)
882 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
883 cur_fanout_pos, fanout_value, i);
884 cur_fanout_pos++;
885 }
886 }
887
888 while (cur_fanout_pos < 256) {
889 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
890
891 if (g->num_commits != fanout_value)
892 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
893 cur_fanout_pos, fanout_value, i);
894
895 cur_fanout_pos++;
896 }
897
898 if (verify_commit_graph_error)
899 return verify_commit_graph_error;
900
901 for (i = 0; i < g->num_commits; i++) {
902 struct commit *odb_commit;
903
904 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
905
906 odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
907 if (parse_commit_internal(odb_commit, 0, 0)) {
908 graph_report("failed to parse %s from object database",
909 oid_to_hex(&cur_oid));
910 continue;
911 }
912 }
913
914 return verify_commit_graph_error;
915}