commit-graph: add free_commit_graph
[git/git.git] / commit-graph.c
CommitLineData
08fd81c9
DS
1#include "cache.h"
2#include "config.h"
33286dcd 3#include "dir.h"
08fd81c9
DS
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"
59fb8770 10#include "refs.h"
08fd81c9
DS
11#include "revision.h"
12#include "sha1-lookup.h"
13#include "commit-graph.h"
b10edb2d 14#include "object-store.h"
96af91d4 15#include "alloc.h"
08fd81c9
DS
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
0e3b97cc 40#define GRAPH_HEADER_SIZE 8
08fd81c9
DS
41#define GRAPH_FANOUT_SIZE (4 * 256)
42#define GRAPH_CHUNKLOOKUP_WIDTH 12
0e3b97cc
DS
43#define GRAPH_MIN_SIZE (GRAPH_HEADER_SIZE + 4 * GRAPH_CHUNKLOOKUP_WIDTH \
44 + GRAPH_FANOUT_SIZE + GRAPH_OID_LEN)
08fd81c9 45
2a2e32bd 46char *get_commit_graph_filename(const char *obj_dir)
08fd81c9
DS
47{
48 return xstrfmt("%s/info/commit-graph", obj_dir);
49}
50
2a2e32bd
DS
51static 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
59struct 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
180cleanup_fail:
181 munmap(graph_map, graph_size);
182 close(fd);
183 exit(1);
184}
185
177722b3
DS
186/* global storage */
187static struct commit_graph *commit_graph = NULL;
188
189static void prepare_commit_graph_one(const char *obj_dir)
190{
191 char *graph_name;
192
193 if (commit_graph)
194 return;
195
196 graph_name = get_commit_graph_filename(obj_dir);
197 commit_graph = load_commit_graph_one(graph_name);
198
199 FREE_AND_NULL(graph_name);
200}
201
202static int prepare_commit_graph_run_once = 0;
5faf357b
JT
203
204/*
205 * Return 1 if commit_graph is non-NULL, and 0 otherwise.
206 *
207 * On the first invocation, this function attemps to load the commit
208 * graph if the_repository is configured to have one.
209 */
210static int prepare_commit_graph(void)
177722b3
DS
211{
212 struct alternate_object_database *alt;
213 char *obj_dir;
214
215 if (prepare_commit_graph_run_once)
5faf357b 216 return !!commit_graph;
177722b3
DS
217 prepare_commit_graph_run_once = 1;
218
5faf357b
JT
219 if (!core_commit_graph)
220 return 0;
221
177722b3
DS
222 obj_dir = get_object_directory();
223 prepare_commit_graph_one(obj_dir);
b10edb2d
JH
224 prepare_alt_odb(the_repository);
225 for (alt = the_repository->objects->alt_odb_list;
226 !commit_graph && alt;
227 alt = alt->next)
177722b3 228 prepare_commit_graph_one(alt->path);
5faf357b 229 return !!commit_graph;
177722b3
DS
230}
231
232static void close_commit_graph(void)
233{
c3756d5b
JT
234 free_commit_graph(commit_graph);
235 commit_graph = NULL;
177722b3
DS
236}
237
238static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
239{
240 return bsearch_hash(oid->hash, g->chunk_oid_fanout,
241 g->chunk_oid_lookup, g->hash_len, pos);
242}
243
244static struct commit_list **insert_parent_or_die(struct commit_graph *g,
245 uint64_t pos,
246 struct commit_list **pptr)
247{
248 struct commit *c;
249 struct object_id oid;
96af91d4 250
53614b13
DS
251 if (pos >= g->num_commits)
252 die("invalid parent position %"PRIu64, pos);
253
177722b3 254 hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
c1f5eb49 255 c = lookup_commit(the_repository, &oid);
177722b3
DS
256 if (!c)
257 die("could not find commit %s", oid_to_hex(&oid));
258 c->graph_pos = pos;
259 return &commit_list_insert(c, pptr)->next;
260}
261
e2838d85
DS
262static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
263{
264 const unsigned char *commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * pos;
265 item->graph_pos = pos;
266 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
267}
268
177722b3
DS
269static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)
270{
177722b3
DS
271 uint32_t edge_value;
272 uint32_t *parent_data_ptr;
273 uint64_t date_low, date_high;
274 struct commit_list **pptr;
275 const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
276
277 item->object.parsed = 1;
278 item->graph_pos = pos;
279
7b8a21db 280 item->maybe_tree = NULL;
177722b3
DS
281
282 date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
283 date_low = get_be32(commit_data + g->hash_len + 12);
284 item->date = (timestamp_t)((date_high << 32) | date_low);
285
83073cc9
DS
286 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
287
177722b3
DS
288 pptr = &item->parents;
289
290 edge_value = get_be32(commit_data + g->hash_len);
291 if (edge_value == GRAPH_PARENT_NONE)
292 return 1;
293 pptr = insert_parent_or_die(g, edge_value, pptr);
294
295 edge_value = get_be32(commit_data + g->hash_len + 4);
296 if (edge_value == GRAPH_PARENT_NONE)
297 return 1;
298 if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {
299 pptr = insert_parent_or_die(g, edge_value, pptr);
300 return 1;
301 }
302
303 parent_data_ptr = (uint32_t*)(g->chunk_large_edges +
304 4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
305 do {
306 edge_value = get_be32(parent_data_ptr);
307 pptr = insert_parent_or_die(g,
308 edge_value & GRAPH_EDGE_LAST_MASK,
309 pptr);
310 parent_data_ptr++;
311 } while (!(edge_value & GRAPH_LAST_EDGE));
312
313 return 1;
314}
315
e2838d85
DS
316static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
317{
318 if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
319 *pos = item->graph_pos;
320 return 1;
321 } else {
322 return bsearch_graph(g, &(item->object.oid), pos);
323 }
324}
325
ee797053 326static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item)
177722b3 327{
e2838d85
DS
328 uint32_t pos;
329
177722b3
DS
330 if (!core_commit_graph)
331 return 0;
332 if (item->object.parsed)
333 return 1;
ee797053
DS
334
335 if (find_commit_in_graph(item, g, &pos))
336 return fill_commit_in_graph(item, g, pos);
337
338 return 0;
339}
340
341int parse_commit_in_graph(struct commit *item)
342{
5faf357b 343 if (!prepare_commit_graph())
ee797053 344 return 0;
5faf357b 345 return parse_commit_in_graph_one(commit_graph, item);
177722b3
DS
346}
347
e2838d85
DS
348void load_commit_graph_info(struct commit *item)
349{
350 uint32_t pos;
5faf357b 351 if (!prepare_commit_graph())
e2838d85 352 return;
5faf357b 353 if (find_commit_in_graph(item, commit_graph, &pos))
e2838d85
DS
354 fill_commit_graph_info(item, commit_graph, pos);
355}
356
7b8a21db
DS
357static struct tree *load_tree_for_commit(struct commit_graph *g, struct commit *c)
358{
359 struct object_id oid;
360 const unsigned char *commit_data = g->chunk_commit_data +
361 GRAPH_DATA_WIDTH * (c->graph_pos);
362
363 hashcpy(oid.hash, commit_data);
f86bcc7b 364 c->maybe_tree = lookup_tree(the_repository, &oid);
7b8a21db
DS
365
366 return c->maybe_tree;
367}
368
0cbef8f8
DS
369static struct tree *get_commit_tree_in_graph_one(struct commit_graph *g,
370 const struct commit *c)
7b8a21db
DS
371{
372 if (c->maybe_tree)
373 return c->maybe_tree;
374 if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
0cbef8f8
DS
375 BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
376
377 return load_tree_for_commit(g, (struct commit *)c);
378}
7b8a21db 379
0cbef8f8
DS
380struct tree *get_commit_tree_in_graph(const struct commit *c)
381{
382 return get_commit_tree_in_graph_one(commit_graph, c);
7b8a21db
DS
383}
384
08fd81c9
DS
385static void write_graph_chunk_fanout(struct hashfile *f,
386 struct commit **commits,
387 int nr_commits)
388{
389 int i, count = 0;
390 struct commit **list = commits;
391
392 /*
393 * Write the first-level table (the list is sorted,
394 * but we use a 256-entry lookup to be able to avoid
395 * having to do eight extra binary search iterations).
396 */
397 for (i = 0; i < 256; i++) {
398 while (count < nr_commits) {
399 if ((*list)->object.oid.hash[0] != i)
400 break;
401 count++;
402 list++;
403 }
404
405 hashwrite_be32(f, count);
406 }
407}
408
409static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
410 struct commit **commits, int nr_commits)
411{
412 struct commit **list = commits;
413 int count;
414 for (count = 0; count < nr_commits; count++, list++)
415 hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
416}
417
418static const unsigned char *commit_to_sha1(size_t index, void *table)
419{
420 struct commit **commits = table;
421 return commits[index]->object.oid.hash;
422}
423
424static void write_graph_chunk_data(struct hashfile *f, int hash_len,
425 struct commit **commits, int nr_commits)
426{
427 struct commit **list = commits;
428 struct commit **last = commits + nr_commits;
429 uint32_t num_extra_edges = 0;
430
431 while (list < last) {
432 struct commit_list *parent;
433 int edge_value;
434 uint32_t packedDate[2];
435
436 parse_commit(*list);
2e27bd77 437 hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
08fd81c9
DS
438
439 parent = (*list)->parents;
440
441 if (!parent)
442 edge_value = GRAPH_PARENT_NONE;
443 else {
444 edge_value = sha1_pos(parent->item->object.oid.hash,
445 commits,
446 nr_commits,
447 commit_to_sha1);
448
449 if (edge_value < 0)
450 edge_value = GRAPH_PARENT_MISSING;
451 }
452
453 hashwrite_be32(f, edge_value);
454
455 if (parent)
456 parent = parent->next;
457
458 if (!parent)
459 edge_value = GRAPH_PARENT_NONE;
460 else if (parent->next)
461 edge_value = GRAPH_OCTOPUS_EDGES_NEEDED | num_extra_edges;
462 else {
463 edge_value = sha1_pos(parent->item->object.oid.hash,
464 commits,
465 nr_commits,
466 commit_to_sha1);
467 if (edge_value < 0)
468 edge_value = GRAPH_PARENT_MISSING;
469 }
470
471 hashwrite_be32(f, edge_value);
472
473 if (edge_value & GRAPH_OCTOPUS_EDGES_NEEDED) {
474 do {
475 num_extra_edges++;
476 parent = parent->next;
477 } while (parent);
478 }
479
480 if (sizeof((*list)->date) > 4)
481 packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
482 else
483 packedDate[0] = 0;
484
3258c663
DS
485 packedDate[0] |= htonl((*list)->generation << 2);
486
08fd81c9
DS
487 packedDate[1] = htonl((*list)->date);
488 hashwrite(f, packedDate, 8);
489
490 list++;
491 }
492}
493
494static void write_graph_chunk_large_edges(struct hashfile *f,
495 struct commit **commits,
496 int nr_commits)
497{
498 struct commit **list = commits;
499 struct commit **last = commits + nr_commits;
500 struct commit_list *parent;
501
502 while (list < last) {
503 int num_parents = 0;
504 for (parent = (*list)->parents; num_parents < 3 && parent;
505 parent = parent->next)
506 num_parents++;
507
508 if (num_parents <= 2) {
509 list++;
510 continue;
511 }
512
513 /* Since num_parents > 2, this initializer is safe. */
514 for (parent = (*list)->parents->next; parent; parent = parent->next) {
515 int edge_value = sha1_pos(parent->item->object.oid.hash,
516 commits,
517 nr_commits,
518 commit_to_sha1);
519
520 if (edge_value < 0)
521 edge_value = GRAPH_PARENT_MISSING;
522 else if (!parent->next)
523 edge_value |= GRAPH_LAST_EDGE;
524
525 hashwrite_be32(f, edge_value);
526 }
527
528 list++;
529 }
530}
531
532static int commit_compare(const void *_a, const void *_b)
533{
534 const struct object_id *a = (const struct object_id *)_a;
535 const struct object_id *b = (const struct object_id *)_b;
536 return oidcmp(a, b);
537}
538
539struct packed_commit_list {
540 struct commit **list;
541 int nr;
542 int alloc;
543};
544
545struct packed_oid_list {
546 struct object_id *list;
547 int nr;
548 int alloc;
549};
550
551static int add_packed_commits(const struct object_id *oid,
552 struct packed_git *pack,
553 uint32_t pos,
554 void *data)
555{
556 struct packed_oid_list *list = (struct packed_oid_list*)data;
557 enum object_type type;
558 off_t offset = nth_packed_object_offset(pack, pos);
559 struct object_info oi = OBJECT_INFO_INIT;
560
561 oi.typep = &type;
fcb6df32 562 if (packed_object_info(the_repository, pack, offset, &oi) < 0)
08fd81c9
DS
563 die("unable to get type of object %s", oid_to_hex(oid));
564
565 if (type != OBJ_COMMIT)
566 return 0;
567
568 ALLOC_GROW(list->list, list->nr + 1, list->alloc);
569 oidcpy(&(list->list[list->nr]), oid);
570 list->nr++;
571
572 return 0;
573}
574
4f2542b4
DS
575static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)
576{
577 struct commit_list *parent;
578 for (parent = commit->parents; parent; parent = parent->next) {
579 if (!(parent->item->object.flags & UNINTERESTING)) {
580 ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);
581 oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));
582 oids->nr++;
583 parent->item->object.flags |= UNINTERESTING;
584 }
585 }
586}
587
588static void close_reachable(struct packed_oid_list *oids)
589{
590 int i;
591 struct commit *commit;
592
593 for (i = 0; i < oids->nr; i++) {
c1f5eb49 594 commit = lookup_commit(the_repository, &oids->list[i]);
4f2542b4
DS
595 if (commit)
596 commit->object.flags |= UNINTERESTING;
597 }
598
599 /*
600 * As this loop runs, oids->nr may grow, but not more
601 * than the number of missing commits in the reachable
602 * closure.
603 */
604 for (i = 0; i < oids->nr; i++) {
c1f5eb49 605 commit = lookup_commit(the_repository, &oids->list[i]);
4f2542b4
DS
606
607 if (commit && !parse_commit(commit))
608 add_missing_parents(oids, commit);
609 }
610
611 for (i = 0; i < oids->nr; i++) {
c1f5eb49 612 commit = lookup_commit(the_repository, &oids->list[i]);
4f2542b4
DS
613
614 if (commit)
615 commit->object.flags &= ~UNINTERESTING;
616 }
617}
618
3258c663
DS
619static void compute_generation_numbers(struct packed_commit_list* commits)
620{
621 int i;
622 struct commit_list *list = NULL;
623
624 for (i = 0; i < commits->nr; i++) {
625 if (commits->list[i]->generation != GENERATION_NUMBER_INFINITY &&
626 commits->list[i]->generation != GENERATION_NUMBER_ZERO)
627 continue;
628
629 commit_list_insert(commits->list[i], &list);
630 while (list) {
631 struct commit *current = list->item;
632 struct commit_list *parent;
633 int all_parents_computed = 1;
634 uint32_t max_generation = 0;
635
636 for (parent = current->parents; parent; parent = parent->next) {
637 if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
638 parent->item->generation == GENERATION_NUMBER_ZERO) {
639 all_parents_computed = 0;
640 commit_list_insert(parent->item, &list);
641 break;
642 } else if (parent->item->generation > max_generation) {
643 max_generation = parent->item->generation;
644 }
645 }
646
647 if (all_parents_computed) {
648 current->generation = max_generation + 1;
649 pop_commit(&list);
650
651 if (current->generation > GENERATION_NUMBER_MAX)
652 current->generation = GENERATION_NUMBER_MAX;
653 }
654 }
655 }
656}
657
59fb8770
DS
658static int add_ref_to_list(const char *refname,
659 const struct object_id *oid,
660 int flags, void *cb_data)
661{
662 struct string_list *list = (struct string_list *)cb_data;
663
664 string_list_append(list, oid_to_hex(oid));
665 return 0;
666}
667
668void write_commit_graph_reachable(const char *obj_dir, int append)
669{
670 struct string_list list;
671
672 string_list_init(&list, 1);
673 for_each_ref(add_ref_to_list, &list);
674 write_commit_graph(obj_dir, NULL, &list, append);
675}
676
049d51a2 677void write_commit_graph(const char *obj_dir,
d88b14b3
DS
678 struct string_list *pack_indexes,
679 struct string_list *commit_hex,
7547b95b 680 int append)
08fd81c9
DS
681{
682 struct packed_oid_list oids;
683 struct packed_commit_list commits;
684 struct hashfile *f;
685 uint32_t i, count_distinct = 0;
686 char *graph_name;
08fd81c9
DS
687 struct lock_file lk = LOCK_INIT;
688 uint32_t chunk_ids[5];
689 uint64_t chunk_offsets[5];
690 int num_chunks;
691 int num_extra_edges;
692 struct commit_list *parent;
693
694 oids.nr = 0;
695 oids.alloc = approximate_object_count() / 4;
696
7547b95b
DS
697 if (append) {
698 prepare_commit_graph_one(obj_dir);
699 if (commit_graph)
700 oids.alloc += commit_graph->num_commits;
701 }
702
08fd81c9
DS
703 if (oids.alloc < 1024)
704 oids.alloc = 1024;
705 ALLOC_ARRAY(oids.list, oids.alloc);
706
7547b95b
DS
707 if (append && commit_graph) {
708 for (i = 0; i < commit_graph->num_commits; i++) {
709 const unsigned char *hash = commit_graph->chunk_oid_lookup +
710 commit_graph->hash_len * i;
711 hashcpy(oids.list[oids.nr++].hash, hash);
712 }
713 }
714
049d51a2
DS
715 if (pack_indexes) {
716 struct strbuf packname = STRBUF_INIT;
717 int dirlen;
718 strbuf_addf(&packname, "%s/pack/", obj_dir);
719 dirlen = packname.len;
d88b14b3 720 for (i = 0; i < pack_indexes->nr; i++) {
049d51a2
DS
721 struct packed_git *p;
722 strbuf_setlen(&packname, dirlen);
d88b14b3 723 strbuf_addstr(&packname, pack_indexes->items[i].string);
049d51a2
DS
724 p = add_packed_git(packname.buf, packname.len, 1);
725 if (!p)
726 die("error adding pack %s", packname.buf);
727 if (open_pack_index(p))
728 die("error opening index for %s", packname.buf);
729 for_each_object_in_pack(p, add_packed_commits, &oids);
730 close_pack(p);
731 }
732 strbuf_release(&packname);
3d5df01b
DS
733 }
734
735 if (commit_hex) {
d88b14b3 736 for (i = 0; i < commit_hex->nr; i++) {
3d5df01b
DS
737 const char *end;
738 struct object_id oid;
739 struct commit *result;
740
d88b14b3
DS
741 if (commit_hex->items[i].string &&
742 parse_oid_hex(commit_hex->items[i].string, &oid, &end))
3d5df01b
DS
743 continue;
744
21e1ee8f 745 result = lookup_commit_reference_gently(the_repository, &oid, 1);
3d5df01b
DS
746
747 if (result) {
748 ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
749 oidcpy(&oids.list[oids.nr], &(result->object.oid));
750 oids.nr++;
751 }
752 }
753 }
754
755 if (!pack_indexes && !commit_hex)
049d51a2
DS
756 for_each_packed_object(add_packed_commits, &oids, 0);
757
4f2542b4 758 close_reachable(&oids);
08fd81c9
DS
759
760 QSORT(oids.list, oids.nr, commit_compare);
761
762 count_distinct = 1;
763 for (i = 1; i < oids.nr; i++) {
764 if (oidcmp(&oids.list[i-1], &oids.list[i]))
765 count_distinct++;
766 }
767
768 if (count_distinct >= GRAPH_PARENT_MISSING)
769 die(_("the commit graph format cannot write %d commits"), count_distinct);
770
771 commits.nr = 0;
772 commits.alloc = count_distinct;
773 ALLOC_ARRAY(commits.list, commits.alloc);
774
775 num_extra_edges = 0;
776 for (i = 0; i < oids.nr; i++) {
777 int num_parents = 0;
778 if (i > 0 && !oidcmp(&oids.list[i-1], &oids.list[i]))
779 continue;
780
c1f5eb49 781 commits.list[commits.nr] = lookup_commit(the_repository, &oids.list[i]);
08fd81c9
DS
782 parse_commit(commits.list[commits.nr]);
783
784 for (parent = commits.list[commits.nr]->parents;
785 parent; parent = parent->next)
786 num_parents++;
787
788 if (num_parents > 2)
789 num_extra_edges += num_parents - 1;
790
791 commits.nr++;
792 }
793 num_chunks = num_extra_edges ? 4 : 3;
794
795 if (commits.nr >= GRAPH_PARENT_MISSING)
796 die(_("too many commits to write graph"));
797
3258c663 798 compute_generation_numbers(&commits);
08fd81c9 799
08fd81c9 800 graph_name = get_commit_graph_filename(obj_dir);
33286dcd
DS
801 if (safe_create_leading_directories(graph_name))
802 die_errno(_("unable to create leading directories of %s"),
803 graph_name);
08fd81c9 804
33286dcd 805 hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
08fd81c9
DS
806 f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
807
808 hashwrite_be32(f, GRAPH_SIGNATURE);
809
810 hashwrite_u8(f, GRAPH_VERSION);
811 hashwrite_u8(f, GRAPH_OID_VERSION);
812 hashwrite_u8(f, num_chunks);
813 hashwrite_u8(f, 0); /* unused padding byte */
814
815 chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
816 chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
817 chunk_ids[2] = GRAPH_CHUNKID_DATA;
818 if (num_extra_edges)
819 chunk_ids[3] = GRAPH_CHUNKID_LARGEEDGES;
820 else
821 chunk_ids[3] = 0;
822 chunk_ids[4] = 0;
823
824 chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
825 chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
826 chunk_offsets[2] = chunk_offsets[1] + GRAPH_OID_LEN * commits.nr;
827 chunk_offsets[3] = chunk_offsets[2] + (GRAPH_OID_LEN + 16) * commits.nr;
828 chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
829
830 for (i = 0; i <= num_chunks; i++) {
831 uint32_t chunk_write[3];
832
833 chunk_write[0] = htonl(chunk_ids[i]);
834 chunk_write[1] = htonl(chunk_offsets[i] >> 32);
835 chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
836 hashwrite(f, chunk_write, 12);
837 }
838
839 write_graph_chunk_fanout(f, commits.list, commits.nr);
840 write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr);
841 write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr);
842 write_graph_chunk_large_edges(f, commits.list, commits.nr);
843
177722b3 844 close_commit_graph();
08fd81c9
DS
845 finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
846 commit_lock_file(&lk);
847
848 free(oids.list);
849 oids.alloc = 0;
850 oids.nr = 0;
851}
283e68c7 852
41df0e30 853#define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
283e68c7
DS
854static int verify_commit_graph_error;
855
856static void graph_report(const char *fmt, ...)
857{
858 va_list ap;
859
860 verify_commit_graph_error = 1;
861 va_start(ap, fmt);
862 vfprintf(stderr, fmt, ap);
863 fprintf(stderr, "\n");
864 va_end(ap);
865}
866
1373e547
DS
867#define GENERATION_ZERO_EXISTS 1
868#define GENERATION_NUMBER_EXISTS 2
869
283e68c7
DS
870int verify_commit_graph(struct repository *r, struct commit_graph *g)
871{
9bda8467 872 uint32_t i, cur_fanout_pos = 0;
41df0e30 873 struct object_id prev_oid, cur_oid, checksum;
1373e547 874 int generation_zero = 0;
41df0e30
DS
875 struct hashfile *f;
876 int devnull;
9bda8467 877
283e68c7
DS
878 if (!g) {
879 graph_report("no commit-graph file loaded");
880 return 1;
881 }
882
2bd0365f
DS
883 verify_commit_graph_error = 0;
884
885 if (!g->chunk_oid_fanout)
886 graph_report("commit-graph is missing the OID Fanout chunk");
887 if (!g->chunk_oid_lookup)
888 graph_report("commit-graph is missing the OID Lookup chunk");
889 if (!g->chunk_commit_data)
890 graph_report("commit-graph is missing the Commit Data chunk");
891
9bda8467
DS
892 if (verify_commit_graph_error)
893 return verify_commit_graph_error;
894
41df0e30
DS
895 devnull = open("/dev/null", O_WRONLY);
896 f = hashfd(devnull, NULL);
897 hashwrite(f, g->data, g->data_len - g->hash_len);
898 finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
899 if (hashcmp(checksum.hash, g->data + g->data_len - g->hash_len)) {
900 graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
901 verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
902 }
903
9bda8467 904 for (i = 0; i < g->num_commits; i++) {
2e3c0737
DS
905 struct commit *graph_commit;
906
9bda8467
DS
907 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
908
909 if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
910 graph_report("commit-graph has incorrect OID order: %s then %s",
911 oid_to_hex(&prev_oid),
912 oid_to_hex(&cur_oid));
913
914 oidcpy(&prev_oid, &cur_oid);
915
916 while (cur_oid.hash[0] > cur_fanout_pos) {
917 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
918
919 if (i != fanout_value)
920 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
921 cur_fanout_pos, fanout_value, i);
922 cur_fanout_pos++;
923 }
2e3c0737 924
82952964 925 graph_commit = lookup_commit(r, &cur_oid);
2e3c0737
DS
926 if (!parse_commit_in_graph_one(g, graph_commit))
927 graph_report("failed to parse %s from commit-graph",
928 oid_to_hex(&cur_oid));
9bda8467
DS
929 }
930
931 while (cur_fanout_pos < 256) {
932 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
933
934 if (g->num_commits != fanout_value)
935 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
936 cur_fanout_pos, fanout_value, i);
937
938 cur_fanout_pos++;
939 }
940
41df0e30 941 if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
96af91d4
DS
942 return verify_commit_graph_error;
943
944 for (i = 0; i < g->num_commits; i++) {
2e3c0737 945 struct commit *graph_commit, *odb_commit;
53614b13 946 struct commit_list *graph_parents, *odb_parents;
1373e547 947 uint32_t max_generation = 0;
96af91d4
DS
948
949 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
950
82952964 951 graph_commit = lookup_commit(r, &cur_oid);
96af91d4
DS
952 odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
953 if (parse_commit_internal(odb_commit, 0, 0)) {
954 graph_report("failed to parse %s from object database",
955 oid_to_hex(&cur_oid));
956 continue;
957 }
2e3c0737
DS
958
959 if (oidcmp(&get_commit_tree_in_graph_one(g, graph_commit)->object.oid,
960 get_commit_tree_oid(odb_commit)))
961 graph_report("root tree OID for commit %s in commit-graph is %s != %s",
962 oid_to_hex(&cur_oid),
963 oid_to_hex(get_commit_tree_oid(graph_commit)),
964 oid_to_hex(get_commit_tree_oid(odb_commit)));
53614b13
DS
965
966 graph_parents = graph_commit->parents;
967 odb_parents = odb_commit->parents;
968
969 while (graph_parents) {
970 if (odb_parents == NULL) {
971 graph_report("commit-graph parent list for commit %s is too long",
972 oid_to_hex(&cur_oid));
973 break;
974 }
975
976 if (oidcmp(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
977 graph_report("commit-graph parent for %s is %s != %s",
978 oid_to_hex(&cur_oid),
979 oid_to_hex(&graph_parents->item->object.oid),
980 oid_to_hex(&odb_parents->item->object.oid));
981
1373e547
DS
982 if (graph_parents->item->generation > max_generation)
983 max_generation = graph_parents->item->generation;
984
53614b13
DS
985 graph_parents = graph_parents->next;
986 odb_parents = odb_parents->next;
987 }
988
989 if (odb_parents != NULL)
990 graph_report("commit-graph parent list for commit %s terminates early",
991 oid_to_hex(&cur_oid));
1373e547
DS
992
993 if (!graph_commit->generation) {
994 if (generation_zero == GENERATION_NUMBER_EXISTS)
995 graph_report("commit-graph has generation number zero for commit %s, but non-zero elsewhere",
996 oid_to_hex(&cur_oid));
997 generation_zero = GENERATION_ZERO_EXISTS;
998 } else if (generation_zero == GENERATION_ZERO_EXISTS)
999 graph_report("commit-graph has non-zero generation number for commit %s, but zero elsewhere",
1000 oid_to_hex(&cur_oid));
1001
1002 if (generation_zero == GENERATION_ZERO_EXISTS)
1003 continue;
1004
1005 /*
1006 * If one of our parents has generation GENERATION_NUMBER_MAX, then
1007 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
1008 * extra logic in the following condition.
1009 */
1010 if (max_generation == GENERATION_NUMBER_MAX)
1011 max_generation--;
1012
1013 if (graph_commit->generation != max_generation + 1)
1014 graph_report("commit-graph generation for commit %s is %u != %u",
1015 oid_to_hex(&cur_oid),
1016 graph_commit->generation,
1017 max_generation + 1);
88968ebf
DS
1018
1019 if (graph_commit->date != odb_commit->date)
1020 graph_report("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime,
1021 oid_to_hex(&cur_oid),
1022 graph_commit->date,
1023 odb_commit->date);
96af91d4
DS
1024 }
1025
283e68c7
DS
1026 return verify_commit_graph_error;
1027}
c3756d5b
JT
1028
1029void free_commit_graph(struct commit_graph *g)
1030{
1031 if (!g)
1032 return;
1033 if (g->graph_fd >= 0) {
1034 munmap((void *)g->data, g->data_len);
1035 g->data = NULL;
1036 close(g->graph_fd);
1037 }
1038 free(g);
1039}