commit-graph: define GIT_TEST_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);
4f5b532d 83 die(_("graph file %s is too small"), graph_file);
2a2e32bd
DS
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) {
4f5b532d 90 error(_("graph signature %X does not match signature %X"),
2a2e32bd
DS
91 graph_signature, GRAPH_SIGNATURE);
92 goto cleanup_fail;
93 }
94
95 graph_version = *(unsigned char*)(data + 4);
96 if (graph_version != GRAPH_VERSION) {
4f5b532d 97 error(_("graph version %X does not match version %X"),
2a2e32bd
DS
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) {
4f5b532d 104 error(_("hash version %X does not match version %X"),
2a2e32bd
DS
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) {
4f5b532d 128 error(_("improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),
2a2e32bd
DS
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) {
4f5b532d 164 error(_("chunk id %08x appears multiple times"), chunk_id);
2a2e32bd
DS
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
dade47c0 186static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
177722b3
DS
187{
188 char *graph_name;
189
dade47c0 190 if (r->objects->commit_graph)
177722b3
DS
191 return;
192
193 graph_name = get_commit_graph_filename(obj_dir);
dade47c0 194 r->objects->commit_graph =
85277506 195 load_commit_graph_one(graph_name);
177722b3
DS
196
197 FREE_AND_NULL(graph_name);
198}
199
5faf357b
JT
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 */
dade47c0 206static int prepare_commit_graph(struct repository *r)
177722b3
DS
207{
208 struct alternate_object_database *alt;
209 char *obj_dir;
dade47c0
JT
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
859fdc0c
DS
216 if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
217 (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
218 !config_value))
dade47c0
JT
219 /*
220 * This repository is not configured to use commit graphs, so
221 * do not load one. (But report commit_graph_attempted anyway
222 * so that commit graph loading is not attempted again for this
223 * repository.)
224 */
5faf357b
JT
225 return 0;
226
dade47c0
JT
227 obj_dir = r->objects->objectdir;
228 prepare_commit_graph_one(r, obj_dir);
229 prepare_alt_odb(r);
230 for (alt = r->objects->alt_odb_list;
231 !r->objects->commit_graph && alt;
b10edb2d 232 alt = alt->next)
dade47c0
JT
233 prepare_commit_graph_one(r, alt->path);
234 return !!r->objects->commit_graph;
177722b3
DS
235}
236
237static void close_commit_graph(void)
238{
85277506
JT
239 free_commit_graph(the_repository->objects->commit_graph);
240 the_repository->objects->commit_graph = NULL;
177722b3
DS
241}
242
243static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
244{
245 return bsearch_hash(oid->hash, g->chunk_oid_fanout,
246 g->chunk_oid_lookup, g->hash_len, pos);
247}
248
249static struct commit_list **insert_parent_or_die(struct commit_graph *g,
250 uint64_t pos,
251 struct commit_list **pptr)
252{
253 struct commit *c;
254 struct object_id oid;
96af91d4 255
53614b13
DS
256 if (pos >= g->num_commits)
257 die("invalid parent position %"PRIu64, pos);
258
177722b3 259 hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
c1f5eb49 260 c = lookup_commit(the_repository, &oid);
177722b3 261 if (!c)
4f5b532d 262 die(_("could not find commit %s"), oid_to_hex(&oid));
177722b3
DS
263 c->graph_pos = pos;
264 return &commit_list_insert(c, pptr)->next;
265}
266
e2838d85
DS
267static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
268{
269 const unsigned char *commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * pos;
270 item->graph_pos = pos;
271 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
272}
273
177722b3
DS
274static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)
275{
177722b3
DS
276 uint32_t edge_value;
277 uint32_t *parent_data_ptr;
278 uint64_t date_low, date_high;
279 struct commit_list **pptr;
280 const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
281
282 item->object.parsed = 1;
283 item->graph_pos = pos;
284
7b8a21db 285 item->maybe_tree = NULL;
177722b3
DS
286
287 date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
288 date_low = get_be32(commit_data + g->hash_len + 12);
289 item->date = (timestamp_t)((date_high << 32) | date_low);
290
83073cc9
DS
291 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
292
177722b3
DS
293 pptr = &item->parents;
294
295 edge_value = get_be32(commit_data + g->hash_len);
296 if (edge_value == GRAPH_PARENT_NONE)
297 return 1;
298 pptr = insert_parent_or_die(g, edge_value, pptr);
299
300 edge_value = get_be32(commit_data + g->hash_len + 4);
301 if (edge_value == GRAPH_PARENT_NONE)
302 return 1;
303 if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {
304 pptr = insert_parent_or_die(g, edge_value, pptr);
305 return 1;
306 }
307
308 parent_data_ptr = (uint32_t*)(g->chunk_large_edges +
309 4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
310 do {
311 edge_value = get_be32(parent_data_ptr);
312 pptr = insert_parent_or_die(g,
313 edge_value & GRAPH_EDGE_LAST_MASK,
314 pptr);
315 parent_data_ptr++;
316 } while (!(edge_value & GRAPH_LAST_EDGE));
317
318 return 1;
319}
320
e2838d85
DS
321static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
322{
323 if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
324 *pos = item->graph_pos;
325 return 1;
326 } else {
327 return bsearch_graph(g, &(item->object.oid), pos);
328 }
329}
330
ee797053 331static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item)
177722b3 332{
e2838d85
DS
333 uint32_t pos;
334
177722b3
DS
335 if (item->object.parsed)
336 return 1;
ee797053
DS
337
338 if (find_commit_in_graph(item, g, &pos))
339 return fill_commit_in_graph(item, g, pos);
340
341 return 0;
342}
343
dade47c0 344int parse_commit_in_graph(struct repository *r, struct commit *item)
ee797053 345{
dade47c0 346 if (!prepare_commit_graph(r))
ee797053 347 return 0;
dade47c0 348 return parse_commit_in_graph_one(r->objects->commit_graph, item);
177722b3
DS
349}
350
dade47c0 351void load_commit_graph_info(struct repository *r, struct commit *item)
e2838d85
DS
352{
353 uint32_t pos;
dade47c0 354 if (!prepare_commit_graph(r))
e2838d85 355 return;
dade47c0
JT
356 if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
357 fill_commit_graph_info(item, r->objects->commit_graph, pos);
e2838d85
DS
358}
359
7b8a21db
DS
360static struct tree *load_tree_for_commit(struct commit_graph *g, struct commit *c)
361{
362 struct object_id oid;
363 const unsigned char *commit_data = g->chunk_commit_data +
364 GRAPH_DATA_WIDTH * (c->graph_pos);
365
366 hashcpy(oid.hash, commit_data);
f86bcc7b 367 c->maybe_tree = lookup_tree(the_repository, &oid);
7b8a21db
DS
368
369 return c->maybe_tree;
370}
371
0cbef8f8
DS
372static struct tree *get_commit_tree_in_graph_one(struct commit_graph *g,
373 const struct commit *c)
7b8a21db
DS
374{
375 if (c->maybe_tree)
376 return c->maybe_tree;
377 if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
0cbef8f8
DS
378 BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
379
380 return load_tree_for_commit(g, (struct commit *)c);
381}
7b8a21db 382
dade47c0 383struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
0cbef8f8 384{
dade47c0 385 return get_commit_tree_in_graph_one(r->objects->commit_graph, c);
7b8a21db
DS
386}
387
08fd81c9
DS
388static void write_graph_chunk_fanout(struct hashfile *f,
389 struct commit **commits,
390 int nr_commits)
391{
392 int i, count = 0;
393 struct commit **list = commits;
394
395 /*
396 * Write the first-level table (the list is sorted,
397 * but we use a 256-entry lookup to be able to avoid
398 * having to do eight extra binary search iterations).
399 */
400 for (i = 0; i < 256; i++) {
401 while (count < nr_commits) {
402 if ((*list)->object.oid.hash[0] != i)
403 break;
404 count++;
405 list++;
406 }
407
408 hashwrite_be32(f, count);
409 }
410}
411
412static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
413 struct commit **commits, int nr_commits)
414{
415 struct commit **list = commits;
416 int count;
417 for (count = 0; count < nr_commits; count++, list++)
418 hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
419}
420
421static const unsigned char *commit_to_sha1(size_t index, void *table)
422{
423 struct commit **commits = table;
424 return commits[index]->object.oid.hash;
425}
426
427static void write_graph_chunk_data(struct hashfile *f, int hash_len,
428 struct commit **commits, int nr_commits)
429{
430 struct commit **list = commits;
431 struct commit **last = commits + nr_commits;
432 uint32_t num_extra_edges = 0;
433
434 while (list < last) {
435 struct commit_list *parent;
436 int edge_value;
437 uint32_t packedDate[2];
438
439 parse_commit(*list);
2e27bd77 440 hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
08fd81c9
DS
441
442 parent = (*list)->parents;
443
444 if (!parent)
445 edge_value = GRAPH_PARENT_NONE;
446 else {
447 edge_value = sha1_pos(parent->item->object.oid.hash,
448 commits,
449 nr_commits,
450 commit_to_sha1);
451
452 if (edge_value < 0)
453 edge_value = GRAPH_PARENT_MISSING;
454 }
455
456 hashwrite_be32(f, edge_value);
457
458 if (parent)
459 parent = parent->next;
460
461 if (!parent)
462 edge_value = GRAPH_PARENT_NONE;
463 else if (parent->next)
464 edge_value = GRAPH_OCTOPUS_EDGES_NEEDED | num_extra_edges;
465 else {
466 edge_value = sha1_pos(parent->item->object.oid.hash,
467 commits,
468 nr_commits,
469 commit_to_sha1);
470 if (edge_value < 0)
471 edge_value = GRAPH_PARENT_MISSING;
472 }
473
474 hashwrite_be32(f, edge_value);
475
476 if (edge_value & GRAPH_OCTOPUS_EDGES_NEEDED) {
477 do {
478 num_extra_edges++;
479 parent = parent->next;
480 } while (parent);
481 }
482
483 if (sizeof((*list)->date) > 4)
484 packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
485 else
486 packedDate[0] = 0;
487
3258c663
DS
488 packedDate[0] |= htonl((*list)->generation << 2);
489
08fd81c9
DS
490 packedDate[1] = htonl((*list)->date);
491 hashwrite(f, packedDate, 8);
492
493 list++;
494 }
495}
496
497static void write_graph_chunk_large_edges(struct hashfile *f,
498 struct commit **commits,
499 int nr_commits)
500{
501 struct commit **list = commits;
502 struct commit **last = commits + nr_commits;
503 struct commit_list *parent;
504
505 while (list < last) {
506 int num_parents = 0;
507 for (parent = (*list)->parents; num_parents < 3 && parent;
508 parent = parent->next)
509 num_parents++;
510
511 if (num_parents <= 2) {
512 list++;
513 continue;
514 }
515
516 /* Since num_parents > 2, this initializer is safe. */
517 for (parent = (*list)->parents->next; parent; parent = parent->next) {
518 int edge_value = sha1_pos(parent->item->object.oid.hash,
519 commits,
520 nr_commits,
521 commit_to_sha1);
522
523 if (edge_value < 0)
524 edge_value = GRAPH_PARENT_MISSING;
525 else if (!parent->next)
526 edge_value |= GRAPH_LAST_EDGE;
527
528 hashwrite_be32(f, edge_value);
529 }
530
531 list++;
532 }
533}
534
535static int commit_compare(const void *_a, const void *_b)
536{
537 const struct object_id *a = (const struct object_id *)_a;
538 const struct object_id *b = (const struct object_id *)_b;
539 return oidcmp(a, b);
540}
541
542struct packed_commit_list {
543 struct commit **list;
544 int nr;
545 int alloc;
546};
547
548struct packed_oid_list {
549 struct object_id *list;
550 int nr;
551 int alloc;
552};
553
554static int add_packed_commits(const struct object_id *oid,
555 struct packed_git *pack,
556 uint32_t pos,
557 void *data)
558{
559 struct packed_oid_list *list = (struct packed_oid_list*)data;
560 enum object_type type;
561 off_t offset = nth_packed_object_offset(pack, pos);
562 struct object_info oi = OBJECT_INFO_INIT;
563
564 oi.typep = &type;
fcb6df32 565 if (packed_object_info(the_repository, pack, offset, &oi) < 0)
4f5b532d 566 die(_("unable to get type of object %s"), oid_to_hex(oid));
08fd81c9
DS
567
568 if (type != OBJ_COMMIT)
569 return 0;
570
571 ALLOC_GROW(list->list, list->nr + 1, list->alloc);
572 oidcpy(&(list->list[list->nr]), oid);
573 list->nr++;
574
575 return 0;
576}
577
4f2542b4
DS
578static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)
579{
580 struct commit_list *parent;
581 for (parent = commit->parents; parent; parent = parent->next) {
582 if (!(parent->item->object.flags & UNINTERESTING)) {
583 ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);
584 oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));
585 oids->nr++;
586 parent->item->object.flags |= UNINTERESTING;
587 }
588 }
589}
590
591static void close_reachable(struct packed_oid_list *oids)
592{
593 int i;
594 struct commit *commit;
595
596 for (i = 0; i < oids->nr; i++) {
c1f5eb49 597 commit = lookup_commit(the_repository, &oids->list[i]);
4f2542b4
DS
598 if (commit)
599 commit->object.flags |= UNINTERESTING;
600 }
601
602 /*
603 * As this loop runs, oids->nr may grow, but not more
604 * than the number of missing commits in the reachable
605 * closure.
606 */
607 for (i = 0; i < oids->nr; i++) {
c1f5eb49 608 commit = lookup_commit(the_repository, &oids->list[i]);
4f2542b4
DS
609
610 if (commit && !parse_commit(commit))
611 add_missing_parents(oids, commit);
612 }
613
614 for (i = 0; i < oids->nr; i++) {
c1f5eb49 615 commit = lookup_commit(the_repository, &oids->list[i]);
4f2542b4
DS
616
617 if (commit)
618 commit->object.flags &= ~UNINTERESTING;
619 }
620}
621
3258c663
DS
622static void compute_generation_numbers(struct packed_commit_list* commits)
623{
624 int i;
625 struct commit_list *list = NULL;
626
627 for (i = 0; i < commits->nr; i++) {
628 if (commits->list[i]->generation != GENERATION_NUMBER_INFINITY &&
629 commits->list[i]->generation != GENERATION_NUMBER_ZERO)
630 continue;
631
632 commit_list_insert(commits->list[i], &list);
633 while (list) {
634 struct commit *current = list->item;
635 struct commit_list *parent;
636 int all_parents_computed = 1;
637 uint32_t max_generation = 0;
638
639 for (parent = current->parents; parent; parent = parent->next) {
640 if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
641 parent->item->generation == GENERATION_NUMBER_ZERO) {
642 all_parents_computed = 0;
643 commit_list_insert(parent->item, &list);
644 break;
645 } else if (parent->item->generation > max_generation) {
646 max_generation = parent->item->generation;
647 }
648 }
649
650 if (all_parents_computed) {
651 current->generation = max_generation + 1;
652 pop_commit(&list);
653
654 if (current->generation > GENERATION_NUMBER_MAX)
655 current->generation = GENERATION_NUMBER_MAX;
656 }
657 }
658 }
659}
660
59fb8770
DS
661static int add_ref_to_list(const char *refname,
662 const struct object_id *oid,
663 int flags, void *cb_data)
664{
665 struct string_list *list = (struct string_list *)cb_data;
666
667 string_list_append(list, oid_to_hex(oid));
668 return 0;
669}
670
671void write_commit_graph_reachable(const char *obj_dir, int append)
672{
673 struct string_list list;
674
675 string_list_init(&list, 1);
676 for_each_ref(add_ref_to_list, &list);
677 write_commit_graph(obj_dir, NULL, &list, append);
678}
679
049d51a2 680void write_commit_graph(const char *obj_dir,
d88b14b3
DS
681 struct string_list *pack_indexes,
682 struct string_list *commit_hex,
7547b95b 683 int append)
08fd81c9
DS
684{
685 struct packed_oid_list oids;
686 struct packed_commit_list commits;
687 struct hashfile *f;
688 uint32_t i, count_distinct = 0;
689 char *graph_name;
08fd81c9
DS
690 struct lock_file lk = LOCK_INIT;
691 uint32_t chunk_ids[5];
692 uint64_t chunk_offsets[5];
693 int num_chunks;
694 int num_extra_edges;
695 struct commit_list *parent;
696
697 oids.nr = 0;
698 oids.alloc = approximate_object_count() / 4;
699
7547b95b 700 if (append) {
dade47c0 701 prepare_commit_graph_one(the_repository, obj_dir);
85277506
JT
702 if (the_repository->objects->commit_graph)
703 oids.alloc += the_repository->objects->commit_graph->num_commits;
7547b95b
DS
704 }
705
08fd81c9
DS
706 if (oids.alloc < 1024)
707 oids.alloc = 1024;
708 ALLOC_ARRAY(oids.list, oids.alloc);
709
85277506
JT
710 if (append && the_repository->objects->commit_graph) {
711 struct commit_graph *commit_graph =
712 the_repository->objects->commit_graph;
7547b95b
DS
713 for (i = 0; i < commit_graph->num_commits; i++) {
714 const unsigned char *hash = commit_graph->chunk_oid_lookup +
715 commit_graph->hash_len * i;
716 hashcpy(oids.list[oids.nr++].hash, hash);
717 }
718 }
719
049d51a2
DS
720 if (pack_indexes) {
721 struct strbuf packname = STRBUF_INIT;
722 int dirlen;
723 strbuf_addf(&packname, "%s/pack/", obj_dir);
724 dirlen = packname.len;
d88b14b3 725 for (i = 0; i < pack_indexes->nr; i++) {
049d51a2
DS
726 struct packed_git *p;
727 strbuf_setlen(&packname, dirlen);
d88b14b3 728 strbuf_addstr(&packname, pack_indexes->items[i].string);
049d51a2
DS
729 p = add_packed_git(packname.buf, packname.len, 1);
730 if (!p)
4f5b532d 731 die(_("error adding pack %s"), packname.buf);
049d51a2 732 if (open_pack_index(p))
4f5b532d 733 die(_("error opening index for %s"), packname.buf);
736eb88f 734 for_each_object_in_pack(p, add_packed_commits, &oids, 0);
049d51a2
DS
735 close_pack(p);
736 }
737 strbuf_release(&packname);
3d5df01b
DS
738 }
739
740 if (commit_hex) {
d88b14b3 741 for (i = 0; i < commit_hex->nr; i++) {
3d5df01b
DS
742 const char *end;
743 struct object_id oid;
744 struct commit *result;
745
d88b14b3
DS
746 if (commit_hex->items[i].string &&
747 parse_oid_hex(commit_hex->items[i].string, &oid, &end))
3d5df01b
DS
748 continue;
749
21e1ee8f 750 result = lookup_commit_reference_gently(the_repository, &oid, 1);
3d5df01b
DS
751
752 if (result) {
753 ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
754 oidcpy(&oids.list[oids.nr], &(result->object.oid));
755 oids.nr++;
756 }
757 }
758 }
759
760 if (!pack_indexes && !commit_hex)
049d51a2
DS
761 for_each_packed_object(add_packed_commits, &oids, 0);
762
4f2542b4 763 close_reachable(&oids);
08fd81c9
DS
764
765 QSORT(oids.list, oids.nr, commit_compare);
766
767 count_distinct = 1;
768 for (i = 1; i < oids.nr; i++) {
769 if (oidcmp(&oids.list[i-1], &oids.list[i]))
770 count_distinct++;
771 }
772
773 if (count_distinct >= GRAPH_PARENT_MISSING)
774 die(_("the commit graph format cannot write %d commits"), count_distinct);
775
776 commits.nr = 0;
777 commits.alloc = count_distinct;
778 ALLOC_ARRAY(commits.list, commits.alloc);
779
780 num_extra_edges = 0;
781 for (i = 0; i < oids.nr; i++) {
782 int num_parents = 0;
783 if (i > 0 && !oidcmp(&oids.list[i-1], &oids.list[i]))
784 continue;
785
c1f5eb49 786 commits.list[commits.nr] = lookup_commit(the_repository, &oids.list[i]);
08fd81c9
DS
787 parse_commit(commits.list[commits.nr]);
788
789 for (parent = commits.list[commits.nr]->parents;
790 parent; parent = parent->next)
791 num_parents++;
792
793 if (num_parents > 2)
794 num_extra_edges += num_parents - 1;
795
796 commits.nr++;
797 }
798 num_chunks = num_extra_edges ? 4 : 3;
799
800 if (commits.nr >= GRAPH_PARENT_MISSING)
801 die(_("too many commits to write graph"));
802
3258c663 803 compute_generation_numbers(&commits);
08fd81c9 804
08fd81c9 805 graph_name = get_commit_graph_filename(obj_dir);
33286dcd
DS
806 if (safe_create_leading_directories(graph_name))
807 die_errno(_("unable to create leading directories of %s"),
808 graph_name);
08fd81c9 809
33286dcd 810 hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
08fd81c9
DS
811 f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
812
813 hashwrite_be32(f, GRAPH_SIGNATURE);
814
815 hashwrite_u8(f, GRAPH_VERSION);
816 hashwrite_u8(f, GRAPH_OID_VERSION);
817 hashwrite_u8(f, num_chunks);
818 hashwrite_u8(f, 0); /* unused padding byte */
819
820 chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
821 chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
822 chunk_ids[2] = GRAPH_CHUNKID_DATA;
823 if (num_extra_edges)
824 chunk_ids[3] = GRAPH_CHUNKID_LARGEEDGES;
825 else
826 chunk_ids[3] = 0;
827 chunk_ids[4] = 0;
828
829 chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
830 chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
831 chunk_offsets[2] = chunk_offsets[1] + GRAPH_OID_LEN * commits.nr;
832 chunk_offsets[3] = chunk_offsets[2] + (GRAPH_OID_LEN + 16) * commits.nr;
833 chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
834
835 for (i = 0; i <= num_chunks; i++) {
836 uint32_t chunk_write[3];
837
838 chunk_write[0] = htonl(chunk_ids[i]);
839 chunk_write[1] = htonl(chunk_offsets[i] >> 32);
840 chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
841 hashwrite(f, chunk_write, 12);
842 }
843
844 write_graph_chunk_fanout(f, commits.list, commits.nr);
845 write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr);
846 write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr);
847 write_graph_chunk_large_edges(f, commits.list, commits.nr);
848
177722b3 849 close_commit_graph();
08fd81c9
DS
850 finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
851 commit_lock_file(&lk);
852
853 free(oids.list);
854 oids.alloc = 0;
855 oids.nr = 0;
856}
283e68c7 857
41df0e30 858#define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
283e68c7
DS
859static int verify_commit_graph_error;
860
861static void graph_report(const char *fmt, ...)
862{
863 va_list ap;
864
865 verify_commit_graph_error = 1;
866 va_start(ap, fmt);
867 vfprintf(stderr, fmt, ap);
868 fprintf(stderr, "\n");
869 va_end(ap);
870}
871
1373e547
DS
872#define GENERATION_ZERO_EXISTS 1
873#define GENERATION_NUMBER_EXISTS 2
874
283e68c7
DS
875int verify_commit_graph(struct repository *r, struct commit_graph *g)
876{
9bda8467 877 uint32_t i, cur_fanout_pos = 0;
41df0e30 878 struct object_id prev_oid, cur_oid, checksum;
1373e547 879 int generation_zero = 0;
41df0e30
DS
880 struct hashfile *f;
881 int devnull;
9bda8467 882
283e68c7
DS
883 if (!g) {
884 graph_report("no commit-graph file loaded");
885 return 1;
886 }
887
2bd0365f
DS
888 verify_commit_graph_error = 0;
889
890 if (!g->chunk_oid_fanout)
891 graph_report("commit-graph is missing the OID Fanout chunk");
892 if (!g->chunk_oid_lookup)
893 graph_report("commit-graph is missing the OID Lookup chunk");
894 if (!g->chunk_commit_data)
895 graph_report("commit-graph is missing the Commit Data chunk");
896
9bda8467
DS
897 if (verify_commit_graph_error)
898 return verify_commit_graph_error;
899
41df0e30
DS
900 devnull = open("/dev/null", O_WRONLY);
901 f = hashfd(devnull, NULL);
902 hashwrite(f, g->data, g->data_len - g->hash_len);
903 finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
904 if (hashcmp(checksum.hash, g->data + g->data_len - g->hash_len)) {
905 graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
906 verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
907 }
908
9bda8467 909 for (i = 0; i < g->num_commits; i++) {
2e3c0737
DS
910 struct commit *graph_commit;
911
9bda8467
DS
912 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
913
914 if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
915 graph_report("commit-graph has incorrect OID order: %s then %s",
916 oid_to_hex(&prev_oid),
917 oid_to_hex(&cur_oid));
918
919 oidcpy(&prev_oid, &cur_oid);
920
921 while (cur_oid.hash[0] > cur_fanout_pos) {
922 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
923
924 if (i != fanout_value)
925 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
926 cur_fanout_pos, fanout_value, i);
927 cur_fanout_pos++;
928 }
2e3c0737 929
82952964 930 graph_commit = lookup_commit(r, &cur_oid);
2e3c0737
DS
931 if (!parse_commit_in_graph_one(g, graph_commit))
932 graph_report("failed to parse %s from commit-graph",
933 oid_to_hex(&cur_oid));
9bda8467
DS
934 }
935
936 while (cur_fanout_pos < 256) {
937 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
938
939 if (g->num_commits != fanout_value)
940 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
941 cur_fanout_pos, fanout_value, i);
942
943 cur_fanout_pos++;
944 }
945
41df0e30 946 if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
96af91d4
DS
947 return verify_commit_graph_error;
948
949 for (i = 0; i < g->num_commits; i++) {
2e3c0737 950 struct commit *graph_commit, *odb_commit;
53614b13 951 struct commit_list *graph_parents, *odb_parents;
1373e547 952 uint32_t max_generation = 0;
96af91d4
DS
953
954 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
955
82952964 956 graph_commit = lookup_commit(r, &cur_oid);
96af91d4
DS
957 odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
958 if (parse_commit_internal(odb_commit, 0, 0)) {
959 graph_report("failed to parse %s from object database",
960 oid_to_hex(&cur_oid));
961 continue;
962 }
2e3c0737
DS
963
964 if (oidcmp(&get_commit_tree_in_graph_one(g, graph_commit)->object.oid,
965 get_commit_tree_oid(odb_commit)))
966 graph_report("root tree OID for commit %s in commit-graph is %s != %s",
967 oid_to_hex(&cur_oid),
968 oid_to_hex(get_commit_tree_oid(graph_commit)),
969 oid_to_hex(get_commit_tree_oid(odb_commit)));
53614b13
DS
970
971 graph_parents = graph_commit->parents;
972 odb_parents = odb_commit->parents;
973
974 while (graph_parents) {
975 if (odb_parents == NULL) {
976 graph_report("commit-graph parent list for commit %s is too long",
977 oid_to_hex(&cur_oid));
978 break;
979 }
980
981 if (oidcmp(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
982 graph_report("commit-graph parent for %s is %s != %s",
983 oid_to_hex(&cur_oid),
984 oid_to_hex(&graph_parents->item->object.oid),
985 oid_to_hex(&odb_parents->item->object.oid));
986
1373e547
DS
987 if (graph_parents->item->generation > max_generation)
988 max_generation = graph_parents->item->generation;
989
53614b13
DS
990 graph_parents = graph_parents->next;
991 odb_parents = odb_parents->next;
992 }
993
994 if (odb_parents != NULL)
995 graph_report("commit-graph parent list for commit %s terminates early",
996 oid_to_hex(&cur_oid));
1373e547
DS
997
998 if (!graph_commit->generation) {
999 if (generation_zero == GENERATION_NUMBER_EXISTS)
1000 graph_report("commit-graph has generation number zero for commit %s, but non-zero elsewhere",
1001 oid_to_hex(&cur_oid));
1002 generation_zero = GENERATION_ZERO_EXISTS;
1003 } else if (generation_zero == GENERATION_ZERO_EXISTS)
1004 graph_report("commit-graph has non-zero generation number for commit %s, but zero elsewhere",
1005 oid_to_hex(&cur_oid));
1006
1007 if (generation_zero == GENERATION_ZERO_EXISTS)
1008 continue;
1009
1010 /*
1011 * If one of our parents has generation GENERATION_NUMBER_MAX, then
1012 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
1013 * extra logic in the following condition.
1014 */
1015 if (max_generation == GENERATION_NUMBER_MAX)
1016 max_generation--;
1017
1018 if (graph_commit->generation != max_generation + 1)
1019 graph_report("commit-graph generation for commit %s is %u != %u",
1020 oid_to_hex(&cur_oid),
1021 graph_commit->generation,
1022 max_generation + 1);
88968ebf
DS
1023
1024 if (graph_commit->date != odb_commit->date)
1025 graph_report("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime,
1026 oid_to_hex(&cur_oid),
1027 graph_commit->date,
1028 odb_commit->date);
96af91d4
DS
1029 }
1030
283e68c7
DS
1031 return verify_commit_graph_error;
1032}
c3756d5b
JT
1033
1034void free_commit_graph(struct commit_graph *g)
1035{
1036 if (!g)
1037 return;
1038 if (g->graph_fd >= 0) {
1039 munmap((void *)g->data, g->data_len);
1040 g->data = NULL;
1041 close(g->graph_fd);
1042 }
1043 free(g);
1044}