t/helper: add a test helper to compute hash speed
[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
6cc01743
DS
237int generation_numbers_enabled(struct repository *r)
238{
239 uint32_t first_generation;
240 struct commit_graph *g;
241 if (!prepare_commit_graph(r))
242 return 0;
243
244 g = r->objects->commit_graph;
245
246 if (!g->num_commits)
247 return 0;
248
249 first_generation = get_be32(g->chunk_commit_data +
250 g->hash_len + 8) >> 2;
251
252 return !!first_generation;
253}
254
177722b3
DS
255static void close_commit_graph(void)
256{
85277506
JT
257 free_commit_graph(the_repository->objects->commit_graph);
258 the_repository->objects->commit_graph = NULL;
177722b3
DS
259}
260
261static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
262{
263 return bsearch_hash(oid->hash, g->chunk_oid_fanout,
264 g->chunk_oid_lookup, g->hash_len, pos);
265}
266
267static struct commit_list **insert_parent_or_die(struct commit_graph *g,
268 uint64_t pos,
269 struct commit_list **pptr)
270{
271 struct commit *c;
272 struct object_id oid;
96af91d4 273
53614b13
DS
274 if (pos >= g->num_commits)
275 die("invalid parent position %"PRIu64, pos);
276
177722b3 277 hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
c1f5eb49 278 c = lookup_commit(the_repository, &oid);
177722b3 279 if (!c)
4f5b532d 280 die(_("could not find commit %s"), oid_to_hex(&oid));
177722b3
DS
281 c->graph_pos = pos;
282 return &commit_list_insert(c, pptr)->next;
283}
284
e2838d85
DS
285static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
286{
287 const unsigned char *commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * pos;
288 item->graph_pos = pos;
289 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
290}
291
177722b3
DS
292static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)
293{
177722b3
DS
294 uint32_t edge_value;
295 uint32_t *parent_data_ptr;
296 uint64_t date_low, date_high;
297 struct commit_list **pptr;
298 const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
299
300 item->object.parsed = 1;
301 item->graph_pos = pos;
302
7b8a21db 303 item->maybe_tree = NULL;
177722b3
DS
304
305 date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
306 date_low = get_be32(commit_data + g->hash_len + 12);
307 item->date = (timestamp_t)((date_high << 32) | date_low);
308
83073cc9
DS
309 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
310
177722b3
DS
311 pptr = &item->parents;
312
313 edge_value = get_be32(commit_data + g->hash_len);
314 if (edge_value == GRAPH_PARENT_NONE)
315 return 1;
316 pptr = insert_parent_or_die(g, edge_value, pptr);
317
318 edge_value = get_be32(commit_data + g->hash_len + 4);
319 if (edge_value == GRAPH_PARENT_NONE)
320 return 1;
321 if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {
322 pptr = insert_parent_or_die(g, edge_value, pptr);
323 return 1;
324 }
325
326 parent_data_ptr = (uint32_t*)(g->chunk_large_edges +
327 4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
328 do {
329 edge_value = get_be32(parent_data_ptr);
330 pptr = insert_parent_or_die(g,
331 edge_value & GRAPH_EDGE_LAST_MASK,
332 pptr);
333 parent_data_ptr++;
334 } while (!(edge_value & GRAPH_LAST_EDGE));
335
336 return 1;
337}
338
e2838d85
DS
339static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
340{
341 if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
342 *pos = item->graph_pos;
343 return 1;
344 } else {
345 return bsearch_graph(g, &(item->object.oid), pos);
346 }
347}
348
ee797053 349static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item)
177722b3 350{
e2838d85
DS
351 uint32_t pos;
352
177722b3
DS
353 if (item->object.parsed)
354 return 1;
ee797053
DS
355
356 if (find_commit_in_graph(item, g, &pos))
357 return fill_commit_in_graph(item, g, pos);
358
359 return 0;
360}
361
dade47c0 362int parse_commit_in_graph(struct repository *r, struct commit *item)
ee797053 363{
dade47c0 364 if (!prepare_commit_graph(r))
ee797053 365 return 0;
dade47c0 366 return parse_commit_in_graph_one(r->objects->commit_graph, item);
177722b3
DS
367}
368
dade47c0 369void load_commit_graph_info(struct repository *r, struct commit *item)
e2838d85
DS
370{
371 uint32_t pos;
dade47c0 372 if (!prepare_commit_graph(r))
e2838d85 373 return;
dade47c0
JT
374 if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
375 fill_commit_graph_info(item, r->objects->commit_graph, pos);
e2838d85
DS
376}
377
7b8a21db
DS
378static struct tree *load_tree_for_commit(struct commit_graph *g, struct commit *c)
379{
380 struct object_id oid;
381 const unsigned char *commit_data = g->chunk_commit_data +
382 GRAPH_DATA_WIDTH * (c->graph_pos);
383
384 hashcpy(oid.hash, commit_data);
f86bcc7b 385 c->maybe_tree = lookup_tree(the_repository, &oid);
7b8a21db
DS
386
387 return c->maybe_tree;
388}
389
0cbef8f8
DS
390static struct tree *get_commit_tree_in_graph_one(struct commit_graph *g,
391 const struct commit *c)
7b8a21db
DS
392{
393 if (c->maybe_tree)
394 return c->maybe_tree;
395 if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
0cbef8f8
DS
396 BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
397
398 return load_tree_for_commit(g, (struct commit *)c);
399}
7b8a21db 400
dade47c0 401struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
0cbef8f8 402{
dade47c0 403 return get_commit_tree_in_graph_one(r->objects->commit_graph, c);
7b8a21db
DS
404}
405
08fd81c9
DS
406static void write_graph_chunk_fanout(struct hashfile *f,
407 struct commit **commits,
408 int nr_commits)
409{
410 int i, count = 0;
411 struct commit **list = commits;
412
413 /*
414 * Write the first-level table (the list is sorted,
415 * but we use a 256-entry lookup to be able to avoid
416 * having to do eight extra binary search iterations).
417 */
418 for (i = 0; i < 256; i++) {
419 while (count < nr_commits) {
420 if ((*list)->object.oid.hash[0] != i)
421 break;
422 count++;
423 list++;
424 }
425
426 hashwrite_be32(f, count);
427 }
428}
429
430static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
431 struct commit **commits, int nr_commits)
432{
433 struct commit **list = commits;
434 int count;
435 for (count = 0; count < nr_commits; count++, list++)
436 hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
437}
438
439static const unsigned char *commit_to_sha1(size_t index, void *table)
440{
441 struct commit **commits = table;
442 return commits[index]->object.oid.hash;
443}
444
445static void write_graph_chunk_data(struct hashfile *f, int hash_len,
446 struct commit **commits, int nr_commits)
447{
448 struct commit **list = commits;
449 struct commit **last = commits + nr_commits;
450 uint32_t num_extra_edges = 0;
451
452 while (list < last) {
453 struct commit_list *parent;
454 int edge_value;
455 uint32_t packedDate[2];
456
457 parse_commit(*list);
2e27bd77 458 hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
08fd81c9
DS
459
460 parent = (*list)->parents;
461
462 if (!parent)
463 edge_value = GRAPH_PARENT_NONE;
464 else {
465 edge_value = sha1_pos(parent->item->object.oid.hash,
466 commits,
467 nr_commits,
468 commit_to_sha1);
469
470 if (edge_value < 0)
471 edge_value = GRAPH_PARENT_MISSING;
472 }
473
474 hashwrite_be32(f, edge_value);
475
476 if (parent)
477 parent = parent->next;
478
479 if (!parent)
480 edge_value = GRAPH_PARENT_NONE;
481 else if (parent->next)
482 edge_value = GRAPH_OCTOPUS_EDGES_NEEDED | num_extra_edges;
483 else {
484 edge_value = sha1_pos(parent->item->object.oid.hash,
485 commits,
486 nr_commits,
487 commit_to_sha1);
488 if (edge_value < 0)
489 edge_value = GRAPH_PARENT_MISSING;
490 }
491
492 hashwrite_be32(f, edge_value);
493
494 if (edge_value & GRAPH_OCTOPUS_EDGES_NEEDED) {
495 do {
496 num_extra_edges++;
497 parent = parent->next;
498 } while (parent);
499 }
500
501 if (sizeof((*list)->date) > 4)
502 packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
503 else
504 packedDate[0] = 0;
505
3258c663
DS
506 packedDate[0] |= htonl((*list)->generation << 2);
507
08fd81c9
DS
508 packedDate[1] = htonl((*list)->date);
509 hashwrite(f, packedDate, 8);
510
511 list++;
512 }
513}
514
515static void write_graph_chunk_large_edges(struct hashfile *f,
516 struct commit **commits,
517 int nr_commits)
518{
519 struct commit **list = commits;
520 struct commit **last = commits + nr_commits;
521 struct commit_list *parent;
522
523 while (list < last) {
524 int num_parents = 0;
525 for (parent = (*list)->parents; num_parents < 3 && parent;
526 parent = parent->next)
527 num_parents++;
528
529 if (num_parents <= 2) {
530 list++;
531 continue;
532 }
533
534 /* Since num_parents > 2, this initializer is safe. */
535 for (parent = (*list)->parents->next; parent; parent = parent->next) {
536 int edge_value = sha1_pos(parent->item->object.oid.hash,
537 commits,
538 nr_commits,
539 commit_to_sha1);
540
541 if (edge_value < 0)
542 edge_value = GRAPH_PARENT_MISSING;
543 else if (!parent->next)
544 edge_value |= GRAPH_LAST_EDGE;
545
546 hashwrite_be32(f, edge_value);
547 }
548
549 list++;
550 }
551}
552
553static int commit_compare(const void *_a, const void *_b)
554{
555 const struct object_id *a = (const struct object_id *)_a;
556 const struct object_id *b = (const struct object_id *)_b;
557 return oidcmp(a, b);
558}
559
560struct packed_commit_list {
561 struct commit **list;
562 int nr;
563 int alloc;
564};
565
566struct packed_oid_list {
567 struct object_id *list;
568 int nr;
569 int alloc;
570};
571
572static int add_packed_commits(const struct object_id *oid,
573 struct packed_git *pack,
574 uint32_t pos,
575 void *data)
576{
577 struct packed_oid_list *list = (struct packed_oid_list*)data;
578 enum object_type type;
579 off_t offset = nth_packed_object_offset(pack, pos);
580 struct object_info oi = OBJECT_INFO_INIT;
581
582 oi.typep = &type;
fcb6df32 583 if (packed_object_info(the_repository, pack, offset, &oi) < 0)
4f5b532d 584 die(_("unable to get type of object %s"), oid_to_hex(oid));
08fd81c9
DS
585
586 if (type != OBJ_COMMIT)
587 return 0;
588
589 ALLOC_GROW(list->list, list->nr + 1, list->alloc);
590 oidcpy(&(list->list[list->nr]), oid);
591 list->nr++;
592
593 return 0;
594}
595
4f2542b4
DS
596static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)
597{
598 struct commit_list *parent;
599 for (parent = commit->parents; parent; parent = parent->next) {
600 if (!(parent->item->object.flags & UNINTERESTING)) {
601 ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);
602 oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));
603 oids->nr++;
604 parent->item->object.flags |= UNINTERESTING;
605 }
606 }
607}
608
609static void close_reachable(struct packed_oid_list *oids)
610{
611 int i;
612 struct commit *commit;
613
614 for (i = 0; i < oids->nr; i++) {
c1f5eb49 615 commit = lookup_commit(the_repository, &oids->list[i]);
4f2542b4
DS
616 if (commit)
617 commit->object.flags |= UNINTERESTING;
618 }
619
620 /*
621 * As this loop runs, oids->nr may grow, but not more
622 * than the number of missing commits in the reachable
623 * closure.
624 */
625 for (i = 0; i < oids->nr; i++) {
c1f5eb49 626 commit = lookup_commit(the_repository, &oids->list[i]);
4f2542b4
DS
627
628 if (commit && !parse_commit(commit))
629 add_missing_parents(oids, commit);
630 }
631
632 for (i = 0; i < oids->nr; i++) {
c1f5eb49 633 commit = lookup_commit(the_repository, &oids->list[i]);
4f2542b4
DS
634
635 if (commit)
636 commit->object.flags &= ~UNINTERESTING;
637 }
638}
639
3258c663
DS
640static void compute_generation_numbers(struct packed_commit_list* commits)
641{
642 int i;
643 struct commit_list *list = NULL;
644
645 for (i = 0; i < commits->nr; i++) {
646 if (commits->list[i]->generation != GENERATION_NUMBER_INFINITY &&
647 commits->list[i]->generation != GENERATION_NUMBER_ZERO)
648 continue;
649
650 commit_list_insert(commits->list[i], &list);
651 while (list) {
652 struct commit *current = list->item;
653 struct commit_list *parent;
654 int all_parents_computed = 1;
655 uint32_t max_generation = 0;
656
657 for (parent = current->parents; parent; parent = parent->next) {
658 if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
659 parent->item->generation == GENERATION_NUMBER_ZERO) {
660 all_parents_computed = 0;
661 commit_list_insert(parent->item, &list);
662 break;
663 } else if (parent->item->generation > max_generation) {
664 max_generation = parent->item->generation;
665 }
666 }
667
668 if (all_parents_computed) {
669 current->generation = max_generation + 1;
670 pop_commit(&list);
671
672 if (current->generation > GENERATION_NUMBER_MAX)
673 current->generation = GENERATION_NUMBER_MAX;
674 }
675 }
676 }
677}
678
59fb8770
DS
679static int add_ref_to_list(const char *refname,
680 const struct object_id *oid,
681 int flags, void *cb_data)
682{
683 struct string_list *list = (struct string_list *)cb_data;
684
685 string_list_append(list, oid_to_hex(oid));
686 return 0;
687}
688
689void write_commit_graph_reachable(const char *obj_dir, int append)
690{
691 struct string_list list;
692
693 string_list_init(&list, 1);
694 for_each_ref(add_ref_to_list, &list);
695 write_commit_graph(obj_dir, NULL, &list, append);
696}
697
049d51a2 698void write_commit_graph(const char *obj_dir,
d88b14b3
DS
699 struct string_list *pack_indexes,
700 struct string_list *commit_hex,
7547b95b 701 int append)
08fd81c9
DS
702{
703 struct packed_oid_list oids;
704 struct packed_commit_list commits;
705 struct hashfile *f;
706 uint32_t i, count_distinct = 0;
707 char *graph_name;
08fd81c9
DS
708 struct lock_file lk = LOCK_INIT;
709 uint32_t chunk_ids[5];
710 uint64_t chunk_offsets[5];
711 int num_chunks;
712 int num_extra_edges;
713 struct commit_list *parent;
714
715 oids.nr = 0;
716 oids.alloc = approximate_object_count() / 4;
717
7547b95b 718 if (append) {
dade47c0 719 prepare_commit_graph_one(the_repository, obj_dir);
85277506
JT
720 if (the_repository->objects->commit_graph)
721 oids.alloc += the_repository->objects->commit_graph->num_commits;
7547b95b
DS
722 }
723
08fd81c9
DS
724 if (oids.alloc < 1024)
725 oids.alloc = 1024;
726 ALLOC_ARRAY(oids.list, oids.alloc);
727
85277506
JT
728 if (append && the_repository->objects->commit_graph) {
729 struct commit_graph *commit_graph =
730 the_repository->objects->commit_graph;
7547b95b
DS
731 for (i = 0; i < commit_graph->num_commits; i++) {
732 const unsigned char *hash = commit_graph->chunk_oid_lookup +
733 commit_graph->hash_len * i;
734 hashcpy(oids.list[oids.nr++].hash, hash);
735 }
736 }
737
049d51a2
DS
738 if (pack_indexes) {
739 struct strbuf packname = STRBUF_INIT;
740 int dirlen;
741 strbuf_addf(&packname, "%s/pack/", obj_dir);
742 dirlen = packname.len;
d88b14b3 743 for (i = 0; i < pack_indexes->nr; i++) {
049d51a2
DS
744 struct packed_git *p;
745 strbuf_setlen(&packname, dirlen);
d88b14b3 746 strbuf_addstr(&packname, pack_indexes->items[i].string);
049d51a2
DS
747 p = add_packed_git(packname.buf, packname.len, 1);
748 if (!p)
4f5b532d 749 die(_("error adding pack %s"), packname.buf);
049d51a2 750 if (open_pack_index(p))
4f5b532d 751 die(_("error opening index for %s"), packname.buf);
736eb88f 752 for_each_object_in_pack(p, add_packed_commits, &oids, 0);
049d51a2
DS
753 close_pack(p);
754 }
755 strbuf_release(&packname);
3d5df01b
DS
756 }
757
758 if (commit_hex) {
d88b14b3 759 for (i = 0; i < commit_hex->nr; i++) {
3d5df01b
DS
760 const char *end;
761 struct object_id oid;
762 struct commit *result;
763
d88b14b3
DS
764 if (commit_hex->items[i].string &&
765 parse_oid_hex(commit_hex->items[i].string, &oid, &end))
3d5df01b
DS
766 continue;
767
21e1ee8f 768 result = lookup_commit_reference_gently(the_repository, &oid, 1);
3d5df01b
DS
769
770 if (result) {
771 ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
772 oidcpy(&oids.list[oids.nr], &(result->object.oid));
773 oids.nr++;
774 }
775 }
776 }
777
778 if (!pack_indexes && !commit_hex)
049d51a2
DS
779 for_each_packed_object(add_packed_commits, &oids, 0);
780
4f2542b4 781 close_reachable(&oids);
08fd81c9
DS
782
783 QSORT(oids.list, oids.nr, commit_compare);
784
785 count_distinct = 1;
786 for (i = 1; i < oids.nr; i++) {
9001dc2a 787 if (!oideq(&oids.list[i - 1], &oids.list[i]))
08fd81c9
DS
788 count_distinct++;
789 }
790
791 if (count_distinct >= GRAPH_PARENT_MISSING)
792 die(_("the commit graph format cannot write %d commits"), count_distinct);
793
794 commits.nr = 0;
795 commits.alloc = count_distinct;
796 ALLOC_ARRAY(commits.list, commits.alloc);
797
798 num_extra_edges = 0;
799 for (i = 0; i < oids.nr; i++) {
800 int num_parents = 0;
4a7e27e9 801 if (i > 0 && oideq(&oids.list[i - 1], &oids.list[i]))
08fd81c9
DS
802 continue;
803
c1f5eb49 804 commits.list[commits.nr] = lookup_commit(the_repository, &oids.list[i]);
08fd81c9
DS
805 parse_commit(commits.list[commits.nr]);
806
807 for (parent = commits.list[commits.nr]->parents;
808 parent; parent = parent->next)
809 num_parents++;
810
811 if (num_parents > 2)
812 num_extra_edges += num_parents - 1;
813
814 commits.nr++;
815 }
816 num_chunks = num_extra_edges ? 4 : 3;
817
818 if (commits.nr >= GRAPH_PARENT_MISSING)
819 die(_("too many commits to write graph"));
820
3258c663 821 compute_generation_numbers(&commits);
08fd81c9 822
08fd81c9 823 graph_name = get_commit_graph_filename(obj_dir);
33286dcd
DS
824 if (safe_create_leading_directories(graph_name))
825 die_errno(_("unable to create leading directories of %s"),
826 graph_name);
08fd81c9 827
33286dcd 828 hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
08fd81c9
DS
829 f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
830
831 hashwrite_be32(f, GRAPH_SIGNATURE);
832
833 hashwrite_u8(f, GRAPH_VERSION);
834 hashwrite_u8(f, GRAPH_OID_VERSION);
835 hashwrite_u8(f, num_chunks);
836 hashwrite_u8(f, 0); /* unused padding byte */
837
838 chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
839 chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
840 chunk_ids[2] = GRAPH_CHUNKID_DATA;
841 if (num_extra_edges)
842 chunk_ids[3] = GRAPH_CHUNKID_LARGEEDGES;
843 else
844 chunk_ids[3] = 0;
845 chunk_ids[4] = 0;
846
847 chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
848 chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
849 chunk_offsets[2] = chunk_offsets[1] + GRAPH_OID_LEN * commits.nr;
850 chunk_offsets[3] = chunk_offsets[2] + (GRAPH_OID_LEN + 16) * commits.nr;
851 chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
852
853 for (i = 0; i <= num_chunks; i++) {
854 uint32_t chunk_write[3];
855
856 chunk_write[0] = htonl(chunk_ids[i]);
857 chunk_write[1] = htonl(chunk_offsets[i] >> 32);
858 chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
859 hashwrite(f, chunk_write, 12);
860 }
861
862 write_graph_chunk_fanout(f, commits.list, commits.nr);
863 write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr);
864 write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr);
865 write_graph_chunk_large_edges(f, commits.list, commits.nr);
866
177722b3 867 close_commit_graph();
08fd81c9
DS
868 finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
869 commit_lock_file(&lk);
870
871 free(oids.list);
872 oids.alloc = 0;
873 oids.nr = 0;
874}
283e68c7 875
41df0e30 876#define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
283e68c7
DS
877static int verify_commit_graph_error;
878
879static void graph_report(const char *fmt, ...)
880{
881 va_list ap;
882
883 verify_commit_graph_error = 1;
884 va_start(ap, fmt);
885 vfprintf(stderr, fmt, ap);
886 fprintf(stderr, "\n");
887 va_end(ap);
888}
889
1373e547
DS
890#define GENERATION_ZERO_EXISTS 1
891#define GENERATION_NUMBER_EXISTS 2
892
283e68c7
DS
893int verify_commit_graph(struct repository *r, struct commit_graph *g)
894{
9bda8467 895 uint32_t i, cur_fanout_pos = 0;
41df0e30 896 struct object_id prev_oid, cur_oid, checksum;
1373e547 897 int generation_zero = 0;
41df0e30
DS
898 struct hashfile *f;
899 int devnull;
9bda8467 900
283e68c7
DS
901 if (!g) {
902 graph_report("no commit-graph file loaded");
903 return 1;
904 }
905
2bd0365f
DS
906 verify_commit_graph_error = 0;
907
908 if (!g->chunk_oid_fanout)
909 graph_report("commit-graph is missing the OID Fanout chunk");
910 if (!g->chunk_oid_lookup)
911 graph_report("commit-graph is missing the OID Lookup chunk");
912 if (!g->chunk_commit_data)
913 graph_report("commit-graph is missing the Commit Data chunk");
914
9bda8467
DS
915 if (verify_commit_graph_error)
916 return verify_commit_graph_error;
917
41df0e30
DS
918 devnull = open("/dev/null", O_WRONLY);
919 f = hashfd(devnull, NULL);
920 hashwrite(f, g->data, g->data_len - g->hash_len);
921 finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
67947c34 922 if (!hasheq(checksum.hash, g->data + g->data_len - g->hash_len)) {
41df0e30
DS
923 graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
924 verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
925 }
926
9bda8467 927 for (i = 0; i < g->num_commits; i++) {
2e3c0737
DS
928 struct commit *graph_commit;
929
9bda8467
DS
930 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
931
932 if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
933 graph_report("commit-graph has incorrect OID order: %s then %s",
934 oid_to_hex(&prev_oid),
935 oid_to_hex(&cur_oid));
936
937 oidcpy(&prev_oid, &cur_oid);
938
939 while (cur_oid.hash[0] > cur_fanout_pos) {
940 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
941
942 if (i != fanout_value)
943 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
944 cur_fanout_pos, fanout_value, i);
945 cur_fanout_pos++;
946 }
2e3c0737 947
82952964 948 graph_commit = lookup_commit(r, &cur_oid);
2e3c0737
DS
949 if (!parse_commit_in_graph_one(g, graph_commit))
950 graph_report("failed to parse %s from commit-graph",
951 oid_to_hex(&cur_oid));
9bda8467
DS
952 }
953
954 while (cur_fanout_pos < 256) {
955 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
956
957 if (g->num_commits != fanout_value)
958 graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
959 cur_fanout_pos, fanout_value, i);
960
961 cur_fanout_pos++;
962 }
963
41df0e30 964 if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
96af91d4
DS
965 return verify_commit_graph_error;
966
967 for (i = 0; i < g->num_commits; i++) {
2e3c0737 968 struct commit *graph_commit, *odb_commit;
53614b13 969 struct commit_list *graph_parents, *odb_parents;
1373e547 970 uint32_t max_generation = 0;
96af91d4
DS
971
972 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
973
82952964 974 graph_commit = lookup_commit(r, &cur_oid);
96af91d4
DS
975 odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
976 if (parse_commit_internal(odb_commit, 0, 0)) {
977 graph_report("failed to parse %s from object database",
978 oid_to_hex(&cur_oid));
979 continue;
980 }
2e3c0737 981
9001dc2a 982 if (!oideq(&get_commit_tree_in_graph_one(g, graph_commit)->object.oid,
2e3c0737
DS
983 get_commit_tree_oid(odb_commit)))
984 graph_report("root tree OID for commit %s in commit-graph is %s != %s",
985 oid_to_hex(&cur_oid),
986 oid_to_hex(get_commit_tree_oid(graph_commit)),
987 oid_to_hex(get_commit_tree_oid(odb_commit)));
53614b13
DS
988
989 graph_parents = graph_commit->parents;
990 odb_parents = odb_commit->parents;
991
992 while (graph_parents) {
993 if (odb_parents == NULL) {
994 graph_report("commit-graph parent list for commit %s is too long",
995 oid_to_hex(&cur_oid));
996 break;
997 }
998
9001dc2a 999 if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
53614b13
DS
1000 graph_report("commit-graph parent for %s is %s != %s",
1001 oid_to_hex(&cur_oid),
1002 oid_to_hex(&graph_parents->item->object.oid),
1003 oid_to_hex(&odb_parents->item->object.oid));
1004
1373e547
DS
1005 if (graph_parents->item->generation > max_generation)
1006 max_generation = graph_parents->item->generation;
1007
53614b13
DS
1008 graph_parents = graph_parents->next;
1009 odb_parents = odb_parents->next;
1010 }
1011
1012 if (odb_parents != NULL)
1013 graph_report("commit-graph parent list for commit %s terminates early",
1014 oid_to_hex(&cur_oid));
1373e547
DS
1015
1016 if (!graph_commit->generation) {
1017 if (generation_zero == GENERATION_NUMBER_EXISTS)
1018 graph_report("commit-graph has generation number zero for commit %s, but non-zero elsewhere",
1019 oid_to_hex(&cur_oid));
1020 generation_zero = GENERATION_ZERO_EXISTS;
1021 } else if (generation_zero == GENERATION_ZERO_EXISTS)
1022 graph_report("commit-graph has non-zero generation number for commit %s, but zero elsewhere",
1023 oid_to_hex(&cur_oid));
1024
1025 if (generation_zero == GENERATION_ZERO_EXISTS)
1026 continue;
1027
1028 /*
1029 * If one of our parents has generation GENERATION_NUMBER_MAX, then
1030 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
1031 * extra logic in the following condition.
1032 */
1033 if (max_generation == GENERATION_NUMBER_MAX)
1034 max_generation--;
1035
1036 if (graph_commit->generation != max_generation + 1)
1037 graph_report("commit-graph generation for commit %s is %u != %u",
1038 oid_to_hex(&cur_oid),
1039 graph_commit->generation,
1040 max_generation + 1);
88968ebf
DS
1041
1042 if (graph_commit->date != odb_commit->date)
1043 graph_report("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime,
1044 oid_to_hex(&cur_oid),
1045 graph_commit->date,
1046 odb_commit->date);
96af91d4
DS
1047 }
1048
283e68c7
DS
1049 return verify_commit_graph_error;
1050}
c3756d5b
JT
1051
1052void free_commit_graph(struct commit_graph *g)
1053{
1054 if (!g)
1055 return;
1056 if (g->graph_fd >= 0) {
1057 munmap((void *)g->data, g->data_len);
1058 g->data = NULL;
1059 close(g->graph_fd);
1060 }
1061 free(g);
1062}