commit-graph: allow cross-alternate chains
[git/git.git] / commit-graph.c
1 #include "cache.h"
2 #include "config.h"
3 #include "dir.h"
4 #include "git-compat-util.h"
5 #include "lockfile.h"
6 #include "pack.h"
7 #include "packfile.h"
8 #include "commit.h"
9 #include "object.h"
10 #include "refs.h"
11 #include "revision.h"
12 #include "sha1-lookup.h"
13 #include "commit-graph.h"
14 #include "object-store.h"
15 #include "alloc.h"
16 #include "hashmap.h"
17 #include "replace-object.h"
18 #include "progress.h"
19
20 #define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */
21 #define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
22 #define GRAPH_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
23 #define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */
24 #define GRAPH_CHUNKID_EXTRAEDGES 0x45444745 /* "EDGE" */
25 #define GRAPH_CHUNKID_BASE 0x42415345 /* "BASE" */
26
27 #define GRAPH_DATA_WIDTH (the_hash_algo->rawsz + 16)
28
29 #define GRAPH_VERSION_1 0x1
30 #define GRAPH_VERSION GRAPH_VERSION_1
31
32 #define GRAPH_EXTRA_EDGES_NEEDED 0x80000000
33 #define GRAPH_EDGE_LAST_MASK 0x7fffffff
34 #define GRAPH_PARENT_NONE 0x70000000
35
36 #define GRAPH_LAST_EDGE 0x80000000
37
38 #define GRAPH_HEADER_SIZE 8
39 #define GRAPH_FANOUT_SIZE (4 * 256)
40 #define GRAPH_CHUNKLOOKUP_WIDTH 12
41 #define GRAPH_MIN_SIZE (GRAPH_HEADER_SIZE + 4 * GRAPH_CHUNKLOOKUP_WIDTH \
42 + GRAPH_FANOUT_SIZE + the_hash_algo->rawsz)
43
44 char *get_commit_graph_filename(const char *obj_dir)
45 {
46 return xstrfmt("%s/info/commit-graph", obj_dir);
47 }
48
49 static char *get_split_graph_filename(const char *obj_dir,
50 const char *oid_hex)
51 {
52 return xstrfmt("%s/info/commit-graphs/graph-%s.graph",
53 obj_dir,
54 oid_hex);
55 }
56
57 static char *get_chain_filename(const char *obj_dir)
58 {
59 return xstrfmt("%s/info/commit-graphs/commit-graph-chain", obj_dir);
60 }
61
62 static uint8_t oid_version(void)
63 {
64 return 1;
65 }
66
67 static struct commit_graph *alloc_commit_graph(void)
68 {
69 struct commit_graph *g = xcalloc(1, sizeof(*g));
70 g->graph_fd = -1;
71
72 return g;
73 }
74
75 extern int read_replace_refs;
76
77 static int commit_graph_compatible(struct repository *r)
78 {
79 if (!r->gitdir)
80 return 0;
81
82 if (read_replace_refs) {
83 prepare_replace_object(r);
84 if (hashmap_get_size(&r->objects->replace_map->map))
85 return 0;
86 }
87
88 prepare_commit_graft(r);
89 if (r->parsed_objects && r->parsed_objects->grafts_nr)
90 return 0;
91 if (is_repository_shallow(r))
92 return 0;
93
94 return 1;
95 }
96
97 int open_commit_graph(const char *graph_file, int *fd, struct stat *st)
98 {
99 *fd = git_open(graph_file);
100 if (*fd < 0)
101 return 0;
102 if (fstat(*fd, st)) {
103 close(*fd);
104 return 0;
105 }
106 return 1;
107 }
108
109 struct commit_graph *load_commit_graph_one_fd_st(int fd, struct stat *st)
110 {
111 void *graph_map;
112 size_t graph_size;
113 struct commit_graph *ret;
114
115 graph_size = xsize_t(st->st_size);
116
117 if (graph_size < GRAPH_MIN_SIZE) {
118 close(fd);
119 error(_("commit-graph file is too small"));
120 return NULL;
121 }
122 graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
123 ret = parse_commit_graph(graph_map, fd, graph_size);
124
125 if (!ret) {
126 munmap(graph_map, graph_size);
127 close(fd);
128 }
129
130 return ret;
131 }
132
133 static int verify_commit_graph_lite(struct commit_graph *g)
134 {
135 /*
136 * Basic validation shared between parse_commit_graph()
137 * which'll be called every time the graph is used, and the
138 * much more expensive verify_commit_graph() used by
139 * "commit-graph verify".
140 *
141 * There should only be very basic checks here to ensure that
142 * we don't e.g. segfault in fill_commit_in_graph(), but
143 * because this is a very hot codepath nothing that e.g. loops
144 * over g->num_commits, or runs a checksum on the commit-graph
145 * itself.
146 */
147 if (!g->chunk_oid_fanout) {
148 error("commit-graph is missing the OID Fanout chunk");
149 return 1;
150 }
151 if (!g->chunk_oid_lookup) {
152 error("commit-graph is missing the OID Lookup chunk");
153 return 1;
154 }
155 if (!g->chunk_commit_data) {
156 error("commit-graph is missing the Commit Data chunk");
157 return 1;
158 }
159
160 return 0;
161 }
162
163 struct commit_graph *parse_commit_graph(void *graph_map, int fd,
164 size_t graph_size)
165 {
166 const unsigned char *data, *chunk_lookup;
167 uint32_t i;
168 struct commit_graph *graph;
169 uint64_t last_chunk_offset;
170 uint32_t last_chunk_id;
171 uint32_t graph_signature;
172 unsigned char graph_version, hash_version;
173
174 if (!graph_map)
175 return NULL;
176
177 if (graph_size < GRAPH_MIN_SIZE)
178 return NULL;
179
180 data = (const unsigned char *)graph_map;
181
182 graph_signature = get_be32(data);
183 if (graph_signature != GRAPH_SIGNATURE) {
184 error(_("commit-graph signature %X does not match signature %X"),
185 graph_signature, GRAPH_SIGNATURE);
186 return NULL;
187 }
188
189 graph_version = *(unsigned char*)(data + 4);
190 if (graph_version != GRAPH_VERSION) {
191 error(_("commit-graph version %X does not match version %X"),
192 graph_version, GRAPH_VERSION);
193 return NULL;
194 }
195
196 hash_version = *(unsigned char*)(data + 5);
197 if (hash_version != oid_version()) {
198 error(_("commit-graph hash version %X does not match version %X"),
199 hash_version, oid_version());
200 return NULL;
201 }
202
203 graph = alloc_commit_graph();
204
205 graph->hash_len = the_hash_algo->rawsz;
206 graph->num_chunks = *(unsigned char*)(data + 6);
207 graph->graph_fd = fd;
208 graph->data = graph_map;
209 graph->data_len = graph_size;
210
211 last_chunk_id = 0;
212 last_chunk_offset = 8;
213 chunk_lookup = data + 8;
214 for (i = 0; i < graph->num_chunks; i++) {
215 uint32_t chunk_id;
216 uint64_t chunk_offset;
217 int chunk_repeated = 0;
218
219 if (data + graph_size - chunk_lookup <
220 GRAPH_CHUNKLOOKUP_WIDTH) {
221 error(_("commit-graph chunk lookup table entry missing; file may be incomplete"));
222 free(graph);
223 return NULL;
224 }
225
226 chunk_id = get_be32(chunk_lookup + 0);
227 chunk_offset = get_be64(chunk_lookup + 4);
228
229 chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
230
231 if (chunk_offset > graph_size - the_hash_algo->rawsz) {
232 error(_("commit-graph improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),
233 (uint32_t)chunk_offset);
234 free(graph);
235 return NULL;
236 }
237
238 switch (chunk_id) {
239 case GRAPH_CHUNKID_OIDFANOUT:
240 if (graph->chunk_oid_fanout)
241 chunk_repeated = 1;
242 else
243 graph->chunk_oid_fanout = (uint32_t*)(data + chunk_offset);
244 break;
245
246 case GRAPH_CHUNKID_OIDLOOKUP:
247 if (graph->chunk_oid_lookup)
248 chunk_repeated = 1;
249 else
250 graph->chunk_oid_lookup = data + chunk_offset;
251 break;
252
253 case GRAPH_CHUNKID_DATA:
254 if (graph->chunk_commit_data)
255 chunk_repeated = 1;
256 else
257 graph->chunk_commit_data = data + chunk_offset;
258 break;
259
260 case GRAPH_CHUNKID_EXTRAEDGES:
261 if (graph->chunk_extra_edges)
262 chunk_repeated = 1;
263 else
264 graph->chunk_extra_edges = data + chunk_offset;
265 break;
266
267 case GRAPH_CHUNKID_BASE:
268 if (graph->chunk_base_graphs)
269 chunk_repeated = 1;
270 else
271 graph->chunk_base_graphs = data + chunk_offset;
272 }
273
274 if (chunk_repeated) {
275 error(_("commit-graph chunk id %08x appears multiple times"), chunk_id);
276 free(graph);
277 return NULL;
278 }
279
280 if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)
281 {
282 graph->num_commits = (chunk_offset - last_chunk_offset)
283 / graph->hash_len;
284 }
285
286 last_chunk_id = chunk_id;
287 last_chunk_offset = chunk_offset;
288 }
289
290 hashcpy(graph->oid.hash, graph->data + graph->data_len - graph->hash_len);
291
292 if (verify_commit_graph_lite(graph))
293 return NULL;
294
295 return graph;
296 }
297
298 static struct commit_graph *load_commit_graph_one(const char *graph_file)
299 {
300
301 struct stat st;
302 int fd;
303 struct commit_graph *g;
304 int open_ok = open_commit_graph(graph_file, &fd, &st);
305
306 if (!open_ok)
307 return NULL;
308
309 g = load_commit_graph_one_fd_st(fd, &st);
310
311 if (g)
312 g->filename = xstrdup(graph_file);
313
314 return g;
315 }
316
317 static struct commit_graph *load_commit_graph_v1(struct repository *r, const char *obj_dir)
318 {
319 char *graph_name = get_commit_graph_filename(obj_dir);
320 struct commit_graph *g = load_commit_graph_one(graph_name);
321 free(graph_name);
322
323 if (g)
324 g->obj_dir = obj_dir;
325
326 return g;
327 }
328
329 static int add_graph_to_chain(struct commit_graph *g,
330 struct commit_graph *chain,
331 struct object_id *oids,
332 int n)
333 {
334 struct commit_graph *cur_g = chain;
335
336 if (n && !g->chunk_base_graphs) {
337 warning(_("commit-graph has no base graphs chunk"));
338 return 0;
339 }
340
341 while (n) {
342 n--;
343
344 if (!cur_g ||
345 !oideq(&oids[n], &cur_g->oid) ||
346 !hasheq(oids[n].hash, g->chunk_base_graphs + g->hash_len * n)) {
347 warning(_("commit-graph chain does not match"));
348 return 0;
349 }
350
351 cur_g = cur_g->base_graph;
352 }
353
354 g->base_graph = chain;
355
356 if (chain)
357 g->num_commits_in_base = chain->num_commits + chain->num_commits_in_base;
358
359 return 1;
360 }
361
362 static struct commit_graph *load_commit_graph_chain(struct repository *r, const char *obj_dir)
363 {
364 struct commit_graph *graph_chain = NULL;
365 struct strbuf line = STRBUF_INIT;
366 struct stat st;
367 struct object_id *oids;
368 int i = 0, valid = 1, count;
369 char *chain_name = get_chain_filename(obj_dir);
370 FILE *fp;
371 int stat_res;
372
373 fp = fopen(chain_name, "r");
374 stat_res = stat(chain_name, &st);
375 free(chain_name);
376
377 if (!fp ||
378 stat_res ||
379 st.st_size <= the_hash_algo->hexsz)
380 return NULL;
381
382 count = st.st_size / (the_hash_algo->hexsz + 1);
383 oids = xcalloc(count, sizeof(struct object_id));
384
385 prepare_alt_odb(r);
386
387 for (i = 0; i < count; i++) {
388 struct object_directory *odb;
389
390 if (strbuf_getline_lf(&line, fp) == EOF)
391 break;
392
393 if (get_oid_hex(line.buf, &oids[i])) {
394 warning(_("invalid commit-graph chain: line '%s' not a hash"),
395 line.buf);
396 valid = 0;
397 break;
398 }
399
400 valid = 0;
401 for (odb = r->objects->odb; odb; odb = odb->next) {
402 char *graph_name = get_split_graph_filename(odb->path, line.buf);
403 struct commit_graph *g = load_commit_graph_one(graph_name);
404
405 free(graph_name);
406
407 if (g) {
408 g->obj_dir = odb->path;
409
410 if (add_graph_to_chain(g, graph_chain, oids, i)) {
411 graph_chain = g;
412 valid = 1;
413 }
414
415 break;
416 }
417 }
418
419 if (!valid) {
420 warning(_("unable to find all commit-graph files"));
421 break;
422 }
423 }
424
425 free(oids);
426 fclose(fp);
427
428 return graph_chain;
429 }
430
431 static struct commit_graph *read_commit_graph_one(struct repository *r, const char *obj_dir)
432 {
433 struct commit_graph *g = load_commit_graph_v1(r, obj_dir);
434
435 if (!g)
436 g = load_commit_graph_chain(r, obj_dir);
437
438 return g;
439 }
440
441 static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
442 {
443
444 if (r->objects->commit_graph)
445 return;
446
447 r->objects->commit_graph = read_commit_graph_one(r, obj_dir);
448 }
449
450 /*
451 * Return 1 if commit_graph is non-NULL, and 0 otherwise.
452 *
453 * On the first invocation, this function attemps to load the commit
454 * graph if the_repository is configured to have one.
455 */
456 static int prepare_commit_graph(struct repository *r)
457 {
458 struct object_directory *odb;
459 int config_value;
460
461 if (git_env_bool(GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD, 0))
462 die("dying as requested by the '%s' variable on commit-graph load!",
463 GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD);
464
465 if (r->objects->commit_graph_attempted)
466 return !!r->objects->commit_graph;
467 r->objects->commit_graph_attempted = 1;
468
469 if (!git_env_bool(GIT_TEST_COMMIT_GRAPH, 0) &&
470 (repo_config_get_bool(r, "core.commitgraph", &config_value) ||
471 !config_value))
472 /*
473 * This repository is not configured to use commit graphs, so
474 * do not load one. (But report commit_graph_attempted anyway
475 * so that commit graph loading is not attempted again for this
476 * repository.)
477 */
478 return 0;
479
480 if (!commit_graph_compatible(r))
481 return 0;
482
483 prepare_alt_odb(r);
484 for (odb = r->objects->odb;
485 !r->objects->commit_graph && odb;
486 odb = odb->next)
487 prepare_commit_graph_one(r, odb->path);
488 return !!r->objects->commit_graph;
489 }
490
491 int generation_numbers_enabled(struct repository *r)
492 {
493 uint32_t first_generation;
494 struct commit_graph *g;
495 if (!prepare_commit_graph(r))
496 return 0;
497
498 g = r->objects->commit_graph;
499
500 if (!g->num_commits)
501 return 0;
502
503 first_generation = get_be32(g->chunk_commit_data +
504 g->hash_len + 8) >> 2;
505
506 return !!first_generation;
507 }
508
509 static void close_commit_graph_one(struct commit_graph *g)
510 {
511 if (!g)
512 return;
513
514 close_commit_graph_one(g->base_graph);
515 free_commit_graph(g);
516 }
517
518 void close_commit_graph(struct raw_object_store *o)
519 {
520 close_commit_graph_one(o->commit_graph);
521 o->commit_graph = NULL;
522 }
523
524 static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
525 {
526 return bsearch_hash(oid->hash, g->chunk_oid_fanout,
527 g->chunk_oid_lookup, g->hash_len, pos);
528 }
529
530 static void load_oid_from_graph(struct commit_graph *g,
531 uint32_t pos,
532 struct object_id *oid)
533 {
534 uint32_t lex_index;
535
536 while (g && pos < g->num_commits_in_base)
537 g = g->base_graph;
538
539 if (!g)
540 BUG("NULL commit-graph");
541
542 if (pos >= g->num_commits + g->num_commits_in_base)
543 die(_("invalid commit position. commit-graph is likely corrupt"));
544
545 lex_index = pos - g->num_commits_in_base;
546
547 hashcpy(oid->hash, g->chunk_oid_lookup + g->hash_len * lex_index);
548 }
549
550 static struct commit_list **insert_parent_or_die(struct repository *r,
551 struct commit_graph *g,
552 uint32_t pos,
553 struct commit_list **pptr)
554 {
555 struct commit *c;
556 struct object_id oid;
557
558 if (pos >= g->num_commits + g->num_commits_in_base)
559 die("invalid parent position %"PRIu32, pos);
560
561 load_oid_from_graph(g, pos, &oid);
562 c = lookup_commit(r, &oid);
563 if (!c)
564 die(_("could not find commit %s"), oid_to_hex(&oid));
565 c->graph_pos = pos;
566 return &commit_list_insert(c, pptr)->next;
567 }
568
569 static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos)
570 {
571 const unsigned char *commit_data;
572 uint32_t lex_index;
573
574 while (pos < g->num_commits_in_base)
575 g = g->base_graph;
576
577 lex_index = pos - g->num_commits_in_base;
578 commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * lex_index;
579 item->graph_pos = pos;
580 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
581 }
582
583 static int fill_commit_in_graph(struct repository *r,
584 struct commit *item,
585 struct commit_graph *g, uint32_t pos)
586 {
587 uint32_t edge_value;
588 uint32_t *parent_data_ptr;
589 uint64_t date_low, date_high;
590 struct commit_list **pptr;
591 const unsigned char *commit_data;
592 uint32_t lex_index;
593
594 while (pos < g->num_commits_in_base)
595 g = g->base_graph;
596
597 if (pos >= g->num_commits + g->num_commits_in_base)
598 die(_("invalid commit position. commit-graph is likely corrupt"));
599
600 /*
601 * Store the "full" position, but then use the
602 * "local" position for the rest of the calculation.
603 */
604 item->graph_pos = pos;
605 lex_index = pos - g->num_commits_in_base;
606
607 commit_data = g->chunk_commit_data + (g->hash_len + 16) * lex_index;
608
609 item->object.parsed = 1;
610
611 item->maybe_tree = NULL;
612
613 date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
614 date_low = get_be32(commit_data + g->hash_len + 12);
615 item->date = (timestamp_t)((date_high << 32) | date_low);
616
617 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
618
619 pptr = &item->parents;
620
621 edge_value = get_be32(commit_data + g->hash_len);
622 if (edge_value == GRAPH_PARENT_NONE)
623 return 1;
624 pptr = insert_parent_or_die(r, g, edge_value, pptr);
625
626 edge_value = get_be32(commit_data + g->hash_len + 4);
627 if (edge_value == GRAPH_PARENT_NONE)
628 return 1;
629 if (!(edge_value & GRAPH_EXTRA_EDGES_NEEDED)) {
630 pptr = insert_parent_or_die(r, g, edge_value, pptr);
631 return 1;
632 }
633
634 parent_data_ptr = (uint32_t*)(g->chunk_extra_edges +
635 4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
636 do {
637 edge_value = get_be32(parent_data_ptr);
638 pptr = insert_parent_or_die(r, g,
639 edge_value & GRAPH_EDGE_LAST_MASK,
640 pptr);
641 parent_data_ptr++;
642 } while (!(edge_value & GRAPH_LAST_EDGE));
643
644 return 1;
645 }
646
647 static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t *pos)
648 {
649 if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
650 *pos = item->graph_pos;
651 return 1;
652 } else {
653 struct commit_graph *cur_g = g;
654 uint32_t lex_index;
655
656 while (cur_g && !bsearch_graph(cur_g, &(item->object.oid), &lex_index))
657 cur_g = cur_g->base_graph;
658
659 if (cur_g) {
660 *pos = lex_index + cur_g->num_commits_in_base;
661 return 1;
662 }
663
664 return 0;
665 }
666 }
667
668 static int parse_commit_in_graph_one(struct repository *r,
669 struct commit_graph *g,
670 struct commit *item)
671 {
672 uint32_t pos;
673
674 if (item->object.parsed)
675 return 1;
676
677 if (find_commit_in_graph(item, g, &pos))
678 return fill_commit_in_graph(r, item, g, pos);
679
680 return 0;
681 }
682
683 int parse_commit_in_graph(struct repository *r, struct commit *item)
684 {
685 if (!prepare_commit_graph(r))
686 return 0;
687 return parse_commit_in_graph_one(r, r->objects->commit_graph, item);
688 }
689
690 void load_commit_graph_info(struct repository *r, struct commit *item)
691 {
692 uint32_t pos;
693 if (!prepare_commit_graph(r))
694 return;
695 if (find_commit_in_graph(item, r->objects->commit_graph, &pos))
696 fill_commit_graph_info(item, r->objects->commit_graph, pos);
697 }
698
699 static struct tree *load_tree_for_commit(struct repository *r,
700 struct commit_graph *g,
701 struct commit *c)
702 {
703 struct object_id oid;
704 const unsigned char *commit_data;
705
706 while (c->graph_pos < g->num_commits_in_base)
707 g = g->base_graph;
708
709 commit_data = g->chunk_commit_data +
710 GRAPH_DATA_WIDTH * (c->graph_pos - g->num_commits_in_base);
711
712 hashcpy(oid.hash, commit_data);
713 c->maybe_tree = lookup_tree(r, &oid);
714
715 return c->maybe_tree;
716 }
717
718 static struct tree *get_commit_tree_in_graph_one(struct repository *r,
719 struct commit_graph *g,
720 const struct commit *c)
721 {
722 if (c->maybe_tree)
723 return c->maybe_tree;
724 if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
725 BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
726
727 return load_tree_for_commit(r, g, (struct commit *)c);
728 }
729
730 struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
731 {
732 return get_commit_tree_in_graph_one(r, r->objects->commit_graph, c);
733 }
734
735 struct packed_commit_list {
736 struct commit **list;
737 int nr;
738 int alloc;
739 };
740
741 struct packed_oid_list {
742 struct object_id *list;
743 int nr;
744 int alloc;
745 };
746
747 struct write_commit_graph_context {
748 struct repository *r;
749 const char *obj_dir;
750 char *graph_name;
751 struct packed_oid_list oids;
752 struct packed_commit_list commits;
753 int num_extra_edges;
754 unsigned long approx_nr_objects;
755 struct progress *progress;
756 int progress_done;
757 uint64_t progress_cnt;
758
759 char *base_graph_name;
760 int num_commit_graphs_before;
761 int num_commit_graphs_after;
762 char **commit_graph_filenames_before;
763 char **commit_graph_filenames_after;
764 char **commit_graph_hash_after;
765 uint32_t new_num_commits_in_base;
766 struct commit_graph *new_base_graph;
767
768 unsigned append:1,
769 report_progress:1,
770 split:1;
771 };
772
773 static void write_graph_chunk_fanout(struct hashfile *f,
774 struct write_commit_graph_context *ctx)
775 {
776 int i, count = 0;
777 struct commit **list = ctx->commits.list;
778
779 /*
780 * Write the first-level table (the list is sorted,
781 * but we use a 256-entry lookup to be able to avoid
782 * having to do eight extra binary search iterations).
783 */
784 for (i = 0; i < 256; i++) {
785 while (count < ctx->commits.nr) {
786 if ((*list)->object.oid.hash[0] != i)
787 break;
788 display_progress(ctx->progress, ++ctx->progress_cnt);
789 count++;
790 list++;
791 }
792
793 hashwrite_be32(f, count);
794 }
795 }
796
797 static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
798 struct write_commit_graph_context *ctx)
799 {
800 struct commit **list = ctx->commits.list;
801 int count;
802 for (count = 0; count < ctx->commits.nr; count++, list++) {
803 display_progress(ctx->progress, ++ctx->progress_cnt);
804 hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
805 }
806 }
807
808 static const unsigned char *commit_to_sha1(size_t index, void *table)
809 {
810 struct commit **commits = table;
811 return commits[index]->object.oid.hash;
812 }
813
814 static void write_graph_chunk_data(struct hashfile *f, int hash_len,
815 struct write_commit_graph_context *ctx)
816 {
817 struct commit **list = ctx->commits.list;
818 struct commit **last = ctx->commits.list + ctx->commits.nr;
819 uint32_t num_extra_edges = 0;
820
821 while (list < last) {
822 struct commit_list *parent;
823 int edge_value;
824 uint32_t packedDate[2];
825 display_progress(ctx->progress, ++ctx->progress_cnt);
826
827 parse_commit_no_graph(*list);
828 hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
829
830 parent = (*list)->parents;
831
832 if (!parent)
833 edge_value = GRAPH_PARENT_NONE;
834 else {
835 edge_value = sha1_pos(parent->item->object.oid.hash,
836 ctx->commits.list,
837 ctx->commits.nr,
838 commit_to_sha1);
839
840 if (edge_value >= 0)
841 edge_value += ctx->new_num_commits_in_base;
842 else {
843 uint32_t pos;
844 if (find_commit_in_graph(parent->item,
845 ctx->new_base_graph,
846 &pos))
847 edge_value = pos;
848 }
849
850 if (edge_value < 0)
851 BUG("missing parent %s for commit %s",
852 oid_to_hex(&parent->item->object.oid),
853 oid_to_hex(&(*list)->object.oid));
854 }
855
856 hashwrite_be32(f, edge_value);
857
858 if (parent)
859 parent = parent->next;
860
861 if (!parent)
862 edge_value = GRAPH_PARENT_NONE;
863 else if (parent->next)
864 edge_value = GRAPH_EXTRA_EDGES_NEEDED | num_extra_edges;
865 else {
866 edge_value = sha1_pos(parent->item->object.oid.hash,
867 ctx->commits.list,
868 ctx->commits.nr,
869 commit_to_sha1);
870
871 if (edge_value >= 0)
872 edge_value += ctx->new_num_commits_in_base;
873 else {
874 uint32_t pos;
875 if (find_commit_in_graph(parent->item,
876 ctx->new_base_graph,
877 &pos))
878 edge_value = pos;
879 }
880
881 if (edge_value < 0)
882 BUG("missing parent %s for commit %s",
883 oid_to_hex(&parent->item->object.oid),
884 oid_to_hex(&(*list)->object.oid));
885 }
886
887 hashwrite_be32(f, edge_value);
888
889 if (edge_value & GRAPH_EXTRA_EDGES_NEEDED) {
890 do {
891 num_extra_edges++;
892 parent = parent->next;
893 } while (parent);
894 }
895
896 if (sizeof((*list)->date) > 4)
897 packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
898 else
899 packedDate[0] = 0;
900
901 packedDate[0] |= htonl((*list)->generation << 2);
902
903 packedDate[1] = htonl((*list)->date);
904 hashwrite(f, packedDate, 8);
905
906 list++;
907 }
908 }
909
910 static void write_graph_chunk_extra_edges(struct hashfile *f,
911 struct write_commit_graph_context *ctx)
912 {
913 struct commit **list = ctx->commits.list;
914 struct commit **last = ctx->commits.list + ctx->commits.nr;
915 struct commit_list *parent;
916
917 while (list < last) {
918 int num_parents = 0;
919
920 display_progress(ctx->progress, ++ctx->progress_cnt);
921
922 for (parent = (*list)->parents; num_parents < 3 && parent;
923 parent = parent->next)
924 num_parents++;
925
926 if (num_parents <= 2) {
927 list++;
928 continue;
929 }
930
931 /* Since num_parents > 2, this initializer is safe. */
932 for (parent = (*list)->parents->next; parent; parent = parent->next) {
933 int edge_value = sha1_pos(parent->item->object.oid.hash,
934 ctx->commits.list,
935 ctx->commits.nr,
936 commit_to_sha1);
937
938 if (edge_value >= 0)
939 edge_value += ctx->new_num_commits_in_base;
940 else {
941 uint32_t pos;
942 if (find_commit_in_graph(parent->item,
943 ctx->new_base_graph,
944 &pos))
945 edge_value = pos;
946 }
947
948 if (edge_value < 0)
949 BUG("missing parent %s for commit %s",
950 oid_to_hex(&parent->item->object.oid),
951 oid_to_hex(&(*list)->object.oid));
952 else if (!parent->next)
953 edge_value |= GRAPH_LAST_EDGE;
954
955 hashwrite_be32(f, edge_value);
956 }
957
958 list++;
959 }
960 }
961
962 static int oid_compare(const void *_a, const void *_b)
963 {
964 const struct object_id *a = (const struct object_id *)_a;
965 const struct object_id *b = (const struct object_id *)_b;
966 return oidcmp(a, b);
967 }
968
969 static int add_packed_commits(const struct object_id *oid,
970 struct packed_git *pack,
971 uint32_t pos,
972 void *data)
973 {
974 struct write_commit_graph_context *ctx = (struct write_commit_graph_context*)data;
975 enum object_type type;
976 off_t offset = nth_packed_object_offset(pack, pos);
977 struct object_info oi = OBJECT_INFO_INIT;
978
979 if (ctx->progress)
980 display_progress(ctx->progress, ++ctx->progress_done);
981
982 oi.typep = &type;
983 if (packed_object_info(ctx->r, pack, offset, &oi) < 0)
984 die(_("unable to get type of object %s"), oid_to_hex(oid));
985
986 if (type != OBJ_COMMIT)
987 return 0;
988
989 ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
990 oidcpy(&(ctx->oids.list[ctx->oids.nr]), oid);
991 ctx->oids.nr++;
992
993 return 0;
994 }
995
996 static void add_missing_parents(struct write_commit_graph_context *ctx, struct commit *commit)
997 {
998 struct commit_list *parent;
999 for (parent = commit->parents; parent; parent = parent->next) {
1000 if (!(parent->item->object.flags & UNINTERESTING)) {
1001 ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1002 oidcpy(&ctx->oids.list[ctx->oids.nr], &(parent->item->object.oid));
1003 ctx->oids.nr++;
1004 parent->item->object.flags |= UNINTERESTING;
1005 }
1006 }
1007 }
1008
1009 static void close_reachable(struct write_commit_graph_context *ctx)
1010 {
1011 int i;
1012 struct commit *commit;
1013
1014 if (ctx->report_progress)
1015 ctx->progress = start_delayed_progress(
1016 _("Loading known commits in commit graph"),
1017 ctx->oids.nr);
1018 for (i = 0; i < ctx->oids.nr; i++) {
1019 display_progress(ctx->progress, i + 1);
1020 commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1021 if (commit)
1022 commit->object.flags |= UNINTERESTING;
1023 }
1024 stop_progress(&ctx->progress);
1025
1026 /*
1027 * As this loop runs, ctx->oids.nr may grow, but not more
1028 * than the number of missing commits in the reachable
1029 * closure.
1030 */
1031 if (ctx->report_progress)
1032 ctx->progress = start_delayed_progress(
1033 _("Expanding reachable commits in commit graph"),
1034 ctx->oids.nr);
1035 for (i = 0; i < ctx->oids.nr; i++) {
1036 display_progress(ctx->progress, i + 1);
1037 commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1038
1039 if (!commit)
1040 continue;
1041 if (ctx->split) {
1042 if (!parse_commit(commit) &&
1043 commit->graph_pos == COMMIT_NOT_FROM_GRAPH)
1044 add_missing_parents(ctx, commit);
1045 } else if (!parse_commit_no_graph(commit))
1046 add_missing_parents(ctx, commit);
1047 }
1048 stop_progress(&ctx->progress);
1049
1050 if (ctx->report_progress)
1051 ctx->progress = start_delayed_progress(
1052 _("Clearing commit marks in commit graph"),
1053 ctx->oids.nr);
1054 for (i = 0; i < ctx->oids.nr; i++) {
1055 display_progress(ctx->progress, i + 1);
1056 commit = lookup_commit(ctx->r, &ctx->oids.list[i]);
1057
1058 if (commit)
1059 commit->object.flags &= ~UNINTERESTING;
1060 }
1061 stop_progress(&ctx->progress);
1062 }
1063
1064 static void compute_generation_numbers(struct write_commit_graph_context *ctx)
1065 {
1066 int i;
1067 struct commit_list *list = NULL;
1068
1069 if (ctx->report_progress)
1070 ctx->progress = start_progress(
1071 _("Computing commit graph generation numbers"),
1072 ctx->commits.nr);
1073 for (i = 0; i < ctx->commits.nr; i++) {
1074 display_progress(ctx->progress, i + 1);
1075 if (ctx->commits.list[i]->generation != GENERATION_NUMBER_INFINITY &&
1076 ctx->commits.list[i]->generation != GENERATION_NUMBER_ZERO)
1077 continue;
1078
1079 commit_list_insert(ctx->commits.list[i], &list);
1080 while (list) {
1081 struct commit *current = list->item;
1082 struct commit_list *parent;
1083 int all_parents_computed = 1;
1084 uint32_t max_generation = 0;
1085
1086 for (parent = current->parents; parent; parent = parent->next) {
1087 if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
1088 parent->item->generation == GENERATION_NUMBER_ZERO) {
1089 all_parents_computed = 0;
1090 commit_list_insert(parent->item, &list);
1091 break;
1092 } else if (parent->item->generation > max_generation) {
1093 max_generation = parent->item->generation;
1094 }
1095 }
1096
1097 if (all_parents_computed) {
1098 current->generation = max_generation + 1;
1099 pop_commit(&list);
1100
1101 if (current->generation > GENERATION_NUMBER_MAX)
1102 current->generation = GENERATION_NUMBER_MAX;
1103 }
1104 }
1105 }
1106 stop_progress(&ctx->progress);
1107 }
1108
1109 static int add_ref_to_list(const char *refname,
1110 const struct object_id *oid,
1111 int flags, void *cb_data)
1112 {
1113 struct string_list *list = (struct string_list *)cb_data;
1114
1115 string_list_append(list, oid_to_hex(oid));
1116 return 0;
1117 }
1118
1119 int write_commit_graph_reachable(const char *obj_dir, unsigned int flags)
1120 {
1121 struct string_list list = STRING_LIST_INIT_DUP;
1122 int result;
1123
1124 for_each_ref(add_ref_to_list, &list);
1125 result = write_commit_graph(obj_dir, NULL, &list,
1126 flags);
1127
1128 string_list_clear(&list, 0);
1129 return result;
1130 }
1131
1132 static int fill_oids_from_packs(struct write_commit_graph_context *ctx,
1133 struct string_list *pack_indexes)
1134 {
1135 uint32_t i;
1136 struct strbuf progress_title = STRBUF_INIT;
1137 struct strbuf packname = STRBUF_INIT;
1138 int dirlen;
1139
1140 strbuf_addf(&packname, "%s/pack/", ctx->obj_dir);
1141 dirlen = packname.len;
1142 if (ctx->report_progress) {
1143 strbuf_addf(&progress_title,
1144 Q_("Finding commits for commit graph in %d pack",
1145 "Finding commits for commit graph in %d packs",
1146 pack_indexes->nr),
1147 pack_indexes->nr);
1148 ctx->progress = start_delayed_progress(progress_title.buf, 0);
1149 ctx->progress_done = 0;
1150 }
1151 for (i = 0; i < pack_indexes->nr; i++) {
1152 struct packed_git *p;
1153 strbuf_setlen(&packname, dirlen);
1154 strbuf_addstr(&packname, pack_indexes->items[i].string);
1155 p = add_packed_git(packname.buf, packname.len, 1);
1156 if (!p) {
1157 error(_("error adding pack %s"), packname.buf);
1158 return -1;
1159 }
1160 if (open_pack_index(p)) {
1161 error(_("error opening index for %s"), packname.buf);
1162 return -1;
1163 }
1164 for_each_object_in_pack(p, add_packed_commits, ctx,
1165 FOR_EACH_OBJECT_PACK_ORDER);
1166 close_pack(p);
1167 free(p);
1168 }
1169
1170 stop_progress(&ctx->progress);
1171 strbuf_reset(&progress_title);
1172 strbuf_release(&packname);
1173
1174 return 0;
1175 }
1176
1177 static void fill_oids_from_commit_hex(struct write_commit_graph_context *ctx,
1178 struct string_list *commit_hex)
1179 {
1180 uint32_t i;
1181 struct strbuf progress_title = STRBUF_INIT;
1182
1183 if (ctx->report_progress) {
1184 strbuf_addf(&progress_title,
1185 Q_("Finding commits for commit graph from %d ref",
1186 "Finding commits for commit graph from %d refs",
1187 commit_hex->nr),
1188 commit_hex->nr);
1189 ctx->progress = start_delayed_progress(
1190 progress_title.buf,
1191 commit_hex->nr);
1192 }
1193 for (i = 0; i < commit_hex->nr; i++) {
1194 const char *end;
1195 struct object_id oid;
1196 struct commit *result;
1197
1198 display_progress(ctx->progress, i + 1);
1199 if (commit_hex->items[i].string &&
1200 parse_oid_hex(commit_hex->items[i].string, &oid, &end))
1201 continue;
1202
1203 result = lookup_commit_reference_gently(ctx->r, &oid, 1);
1204
1205 if (result) {
1206 ALLOC_GROW(ctx->oids.list, ctx->oids.nr + 1, ctx->oids.alloc);
1207 oidcpy(&ctx->oids.list[ctx->oids.nr], &(result->object.oid));
1208 ctx->oids.nr++;
1209 }
1210 }
1211 stop_progress(&ctx->progress);
1212 strbuf_release(&progress_title);
1213 }
1214
1215 static void fill_oids_from_all_packs(struct write_commit_graph_context *ctx)
1216 {
1217 if (ctx->report_progress)
1218 ctx->progress = start_delayed_progress(
1219 _("Finding commits for commit graph among packed objects"),
1220 ctx->approx_nr_objects);
1221 for_each_packed_object(add_packed_commits, ctx,
1222 FOR_EACH_OBJECT_PACK_ORDER);
1223 if (ctx->progress_done < ctx->approx_nr_objects)
1224 display_progress(ctx->progress, ctx->approx_nr_objects);
1225 stop_progress(&ctx->progress);
1226 }
1227
1228 static uint32_t count_distinct_commits(struct write_commit_graph_context *ctx)
1229 {
1230 uint32_t i, count_distinct = 1;
1231
1232 if (ctx->report_progress)
1233 ctx->progress = start_delayed_progress(
1234 _("Counting distinct commits in commit graph"),
1235 ctx->oids.nr);
1236 display_progress(ctx->progress, 0); /* TODO: Measure QSORT() progress */
1237 QSORT(ctx->oids.list, ctx->oids.nr, oid_compare);
1238
1239 for (i = 1; i < ctx->oids.nr; i++) {
1240 display_progress(ctx->progress, i + 1);
1241 if (!oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i])) {
1242 if (ctx->split) {
1243 struct commit *c = lookup_commit(ctx->r, &ctx->oids.list[i]);
1244
1245 if (!c || c->graph_pos != COMMIT_NOT_FROM_GRAPH)
1246 continue;
1247 }
1248
1249 count_distinct++;
1250 }
1251 }
1252 stop_progress(&ctx->progress);
1253
1254 return count_distinct;
1255 }
1256
1257 static void copy_oids_to_commits(struct write_commit_graph_context *ctx)
1258 {
1259 uint32_t i;
1260 struct commit_list *parent;
1261
1262 ctx->num_extra_edges = 0;
1263 if (ctx->report_progress)
1264 ctx->progress = start_delayed_progress(
1265 _("Finding extra edges in commit graph"),
1266 ctx->oids.nr);
1267 for (i = 0; i < ctx->oids.nr; i++) {
1268 int num_parents = 0;
1269 display_progress(ctx->progress, i + 1);
1270 if (i > 0 && oideq(&ctx->oids.list[i - 1], &ctx->oids.list[i]))
1271 continue;
1272
1273 ALLOC_GROW(ctx->commits.list, ctx->commits.nr + 1, ctx->commits.alloc);
1274 ctx->commits.list[ctx->commits.nr] = lookup_commit(ctx->r, &ctx->oids.list[i]);
1275
1276 if (ctx->split &&
1277 ctx->commits.list[ctx->commits.nr]->graph_pos != COMMIT_NOT_FROM_GRAPH)
1278 continue;
1279
1280 parse_commit_no_graph(ctx->commits.list[ctx->commits.nr]);
1281
1282 for (parent = ctx->commits.list[ctx->commits.nr]->parents;
1283 parent; parent = parent->next)
1284 num_parents++;
1285
1286 if (num_parents > 2)
1287 ctx->num_extra_edges += num_parents - 1;
1288
1289 ctx->commits.nr++;
1290 }
1291 stop_progress(&ctx->progress);
1292 }
1293
1294 static int write_graph_chunk_base_1(struct hashfile *f,
1295 struct commit_graph *g)
1296 {
1297 int num = 0;
1298
1299 if (!g)
1300 return 0;
1301
1302 num = write_graph_chunk_base_1(f, g->base_graph);
1303 hashwrite(f, g->oid.hash, the_hash_algo->rawsz);
1304 return num + 1;
1305 }
1306
1307 static int write_graph_chunk_base(struct hashfile *f,
1308 struct write_commit_graph_context *ctx)
1309 {
1310 int num = write_graph_chunk_base_1(f, ctx->new_base_graph);
1311
1312 if (num != ctx->num_commit_graphs_after - 1) {
1313 error(_("failed to write correct number of base graph ids"));
1314 return -1;
1315 }
1316
1317 return 0;
1318 }
1319
1320 static int write_commit_graph_file(struct write_commit_graph_context *ctx)
1321 {
1322 uint32_t i;
1323 int fd;
1324 struct hashfile *f;
1325 struct lock_file lk = LOCK_INIT;
1326 uint32_t chunk_ids[6];
1327 uint64_t chunk_offsets[6];
1328 const unsigned hashsz = the_hash_algo->rawsz;
1329 struct strbuf progress_title = STRBUF_INIT;
1330 int num_chunks = 3;
1331 struct object_id file_hash;
1332
1333 if (ctx->split) {
1334 struct strbuf tmp_file = STRBUF_INIT;
1335
1336 strbuf_addf(&tmp_file,
1337 "%s/info/commit-graphs/tmp_graph_XXXXXX",
1338 ctx->obj_dir);
1339 ctx->graph_name = strbuf_detach(&tmp_file, NULL);
1340 } else {
1341 ctx->graph_name = get_commit_graph_filename(ctx->obj_dir);
1342 }
1343
1344 if (safe_create_leading_directories(ctx->graph_name)) {
1345 UNLEAK(ctx->graph_name);
1346 error(_("unable to create leading directories of %s"),
1347 ctx->graph_name);
1348 return -1;
1349 }
1350
1351 if (ctx->split) {
1352 char *lock_name = get_chain_filename(ctx->obj_dir);
1353
1354 hold_lock_file_for_update(&lk, lock_name, LOCK_DIE_ON_ERROR);
1355
1356 fd = git_mkstemp_mode(ctx->graph_name, 0444);
1357 if (fd < 0) {
1358 error(_("unable to create '%s'"), ctx->graph_name);
1359 return -1;
1360 }
1361
1362 f = hashfd(fd, ctx->graph_name);
1363 } else {
1364 hold_lock_file_for_update(&lk, ctx->graph_name, LOCK_DIE_ON_ERROR);
1365 fd = lk.tempfile->fd;
1366 f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
1367 }
1368
1369 chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
1370 chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
1371 chunk_ids[2] = GRAPH_CHUNKID_DATA;
1372 if (ctx->num_extra_edges) {
1373 chunk_ids[num_chunks] = GRAPH_CHUNKID_EXTRAEDGES;
1374 num_chunks++;
1375 }
1376 if (ctx->num_commit_graphs_after > 1) {
1377 chunk_ids[num_chunks] = GRAPH_CHUNKID_BASE;
1378 num_chunks++;
1379 }
1380
1381 chunk_ids[num_chunks] = 0;
1382
1383 chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
1384 chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
1385 chunk_offsets[2] = chunk_offsets[1] + hashsz * ctx->commits.nr;
1386 chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * ctx->commits.nr;
1387
1388 num_chunks = 3;
1389 if (ctx->num_extra_edges) {
1390 chunk_offsets[num_chunks + 1] = chunk_offsets[num_chunks] +
1391 4 * ctx->num_extra_edges;
1392 num_chunks++;
1393 }
1394 if (ctx->num_commit_graphs_after > 1) {
1395 chunk_offsets[num_chunks + 1] = chunk_offsets[num_chunks] +
1396 hashsz * (ctx->num_commit_graphs_after - 1);
1397 num_chunks++;
1398 }
1399
1400 hashwrite_be32(f, GRAPH_SIGNATURE);
1401
1402 hashwrite_u8(f, GRAPH_VERSION);
1403 hashwrite_u8(f, oid_version());
1404 hashwrite_u8(f, num_chunks);
1405 hashwrite_u8(f, ctx->num_commit_graphs_after - 1);
1406
1407 for (i = 0; i <= num_chunks; i++) {
1408 uint32_t chunk_write[3];
1409
1410 chunk_write[0] = htonl(chunk_ids[i]);
1411 chunk_write[1] = htonl(chunk_offsets[i] >> 32);
1412 chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
1413 hashwrite(f, chunk_write, 12);
1414 }
1415
1416 if (ctx->report_progress) {
1417 strbuf_addf(&progress_title,
1418 Q_("Writing out commit graph in %d pass",
1419 "Writing out commit graph in %d passes",
1420 num_chunks),
1421 num_chunks);
1422 ctx->progress = start_delayed_progress(
1423 progress_title.buf,
1424 num_chunks * ctx->commits.nr);
1425 }
1426 write_graph_chunk_fanout(f, ctx);
1427 write_graph_chunk_oids(f, hashsz, ctx);
1428 write_graph_chunk_data(f, hashsz, ctx);
1429 if (ctx->num_extra_edges)
1430 write_graph_chunk_extra_edges(f, ctx);
1431 if (ctx->num_commit_graphs_after > 1 &&
1432 write_graph_chunk_base(f, ctx)) {
1433 return -1;
1434 }
1435 stop_progress(&ctx->progress);
1436 strbuf_release(&progress_title);
1437
1438 if (ctx->split && ctx->base_graph_name && ctx->num_commit_graphs_after > 1) {
1439 char *new_base_hash = xstrdup(oid_to_hex(&ctx->new_base_graph->oid));
1440 char *new_base_name = get_split_graph_filename(ctx->new_base_graph->obj_dir, new_base_hash);
1441
1442 free(ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 2]);
1443 free(ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 2]);
1444 ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 2] = new_base_name;
1445 ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 2] = new_base_hash;
1446 }
1447
1448 close_commit_graph(ctx->r->objects);
1449 finalize_hashfile(f, file_hash.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
1450
1451 if (ctx->split) {
1452 FILE *chainf = fdopen_lock_file(&lk, "w");
1453 char *final_graph_name;
1454 int result;
1455
1456 close(fd);
1457
1458 if (!chainf) {
1459 error(_("unable to open commit-graph chain file"));
1460 return -1;
1461 }
1462
1463 if (ctx->base_graph_name) {
1464 const char *dest = ctx->commit_graph_filenames_after[
1465 ctx->num_commit_graphs_after - 2];
1466
1467 if (strcmp(ctx->base_graph_name, dest)) {
1468 result = rename(ctx->base_graph_name, dest);
1469
1470 if (result) {
1471 error(_("failed to rename base commit-graph file"));
1472 return -1;
1473 }
1474 }
1475 } else {
1476 char *graph_name = get_commit_graph_filename(ctx->obj_dir);
1477 unlink(graph_name);
1478 }
1479
1480 ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 1] = xstrdup(oid_to_hex(&file_hash));
1481 final_graph_name = get_split_graph_filename(ctx->obj_dir,
1482 ctx->commit_graph_hash_after[ctx->num_commit_graphs_after - 1]);
1483 ctx->commit_graph_filenames_after[ctx->num_commit_graphs_after - 1] = final_graph_name;
1484
1485 result = rename(ctx->graph_name, final_graph_name);
1486
1487 for (i = 0; i < ctx->num_commit_graphs_after; i++)
1488 fprintf(lk.tempfile->fp, "%s\n", ctx->commit_graph_hash_after[i]);
1489
1490 if (result) {
1491 error(_("failed to rename temporary commit-graph file"));
1492 return -1;
1493 }
1494 }
1495
1496 commit_lock_file(&lk);
1497
1498 return 0;
1499 }
1500
1501 static int split_strategy_max_commits = 64000;
1502 static float split_strategy_size_mult = 2.0f;
1503
1504 static void split_graph_merge_strategy(struct write_commit_graph_context *ctx)
1505 {
1506 struct commit_graph *g = ctx->r->objects->commit_graph;
1507 uint32_t num_commits = ctx->commits.nr;
1508 uint32_t i;
1509
1510 g = ctx->r->objects->commit_graph;
1511 ctx->num_commit_graphs_after = ctx->num_commit_graphs_before + 1;
1512
1513 while (g && (g->num_commits <= split_strategy_size_mult * num_commits ||
1514 num_commits > split_strategy_max_commits)) {
1515 if (strcmp(g->obj_dir, ctx->obj_dir))
1516 break;
1517
1518 num_commits += g->num_commits;
1519 g = g->base_graph;
1520
1521 ctx->num_commit_graphs_after--;
1522 }
1523
1524 ctx->new_base_graph = g;
1525
1526 if (ctx->num_commit_graphs_after == 2) {
1527 char *old_graph_name = get_commit_graph_filename(g->obj_dir);
1528
1529 if (!strcmp(g->filename, old_graph_name) &&
1530 strcmp(g->obj_dir, ctx->obj_dir)) {
1531 ctx->num_commit_graphs_after = 1;
1532 ctx->new_base_graph = NULL;
1533 }
1534
1535 free(old_graph_name);
1536 }
1537
1538 ALLOC_ARRAY(ctx->commit_graph_filenames_after, ctx->num_commit_graphs_after);
1539 ALLOC_ARRAY(ctx->commit_graph_hash_after, ctx->num_commit_graphs_after);
1540
1541 for (i = 0; i < ctx->num_commit_graphs_after &&
1542 i < ctx->num_commit_graphs_before; i++)
1543 ctx->commit_graph_filenames_after[i] = xstrdup(ctx->commit_graph_filenames_before[i]);
1544
1545 i = ctx->num_commit_graphs_before - 1;
1546 g = ctx->r->objects->commit_graph;
1547
1548 while (g) {
1549 if (i < ctx->num_commit_graphs_after)
1550 ctx->commit_graph_hash_after[i] = xstrdup(oid_to_hex(&g->oid));
1551
1552 i--;
1553 g = g->base_graph;
1554 }
1555 }
1556
1557 static void merge_commit_graph(struct write_commit_graph_context *ctx,
1558 struct commit_graph *g)
1559 {
1560 uint32_t i;
1561 uint32_t offset = g->num_commits_in_base;
1562
1563 ALLOC_GROW(ctx->commits.list, ctx->commits.nr + g->num_commits, ctx->commits.alloc);
1564
1565 for (i = 0; i < g->num_commits; i++) {
1566 struct object_id oid;
1567 struct commit *result;
1568
1569 display_progress(ctx->progress, i + 1);
1570
1571 load_oid_from_graph(g, i + offset, &oid);
1572
1573 /* only add commits if they still exist in the repo */
1574 result = lookup_commit_reference_gently(ctx->r, &oid, 1);
1575
1576 if (result) {
1577 ctx->commits.list[ctx->commits.nr] = result;
1578 ctx->commits.nr++;
1579 }
1580 }
1581 }
1582
1583 static int commit_compare(const void *_a, const void *_b)
1584 {
1585 const struct commit *a = *(const struct commit **)_a;
1586 const struct commit *b = *(const struct commit **)_b;
1587 return oidcmp(&a->object.oid, &b->object.oid);
1588 }
1589
1590 static void sort_and_scan_merged_commits(struct write_commit_graph_context *ctx)
1591 {
1592 uint32_t i, num_parents;
1593 struct commit_list *parent;
1594
1595 if (ctx->report_progress)
1596 ctx->progress = start_delayed_progress(
1597 _("Scanning merged commits"),
1598 ctx->commits.nr);
1599
1600 QSORT(ctx->commits.list, ctx->commits.nr, commit_compare);
1601
1602 ctx->num_extra_edges = 0;
1603 for (i = 0; i < ctx->commits.nr; i++) {
1604 display_progress(ctx->progress, i);
1605
1606 if (i && oideq(&ctx->commits.list[i - 1]->object.oid,
1607 &ctx->commits.list[i]->object.oid)) {
1608 die(_("unexpected duplicate commit id %s"),
1609 oid_to_hex(&ctx->commits.list[i]->object.oid));
1610 } else {
1611 num_parents = 0;
1612 for (parent = ctx->commits.list[i]->parents; parent; parent = parent->next)
1613 num_parents++;
1614
1615 if (num_parents > 2)
1616 ctx->num_extra_edges += num_parents - 2;
1617 }
1618 }
1619
1620 stop_progress(&ctx->progress);
1621 }
1622
1623 static void merge_commit_graphs(struct write_commit_graph_context *ctx)
1624 {
1625 struct commit_graph *g = ctx->r->objects->commit_graph;
1626 uint32_t current_graph_number = ctx->num_commit_graphs_before;
1627 struct strbuf progress_title = STRBUF_INIT;
1628
1629 while (g && current_graph_number >= ctx->num_commit_graphs_after) {
1630 current_graph_number--;
1631
1632 if (ctx->report_progress) {
1633 strbuf_addstr(&progress_title, _("Merging commit-graph"));
1634 ctx->progress = start_delayed_progress(progress_title.buf, 0);
1635 }
1636
1637 merge_commit_graph(ctx, g);
1638 stop_progress(&ctx->progress);
1639 strbuf_release(&progress_title);
1640
1641 g = g->base_graph;
1642 }
1643
1644 if (g) {
1645 ctx->new_base_graph = g;
1646 ctx->new_num_commits_in_base = g->num_commits + g->num_commits_in_base;
1647 }
1648
1649 if (ctx->new_base_graph)
1650 ctx->base_graph_name = xstrdup(ctx->new_base_graph->filename);
1651
1652 sort_and_scan_merged_commits(ctx);
1653 }
1654
1655 int write_commit_graph(const char *obj_dir,
1656 struct string_list *pack_indexes,
1657 struct string_list *commit_hex,
1658 unsigned int flags)
1659 {
1660 struct write_commit_graph_context *ctx;
1661 uint32_t i, count_distinct = 0;
1662 int res = 0;
1663
1664 if (!commit_graph_compatible(the_repository))
1665 return 0;
1666
1667 ctx = xcalloc(1, sizeof(struct write_commit_graph_context));
1668 ctx->r = the_repository;
1669 ctx->obj_dir = obj_dir;
1670 ctx->append = flags & COMMIT_GRAPH_APPEND ? 1 : 0;
1671 ctx->report_progress = flags & COMMIT_GRAPH_PROGRESS ? 1 : 0;
1672 ctx->split = flags & COMMIT_GRAPH_SPLIT ? 1 : 0;
1673
1674 if (ctx->split) {
1675 struct commit_graph *g;
1676 prepare_commit_graph(ctx->r);
1677
1678 g = ctx->r->objects->commit_graph;
1679
1680 while (g) {
1681 ctx->num_commit_graphs_before++;
1682 g = g->base_graph;
1683 }
1684
1685 if (ctx->num_commit_graphs_before) {
1686 ALLOC_ARRAY(ctx->commit_graph_filenames_before, ctx->num_commit_graphs_before);
1687 i = ctx->num_commit_graphs_before;
1688 g = ctx->r->objects->commit_graph;
1689
1690 while (g) {
1691 ctx->commit_graph_filenames_before[--i] = xstrdup(g->filename);
1692 g = g->base_graph;
1693 }
1694 }
1695 }
1696
1697 ctx->approx_nr_objects = approximate_object_count();
1698 ctx->oids.alloc = ctx->approx_nr_objects / 32;
1699
1700 if (ctx->split && ctx->oids.alloc > split_strategy_max_commits)
1701 ctx->oids.alloc = split_strategy_max_commits;
1702
1703 if (ctx->append) {
1704 prepare_commit_graph_one(ctx->r, ctx->obj_dir);
1705 if (ctx->r->objects->commit_graph)
1706 ctx->oids.alloc += ctx->r->objects->commit_graph->num_commits;
1707 }
1708
1709 if (ctx->oids.alloc < 1024)
1710 ctx->oids.alloc = 1024;
1711 ALLOC_ARRAY(ctx->oids.list, ctx->oids.alloc);
1712
1713 if (ctx->append && ctx->r->objects->commit_graph) {
1714 struct commit_graph *g = ctx->r->objects->commit_graph;
1715 for (i = 0; i < g->num_commits; i++) {
1716 const unsigned char *hash = g->chunk_oid_lookup + g->hash_len * i;
1717 hashcpy(ctx->oids.list[ctx->oids.nr++].hash, hash);
1718 }
1719 }
1720
1721 if (pack_indexes) {
1722 if ((res = fill_oids_from_packs(ctx, pack_indexes)))
1723 goto cleanup;
1724 }
1725
1726 if (commit_hex)
1727 fill_oids_from_commit_hex(ctx, commit_hex);
1728
1729 if (!pack_indexes && !commit_hex)
1730 fill_oids_from_all_packs(ctx);
1731
1732 close_reachable(ctx);
1733
1734 count_distinct = count_distinct_commits(ctx);
1735
1736 if (count_distinct >= GRAPH_EDGE_LAST_MASK) {
1737 error(_("the commit graph format cannot write %d commits"), count_distinct);
1738 res = -1;
1739 goto cleanup;
1740 }
1741
1742 ctx->commits.alloc = count_distinct;
1743 ALLOC_ARRAY(ctx->commits.list, ctx->commits.alloc);
1744
1745 copy_oids_to_commits(ctx);
1746
1747 if (ctx->commits.nr >= GRAPH_EDGE_LAST_MASK) {
1748 error(_("too many commits to write graph"));
1749 res = -1;
1750 goto cleanup;
1751 }
1752
1753 if (!ctx->commits.nr)
1754 goto cleanup;
1755
1756 if (ctx->split) {
1757 split_graph_merge_strategy(ctx);
1758
1759 merge_commit_graphs(ctx);
1760 } else
1761 ctx->num_commit_graphs_after = 1;
1762
1763 compute_generation_numbers(ctx);
1764
1765 res = write_commit_graph_file(ctx);
1766
1767 cleanup:
1768 free(ctx->graph_name);
1769 free(ctx->commits.list);
1770 free(ctx->oids.list);
1771
1772 if (ctx->commit_graph_filenames_after) {
1773 for (i = 0; i < ctx->num_commit_graphs_after; i++) {
1774 free(ctx->commit_graph_filenames_after[i]);
1775 free(ctx->commit_graph_hash_after[i]);
1776 }
1777
1778 for (i = 0; i < ctx->num_commit_graphs_before; i++)
1779 free(ctx->commit_graph_filenames_before[i]);
1780
1781 free(ctx->commit_graph_filenames_after);
1782 free(ctx->commit_graph_filenames_before);
1783 free(ctx->commit_graph_hash_after);
1784 }
1785
1786 free(ctx);
1787
1788 return res;
1789 }
1790
1791 #define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
1792 static int verify_commit_graph_error;
1793
1794 static void graph_report(const char *fmt, ...)
1795 {
1796 va_list ap;
1797
1798 verify_commit_graph_error = 1;
1799 va_start(ap, fmt);
1800 vfprintf(stderr, fmt, ap);
1801 fprintf(stderr, "\n");
1802 va_end(ap);
1803 }
1804
1805 #define GENERATION_ZERO_EXISTS 1
1806 #define GENERATION_NUMBER_EXISTS 2
1807
1808 int verify_commit_graph(struct repository *r, struct commit_graph *g)
1809 {
1810 uint32_t i, cur_fanout_pos = 0;
1811 struct object_id prev_oid, cur_oid, checksum;
1812 int generation_zero = 0;
1813 struct hashfile *f;
1814 int devnull;
1815 struct progress *progress = NULL;
1816
1817 if (!g) {
1818 graph_report("no commit-graph file loaded");
1819 return 1;
1820 }
1821
1822 verify_commit_graph_error = verify_commit_graph_lite(g);
1823 if (verify_commit_graph_error)
1824 return verify_commit_graph_error;
1825
1826 devnull = open("/dev/null", O_WRONLY);
1827 f = hashfd(devnull, NULL);
1828 hashwrite(f, g->data, g->data_len - g->hash_len);
1829 finalize_hashfile(f, checksum.hash, CSUM_CLOSE);
1830 if (!hasheq(checksum.hash, g->data + g->data_len - g->hash_len)) {
1831 graph_report(_("the commit-graph file has incorrect checksum and is likely corrupt"));
1832 verify_commit_graph_error = VERIFY_COMMIT_GRAPH_ERROR_HASH;
1833 }
1834
1835 for (i = 0; i < g->num_commits; i++) {
1836 struct commit *graph_commit;
1837
1838 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1839
1840 if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
1841 graph_report(_("commit-graph has incorrect OID order: %s then %s"),
1842 oid_to_hex(&prev_oid),
1843 oid_to_hex(&cur_oid));
1844
1845 oidcpy(&prev_oid, &cur_oid);
1846
1847 while (cur_oid.hash[0] > cur_fanout_pos) {
1848 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1849
1850 if (i != fanout_value)
1851 graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1852 cur_fanout_pos, fanout_value, i);
1853 cur_fanout_pos++;
1854 }
1855
1856 graph_commit = lookup_commit(r, &cur_oid);
1857 if (!parse_commit_in_graph_one(r, g, graph_commit))
1858 graph_report(_("failed to parse commit %s from commit-graph"),
1859 oid_to_hex(&cur_oid));
1860 }
1861
1862 while (cur_fanout_pos < 256) {
1863 uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
1864
1865 if (g->num_commits != fanout_value)
1866 graph_report(_("commit-graph has incorrect fanout value: fanout[%d] = %u != %u"),
1867 cur_fanout_pos, fanout_value, i);
1868
1869 cur_fanout_pos++;
1870 }
1871
1872 if (verify_commit_graph_error & ~VERIFY_COMMIT_GRAPH_ERROR_HASH)
1873 return verify_commit_graph_error;
1874
1875 progress = start_progress(_("Verifying commits in commit graph"),
1876 g->num_commits);
1877 for (i = 0; i < g->num_commits; i++) {
1878 struct commit *graph_commit, *odb_commit;
1879 struct commit_list *graph_parents, *odb_parents;
1880 uint32_t max_generation = 0;
1881
1882 display_progress(progress, i + 1);
1883 hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
1884
1885 graph_commit = lookup_commit(r, &cur_oid);
1886 odb_commit = (struct commit *)create_object(r, cur_oid.hash, alloc_commit_node(r));
1887 if (parse_commit_internal(odb_commit, 0, 0)) {
1888 graph_report(_("failed to parse commit %s from object database for commit-graph"),
1889 oid_to_hex(&cur_oid));
1890 continue;
1891 }
1892
1893 if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
1894 get_commit_tree_oid(odb_commit)))
1895 graph_report(_("root tree OID for commit %s in commit-graph is %s != %s"),
1896 oid_to_hex(&cur_oid),
1897 oid_to_hex(get_commit_tree_oid(graph_commit)),
1898 oid_to_hex(get_commit_tree_oid(odb_commit)));
1899
1900 graph_parents = graph_commit->parents;
1901 odb_parents = odb_commit->parents;
1902
1903 while (graph_parents) {
1904 if (odb_parents == NULL) {
1905 graph_report(_("commit-graph parent list for commit %s is too long"),
1906 oid_to_hex(&cur_oid));
1907 break;
1908 }
1909
1910 if (!oideq(&graph_parents->item->object.oid, &odb_parents->item->object.oid))
1911 graph_report(_("commit-graph parent for %s is %s != %s"),
1912 oid_to_hex(&cur_oid),
1913 oid_to_hex(&graph_parents->item->object.oid),
1914 oid_to_hex(&odb_parents->item->object.oid));
1915
1916 if (graph_parents->item->generation > max_generation)
1917 max_generation = graph_parents->item->generation;
1918
1919 graph_parents = graph_parents->next;
1920 odb_parents = odb_parents->next;
1921 }
1922
1923 if (odb_parents != NULL)
1924 graph_report(_("commit-graph parent list for commit %s terminates early"),
1925 oid_to_hex(&cur_oid));
1926
1927 if (!graph_commit->generation) {
1928 if (generation_zero == GENERATION_NUMBER_EXISTS)
1929 graph_report(_("commit-graph has generation number zero for commit %s, but non-zero elsewhere"),
1930 oid_to_hex(&cur_oid));
1931 generation_zero = GENERATION_ZERO_EXISTS;
1932 } else if (generation_zero == GENERATION_ZERO_EXISTS)
1933 graph_report(_("commit-graph has non-zero generation number for commit %s, but zero elsewhere"),
1934 oid_to_hex(&cur_oid));
1935
1936 if (generation_zero == GENERATION_ZERO_EXISTS)
1937 continue;
1938
1939 /*
1940 * If one of our parents has generation GENERATION_NUMBER_MAX, then
1941 * our generation is also GENERATION_NUMBER_MAX. Decrement to avoid
1942 * extra logic in the following condition.
1943 */
1944 if (max_generation == GENERATION_NUMBER_MAX)
1945 max_generation--;
1946
1947 if (graph_commit->generation != max_generation + 1)
1948 graph_report(_("commit-graph generation for commit %s is %u != %u"),
1949 oid_to_hex(&cur_oid),
1950 graph_commit->generation,
1951 max_generation + 1);
1952
1953 if (graph_commit->date != odb_commit->date)
1954 graph_report(_("commit date for commit %s in commit-graph is %"PRItime" != %"PRItime),
1955 oid_to_hex(&cur_oid),
1956 graph_commit->date,
1957 odb_commit->date);
1958 }
1959 stop_progress(&progress);
1960
1961 return verify_commit_graph_error;
1962 }
1963
1964 void free_commit_graph(struct commit_graph *g)
1965 {
1966 if (!g)
1967 return;
1968 if (g->graph_fd >= 0) {
1969 munmap((void *)g->data, g->data_len);
1970 g->data = NULL;
1971 close(g->graph_fd);
1972 }
1973 free(g->filename);
1974 free(g);
1975 }