]> git.ipfire.org Git - thirdparty/git.git/blame - commit-graph.c
commit: use generations in paint_down_to_common()
[thirdparty/git.git] / commit-graph.c
CommitLineData
08fd81c9
DS
1#include "cache.h"
2#include "config.h"
3#include "git-compat-util.h"
4#include "lockfile.h"
5#include "pack.h"
6#include "packfile.h"
7#include "commit.h"
8#include "object.h"
9#include "revision.h"
10#include "sha1-lookup.h"
11#include "commit-graph.h"
12
13#define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */
14#define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
15#define GRAPH_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
16#define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */
17#define GRAPH_CHUNKID_LARGEEDGES 0x45444745 /* "EDGE" */
18
19#define GRAPH_DATA_WIDTH 36
20
21#define GRAPH_VERSION_1 0x1
22#define GRAPH_VERSION GRAPH_VERSION_1
23
24#define GRAPH_OID_VERSION_SHA1 1
25#define GRAPH_OID_LEN_SHA1 GIT_SHA1_RAWSZ
26#define GRAPH_OID_VERSION GRAPH_OID_VERSION_SHA1
27#define GRAPH_OID_LEN GRAPH_OID_LEN_SHA1
28
29#define GRAPH_OCTOPUS_EDGES_NEEDED 0x80000000
30#define GRAPH_PARENT_MISSING 0x7fffffff
31#define GRAPH_EDGE_LAST_MASK 0x7fffffff
32#define GRAPH_PARENT_NONE 0x70000000
33
34#define GRAPH_LAST_EDGE 0x80000000
35
36#define GRAPH_FANOUT_SIZE (4 * 256)
37#define GRAPH_CHUNKLOOKUP_WIDTH 12
38#define GRAPH_MIN_SIZE (5 * GRAPH_CHUNKLOOKUP_WIDTH + GRAPH_FANOUT_SIZE + \
39 GRAPH_OID_LEN + 8)
40
2a2e32bd 41char *get_commit_graph_filename(const char *obj_dir)
08fd81c9
DS
42{
43 return xstrfmt("%s/info/commit-graph", obj_dir);
44}
45
2a2e32bd
DS
46static struct commit_graph *alloc_commit_graph(void)
47{
48 struct commit_graph *g = xcalloc(1, sizeof(*g));
49 g->graph_fd = -1;
50
51 return g;
52}
53
54struct commit_graph *load_commit_graph_one(const char *graph_file)
55{
56 void *graph_map;
57 const unsigned char *data, *chunk_lookup;
58 size_t graph_size;
59 struct stat st;
60 uint32_t i;
61 struct commit_graph *graph;
62 int fd = git_open(graph_file);
63 uint64_t last_chunk_offset;
64 uint32_t last_chunk_id;
65 uint32_t graph_signature;
66 unsigned char graph_version, hash_version;
67
68 if (fd < 0)
69 return NULL;
70 if (fstat(fd, &st)) {
71 close(fd);
72 return NULL;
73 }
74 graph_size = xsize_t(st.st_size);
75
76 if (graph_size < GRAPH_MIN_SIZE) {
77 close(fd);
78 die("graph file %s is too small", graph_file);
79 }
80 graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
81 data = (const unsigned char *)graph_map;
82
83 graph_signature = get_be32(data);
84 if (graph_signature != GRAPH_SIGNATURE) {
85 error("graph signature %X does not match signature %X",
86 graph_signature, GRAPH_SIGNATURE);
87 goto cleanup_fail;
88 }
89
90 graph_version = *(unsigned char*)(data + 4);
91 if (graph_version != GRAPH_VERSION) {
92 error("graph version %X does not match version %X",
93 graph_version, GRAPH_VERSION);
94 goto cleanup_fail;
95 }
96
97 hash_version = *(unsigned char*)(data + 5);
98 if (hash_version != GRAPH_OID_VERSION) {
99 error("hash version %X does not match version %X",
100 hash_version, GRAPH_OID_VERSION);
101 goto cleanup_fail;
102 }
103
104 graph = alloc_commit_graph();
105
106 graph->hash_len = GRAPH_OID_LEN;
107 graph->num_chunks = *(unsigned char*)(data + 6);
108 graph->graph_fd = fd;
109 graph->data = graph_map;
110 graph->data_len = graph_size;
111
112 last_chunk_id = 0;
113 last_chunk_offset = 8;
114 chunk_lookup = data + 8;
115 for (i = 0; i < graph->num_chunks; i++) {
116 uint32_t chunk_id = get_be32(chunk_lookup + 0);
117 uint64_t chunk_offset = get_be64(chunk_lookup + 4);
118 int chunk_repeated = 0;
119
120 chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
121
122 if (chunk_offset > graph_size - GIT_MAX_RAWSZ) {
123 error("improper chunk offset %08x%08x", (uint32_t)(chunk_offset >> 32),
124 (uint32_t)chunk_offset);
125 goto cleanup_fail;
126 }
127
128 switch (chunk_id) {
129 case GRAPH_CHUNKID_OIDFANOUT:
130 if (graph->chunk_oid_fanout)
131 chunk_repeated = 1;
132 else
133 graph->chunk_oid_fanout = (uint32_t*)(data + chunk_offset);
134 break;
135
136 case GRAPH_CHUNKID_OIDLOOKUP:
137 if (graph->chunk_oid_lookup)
138 chunk_repeated = 1;
139 else
140 graph->chunk_oid_lookup = data + chunk_offset;
141 break;
142
143 case GRAPH_CHUNKID_DATA:
144 if (graph->chunk_commit_data)
145 chunk_repeated = 1;
146 else
147 graph->chunk_commit_data = data + chunk_offset;
148 break;
149
150 case GRAPH_CHUNKID_LARGEEDGES:
151 if (graph->chunk_large_edges)
152 chunk_repeated = 1;
153 else
154 graph->chunk_large_edges = data + chunk_offset;
155 break;
156 }
157
158 if (chunk_repeated) {
159 error("chunk id %08x appears multiple times", chunk_id);
160 goto cleanup_fail;
161 }
162
163 if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)
164 {
165 graph->num_commits = (chunk_offset - last_chunk_offset)
166 / graph->hash_len;
167 }
168
169 last_chunk_id = chunk_id;
170 last_chunk_offset = chunk_offset;
171 }
172
173 return graph;
174
175cleanup_fail:
176 munmap(graph_map, graph_size);
177 close(fd);
178 exit(1);
179}
180
177722b3
DS
181/* global storage */
182static struct commit_graph *commit_graph = NULL;
183
184static void prepare_commit_graph_one(const char *obj_dir)
185{
186 char *graph_name;
187
188 if (commit_graph)
189 return;
190
191 graph_name = get_commit_graph_filename(obj_dir);
192 commit_graph = load_commit_graph_one(graph_name);
193
194 FREE_AND_NULL(graph_name);
195}
196
197static int prepare_commit_graph_run_once = 0;
198static void prepare_commit_graph(void)
199{
200 struct alternate_object_database *alt;
201 char *obj_dir;
202
203 if (prepare_commit_graph_run_once)
204 return;
205 prepare_commit_graph_run_once = 1;
206
207 obj_dir = get_object_directory();
208 prepare_commit_graph_one(obj_dir);
209 prepare_alt_odb();
210 for (alt = alt_odb_list; !commit_graph && alt; alt = alt->next)
211 prepare_commit_graph_one(alt->path);
212}
213
214static void close_commit_graph(void)
215{
216 if (!commit_graph)
217 return;
218
219 if (commit_graph->graph_fd >= 0) {
220 munmap((void *)commit_graph->data, commit_graph->data_len);
221 commit_graph->data = NULL;
222 close(commit_graph->graph_fd);
223 }
224
225 FREE_AND_NULL(commit_graph);
226}
227
228static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t *pos)
229{
230 return bsearch_hash(oid->hash, g->chunk_oid_fanout,
231 g->chunk_oid_lookup, g->hash_len, pos);
232}
233
234static struct commit_list **insert_parent_or_die(struct commit_graph *g,
235 uint64_t pos,
236 struct commit_list **pptr)
237{
238 struct commit *c;
239 struct object_id oid;
240 hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
241 c = lookup_commit(&oid);
242 if (!c)
243 die("could not find commit %s", oid_to_hex(&oid));
244 c->graph_pos = pos;
245 return &commit_list_insert(c, pptr)->next;
246}
247
248static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)
249{
177722b3
DS
250 uint32_t edge_value;
251 uint32_t *parent_data_ptr;
252 uint64_t date_low, date_high;
253 struct commit_list **pptr;
254 const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos;
255
256 item->object.parsed = 1;
257 item->graph_pos = pos;
258
7b8a21db 259 item->maybe_tree = NULL;
177722b3
DS
260
261 date_high = get_be32(commit_data + g->hash_len + 8) & 0x3;
262 date_low = get_be32(commit_data + g->hash_len + 12);
263 item->date = (timestamp_t)((date_high << 32) | date_low);
264
83073cc9
DS
265 item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
266
177722b3
DS
267 pptr = &item->parents;
268
269 edge_value = get_be32(commit_data + g->hash_len);
270 if (edge_value == GRAPH_PARENT_NONE)
271 return 1;
272 pptr = insert_parent_or_die(g, edge_value, pptr);
273
274 edge_value = get_be32(commit_data + g->hash_len + 4);
275 if (edge_value == GRAPH_PARENT_NONE)
276 return 1;
277 if (!(edge_value & GRAPH_OCTOPUS_EDGES_NEEDED)) {
278 pptr = insert_parent_or_die(g, edge_value, pptr);
279 return 1;
280 }
281
282 parent_data_ptr = (uint32_t*)(g->chunk_large_edges +
283 4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
284 do {
285 edge_value = get_be32(parent_data_ptr);
286 pptr = insert_parent_or_die(g,
287 edge_value & GRAPH_EDGE_LAST_MASK,
288 pptr);
289 parent_data_ptr++;
290 } while (!(edge_value & GRAPH_LAST_EDGE));
291
292 return 1;
293}
294
295int parse_commit_in_graph(struct commit *item)
296{
297 if (!core_commit_graph)
298 return 0;
299 if (item->object.parsed)
300 return 1;
301
302 prepare_commit_graph();
303 if (commit_graph) {
304 uint32_t pos;
305 int found;
306 if (item->graph_pos != COMMIT_NOT_FROM_GRAPH) {
307 pos = item->graph_pos;
308 found = 1;
309 } else {
310 found = bsearch_graph(commit_graph, &(item->object.oid), &pos);
311 }
312
313 if (found)
314 return fill_commit_in_graph(item, commit_graph, pos);
315 }
316
317 return 0;
318}
319
7b8a21db
DS
320static struct tree *load_tree_for_commit(struct commit_graph *g, struct commit *c)
321{
322 struct object_id oid;
323 const unsigned char *commit_data = g->chunk_commit_data +
324 GRAPH_DATA_WIDTH * (c->graph_pos);
325
326 hashcpy(oid.hash, commit_data);
327 c->maybe_tree = lookup_tree(&oid);
328
329 return c->maybe_tree;
330}
331
332struct tree *get_commit_tree_in_graph(const struct commit *c)
333{
334 if (c->maybe_tree)
335 return c->maybe_tree;
336 if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
337 BUG("get_commit_tree_in_graph called from non-commit-graph commit");
338
339 return load_tree_for_commit(commit_graph, (struct commit *)c);
340}
341
08fd81c9
DS
342static void write_graph_chunk_fanout(struct hashfile *f,
343 struct commit **commits,
344 int nr_commits)
345{
346 int i, count = 0;
347 struct commit **list = commits;
348
349 /*
350 * Write the first-level table (the list is sorted,
351 * but we use a 256-entry lookup to be able to avoid
352 * having to do eight extra binary search iterations).
353 */
354 for (i = 0; i < 256; i++) {
355 while (count < nr_commits) {
356 if ((*list)->object.oid.hash[0] != i)
357 break;
358 count++;
359 list++;
360 }
361
362 hashwrite_be32(f, count);
363 }
364}
365
366static void write_graph_chunk_oids(struct hashfile *f, int hash_len,
367 struct commit **commits, int nr_commits)
368{
369 struct commit **list = commits;
370 int count;
371 for (count = 0; count < nr_commits; count++, list++)
372 hashwrite(f, (*list)->object.oid.hash, (int)hash_len);
373}
374
375static const unsigned char *commit_to_sha1(size_t index, void *table)
376{
377 struct commit **commits = table;
378 return commits[index]->object.oid.hash;
379}
380
381static void write_graph_chunk_data(struct hashfile *f, int hash_len,
382 struct commit **commits, int nr_commits)
383{
384 struct commit **list = commits;
385 struct commit **last = commits + nr_commits;
386 uint32_t num_extra_edges = 0;
387
388 while (list < last) {
389 struct commit_list *parent;
390 int edge_value;
391 uint32_t packedDate[2];
392
393 parse_commit(*list);
2e27bd77 394 hashwrite(f, get_commit_tree_oid(*list)->hash, hash_len);
08fd81c9
DS
395
396 parent = (*list)->parents;
397
398 if (!parent)
399 edge_value = GRAPH_PARENT_NONE;
400 else {
401 edge_value = sha1_pos(parent->item->object.oid.hash,
402 commits,
403 nr_commits,
404 commit_to_sha1);
405
406 if (edge_value < 0)
407 edge_value = GRAPH_PARENT_MISSING;
408 }
409
410 hashwrite_be32(f, edge_value);
411
412 if (parent)
413 parent = parent->next;
414
415 if (!parent)
416 edge_value = GRAPH_PARENT_NONE;
417 else if (parent->next)
418 edge_value = GRAPH_OCTOPUS_EDGES_NEEDED | num_extra_edges;
419 else {
420 edge_value = sha1_pos(parent->item->object.oid.hash,
421 commits,
422 nr_commits,
423 commit_to_sha1);
424 if (edge_value < 0)
425 edge_value = GRAPH_PARENT_MISSING;
426 }
427
428 hashwrite_be32(f, edge_value);
429
430 if (edge_value & GRAPH_OCTOPUS_EDGES_NEEDED) {
431 do {
432 num_extra_edges++;
433 parent = parent->next;
434 } while (parent);
435 }
436
437 if (sizeof((*list)->date) > 4)
438 packedDate[0] = htonl(((*list)->date >> 32) & 0x3);
439 else
440 packedDate[0] = 0;
441
3258c663
DS
442 packedDate[0] |= htonl((*list)->generation << 2);
443
08fd81c9
DS
444 packedDate[1] = htonl((*list)->date);
445 hashwrite(f, packedDate, 8);
446
447 list++;
448 }
449}
450
451static void write_graph_chunk_large_edges(struct hashfile *f,
452 struct commit **commits,
453 int nr_commits)
454{
455 struct commit **list = commits;
456 struct commit **last = commits + nr_commits;
457 struct commit_list *parent;
458
459 while (list < last) {
460 int num_parents = 0;
461 for (parent = (*list)->parents; num_parents < 3 && parent;
462 parent = parent->next)
463 num_parents++;
464
465 if (num_parents <= 2) {
466 list++;
467 continue;
468 }
469
470 /* Since num_parents > 2, this initializer is safe. */
471 for (parent = (*list)->parents->next; parent; parent = parent->next) {
472 int edge_value = sha1_pos(parent->item->object.oid.hash,
473 commits,
474 nr_commits,
475 commit_to_sha1);
476
477 if (edge_value < 0)
478 edge_value = GRAPH_PARENT_MISSING;
479 else if (!parent->next)
480 edge_value |= GRAPH_LAST_EDGE;
481
482 hashwrite_be32(f, edge_value);
483 }
484
485 list++;
486 }
487}
488
489static int commit_compare(const void *_a, const void *_b)
490{
491 const struct object_id *a = (const struct object_id *)_a;
492 const struct object_id *b = (const struct object_id *)_b;
493 return oidcmp(a, b);
494}
495
496struct packed_commit_list {
497 struct commit **list;
498 int nr;
499 int alloc;
500};
501
502struct packed_oid_list {
503 struct object_id *list;
504 int nr;
505 int alloc;
506};
507
508static int add_packed_commits(const struct object_id *oid,
509 struct packed_git *pack,
510 uint32_t pos,
511 void *data)
512{
513 struct packed_oid_list *list = (struct packed_oid_list*)data;
514 enum object_type type;
515 off_t offset = nth_packed_object_offset(pack, pos);
516 struct object_info oi = OBJECT_INFO_INIT;
517
518 oi.typep = &type;
519 if (packed_object_info(pack, offset, &oi) < 0)
520 die("unable to get type of object %s", oid_to_hex(oid));
521
522 if (type != OBJ_COMMIT)
523 return 0;
524
525 ALLOC_GROW(list->list, list->nr + 1, list->alloc);
526 oidcpy(&(list->list[list->nr]), oid);
527 list->nr++;
528
529 return 0;
530}
531
4f2542b4
DS
532static void add_missing_parents(struct packed_oid_list *oids, struct commit *commit)
533{
534 struct commit_list *parent;
535 for (parent = commit->parents; parent; parent = parent->next) {
536 if (!(parent->item->object.flags & UNINTERESTING)) {
537 ALLOC_GROW(oids->list, oids->nr + 1, oids->alloc);
538 oidcpy(&oids->list[oids->nr], &(parent->item->object.oid));
539 oids->nr++;
540 parent->item->object.flags |= UNINTERESTING;
541 }
542 }
543}
544
545static void close_reachable(struct packed_oid_list *oids)
546{
547 int i;
548 struct commit *commit;
549
550 for (i = 0; i < oids->nr; i++) {
551 commit = lookup_commit(&oids->list[i]);
552 if (commit)
553 commit->object.flags |= UNINTERESTING;
554 }
555
556 /*
557 * As this loop runs, oids->nr may grow, but not more
558 * than the number of missing commits in the reachable
559 * closure.
560 */
561 for (i = 0; i < oids->nr; i++) {
562 commit = lookup_commit(&oids->list[i]);
563
564 if (commit && !parse_commit(commit))
565 add_missing_parents(oids, commit);
566 }
567
568 for (i = 0; i < oids->nr; i++) {
569 commit = lookup_commit(&oids->list[i]);
570
571 if (commit)
572 commit->object.flags &= ~UNINTERESTING;
573 }
574}
575
3258c663
DS
576static void compute_generation_numbers(struct packed_commit_list* commits)
577{
578 int i;
579 struct commit_list *list = NULL;
580
581 for (i = 0; i < commits->nr; i++) {
582 if (commits->list[i]->generation != GENERATION_NUMBER_INFINITY &&
583 commits->list[i]->generation != GENERATION_NUMBER_ZERO)
584 continue;
585
586 commit_list_insert(commits->list[i], &list);
587 while (list) {
588 struct commit *current = list->item;
589 struct commit_list *parent;
590 int all_parents_computed = 1;
591 uint32_t max_generation = 0;
592
593 for (parent = current->parents; parent; parent = parent->next) {
594 if (parent->item->generation == GENERATION_NUMBER_INFINITY ||
595 parent->item->generation == GENERATION_NUMBER_ZERO) {
596 all_parents_computed = 0;
597 commit_list_insert(parent->item, &list);
598 break;
599 } else if (parent->item->generation > max_generation) {
600 max_generation = parent->item->generation;
601 }
602 }
603
604 if (all_parents_computed) {
605 current->generation = max_generation + 1;
606 pop_commit(&list);
607
608 if (current->generation > GENERATION_NUMBER_MAX)
609 current->generation = GENERATION_NUMBER_MAX;
610 }
611 }
612 }
613}
614
049d51a2
DS
615void write_commit_graph(const char *obj_dir,
616 const char **pack_indexes,
3d5df01b
DS
617 int nr_packs,
618 const char **commit_hex,
7547b95b
DS
619 int nr_commits,
620 int append)
08fd81c9
DS
621{
622 struct packed_oid_list oids;
623 struct packed_commit_list commits;
624 struct hashfile *f;
625 uint32_t i, count_distinct = 0;
626 char *graph_name;
627 int fd;
628 struct lock_file lk = LOCK_INIT;
629 uint32_t chunk_ids[5];
630 uint64_t chunk_offsets[5];
631 int num_chunks;
632 int num_extra_edges;
633 struct commit_list *parent;
634
635 oids.nr = 0;
636 oids.alloc = approximate_object_count() / 4;
637
7547b95b
DS
638 if (append) {
639 prepare_commit_graph_one(obj_dir);
640 if (commit_graph)
641 oids.alloc += commit_graph->num_commits;
642 }
643
08fd81c9
DS
644 if (oids.alloc < 1024)
645 oids.alloc = 1024;
646 ALLOC_ARRAY(oids.list, oids.alloc);
647
7547b95b
DS
648 if (append && commit_graph) {
649 for (i = 0; i < commit_graph->num_commits; i++) {
650 const unsigned char *hash = commit_graph->chunk_oid_lookup +
651 commit_graph->hash_len * i;
652 hashcpy(oids.list[oids.nr++].hash, hash);
653 }
654 }
655
049d51a2
DS
656 if (pack_indexes) {
657 struct strbuf packname = STRBUF_INIT;
658 int dirlen;
659 strbuf_addf(&packname, "%s/pack/", obj_dir);
660 dirlen = packname.len;
661 for (i = 0; i < nr_packs; i++) {
662 struct packed_git *p;
663 strbuf_setlen(&packname, dirlen);
664 strbuf_addstr(&packname, pack_indexes[i]);
665 p = add_packed_git(packname.buf, packname.len, 1);
666 if (!p)
667 die("error adding pack %s", packname.buf);
668 if (open_pack_index(p))
669 die("error opening index for %s", packname.buf);
670 for_each_object_in_pack(p, add_packed_commits, &oids);
671 close_pack(p);
672 }
673 strbuf_release(&packname);
3d5df01b
DS
674 }
675
676 if (commit_hex) {
677 for (i = 0; i < nr_commits; i++) {
678 const char *end;
679 struct object_id oid;
680 struct commit *result;
681
682 if (commit_hex[i] && parse_oid_hex(commit_hex[i], &oid, &end))
683 continue;
684
685 result = lookup_commit_reference_gently(&oid, 1);
686
687 if (result) {
688 ALLOC_GROW(oids.list, oids.nr + 1, oids.alloc);
689 oidcpy(&oids.list[oids.nr], &(result->object.oid));
690 oids.nr++;
691 }
692 }
693 }
694
695 if (!pack_indexes && !commit_hex)
049d51a2
DS
696 for_each_packed_object(add_packed_commits, &oids, 0);
697
4f2542b4 698 close_reachable(&oids);
08fd81c9
DS
699
700 QSORT(oids.list, oids.nr, commit_compare);
701
702 count_distinct = 1;
703 for (i = 1; i < oids.nr; i++) {
704 if (oidcmp(&oids.list[i-1], &oids.list[i]))
705 count_distinct++;
706 }
707
708 if (count_distinct >= GRAPH_PARENT_MISSING)
709 die(_("the commit graph format cannot write %d commits"), count_distinct);
710
711 commits.nr = 0;
712 commits.alloc = count_distinct;
713 ALLOC_ARRAY(commits.list, commits.alloc);
714
715 num_extra_edges = 0;
716 for (i = 0; i < oids.nr; i++) {
717 int num_parents = 0;
718 if (i > 0 && !oidcmp(&oids.list[i-1], &oids.list[i]))
719 continue;
720
721 commits.list[commits.nr] = lookup_commit(&oids.list[i]);
722 parse_commit(commits.list[commits.nr]);
723
724 for (parent = commits.list[commits.nr]->parents;
725 parent; parent = parent->next)
726 num_parents++;
727
728 if (num_parents > 2)
729 num_extra_edges += num_parents - 1;
730
731 commits.nr++;
732 }
733 num_chunks = num_extra_edges ? 4 : 3;
734
735 if (commits.nr >= GRAPH_PARENT_MISSING)
736 die(_("too many commits to write graph"));
737
3258c663
DS
738 compute_generation_numbers(&commits);
739
08fd81c9
DS
740 graph_name = get_commit_graph_filename(obj_dir);
741 fd = hold_lock_file_for_update(&lk, graph_name, 0);
742
743 if (fd < 0) {
744 struct strbuf folder = STRBUF_INIT;
745 strbuf_addstr(&folder, graph_name);
746 strbuf_setlen(&folder, strrchr(folder.buf, '/') - folder.buf);
747
748 if (mkdir(folder.buf, 0777) < 0)
749 die_errno(_("cannot mkdir %s"), folder.buf);
750 strbuf_release(&folder);
751
752 fd = hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
753
754 if (fd < 0)
755 die_errno("unable to create '%s'", graph_name);
756 }
757
758 f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
759
760 hashwrite_be32(f, GRAPH_SIGNATURE);
761
762 hashwrite_u8(f, GRAPH_VERSION);
763 hashwrite_u8(f, GRAPH_OID_VERSION);
764 hashwrite_u8(f, num_chunks);
765 hashwrite_u8(f, 0); /* unused padding byte */
766
767 chunk_ids[0] = GRAPH_CHUNKID_OIDFANOUT;
768 chunk_ids[1] = GRAPH_CHUNKID_OIDLOOKUP;
769 chunk_ids[2] = GRAPH_CHUNKID_DATA;
770 if (num_extra_edges)
771 chunk_ids[3] = GRAPH_CHUNKID_LARGEEDGES;
772 else
773 chunk_ids[3] = 0;
774 chunk_ids[4] = 0;
775
776 chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
777 chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
778 chunk_offsets[2] = chunk_offsets[1] + GRAPH_OID_LEN * commits.nr;
779 chunk_offsets[3] = chunk_offsets[2] + (GRAPH_OID_LEN + 16) * commits.nr;
780 chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
781
782 for (i = 0; i <= num_chunks; i++) {
783 uint32_t chunk_write[3];
784
785 chunk_write[0] = htonl(chunk_ids[i]);
786 chunk_write[1] = htonl(chunk_offsets[i] >> 32);
787 chunk_write[2] = htonl(chunk_offsets[i] & 0xffffffff);
788 hashwrite(f, chunk_write, 12);
789 }
790
791 write_graph_chunk_fanout(f, commits.list, commits.nr);
792 write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr);
793 write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr);
794 write_graph_chunk_large_edges(f, commits.list, commits.nr);
795
177722b3 796 close_commit_graph();
08fd81c9
DS
797 finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
798 commit_lock_file(&lk);
799
800 free(oids.list);
801 oids.alloc = 0;
802 oids.nr = 0;
803}