Merge tag 'v2.14.1'
[git/raj.git] / shallow.c
blob54359d549075b5cfe1670ca979ff3cf5eeedc9d1
1 #include "cache.h"
2 #include "tempfile.h"
3 #include "lockfile.h"
4 #include "commit.h"
5 #include "tag.h"
6 #include "pkt-line.h"
7 #include "remote.h"
8 #include "refs.h"
9 #include "sha1-array.h"
10 #include "diff.h"
11 #include "revision.h"
12 #include "commit-slab.h"
13 #include "revision.h"
14 #include "list-objects.h"
16 static int is_shallow = -1;
17 static struct stat_validity shallow_stat;
18 static char *alternate_shallow_file;
20 void set_alternate_shallow_file(const char *path, int override)
22 if (is_shallow != -1)
23 die("BUG: is_repository_shallow must not be called before set_alternate_shallow_file");
24 if (alternate_shallow_file && !override)
25 return;
26 free(alternate_shallow_file);
27 alternate_shallow_file = xstrdup_or_null(path);
30 int register_shallow(const struct object_id *oid)
32 struct commit_graft *graft =
33 xmalloc(sizeof(struct commit_graft));
34 struct commit *commit = lookup_commit(oid);
36 oidcpy(&graft->oid, oid);
37 graft->nr_parent = -1;
38 if (commit && commit->object.parsed)
39 commit->parents = NULL;
40 return register_commit_graft(graft, 0);
43 int is_repository_shallow(void)
45 FILE *fp;
46 char buf[1024];
47 const char *path = alternate_shallow_file;
49 if (is_shallow >= 0)
50 return is_shallow;
52 if (!path)
53 path = git_path_shallow();
55 * fetch-pack sets '--shallow-file ""' as an indicator that no
56 * shallow file should be used. We could just open it and it
57 * will likely fail. But let's do an explicit check instead.
59 if (!*path || (fp = fopen(path, "r")) == NULL) {
60 stat_validity_clear(&shallow_stat);
61 is_shallow = 0;
62 return is_shallow;
64 stat_validity_update(&shallow_stat, fileno(fp));
65 is_shallow = 1;
67 while (fgets(buf, sizeof(buf), fp)) {
68 struct object_id oid;
69 if (get_oid_hex(buf, &oid))
70 die("bad shallow line: %s", buf);
71 register_shallow(&oid);
73 fclose(fp);
74 return is_shallow;
77 struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
78 int shallow_flag, int not_shallow_flag)
80 int i = 0, cur_depth = 0;
81 struct commit_list *result = NULL;
82 struct object_array stack = OBJECT_ARRAY_INIT;
83 struct commit *commit = NULL;
84 struct commit_graft *graft;
86 while (commit || i < heads->nr || stack.nr) {
87 struct commit_list *p;
88 if (!commit) {
89 if (i < heads->nr) {
90 commit = (struct commit *)
91 deref_tag(heads->objects[i++].item, NULL, 0);
92 if (!commit || commit->object.type != OBJ_COMMIT) {
93 commit = NULL;
94 continue;
96 if (!commit->util)
97 commit->util = xmalloc(sizeof(int));
98 *(int *)commit->util = 0;
99 cur_depth = 0;
100 } else {
101 commit = (struct commit *)
102 stack.objects[--stack.nr].item;
103 cur_depth = *(int *)commit->util;
106 parse_commit_or_die(commit);
107 cur_depth++;
108 if ((depth != INFINITE_DEPTH && cur_depth >= depth) ||
109 (is_repository_shallow() && !commit->parents &&
110 (graft = lookup_commit_graft(commit->object.oid.hash)) != NULL &&
111 graft->nr_parent < 0)) {
112 commit_list_insert(commit, &result);
113 commit->object.flags |= shallow_flag;
114 commit = NULL;
115 continue;
117 commit->object.flags |= not_shallow_flag;
118 for (p = commit->parents, commit = NULL; p; p = p->next) {
119 if (!p->item->util) {
120 int *pointer = xmalloc(sizeof(int));
121 p->item->util = pointer;
122 *pointer = cur_depth;
123 } else {
124 int *pointer = p->item->util;
125 if (cur_depth >= *pointer)
126 continue;
127 *pointer = cur_depth;
129 if (p->next)
130 add_object_array(&p->item->object,
131 NULL, &stack);
132 else {
133 commit = p->item;
134 cur_depth = *(int *)commit->util;
139 return result;
142 static void show_commit(struct commit *commit, void *data)
144 commit_list_insert(commit, data);
148 * Given rev-list arguments, run rev-list. All reachable commits
149 * except border ones are marked with not_shallow_flag. Border commits
150 * are marked with shallow_flag. The list of border/shallow commits
151 * are also returned.
153 struct commit_list *get_shallow_commits_by_rev_list(int ac, const char **av,
154 int shallow_flag,
155 int not_shallow_flag)
157 struct commit_list *result = NULL, *p;
158 struct commit_list *not_shallow_list = NULL;
159 struct rev_info revs;
160 int both_flags = shallow_flag | not_shallow_flag;
163 * SHALLOW (excluded) and NOT_SHALLOW (included) should not be
164 * set at this point. But better be safe than sorry.
166 clear_object_flags(both_flags);
168 is_repository_shallow(); /* make sure shallows are read */
170 init_revisions(&revs, NULL);
171 save_commit_buffer = 0;
172 setup_revisions(ac, av, &revs, NULL);
174 if (prepare_revision_walk(&revs))
175 die("revision walk setup failed");
176 traverse_commit_list(&revs, show_commit, NULL, &not_shallow_list);
178 /* Mark all reachable commits as NOT_SHALLOW */
179 for (p = not_shallow_list; p; p = p->next)
180 p->item->object.flags |= not_shallow_flag;
183 * mark border commits SHALLOW + NOT_SHALLOW.
184 * We cannot clear NOT_SHALLOW right now. Imagine border
185 * commit A is processed first, then commit B, whose parent is
186 * A, later. If NOT_SHALLOW on A is cleared at step 1, B
187 * itself is considered border at step 2, which is incorrect.
189 for (p = not_shallow_list; p; p = p->next) {
190 struct commit *c = p->item;
191 struct commit_list *parent;
193 if (parse_commit(c))
194 die("unable to parse commit %s",
195 oid_to_hex(&c->object.oid));
197 for (parent = c->parents; parent; parent = parent->next)
198 if (!(parent->item->object.flags & not_shallow_flag)) {
199 c->object.flags |= shallow_flag;
200 commit_list_insert(c, &result);
201 break;
204 free_commit_list(not_shallow_list);
207 * Now we can clean up NOT_SHALLOW on border commits. Having
208 * both flags set can confuse the caller.
210 for (p = result; p; p = p->next) {
211 struct object *o = &p->item->object;
212 if ((o->flags & both_flags) == both_flags)
213 o->flags &= ~not_shallow_flag;
215 return result;
218 static void check_shallow_file_for_update(void)
220 if (is_shallow == -1)
221 die("BUG: shallow must be initialized by now");
223 if (!stat_validity_check(&shallow_stat, git_path_shallow()))
224 die("shallow file has changed since we read it");
227 #define SEEN_ONLY 1
228 #define VERBOSE 2
230 struct write_shallow_data {
231 struct strbuf *out;
232 int use_pack_protocol;
233 int count;
234 unsigned flags;
237 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
239 struct write_shallow_data *data = cb_data;
240 const char *hex = oid_to_hex(&graft->oid);
241 if (graft->nr_parent != -1)
242 return 0;
243 if (data->flags & SEEN_ONLY) {
244 struct commit *c = lookup_commit(&graft->oid);
245 if (!c || !(c->object.flags & SEEN)) {
246 if (data->flags & VERBOSE)
247 printf("Removing %s from .git/shallow\n",
248 oid_to_hex(&c->object.oid));
249 return 0;
252 data->count++;
253 if (data->use_pack_protocol)
254 packet_buf_write(data->out, "shallow %s", hex);
255 else {
256 strbuf_addstr(data->out, hex);
257 strbuf_addch(data->out, '\n');
259 return 0;
262 static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
263 const struct oid_array *extra,
264 unsigned flags)
266 struct write_shallow_data data;
267 int i;
268 data.out = out;
269 data.use_pack_protocol = use_pack_protocol;
270 data.count = 0;
271 data.flags = flags;
272 for_each_commit_graft(write_one_shallow, &data);
273 if (!extra)
274 return data.count;
275 for (i = 0; i < extra->nr; i++) {
276 strbuf_addstr(out, oid_to_hex(extra->oid + i));
277 strbuf_addch(out, '\n');
278 data.count++;
280 return data.count;
283 int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
284 const struct oid_array *extra)
286 return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
289 static struct tempfile temporary_shallow;
291 const char *setup_temporary_shallow(const struct oid_array *extra)
293 struct strbuf sb = STRBUF_INIT;
294 int fd;
296 if (write_shallow_commits(&sb, 0, extra)) {
297 fd = xmks_tempfile(&temporary_shallow, git_path("shallow_XXXXXX"));
299 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
300 die_errno("failed to write to %s",
301 get_tempfile_path(&temporary_shallow));
302 close_tempfile(&temporary_shallow);
303 strbuf_release(&sb);
304 return get_tempfile_path(&temporary_shallow);
307 * is_repository_shallow() sees empty string as "no shallow
308 * file".
310 return get_tempfile_path(&temporary_shallow);
313 void setup_alternate_shallow(struct lock_file *shallow_lock,
314 const char **alternate_shallow_file,
315 const struct oid_array *extra)
317 struct strbuf sb = STRBUF_INIT;
318 int fd;
320 fd = hold_lock_file_for_update(shallow_lock, git_path_shallow(),
321 LOCK_DIE_ON_ERROR);
322 check_shallow_file_for_update();
323 if (write_shallow_commits(&sb, 0, extra)) {
324 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
325 die_errno("failed to write to %s",
326 get_lock_file_path(shallow_lock));
327 *alternate_shallow_file = get_lock_file_path(shallow_lock);
328 } else
330 * is_repository_shallow() sees empty string as "no
331 * shallow file".
333 *alternate_shallow_file = "";
334 strbuf_release(&sb);
337 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
339 int fd = *(int *)cb;
340 if (graft->nr_parent == -1)
341 packet_write_fmt(fd, "shallow %s\n", oid_to_hex(&graft->oid));
342 return 0;
345 void advertise_shallow_grafts(int fd)
347 if (!is_repository_shallow())
348 return;
349 for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
353 * mark_reachable_objects() should have been run prior to this and all
354 * reachable commits marked as "SEEN".
356 void prune_shallow(int show_only)
358 static struct lock_file shallow_lock;
359 struct strbuf sb = STRBUF_INIT;
360 int fd;
362 if (show_only) {
363 write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY | VERBOSE);
364 strbuf_release(&sb);
365 return;
367 fd = hold_lock_file_for_update(&shallow_lock, git_path_shallow(),
368 LOCK_DIE_ON_ERROR);
369 check_shallow_file_for_update();
370 if (write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY)) {
371 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
372 die_errno("failed to write to %s",
373 get_lock_file_path(&shallow_lock));
374 commit_lock_file(&shallow_lock);
375 } else {
376 unlink(git_path_shallow());
377 rollback_lock_file(&shallow_lock);
379 strbuf_release(&sb);
382 struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
385 * Step 1, split sender shallow commits into "ours" and "theirs"
386 * Step 2, clean "ours" based on .git/shallow
388 void prepare_shallow_info(struct shallow_info *info, struct oid_array *sa)
390 int i;
391 trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
392 memset(info, 0, sizeof(*info));
393 info->shallow = sa;
394 if (!sa)
395 return;
396 ALLOC_ARRAY(info->ours, sa->nr);
397 ALLOC_ARRAY(info->theirs, sa->nr);
398 for (i = 0; i < sa->nr; i++) {
399 if (has_object_file(sa->oid + i)) {
400 struct commit_graft *graft;
401 graft = lookup_commit_graft(sa->oid[i].hash);
402 if (graft && graft->nr_parent < 0)
403 continue;
404 info->ours[info->nr_ours++] = i;
405 } else
406 info->theirs[info->nr_theirs++] = i;
410 void clear_shallow_info(struct shallow_info *info)
412 free(info->ours);
413 free(info->theirs);
416 /* Step 4, remove non-existent ones in "theirs" after getting the pack */
418 void remove_nonexistent_theirs_shallow(struct shallow_info *info)
420 struct object_id *oid = info->shallow->oid;
421 int i, dst;
422 trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
423 for (i = dst = 0; i < info->nr_theirs; i++) {
424 if (i != dst)
425 info->theirs[dst] = info->theirs[i];
426 if (has_object_file(oid + info->theirs[i]))
427 dst++;
429 info->nr_theirs = dst;
432 define_commit_slab(ref_bitmap, uint32_t *);
434 #define POOL_SIZE (512 * 1024)
436 struct paint_info {
437 struct ref_bitmap ref_bitmap;
438 unsigned nr_bits;
439 char **pools;
440 char *free, *end;
441 unsigned pool_count;
444 static uint32_t *paint_alloc(struct paint_info *info)
446 unsigned nr = DIV_ROUND_UP(info->nr_bits, 32);
447 unsigned size = nr * sizeof(uint32_t);
448 void *p;
449 if (!info->pool_count || size > info->end - info->free) {
450 if (size > POOL_SIZE)
451 die("BUG: pool size too small for %d in paint_alloc()",
452 size);
453 info->pool_count++;
454 REALLOC_ARRAY(info->pools, info->pool_count);
455 info->free = xmalloc(POOL_SIZE);
456 info->pools[info->pool_count - 1] = info->free;
457 info->end = info->free + POOL_SIZE;
459 p = info->free;
460 info->free += size;
461 return p;
465 * Given a commit SHA-1, walk down to parents until either SEEN,
466 * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
467 * all walked commits.
469 static void paint_down(struct paint_info *info, const struct object_id *oid,
470 unsigned int id)
472 unsigned int i, nr;
473 struct commit_list *head = NULL;
474 int bitmap_nr = DIV_ROUND_UP(info->nr_bits, 32);
475 size_t bitmap_size = st_mult(sizeof(uint32_t), bitmap_nr);
476 struct commit *c = lookup_commit_reference_gently(oid, 1);
477 uint32_t *tmp; /* to be freed before return */
478 uint32_t *bitmap;
480 if (!c)
481 return;
483 tmp = xmalloc(bitmap_size);
484 bitmap = paint_alloc(info);
485 memset(bitmap, 0, bitmap_size);
486 bitmap[id / 32] |= (1U << (id % 32));
487 commit_list_insert(c, &head);
488 while (head) {
489 struct commit_list *p;
490 struct commit *c = pop_commit(&head);
491 uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
493 /* XXX check "UNINTERESTING" from pack bitmaps if available */
494 if (c->object.flags & (SEEN | UNINTERESTING))
495 continue;
496 else
497 c->object.flags |= SEEN;
499 if (*refs == NULL)
500 *refs = bitmap;
501 else {
502 memcpy(tmp, *refs, bitmap_size);
503 for (i = 0; i < bitmap_nr; i++)
504 tmp[i] |= bitmap[i];
505 if (memcmp(tmp, *refs, bitmap_size)) {
506 *refs = paint_alloc(info);
507 memcpy(*refs, tmp, bitmap_size);
511 if (c->object.flags & BOTTOM)
512 continue;
514 if (parse_commit(c))
515 die("unable to parse commit %s",
516 oid_to_hex(&c->object.oid));
518 for (p = c->parents; p; p = p->next) {
519 if (p->item->object.flags & SEEN)
520 continue;
521 commit_list_insert(p->item, &head);
525 nr = get_max_object_index();
526 for (i = 0; i < nr; i++) {
527 struct object *o = get_indexed_object(i);
528 if (o && o->type == OBJ_COMMIT)
529 o->flags &= ~SEEN;
532 free(tmp);
535 static int mark_uninteresting(const char *refname, const struct object_id *oid,
536 int flags, void *cb_data)
538 struct commit *commit = lookup_commit_reference_gently(oid, 1);
539 if (!commit)
540 return 0;
541 commit->object.flags |= UNINTERESTING;
542 mark_parents_uninteresting(commit);
543 return 0;
546 static void post_assign_shallow(struct shallow_info *info,
547 struct ref_bitmap *ref_bitmap,
548 int *ref_status);
550 * Step 6(+7), associate shallow commits with new refs
552 * info->ref must be initialized before calling this function.
554 * If used is not NULL, it's an array of info->shallow->nr
555 * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
556 * m-th shallow commit from info->shallow.
558 * If used is NULL, "ours" and "theirs" are updated. And if ref_status
559 * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
560 * the ref needs some shallow commits from either info->ours or
561 * info->theirs.
563 void assign_shallow_commits_to_refs(struct shallow_info *info,
564 uint32_t **used, int *ref_status)
566 struct object_id *oid = info->shallow->oid;
567 struct oid_array *ref = info->ref;
568 unsigned int i, nr;
569 int *shallow, nr_shallow = 0;
570 struct paint_info pi;
572 trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
573 ALLOC_ARRAY(shallow, info->nr_ours + info->nr_theirs);
574 for (i = 0; i < info->nr_ours; i++)
575 shallow[nr_shallow++] = info->ours[i];
576 for (i = 0; i < info->nr_theirs; i++)
577 shallow[nr_shallow++] = info->theirs[i];
580 * Prepare the commit graph to track what refs can reach what
581 * (new) shallow commits.
583 nr = get_max_object_index();
584 for (i = 0; i < nr; i++) {
585 struct object *o = get_indexed_object(i);
586 if (!o || o->type != OBJ_COMMIT)
587 continue;
589 o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
592 memset(&pi, 0, sizeof(pi));
593 init_ref_bitmap(&pi.ref_bitmap);
594 pi.nr_bits = ref->nr;
597 * "--not --all" to cut short the traversal if new refs
598 * connect to old refs. If not (e.g. force ref updates) it'll
599 * have to go down to the current shallow commits.
601 head_ref(mark_uninteresting, NULL);
602 for_each_ref(mark_uninteresting, NULL);
604 /* Mark potential bottoms so we won't go out of bound */
605 for (i = 0; i < nr_shallow; i++) {
606 struct commit *c = lookup_commit(&oid[shallow[i]]);
607 c->object.flags |= BOTTOM;
610 for (i = 0; i < ref->nr; i++)
611 paint_down(&pi, ref->oid + i, i);
613 if (used) {
614 int bitmap_size = DIV_ROUND_UP(pi.nr_bits, 32) * sizeof(uint32_t);
615 memset(used, 0, sizeof(*used) * info->shallow->nr);
616 for (i = 0; i < nr_shallow; i++) {
617 const struct commit *c = lookup_commit(&oid[shallow[i]]);
618 uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
619 if (*map)
620 used[shallow[i]] = xmemdupz(*map, bitmap_size);
623 * unreachable shallow commits are not removed from
624 * "ours" and "theirs". The user is supposed to run
625 * step 7 on every ref separately and not trust "ours"
626 * and "theirs" any more.
628 } else
629 post_assign_shallow(info, &pi.ref_bitmap, ref_status);
631 clear_ref_bitmap(&pi.ref_bitmap);
632 for (i = 0; i < pi.pool_count; i++)
633 free(pi.pools[i]);
634 free(pi.pools);
635 free(shallow);
638 struct commit_array {
639 struct commit **commits;
640 int nr, alloc;
643 static int add_ref(const char *refname, const struct object_id *oid,
644 int flags, void *cb_data)
646 struct commit_array *ca = cb_data;
647 ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
648 ca->commits[ca->nr] = lookup_commit_reference_gently(oid, 1);
649 if (ca->commits[ca->nr])
650 ca->nr++;
651 return 0;
654 static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
656 unsigned int i;
657 if (!ref_status)
658 return;
659 for (i = 0; i < nr; i++)
660 if (bitmap[i / 32] & (1U << (i % 32)))
661 ref_status[i]++;
665 * Step 7, reachability test on "ours" at commit level
667 static void post_assign_shallow(struct shallow_info *info,
668 struct ref_bitmap *ref_bitmap,
669 int *ref_status)
671 struct object_id *oid = info->shallow->oid;
672 struct commit *c;
673 uint32_t **bitmap;
674 int dst, i, j;
675 int bitmap_nr = DIV_ROUND_UP(info->ref->nr, 32);
676 struct commit_array ca;
678 trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
679 if (ref_status)
680 memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);
682 /* Remove unreachable shallow commits from "theirs" */
683 for (i = dst = 0; i < info->nr_theirs; i++) {
684 if (i != dst)
685 info->theirs[dst] = info->theirs[i];
686 c = lookup_commit(&oid[info->theirs[i]]);
687 bitmap = ref_bitmap_at(ref_bitmap, c);
688 if (!*bitmap)
689 continue;
690 for (j = 0; j < bitmap_nr; j++)
691 if (bitmap[0][j]) {
692 update_refstatus(ref_status, info->ref->nr, *bitmap);
693 dst++;
694 break;
697 info->nr_theirs = dst;
699 memset(&ca, 0, sizeof(ca));
700 head_ref(add_ref, &ca);
701 for_each_ref(add_ref, &ca);
703 /* Remove unreachable shallow commits from "ours" */
704 for (i = dst = 0; i < info->nr_ours; i++) {
705 if (i != dst)
706 info->ours[dst] = info->ours[i];
707 c = lookup_commit(&oid[info->ours[i]]);
708 bitmap = ref_bitmap_at(ref_bitmap, c);
709 if (!*bitmap)
710 continue;
711 for (j = 0; j < bitmap_nr; j++)
712 if (bitmap[0][j] &&
713 /* Step 7, reachability test at commit level */
714 !in_merge_bases_many(c, ca.nr, ca.commits)) {
715 update_refstatus(ref_status, info->ref->nr, *bitmap);
716 dst++;
717 break;
720 info->nr_ours = dst;
722 free(ca.commits);
725 /* (Delayed) step 7, reachability test at commit level */
726 int delayed_reachability_test(struct shallow_info *si, int c)
728 if (si->need_reachability_test[c]) {
729 struct commit *commit = lookup_commit(&si->shallow->oid[c]);
731 if (!si->commits) {
732 struct commit_array ca;
734 memset(&ca, 0, sizeof(ca));
735 head_ref(add_ref, &ca);
736 for_each_ref(add_ref, &ca);
737 si->commits = ca.commits;
738 si->nr_commits = ca.nr;
741 si->reachable[c] = in_merge_bases_many(commit,
742 si->nr_commits,
743 si->commits);
744 si->need_reachability_test[c] = 0;
746 return si->reachable[c];