git

1
#define USE_THE_REPOSITORY_VARIABLE
2

3
#include "git-compat-util.h"
4
#include "hex.h"
5
#include "repository.h"
6
#include "tempfile.h"
7
#include "lockfile.h"
8
#include "object-store-ll.h"
9
#include "commit.h"
10
#include "tag.h"
11
#include "pkt-line.h"
12
#include "refs.h"
13
#include "oid-array.h"
14
#include "path.h"
15
#include "diff.h"
16
#include "revision.h"
17
#include "commit-slab.h"
18
#include "list-objects.h"
19
#include "commit-reach.h"
20
#include "shallow.h"
21
#include "statinfo.h"
22
#include "trace.h"
23

24
void set_alternate_shallow_file(struct repository *r, const char *path, int override)
25
{
26
	if (r->parsed_objects->is_shallow != -1)
27
		BUG("is_repository_shallow must not be called before set_alternate_shallow_file");
28
	if (r->parsed_objects->alternate_shallow_file && !override)
29
		return;
30
	free(r->parsed_objects->alternate_shallow_file);
31
	r->parsed_objects->alternate_shallow_file = xstrdup_or_null(path);
32
}
33

34
int register_shallow(struct repository *r, const struct object_id *oid)
35
{
36
	struct commit_graft *graft =
37
		xmalloc(sizeof(struct commit_graft));
38
	struct commit *commit = lookup_commit(r, oid);
39

40
	oidcpy(&graft->oid, oid);
41
	graft->nr_parent = -1;
42
	if (commit && commit->object.parsed) {
43
		free_commit_list(commit->parents);
44
		commit->parents = NULL;
45
	}
46
	return register_commit_graft(r, graft, 0);
47
}
48

49
int unregister_shallow(const struct object_id *oid)
50
{
51
	int pos = commit_graft_pos(the_repository, oid);
52
	if (pos < 0)
53
		return -1;
54
	if (pos + 1 < the_repository->parsed_objects->grafts_nr)
55
		MOVE_ARRAY(the_repository->parsed_objects->grafts + pos,
56
			   the_repository->parsed_objects->grafts + pos + 1,
57
			   the_repository->parsed_objects->grafts_nr - pos - 1);
58
	the_repository->parsed_objects->grafts_nr--;
59
	return 0;
60
}
61

62
int is_repository_shallow(struct repository *r)
63
{
64
	FILE *fp;
65
	char buf[1024];
66
	const char *path = r->parsed_objects->alternate_shallow_file;
67

68
	if (r->parsed_objects->is_shallow >= 0)
69
		return r->parsed_objects->is_shallow;
70

71
	if (!path)
72
		path = git_path_shallow(r);
73
	/*
74
	 * fetch-pack sets '--shallow-file ""' as an indicator that no
75
	 * shallow file should be used. We could just open it and it
76
	 * will likely fail. But let's do an explicit check instead.
77
	 */
78
	if (!*path || (fp = fopen(path, "r")) == NULL) {
79
		stat_validity_clear(r->parsed_objects->shallow_stat);
80
		r->parsed_objects->is_shallow = 0;
81
		return r->parsed_objects->is_shallow;
82
	}
83
	stat_validity_update(r->parsed_objects->shallow_stat, fileno(fp));
84
	r->parsed_objects->is_shallow = 1;
85

86
	while (fgets(buf, sizeof(buf), fp)) {
87
		struct object_id oid;
88
		if (get_oid_hex(buf, &oid))
89
			die("bad shallow line: %s", buf);
90
		register_shallow(r, &oid);
91
	}
92
	fclose(fp);
93
	return r->parsed_objects->is_shallow;
94
}
95

96
static void reset_repository_shallow(struct repository *r)
97
{
98
	r->parsed_objects->is_shallow = -1;
99
	stat_validity_clear(r->parsed_objects->shallow_stat);
100
	reset_commit_grafts(r);
101
}
102

103
int commit_shallow_file(struct repository *r, struct shallow_lock *lk)
104
{
105
	int res = commit_lock_file(&lk->lock);
106
	reset_repository_shallow(r);
107

108
	/*
109
	 * Update in-memory data structures with the new shallow information,
110
	 * including unparsing all commits that now have grafts.
111
	 */
112
	is_repository_shallow(r);
113

114
	return res;
115
}
116

117
void rollback_shallow_file(struct repository *r, struct shallow_lock *lk)
118
{
119
	rollback_lock_file(&lk->lock);
120
	reset_repository_shallow(r);
121
}
122

123
/*
124
 * TODO: use "int" elemtype instead of "int *" when/if commit-slab
125
 * supports a "valid" flag.
126
 */
127
define_commit_slab(commit_depth, int *);
128
static void free_depth_in_slab(int **ptr)
129
{
130
	FREE_AND_NULL(*ptr);
131
}
132
struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
133
		int shallow_flag, int not_shallow_flag)
134
{
135
	int i = 0, cur_depth = 0;
136
	struct commit_list *result = NULL;
137
	struct object_array stack = OBJECT_ARRAY_INIT;
138
	struct commit *commit = NULL;
139
	struct commit_graft *graft;
140
	struct commit_depth depths;
141

142
	init_commit_depth(&depths);
143
	while (commit || i < heads->nr || stack.nr) {
144
		struct commit_list *p;
145
		if (!commit) {
146
			if (i < heads->nr) {
147
				int **depth_slot;
148
				commit = (struct commit *)
149
					deref_tag(the_repository,
150
						  heads->objects[i++].item,
151
						  NULL, 0);
152
				if (!commit || commit->object.type != OBJ_COMMIT) {
153
					commit = NULL;
154
					continue;
155
				}
156
				depth_slot = commit_depth_at(&depths, commit);
157
				if (!*depth_slot)
158
					*depth_slot = xmalloc(sizeof(int));
159
				**depth_slot = 0;
160
				cur_depth = 0;
161
			} else {
162
				commit = (struct commit *)
163
					object_array_pop(&stack);
164
				cur_depth = **commit_depth_at(&depths, commit);
165
			}
166
		}
167
		parse_commit_or_die(commit);
168
		cur_depth++;
169
		if ((depth != INFINITE_DEPTH && cur_depth >= depth) ||
170
		    (is_repository_shallow(the_repository) && !commit->parents &&
171
		     (graft = lookup_commit_graft(the_repository, &commit->object.oid)) != NULL &&
172
		     graft->nr_parent < 0)) {
173
			commit_list_insert(commit, &result);
174
			commit->object.flags |= shallow_flag;
175
			commit = NULL;
176
			continue;
177
		}
178
		commit->object.flags |= not_shallow_flag;
179
		for (p = commit->parents, commit = NULL; p; p = p->next) {
180
			int **depth_slot = commit_depth_at(&depths, p->item);
181
			if (!*depth_slot) {
182
				*depth_slot = xmalloc(sizeof(int));
183
				**depth_slot = cur_depth;
184
			} else {
185
				if (cur_depth >= **depth_slot)
186
					continue;
187
				**depth_slot = cur_depth;
188
			}
189
			if (p->next)
190
				add_object_array(&p->item->object,
191
						NULL, &stack);
192
			else {
193
				commit = p->item;
194
				cur_depth = **commit_depth_at(&depths, commit);
195
			}
196
		}
197
	}
198
	deep_clear_commit_depth(&depths, free_depth_in_slab);
199

200
	return result;
201
}
202

203
static void show_commit(struct commit *commit, void *data)
204
{
205
	commit_list_insert(commit, data);
206
}
207

208
/*
209
 * Given rev-list arguments, run rev-list. All reachable commits
210
 * except border ones are marked with not_shallow_flag. Border commits
211
 * are marked with shallow_flag. The list of border/shallow commits
212
 * are also returned.
213
 */
214
struct commit_list *get_shallow_commits_by_rev_list(int ac, const char **av,
215
						    int shallow_flag,
216
						    int not_shallow_flag)
217
{
218
	struct commit_list *result = NULL, *p;
219
	struct commit_list *not_shallow_list = NULL;
220
	struct rev_info revs;
221
	int both_flags = shallow_flag | not_shallow_flag;
222

223
	/*
224
	 * SHALLOW (excluded) and NOT_SHALLOW (included) should not be
225
	 * set at this point. But better be safe than sorry.
226
	 */
227
	clear_object_flags(both_flags);
228

229
	is_repository_shallow(the_repository); /* make sure shallows are read */
230

231
	repo_init_revisions(the_repository, &revs, NULL);
232
	save_commit_buffer = 0;
233
	setup_revisions(ac, av, &revs, NULL);
234

235
	if (prepare_revision_walk(&revs))
236
		die("revision walk setup failed");
237
	traverse_commit_list(&revs, show_commit, NULL, &not_shallow_list);
238

239
	if (!not_shallow_list)
240
		die("no commits selected for shallow requests");
241

242
	/* Mark all reachable commits as NOT_SHALLOW */
243
	for (p = not_shallow_list; p; p = p->next)
244
		p->item->object.flags |= not_shallow_flag;
245

246
	/*
247
	 * mark border commits SHALLOW + NOT_SHALLOW.
248
	 * We cannot clear NOT_SHALLOW right now. Imagine border
249
	 * commit A is processed first, then commit B, whose parent is
250
	 * A, later. If NOT_SHALLOW on A is cleared at step 1, B
251
	 * itself is considered border at step 2, which is incorrect.
252
	 */
253
	for (p = not_shallow_list; p; p = p->next) {
254
		struct commit *c = p->item;
255
		struct commit_list *parent;
256

257
		if (repo_parse_commit(the_repository, c))
258
			die("unable to parse commit %s",
259
			    oid_to_hex(&c->object.oid));
260

261
		for (parent = c->parents; parent; parent = parent->next)
262
			if (!(parent->item->object.flags & not_shallow_flag)) {
263
				c->object.flags |= shallow_flag;
264
				commit_list_insert(c, &result);
265
				break;
266
			}
267
	}
268
	free_commit_list(not_shallow_list);
269

270
	/*
271
	 * Now we can clean up NOT_SHALLOW on border commits. Having
272
	 * both flags set can confuse the caller.
273
	 */
274
	for (p = result; p; p = p->next) {
275
		struct object *o = &p->item->object;
276
		if ((o->flags & both_flags) == both_flags)
277
			o->flags &= ~not_shallow_flag;
278
	}
279
	release_revisions(&revs);
280
	return result;
281
}
282

283
static void check_shallow_file_for_update(struct repository *r)
284
{
285
	if (r->parsed_objects->is_shallow == -1)
286
		BUG("shallow must be initialized by now");
287

288
	if (!stat_validity_check(r->parsed_objects->shallow_stat,
289
				 git_path_shallow(r)))
290
		die("shallow file has changed since we read it");
291
}
292

293
#define SEEN_ONLY 1
294
#define VERBOSE   2
295
#define QUICK 4
296

297
struct write_shallow_data {
298
	struct strbuf *out;
299
	int use_pack_protocol;
300
	int count;
301
	unsigned flags;
302
};
303

304
static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
305
{
306
	struct write_shallow_data *data = cb_data;
307
	const char *hex = oid_to_hex(&graft->oid);
308
	if (graft->nr_parent != -1)
309
		return 0;
310
	if (data->flags & QUICK) {
311
		if (!repo_has_object_file(the_repository, &graft->oid))
312
			return 0;
313
	} else if (data->flags & SEEN_ONLY) {
314
		struct commit *c = lookup_commit(the_repository, &graft->oid);
315
		if (!c || !(c->object.flags & SEEN)) {
316
			if (data->flags & VERBOSE)
317
				printf("Removing %s from .git/shallow\n",
318
				       oid_to_hex(&c->object.oid));
319
			return 0;
320
		}
321
	}
322
	data->count++;
323
	if (data->use_pack_protocol)
324
		packet_buf_write(data->out, "shallow %s", hex);
325
	else {
326
		strbuf_addstr(data->out, hex);
327
		strbuf_addch(data->out, '\n');
328
	}
329
	return 0;
330
}
331

332
static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
333
				   const struct oid_array *extra,
334
				   unsigned flags)
335
{
336
	struct write_shallow_data data;
337
	int i;
338
	data.out = out;
339
	data.use_pack_protocol = use_pack_protocol;
340
	data.count = 0;
341
	data.flags = flags;
342
	for_each_commit_graft(write_one_shallow, &data);
343
	if (!extra)
344
		return data.count;
345
	for (i = 0; i < extra->nr; i++) {
346
		strbuf_addstr(out, oid_to_hex(extra->oid + i));
347
		strbuf_addch(out, '\n');
348
		data.count++;
349
	}
350
	return data.count;
351
}
352

353
int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
354
			  const struct oid_array *extra)
355
{
356
	return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
357
}
358

359
const char *setup_temporary_shallow(const struct oid_array *extra)
360
{
361
	struct tempfile *temp;
362
	struct strbuf sb = STRBUF_INIT;
363

364
	if (write_shallow_commits(&sb, 0, extra)) {
365
		temp = xmks_tempfile(git_path("shallow_XXXXXX"));
366

367
		if (write_in_full(temp->fd, sb.buf, sb.len) < 0 ||
368
		    close_tempfile_gently(temp) < 0)
369
			die_errno("failed to write to %s",
370
				  get_tempfile_path(temp));
371
		strbuf_release(&sb);
372
		return get_tempfile_path(temp);
373
	}
374
	/*
375
	 * is_repository_shallow() sees empty string as "no shallow
376
	 * file".
377
	 */
378
	return "";
379
}
380

381
void setup_alternate_shallow(struct shallow_lock *shallow_lock,
382
			     const char **alternate_shallow_file,
383
			     const struct oid_array *extra)
384
{
385
	struct strbuf sb = STRBUF_INIT;
386
	int fd;
387

388
	fd = hold_lock_file_for_update(&shallow_lock->lock,
389
				       git_path_shallow(the_repository),
390
				       LOCK_DIE_ON_ERROR);
391
	check_shallow_file_for_update(the_repository);
392
	if (write_shallow_commits(&sb, 0, extra)) {
393
		if (write_in_full(fd, sb.buf, sb.len) < 0)
394
			die_errno("failed to write to %s",
395
				  get_lock_file_path(&shallow_lock->lock));
396
		*alternate_shallow_file = get_lock_file_path(&shallow_lock->lock);
397
	} else
398
		/*
399
		 * is_repository_shallow() sees empty string as "no
400
		 * shallow file".
401
		 */
402
		*alternate_shallow_file = "";
403
	strbuf_release(&sb);
404
}
405

406
static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
407
{
408
	int fd = *(int *)cb;
409
	if (graft->nr_parent == -1)
410
		packet_write_fmt(fd, "shallow %s\n", oid_to_hex(&graft->oid));
411
	return 0;
412
}
413

414
void advertise_shallow_grafts(int fd)
415
{
416
	if (!is_repository_shallow(the_repository))
417
		return;
418
	for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
419
}
420

421
/*
422
 * mark_reachable_objects() should have been run prior to this and all
423
 * reachable commits marked as "SEEN", except when quick_prune is non-zero,
424
 * in which case lines are excised from the shallow file if they refer to
425
 * commits that do not exist (any longer).
426
 */
427
void prune_shallow(unsigned options)
428
{
429
	struct shallow_lock shallow_lock = SHALLOW_LOCK_INIT;
430
	struct strbuf sb = STRBUF_INIT;
431
	unsigned flags = SEEN_ONLY;
432
	int fd;
433

434
	if (options & PRUNE_QUICK)
435
		flags |= QUICK;
436

437
	if (options & PRUNE_SHOW_ONLY) {
438
		flags |= VERBOSE;
439
		write_shallow_commits_1(&sb, 0, NULL, flags);
440
		strbuf_release(&sb);
441
		return;
442
	}
443
	fd = hold_lock_file_for_update(&shallow_lock.lock,
444
				       git_path_shallow(the_repository),
445
				       LOCK_DIE_ON_ERROR);
446
	check_shallow_file_for_update(the_repository);
447
	if (write_shallow_commits_1(&sb, 0, NULL, flags)) {
448
		if (write_in_full(fd, sb.buf, sb.len) < 0)
449
			die_errno("failed to write to %s",
450
				  get_lock_file_path(&shallow_lock.lock));
451
		commit_shallow_file(the_repository, &shallow_lock);
452
	} else {
453
		unlink(git_path_shallow(the_repository));
454
		rollback_shallow_file(the_repository, &shallow_lock);
455
	}
456
	strbuf_release(&sb);
457
}
458

459
struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
460

461
/*
462
 * Step 1, split sender shallow commits into "ours" and "theirs"
463
 * Step 2, clean "ours" based on .git/shallow
464
 */
465
void prepare_shallow_info(struct shallow_info *info, struct oid_array *sa)
466
{
467
	int i;
468
	trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
469
	memset(info, 0, sizeof(*info));
470
	info->shallow = sa;
471
	if (!sa)
472
		return;
473
	ALLOC_ARRAY(info->ours, sa->nr);
474
	ALLOC_ARRAY(info->theirs, sa->nr);
475
	for (i = 0; i < sa->nr; i++) {
476
		if (repo_has_object_file(the_repository, sa->oid + i)) {
477
			struct commit_graft *graft;
478
			graft = lookup_commit_graft(the_repository,
479
						    &sa->oid[i]);
480
			if (graft && graft->nr_parent < 0)
481
				continue;
482
			info->ours[info->nr_ours++] = i;
483
		} else
484
			info->theirs[info->nr_theirs++] = i;
485
	}
486
}
487

488
void clear_shallow_info(struct shallow_info *info)
489
{
490
	free(info->ours);
491
	free(info->theirs);
492
}
493

494
/* Step 4, remove non-existent ones in "theirs" after getting the pack */
495

496
void remove_nonexistent_theirs_shallow(struct shallow_info *info)
497
{
498
	struct object_id *oid = info->shallow->oid;
499
	int i, dst;
500
	trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
501
	for (i = dst = 0; i < info->nr_theirs; i++) {
502
		if (i != dst)
503
			info->theirs[dst] = info->theirs[i];
504
		if (repo_has_object_file(the_repository, oid + info->theirs[i]))
505
			dst++;
506
	}
507
	info->nr_theirs = dst;
508
}
509

510
define_commit_slab(ref_bitmap, uint32_t *);
511

512
#define POOL_SIZE (512 * 1024)
513

514
struct paint_info {
515
	struct ref_bitmap ref_bitmap;
516
	unsigned nr_bits;
517
	char **pools;
518
	char *free, *end;
519
	unsigned pool_count;
520
};
521

522
static uint32_t *paint_alloc(struct paint_info *info)
523
{
524
	unsigned nr = DIV_ROUND_UP(info->nr_bits, 32);
525
	unsigned size = nr * sizeof(uint32_t);
526
	void *p;
527
	if (!info->pool_count || size > info->end - info->free) {
528
		if (size > POOL_SIZE)
529
			BUG("pool size too small for %d in paint_alloc()",
530
			    size);
531
		info->pool_count++;
532
		REALLOC_ARRAY(info->pools, info->pool_count);
533
		info->free = xmalloc(POOL_SIZE);
534
		info->pools[info->pool_count - 1] = info->free;
535
		info->end = info->free + POOL_SIZE;
536
	}
537
	p = info->free;
538
	info->free += size;
539
	return p;
540
}
541

542
/*
543
 * Given a commit SHA-1, walk down to parents until either SEEN,
544
 * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
545
 * all walked commits.
546
 */
547
static void paint_down(struct paint_info *info, const struct object_id *oid,
548
		       unsigned int id)
549
{
550
	unsigned int i, nr;
551
	struct commit_list *head = NULL;
552
	int bitmap_nr = DIV_ROUND_UP(info->nr_bits, 32);
553
	size_t bitmap_size = st_mult(sizeof(uint32_t), bitmap_nr);
554
	struct commit *c = lookup_commit_reference_gently(the_repository, oid,
555
							  1);
556
	uint32_t *tmp; /* to be freed before return */
557
	uint32_t *bitmap;
558

559
	if (!c)
560
		return;
561

562
	tmp = xmalloc(bitmap_size);
563
	bitmap = paint_alloc(info);
564
	memset(bitmap, 0, bitmap_size);
565
	bitmap[id / 32] |= (1U << (id % 32));
566
	commit_list_insert(c, &head);
567
	while (head) {
568
		struct commit_list *p;
569
		struct commit *c = pop_commit(&head);
570
		uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
571

572
		/* XXX check "UNINTERESTING" from pack bitmaps if available */
573
		if (c->object.flags & (SEEN | UNINTERESTING))
574
			continue;
575
		else
576
			c->object.flags |= SEEN;
577

578
		if (!*refs)
579
			*refs = bitmap;
580
		else {
581
			memcpy(tmp, *refs, bitmap_size);
582
			for (i = 0; i < bitmap_nr; i++)
583
				tmp[i] |= bitmap[i];
584
			if (memcmp(tmp, *refs, bitmap_size)) {
585
				*refs = paint_alloc(info);
586
				memcpy(*refs, tmp, bitmap_size);
587
			}
588
		}
589

590
		if (c->object.flags & BOTTOM)
591
			continue;
592

593
		if (repo_parse_commit(the_repository, c))
594
			die("unable to parse commit %s",
595
			    oid_to_hex(&c->object.oid));
596

597
		for (p = c->parents; p; p = p->next) {
598
			if (p->item->object.flags & SEEN)
599
				continue;
600
			commit_list_insert(p->item, &head);
601
		}
602
	}
603

604
	nr = get_max_object_index();
605
	for (i = 0; i < nr; i++) {
606
		struct object *o = get_indexed_object(i);
607
		if (o && o->type == OBJ_COMMIT)
608
			o->flags &= ~SEEN;
609
	}
610

611
	free(tmp);
612
}
613

614
static int mark_uninteresting(const char *refname UNUSED,
615
			      const char *referent UNUSED,
616
			      const struct object_id *oid,
617
			      int flags UNUSED,
618
			      void *cb_data UNUSED)
619
{
620
	struct commit *commit = lookup_commit_reference_gently(the_repository,
621
							       oid, 1);
622
	if (!commit)
623
		return 0;
624
	commit->object.flags |= UNINTERESTING;
625
	mark_parents_uninteresting(NULL, commit);
626
	return 0;
627
}
628

629
static void post_assign_shallow(struct shallow_info *info,
630
				struct ref_bitmap *ref_bitmap,
631
				int *ref_status);
632
/*
633
 * Step 6(+7), associate shallow commits with new refs
634
 *
635
 * info->ref must be initialized before calling this function.
636
 *
637
 * If used is not NULL, it's an array of info->shallow->nr
638
 * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
639
 * m-th shallow commit from info->shallow.
640
 *
641
 * If used is NULL, "ours" and "theirs" are updated. And if ref_status
642
 * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
643
 * the ref needs some shallow commits from either info->ours or
644
 * info->theirs.
645
 */
646
void assign_shallow_commits_to_refs(struct shallow_info *info,
647
				    uint32_t **used, int *ref_status)
648
{
649
	struct object_id *oid = info->shallow->oid;
650
	struct oid_array *ref = info->ref;
651
	unsigned int i, nr;
652
	int *shallow, nr_shallow = 0;
653
	struct paint_info pi;
654

655
	trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
656
	ALLOC_ARRAY(shallow, info->nr_ours + info->nr_theirs);
657
	for (i = 0; i < info->nr_ours; i++)
658
		shallow[nr_shallow++] = info->ours[i];
659
	for (i = 0; i < info->nr_theirs; i++)
660
		shallow[nr_shallow++] = info->theirs[i];
661

662
	/*
663
	 * Prepare the commit graph to track what refs can reach what
664
	 * (new) shallow commits.
665
	 */
666
	nr = get_max_object_index();
667
	for (i = 0; i < nr; i++) {
668
		struct object *o = get_indexed_object(i);
669
		if (!o || o->type != OBJ_COMMIT)
670
			continue;
671

672
		o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
673
	}
674

675
	memset(&pi, 0, sizeof(pi));
676
	init_ref_bitmap(&pi.ref_bitmap);
677
	pi.nr_bits = ref->nr;
678

679
	/*
680
	 * "--not --all" to cut short the traversal if new refs
681
	 * connect to old refs. If not (e.g. force ref updates) it'll
682
	 * have to go down to the current shallow commits.
683
	 */
684
	refs_head_ref(get_main_ref_store(the_repository), mark_uninteresting,
685
		      NULL);
686
	refs_for_each_ref(get_main_ref_store(the_repository),
687
			  mark_uninteresting, NULL);
688

689
	/* Mark potential bottoms so we won't go out of bound */
690
	for (i = 0; i < nr_shallow; i++) {
691
		struct commit *c = lookup_commit(the_repository,
692
						 &oid[shallow[i]]);
693
		c->object.flags |= BOTTOM;
694
	}
695

696
	for (i = 0; i < ref->nr; i++)
697
		paint_down(&pi, ref->oid + i, i);
698

699
	if (used) {
700
		int bitmap_size = DIV_ROUND_UP(pi.nr_bits, 32) * sizeof(uint32_t);
701
		memset(used, 0, sizeof(*used) * info->shallow->nr);
702
		for (i = 0; i < nr_shallow; i++) {
703
			const struct commit *c = lookup_commit(the_repository,
704
							       &oid[shallow[i]]);
705
			uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
706
			if (*map)
707
				used[shallow[i]] = xmemdupz(*map, bitmap_size);
708
		}
709
		/*
710
		 * unreachable shallow commits are not removed from
711
		 * "ours" and "theirs". The user is supposed to run
712
		 * step 7 on every ref separately and not trust "ours"
713
		 * and "theirs" any more.
714
		 */
715
	} else
716
		post_assign_shallow(info, &pi.ref_bitmap, ref_status);
717

718
	clear_ref_bitmap(&pi.ref_bitmap);
719
	for (i = 0; i < pi.pool_count; i++)
720
		free(pi.pools[i]);
721
	free(pi.pools);
722
	free(shallow);
723
}
724

725
struct commit_array {
726
	struct commit **commits;
727
	int nr, alloc;
728
};
729

730
static int add_ref(const char *refname UNUSED,
731
		  const char *referent UNUSED,
732
		   const struct object_id *oid,
733
		   int flags UNUSED,
734
		   void *cb_data)
735
{
736
	struct commit_array *ca = cb_data;
737
	ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
738
	ca->commits[ca->nr] = lookup_commit_reference_gently(the_repository,
739
							     oid, 1);
740
	if (ca->commits[ca->nr])
741
		ca->nr++;
742
	return 0;
743
}
744

745
static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
746
{
747
	unsigned int i;
748
	if (!ref_status)
749
		return;
750
	for (i = 0; i < nr; i++)
751
		if (bitmap[i / 32] & (1U << (i % 32)))
752
			ref_status[i]++;
753
}
754

755
/*
756
 * Step 7, reachability test on "ours" at commit level
757
 */
758
static void post_assign_shallow(struct shallow_info *info,
759
				struct ref_bitmap *ref_bitmap,
760
				int *ref_status)
761
{
762
	struct object_id *oid = info->shallow->oid;
763
	struct commit *c;
764
	uint32_t **bitmap;
765
	int dst, i, j;
766
	int bitmap_nr = DIV_ROUND_UP(info->ref->nr, 32);
767
	struct commit_array ca;
768

769
	trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
770
	if (ref_status)
771
		memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);
772

773
	/* Remove unreachable shallow commits from "theirs" */
774
	for (i = dst = 0; i < info->nr_theirs; i++) {
775
		if (i != dst)
776
			info->theirs[dst] = info->theirs[i];
777
		c = lookup_commit(the_repository, &oid[info->theirs[i]]);
778
		bitmap = ref_bitmap_at(ref_bitmap, c);
779
		if (!*bitmap)
780
			continue;
781
		for (j = 0; j < bitmap_nr; j++)
782
			if (bitmap[0][j]) {
783
				update_refstatus(ref_status, info->ref->nr, *bitmap);
784
				dst++;
785
				break;
786
			}
787
	}
788
	info->nr_theirs = dst;
789

790
	memset(&ca, 0, sizeof(ca));
791
	refs_head_ref(get_main_ref_store(the_repository), add_ref, &ca);
792
	refs_for_each_ref(get_main_ref_store(the_repository), add_ref, &ca);
793

794
	/* Remove unreachable shallow commits from "ours" */
795
	for (i = dst = 0; i < info->nr_ours; i++) {
796
		if (i != dst)
797
			info->ours[dst] = info->ours[i];
798
		c = lookup_commit(the_repository, &oid[info->ours[i]]);
799
		bitmap = ref_bitmap_at(ref_bitmap, c);
800
		if (!*bitmap)
801
			continue;
802
		for (j = 0; j < bitmap_nr; j++)
803
			if (bitmap[0][j]) {
804
				/* Step 7, reachability test at commit level */
805
				int ret = repo_in_merge_bases_many(the_repository, c, ca.nr, ca.commits, 1);
806
				if (ret < 0)
807
					exit(128);
808
				if (!ret) {
809
					update_refstatus(ref_status, info->ref->nr, *bitmap);
810
					dst++;
811
					break;
812
				}
813
			}
814
	}
815
	info->nr_ours = dst;
816

817
	free(ca.commits);
818
}
819

820
/* (Delayed) step 7, reachability test at commit level */
821
int delayed_reachability_test(struct shallow_info *si, int c)
822
{
823
	if (si->need_reachability_test[c]) {
824
		struct commit *commit = lookup_commit(the_repository,
825
						      &si->shallow->oid[c]);
826

827
		if (!si->commits) {
828
			struct commit_array ca;
829

830
			memset(&ca, 0, sizeof(ca));
831
			refs_head_ref(get_main_ref_store(the_repository),
832
				      add_ref, &ca);
833
			refs_for_each_ref(get_main_ref_store(the_repository),
834
					  add_ref, &ca);
835
			si->commits = ca.commits;
836
			si->nr_commits = ca.nr;
837
		}
838

839
		si->reachable[c] = repo_in_merge_bases_many(the_repository,
840
							    commit,
841
							    si->nr_commits,
842
							    si->commits,
843
							    1);
844
		if (si->reachable[c] < 0)
845
			exit(128);
846
		si->need_reachability_test[c] = 0;
847
	}
848
	return si->reachable[c];
849
}
850