Merge branch 'rs/plug-leak-in-pack-bitmaps' into maint
[git.git] / shallow.c
blobd8bf40ad4bed3bc846bb71945f1c2bfce76a202d
1 #include "cache.h"
2 #include "lockfile.h"
3 #include "commit.h"
4 #include "tag.h"
5 #include "pkt-line.h"
6 #include "remote.h"
7 #include "refs.h"
8 #include "sha1-array.h"
9 #include "diff.h"
10 #include "revision.h"
11 #include "commit-slab.h"
12 #include "sigchain.h"
14 static int is_shallow = -1;
15 static struct stat_validity shallow_stat;
16 static char *alternate_shallow_file;
18 void set_alternate_shallow_file(const char *path, int override)
20 if (is_shallow != -1)
21 die("BUG: is_repository_shallow must not be called before set_alternate_shallow_file");
22 if (alternate_shallow_file && !override)
23 return;
24 free(alternate_shallow_file);
25 alternate_shallow_file = xstrdup_or_null(path);
28 int register_shallow(const unsigned char *sha1)
30 struct commit_graft *graft =
31 xmalloc(sizeof(struct commit_graft));
32 struct commit *commit = lookup_commit(sha1);
34 hashcpy(graft->sha1, sha1);
35 graft->nr_parent = -1;
36 if (commit && commit->object.parsed)
37 commit->parents = NULL;
38 return register_commit_graft(graft, 0);
41 int is_repository_shallow(void)
43 FILE *fp;
44 char buf[1024];
45 const char *path = alternate_shallow_file;
47 if (is_shallow >= 0)
48 return is_shallow;
50 if (!path)
51 path = git_path("shallow");
53 * fetch-pack sets '--shallow-file ""' as an indicator that no
54 * shallow file should be used. We could just open it and it
55 * will likely fail. But let's do an explicit check instead.
57 if (!*path || (fp = fopen(path, "r")) == NULL) {
58 stat_validity_clear(&shallow_stat);
59 is_shallow = 0;
60 return is_shallow;
62 stat_validity_update(&shallow_stat, fileno(fp));
63 is_shallow = 1;
65 while (fgets(buf, sizeof(buf), fp)) {
66 unsigned char sha1[20];
67 if (get_sha1_hex(buf, sha1))
68 die("bad shallow line: %s", buf);
69 register_shallow(sha1);
71 fclose(fp);
72 return is_shallow;
75 struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
76 int shallow_flag, int not_shallow_flag)
78 int i = 0, cur_depth = 0;
79 struct commit_list *result = NULL;
80 struct object_array stack = OBJECT_ARRAY_INIT;
81 struct commit *commit = NULL;
82 struct commit_graft *graft;
84 while (commit || i < heads->nr || stack.nr) {
85 struct commit_list *p;
86 if (!commit) {
87 if (i < heads->nr) {
88 commit = (struct commit *)
89 deref_tag(heads->objects[i++].item, NULL, 0);
90 if (!commit || commit->object.type != OBJ_COMMIT) {
91 commit = NULL;
92 continue;
94 if (!commit->util)
95 commit->util = xmalloc(sizeof(int));
96 *(int *)commit->util = 0;
97 cur_depth = 0;
98 } else {
99 commit = (struct commit *)
100 stack.objects[--stack.nr].item;
101 cur_depth = *(int *)commit->util;
104 parse_commit_or_die(commit);
105 cur_depth++;
106 if ((depth != INFINITE_DEPTH && cur_depth >= depth) ||
107 (is_repository_shallow() && !commit->parents &&
108 (graft = lookup_commit_graft(commit->object.sha1)) != NULL &&
109 graft->nr_parent < 0)) {
110 commit_list_insert(commit, &result);
111 commit->object.flags |= shallow_flag;
112 commit = NULL;
113 continue;
115 commit->object.flags |= not_shallow_flag;
116 for (p = commit->parents, commit = NULL; p; p = p->next) {
117 if (!p->item->util) {
118 int *pointer = xmalloc(sizeof(int));
119 p->item->util = pointer;
120 *pointer = cur_depth;
121 } else {
122 int *pointer = p->item->util;
123 if (cur_depth >= *pointer)
124 continue;
125 *pointer = cur_depth;
127 if (p->next)
128 add_object_array(&p->item->object,
129 NULL, &stack);
130 else {
131 commit = p->item;
132 cur_depth = *(int *)commit->util;
137 return result;
140 static void check_shallow_file_for_update(void)
142 if (is_shallow == -1)
143 die("BUG: shallow must be initialized by now");
145 if (!stat_validity_check(&shallow_stat, git_path("shallow")))
146 die("shallow file has changed since we read it");
149 #define SEEN_ONLY 1
150 #define VERBOSE 2
152 struct write_shallow_data {
153 struct strbuf *out;
154 int use_pack_protocol;
155 int count;
156 unsigned flags;
159 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
161 struct write_shallow_data *data = cb_data;
162 const char *hex = sha1_to_hex(graft->sha1);
163 if (graft->nr_parent != -1)
164 return 0;
165 if (data->flags & SEEN_ONLY) {
166 struct commit *c = lookup_commit(graft->sha1);
167 if (!c || !(c->object.flags & SEEN)) {
168 if (data->flags & VERBOSE)
169 printf("Removing %s from .git/shallow\n",
170 sha1_to_hex(c->object.sha1));
171 return 0;
174 data->count++;
175 if (data->use_pack_protocol)
176 packet_buf_write(data->out, "shallow %s", hex);
177 else {
178 strbuf_addstr(data->out, hex);
179 strbuf_addch(data->out, '\n');
181 return 0;
184 static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
185 const struct sha1_array *extra,
186 unsigned flags)
188 struct write_shallow_data data;
189 int i;
190 data.out = out;
191 data.use_pack_protocol = use_pack_protocol;
192 data.count = 0;
193 data.flags = flags;
194 for_each_commit_graft(write_one_shallow, &data);
195 if (!extra)
196 return data.count;
197 for (i = 0; i < extra->nr; i++) {
198 strbuf_addstr(out, sha1_to_hex(extra->sha1[i]));
199 strbuf_addch(out, '\n');
200 data.count++;
202 return data.count;
205 int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
206 const struct sha1_array *extra)
208 return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
211 static struct strbuf temporary_shallow = STRBUF_INIT;
213 static void remove_temporary_shallow(void)
215 if (temporary_shallow.len) {
216 unlink_or_warn(temporary_shallow.buf);
217 strbuf_reset(&temporary_shallow);
221 static void remove_temporary_shallow_on_signal(int signo)
223 remove_temporary_shallow();
224 sigchain_pop(signo);
225 raise(signo);
228 const char *setup_temporary_shallow(const struct sha1_array *extra)
230 struct strbuf sb = STRBUF_INIT;
231 int fd;
233 if (temporary_shallow.len)
234 die("BUG: attempt to create two temporary shallow files");
236 if (write_shallow_commits(&sb, 0, extra)) {
237 strbuf_addstr(&temporary_shallow, git_path("shallow_XXXXXX"));
238 fd = xmkstemp(temporary_shallow.buf);
240 atexit(remove_temporary_shallow);
241 sigchain_push_common(remove_temporary_shallow_on_signal);
243 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
244 die_errno("failed to write to %s",
245 temporary_shallow.buf);
246 close(fd);
247 strbuf_release(&sb);
248 return temporary_shallow.buf;
251 * is_repository_shallow() sees empty string as "no shallow
252 * file".
254 return temporary_shallow.buf;
257 void setup_alternate_shallow(struct lock_file *shallow_lock,
258 const char **alternate_shallow_file,
259 const struct sha1_array *extra)
261 struct strbuf sb = STRBUF_INIT;
262 int fd;
264 fd = hold_lock_file_for_update(shallow_lock, git_path("shallow"),
265 LOCK_DIE_ON_ERROR);
266 check_shallow_file_for_update();
267 if (write_shallow_commits(&sb, 0, extra)) {
268 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
269 die_errno("failed to write to %s",
270 shallow_lock->filename.buf);
271 *alternate_shallow_file = shallow_lock->filename.buf;
272 } else
274 * is_repository_shallow() sees empty string as "no
275 * shallow file".
277 *alternate_shallow_file = "";
278 strbuf_release(&sb);
281 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
283 int fd = *(int *)cb;
284 if (graft->nr_parent == -1)
285 packet_write(fd, "shallow %s\n", sha1_to_hex(graft->sha1));
286 return 0;
289 void advertise_shallow_grafts(int fd)
291 if (!is_repository_shallow())
292 return;
293 for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
297 * mark_reachable_objects() should have been run prior to this and all
298 * reachable commits marked as "SEEN".
300 void prune_shallow(int show_only)
302 static struct lock_file shallow_lock;
303 struct strbuf sb = STRBUF_INIT;
304 int fd;
306 if (show_only) {
307 write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY | VERBOSE);
308 strbuf_release(&sb);
309 return;
311 fd = hold_lock_file_for_update(&shallow_lock, git_path("shallow"),
312 LOCK_DIE_ON_ERROR);
313 check_shallow_file_for_update();
314 if (write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY)) {
315 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
316 die_errno("failed to write to %s",
317 shallow_lock.filename.buf);
318 commit_lock_file(&shallow_lock);
319 } else {
320 unlink(git_path("shallow"));
321 rollback_lock_file(&shallow_lock);
323 strbuf_release(&sb);
326 struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
329 * Step 1, split sender shallow commits into "ours" and "theirs"
330 * Step 2, clean "ours" based on .git/shallow
332 void prepare_shallow_info(struct shallow_info *info, struct sha1_array *sa)
334 int i;
335 trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
336 memset(info, 0, sizeof(*info));
337 info->shallow = sa;
338 if (!sa)
339 return;
340 info->ours = xmalloc(sizeof(*info->ours) * sa->nr);
341 info->theirs = xmalloc(sizeof(*info->theirs) * sa->nr);
342 for (i = 0; i < sa->nr; i++) {
343 if (has_sha1_file(sa->sha1[i])) {
344 struct commit_graft *graft;
345 graft = lookup_commit_graft(sa->sha1[i]);
346 if (graft && graft->nr_parent < 0)
347 continue;
348 info->ours[info->nr_ours++] = i;
349 } else
350 info->theirs[info->nr_theirs++] = i;
354 void clear_shallow_info(struct shallow_info *info)
356 free(info->ours);
357 free(info->theirs);
360 /* Step 4, remove non-existent ones in "theirs" after getting the pack */
362 void remove_nonexistent_theirs_shallow(struct shallow_info *info)
364 unsigned char (*sha1)[20] = info->shallow->sha1;
365 int i, dst;
366 trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
367 for (i = dst = 0; i < info->nr_theirs; i++) {
368 if (i != dst)
369 info->theirs[dst] = info->theirs[i];
370 if (has_sha1_file(sha1[info->theirs[i]]))
371 dst++;
373 info->nr_theirs = dst;
376 define_commit_slab(ref_bitmap, uint32_t *);
378 struct paint_info {
379 struct ref_bitmap ref_bitmap;
380 unsigned nr_bits;
381 char **slab;
382 char *free, *end;
383 unsigned slab_count;
386 static uint32_t *paint_alloc(struct paint_info *info)
388 unsigned nr = (info->nr_bits + 31) / 32;
389 unsigned size = nr * sizeof(uint32_t);
390 void *p;
391 if (!info->slab_count || info->free + size > info->end) {
392 info->slab_count++;
393 REALLOC_ARRAY(info->slab, info->slab_count);
394 info->free = xmalloc(COMMIT_SLAB_SIZE);
395 info->slab[info->slab_count - 1] = info->free;
396 info->end = info->free + COMMIT_SLAB_SIZE;
398 p = info->free;
399 info->free += size;
400 return p;
404 * Given a commit SHA-1, walk down to parents until either SEEN,
405 * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
406 * all walked commits.
408 static void paint_down(struct paint_info *info, const unsigned char *sha1,
409 int id)
411 unsigned int i, nr;
412 struct commit_list *head = NULL;
413 int bitmap_nr = (info->nr_bits + 31) / 32;
414 int bitmap_size = bitmap_nr * sizeof(uint32_t);
415 uint32_t *tmp = xmalloc(bitmap_size); /* to be freed before return */
416 uint32_t *bitmap = paint_alloc(info);
417 struct commit *c = lookup_commit_reference_gently(sha1, 1);
418 if (!c)
419 return;
420 memset(bitmap, 0, bitmap_size);
421 bitmap[id / 32] |= (1 << (id % 32));
422 commit_list_insert(c, &head);
423 while (head) {
424 struct commit_list *p;
425 struct commit *c = head->item;
426 uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
428 p = head;
429 head = head->next;
430 free(p);
432 /* XXX check "UNINTERESTING" from pack bitmaps if available */
433 if (c->object.flags & (SEEN | UNINTERESTING))
434 continue;
435 else
436 c->object.flags |= SEEN;
438 if (*refs == NULL)
439 *refs = bitmap;
440 else {
441 memcpy(tmp, *refs, bitmap_size);
442 for (i = 0; i < bitmap_nr; i++)
443 tmp[i] |= bitmap[i];
444 if (memcmp(tmp, *refs, bitmap_size)) {
445 *refs = paint_alloc(info);
446 memcpy(*refs, tmp, bitmap_size);
450 if (c->object.flags & BOTTOM)
451 continue;
453 if (parse_commit(c))
454 die("unable to parse commit %s",
455 sha1_to_hex(c->object.sha1));
457 for (p = c->parents; p; p = p->next) {
458 uint32_t **p_refs = ref_bitmap_at(&info->ref_bitmap,
459 p->item);
460 if (p->item->object.flags & SEEN)
461 continue;
462 if (*p_refs == NULL || *p_refs == *refs)
463 *p_refs = *refs;
464 commit_list_insert(p->item, &head);
468 nr = get_max_object_index();
469 for (i = 0; i < nr; i++) {
470 struct object *o = get_indexed_object(i);
471 if (o && o->type == OBJ_COMMIT)
472 o->flags &= ~SEEN;
475 free(tmp);
478 static int mark_uninteresting(const char *refname,
479 const unsigned char *sha1,
480 int flags, void *cb_data)
482 struct commit *commit = lookup_commit_reference_gently(sha1, 1);
483 if (!commit)
484 return 0;
485 commit->object.flags |= UNINTERESTING;
486 mark_parents_uninteresting(commit);
487 return 0;
490 static void post_assign_shallow(struct shallow_info *info,
491 struct ref_bitmap *ref_bitmap,
492 int *ref_status);
494 * Step 6(+7), associate shallow commits with new refs
496 * info->ref must be initialized before calling this function.
498 * If used is not NULL, it's an array of info->shallow->nr
499 * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
500 * m-th shallow commit from info->shallow.
502 * If used is NULL, "ours" and "theirs" are updated. And if ref_status
503 * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
504 * the ref needs some shallow commits from either info->ours or
505 * info->theirs.
507 void assign_shallow_commits_to_refs(struct shallow_info *info,
508 uint32_t **used, int *ref_status)
510 unsigned char (*sha1)[20] = info->shallow->sha1;
511 struct sha1_array *ref = info->ref;
512 unsigned int i, nr;
513 int *shallow, nr_shallow = 0;
514 struct paint_info pi;
516 trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
517 shallow = xmalloc(sizeof(*shallow) * (info->nr_ours + info->nr_theirs));
518 for (i = 0; i < info->nr_ours; i++)
519 shallow[nr_shallow++] = info->ours[i];
520 for (i = 0; i < info->nr_theirs; i++)
521 shallow[nr_shallow++] = info->theirs[i];
524 * Prepare the commit graph to track what refs can reach what
525 * (new) shallow commits.
527 nr = get_max_object_index();
528 for (i = 0; i < nr; i++) {
529 struct object *o = get_indexed_object(i);
530 if (!o || o->type != OBJ_COMMIT)
531 continue;
533 o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
536 memset(&pi, 0, sizeof(pi));
537 init_ref_bitmap(&pi.ref_bitmap);
538 pi.nr_bits = ref->nr;
541 * "--not --all" to cut short the traversal if new refs
542 * connect to old refs. If not (e.g. force ref updates) it'll
543 * have to go down to the current shallow commits.
545 head_ref(mark_uninteresting, NULL);
546 for_each_ref(mark_uninteresting, NULL);
548 /* Mark potential bottoms so we won't go out of bound */
549 for (i = 0; i < nr_shallow; i++) {
550 struct commit *c = lookup_commit(sha1[shallow[i]]);
551 c->object.flags |= BOTTOM;
554 for (i = 0; i < ref->nr; i++)
555 paint_down(&pi, ref->sha1[i], i);
557 if (used) {
558 int bitmap_size = ((pi.nr_bits + 31) / 32) * sizeof(uint32_t);
559 memset(used, 0, sizeof(*used) * info->shallow->nr);
560 for (i = 0; i < nr_shallow; i++) {
561 const struct commit *c = lookup_commit(sha1[shallow[i]]);
562 uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
563 if (*map)
564 used[shallow[i]] = xmemdupz(*map, bitmap_size);
567 * unreachable shallow commits are not removed from
568 * "ours" and "theirs". The user is supposed to run
569 * step 7 on every ref separately and not trust "ours"
570 * and "theirs" any more.
572 } else
573 post_assign_shallow(info, &pi.ref_bitmap, ref_status);
575 clear_ref_bitmap(&pi.ref_bitmap);
576 for (i = 0; i < pi.slab_count; i++)
577 free(pi.slab[i]);
578 free(pi.slab);
579 free(shallow);
582 struct commit_array {
583 struct commit **commits;
584 int nr, alloc;
587 static int add_ref(const char *refname,
588 const unsigned char *sha1, int flags, void *cb_data)
590 struct commit_array *ca = cb_data;
591 ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
592 ca->commits[ca->nr] = lookup_commit_reference_gently(sha1, 1);
593 if (ca->commits[ca->nr])
594 ca->nr++;
595 return 0;
598 static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
600 int i;
601 if (!ref_status)
602 return;
603 for (i = 0; i < nr; i++)
604 if (bitmap[i / 32] & (1 << (i % 32)))
605 ref_status[i]++;
609 * Step 7, reachability test on "ours" at commit level
611 static void post_assign_shallow(struct shallow_info *info,
612 struct ref_bitmap *ref_bitmap,
613 int *ref_status)
615 unsigned char (*sha1)[20] = info->shallow->sha1;
616 struct commit *c;
617 uint32_t **bitmap;
618 int dst, i, j;
619 int bitmap_nr = (info->ref->nr + 31) / 32;
620 struct commit_array ca;
622 trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
623 if (ref_status)
624 memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);
626 /* Remove unreachable shallow commits from "theirs" */
627 for (i = dst = 0; i < info->nr_theirs; i++) {
628 if (i != dst)
629 info->theirs[dst] = info->theirs[i];
630 c = lookup_commit(sha1[info->theirs[i]]);
631 bitmap = ref_bitmap_at(ref_bitmap, c);
632 if (!*bitmap)
633 continue;
634 for (j = 0; j < bitmap_nr; j++)
635 if (bitmap[0][j]) {
636 update_refstatus(ref_status, info->ref->nr, *bitmap);
637 dst++;
638 break;
641 info->nr_theirs = dst;
643 memset(&ca, 0, sizeof(ca));
644 head_ref(add_ref, &ca);
645 for_each_ref(add_ref, &ca);
647 /* Remove unreachable shallow commits from "ours" */
648 for (i = dst = 0; i < info->nr_ours; i++) {
649 if (i != dst)
650 info->ours[dst] = info->ours[i];
651 c = lookup_commit(sha1[info->ours[i]]);
652 bitmap = ref_bitmap_at(ref_bitmap, c);
653 if (!*bitmap)
654 continue;
655 for (j = 0; j < bitmap_nr; j++)
656 if (bitmap[0][j] &&
657 /* Step 7, reachability test at commit level */
658 !in_merge_bases_many(c, ca.nr, ca.commits)) {
659 update_refstatus(ref_status, info->ref->nr, *bitmap);
660 dst++;
661 break;
664 info->nr_ours = dst;
666 free(ca.commits);
669 /* (Delayed) step 7, reachability test at commit level */
670 int delayed_reachability_test(struct shallow_info *si, int c)
672 if (si->need_reachability_test[c]) {
673 struct commit *commit = lookup_commit(si->shallow->sha1[c]);
675 if (!si->commits) {
676 struct commit_array ca;
677 memset(&ca, 0, sizeof(ca));
678 head_ref(add_ref, &ca);
679 for_each_ref(add_ref, &ca);
680 si->commits = ca.commits;
681 si->nr_commits = ca.nr;
684 si->reachable[c] = in_merge_bases_many(commit,
685 si->nr_commits,
686 si->commits);
687 si->need_reachability_test[c] = 0;
689 return si->reachable[c];