git-multimail: update to release 1.2.0
[git.git] / shallow.c
blobd49a3d6e9f02e292a04981e34f0a2d0b1ffa00d0
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 "sigchain.h"
15 static int is_shallow = -1;
16 static struct stat_validity shallow_stat;
17 static char *alternate_shallow_file;
19 void set_alternate_shallow_file(const char *path, int override)
21 if (is_shallow != -1)
22 die("BUG: is_repository_shallow must not be called before set_alternate_shallow_file");
23 if (alternate_shallow_file && !override)
24 return;
25 free(alternate_shallow_file);
26 alternate_shallow_file = xstrdup_or_null(path);
29 int register_shallow(const unsigned char *sha1)
31 struct commit_graft *graft =
32 xmalloc(sizeof(struct commit_graft));
33 struct commit *commit = lookup_commit(sha1);
35 hashcpy(graft->oid.hash, sha1);
36 graft->nr_parent = -1;
37 if (commit && commit->object.parsed)
38 commit->parents = NULL;
39 return register_commit_graft(graft, 0);
42 int is_repository_shallow(void)
44 FILE *fp;
45 char buf[1024];
46 const char *path = alternate_shallow_file;
48 if (is_shallow >= 0)
49 return is_shallow;
51 if (!path)
52 path = git_path_shallow();
54 * fetch-pack sets '--shallow-file ""' as an indicator that no
55 * shallow file should be used. We could just open it and it
56 * will likely fail. But let's do an explicit check instead.
58 if (!*path || (fp = fopen(path, "r")) == NULL) {
59 stat_validity_clear(&shallow_stat);
60 is_shallow = 0;
61 return is_shallow;
63 stat_validity_update(&shallow_stat, fileno(fp));
64 is_shallow = 1;
66 while (fgets(buf, sizeof(buf), fp)) {
67 unsigned char sha1[20];
68 if (get_sha1_hex(buf, sha1))
69 die("bad shallow line: %s", buf);
70 register_shallow(sha1);
72 fclose(fp);
73 return is_shallow;
76 struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
77 int shallow_flag, int not_shallow_flag)
79 int i = 0, cur_depth = 0;
80 struct commit_list *result = NULL;
81 struct object_array stack = OBJECT_ARRAY_INIT;
82 struct commit *commit = NULL;
83 struct commit_graft *graft;
85 while (commit || i < heads->nr || stack.nr) {
86 struct commit_list *p;
87 if (!commit) {
88 if (i < heads->nr) {
89 commit = (struct commit *)
90 deref_tag(heads->objects[i++].item, NULL, 0);
91 if (!commit || commit->object.type != OBJ_COMMIT) {
92 commit = NULL;
93 continue;
95 if (!commit->util)
96 commit->util = xmalloc(sizeof(int));
97 *(int *)commit->util = 0;
98 cur_depth = 0;
99 } else {
100 commit = (struct commit *)
101 stack.objects[--stack.nr].item;
102 cur_depth = *(int *)commit->util;
105 parse_commit_or_die(commit);
106 cur_depth++;
107 if ((depth != INFINITE_DEPTH && cur_depth >= depth) ||
108 (is_repository_shallow() && !commit->parents &&
109 (graft = lookup_commit_graft(commit->object.sha1)) != NULL &&
110 graft->nr_parent < 0)) {
111 commit_list_insert(commit, &result);
112 commit->object.flags |= shallow_flag;
113 commit = NULL;
114 continue;
116 commit->object.flags |= not_shallow_flag;
117 for (p = commit->parents, commit = NULL; p; p = p->next) {
118 if (!p->item->util) {
119 int *pointer = xmalloc(sizeof(int));
120 p->item->util = pointer;
121 *pointer = cur_depth;
122 } else {
123 int *pointer = p->item->util;
124 if (cur_depth >= *pointer)
125 continue;
126 *pointer = cur_depth;
128 if (p->next)
129 add_object_array(&p->item->object,
130 NULL, &stack);
131 else {
132 commit = p->item;
133 cur_depth = *(int *)commit->util;
138 return result;
141 static void check_shallow_file_for_update(void)
143 if (is_shallow == -1)
144 die("BUG: shallow must be initialized by now");
146 if (!stat_validity_check(&shallow_stat, git_path_shallow()))
147 die("shallow file has changed since we read it");
150 #define SEEN_ONLY 1
151 #define VERBOSE 2
153 struct write_shallow_data {
154 struct strbuf *out;
155 int use_pack_protocol;
156 int count;
157 unsigned flags;
160 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
162 struct write_shallow_data *data = cb_data;
163 const char *hex = oid_to_hex(&graft->oid);
164 if (graft->nr_parent != -1)
165 return 0;
166 if (data->flags & SEEN_ONLY) {
167 struct commit *c = lookup_commit(graft->oid.hash);
168 if (!c || !(c->object.flags & SEEN)) {
169 if (data->flags & VERBOSE)
170 printf("Removing %s from .git/shallow\n",
171 sha1_to_hex(c->object.sha1));
172 return 0;
175 data->count++;
176 if (data->use_pack_protocol)
177 packet_buf_write(data->out, "shallow %s", hex);
178 else {
179 strbuf_addstr(data->out, hex);
180 strbuf_addch(data->out, '\n');
182 return 0;
185 static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
186 const struct sha1_array *extra,
187 unsigned flags)
189 struct write_shallow_data data;
190 int i;
191 data.out = out;
192 data.use_pack_protocol = use_pack_protocol;
193 data.count = 0;
194 data.flags = flags;
195 for_each_commit_graft(write_one_shallow, &data);
196 if (!extra)
197 return data.count;
198 for (i = 0; i < extra->nr; i++) {
199 strbuf_addstr(out, sha1_to_hex(extra->sha1[i]));
200 strbuf_addch(out, '\n');
201 data.count++;
203 return data.count;
206 int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
207 const struct sha1_array *extra)
209 return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
212 static struct tempfile temporary_shallow;
214 const char *setup_temporary_shallow(const struct sha1_array *extra)
216 struct strbuf sb = STRBUF_INIT;
217 int fd;
219 if (write_shallow_commits(&sb, 0, extra)) {
220 fd = xmks_tempfile(&temporary_shallow, git_path("shallow_XXXXXX"));
222 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
223 die_errno("failed to write to %s",
224 get_tempfile_path(&temporary_shallow));
225 close_tempfile(&temporary_shallow);
226 strbuf_release(&sb);
227 return get_tempfile_path(&temporary_shallow);
230 * is_repository_shallow() sees empty string as "no shallow
231 * file".
233 return get_tempfile_path(&temporary_shallow);
236 void setup_alternate_shallow(struct lock_file *shallow_lock,
237 const char **alternate_shallow_file,
238 const struct sha1_array *extra)
240 struct strbuf sb = STRBUF_INIT;
241 int fd;
243 fd = hold_lock_file_for_update(shallow_lock, git_path_shallow(),
244 LOCK_DIE_ON_ERROR);
245 check_shallow_file_for_update();
246 if (write_shallow_commits(&sb, 0, extra)) {
247 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
248 die_errno("failed to write to %s",
249 get_lock_file_path(shallow_lock));
250 *alternate_shallow_file = get_lock_file_path(shallow_lock);
251 } else
253 * is_repository_shallow() sees empty string as "no
254 * shallow file".
256 *alternate_shallow_file = "";
257 strbuf_release(&sb);
260 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
262 int fd = *(int *)cb;
263 if (graft->nr_parent == -1)
264 packet_write(fd, "shallow %s\n", oid_to_hex(&graft->oid));
265 return 0;
268 void advertise_shallow_grafts(int fd)
270 if (!is_repository_shallow())
271 return;
272 for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
276 * mark_reachable_objects() should have been run prior to this and all
277 * reachable commits marked as "SEEN".
279 void prune_shallow(int show_only)
281 static struct lock_file shallow_lock;
282 struct strbuf sb = STRBUF_INIT;
283 int fd;
285 if (show_only) {
286 write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY | VERBOSE);
287 strbuf_release(&sb);
288 return;
290 fd = hold_lock_file_for_update(&shallow_lock, git_path_shallow(),
291 LOCK_DIE_ON_ERROR);
292 check_shallow_file_for_update();
293 if (write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY)) {
294 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
295 die_errno("failed to write to %s",
296 get_lock_file_path(&shallow_lock));
297 commit_lock_file(&shallow_lock);
298 } else {
299 unlink(git_path_shallow());
300 rollback_lock_file(&shallow_lock);
302 strbuf_release(&sb);
305 struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
308 * Step 1, split sender shallow commits into "ours" and "theirs"
309 * Step 2, clean "ours" based on .git/shallow
311 void prepare_shallow_info(struct shallow_info *info, struct sha1_array *sa)
313 int i;
314 trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
315 memset(info, 0, sizeof(*info));
316 info->shallow = sa;
317 if (!sa)
318 return;
319 info->ours = xmalloc(sizeof(*info->ours) * sa->nr);
320 info->theirs = xmalloc(sizeof(*info->theirs) * sa->nr);
321 for (i = 0; i < sa->nr; i++) {
322 if (has_sha1_file(sa->sha1[i])) {
323 struct commit_graft *graft;
324 graft = lookup_commit_graft(sa->sha1[i]);
325 if (graft && graft->nr_parent < 0)
326 continue;
327 info->ours[info->nr_ours++] = i;
328 } else
329 info->theirs[info->nr_theirs++] = i;
333 void clear_shallow_info(struct shallow_info *info)
335 free(info->ours);
336 free(info->theirs);
339 /* Step 4, remove non-existent ones in "theirs" after getting the pack */
341 void remove_nonexistent_theirs_shallow(struct shallow_info *info)
343 unsigned char (*sha1)[20] = info->shallow->sha1;
344 int i, dst;
345 trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
346 for (i = dst = 0; i < info->nr_theirs; i++) {
347 if (i != dst)
348 info->theirs[dst] = info->theirs[i];
349 if (has_sha1_file(sha1[info->theirs[i]]))
350 dst++;
352 info->nr_theirs = dst;
355 define_commit_slab(ref_bitmap, uint32_t *);
357 struct paint_info {
358 struct ref_bitmap ref_bitmap;
359 unsigned nr_bits;
360 char **slab;
361 char *free, *end;
362 unsigned slab_count;
365 static uint32_t *paint_alloc(struct paint_info *info)
367 unsigned nr = (info->nr_bits + 31) / 32;
368 unsigned size = nr * sizeof(uint32_t);
369 void *p;
370 if (!info->slab_count || info->free + size > info->end) {
371 info->slab_count++;
372 REALLOC_ARRAY(info->slab, info->slab_count);
373 info->free = xmalloc(COMMIT_SLAB_SIZE);
374 info->slab[info->slab_count - 1] = info->free;
375 info->end = info->free + COMMIT_SLAB_SIZE;
377 p = info->free;
378 info->free += size;
379 return p;
383 * Given a commit SHA-1, walk down to parents until either SEEN,
384 * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
385 * all walked commits.
387 static void paint_down(struct paint_info *info, const unsigned char *sha1,
388 int id)
390 unsigned int i, nr;
391 struct commit_list *head = NULL;
392 int bitmap_nr = (info->nr_bits + 31) / 32;
393 int bitmap_size = bitmap_nr * sizeof(uint32_t);
394 uint32_t *tmp = xmalloc(bitmap_size); /* to be freed before return */
395 uint32_t *bitmap = paint_alloc(info);
396 struct commit *c = lookup_commit_reference_gently(sha1, 1);
397 if (!c)
398 return;
399 memset(bitmap, 0, bitmap_size);
400 bitmap[id / 32] |= (1 << (id % 32));
401 commit_list_insert(c, &head);
402 while (head) {
403 struct commit_list *p;
404 struct commit *c = head->item;
405 uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
407 p = head;
408 head = head->next;
409 free(p);
411 /* XXX check "UNINTERESTING" from pack bitmaps if available */
412 if (c->object.flags & (SEEN | UNINTERESTING))
413 continue;
414 else
415 c->object.flags |= SEEN;
417 if (*refs == NULL)
418 *refs = bitmap;
419 else {
420 memcpy(tmp, *refs, bitmap_size);
421 for (i = 0; i < bitmap_nr; i++)
422 tmp[i] |= bitmap[i];
423 if (memcmp(tmp, *refs, bitmap_size)) {
424 *refs = paint_alloc(info);
425 memcpy(*refs, tmp, bitmap_size);
429 if (c->object.flags & BOTTOM)
430 continue;
432 if (parse_commit(c))
433 die("unable to parse commit %s",
434 sha1_to_hex(c->object.sha1));
436 for (p = c->parents; p; p = p->next) {
437 uint32_t **p_refs = ref_bitmap_at(&info->ref_bitmap,
438 p->item);
439 if (p->item->object.flags & SEEN)
440 continue;
441 if (*p_refs == NULL || *p_refs == *refs)
442 *p_refs = *refs;
443 commit_list_insert(p->item, &head);
447 nr = get_max_object_index();
448 for (i = 0; i < nr; i++) {
449 struct object *o = get_indexed_object(i);
450 if (o && o->type == OBJ_COMMIT)
451 o->flags &= ~SEEN;
454 free(tmp);
457 static int mark_uninteresting(const char *refname, const struct object_id *oid,
458 int flags, void *cb_data)
460 struct commit *commit = lookup_commit_reference_gently(oid->hash, 1);
461 if (!commit)
462 return 0;
463 commit->object.flags |= UNINTERESTING;
464 mark_parents_uninteresting(commit);
465 return 0;
468 static void post_assign_shallow(struct shallow_info *info,
469 struct ref_bitmap *ref_bitmap,
470 int *ref_status);
472 * Step 6(+7), associate shallow commits with new refs
474 * info->ref must be initialized before calling this function.
476 * If used is not NULL, it's an array of info->shallow->nr
477 * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
478 * m-th shallow commit from info->shallow.
480 * If used is NULL, "ours" and "theirs" are updated. And if ref_status
481 * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
482 * the ref needs some shallow commits from either info->ours or
483 * info->theirs.
485 void assign_shallow_commits_to_refs(struct shallow_info *info,
486 uint32_t **used, int *ref_status)
488 unsigned char (*sha1)[20] = info->shallow->sha1;
489 struct sha1_array *ref = info->ref;
490 unsigned int i, nr;
491 int *shallow, nr_shallow = 0;
492 struct paint_info pi;
494 trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
495 shallow = xmalloc(sizeof(*shallow) * (info->nr_ours + info->nr_theirs));
496 for (i = 0; i < info->nr_ours; i++)
497 shallow[nr_shallow++] = info->ours[i];
498 for (i = 0; i < info->nr_theirs; i++)
499 shallow[nr_shallow++] = info->theirs[i];
502 * Prepare the commit graph to track what refs can reach what
503 * (new) shallow commits.
505 nr = get_max_object_index();
506 for (i = 0; i < nr; i++) {
507 struct object *o = get_indexed_object(i);
508 if (!o || o->type != OBJ_COMMIT)
509 continue;
511 o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
514 memset(&pi, 0, sizeof(pi));
515 init_ref_bitmap(&pi.ref_bitmap);
516 pi.nr_bits = ref->nr;
519 * "--not --all" to cut short the traversal if new refs
520 * connect to old refs. If not (e.g. force ref updates) it'll
521 * have to go down to the current shallow commits.
523 head_ref(mark_uninteresting, NULL);
524 for_each_ref(mark_uninteresting, NULL);
526 /* Mark potential bottoms so we won't go out of bound */
527 for (i = 0; i < nr_shallow; i++) {
528 struct commit *c = lookup_commit(sha1[shallow[i]]);
529 c->object.flags |= BOTTOM;
532 for (i = 0; i < ref->nr; i++)
533 paint_down(&pi, ref->sha1[i], i);
535 if (used) {
536 int bitmap_size = ((pi.nr_bits + 31) / 32) * sizeof(uint32_t);
537 memset(used, 0, sizeof(*used) * info->shallow->nr);
538 for (i = 0; i < nr_shallow; i++) {
539 const struct commit *c = lookup_commit(sha1[shallow[i]]);
540 uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
541 if (*map)
542 used[shallow[i]] = xmemdupz(*map, bitmap_size);
545 * unreachable shallow commits are not removed from
546 * "ours" and "theirs". The user is supposed to run
547 * step 7 on every ref separately and not trust "ours"
548 * and "theirs" any more.
550 } else
551 post_assign_shallow(info, &pi.ref_bitmap, ref_status);
553 clear_ref_bitmap(&pi.ref_bitmap);
554 for (i = 0; i < pi.slab_count; i++)
555 free(pi.slab[i]);
556 free(pi.slab);
557 free(shallow);
560 struct commit_array {
561 struct commit **commits;
562 int nr, alloc;
565 static int add_ref(const char *refname, const struct object_id *oid,
566 int flags, void *cb_data)
568 struct commit_array *ca = cb_data;
569 ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
570 ca->commits[ca->nr] = lookup_commit_reference_gently(oid->hash, 1);
571 if (ca->commits[ca->nr])
572 ca->nr++;
573 return 0;
576 static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
578 int i;
579 if (!ref_status)
580 return;
581 for (i = 0; i < nr; i++)
582 if (bitmap[i / 32] & (1 << (i % 32)))
583 ref_status[i]++;
587 * Step 7, reachability test on "ours" at commit level
589 static void post_assign_shallow(struct shallow_info *info,
590 struct ref_bitmap *ref_bitmap,
591 int *ref_status)
593 unsigned char (*sha1)[20] = info->shallow->sha1;
594 struct commit *c;
595 uint32_t **bitmap;
596 int dst, i, j;
597 int bitmap_nr = (info->ref->nr + 31) / 32;
598 struct commit_array ca;
600 trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
601 if (ref_status)
602 memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);
604 /* Remove unreachable shallow commits from "theirs" */
605 for (i = dst = 0; i < info->nr_theirs; i++) {
606 if (i != dst)
607 info->theirs[dst] = info->theirs[i];
608 c = lookup_commit(sha1[info->theirs[i]]);
609 bitmap = ref_bitmap_at(ref_bitmap, c);
610 if (!*bitmap)
611 continue;
612 for (j = 0; j < bitmap_nr; j++)
613 if (bitmap[0][j]) {
614 update_refstatus(ref_status, info->ref->nr, *bitmap);
615 dst++;
616 break;
619 info->nr_theirs = dst;
621 memset(&ca, 0, sizeof(ca));
622 head_ref(add_ref, &ca);
623 for_each_ref(add_ref, &ca);
625 /* Remove unreachable shallow commits from "ours" */
626 for (i = dst = 0; i < info->nr_ours; i++) {
627 if (i != dst)
628 info->ours[dst] = info->ours[i];
629 c = lookup_commit(sha1[info->ours[i]]);
630 bitmap = ref_bitmap_at(ref_bitmap, c);
631 if (!*bitmap)
632 continue;
633 for (j = 0; j < bitmap_nr; j++)
634 if (bitmap[0][j] &&
635 /* Step 7, reachability test at commit level */
636 !in_merge_bases_many(c, ca.nr, ca.commits)) {
637 update_refstatus(ref_status, info->ref->nr, *bitmap);
638 dst++;
639 break;
642 info->nr_ours = dst;
644 free(ca.commits);
647 /* (Delayed) step 7, reachability test at commit level */
648 int delayed_reachability_test(struct shallow_info *si, int c)
650 if (si->need_reachability_test[c]) {
651 struct commit *commit = lookup_commit(si->shallow->sha1[c]);
653 if (!si->commits) {
654 struct commit_array ca;
656 memset(&ca, 0, sizeof(ca));
657 head_ref(add_ref, &ca);
658 for_each_ref(add_ref, &ca);
659 si->commits = ca.commits;
660 si->nr_commits = ca.nr;
663 si->reachable[c] = in_merge_bases_many(commit,
664 si->nr_commits,
665 si->commits);
666 si->need_reachability_test[c] = 0;
668 return si->reachable[c];