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"
13static int is_shallow = -1;
15static struct stat_validity shallow_stat;
16static char *alternate_shallow_file;
17void set_alternate_shallow_file(const char *path, int override)
19{
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);
26}
27int register_shallow(const unsigned char *sha1)
29{
30 struct commit_graft *graft =
31 xmalloc(sizeof(struct commit_graft));
32 struct commit *commit = lookup_commit(sha1);
33 hashcpy(graft->oid.hash, sha1);
35 graft->nr_parent = -1;
36 if (commit && commit->object.parsed)
37 commit->parents = NULL;
38 return register_commit_graft(graft, 0);
39}
40int is_repository_shallow(void)
42{
43 FILE *fp;
44 char buf[1024];
45 const char *path = alternate_shallow_file;
46 if (is_shallow >= 0)
48 return is_shallow;
49 if (!path)
51 path = git_path_shallow();
52 /*
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.
56 */
57 if (!*path || (fp = fopen(path, "r")) == NULL) {
58 stat_validity_clear(&shallow_stat);
59 is_shallow = 0;
60 return is_shallow;
61 }
62 stat_validity_update(&shallow_stat, fileno(fp));
63 is_shallow = 1;
64 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);
70 }
71 fclose(fp);
72 return is_shallow;
73}
74struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
76 int shallow_flag, int not_shallow_flag)
77{
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;
83 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;
93 }
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;
102 }
103 }
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.oid.hash)) != NULL &&
109 graft->nr_parent < 0)) {
110 commit_list_insert(commit, &result);
111 commit->object.flags |= shallow_flag;
112 commit = NULL;
113 continue;
114 }
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;
126 }
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;
133 }
134 }
135 }
136 return result;
138}
139static void check_shallow_file_for_update(void)
141{
142 if (is_shallow == -1)
143 die("BUG: shallow must be initialized by now");
144 if (!stat_validity_check(&shallow_stat, git_path_shallow()))
146 die("shallow file has changed since we read it");
147}
148#define SEEN_ONLY 1
150#define VERBOSE 2
151struct write_shallow_data {
153 struct strbuf *out;
154 int use_pack_protocol;
155 int count;
156 unsigned flags;
157};
158static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
160{
161 struct write_shallow_data *data = cb_data;
162 const char *hex = oid_to_hex(&graft->oid);
163 if (graft->nr_parent != -1)
164 return 0;
165 if (data->flags & SEEN_ONLY) {
166 struct commit *c = lookup_commit(graft->oid.hash);
167 if (!c || !(c->object.flags & SEEN)) {
168 if (data->flags & VERBOSE)
169 printf("Removing %s from .git/shallow\n",
170 oid_to_hex(&c->object.oid));
171 return 0;
172 }
173 }
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');
180 }
181 return 0;
182}
183static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
185 const struct sha1_array *extra,
186 unsigned flags)
187{
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++;
201 }
202 return data.count;
203}
204int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
206 const struct sha1_array *extra)
207{
208 return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
209}
210static struct tempfile temporary_shallow;
212const char *setup_temporary_shallow(const struct sha1_array *extra)
214{
215 struct strbuf sb = STRBUF_INIT;
216 int fd;
217 if (write_shallow_commits(&sb, 0, extra)) {
219 fd = xmks_tempfile(&temporary_shallow, git_path("shallow_XXXXXX"));
220 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
222 die_errno("failed to write to %s",
223 get_tempfile_path(&temporary_shallow));
224 close_tempfile(&temporary_shallow);
225 strbuf_release(&sb);
226 return get_tempfile_path(&temporary_shallow);
227 }
228 /*
229 * is_repository_shallow() sees empty string as "no shallow
230 * file".
231 */
232 return get_tempfile_path(&temporary_shallow);
233}
234void setup_alternate_shallow(struct lock_file *shallow_lock,
236 const char **alternate_shallow_file,
237 const struct sha1_array *extra)
238{
239 struct strbuf sb = STRBUF_INIT;
240 int fd;
241 fd = hold_lock_file_for_update(shallow_lock, git_path_shallow(),
243 LOCK_DIE_ON_ERROR);
244 check_shallow_file_for_update();
245 if (write_shallow_commits(&sb, 0, extra)) {
246 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
247 die_errno("failed to write to %s",
248 get_lock_file_path(shallow_lock));
249 *alternate_shallow_file = get_lock_file_path(shallow_lock);
250 } else
251 /*
252 * is_repository_shallow() sees empty string as "no
253 * shallow file".
254 */
255 *alternate_shallow_file = "";
256 strbuf_release(&sb);
257}
258static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
260{
261 int fd = *(int *)cb;
262 if (graft->nr_parent == -1)
263 packet_write(fd, "shallow %s\n", oid_to_hex(&graft->oid));
264 return 0;
265}
266void advertise_shallow_grafts(int fd)
268{
269 if (!is_repository_shallow())
270 return;
271 for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
272}
273/*
275 * mark_reachable_objects() should have been run prior to this and all
276 * reachable commits marked as "SEEN".
277 */
278void prune_shallow(int show_only)
279{
280 static struct lock_file shallow_lock;
281 struct strbuf sb = STRBUF_INIT;
282 int fd;
283 if (show_only) {
285 write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY | VERBOSE);
286 strbuf_release(&sb);
287 return;
288 }
289 fd = hold_lock_file_for_update(&shallow_lock, git_path_shallow(),
290 LOCK_DIE_ON_ERROR);
291 check_shallow_file_for_update();
292 if (write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY)) {
293 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
294 die_errno("failed to write to %s",
295 get_lock_file_path(&shallow_lock));
296 commit_lock_file(&shallow_lock);
297 } else {
298 unlink(git_path_shallow());
299 rollback_lock_file(&shallow_lock);
300 }
301 strbuf_release(&sb);
302}
303struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
305/*
307 * Step 1, split sender shallow commits into "ours" and "theirs"
308 * Step 2, clean "ours" based on .git/shallow
309 */
310void prepare_shallow_info(struct shallow_info *info, struct sha1_array *sa)
311{
312 int i;
313 trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
314 memset(info, 0, sizeof(*info));
315 info->shallow = sa;
316 if (!sa)
317 return;
318 ALLOC_ARRAY(info->ours, sa->nr);
319 ALLOC_ARRAY(info->theirs, sa->nr);
320 for (i = 0; i < sa->nr; i++) {
321 if (has_sha1_file(sa->sha1[i])) {
322 struct commit_graft *graft;
323 graft = lookup_commit_graft(sa->sha1[i]);
324 if (graft && graft->nr_parent < 0)
325 continue;
326 info->ours[info->nr_ours++] = i;
327 } else
328 info->theirs[info->nr_theirs++] = i;
329 }
330}
331void clear_shallow_info(struct shallow_info *info)
333{
334 free(info->ours);
335 free(info->theirs);
336}
337/* Step 4, remove non-existent ones in "theirs" after getting the pack */
339void remove_nonexistent_theirs_shallow(struct shallow_info *info)
341{
342 unsigned char (*sha1)[20] = info->shallow->sha1;
343 int i, dst;
344 trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
345 for (i = dst = 0; i < info->nr_theirs; i++) {
346 if (i != dst)
347 info->theirs[dst] = info->theirs[i];
348 if (has_sha1_file(sha1[info->theirs[i]]))
349 dst++;
350 }
351 info->nr_theirs = dst;
352}
353define_commit_slab(ref_bitmap, uint32_t *);
355struct paint_info {
357 struct ref_bitmap ref_bitmap;
358 unsigned nr_bits;
359 char **slab;
360 char *free, *end;
361 unsigned slab_count;
362};
363static uint32_t *paint_alloc(struct paint_info *info)
365{
366 unsigned nr = (info->nr_bits + 31) / 32;
367 unsigned size = nr * sizeof(uint32_t);
368 void *p;
369 if (!info->slab_count || info->free + size > info->end) {
370 info->slab_count++;
371 REALLOC_ARRAY(info->slab, info->slab_count);
372 info->free = xmalloc(COMMIT_SLAB_SIZE);
373 info->slab[info->slab_count - 1] = info->free;
374 info->end = info->free + COMMIT_SLAB_SIZE;
375 }
376 p = info->free;
377 info->free += size;
378 return p;
379}
380/*
382 * Given a commit SHA-1, walk down to parents until either SEEN,
383 * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
384 * all walked commits.
385 */
386static void paint_down(struct paint_info *info, const unsigned char *sha1,
387 int id)
388{
389 unsigned int i, nr;
390 struct commit_list *head = NULL;
391 int bitmap_nr = (info->nr_bits + 31) / 32;
392 size_t bitmap_size = st_mult(bitmap_nr, sizeof(uint32_t));
393 uint32_t *tmp = xmalloc(bitmap_size); /* to be freed before return */
394 uint32_t *bitmap = paint_alloc(info);
395 struct commit *c = lookup_commit_reference_gently(sha1, 1);
396 if (!c)
397 return;
398 memset(bitmap, 0, bitmap_size);
399 bitmap[id / 32] |= (1 << (id % 32));
400 commit_list_insert(c, &head);
401 while (head) {
402 struct commit_list *p;
403 struct commit *c = pop_commit(&head);
404 uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
405 /* XXX check "UNINTERESTING" from pack bitmaps if available */
407 if (c->object.flags & (SEEN | UNINTERESTING))
408 continue;
409 else
410 c->object.flags |= SEEN;
411 if (*refs == NULL)
413 *refs = bitmap;
414 else {
415 memcpy(tmp, *refs, bitmap_size);
416 for (i = 0; i < bitmap_nr; i++)
417 tmp[i] |= bitmap[i];
418 if (memcmp(tmp, *refs, bitmap_size)) {
419 *refs = paint_alloc(info);
420 memcpy(*refs, tmp, bitmap_size);
421 }
422 }
423 if (c->object.flags & BOTTOM)
425 continue;
426 if (parse_commit(c))
428 die("unable to parse commit %s",
429 oid_to_hex(&c->object.oid));
430 for (p = c->parents; p; p = p->next) {
432 uint32_t **p_refs = ref_bitmap_at(&info->ref_bitmap,
433 p->item);
434 if (p->item->object.flags & SEEN)
435 continue;
436 if (*p_refs == NULL || *p_refs == *refs)
437 *p_refs = *refs;
438 commit_list_insert(p->item, &head);
439 }
440 }
441 nr = get_max_object_index();
443 for (i = 0; i < nr; i++) {
444 struct object *o = get_indexed_object(i);
445 if (o && o->type == OBJ_COMMIT)
446 o->flags &= ~SEEN;
447 }
448 free(tmp);
450}
451static int mark_uninteresting(const char *refname, const struct object_id *oid,
453 int flags, void *cb_data)
454{
455 struct commit *commit = lookup_commit_reference_gently(oid->hash, 1);
456 if (!commit)
457 return 0;
458 commit->object.flags |= UNINTERESTING;
459 mark_parents_uninteresting(commit);
460 return 0;
461}
462static void post_assign_shallow(struct shallow_info *info,
464 struct ref_bitmap *ref_bitmap,
465 int *ref_status);
466/*
467 * Step 6(+7), associate shallow commits with new refs
468 *
469 * info->ref must be initialized before calling this function.
470 *
471 * If used is not NULL, it's an array of info->shallow->nr
472 * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
473 * m-th shallow commit from info->shallow.
474 *
475 * If used is NULL, "ours" and "theirs" are updated. And if ref_status
476 * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
477 * the ref needs some shallow commits from either info->ours or
478 * info->theirs.
479 */
480void assign_shallow_commits_to_refs(struct shallow_info *info,
481 uint32_t **used, int *ref_status)
482{
483 unsigned char (*sha1)[20] = info->shallow->sha1;
484 struct sha1_array *ref = info->ref;
485 unsigned int i, nr;
486 int *shallow, nr_shallow = 0;
487 struct paint_info pi;
488 trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
490 ALLOC_ARRAY(shallow, info->nr_ours + info->nr_theirs);
491 for (i = 0; i < info->nr_ours; i++)
492 shallow[nr_shallow++] = info->ours[i];
493 for (i = 0; i < info->nr_theirs; i++)
494 shallow[nr_shallow++] = info->theirs[i];
495 /*
497 * Prepare the commit graph to track what refs can reach what
498 * (new) shallow commits.
499 */
500 nr = get_max_object_index();
501 for (i = 0; i < nr; i++) {
502 struct object *o = get_indexed_object(i);
503 if (!o || o->type != OBJ_COMMIT)
504 continue;
505 o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
507 }
508 memset(&pi, 0, sizeof(pi));
510 init_ref_bitmap(&pi.ref_bitmap);
511 pi.nr_bits = ref->nr;
512 /*
514 * "--not --all" to cut short the traversal if new refs
515 * connect to old refs. If not (e.g. force ref updates) it'll
516 * have to go down to the current shallow commits.
517 */
518 head_ref(mark_uninteresting, NULL);
519 for_each_ref(mark_uninteresting, NULL);
520 /* Mark potential bottoms so we won't go out of bound */
522 for (i = 0; i < nr_shallow; i++) {
523 struct commit *c = lookup_commit(sha1[shallow[i]]);
524 c->object.flags |= BOTTOM;
525 }
526 for (i = 0; i < ref->nr; i++)
528 paint_down(&pi, ref->sha1[i], i);
529 if (used) {
531 int bitmap_size = ((pi.nr_bits + 31) / 32) * sizeof(uint32_t);
532 memset(used, 0, sizeof(*used) * info->shallow->nr);
533 for (i = 0; i < nr_shallow; i++) {
534 const struct commit *c = lookup_commit(sha1[shallow[i]]);
535 uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
536 if (*map)
537 used[shallow[i]] = xmemdupz(*map, bitmap_size);
538 }
539 /*
540 * unreachable shallow commits are not removed from
541 * "ours" and "theirs". The user is supposed to run
542 * step 7 on every ref separately and not trust "ours"
543 * and "theirs" any more.
544 */
545 } else
546 post_assign_shallow(info, &pi.ref_bitmap, ref_status);
547 clear_ref_bitmap(&pi.ref_bitmap);
549 for (i = 0; i < pi.slab_count; i++)
550 free(pi.slab[i]);
551 free(pi.slab);
552 free(shallow);
553}
554struct commit_array {
556 struct commit **commits;
557 int nr, alloc;
558};
559static int add_ref(const char *refname, const struct object_id *oid,
561 int flags, void *cb_data)
562{
563 struct commit_array *ca = cb_data;
564 ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
565 ca->commits[ca->nr] = lookup_commit_reference_gently(oid->hash, 1);
566 if (ca->commits[ca->nr])
567 ca->nr++;
568 return 0;
569}
570static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
572{
573 int i;
574 if (!ref_status)
575 return;
576 for (i = 0; i < nr; i++)
577 if (bitmap[i / 32] & (1 << (i % 32)))
578 ref_status[i]++;
579}
580/*
582 * Step 7, reachability test on "ours" at commit level
583 */
584static void post_assign_shallow(struct shallow_info *info,
585 struct ref_bitmap *ref_bitmap,
586 int *ref_status)
587{
588 unsigned char (*sha1)[20] = info->shallow->sha1;
589 struct commit *c;
590 uint32_t **bitmap;
591 int dst, i, j;
592 int bitmap_nr = (info->ref->nr + 31) / 32;
593 struct commit_array ca;
594 trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
596 if (ref_status)
597 memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);
598 /* Remove unreachable shallow commits from "theirs" */
600 for (i = dst = 0; i < info->nr_theirs; i++) {
601 if (i != dst)
602 info->theirs[dst] = info->theirs[i];
603 c = lookup_commit(sha1[info->theirs[i]]);
604 bitmap = ref_bitmap_at(ref_bitmap, c);
605 if (!*bitmap)
606 continue;
607 for (j = 0; j < bitmap_nr; j++)
608 if (bitmap[0][j]) {
609 update_refstatus(ref_status, info->ref->nr, *bitmap);
610 dst++;
611 break;
612 }
613 }
614 info->nr_theirs = dst;
615 memset(&ca, 0, sizeof(ca));
617 head_ref(add_ref, &ca);
618 for_each_ref(add_ref, &ca);
619 /* Remove unreachable shallow commits from "ours" */
621 for (i = dst = 0; i < info->nr_ours; i++) {
622 if (i != dst)
623 info->ours[dst] = info->ours[i];
624 c = lookup_commit(sha1[info->ours[i]]);
625 bitmap = ref_bitmap_at(ref_bitmap, c);
626 if (!*bitmap)
627 continue;
628 for (j = 0; j < bitmap_nr; j++)
629 if (bitmap[0][j] &&
630 /* Step 7, reachability test at commit level */
631 !in_merge_bases_many(c, ca.nr, ca.commits)) {
632 update_refstatus(ref_status, info->ref->nr, *bitmap);
633 dst++;
634 break;
635 }
636 }
637 info->nr_ours = dst;
638 free(ca.commits);
640}
641/* (Delayed) step 7, reachability test at commit level */
643int delayed_reachability_test(struct shallow_info *si, int c)
644{
645 if (si->need_reachability_test[c]) {
646 struct commit *commit = lookup_commit(si->shallow->sha1[c]);
647 if (!si->commits) {
649 struct commit_array ca;
650 memset(&ca, 0, sizeof(ca));
652 head_ref(add_ref, &ca);
653 for_each_ref(add_ref, &ca);
654 si->commits = ca.commits;
655 si->nr_commits = ca.nr;
656 }
657 si->reachable[c] = in_merge_bases_many(commit,
659 si->nr_commits,
660 si->commits);
661 si->need_reachability_test[c] = 0;
662 }
663 return si->reachable[c];
664}