Implement the patience diff algorithm
[git/platforms.git] / builtin-fetch.c
blob7568163af24df630c215e05b6082ed764150a315
1 /*
2 * "git fetch"
3 */
4 #include "cache.h"
5 #include "refs.h"
6 #include "commit.h"
7 #include "builtin.h"
8 #include "string-list.h"
9 #include "remote.h"
10 #include "transport.h"
11 #include "run-command.h"
12 #include "parse-options.h"
14 static const char * const builtin_fetch_usage[] = {
15 "git fetch [options] [<repository> <refspec>...]",
16 NULL
19 enum {
20 TAGS_UNSET = 0,
21 TAGS_DEFAULT = 1,
22 TAGS_SET = 2
25 static int append, force, keep, update_head_ok, verbosity;
26 static int tags = TAGS_DEFAULT;
27 static const char *depth;
28 static const char *upload_pack;
29 static struct strbuf default_rla = STRBUF_INIT;
30 static struct transport *transport;
32 static struct option builtin_fetch_options[] = {
33 OPT__VERBOSITY(&verbosity),
34 OPT_BOOLEAN('a', "append", &append,
35 "append to .git/FETCH_HEAD instead of overwriting"),
36 OPT_STRING(0, "upload-pack", &upload_pack, "PATH",
37 "path to upload pack on remote end"),
38 OPT_BOOLEAN('f', "force", &force,
39 "force overwrite of local branch"),
40 OPT_SET_INT('t', "tags", &tags,
41 "fetch all tags and associated objects", TAGS_SET),
42 OPT_SET_INT('n', NULL, &tags,
43 "do not fetch all tags (--no-tags)", TAGS_UNSET),
44 OPT_BOOLEAN('k', "keep", &keep, "keep downloaded pack"),
45 OPT_BOOLEAN('u', "update-head-ok", &update_head_ok,
46 "allow updating of HEAD ref"),
47 OPT_STRING(0, "depth", &depth, "DEPTH",
48 "deepen history of shallow clone"),
49 OPT_END()
52 static void unlock_pack(void)
54 if (transport)
55 transport_unlock_pack(transport);
58 static void unlock_pack_on_signal(int signo)
60 unlock_pack();
61 signal(SIGINT, SIG_DFL);
62 raise(signo);
65 static void add_merge_config(struct ref **head,
66 const struct ref *remote_refs,
67 struct branch *branch,
68 struct ref ***tail)
70 int i;
72 for (i = 0; i < branch->merge_nr; i++) {
73 struct ref *rm, **old_tail = *tail;
74 struct refspec refspec;
76 for (rm = *head; rm; rm = rm->next) {
77 if (branch_merge_matches(branch, i, rm->name)) {
78 rm->merge = 1;
79 break;
82 if (rm)
83 continue;
86 * Not fetched to a tracking branch? We need to fetch
87 * it anyway to allow this branch's "branch.$name.merge"
88 * to be honored by 'git pull', but we do not have to
89 * fail if branch.$name.merge is misconfigured to point
90 * at a nonexisting branch. If we were indeed called by
91 * 'git pull', it will notice the misconfiguration because
92 * there is no entry in the resulting FETCH_HEAD marked
93 * for merging.
95 refspec.src = branch->merge[i]->src;
96 refspec.dst = NULL;
97 refspec.pattern = 0;
98 refspec.force = 0;
99 get_fetch_map(remote_refs, &refspec, tail, 1);
100 for (rm = *old_tail; rm; rm = rm->next)
101 rm->merge = 1;
105 static void find_non_local_tags(struct transport *transport,
106 struct ref **head,
107 struct ref ***tail);
109 static struct ref *get_ref_map(struct transport *transport,
110 struct refspec *refs, int ref_count, int tags,
111 int *autotags)
113 int i;
114 struct ref *rm;
115 struct ref *ref_map = NULL;
116 struct ref **tail = &ref_map;
118 const struct ref *remote_refs = transport_get_remote_refs(transport);
120 if (ref_count || tags == TAGS_SET) {
121 for (i = 0; i < ref_count; i++) {
122 get_fetch_map(remote_refs, &refs[i], &tail, 0);
123 if (refs[i].dst && refs[i].dst[0])
124 *autotags = 1;
126 /* Merge everything on the command line, but not --tags */
127 for (rm = ref_map; rm; rm = rm->next)
128 rm->merge = 1;
129 if (tags == TAGS_SET)
130 get_fetch_map(remote_refs, tag_refspec, &tail, 0);
131 } else {
132 /* Use the defaults */
133 struct remote *remote = transport->remote;
134 struct branch *branch = branch_get(NULL);
135 int has_merge = branch_has_merge_config(branch);
136 if (remote && (remote->fetch_refspec_nr || has_merge)) {
137 for (i = 0; i < remote->fetch_refspec_nr; i++) {
138 get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
139 if (remote->fetch[i].dst &&
140 remote->fetch[i].dst[0])
141 *autotags = 1;
142 if (!i && !has_merge && ref_map &&
143 !remote->fetch[0].pattern)
144 ref_map->merge = 1;
147 * if the remote we're fetching from is the same
148 * as given in branch.<name>.remote, we add the
149 * ref given in branch.<name>.merge, too.
151 if (has_merge &&
152 !strcmp(branch->remote_name, remote->name))
153 add_merge_config(&ref_map, remote_refs, branch, &tail);
154 } else {
155 ref_map = get_remote_ref(remote_refs, "HEAD");
156 if (!ref_map)
157 die("Couldn't find remote ref HEAD");
158 ref_map->merge = 1;
159 tail = &ref_map->next;
162 if (tags == TAGS_DEFAULT && *autotags)
163 find_non_local_tags(transport, &ref_map, &tail);
164 ref_remove_duplicates(ref_map);
166 return ref_map;
169 static int s_update_ref(const char *action,
170 struct ref *ref,
171 int check_old)
173 char msg[1024];
174 char *rla = getenv("GIT_REFLOG_ACTION");
175 static struct ref_lock *lock;
177 if (!rla)
178 rla = default_rla.buf;
179 snprintf(msg, sizeof(msg), "%s: %s", rla, action);
180 lock = lock_any_ref_for_update(ref->name,
181 check_old ? ref->old_sha1 : NULL, 0);
182 if (!lock)
183 return 2;
184 if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
185 return 2;
186 return 0;
189 #define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
190 #define REFCOL_WIDTH 10
192 static int update_local_ref(struct ref *ref,
193 const char *remote,
194 char *display)
196 struct commit *current = NULL, *updated;
197 enum object_type type;
198 struct branch *current_branch = branch_get(NULL);
199 const char *pretty_ref = ref->name + (
200 !prefixcmp(ref->name, "refs/heads/") ? 11 :
201 !prefixcmp(ref->name, "refs/tags/") ? 10 :
202 !prefixcmp(ref->name, "refs/remotes/") ? 13 :
205 *display = 0;
206 type = sha1_object_info(ref->new_sha1, NULL);
207 if (type < 0)
208 die("object %s not found", sha1_to_hex(ref->new_sha1));
210 if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
211 if (verbosity > 0)
212 sprintf(display, "= %-*s %-*s -> %s", SUMMARY_WIDTH,
213 "[up to date]", REFCOL_WIDTH, remote,
214 pretty_ref);
215 return 0;
218 if (current_branch &&
219 !strcmp(ref->name, current_branch->name) &&
220 !(update_head_ok || is_bare_repository()) &&
221 !is_null_sha1(ref->old_sha1)) {
223 * If this is the head, and it's not okay to update
224 * the head, and the old value of the head isn't empty...
226 sprintf(display, "! %-*s %-*s -> %s (can't fetch in current branch)",
227 SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
228 pretty_ref);
229 return 1;
232 if (!is_null_sha1(ref->old_sha1) &&
233 !prefixcmp(ref->name, "refs/tags/")) {
234 int r;
235 r = s_update_ref("updating tag", ref, 0);
236 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '-',
237 SUMMARY_WIDTH, "[tag update]", REFCOL_WIDTH, remote,
238 pretty_ref, r ? " (unable to update local ref)" : "");
239 return r;
242 current = lookup_commit_reference_gently(ref->old_sha1, 1);
243 updated = lookup_commit_reference_gently(ref->new_sha1, 1);
244 if (!current || !updated) {
245 const char *msg;
246 const char *what;
247 int r;
248 if (!strncmp(ref->name, "refs/tags/", 10)) {
249 msg = "storing tag";
250 what = "[new tag]";
252 else {
253 msg = "storing head";
254 what = "[new branch]";
257 r = s_update_ref(msg, ref, 0);
258 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '*',
259 SUMMARY_WIDTH, what, REFCOL_WIDTH, remote, pretty_ref,
260 r ? " (unable to update local ref)" : "");
261 return r;
264 if (in_merge_bases(current, &updated, 1)) {
265 char quickref[83];
266 int r;
267 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
268 strcat(quickref, "..");
269 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
270 r = s_update_ref("fast forward", ref, 1);
271 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : ' ',
272 SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
273 pretty_ref, r ? " (unable to update local ref)" : "");
274 return r;
275 } else if (force || ref->force) {
276 char quickref[84];
277 int r;
278 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
279 strcat(quickref, "...");
280 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
281 r = s_update_ref("forced-update", ref, 1);
282 sprintf(display, "%c %-*s %-*s -> %s (%s)", r ? '!' : '+',
283 SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
284 pretty_ref,
285 r ? "unable to update local ref" : "forced update");
286 return r;
287 } else {
288 sprintf(display, "! %-*s %-*s -> %s (non fast forward)",
289 SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
290 pretty_ref);
291 return 1;
295 static int store_updated_refs(const char *url, const char *remote_name,
296 struct ref *ref_map)
298 FILE *fp;
299 struct commit *commit;
300 int url_len, i, note_len, shown_url = 0, rc = 0;
301 char note[1024];
302 const char *what, *kind;
303 struct ref *rm;
304 char *filename = git_path("FETCH_HEAD");
306 fp = fopen(filename, "a");
307 if (!fp)
308 return error("cannot open %s: %s\n", filename, strerror(errno));
309 for (rm = ref_map; rm; rm = rm->next) {
310 struct ref *ref = NULL;
312 if (rm->peer_ref) {
313 ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
314 strcpy(ref->name, rm->peer_ref->name);
315 hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
316 hashcpy(ref->new_sha1, rm->old_sha1);
317 ref->force = rm->peer_ref->force;
320 commit = lookup_commit_reference_gently(rm->old_sha1, 1);
321 if (!commit)
322 rm->merge = 0;
324 if (!strcmp(rm->name, "HEAD")) {
325 kind = "";
326 what = "";
328 else if (!prefixcmp(rm->name, "refs/heads/")) {
329 kind = "branch";
330 what = rm->name + 11;
332 else if (!prefixcmp(rm->name, "refs/tags/")) {
333 kind = "tag";
334 what = rm->name + 10;
336 else if (!prefixcmp(rm->name, "refs/remotes/")) {
337 kind = "remote branch";
338 what = rm->name + 13;
340 else {
341 kind = "";
342 what = rm->name;
345 url_len = strlen(url);
346 for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
348 url_len = i + 1;
349 if (4 < i && !strncmp(".git", url + i - 3, 4))
350 url_len = i - 3;
352 note_len = 0;
353 if (*what) {
354 if (*kind)
355 note_len += sprintf(note + note_len, "%s ",
356 kind);
357 note_len += sprintf(note + note_len, "'%s' of ", what);
359 note_len += sprintf(note + note_len, "%.*s", url_len, url);
360 fprintf(fp, "%s\t%s\t%s\n",
361 sha1_to_hex(commit ? commit->object.sha1 :
362 rm->old_sha1),
363 rm->merge ? "" : "not-for-merge",
364 note);
366 if (ref)
367 rc |= update_local_ref(ref, what, note);
368 else
369 sprintf(note, "* %-*s %-*s -> FETCH_HEAD",
370 SUMMARY_WIDTH, *kind ? kind : "branch",
371 REFCOL_WIDTH, *what ? what : "HEAD");
372 if (*note) {
373 if (verbosity >= 0 && !shown_url) {
374 fprintf(stderr, "From %.*s\n",
375 url_len, url);
376 shown_url = 1;
378 if (verbosity >= 0)
379 fprintf(stderr, " %s\n", note);
382 fclose(fp);
383 if (rc & 2)
384 error("some local refs could not be updated; try running\n"
385 " 'git remote prune %s' to remove any old, conflicting "
386 "branches", remote_name);
387 return rc;
391 * We would want to bypass the object transfer altogether if
392 * everything we are going to fetch already exists and connected
393 * locally.
395 * The refs we are going to fetch are in to_fetch (nr_heads in
396 * total). If running
398 * $ git rev-list --objects to_fetch[0] to_fetch[1] ... --not --all
400 * does not error out, that means everything reachable from the
401 * refs we are going to fetch exists and is connected to some of
402 * our existing refs.
404 static int quickfetch(struct ref *ref_map)
406 struct child_process revlist;
407 struct ref *ref;
408 char **argv;
409 int i, err;
412 * If we are deepening a shallow clone we already have these
413 * objects reachable. Running rev-list here will return with
414 * a good (0) exit status and we'll bypass the fetch that we
415 * really need to perform. Claiming failure now will ensure
416 * we perform the network exchange to deepen our history.
418 if (depth)
419 return -1;
421 for (i = 0, ref = ref_map; ref; ref = ref->next)
422 i++;
423 if (!i)
424 return 0;
426 argv = xmalloc(sizeof(*argv) * (i + 6));
427 i = 0;
428 argv[i++] = xstrdup("rev-list");
429 argv[i++] = xstrdup("--quiet");
430 argv[i++] = xstrdup("--objects");
431 for (ref = ref_map; ref; ref = ref->next)
432 argv[i++] = xstrdup(sha1_to_hex(ref->old_sha1));
433 argv[i++] = xstrdup("--not");
434 argv[i++] = xstrdup("--all");
435 argv[i++] = NULL;
437 memset(&revlist, 0, sizeof(revlist));
438 revlist.argv = (const char**)argv;
439 revlist.git_cmd = 1;
440 revlist.no_stdin = 1;
441 revlist.no_stdout = 1;
442 revlist.no_stderr = 1;
443 err = run_command(&revlist);
445 for (i = 0; argv[i]; i++)
446 free(argv[i]);
447 free(argv);
448 return err;
451 static int fetch_refs(struct transport *transport, struct ref *ref_map)
453 int ret = quickfetch(ref_map);
454 if (ret)
455 ret = transport_fetch_refs(transport, ref_map);
456 if (!ret)
457 ret |= store_updated_refs(transport->url,
458 transport->remote->name,
459 ref_map);
460 transport_unlock_pack(transport);
461 return ret;
464 static int add_existing(const char *refname, const unsigned char *sha1,
465 int flag, void *cbdata)
467 struct string_list *list = (struct string_list *)cbdata;
468 string_list_insert(refname, list);
469 return 0;
472 static int will_fetch(struct ref **head, const unsigned char *sha1)
474 struct ref *rm = *head;
475 while (rm) {
476 if (!hashcmp(rm->old_sha1, sha1))
477 return 1;
478 rm = rm->next;
480 return 0;
483 static void find_non_local_tags(struct transport *transport,
484 struct ref **head,
485 struct ref ***tail)
487 struct string_list existing_refs = { NULL, 0, 0, 0 };
488 struct string_list new_refs = { NULL, 0, 0, 1 };
489 char *ref_name;
490 int ref_name_len;
491 const unsigned char *ref_sha1;
492 const struct ref *tag_ref;
493 struct ref *rm = NULL;
494 const struct ref *ref;
496 for_each_ref(add_existing, &existing_refs);
497 for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
498 if (prefixcmp(ref->name, "refs/tags"))
499 continue;
501 ref_name = xstrdup(ref->name);
502 ref_name_len = strlen(ref_name);
503 ref_sha1 = ref->old_sha1;
505 if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
506 ref_name[ref_name_len - 3] = 0;
507 tag_ref = transport_get_remote_refs(transport);
508 while (tag_ref) {
509 if (!strcmp(tag_ref->name, ref_name)) {
510 ref_sha1 = tag_ref->old_sha1;
511 break;
513 tag_ref = tag_ref->next;
517 if (!string_list_has_string(&existing_refs, ref_name) &&
518 !string_list_has_string(&new_refs, ref_name) &&
519 (has_sha1_file(ref->old_sha1) ||
520 will_fetch(head, ref->old_sha1))) {
521 string_list_insert(ref_name, &new_refs);
523 rm = alloc_ref(ref_name);
524 rm->peer_ref = alloc_ref(ref_name);
525 hashcpy(rm->old_sha1, ref_sha1);
527 **tail = rm;
528 *tail = &rm->next;
530 free(ref_name);
532 string_list_clear(&existing_refs, 0);
533 string_list_clear(&new_refs, 0);
536 static void check_not_current_branch(struct ref *ref_map)
538 struct branch *current_branch = branch_get(NULL);
540 if (is_bare_repository() || !current_branch)
541 return;
543 for (; ref_map; ref_map = ref_map->next)
544 if (ref_map->peer_ref && !strcmp(current_branch->refname,
545 ref_map->peer_ref->name))
546 die("Refusing to fetch into current branch");
549 static int do_fetch(struct transport *transport,
550 struct refspec *refs, int ref_count)
552 struct ref *ref_map;
553 struct ref *rm;
554 int autotags = (transport->remote->fetch_tags == 1);
555 if (transport->remote->fetch_tags == 2 && tags != TAGS_UNSET)
556 tags = TAGS_SET;
557 if (transport->remote->fetch_tags == -1)
558 tags = TAGS_UNSET;
560 if (!transport->get_refs_list || !transport->fetch)
561 die("Don't know how to fetch from %s", transport->url);
563 /* if not appending, truncate FETCH_HEAD */
564 if (!append) {
565 char *filename = git_path("FETCH_HEAD");
566 FILE *fp = fopen(filename, "w");
567 if (!fp)
568 return error("cannot open %s: %s\n", filename, strerror(errno));
569 fclose(fp);
572 ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
573 if (!update_head_ok)
574 check_not_current_branch(ref_map);
576 for (rm = ref_map; rm; rm = rm->next) {
577 if (rm->peer_ref)
578 read_ref(rm->peer_ref->name, rm->peer_ref->old_sha1);
581 if (tags == TAGS_DEFAULT && autotags)
582 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
583 if (fetch_refs(transport, ref_map)) {
584 free_refs(ref_map);
585 return 1;
587 free_refs(ref_map);
589 /* if neither --no-tags nor --tags was specified, do automated tag
590 * following ... */
591 if (tags == TAGS_DEFAULT && autotags) {
592 struct ref **tail = &ref_map;
593 ref_map = NULL;
594 find_non_local_tags(transport, &ref_map, &tail);
595 if (ref_map) {
596 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
597 transport_set_option(transport, TRANS_OPT_DEPTH, "0");
598 fetch_refs(transport, ref_map);
600 free_refs(ref_map);
603 return 0;
606 static void set_option(const char *name, const char *value)
608 int r = transport_set_option(transport, name, value);
609 if (r < 0)
610 die("Option \"%s\" value \"%s\" is not valid for %s\n",
611 name, value, transport->url);
612 if (r > 0)
613 warning("Option \"%s\" is ignored for %s\n",
614 name, transport->url);
617 int cmd_fetch(int argc, const char **argv, const char *prefix)
619 struct remote *remote;
620 int i;
621 static const char **refs = NULL;
622 int ref_nr = 0;
623 int exit_code;
625 /* Record the command line for the reflog */
626 strbuf_addstr(&default_rla, "fetch");
627 for (i = 1; i < argc; i++)
628 strbuf_addf(&default_rla, " %s", argv[i]);
630 argc = parse_options(argc, argv,
631 builtin_fetch_options, builtin_fetch_usage, 0);
633 if (argc == 0)
634 remote = remote_get(NULL);
635 else
636 remote = remote_get(argv[0]);
638 transport = transport_get(remote, remote->url[0]);
639 if (verbosity >= 2)
640 transport->verbose = 1;
641 if (verbosity < 0)
642 transport->verbose = -1;
643 if (upload_pack)
644 set_option(TRANS_OPT_UPLOADPACK, upload_pack);
645 if (keep)
646 set_option(TRANS_OPT_KEEP, "yes");
647 if (depth)
648 set_option(TRANS_OPT_DEPTH, depth);
650 if (!transport->url)
651 die("Where do you want to fetch from today?");
653 if (argc > 1) {
654 int j = 0;
655 refs = xcalloc(argc + 1, sizeof(const char *));
656 for (i = 1; i < argc; i++) {
657 if (!strcmp(argv[i], "tag")) {
658 char *ref;
659 i++;
660 if (i >= argc)
661 die("You need to specify a tag name.");
662 ref = xmalloc(strlen(argv[i]) * 2 + 22);
663 strcpy(ref, "refs/tags/");
664 strcat(ref, argv[i]);
665 strcat(ref, ":refs/tags/");
666 strcat(ref, argv[i]);
667 refs[j++] = ref;
668 } else
669 refs[j++] = argv[i];
671 refs[j] = NULL;
672 ref_nr = j;
675 signal(SIGINT, unlock_pack_on_signal);
676 atexit(unlock_pack);
677 exit_code = do_fetch(transport,
678 parse_fetch_refspec(ref_nr, refs), ref_nr);
679 transport_disconnect(transport);
680 transport = NULL;
681 return exit_code;