Documentation/git-merge: document subtree strategy.
[git/jnareb-git/bp-gitweb.git] / builtin-fetch.c
blobb2b9935ed65cfa80daf9f9071a3dd5d381ef3426
1 /*
2 * "git fetch"
3 */
4 #include "cache.h"
5 #include "refs.h"
6 #include "commit.h"
7 #include "builtin.h"
8 #include "path-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, verbose, quiet;
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__QUIET(&quiet),
34 OPT__VERBOSE(&verbose),
35 OPT_BOOLEAN('a', "append", &append,
36 "append to .git/FETCH_HEAD instead of overwriting"),
37 OPT_STRING(0, "upload-pack", &upload_pack, "PATH",
38 "path to upload pack on remote end"),
39 OPT_BOOLEAN('f', "force", &force,
40 "force overwrite of local branch"),
41 OPT_SET_INT('t', "tags", &tags,
42 "fetch all tags and associated objects", TAGS_SET),
43 OPT_SET_INT('n', NULL, &tags,
44 "do not fetch all tags (--no-tags)", TAGS_UNSET),
45 OPT_BOOLEAN('k', "keep", &keep, "keep downloaded pack"),
46 OPT_BOOLEAN('u', "update-head-ok", &update_head_ok,
47 "allow updating of HEAD ref"),
48 OPT_STRING(0, "depth", &depth, "DEPTH",
49 "deepen history of shallow clone"),
50 OPT_END()
53 static void unlock_pack(void)
55 if (transport)
56 transport_unlock_pack(transport);
59 static void unlock_pack_on_signal(int signo)
61 unlock_pack();
62 signal(SIGINT, SIG_DFL);
63 raise(signo);
66 static void add_merge_config(struct ref **head,
67 const struct ref *remote_refs,
68 struct branch *branch,
69 struct ref ***tail)
71 int i;
73 for (i = 0; i < branch->merge_nr; i++) {
74 struct ref *rm, **old_tail = *tail;
75 struct refspec refspec;
77 for (rm = *head; rm; rm = rm->next) {
78 if (branch_merge_matches(branch, i, rm->name)) {
79 rm->merge = 1;
80 break;
83 if (rm)
84 continue;
87 * Not fetched to a tracking branch? We need to fetch
88 * it anyway to allow this branch's "branch.$name.merge"
89 * to be honored by git-pull, but we do not have to
90 * fail if branch.$name.merge is misconfigured to point
91 * at a nonexisting branch. If we were indeed called by
92 * git-pull, it will notice the misconfiguration because
93 * there is no entry in the resulting FETCH_HEAD marked
94 * for merging.
96 refspec.src = branch->merge[i]->src;
97 refspec.dst = NULL;
98 refspec.pattern = 0;
99 refspec.force = 0;
100 get_fetch_map(remote_refs, &refspec, tail, 1);
101 for (rm = *old_tail; rm; rm = rm->next)
102 rm->merge = 1;
106 static void find_non_local_tags(struct transport *transport,
107 struct ref **head,
108 struct ref ***tail);
110 static struct ref *get_ref_map(struct transport *transport,
111 struct refspec *refs, int ref_count, int tags,
112 int *autotags)
114 int i;
115 struct ref *rm;
116 struct ref *ref_map = NULL;
117 struct ref **tail = &ref_map;
119 const struct ref *remote_refs = transport_get_remote_refs(transport);
121 if (ref_count || tags == TAGS_SET) {
122 for (i = 0; i < ref_count; i++) {
123 get_fetch_map(remote_refs, &refs[i], &tail, 0);
124 if (refs[i].dst && refs[i].dst[0])
125 *autotags = 1;
127 /* Merge everything on the command line, but not --tags */
128 for (rm = ref_map; rm; rm = rm->next)
129 rm->merge = 1;
130 if (tags == TAGS_SET) {
131 struct refspec refspec;
132 refspec.src = "refs/tags/";
133 refspec.dst = "refs/tags/";
134 refspec.pattern = 1;
135 refspec.force = 0;
136 get_fetch_map(remote_refs, &refspec, &tail, 0);
138 } else {
139 /* Use the defaults */
140 struct remote *remote = transport->remote;
141 struct branch *branch = branch_get(NULL);
142 int has_merge = branch_has_merge_config(branch);
143 if (remote && (remote->fetch_refspec_nr || has_merge)) {
144 for (i = 0; i < remote->fetch_refspec_nr; i++) {
145 get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
146 if (remote->fetch[i].dst &&
147 remote->fetch[i].dst[0])
148 *autotags = 1;
149 if (!i && !has_merge && ref_map &&
150 !remote->fetch[0].pattern)
151 ref_map->merge = 1;
154 * if the remote we're fetching from is the same
155 * as given in branch.<name>.remote, we add the
156 * ref given in branch.<name>.merge, too.
158 if (has_merge &&
159 !strcmp(branch->remote_name, remote->name))
160 add_merge_config(&ref_map, remote_refs, branch, &tail);
161 } else {
162 ref_map = get_remote_ref(remote_refs, "HEAD");
163 if (!ref_map)
164 die("Couldn't find remote ref HEAD");
165 ref_map->merge = 1;
166 tail = &ref_map->next;
169 if (tags == TAGS_DEFAULT && *autotags)
170 find_non_local_tags(transport, &ref_map, &tail);
171 ref_remove_duplicates(ref_map);
173 return ref_map;
176 static int s_update_ref(const char *action,
177 struct ref *ref,
178 int check_old)
180 char msg[1024];
181 char *rla = getenv("GIT_REFLOG_ACTION");
182 static struct ref_lock *lock;
184 if (!rla)
185 rla = default_rla.buf;
186 snprintf(msg, sizeof(msg), "%s: %s", rla, action);
187 lock = lock_any_ref_for_update(ref->name,
188 check_old ? ref->old_sha1 : NULL, 0);
189 if (!lock)
190 return 1;
191 if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
192 return 1;
193 return 0;
196 #define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
197 #define REFCOL_WIDTH 10
199 static int update_local_ref(struct ref *ref,
200 const char *remote,
201 int verbose,
202 char *display)
204 struct commit *current = NULL, *updated;
205 enum object_type type;
206 struct branch *current_branch = branch_get(NULL);
207 const char *pretty_ref = ref->name + (
208 !prefixcmp(ref->name, "refs/heads/") ? 11 :
209 !prefixcmp(ref->name, "refs/tags/") ? 10 :
210 !prefixcmp(ref->name, "refs/remotes/") ? 13 :
213 *display = 0;
214 type = sha1_object_info(ref->new_sha1, NULL);
215 if (type < 0)
216 die("object %s not found", sha1_to_hex(ref->new_sha1));
218 if (!*ref->name) {
219 /* Not storing */
220 if (verbose)
221 sprintf(display, "* branch %s -> FETCH_HEAD", remote);
222 return 0;
225 if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
226 if (verbose)
227 sprintf(display, "= %-*s %-*s -> %s", SUMMARY_WIDTH,
228 "[up to date]", REFCOL_WIDTH, remote,
229 pretty_ref);
230 return 0;
233 if (current_branch &&
234 !strcmp(ref->name, current_branch->name) &&
235 !(update_head_ok || is_bare_repository()) &&
236 !is_null_sha1(ref->old_sha1)) {
238 * If this is the head, and it's not okay to update
239 * the head, and the old value of the head isn't empty...
241 sprintf(display, "! %-*s %-*s -> %s (can't fetch in current branch)",
242 SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
243 pretty_ref);
244 return 1;
247 if (!is_null_sha1(ref->old_sha1) &&
248 !prefixcmp(ref->name, "refs/tags/")) {
249 sprintf(display, "- %-*s %-*s -> %s",
250 SUMMARY_WIDTH, "[tag update]", REFCOL_WIDTH, remote,
251 pretty_ref);
252 return s_update_ref("updating tag", ref, 0);
255 current = lookup_commit_reference_gently(ref->old_sha1, 1);
256 updated = lookup_commit_reference_gently(ref->new_sha1, 1);
257 if (!current || !updated) {
258 const char *msg;
259 const char *what;
260 if (!strncmp(ref->name, "refs/tags/", 10)) {
261 msg = "storing tag";
262 what = "[new tag]";
264 else {
265 msg = "storing head";
266 what = "[new branch]";
269 sprintf(display, "* %-*s %-*s -> %s", SUMMARY_WIDTH, what,
270 REFCOL_WIDTH, remote, pretty_ref);
271 return s_update_ref(msg, ref, 0);
274 if (in_merge_bases(current, &updated, 1)) {
275 char quickref[83];
276 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
277 strcat(quickref, "..");
278 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
279 sprintf(display, " %-*s %-*s -> %s", SUMMARY_WIDTH, quickref,
280 REFCOL_WIDTH, remote, pretty_ref);
281 return s_update_ref("fast forward", ref, 1);
282 } else if (force || ref->force) {
283 char quickref[84];
284 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
285 strcat(quickref, "...");
286 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
287 sprintf(display, "+ %-*s %-*s -> %s (forced update)",
288 SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote, pretty_ref);
289 return s_update_ref("forced-update", ref, 1);
290 } else {
291 sprintf(display, "! %-*s %-*s -> %s (non fast forward)",
292 SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
293 pretty_ref);
294 return 1;
298 static int store_updated_refs(const char *url, struct ref *ref_map)
300 FILE *fp;
301 struct commit *commit;
302 int url_len, i, note_len, shown_url = 0;
303 char note[1024];
304 const char *what, *kind;
305 struct ref *rm;
306 char *filename = git_path("FETCH_HEAD");
308 fp = fopen(filename, "a");
309 if (!fp)
310 return error("cannot open %s: %s\n", filename, strerror(errno));
311 for (rm = ref_map; rm; rm = rm->next) {
312 struct ref *ref = NULL;
314 if (rm->peer_ref) {
315 ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
316 strcpy(ref->name, rm->peer_ref->name);
317 hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
318 hashcpy(ref->new_sha1, rm->old_sha1);
319 ref->force = rm->peer_ref->force;
322 commit = lookup_commit_reference_gently(rm->old_sha1, 1);
323 if (!commit)
324 rm->merge = 0;
326 if (!strcmp(rm->name, "HEAD")) {
327 kind = "";
328 what = "";
330 else if (!prefixcmp(rm->name, "refs/heads/")) {
331 kind = "branch";
332 what = rm->name + 11;
334 else if (!prefixcmp(rm->name, "refs/tags/")) {
335 kind = "tag";
336 what = rm->name + 10;
338 else if (!prefixcmp(rm->name, "refs/remotes/")) {
339 kind = "remote branch";
340 what = rm->name + 13;
342 else {
343 kind = "";
344 what = rm->name;
347 url_len = strlen(url);
348 for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
350 url_len = i + 1;
351 if (4 < i && !strncmp(".git", url + i - 3, 4))
352 url_len = i - 3;
354 note_len = 0;
355 if (*what) {
356 if (*kind)
357 note_len += sprintf(note + note_len, "%s ",
358 kind);
359 note_len += sprintf(note + note_len, "'%s' of ", what);
361 note_len += sprintf(note + note_len, "%.*s", url_len, url);
362 fprintf(fp, "%s\t%s\t%s\n",
363 sha1_to_hex(commit ? commit->object.sha1 :
364 rm->old_sha1),
365 rm->merge ? "" : "not-for-merge",
366 note);
368 if (ref) {
369 update_local_ref(ref, what, verbose, note);
370 if (*note) {
371 if (!shown_url) {
372 fprintf(stderr, "From %.*s\n",
373 url_len, url);
374 shown_url = 1;
376 fprintf(stderr, " %s\n", note);
380 fclose(fp);
381 return 0;
385 * We would want to bypass the object transfer altogether if
386 * everything we are going to fetch already exists and connected
387 * locally.
389 * The refs we are going to fetch are in to_fetch (nr_heads in
390 * total). If running
392 * $ git-rev-list --objects to_fetch[0] to_fetch[1] ... --not --all
394 * does not error out, that means everything reachable from the
395 * refs we are going to fetch exists and is connected to some of
396 * our existing refs.
398 static int quickfetch(struct ref *ref_map)
400 struct child_process revlist;
401 struct ref *ref;
402 char **argv;
403 int i, err;
406 * If we are deepening a shallow clone we already have these
407 * objects reachable. Running rev-list here will return with
408 * a good (0) exit status and we'll bypass the fetch that we
409 * really need to perform. Claiming failure now will ensure
410 * we perform the network exchange to deepen our history.
412 if (depth)
413 return -1;
415 for (i = 0, ref = ref_map; ref; ref = ref->next)
416 i++;
417 if (!i)
418 return 0;
420 argv = xmalloc(sizeof(*argv) * (i + 6));
421 i = 0;
422 argv[i++] = xstrdup("rev-list");
423 argv[i++] = xstrdup("--quiet");
424 argv[i++] = xstrdup("--objects");
425 for (ref = ref_map; ref; ref = ref->next)
426 argv[i++] = xstrdup(sha1_to_hex(ref->old_sha1));
427 argv[i++] = xstrdup("--not");
428 argv[i++] = xstrdup("--all");
429 argv[i++] = NULL;
431 memset(&revlist, 0, sizeof(revlist));
432 revlist.argv = (const char**)argv;
433 revlist.git_cmd = 1;
434 revlist.no_stdin = 1;
435 revlist.no_stdout = 1;
436 revlist.no_stderr = 1;
437 err = run_command(&revlist);
439 for (i = 0; argv[i]; i++)
440 free(argv[i]);
441 free(argv);
442 return err;
445 static int fetch_refs(struct transport *transport, struct ref *ref_map)
447 int ret = quickfetch(ref_map);
448 if (ret)
449 ret = transport_fetch_refs(transport, ref_map);
450 if (!ret)
451 ret |= store_updated_refs(transport->url, ref_map);
452 transport_unlock_pack(transport);
453 return ret;
456 static int add_existing(const char *refname, const unsigned char *sha1,
457 int flag, void *cbdata)
459 struct path_list *list = (struct path_list *)cbdata;
460 path_list_insert(refname, list);
461 return 0;
464 static int will_fetch(struct ref **head, const unsigned char *sha1)
466 struct ref *rm = *head;
467 while (rm) {
468 if (!hashcmp(rm->old_sha1, sha1))
469 return 1;
470 rm = rm->next;
472 return 0;
475 static void find_non_local_tags(struct transport *transport,
476 struct ref **head,
477 struct ref ***tail)
479 struct path_list existing_refs = { NULL, 0, 0, 0 };
480 struct path_list new_refs = { NULL, 0, 0, 1 };
481 char *ref_name;
482 int ref_name_len;
483 const unsigned char *ref_sha1;
484 const struct ref *tag_ref;
485 struct ref *rm = NULL;
486 const struct ref *ref;
488 for_each_ref(add_existing, &existing_refs);
489 for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
490 if (prefixcmp(ref->name, "refs/tags"))
491 continue;
493 ref_name = xstrdup(ref->name);
494 ref_name_len = strlen(ref_name);
495 ref_sha1 = ref->old_sha1;
497 if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
498 ref_name[ref_name_len - 3] = 0;
499 tag_ref = transport_get_remote_refs(transport);
500 while (tag_ref) {
501 if (!strcmp(tag_ref->name, ref_name)) {
502 ref_sha1 = tag_ref->old_sha1;
503 break;
505 tag_ref = tag_ref->next;
509 if (!path_list_has_path(&existing_refs, ref_name) &&
510 !path_list_has_path(&new_refs, ref_name) &&
511 (has_sha1_file(ref->old_sha1) ||
512 will_fetch(head, ref->old_sha1))) {
513 path_list_insert(ref_name, &new_refs);
515 rm = alloc_ref(strlen(ref_name) + 1);
516 strcpy(rm->name, ref_name);
517 rm->peer_ref = alloc_ref(strlen(ref_name) + 1);
518 strcpy(rm->peer_ref->name, ref_name);
519 hashcpy(rm->old_sha1, ref_sha1);
521 **tail = rm;
522 *tail = &rm->next;
524 free(ref_name);
526 path_list_clear(&existing_refs, 0);
527 path_list_clear(&new_refs, 0);
530 static int do_fetch(struct transport *transport,
531 struct refspec *refs, int ref_count)
533 struct ref *ref_map;
534 struct ref *rm;
535 int autotags = (transport->remote->fetch_tags == 1);
536 if (transport->remote->fetch_tags == 2 && tags != TAGS_UNSET)
537 tags = TAGS_SET;
538 if (transport->remote->fetch_tags == -1)
539 tags = TAGS_UNSET;
541 if (!transport->get_refs_list || !transport->fetch)
542 die("Don't know how to fetch from %s", transport->url);
544 /* if not appending, truncate FETCH_HEAD */
545 if (!append) {
546 char *filename = git_path("FETCH_HEAD");
547 FILE *fp = fopen(filename, "w");
548 if (!fp)
549 return error("cannot open %s: %s\n", filename, strerror(errno));
550 fclose(fp);
553 ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
555 for (rm = ref_map; rm; rm = rm->next) {
556 if (rm->peer_ref)
557 read_ref(rm->peer_ref->name, rm->peer_ref->old_sha1);
560 if (tags == TAGS_DEFAULT && autotags)
561 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
562 if (fetch_refs(transport, ref_map)) {
563 free_refs(ref_map);
564 return 1;
566 free_refs(ref_map);
568 /* if neither --no-tags nor --tags was specified, do automated tag
569 * following ... */
570 if (tags == TAGS_DEFAULT && autotags) {
571 struct ref **tail = &ref_map;
572 ref_map = NULL;
573 find_non_local_tags(transport, &ref_map, &tail);
574 if (ref_map) {
575 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
576 transport_set_option(transport, TRANS_OPT_DEPTH, "0");
577 fetch_refs(transport, ref_map);
579 free_refs(ref_map);
582 transport_disconnect(transport);
584 return 0;
587 static void set_option(const char *name, const char *value)
589 int r = transport_set_option(transport, name, value);
590 if (r < 0)
591 die("Option \"%s\" value \"%s\" is not valid for %s\n",
592 name, value, transport->url);
593 if (r > 0)
594 warning("Option \"%s\" is ignored for %s\n",
595 name, transport->url);
598 int cmd_fetch(int argc, const char **argv, const char *prefix)
600 struct remote *remote;
601 int i;
602 static const char **refs = NULL;
603 int ref_nr = 0;
605 /* Record the command line for the reflog */
606 strbuf_addstr(&default_rla, "fetch");
607 for (i = 1; i < argc; i++)
608 strbuf_addf(&default_rla, " %s", argv[i]);
610 argc = parse_options(argc, argv,
611 builtin_fetch_options, builtin_fetch_usage, 0);
613 if (argc == 0)
614 remote = remote_get(NULL);
615 else
616 remote = remote_get(argv[0]);
618 transport = transport_get(remote, remote->url[0]);
619 if (verbose >= 2)
620 transport->verbose = 1;
621 if (quiet)
622 transport->verbose = -1;
623 if (upload_pack)
624 set_option(TRANS_OPT_UPLOADPACK, upload_pack);
625 if (keep)
626 set_option(TRANS_OPT_KEEP, "yes");
627 if (depth)
628 set_option(TRANS_OPT_DEPTH, depth);
630 if (!transport->url)
631 die("Where do you want to fetch from today?");
633 if (argc > 1) {
634 int j = 0;
635 refs = xcalloc(argc + 1, sizeof(const char *));
636 for (i = 1; i < argc; i++) {
637 if (!strcmp(argv[i], "tag")) {
638 char *ref;
639 i++;
640 ref = xmalloc(strlen(argv[i]) * 2 + 22);
641 strcpy(ref, "refs/tags/");
642 strcat(ref, argv[i]);
643 strcat(ref, ":refs/tags/");
644 strcat(ref, argv[i]);
645 refs[j++] = ref;
646 } else
647 refs[j++] = argv[i];
649 refs[j] = NULL;
650 ref_nr = j;
653 signal(SIGINT, unlock_pack_on_signal);
654 atexit(unlock_pack);
655 return do_fetch(transport, parse_ref_spec(ref_nr, refs), ref_nr);