builtin-fetch.c

   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"
  13
  14 static const char * const builtin_fetch_usage[] = {
  15         "git-fetch [options] [<repository> <refspec>...]",
  16         NULL
  17 };
  18
  19 enum {
  20         TAGS_UNSET = 0,
  21         TAGS_DEFAULT = 1,
  22         TAGS_SET = 2
  23 };
  24
  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;
  31
  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_BOOLEAN('k', "keep", &keep, "keep downloaded pack"),
  44         OPT_BOOLEAN('u', "update-head-ok", &update_head_ok,
  45                     "allow updating of HEAD ref"),
  46         OPT_STRING(0, "depth", &depth, "DEPTH",
  47                    "deepen history of shallow clone"),
  48         OPT_END()
  49 };
  50
  51 static void unlock_pack(void)
  52 {
  53         if (transport)
  54                 transport_unlock_pack(transport);
  55 }
  56
  57 static void unlock_pack_on_signal(int signo)
  58 {
  59         unlock_pack();
  60         signal(SIGINT, SIG_DFL);
  61         raise(signo);
  62 }
  63
  64 static void add_merge_config(struct ref **head,
  65                            const struct ref *remote_refs,
  66                            struct branch *branch,
  67                            struct ref ***tail)
  68 {
  69         int i;
  70
  71         for (i = 0; i < branch->merge_nr; i++) {
  72                 struct ref *rm, **old_tail = *tail;
  73                 struct refspec refspec;
  74
  75                 for (rm = *head; rm; rm = rm->next) {
  76                         if (branch_merge_matches(branch, i, rm->name)) {
  77                                 rm->merge = 1;
  78                                 break;
  79                         }
  80                 }
  81                 if (rm)
  82                         continue;
  83
  84                 /*
  85                  * Not fetched to a tracking branch?  We need to fetch
  86                  * it anyway to allow this branch's "branch.$name.merge"
  87                  * to be honored by git-pull, but we do not have to
  88                  * fail if branch.$name.merge is misconfigured to point
  89                  * at a nonexisting branch.  If we were indeed called by
  90                  * git-pull, it will notice the misconfiguration because
  91                  * there is no entry in the resulting FETCH_HEAD marked
  92                  * for merging.
  93                  */
  94                 refspec.src = branch->merge[i]->src;
  95                 refspec.dst = NULL;
  96                 refspec.pattern = 0;
  97                 refspec.force = 0;
  98                 get_fetch_map(remote_refs, &refspec, tail, 1);
  99                 for (rm = *old_tail; rm; rm = rm->next)
 100                         rm->merge = 1;
 101         }
 102 }
 103
 104 static struct ref *get_ref_map(struct transport *transport,
 105                                struct refspec *refs, int ref_count, int tags,
 106                                int *autotags)
 107 {
 108         int i;
 109         struct ref *rm;
 110         struct ref *ref_map = NULL;
 111         struct ref **tail = &ref_map;
 112
 113         const struct ref *remote_refs = transport_get_remote_refs(transport);
 114
 115         if (ref_count || tags == TAGS_SET) {
 116                 for (i = 0; i < ref_count; i++) {
 117                         get_fetch_map(remote_refs, &refs[i], &tail, 0);
 118                         if (refs[i].dst && refs[i].dst[0])
 119                                 *autotags = 1;
 120                 }
 121                 /* Merge everything on the command line, but not --tags */
 122                 for (rm = ref_map; rm; rm = rm->next)
 123                         rm->merge = 1;
 124                 if (tags == TAGS_SET) {
 125                         struct refspec refspec;
 126                         refspec.src = "refs/tags/";
 127                         refspec.dst = "refs/tags/";
 128                         refspec.pattern = 1;
 129                         refspec.force = 0;
 130                         get_fetch_map(remote_refs, &refspec, &tail, 0);
 131                 }
 132         } else {
 133                 /* Use the defaults */
 134                 struct remote *remote = transport->remote;
 135                 struct branch *branch = branch_get(NULL);
 136                 int has_merge = branch_has_merge_config(branch);
 137                 if (remote && (remote->fetch_refspec_nr || has_merge)) {
 138                         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 139                                 get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
 140                                 if (remote->fetch[i].dst &&
 141                                     remote->fetch[i].dst[0])
 142                                         *autotags = 1;
 143                                 if (!i && !has_merge && ref_map &&
 144                                     !remote->fetch[0].pattern)
 145                                         ref_map->merge = 1;
 146                         }
 147                         /*
 148                          * if the remote we're fetching from is the same
 149                          * as given in branch.<name>.remote, we add the
 150                          * ref given in branch.<name>.merge, too.
 151                          */
 152                         if (has_merge &&
 153                             !strcmp(branch->remote_name, remote->name))
 154                                 add_merge_config(&ref_map, remote_refs, branch, &tail);
 155                 } else {
 156                         ref_map = get_remote_ref(remote_refs, "HEAD");
 157                         if (!ref_map)
 158                                 die("Couldn't find remote ref HEAD");
 159                         ref_map->merge = 1;
 160                 }
 161         }
 162         ref_remove_duplicates(ref_map);
 163
 164         return ref_map;
 165 }
 166
 167 static int s_update_ref(const char *action,
 168                         struct ref *ref,
 169                         int check_old)
 170 {
 171         char msg[1024];
 172         char *rla = getenv("GIT_REFLOG_ACTION");
 173         static struct ref_lock *lock;
 174
 175         if (!rla)
 176                 rla = default_rla.buf;
 177         snprintf(msg, sizeof(msg), "%s: %s", rla, action);
 178         lock = lock_any_ref_for_update(ref->name,
 179                                        check_old ? ref->old_sha1 : NULL, 0);
 180         if (!lock)
 181                 return 1;
 182         if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
 183                 return 1;
 184         return 0;
 185 }
 186
 187 #define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
 188 #define REFCOL_WIDTH  10
 189
 190 static int update_local_ref(struct ref *ref,
 191                             const char *remote,
 192                             int verbose,
 193                             char *display)
 194 {
 195         struct commit *current = NULL, *updated;
 196         enum object_type type;
 197         struct branch *current_branch = branch_get(NULL);
 198         const char *pretty_ref = ref->name + (
 199                 !prefixcmp(ref->name, "refs/heads/") ? 11 :
 200                 !prefixcmp(ref->name, "refs/tags/") ? 10 :
 201                 !prefixcmp(ref->name, "refs/remotes/") ? 13 :
 202                 0);
 203
 204         *display = 0;
 205         type = sha1_object_info(ref->new_sha1, NULL);
 206         if (type < 0)
 207                 die("object %s not found", sha1_to_hex(ref->new_sha1));
 208
 209         if (!*ref->name) {
 210                 /* Not storing */
 211                 if (verbose)
 212                         sprintf(display, "* branch %s -> FETCH_HEAD", remote);
 213                 return 0;
 214         }
 215
 216         if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
 217                 if (verbose)
 218                         sprintf(display, "= %-*s %-*s -> %s", SUMMARY_WIDTH,
 219                                 "[up to date]", REFCOL_WIDTH, remote,
 220                                 pretty_ref);
 221                 return 0;
 222         }
 223
 224         if (current_branch &&
 225             !strcmp(ref->name, current_branch->name) &&
 226             !(update_head_ok || is_bare_repository()) &&
 227             !is_null_sha1(ref->old_sha1)) {
 228                 /*
 229                  * If this is the head, and it's not okay to update
 230                  * the head, and the old value of the head isn't empty...
 231                  */
 232                 sprintf(display, "! %-*s %-*s -> %s  (can't fetch in current branch)",
 233                         SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
 234                         pretty_ref);
 235                 return 1;
 236         }
 237
 238         if (!is_null_sha1(ref->old_sha1) &&
 239             !prefixcmp(ref->name, "refs/tags/")) {
 240                 sprintf(display, "- %-*s %-*s -> %s",
 241                         SUMMARY_WIDTH, "[tag update]", REFCOL_WIDTH, remote,
 242                         pretty_ref);
 243                 return s_update_ref("updating tag", ref, 0);
 244         }
 245
 246         current = lookup_commit_reference_gently(ref->old_sha1, 1);
 247         updated = lookup_commit_reference_gently(ref->new_sha1, 1);
 248         if (!current || !updated) {
 249                 const char *msg;
 250                 const char *what;
 251                 if (!strncmp(ref->name, "refs/tags/", 10)) {
 252                         msg = "storing tag";
 253                         what = "[new tag]";
 254                 }
 255                 else {
 256                         msg = "storing head";
 257                         what = "[new branch]";
 258                 }
 259
 260                 sprintf(display, "* %-*s %-*s -> %s", SUMMARY_WIDTH, what,
 261                         REFCOL_WIDTH, remote, pretty_ref);
 262                 return s_update_ref(msg, ref, 0);
 263         }
 264
 265         if (in_merge_bases(current, &updated, 1)) {
 266                 char quickref[83];
 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                 sprintf(display, "  %-*s %-*s -> %s", SUMMARY_WIDTH, quickref,
 271                         REFCOL_WIDTH, remote, pretty_ref);
 272                 return s_update_ref("fast forward", ref, 1);
 273         } else if (force || ref->force) {
 274                 char quickref[84];
 275                 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
 276                 strcat(quickref, "...");
 277                 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
 278                 sprintf(display, "+ %-*s %-*s -> %s  (forced update)",
 279                         SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote, pretty_ref);
 280                 return s_update_ref("forced-update", ref, 1);
 281         } else {
 282                 sprintf(display, "! %-*s %-*s -> %s  (non fast forward)",
 283                         SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
 284                         pretty_ref);
 285                 return 1;
 286         }
 287 }
 288
 289 static int store_updated_refs(const char *url, struct ref *ref_map)
 290 {
 291         FILE *fp;
 292         struct commit *commit;
 293         int url_len, i, note_len, shown_url = 0;
 294         char note[1024];
 295         const char *what, *kind;
 296         struct ref *rm;
 297         char *filename = git_path("FETCH_HEAD");
 298
 299         fp = fopen(filename, "a");
 300         if (!fp)
 301                 return error("cannot open %s: %s\n", filename, strerror(errno));
 302         for (rm = ref_map; rm; rm = rm->next) {
 303                 struct ref *ref = NULL;
 304
 305                 if (rm->peer_ref) {
 306                         ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
 307                         strcpy(ref->name, rm->peer_ref->name);
 308                         hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
 309                         hashcpy(ref->new_sha1, rm->old_sha1);
 310                         ref->force = rm->peer_ref->force;
 311                 }
 312
 313                 commit = lookup_commit_reference_gently(rm->old_sha1, 1);
 314                 if (!commit)
 315                         rm->merge = 0;
 316
 317                 if (!strcmp(rm->name, "HEAD")) {
 318                         kind = "";
 319                         what = "";
 320                 }
 321                 else if (!prefixcmp(rm->name, "refs/heads/")) {
 322                         kind = "branch";
 323                         what = rm->name + 11;
 324                 }
 325                 else if (!prefixcmp(rm->name, "refs/tags/")) {
 326                         kind = "tag";
 327                         what = rm->name + 10;
 328                 }
 329                 else if (!prefixcmp(rm->name, "refs/remotes/")) {
 330                         kind = "remote branch";
 331                         what = rm->name + 13;
 332                 }
 333                 else {
 334                         kind = "";
 335                         what = rm->name;
 336                 }
 337
 338                 url_len = strlen(url);
 339                 for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
 340                         ;
 341                 url_len = i + 1;
 342                 if (4 < i && !strncmp(".git", url + i - 3, 4))
 343                         url_len = i - 3;
 344
 345                 note_len = 0;
 346                 if (*what) {
 347                         if (*kind)
 348                                 note_len += sprintf(note + note_len, "%s ",
 349                                                     kind);
 350                         note_len += sprintf(note + note_len, "'%s' of ", what);
 351                 }
 352                 note_len += sprintf(note + note_len, "%.*s", url_len, url);
 353                 fprintf(fp, "%s\t%s\t%s\n",
 354                         sha1_to_hex(commit ? commit->object.sha1 :
 355                                     rm->old_sha1),
 356                         rm->merge ? "" : "not-for-merge",
 357                         note);
 358
 359                 if (ref) {
 360                         update_local_ref(ref, what, verbose, note);
 361                         if (*note) {
 362                                 if (!shown_url) {
 363                                         fprintf(stderr, "From %.*s\n",
 364                                                         url_len, url);
 365                                         shown_url = 1;
 366                                 }
 367                                 fprintf(stderr, " %s\n", note);
 368                         }
 369                 }
 370         }
 371         fclose(fp);
 372         return 0;
 373 }
 374
 375 /*
 376  * We would want to bypass the object transfer altogether if
 377  * everything we are going to fetch already exists and connected
 378  * locally.
 379  *
 380  * The refs we are going to fetch are in to_fetch (nr_heads in
 381  * total).  If running
 382  *
 383  *  $ git-rev-list --objects to_fetch[0] to_fetch[1] ... --not --all
 384  *
 385  * does not error out, that means everything reachable from the
 386  * refs we are going to fetch exists and is connected to some of
 387  * our existing refs.
 388  */
 389 static int quickfetch(struct ref *ref_map)
 390 {
 391         struct child_process revlist;
 392         struct ref *ref;
 393         char **argv;
 394         int i, err;
 395
 396         /*
 397          * If we are deepening a shallow clone we already have these
 398          * objects reachable.  Running rev-list here will return with
 399          * a good (0) exit status and we'll bypass the fetch that we
 400          * really need to perform.  Claiming failure now will ensure
 401          * we perform the network exchange to deepen our history.
 402          */
 403         if (depth)
 404                 return -1;
 405
 406         for (i = 0, ref = ref_map; ref; ref = ref->next)
 407                 i++;
 408         if (!i)
 409                 return 0;
 410
 411         argv = xmalloc(sizeof(*argv) * (i + 6));
 412         i = 0;
 413         argv[i++] = xstrdup("rev-list");
 414         argv[i++] = xstrdup("--quiet");
 415         argv[i++] = xstrdup("--objects");
 416         for (ref = ref_map; ref; ref = ref->next)
 417                 argv[i++] = xstrdup(sha1_to_hex(ref->old_sha1));
 418         argv[i++] = xstrdup("--not");
 419         argv[i++] = xstrdup("--all");
 420         argv[i++] = NULL;
 421
 422         memset(&revlist, 0, sizeof(revlist));
 423         revlist.argv = (const char**)argv;
 424         revlist.git_cmd = 1;
 425         revlist.no_stdin = 1;
 426         revlist.no_stdout = 1;
 427         revlist.no_stderr = 1;
 428         err = run_command(&revlist);
 429
 430         for (i = 0; argv[i]; i++)
 431                 free(argv[i]);
 432         free(argv);
 433         return err;
 434 }
 435
 436 static int fetch_refs(struct transport *transport, struct ref *ref_map)
 437 {
 438         int ret = quickfetch(ref_map);
 439         if (ret)
 440                 ret = transport_fetch_refs(transport, ref_map);
 441         if (!ret)
 442                 ret |= store_updated_refs(transport->url, ref_map);
 443         transport_unlock_pack(transport);
 444         return ret;
 445 }
 446
 447 static int add_existing(const char *refname, const unsigned char *sha1,
 448                         int flag, void *cbdata)
 449 {
 450         struct path_list *list = (struct path_list *)cbdata;
 451         path_list_insert(refname, list);
 452         return 0;
 453 }
 454
 455 static struct ref *find_non_local_tags(struct transport *transport)
 456 {
 457         static struct path_list existing_refs = { NULL, 0, 0, 0 };
 458         struct path_list new_refs = { NULL, 0, 0, 1 };
 459         char *ref_name;
 460         int ref_name_len;
 461         const unsigned char *ref_sha1;
 462         const struct ref *tag_ref;
 463         struct ref *rm = NULL;
 464         struct ref *ref_map = NULL;
 465         struct ref **tail = &ref_map;
 466         const struct ref *ref;
 467
 468         for_each_ref(add_existing, &existing_refs);
 469         for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
 470                 if (prefixcmp(ref->name, "refs/tags"))
 471                         continue;
 472
 473                 ref_name = xstrdup(ref->name);
 474                 ref_name_len = strlen(ref_name);
 475                 ref_sha1 = ref->old_sha1;
 476
 477                 if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
 478                         ref_name[ref_name_len - 3] = 0;
 479                         tag_ref = transport_get_remote_refs(transport);
 480                         while (tag_ref) {
 481                                 if (!strcmp(tag_ref->name, ref_name)) {
 482                                         ref_sha1 = tag_ref->old_sha1;
 483                                         break;
 484                                 }
 485                                 tag_ref = tag_ref->next;
 486                         }
 487                 }
 488
 489                 if (!path_list_has_path(&existing_refs, ref_name) &&
 490                     !path_list_has_path(&new_refs, ref_name) &&
 491                     has_sha1_file(ref->old_sha1)) {
 492                         path_list_insert(ref_name, &new_refs);
 493
 494                         rm = alloc_ref(strlen(ref_name) + 1);
 495                         strcpy(rm->name, ref_name);
 496                         rm->peer_ref = alloc_ref(strlen(ref_name) + 1);
 497                         strcpy(rm->peer_ref->name, ref_name);
 498                         hashcpy(rm->old_sha1, ref_sha1);
 499
 500                         *tail = rm;
 501                         tail = &rm->next;
 502                 }
 503                 free(ref_name);
 504         }
 505
 506         return ref_map;
 507 }
 508
 509 static int do_fetch(struct transport *transport,
 510                     struct refspec *refs, int ref_count)
 511 {
 512         struct ref *ref_map, *fetch_map;
 513         struct ref *rm;
 514         int autotags = (transport->remote->fetch_tags == 1);
 515         if (transport->remote->fetch_tags == 2 && tags != TAGS_UNSET)
 516                 tags = TAGS_SET;
 517         if (transport->remote->fetch_tags == -1)
 518                 tags = TAGS_UNSET;
 519
 520         if (!transport->get_refs_list || !transport->fetch)
 521                 die("Don't know how to fetch from %s", transport->url);
 522
 523         /* if not appending, truncate FETCH_HEAD */
 524         if (!append) {
 525                 char *filename = git_path("FETCH_HEAD");
 526                 FILE *fp = fopen(filename, "w");
 527                 if (!fp)
 528                         return error("cannot open %s: %s\n", filename, strerror(errno));
 529                 fclose(fp);
 530         }
 531
 532         ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
 533
 534         for (rm = ref_map; rm; rm = rm->next) {
 535                 if (rm->peer_ref)
 536                         read_ref(rm->peer_ref->name, rm->peer_ref->old_sha1);
 537         }
 538
 539         if (fetch_refs(transport, ref_map)) {
 540                 free_refs(ref_map);
 541                 return 1;
 542         }
 543
 544         fetch_map = ref_map;
 545
 546         /* if neither --no-tags nor --tags was specified, do automated tag
 547          * following ... */
 548         if (tags == TAGS_DEFAULT && autotags) {
 549                 ref_map = find_non_local_tags(transport);
 550                 if (ref_map) {
 551                         transport_set_option(transport, TRANS_OPT_DEPTH, "0");
 552                         fetch_refs(transport, ref_map);
 553                 }
 554                 free_refs(ref_map);
 555         }
 556
 557         free_refs(fetch_map);
 558
 559         transport_disconnect(transport);
 560
 561         return 0;
 562 }
 563
 564 static void set_option(const char *name, const char *value)
 565 {
 566         int r = transport_set_option(transport, name, value);
 567         if (r < 0)
 568                 die("Option \"%s\" value \"%s\" is not valid for %s\n",
 569                         name, value, transport->url);
 570         if (r > 0)
 571                 warning("Option \"%s\" is ignored for %s\n",
 572                         name, transport->url);
 573 }
 574
 575 int cmd_fetch(int argc, const char **argv, const char *prefix)
 576 {
 577         struct remote *remote;
 578         int i;
 579         static const char **refs = NULL;
 580         int ref_nr = 0;
 581
 582         /* Record the command line for the reflog */
 583         strbuf_addstr(&default_rla, "fetch");
 584         for (i = 1; i < argc; i++)
 585                 strbuf_addf(&default_rla, " %s", argv[i]);
 586
 587         argc = parse_options(argc, argv,
 588                              builtin_fetch_options, builtin_fetch_usage, 0);
 589
 590         if (argc == 0)
 591                 remote = remote_get(NULL);
 592         else
 593                 remote = remote_get(argv[0]);
 594
 595         transport = transport_get(remote, remote->url[0]);
 596         if (verbose >= 2)
 597                 transport->verbose = 1;
 598         if (quiet)
 599                 transport->verbose = -1;
 600         if (upload_pack)
 601                 set_option(TRANS_OPT_UPLOADPACK, upload_pack);
 602         if (keep)
 603                 set_option(TRANS_OPT_KEEP, "yes");
 604         if (depth)
 605                 set_option(TRANS_OPT_DEPTH, depth);
 606
 607         if (!transport->url)
 608                 die("Where do you want to fetch from today?");
 609
 610         if (argc > 1) {
 611                 int j = 0;
 612                 refs = xcalloc(argc + 1, sizeof(const char *));
 613                 for (i = 1; i < argc; i++) {
 614                         if (!strcmp(argv[i], "tag")) {
 615                                 char *ref;
 616                                 i++;
 617                                 ref = xmalloc(strlen(argv[i]) * 2 + 22);
 618                                 strcpy(ref, "refs/tags/");
 619                                 strcat(ref, argv[i]);
 620                                 strcat(ref, ":refs/tags/");
 621                                 strcat(ref, argv[i]);
 622                                 refs[j++] = ref;
 623                         } else
 624                                 refs[j++] = argv[i];
 625                 }
 626                 refs[j] = NULL;
 627                 ref_nr = j;
 628         }
 629
 630         signal(SIGINT, unlock_pack_on_signal);
 631         atexit(unlock_pack);
 632         return do_fetch(transport, parse_ref_spec(ref_nr, refs), ref_nr);
 633 }