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_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()
  51 };
  52
  53 static void unlock_pack(void)
  54 {
  55         if (transport)
  56                 transport_unlock_pack(transport);
  57 }
  58
  59 static void unlock_pack_on_signal(int signo)
  60 {
  61         unlock_pack();
  62         signal(SIGINT, SIG_DFL);
  63         raise(signo);
  64 }
  65
  66 static void add_merge_config(struct ref **head,
  67                            const struct ref *remote_refs,
  68                            struct branch *branch,
  69                            struct ref ***tail)
  70 {
  71         int i;
  72
  73         for (i = 0; i < branch->merge_nr; i++) {
  74                 struct ref *rm, **old_tail = *tail;
  75                 struct refspec refspec;
  76
  77                 for (rm = *head; rm; rm = rm->next) {
  78                         if (branch_merge_matches(branch, i, rm->name)) {
  79                                 rm->merge = 1;
  80                                 break;
  81                         }
  82                 }
  83                 if (rm)
  84                         continue;
  85
  86                 /*
  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.
  95                  */
  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;
 103         }
 104 }
 105
 106 static struct ref *get_ref_map(struct transport *transport,
 107                                struct refspec *refs, int ref_count, int tags,
 108                                int *autotags)
 109 {
 110         int i;
 111         struct ref *rm;
 112         struct ref *ref_map = NULL;
 113         struct ref **tail = &ref_map;
 114
 115         const struct ref *remote_refs = transport_get_remote_refs(transport);
 116
 117         if (ref_count || tags == TAGS_SET) {
 118                 for (i = 0; i < ref_count; i++) {
 119                         get_fetch_map(remote_refs, &refs[i], &tail, 0);
 120                         if (refs[i].dst && refs[i].dst[0])
 121                                 *autotags = 1;
 122                 }
 123                 /* Merge everything on the command line, but not --tags */
 124                 for (rm = ref_map; rm; rm = rm->next)
 125                         rm->merge = 1;
 126                 if (tags == TAGS_SET) {
 127                         struct refspec refspec;
 128                         refspec.src = "refs/tags/";
 129                         refspec.dst = "refs/tags/";
 130                         refspec.pattern = 1;
 131                         refspec.force = 0;
 132                         get_fetch_map(remote_refs, &refspec, &tail, 0);
 133                 }
 134         } else {
 135                 /* Use the defaults */
 136                 struct remote *remote = transport->remote;
 137                 struct branch *branch = branch_get(NULL);
 138                 int has_merge = branch_has_merge_config(branch);
 139                 if (remote && (remote->fetch_refspec_nr || has_merge)) {
 140                         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 141                                 get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
 142                                 if (remote->fetch[i].dst &&
 143                                     remote->fetch[i].dst[0])
 144                                         *autotags = 1;
 145                                 if (!i && !has_merge && ref_map &&
 146                                     !remote->fetch[0].pattern)
 147                                         ref_map->merge = 1;
 148                         }
 149                         /*
 150                          * if the remote we're fetching from is the same
 151                          * as given in branch.<name>.remote, we add the
 152                          * ref given in branch.<name>.merge, too.
 153                          */
 154                         if (has_merge &&
 155                             !strcmp(branch->remote_name, remote->name))
 156                                 add_merge_config(&ref_map, remote_refs, branch, &tail);
 157                 } else {
 158                         ref_map = get_remote_ref(remote_refs, "HEAD");
 159                         if (!ref_map)
 160                                 die("Couldn't find remote ref HEAD");
 161                         ref_map->merge = 1;
 162                 }
 163         }
 164         ref_remove_duplicates(ref_map);
 165
 166         return ref_map;
 167 }
 168
 169 static int s_update_ref(const char *action,
 170                         struct ref *ref,
 171                         int check_old)
 172 {
 173         char msg[1024];
 174         char *rla = getenv("GIT_REFLOG_ACTION");
 175         static struct ref_lock *lock;
 176
 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 1;
 184         if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
 185                 return 1;
 186         return 0;
 187 }
 188
 189 #define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
 190 #define REFCOL_WIDTH  10
 191
 192 static int update_local_ref(struct ref *ref,
 193                             const char *remote,
 194                             int verbose,
 195                             char *display)
 196 {
 197         struct commit *current = NULL, *updated;
 198         enum object_type type;
 199         struct branch *current_branch = branch_get(NULL);
 200         const char *pretty_ref = ref->name + (
 201                 !prefixcmp(ref->name, "refs/heads/") ? 11 :
 202                 !prefixcmp(ref->name, "refs/tags/") ? 10 :
 203                 !prefixcmp(ref->name, "refs/remotes/") ? 13 :
 204                 0);
 205
 206         *display = 0;
 207         type = sha1_object_info(ref->new_sha1, NULL);
 208         if (type < 0)
 209                 die("object %s not found", sha1_to_hex(ref->new_sha1));
 210
 211         if (!*ref->name) {
 212                 /* Not storing */
 213                 if (verbose)
 214                         sprintf(display, "* branch %s -> FETCH_HEAD", remote);
 215                 return 0;
 216         }
 217
 218         if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
 219                 if (verbose)
 220                         sprintf(display, "= %-*s %-*s -> %s", SUMMARY_WIDTH,
 221                                 "[up to date]", REFCOL_WIDTH, remote,
 222                                 pretty_ref);
 223                 return 0;
 224         }
 225
 226         if (current_branch &&
 227             !strcmp(ref->name, current_branch->name) &&
 228             !(update_head_ok || is_bare_repository()) &&
 229             !is_null_sha1(ref->old_sha1)) {
 230                 /*
 231                  * If this is the head, and it's not okay to update
 232                  * the head, and the old value of the head isn't empty...
 233                  */
 234                 sprintf(display, "! %-*s %-*s -> %s  (can't fetch in current branch)",
 235                         SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
 236                         pretty_ref);
 237                 return 1;
 238         }
 239
 240         if (!is_null_sha1(ref->old_sha1) &&
 241             !prefixcmp(ref->name, "refs/tags/")) {
 242                 sprintf(display, "- %-*s %-*s -> %s",
 243                         SUMMARY_WIDTH, "[tag update]", REFCOL_WIDTH, remote,
 244                         pretty_ref);
 245                 return s_update_ref("updating tag", ref, 0);
 246         }
 247
 248         current = lookup_commit_reference_gently(ref->old_sha1, 1);
 249         updated = lookup_commit_reference_gently(ref->new_sha1, 1);
 250         if (!current || !updated) {
 251                 const char *msg;
 252                 const char *what;
 253                 if (!strncmp(ref->name, "refs/tags/", 10)) {
 254                         msg = "storing tag";
 255                         what = "[new tag]";
 256                 }
 257                 else {
 258                         msg = "storing head";
 259                         what = "[new branch]";
 260                 }
 261
 262                 sprintf(display, "* %-*s %-*s -> %s", SUMMARY_WIDTH, what,
 263                         REFCOL_WIDTH, remote, pretty_ref);
 264                 return s_update_ref(msg, ref, 0);
 265         }
 266
 267         if (in_merge_bases(current, &updated, 1)) {
 268                 char quickref[83];
 269                 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
 270                 strcat(quickref, "..");
 271                 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
 272                 sprintf(display, "  %-*s %-*s -> %s", SUMMARY_WIDTH, quickref,
 273                         REFCOL_WIDTH, remote, pretty_ref);
 274                 return s_update_ref("fast forward", ref, 1);
 275         } else if (force || ref->force) {
 276                 char quickref[84];
 277                 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
 278                 strcat(quickref, "...");
 279                 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
 280                 sprintf(display, "+ %-*s %-*s -> %s  (forced update)",
 281                         SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote, pretty_ref);
 282                 return s_update_ref("forced-update", ref, 1);
 283         } else {
 284                 sprintf(display, "! %-*s %-*s -> %s  (non fast forward)",
 285                         SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
 286                         pretty_ref);
 287                 return 1;
 288         }
 289 }
 290
 291 static int store_updated_refs(const char *url, struct ref *ref_map)
 292 {
 293         FILE *fp;
 294         struct commit *commit;
 295         int url_len, i, note_len, shown_url = 0;
 296         char note[1024];
 297         const char *what, *kind;
 298         struct ref *rm;
 299         char *filename = git_path("FETCH_HEAD");
 300
 301         fp = fopen(filename, "a");
 302         if (!fp)
 303                 return error("cannot open %s: %s\n", filename, strerror(errno));
 304         for (rm = ref_map; rm; rm = rm->next) {
 305                 struct ref *ref = NULL;
 306
 307                 if (rm->peer_ref) {
 308                         ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
 309                         strcpy(ref->name, rm->peer_ref->name);
 310                         hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
 311                         hashcpy(ref->new_sha1, rm->old_sha1);
 312                         ref->force = rm->peer_ref->force;
 313                 }
 314
 315                 commit = lookup_commit_reference_gently(rm->old_sha1, 1);
 316                 if (!commit)
 317                         rm->merge = 0;
 318
 319                 if (!strcmp(rm->name, "HEAD")) {
 320                         kind = "";
 321                         what = "";
 322                 }
 323                 else if (!prefixcmp(rm->name, "refs/heads/")) {
 324                         kind = "branch";
 325                         what = rm->name + 11;
 326                 }
 327                 else if (!prefixcmp(rm->name, "refs/tags/")) {
 328                         kind = "tag";
 329                         what = rm->name + 10;
 330                 }
 331                 else if (!prefixcmp(rm->name, "refs/remotes/")) {
 332                         kind = "remote branch";
 333                         what = rm->name + 13;
 334                 }
 335                 else {
 336                         kind = "";
 337                         what = rm->name;
 338                 }
 339
 340                 url_len = strlen(url);
 341                 for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
 342                         ;
 343                 url_len = i + 1;
 344                 if (4 < i && !strncmp(".git", url + i - 3, 4))
 345                         url_len = i - 3;
 346
 347                 note_len = 0;
 348                 if (*what) {
 349                         if (*kind)
 350                                 note_len += sprintf(note + note_len, "%s ",
 351                                                     kind);
 352                         note_len += sprintf(note + note_len, "'%s' of ", what);
 353                 }
 354                 note_len += sprintf(note + note_len, "%.*s", url_len, url);
 355                 fprintf(fp, "%s\t%s\t%s\n",
 356                         sha1_to_hex(commit ? commit->object.sha1 :
 357                                     rm->old_sha1),
 358                         rm->merge ? "" : "not-for-merge",
 359                         note);
 360
 361                 if (ref) {
 362                         update_local_ref(ref, what, verbose, note);
 363                         if (*note) {
 364                                 if (!shown_url) {
 365                                         fprintf(stderr, "From %.*s\n",
 366                                                         url_len, url);
 367                                         shown_url = 1;
 368                                 }
 369                                 fprintf(stderr, " %s\n", note);
 370                         }
 371                 }
 372         }
 373         fclose(fp);
 374         return 0;
 375 }
 376
 377 /*
 378  * We would want to bypass the object transfer altogether if
 379  * everything we are going to fetch already exists and connected
 380  * locally.
 381  *
 382  * The refs we are going to fetch are in to_fetch (nr_heads in
 383  * total).  If running
 384  *
 385  *  $ git-rev-list --objects to_fetch[0] to_fetch[1] ... --not --all
 386  *
 387  * does not error out, that means everything reachable from the
 388  * refs we are going to fetch exists and is connected to some of
 389  * our existing refs.
 390  */
 391 static int quickfetch(struct ref *ref_map)
 392 {
 393         struct child_process revlist;
 394         struct ref *ref;
 395         char **argv;
 396         int i, err;
 397
 398         /*
 399          * If we are deepening a shallow clone we already have these
 400          * objects reachable.  Running rev-list here will return with
 401          * a good (0) exit status and we'll bypass the fetch that we
 402          * really need to perform.  Claiming failure now will ensure
 403          * we perform the network exchange to deepen our history.
 404          */
 405         if (depth)
 406                 return -1;
 407
 408         for (i = 0, ref = ref_map; ref; ref = ref->next)
 409                 i++;
 410         if (!i)
 411                 return 0;
 412
 413         argv = xmalloc(sizeof(*argv) * (i + 6));
 414         i = 0;
 415         argv[i++] = xstrdup("rev-list");
 416         argv[i++] = xstrdup("--quiet");
 417         argv[i++] = xstrdup("--objects");
 418         for (ref = ref_map; ref; ref = ref->next)
 419                 argv[i++] = xstrdup(sha1_to_hex(ref->old_sha1));
 420         argv[i++] = xstrdup("--not");
 421         argv[i++] = xstrdup("--all");
 422         argv[i++] = NULL;
 423
 424         memset(&revlist, 0, sizeof(revlist));
 425         revlist.argv = (const char**)argv;
 426         revlist.git_cmd = 1;
 427         revlist.no_stdin = 1;
 428         revlist.no_stdout = 1;
 429         revlist.no_stderr = 1;
 430         err = run_command(&revlist);
 431
 432         for (i = 0; argv[i]; i++)
 433                 free(argv[i]);
 434         free(argv);
 435         return err;
 436 }
 437
 438 static int fetch_refs(struct transport *transport, struct ref *ref_map)
 439 {
 440         int ret = quickfetch(ref_map);
 441         if (ret)
 442                 ret = transport_fetch_refs(transport, ref_map);
 443         if (!ret)
 444                 ret |= store_updated_refs(transport->url, ref_map);
 445         transport_unlock_pack(transport);
 446         return ret;
 447 }
 448
 449 static int add_existing(const char *refname, const unsigned char *sha1,
 450                         int flag, void *cbdata)
 451 {
 452         struct path_list *list = (struct path_list *)cbdata;
 453         path_list_insert(refname, list);
 454         return 0;
 455 }
 456
 457 static struct ref *find_non_local_tags(struct transport *transport,
 458                                        struct ref *fetch_map)
 459 {
 460         static struct path_list existing_refs = { NULL, 0, 0, 0 };
 461         struct path_list new_refs = { NULL, 0, 0, 1 };
 462         char *ref_name;
 463         int ref_name_len;
 464         const unsigned char *ref_sha1;
 465         const struct ref *tag_ref;
 466         struct ref *rm = NULL;
 467         struct ref *ref_map = NULL;
 468         struct ref **tail = &ref_map;
 469         const struct ref *ref;
 470
 471         for_each_ref(add_existing, &existing_refs);
 472         for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
 473                 if (prefixcmp(ref->name, "refs/tags"))
 474                         continue;
 475
 476                 ref_name = xstrdup(ref->name);
 477                 ref_name_len = strlen(ref_name);
 478                 ref_sha1 = ref->old_sha1;
 479
 480                 if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
 481                         ref_name[ref_name_len - 3] = 0;
 482                         tag_ref = transport_get_remote_refs(transport);
 483                         while (tag_ref) {
 484                                 if (!strcmp(tag_ref->name, ref_name)) {
 485                                         ref_sha1 = tag_ref->old_sha1;
 486                                         break;
 487                                 }
 488                                 tag_ref = tag_ref->next;
 489                         }
 490                 }
 491
 492                 if (!path_list_has_path(&existing_refs, ref_name) &&
 493                     !path_list_has_path(&new_refs, ref_name) &&
 494                     has_sha1_file(ref->old_sha1)) {
 495                         path_list_insert(ref_name, &new_refs);
 496
 497                         rm = alloc_ref(strlen(ref_name) + 1);
 498                         strcpy(rm->name, ref_name);
 499                         rm->peer_ref = alloc_ref(strlen(ref_name) + 1);
 500                         strcpy(rm->peer_ref->name, ref_name);
 501                         hashcpy(rm->old_sha1, ref_sha1);
 502
 503                         *tail = rm;
 504                         tail = &rm->next;
 505                 }
 506                 free(ref_name);
 507         }
 508
 509         return ref_map;
 510 }
 511
 512 static int do_fetch(struct transport *transport,
 513                     struct refspec *refs, int ref_count)
 514 {
 515         struct ref *ref_map, *fetch_map;
 516         struct ref *rm;
 517         int autotags = (transport->remote->fetch_tags == 1);
 518         if (transport->remote->fetch_tags == 2 && tags != TAGS_UNSET)
 519                 tags = TAGS_SET;
 520         if (transport->remote->fetch_tags == -1)
 521                 tags = TAGS_UNSET;
 522
 523         if (!transport->get_refs_list || !transport->fetch)
 524                 die("Don't know how to fetch from %s", transport->url);
 525
 526         /* if not appending, truncate FETCH_HEAD */
 527         if (!append) {
 528                 char *filename = git_path("FETCH_HEAD");
 529                 FILE *fp = fopen(filename, "w");
 530                 if (!fp)
 531                         return error("cannot open %s: %s\n", filename, strerror(errno));
 532                 fclose(fp);
 533         }
 534
 535         ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
 536
 537         for (rm = ref_map; rm; rm = rm->next) {
 538                 if (rm->peer_ref)
 539                         read_ref(rm->peer_ref->name, rm->peer_ref->old_sha1);
 540         }
 541
 542         if (fetch_refs(transport, ref_map)) {
 543                 free_refs(ref_map);
 544                 return 1;
 545         }
 546
 547         fetch_map = ref_map;
 548
 549         /* if neither --no-tags nor --tags was specified, do automated tag
 550          * following ... */
 551         if (tags == TAGS_DEFAULT && autotags) {
 552                 ref_map = find_non_local_tags(transport, fetch_map);
 553                 if (ref_map) {
 554                         transport_set_option(transport, TRANS_OPT_DEPTH, "0");
 555                         fetch_refs(transport, ref_map);
 556                 }
 557                 free_refs(ref_map);
 558         }
 559
 560         free_refs(fetch_map);
 561
 562         return 0;
 563 }
 564
 565 static void set_option(const char *name, const char *value)
 566 {
 567         int r = transport_set_option(transport, name, value);
 568         if (r < 0)
 569                 die("Option \"%s\" value \"%s\" is not valid for %s\n",
 570                         name, value, transport->url);
 571         if (r > 0)
 572                 warning("Option \"%s\" is ignored for %s\n",
 573                         name, transport->url);
 574 }
 575
 576 int cmd_fetch(int argc, const char **argv, const char *prefix)
 577 {
 578         struct remote *remote;
 579         int i;
 580         static const char **refs = NULL;
 581         int ref_nr = 0;
 582
 583         /* Record the command line for the reflog */
 584         strbuf_addstr(&default_rla, "fetch");
 585         for (i = 1; i < argc; i++)
 586                 strbuf_addf(&default_rla, " %s", argv[i]);
 587
 588         argc = parse_options(argc, argv,
 589                              builtin_fetch_options, builtin_fetch_usage, 0);
 590
 591         if (argc == 0)
 592                 remote = remote_get(NULL);
 593         else
 594                 remote = remote_get(argv[0]);
 595
 596         transport = transport_get(remote, remote->url[0]);
 597         if (verbose >= 2)
 598                 transport->verbose = 1;
 599         if (quiet)
 600                 transport->verbose = -1;
 601         if (upload_pack)
 602                 set_option(TRANS_OPT_UPLOADPACK, upload_pack);
 603         if (keep)
 604                 set_option(TRANS_OPT_KEEP, "yes");
 605         if (depth)
 606                 set_option(TRANS_OPT_DEPTH, depth);
 607
 608         if (!transport->url)
 609                 die("Where do you want to fetch from today?");
 610
 611         if (argc > 1) {
 612                 int j = 0;
 613                 refs = xcalloc(argc + 1, sizeof(const char *));
 614                 for (i = 1; i < argc; i++) {
 615                         if (!strcmp(argv[i], "tag")) {
 616                                 char *ref;
 617                                 i++;
 618                                 ref = xmalloc(strlen(argv[i]) * 2 + 22);
 619                                 strcpy(ref, "refs/tags/");
 620                                 strcat(ref, argv[i]);
 621                                 strcat(ref, ":refs/tags/");
 622                                 strcat(ref, argv[i]);
 623                                 refs[j++] = ref;
 624                         } else
 625                                 refs[j++] = argv[i];
 626                 }
 627                 refs[j] = NULL;
 628                 ref_nr = j;
 629         }
 630
 631         signal(SIGINT, unlock_pack_on_signal);
 632         atexit(unlock_pack);
 633         return do_fetch(transport, parse_ref_spec(ref_nr, refs), ref_nr);
 634 }