builtin-fetch-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include "commit.h"
   5 #include "tag.h"
   6 #include "exec_cmd.h"
   7 #include "pack.h"
   8 #include "sideband.h"
   9 #include "fetch-pack.h"
  10 #include "remote.h"
  11 #include "run-command.h"
  12
  13 static int transfer_unpack_limit = -1;
  14 static int fetch_unpack_limit = -1;
  15 static int unpack_limit = 100;
  16 static struct fetch_pack_args args = {
  17         /* .uploadpack = */ "git-upload-pack",
  18 };
  19
  20 static const char fetch_pack_usage[] =
  21 "git-fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
  22
  23 #define COMPLETE        (1U << 0)
  24 #define COMMON          (1U << 1)
  25 #define COMMON_REF      (1U << 2)
  26 #define SEEN            (1U << 3)
  27 #define POPPED          (1U << 4)
  28
  29 /*
  30  * After sending this many "have"s if we do not get any new ACK , we
  31  * give up traversing our history.
  32  */
  33 #define MAX_IN_VAIN 256
  34
  35 static struct commit_list *rev_list;
  36 static int non_common_revs, multi_ack, use_sideband;
  37
  38 static void rev_list_push(struct commit *commit, int mark)
  39 {
  40         if (!(commit->object.flags & mark)) {
  41                 commit->object.flags |= mark;
  42
  43                 if (!(commit->object.parsed))
  44                         parse_commit(commit);
  45
  46                 insert_by_date(commit, &rev_list);
  47
  48                 if (!(commit->object.flags & COMMON))
  49                         non_common_revs++;
  50         }
  51 }
  52
  53 static int rev_list_insert_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  54 {
  55         struct object *o = deref_tag(parse_object(sha1), path, 0);
  56
  57         if (o && o->type == OBJ_COMMIT)
  58                 rev_list_push((struct commit *)o, SEEN);
  59
  60         return 0;
  61 }
  62
  63 /*
  64    This function marks a rev and its ancestors as common.
  65    In some cases, it is desirable to mark only the ancestors (for example
  66    when only the server does not yet know that they are common).
  67 */
  68
  69 static void mark_common(struct commit *commit,
  70                 int ancestors_only, int dont_parse)
  71 {
  72         if (commit != NULL && !(commit->object.flags & COMMON)) {
  73                 struct object *o = (struct object *)commit;
  74
  75                 if (!ancestors_only)
  76                         o->flags |= COMMON;
  77
  78                 if (!(o->flags & SEEN))
  79                         rev_list_push(commit, SEEN);
  80                 else {
  81                         struct commit_list *parents;
  82
  83                         if (!ancestors_only && !(o->flags & POPPED))
  84                                 non_common_revs--;
  85                         if (!o->parsed && !dont_parse)
  86                                 parse_commit(commit);
  87
  88                         for (parents = commit->parents;
  89                                         parents;
  90                                         parents = parents->next)
  91                                 mark_common(parents->item, 0, dont_parse);
  92                 }
  93         }
  94 }
  95
  96 /*
  97   Get the next rev to send, ignoring the common.
  98 */
  99
 100 static const unsigned char* get_rev(void)
 101 {
 102         struct commit *commit = NULL;
 103
 104         while (commit == NULL) {
 105                 unsigned int mark;
 106                 struct commit_list* parents;
 107
 108                 if (rev_list == NULL || non_common_revs == 0)
 109                         return NULL;
 110
 111                 commit = rev_list->item;
 112                 if (!(commit->object.parsed))
 113                         parse_commit(commit);
 114                 commit->object.flags |= POPPED;
 115                 if (!(commit->object.flags & COMMON))
 116                         non_common_revs--;
 117
 118                 parents = commit->parents;
 119
 120                 if (commit->object.flags & COMMON) {
 121                         /* do not send "have", and ignore ancestors */
 122                         commit = NULL;
 123                         mark = COMMON | SEEN;
 124                 } else if (commit->object.flags & COMMON_REF)
 125                         /* send "have", and ignore ancestors */
 126                         mark = COMMON | SEEN;
 127                 else
 128                         /* send "have", also for its ancestors */
 129                         mark = SEEN;
 130
 131                 while (parents) {
 132                         if (!(parents->item->object.flags & SEEN))
 133                                 rev_list_push(parents->item, mark);
 134                         if (mark & COMMON)
 135                                 mark_common(parents->item, 1, 0);
 136                         parents = parents->next;
 137                 }
 138
 139                 rev_list = rev_list->next;
 140         }
 141
 142         return commit->object.sha1;
 143 }
 144
 145 static int find_common(int fd[2], unsigned char *result_sha1,
 146                        struct ref *refs)
 147 {
 148         int fetching;
 149         int count = 0, flushes = 0, retval;
 150         const unsigned char *sha1;
 151         unsigned in_vain = 0;
 152         int got_continue = 0;
 153
 154         for_each_ref(rev_list_insert_ref, NULL);
 155
 156         fetching = 0;
 157         for ( ; refs ; refs = refs->next) {
 158                 unsigned char *remote = refs->old_sha1;
 159                 struct object *o;
 160
 161                 /*
 162                  * If that object is complete (i.e. it is an ancestor of a
 163                  * local ref), we tell them we have it but do not have to
 164                  * tell them about its ancestors, which they already know
 165                  * about.
 166                  *
 167                  * We use lookup_object here because we are only
 168                  * interested in the case we *know* the object is
 169                  * reachable and we have already scanned it.
 170                  */
 171                 if (((o = lookup_object(remote)) != NULL) &&
 172                                 (o->flags & COMPLETE)) {
 173                         continue;
 174                 }
 175
 176                 if (!fetching)
 177                         packet_write(fd[1], "want %s%s%s%s%s%s%s\n",
 178                                      sha1_to_hex(remote),
 179                                      (multi_ack ? " multi_ack" : ""),
 180                                      (use_sideband == 2 ? " side-band-64k" : ""),
 181                                      (use_sideband == 1 ? " side-band" : ""),
 182                                      (args.use_thin_pack ? " thin-pack" : ""),
 183                                      (args.no_progress ? " no-progress" : ""),
 184                                      " ofs-delta");
 185                 else
 186                         packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
 187                 fetching++;
 188         }
 189         if (is_repository_shallow())
 190                 write_shallow_commits(fd[1], 1);
 191         if (args.depth > 0)
 192                 packet_write(fd[1], "deepen %d", args.depth);
 193         packet_flush(fd[1]);
 194         if (!fetching)
 195                 return 1;
 196
 197         if (args.depth > 0) {
 198                 char line[1024];
 199                 unsigned char sha1[20];
 200                 int len;
 201
 202                 while ((len = packet_read_line(fd[0], line, sizeof(line)))) {
 203                         if (!prefixcmp(line, "shallow ")) {
 204                                 if (get_sha1_hex(line + 8, sha1))
 205                                         die("invalid shallow line: %s", line);
 206                                 register_shallow(sha1);
 207                                 continue;
 208                         }
 209                         if (!prefixcmp(line, "unshallow ")) {
 210                                 if (get_sha1_hex(line + 10, sha1))
 211                                         die("invalid unshallow line: %s", line);
 212                                 if (!lookup_object(sha1))
 213                                         die("object not found: %s", line);
 214                                 /* make sure that it is parsed as shallow */
 215                                 parse_object(sha1);
 216                                 if (unregister_shallow(sha1))
 217                                         die("no shallow found: %s", line);
 218                                 continue;
 219                         }
 220                         die("expected shallow/unshallow, got %s", line);
 221                 }
 222         }
 223
 224         flushes = 0;
 225         retval = -1;
 226         while ((sha1 = get_rev())) {
 227                 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
 228                 if (args.verbose)
 229                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 230                 in_vain++;
 231                 if (!(31 & ++count)) {
 232                         int ack;
 233
 234                         packet_flush(fd[1]);
 235                         flushes++;
 236
 237                         /*
 238                          * We keep one window "ahead" of the other side, and
 239                          * will wait for an ACK only on the next one
 240                          */
 241                         if (count == 32)
 242                                 continue;
 243
 244                         do {
 245                                 ack = get_ack(fd[0], result_sha1);
 246                                 if (args.verbose && ack)
 247                                         fprintf(stderr, "got ack %d %s\n", ack,
 248                                                         sha1_to_hex(result_sha1));
 249                                 if (ack == 1) {
 250                                         flushes = 0;
 251                                         multi_ack = 0;
 252                                         retval = 0;
 253                                         goto done;
 254                                 } else if (ack == 2) {
 255                                         struct commit *commit =
 256                                                 lookup_commit(result_sha1);
 257                                         mark_common(commit, 0, 1);
 258                                         retval = 0;
 259                                         in_vain = 0;
 260                                         got_continue = 1;
 261                                 }
 262                         } while (ack);
 263                         flushes--;
 264                         if (got_continue && MAX_IN_VAIN < in_vain) {
 265                                 if (args.verbose)
 266                                         fprintf(stderr, "giving up\n");
 267                                 break; /* give up */
 268                         }
 269                 }
 270         }
 271 done:
 272         packet_write(fd[1], "done\n");
 273         if (args.verbose)
 274                 fprintf(stderr, "done\n");
 275         if (retval != 0) {
 276                 multi_ack = 0;
 277                 flushes++;
 278         }
 279         while (flushes || multi_ack) {
 280                 int ack = get_ack(fd[0], result_sha1);
 281                 if (ack) {
 282                         if (args.verbose)
 283                                 fprintf(stderr, "got ack (%d) %s\n", ack,
 284                                         sha1_to_hex(result_sha1));
 285                         if (ack == 1)
 286                                 return 0;
 287                         multi_ack = 1;
 288                         continue;
 289                 }
 290                 flushes--;
 291         }
 292         return retval;
 293 }
 294
 295 static struct commit_list *complete;
 296
 297 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 298 {
 299         struct object *o = parse_object(sha1);
 300
 301         while (o && o->type == OBJ_TAG) {
 302                 struct tag *t = (struct tag *) o;
 303                 if (!t->tagged)
 304                         break; /* broken repository */
 305                 o->flags |= COMPLETE;
 306                 o = parse_object(t->tagged->sha1);
 307         }
 308         if (o && o->type == OBJ_COMMIT) {
 309                 struct commit *commit = (struct commit *)o;
 310                 commit->object.flags |= COMPLETE;
 311                 insert_by_date(commit, &complete);
 312         }
 313         return 0;
 314 }
 315
 316 static void mark_recent_complete_commits(unsigned long cutoff)
 317 {
 318         while (complete && cutoff <= complete->item->date) {
 319                 if (args.verbose)
 320                         fprintf(stderr, "Marking %s as complete\n",
 321                                 sha1_to_hex(complete->item->object.sha1));
 322                 pop_most_recent_commit(&complete, COMPLETE);
 323         }
 324 }
 325
 326 static void filter_refs(struct ref **refs, int nr_match, char **match)
 327 {
 328         struct ref **return_refs;
 329         struct ref *newlist = NULL;
 330         struct ref **newtail = &newlist;
 331         struct ref *ref, *next;
 332         struct ref *fastarray[32];
 333
 334         if (nr_match && !args.fetch_all) {
 335                 if (ARRAY_SIZE(fastarray) < nr_match)
 336                         return_refs = xcalloc(nr_match, sizeof(struct ref *));
 337                 else {
 338                         return_refs = fastarray;
 339                         memset(return_refs, 0, sizeof(struct ref *) * nr_match);
 340                 }
 341         }
 342         else
 343                 return_refs = NULL;
 344
 345         for (ref = *refs; ref; ref = next) {
 346                 next = ref->next;
 347                 if (!memcmp(ref->name, "refs/", 5) &&
 348                     check_ref_format(ref->name + 5))
 349                         ; /* trash */
 350                 else if (args.fetch_all &&
 351                          (!args.depth || prefixcmp(ref->name, "refs/tags/") )) {
 352                         *newtail = ref;
 353                         ref->next = NULL;
 354                         newtail = &ref->next;
 355                         continue;
 356                 }
 357                 else {
 358                         int order = path_match(ref->name, nr_match, match);
 359                         if (order) {
 360                                 return_refs[order-1] = ref;
 361                                 continue; /* we will link it later */
 362                         }
 363                 }
 364                 free(ref);
 365         }
 366
 367         if (!args.fetch_all) {
 368                 int i;
 369                 for (i = 0; i < nr_match; i++) {
 370                         ref = return_refs[i];
 371                         if (ref) {
 372                                 *newtail = ref;
 373                                 ref->next = NULL;
 374                                 newtail = &ref->next;
 375                         }
 376                 }
 377                 if (return_refs != fastarray)
 378                         free(return_refs);
 379         }
 380         *refs = newlist;
 381 }
 382
 383 static int everything_local(struct ref **refs, int nr_match, char **match)
 384 {
 385         struct ref *ref;
 386         int retval;
 387         unsigned long cutoff = 0;
 388
 389         track_object_refs = 0;
 390         save_commit_buffer = 0;
 391
 392         for (ref = *refs; ref; ref = ref->next) {
 393                 struct object *o;
 394
 395                 o = parse_object(ref->old_sha1);
 396                 if (!o)
 397                         continue;
 398
 399                 /* We already have it -- which may mean that we were
 400                  * in sync with the other side at some time after
 401                  * that (it is OK if we guess wrong here).
 402                  */
 403                 if (o->type == OBJ_COMMIT) {
 404                         struct commit *commit = (struct commit *)o;
 405                         if (!cutoff || cutoff < commit->date)
 406                                 cutoff = commit->date;
 407                 }
 408         }
 409
 410         if (!args.depth) {
 411                 for_each_ref(mark_complete, NULL);
 412                 if (cutoff)
 413                         mark_recent_complete_commits(cutoff);
 414         }
 415
 416         /*
 417          * Mark all complete remote refs as common refs.
 418          * Don't mark them common yet; the server has to be told so first.
 419          */
 420         for (ref = *refs; ref; ref = ref->next) {
 421                 struct object *o = deref_tag(lookup_object(ref->old_sha1),
 422                                              NULL, 0);
 423
 424                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 425                         continue;
 426
 427                 if (!(o->flags & SEEN)) {
 428                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 429
 430                         mark_common((struct commit *)o, 1, 1);
 431                 }
 432         }
 433
 434         filter_refs(refs, nr_match, match);
 435
 436         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 437                 const unsigned char *remote = ref->old_sha1;
 438                 unsigned char local[20];
 439                 struct object *o;
 440
 441                 o = lookup_object(remote);
 442                 if (!o || !(o->flags & COMPLETE)) {
 443                         retval = 0;
 444                         if (!args.verbose)
 445                                 continue;
 446                         fprintf(stderr,
 447                                 "want %s (%s)\n", sha1_to_hex(remote),
 448                                 ref->name);
 449                         continue;
 450                 }
 451
 452                 hashcpy(ref->new_sha1, local);
 453                 if (!args.verbose)
 454                         continue;
 455                 fprintf(stderr,
 456                         "already have %s (%s)\n", sha1_to_hex(remote),
 457                         ref->name);
 458         }
 459         return retval;
 460 }
 461
 462 static int sideband_demux(int fd, void *data)
 463 {
 464         int *xd = data;
 465
 466         return recv_sideband("fetch-pack", xd[0], fd, 2);
 467 }
 468
 469 static int get_pack(int xd[2], char **pack_lockfile)
 470 {
 471         struct async demux;
 472         const char *argv[20];
 473         char keep_arg[256];
 474         char hdr_arg[256];
 475         const char **av;
 476         int do_keep = args.keep_pack;
 477         struct child_process cmd;
 478
 479         memset(&demux, 0, sizeof(demux));
 480         if (use_sideband) {
 481                 /* xd[] is talking with upload-pack; subprocess reads from
 482                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 483                  * through demux->out.
 484                  */
 485                 demux.proc = sideband_demux;
 486                 demux.data = xd;
 487                 if (start_async(&demux))
 488                         die("fetch-pack: unable to fork off sideband"
 489                             " demultiplexer");
 490         }
 491         else
 492                 demux.out = xd[0];
 493
 494         memset(&cmd, 0, sizeof(cmd));
 495         cmd.argv = argv;
 496         av = argv;
 497         *hdr_arg = 0;
 498         if (!args.keep_pack && unpack_limit) {
 499                 struct pack_header header;
 500
 501                 if (read_pack_header(demux.out, &header))
 502                         die("protocol error: bad pack header");
 503                 snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 504                          ntohl(header.hdr_version), ntohl(header.hdr_entries));
 505                 if (ntohl(header.hdr_entries) < unpack_limit)
 506                         do_keep = 0;
 507                 else
 508                         do_keep = 1;
 509         }
 510
 511         if (do_keep) {
 512                 if (pack_lockfile)
 513                         cmd.out = -1;
 514                 *av++ = "index-pack";
 515                 *av++ = "--stdin";
 516                 if (!args.quiet && !args.no_progress)
 517                         *av++ = "-v";
 518                 if (args.use_thin_pack)
 519                         *av++ = "--fix-thin";
 520                 if (args.lock_pack || unpack_limit) {
 521                         int s = sprintf(keep_arg,
 522                                         "--keep=fetch-pack %d on ", getpid());
 523                         if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 524                                 strcpy(keep_arg + s, "localhost");
 525                         *av++ = keep_arg;
 526                 }
 527         }
 528         else {
 529                 *av++ = "unpack-objects";
 530                 if (args.quiet)
 531                         *av++ = "-q";
 532         }
 533         if (*hdr_arg)
 534                 *av++ = hdr_arg;
 535         *av++ = NULL;
 536
 537         cmd.in = demux.out;
 538         cmd.git_cmd = 1;
 539         if (start_command(&cmd))
 540                 die("fetch-pack: unable to fork off %s", argv[0]);
 541         if (do_keep && pack_lockfile)
 542                 *pack_lockfile = index_pack_lockfile(cmd.out);
 543
 544         if (finish_command(&cmd))
 545                 die("%s failed", argv[0]);
 546         if (use_sideband && finish_async(&demux))
 547                 die("error in sideband demultiplexer");
 548         return 0;
 549 }
 550
 551 static struct ref *do_fetch_pack(int fd[2],
 552                 const struct ref *orig_ref,
 553                 int nr_match,
 554                 char **match,
 555                 char **pack_lockfile)
 556 {
 557         struct ref *ref = copy_ref_list(orig_ref);
 558         unsigned char sha1[20];
 559
 560         if (is_repository_shallow() && !server_supports("shallow"))
 561                 die("Server does not support shallow clients");
 562         if (server_supports("multi_ack")) {
 563                 if (args.verbose)
 564                         fprintf(stderr, "Server supports multi_ack\n");
 565                 multi_ack = 1;
 566         }
 567         if (server_supports("side-band-64k")) {
 568                 if (args.verbose)
 569                         fprintf(stderr, "Server supports side-band-64k\n");
 570                 use_sideband = 2;
 571         }
 572         else if (server_supports("side-band")) {
 573                 if (args.verbose)
 574                         fprintf(stderr, "Server supports side-band\n");
 575                 use_sideband = 1;
 576         }
 577         if (everything_local(&ref, nr_match, match)) {
 578                 packet_flush(fd[1]);
 579                 goto all_done;
 580         }
 581         if (find_common(fd, sha1, ref) < 0)
 582                 if (!args.keep_pack)
 583                         /* When cloning, it is not unusual to have
 584                          * no common commit.
 585                          */
 586                         fprintf(stderr, "warning: no common commits\n");
 587
 588         if (get_pack(fd, pack_lockfile))
 589                 die("git-fetch-pack: fetch failed.");
 590
 591  all_done:
 592         return ref;
 593 }
 594
 595 static int remove_duplicates(int nr_heads, char **heads)
 596 {
 597         int src, dst;
 598
 599         for (src = dst = 0; src < nr_heads; src++) {
 600                 /* If heads[src] is different from any of
 601                  * heads[0..dst], push it in.
 602                  */
 603                 int i;
 604                 for (i = 0; i < dst; i++) {
 605                         if (!strcmp(heads[i], heads[src]))
 606                                 break;
 607                 }
 608                 if (i < dst)
 609                         continue;
 610                 if (src != dst)
 611                         heads[dst] = heads[src];
 612                 dst++;
 613         }
 614         return dst;
 615 }
 616
 617 static int fetch_pack_config(const char *var, const char *value)
 618 {
 619         if (strcmp(var, "fetch.unpacklimit") == 0) {
 620                 fetch_unpack_limit = git_config_int(var, value);
 621                 return 0;
 622         }
 623
 624         if (strcmp(var, "transfer.unpacklimit") == 0) {
 625                 transfer_unpack_limit = git_config_int(var, value);
 626                 return 0;
 627         }
 628
 629         return git_default_config(var, value);
 630 }
 631
 632 static struct lock_file lock;
 633
 634 static void fetch_pack_setup(void)
 635 {
 636         static int did_setup;
 637         if (did_setup)
 638                 return;
 639         git_config(fetch_pack_config);
 640         if (0 <= transfer_unpack_limit)
 641                 unpack_limit = transfer_unpack_limit;
 642         else if (0 <= fetch_unpack_limit)
 643                 unpack_limit = fetch_unpack_limit;
 644         did_setup = 1;
 645 }
 646
 647 int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 648 {
 649         int i, ret, nr_heads;
 650         struct ref *ref = NULL;
 651         char *dest = NULL, **heads;
 652         int fd[2];
 653         struct child_process *conn;
 654
 655         nr_heads = 0;
 656         heads = NULL;
 657         for (i = 1; i < argc; i++) {
 658                 const char *arg = argv[i];
 659
 660                 if (*arg == '-') {
 661                         if (!prefixcmp(arg, "--upload-pack=")) {
 662                                 args.uploadpack = arg + 14;
 663                                 continue;
 664                         }
 665                         if (!prefixcmp(arg, "--exec=")) {
 666                                 args.uploadpack = arg + 7;
 667                                 continue;
 668                         }
 669                         if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
 670                                 args.quiet = 1;
 671                                 continue;
 672                         }
 673                         if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
 674                                 args.lock_pack = args.keep_pack;
 675                                 args.keep_pack = 1;
 676                                 continue;
 677                         }
 678                         if (!strcmp("--thin", arg)) {
 679                                 args.use_thin_pack = 1;
 680                                 continue;
 681                         }
 682                         if (!strcmp("--all", arg)) {
 683                                 args.fetch_all = 1;
 684                                 continue;
 685                         }
 686                         if (!strcmp("-v", arg)) {
 687                                 args.verbose = 1;
 688                                 continue;
 689                         }
 690                         if (!prefixcmp(arg, "--depth=")) {
 691                                 args.depth = strtol(arg + 8, NULL, 0);
 692                                 continue;
 693                         }
 694                         if (!strcmp("--no-progress", arg)) {
 695                                 args.no_progress = 1;
 696                                 continue;
 697                         }
 698                         usage(fetch_pack_usage);
 699                 }
 700                 dest = (char *)arg;
 701                 heads = (char **)(argv + i + 1);
 702                 nr_heads = argc - i - 1;
 703                 break;
 704         }
 705         if (!dest)
 706                 usage(fetch_pack_usage);
 707
 708         conn = git_connect(fd, (char *)dest, args.uploadpack,
 709                            args.verbose ? CONNECT_VERBOSE : 0);
 710         if (conn) {
 711                 get_remote_heads(fd[0], &ref, 0, NULL, 0);
 712
 713                 ref = fetch_pack(&args, fd, conn, ref, dest, nr_heads, heads, NULL);
 714                 close(fd[0]);
 715                 close(fd[1]);
 716                 if (finish_connect(conn))
 717                         ref = NULL;
 718         } else {
 719                 ref = NULL;
 720         }
 721         ret = !ref;
 722
 723         if (!ret && nr_heads) {
 724                 /* If the heads to pull were given, we should have
 725                  * consumed all of them by matching the remote.
 726                  * Otherwise, 'git-fetch remote no-such-ref' would
 727                  * silently succeed without issuing an error.
 728                  */
 729                 for (i = 0; i < nr_heads; i++)
 730                         if (heads[i] && heads[i][0]) {
 731                                 error("no such remote ref %s", heads[i]);
 732                                 ret = 1;
 733                         }
 734         }
 735         while (ref) {
 736                 printf("%s %s\n",
 737                        sha1_to_hex(ref->old_sha1), ref->name);
 738                 ref = ref->next;
 739         }
 740
 741         return ret;
 742 }
 743
 744 struct ref *fetch_pack(struct fetch_pack_args *my_args,
 745                        int fd[], struct child_process *conn,
 746                        const struct ref *ref,
 747                 const char *dest,
 748                 int nr_heads,
 749                 char **heads,
 750                 char **pack_lockfile)
 751 {
 752         struct stat st;
 753         struct ref *ref_cpy;
 754
 755         fetch_pack_setup();
 756         memcpy(&args, my_args, sizeof(args));
 757         if (args.depth > 0) {
 758                 if (stat(git_path("shallow"), &st))
 759                         st.st_mtime = 0;
 760         }
 761
 762         if (heads && nr_heads)
 763                 nr_heads = remove_duplicates(nr_heads, heads);
 764         if (!ref) {
 765                 packet_flush(fd[1]);
 766                 die("no matching remote head");
 767         }
 768         ref_cpy = do_fetch_pack(fd, ref, nr_heads, heads, pack_lockfile);
 769
 770         if (args.depth > 0) {
 771                 struct cache_time mtime;
 772                 char *shallow = git_path("shallow");
 773                 int fd;
 774
 775                 mtime.sec = st.st_mtime;
 776 #ifdef USE_NSEC
 777                 mtime.usec = st.st_mtim.usec;
 778 #endif
 779                 if (stat(shallow, &st)) {
 780                         if (mtime.sec)
 781                                 die("shallow file was removed during fetch");
 782                 } else if (st.st_mtime != mtime.sec
 783 #ifdef USE_NSEC
 784                                 || st.st_mtim.usec != mtime.usec
 785 #endif
 786                           )
 787                         die("shallow file was changed during fetch");
 788
 789                 fd = hold_lock_file_for_update(&lock, shallow, 1);
 790                 if (!write_shallow_commits(fd, 0)) {
 791                         unlink(shallow);
 792                         rollback_lock_file(&lock);
 793                 } else {
 794                         commit_lock_file(&lock);
 795                 }
 796         }
 797
 798         return ref_cpy;
 799 }