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 "run-command.h"
  11
  12 static int transfer_unpack_limit = -1;
  13 static int fetch_unpack_limit = -1;
  14 static int unpack_limit = 100;
  15 static struct fetch_pack_args args;
  16
  17 static const char fetch_pack_usage[] =
  18 "git-fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
  19 static const char *uploadpack = "git-upload-pack";
  20
  21 #define COMPLETE        (1U << 0)
  22 #define COMMON          (1U << 1)
  23 #define COMMON_REF      (1U << 2)
  24 #define SEEN            (1U << 3)
  25 #define POPPED          (1U << 4)
  26
  27 /*
  28  * After sending this many "have"s if we do not get any new ACK , we
  29  * give up traversing our history.
  30  */
  31 #define MAX_IN_VAIN 256
  32
  33 static struct commit_list *rev_list;
  34 static int non_common_revs, multi_ack, use_thin_pack, use_sideband;
  35
  36 static void rev_list_push(struct commit *commit, int mark)
  37 {
  38         if (!(commit->object.flags & mark)) {
  39                 commit->object.flags |= mark;
  40
  41                 if (!(commit->object.parsed))
  42                         parse_commit(commit);
  43
  44                 insert_by_date(commit, &rev_list);
  45
  46                 if (!(commit->object.flags & COMMON))
  47                         non_common_revs++;
  48         }
  49 }
  50
  51 static int rev_list_insert_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  52 {
  53         struct object *o = deref_tag(parse_object(sha1), path, 0);
  54
  55         if (o && o->type == OBJ_COMMIT)
  56                 rev_list_push((struct commit *)o, SEEN);
  57
  58         return 0;
  59 }
  60
  61 /*
  62    This function marks a rev and its ancestors as common.
  63    In some cases, it is desirable to mark only the ancestors (for example
  64    when only the server does not yet know that they are common).
  65 */
  66
  67 static void mark_common(struct commit *commit,
  68                 int ancestors_only, int dont_parse)
  69 {
  70         if (commit != NULL && !(commit->object.flags & COMMON)) {
  71                 struct object *o = (struct object *)commit;
  72
  73                 if (!ancestors_only)
  74                         o->flags |= COMMON;
  75
  76                 if (!(o->flags & SEEN))
  77                         rev_list_push(commit, SEEN);
  78                 else {
  79                         struct commit_list *parents;
  80
  81                         if (!ancestors_only && !(o->flags & POPPED))
  82                                 non_common_revs--;
  83                         if (!o->parsed && !dont_parse)
  84                                 parse_commit(commit);
  85
  86                         for (parents = commit->parents;
  87                                         parents;
  88                                         parents = parents->next)
  89                                 mark_common(parents->item, 0, dont_parse);
  90                 }
  91         }
  92 }
  93
  94 /*
  95   Get the next rev to send, ignoring the common.
  96 */
  97
  98 static const unsigned char* get_rev(void)
  99 {
 100         struct commit *commit = NULL;
 101
 102         while (commit == NULL) {
 103                 unsigned int mark;
 104                 struct commit_list* parents;
 105
 106                 if (rev_list == NULL || non_common_revs == 0)
 107                         return NULL;
 108
 109                 commit = rev_list->item;
 110                 if (!(commit->object.parsed))
 111                         parse_commit(commit);
 112                 commit->object.flags |= POPPED;
 113                 if (!(commit->object.flags & COMMON))
 114                         non_common_revs--;
 115
 116                 parents = commit->parents;
 117
 118                 if (commit->object.flags & COMMON) {
 119                         /* do not send "have", and ignore ancestors */
 120                         commit = NULL;
 121                         mark = COMMON | SEEN;
 122                 } else if (commit->object.flags & COMMON_REF)
 123                         /* send "have", and ignore ancestors */
 124                         mark = COMMON | SEEN;
 125                 else
 126                         /* send "have", also for its ancestors */
 127                         mark = SEEN;
 128
 129                 while (parents) {
 130                         if (!(parents->item->object.flags & SEEN))
 131                                 rev_list_push(parents->item, mark);
 132                         if (mark & COMMON)
 133                                 mark_common(parents->item, 1, 0);
 134                         parents = parents->next;
 135                 }
 136
 137                 rev_list = rev_list->next;
 138         }
 139
 140         return commit->object.sha1;
 141 }
 142
 143 static int find_common(int fd[2], unsigned char *result_sha1,
 144                        struct ref *refs)
 145 {
 146         int fetching;
 147         int count = 0, flushes = 0, retval;
 148         const unsigned char *sha1;
 149         unsigned in_vain = 0;
 150         int got_continue = 0;
 151
 152         for_each_ref(rev_list_insert_ref, NULL);
 153
 154         fetching = 0;
 155         for ( ; refs ; refs = refs->next) {
 156                 unsigned char *remote = refs->old_sha1;
 157                 struct object *o;
 158
 159                 /*
 160                  * If that object is complete (i.e. it is an ancestor of a
 161                  * local ref), we tell them we have it but do not have to
 162                  * tell them about its ancestors, which they already know
 163                  * about.
 164                  *
 165                  * We use lookup_object here because we are only
 166                  * interested in the case we *know* the object is
 167                  * reachable and we have already scanned it.
 168                  */
 169                 if (((o = lookup_object(remote)) != NULL) &&
 170                                 (o->flags & COMPLETE)) {
 171                         continue;
 172                 }
 173
 174                 if (!fetching)
 175                         packet_write(fd[1], "want %s%s%s%s%s%s%s\n",
 176                                      sha1_to_hex(remote),
 177                                      (multi_ack ? " multi_ack" : ""),
 178                                      (use_sideband == 2 ? " side-band-64k" : ""),
 179                                      (use_sideband == 1 ? " side-band" : ""),
 180                                      (use_thin_pack ? " thin-pack" : ""),
 181                                      (args.no_progress ? " no-progress" : ""),
 182                                      " ofs-delta");
 183                 else
 184                         packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
 185                 fetching++;
 186         }
 187         if (is_repository_shallow())
 188                 write_shallow_commits(fd[1], 1);
 189         if (args.depth > 0)
 190                 packet_write(fd[1], "deepen %d", args.depth);
 191         packet_flush(fd[1]);
 192         if (!fetching)
 193                 return 1;
 194
 195         if (args.depth > 0) {
 196                 char line[1024];
 197                 unsigned char sha1[20];
 198                 int len;
 199
 200                 while ((len = packet_read_line(fd[0], line, sizeof(line)))) {
 201                         if (!prefixcmp(line, "shallow ")) {
 202                                 if (get_sha1_hex(line + 8, sha1))
 203                                         die("invalid shallow line: %s", line);
 204                                 register_shallow(sha1);
 205                                 continue;
 206                         }
 207                         if (!prefixcmp(line, "unshallow ")) {
 208                                 if (get_sha1_hex(line + 10, sha1))
 209                                         die("invalid unshallow line: %s", line);
 210                                 if (!lookup_object(sha1))
 211                                         die("object not found: %s", line);
 212                                 /* make sure that it is parsed as shallow */
 213                                 parse_object(sha1);
 214                                 if (unregister_shallow(sha1))
 215                                         die("no shallow found: %s", line);
 216                                 continue;
 217                         }
 218                         die("expected shallow/unshallow, got %s", line);
 219                 }
 220         }
 221
 222         flushes = 0;
 223         retval = -1;
 224         while ((sha1 = get_rev())) {
 225                 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
 226                 if (args.verbose)
 227                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 228                 in_vain++;
 229                 if (!(31 & ++count)) {
 230                         int ack;
 231
 232                         packet_flush(fd[1]);
 233                         flushes++;
 234
 235                         /*
 236                          * We keep one window "ahead" of the other side, and
 237                          * will wait for an ACK only on the next one
 238                          */
 239                         if (count == 32)
 240                                 continue;
 241
 242                         do {
 243                                 ack = get_ack(fd[0], result_sha1);
 244                                 if (args.verbose && ack)
 245                                         fprintf(stderr, "got ack %d %s\n", ack,
 246                                                         sha1_to_hex(result_sha1));
 247                                 if (ack == 1) {
 248                                         flushes = 0;
 249                                         multi_ack = 0;
 250                                         retval = 0;
 251                                         goto done;
 252                                 } else if (ack == 2) {
 253                                         struct commit *commit =
 254                                                 lookup_commit(result_sha1);
 255                                         mark_common(commit, 0, 1);
 256                                         retval = 0;
 257                                         in_vain = 0;
 258                                         got_continue = 1;
 259                                 }
 260                         } while (ack);
 261                         flushes--;
 262                         if (got_continue && MAX_IN_VAIN < in_vain) {
 263                                 if (args.verbose)
 264                                         fprintf(stderr, "giving up\n");
 265                                 break; /* give up */
 266                         }
 267                 }
 268         }
 269 done:
 270         packet_write(fd[1], "done\n");
 271         if (args.verbose)
 272                 fprintf(stderr, "done\n");
 273         if (retval != 0) {
 274                 multi_ack = 0;
 275                 flushes++;
 276         }
 277         while (flushes || multi_ack) {
 278                 int ack = get_ack(fd[0], result_sha1);
 279                 if (ack) {
 280                         if (args.verbose)
 281                                 fprintf(stderr, "got ack (%d) %s\n", ack,
 282                                         sha1_to_hex(result_sha1));
 283                         if (ack == 1)
 284                                 return 0;
 285                         multi_ack = 1;
 286                         continue;
 287                 }
 288                 flushes--;
 289         }
 290         return retval;
 291 }
 292
 293 static struct commit_list *complete;
 294
 295 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 296 {
 297         struct object *o = parse_object(sha1);
 298
 299         while (o && o->type == OBJ_TAG) {
 300                 struct tag *t = (struct tag *) o;
 301                 if (!t->tagged)
 302                         break; /* broken repository */
 303                 o->flags |= COMPLETE;
 304                 o = parse_object(t->tagged->sha1);
 305         }
 306         if (o && o->type == OBJ_COMMIT) {
 307                 struct commit *commit = (struct commit *)o;
 308                 commit->object.flags |= COMPLETE;
 309                 insert_by_date(commit, &complete);
 310         }
 311         return 0;
 312 }
 313
 314 static void mark_recent_complete_commits(unsigned long cutoff)
 315 {
 316         while (complete && cutoff <= complete->item->date) {
 317                 if (args.verbose)
 318                         fprintf(stderr, "Marking %s as complete\n",
 319                                 sha1_to_hex(complete->item->object.sha1));
 320                 pop_most_recent_commit(&complete, COMPLETE);
 321         }
 322 }
 323
 324 static void filter_refs(struct ref **refs, int nr_match, char **match)
 325 {
 326         struct ref **return_refs;
 327         struct ref *newlist = NULL;
 328         struct ref **newtail = &newlist;
 329         struct ref *ref, *next;
 330         struct ref *fastarray[32];
 331
 332         if (nr_match && !args.fetch_all) {
 333                 if (ARRAY_SIZE(fastarray) < nr_match)
 334                         return_refs = xcalloc(nr_match, sizeof(struct ref *));
 335                 else {
 336                         return_refs = fastarray;
 337                         memset(return_refs, 0, sizeof(struct ref *) * nr_match);
 338                 }
 339         }
 340         else
 341                 return_refs = NULL;
 342
 343         for (ref = *refs; ref; ref = next) {
 344                 next = ref->next;
 345                 if (!memcmp(ref->name, "refs/", 5) &&
 346                     check_ref_format(ref->name + 5))
 347                         ; /* trash */
 348                 else if (args.fetch_all &&
 349                          (!args.depth || prefixcmp(ref->name, "refs/tags/") )) {
 350                         *newtail = ref;
 351                         ref->next = NULL;
 352                         newtail = &ref->next;
 353                         continue;
 354                 }
 355                 else {
 356                         int order = path_match(ref->name, nr_match, match);
 357                         if (order) {
 358                                 return_refs[order-1] = ref;
 359                                 continue; /* we will link it later */
 360                         }
 361                 }
 362                 free(ref);
 363         }
 364
 365         if (!args.fetch_all) {
 366                 int i;
 367                 for (i = 0; i < nr_match; i++) {
 368                         ref = return_refs[i];
 369                         if (ref) {
 370                                 *newtail = ref;
 371                                 ref->next = NULL;
 372                                 newtail = &ref->next;
 373                         }
 374                 }
 375                 if (return_refs != fastarray)
 376                         free(return_refs);
 377         }
 378         *refs = newlist;
 379 }
 380
 381 static int everything_local(struct ref **refs, int nr_match, char **match)
 382 {
 383         struct ref *ref;
 384         int retval;
 385         unsigned long cutoff = 0;
 386
 387         track_object_refs = 0;
 388         save_commit_buffer = 0;
 389
 390         for (ref = *refs; ref; ref = ref->next) {
 391                 struct object *o;
 392
 393                 o = parse_object(ref->old_sha1);
 394                 if (!o)
 395                         continue;
 396
 397                 /* We already have it -- which may mean that we were
 398                  * in sync with the other side at some time after
 399                  * that (it is OK if we guess wrong here).
 400                  */
 401                 if (o->type == OBJ_COMMIT) {
 402                         struct commit *commit = (struct commit *)o;
 403                         if (!cutoff || cutoff < commit->date)
 404                                 cutoff = commit->date;
 405                 }
 406         }
 407
 408         if (!args.depth) {
 409                 for_each_ref(mark_complete, NULL);
 410                 if (cutoff)
 411                         mark_recent_complete_commits(cutoff);
 412         }
 413
 414         /*
 415          * Mark all complete remote refs as common refs.
 416          * Don't mark them common yet; the server has to be told so first.
 417          */
 418         for (ref = *refs; ref; ref = ref->next) {
 419                 struct object *o = deref_tag(lookup_object(ref->old_sha1),
 420                                              NULL, 0);
 421
 422                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 423                         continue;
 424
 425                 if (!(o->flags & SEEN)) {
 426                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 427
 428                         mark_common((struct commit *)o, 1, 1);
 429                 }
 430         }
 431
 432         filter_refs(refs, nr_match, match);
 433
 434         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 435                 const unsigned char *remote = ref->old_sha1;
 436                 unsigned char local[20];
 437                 struct object *o;
 438
 439                 o = lookup_object(remote);
 440                 if (!o || !(o->flags & COMPLETE)) {
 441                         retval = 0;
 442                         if (!args.verbose)
 443                                 continue;
 444                         fprintf(stderr,
 445                                 "want %s (%s)\n", sha1_to_hex(remote),
 446                                 ref->name);
 447                         continue;
 448                 }
 449
 450                 hashcpy(ref->new_sha1, local);
 451                 if (!args.verbose)
 452                         continue;
 453                 fprintf(stderr,
 454                         "already have %s (%s)\n", sha1_to_hex(remote),
 455                         ref->name);
 456         }
 457         return retval;
 458 }
 459
 460 static pid_t setup_sideband(int fd[2], int xd[2])
 461 {
 462         pid_t side_pid;
 463
 464         if (!use_sideband) {
 465                 fd[0] = xd[0];
 466                 fd[1] = xd[1];
 467                 return 0;
 468         }
 469         /* xd[] is talking with upload-pack; subprocess reads from
 470          * xd[0], spits out band#2 to stderr, and feeds us band#1
 471          * through our fd[0].
 472          */
 473         if (pipe(fd) < 0)
 474                 die("fetch-pack: unable to set up pipe");
 475         side_pid = fork();
 476         if (side_pid < 0)
 477                 die("fetch-pack: unable to fork off sideband demultiplexer");
 478         if (!side_pid) {
 479                 /* subprocess */
 480                 close(fd[0]);
 481                 if (xd[0] != xd[1])
 482                         close(xd[1]);
 483                 if (recv_sideband("fetch-pack", xd[0], fd[1], 2))
 484                         exit(1);
 485                 exit(0);
 486         }
 487         close(xd[0]);
 488         close(fd[1]);
 489         fd[1] = xd[1];
 490         return side_pid;
 491 }
 492
 493 static int get_pack(int xd[2], char **pack_lockfile)
 494 {
 495         pid_t side_pid;
 496         int fd[2];
 497         const char *argv[20];
 498         char keep_arg[256];
 499         char hdr_arg[256];
 500         const char **av;
 501         int do_keep = args.keep_pack;
 502         struct child_process cmd;
 503
 504         side_pid = setup_sideband(fd, xd);
 505
 506         memset(&cmd, 0, sizeof(cmd));
 507         cmd.argv = argv;
 508         av = argv;
 509         *hdr_arg = 0;
 510         if (!args.keep_pack && unpack_limit) {
 511                 struct pack_header header;
 512
 513                 if (read_pack_header(fd[0], &header))
 514                         die("protocol error: bad pack header");
 515                 snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 516                          ntohl(header.hdr_version), ntohl(header.hdr_entries));
 517                 if (ntohl(header.hdr_entries) < unpack_limit)
 518                         do_keep = 0;
 519                 else
 520                         do_keep = 1;
 521         }
 522
 523         if (do_keep) {
 524                 if (pack_lockfile)
 525                         cmd.out = -1;
 526                 *av++ = "index-pack";
 527                 *av++ = "--stdin";
 528                 if (!args.quiet && !args.no_progress)
 529                         *av++ = "-v";
 530                 if (args.use_thin_pack)
 531                         *av++ = "--fix-thin";
 532                 if (args.lock_pack || unpack_limit) {
 533                         int s = sprintf(keep_arg,
 534                                         "--keep=fetch-pack %d on ", getpid());
 535                         if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 536                                 strcpy(keep_arg + s, "localhost");
 537                         *av++ = keep_arg;
 538                 }
 539         }
 540         else {
 541                 *av++ = "unpack-objects";
 542                 if (args.quiet)
 543                         *av++ = "-q";
 544         }
 545         if (*hdr_arg)
 546                 *av++ = hdr_arg;
 547         *av++ = NULL;
 548
 549         cmd.in = fd[0];
 550         cmd.git_cmd = 1;
 551         if (start_command(&cmd))
 552                 die("fetch-pack: unable to fork off %s", argv[0]);
 553         close(fd[1]);
 554         if (do_keep && pack_lockfile)
 555                 *pack_lockfile = index_pack_lockfile(cmd.out);
 556
 557         if (finish_command(&cmd))
 558                 die("%s failed", argv[0]);
 559         return 0;
 560 }
 561
 562 static struct ref *do_fetch_pack(int fd[2],
 563                 int nr_match,
 564                 char **match,
 565                 char **pack_lockfile)
 566 {
 567         struct ref *ref;
 568         unsigned char sha1[20];
 569
 570         get_remote_heads(fd[0], &ref, 0, NULL, 0);
 571         if (is_repository_shallow() && !server_supports("shallow"))
 572                 die("Server does not support shallow clients");
 573         if (server_supports("multi_ack")) {
 574                 if (args.verbose)
 575                         fprintf(stderr, "Server supports multi_ack\n");
 576                 multi_ack = 1;
 577         }
 578         if (server_supports("side-band-64k")) {
 579                 if (args.verbose)
 580                         fprintf(stderr, "Server supports side-band-64k\n");
 581                 use_sideband = 2;
 582         }
 583         else if (server_supports("side-band")) {
 584                 if (args.verbose)
 585                         fprintf(stderr, "Server supports side-band\n");
 586                 use_sideband = 1;
 587         }
 588         if (!ref) {
 589                 packet_flush(fd[1]);
 590                 die("no matching remote head");
 591         }
 592         if (everything_local(&ref, nr_match, match)) {
 593                 packet_flush(fd[1]);
 594                 goto all_done;
 595         }
 596         if (find_common(fd, sha1, ref) < 0)
 597                 if (!args.keep_pack)
 598                         /* When cloning, it is not unusual to have
 599                          * no common commit.
 600                          */
 601                         fprintf(stderr, "warning: no common commits\n");
 602
 603         if (get_pack(fd, pack_lockfile))
 604                 die("git-fetch-pack: fetch failed.");
 605
 606  all_done:
 607         return ref;
 608 }
 609
 610 static int remove_duplicates(int nr_heads, char **heads)
 611 {
 612         int src, dst;
 613
 614         for (src = dst = 0; src < nr_heads; src++) {
 615                 /* If heads[src] is different from any of
 616                  * heads[0..dst], push it in.
 617                  */
 618                 int i;
 619                 for (i = 0; i < dst; i++) {
 620                         if (!strcmp(heads[i], heads[src]))
 621                                 break;
 622                 }
 623                 if (i < dst)
 624                         continue;
 625                 if (src != dst)
 626                         heads[dst] = heads[src];
 627                 dst++;
 628         }
 629         return dst;
 630 }
 631
 632 static int fetch_pack_config(const char *var, const char *value)
 633 {
 634         if (strcmp(var, "fetch.unpacklimit") == 0) {
 635                 fetch_unpack_limit = git_config_int(var, value);
 636                 return 0;
 637         }
 638
 639         if (strcmp(var, "transfer.unpacklimit") == 0) {
 640                 transfer_unpack_limit = git_config_int(var, value);
 641                 return 0;
 642         }
 643
 644         return git_default_config(var, value);
 645 }
 646
 647 static struct lock_file lock;
 648
 649 static void fetch_pack_setup(void)
 650 {
 651         static int did_setup;
 652         if (did_setup)
 653                 return;
 654         git_config(fetch_pack_config);
 655         if (0 <= transfer_unpack_limit)
 656                 unpack_limit = transfer_unpack_limit;
 657         else if (0 <= fetch_unpack_limit)
 658                 unpack_limit = fetch_unpack_limit;
 659         did_setup = 1;
 660 }
 661
 662 int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 663 {
 664         int i, ret, nr_heads;
 665         struct ref *ref;
 666         char *dest = NULL, **heads;
 667
 668         nr_heads = 0;
 669         heads = NULL;
 670         for (i = 1; i < argc; i++) {
 671                 const char *arg = argv[i];
 672
 673                 if (*arg == '-') {
 674                         if (!prefixcmp(arg, "--upload-pack=")) {
 675                                 args.uploadpack = arg + 14;
 676                                 continue;
 677                         }
 678                         if (!prefixcmp(arg, "--exec=")) {
 679                                 args.uploadpack = arg + 7;
 680                                 continue;
 681                         }
 682                         if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
 683                                 args.quiet = 1;
 684                                 continue;
 685                         }
 686                         if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
 687                                 args.lock_pack = args.keep_pack;
 688                                 args.keep_pack = 1;
 689                                 continue;
 690                         }
 691                         if (!strcmp("--thin", arg)) {
 692                                 args.use_thin_pack = 1;
 693                                 continue;
 694                         }
 695                         if (!strcmp("--all", arg)) {
 696                                 args.fetch_all = 1;
 697                                 continue;
 698                         }
 699                         if (!strcmp("-v", arg)) {
 700                                 args.verbose = 1;
 701                                 continue;
 702                         }
 703                         if (!prefixcmp(arg, "--depth=")) {
 704                                 args.depth = strtol(arg + 8, NULL, 0);
 705                                 continue;
 706                         }
 707                         if (!strcmp("--no-progress", arg)) {
 708                                 args.no_progress = 1;
 709                                 continue;
 710                         }
 711                         usage(fetch_pack_usage);
 712                 }
 713                 dest = (char *)arg;
 714                 heads = (char **)(argv + i + 1);
 715                 nr_heads = argc - i - 1;
 716                 break;
 717         }
 718         if (!dest)
 719                 usage(fetch_pack_usage);
 720
 721         ref = fetch_pack(&args, dest, nr_heads, heads, NULL);
 722         ret = !ref;
 723
 724         while (ref) {
 725                 printf("%s %s\n",
 726                        sha1_to_hex(ref->old_sha1), ref->name);
 727                 ref = ref->next;
 728         }
 729
 730         return ret;
 731 }
 732
 733 struct ref *fetch_pack(struct fetch_pack_args *my_args,
 734                 const char *dest,
 735                 int nr_heads,
 736                 char **heads,
 737                 char **pack_lockfile)
 738 {
 739         int i, ret;
 740         int fd[2];
 741         struct child_process *conn;
 742         struct ref *ref;
 743         struct stat st;
 744
 745         fetch_pack_setup();
 746         memcpy(&args, my_args, sizeof(args));
 747         if (args.depth > 0) {
 748                 if (stat(git_path("shallow"), &st))
 749                         st.st_mtime = 0;
 750         }
 751
 752         conn = git_connect(fd, (char *)dest, uploadpack,
 753                           args.verbose ? CONNECT_VERBOSE : 0);
 754         if (heads && nr_heads)
 755                 nr_heads = remove_duplicates(nr_heads, heads);
 756         ref = do_fetch_pack(fd, nr_heads, heads, pack_lockfile);
 757         close(fd[0]);
 758         close(fd[1]);
 759         ret = finish_connect(conn);
 760
 761         if (!ret && nr_heads) {
 762                 /* If the heads to pull were given, we should have
 763                  * consumed all of them by matching the remote.
 764                  * Otherwise, 'git-fetch remote no-such-ref' would
 765                  * silently succeed without issuing an error.
 766                  */
 767                 for (i = 0; i < nr_heads; i++)
 768                         if (heads[i] && heads[i][0]) {
 769                                 error("no such remote ref %s", heads[i]);
 770                                 ret = 1;
 771                         }
 772         }
 773
 774         if (!ret && args.depth > 0) {
 775                 struct cache_time mtime;
 776                 char *shallow = git_path("shallow");
 777                 int fd;
 778
 779                 mtime.sec = st.st_mtime;
 780 #ifdef USE_NSEC
 781                 mtime.usec = st.st_mtim.usec;
 782 #endif
 783                 if (stat(shallow, &st)) {
 784                         if (mtime.sec)
 785                                 die("shallow file was removed during fetch");
 786                 } else if (st.st_mtime != mtime.sec
 787 #ifdef USE_NSEC
 788                                 || st.st_mtim.usec != mtime.usec
 789 #endif
 790                           )
 791                         die("shallow file was changed during fetch");
 792
 793                 fd = hold_lock_file_for_update(&lock, shallow, 1);
 794                 if (!write_shallow_commits(fd, 0)) {
 795                         unlink(shallow);
 796                         rollback_lock_file(&lock);
 797                 } else {
 798                         close(fd);
 799                         commit_lock_file(&lock);
 800                 }
 801         }
 802
 803         if (ret)
 804                 ref = NULL;
 805
 806         return ref;
 807 }