git.oblomov.eu Git - git/blob - 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 int prefer_ofs_delta = 1;
  17 static int no_done = 0;
  18 static struct fetch_pack_args args = {
  19         /* .uploadpack = */ "git-upload-pack",
  20 };
  21
  22 static const char fetch_pack_usage[] =
  23 "git fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--include-tag] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
  24
  25 #define COMPLETE        (1U << 0)
  26 #define COMMON          (1U << 1)
  27 #define COMMON_REF      (1U << 2)
  28 #define SEEN            (1U << 3)
  29 #define POPPED          (1U << 4)
  30
  31 static int marked;
  32
  33 /*
  34  * After sending this many "have"s if we do not get any new ACK , we
  35  * give up traversing our history.
  36  */
  37 #define MAX_IN_VAIN 256
  38
  39 static struct commit_list *rev_list;
  40 static int non_common_revs, multi_ack, use_sideband;
  41
  42 static void rev_list_push(struct commit *commit, int mark)
  43 {
  44         if (!(commit->object.flags & mark)) {
  45                 commit->object.flags |= mark;
  46
  47                 if (!(commit->object.parsed))
  48                         if (parse_commit(commit))
  49                                 return;
  50
  51                 commit_list_insert_by_date(commit, &rev_list);
  52
  53                 if (!(commit->object.flags & COMMON))
  54                         non_common_revs++;
  55         }
  56 }
  57
  58 static int rev_list_insert_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  59 {
  60         struct object *o = deref_tag(parse_object(sha1), path, 0);
  61
  62         if (o && o->type == OBJ_COMMIT)
  63                 rev_list_push((struct commit *)o, SEEN);
  64
  65         return 0;
  66 }
  67
  68 static int clear_marks(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  69 {
  70         struct object *o = deref_tag(parse_object(sha1), path, 0);
  71
  72         if (o && o->type == OBJ_COMMIT)
  73                 clear_commit_marks((struct commit *)o,
  74                                    COMMON | COMMON_REF | SEEN | POPPED);
  75         return 0;
  76 }
  77
  78 /*
  79    This function marks a rev and its ancestors as common.
  80    In some cases, it is desirable to mark only the ancestors (for example
  81    when only the server does not yet know that they are common).
  82 */
  83
  84 static void mark_common(struct commit *commit,
  85                 int ancestors_only, int dont_parse)
  86 {
  87         if (commit != NULL && !(commit->object.flags & COMMON)) {
  88                 struct object *o = (struct object *)commit;
  89
  90                 if (!ancestors_only)
  91                         o->flags |= COMMON;
  92
  93                 if (!(o->flags & SEEN))
  94                         rev_list_push(commit, SEEN);
  95                 else {
  96                         struct commit_list *parents;
  97
  98                         if (!ancestors_only && !(o->flags & POPPED))
  99                                 non_common_revs--;
 100                         if (!o->parsed && !dont_parse)
 101                                 if (parse_commit(commit))
 102                                         return;
 103
 104                         for (parents = commit->parents;
 105                                         parents;
 106                                         parents = parents->next)
 107                                 mark_common(parents->item, 0, dont_parse);
 108                 }
 109         }
 110 }
 111
 112 /*
 113   Get the next rev to send, ignoring the common.
 114 */
 115
 116 static const unsigned char *get_rev(void)
 117 {
 118         struct commit *commit = NULL;
 119
 120         while (commit == NULL) {
 121                 unsigned int mark;
 122                 struct commit_list *parents;
 123
 124                 if (rev_list == NULL || non_common_revs == 0)
 125                         return NULL;
 126
 127                 commit = rev_list->item;
 128                 if (!commit->object.parsed)
 129                         parse_commit(commit);
 130                 parents = commit->parents;
 131
 132                 commit->object.flags |= POPPED;
 133                 if (!(commit->object.flags & COMMON))
 134                         non_common_revs--;
 135
 136                 if (commit->object.flags & COMMON) {
 137                         /* do not send "have", and ignore ancestors */
 138                         commit = NULL;
 139                         mark = COMMON | SEEN;
 140                 } else if (commit->object.flags & COMMON_REF)
 141                         /* send "have", and ignore ancestors */
 142                         mark = COMMON | SEEN;
 143                 else
 144                         /* send "have", also for its ancestors */
 145                         mark = SEEN;
 146
 147                 while (parents) {
 148                         if (!(parents->item->object.flags & SEEN))
 149                                 rev_list_push(parents->item, mark);
 150                         if (mark & COMMON)
 151                                 mark_common(parents->item, 1, 0);
 152                         parents = parents->next;
 153                 }
 154
 155                 rev_list = rev_list->next;
 156         }
 157
 158         return commit->object.sha1;
 159 }
 160
 161 enum ack_type {
 162         NAK = 0,
 163         ACK,
 164         ACK_continue,
 165         ACK_common,
 166         ACK_ready
 167 };
 168
 169 static void consume_shallow_list(int fd)
 170 {
 171         if (args.stateless_rpc && args.depth > 0) {
 172                 /* If we sent a depth we will get back "duplicate"
 173                  * shallow and unshallow commands every time there
 174                  * is a block of have lines exchanged.
 175                  */
 176                 char line[1000];
 177                 while (packet_read_line(fd, line, sizeof(line))) {
 178                         if (!prefixcmp(line, "shallow "))
 179                                 continue;
 180                         if (!prefixcmp(line, "unshallow "))
 181                                 continue;
 182                         die("git fetch-pack: expected shallow list");
 183                 }
 184         }
 185 }
 186
 187 static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 188 {
 189         static char line[1000];
 190         int len = packet_read_line(fd, line, sizeof(line));
 191
 192         if (!len)
 193                 die("git fetch-pack: expected ACK/NAK, got EOF");
 194         if (line[len-1] == '\n')
 195                 line[--len] = 0;
 196         if (!strcmp(line, "NAK"))
 197                 return NAK;
 198         if (!prefixcmp(line, "ACK ")) {
 199                 if (!get_sha1_hex(line+4, result_sha1)) {
 200                         if (strstr(line+45, "continue"))
 201                                 return ACK_continue;
 202                         if (strstr(line+45, "common"))
 203                                 return ACK_common;
 204                         if (strstr(line+45, "ready"))
 205                                 return ACK_ready;
 206                         return ACK;
 207                 }
 208         }
 209         die("git fetch_pack: expected ACK/NAK, got '%s'", line);
 210 }
 211
 212 static void send_request(int fd, struct strbuf *buf)
 213 {
 214         if (args.stateless_rpc) {
 215                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 216                 packet_flush(fd);
 217         } else
 218                 safe_write(fd, buf->buf, buf->len);
 219 }
 220
 221 #define INITIAL_FLUSH 16
 222 #define PIPESAFE_FLUSH 32
 223 #define LARGE_FLUSH 1024
 224
 225 static int next_flush(int count)
 226 {
 227         int flush_limit = args.stateless_rpc ? LARGE_FLUSH : PIPESAFE_FLUSH;
 228
 229         if (count < flush_limit)
 230                 count <<= 1;
 231         else
 232                 count += flush_limit;
 233         return count;
 234 }
 235
 236 static int find_common(int fd[2], unsigned char *result_sha1,
 237                        struct ref *refs)
 238 {
 239         int fetching;
 240         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 241         const unsigned char *sha1;
 242         unsigned in_vain = 0;
 243         int got_continue = 0;
 244         int got_ready = 0;
 245         struct strbuf req_buf = STRBUF_INIT;
 246         size_t state_len = 0;
 247
 248         if (args.stateless_rpc && multi_ack == 1)
 249                 die("--stateless-rpc requires multi_ack_detailed");
 250         if (marked)
 251                 for_each_ref(clear_marks, NULL);
 252         marked = 1;
 253
 254         for_each_ref(rev_list_insert_ref, NULL);
 255
 256         fetching = 0;
 257         for ( ; refs ; refs = refs->next) {
 258                 unsigned char *remote = refs->old_sha1;
 259                 const char *remote_hex;
 260                 struct object *o;
 261
 262                 /*
 263                  * If that object is complete (i.e. it is an ancestor of a
 264                  * local ref), we tell them we have it but do not have to
 265                  * tell them about its ancestors, which they already know
 266                  * about.
 267                  *
 268                  * We use lookup_object here because we are only
 269                  * interested in the case we *know* the object is
 270                  * reachable and we have already scanned it.
 271                  */
 272                 if (((o = lookup_object(remote)) != NULL) &&
 273                                 (o->flags & COMPLETE)) {
 274                         continue;
 275                 }
 276
 277                 remote_hex = sha1_to_hex(remote);
 278                 if (!fetching) {
 279                         struct strbuf c = STRBUF_INIT;
 280                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 281                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 282                         if (no_done)            strbuf_addstr(&c, " no-done");
 283                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 284                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 285                         if (args.use_thin_pack) strbuf_addstr(&c, " thin-pack");
 286                         if (args.no_progress)   strbuf_addstr(&c, " no-progress");
 287                         if (args.include_tag)   strbuf_addstr(&c, " include-tag");
 288                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 289                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 290                         strbuf_release(&c);
 291                 } else
 292                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 293                 fetching++;
 294         }
 295
 296         if (!fetching) {
 297                 strbuf_release(&req_buf);
 298                 packet_flush(fd[1]);
 299                 return 1;
 300         }
 301
 302         if (is_repository_shallow())
 303                 write_shallow_commits(&req_buf, 1);
 304         if (args.depth > 0)
 305                 packet_buf_write(&req_buf, "deepen %d", args.depth);
 306         packet_buf_flush(&req_buf);
 307         state_len = req_buf.len;
 308
 309         if (args.depth > 0) {
 310                 char line[1024];
 311                 unsigned char sha1[20];
 312
 313                 send_request(fd[1], &req_buf);
 314                 while (packet_read_line(fd[0], line, sizeof(line))) {
 315                         if (!prefixcmp(line, "shallow ")) {
 316                                 if (get_sha1_hex(line + 8, sha1))
 317                                         die("invalid shallow line: %s", line);
 318                                 register_shallow(sha1);
 319                                 continue;
 320                         }
 321                         if (!prefixcmp(line, "unshallow ")) {
 322                                 if (get_sha1_hex(line + 10, sha1))
 323                                         die("invalid unshallow line: %s", line);
 324                                 if (!lookup_object(sha1))
 325                                         die("object not found: %s", line);
 326                                 /* make sure that it is parsed as shallow */
 327                                 if (!parse_object(sha1))
 328                                         die("error in object: %s", line);
 329                                 if (unregister_shallow(sha1))
 330                                         die("no shallow found: %s", line);
 331                                 continue;
 332                         }
 333                         die("expected shallow/unshallow, got %s", line);
 334                 }
 335         } else if (!args.stateless_rpc)
 336                 send_request(fd[1], &req_buf);
 337
 338         if (!args.stateless_rpc) {
 339                 /* If we aren't using the stateless-rpc interface
 340                  * we don't need to retain the headers.
 341                  */
 342                 strbuf_setlen(&req_buf, 0);
 343                 state_len = 0;
 344         }
 345
 346         flushes = 0;
 347         retval = -1;
 348         while ((sha1 = get_rev())) {
 349                 packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
 350                 if (args.verbose)
 351                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 352                 in_vain++;
 353                 if (flush_at <= ++count) {
 354                         int ack;
 355
 356                         packet_buf_flush(&req_buf);
 357                         send_request(fd[1], &req_buf);
 358                         strbuf_setlen(&req_buf, state_len);
 359                         flushes++;
 360                         flush_at = next_flush(count);
 361
 362                         /*
 363                          * We keep one window "ahead" of the other side, and
 364                          * will wait for an ACK only on the next one
 365                          */
 366                         if (!args.stateless_rpc && count == INITIAL_FLUSH)
 367                                 continue;
 368
 369                         consume_shallow_list(fd[0]);
 370                         do {
 371                                 ack = get_ack(fd[0], result_sha1);
 372                                 if (args.verbose && ack)
 373                                         fprintf(stderr, "got ack %d %s\n", ack,
 374                                                         sha1_to_hex(result_sha1));
 375                                 switch (ack) {
 376                                 case ACK:
 377                                         flushes = 0;
 378                                         multi_ack = 0;
 379                                         retval = 0;
 380                                         goto done;
 381                                 case ACK_common:
 382                                 case ACK_ready:
 383                                 case ACK_continue: {
 384                                         struct commit *commit =
 385                                                 lookup_commit(result_sha1);
 386                                         if (args.stateless_rpc
 387                                          && ack == ACK_common
 388                                          && !(commit->object.flags & COMMON)) {
 389                                                 /* We need to replay the have for this object
 390                                                  * on the next RPC request so the peer knows
 391                                                  * it is in common with us.
 392                                                  */
 393                                                 const char *hex = sha1_to_hex(result_sha1);
 394                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 395                                                 state_len = req_buf.len;
 396                                         }
 397                                         mark_common(commit, 0, 1);
 398                                         retval = 0;
 399                                         in_vain = 0;
 400                                         got_continue = 1;
 401                                         if (ack == ACK_ready) {
 402                                                 rev_list = NULL;
 403                                                 got_ready = 1;
 404                                         }
 405                                         break;
 406                                         }
 407                                 }
 408                         } while (ack);
 409                         flushes--;
 410                         if (got_continue && MAX_IN_VAIN < in_vain) {
 411                                 if (args.verbose)
 412                                         fprintf(stderr, "giving up\n");
 413                                 break; /* give up */
 414                         }
 415                 }
 416         }
 417 done:
 418         if (!got_ready || !no_done) {
 419                 packet_buf_write(&req_buf, "done\n");
 420                 send_request(fd[1], &req_buf);
 421         }
 422         if (args.verbose)
 423                 fprintf(stderr, "done\n");
 424         if (retval != 0) {
 425                 multi_ack = 0;
 426                 flushes++;
 427         }
 428         strbuf_release(&req_buf);
 429
 430         consume_shallow_list(fd[0]);
 431         while (flushes || multi_ack) {
 432                 int ack = get_ack(fd[0], result_sha1);
 433                 if (ack) {
 434                         if (args.verbose)
 435                                 fprintf(stderr, "got ack (%d) %s\n", ack,
 436                                         sha1_to_hex(result_sha1));
 437                         if (ack == ACK)
 438                                 return 0;
 439                         multi_ack = 1;
 440                         continue;
 441                 }
 442                 flushes--;
 443         }
 444         /* it is no error to fetch into a completely empty repo */
 445         return count ? retval : 0;
 446 }
 447
 448 static struct commit_list *complete;
 449
 450 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 451 {
 452         struct object *o = parse_object(sha1);
 453
 454         while (o && o->type == OBJ_TAG) {
 455                 struct tag *t = (struct tag *) o;
 456                 if (!t->tagged)
 457                         break; /* broken repository */
 458                 o->flags |= COMPLETE;
 459                 o = parse_object(t->tagged->sha1);
 460         }
 461         if (o && o->type == OBJ_COMMIT) {
 462                 struct commit *commit = (struct commit *)o;
 463                 commit->object.flags |= COMPLETE;
 464                 commit_list_insert_by_date(commit, &complete);
 465         }
 466         return 0;
 467 }
 468
 469 static void mark_recent_complete_commits(unsigned long cutoff)
 470 {
 471         while (complete && cutoff <= complete->item->date) {
 472                 if (args.verbose)
 473                         fprintf(stderr, "Marking %s as complete\n",
 474                                 sha1_to_hex(complete->item->object.sha1));
 475                 pop_most_recent_commit(&complete, COMPLETE);
 476         }
 477 }
 478
 479 static void filter_refs(struct ref **refs, int nr_match, char **match)
 480 {
 481         struct ref **return_refs;
 482         struct ref *newlist = NULL;
 483         struct ref **newtail = &newlist;
 484         struct ref *ref, *next;
 485         struct ref *fastarray[32];
 486
 487         if (nr_match && !args.fetch_all) {
 488                 if (ARRAY_SIZE(fastarray) < nr_match)
 489                         return_refs = xcalloc(nr_match, sizeof(struct ref *));
 490                 else {
 491                         return_refs = fastarray;
 492                         memset(return_refs, 0, sizeof(struct ref *) * nr_match);
 493                 }
 494         }
 495         else
 496                 return_refs = NULL;
 497
 498         for (ref = *refs; ref; ref = next) {
 499                 next = ref->next;
 500                 if (!memcmp(ref->name, "refs/", 5) &&
 501                     check_ref_format(ref->name + 5))
 502                         ; /* trash */
 503                 else if (args.fetch_all &&
 504                          (!args.depth || prefixcmp(ref->name, "refs/tags/") )) {
 505                         *newtail = ref;
 506                         ref->next = NULL;
 507                         newtail = &ref->next;
 508                         continue;
 509                 }
 510                 else {
 511                         int order = path_match(ref->name, nr_match, match);
 512                         if (order) {
 513                                 return_refs[order-1] = ref;
 514                                 continue; /* we will link it later */
 515                         }
 516                 }
 517                 free(ref);
 518         }
 519
 520         if (!args.fetch_all) {
 521                 int i;
 522                 for (i = 0; i < nr_match; i++) {
 523                         ref = return_refs[i];
 524                         if (ref) {
 525                                 *newtail = ref;
 526                                 ref->next = NULL;
 527                                 newtail = &ref->next;
 528                         }
 529                 }
 530                 if (return_refs != fastarray)
 531                         free(return_refs);
 532         }
 533         *refs = newlist;
 534 }
 535
 536 static int everything_local(struct ref **refs, int nr_match, char **match)
 537 {
 538         struct ref *ref;
 539         int retval;
 540         unsigned long cutoff = 0;
 541
 542         save_commit_buffer = 0;
 543
 544         for (ref = *refs; ref; ref = ref->next) {
 545                 struct object *o;
 546
 547                 o = parse_object(ref->old_sha1);
 548                 if (!o)
 549                         continue;
 550
 551                 /* We already have it -- which may mean that we were
 552                  * in sync with the other side at some time after
 553                  * that (it is OK if we guess wrong here).
 554                  */
 555                 if (o->type == OBJ_COMMIT) {
 556                         struct commit *commit = (struct commit *)o;
 557                         if (!cutoff || cutoff < commit->date)
 558                                 cutoff = commit->date;
 559                 }
 560         }
 561
 562         if (!args.depth) {
 563                 for_each_ref(mark_complete, NULL);
 564                 if (cutoff)
 565                         mark_recent_complete_commits(cutoff);
 566         }
 567
 568         /*
 569          * Mark all complete remote refs as common refs.
 570          * Don't mark them common yet; the server has to be told so first.
 571          */
 572         for (ref = *refs; ref; ref = ref->next) {
 573                 struct object *o = deref_tag(lookup_object(ref->old_sha1),
 574                                              NULL, 0);
 575
 576                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 577                         continue;
 578
 579                 if (!(o->flags & SEEN)) {
 580                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 581
 582                         mark_common((struct commit *)o, 1, 1);
 583                 }
 584         }
 585
 586         filter_refs(refs, nr_match, match);
 587
 588         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 589                 const unsigned char *remote = ref->old_sha1;
 590                 unsigned char local[20];
 591                 struct object *o;
 592
 593                 o = lookup_object(remote);
 594                 if (!o || !(o->flags & COMPLETE)) {
 595                         retval = 0;
 596                         if (!args.verbose)
 597                                 continue;
 598                         fprintf(stderr,
 599                                 "want %s (%s)\n", sha1_to_hex(remote),
 600                                 ref->name);
 601                         continue;
 602                 }
 603
 604                 hashcpy(ref->new_sha1, local);
 605                 if (!args.verbose)
 606                         continue;
 607                 fprintf(stderr,
 608                         "already have %s (%s)\n", sha1_to_hex(remote),
 609                         ref->name);
 610         }
 611         return retval;
 612 }
 613
 614 static int sideband_demux(int in, int out, void *data)
 615 {
 616         int *xd = data;
 617
 618         int ret = recv_sideband("fetch-pack", xd[0], out);
 619         close(out);
 620         return ret;
 621 }
 622
 623 static int get_pack(int xd[2], char **pack_lockfile)
 624 {
 625         struct async demux;
 626         const char *argv[20];
 627         char keep_arg[256];
 628         char hdr_arg[256];
 629         const char **av;
 630         int do_keep = args.keep_pack;
 631         struct child_process cmd;
 632
 633         memset(&demux, 0, sizeof(demux));
 634         if (use_sideband) {
 635                 /* xd[] is talking with upload-pack; subprocess reads from
 636                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 637                  * through demux->out.
 638                  */
 639                 demux.proc = sideband_demux;
 640                 demux.data = xd;
 641                 demux.out = -1;
 642                 if (start_async(&demux))
 643                         die("fetch-pack: unable to fork off sideband"
 644                             " demultiplexer");
 645         }
 646         else
 647                 demux.out = xd[0];
 648
 649         memset(&cmd, 0, sizeof(cmd));
 650         cmd.argv = argv;
 651         av = argv;
 652         *hdr_arg = 0;
 653         if (!args.keep_pack && unpack_limit) {
 654                 struct pack_header header;
 655
 656                 if (read_pack_header(demux.out, &header))
 657                         die("protocol error: bad pack header");
 658                 snprintf(hdr_arg, sizeof(hdr_arg),
 659                          "--pack_header=%"PRIu32",%"PRIu32,
 660                          ntohl(header.hdr_version), ntohl(header.hdr_entries));
 661                 if (ntohl(header.hdr_entries) < unpack_limit)
 662                         do_keep = 0;
 663                 else
 664                         do_keep = 1;
 665         }
 666
 667         if (do_keep) {
 668                 if (pack_lockfile)
 669                         cmd.out = -1;
 670                 *av++ = "index-pack";
 671                 *av++ = "--stdin";
 672                 if (!args.quiet && !args.no_progress)
 673                         *av++ = "-v";
 674                 if (args.use_thin_pack)
 675                         *av++ = "--fix-thin";
 676                 if (args.lock_pack || unpack_limit) {
 677                         int s = sprintf(keep_arg,
 678                                         "--keep=fetch-pack %"PRIuMAX " on ", (uintmax_t) getpid());
 679                         if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 680                                 strcpy(keep_arg + s, "localhost");
 681                         *av++ = keep_arg;
 682                 }
 683         }
 684         else {
 685                 *av++ = "unpack-objects";
 686                 if (args.quiet)
 687                         *av++ = "-q";
 688         }
 689         if (*hdr_arg)
 690                 *av++ = hdr_arg;
 691         *av++ = NULL;
 692
 693         cmd.in = demux.out;
 694         cmd.git_cmd = 1;
 695         if (start_command(&cmd))
 696                 die("fetch-pack: unable to fork off %s", argv[0]);
 697         if (do_keep && pack_lockfile) {
 698                 *pack_lockfile = index_pack_lockfile(cmd.out);
 699                 close(cmd.out);
 700         }
 701
 702         if (finish_command(&cmd))
 703                 die("%s failed", argv[0]);
 704         if (use_sideband && finish_async(&demux))
 705                 die("error in sideband demultiplexer");
 706         return 0;
 707 }
 708
 709 static struct ref *do_fetch_pack(int fd[2],
 710                 const struct ref *orig_ref,
 711                 int nr_match,
 712                 char **match,
 713                 char **pack_lockfile)
 714 {
 715         struct ref *ref = copy_ref_list(orig_ref);
 716         unsigned char sha1[20];
 717
 718         if (is_repository_shallow() && !server_supports("shallow"))
 719                 die("Server does not support shallow clients");
 720         if (server_supports("multi_ack_detailed")) {
 721                 if (args.verbose)
 722                         fprintf(stderr, "Server supports multi_ack_detailed\n");
 723                 multi_ack = 2;
 724                 if (server_supports("no-done")) {
 725                         if (args.verbose)
 726                                 fprintf(stderr, "Server supports no-done\n");
 727                         no_done = 1;
 728                 }
 729         }
 730         else if (server_supports("multi_ack")) {
 731                 if (args.verbose)
 732                         fprintf(stderr, "Server supports multi_ack\n");
 733                 multi_ack = 1;
 734         }
 735         if (server_supports("side-band-64k")) {
 736                 if (args.verbose)
 737                         fprintf(stderr, "Server supports side-band-64k\n");
 738                 use_sideband = 2;
 739         }
 740         else if (server_supports("side-band")) {
 741                 if (args.verbose)
 742                         fprintf(stderr, "Server supports side-band\n");
 743                 use_sideband = 1;
 744         }
 745         if (server_supports("ofs-delta")) {
 746                 if (args.verbose)
 747                         fprintf(stderr, "Server supports ofs-delta\n");
 748         } else
 749                 prefer_ofs_delta = 0;
 750         if (everything_local(&ref, nr_match, match)) {
 751                 packet_flush(fd[1]);
 752                 goto all_done;
 753         }
 754         if (find_common(fd, sha1, ref) < 0)
 755                 if (!args.keep_pack)
 756                         /* When cloning, it is not unusual to have
 757                          * no common commit.
 758                          */
 759                         warning("no common commits");
 760
 761         if (args.stateless_rpc)
 762                 packet_flush(fd[1]);
 763         if (get_pack(fd, pack_lockfile))
 764                 die("git fetch-pack: fetch failed.");
 765
 766  all_done:
 767         return ref;
 768 }
 769
 770 static int remove_duplicates(int nr_heads, char **heads)
 771 {
 772         int src, dst;
 773
 774         for (src = dst = 0; src < nr_heads; src++) {
 775                 /* If heads[src] is different from any of
 776                  * heads[0..dst], push it in.
 777                  */
 778                 int i;
 779                 for (i = 0; i < dst; i++) {
 780                         if (!strcmp(heads[i], heads[src]))
 781                                 break;
 782                 }
 783                 if (i < dst)
 784                         continue;
 785                 if (src != dst)
 786                         heads[dst] = heads[src];
 787                 dst++;
 788         }
 789         return dst;
 790 }
 791
 792 static int fetch_pack_config(const char *var, const char *value, void *cb)
 793 {
 794         if (strcmp(var, "fetch.unpacklimit") == 0) {
 795                 fetch_unpack_limit = git_config_int(var, value);
 796                 return 0;
 797         }
 798
 799         if (strcmp(var, "transfer.unpacklimit") == 0) {
 800                 transfer_unpack_limit = git_config_int(var, value);
 801                 return 0;
 802         }
 803
 804         if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
 805                 prefer_ofs_delta = git_config_bool(var, value);
 806                 return 0;
 807         }
 808
 809         return git_default_config(var, value, cb);
 810 }
 811
 812 static struct lock_file lock;
 813
 814 static void fetch_pack_setup(void)
 815 {
 816         static int did_setup;
 817         if (did_setup)
 818                 return;
 819         git_config(fetch_pack_config, NULL);
 820         if (0 <= transfer_unpack_limit)
 821                 unpack_limit = transfer_unpack_limit;
 822         else if (0 <= fetch_unpack_limit)
 823                 unpack_limit = fetch_unpack_limit;
 824         did_setup = 1;
 825 }
 826
 827 int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 828 {
 829         int i, ret, nr_heads;
 830         struct ref *ref = NULL;
 831         char *dest = NULL, **heads;
 832         int fd[2];
 833         char *pack_lockfile = NULL;
 834         char **pack_lockfile_ptr = NULL;
 835         struct child_process *conn;
 836
 837         nr_heads = 0;
 838         heads = NULL;
 839         for (i = 1; i < argc; i++) {
 840                 const char *arg = argv[i];
 841
 842                 if (*arg == '-') {
 843                         if (!prefixcmp(arg, "--upload-pack=")) {
 844                                 args.uploadpack = arg + 14;
 845                                 continue;
 846                         }
 847                         if (!prefixcmp(arg, "--exec=")) {
 848                                 args.uploadpack = arg + 7;
 849                                 continue;
 850                         }
 851                         if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
 852                                 args.quiet = 1;
 853                                 continue;
 854                         }
 855                         if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
 856                                 args.lock_pack = args.keep_pack;
 857                                 args.keep_pack = 1;
 858                                 continue;
 859                         }
 860                         if (!strcmp("--thin", arg)) {
 861                                 args.use_thin_pack = 1;
 862                                 continue;
 863                         }
 864                         if (!strcmp("--include-tag", arg)) {
 865                                 args.include_tag = 1;
 866                                 continue;
 867                         }
 868                         if (!strcmp("--all", arg)) {
 869                                 args.fetch_all = 1;
 870                                 continue;
 871                         }
 872                         if (!strcmp("-v", arg)) {
 873                                 args.verbose = 1;
 874                                 continue;
 875                         }
 876                         if (!prefixcmp(arg, "--depth=")) {
 877                                 args.depth = strtol(arg + 8, NULL, 0);
 878                                 continue;
 879                         }
 880                         if (!strcmp("--no-progress", arg)) {
 881                                 args.no_progress = 1;
 882                                 continue;
 883                         }
 884                         if (!strcmp("--stateless-rpc", arg)) {
 885                                 args.stateless_rpc = 1;
 886                                 continue;
 887                         }
 888                         if (!strcmp("--lock-pack", arg)) {
 889                                 args.lock_pack = 1;
 890                                 pack_lockfile_ptr = &pack_lockfile;
 891                                 continue;
 892                         }
 893                         usage(fetch_pack_usage);
 894                 }
 895                 dest = (char *)arg;
 896                 heads = (char **)(argv + i + 1);
 897                 nr_heads = argc - i - 1;
 898                 break;
 899         }
 900         if (!dest)
 901                 usage(fetch_pack_usage);
 902
 903         if (args.stateless_rpc) {
 904                 conn = NULL;
 905                 fd[0] = 0;
 906                 fd[1] = 1;
 907         } else {
 908                 conn = git_connect(fd, (char *)dest, args.uploadpack,
 909                                    args.verbose ? CONNECT_VERBOSE : 0);
 910         }
 911
 912         get_remote_heads(fd[0], &ref, 0, NULL, 0, NULL);
 913
 914         ref = fetch_pack(&args, fd, conn, ref, dest,
 915                 nr_heads, heads, pack_lockfile_ptr);
 916         if (pack_lockfile) {
 917                 printf("lock %s\n", pack_lockfile);
 918                 fflush(stdout);
 919         }
 920         close(fd[0]);
 921         close(fd[1]);
 922         if (finish_connect(conn))
 923                 ref = NULL;
 924         ret = !ref;
 925
 926         if (!ret && nr_heads) {
 927                 /* If the heads to pull were given, we should have
 928                  * consumed all of them by matching the remote.
 929                  * Otherwise, 'git fetch remote no-such-ref' would
 930                  * silently succeed without issuing an error.
 931                  */
 932                 for (i = 0; i < nr_heads; i++)
 933                         if (heads[i] && heads[i][0]) {
 934                                 error("no such remote ref %s", heads[i]);
 935                                 ret = 1;
 936                         }
 937         }
 938         while (ref) {
 939                 printf("%s %s\n",
 940                        sha1_to_hex(ref->old_sha1), ref->name);
 941                 ref = ref->next;
 942         }
 943
 944         return ret;
 945 }
 946
 947 struct ref *fetch_pack(struct fetch_pack_args *my_args,
 948                        int fd[], struct child_process *conn,
 949                        const struct ref *ref,
 950                 const char *dest,
 951                 int nr_heads,
 952                 char **heads,
 953                 char **pack_lockfile)
 954 {
 955         struct stat st;
 956         struct ref *ref_cpy;
 957
 958         fetch_pack_setup();
 959         if (&args != my_args)
 960                 memcpy(&args, my_args, sizeof(args));
 961         if (args.depth > 0) {
 962                 if (stat(git_path("shallow"), &st))
 963                         st.st_mtime = 0;
 964         }
 965
 966         if (heads && nr_heads)
 967                 nr_heads = remove_duplicates(nr_heads, heads);
 968         if (!ref) {
 969                 packet_flush(fd[1]);
 970                 die("no matching remote head");
 971         }
 972         ref_cpy = do_fetch_pack(fd, ref, nr_heads, heads, pack_lockfile);
 973
 974         if (args.depth > 0) {
 975                 struct cache_time mtime;
 976                 struct strbuf sb = STRBUF_INIT;
 977                 char *shallow = git_path("shallow");
 978                 int fd;
 979
 980                 mtime.sec = st.st_mtime;
 981                 mtime.nsec = ST_MTIME_NSEC(st);
 982                 if (stat(shallow, &st)) {
 983                         if (mtime.sec)
 984                                 die("shallow file was removed during fetch");
 985                 } else if (st.st_mtime != mtime.sec
 986 #ifdef USE_NSEC
 987                                 || ST_MTIME_NSEC(st) != mtime.nsec
 988 #endif
 989                           )
 990                         die("shallow file was changed during fetch");
 991
 992                 fd = hold_lock_file_for_update(&lock, shallow,
 993                                                LOCK_DIE_ON_ERROR);
 994                 if (!write_shallow_commits(&sb, 0)
 995                  || write_in_full(fd, sb.buf, sb.len) != sb.len) {
 996                         unlink_or_warn(shallow);
 997                         rollback_lock_file(&lock);
 998                 } else {
 999                         commit_lock_file(&lock);
1000                 }
1001                 strbuf_release(&sb);
1002         }
1003
1004         reprepare_packed_git();
1005         return ref_cpy;
1006 }