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