builtin/fetch-pack.c

   1 #include "builtin.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 #include "transport.h"
  13
  14 static int transfer_unpack_limit = -1;
  15 static int fetch_unpack_limit = -1;
  16 static int unpack_limit = 100;
  17 static int prefer_ofs_delta = 1;
  18 static int no_done = 0;
  19 static struct fetch_pack_args args = {
  20         /* .uploadpack = */ "git-upload-pack",
  21 };
  22
  23 static const char fetch_pack_usage[] =
  24 "git fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--include-tag] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
  25
  26 #define COMPLETE        (1U << 0)
  27 #define COMMON          (1U << 1)
  28 #define COMMON_REF      (1U << 2)
  29 #define SEEN            (1U << 3)
  30 #define POPPED          (1U << 4)
  31
  32 static int marked;
  33
  34 /*
  35  * After sending this many "have"s if we do not get any new ACK , we
  36  * give up traversing our history.
  37  */
  38 #define MAX_IN_VAIN 256
  39
  40 static struct commit_list *rev_list;
  41 static int non_common_revs, multi_ack, use_sideband;
  42
  43 static void rev_list_push(struct commit *commit, int mark)
  44 {
  45         if (!(commit->object.flags & mark)) {
  46                 commit->object.flags |= mark;
  47
  48                 if (!(commit->object.parsed))
  49                         if (parse_commit(commit))
  50                                 return;
  51
  52                 commit_list_insert_by_date(commit, &rev_list);
  53
  54                 if (!(commit->object.flags & COMMON))
  55                         non_common_revs++;
  56         }
  57 }
  58
  59 static int rev_list_insert_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  60 {
  61         struct object *o = deref_tag(parse_object(sha1), path, 0);
  62
  63         if (o && o->type == OBJ_COMMIT)
  64                 rev_list_push((struct commit *)o, SEEN);
  65
  66         return 0;
  67 }
  68
  69 static int clear_marks(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  70 {
  71         struct object *o = deref_tag(parse_object(sha1), path, 0);
  72
  73         if (o && o->type == OBJ_COMMIT)
  74                 clear_commit_marks((struct commit *)o,
  75                                    COMMON | COMMON_REF | SEEN | POPPED);
  76         return 0;
  77 }
  78
  79 /*
  80    This function marks a rev and its ancestors as common.
  81    In some cases, it is desirable to mark only the ancestors (for example
  82    when only the server does not yet know that they are common).
  83 */
  84
  85 static void mark_common(struct commit *commit,
  86                 int ancestors_only, int dont_parse)
  87 {
  88         if (commit != NULL && !(commit->object.flags & COMMON)) {
  89                 struct object *o = (struct object *)commit;
  90
  91                 if (!ancestors_only)
  92                         o->flags |= COMMON;
  93
  94                 if (!(o->flags & SEEN))
  95                         rev_list_push(commit, SEEN);
  96                 else {
  97                         struct commit_list *parents;
  98
  99                         if (!ancestors_only && !(o->flags & POPPED))
 100                                 non_common_revs--;
 101                         if (!o->parsed && !dont_parse)
 102                                 if (parse_commit(commit))
 103                                         return;
 104
 105                         for (parents = commit->parents;
 106                                         parents;
 107                                         parents = parents->next)
 108                                 mark_common(parents->item, 0, dont_parse);
 109                 }
 110         }
 111 }
 112
 113 /*
 114   Get the next rev to send, ignoring the common.
 115 */
 116
 117 static const unsigned char *get_rev(void)
 118 {
 119         struct commit *commit = NULL;
 120
 121         while (commit == NULL) {
 122                 unsigned int mark;
 123                 struct commit_list *parents;
 124
 125                 if (rev_list == NULL || non_common_revs == 0)
 126                         return NULL;
 127
 128                 commit = rev_list->item;
 129                 if (!commit->object.parsed)
 130                         parse_commit(commit);
 131                 parents = commit->parents;
 132
 133                 commit->object.flags |= POPPED;
 134                 if (!(commit->object.flags & COMMON))
 135                         non_common_revs--;
 136
 137                 if (commit->object.flags & COMMON) {
 138                         /* do not send "have", and ignore ancestors */
 139                         commit = NULL;
 140                         mark = COMMON | SEEN;
 141                 } else if (commit->object.flags & COMMON_REF)
 142                         /* send "have", and ignore ancestors */
 143                         mark = COMMON | SEEN;
 144                 else
 145                         /* send "have", also for its ancestors */
 146                         mark = SEEN;
 147
 148                 while (parents) {
 149                         if (!(parents->item->object.flags & SEEN))
 150                                 rev_list_push(parents->item, mark);
 151                         if (mark & COMMON)
 152                                 mark_common(parents->item, 1, 0);
 153                         parents = parents->next;
 154                 }
 155
 156                 rev_list = rev_list->next;
 157         }
 158
 159         return commit->object.sha1;
 160 }
 161
 162 enum ack_type {
 163         NAK = 0,
 164         ACK,
 165         ACK_continue,
 166         ACK_common,
 167         ACK_ready
 168 };
 169
 170 static void consume_shallow_list(int fd)
 171 {
 172         if (args.stateless_rpc && args.depth > 0) {
 173                 /* If we sent a depth we will get back "duplicate"
 174                  * shallow and unshallow commands every time there
 175                  * is a block of have lines exchanged.
 176                  */
 177                 char line[1000];
 178                 while (packet_read_line(fd, line, sizeof(line))) {
 179                         if (!prefixcmp(line, "shallow "))
 180                                 continue;
 181                         if (!prefixcmp(line, "unshallow "))
 182                                 continue;
 183                         die("git fetch-pack: expected shallow list");
 184                 }
 185         }
 186 }
 187
 188 static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 189 {
 190         static char line[1000];
 191         int len = packet_read_line(fd, line, sizeof(line));
 192
 193         if (!len)
 194                 die("git fetch-pack: expected ACK/NAK, got EOF");
 195         if (line[len-1] == '\n')
 196                 line[--len] = 0;
 197         if (!strcmp(line, "NAK"))
 198                 return NAK;
 199         if (!prefixcmp(line, "ACK ")) {
 200                 if (!get_sha1_hex(line+4, result_sha1)) {
 201                         if (strstr(line+45, "continue"))
 202                                 return ACK_continue;
 203                         if (strstr(line+45, "common"))
 204                                 return ACK_common;
 205                         if (strstr(line+45, "ready"))
 206                                 return ACK_ready;
 207                         return ACK;
 208                 }
 209         }
 210         die("git fetch_pack: expected ACK/NAK, got '%s'", line);
 211 }
 212
 213 static void send_request(int fd, struct strbuf *buf)
 214 {
 215         if (args.stateless_rpc) {
 216                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 217                 packet_flush(fd);
 218         } else
 219                 safe_write(fd, buf->buf, buf->len);
 220 }
 221
 222 static void insert_one_alternate_ref(const struct ref *ref, void *unused)
 223 {
 224         rev_list_insert_ref(NULL, ref->old_sha1, 0, NULL);
 225 }
 226
 227 static void insert_alternate_refs(void)
 228 {
 229         for_each_alternate_ref(insert_one_alternate_ref, NULL);
 230 }
 231
 232 #define INITIAL_FLUSH 16
 233 #define PIPESAFE_FLUSH 32
 234 #define LARGE_FLUSH 1024
 235
 236 static int next_flush(int count)
 237 {
 238         int flush_limit = args.stateless_rpc ? LARGE_FLUSH : PIPESAFE_FLUSH;
 239
 240         if (count < flush_limit)
 241                 count <<= 1;
 242         else
 243                 count += flush_limit;
 244         return count;
 245 }
 246
 247 static int find_common(int fd[2], unsigned char *result_sha1,
 248                        struct ref *refs)
 249 {
 250         int fetching;
 251         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 252         const unsigned char *sha1;
 253         unsigned in_vain = 0;
 254         int got_continue = 0;
 255         int got_ready = 0;
 256         struct strbuf req_buf = STRBUF_INIT;
 257         size_t state_len = 0;
 258
 259         if (args.stateless_rpc && multi_ack == 1)
 260                 die("--stateless-rpc requires multi_ack_detailed");
 261         if (marked)
 262                 for_each_ref(clear_marks, NULL);
 263         marked = 1;
 264
 265         for_each_ref(rev_list_insert_ref, NULL);
 266         insert_alternate_refs();
 267
 268         fetching = 0;
 269         for ( ; refs ; refs = refs->next) {
 270                 unsigned char *remote = refs->old_sha1;
 271                 const char *remote_hex;
 272                 struct object *o;
 273
 274                 /*
 275                  * If that object is complete (i.e. it is an ancestor of a
 276                  * local ref), we tell them we have it but do not have to
 277                  * tell them about its ancestors, which they already know
 278                  * about.
 279                  *
 280                  * We use lookup_object here because we are only
 281                  * interested in the case we *know* the object is
 282                  * reachable and we have already scanned it.
 283                  */
 284                 if (((o = lookup_object(remote)) != NULL) &&
 285                                 (o->flags & COMPLETE)) {
 286                         continue;
 287                 }
 288
 289                 remote_hex = sha1_to_hex(remote);
 290                 if (!fetching) {
 291                         struct strbuf c = STRBUF_INIT;
 292                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 293                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 294                         if (no_done)            strbuf_addstr(&c, " no-done");
 295                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 296                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 297                         if (args.use_thin_pack) strbuf_addstr(&c, " thin-pack");
 298                         if (args.no_progress)   strbuf_addstr(&c, " no-progress");
 299                         if (args.include_tag)   strbuf_addstr(&c, " include-tag");
 300                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 301                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 302                         strbuf_release(&c);
 303                 } else
 304                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 305                 fetching++;
 306         }
 307
 308         if (!fetching) {
 309                 strbuf_release(&req_buf);
 310                 packet_flush(fd[1]);
 311                 return 1;
 312         }
 313
 314         if (is_repository_shallow())
 315                 write_shallow_commits(&req_buf, 1);
 316         if (args.depth > 0)
 317                 packet_buf_write(&req_buf, "deepen %d", args.depth);
 318         packet_buf_flush(&req_buf);
 319         state_len = req_buf.len;
 320
 321         if (args.depth > 0) {
 322                 char line[1024];
 323                 unsigned char sha1[20];
 324
 325                 send_request(fd[1], &req_buf);
 326                 while (packet_read_line(fd[0], line, sizeof(line))) {
 327                         if (!prefixcmp(line, "shallow ")) {
 328                                 if (get_sha1_hex(line + 8, sha1))
 329                                         die("invalid shallow line: %s", line);
 330                                 register_shallow(sha1);
 331                                 continue;
 332                         }
 333                         if (!prefixcmp(line, "unshallow ")) {
 334                                 if (get_sha1_hex(line + 10, sha1))
 335                                         die("invalid unshallow line: %s", line);
 336                                 if (!lookup_object(sha1))
 337                                         die("object not found: %s", line);
 338                                 /* make sure that it is parsed as shallow */
 339                                 if (!parse_object(sha1))
 340                                         die("error in object: %s", line);
 341                                 if (unregister_shallow(sha1))
 342                                         die("no shallow found: %s", line);
 343                                 continue;
 344                         }
 345                         die("expected shallow/unshallow, got %s", line);
 346                 }
 347         } else if (!args.stateless_rpc)
 348                 send_request(fd[1], &req_buf);
 349
 350         if (!args.stateless_rpc) {
 351                 /* If we aren't using the stateless-rpc interface
 352                  * we don't need to retain the headers.
 353                  */
 354                 strbuf_setlen(&req_buf, 0);
 355                 state_len = 0;
 356         }
 357
 358         flushes = 0;
 359         retval = -1;
 360         while ((sha1 = get_rev())) {
 361                 packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
 362                 if (args.verbose)
 363                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 364                 in_vain++;
 365                 if (flush_at <= ++count) {
 366                         int ack;
 367
 368                         packet_buf_flush(&req_buf);
 369                         send_request(fd[1], &req_buf);
 370                         strbuf_setlen(&req_buf, state_len);
 371                         flushes++;
 372                         flush_at = next_flush(count);
 373
 374                         /*
 375                          * We keep one window "ahead" of the other side, and
 376                          * will wait for an ACK only on the next one
 377                          */
 378                         if (!args.stateless_rpc && count == INITIAL_FLUSH)
 379                                 continue;
 380
 381                         consume_shallow_list(fd[0]);
 382                         do {
 383                                 ack = get_ack(fd[0], result_sha1);
 384                                 if (args.verbose && ack)
 385                                         fprintf(stderr, "got ack %d %s\n", ack,
 386                                                         sha1_to_hex(result_sha1));
 387                                 switch (ack) {
 388                                 case ACK:
 389                                         flushes = 0;
 390                                         multi_ack = 0;
 391                                         retval = 0;
 392                                         goto done;
 393                                 case ACK_common:
 394                                 case ACK_ready:
 395                                 case ACK_continue: {
 396                                         struct commit *commit =
 397                                                 lookup_commit(result_sha1);
 398                                         if (!commit)
 399                                                 die("invalid commit %s", sha1_to_hex(result_sha1));
 400                                         if (args.stateless_rpc
 401                                          && ack == ACK_common
 402                                          && !(commit->object.flags & COMMON)) {
 403                                                 /* We need to replay the have for this object
 404                                                  * on the next RPC request so the peer knows
 405                                                  * it is in common with us.
 406                                                  */
 407                                                 const char *hex = sha1_to_hex(result_sha1);
 408                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 409                                                 state_len = req_buf.len;
 410                                         }
 411                                         mark_common(commit, 0, 1);
 412                                         retval = 0;
 413                                         in_vain = 0;
 414                                         got_continue = 1;
 415                                         if (ack == ACK_ready) {
 416                                                 rev_list = NULL;
 417                                                 got_ready = 1;
 418                                         }
 419                                         break;
 420                                         }
 421                                 }
 422                         } while (ack);
 423                         flushes--;
 424                         if (got_continue && MAX_IN_VAIN < in_vain) {
 425                                 if (args.verbose)
 426                                         fprintf(stderr, "giving up\n");
 427                                 break; /* give up */
 428                         }
 429                 }
 430         }
 431 done:
 432         if (!got_ready || !no_done) {
 433                 packet_buf_write(&req_buf, "done\n");
 434                 send_request(fd[1], &req_buf);
 435         }
 436         if (args.verbose)
 437                 fprintf(stderr, "done\n");
 438         if (retval != 0) {
 439                 multi_ack = 0;
 440                 flushes++;
 441         }
 442         strbuf_release(&req_buf);
 443
 444         consume_shallow_list(fd[0]);
 445         while (flushes || multi_ack) {
 446                 int ack = get_ack(fd[0], result_sha1);
 447                 if (ack) {
 448                         if (args.verbose)
 449                                 fprintf(stderr, "got ack (%d) %s\n", ack,
 450                                         sha1_to_hex(result_sha1));
 451                         if (ack == ACK)
 452                                 return 0;
 453                         multi_ack = 1;
 454                         continue;
 455                 }
 456                 flushes--;
 457         }
 458         /* it is no error to fetch into a completely empty repo */
 459         return count ? retval : 0;
 460 }
 461
 462 static struct commit_list *complete;
 463
 464 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 465 {
 466         struct object *o = parse_object(sha1);
 467
 468         while (o && o->type == OBJ_TAG) {
 469                 struct tag *t = (struct tag *) o;
 470                 if (!t->tagged)
 471                         break; /* broken repository */
 472                 o->flags |= COMPLETE;
 473                 o = parse_object(t->tagged->sha1);
 474         }
 475         if (o && o->type == OBJ_COMMIT) {
 476                 struct commit *commit = (struct commit *)o;
 477                 if (!(commit->object.flags & COMPLETE)) {
 478                         commit->object.flags |= COMPLETE;
 479                         commit_list_insert_by_date(commit, &complete);
 480                 }
 481         }
 482         return 0;
 483 }
 484
 485 static void mark_recent_complete_commits(unsigned long cutoff)
 486 {
 487         while (complete && cutoff <= complete->item->date) {
 488                 if (args.verbose)
 489                         fprintf(stderr, "Marking %s as complete\n",
 490                                 sha1_to_hex(complete->item->object.sha1));
 491                 pop_most_recent_commit(&complete, COMPLETE);
 492         }
 493 }
 494
 495 static void filter_refs(struct ref **refs, int nr_match, char **match)
 496 {
 497         struct ref **return_refs;
 498         struct ref *newlist = NULL;
 499         struct ref **newtail = &newlist;
 500         struct ref *ref, *next;
 501         struct ref *fastarray[32];
 502
 503         if (nr_match && !args.fetch_all) {
 504                 if (ARRAY_SIZE(fastarray) < nr_match)
 505                         return_refs = xcalloc(nr_match, sizeof(struct ref *));
 506                 else {
 507                         return_refs = fastarray;
 508                         memset(return_refs, 0, sizeof(struct ref *) * nr_match);
 509                 }
 510         }
 511         else
 512                 return_refs = NULL;
 513
 514         for (ref = *refs; ref; ref = next) {
 515                 next = ref->next;
 516                 if (!memcmp(ref->name, "refs/", 5) &&
 517                     check_ref_format(ref->name + 5))
 518                         ; /* trash */
 519                 else if (args.fetch_all &&
 520                          (!args.depth || prefixcmp(ref->name, "refs/tags/") )) {
 521                         *newtail = ref;
 522                         ref->next = NULL;
 523                         newtail = &ref->next;
 524                         continue;
 525                 }
 526                 else {
 527                         int order = path_match(ref->name, nr_match, match);
 528                         if (order) {
 529                                 return_refs[order-1] = ref;
 530                                 continue; /* we will link it later */
 531                         }
 532                 }
 533                 free(ref);
 534         }
 535
 536         if (!args.fetch_all) {
 537                 int i;
 538                 for (i = 0; i < nr_match; i++) {
 539                         ref = return_refs[i];
 540                         if (ref) {
 541                                 *newtail = ref;
 542                                 ref->next = NULL;
 543                                 newtail = &ref->next;
 544                         }
 545                 }
 546                 if (return_refs != fastarray)
 547                         free(return_refs);
 548         }
 549         *refs = newlist;
 550 }
 551
 552 static int everything_local(struct ref **refs, int nr_match, char **match)
 553 {
 554         struct ref *ref;
 555         int retval;
 556         unsigned long cutoff = 0;
 557
 558         save_commit_buffer = 0;
 559
 560         for (ref = *refs; ref; ref = ref->next) {
 561                 struct object *o;
 562
 563                 o = parse_object(ref->old_sha1);
 564                 if (!o)
 565                         continue;
 566
 567                 /* We already have it -- which may mean that we were
 568                  * in sync with the other side at some time after
 569                  * that (it is OK if we guess wrong here).
 570                  */
 571                 if (o->type == OBJ_COMMIT) {
 572                         struct commit *commit = (struct commit *)o;
 573                         if (!cutoff || cutoff < commit->date)
 574                                 cutoff = commit->date;
 575                 }
 576         }
 577
 578         if (!args.depth) {
 579                 for_each_ref(mark_complete, NULL);
 580                 if (cutoff)
 581                         mark_recent_complete_commits(cutoff);
 582         }
 583
 584         /*
 585          * Mark all complete remote refs as common refs.
 586          * Don't mark them common yet; the server has to be told so first.
 587          */
 588         for (ref = *refs; ref; ref = ref->next) {
 589                 struct object *o = deref_tag(lookup_object(ref->old_sha1),
 590                                              NULL, 0);
 591
 592                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 593                         continue;
 594
 595                 if (!(o->flags & SEEN)) {
 596                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 597
 598                         mark_common((struct commit *)o, 1, 1);
 599                 }
 600         }
 601
 602         filter_refs(refs, nr_match, match);
 603
 604         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 605                 const unsigned char *remote = ref->old_sha1;
 606                 unsigned char local[20];
 607                 struct object *o;
 608
 609                 o = lookup_object(remote);
 610                 if (!o || !(o->flags & COMPLETE)) {
 611                         retval = 0;
 612                         if (!args.verbose)
 613                                 continue;
 614                         fprintf(stderr,
 615                                 "want %s (%s)\n", sha1_to_hex(remote),
 616                                 ref->name);
 617                         continue;
 618                 }
 619
 620                 hashcpy(ref->new_sha1, local);
 621                 if (!args.verbose)
 622                         continue;
 623                 fprintf(stderr,
 624                         "already have %s (%s)\n", sha1_to_hex(remote),
 625                         ref->name);
 626         }
 627         return retval;
 628 }
 629
 630 static int sideband_demux(int in, int out, void *data)
 631 {
 632         int *xd = data;
 633
 634         int ret = recv_sideband("fetch-pack", xd[0], out);
 635         close(out);
 636         return ret;
 637 }
 638
 639 static int get_pack(int xd[2], char **pack_lockfile)
 640 {
 641         struct async demux;
 642         const char *argv[20];
 643         char keep_arg[256];
 644         char hdr_arg[256];
 645         const char **av;
 646         int do_keep = args.keep_pack;
 647         struct child_process cmd;
 648
 649         memset(&demux, 0, sizeof(demux));
 650         if (use_sideband) {
 651                 /* xd[] is talking with upload-pack; subprocess reads from
 652                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 653                  * through demux->out.
 654                  */
 655                 demux.proc = sideband_demux;
 656                 demux.data = xd;
 657                 demux.out = -1;
 658                 if (start_async(&demux))
 659                         die("fetch-pack: unable to fork off sideband"
 660                             " demultiplexer");
 661         }
 662         else
 663                 demux.out = xd[0];
 664
 665         memset(&cmd, 0, sizeof(cmd));
 666         cmd.argv = argv;
 667         av = argv;
 668         *hdr_arg = 0;
 669         if (!args.keep_pack && unpack_limit) {
 670                 struct pack_header header;
 671
 672                 if (read_pack_header(demux.out, &header))
 673                         die("protocol error: bad pack header");
 674                 snprintf(hdr_arg, sizeof(hdr_arg),
 675                          "--pack_header=%"PRIu32",%"PRIu32,
 676                          ntohl(header.hdr_version), ntohl(header.hdr_entries));
 677                 if (ntohl(header.hdr_entries) < unpack_limit)
 678                         do_keep = 0;
 679                 else
 680                         do_keep = 1;
 681         }
 682
 683         if (do_keep) {
 684                 if (pack_lockfile)
 685                         cmd.out = -1;
 686                 *av++ = "index-pack";
 687                 *av++ = "--stdin";
 688                 if (!args.quiet && !args.no_progress)
 689                         *av++ = "-v";
 690                 if (args.use_thin_pack)
 691                         *av++ = "--fix-thin";
 692                 if (args.lock_pack || unpack_limit) {
 693                         int s = sprintf(keep_arg,
 694                                         "--keep=fetch-pack %"PRIuMAX " on ", (uintmax_t) getpid());
 695                         if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 696                                 strcpy(keep_arg + s, "localhost");
 697                         *av++ = keep_arg;
 698                 }
 699         }
 700         else {
 701                 *av++ = "unpack-objects";
 702                 if (args.quiet)
 703                         *av++ = "-q";
 704         }
 705         if (*hdr_arg)
 706                 *av++ = hdr_arg;
 707         *av++ = NULL;
 708
 709         cmd.in = demux.out;
 710         cmd.git_cmd = 1;
 711         if (start_command(&cmd))
 712                 die("fetch-pack: unable to fork off %s", argv[0]);
 713         if (do_keep && pack_lockfile) {
 714                 *pack_lockfile = index_pack_lockfile(cmd.out);
 715                 close(cmd.out);
 716         }
 717
 718         if (finish_command(&cmd))
 719                 die("%s failed", argv[0]);
 720         if (use_sideband && finish_async(&demux))
 721                 die("error in sideband demultiplexer");
 722         return 0;
 723 }
 724
 725 static struct ref *do_fetch_pack(int fd[2],
 726                 const struct ref *orig_ref,
 727                 int nr_match,
 728                 char **match,
 729                 char **pack_lockfile)
 730 {
 731         struct ref *ref = copy_ref_list(orig_ref);
 732         unsigned char sha1[20];
 733
 734         if (is_repository_shallow() && !server_supports("shallow"))
 735                 die("Server does not support shallow clients");
 736         if (server_supports("multi_ack_detailed")) {
 737                 if (args.verbose)
 738                         fprintf(stderr, "Server supports multi_ack_detailed\n");
 739                 multi_ack = 2;
 740                 if (server_supports("no-done")) {
 741                         if (args.verbose)
 742                                 fprintf(stderr, "Server supports no-done\n");
 743                         if (args.stateless_rpc)
 744                                 no_done = 1;
 745                 }
 746         }
 747         else if (server_supports("multi_ack")) {
 748                 if (args.verbose)
 749                         fprintf(stderr, "Server supports multi_ack\n");
 750                 multi_ack = 1;
 751         }
 752         if (server_supports("side-band-64k")) {
 753                 if (args.verbose)
 754                         fprintf(stderr, "Server supports side-band-64k\n");
 755                 use_sideband = 2;
 756         }
 757         else if (server_supports("side-band")) {
 758                 if (args.verbose)
 759                         fprintf(stderr, "Server supports side-band\n");
 760                 use_sideband = 1;
 761         }
 762         if (server_supports("ofs-delta")) {
 763                 if (args.verbose)
 764                         fprintf(stderr, "Server supports ofs-delta\n");
 765         } else
 766                 prefer_ofs_delta = 0;
 767         if (everything_local(&ref, nr_match, match)) {
 768                 packet_flush(fd[1]);
 769                 goto all_done;
 770         }
 771         if (find_common(fd, sha1, ref) < 0)
 772                 if (!args.keep_pack)
 773                         /* When cloning, it is not unusual to have
 774                          * no common commit.
 775                          */
 776                         warning("no common commits");
 777
 778         if (args.stateless_rpc)
 779                 packet_flush(fd[1]);
 780         if (get_pack(fd, pack_lockfile))
 781                 die("git fetch-pack: fetch failed.");
 782
 783  all_done:
 784         return ref;
 785 }
 786
 787 static int remove_duplicates(int nr_heads, char **heads)
 788 {
 789         int src, dst;
 790
 791         for (src = dst = 0; src < nr_heads; src++) {
 792                 /* If heads[src] is different from any of
 793                  * heads[0..dst], push it in.
 794                  */
 795                 int i;
 796                 for (i = 0; i < dst; i++) {
 797                         if (!strcmp(heads[i], heads[src]))
 798                                 break;
 799                 }
 800                 if (i < dst)
 801                         continue;
 802                 if (src != dst)
 803                         heads[dst] = heads[src];
 804                 dst++;
 805         }
 806         return dst;
 807 }
 808
 809 static int fetch_pack_config(const char *var, const char *value, void *cb)
 810 {
 811         if (strcmp(var, "fetch.unpacklimit") == 0) {
 812                 fetch_unpack_limit = git_config_int(var, value);
 813                 return 0;
 814         }
 815
 816         if (strcmp(var, "transfer.unpacklimit") == 0) {
 817                 transfer_unpack_limit = git_config_int(var, value);
 818                 return 0;
 819         }
 820
 821         if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
 822                 prefer_ofs_delta = git_config_bool(var, value);
 823                 return 0;
 824         }
 825
 826         return git_default_config(var, value, cb);
 827 }
 828
 829 static struct lock_file lock;
 830
 831 static void fetch_pack_setup(void)
 832 {
 833         static int did_setup;
 834         if (did_setup)
 835                 return;
 836         git_config(fetch_pack_config, NULL);
 837         if (0 <= transfer_unpack_limit)
 838                 unpack_limit = transfer_unpack_limit;
 839         else if (0 <= fetch_unpack_limit)
 840                 unpack_limit = fetch_unpack_limit;
 841         did_setup = 1;
 842 }
 843
 844 int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 845 {
 846         int i, ret, nr_heads;
 847         struct ref *ref = NULL;
 848         char *dest = NULL, **heads;
 849         int fd[2];
 850         char *pack_lockfile = NULL;
 851         char **pack_lockfile_ptr = NULL;
 852         struct child_process *conn;
 853
 854         packet_trace_identity("fetch-pack");
 855
 856         nr_heads = 0;
 857         heads = NULL;
 858         for (i = 1; i < argc; i++) {
 859                 const char *arg = argv[i];
 860
 861                 if (*arg == '-') {
 862                         if (!prefixcmp(arg, "--upload-pack=")) {
 863                                 args.uploadpack = arg + 14;
 864                                 continue;
 865                         }
 866                         if (!prefixcmp(arg, "--exec=")) {
 867                                 args.uploadpack = arg + 7;
 868                                 continue;
 869                         }
 870                         if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
 871                                 args.quiet = 1;
 872                                 continue;
 873                         }
 874                         if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
 875                                 args.lock_pack = args.keep_pack;
 876                                 args.keep_pack = 1;
 877                                 continue;
 878                         }
 879                         if (!strcmp("--thin", arg)) {
 880                                 args.use_thin_pack = 1;
 881                                 continue;
 882                         }
 883                         if (!strcmp("--include-tag", arg)) {
 884                                 args.include_tag = 1;
 885                                 continue;
 886                         }
 887                         if (!strcmp("--all", arg)) {
 888                                 args.fetch_all = 1;
 889                                 continue;
 890                         }
 891                         if (!strcmp("-v", arg)) {
 892                                 args.verbose = 1;
 893                                 continue;
 894                         }
 895                         if (!prefixcmp(arg, "--depth=")) {
 896                                 args.depth = strtol(arg + 8, NULL, 0);
 897                                 continue;
 898                         }
 899                         if (!strcmp("--no-progress", arg)) {
 900                                 args.no_progress = 1;
 901                                 continue;
 902                         }
 903                         if (!strcmp("--stateless-rpc", arg)) {
 904                                 args.stateless_rpc = 1;
 905                                 continue;
 906                         }
 907                         if (!strcmp("--lock-pack", arg)) {
 908                                 args.lock_pack = 1;
 909                                 pack_lockfile_ptr = &pack_lockfile;
 910                                 continue;
 911                         }
 912                         usage(fetch_pack_usage);
 913                 }
 914                 dest = (char *)arg;
 915                 heads = (char **)(argv + i + 1);
 916                 nr_heads = argc - i - 1;
 917                 break;
 918         }
 919         if (!dest)
 920                 usage(fetch_pack_usage);
 921
 922         if (args.stateless_rpc) {
 923                 conn = NULL;
 924                 fd[0] = 0;
 925                 fd[1] = 1;
 926         } else {
 927                 conn = git_connect(fd, (char *)dest, args.uploadpack,
 928                                    args.verbose ? CONNECT_VERBOSE : 0);
 929         }
 930
 931         get_remote_heads(fd[0], &ref, 0, NULL, 0, NULL);
 932
 933         ref = fetch_pack(&args, fd, conn, ref, dest,
 934                 nr_heads, heads, pack_lockfile_ptr);
 935         if (pack_lockfile) {
 936                 printf("lock %s\n", pack_lockfile);
 937                 fflush(stdout);
 938         }
 939         close(fd[0]);
 940         close(fd[1]);
 941         if (finish_connect(conn))
 942                 ref = NULL;
 943         ret = !ref;
 944
 945         if (!ret && nr_heads) {
 946                 /* If the heads to pull were given, we should have
 947                  * consumed all of them by matching the remote.
 948                  * Otherwise, 'git fetch remote no-such-ref' would
 949                  * silently succeed without issuing an error.
 950                  */
 951                 for (i = 0; i < nr_heads; i++)
 952                         if (heads[i] && heads[i][0]) {
 953                                 error("no such remote ref %s", heads[i]);
 954                                 ret = 1;
 955                         }
 956         }
 957         while (ref) {
 958                 printf("%s %s\n",
 959                        sha1_to_hex(ref->old_sha1), ref->name);
 960                 ref = ref->next;
 961         }
 962
 963         return ret;
 964 }
 965
 966 struct ref *fetch_pack(struct fetch_pack_args *my_args,
 967                        int fd[], struct child_process *conn,
 968                        const struct ref *ref,
 969                 const char *dest,
 970                 int nr_heads,
 971                 char **heads,
 972                 char **pack_lockfile)
 973 {
 974         struct stat st;
 975         struct ref *ref_cpy;
 976
 977         fetch_pack_setup();
 978         if (&args != my_args)
 979                 memcpy(&args, my_args, sizeof(args));
 980         if (args.depth > 0) {
 981                 if (stat(git_path("shallow"), &st))
 982                         st.st_mtime = 0;
 983         }
 984
 985         if (heads && nr_heads)
 986                 nr_heads = remove_duplicates(nr_heads, heads);
 987         if (!ref) {
 988                 packet_flush(fd[1]);
 989                 die("no matching remote head");
 990         }
 991         ref_cpy = do_fetch_pack(fd, ref, nr_heads, heads, pack_lockfile);
 992
 993         if (args.depth > 0) {
 994                 struct cache_time mtime;
 995                 struct strbuf sb = STRBUF_INIT;
 996                 char *shallow = git_path("shallow");
 997                 int fd;
 998
 999                 mtime.sec = st.st_mtime;
1000                 mtime.nsec = ST_MTIME_NSEC(st);
1001                 if (stat(shallow, &st)) {
1002                         if (mtime.sec)
1003                                 die("shallow file was removed during fetch");
1004                 } else if (st.st_mtime != mtime.sec
1005 #ifdef USE_NSEC
1006                                 || ST_MTIME_NSEC(st) != mtime.nsec
1007 #endif
1008                           )
1009                         die("shallow file was changed during fetch");
1010
1011                 fd = hold_lock_file_for_update(&lock, shallow,
1012                                                LOCK_DIE_ON_ERROR);
1013                 if (!write_shallow_commits(&sb, 0)
1014                  || write_in_full(fd, sb.buf, sb.len) != sb.len) {
1015                         unlink_or_warn(shallow);
1016                         rollback_lock_file(&lock);
1017                 } else {
1018                         commit_lock_file(&lock);
1019                 }
1020                 strbuf_release(&sb);
1021         }
1022
1023         reprepare_packed_git();
1024         return ref_cpy;
1025 }