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;
  19 static int fetch_fsck_objects = -1;
  20 static int transfer_fsck_objects = -1;
  21 static struct fetch_pack_args args = {
  22         /* .uploadpack = */ "git-upload-pack",
  23 };
  24
  25 static const char fetch_pack_usage[] =
  26 "git fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--include-tag] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
  27
  28 #define COMPLETE        (1U << 0)
  29 #define COMMON          (1U << 1)
  30 #define COMMON_REF      (1U << 2)
  31 #define SEEN            (1U << 3)
  32 #define POPPED          (1U << 4)
  33
  34 static int marked;
  35
  36 /*
  37  * After sending this many "have"s if we do not get any new ACK , we
  38  * give up traversing our history.
  39  */
  40 #define MAX_IN_VAIN 256
  41
  42 static struct commit_list *rev_list;
  43 static int non_common_revs, multi_ack, use_sideband;
  44
  45 static void rev_list_push(struct commit *commit, int mark)
  46 {
  47         if (!(commit->object.flags & mark)) {
  48                 commit->object.flags |= mark;
  49
  50                 if (!(commit->object.parsed))
  51                         if (parse_commit(commit))
  52                                 return;
  53
  54                 commit_list_insert_by_date(commit, &rev_list);
  55
  56                 if (!(commit->object.flags & COMMON))
  57                         non_common_revs++;
  58         }
  59 }
  60
  61 static int rev_list_insert_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
  62 {
  63         struct object *o = deref_tag(parse_object(sha1), refname, 0);
  64
  65         if (o && o->type == OBJ_COMMIT)
  66                 rev_list_push((struct commit *)o, SEEN);
  67
  68         return 0;
  69 }
  70
  71 static int clear_marks(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
  72 {
  73         struct object *o = deref_tag(parse_object(sha1), refname, 0);
  74
  75         if (o && o->type == OBJ_COMMIT)
  76                 clear_commit_marks((struct commit *)o,
  77                                    COMMON | COMMON_REF | SEEN | POPPED);
  78         return 0;
  79 }
  80
  81 /*
  82    This function marks a rev and its ancestors as common.
  83    In some cases, it is desirable to mark only the ancestors (for example
  84    when only the server does not yet know that they are common).
  85 */
  86
  87 static void mark_common(struct commit *commit,
  88                 int ancestors_only, int dont_parse)
  89 {
  90         if (commit != NULL && !(commit->object.flags & COMMON)) {
  91                 struct object *o = (struct object *)commit;
  92
  93                 if (!ancestors_only)
  94                         o->flags |= COMMON;
  95
  96                 if (!(o->flags & SEEN))
  97                         rev_list_push(commit, SEEN);
  98                 else {
  99                         struct commit_list *parents;
 100
 101                         if (!ancestors_only && !(o->flags & POPPED))
 102                                 non_common_revs--;
 103                         if (!o->parsed && !dont_parse)
 104                                 if (parse_commit(commit))
 105                                         return;
 106
 107                         for (parents = commit->parents;
 108                                         parents;
 109                                         parents = parents->next)
 110                                 mark_common(parents->item, 0, dont_parse);
 111                 }
 112         }
 113 }
 114
 115 /*
 116   Get the next rev to send, ignoring the common.
 117 */
 118
 119 static const unsigned char *get_rev(void)
 120 {
 121         struct commit *commit = NULL;
 122
 123         while (commit == NULL) {
 124                 unsigned int mark;
 125                 struct commit_list *parents;
 126
 127                 if (rev_list == NULL || non_common_revs == 0)
 128                         return NULL;
 129
 130                 commit = rev_list->item;
 131                 if (!commit->object.parsed)
 132                         parse_commit(commit);
 133                 parents = commit->parents;
 134
 135                 commit->object.flags |= POPPED;
 136                 if (!(commit->object.flags & COMMON))
 137                         non_common_revs--;
 138
 139                 if (commit->object.flags & COMMON) {
 140                         /* do not send "have", and ignore ancestors */
 141                         commit = NULL;
 142                         mark = COMMON | SEEN;
 143                 } else if (commit->object.flags & COMMON_REF)
 144                         /* send "have", and ignore ancestors */
 145                         mark = COMMON | SEEN;
 146                 else
 147                         /* send "have", also for its ancestors */
 148                         mark = SEEN;
 149
 150                 while (parents) {
 151                         if (!(parents->item->object.flags & SEEN))
 152                                 rev_list_push(parents->item, mark);
 153                         if (mark & COMMON)
 154                                 mark_common(parents->item, 1, 0);
 155                         parents = parents->next;
 156                 }
 157
 158                 rev_list = rev_list->next;
 159         }
 160
 161         return commit->object.sha1;
 162 }
 163
 164 enum ack_type {
 165         NAK = 0,
 166         ACK,
 167         ACK_continue,
 168         ACK_common,
 169         ACK_ready
 170 };
 171
 172 static void consume_shallow_list(int fd)
 173 {
 174         if (args.stateless_rpc && args.depth > 0) {
 175                 /* If we sent a depth we will get back "duplicate"
 176                  * shallow and unshallow commands every time there
 177                  * is a block of have lines exchanged.
 178                  */
 179                 char line[1000];
 180                 while (packet_read_line(fd, line, sizeof(line))) {
 181                         if (!prefixcmp(line, "shallow "))
 182                                 continue;
 183                         if (!prefixcmp(line, "unshallow "))
 184                                 continue;
 185                         die("git fetch-pack: expected shallow list");
 186                 }
 187         }
 188 }
 189
 190 struct write_shallow_data {
 191         struct strbuf *out;
 192         int use_pack_protocol;
 193         int count;
 194 };
 195
 196 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 197 {
 198         struct write_shallow_data *data = cb_data;
 199         const char *hex = sha1_to_hex(graft->sha1);
 200         data->count++;
 201         if (data->use_pack_protocol)
 202                 packet_buf_write(data->out, "shallow %s", hex);
 203         else {
 204                 strbuf_addstr(data->out, hex);
 205                 strbuf_addch(data->out, '\n');
 206         }
 207         return 0;
 208 }
 209
 210 static int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
 211 {
 212         struct write_shallow_data data;
 213         data.out = out;
 214         data.use_pack_protocol = use_pack_protocol;
 215         data.count = 0;
 216         for_each_commit_graft(write_one_shallow, &data);
 217         return data.count;
 218 }
 219
 220 static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 221 {
 222         static char line[1000];
 223         int len = packet_read_line(fd, line, sizeof(line));
 224
 225         if (!len)
 226                 die("git fetch-pack: expected ACK/NAK, got EOF");
 227         if (line[len-1] == '\n')
 228                 line[--len] = 0;
 229         if (!strcmp(line, "NAK"))
 230                 return NAK;
 231         if (!prefixcmp(line, "ACK ")) {
 232                 if (!get_sha1_hex(line+4, result_sha1)) {
 233                         if (strstr(line+45, "continue"))
 234                                 return ACK_continue;
 235                         if (strstr(line+45, "common"))
 236                                 return ACK_common;
 237                         if (strstr(line+45, "ready"))
 238                                 return ACK_ready;
 239                         return ACK;
 240                 }
 241         }
 242         die("git fetch_pack: expected ACK/NAK, got '%s'", line);
 243 }
 244
 245 static void send_request(int fd, struct strbuf *buf)
 246 {
 247         if (args.stateless_rpc) {
 248                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 249                 packet_flush(fd);
 250         } else
 251                 safe_write(fd, buf->buf, buf->len);
 252 }
 253
 254 static void insert_one_alternate_ref(const struct ref *ref, void *unused)
 255 {
 256         rev_list_insert_ref(NULL, ref->old_sha1, 0, NULL);
 257 }
 258
 259 #define INITIAL_FLUSH 16
 260 #define PIPESAFE_FLUSH 32
 261 #define LARGE_FLUSH 1024
 262
 263 static int next_flush(int count)
 264 {
 265         int flush_limit = args.stateless_rpc ? LARGE_FLUSH : PIPESAFE_FLUSH;
 266
 267         if (count < flush_limit)
 268                 count <<= 1;
 269         else
 270                 count += flush_limit;
 271         return count;
 272 }
 273
 274 static int find_common(int fd[2], unsigned char *result_sha1,
 275                        struct ref *refs)
 276 {
 277         int fetching;
 278         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 279         const unsigned char *sha1;
 280         unsigned in_vain = 0;
 281         int got_continue = 0;
 282         int got_ready = 0;
 283         struct strbuf req_buf = STRBUF_INIT;
 284         size_t state_len = 0;
 285
 286         if (args.stateless_rpc && multi_ack == 1)
 287                 die("--stateless-rpc requires multi_ack_detailed");
 288         if (marked)
 289                 for_each_ref(clear_marks, NULL);
 290         marked = 1;
 291
 292         for_each_ref(rev_list_insert_ref, NULL);
 293         for_each_alternate_ref(insert_one_alternate_ref, NULL);
 294
 295         fetching = 0;
 296         for ( ; refs ; refs = refs->next) {
 297                 unsigned char *remote = refs->old_sha1;
 298                 const char *remote_hex;
 299                 struct object *o;
 300
 301                 /*
 302                  * If that object is complete (i.e. it is an ancestor of a
 303                  * local ref), we tell them we have it but do not have to
 304                  * tell them about its ancestors, which they already know
 305                  * about.
 306                  *
 307                  * We use lookup_object here because we are only
 308                  * interested in the case we *know* the object is
 309                  * reachable and we have already scanned it.
 310                  */
 311                 if (((o = lookup_object(remote)) != NULL) &&
 312                                 (o->flags & COMPLETE)) {
 313                         continue;
 314                 }
 315
 316                 remote_hex = sha1_to_hex(remote);
 317                 if (!fetching) {
 318                         struct strbuf c = STRBUF_INIT;
 319                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 320                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 321                         if (no_done)            strbuf_addstr(&c, " no-done");
 322                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 323                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 324                         if (args.use_thin_pack) strbuf_addstr(&c, " thin-pack");
 325                         if (args.no_progress)   strbuf_addstr(&c, " no-progress");
 326                         if (args.include_tag)   strbuf_addstr(&c, " include-tag");
 327                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 328                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 329                         strbuf_release(&c);
 330                 } else
 331                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 332                 fetching++;
 333         }
 334
 335         if (!fetching) {
 336                 strbuf_release(&req_buf);
 337                 packet_flush(fd[1]);
 338                 return 1;
 339         }
 340
 341         if (is_repository_shallow())
 342                 write_shallow_commits(&req_buf, 1);
 343         if (args.depth > 0)
 344                 packet_buf_write(&req_buf, "deepen %d", args.depth);
 345         packet_buf_flush(&req_buf);
 346         state_len = req_buf.len;
 347
 348         if (args.depth > 0) {
 349                 char line[1024];
 350                 unsigned char sha1[20];
 351
 352                 send_request(fd[1], &req_buf);
 353                 while (packet_read_line(fd[0], line, sizeof(line))) {
 354                         if (!prefixcmp(line, "shallow ")) {
 355                                 if (get_sha1_hex(line + 8, sha1))
 356                                         die("invalid shallow line: %s", line);
 357                                 register_shallow(sha1);
 358                                 continue;
 359                         }
 360                         if (!prefixcmp(line, "unshallow ")) {
 361                                 if (get_sha1_hex(line + 10, sha1))
 362                                         die("invalid unshallow line: %s", line);
 363                                 if (!lookup_object(sha1))
 364                                         die("object not found: %s", line);
 365                                 /* make sure that it is parsed as shallow */
 366                                 if (!parse_object(sha1))
 367                                         die("error in object: %s", line);
 368                                 if (unregister_shallow(sha1))
 369                                         die("no shallow found: %s", line);
 370                                 continue;
 371                         }
 372                         die("expected shallow/unshallow, got %s", line);
 373                 }
 374         } else if (!args.stateless_rpc)
 375                 send_request(fd[1], &req_buf);
 376
 377         if (!args.stateless_rpc) {
 378                 /* If we aren't using the stateless-rpc interface
 379                  * we don't need to retain the headers.
 380                  */
 381                 strbuf_setlen(&req_buf, 0);
 382                 state_len = 0;
 383         }
 384
 385         flushes = 0;
 386         retval = -1;
 387         while ((sha1 = get_rev())) {
 388                 packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
 389                 if (args.verbose)
 390                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 391                 in_vain++;
 392                 if (flush_at <= ++count) {
 393                         int ack;
 394
 395                         packet_buf_flush(&req_buf);
 396                         send_request(fd[1], &req_buf);
 397                         strbuf_setlen(&req_buf, state_len);
 398                         flushes++;
 399                         flush_at = next_flush(count);
 400
 401                         /*
 402                          * We keep one window "ahead" of the other side, and
 403                          * will wait for an ACK only on the next one
 404                          */
 405                         if (!args.stateless_rpc && count == INITIAL_FLUSH)
 406                                 continue;
 407
 408                         consume_shallow_list(fd[0]);
 409                         do {
 410                                 ack = get_ack(fd[0], result_sha1);
 411                                 if (args.verbose && ack)
 412                                         fprintf(stderr, "got ack %d %s\n", ack,
 413                                                         sha1_to_hex(result_sha1));
 414                                 switch (ack) {
 415                                 case ACK:
 416                                         flushes = 0;
 417                                         multi_ack = 0;
 418                                         retval = 0;
 419                                         goto done;
 420                                 case ACK_common:
 421                                 case ACK_ready:
 422                                 case ACK_continue: {
 423                                         struct commit *commit =
 424                                                 lookup_commit(result_sha1);
 425                                         if (!commit)
 426                                                 die("invalid commit %s", sha1_to_hex(result_sha1));
 427                                         if (args.stateless_rpc
 428                                          && ack == ACK_common
 429                                          && !(commit->object.flags & COMMON)) {
 430                                                 /* We need to replay the have for this object
 431                                                  * on the next RPC request so the peer knows
 432                                                  * it is in common with us.
 433                                                  */
 434                                                 const char *hex = sha1_to_hex(result_sha1);
 435                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 436                                                 state_len = req_buf.len;
 437                                         }
 438                                         mark_common(commit, 0, 1);
 439                                         retval = 0;
 440                                         in_vain = 0;
 441                                         got_continue = 1;
 442                                         if (ack == ACK_ready) {
 443                                                 rev_list = NULL;
 444                                                 got_ready = 1;
 445                                         }
 446                                         break;
 447                                         }
 448                                 }
 449                         } while (ack);
 450                         flushes--;
 451                         if (got_continue && MAX_IN_VAIN < in_vain) {
 452                                 if (args.verbose)
 453                                         fprintf(stderr, "giving up\n");
 454                                 break; /* give up */
 455                         }
 456                 }
 457         }
 458 done:
 459         if (!got_ready || !no_done) {
 460                 packet_buf_write(&req_buf, "done\n");
 461                 send_request(fd[1], &req_buf);
 462         }
 463         if (args.verbose)
 464                 fprintf(stderr, "done\n");
 465         if (retval != 0) {
 466                 multi_ack = 0;
 467                 flushes++;
 468         }
 469         strbuf_release(&req_buf);
 470
 471         consume_shallow_list(fd[0]);
 472         while (flushes || multi_ack) {
 473                 int ack = get_ack(fd[0], result_sha1);
 474                 if (ack) {
 475                         if (args.verbose)
 476                                 fprintf(stderr, "got ack (%d) %s\n", ack,
 477                                         sha1_to_hex(result_sha1));
 478                         if (ack == ACK)
 479                                 return 0;
 480                         multi_ack = 1;
 481                         continue;
 482                 }
 483                 flushes--;
 484         }
 485         /* it is no error to fetch into a completely empty repo */
 486         return count ? retval : 0;
 487 }
 488
 489 static struct commit_list *complete;
 490
 491 static int mark_complete(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 492 {
 493         struct object *o = parse_object(sha1);
 494
 495         while (o && o->type == OBJ_TAG) {
 496                 struct tag *t = (struct tag *) o;
 497                 if (!t->tagged)
 498                         break; /* broken repository */
 499                 o->flags |= COMPLETE;
 500                 o = parse_object(t->tagged->sha1);
 501         }
 502         if (o && o->type == OBJ_COMMIT) {
 503                 struct commit *commit = (struct commit *)o;
 504                 if (!(commit->object.flags & COMPLETE)) {
 505                         commit->object.flags |= COMPLETE;
 506                         commit_list_insert_by_date(commit, &complete);
 507                 }
 508         }
 509         return 0;
 510 }
 511
 512 static void mark_recent_complete_commits(unsigned long cutoff)
 513 {
 514         while (complete && cutoff <= complete->item->date) {
 515                 if (args.verbose)
 516                         fprintf(stderr, "Marking %s as complete\n",
 517                                 sha1_to_hex(complete->item->object.sha1));
 518                 pop_most_recent_commit(&complete, COMPLETE);
 519         }
 520 }
 521
 522 static void filter_refs(struct ref **refs, int nr_match, char **match)
 523 {
 524         struct ref **return_refs;
 525         struct ref *newlist = NULL;
 526         struct ref **newtail = &newlist;
 527         struct ref *ref, *next;
 528         struct ref *fastarray[32];
 529
 530         if (nr_match && !args.fetch_all) {
 531                 if (ARRAY_SIZE(fastarray) < nr_match)
 532                         return_refs = xcalloc(nr_match, sizeof(struct ref *));
 533                 else {
 534                         return_refs = fastarray;
 535                         memset(return_refs, 0, sizeof(struct ref *) * nr_match);
 536                 }
 537         }
 538         else
 539                 return_refs = NULL;
 540
 541         for (ref = *refs; ref; ref = next) {
 542                 next = ref->next;
 543                 if (!memcmp(ref->name, "refs/", 5) &&
 544                     check_refname_format(ref->name + 5, 0))
 545                         ; /* trash */
 546                 else if (args.fetch_all &&
 547                          (!args.depth || prefixcmp(ref->name, "refs/tags/") )) {
 548                         *newtail = ref;
 549                         ref->next = NULL;
 550                         newtail = &ref->next;
 551                         continue;
 552                 }
 553                 else {
 554                         int i;
 555                         for (i = 0; i < nr_match; i++) {
 556                                 if (!strcmp(ref->name, match[i])) {
 557                                         match[i][0] = '\0';
 558                                         return_refs[i] = ref;
 559                                         break;
 560                                 }
 561                         }
 562                         if (i < nr_match)
 563                                 continue; /* we will link it later */
 564                 }
 565                 free(ref);
 566         }
 567
 568         if (!args.fetch_all) {
 569                 int i;
 570                 for (i = 0; i < nr_match; i++) {
 571                         ref = return_refs[i];
 572                         if (ref) {
 573                                 *newtail = ref;
 574                                 ref->next = NULL;
 575                                 newtail = &ref->next;
 576                         }
 577                 }
 578                 if (return_refs != fastarray)
 579                         free(return_refs);
 580         }
 581         *refs = newlist;
 582 }
 583
 584 static int everything_local(struct ref **refs, int nr_match, char **match)
 585 {
 586         struct ref *ref;
 587         int retval;
 588         unsigned long cutoff = 0;
 589
 590         save_commit_buffer = 0;
 591
 592         for (ref = *refs; ref; ref = ref->next) {
 593                 struct object *o;
 594
 595                 o = parse_object(ref->old_sha1);
 596                 if (!o)
 597                         continue;
 598
 599                 /* We already have it -- which may mean that we were
 600                  * in sync with the other side at some time after
 601                  * that (it is OK if we guess wrong here).
 602                  */
 603                 if (o->type == OBJ_COMMIT) {
 604                         struct commit *commit = (struct commit *)o;
 605                         if (!cutoff || cutoff < commit->date)
 606                                 cutoff = commit->date;
 607                 }
 608         }
 609
 610         if (!args.depth) {
 611                 for_each_ref(mark_complete, NULL);
 612                 if (cutoff)
 613                         mark_recent_complete_commits(cutoff);
 614         }
 615
 616         /*
 617          * Mark all complete remote refs as common refs.
 618          * Don't mark them common yet; the server has to be told so first.
 619          */
 620         for (ref = *refs; ref; ref = ref->next) {
 621                 struct object *o = deref_tag(lookup_object(ref->old_sha1),
 622                                              NULL, 0);
 623
 624                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 625                         continue;
 626
 627                 if (!(o->flags & SEEN)) {
 628                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 629
 630                         mark_common((struct commit *)o, 1, 1);
 631                 }
 632         }
 633
 634         filter_refs(refs, nr_match, match);
 635
 636         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 637                 const unsigned char *remote = ref->old_sha1;
 638                 unsigned char local[20];
 639                 struct object *o;
 640
 641                 o = lookup_object(remote);
 642                 if (!o || !(o->flags & COMPLETE)) {
 643                         retval = 0;
 644                         if (!args.verbose)
 645                                 continue;
 646                         fprintf(stderr,
 647                                 "want %s (%s)\n", sha1_to_hex(remote),
 648                                 ref->name);
 649                         continue;
 650                 }
 651
 652                 hashcpy(ref->new_sha1, local);
 653                 if (!args.verbose)
 654                         continue;
 655                 fprintf(stderr,
 656                         "already have %s (%s)\n", sha1_to_hex(remote),
 657                         ref->name);
 658         }
 659         return retval;
 660 }
 661
 662 static int sideband_demux(int in, int out, void *data)
 663 {
 664         int *xd = data;
 665
 666         int ret = recv_sideband("fetch-pack", xd[0], out);
 667         close(out);
 668         return ret;
 669 }
 670
 671 static int get_pack(int xd[2], char **pack_lockfile)
 672 {
 673         struct async demux;
 674         const char *argv[20];
 675         char keep_arg[256];
 676         char hdr_arg[256];
 677         const char **av;
 678         int do_keep = args.keep_pack;
 679         struct child_process cmd;
 680
 681         memset(&demux, 0, sizeof(demux));
 682         if (use_sideband) {
 683                 /* xd[] is talking with upload-pack; subprocess reads from
 684                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 685                  * through demux->out.
 686                  */
 687                 demux.proc = sideband_demux;
 688                 demux.data = xd;
 689                 demux.out = -1;
 690                 if (start_async(&demux))
 691                         die("fetch-pack: unable to fork off sideband"
 692                             " demultiplexer");
 693         }
 694         else
 695                 demux.out = xd[0];
 696
 697         memset(&cmd, 0, sizeof(cmd));
 698         cmd.argv = argv;
 699         av = argv;
 700         *hdr_arg = 0;
 701         if (!args.keep_pack && unpack_limit) {
 702                 struct pack_header header;
 703
 704                 if (read_pack_header(demux.out, &header))
 705                         die("protocol error: bad pack header");
 706                 snprintf(hdr_arg, sizeof(hdr_arg),
 707                          "--pack_header=%"PRIu32",%"PRIu32,
 708                          ntohl(header.hdr_version), ntohl(header.hdr_entries));
 709                 if (ntohl(header.hdr_entries) < unpack_limit)
 710                         do_keep = 0;
 711                 else
 712                         do_keep = 1;
 713         }
 714
 715         if (do_keep) {
 716                 if (pack_lockfile)
 717                         cmd.out = -1;
 718                 *av++ = "index-pack";
 719                 *av++ = "--stdin";
 720                 if (!args.quiet && !args.no_progress)
 721                         *av++ = "-v";
 722                 if (args.use_thin_pack)
 723                         *av++ = "--fix-thin";
 724                 if (args.lock_pack || unpack_limit) {
 725                         int s = sprintf(keep_arg,
 726                                         "--keep=fetch-pack %"PRIuMAX " on ", (uintmax_t) getpid());
 727                         if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 728                                 strcpy(keep_arg + s, "localhost");
 729                         *av++ = keep_arg;
 730                 }
 731         }
 732         else {
 733                 *av++ = "unpack-objects";
 734                 if (args.quiet)
 735                         *av++ = "-q";
 736         }
 737         if (*hdr_arg)
 738                 *av++ = hdr_arg;
 739         if (fetch_fsck_objects >= 0
 740             ? fetch_fsck_objects
 741             : transfer_fsck_objects >= 0
 742             ? transfer_fsck_objects
 743             : 0)
 744                 *av++ = "--strict";
 745         *av++ = NULL;
 746
 747         cmd.in = demux.out;
 748         cmd.git_cmd = 1;
 749         if (start_command(&cmd))
 750                 die("fetch-pack: unable to fork off %s", argv[0]);
 751         if (do_keep && pack_lockfile) {
 752                 *pack_lockfile = index_pack_lockfile(cmd.out);
 753                 close(cmd.out);
 754         }
 755
 756         if (finish_command(&cmd))
 757                 die("%s failed", argv[0]);
 758         if (use_sideband && finish_async(&demux))
 759                 die("error in sideband demultiplexer");
 760         return 0;
 761 }
 762
 763 static struct ref *do_fetch_pack(int fd[2],
 764                 const struct ref *orig_ref,
 765                 int nr_match,
 766                 char **match,
 767                 char **pack_lockfile)
 768 {
 769         struct ref *ref = copy_ref_list(orig_ref);
 770         unsigned char sha1[20];
 771
 772         if (is_repository_shallow() && !server_supports("shallow"))
 773                 die("Server does not support shallow clients");
 774         if (server_supports("multi_ack_detailed")) {
 775                 if (args.verbose)
 776                         fprintf(stderr, "Server supports multi_ack_detailed\n");
 777                 multi_ack = 2;
 778                 if (server_supports("no-done")) {
 779                         if (args.verbose)
 780                                 fprintf(stderr, "Server supports no-done\n");
 781                         if (args.stateless_rpc)
 782                                 no_done = 1;
 783                 }
 784         }
 785         else if (server_supports("multi_ack")) {
 786                 if (args.verbose)
 787                         fprintf(stderr, "Server supports multi_ack\n");
 788                 multi_ack = 1;
 789         }
 790         if (server_supports("side-band-64k")) {
 791                 if (args.verbose)
 792                         fprintf(stderr, "Server supports side-band-64k\n");
 793                 use_sideband = 2;
 794         }
 795         else if (server_supports("side-band")) {
 796                 if (args.verbose)
 797                         fprintf(stderr, "Server supports side-band\n");
 798                 use_sideband = 1;
 799         }
 800         if (server_supports("ofs-delta")) {
 801                 if (args.verbose)
 802                         fprintf(stderr, "Server supports ofs-delta\n");
 803         } else
 804                 prefer_ofs_delta = 0;
 805         if (everything_local(&ref, nr_match, match)) {
 806                 packet_flush(fd[1]);
 807                 goto all_done;
 808         }
 809         if (find_common(fd, sha1, ref) < 0)
 810                 if (!args.keep_pack)
 811                         /* When cloning, it is not unusual to have
 812                          * no common commit.
 813                          */
 814                         warning("no common commits");
 815
 816         if (args.stateless_rpc)
 817                 packet_flush(fd[1]);
 818         if (get_pack(fd, pack_lockfile))
 819                 die("git fetch-pack: fetch failed.");
 820
 821  all_done:
 822         return ref;
 823 }
 824
 825 static int remove_duplicates(int nr_heads, char **heads)
 826 {
 827         int src, dst;
 828
 829         for (src = dst = 0; src < nr_heads; src++) {
 830                 /* If heads[src] is different from any of
 831                  * heads[0..dst], push it in.
 832                  */
 833                 int i;
 834                 for (i = 0; i < dst; i++) {
 835                         if (!strcmp(heads[i], heads[src]))
 836                                 break;
 837                 }
 838                 if (i < dst)
 839                         continue;
 840                 if (src != dst)
 841                         heads[dst] = heads[src];
 842                 dst++;
 843         }
 844         return dst;
 845 }
 846
 847 static int fetch_pack_config(const char *var, const char *value, void *cb)
 848 {
 849         if (strcmp(var, "fetch.unpacklimit") == 0) {
 850                 fetch_unpack_limit = git_config_int(var, value);
 851                 return 0;
 852         }
 853
 854         if (strcmp(var, "transfer.unpacklimit") == 0) {
 855                 transfer_unpack_limit = git_config_int(var, value);
 856                 return 0;
 857         }
 858
 859         if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
 860                 prefer_ofs_delta = git_config_bool(var, value);
 861                 return 0;
 862         }
 863
 864         if (!strcmp(var, "fetch.fsckobjects")) {
 865                 fetch_fsck_objects = git_config_bool(var, value);
 866                 return 0;
 867         }
 868
 869         if (!strcmp(var, "transfer.fsckobjects")) {
 870                 transfer_fsck_objects = git_config_bool(var, value);
 871                 return 0;
 872         }
 873
 874         return git_default_config(var, value, cb);
 875 }
 876
 877 static struct lock_file lock;
 878
 879 static void fetch_pack_setup(void)
 880 {
 881         static int did_setup;
 882         if (did_setup)
 883                 return;
 884         git_config(fetch_pack_config, NULL);
 885         if (0 <= transfer_unpack_limit)
 886                 unpack_limit = transfer_unpack_limit;
 887         else if (0 <= fetch_unpack_limit)
 888                 unpack_limit = fetch_unpack_limit;
 889         did_setup = 1;
 890 }
 891
 892 int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 893 {
 894         int i, ret, nr_heads;
 895         struct ref *ref = NULL;
 896         char *dest = NULL, **heads;
 897         int fd[2];
 898         char *pack_lockfile = NULL;
 899         char **pack_lockfile_ptr = NULL;
 900         struct child_process *conn;
 901
 902         packet_trace_identity("fetch-pack");
 903
 904         nr_heads = 0;
 905         heads = NULL;
 906         for (i = 1; i < argc; i++) {
 907                 const char *arg = argv[i];
 908
 909                 if (*arg == '-') {
 910                         if (!prefixcmp(arg, "--upload-pack=")) {
 911                                 args.uploadpack = arg + 14;
 912                                 continue;
 913                         }
 914                         if (!prefixcmp(arg, "--exec=")) {
 915                                 args.uploadpack = arg + 7;
 916                                 continue;
 917                         }
 918                         if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
 919                                 args.quiet = 1;
 920                                 continue;
 921                         }
 922                         if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
 923                                 args.lock_pack = args.keep_pack;
 924                                 args.keep_pack = 1;
 925                                 continue;
 926                         }
 927                         if (!strcmp("--thin", arg)) {
 928                                 args.use_thin_pack = 1;
 929                                 continue;
 930                         }
 931                         if (!strcmp("--include-tag", arg)) {
 932                                 args.include_tag = 1;
 933                                 continue;
 934                         }
 935                         if (!strcmp("--all", arg)) {
 936                                 args.fetch_all = 1;
 937                                 continue;
 938                         }
 939                         if (!strcmp("-v", arg)) {
 940                                 args.verbose = 1;
 941                                 continue;
 942                         }
 943                         if (!prefixcmp(arg, "--depth=")) {
 944                                 args.depth = strtol(arg + 8, NULL, 0);
 945                                 continue;
 946                         }
 947                         if (!strcmp("--no-progress", arg)) {
 948                                 args.no_progress = 1;
 949                                 continue;
 950                         }
 951                         if (!strcmp("--stateless-rpc", arg)) {
 952                                 args.stateless_rpc = 1;
 953                                 continue;
 954                         }
 955                         if (!strcmp("--lock-pack", arg)) {
 956                                 args.lock_pack = 1;
 957                                 pack_lockfile_ptr = &pack_lockfile;
 958                                 continue;
 959                         }
 960                         usage(fetch_pack_usage);
 961                 }
 962                 dest = (char *)arg;
 963                 heads = (char **)(argv + i + 1);
 964                 nr_heads = argc - i - 1;
 965                 break;
 966         }
 967         if (!dest)
 968                 usage(fetch_pack_usage);
 969
 970         if (args.stateless_rpc) {
 971                 conn = NULL;
 972                 fd[0] = 0;
 973                 fd[1] = 1;
 974         } else {
 975                 conn = git_connect(fd, (char *)dest, args.uploadpack,
 976                                    args.verbose ? CONNECT_VERBOSE : 0);
 977         }
 978
 979         get_remote_heads(fd[0], &ref, 0, NULL);
 980
 981         ref = fetch_pack(&args, fd, conn, ref, dest,
 982                 nr_heads, heads, pack_lockfile_ptr);
 983         if (pack_lockfile) {
 984                 printf("lock %s\n", pack_lockfile);
 985                 fflush(stdout);
 986         }
 987         close(fd[0]);
 988         close(fd[1]);
 989         if (finish_connect(conn))
 990                 ref = NULL;
 991         ret = !ref;
 992
 993         if (!ret && nr_heads) {
 994                 /* If the heads to pull were given, we should have
 995                  * consumed all of them by matching the remote.
 996                  * Otherwise, 'git fetch remote no-such-ref' would
 997                  * silently succeed without issuing an error.
 998                  */
 999                 for (i = 0; i < nr_heads; i++)
1000                         if (heads[i] && heads[i][0]) {
1001                                 error("no such remote ref %s", heads[i]);
1002                                 ret = 1;
1003                         }
1004         }
1005         while (ref) {
1006                 printf("%s %s\n",
1007                        sha1_to_hex(ref->old_sha1), ref->name);
1008                 ref = ref->next;
1009         }
1010
1011         return ret;
1012 }
1013
1014 struct ref *fetch_pack(struct fetch_pack_args *my_args,
1015                        int fd[], struct child_process *conn,
1016                        const struct ref *ref,
1017                 const char *dest,
1018                 int nr_heads,
1019                 char **heads,
1020                 char **pack_lockfile)
1021 {
1022         struct stat st;
1023         struct ref *ref_cpy;
1024
1025         fetch_pack_setup();
1026         if (&args != my_args)
1027                 memcpy(&args, my_args, sizeof(args));
1028         if (args.depth > 0) {
1029                 if (stat(git_path("shallow"), &st))
1030                         st.st_mtime = 0;
1031         }
1032
1033         if (heads && nr_heads)
1034                 nr_heads = remove_duplicates(nr_heads, heads);
1035         if (!ref) {
1036                 packet_flush(fd[1]);
1037                 die("no matching remote head");
1038         }
1039         ref_cpy = do_fetch_pack(fd, ref, nr_heads, heads, pack_lockfile);
1040
1041         if (args.depth > 0) {
1042                 struct cache_time mtime;
1043                 struct strbuf sb = STRBUF_INIT;
1044                 char *shallow = git_path("shallow");
1045                 int fd;
1046
1047                 mtime.sec = st.st_mtime;
1048                 mtime.nsec = ST_MTIME_NSEC(st);
1049                 if (stat(shallow, &st)) {
1050                         if (mtime.sec)
1051                                 die("shallow file was removed during fetch");
1052                 } else if (st.st_mtime != mtime.sec
1053 #ifdef USE_NSEC
1054                                 || ST_MTIME_NSEC(st) != mtime.nsec
1055 #endif
1056                           )
1057                         die("shallow file was changed during fetch");
1058
1059                 fd = hold_lock_file_for_update(&lock, shallow,
1060                                                LOCK_DIE_ON_ERROR);
1061                 if (!write_shallow_commits(&sb, 0)
1062                  || write_in_full(fd, sb.buf, sb.len) != sb.len) {
1063                         unlink_or_warn(shallow);
1064                         rollback_lock_file(&lock);
1065                 } else {
1066                         commit_lock_file(&lock);
1067                 }
1068                 strbuf_release(&sb);
1069         }
1070
1071         reprepare_packed_git();
1072         return ref_cpy;
1073 }