git.oblomov.eu Git - git/blob - fetch-pack.c

   1 #include "cache.h"
   2 #include "repository.h"
   3 #include "config.h"
   4 #include "lockfile.h"
   5 #include "refs.h"
   6 #include "pkt-line.h"
   7 #include "commit.h"
   8 #include "tag.h"
   9 #include "exec-cmd.h"
  10 #include "pack.h"
  11 #include "sideband.h"
  12 #include "fetch-pack.h"
  13 #include "remote.h"
  14 #include "run-command.h"
  15 #include "connect.h"
  16 #include "transport.h"
  17 #include "version.h"
  18 #include "sha1-array.h"
  19 #include "oidset.h"
  20 #include "packfile.h"
  21 #include "object-store.h"
  22 #include "connected.h"
  23 #include "fetch-negotiator.h"
  24 #include "fsck.h"
  25
  26 static int transfer_unpack_limit = -1;
  27 static int fetch_unpack_limit = -1;
  28 static int unpack_limit = 100;
  29 static int prefer_ofs_delta = 1;
  30 static int no_done;
  31 static int deepen_since_ok;
  32 static int deepen_not_ok;
  33 static int fetch_fsck_objects = -1;
  34 static int transfer_fsck_objects = -1;
  35 static int agent_supported;
  36 static int server_supports_filtering;
  37 static struct lock_file shallow_lock;
  38 static const char *alternate_shallow_file;
  39 static char *negotiation_algorithm;
  40 static struct strbuf fsck_msg_types = STRBUF_INIT;
  41
  42 /* Remember to update object flag allocation in object.h */
  43 #define COMPLETE        (1U << 0)
  44 #define ALTERNATE       (1U << 1)
  45
  46 /*
  47  * After sending this many "have"s if we do not get any new ACK , we
  48  * give up traversing our history.
  49  */
  50 #define MAX_IN_VAIN 256
  51
  52 static int multi_ack, use_sideband;
  53 /* Allow specifying sha1 if it is a ref tip. */
  54 #define ALLOW_TIP_SHA1  01
  55 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  56 #define ALLOW_REACHABLE_SHA1    02
  57 static unsigned int allow_unadvertised_object_request;
  58
  59 __attribute__((format (printf, 2, 3)))
  60 static inline void print_verbose(const struct fetch_pack_args *args,
  61                                  const char *fmt, ...)
  62 {
  63         va_list params;
  64
  65         if (!args->verbose)
  66                 return;
  67
  68         va_start(params, fmt);
  69         vfprintf(stderr, fmt, params);
  70         va_end(params);
  71         fputc('\n', stderr);
  72 }
  73
  74 struct alternate_object_cache {
  75         struct object **items;
  76         size_t nr, alloc;
  77 };
  78
  79 static void cache_one_alternate(const char *refname,
  80                                 const struct object_id *oid,
  81                                 void *vcache)
  82 {
  83         struct alternate_object_cache *cache = vcache;
  84         struct object *obj = parse_object(the_repository, oid);
  85
  86         if (!obj || (obj->flags & ALTERNATE))
  87                 return;
  88
  89         obj->flags |= ALTERNATE;
  90         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  91         cache->items[cache->nr++] = obj;
  92 }
  93
  94 static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
  95                                       void (*cb)(struct fetch_negotiator *,
  96                                                  struct object *))
  97 {
  98         static int initialized;
  99         static struct alternate_object_cache cache;
 100         size_t i;
 101
 102         if (!initialized) {
 103                 for_each_alternate_ref(cache_one_alternate, &cache);
 104                 initialized = 1;
 105         }
 106
 107         for (i = 0; i < cache.nr; i++)
 108                 cb(negotiator, cache.items[i]);
 109 }
 110
 111 static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
 112                                const char *refname,
 113                                const struct object_id *oid)
 114 {
 115         struct object *o = deref_tag(the_repository,
 116                                      parse_object(the_repository, oid),
 117                                      refname, 0);
 118
 119         if (o && o->type == OBJ_COMMIT)
 120                 negotiator->add_tip(negotiator, (struct commit *)o);
 121
 122         return 0;
 123 }
 124
 125 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 126                                    int flag, void *cb_data)
 127 {
 128         return rev_list_insert_ref(cb_data, refname, oid);
 129 }
 130
 131 enum ack_type {
 132         NAK = 0,
 133         ACK,
 134         ACK_continue,
 135         ACK_common,
 136         ACK_ready
 137 };
 138
 139 static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 140 {
 141         if (args->stateless_rpc && args->deepen) {
 142                 /* If we sent a depth we will get back "duplicate"
 143                  * shallow and unshallow commands every time there
 144                  * is a block of have lines exchanged.
 145                  */
 146                 char *line;
 147                 while ((line = packet_read_line(fd, NULL))) {
 148                         if (starts_with(line, "shallow "))
 149                                 continue;
 150                         if (starts_with(line, "unshallow "))
 151                                 continue;
 152                         die(_("git fetch-pack: expected shallow list"));
 153                 }
 154         }
 155 }
 156
 157 static enum ack_type get_ack(int fd, struct object_id *result_oid)
 158 {
 159         int len;
 160         char *line = packet_read_line(fd, &len);
 161         const char *arg;
 162
 163         if (!line)
 164                 die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 165         if (!strcmp(line, "NAK"))
 166                 return NAK;
 167         if (skip_prefix(line, "ACK ", &arg)) {
 168                 if (!get_oid_hex(arg, result_oid)) {
 169                         arg += 40;
 170                         len -= arg - line;
 171                         if (len < 1)
 172                                 return ACK;
 173                         if (strstr(arg, "continue"))
 174                                 return ACK_continue;
 175                         if (strstr(arg, "common"))
 176                                 return ACK_common;
 177                         if (strstr(arg, "ready"))
 178                                 return ACK_ready;
 179                         return ACK;
 180                 }
 181         }
 182         if (skip_prefix(line, "ERR ", &arg))
 183                 die(_("remote error: %s"), arg);
 184         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 185 }
 186
 187 static void send_request(struct fetch_pack_args *args,
 188                          int fd, struct strbuf *buf)
 189 {
 190         if (args->stateless_rpc) {
 191                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 192                 packet_flush(fd);
 193         } else
 194                 write_or_die(fd, buf->buf, buf->len);
 195 }
 196
 197 static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 198                                         struct object *obj)
 199 {
 200         rev_list_insert_ref(negotiator, NULL, &obj->oid);
 201 }
 202
 203 #define INITIAL_FLUSH 16
 204 #define PIPESAFE_FLUSH 32
 205 #define LARGE_FLUSH 16384
 206
 207 static int next_flush(int stateless_rpc, int count)
 208 {
 209         if (stateless_rpc) {
 210                 if (count < LARGE_FLUSH)
 211                         count <<= 1;
 212                 else
 213                         count = count * 11 / 10;
 214         } else {
 215                 if (count < PIPESAFE_FLUSH)
 216                         count <<= 1;
 217                 else
 218                         count += PIPESAFE_FLUSH;
 219         }
 220         return count;
 221 }
 222
 223 static void mark_tips(struct fetch_negotiator *negotiator,
 224                       const struct oid_array *negotiation_tips)
 225 {
 226         int i;
 227
 228         if (!negotiation_tips) {
 229                 for_each_ref(rev_list_insert_ref_oid, negotiator);
 230                 return;
 231         }
 232
 233         for (i = 0; i < negotiation_tips->nr; i++)
 234                 rev_list_insert_ref(negotiator, NULL,
 235                                     &negotiation_tips->oid[i]);
 236         return;
 237 }
 238
 239 static int find_common(struct fetch_negotiator *negotiator,
 240                        struct fetch_pack_args *args,
 241                        int fd[2], struct object_id *result_oid,
 242                        struct ref *refs)
 243 {
 244         int fetching;
 245         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 246         const struct object_id *oid;
 247         unsigned in_vain = 0;
 248         int got_continue = 0;
 249         int got_ready = 0;
 250         struct strbuf req_buf = STRBUF_INIT;
 251         size_t state_len = 0;
 252
 253         if (args->stateless_rpc && multi_ack == 1)
 254                 die(_("--stateless-rpc requires multi_ack_detailed"));
 255
 256         mark_tips(negotiator, args->negotiation_tips);
 257         for_each_cached_alternate(negotiator, insert_one_alternate_object);
 258
 259         fetching = 0;
 260         for ( ; refs ; refs = refs->next) {
 261                 struct object_id *remote = &refs->old_oid;
 262                 const char *remote_hex;
 263                 struct object *o;
 264
 265                 /*
 266                  * If that object is complete (i.e. it is an ancestor of a
 267                  * local ref), we tell them we have it but do not have to
 268                  * tell them about its ancestors, which they already know
 269                  * about.
 270                  *
 271                  * We use lookup_object here because we are only
 272                  * interested in the case we *know* the object is
 273                  * reachable and we have already scanned it.
 274                  */
 275                 if (((o = lookup_object(the_repository, remote->hash)) != NULL) &&
 276                                 (o->flags & COMPLETE)) {
 277                         continue;
 278                 }
 279
 280                 remote_hex = oid_to_hex(remote);
 281                 if (!fetching) {
 282                         struct strbuf c = STRBUF_INIT;
 283                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 284                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 285                         if (no_done)            strbuf_addstr(&c, " no-done");
 286                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 287                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 288                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 289                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 290                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 291                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 292                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 293                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 294                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 295                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 296                                                             git_user_agent_sanitized());
 297                         if (args->filter_options.choice)
 298                                 strbuf_addstr(&c, " filter");
 299                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 300                         strbuf_release(&c);
 301                 } else
 302                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 303                 fetching++;
 304         }
 305
 306         if (!fetching) {
 307                 strbuf_release(&req_buf);
 308                 packet_flush(fd[1]);
 309                 return 1;
 310         }
 311
 312         if (is_repository_shallow(the_repository))
 313                 write_shallow_commits(&req_buf, 1, NULL);
 314         if (args->depth > 0)
 315                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 316         if (args->deepen_since) {
 317                 timestamp_t max_age = approxidate(args->deepen_since);
 318                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 319         }
 320         if (args->deepen_not) {
 321                 int i;
 322                 for (i = 0; i < args->deepen_not->nr; i++) {
 323                         struct string_list_item *s = args->deepen_not->items + i;
 324                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 325                 }
 326         }
 327         if (server_supports_filtering && args->filter_options.choice)
 328                 packet_buf_write(&req_buf, "filter %s",
 329                                  args->filter_options.filter_spec);
 330         packet_buf_flush(&req_buf);
 331         state_len = req_buf.len;
 332
 333         if (args->deepen) {
 334                 char *line;
 335                 const char *arg;
 336                 struct object_id oid;
 337
 338                 send_request(args, fd[1], &req_buf);
 339                 while ((line = packet_read_line(fd[0], NULL))) {
 340                         if (skip_prefix(line, "shallow ", &arg)) {
 341                                 if (get_oid_hex(arg, &oid))
 342                                         die(_("invalid shallow line: %s"), line);
 343                                 register_shallow(the_repository, &oid);
 344                                 continue;
 345                         }
 346                         if (skip_prefix(line, "unshallow ", &arg)) {
 347                                 if (get_oid_hex(arg, &oid))
 348                                         die(_("invalid unshallow line: %s"), line);
 349                                 if (!lookup_object(the_repository, oid.hash))
 350                                         die(_("object not found: %s"), line);
 351                                 /* make sure that it is parsed as shallow */
 352                                 if (!parse_object(the_repository, &oid))
 353                                         die(_("error in object: %s"), line);
 354                                 if (unregister_shallow(&oid))
 355                                         die(_("no shallow found: %s"), line);
 356                                 continue;
 357                         }
 358                         die(_("expected shallow/unshallow, got %s"), line);
 359                 }
 360         } else if (!args->stateless_rpc)
 361                 send_request(args, fd[1], &req_buf);
 362
 363         if (!args->stateless_rpc) {
 364                 /* If we aren't using the stateless-rpc interface
 365                  * we don't need to retain the headers.
 366                  */
 367                 strbuf_setlen(&req_buf, 0);
 368                 state_len = 0;
 369         }
 370
 371         flushes = 0;
 372         retval = -1;
 373         if (args->no_dependents)
 374                 goto done;
 375         while ((oid = negotiator->next(negotiator))) {
 376                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 377                 print_verbose(args, "have %s", oid_to_hex(oid));
 378                 in_vain++;
 379                 if (flush_at <= ++count) {
 380                         int ack;
 381
 382                         packet_buf_flush(&req_buf);
 383                         send_request(args, fd[1], &req_buf);
 384                         strbuf_setlen(&req_buf, state_len);
 385                         flushes++;
 386                         flush_at = next_flush(args->stateless_rpc, count);
 387
 388                         /*
 389                          * We keep one window "ahead" of the other side, and
 390                          * will wait for an ACK only on the next one
 391                          */
 392                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 393                                 continue;
 394
 395                         consume_shallow_list(args, fd[0]);
 396                         do {
 397                                 ack = get_ack(fd[0], result_oid);
 398                                 if (ack)
 399                                         print_verbose(args, _("got %s %d %s"), "ack",
 400                                                       ack, oid_to_hex(result_oid));
 401                                 switch (ack) {
 402                                 case ACK:
 403                                         flushes = 0;
 404                                         multi_ack = 0;
 405                                         retval = 0;
 406                                         goto done;
 407                                 case ACK_common:
 408                                 case ACK_ready:
 409                                 case ACK_continue: {
 410                                         struct commit *commit =
 411                                                 lookup_commit(the_repository,
 412                                                               result_oid);
 413                                         int was_common;
 414
 415                                         if (!commit)
 416                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
 417                                         was_common = negotiator->ack(negotiator, commit);
 418                                         if (args->stateless_rpc
 419                                          && ack == ACK_common
 420                                          && !was_common) {
 421                                                 /* We need to replay the have for this object
 422                                                  * on the next RPC request so the peer knows
 423                                                  * it is in common with us.
 424                                                  */
 425                                                 const char *hex = oid_to_hex(result_oid);
 426                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 427                                                 state_len = req_buf.len;
 428                                                 /*
 429                                                  * Reset in_vain because an ack
 430                                                  * for this commit has not been
 431                                                  * seen.
 432                                                  */
 433                                                 in_vain = 0;
 434                                         } else if (!args->stateless_rpc
 435                                                    || ack != ACK_common)
 436                                                 in_vain = 0;
 437                                         retval = 0;
 438                                         got_continue = 1;
 439                                         if (ack == ACK_ready)
 440                                                 got_ready = 1;
 441                                         break;
 442                                         }
 443                                 }
 444                         } while (ack);
 445                         flushes--;
 446                         if (got_continue && MAX_IN_VAIN < in_vain) {
 447                                 print_verbose(args, _("giving up"));
 448                                 break; /* give up */
 449                         }
 450                         if (got_ready)
 451                                 break;
 452                 }
 453         }
 454 done:
 455         if (!got_ready || !no_done) {
 456                 packet_buf_write(&req_buf, "done\n");
 457                 send_request(args, fd[1], &req_buf);
 458         }
 459         print_verbose(args, _("done"));
 460         if (retval != 0) {
 461                 multi_ack = 0;
 462                 flushes++;
 463         }
 464         strbuf_release(&req_buf);
 465
 466         if (!got_ready || !no_done)
 467                 consume_shallow_list(args, fd[0]);
 468         while (flushes || multi_ack) {
 469                 int ack = get_ack(fd[0], result_oid);
 470                 if (ack) {
 471                         print_verbose(args, _("got %s (%d) %s"), "ack",
 472                                       ack, oid_to_hex(result_oid));
 473                         if (ack == ACK)
 474                                 return 0;
 475                         multi_ack = 1;
 476                         continue;
 477                 }
 478                 flushes--;
 479         }
 480         /* it is no error to fetch into a completely empty repo */
 481         return count ? retval : 0;
 482 }
 483
 484 static struct commit_list *complete;
 485
 486 static int mark_complete(const struct object_id *oid)
 487 {
 488         struct object *o = parse_object(the_repository, oid);
 489
 490         while (o && o->type == OBJ_TAG) {
 491                 struct tag *t = (struct tag *) o;
 492                 if (!t->tagged)
 493                         break; /* broken repository */
 494                 o->flags |= COMPLETE;
 495                 o = parse_object(the_repository, &t->tagged->oid);
 496         }
 497         if (o && o->type == OBJ_COMMIT) {
 498                 struct commit *commit = (struct commit *)o;
 499                 if (!(commit->object.flags & COMPLETE)) {
 500                         commit->object.flags |= COMPLETE;
 501                         commit_list_insert(commit, &complete);
 502                 }
 503         }
 504         return 0;
 505 }
 506
 507 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 508                              int flag, void *cb_data)
 509 {
 510         return mark_complete(oid);
 511 }
 512
 513 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 514                                          timestamp_t cutoff)
 515 {
 516         while (complete && cutoff <= complete->item->date) {
 517                 print_verbose(args, _("Marking %s as complete"),
 518                               oid_to_hex(&complete->item->object.oid));
 519                 pop_most_recent_commit(&complete, COMPLETE);
 520         }
 521 }
 522
 523 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 524 {
 525         for (; refs; refs = refs->next)
 526                 oidset_insert(oids, &refs->old_oid);
 527 }
 528
 529 static int is_unmatched_ref(const struct ref *ref)
 530 {
 531         struct object_id oid;
 532         const char *p;
 533         return  ref->match_status == REF_NOT_MATCHED &&
 534                 !parse_oid_hex(ref->name, &oid, &p) &&
 535                 *p == '\0' &&
 536                 oideq(&oid, &ref->old_oid);
 537 }
 538
 539 static void filter_refs(struct fetch_pack_args *args,
 540                         struct ref **refs,
 541                         struct ref **sought, int nr_sought)
 542 {
 543         struct ref *newlist = NULL;
 544         struct ref **newtail = &newlist;
 545         struct ref *unmatched = NULL;
 546         struct ref *ref, *next;
 547         struct oidset tip_oids = OIDSET_INIT;
 548         int i;
 549         int strict = !(allow_unadvertised_object_request &
 550                        (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
 551
 552         i = 0;
 553         for (ref = *refs; ref; ref = next) {
 554                 int keep = 0;
 555                 next = ref->next;
 556
 557                 if (starts_with(ref->name, "refs/") &&
 558                     check_refname_format(ref->name, 0))
 559                         ; /* trash */
 560                 else {
 561                         while (i < nr_sought) {
 562                                 int cmp = strcmp(ref->name, sought[i]->name);
 563                                 if (cmp < 0)
 564                                         break; /* definitely do not have it */
 565                                 else if (cmp == 0) {
 566                                         keep = 1; /* definitely have it */
 567                                         sought[i]->match_status = REF_MATCHED;
 568                                 }
 569                                 i++;
 570                         }
 571
 572                         if (!keep && args->fetch_all &&
 573                             (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 574                                 keep = 1;
 575                 }
 576
 577                 if (keep) {
 578                         *newtail = ref;
 579                         ref->next = NULL;
 580                         newtail = &ref->next;
 581                 } else {
 582                         ref->next = unmatched;
 583                         unmatched = ref;
 584                 }
 585         }
 586
 587         if (strict) {
 588                 for (i = 0; i < nr_sought; i++) {
 589                         ref = sought[i];
 590                         if (!is_unmatched_ref(ref))
 591                                 continue;
 592
 593                         add_refs_to_oidset(&tip_oids, unmatched);
 594                         add_refs_to_oidset(&tip_oids, newlist);
 595                         break;
 596                 }
 597         }
 598
 599         /* Append unmatched requests to the list */
 600         for (i = 0; i < nr_sought; i++) {
 601                 ref = sought[i];
 602                 if (!is_unmatched_ref(ref))
 603                         continue;
 604
 605                 if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
 606                         ref->match_status = REF_MATCHED;
 607                         *newtail = copy_ref(ref);
 608                         newtail = &(*newtail)->next;
 609                 } else {
 610                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 611                 }
 612         }
 613
 614         oidset_clear(&tip_oids);
 615         for (ref = unmatched; ref; ref = next) {
 616                 next = ref->next;
 617                 free(ref);
 618         }
 619
 620         *refs = newlist;
 621 }
 622
 623 static void mark_alternate_complete(struct fetch_negotiator *unused,
 624                                     struct object *obj)
 625 {
 626         mark_complete(&obj->oid);
 627 }
 628
 629 struct loose_object_iter {
 630         struct oidset *loose_object_set;
 631         struct ref *refs;
 632 };
 633
 634 /*
 635  *  If the number of refs is not larger than the number of loose objects,
 636  *  this function stops inserting.
 637  */
 638 static int add_loose_objects_to_set(const struct object_id *oid,
 639                                     const char *path,
 640                                     void *data)
 641 {
 642         struct loose_object_iter *iter = data;
 643         oidset_insert(iter->loose_object_set, oid);
 644         if (iter->refs == NULL)
 645                 return 1;
 646
 647         iter->refs = iter->refs->next;
 648         return 0;
 649 }
 650
 651 /*
 652  * Mark recent commits available locally and reachable from a local ref as
 653  * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 654  * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 655  * thus do not need COMMON_REF marks).
 656  *
 657  * The cutoff time for recency is determined by this heuristic: it is the
 658  * earliest commit time of the objects in refs that are commits and that we know
 659  * the commit time of.
 660  */
 661 static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 662                                          struct fetch_pack_args *args,
 663                                          struct ref **refs)
 664 {
 665         struct ref *ref;
 666         int old_save_commit_buffer = save_commit_buffer;
 667         timestamp_t cutoff = 0;
 668         struct oidset loose_oid_set = OIDSET_INIT;
 669         int use_oidset = 0;
 670         struct loose_object_iter iter = {&loose_oid_set, *refs};
 671
 672         /* Enumerate all loose objects or know refs are not so many. */
 673         use_oidset = !for_each_loose_object(add_loose_objects_to_set,
 674                                             &iter, 0);
 675
 676         save_commit_buffer = 0;
 677
 678         for (ref = *refs; ref; ref = ref->next) {
 679                 struct object *o;
 680                 unsigned int flags = OBJECT_INFO_QUICK;
 681
 682                 if (use_oidset &&
 683                     !oidset_contains(&loose_oid_set, &ref->old_oid)) {
 684                         /*
 685                          * I know this does not exist in the loose form,
 686                          * so check if it exists in a non-loose form.
 687                          */
 688                         flags |= OBJECT_INFO_IGNORE_LOOSE;
 689                 }
 690
 691                 if (!has_object_file_with_flags(&ref->old_oid, flags))
 692                         continue;
 693                 o = parse_object(the_repository, &ref->old_oid);
 694                 if (!o)
 695                         continue;
 696
 697                 /* We already have it -- which may mean that we were
 698                  * in sync with the other side at some time after
 699                  * that (it is OK if we guess wrong here).
 700                  */
 701                 if (o->type == OBJ_COMMIT) {
 702                         struct commit *commit = (struct commit *)o;
 703                         if (!cutoff || cutoff < commit->date)
 704                                 cutoff = commit->date;
 705                 }
 706         }
 707
 708         oidset_clear(&loose_oid_set);
 709
 710         if (!args->no_dependents) {
 711                 if (!args->deepen) {
 712                         for_each_ref(mark_complete_oid, NULL);
 713                         for_each_cached_alternate(NULL, mark_alternate_complete);
 714                         commit_list_sort_by_date(&complete);
 715                         if (cutoff)
 716                                 mark_recent_complete_commits(args, cutoff);
 717                 }
 718
 719                 /*
 720                  * Mark all complete remote refs as common refs.
 721                  * Don't mark them common yet; the server has to be told so first.
 722                  */
 723                 for (ref = *refs; ref; ref = ref->next) {
 724                         struct object *o = deref_tag(the_repository,
 725                                                      lookup_object(the_repository,
 726                                                      ref->old_oid.hash),
 727                                                      NULL, 0);
 728
 729                         if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 730                                 continue;
 731
 732                         negotiator->known_common(negotiator,
 733                                                  (struct commit *)o);
 734                 }
 735         }
 736
 737         save_commit_buffer = old_save_commit_buffer;
 738 }
 739
 740 /*
 741  * Returns 1 if every object pointed to by the given remote refs is available
 742  * locally and reachable from a local ref, and 0 otherwise.
 743  */
 744 static int everything_local(struct fetch_pack_args *args,
 745                             struct ref **refs)
 746 {
 747         struct ref *ref;
 748         int retval;
 749
 750         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 751                 const struct object_id *remote = &ref->old_oid;
 752                 struct object *o;
 753
 754                 o = lookup_object(the_repository, remote->hash);
 755                 if (!o || !(o->flags & COMPLETE)) {
 756                         retval = 0;
 757                         print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 758                                       ref->name);
 759                         continue;
 760                 }
 761                 print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 762                               ref->name);
 763         }
 764
 765         return retval;
 766 }
 767
 768 static int sideband_demux(int in, int out, void *data)
 769 {
 770         int *xd = data;
 771         int ret;
 772
 773         ret = recv_sideband("fetch-pack", xd[0], out);
 774         close(out);
 775         return ret;
 776 }
 777
 778 static int get_pack(struct fetch_pack_args *args,
 779                     int xd[2], char **pack_lockfile)
 780 {
 781         struct async demux;
 782         int do_keep = args->keep_pack;
 783         const char *cmd_name;
 784         struct pack_header header;
 785         int pass_header = 0;
 786         struct child_process cmd = CHILD_PROCESS_INIT;
 787         int ret;
 788
 789         memset(&demux, 0, sizeof(demux));
 790         if (use_sideband) {
 791                 /* xd[] is talking with upload-pack; subprocess reads from
 792                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 793                  * through demux->out.
 794                  */
 795                 demux.proc = sideband_demux;
 796                 demux.data = xd;
 797                 demux.out = -1;
 798                 demux.isolate_sigpipe = 1;
 799                 if (start_async(&demux))
 800                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 801         }
 802         else
 803                 demux.out = xd[0];
 804
 805         if (!args->keep_pack && unpack_limit) {
 806
 807                 if (read_pack_header(demux.out, &header))
 808                         die(_("protocol error: bad pack header"));
 809                 pass_header = 1;
 810                 if (ntohl(header.hdr_entries) < unpack_limit)
 811                         do_keep = 0;
 812                 else
 813                         do_keep = 1;
 814         }
 815
 816         if (alternate_shallow_file) {
 817                 argv_array_push(&cmd.args, "--shallow-file");
 818                 argv_array_push(&cmd.args, alternate_shallow_file);
 819         }
 820
 821         if (do_keep || args->from_promisor) {
 822                 if (pack_lockfile)
 823                         cmd.out = -1;
 824                 cmd_name = "index-pack";
 825                 argv_array_push(&cmd.args, cmd_name);
 826                 argv_array_push(&cmd.args, "--stdin");
 827                 if (!args->quiet && !args->no_progress)
 828                         argv_array_push(&cmd.args, "-v");
 829                 if (args->use_thin_pack)
 830                         argv_array_push(&cmd.args, "--fix-thin");
 831                 if (do_keep && (args->lock_pack || unpack_limit)) {
 832                         char hostname[HOST_NAME_MAX + 1];
 833                         if (xgethostname(hostname, sizeof(hostname)))
 834                                 xsnprintf(hostname, sizeof(hostname), "localhost");
 835                         argv_array_pushf(&cmd.args,
 836                                         "--keep=fetch-pack %"PRIuMAX " on %s",
 837                                         (uintmax_t)getpid(), hostname);
 838                 }
 839                 if (args->check_self_contained_and_connected)
 840                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 841                 if (args->from_promisor)
 842                         argv_array_push(&cmd.args, "--promisor");
 843         }
 844         else {
 845                 cmd_name = "unpack-objects";
 846                 argv_array_push(&cmd.args, cmd_name);
 847                 if (args->quiet || args->no_progress)
 848                         argv_array_push(&cmd.args, "-q");
 849                 args->check_self_contained_and_connected = 0;
 850         }
 851
 852         if (pass_header)
 853                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 854                                  ntohl(header.hdr_version),
 855                                  ntohl(header.hdr_entries));
 856         if (fetch_fsck_objects >= 0
 857             ? fetch_fsck_objects
 858             : transfer_fsck_objects >= 0
 859             ? transfer_fsck_objects
 860             : 0) {
 861                 if (args->from_promisor)
 862                         /*
 863                          * We cannot use --strict in index-pack because it
 864                          * checks both broken objects and links, but we only
 865                          * want to check for broken objects.
 866                          */
 867                         argv_array_push(&cmd.args, "--fsck-objects");
 868                 else
 869                         argv_array_pushf(&cmd.args, "--strict%s",
 870                                          fsck_msg_types.buf);
 871         }
 872
 873         cmd.in = demux.out;
 874         cmd.git_cmd = 1;
 875         if (start_command(&cmd))
 876                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
 877         if (do_keep && pack_lockfile) {
 878                 *pack_lockfile = index_pack_lockfile(cmd.out);
 879                 close(cmd.out);
 880         }
 881
 882         if (!use_sideband)
 883                 /* Closed by start_command() */
 884                 xd[0] = -1;
 885
 886         ret = finish_command(&cmd);
 887         if (!ret || (args->check_self_contained_and_connected && ret == 1))
 888                 args->self_contained_and_connected =
 889                         args->check_self_contained_and_connected &&
 890                         ret == 0;
 891         else
 892                 die(_("%s failed"), cmd_name);
 893         if (use_sideband && finish_async(&demux))
 894                 die(_("error in sideband demultiplexer"));
 895         return 0;
 896 }
 897
 898 static int cmp_ref_by_name(const void *a_, const void *b_)
 899 {
 900         const struct ref *a = *((const struct ref **)a_);
 901         const struct ref *b = *((const struct ref **)b_);
 902         return strcmp(a->name, b->name);
 903 }
 904
 905 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 906                                  int fd[2],
 907                                  const struct ref *orig_ref,
 908                                  struct ref **sought, int nr_sought,
 909                                  struct shallow_info *si,
 910                                  char **pack_lockfile)
 911 {
 912         struct ref *ref = copy_ref_list(orig_ref);
 913         struct object_id oid;
 914         const char *agent_feature;
 915         int agent_len;
 916         struct fetch_negotiator negotiator;
 917         fetch_negotiator_init(&negotiator, negotiation_algorithm);
 918
 919         sort_ref_list(&ref, ref_compare_name);
 920         QSORT(sought, nr_sought, cmp_ref_by_name);
 921
 922         if ((args->depth > 0 || is_repository_shallow(the_repository)) && !server_supports("shallow"))
 923                 die(_("Server does not support shallow clients"));
 924         if (args->depth > 0 || args->deepen_since || args->deepen_not)
 925                 args->deepen = 1;
 926         if (server_supports("multi_ack_detailed")) {
 927                 print_verbose(args, _("Server supports multi_ack_detailed"));
 928                 multi_ack = 2;
 929                 if (server_supports("no-done")) {
 930                         print_verbose(args, _("Server supports no-done"));
 931                         if (args->stateless_rpc)
 932                                 no_done = 1;
 933                 }
 934         }
 935         else if (server_supports("multi_ack")) {
 936                 print_verbose(args, _("Server supports multi_ack"));
 937                 multi_ack = 1;
 938         }
 939         if (server_supports("side-band-64k")) {
 940                 print_verbose(args, _("Server supports side-band-64k"));
 941                 use_sideband = 2;
 942         }
 943         else if (server_supports("side-band")) {
 944                 print_verbose(args, _("Server supports side-band"));
 945                 use_sideband = 1;
 946         }
 947         if (server_supports("allow-tip-sha1-in-want")) {
 948                 print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 949                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 950         }
 951         if (server_supports("allow-reachable-sha1-in-want")) {
 952                 print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 953                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 954         }
 955         if (!server_supports("thin-pack"))
 956                 args->use_thin_pack = 0;
 957         if (!server_supports("no-progress"))
 958                 args->no_progress = 0;
 959         if (!server_supports("include-tag"))
 960                 args->include_tag = 0;
 961         if (server_supports("ofs-delta"))
 962                 print_verbose(args, _("Server supports ofs-delta"));
 963         else
 964                 prefer_ofs_delta = 0;
 965
 966         if (server_supports("filter")) {
 967                 server_supports_filtering = 1;
 968                 print_verbose(args, _("Server supports filter"));
 969         } else if (args->filter_options.choice) {
 970                 warning("filtering not recognized by server, ignoring");
 971         }
 972
 973         if ((agent_feature = server_feature_value("agent", &agent_len))) {
 974                 agent_supported = 1;
 975                 if (agent_len)
 976                         print_verbose(args, _("Server version is %.*s"),
 977                                       agent_len, agent_feature);
 978         }
 979         if (server_supports("deepen-since"))
 980                 deepen_since_ok = 1;
 981         else if (args->deepen_since)
 982                 die(_("Server does not support --shallow-since"));
 983         if (server_supports("deepen-not"))
 984                 deepen_not_ok = 1;
 985         else if (args->deepen_not)
 986                 die(_("Server does not support --shallow-exclude"));
 987         if (!server_supports("deepen-relative") && args->deepen_relative)
 988                 die(_("Server does not support --deepen"));
 989
 990         mark_complete_and_common_ref(&negotiator, args, &ref);
 991         filter_refs(args, &ref, sought, nr_sought);
 992         if (everything_local(args, &ref)) {
 993                 packet_flush(fd[1]);
 994                 goto all_done;
 995         }
 996         if (find_common(&negotiator, args, fd, &oid, ref) < 0)
 997                 if (!args->keep_pack)
 998                         /* When cloning, it is not unusual to have
 999                          * no common commit.
1000                          */
1001                         warning(_("no common commits"));
1002
1003         if (args->stateless_rpc)
1004                 packet_flush(fd[1]);
1005         if (args->deepen)
1006                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1007                                         NULL);
1008         else if (si->nr_ours || si->nr_theirs)
1009                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
1010         else
1011                 alternate_shallow_file = NULL;
1012         if (get_pack(args, fd, pack_lockfile))
1013                 die(_("git fetch-pack: fetch failed."));
1014
1015  all_done:
1016         negotiator.release(&negotiator);
1017         return ref;
1018 }
1019
1020 static void add_shallow_requests(struct strbuf *req_buf,
1021                                  const struct fetch_pack_args *args)
1022 {
1023         if (is_repository_shallow(the_repository))
1024                 write_shallow_commits(req_buf, 1, NULL);
1025         if (args->depth > 0)
1026                 packet_buf_write(req_buf, "deepen %d", args->depth);
1027         if (args->deepen_since) {
1028                 timestamp_t max_age = approxidate(args->deepen_since);
1029                 packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1030         }
1031         if (args->deepen_not) {
1032                 int i;
1033                 for (i = 0; i < args->deepen_not->nr; i++) {
1034                         struct string_list_item *s = args->deepen_not->items + i;
1035                         packet_buf_write(req_buf, "deepen-not %s", s->string);
1036                 }
1037         }
1038 }
1039
1040 static void add_wants(const struct ref *wants, struct strbuf *req_buf)
1041 {
1042         int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1043
1044         for ( ; wants ; wants = wants->next) {
1045                 const struct object_id *remote = &wants->old_oid;
1046                 struct object *o;
1047
1048                 /*
1049                  * If that object is complete (i.e. it is an ancestor of a
1050                  * local ref), we tell them we have it but do not have to
1051                  * tell them about its ancestors, which they already know
1052                  * about.
1053                  *
1054                  * We use lookup_object here because we are only
1055                  * interested in the case we *know* the object is
1056                  * reachable and we have already scanned it.
1057                  */
1058                 if (((o = lookup_object(the_repository, remote->hash)) != NULL) &&
1059                     (o->flags & COMPLETE)) {
1060                         continue;
1061                 }
1062
1063                 if (!use_ref_in_want || wants->exact_oid)
1064                         packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1065                 else
1066                         packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1067         }
1068 }
1069
1070 static void add_common(struct strbuf *req_buf, struct oidset *common)
1071 {
1072         struct oidset_iter iter;
1073         const struct object_id *oid;
1074         oidset_iter_init(common, &iter);
1075
1076         while ((oid = oidset_iter_next(&iter))) {
1077                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1078         }
1079 }
1080
1081 static int add_haves(struct fetch_negotiator *negotiator,
1082                      struct strbuf *req_buf,
1083                      int *haves_to_send, int *in_vain)
1084 {
1085         int ret = 0;
1086         int haves_added = 0;
1087         const struct object_id *oid;
1088
1089         while ((oid = negotiator->next(negotiator))) {
1090                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1091                 if (++haves_added >= *haves_to_send)
1092                         break;
1093         }
1094
1095         *in_vain += haves_added;
1096         if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1097                 /* Send Done */
1098                 packet_buf_write(req_buf, "done\n");
1099                 ret = 1;
1100         }
1101
1102         /* Increase haves to send on next round */
1103         *haves_to_send = next_flush(1, *haves_to_send);
1104
1105         return ret;
1106 }
1107
1108 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1109                               const struct fetch_pack_args *args,
1110                               const struct ref *wants, struct oidset *common,
1111                               int *haves_to_send, int *in_vain)
1112 {
1113         int ret = 0;
1114         struct strbuf req_buf = STRBUF_INIT;
1115
1116         if (server_supports_v2("fetch", 1))
1117                 packet_buf_write(&req_buf, "command=fetch");
1118         if (server_supports_v2("agent", 0))
1119                 packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1120         if (args->server_options && args->server_options->nr &&
1121             server_supports_v2("server-option", 1)) {
1122                 int i;
1123                 for (i = 0; i < args->server_options->nr; i++)
1124                         packet_write_fmt(fd_out, "server-option=%s",
1125                                          args->server_options->items[i].string);
1126         }
1127
1128         packet_buf_delim(&req_buf);
1129         if (args->use_thin_pack)
1130                 packet_buf_write(&req_buf, "thin-pack");
1131         if (args->no_progress)
1132                 packet_buf_write(&req_buf, "no-progress");
1133         if (args->include_tag)
1134                 packet_buf_write(&req_buf, "include-tag");
1135         if (prefer_ofs_delta)
1136                 packet_buf_write(&req_buf, "ofs-delta");
1137
1138         /* Add shallow-info and deepen request */
1139         if (server_supports_feature("fetch", "shallow", 0))
1140                 add_shallow_requests(&req_buf, args);
1141         else if (is_repository_shallow(the_repository) || args->deepen)
1142                 die(_("Server does not support shallow requests"));
1143
1144         /* Add filter */
1145         if (server_supports_feature("fetch", "filter", 0) &&
1146             args->filter_options.choice) {
1147                 print_verbose(args, _("Server supports filter"));
1148                 packet_buf_write(&req_buf, "filter %s",
1149                                  args->filter_options.filter_spec);
1150         } else if (args->filter_options.choice) {
1151                 warning("filtering not recognized by server, ignoring");
1152         }
1153
1154         /* add wants */
1155         add_wants(wants, &req_buf);
1156
1157         if (args->no_dependents) {
1158                 packet_buf_write(&req_buf, "done");
1159                 ret = 1;
1160         } else {
1161                 /* Add all of the common commits we've found in previous rounds */
1162                 add_common(&req_buf, common);
1163
1164                 /* Add initial haves */
1165                 ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1166         }
1167
1168         /* Send request */
1169         packet_buf_flush(&req_buf);
1170         write_or_die(fd_out, req_buf.buf, req_buf.len);
1171
1172         strbuf_release(&req_buf);
1173         return ret;
1174 }
1175
1176 /*
1177  * Processes a section header in a server's response and checks if it matches
1178  * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1179  * not consumed); if 0, the line will be consumed and the function will die if
1180  * the section header doesn't match what was expected.
1181  */
1182 static int process_section_header(struct packet_reader *reader,
1183                                   const char *section, int peek)
1184 {
1185         int ret;
1186
1187         if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1188                 die(_("error reading section header '%s'"), section);
1189
1190         ret = !strcmp(reader->line, section);
1191
1192         if (!peek) {
1193                 if (!ret)
1194                         die(_("expected '%s', received '%s'"),
1195                             section, reader->line);
1196                 packet_reader_read(reader);
1197         }
1198
1199         return ret;
1200 }
1201
1202 static int process_acks(struct fetch_negotiator *negotiator,
1203                         struct packet_reader *reader,
1204                         struct oidset *common)
1205 {
1206         /* received */
1207         int received_ready = 0;
1208         int received_ack = 0;
1209
1210         process_section_header(reader, "acknowledgments", 0);
1211         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1212                 const char *arg;
1213
1214                 if (!strcmp(reader->line, "NAK"))
1215                         continue;
1216
1217                 if (skip_prefix(reader->line, "ACK ", &arg)) {
1218                         struct object_id oid;
1219                         if (!get_oid_hex(arg, &oid)) {
1220                                 struct commit *commit;
1221                                 oidset_insert(common, &oid);
1222                                 commit = lookup_commit(the_repository, &oid);
1223                                 negotiator->ack(negotiator, commit);
1224                         }
1225                         continue;
1226                 }
1227
1228                 if (!strcmp(reader->line, "ready")) {
1229                         received_ready = 1;
1230                         continue;
1231                 }
1232
1233                 die(_("unexpected acknowledgment line: '%s'"), reader->line);
1234         }
1235
1236         if (reader->status != PACKET_READ_FLUSH &&
1237             reader->status != PACKET_READ_DELIM)
1238                 die(_("error processing acks: %d"), reader->status);
1239
1240         /* return 0 if no common, 1 if there are common, or 2 if ready */
1241         return received_ready ? 2 : (received_ack ? 1 : 0);
1242 }
1243
1244 static void receive_shallow_info(struct fetch_pack_args *args,
1245                                  struct packet_reader *reader)
1246 {
1247         process_section_header(reader, "shallow-info", 0);
1248         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1249                 const char *arg;
1250                 struct object_id oid;
1251
1252                 if (skip_prefix(reader->line, "shallow ", &arg)) {
1253                         if (get_oid_hex(arg, &oid))
1254                                 die(_("invalid shallow line: %s"), reader->line);
1255                         register_shallow(the_repository, &oid);
1256                         continue;
1257                 }
1258                 if (skip_prefix(reader->line, "unshallow ", &arg)) {
1259                         if (get_oid_hex(arg, &oid))
1260                                 die(_("invalid unshallow line: %s"), reader->line);
1261                         if (!lookup_object(the_repository, oid.hash))
1262                                 die(_("object not found: %s"), reader->line);
1263                         /* make sure that it is parsed as shallow */
1264                         if (!parse_object(the_repository, &oid))
1265                                 die(_("error in object: %s"), reader->line);
1266                         if (unregister_shallow(&oid))
1267                                 die(_("no shallow found: %s"), reader->line);
1268                         continue;
1269                 }
1270                 die(_("expected shallow/unshallow, got %s"), reader->line);
1271         }
1272
1273         if (reader->status != PACKET_READ_FLUSH &&
1274             reader->status != PACKET_READ_DELIM)
1275                 die(_("error processing shallow info: %d"), reader->status);
1276
1277         setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, NULL);
1278         args->deepen = 1;
1279 }
1280
1281 static void receive_wanted_refs(struct packet_reader *reader,
1282                                 struct ref **sought, int nr_sought)
1283 {
1284         process_section_header(reader, "wanted-refs", 0);
1285         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1286                 struct object_id oid;
1287                 const char *end;
1288                 int i;
1289
1290                 if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1291                         die(_("expected wanted-ref, got '%s'"), reader->line);
1292
1293                 for (i = 0; i < nr_sought; i++) {
1294                         if (!strcmp(end, sought[i]->name)) {
1295                                 oidcpy(&sought[i]->old_oid, &oid);
1296                                 break;
1297                         }
1298                 }
1299
1300                 if (i == nr_sought)
1301                         die(_("unexpected wanted-ref: '%s'"), reader->line);
1302         }
1303
1304         if (reader->status != PACKET_READ_DELIM)
1305                 die(_("error processing wanted refs: %d"), reader->status);
1306 }
1307
1308 enum fetch_state {
1309         FETCH_CHECK_LOCAL = 0,
1310         FETCH_SEND_REQUEST,
1311         FETCH_PROCESS_ACKS,
1312         FETCH_GET_PACK,
1313         FETCH_DONE,
1314 };
1315
1316 static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1317                                     int fd[2],
1318                                     const struct ref *orig_ref,
1319                                     struct ref **sought, int nr_sought,
1320                                     char **pack_lockfile)
1321 {
1322         struct ref *ref = copy_ref_list(orig_ref);
1323         enum fetch_state state = FETCH_CHECK_LOCAL;
1324         struct oidset common = OIDSET_INIT;
1325         struct packet_reader reader;
1326         int in_vain = 0;
1327         int haves_to_send = INITIAL_FLUSH;
1328         struct fetch_negotiator negotiator;
1329         fetch_negotiator_init(&negotiator, negotiation_algorithm);
1330         packet_reader_init(&reader, fd[0], NULL, 0,
1331                            PACKET_READ_CHOMP_NEWLINE);
1332
1333         while (state != FETCH_DONE) {
1334                 switch (state) {
1335                 case FETCH_CHECK_LOCAL:
1336                         sort_ref_list(&ref, ref_compare_name);
1337                         QSORT(sought, nr_sought, cmp_ref_by_name);
1338
1339                         /* v2 supports these by default */
1340                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1341                         use_sideband = 2;
1342                         if (args->depth > 0 || args->deepen_since || args->deepen_not)
1343                                 args->deepen = 1;
1344
1345                         /* Filter 'ref' by 'sought' and those that aren't local */
1346                         mark_complete_and_common_ref(&negotiator, args, &ref);
1347                         filter_refs(args, &ref, sought, nr_sought);
1348                         if (everything_local(args, &ref))
1349                                 state = FETCH_DONE;
1350                         else
1351                                 state = FETCH_SEND_REQUEST;
1352
1353                         mark_tips(&negotiator, args->negotiation_tips);
1354                         for_each_cached_alternate(&negotiator,
1355                                                   insert_one_alternate_object);
1356                         break;
1357                 case FETCH_SEND_REQUEST:
1358                         if (send_fetch_request(&negotiator, fd[1], args, ref,
1359                                                &common,
1360                                                &haves_to_send, &in_vain))
1361                                 state = FETCH_GET_PACK;
1362                         else
1363                                 state = FETCH_PROCESS_ACKS;
1364                         break;
1365                 case FETCH_PROCESS_ACKS:
1366                         /* Process ACKs/NAKs */
1367                         switch (process_acks(&negotiator, &reader, &common)) {
1368                         case 2:
1369                                 state = FETCH_GET_PACK;
1370                                 break;
1371                         case 1:
1372                                 in_vain = 0;
1373                                 /* fallthrough */
1374                         default:
1375                                 state = FETCH_SEND_REQUEST;
1376                                 break;
1377                         }
1378                         break;
1379                 case FETCH_GET_PACK:
1380                         /* Check for shallow-info section */
1381                         if (process_section_header(&reader, "shallow-info", 1))
1382                                 receive_shallow_info(args, &reader);
1383
1384                         if (process_section_header(&reader, "wanted-refs", 1))
1385                                 receive_wanted_refs(&reader, sought, nr_sought);
1386
1387                         /* get the pack */
1388                         process_section_header(&reader, "packfile", 0);
1389                         if (get_pack(args, fd, pack_lockfile))
1390                                 die(_("git fetch-pack: fetch failed."));
1391
1392                         state = FETCH_DONE;
1393                         break;
1394                 case FETCH_DONE:
1395                         continue;
1396                 }
1397         }
1398
1399         negotiator.release(&negotiator);
1400         oidset_clear(&common);
1401         return ref;
1402 }
1403
1404 static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1405 {
1406         if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1407                 const char *path;
1408
1409                 if (git_config_pathname(&path, var, value))
1410                         return 1;
1411                 strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1412                         fsck_msg_types.len ? ',' : '=', path);
1413                 free((char *)path);
1414                 return 0;
1415         }
1416
1417         if (skip_prefix(var, "fetch.fsck.", &var)) {
1418                 if (is_valid_msg_type(var, value))
1419                         strbuf_addf(&fsck_msg_types, "%c%s=%s",
1420                                 fsck_msg_types.len ? ',' : '=', var, value);
1421                 else
1422                         warning("Skipping unknown msg id '%s'", var);
1423                 return 0;
1424         }
1425
1426         return git_default_config(var, value, cb);
1427 }
1428
1429 static void fetch_pack_config(void)
1430 {
1431         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1432         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1433         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1434         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1435         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1436         git_config_get_string("fetch.negotiationalgorithm",
1437                               &negotiation_algorithm);
1438
1439         git_config(fetch_pack_config_cb, NULL);
1440 }
1441
1442 static void fetch_pack_setup(void)
1443 {
1444         static int did_setup;
1445         if (did_setup)
1446                 return;
1447         fetch_pack_config();
1448         if (0 <= transfer_unpack_limit)
1449                 unpack_limit = transfer_unpack_limit;
1450         else if (0 <= fetch_unpack_limit)
1451                 unpack_limit = fetch_unpack_limit;
1452         did_setup = 1;
1453 }
1454
1455 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1456 {
1457         struct string_list names = STRING_LIST_INIT_NODUP;
1458         int src, dst;
1459
1460         for (src = dst = 0; src < nr; src++) {
1461                 struct string_list_item *item;
1462                 item = string_list_insert(&names, ref[src]->name);
1463                 if (item->util)
1464                         continue; /* already have it */
1465                 item->util = ref[src];
1466                 if (src != dst)
1467                         ref[dst] = ref[src];
1468                 dst++;
1469         }
1470         for (src = dst; src < nr; src++)
1471                 ref[src] = NULL;
1472         string_list_clear(&names, 0);
1473         return dst;
1474 }
1475
1476 static void update_shallow(struct fetch_pack_args *args,
1477                            struct ref **sought, int nr_sought,
1478                            struct shallow_info *si)
1479 {
1480         struct oid_array ref = OID_ARRAY_INIT;
1481         int *status;
1482         int i;
1483
1484         if (args->deepen && alternate_shallow_file) {
1485                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1486                         unlink_or_warn(git_path_shallow(the_repository));
1487                         rollback_lock_file(&shallow_lock);
1488                 } else
1489                         commit_lock_file(&shallow_lock);
1490                 return;
1491         }
1492
1493         if (!si->shallow || !si->shallow->nr)
1494                 return;
1495
1496         if (args->cloning) {
1497                 /*
1498                  * remote is shallow, but this is a clone, there are
1499                  * no objects in repo to worry about. Accept any
1500                  * shallow points that exist in the pack (iow in repo
1501                  * after get_pack() and reprepare_packed_git())
1502                  */
1503                 struct oid_array extra = OID_ARRAY_INIT;
1504                 struct object_id *oid = si->shallow->oid;
1505                 for (i = 0; i < si->shallow->nr; i++)
1506                         if (has_object_file(&oid[i]))
1507                                 oid_array_append(&extra, &oid[i]);
1508                 if (extra.nr) {
1509                         setup_alternate_shallow(&shallow_lock,
1510                                                 &alternate_shallow_file,
1511                                                 &extra);
1512                         commit_lock_file(&shallow_lock);
1513                 }
1514                 oid_array_clear(&extra);
1515                 return;
1516         }
1517
1518         if (!si->nr_ours && !si->nr_theirs)
1519                 return;
1520
1521         remove_nonexistent_theirs_shallow(si);
1522         if (!si->nr_ours && !si->nr_theirs)
1523                 return;
1524         for (i = 0; i < nr_sought; i++)
1525                 oid_array_append(&ref, &sought[i]->old_oid);
1526         si->ref = &ref;
1527
1528         if (args->update_shallow) {
1529                 /*
1530                  * remote is also shallow, .git/shallow may be updated
1531                  * so all refs can be accepted. Make sure we only add
1532                  * shallow roots that are actually reachable from new
1533                  * refs.
1534                  */
1535                 struct oid_array extra = OID_ARRAY_INIT;
1536                 struct object_id *oid = si->shallow->oid;
1537                 assign_shallow_commits_to_refs(si, NULL, NULL);
1538                 if (!si->nr_ours && !si->nr_theirs) {
1539                         oid_array_clear(&ref);
1540                         return;
1541                 }
1542                 for (i = 0; i < si->nr_ours; i++)
1543                         oid_array_append(&extra, &oid[si->ours[i]]);
1544                 for (i = 0; i < si->nr_theirs; i++)
1545                         oid_array_append(&extra, &oid[si->theirs[i]]);
1546                 setup_alternate_shallow(&shallow_lock,
1547                                         &alternate_shallow_file,
1548                                         &extra);
1549                 commit_lock_file(&shallow_lock);
1550                 oid_array_clear(&extra);
1551                 oid_array_clear(&ref);
1552                 return;
1553         }
1554
1555         /*
1556          * remote is also shallow, check what ref is safe to update
1557          * without updating .git/shallow
1558          */
1559         status = xcalloc(nr_sought, sizeof(*status));
1560         assign_shallow_commits_to_refs(si, NULL, status);
1561         if (si->nr_ours || si->nr_theirs) {
1562                 for (i = 0; i < nr_sought; i++)
1563                         if (status[i])
1564                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1565         }
1566         free(status);
1567         oid_array_clear(&ref);
1568 }
1569
1570 static int iterate_ref_map(void *cb_data, struct object_id *oid)
1571 {
1572         struct ref **rm = cb_data;
1573         struct ref *ref = *rm;
1574
1575         if (!ref)
1576                 return -1; /* end of the list */
1577         *rm = ref->next;
1578         oidcpy(oid, &ref->old_oid);
1579         return 0;
1580 }
1581
1582 struct ref *fetch_pack(struct fetch_pack_args *args,
1583                        int fd[], struct child_process *conn,
1584                        const struct ref *ref,
1585                        const char *dest,
1586                        struct ref **sought, int nr_sought,
1587                        struct oid_array *shallow,
1588                        char **pack_lockfile,
1589                        enum protocol_version version)
1590 {
1591         struct ref *ref_cpy;
1592         struct shallow_info si;
1593
1594         fetch_pack_setup();
1595         if (nr_sought)
1596                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1597
1598         if (!ref) {
1599                 packet_flush(fd[1]);
1600                 die(_("no matching remote head"));
1601         }
1602         prepare_shallow_info(&si, shallow);
1603         if (version == protocol_v2)
1604                 ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1605                                            pack_lockfile);
1606         else
1607                 ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1608                                         &si, pack_lockfile);
1609         reprepare_packed_git(the_repository);
1610
1611         if (!args->cloning && args->deepen) {
1612                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
1613                 struct ref *iterator = ref_cpy;
1614                 opt.shallow_file = alternate_shallow_file;
1615                 if (args->deepen)
1616                         opt.is_deepening_fetch = 1;
1617                 if (check_connected(iterate_ref_map, &iterator, &opt)) {
1618                         error(_("remote did not send all necessary objects"));
1619                         free_refs(ref_cpy);
1620                         ref_cpy = NULL;
1621                         rollback_lock_file(&shallow_lock);
1622                         goto cleanup;
1623                 }
1624                 args->connectivity_checked = 1;
1625         }
1626
1627         update_shallow(args, sought, nr_sought, &si);
1628 cleanup:
1629         clear_shallow_info(&si);
1630         return ref_cpy;
1631 }
1632
1633 int report_unmatched_refs(struct ref **sought, int nr_sought)
1634 {
1635         int i, ret = 0;
1636
1637         for (i = 0; i < nr_sought; i++) {
1638                 if (!sought[i])
1639                         continue;
1640                 switch (sought[i]->match_status) {
1641                 case REF_MATCHED:
1642                         continue;
1643                 case REF_NOT_MATCHED:
1644                         error(_("no such remote ref %s"), sought[i]->name);
1645                         break;
1646                 case REF_UNADVERTISED_NOT_ALLOWED:
1647                         error(_("Server does not allow request for unadvertised object %s"),
1648                               sought[i]->name);
1649                         break;
1650                 }
1651                 ret = 1;
1652         }
1653         return ret;
1654 }