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 struct object_id *oid,
  80                                 void *vcache)
  81 {
  82         struct alternate_object_cache *cache = vcache;
  83         struct object *obj = parse_object(the_repository, oid);
  84
  85         if (!obj || (obj->flags & ALTERNATE))
  86                 return;
  87
  88         obj->flags |= ALTERNATE;
  89         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  90         cache->items[cache->nr++] = obj;
  91 }
  92
  93 static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
  94                                       void (*cb)(struct fetch_negotiator *,
  95                                                  struct object *))
  96 {
  97         static int initialized;
  98         static struct alternate_object_cache cache;
  99         size_t i;
 100
 101         if (!initialized) {
 102                 for_each_alternate_ref(cache_one_alternate, &cache);
 103                 initialized = 1;
 104         }
 105
 106         for (i = 0; i < cache.nr; i++)
 107                 cb(negotiator, cache.items[i]);
 108 }
 109
 110 static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
 111                                const char *refname,
 112                                const struct object_id *oid)
 113 {
 114         struct object *o = deref_tag(the_repository,
 115                                      parse_object(the_repository, oid),
 116                                      refname, 0);
 117
 118         if (o && o->type == OBJ_COMMIT)
 119                 negotiator->add_tip(negotiator, (struct commit *)o);
 120
 121         return 0;
 122 }
 123
 124 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 125                                    int flag, void *cb_data)
 126 {
 127         return rev_list_insert_ref(cb_data, refname, oid);
 128 }
 129
 130 enum ack_type {
 131         NAK = 0,
 132         ACK,
 133         ACK_continue,
 134         ACK_common,
 135         ACK_ready
 136 };
 137
 138 static void consume_shallow_list(struct fetch_pack_args *args,
 139                                  struct packet_reader *reader)
 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                 while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 147                         if (starts_with(reader->line, "shallow "))
 148                                 continue;
 149                         if (starts_with(reader->line, "unshallow "))
 150                                 continue;
 151                         die(_("git fetch-pack: expected shallow list"));
 152                 }
 153                 if (reader->status != PACKET_READ_FLUSH)
 154                         die(_("git fetch-pack: expected a flush packet after shallow list"));
 155         }
 156 }
 157
 158 static enum ack_type get_ack(struct packet_reader *reader,
 159                              struct object_id *result_oid)
 160 {
 161         int len;
 162         const char *arg;
 163
 164         if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 165                 die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 166         len = reader->pktlen;
 167
 168         if (!strcmp(reader->line, "NAK"))
 169                 return NAK;
 170         if (skip_prefix(reader->line, "ACK ", &arg)) {
 171                 if (!get_oid_hex(arg, result_oid)) {
 172                         arg += 40;
 173                         len -= arg - reader->line;
 174                         if (len < 1)
 175                                 return ACK;
 176                         if (strstr(arg, "continue"))
 177                                 return ACK_continue;
 178                         if (strstr(arg, "common"))
 179                                 return ACK_common;
 180                         if (strstr(arg, "ready"))
 181                                 return ACK_ready;
 182                         return ACK;
 183                 }
 184         }
 185         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
 186 }
 187
 188 static void send_request(struct fetch_pack_args *args,
 189                          int fd, struct strbuf *buf)
 190 {
 191         if (args->stateless_rpc) {
 192                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 193                 packet_flush(fd);
 194         } else {
 195                 if (write_in_full(fd, buf->buf, buf->len) < 0)
 196                         die_errno(_("unable to write to remote"));
 197         }
 198 }
 199
 200 static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 201                                         struct object *obj)
 202 {
 203         rev_list_insert_ref(negotiator, NULL, &obj->oid);
 204 }
 205
 206 #define INITIAL_FLUSH 16
 207 #define PIPESAFE_FLUSH 32
 208 #define LARGE_FLUSH 16384
 209
 210 static int next_flush(int stateless_rpc, int count)
 211 {
 212         if (stateless_rpc) {
 213                 if (count < LARGE_FLUSH)
 214                         count <<= 1;
 215                 else
 216                         count = count * 11 / 10;
 217         } else {
 218                 if (count < PIPESAFE_FLUSH)
 219                         count <<= 1;
 220                 else
 221                         count += PIPESAFE_FLUSH;
 222         }
 223         return count;
 224 }
 225
 226 static void mark_tips(struct fetch_negotiator *negotiator,
 227                       const struct oid_array *negotiation_tips)
 228 {
 229         int i;
 230
 231         if (!negotiation_tips) {
 232                 for_each_ref(rev_list_insert_ref_oid, negotiator);
 233                 return;
 234         }
 235
 236         for (i = 0; i < negotiation_tips->nr; i++)
 237                 rev_list_insert_ref(negotiator, NULL,
 238                                     &negotiation_tips->oid[i]);
 239         return;
 240 }
 241
 242 static int find_common(struct fetch_negotiator *negotiator,
 243                        struct fetch_pack_args *args,
 244                        int fd[2], struct object_id *result_oid,
 245                        struct ref *refs)
 246 {
 247         int fetching;
 248         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 249         const struct object_id *oid;
 250         unsigned in_vain = 0;
 251         int got_continue = 0;
 252         int got_ready = 0;
 253         struct strbuf req_buf = STRBUF_INIT;
 254         size_t state_len = 0;
 255         struct packet_reader reader;
 256
 257         if (args->stateless_rpc && multi_ack == 1)
 258                 die(_("--stateless-rpc requires multi_ack_detailed"));
 259
 260         packet_reader_init(&reader, fd[0], NULL, 0,
 261                            PACKET_READ_CHOMP_NEWLINE |
 262                            PACKET_READ_DIE_ON_ERR_PACKET);
 263
 264         if (!args->no_dependents) {
 265                 mark_tips(negotiator, args->negotiation_tips);
 266                 for_each_cached_alternate(negotiator, insert_one_alternate_object);
 267         }
 268
 269         fetching = 0;
 270         for ( ; refs ; refs = refs->next) {
 271                 struct object_id *remote = &refs->old_oid;
 272                 const char *remote_hex;
 273                 struct object *o;
 274
 275                 /*
 276                  * If that object is complete (i.e. it is an ancestor of a
 277                  * local ref), we tell them we have it but do not have to
 278                  * tell them about its ancestors, which they already know
 279                  * about.
 280                  *
 281                  * We use lookup_object here because we are only
 282                  * interested in the case we *know* the object is
 283                  * reachable and we have already scanned it.
 284                  *
 285                  * Do this only if args->no_dependents is false (if it is true,
 286                  * we cannot trust the object flags).
 287                  */
 288                 if (!args->no_dependents &&
 289                     ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
 290                                 (o->flags & COMPLETE)) {
 291                         continue;
 292                 }
 293
 294                 remote_hex = oid_to_hex(remote);
 295                 if (!fetching) {
 296                         struct strbuf c = STRBUF_INIT;
 297                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 298                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 299                         if (no_done)            strbuf_addstr(&c, " no-done");
 300                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 301                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 302                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 303                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 304                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 305                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 306                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 307                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 308                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 309                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 310                                                             git_user_agent_sanitized());
 311                         if (args->filter_options.choice)
 312                                 strbuf_addstr(&c, " filter");
 313                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 314                         strbuf_release(&c);
 315                 } else
 316                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 317                 fetching++;
 318         }
 319
 320         if (!fetching) {
 321                 strbuf_release(&req_buf);
 322                 packet_flush(fd[1]);
 323                 return 1;
 324         }
 325
 326         if (is_repository_shallow(the_repository))
 327                 write_shallow_commits(&req_buf, 1, NULL);
 328         if (args->depth > 0)
 329                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 330         if (args->deepen_since) {
 331                 timestamp_t max_age = approxidate(args->deepen_since);
 332                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 333         }
 334         if (args->deepen_not) {
 335                 int i;
 336                 for (i = 0; i < args->deepen_not->nr; i++) {
 337                         struct string_list_item *s = args->deepen_not->items + i;
 338                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 339                 }
 340         }
 341         if (server_supports_filtering && args->filter_options.choice) {
 342                 struct strbuf expanded_filter_spec = STRBUF_INIT;
 343                 expand_list_objects_filter_spec(&args->filter_options,
 344                                                 &expanded_filter_spec);
 345                 packet_buf_write(&req_buf, "filter %s",
 346                                  expanded_filter_spec.buf);
 347                 strbuf_release(&expanded_filter_spec);
 348         }
 349         packet_buf_flush(&req_buf);
 350         state_len = req_buf.len;
 351
 352         if (args->deepen) {
 353                 const char *arg;
 354                 struct object_id oid;
 355
 356                 send_request(args, fd[1], &req_buf);
 357                 while (packet_reader_read(&reader) == PACKET_READ_NORMAL) {
 358                         if (skip_prefix(reader.line, "shallow ", &arg)) {
 359                                 if (get_oid_hex(arg, &oid))
 360                                         die(_("invalid shallow line: %s"), reader.line);
 361                                 register_shallow(the_repository, &oid);
 362                                 continue;
 363                         }
 364                         if (skip_prefix(reader.line, "unshallow ", &arg)) {
 365                                 if (get_oid_hex(arg, &oid))
 366                                         die(_("invalid unshallow line: %s"), reader.line);
 367                                 if (!lookup_object(the_repository, oid.hash))
 368                                         die(_("object not found: %s"), reader.line);
 369                                 /* make sure that it is parsed as shallow */
 370                                 if (!parse_object(the_repository, &oid))
 371                                         die(_("error in object: %s"), reader.line);
 372                                 if (unregister_shallow(&oid))
 373                                         die(_("no shallow found: %s"), reader.line);
 374                                 continue;
 375                         }
 376                         die(_("expected shallow/unshallow, got %s"), reader.line);
 377                 }
 378         } else if (!args->stateless_rpc)
 379                 send_request(args, fd[1], &req_buf);
 380
 381         if (!args->stateless_rpc) {
 382                 /* If we aren't using the stateless-rpc interface
 383                  * we don't need to retain the headers.
 384                  */
 385                 strbuf_setlen(&req_buf, 0);
 386                 state_len = 0;
 387         }
 388
 389         flushes = 0;
 390         retval = -1;
 391         if (args->no_dependents)
 392                 goto done;
 393         while ((oid = negotiator->next(negotiator))) {
 394                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 395                 print_verbose(args, "have %s", oid_to_hex(oid));
 396                 in_vain++;
 397                 if (flush_at <= ++count) {
 398                         int ack;
 399
 400                         packet_buf_flush(&req_buf);
 401                         send_request(args, fd[1], &req_buf);
 402                         strbuf_setlen(&req_buf, state_len);
 403                         flushes++;
 404                         flush_at = next_flush(args->stateless_rpc, count);
 405
 406                         /*
 407                          * We keep one window "ahead" of the other side, and
 408                          * will wait for an ACK only on the next one
 409                          */
 410                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 411                                 continue;
 412
 413                         consume_shallow_list(args, &reader);
 414                         do {
 415                                 ack = get_ack(&reader, result_oid);
 416                                 if (ack)
 417                                         print_verbose(args, _("got %s %d %s"), "ack",
 418                                                       ack, oid_to_hex(result_oid));
 419                                 switch (ack) {
 420                                 case ACK:
 421                                         flushes = 0;
 422                                         multi_ack = 0;
 423                                         retval = 0;
 424                                         goto done;
 425                                 case ACK_common:
 426                                 case ACK_ready:
 427                                 case ACK_continue: {
 428                                         struct commit *commit =
 429                                                 lookup_commit(the_repository,
 430                                                               result_oid);
 431                                         int was_common;
 432
 433                                         if (!commit)
 434                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
 435                                         was_common = negotiator->ack(negotiator, commit);
 436                                         if (args->stateless_rpc
 437                                          && ack == ACK_common
 438                                          && !was_common) {
 439                                                 /* We need to replay the have for this object
 440                                                  * on the next RPC request so the peer knows
 441                                                  * it is in common with us.
 442                                                  */
 443                                                 const char *hex = oid_to_hex(result_oid);
 444                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 445                                                 state_len = req_buf.len;
 446                                                 /*
 447                                                  * Reset in_vain because an ack
 448                                                  * for this commit has not been
 449                                                  * seen.
 450                                                  */
 451                                                 in_vain = 0;
 452                                         } else if (!args->stateless_rpc
 453                                                    || ack != ACK_common)
 454                                                 in_vain = 0;
 455                                         retval = 0;
 456                                         got_continue = 1;
 457                                         if (ack == ACK_ready)
 458                                                 got_ready = 1;
 459                                         break;
 460                                         }
 461                                 }
 462                         } while (ack);
 463                         flushes--;
 464                         if (got_continue && MAX_IN_VAIN < in_vain) {
 465                                 print_verbose(args, _("giving up"));
 466                                 break; /* give up */
 467                         }
 468                         if (got_ready)
 469                                 break;
 470                 }
 471         }
 472 done:
 473         if (!got_ready || !no_done) {
 474                 packet_buf_write(&req_buf, "done\n");
 475                 send_request(args, fd[1], &req_buf);
 476         }
 477         print_verbose(args, _("done"));
 478         if (retval != 0) {
 479                 multi_ack = 0;
 480                 flushes++;
 481         }
 482         strbuf_release(&req_buf);
 483
 484         if (!got_ready || !no_done)
 485                 consume_shallow_list(args, &reader);
 486         while (flushes || multi_ack) {
 487                 int ack = get_ack(&reader, result_oid);
 488                 if (ack) {
 489                         print_verbose(args, _("got %s (%d) %s"), "ack",
 490                                       ack, oid_to_hex(result_oid));
 491                         if (ack == ACK)
 492                                 return 0;
 493                         multi_ack = 1;
 494                         continue;
 495                 }
 496                 flushes--;
 497         }
 498         /* it is no error to fetch into a completely empty repo */
 499         return count ? retval : 0;
 500 }
 501
 502 static struct commit_list *complete;
 503
 504 static int mark_complete(const struct object_id *oid)
 505 {
 506         struct object *o = parse_object(the_repository, oid);
 507
 508         while (o && o->type == OBJ_TAG) {
 509                 struct tag *t = (struct tag *) o;
 510                 if (!t->tagged)
 511                         break; /* broken repository */
 512                 o->flags |= COMPLETE;
 513                 o = parse_object(the_repository, &t->tagged->oid);
 514         }
 515         if (o && o->type == OBJ_COMMIT) {
 516                 struct commit *commit = (struct commit *)o;
 517                 if (!(commit->object.flags & COMPLETE)) {
 518                         commit->object.flags |= COMPLETE;
 519                         commit_list_insert(commit, &complete);
 520                 }
 521         }
 522         return 0;
 523 }
 524
 525 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 526                              int flag, void *cb_data)
 527 {
 528         return mark_complete(oid);
 529 }
 530
 531 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 532                                          timestamp_t cutoff)
 533 {
 534         while (complete && cutoff <= complete->item->date) {
 535                 print_verbose(args, _("Marking %s as complete"),
 536                               oid_to_hex(&complete->item->object.oid));
 537                 pop_most_recent_commit(&complete, COMPLETE);
 538         }
 539 }
 540
 541 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 542 {
 543         for (; refs; refs = refs->next)
 544                 oidset_insert(oids, &refs->old_oid);
 545 }
 546
 547 static int is_unmatched_ref(const struct ref *ref)
 548 {
 549         struct object_id oid;
 550         const char *p;
 551         return  ref->match_status == REF_NOT_MATCHED &&
 552                 !parse_oid_hex(ref->name, &oid, &p) &&
 553                 *p == '\0' &&
 554                 oideq(&oid, &ref->old_oid);
 555 }
 556
 557 static void filter_refs(struct fetch_pack_args *args,
 558                         struct ref **refs,
 559                         struct ref **sought, int nr_sought)
 560 {
 561         struct ref *newlist = NULL;
 562         struct ref **newtail = &newlist;
 563         struct ref *unmatched = NULL;
 564         struct ref *ref, *next;
 565         struct oidset tip_oids = OIDSET_INIT;
 566         int i;
 567         int strict = !(allow_unadvertised_object_request &
 568                        (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
 569
 570         i = 0;
 571         for (ref = *refs; ref; ref = next) {
 572                 int keep = 0;
 573                 next = ref->next;
 574
 575                 if (starts_with(ref->name, "refs/") &&
 576                     check_refname_format(ref->name, 0))
 577                         ; /* trash */
 578                 else {
 579                         while (i < nr_sought) {
 580                                 int cmp = strcmp(ref->name, sought[i]->name);
 581                                 if (cmp < 0)
 582                                         break; /* definitely do not have it */
 583                                 else if (cmp == 0) {
 584                                         keep = 1; /* definitely have it */
 585                                         sought[i]->match_status = REF_MATCHED;
 586                                 }
 587                                 i++;
 588                         }
 589
 590                         if (!keep && args->fetch_all &&
 591                             (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 592                                 keep = 1;
 593                 }
 594
 595                 if (keep) {
 596                         *newtail = ref;
 597                         ref->next = NULL;
 598                         newtail = &ref->next;
 599                 } else {
 600                         ref->next = unmatched;
 601                         unmatched = ref;
 602                 }
 603         }
 604
 605         if (strict) {
 606                 for (i = 0; i < nr_sought; i++) {
 607                         ref = sought[i];
 608                         if (!is_unmatched_ref(ref))
 609                                 continue;
 610
 611                         add_refs_to_oidset(&tip_oids, unmatched);
 612                         add_refs_to_oidset(&tip_oids, newlist);
 613                         break;
 614                 }
 615         }
 616
 617         /* Append unmatched requests to the list */
 618         for (i = 0; i < nr_sought; i++) {
 619                 ref = sought[i];
 620                 if (!is_unmatched_ref(ref))
 621                         continue;
 622
 623                 if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
 624                         ref->match_status = REF_MATCHED;
 625                         *newtail = copy_ref(ref);
 626                         newtail = &(*newtail)->next;
 627                 } else {
 628                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 629                 }
 630         }
 631
 632         oidset_clear(&tip_oids);
 633         free_refs(unmatched);
 634
 635         *refs = newlist;
 636 }
 637
 638 static void mark_alternate_complete(struct fetch_negotiator *unused,
 639                                     struct object *obj)
 640 {
 641         mark_complete(&obj->oid);
 642 }
 643
 644 struct loose_object_iter {
 645         struct oidset *loose_object_set;
 646         struct ref *refs;
 647 };
 648
 649 /*
 650  * Mark recent commits available locally and reachable from a local ref as
 651  * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 652  * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 653  * thus do not need COMMON_REF marks).
 654  *
 655  * The cutoff time for recency is determined by this heuristic: it is the
 656  * earliest commit time of the objects in refs that are commits and that we know
 657  * the commit time of.
 658  */
 659 static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 660                                          struct fetch_pack_args *args,
 661                                          struct ref **refs)
 662 {
 663         struct ref *ref;
 664         int old_save_commit_buffer = save_commit_buffer;
 665         timestamp_t cutoff = 0;
 666
 667         save_commit_buffer = 0;
 668
 669         for (ref = *refs; ref; ref = ref->next) {
 670                 struct object *o;
 671
 672                 if (!has_object_file_with_flags(&ref->old_oid,
 673                                                 OBJECT_INFO_QUICK))
 674                         continue;
 675                 o = parse_object(the_repository, &ref->old_oid);
 676                 if (!o)
 677                         continue;
 678
 679                 /* We already have it -- which may mean that we were
 680                  * in sync with the other side at some time after
 681                  * that (it is OK if we guess wrong here).
 682                  */
 683                 if (o->type == OBJ_COMMIT) {
 684                         struct commit *commit = (struct commit *)o;
 685                         if (!cutoff || cutoff < commit->date)
 686                                 cutoff = commit->date;
 687                 }
 688         }
 689
 690         if (!args->deepen) {
 691                 for_each_ref(mark_complete_oid, NULL);
 692                 for_each_cached_alternate(NULL, mark_alternate_complete);
 693                 commit_list_sort_by_date(&complete);
 694                 if (cutoff)
 695                         mark_recent_complete_commits(args, cutoff);
 696         }
 697
 698         /*
 699          * Mark all complete remote refs as common refs.
 700          * Don't mark them common yet; the server has to be told so first.
 701          */
 702         for (ref = *refs; ref; ref = ref->next) {
 703                 struct object *o = deref_tag(the_repository,
 704                                              lookup_object(the_repository,
 705                                              ref->old_oid.hash),
 706                                              NULL, 0);
 707
 708                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 709                         continue;
 710
 711                 negotiator->known_common(negotiator,
 712                                          (struct commit *)o);
 713         }
 714
 715         save_commit_buffer = old_save_commit_buffer;
 716 }
 717
 718 /*
 719  * Returns 1 if every object pointed to by the given remote refs is available
 720  * locally and reachable from a local ref, and 0 otherwise.
 721  */
 722 static int everything_local(struct fetch_pack_args *args,
 723                             struct ref **refs)
 724 {
 725         struct ref *ref;
 726         int retval;
 727
 728         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 729                 const struct object_id *remote = &ref->old_oid;
 730                 struct object *o;
 731
 732                 o = lookup_object(the_repository, remote->hash);
 733                 if (!o || !(o->flags & COMPLETE)) {
 734                         retval = 0;
 735                         print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 736                                       ref->name);
 737                         continue;
 738                 }
 739                 print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 740                               ref->name);
 741         }
 742
 743         return retval;
 744 }
 745
 746 static int sideband_demux(int in, int out, void *data)
 747 {
 748         int *xd = data;
 749         int ret;
 750
 751         ret = recv_sideband("fetch-pack", xd[0], out);
 752         close(out);
 753         return ret;
 754 }
 755
 756 static int get_pack(struct fetch_pack_args *args,
 757                     int xd[2], char **pack_lockfile)
 758 {
 759         struct async demux;
 760         int do_keep = args->keep_pack;
 761         const char *cmd_name;
 762         struct pack_header header;
 763         int pass_header = 0;
 764         struct child_process cmd = CHILD_PROCESS_INIT;
 765         int ret;
 766
 767         memset(&demux, 0, sizeof(demux));
 768         if (use_sideband) {
 769                 /* xd[] is talking with upload-pack; subprocess reads from
 770                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 771                  * through demux->out.
 772                  */
 773                 demux.proc = sideband_demux;
 774                 demux.data = xd;
 775                 demux.out = -1;
 776                 demux.isolate_sigpipe = 1;
 777                 if (start_async(&demux))
 778                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 779         }
 780         else
 781                 demux.out = xd[0];
 782
 783         if (!args->keep_pack && unpack_limit) {
 784
 785                 if (read_pack_header(demux.out, &header))
 786                         die(_("protocol error: bad pack header"));
 787                 pass_header = 1;
 788                 if (ntohl(header.hdr_entries) < unpack_limit)
 789                         do_keep = 0;
 790                 else
 791                         do_keep = 1;
 792         }
 793
 794         if (alternate_shallow_file) {
 795                 argv_array_push(&cmd.args, "--shallow-file");
 796                 argv_array_push(&cmd.args, alternate_shallow_file);
 797         }
 798
 799         if (do_keep || args->from_promisor) {
 800                 if (pack_lockfile)
 801                         cmd.out = -1;
 802                 cmd_name = "index-pack";
 803                 argv_array_push(&cmd.args, cmd_name);
 804                 argv_array_push(&cmd.args, "--stdin");
 805                 if (!args->quiet && !args->no_progress)
 806                         argv_array_push(&cmd.args, "-v");
 807                 if (args->use_thin_pack)
 808                         argv_array_push(&cmd.args, "--fix-thin");
 809                 if (do_keep && (args->lock_pack || unpack_limit)) {
 810                         char hostname[HOST_NAME_MAX + 1];
 811                         if (xgethostname(hostname, sizeof(hostname)))
 812                                 xsnprintf(hostname, sizeof(hostname), "localhost");
 813                         argv_array_pushf(&cmd.args,
 814                                         "--keep=fetch-pack %"PRIuMAX " on %s",
 815                                         (uintmax_t)getpid(), hostname);
 816                 }
 817                 if (args->check_self_contained_and_connected)
 818                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 819                 if (args->from_promisor)
 820                         argv_array_push(&cmd.args, "--promisor");
 821         }
 822         else {
 823                 cmd_name = "unpack-objects";
 824                 argv_array_push(&cmd.args, cmd_name);
 825                 if (args->quiet || args->no_progress)
 826                         argv_array_push(&cmd.args, "-q");
 827                 args->check_self_contained_and_connected = 0;
 828         }
 829
 830         if (pass_header)
 831                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 832                                  ntohl(header.hdr_version),
 833                                  ntohl(header.hdr_entries));
 834         if (fetch_fsck_objects >= 0
 835             ? fetch_fsck_objects
 836             : transfer_fsck_objects >= 0
 837             ? transfer_fsck_objects
 838             : 0) {
 839                 if (args->from_promisor)
 840                         /*
 841                          * We cannot use --strict in index-pack because it
 842                          * checks both broken objects and links, but we only
 843                          * want to check for broken objects.
 844                          */
 845                         argv_array_push(&cmd.args, "--fsck-objects");
 846                 else
 847                         argv_array_pushf(&cmd.args, "--strict%s",
 848                                          fsck_msg_types.buf);
 849         }
 850
 851         cmd.in = demux.out;
 852         cmd.git_cmd = 1;
 853         if (start_command(&cmd))
 854                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
 855         if (do_keep && pack_lockfile) {
 856                 *pack_lockfile = index_pack_lockfile(cmd.out);
 857                 close(cmd.out);
 858         }
 859
 860         if (!use_sideband)
 861                 /* Closed by start_command() */
 862                 xd[0] = -1;
 863
 864         ret = finish_command(&cmd);
 865         if (!ret || (args->check_self_contained_and_connected && ret == 1))
 866                 args->self_contained_and_connected =
 867                         args->check_self_contained_and_connected &&
 868                         ret == 0;
 869         else
 870                 die(_("%s failed"), cmd_name);
 871         if (use_sideband && finish_async(&demux))
 872                 die(_("error in sideband demultiplexer"));
 873         return 0;
 874 }
 875
 876 static int cmp_ref_by_name(const void *a_, const void *b_)
 877 {
 878         const struct ref *a = *((const struct ref **)a_);
 879         const struct ref *b = *((const struct ref **)b_);
 880         return strcmp(a->name, b->name);
 881 }
 882
 883 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 884                                  int fd[2],
 885                                  const struct ref *orig_ref,
 886                                  struct ref **sought, int nr_sought,
 887                                  struct shallow_info *si,
 888                                  char **pack_lockfile)
 889 {
 890         struct ref *ref = copy_ref_list(orig_ref);
 891         struct object_id oid;
 892         const char *agent_feature;
 893         int agent_len;
 894         struct fetch_negotiator negotiator;
 895         fetch_negotiator_init(&negotiator, negotiation_algorithm);
 896
 897         sort_ref_list(&ref, ref_compare_name);
 898         QSORT(sought, nr_sought, cmp_ref_by_name);
 899
 900         if ((args->depth > 0 || is_repository_shallow(the_repository)) && !server_supports("shallow"))
 901                 die(_("Server does not support shallow clients"));
 902         if (args->depth > 0 || args->deepen_since || args->deepen_not)
 903                 args->deepen = 1;
 904         if (server_supports("multi_ack_detailed")) {
 905                 print_verbose(args, _("Server supports multi_ack_detailed"));
 906                 multi_ack = 2;
 907                 if (server_supports("no-done")) {
 908                         print_verbose(args, _("Server supports no-done"));
 909                         if (args->stateless_rpc)
 910                                 no_done = 1;
 911                 }
 912         }
 913         else if (server_supports("multi_ack")) {
 914                 print_verbose(args, _("Server supports multi_ack"));
 915                 multi_ack = 1;
 916         }
 917         if (server_supports("side-band-64k")) {
 918                 print_verbose(args, _("Server supports side-band-64k"));
 919                 use_sideband = 2;
 920         }
 921         else if (server_supports("side-band")) {
 922                 print_verbose(args, _("Server supports side-band"));
 923                 use_sideband = 1;
 924         }
 925         if (server_supports("allow-tip-sha1-in-want")) {
 926                 print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 927                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 928         }
 929         if (server_supports("allow-reachable-sha1-in-want")) {
 930                 print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 931                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 932         }
 933         if (!server_supports("thin-pack"))
 934                 args->use_thin_pack = 0;
 935         if (!server_supports("no-progress"))
 936                 args->no_progress = 0;
 937         if (!server_supports("include-tag"))
 938                 args->include_tag = 0;
 939         if (server_supports("ofs-delta"))
 940                 print_verbose(args, _("Server supports ofs-delta"));
 941         else
 942                 prefer_ofs_delta = 0;
 943
 944         if (server_supports("filter")) {
 945                 server_supports_filtering = 1;
 946                 print_verbose(args, _("Server supports filter"));
 947         } else if (args->filter_options.choice) {
 948                 warning("filtering not recognized by server, ignoring");
 949         }
 950
 951         if ((agent_feature = server_feature_value("agent", &agent_len))) {
 952                 agent_supported = 1;
 953                 if (agent_len)
 954                         print_verbose(args, _("Server version is %.*s"),
 955                                       agent_len, agent_feature);
 956         }
 957         if (server_supports("deepen-since"))
 958                 deepen_since_ok = 1;
 959         else if (args->deepen_since)
 960                 die(_("Server does not support --shallow-since"));
 961         if (server_supports("deepen-not"))
 962                 deepen_not_ok = 1;
 963         else if (args->deepen_not)
 964                 die(_("Server does not support --shallow-exclude"));
 965         if (!server_supports("deepen-relative") && args->deepen_relative)
 966                 die(_("Server does not support --deepen"));
 967
 968         if (!args->no_dependents) {
 969                 mark_complete_and_common_ref(&negotiator, args, &ref);
 970                 filter_refs(args, &ref, sought, nr_sought);
 971                 if (everything_local(args, &ref)) {
 972                         packet_flush(fd[1]);
 973                         goto all_done;
 974                 }
 975         } else {
 976                 filter_refs(args, &ref, sought, nr_sought);
 977         }
 978         if (find_common(&negotiator, args, fd, &oid, ref) < 0)
 979                 if (!args->keep_pack)
 980                         /* When cloning, it is not unusual to have
 981                          * no common commit.
 982                          */
 983                         warning(_("no common commits"));
 984
 985         if (args->stateless_rpc)
 986                 packet_flush(fd[1]);
 987         if (args->deepen)
 988                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
 989                                         NULL);
 990         else if (si->nr_ours || si->nr_theirs)
 991                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
 992         else
 993                 alternate_shallow_file = NULL;
 994         if (get_pack(args, fd, pack_lockfile))
 995                 die(_("git fetch-pack: fetch failed."));
 996
 997  all_done:
 998         negotiator.release(&negotiator);
 999         return ref;
1000 }
1001
1002 static void add_shallow_requests(struct strbuf *req_buf,
1003                                  const struct fetch_pack_args *args)
1004 {
1005         if (is_repository_shallow(the_repository))
1006                 write_shallow_commits(req_buf, 1, NULL);
1007         if (args->depth > 0)
1008                 packet_buf_write(req_buf, "deepen %d", args->depth);
1009         if (args->deepen_since) {
1010                 timestamp_t max_age = approxidate(args->deepen_since);
1011                 packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1012         }
1013         if (args->deepen_not) {
1014                 int i;
1015                 for (i = 0; i < args->deepen_not->nr; i++) {
1016                         struct string_list_item *s = args->deepen_not->items + i;
1017                         packet_buf_write(req_buf, "deepen-not %s", s->string);
1018                 }
1019         }
1020         if (args->deepen_relative)
1021                 packet_buf_write(req_buf, "deepen-relative\n");
1022 }
1023
1024 static void add_wants(int no_dependents, const struct ref *wants, struct strbuf *req_buf)
1025 {
1026         int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1027
1028         for ( ; wants ; wants = wants->next) {
1029                 const struct object_id *remote = &wants->old_oid;
1030                 struct object *o;
1031
1032                 /*
1033                  * If that object is complete (i.e. it is an ancestor of a
1034                  * local ref), we tell them we have it but do not have to
1035                  * tell them about its ancestors, which they already know
1036                  * about.
1037                  *
1038                  * We use lookup_object here because we are only
1039                  * interested in the case we *know* the object is
1040                  * reachable and we have already scanned it.
1041                  *
1042                  * Do this only if args->no_dependents is false (if it is true,
1043                  * we cannot trust the object flags).
1044                  */
1045                 if (!no_dependents &&
1046                     ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
1047                     (o->flags & COMPLETE)) {
1048                         continue;
1049                 }
1050
1051                 if (!use_ref_in_want || wants->exact_oid)
1052                         packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1053                 else
1054                         packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1055         }
1056 }
1057
1058 static void add_common(struct strbuf *req_buf, struct oidset *common)
1059 {
1060         struct oidset_iter iter;
1061         const struct object_id *oid;
1062         oidset_iter_init(common, &iter);
1063
1064         while ((oid = oidset_iter_next(&iter))) {
1065                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1066         }
1067 }
1068
1069 static int add_haves(struct fetch_negotiator *negotiator,
1070                      struct strbuf *req_buf,
1071                      int *haves_to_send, int *in_vain)
1072 {
1073         int ret = 0;
1074         int haves_added = 0;
1075         const struct object_id *oid;
1076
1077         while ((oid = negotiator->next(negotiator))) {
1078                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1079                 if (++haves_added >= *haves_to_send)
1080                         break;
1081         }
1082
1083         *in_vain += haves_added;
1084         if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1085                 /* Send Done */
1086                 packet_buf_write(req_buf, "done\n");
1087                 ret = 1;
1088         }
1089
1090         /* Increase haves to send on next round */
1091         *haves_to_send = next_flush(1, *haves_to_send);
1092
1093         return ret;
1094 }
1095
1096 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1097                               const struct fetch_pack_args *args,
1098                               const struct ref *wants, struct oidset *common,
1099                               int *haves_to_send, int *in_vain,
1100                               int sideband_all)
1101 {
1102         int ret = 0;
1103         struct strbuf req_buf = STRBUF_INIT;
1104
1105         if (server_supports_v2("fetch", 1))
1106                 packet_buf_write(&req_buf, "command=fetch");
1107         if (server_supports_v2("agent", 0))
1108                 packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1109         if (args->server_options && args->server_options->nr &&
1110             server_supports_v2("server-option", 1)) {
1111                 int i;
1112                 for (i = 0; i < args->server_options->nr; i++)
1113                         packet_write_fmt(fd_out, "server-option=%s",
1114                                          args->server_options->items[i].string);
1115         }
1116
1117         packet_buf_delim(&req_buf);
1118         if (args->use_thin_pack)
1119                 packet_buf_write(&req_buf, "thin-pack");
1120         if (args->no_progress)
1121                 packet_buf_write(&req_buf, "no-progress");
1122         if (args->include_tag)
1123                 packet_buf_write(&req_buf, "include-tag");
1124         if (prefer_ofs_delta)
1125                 packet_buf_write(&req_buf, "ofs-delta");
1126         if (sideband_all)
1127                 packet_buf_write(&req_buf, "sideband-all");
1128
1129         /* Add shallow-info and deepen request */
1130         if (server_supports_feature("fetch", "shallow", 0))
1131                 add_shallow_requests(&req_buf, args);
1132         else if (is_repository_shallow(the_repository) || args->deepen)
1133                 die(_("Server does not support shallow requests"));
1134
1135         /* Add filter */
1136         if (server_supports_feature("fetch", "filter", 0) &&
1137             args->filter_options.choice) {
1138                 struct strbuf expanded_filter_spec = STRBUF_INIT;
1139                 print_verbose(args, _("Server supports filter"));
1140                 expand_list_objects_filter_spec(&args->filter_options,
1141                                                 &expanded_filter_spec);
1142                 packet_buf_write(&req_buf, "filter %s",
1143                                  expanded_filter_spec.buf);
1144                 strbuf_release(&expanded_filter_spec);
1145         } else if (args->filter_options.choice) {
1146                 warning("filtering not recognized by server, ignoring");
1147         }
1148
1149         /* add wants */
1150         add_wants(args->no_dependents, wants, &req_buf);
1151
1152         if (args->no_dependents) {
1153                 packet_buf_write(&req_buf, "done");
1154                 ret = 1;
1155         } else {
1156                 /* Add all of the common commits we've found in previous rounds */
1157                 add_common(&req_buf, common);
1158
1159                 /* Add initial haves */
1160                 ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1161         }
1162
1163         /* Send request */
1164         packet_buf_flush(&req_buf);
1165         if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
1166                 die_errno(_("unable to write request to remote"));
1167
1168         strbuf_release(&req_buf);
1169         return ret;
1170 }
1171
1172 /*
1173  * Processes a section header in a server's response and checks if it matches
1174  * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1175  * not consumed); if 0, the line will be consumed and the function will die if
1176  * the section header doesn't match what was expected.
1177  */
1178 static int process_section_header(struct packet_reader *reader,
1179                                   const char *section, int peek)
1180 {
1181         int ret;
1182
1183         if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1184                 die(_("error reading section header '%s'"), section);
1185
1186         ret = !strcmp(reader->line, section);
1187
1188         if (!peek) {
1189                 if (!ret)
1190                         die(_("expected '%s', received '%s'"),
1191                             section, reader->line);
1192                 packet_reader_read(reader);
1193         }
1194
1195         return ret;
1196 }
1197
1198 static int process_acks(struct fetch_negotiator *negotiator,
1199                         struct packet_reader *reader,
1200                         struct oidset *common)
1201 {
1202         /* received */
1203         int received_ready = 0;
1204         int received_ack = 0;
1205
1206         process_section_header(reader, "acknowledgments", 0);
1207         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1208                 const char *arg;
1209
1210                 if (!strcmp(reader->line, "NAK"))
1211                         continue;
1212
1213                 if (skip_prefix(reader->line, "ACK ", &arg)) {
1214                         struct object_id oid;
1215                         if (!get_oid_hex(arg, &oid)) {
1216                                 struct commit *commit;
1217                                 oidset_insert(common, &oid);
1218                                 commit = lookup_commit(the_repository, &oid);
1219                                 negotiator->ack(negotiator, commit);
1220                         }
1221                         continue;
1222                 }
1223
1224                 if (!strcmp(reader->line, "ready")) {
1225                         received_ready = 1;
1226                         continue;
1227                 }
1228
1229                 die(_("unexpected acknowledgment line: '%s'"), reader->line);
1230         }
1231
1232         if (reader->status != PACKET_READ_FLUSH &&
1233             reader->status != PACKET_READ_DELIM)
1234                 die(_("error processing acks: %d"), reader->status);
1235
1236         /*
1237          * If an "acknowledgments" section is sent, a packfile is sent if and
1238          * only if "ready" was sent in this section. The other sections
1239          * ("shallow-info" and "wanted-refs") are sent only if a packfile is
1240          * sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
1241          * otherwise.
1242          */
1243         if (received_ready && reader->status != PACKET_READ_DELIM)
1244                 die(_("expected packfile to be sent after 'ready'"));
1245         if (!received_ready && reader->status != PACKET_READ_FLUSH)
1246                 die(_("expected no other sections to be sent after no 'ready'"));
1247
1248         /* return 0 if no common, 1 if there are common, or 2 if ready */
1249         return received_ready ? 2 : (received_ack ? 1 : 0);
1250 }
1251
1252 static void receive_shallow_info(struct fetch_pack_args *args,
1253                                  struct packet_reader *reader)
1254 {
1255         int line_received = 0;
1256
1257         process_section_header(reader, "shallow-info", 0);
1258         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1259                 const char *arg;
1260                 struct object_id oid;
1261
1262                 if (skip_prefix(reader->line, "shallow ", &arg)) {
1263                         if (get_oid_hex(arg, &oid))
1264                                 die(_("invalid shallow line: %s"), reader->line);
1265                         register_shallow(the_repository, &oid);
1266                         line_received = 1;
1267                         continue;
1268                 }
1269                 if (skip_prefix(reader->line, "unshallow ", &arg)) {
1270                         if (get_oid_hex(arg, &oid))
1271                                 die(_("invalid unshallow line: %s"), reader->line);
1272                         if (!lookup_object(the_repository, oid.hash))
1273                                 die(_("object not found: %s"), reader->line);
1274                         /* make sure that it is parsed as shallow */
1275                         if (!parse_object(the_repository, &oid))
1276                                 die(_("error in object: %s"), reader->line);
1277                         if (unregister_shallow(&oid))
1278                                 die(_("no shallow found: %s"), reader->line);
1279                         line_received = 1;
1280                         continue;
1281                 }
1282                 die(_("expected shallow/unshallow, got %s"), reader->line);
1283         }
1284
1285         if (reader->status != PACKET_READ_FLUSH &&
1286             reader->status != PACKET_READ_DELIM)
1287                 die(_("error processing shallow info: %d"), reader->status);
1288
1289         if (line_received) {
1290                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1291                                         NULL);
1292                 args->deepen = 1;
1293         } else {
1294                 alternate_shallow_file = NULL;
1295         }
1296 }
1297
1298 static void receive_wanted_refs(struct packet_reader *reader,
1299                                 struct ref **sought, int nr_sought)
1300 {
1301         process_section_header(reader, "wanted-refs", 0);
1302         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1303                 struct object_id oid;
1304                 const char *end;
1305                 int i;
1306
1307                 if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1308                         die(_("expected wanted-ref, got '%s'"), reader->line);
1309
1310                 for (i = 0; i < nr_sought; i++) {
1311                         if (!strcmp(end, sought[i]->name)) {
1312                                 oidcpy(&sought[i]->old_oid, &oid);
1313                                 break;
1314                         }
1315                 }
1316
1317                 if (i == nr_sought)
1318                         die(_("unexpected wanted-ref: '%s'"), reader->line);
1319         }
1320
1321         if (reader->status != PACKET_READ_DELIM)
1322                 die(_("error processing wanted refs: %d"), reader->status);
1323 }
1324
1325 enum fetch_state {
1326         FETCH_CHECK_LOCAL = 0,
1327         FETCH_SEND_REQUEST,
1328         FETCH_PROCESS_ACKS,
1329         FETCH_GET_PACK,
1330         FETCH_DONE,
1331 };
1332
1333 static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1334                                     int fd[2],
1335                                     const struct ref *orig_ref,
1336                                     struct ref **sought, int nr_sought,
1337                                     char **pack_lockfile)
1338 {
1339         struct ref *ref = copy_ref_list(orig_ref);
1340         enum fetch_state state = FETCH_CHECK_LOCAL;
1341         struct oidset common = OIDSET_INIT;
1342         struct packet_reader reader;
1343         int in_vain = 0;
1344         int haves_to_send = INITIAL_FLUSH;
1345         struct fetch_negotiator negotiator;
1346         fetch_negotiator_init(&negotiator, negotiation_algorithm);
1347         packet_reader_init(&reader, fd[0], NULL, 0,
1348                            PACKET_READ_CHOMP_NEWLINE |
1349                            PACKET_READ_DIE_ON_ERR_PACKET);
1350         if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
1351             server_supports_feature("fetch", "sideband-all", 0)) {
1352                 reader.use_sideband = 1;
1353                 reader.me = "fetch-pack";
1354         }
1355
1356         while (state != FETCH_DONE) {
1357                 switch (state) {
1358                 case FETCH_CHECK_LOCAL:
1359                         sort_ref_list(&ref, ref_compare_name);
1360                         QSORT(sought, nr_sought, cmp_ref_by_name);
1361
1362                         /* v2 supports these by default */
1363                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1364                         use_sideband = 2;
1365                         if (args->depth > 0 || args->deepen_since || args->deepen_not)
1366                                 args->deepen = 1;
1367
1368                         /* Filter 'ref' by 'sought' and those that aren't local */
1369                         if (!args->no_dependents) {
1370                                 mark_complete_and_common_ref(&negotiator, args, &ref);
1371                                 filter_refs(args, &ref, sought, nr_sought);
1372                                 if (everything_local(args, &ref))
1373                                         state = FETCH_DONE;
1374                                 else
1375                                         state = FETCH_SEND_REQUEST;
1376
1377                                 mark_tips(&negotiator, args->negotiation_tips);
1378                                 for_each_cached_alternate(&negotiator,
1379                                                           insert_one_alternate_object);
1380                         } else {
1381                                 filter_refs(args, &ref, sought, nr_sought);
1382                                 state = FETCH_SEND_REQUEST;
1383                         }
1384                         break;
1385                 case FETCH_SEND_REQUEST:
1386                         if (send_fetch_request(&negotiator, fd[1], args, ref,
1387                                                &common,
1388                                                &haves_to_send, &in_vain,
1389                                                reader.use_sideband))
1390                                 state = FETCH_GET_PACK;
1391                         else
1392                                 state = FETCH_PROCESS_ACKS;
1393                         break;
1394                 case FETCH_PROCESS_ACKS:
1395                         /* Process ACKs/NAKs */
1396                         switch (process_acks(&negotiator, &reader, &common)) {
1397                         case 2:
1398                                 state = FETCH_GET_PACK;
1399                                 break;
1400                         case 1:
1401                                 in_vain = 0;
1402                                 /* fallthrough */
1403                         default:
1404                                 state = FETCH_SEND_REQUEST;
1405                                 break;
1406                         }
1407                         break;
1408                 case FETCH_GET_PACK:
1409                         /* Check for shallow-info section */
1410                         if (process_section_header(&reader, "shallow-info", 1))
1411                                 receive_shallow_info(args, &reader);
1412
1413                         if (process_section_header(&reader, "wanted-refs", 1))
1414                                 receive_wanted_refs(&reader, sought, nr_sought);
1415
1416                         /* get the pack */
1417                         process_section_header(&reader, "packfile", 0);
1418                         if (get_pack(args, fd, pack_lockfile))
1419                                 die(_("git fetch-pack: fetch failed."));
1420
1421                         state = FETCH_DONE;
1422                         break;
1423                 case FETCH_DONE:
1424                         continue;
1425                 }
1426         }
1427
1428         negotiator.release(&negotiator);
1429         oidset_clear(&common);
1430         return ref;
1431 }
1432
1433 static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1434 {
1435         if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1436                 const char *path;
1437
1438                 if (git_config_pathname(&path, var, value))
1439                         return 1;
1440                 strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1441                         fsck_msg_types.len ? ',' : '=', path);
1442                 free((char *)path);
1443                 return 0;
1444         }
1445
1446         if (skip_prefix(var, "fetch.fsck.", &var)) {
1447                 if (is_valid_msg_type(var, value))
1448                         strbuf_addf(&fsck_msg_types, "%c%s=%s",
1449                                 fsck_msg_types.len ? ',' : '=', var, value);
1450                 else
1451                         warning("Skipping unknown msg id '%s'", var);
1452                 return 0;
1453         }
1454
1455         return git_default_config(var, value, cb);
1456 }
1457
1458 static void fetch_pack_config(void)
1459 {
1460         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1461         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1462         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1463         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1464         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1465         git_config_get_string("fetch.negotiationalgorithm",
1466                               &negotiation_algorithm);
1467
1468         git_config(fetch_pack_config_cb, NULL);
1469 }
1470
1471 static void fetch_pack_setup(void)
1472 {
1473         static int did_setup;
1474         if (did_setup)
1475                 return;
1476         fetch_pack_config();
1477         if (0 <= transfer_unpack_limit)
1478                 unpack_limit = transfer_unpack_limit;
1479         else if (0 <= fetch_unpack_limit)
1480                 unpack_limit = fetch_unpack_limit;
1481         did_setup = 1;
1482 }
1483
1484 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1485 {
1486         struct string_list names = STRING_LIST_INIT_NODUP;
1487         int src, dst;
1488
1489         for (src = dst = 0; src < nr; src++) {
1490                 struct string_list_item *item;
1491                 item = string_list_insert(&names, ref[src]->name);
1492                 if (item->util)
1493                         continue; /* already have it */
1494                 item->util = ref[src];
1495                 if (src != dst)
1496                         ref[dst] = ref[src];
1497                 dst++;
1498         }
1499         for (src = dst; src < nr; src++)
1500                 ref[src] = NULL;
1501         string_list_clear(&names, 0);
1502         return dst;
1503 }
1504
1505 static void update_shallow(struct fetch_pack_args *args,
1506                            struct ref **sought, int nr_sought,
1507                            struct shallow_info *si)
1508 {
1509         struct oid_array ref = OID_ARRAY_INIT;
1510         int *status;
1511         int i;
1512
1513         if (args->deepen && alternate_shallow_file) {
1514                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1515                         unlink_or_warn(git_path_shallow(the_repository));
1516                         rollback_lock_file(&shallow_lock);
1517                 } else
1518                         commit_lock_file(&shallow_lock);
1519                 alternate_shallow_file = NULL;
1520                 return;
1521         }
1522
1523         if (!si->shallow || !si->shallow->nr)
1524                 return;
1525
1526         if (args->cloning) {
1527                 /*
1528                  * remote is shallow, but this is a clone, there are
1529                  * no objects in repo to worry about. Accept any
1530                  * shallow points that exist in the pack (iow in repo
1531                  * after get_pack() and reprepare_packed_git())
1532                  */
1533                 struct oid_array extra = OID_ARRAY_INIT;
1534                 struct object_id *oid = si->shallow->oid;
1535                 for (i = 0; i < si->shallow->nr; i++)
1536                         if (has_object_file(&oid[i]))
1537                                 oid_array_append(&extra, &oid[i]);
1538                 if (extra.nr) {
1539                         setup_alternate_shallow(&shallow_lock,
1540                                                 &alternate_shallow_file,
1541                                                 &extra);
1542                         commit_lock_file(&shallow_lock);
1543                         alternate_shallow_file = NULL;
1544                 }
1545                 oid_array_clear(&extra);
1546                 return;
1547         }
1548
1549         if (!si->nr_ours && !si->nr_theirs)
1550                 return;
1551
1552         remove_nonexistent_theirs_shallow(si);
1553         if (!si->nr_ours && !si->nr_theirs)
1554                 return;
1555         for (i = 0; i < nr_sought; i++)
1556                 oid_array_append(&ref, &sought[i]->old_oid);
1557         si->ref = &ref;
1558
1559         if (args->update_shallow) {
1560                 /*
1561                  * remote is also shallow, .git/shallow may be updated
1562                  * so all refs can be accepted. Make sure we only add
1563                  * shallow roots that are actually reachable from new
1564                  * refs.
1565                  */
1566                 struct oid_array extra = OID_ARRAY_INIT;
1567                 struct object_id *oid = si->shallow->oid;
1568                 assign_shallow_commits_to_refs(si, NULL, NULL);
1569                 if (!si->nr_ours && !si->nr_theirs) {
1570                         oid_array_clear(&ref);
1571                         return;
1572                 }
1573                 for (i = 0; i < si->nr_ours; i++)
1574                         oid_array_append(&extra, &oid[si->ours[i]]);
1575                 for (i = 0; i < si->nr_theirs; i++)
1576                         oid_array_append(&extra, &oid[si->theirs[i]]);
1577                 setup_alternate_shallow(&shallow_lock,
1578                                         &alternate_shallow_file,
1579                                         &extra);
1580                 commit_lock_file(&shallow_lock);
1581                 oid_array_clear(&extra);
1582                 oid_array_clear(&ref);
1583                 alternate_shallow_file = NULL;
1584                 return;
1585         }
1586
1587         /*
1588          * remote is also shallow, check what ref is safe to update
1589          * without updating .git/shallow
1590          */
1591         status = xcalloc(nr_sought, sizeof(*status));
1592         assign_shallow_commits_to_refs(si, NULL, status);
1593         if (si->nr_ours || si->nr_theirs) {
1594                 for (i = 0; i < nr_sought; i++)
1595                         if (status[i])
1596                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1597         }
1598         free(status);
1599         oid_array_clear(&ref);
1600 }
1601
1602 static int iterate_ref_map(void *cb_data, struct object_id *oid)
1603 {
1604         struct ref **rm = cb_data;
1605         struct ref *ref = *rm;
1606
1607         if (!ref)
1608                 return -1; /* end of the list */
1609         *rm = ref->next;
1610         oidcpy(oid, &ref->old_oid);
1611         return 0;
1612 }
1613
1614 struct ref *fetch_pack(struct fetch_pack_args *args,
1615                        int fd[], struct child_process *conn,
1616                        const struct ref *ref,
1617                        const char *dest,
1618                        struct ref **sought, int nr_sought,
1619                        struct oid_array *shallow,
1620                        char **pack_lockfile,
1621                        enum protocol_version version)
1622 {
1623         struct ref *ref_cpy;
1624         struct shallow_info si;
1625
1626         fetch_pack_setup();
1627         if (nr_sought)
1628                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1629
1630         if (args->no_dependents && !args->filter_options.choice) {
1631                 /*
1632                  * The protocol does not support requesting that only the
1633                  * wanted objects be sent, so approximate this by setting a
1634                  * "blob:none" filter if no filter is already set. This works
1635                  * for all object types: note that wanted blobs will still be
1636                  * sent because they are directly specified as a "want".
1637                  *
1638                  * NEEDSWORK: Add an option in the protocol to request that
1639                  * only the wanted objects be sent, and implement it.
1640                  */
1641                 parse_list_objects_filter(&args->filter_options, "blob:none");
1642         }
1643
1644         if (version != protocol_v2 && !ref) {
1645                 packet_flush(fd[1]);
1646                 die(_("no matching remote head"));
1647         }
1648         prepare_shallow_info(&si, shallow);
1649         if (version == protocol_v2)
1650                 ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1651                                            pack_lockfile);
1652         else
1653                 ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1654                                         &si, pack_lockfile);
1655         reprepare_packed_git(the_repository);
1656
1657         if (!args->cloning && args->deepen) {
1658                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
1659                 struct ref *iterator = ref_cpy;
1660                 opt.shallow_file = alternate_shallow_file;
1661                 if (args->deepen)
1662                         opt.is_deepening_fetch = 1;
1663                 if (check_connected(iterate_ref_map, &iterator, &opt)) {
1664                         error(_("remote did not send all necessary objects"));
1665                         free_refs(ref_cpy);
1666                         ref_cpy = NULL;
1667                         rollback_lock_file(&shallow_lock);
1668                         goto cleanup;
1669                 }
1670                 args->connectivity_checked = 1;
1671         }
1672
1673         update_shallow(args, sought, nr_sought, &si);
1674 cleanup:
1675         clear_shallow_info(&si);
1676         return ref_cpy;
1677 }
1678
1679 int report_unmatched_refs(struct ref **sought, int nr_sought)
1680 {
1681         int i, ret = 0;
1682
1683         for (i = 0; i < nr_sought; i++) {
1684                 if (!sought[i])
1685                         continue;
1686                 switch (sought[i]->match_status) {
1687                 case REF_MATCHED:
1688                         continue;
1689                 case REF_NOT_MATCHED:
1690                         error(_("no such remote ref %s"), sought[i]->name);
1691                         break;
1692                 case REF_UNADVERTISED_NOT_ALLOWED:
1693                         error(_("Server does not allow request for unadvertised object %s"),
1694                               sought[i]->name);
1695                         break;
1696                 }
1697                 ret = 1;
1698         }
1699         return ret;
1700 }