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
  25 static int transfer_unpack_limit = -1;
  26 static int fetch_unpack_limit = -1;
  27 static int unpack_limit = 100;
  28 static int prefer_ofs_delta = 1;
  29 static int no_done;
  30 static int deepen_since_ok;
  31 static int deepen_not_ok;
  32 static int fetch_fsck_objects = -1;
  33 static int transfer_fsck_objects = -1;
  34 static int agent_supported;
  35 static int server_supports_filtering;
  36 static struct lock_file shallow_lock;
  37 static const char *alternate_shallow_file;
  38 static char *negotiation_algorithm;
  39
  40 /* Remember to update object flag allocation in object.h */
  41 #define COMPLETE        (1U << 0)
  42 #define ALTERNATE       (1U << 1)
  43
  44 /*
  45  * After sending this many "have"s if we do not get any new ACK , we
  46  * give up traversing our history.
  47  */
  48 #define MAX_IN_VAIN 256
  49
  50 static int multi_ack, use_sideband;
  51 /* Allow specifying sha1 if it is a ref tip. */
  52 #define ALLOW_TIP_SHA1  01
  53 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  54 #define ALLOW_REACHABLE_SHA1    02
  55 static unsigned int allow_unadvertised_object_request;
  56
  57 __attribute__((format (printf, 2, 3)))
  58 static inline void print_verbose(const struct fetch_pack_args *args,
  59                                  const char *fmt, ...)
  60 {
  61         va_list params;
  62
  63         if (!args->verbose)
  64                 return;
  65
  66         va_start(params, fmt);
  67         vfprintf(stderr, fmt, params);
  68         va_end(params);
  69         fputc('\n', stderr);
  70 }
  71
  72 struct alternate_object_cache {
  73         struct object **items;
  74         size_t nr, alloc;
  75 };
  76
  77 static void cache_one_alternate(const char *refname,
  78                                 const struct object_id *oid,
  79                                 void *vcache)
  80 {
  81         struct alternate_object_cache *cache = vcache;
  82         struct object *obj = parse_object(the_repository, oid);
  83
  84         if (!obj || (obj->flags & ALTERNATE))
  85                 return;
  86
  87         obj->flags |= ALTERNATE;
  88         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  89         cache->items[cache->nr++] = obj;
  90 }
  91
  92 static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
  93                                       void (*cb)(struct fetch_negotiator *,
  94                                                  struct object *))
  95 {
  96         static int initialized;
  97         static struct alternate_object_cache cache;
  98         size_t i;
  99
 100         if (!initialized) {
 101                 for_each_alternate_ref(cache_one_alternate, &cache);
 102                 initialized = 1;
 103         }
 104
 105         for (i = 0; i < cache.nr; i++)
 106                 cb(negotiator, cache.items[i]);
 107 }
 108
 109 static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
 110                                const char *refname,
 111                                const struct object_id *oid)
 112 {
 113         struct object *o = deref_tag(the_repository,
 114                                      parse_object(the_repository, oid),
 115                                      refname, 0);
 116
 117         if (o && o->type == OBJ_COMMIT)
 118                 negotiator->add_tip(negotiator, (struct commit *)o);
 119
 120         return 0;
 121 }
 122
 123 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 124                                    int flag, void *cb_data)
 125 {
 126         return rev_list_insert_ref(cb_data, refname, oid);
 127 }
 128
 129 enum ack_type {
 130         NAK = 0,
 131         ACK,
 132         ACK_continue,
 133         ACK_common,
 134         ACK_ready
 135 };
 136
 137 static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 138 {
 139         if (args->stateless_rpc && args->deepen) {
 140                 /* If we sent a depth we will get back "duplicate"
 141                  * shallow and unshallow commands every time there
 142                  * is a block of have lines exchanged.
 143                  */
 144                 char *line;
 145                 while ((line = packet_read_line(fd, NULL))) {
 146                         if (starts_with(line, "shallow "))
 147                                 continue;
 148                         if (starts_with(line, "unshallow "))
 149                                 continue;
 150                         die(_("git fetch-pack: expected shallow list"));
 151                 }
 152         }
 153 }
 154
 155 static enum ack_type get_ack(int fd, struct object_id *result_oid)
 156 {
 157         int len;
 158         char *line = packet_read_line(fd, &len);
 159         const char *arg;
 160
 161         if (!line)
 162                 die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 163         if (!strcmp(line, "NAK"))
 164                 return NAK;
 165         if (skip_prefix(line, "ACK ", &arg)) {
 166                 if (!get_oid_hex(arg, result_oid)) {
 167                         arg += 40;
 168                         len -= arg - line;
 169                         if (len < 1)
 170                                 return ACK;
 171                         if (strstr(arg, "continue"))
 172                                 return ACK_continue;
 173                         if (strstr(arg, "common"))
 174                                 return ACK_common;
 175                         if (strstr(arg, "ready"))
 176                                 return ACK_ready;
 177                         return ACK;
 178                 }
 179         }
 180         if (skip_prefix(line, "ERR ", &arg))
 181                 die(_("remote error: %s"), arg);
 182         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 183 }
 184
 185 static void send_request(struct fetch_pack_args *args,
 186                          int fd, struct strbuf *buf)
 187 {
 188         if (args->stateless_rpc) {
 189                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 190                 packet_flush(fd);
 191         } else
 192                 write_or_die(fd, buf->buf, buf->len);
 193 }
 194
 195 static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 196                                         struct object *obj)
 197 {
 198         rev_list_insert_ref(negotiator, NULL, &obj->oid);
 199 }
 200
 201 #define INITIAL_FLUSH 16
 202 #define PIPESAFE_FLUSH 32
 203 #define LARGE_FLUSH 16384
 204
 205 static int next_flush(int stateless_rpc, int count)
 206 {
 207         if (stateless_rpc) {
 208                 if (count < LARGE_FLUSH)
 209                         count <<= 1;
 210                 else
 211                         count = count * 11 / 10;
 212         } else {
 213                 if (count < PIPESAFE_FLUSH)
 214                         count <<= 1;
 215                 else
 216                         count += PIPESAFE_FLUSH;
 217         }
 218         return count;
 219 }
 220
 221 static void mark_tips(struct fetch_negotiator *negotiator,
 222                       const struct oid_array *negotiation_tips)
 223 {
 224         int i;
 225
 226         if (!negotiation_tips) {
 227                 for_each_ref(rev_list_insert_ref_oid, negotiator);
 228                 return;
 229         }
 230
 231         for (i = 0; i < negotiation_tips->nr; i++)
 232                 rev_list_insert_ref(negotiator, NULL,
 233                                     &negotiation_tips->oid[i]);
 234         return;
 235 }
 236
 237 static int find_common(struct fetch_negotiator *negotiator,
 238                        struct fetch_pack_args *args,
 239                        int fd[2], struct object_id *result_oid,
 240                        struct ref *refs)
 241 {
 242         int fetching;
 243         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 244         const struct object_id *oid;
 245         unsigned in_vain = 0;
 246         int got_continue = 0;
 247         int got_ready = 0;
 248         struct strbuf req_buf = STRBUF_INIT;
 249         size_t state_len = 0;
 250
 251         if (args->stateless_rpc && multi_ack == 1)
 252                 die(_("--stateless-rpc requires multi_ack_detailed"));
 253
 254         mark_tips(negotiator, args->negotiation_tips);
 255         for_each_cached_alternate(negotiator, insert_one_alternate_object);
 256
 257         fetching = 0;
 258         for ( ; refs ; refs = refs->next) {
 259                 struct object_id *remote = &refs->old_oid;
 260                 const char *remote_hex;
 261                 struct object *o;
 262
 263                 /*
 264                  * If that object is complete (i.e. it is an ancestor of a
 265                  * local ref), we tell them we have it but do not have to
 266                  * tell them about its ancestors, which they already know
 267                  * about.
 268                  *
 269                  * We use lookup_object here because we are only
 270                  * interested in the case we *know* the object is
 271                  * reachable and we have already scanned it.
 272                  */
 273                 if (((o = lookup_object(the_repository, remote->hash)) != NULL) &&
 274                                 (o->flags & COMPLETE)) {
 275                         continue;
 276                 }
 277
 278                 remote_hex = oid_to_hex(remote);
 279                 if (!fetching) {
 280                         struct strbuf c = STRBUF_INIT;
 281                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 282                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 283                         if (no_done)            strbuf_addstr(&c, " no-done");
 284                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 285                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 286                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 287                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 288                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 289                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 290                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 291                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 292                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 293                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 294                                                             git_user_agent_sanitized());
 295                         if (args->filter_options.choice)
 296                                 strbuf_addstr(&c, " filter");
 297                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 298                         strbuf_release(&c);
 299                 } else
 300                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 301                 fetching++;
 302         }
 303
 304         if (!fetching) {
 305                 strbuf_release(&req_buf);
 306                 packet_flush(fd[1]);
 307                 return 1;
 308         }
 309
 310         if (is_repository_shallow(the_repository))
 311                 write_shallow_commits(&req_buf, 1, NULL);
 312         if (args->depth > 0)
 313                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 314         if (args->deepen_since) {
 315                 timestamp_t max_age = approxidate(args->deepen_since);
 316                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 317         }
 318         if (args->deepen_not) {
 319                 int i;
 320                 for (i = 0; i < args->deepen_not->nr; i++) {
 321                         struct string_list_item *s = args->deepen_not->items + i;
 322                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 323                 }
 324         }
 325         if (server_supports_filtering && args->filter_options.choice)
 326                 packet_buf_write(&req_buf, "filter %s",
 327                                  args->filter_options.filter_spec);
 328         packet_buf_flush(&req_buf);
 329         state_len = req_buf.len;
 330
 331         if (args->deepen) {
 332                 char *line;
 333                 const char *arg;
 334                 struct object_id oid;
 335
 336                 send_request(args, fd[1], &req_buf);
 337                 while ((line = packet_read_line(fd[0], NULL))) {
 338                         if (skip_prefix(line, "shallow ", &arg)) {
 339                                 if (get_oid_hex(arg, &oid))
 340                                         die(_("invalid shallow line: %s"), line);
 341                                 register_shallow(the_repository, &oid);
 342                                 continue;
 343                         }
 344                         if (skip_prefix(line, "unshallow ", &arg)) {
 345                                 if (get_oid_hex(arg, &oid))
 346                                         die(_("invalid unshallow line: %s"), line);
 347                                 if (!lookup_object(the_repository, oid.hash))
 348                                         die(_("object not found: %s"), line);
 349                                 /* make sure that it is parsed as shallow */
 350                                 if (!parse_object(the_repository, &oid))
 351                                         die(_("error in object: %s"), line);
 352                                 if (unregister_shallow(&oid))
 353                                         die(_("no shallow found: %s"), line);
 354                                 continue;
 355                         }
 356                         die(_("expected shallow/unshallow, got %s"), line);
 357                 }
 358         } else if (!args->stateless_rpc)
 359                 send_request(args, fd[1], &req_buf);
 360
 361         if (!args->stateless_rpc) {
 362                 /* If we aren't using the stateless-rpc interface
 363                  * we don't need to retain the headers.
 364                  */
 365                 strbuf_setlen(&req_buf, 0);
 366                 state_len = 0;
 367         }
 368
 369         flushes = 0;
 370         retval = -1;
 371         if (args->no_dependents)
 372                 goto done;
 373         while ((oid = negotiator->next(negotiator))) {
 374                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 375                 print_verbose(args, "have %s", oid_to_hex(oid));
 376                 in_vain++;
 377                 if (flush_at <= ++count) {
 378                         int ack;
 379
 380                         packet_buf_flush(&req_buf);
 381                         send_request(args, fd[1], &req_buf);
 382                         strbuf_setlen(&req_buf, state_len);
 383                         flushes++;
 384                         flush_at = next_flush(args->stateless_rpc, count);
 385
 386                         /*
 387                          * We keep one window "ahead" of the other side, and
 388                          * will wait for an ACK only on the next one
 389                          */
 390                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 391                                 continue;
 392
 393                         consume_shallow_list(args, fd[0]);
 394                         do {
 395                                 ack = get_ack(fd[0], result_oid);
 396                                 if (ack)
 397                                         print_verbose(args, _("got %s %d %s"), "ack",
 398                                                       ack, oid_to_hex(result_oid));
 399                                 switch (ack) {
 400                                 case ACK:
 401                                         flushes = 0;
 402                                         multi_ack = 0;
 403                                         retval = 0;
 404                                         goto done;
 405                                 case ACK_common:
 406                                 case ACK_ready:
 407                                 case ACK_continue: {
 408                                         struct commit *commit =
 409                                                 lookup_commit(the_repository,
 410                                                               result_oid);
 411                                         int was_common;
 412
 413                                         if (!commit)
 414                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
 415                                         was_common = negotiator->ack(negotiator, commit);
 416                                         if (args->stateless_rpc
 417                                          && ack == ACK_common
 418                                          && !was_common) {
 419                                                 /* We need to replay the have for this object
 420                                                  * on the next RPC request so the peer knows
 421                                                  * it is in common with us.
 422                                                  */
 423                                                 const char *hex = oid_to_hex(result_oid);
 424                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 425                                                 state_len = req_buf.len;
 426                                                 /*
 427                                                  * Reset in_vain because an ack
 428                                                  * for this commit has not been
 429                                                  * seen.
 430                                                  */
 431                                                 in_vain = 0;
 432                                         } else if (!args->stateless_rpc
 433                                                    || ack != ACK_common)
 434                                                 in_vain = 0;
 435                                         retval = 0;
 436                                         got_continue = 1;
 437                                         if (ack == ACK_ready)
 438                                                 got_ready = 1;
 439                                         break;
 440                                         }
 441                                 }
 442                         } while (ack);
 443                         flushes--;
 444                         if (got_continue && MAX_IN_VAIN < in_vain) {
 445                                 print_verbose(args, _("giving up"));
 446                                 break; /* give up */
 447                         }
 448                         if (got_ready)
 449                                 break;
 450                 }
 451         }
 452 done:
 453         if (!got_ready || !no_done) {
 454                 packet_buf_write(&req_buf, "done\n");
 455                 send_request(args, fd[1], &req_buf);
 456         }
 457         print_verbose(args, _("done"));
 458         if (retval != 0) {
 459                 multi_ack = 0;
 460                 flushes++;
 461         }
 462         strbuf_release(&req_buf);
 463
 464         if (!got_ready || !no_done)
 465                 consume_shallow_list(args, fd[0]);
 466         while (flushes || multi_ack) {
 467                 int ack = get_ack(fd[0], result_oid);
 468                 if (ack) {
 469                         print_verbose(args, _("got %s (%d) %s"), "ack",
 470                                       ack, oid_to_hex(result_oid));
 471                         if (ack == ACK)
 472                                 return 0;
 473                         multi_ack = 1;
 474                         continue;
 475                 }
 476                 flushes--;
 477         }
 478         /* it is no error to fetch into a completely empty repo */
 479         return count ? retval : 0;
 480 }
 481
 482 static struct commit_list *complete;
 483
 484 static int mark_complete(const struct object_id *oid)
 485 {
 486         struct object *o = parse_object(the_repository, oid);
 487
 488         while (o && o->type == OBJ_TAG) {
 489                 struct tag *t = (struct tag *) o;
 490                 if (!t->tagged)
 491                         break; /* broken repository */
 492                 o->flags |= COMPLETE;
 493                 o = parse_object(the_repository, &t->tagged->oid);
 494         }
 495         if (o && o->type == OBJ_COMMIT) {
 496                 struct commit *commit = (struct commit *)o;
 497                 if (!(commit->object.flags & COMPLETE)) {
 498                         commit->object.flags |= COMPLETE;
 499                         commit_list_insert(commit, &complete);
 500                 }
 501         }
 502         return 0;
 503 }
 504
 505 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 506                              int flag, void *cb_data)
 507 {
 508         return mark_complete(oid);
 509 }
 510
 511 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 512                                          timestamp_t cutoff)
 513 {
 514         while (complete && cutoff <= complete->item->date) {
 515                 print_verbose(args, _("Marking %s as complete"),
 516                               oid_to_hex(&complete->item->object.oid));
 517                 pop_most_recent_commit(&complete, COMPLETE);
 518         }
 519 }
 520
 521 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 522 {
 523         for (; refs; refs = refs->next)
 524                 oidset_insert(oids, &refs->old_oid);
 525 }
 526
 527 static int tip_oids_contain(struct oidset *tip_oids,
 528                             struct ref *unmatched, struct ref *newlist,
 529                             const struct object_id *id)
 530 {
 531         /*
 532          * Note that this only looks at the ref lists the first time it's
 533          * called. This works out in filter_refs() because even though it may
 534          * add to "newlist" between calls, the additions will always be for
 535          * oids that are already in the set.
 536          */
 537         if (!tip_oids->map.map.tablesize) {
 538                 add_refs_to_oidset(tip_oids, unmatched);
 539                 add_refs_to_oidset(tip_oids, newlist);
 540         }
 541         return oidset_contains(tip_oids, id);
 542 }
 543
 544 static void filter_refs(struct fetch_pack_args *args,
 545                         struct ref **refs,
 546                         struct ref **sought, int nr_sought)
 547 {
 548         struct ref *newlist = NULL;
 549         struct ref **newtail = &newlist;
 550         struct ref *unmatched = NULL;
 551         struct ref *ref, *next;
 552         struct oidset tip_oids = OIDSET_INIT;
 553         int i;
 554
 555         i = 0;
 556         for (ref = *refs; ref; ref = next) {
 557                 int keep = 0;
 558                 next = ref->next;
 559
 560                 if (starts_with(ref->name, "refs/") &&
 561                     check_refname_format(ref->name, 0))
 562                         ; /* trash */
 563                 else {
 564                         while (i < nr_sought) {
 565                                 int cmp = strcmp(ref->name, sought[i]->name);
 566                                 if (cmp < 0)
 567                                         break; /* definitely do not have it */
 568                                 else if (cmp == 0) {
 569                                         keep = 1; /* definitely have it */
 570                                         sought[i]->match_status = REF_MATCHED;
 571                                 }
 572                                 i++;
 573                         }
 574
 575                         if (!keep && args->fetch_all &&
 576                             (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 577                                 keep = 1;
 578                 }
 579
 580                 if (keep) {
 581                         *newtail = ref;
 582                         ref->next = NULL;
 583                         newtail = &ref->next;
 584                 } else {
 585                         ref->next = unmatched;
 586                         unmatched = ref;
 587                 }
 588         }
 589
 590         /* Append unmatched requests to the list */
 591         for (i = 0; i < nr_sought; i++) {
 592                 struct object_id oid;
 593                 const char *p;
 594
 595                 ref = sought[i];
 596                 if (ref->match_status != REF_NOT_MATCHED)
 597                         continue;
 598                 if (parse_oid_hex(ref->name, &oid, &p) ||
 599                     *p != '\0' ||
 600                     oidcmp(&oid, &ref->old_oid))
 601                         continue;
 602
 603                 if ((allow_unadvertised_object_request &
 604                      (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1)) ||
 605                     tip_oids_contain(&tip_oids, unmatched, newlist,
 606                                      &ref->old_oid)) {
 607                         ref->match_status = REF_MATCHED;
 608                         *newtail = copy_ref(ref);
 609                         newtail = &(*newtail)->next;
 610                 } else {
 611                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 612                 }
 613         }
 614
 615         oidset_clear(&tip_oids);
 616         for (ref = unmatched; ref; ref = next) {
 617                 next = ref->next;
 618                 free(ref);
 619         }
 620
 621         *refs = newlist;
 622 }
 623
 624 static void mark_alternate_complete(struct fetch_negotiator *unused,
 625                                     struct object *obj)
 626 {
 627         mark_complete(&obj->oid);
 628 }
 629
 630 struct loose_object_iter {
 631         struct oidset *loose_object_set;
 632         struct ref *refs;
 633 };
 634
 635 /*
 636  *  If the number of refs is not larger than the number of loose objects,
 637  *  this function stops inserting.
 638  */
 639 static int add_loose_objects_to_set(const struct object_id *oid,
 640                                     const char *path,
 641                                     void *data)
 642 {
 643         struct loose_object_iter *iter = data;
 644         oidset_insert(iter->loose_object_set, oid);
 645         if (iter->refs == NULL)
 646                 return 1;
 647
 648         iter->refs = iter->refs->next;
 649         return 0;
 650 }
 651
 652 /*
 653  * Mark recent commits available locally and reachable from a local ref as
 654  * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 655  * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 656  * thus do not need COMMON_REF marks).
 657  *
 658  * The cutoff time for recency is determined by this heuristic: it is the
 659  * earliest commit time of the objects in refs that are commits and that we know
 660  * the commit time of.
 661  */
 662 static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 663                                          struct fetch_pack_args *args,
 664                                          struct ref **refs)
 665 {
 666         struct ref *ref;
 667         int old_save_commit_buffer = save_commit_buffer;
 668         timestamp_t cutoff = 0;
 669         struct oidset loose_oid_set = OIDSET_INIT;
 670         int use_oidset = 0;
 671         struct loose_object_iter iter = {&loose_oid_set, *refs};
 672
 673         /* Enumerate all loose objects or know refs are not so many. */
 674         use_oidset = !for_each_loose_object(add_loose_objects_to_set,
 675                                             &iter, 0);
 676
 677         save_commit_buffer = 0;
 678
 679         for (ref = *refs; ref; ref = ref->next) {
 680                 struct object *o;
 681                 unsigned int flags = OBJECT_INFO_QUICK;
 682
 683                 if (use_oidset &&
 684                     !oidset_contains(&loose_oid_set, &ref->old_oid)) {
 685                         /*
 686                          * I know this does not exist in the loose form,
 687                          * so check if it exists in a non-loose form.
 688                          */
 689                         flags |= OBJECT_INFO_IGNORE_LOOSE;
 690                 }
 691
 692                 if (!has_object_file_with_flags(&ref->old_oid, flags))
 693                         continue;
 694                 o = parse_object(the_repository, &ref->old_oid);
 695                 if (!o)
 696                         continue;
 697
 698                 /* We already have it -- which may mean that we were
 699                  * in sync with the other side at some time after
 700                  * that (it is OK if we guess wrong here).
 701                  */
 702                 if (o->type == OBJ_COMMIT) {
 703                         struct commit *commit = (struct commit *)o;
 704                         if (!cutoff || cutoff < commit->date)
 705                                 cutoff = commit->date;
 706                 }
 707         }
 708
 709         oidset_clear(&loose_oid_set);
 710
 711         if (!args->no_dependents) {
 712                 if (!args->deepen) {
 713                         for_each_ref(mark_complete_oid, NULL);
 714                         for_each_cached_alternate(NULL, mark_alternate_complete);
 715                         commit_list_sort_by_date(&complete);
 716                         if (cutoff)
 717                                 mark_recent_complete_commits(args, cutoff);
 718                 }
 719
 720                 /*
 721                  * Mark all complete remote refs as common refs.
 722                  * Don't mark them common yet; the server has to be told so first.
 723                  */
 724                 for (ref = *refs; ref; ref = ref->next) {
 725                         struct object *o = deref_tag(the_repository,
 726                                                      lookup_object(the_repository,
 727                                                      ref->old_oid.hash),
 728                                                      NULL, 0);
 729
 730                         if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 731                                 continue;
 732
 733                         negotiator->known_common(negotiator,
 734                                                  (struct commit *)o);
 735                 }
 736         }
 737
 738         save_commit_buffer = old_save_commit_buffer;
 739 }
 740
 741 /*
 742  * Returns 1 if every object pointed to by the given remote refs is available
 743  * locally and reachable from a local ref, and 0 otherwise.
 744  */
 745 static int everything_local(struct fetch_pack_args *args,
 746                             struct ref **refs)
 747 {
 748         struct ref *ref;
 749         int retval;
 750
 751         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 752                 const struct object_id *remote = &ref->old_oid;
 753                 struct object *o;
 754
 755                 o = lookup_object(the_repository, remote->hash);
 756                 if (!o || !(o->flags & COMPLETE)) {
 757                         retval = 0;
 758                         print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 759                                       ref->name);
 760                         continue;
 761                 }
 762                 print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 763                               ref->name);
 764         }
 765
 766         return retval;
 767 }
 768
 769 static int sideband_demux(int in, int out, void *data)
 770 {
 771         int *xd = data;
 772         int ret;
 773
 774         ret = recv_sideband("fetch-pack", xd[0], out);
 775         close(out);
 776         return ret;
 777 }
 778
 779 static int get_pack(struct fetch_pack_args *args,
 780                     int xd[2], char **pack_lockfile)
 781 {
 782         struct async demux;
 783         int do_keep = args->keep_pack;
 784         const char *cmd_name;
 785         struct pack_header header;
 786         int pass_header = 0;
 787         struct child_process cmd = CHILD_PROCESS_INIT;
 788         int ret;
 789
 790         memset(&demux, 0, sizeof(demux));
 791         if (use_sideband) {
 792                 /* xd[] is talking with upload-pack; subprocess reads from
 793                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 794                  * through demux->out.
 795                  */
 796                 demux.proc = sideband_demux;
 797                 demux.data = xd;
 798                 demux.out = -1;
 799                 demux.isolate_sigpipe = 1;
 800                 if (start_async(&demux))
 801                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 802         }
 803         else
 804                 demux.out = xd[0];
 805
 806         if (!args->keep_pack && unpack_limit) {
 807
 808                 if (read_pack_header(demux.out, &header))
 809                         die(_("protocol error: bad pack header"));
 810                 pass_header = 1;
 811                 if (ntohl(header.hdr_entries) < unpack_limit)
 812                         do_keep = 0;
 813                 else
 814                         do_keep = 1;
 815         }
 816
 817         if (alternate_shallow_file) {
 818                 argv_array_push(&cmd.args, "--shallow-file");
 819                 argv_array_push(&cmd.args, alternate_shallow_file);
 820         }
 821
 822         if (do_keep || args->from_promisor) {
 823                 if (pack_lockfile)
 824                         cmd.out = -1;
 825                 cmd_name = "index-pack";
 826                 argv_array_push(&cmd.args, cmd_name);
 827                 argv_array_push(&cmd.args, "--stdin");
 828                 if (!args->quiet && !args->no_progress)
 829                         argv_array_push(&cmd.args, "-v");
 830                 if (args->use_thin_pack)
 831                         argv_array_push(&cmd.args, "--fix-thin");
 832                 if (do_keep && (args->lock_pack || unpack_limit)) {
 833                         char hostname[HOST_NAME_MAX + 1];
 834                         if (xgethostname(hostname, sizeof(hostname)))
 835                                 xsnprintf(hostname, sizeof(hostname), "localhost");
 836                         argv_array_pushf(&cmd.args,
 837                                         "--keep=fetch-pack %"PRIuMAX " on %s",
 838                                         (uintmax_t)getpid(), hostname);
 839                 }
 840                 if (args->check_self_contained_and_connected)
 841                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 842                 if (args->from_promisor)
 843                         argv_array_push(&cmd.args, "--promisor");
 844         }
 845         else {
 846                 cmd_name = "unpack-objects";
 847                 argv_array_push(&cmd.args, cmd_name);
 848                 if (args->quiet || args->no_progress)
 849                         argv_array_push(&cmd.args, "-q");
 850                 args->check_self_contained_and_connected = 0;
 851         }
 852
 853         if (pass_header)
 854                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 855                                  ntohl(header.hdr_version),
 856                                  ntohl(header.hdr_entries));
 857         if (fetch_fsck_objects >= 0
 858             ? fetch_fsck_objects
 859             : transfer_fsck_objects >= 0
 860             ? transfer_fsck_objects
 861             : 0) {
 862                 if (args->from_promisor)
 863                         /*
 864                          * We cannot use --strict in index-pack because it
 865                          * checks both broken objects and links, but we only
 866                          * want to check for broken objects.
 867                          */
 868                         argv_array_push(&cmd.args, "--fsck-objects");
 869                 else
 870                         argv_array_push(&cmd.args, "--strict");
 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, struct ref *refs)
1282 {
1283         process_section_header(reader, "wanted-refs", 0);
1284         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1285                 struct object_id oid;
1286                 const char *end;
1287                 struct ref *r = NULL;
1288
1289                 if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1290                         die("expected wanted-ref, got '%s'", reader->line);
1291
1292                 for (r = refs; r; r = r->next) {
1293                         if (!strcmp(end, r->name)) {
1294                                 oidcpy(&r->old_oid, &oid);
1295                                 break;
1296                         }
1297                 }
1298
1299                 if (!r)
1300                         die("unexpected wanted-ref: '%s'", reader->line);
1301         }
1302
1303         if (reader->status != PACKET_READ_DELIM)
1304                 die("error processing wanted refs: %d", reader->status);
1305 }
1306
1307 enum fetch_state {
1308         FETCH_CHECK_LOCAL = 0,
1309         FETCH_SEND_REQUEST,
1310         FETCH_PROCESS_ACKS,
1311         FETCH_GET_PACK,
1312         FETCH_DONE,
1313 };
1314
1315 static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1316                                     int fd[2],
1317                                     const struct ref *orig_ref,
1318                                     struct ref **sought, int nr_sought,
1319                                     char **pack_lockfile)
1320 {
1321         struct ref *ref = copy_ref_list(orig_ref);
1322         enum fetch_state state = FETCH_CHECK_LOCAL;
1323         struct oidset common = OIDSET_INIT;
1324         struct packet_reader reader;
1325         int in_vain = 0;
1326         int haves_to_send = INITIAL_FLUSH;
1327         struct fetch_negotiator negotiator;
1328         fetch_negotiator_init(&negotiator, negotiation_algorithm);
1329         packet_reader_init(&reader, fd[0], NULL, 0,
1330                            PACKET_READ_CHOMP_NEWLINE);
1331
1332         while (state != FETCH_DONE) {
1333                 switch (state) {
1334                 case FETCH_CHECK_LOCAL:
1335                         sort_ref_list(&ref, ref_compare_name);
1336                         QSORT(sought, nr_sought, cmp_ref_by_name);
1337
1338                         /* v2 supports these by default */
1339                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1340                         use_sideband = 2;
1341                         if (args->depth > 0 || args->deepen_since || args->deepen_not)
1342                                 args->deepen = 1;
1343
1344                         /* Filter 'ref' by 'sought' and those that aren't local */
1345                         mark_complete_and_common_ref(&negotiator, args, &ref);
1346                         filter_refs(args, &ref, sought, nr_sought);
1347                         if (everything_local(args, &ref))
1348                                 state = FETCH_DONE;
1349                         else
1350                                 state = FETCH_SEND_REQUEST;
1351
1352                         mark_tips(&negotiator, args->negotiation_tips);
1353                         for_each_cached_alternate(&negotiator,
1354                                                   insert_one_alternate_object);
1355                         break;
1356                 case FETCH_SEND_REQUEST:
1357                         if (send_fetch_request(&negotiator, fd[1], args, ref,
1358                                                &common,
1359                                                &haves_to_send, &in_vain))
1360                                 state = FETCH_GET_PACK;
1361                         else
1362                                 state = FETCH_PROCESS_ACKS;
1363                         break;
1364                 case FETCH_PROCESS_ACKS:
1365                         /* Process ACKs/NAKs */
1366                         switch (process_acks(&negotiator, &reader, &common)) {
1367                         case 2:
1368                                 state = FETCH_GET_PACK;
1369                                 break;
1370                         case 1:
1371                                 in_vain = 0;
1372                                 /* fallthrough */
1373                         default:
1374                                 state = FETCH_SEND_REQUEST;
1375                                 break;
1376                         }
1377                         break;
1378                 case FETCH_GET_PACK:
1379                         /* Check for shallow-info section */
1380                         if (process_section_header(&reader, "shallow-info", 1))
1381                                 receive_shallow_info(args, &reader);
1382
1383                         if (process_section_header(&reader, "wanted-refs", 1))
1384                                 receive_wanted_refs(&reader, ref);
1385
1386                         /* get the pack */
1387                         process_section_header(&reader, "packfile", 0);
1388                         if (get_pack(args, fd, pack_lockfile))
1389                                 die(_("git fetch-pack: fetch failed."));
1390
1391                         state = FETCH_DONE;
1392                         break;
1393                 case FETCH_DONE:
1394                         continue;
1395                 }
1396         }
1397
1398         negotiator.release(&negotiator);
1399         oidset_clear(&common);
1400         return ref;
1401 }
1402
1403 static void fetch_pack_config(void)
1404 {
1405         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1406         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1407         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1408         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1409         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1410         git_config_get_string("fetch.negotiationalgorithm",
1411                               &negotiation_algorithm);
1412
1413         git_config(git_default_config, NULL);
1414 }
1415
1416 static void fetch_pack_setup(void)
1417 {
1418         static int did_setup;
1419         if (did_setup)
1420                 return;
1421         fetch_pack_config();
1422         if (0 <= transfer_unpack_limit)
1423                 unpack_limit = transfer_unpack_limit;
1424         else if (0 <= fetch_unpack_limit)
1425                 unpack_limit = fetch_unpack_limit;
1426         did_setup = 1;
1427 }
1428
1429 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1430 {
1431         struct string_list names = STRING_LIST_INIT_NODUP;
1432         int src, dst;
1433
1434         for (src = dst = 0; src < nr; src++) {
1435                 struct string_list_item *item;
1436                 item = string_list_insert(&names, ref[src]->name);
1437                 if (item->util)
1438                         continue; /* already have it */
1439                 item->util = ref[src];
1440                 if (src != dst)
1441                         ref[dst] = ref[src];
1442                 dst++;
1443         }
1444         for (src = dst; src < nr; src++)
1445                 ref[src] = NULL;
1446         string_list_clear(&names, 0);
1447         return dst;
1448 }
1449
1450 static void update_shallow(struct fetch_pack_args *args,
1451                            struct ref *refs,
1452                            struct shallow_info *si)
1453 {
1454         struct oid_array ref = OID_ARRAY_INIT;
1455         int *status;
1456         int i;
1457         struct ref *r;
1458
1459         if (args->deepen && alternate_shallow_file) {
1460                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1461                         unlink_or_warn(git_path_shallow(the_repository));
1462                         rollback_lock_file(&shallow_lock);
1463                 } else
1464                         commit_lock_file(&shallow_lock);
1465                 return;
1466         }
1467
1468         if (!si->shallow || !si->shallow->nr)
1469                 return;
1470
1471         if (args->cloning) {
1472                 /*
1473                  * remote is shallow, but this is a clone, there are
1474                  * no objects in repo to worry about. Accept any
1475                  * shallow points that exist in the pack (iow in repo
1476                  * after get_pack() and reprepare_packed_git())
1477                  */
1478                 struct oid_array extra = OID_ARRAY_INIT;
1479                 struct object_id *oid = si->shallow->oid;
1480                 for (i = 0; i < si->shallow->nr; i++)
1481                         if (has_object_file(&oid[i]))
1482                                 oid_array_append(&extra, &oid[i]);
1483                 if (extra.nr) {
1484                         setup_alternate_shallow(&shallow_lock,
1485                                                 &alternate_shallow_file,
1486                                                 &extra);
1487                         commit_lock_file(&shallow_lock);
1488                 }
1489                 oid_array_clear(&extra);
1490                 return;
1491         }
1492
1493         if (!si->nr_ours && !si->nr_theirs)
1494                 return;
1495
1496         remove_nonexistent_theirs_shallow(si);
1497         if (!si->nr_ours && !si->nr_theirs)
1498                 return;
1499         for (r = refs; r; r = r->next)
1500                 oid_array_append(&ref, &r->old_oid);
1501         si->ref = &ref;
1502
1503         if (args->update_shallow) {
1504                 /*
1505                  * remote is also shallow, .git/shallow may be updated
1506                  * so all refs can be accepted. Make sure we only add
1507                  * shallow roots that are actually reachable from new
1508                  * refs.
1509                  */
1510                 struct oid_array extra = OID_ARRAY_INIT;
1511                 struct object_id *oid = si->shallow->oid;
1512                 assign_shallow_commits_to_refs(si, NULL, NULL);
1513                 if (!si->nr_ours && !si->nr_theirs) {
1514                         oid_array_clear(&ref);
1515                         return;
1516                 }
1517                 for (i = 0; i < si->nr_ours; i++)
1518                         oid_array_append(&extra, &oid[si->ours[i]]);
1519                 for (i = 0; i < si->nr_theirs; i++)
1520                         oid_array_append(&extra, &oid[si->theirs[i]]);
1521                 setup_alternate_shallow(&shallow_lock,
1522                                         &alternate_shallow_file,
1523                                         &extra);
1524                 commit_lock_file(&shallow_lock);
1525                 oid_array_clear(&extra);
1526                 oid_array_clear(&ref);
1527                 return;
1528         }
1529
1530         /*
1531          * remote is also shallow, check what ref is safe to update
1532          * without updating .git/shallow
1533          */
1534         status = xcalloc(ref.nr, sizeof(*status));
1535         assign_shallow_commits_to_refs(si, NULL, status);
1536         if (si->nr_ours || si->nr_theirs) {
1537                 for (r = refs, i = 0; r; r = r->next, i++)
1538                         if (status[i])
1539                                 r->status = REF_STATUS_REJECT_SHALLOW;
1540         }
1541         free(status);
1542         oid_array_clear(&ref);
1543 }
1544
1545 static int iterate_ref_map(void *cb_data, struct object_id *oid)
1546 {
1547         struct ref **rm = cb_data;
1548         struct ref *ref = *rm;
1549
1550         if (!ref)
1551                 return -1; /* end of the list */
1552         *rm = ref->next;
1553         oidcpy(oid, &ref->old_oid);
1554         return 0;
1555 }
1556
1557 struct ref *fetch_pack(struct fetch_pack_args *args,
1558                        int fd[], struct child_process *conn,
1559                        const struct ref *ref,
1560                        const char *dest,
1561                        struct ref **sought, int nr_sought,
1562                        struct oid_array *shallow,
1563                        char **pack_lockfile,
1564                        enum protocol_version version)
1565 {
1566         struct ref *ref_cpy;
1567         struct shallow_info si;
1568
1569         fetch_pack_setup();
1570         if (nr_sought)
1571                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1572
1573         if (!ref) {
1574                 packet_flush(fd[1]);
1575                 die(_("no matching remote head"));
1576         }
1577         prepare_shallow_info(&si, shallow);
1578         if (version == protocol_v2)
1579                 ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1580                                            pack_lockfile);
1581         else
1582                 ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1583                                         &si, pack_lockfile);
1584         reprepare_packed_git(the_repository);
1585
1586         if (!args->cloning && args->deepen) {
1587                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
1588                 struct ref *iterator = ref_cpy;
1589                 opt.shallow_file = alternate_shallow_file;
1590                 if (args->deepen)
1591                         opt.is_deepening_fetch = 1;
1592                 if (check_connected(iterate_ref_map, &iterator, &opt)) {
1593                         error(_("remote did not send all necessary objects"));
1594                         free_refs(ref_cpy);
1595                         ref_cpy = NULL;
1596                         rollback_lock_file(&shallow_lock);
1597                         goto cleanup;
1598                 }
1599                 args->connectivity_checked = 1;
1600         }
1601
1602         update_shallow(args, ref_cpy, &si);
1603 cleanup:
1604         clear_shallow_info(&si);
1605         return ref_cpy;
1606 }
1607
1608 int report_unmatched_refs(struct ref **sought, int nr_sought)
1609 {
1610         int i, ret = 0;
1611
1612         for (i = 0; i < nr_sought; i++) {
1613                 if (!sought[i])
1614                         continue;
1615                 switch (sought[i]->match_status) {
1616                 case REF_MATCHED:
1617                         continue;
1618                 case REF_NOT_MATCHED:
1619                         error(_("no such remote ref %s"), sought[i]->name);
1620                         break;
1621                 case REF_UNADVERTISED_NOT_ALLOWED:
1622                         error(_("Server does not allow request for unadvertised object %s"),
1623                               sought[i]->name);
1624                         break;
1625                 }
1626                 ret = 1;
1627         }
1628         return ret;
1629 }