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