fetch-pack.c

   1 #include "cache.h"
   2 #include "repository.h"
   3 #include "config.h"
   4 #include "lockfile.h"
   5 #include "refs.h"
   6 #include "pkt-line.h"
   7 #include "commit.h"
   8 #include "tag.h"
   9 #include "exec-cmd.h"
  10 #include "pack.h"
  11 #include "sideband.h"
  12 #include "fetch-pack.h"
  13 #include "remote.h"
  14 #include "run-command.h"
  15 #include "connect.h"
  16 #include "transport.h"
  17 #include "version.h"
  18 #include "sha1-array.h"
  19 #include "oidset.h"
  20 #include "packfile.h"
  21 #include "object-store.h"
  22 #include "connected.h"
  23 #include "fetch-negotiator.h"
  24 #include "fsck.h"
  25
  26 static int transfer_unpack_limit = -1;
  27 static int fetch_unpack_limit = -1;
  28 static int unpack_limit = 100;
  29 static int prefer_ofs_delta = 1;
  30 static int no_done;
  31 static int deepen_since_ok;
  32 static int deepen_not_ok;
  33 static int fetch_fsck_objects = -1;
  34 static int transfer_fsck_objects = -1;
  35 static int agent_supported;
  36 static int server_supports_filtering;
  37 static struct lock_file shallow_lock;
  38 static const char *alternate_shallow_file;
  39 static char *negotiation_algorithm;
  40 static struct strbuf fsck_msg_types = STRBUF_INIT;
  41
  42 /* Remember to update object flag allocation in object.h */
  43 #define COMPLETE        (1U << 0)
  44 #define ALTERNATE       (1U << 1)
  45
  46 /*
  47  * After sending this many "have"s if we do not get any new ACK , we
  48  * give up traversing our history.
  49  */
  50 #define MAX_IN_VAIN 256
  51
  52 static int multi_ack, use_sideband;
  53 /* Allow specifying sha1 if it is a ref tip. */
  54 #define ALLOW_TIP_SHA1  01
  55 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  56 #define ALLOW_REACHABLE_SHA1    02
  57 static unsigned int allow_unadvertised_object_request;
  58
  59 __attribute__((format (printf, 2, 3)))
  60 static inline void print_verbose(const struct fetch_pack_args *args,
  61                                  const char *fmt, ...)
  62 {
  63         va_list params;
  64
  65         if (!args->verbose)
  66                 return;
  67
  68         va_start(params, fmt);
  69         vfprintf(stderr, fmt, params);
  70         va_end(params);
  71         fputc('\n', stderr);
  72 }
  73
  74 struct alternate_object_cache {
  75         struct object **items;
  76         size_t nr, alloc;
  77 };
  78
  79 static void cache_one_alternate(const char *refname,
  80                                 const struct object_id *oid,
  81                                 void *vcache)
  82 {
  83         struct alternate_object_cache *cache = vcache;
  84         struct object *obj = parse_object(the_repository, oid);
  85
  86         if (!obj || (obj->flags & ALTERNATE))
  87                 return;
  88
  89         obj->flags |= ALTERNATE;
  90         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  91         cache->items[cache->nr++] = obj;
  92 }
  93
  94 static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
  95                                       void (*cb)(struct fetch_negotiator *,
  96                                                  struct object *))
  97 {
  98         static int initialized;
  99         static struct alternate_object_cache cache;
 100         size_t i;
 101
 102         if (!initialized) {
 103                 for_each_alternate_ref(cache_one_alternate, &cache);
 104                 initialized = 1;
 105         }
 106
 107         for (i = 0; i < cache.nr; i++)
 108                 cb(negotiator, cache.items[i]);
 109 }
 110
 111 static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
 112                                const char *refname,
 113                                const struct object_id *oid)
 114 {
 115         struct object *o = deref_tag(the_repository,
 116                                      parse_object(the_repository, oid),
 117                                      refname, 0);
 118
 119         if (o && o->type == OBJ_COMMIT)
 120                 negotiator->add_tip(negotiator, (struct commit *)o);
 121
 122         return 0;
 123 }
 124
 125 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 126                                    int flag, void *cb_data)
 127 {
 128         return rev_list_insert_ref(cb_data, refname, oid);
 129 }
 130
 131 enum ack_type {
 132         NAK = 0,
 133         ACK,
 134         ACK_continue,
 135         ACK_common,
 136         ACK_ready
 137 };
 138
 139 static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 140 {
 141         if (args->stateless_rpc && args->deepen) {
 142                 /* If we sent a depth we will get back "duplicate"
 143                  * shallow and unshallow commands every time there
 144                  * is a block of have lines exchanged.
 145                  */
 146                 char *line;
 147                 while ((line = packet_read_line(fd, NULL))) {
 148                         if (starts_with(line, "shallow "))
 149                                 continue;
 150                         if (starts_with(line, "unshallow "))
 151                                 continue;
 152                         die(_("git fetch-pack: expected shallow list"));
 153                 }
 154         }
 155 }
 156
 157 static enum ack_type get_ack(int fd, struct object_id *result_oid)
 158 {
 159         int len;
 160         char *line = packet_read_line(fd, &len);
 161         const char *arg;
 162
 163         if (!line)
 164                 die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 165         if (!strcmp(line, "NAK"))
 166                 return NAK;
 167         if (skip_prefix(line, "ACK ", &arg)) {
 168                 if (!get_oid_hex(arg, result_oid)) {
 169                         arg += 40;
 170                         len -= arg - line;
 171                         if (len < 1)
 172                                 return ACK;
 173                         if (strstr(arg, "continue"))
 174                                 return ACK_continue;
 175                         if (strstr(arg, "common"))
 176                                 return ACK_common;
 177                         if (strstr(arg, "ready"))
 178                                 return ACK_ready;
 179                         return ACK;
 180                 }
 181         }
 182         if (skip_prefix(line, "ERR ", &arg))
 183                 die(_("remote error: %s"), arg);
 184         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 185 }
 186
 187 static void send_request(struct fetch_pack_args *args,
 188                          int fd, struct strbuf *buf)
 189 {
 190         if (args->stateless_rpc) {
 191                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 192                 packet_flush(fd);
 193         } else
 194                 write_or_die(fd, buf->buf, buf->len);
 195 }
 196
 197 static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 198                                         struct object *obj)
 199 {
 200         rev_list_insert_ref(negotiator, NULL, &obj->oid);
 201 }
 202
 203 #define INITIAL_FLUSH 16
 204 #define PIPESAFE_FLUSH 32
 205 #define LARGE_FLUSH 16384
 206
 207 static int next_flush(int stateless_rpc, int count)
 208 {
 209         if (stateless_rpc) {
 210                 if (count < LARGE_FLUSH)
 211                         count <<= 1;
 212                 else
 213                         count = count * 11 / 10;
 214         } else {
 215                 if (count < PIPESAFE_FLUSH)
 216                         count <<= 1;
 217                 else
 218                         count += PIPESAFE_FLUSH;
 219         }
 220         return count;
 221 }
 222
 223 static void mark_tips(struct fetch_negotiator *negotiator,
 224                       const struct oid_array *negotiation_tips)
 225 {
 226         int i;
 227
 228         if (!negotiation_tips) {
 229                 for_each_ref(rev_list_insert_ref_oid, negotiator);
 230                 return;
 231         }
 232
 233         for (i = 0; i < negotiation_tips->nr; i++)
 234                 rev_list_insert_ref(negotiator, NULL,
 235                                     &negotiation_tips->oid[i]);
 236         return;
 237 }
 238
 239 static int find_common(struct fetch_negotiator *negotiator,
 240                        struct fetch_pack_args *args,
 241                        int fd[2], struct object_id *result_oid,
 242                        struct ref *refs)
 243 {
 244         int fetching;
 245         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 246         const struct object_id *oid;
 247         unsigned in_vain = 0;
 248         int got_continue = 0;
 249         int got_ready = 0;
 250         struct strbuf req_buf = STRBUF_INIT;
 251         size_t state_len = 0;
 252
 253         if (args->stateless_rpc && multi_ack == 1)
 254                 die(_("--stateless-rpc requires multi_ack_detailed"));
 255
 256         if (!args->no_dependents) {
 257                 mark_tips(negotiator, args->negotiation_tips);
 258                 for_each_cached_alternate(negotiator, insert_one_alternate_object);
 259         }
 260
 261         fetching = 0;
 262         for ( ; refs ; refs = refs->next) {
 263                 struct object_id *remote = &refs->old_oid;
 264                 const char *remote_hex;
 265                 struct object *o;
 266
 267                 /*
 268                  * If that object is complete (i.e. it is an ancestor of a
 269                  * local ref), we tell them we have it but do not have to
 270                  * tell them about its ancestors, which they already know
 271                  * about.
 272                  *
 273                  * We use lookup_object here because we are only
 274                  * interested in the case we *know* the object is
 275                  * reachable and we have already scanned it.
 276                  *
 277                  * Do this only if args->no_dependents is false (if it is true,
 278                  * we cannot trust the object flags).
 279                  */
 280                 if (!args->no_dependents &&
 281                     ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
 282                                 (o->flags & COMPLETE)) {
 283                         continue;
 284                 }
 285
 286                 remote_hex = oid_to_hex(remote);
 287                 if (!fetching) {
 288                         struct strbuf c = STRBUF_INIT;
 289                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 290                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 291                         if (no_done)            strbuf_addstr(&c, " no-done");
 292                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 293                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 294                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 295                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 296                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 297                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 298                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 299                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 300                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 301                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 302                                                             git_user_agent_sanitized());
 303                         if (args->filter_options.choice)
 304                                 strbuf_addstr(&c, " filter");
 305                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 306                         strbuf_release(&c);
 307                 } else
 308                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 309                 fetching++;
 310         }
 311
 312         if (!fetching) {
 313                 strbuf_release(&req_buf);
 314                 packet_flush(fd[1]);
 315                 return 1;
 316         }
 317
 318         if (is_repository_shallow(the_repository))
 319                 write_shallow_commits(&req_buf, 1, NULL);
 320         if (args->depth > 0)
 321                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 322         if (args->deepen_since) {
 323                 timestamp_t max_age = approxidate(args->deepen_since);
 324                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 325         }
 326         if (args->deepen_not) {
 327                 int i;
 328                 for (i = 0; i < args->deepen_not->nr; i++) {
 329                         struct string_list_item *s = args->deepen_not->items + i;
 330                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 331                 }
 332         }
 333         if (server_supports_filtering && args->filter_options.choice)
 334                 packet_buf_write(&req_buf, "filter %s",
 335                                  args->filter_options.filter_spec);
 336         packet_buf_flush(&req_buf);
 337         state_len = req_buf.len;
 338
 339         if (args->deepen) {
 340                 char *line;
 341                 const char *arg;
 342                 struct object_id oid;
 343
 344                 send_request(args, fd[1], &req_buf);
 345                 while ((line = packet_read_line(fd[0], NULL))) {
 346                         if (skip_prefix(line, "shallow ", &arg)) {
 347                                 if (get_oid_hex(arg, &oid))
 348                                         die(_("invalid shallow line: %s"), line);
 349                                 register_shallow(the_repository, &oid);
 350                                 continue;
 351                         }
 352                         if (skip_prefix(line, "unshallow ", &arg)) {
 353                                 if (get_oid_hex(arg, &oid))
 354                                         die(_("invalid unshallow line: %s"), line);
 355                                 if (!lookup_object(the_repository, oid.hash))
 356                                         die(_("object not found: %s"), line);
 357                                 /* make sure that it is parsed as shallow */
 358                                 if (!parse_object(the_repository, &oid))
 359                                         die(_("error in object: %s"), line);
 360                                 if (unregister_shallow(&oid))
 361                                         die(_("no shallow found: %s"), line);
 362                                 continue;
 363                         }
 364                         die(_("expected shallow/unshallow, got %s"), line);
 365                 }
 366         } else if (!args->stateless_rpc)
 367                 send_request(args, fd[1], &req_buf);
 368
 369         if (!args->stateless_rpc) {
 370                 /* If we aren't using the stateless-rpc interface
 371                  * we don't need to retain the headers.
 372                  */
 373                 strbuf_setlen(&req_buf, 0);
 374                 state_len = 0;
 375         }
 376
 377         flushes = 0;
 378         retval = -1;
 379         if (args->no_dependents)
 380                 goto done;
 381         while ((oid = negotiator->next(negotiator))) {
 382                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 383                 print_verbose(args, "have %s", oid_to_hex(oid));
 384                 in_vain++;
 385                 if (flush_at <= ++count) {
 386                         int ack;
 387
 388                         packet_buf_flush(&req_buf);
 389                         send_request(args, fd[1], &req_buf);
 390                         strbuf_setlen(&req_buf, state_len);
 391                         flushes++;
 392                         flush_at = next_flush(args->stateless_rpc, count);
 393
 394                         /*
 395                          * We keep one window "ahead" of the other side, and
 396                          * will wait for an ACK only on the next one
 397                          */
 398                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 399                                 continue;
 400
 401                         consume_shallow_list(args, fd[0]);
 402                         do {
 403                                 ack = get_ack(fd[0], result_oid);
 404                                 if (ack)
 405                                         print_verbose(args, _("got %s %d %s"), "ack",
 406                                                       ack, oid_to_hex(result_oid));
 407                                 switch (ack) {
 408                                 case ACK:
 409                                         flushes = 0;
 410                                         multi_ack = 0;
 411                                         retval = 0;
 412                                         goto done;
 413                                 case ACK_common:
 414                                 case ACK_ready:
 415                                 case ACK_continue: {
 416                                         struct commit *commit =
 417                                                 lookup_commit(the_repository,
 418                                                               result_oid);
 419                                         int was_common;
 420
 421                                         if (!commit)
 422                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
 423                                         was_common = negotiator->ack(negotiator, commit);
 424                                         if (args->stateless_rpc
 425                                          && ack == ACK_common
 426                                          && !was_common) {
 427                                                 /* We need to replay the have for this object
 428                                                  * on the next RPC request so the peer knows
 429                                                  * it is in common with us.
 430                                                  */
 431                                                 const char *hex = oid_to_hex(result_oid);
 432                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 433                                                 state_len = req_buf.len;
 434                                                 /*
 435                                                  * Reset in_vain because an ack
 436                                                  * for this commit has not been
 437                                                  * seen.
 438                                                  */
 439                                                 in_vain = 0;
 440                                         } else if (!args->stateless_rpc
 441                                                    || ack != ACK_common)
 442                                                 in_vain = 0;
 443                                         retval = 0;
 444                                         got_continue = 1;
 445                                         if (ack == ACK_ready)
 446                                                 got_ready = 1;
 447                                         break;
 448                                         }
 449                                 }
 450                         } while (ack);
 451                         flushes--;
 452                         if (got_continue && MAX_IN_VAIN < in_vain) {
 453                                 print_verbose(args, _("giving up"));
 454                                 break; /* give up */
 455                         }
 456                         if (got_ready)
 457                                 break;
 458                 }
 459         }
 460 done:
 461         if (!got_ready || !no_done) {
 462                 packet_buf_write(&req_buf, "done\n");
 463                 send_request(args, fd[1], &req_buf);
 464         }
 465         print_verbose(args, _("done"));
 466         if (retval != 0) {
 467                 multi_ack = 0;
 468                 flushes++;
 469         }
 470         strbuf_release(&req_buf);
 471
 472         if (!got_ready || !no_done)
 473                 consume_shallow_list(args, fd[0]);
 474         while (flushes || multi_ack) {
 475                 int ack = get_ack(fd[0], result_oid);
 476                 if (ack) {
 477                         print_verbose(args, _("got %s (%d) %s"), "ack",
 478                                       ack, oid_to_hex(result_oid));
 479                         if (ack == ACK)
 480                                 return 0;
 481                         multi_ack = 1;
 482                         continue;
 483                 }
 484                 flushes--;
 485         }
 486         /* it is no error to fetch into a completely empty repo */
 487         return count ? retval : 0;
 488 }
 489
 490 static struct commit_list *complete;
 491
 492 static int mark_complete(const struct object_id *oid)
 493 {
 494         struct object *o = parse_object(the_repository, oid);
 495
 496         while (o && o->type == OBJ_TAG) {
 497                 struct tag *t = (struct tag *) o;
 498                 if (!t->tagged)
 499                         break; /* broken repository */
 500                 o->flags |= COMPLETE;
 501                 o = parse_object(the_repository, &t->tagged->oid);
 502         }
 503         if (o && o->type == OBJ_COMMIT) {
 504                 struct commit *commit = (struct commit *)o;
 505                 if (!(commit->object.flags & COMPLETE)) {
 506                         commit->object.flags |= COMPLETE;
 507                         commit_list_insert(commit, &complete);
 508                 }
 509         }
 510         return 0;
 511 }
 512
 513 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 514                              int flag, void *cb_data)
 515 {
 516         return mark_complete(oid);
 517 }
 518
 519 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 520                                          timestamp_t cutoff)
 521 {
 522         while (complete && cutoff <= complete->item->date) {
 523                 print_verbose(args, _("Marking %s as complete"),
 524                               oid_to_hex(&complete->item->object.oid));
 525                 pop_most_recent_commit(&complete, COMPLETE);
 526         }
 527 }
 528
 529 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 530 {
 531         for (; refs; refs = refs->next)
 532                 oidset_insert(oids, &refs->old_oid);
 533 }
 534
 535 static int tip_oids_contain(struct oidset *tip_oids,
 536                             struct ref *unmatched, struct ref *newlist,
 537                             const struct object_id *id)
 538 {
 539         /*
 540          * Note that this only looks at the ref lists the first time it's
 541          * called. This works out in filter_refs() because even though it may
 542          * add to "newlist" between calls, the additions will always be for
 543          * oids that are already in the set.
 544          */
 545         if (!tip_oids->map.map.tablesize) {
 546                 add_refs_to_oidset(tip_oids, unmatched);
 547                 add_refs_to_oidset(tip_oids, newlist);
 548         }
 549         return oidset_contains(tip_oids, id);
 550 }
 551
 552 static void filter_refs(struct fetch_pack_args *args,
 553                         struct ref **refs,
 554                         struct ref **sought, int nr_sought)
 555 {
 556         struct ref *newlist = NULL;
 557         struct ref **newtail = &newlist;
 558         struct ref *unmatched = NULL;
 559         struct ref *ref, *next;
 560         struct oidset tip_oids = OIDSET_INIT;
 561         int i;
 562
 563         i = 0;
 564         for (ref = *refs; ref; ref = next) {
 565                 int keep = 0;
 566                 next = ref->next;
 567
 568                 if (starts_with(ref->name, "refs/") &&
 569                     check_refname_format(ref->name, 0))
 570                         ; /* trash */
 571                 else {
 572                         while (i < nr_sought) {
 573                                 int cmp = strcmp(ref->name, sought[i]->name);
 574                                 if (cmp < 0)
 575                                         break; /* definitely do not have it */
 576                                 else if (cmp == 0) {
 577                                         keep = 1; /* definitely have it */
 578                                         sought[i]->match_status = REF_MATCHED;
 579                                 }
 580                                 i++;
 581                         }
 582
 583                         if (!keep && args->fetch_all &&
 584                             (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 585                                 keep = 1;
 586                 }
 587
 588                 if (keep) {
 589                         *newtail = ref;
 590                         ref->next = NULL;
 591                         newtail = &ref->next;
 592                 } else {
 593                         ref->next = unmatched;
 594                         unmatched = ref;
 595                 }
 596         }
 597
 598         /* Append unmatched requests to the list */
 599         for (i = 0; i < nr_sought; i++) {
 600                 struct object_id oid;
 601                 const char *p;
 602
 603                 ref = sought[i];
 604                 if (ref->match_status != REF_NOT_MATCHED)
 605                         continue;
 606                 if (parse_oid_hex(ref->name, &oid, &p) ||
 607                     *p != '\0' ||
 608                     oidcmp(&oid, &ref->old_oid))
 609                         continue;
 610
 611                 if ((allow_unadvertised_object_request &
 612                      (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1)) ||
 613                     tip_oids_contain(&tip_oids, unmatched, newlist,
 614                                      &ref->old_oid)) {
 615                         ref->match_status = REF_MATCHED;
 616                         *newtail = copy_ref(ref);
 617                         newtail = &(*newtail)->next;
 618                 } else {
 619                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 620                 }
 621         }
 622
 623         oidset_clear(&tip_oids);
 624         for (ref = unmatched; ref; ref = next) {
 625                 next = ref->next;
 626                 free(ref);
 627         }
 628
 629         *refs = newlist;
 630 }
 631
 632 static void mark_alternate_complete(struct fetch_negotiator *unused,
 633                                     struct object *obj)
 634 {
 635         mark_complete(&obj->oid);
 636 }
 637
 638 struct loose_object_iter {
 639         struct oidset *loose_object_set;
 640         struct ref *refs;
 641 };
 642
 643 /*
 644  *  If the number of refs is not larger than the number of loose objects,
 645  *  this function stops inserting.
 646  */
 647 static int add_loose_objects_to_set(const struct object_id *oid,
 648                                     const char *path,
 649                                     void *data)
 650 {
 651         struct loose_object_iter *iter = data;
 652         oidset_insert(iter->loose_object_set, oid);
 653         if (iter->refs == NULL)
 654                 return 1;
 655
 656         iter->refs = iter->refs->next;
 657         return 0;
 658 }
 659
 660 /*
 661  * Mark recent commits available locally and reachable from a local ref as
 662  * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 663  * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 664  * thus do not need COMMON_REF marks).
 665  *
 666  * The cutoff time for recency is determined by this heuristic: it is the
 667  * earliest commit time of the objects in refs that are commits and that we know
 668  * the commit time of.
 669  */
 670 static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 671                                          struct fetch_pack_args *args,
 672                                          struct ref **refs)
 673 {
 674         struct ref *ref;
 675         int old_save_commit_buffer = save_commit_buffer;
 676         timestamp_t cutoff = 0;
 677         struct oidset loose_oid_set = OIDSET_INIT;
 678         int use_oidset = 0;
 679         struct loose_object_iter iter = {&loose_oid_set, *refs};
 680
 681         /* Enumerate all loose objects or know refs are not so many. */
 682         use_oidset = !for_each_loose_object(add_loose_objects_to_set,
 683                                             &iter, 0);
 684
 685         save_commit_buffer = 0;
 686
 687         for (ref = *refs; ref; ref = ref->next) {
 688                 struct object *o;
 689                 unsigned int flags = OBJECT_INFO_QUICK;
 690
 691                 if (use_oidset &&
 692                     !oidset_contains(&loose_oid_set, &ref->old_oid)) {
 693                         /*
 694                          * I know this does not exist in the loose form,
 695                          * so check if it exists in a non-loose form.
 696                          */
 697                         flags |= OBJECT_INFO_IGNORE_LOOSE;
 698                 }
 699
 700                 if (!has_object_file_with_flags(&ref->old_oid, flags))
 701                         continue;
 702                 o = parse_object(the_repository, &ref->old_oid);
 703                 if (!o)
 704                         continue;
 705
 706                 /* We already have it -- which may mean that we were
 707                  * in sync with the other side at some time after
 708                  * that (it is OK if we guess wrong here).
 709                  */
 710                 if (o->type == OBJ_COMMIT) {
 711                         struct commit *commit = (struct commit *)o;
 712                         if (!cutoff || cutoff < commit->date)
 713                                 cutoff = commit->date;
 714                 }
 715         }
 716
 717         oidset_clear(&loose_oid_set);
 718
 719         if (!args->deepen) {
 720                 for_each_ref(mark_complete_oid, NULL);
 721                 for_each_cached_alternate(NULL, mark_alternate_complete);
 722                 commit_list_sort_by_date(&complete);
 723                 if (cutoff)
 724                         mark_recent_complete_commits(args, cutoff);
 725         }
 726
 727         /*
 728          * Mark all complete remote refs as common refs.
 729          * Don't mark them common yet; the server has to be told so first.
 730          */
 731         for (ref = *refs; ref; ref = ref->next) {
 732                 struct object *o = deref_tag(the_repository,
 733                                              lookup_object(the_repository,
 734                                              ref->old_oid.hash),
 735                                              NULL, 0);
 736
 737                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 738                         continue;
 739
 740                 negotiator->known_common(negotiator,
 741                                          (struct commit *)o);
 742         }
 743
 744         save_commit_buffer = old_save_commit_buffer;
 745 }
 746
 747 /*
 748  * Returns 1 if every object pointed to by the given remote refs is available
 749  * locally and reachable from a local ref, and 0 otherwise.
 750  */
 751 static int everything_local(struct fetch_pack_args *args,
 752                             struct ref **refs)
 753 {
 754         struct ref *ref;
 755         int retval;
 756
 757         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 758                 const struct object_id *remote = &ref->old_oid;
 759                 struct object *o;
 760
 761                 o = lookup_object(the_repository, remote->hash);
 762                 if (!o || !(o->flags & COMPLETE)) {
 763                         retval = 0;
 764                         print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 765                                       ref->name);
 766                         continue;
 767                 }
 768                 print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 769                               ref->name);
 770         }
 771
 772         return retval;
 773 }
 774
 775 static int sideband_demux(int in, int out, void *data)
 776 {
 777         int *xd = data;
 778         int ret;
 779
 780         ret = recv_sideband("fetch-pack", xd[0], out);
 781         close(out);
 782         return ret;
 783 }
 784
 785 static int get_pack(struct fetch_pack_args *args,
 786                     int xd[2], char **pack_lockfile)
 787 {
 788         struct async demux;
 789         int do_keep = args->keep_pack;
 790         const char *cmd_name;
 791         struct pack_header header;
 792         int pass_header = 0;
 793         struct child_process cmd = CHILD_PROCESS_INIT;
 794         int ret;
 795
 796         memset(&demux, 0, sizeof(demux));
 797         if (use_sideband) {
 798                 /* xd[] is talking with upload-pack; subprocess reads from
 799                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 800                  * through demux->out.
 801                  */
 802                 demux.proc = sideband_demux;
 803                 demux.data = xd;
 804                 demux.out = -1;
 805                 demux.isolate_sigpipe = 1;
 806                 if (start_async(&demux))
 807                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 808         }
 809         else
 810                 demux.out = xd[0];
 811
 812         if (!args->keep_pack && unpack_limit) {
 813
 814                 if (read_pack_header(demux.out, &header))
 815                         die(_("protocol error: bad pack header"));
 816                 pass_header = 1;
 817                 if (ntohl(header.hdr_entries) < unpack_limit)
 818                         do_keep = 0;
 819                 else
 820                         do_keep = 1;
 821         }
 822
 823         if (alternate_shallow_file) {
 824                 argv_array_push(&cmd.args, "--shallow-file");
 825                 argv_array_push(&cmd.args, alternate_shallow_file);
 826         }
 827
 828         if (do_keep || args->from_promisor) {
 829                 if (pack_lockfile)
 830                         cmd.out = -1;
 831                 cmd_name = "index-pack";
 832                 argv_array_push(&cmd.args, cmd_name);
 833                 argv_array_push(&cmd.args, "--stdin");
 834                 if (!args->quiet && !args->no_progress)
 835                         argv_array_push(&cmd.args, "-v");
 836                 if (args->use_thin_pack)
 837                         argv_array_push(&cmd.args, "--fix-thin");
 838                 if (do_keep && (args->lock_pack || unpack_limit)) {
 839                         char hostname[HOST_NAME_MAX + 1];
 840                         if (xgethostname(hostname, sizeof(hostname)))
 841                                 xsnprintf(hostname, sizeof(hostname), "localhost");
 842                         argv_array_pushf(&cmd.args,
 843                                         "--keep=fetch-pack %"PRIuMAX " on %s",
 844                                         (uintmax_t)getpid(), hostname);
 845                 }
 846                 if (args->check_self_contained_and_connected)
 847                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 848                 if (args->from_promisor)
 849                         argv_array_push(&cmd.args, "--promisor");
 850         }
 851         else {
 852                 cmd_name = "unpack-objects";
 853                 argv_array_push(&cmd.args, cmd_name);
 854                 if (args->quiet || args->no_progress)
 855                         argv_array_push(&cmd.args, "-q");
 856                 args->check_self_contained_and_connected = 0;
 857         }
 858
 859         if (pass_header)
 860                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 861                                  ntohl(header.hdr_version),
 862                                  ntohl(header.hdr_entries));
 863         if (fetch_fsck_objects >= 0
 864             ? fetch_fsck_objects
 865             : transfer_fsck_objects >= 0
 866             ? transfer_fsck_objects
 867             : 0) {
 868                 if (args->from_promisor)
 869                         /*
 870                          * We cannot use --strict in index-pack because it
 871                          * checks both broken objects and links, but we only
 872                          * want to check for broken objects.
 873                          */
 874                         argv_array_push(&cmd.args, "--fsck-objects");
 875                 else
 876                         argv_array_pushf(&cmd.args, "--strict%s",
 877                                          fsck_msg_types.buf);
 878         }
 879
 880         cmd.in = demux.out;
 881         cmd.git_cmd = 1;
 882         if (start_command(&cmd))
 883                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
 884         if (do_keep && pack_lockfile) {
 885                 *pack_lockfile = index_pack_lockfile(cmd.out);
 886                 close(cmd.out);
 887         }
 888
 889         if (!use_sideband)
 890                 /* Closed by start_command() */
 891                 xd[0] = -1;
 892
 893         ret = finish_command(&cmd);
 894         if (!ret || (args->check_self_contained_and_connected && ret == 1))
 895                 args->self_contained_and_connected =
 896                         args->check_self_contained_and_connected &&
 897                         ret == 0;
 898         else
 899                 die(_("%s failed"), cmd_name);
 900         if (use_sideband && finish_async(&demux))
 901                 die(_("error in sideband demultiplexer"));
 902         return 0;
 903 }
 904
 905 static int cmp_ref_by_name(const void *a_, const void *b_)
 906 {
 907         const struct ref *a = *((const struct ref **)a_);
 908         const struct ref *b = *((const struct ref **)b_);
 909         return strcmp(a->name, b->name);
 910 }
 911
 912 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 913                                  int fd[2],
 914                                  const struct ref *orig_ref,
 915                                  struct ref **sought, int nr_sought,
 916                                  struct shallow_info *si,
 917                                  char **pack_lockfile)
 918 {
 919         struct ref *ref = copy_ref_list(orig_ref);
 920         struct object_id oid;
 921         const char *agent_feature;
 922         int agent_len;
 923         struct fetch_negotiator negotiator;
 924         fetch_negotiator_init(&negotiator, negotiation_algorithm);
 925
 926         sort_ref_list(&ref, ref_compare_name);
 927         QSORT(sought, nr_sought, cmp_ref_by_name);
 928
 929         if ((args->depth > 0 || is_repository_shallow(the_repository)) && !server_supports("shallow"))
 930                 die(_("Server does not support shallow clients"));
 931         if (args->depth > 0 || args->deepen_since || args->deepen_not)
 932                 args->deepen = 1;
 933         if (server_supports("multi_ack_detailed")) {
 934                 print_verbose(args, _("Server supports multi_ack_detailed"));
 935                 multi_ack = 2;
 936                 if (server_supports("no-done")) {
 937                         print_verbose(args, _("Server supports no-done"));
 938                         if (args->stateless_rpc)
 939                                 no_done = 1;
 940                 }
 941         }
 942         else if (server_supports("multi_ack")) {
 943                 print_verbose(args, _("Server supports multi_ack"));
 944                 multi_ack = 1;
 945         }
 946         if (server_supports("side-band-64k")) {
 947                 print_verbose(args, _("Server supports side-band-64k"));
 948                 use_sideband = 2;
 949         }
 950         else if (server_supports("side-band")) {
 951                 print_verbose(args, _("Server supports side-band"));
 952                 use_sideband = 1;
 953         }
 954         if (server_supports("allow-tip-sha1-in-want")) {
 955                 print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 956                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 957         }
 958         if (server_supports("allow-reachable-sha1-in-want")) {
 959                 print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 960                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 961         }
 962         if (!server_supports("thin-pack"))
 963                 args->use_thin_pack = 0;
 964         if (!server_supports("no-progress"))
 965                 args->no_progress = 0;
 966         if (!server_supports("include-tag"))
 967                 args->include_tag = 0;
 968         if (server_supports("ofs-delta"))
 969                 print_verbose(args, _("Server supports ofs-delta"));
 970         else
 971                 prefer_ofs_delta = 0;
 972
 973         if (server_supports("filter")) {
 974                 server_supports_filtering = 1;
 975                 print_verbose(args, _("Server supports filter"));
 976         } else if (args->filter_options.choice) {
 977                 warning("filtering not recognized by server, ignoring");
 978         }
 979
 980         if ((agent_feature = server_feature_value("agent", &agent_len))) {
 981                 agent_supported = 1;
 982                 if (agent_len)
 983                         print_verbose(args, _("Server version is %.*s"),
 984                                       agent_len, agent_feature);
 985         }
 986         if (server_supports("deepen-since"))
 987                 deepen_since_ok = 1;
 988         else if (args->deepen_since)
 989                 die(_("Server does not support --shallow-since"));
 990         if (server_supports("deepen-not"))
 991                 deepen_not_ok = 1;
 992         else if (args->deepen_not)
 993                 die(_("Server does not support --shallow-exclude"));
 994         if (!server_supports("deepen-relative") && args->deepen_relative)
 995                 die(_("Server does not support --deepen"));
 996
 997         if (!args->no_dependents) {
 998                 mark_complete_and_common_ref(&negotiator, args, &ref);
 999                 filter_refs(args, &ref, sought, nr_sought);
1000                 if (everything_local(args, &ref)) {
1001                         packet_flush(fd[1]);
1002                         goto all_done;
1003                 }
1004         } else {
1005                 filter_refs(args, &ref, sought, nr_sought);
1006         }
1007         if (find_common(&negotiator, args, fd, &oid, ref) < 0)
1008                 if (!args->keep_pack)
1009                         /* When cloning, it is not unusual to have
1010                          * no common commit.
1011                          */
1012                         warning(_("no common commits"));
1013
1014         if (args->stateless_rpc)
1015                 packet_flush(fd[1]);
1016         if (args->deepen)
1017                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1018                                         NULL);
1019         else if (si->nr_ours || si->nr_theirs)
1020                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
1021         else
1022                 alternate_shallow_file = NULL;
1023         if (get_pack(args, fd, pack_lockfile))
1024                 die(_("git fetch-pack: fetch failed."));
1025
1026  all_done:
1027         negotiator.release(&negotiator);
1028         return ref;
1029 }
1030
1031 static void add_shallow_requests(struct strbuf *req_buf,
1032                                  const struct fetch_pack_args *args)
1033 {
1034         if (is_repository_shallow(the_repository))
1035                 write_shallow_commits(req_buf, 1, NULL);
1036         if (args->depth > 0)
1037                 packet_buf_write(req_buf, "deepen %d", args->depth);
1038         if (args->deepen_since) {
1039                 timestamp_t max_age = approxidate(args->deepen_since);
1040                 packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1041         }
1042         if (args->deepen_not) {
1043                 int i;
1044                 for (i = 0; i < args->deepen_not->nr; i++) {
1045                         struct string_list_item *s = args->deepen_not->items + i;
1046                         packet_buf_write(req_buf, "deepen-not %s", s->string);
1047                 }
1048         }
1049 }
1050
1051 static void add_wants(int no_dependents, const struct ref *wants, struct strbuf *req_buf)
1052 {
1053         int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1054
1055         for ( ; wants ; wants = wants->next) {
1056                 const struct object_id *remote = &wants->old_oid;
1057                 struct object *o;
1058
1059                 /*
1060                  * If that object is complete (i.e. it is an ancestor of a
1061                  * local ref), we tell them we have it but do not have to
1062                  * tell them about its ancestors, which they already know
1063                  * about.
1064                  *
1065                  * We use lookup_object here because we are only
1066                  * interested in the case we *know* the object is
1067                  * reachable and we have already scanned it.
1068                  *
1069                  * Do this only if args->no_dependents is false (if it is true,
1070                  * we cannot trust the object flags).
1071                  */
1072                 if (!no_dependents &&
1073                     ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
1074                     (o->flags & COMPLETE)) {
1075                         continue;
1076                 }
1077
1078                 if (!use_ref_in_want || wants->exact_oid)
1079                         packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1080                 else
1081                         packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1082         }
1083 }
1084
1085 static void add_common(struct strbuf *req_buf, struct oidset *common)
1086 {
1087         struct oidset_iter iter;
1088         const struct object_id *oid;
1089         oidset_iter_init(common, &iter);
1090
1091         while ((oid = oidset_iter_next(&iter))) {
1092                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1093         }
1094 }
1095
1096 static int add_haves(struct fetch_negotiator *negotiator,
1097                      struct strbuf *req_buf,
1098                      int *haves_to_send, int *in_vain)
1099 {
1100         int ret = 0;
1101         int haves_added = 0;
1102         const struct object_id *oid;
1103
1104         while ((oid = negotiator->next(negotiator))) {
1105                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1106                 if (++haves_added >= *haves_to_send)
1107                         break;
1108         }
1109
1110         *in_vain += haves_added;
1111         if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1112                 /* Send Done */
1113                 packet_buf_write(req_buf, "done\n");
1114                 ret = 1;
1115         }
1116
1117         /* Increase haves to send on next round */
1118         *haves_to_send = next_flush(1, *haves_to_send);
1119
1120         return ret;
1121 }
1122
1123 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1124                               const struct fetch_pack_args *args,
1125                               const struct ref *wants, struct oidset *common,
1126                               int *haves_to_send, int *in_vain)
1127 {
1128         int ret = 0;
1129         struct strbuf req_buf = STRBUF_INIT;
1130
1131         if (server_supports_v2("fetch", 1))
1132                 packet_buf_write(&req_buf, "command=fetch");
1133         if (server_supports_v2("agent", 0))
1134                 packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1135         if (args->server_options && args->server_options->nr &&
1136             server_supports_v2("server-option", 1)) {
1137                 int i;
1138                 for (i = 0; i < args->server_options->nr; i++)
1139                         packet_write_fmt(fd_out, "server-option=%s",
1140                                          args->server_options->items[i].string);
1141         }
1142
1143         packet_buf_delim(&req_buf);
1144         if (args->use_thin_pack)
1145                 packet_buf_write(&req_buf, "thin-pack");
1146         if (args->no_progress)
1147                 packet_buf_write(&req_buf, "no-progress");
1148         if (args->include_tag)
1149                 packet_buf_write(&req_buf, "include-tag");
1150         if (prefer_ofs_delta)
1151                 packet_buf_write(&req_buf, "ofs-delta");
1152
1153         /* Add shallow-info and deepen request */
1154         if (server_supports_feature("fetch", "shallow", 0))
1155                 add_shallow_requests(&req_buf, args);
1156         else if (is_repository_shallow(the_repository) || args->deepen)
1157                 die(_("Server does not support shallow requests"));
1158
1159         /* Add filter */
1160         if (server_supports_feature("fetch", "filter", 0) &&
1161             args->filter_options.choice) {
1162                 print_verbose(args, _("Server supports filter"));
1163                 packet_buf_write(&req_buf, "filter %s",
1164                                  args->filter_options.filter_spec);
1165         } else if (args->filter_options.choice) {
1166                 warning("filtering not recognized by server, ignoring");
1167         }
1168
1169         /* add wants */
1170         add_wants(args->no_dependents, wants, &req_buf);
1171
1172         if (args->no_dependents) {
1173                 packet_buf_write(&req_buf, "done");
1174                 ret = 1;
1175         } else {
1176                 /* Add all of the common commits we've found in previous rounds */
1177                 add_common(&req_buf, common);
1178
1179                 /* Add initial haves */
1180                 ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1181         }
1182
1183         /* Send request */
1184         packet_buf_flush(&req_buf);
1185         write_or_die(fd_out, req_buf.buf, req_buf.len);
1186
1187         strbuf_release(&req_buf);
1188         return ret;
1189 }
1190
1191 /*
1192  * Processes a section header in a server's response and checks if it matches
1193  * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1194  * not consumed); if 0, the line will be consumed and the function will die if
1195  * the section header doesn't match what was expected.
1196  */
1197 static int process_section_header(struct packet_reader *reader,
1198                                   const char *section, int peek)
1199 {
1200         int ret;
1201
1202         if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1203                 die(_("error reading section header '%s'"), section);
1204
1205         ret = !strcmp(reader->line, section);
1206
1207         if (!peek) {
1208                 if (!ret)
1209                         die(_("expected '%s', received '%s'"),
1210                             section, reader->line);
1211                 packet_reader_read(reader);
1212         }
1213
1214         return ret;
1215 }
1216
1217 static int process_acks(struct fetch_negotiator *negotiator,
1218                         struct packet_reader *reader,
1219                         struct oidset *common)
1220 {
1221         /* received */
1222         int received_ready = 0;
1223         int received_ack = 0;
1224
1225         process_section_header(reader, "acknowledgments", 0);
1226         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1227                 const char *arg;
1228
1229                 if (!strcmp(reader->line, "NAK"))
1230                         continue;
1231
1232                 if (skip_prefix(reader->line, "ACK ", &arg)) {
1233                         struct object_id oid;
1234                         if (!get_oid_hex(arg, &oid)) {
1235                                 struct commit *commit;
1236                                 oidset_insert(common, &oid);
1237                                 commit = lookup_commit(the_repository, &oid);
1238                                 negotiator->ack(negotiator, commit);
1239                         }
1240                         continue;
1241                 }
1242
1243                 if (!strcmp(reader->line, "ready")) {
1244                         received_ready = 1;
1245                         continue;
1246                 }
1247
1248                 die(_("unexpected acknowledgment line: '%s'"), reader->line);
1249         }
1250
1251         if (reader->status != PACKET_READ_FLUSH &&
1252             reader->status != PACKET_READ_DELIM)
1253                 die(_("error processing acks: %d"), reader->status);
1254
1255         /* return 0 if no common, 1 if there are common, or 2 if ready */
1256         return received_ready ? 2 : (received_ack ? 1 : 0);
1257 }
1258
1259 static void receive_shallow_info(struct fetch_pack_args *args,
1260                                  struct packet_reader *reader)
1261 {
1262         process_section_header(reader, "shallow-info", 0);
1263         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1264                 const char *arg;
1265                 struct object_id oid;
1266
1267                 if (skip_prefix(reader->line, "shallow ", &arg)) {
1268                         if (get_oid_hex(arg, &oid))
1269                                 die(_("invalid shallow line: %s"), reader->line);
1270                         register_shallow(the_repository, &oid);
1271                         continue;
1272                 }
1273                 if (skip_prefix(reader->line, "unshallow ", &arg)) {
1274                         if (get_oid_hex(arg, &oid))
1275                                 die(_("invalid unshallow line: %s"), reader->line);
1276                         if (!lookup_object(the_repository, oid.hash))
1277                                 die(_("object not found: %s"), reader->line);
1278                         /* make sure that it is parsed as shallow */
1279                         if (!parse_object(the_repository, &oid))
1280                                 die(_("error in object: %s"), reader->line);
1281                         if (unregister_shallow(&oid))
1282                                 die(_("no shallow found: %s"), reader->line);
1283                         continue;
1284                 }
1285                 die(_("expected shallow/unshallow, got %s"), reader->line);
1286         }
1287
1288         if (reader->status != PACKET_READ_FLUSH &&
1289             reader->status != PACKET_READ_DELIM)
1290                 die(_("error processing shallow info: %d"), reader->status);
1291
1292         setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, NULL);
1293         args->deepen = 1;
1294 }
1295
1296 static void receive_wanted_refs(struct packet_reader *reader,
1297                                 struct ref **sought, int nr_sought)
1298 {
1299         process_section_header(reader, "wanted-refs", 0);
1300         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1301                 struct object_id oid;
1302                 const char *end;
1303                 int i;
1304
1305                 if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1306                         die(_("expected wanted-ref, got '%s'"), reader->line);
1307
1308                 for (i = 0; i < nr_sought; i++) {
1309                         if (!strcmp(end, sought[i]->name)) {
1310                                 oidcpy(&sought[i]->old_oid, &oid);
1311                                 break;
1312                         }
1313                 }
1314
1315                 if (i == nr_sought)
1316                         die(_("unexpected wanted-ref: '%s'"), reader->line);
1317         }
1318
1319         if (reader->status != PACKET_READ_DELIM)
1320                 die(_("error processing wanted refs: %d"), reader->status);
1321 }
1322
1323 enum fetch_state {
1324         FETCH_CHECK_LOCAL = 0,
1325         FETCH_SEND_REQUEST,
1326         FETCH_PROCESS_ACKS,
1327         FETCH_GET_PACK,
1328         FETCH_DONE,
1329 };
1330
1331 static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1332                                     int fd[2],
1333                                     const struct ref *orig_ref,
1334                                     struct ref **sought, int nr_sought,
1335                                     char **pack_lockfile)
1336 {
1337         struct ref *ref = copy_ref_list(orig_ref);
1338         enum fetch_state state = FETCH_CHECK_LOCAL;
1339         struct oidset common = OIDSET_INIT;
1340         struct packet_reader reader;
1341         int in_vain = 0;
1342         int haves_to_send = INITIAL_FLUSH;
1343         struct fetch_negotiator negotiator;
1344         fetch_negotiator_init(&negotiator, negotiation_algorithm);
1345         packet_reader_init(&reader, fd[0], NULL, 0,
1346                            PACKET_READ_CHOMP_NEWLINE);
1347
1348         while (state != FETCH_DONE) {
1349                 switch (state) {
1350                 case FETCH_CHECK_LOCAL:
1351                         sort_ref_list(&ref, ref_compare_name);
1352                         QSORT(sought, nr_sought, cmp_ref_by_name);
1353
1354                         /* v2 supports these by default */
1355                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1356                         use_sideband = 2;
1357                         if (args->depth > 0 || args->deepen_since || args->deepen_not)
1358                                 args->deepen = 1;
1359
1360                         /* Filter 'ref' by 'sought' and those that aren't local */
1361                         if (!args->no_dependents) {
1362                                 mark_complete_and_common_ref(&negotiator, args, &ref);
1363                                 filter_refs(args, &ref, sought, nr_sought);
1364                                 if (everything_local(args, &ref))
1365                                         state = FETCH_DONE;
1366                                 else
1367                                         state = FETCH_SEND_REQUEST;
1368
1369                                 mark_tips(&negotiator, args->negotiation_tips);
1370                                 for_each_cached_alternate(&negotiator,
1371                                                           insert_one_alternate_object);
1372                         } else {
1373                                 filter_refs(args, &ref, sought, nr_sought);
1374                                 state = FETCH_SEND_REQUEST;
1375                         }
1376                         break;
1377                 case FETCH_SEND_REQUEST:
1378                         if (send_fetch_request(&negotiator, fd[1], args, ref,
1379                                                &common,
1380                                                &haves_to_send, &in_vain))
1381                                 state = FETCH_GET_PACK;
1382                         else
1383                                 state = FETCH_PROCESS_ACKS;
1384                         break;
1385                 case FETCH_PROCESS_ACKS:
1386                         /* Process ACKs/NAKs */
1387                         switch (process_acks(&negotiator, &reader, &common)) {
1388                         case 2:
1389                                 state = FETCH_GET_PACK;
1390                                 break;
1391                         case 1:
1392                                 in_vain = 0;
1393                                 /* fallthrough */
1394                         default:
1395                                 state = FETCH_SEND_REQUEST;
1396                                 break;
1397                         }
1398                         break;
1399                 case FETCH_GET_PACK:
1400                         /* Check for shallow-info section */
1401                         if (process_section_header(&reader, "shallow-info", 1))
1402                                 receive_shallow_info(args, &reader);
1403
1404                         if (process_section_header(&reader, "wanted-refs", 1))
1405                                 receive_wanted_refs(&reader, sought, nr_sought);
1406
1407                         /* get the pack */
1408                         process_section_header(&reader, "packfile", 0);
1409                         if (get_pack(args, fd, pack_lockfile))
1410                                 die(_("git fetch-pack: fetch failed."));
1411
1412                         state = FETCH_DONE;
1413                         break;
1414                 case FETCH_DONE:
1415                         continue;
1416                 }
1417         }
1418
1419         negotiator.release(&negotiator);
1420         oidset_clear(&common);
1421         return ref;
1422 }
1423
1424 static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1425 {
1426         if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1427                 const char *path;
1428
1429                 if (git_config_pathname(&path, var, value))
1430                         return 1;
1431                 strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1432                         fsck_msg_types.len ? ',' : '=', path);
1433                 free((char *)path);
1434                 return 0;
1435         }
1436
1437         if (skip_prefix(var, "fetch.fsck.", &var)) {
1438                 if (is_valid_msg_type(var, value))
1439                         strbuf_addf(&fsck_msg_types, "%c%s=%s",
1440                                 fsck_msg_types.len ? ',' : '=', var, value);
1441                 else
1442                         warning("Skipping unknown msg id '%s'", var);
1443                 return 0;
1444         }
1445
1446         return git_default_config(var, value, cb);
1447 }
1448
1449 static void fetch_pack_config(void)
1450 {
1451         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1452         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1453         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1454         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1455         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1456         git_config_get_string("fetch.negotiationalgorithm",
1457                               &negotiation_algorithm);
1458
1459         git_config(fetch_pack_config_cb, NULL);
1460 }
1461
1462 static void fetch_pack_setup(void)
1463 {
1464         static int did_setup;
1465         if (did_setup)
1466                 return;
1467         fetch_pack_config();
1468         if (0 <= transfer_unpack_limit)
1469                 unpack_limit = transfer_unpack_limit;
1470         else if (0 <= fetch_unpack_limit)
1471                 unpack_limit = fetch_unpack_limit;
1472         did_setup = 1;
1473 }
1474
1475 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1476 {
1477         struct string_list names = STRING_LIST_INIT_NODUP;
1478         int src, dst;
1479
1480         for (src = dst = 0; src < nr; src++) {
1481                 struct string_list_item *item;
1482                 item = string_list_insert(&names, ref[src]->name);
1483                 if (item->util)
1484                         continue; /* already have it */
1485                 item->util = ref[src];
1486                 if (src != dst)
1487                         ref[dst] = ref[src];
1488                 dst++;
1489         }
1490         for (src = dst; src < nr; src++)
1491                 ref[src] = NULL;
1492         string_list_clear(&names, 0);
1493         return dst;
1494 }
1495
1496 static void update_shallow(struct fetch_pack_args *args,
1497                            struct ref **sought, int nr_sought,
1498                            struct shallow_info *si)
1499 {
1500         struct oid_array ref = OID_ARRAY_INIT;
1501         int *status;
1502         int i;
1503
1504         if (args->deepen && alternate_shallow_file) {
1505                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1506                         unlink_or_warn(git_path_shallow(the_repository));
1507                         rollback_lock_file(&shallow_lock);
1508                 } else
1509                         commit_lock_file(&shallow_lock);
1510                 return;
1511         }
1512
1513         if (!si->shallow || !si->shallow->nr)
1514                 return;
1515
1516         if (args->cloning) {
1517                 /*
1518                  * remote is shallow, but this is a clone, there are
1519                  * no objects in repo to worry about. Accept any
1520                  * shallow points that exist in the pack (iow in repo
1521                  * after get_pack() and reprepare_packed_git())
1522                  */
1523                 struct oid_array extra = OID_ARRAY_INIT;
1524                 struct object_id *oid = si->shallow->oid;
1525                 for (i = 0; i < si->shallow->nr; i++)
1526                         if (has_object_file(&oid[i]))
1527                                 oid_array_append(&extra, &oid[i]);
1528                 if (extra.nr) {
1529                         setup_alternate_shallow(&shallow_lock,
1530                                                 &alternate_shallow_file,
1531                                                 &extra);
1532                         commit_lock_file(&shallow_lock);
1533                 }
1534                 oid_array_clear(&extra);
1535                 return;
1536         }
1537
1538         if (!si->nr_ours && !si->nr_theirs)
1539                 return;
1540
1541         remove_nonexistent_theirs_shallow(si);
1542         if (!si->nr_ours && !si->nr_theirs)
1543                 return;
1544         for (i = 0; i < nr_sought; i++)
1545                 oid_array_append(&ref, &sought[i]->old_oid);
1546         si->ref = &ref;
1547
1548         if (args->update_shallow) {
1549                 /*
1550                  * remote is also shallow, .git/shallow may be updated
1551                  * so all refs can be accepted. Make sure we only add
1552                  * shallow roots that are actually reachable from new
1553                  * refs.
1554                  */
1555                 struct oid_array extra = OID_ARRAY_INIT;
1556                 struct object_id *oid = si->shallow->oid;
1557                 assign_shallow_commits_to_refs(si, NULL, NULL);
1558                 if (!si->nr_ours && !si->nr_theirs) {
1559                         oid_array_clear(&ref);
1560                         return;
1561                 }
1562                 for (i = 0; i < si->nr_ours; i++)
1563                         oid_array_append(&extra, &oid[si->ours[i]]);
1564                 for (i = 0; i < si->nr_theirs; i++)
1565                         oid_array_append(&extra, &oid[si->theirs[i]]);
1566                 setup_alternate_shallow(&shallow_lock,
1567                                         &alternate_shallow_file,
1568                                         &extra);
1569                 commit_lock_file(&shallow_lock);
1570                 oid_array_clear(&extra);
1571                 oid_array_clear(&ref);
1572                 return;
1573         }
1574
1575         /*
1576          * remote is also shallow, check what ref is safe to update
1577          * without updating .git/shallow
1578          */
1579         status = xcalloc(nr_sought, sizeof(*status));
1580         assign_shallow_commits_to_refs(si, NULL, status);
1581         if (si->nr_ours || si->nr_theirs) {
1582                 for (i = 0; i < nr_sought; i++)
1583                         if (status[i])
1584                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1585         }
1586         free(status);
1587         oid_array_clear(&ref);
1588 }
1589
1590 static int iterate_ref_map(void *cb_data, struct object_id *oid)
1591 {
1592         struct ref **rm = cb_data;
1593         struct ref *ref = *rm;
1594
1595         if (!ref)
1596                 return -1; /* end of the list */
1597         *rm = ref->next;
1598         oidcpy(oid, &ref->old_oid);
1599         return 0;
1600 }
1601
1602 struct ref *fetch_pack(struct fetch_pack_args *args,
1603                        int fd[], struct child_process *conn,
1604                        const struct ref *ref,
1605                        const char *dest,
1606                        struct ref **sought, int nr_sought,
1607                        struct oid_array *shallow,
1608                        char **pack_lockfile,
1609                        enum protocol_version version)
1610 {
1611         struct ref *ref_cpy;
1612         struct shallow_info si;
1613
1614         fetch_pack_setup();
1615         if (nr_sought)
1616                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1617
1618         if (args->no_dependents && !args->filter_options.choice) {
1619                 /*
1620                  * The protocol does not support requesting that only the
1621                  * wanted objects be sent, so approximate this by setting a
1622                  * "blob:none" filter if no filter is already set. This works
1623                  * for all object types: note that wanted blobs will still be
1624                  * sent because they are directly specified as a "want".
1625                  *
1626                  * NEEDSWORK: Add an option in the protocol to request that
1627                  * only the wanted objects be sent, and implement it.
1628                  */
1629                 parse_list_objects_filter(&args->filter_options, "blob:none");
1630         }
1631
1632         if (!ref) {
1633                 packet_flush(fd[1]);
1634                 die(_("no matching remote head"));
1635         }
1636         prepare_shallow_info(&si, shallow);
1637         if (version == protocol_v2)
1638                 ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1639                                            pack_lockfile);
1640         else
1641                 ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1642                                         &si, pack_lockfile);
1643         reprepare_packed_git(the_repository);
1644
1645         if (!args->cloning && args->deepen) {
1646                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
1647                 struct ref *iterator = ref_cpy;
1648                 opt.shallow_file = alternate_shallow_file;
1649                 if (args->deepen)
1650                         opt.is_deepening_fetch = 1;
1651                 if (check_connected(iterate_ref_map, &iterator, &opt)) {
1652                         error(_("remote did not send all necessary objects"));
1653                         free_refs(ref_cpy);
1654                         ref_cpy = NULL;
1655                         rollback_lock_file(&shallow_lock);
1656                         goto cleanup;
1657                 }
1658                 args->connectivity_checked = 1;
1659         }
1660
1661         update_shallow(args, sought, nr_sought, &si);
1662 cleanup:
1663         clear_shallow_info(&si);
1664         return ref_cpy;
1665 }
1666
1667 int report_unmatched_refs(struct ref **sought, int nr_sought)
1668 {
1669         int i, ret = 0;
1670
1671         for (i = 0; i < nr_sought; i++) {
1672                 if (!sought[i])
1673                         continue;
1674                 switch (sought[i]->match_status) {
1675                 case REF_MATCHED:
1676                         continue;
1677                 case REF_NOT_MATCHED:
1678                         error(_("no such remote ref %s"), sought[i]->name);
1679                         break;
1680                 case REF_UNADVERTISED_NOT_ALLOWED:
1681                         error(_("Server does not allow request for unadvertised object %s"),
1682                               sought[i]->name);
1683                         break;
1684                 }
1685                 ret = 1;
1686         }
1687         return ret;
1688 }