fetch-pack.c

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