git.oblomov.eu Git - git/blob - fetch-pack.c

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