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,
 139                                  struct packet_reader *reader)
 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                 while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 147                         if (starts_with(reader->line, "shallow "))
 148                                 continue;
 149                         if (starts_with(reader->line, "unshallow "))
 150                                 continue;
 151                         die(_("git fetch-pack: expected shallow list"));
 152                 }
 153                 if (reader->status != PACKET_READ_FLUSH)
 154                         die(_("git fetch-pack: expected a flush packet after shallow list"));
 155         }
 156 }
 157
 158 static enum ack_type get_ack(struct packet_reader *reader,
 159                              struct object_id *result_oid)
 160 {
 161         int len;
 162         const char *arg;
 163
 164         if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 165                 die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 166         len = reader->pktlen;
 167
 168         if (!strcmp(reader->line, "NAK"))
 169                 return NAK;
 170         if (skip_prefix(reader->line, "ACK ", &arg)) {
 171                 if (!get_oid_hex(arg, result_oid)) {
 172                         arg += 40;
 173                         len -= arg - reader->line;
 174                         if (len < 1)
 175                                 return ACK;
 176                         if (strstr(arg, "continue"))
 177                                 return ACK_continue;
 178                         if (strstr(arg, "common"))
 179                                 return ACK_common;
 180                         if (strstr(arg, "ready"))
 181                                 return ACK_ready;
 182                         return ACK;
 183                 }
 184         }
 185         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
 186 }
 187
 188 static void send_request(struct fetch_pack_args *args,
 189                          int fd, struct strbuf *buf)
 190 {
 191         if (args->stateless_rpc) {
 192                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 193                 packet_flush(fd);
 194         } else {
 195                 if (write_in_full(fd, buf->buf, buf->len) < 0)
 196                         die_errno(_("unable to write to remote"));
 197         }
 198 }
 199
 200 static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 201                                         struct object *obj)
 202 {
 203         rev_list_insert_ref(negotiator, NULL, &obj->oid);
 204 }
 205
 206 #define INITIAL_FLUSH 16
 207 #define PIPESAFE_FLUSH 32
 208 #define LARGE_FLUSH 16384
 209
 210 static int next_flush(int stateless_rpc, int count)
 211 {
 212         if (stateless_rpc) {
 213                 if (count < LARGE_FLUSH)
 214                         count <<= 1;
 215                 else
 216                         count = count * 11 / 10;
 217         } else {
 218                 if (count < PIPESAFE_FLUSH)
 219                         count <<= 1;
 220                 else
 221                         count += PIPESAFE_FLUSH;
 222         }
 223         return count;
 224 }
 225
 226 static void mark_tips(struct fetch_negotiator *negotiator,
 227                       const struct oid_array *negotiation_tips)
 228 {
 229         int i;
 230
 231         if (!negotiation_tips) {
 232                 for_each_ref(rev_list_insert_ref_oid, negotiator);
 233                 return;
 234         }
 235
 236         for (i = 0; i < negotiation_tips->nr; i++)
 237                 rev_list_insert_ref(negotiator, NULL,
 238                                     &negotiation_tips->oid[i]);
 239         return;
 240 }
 241
 242 static int find_common(struct fetch_negotiator *negotiator,
 243                        struct fetch_pack_args *args,
 244                        int fd[2], struct object_id *result_oid,
 245                        struct ref *refs)
 246 {
 247         int fetching;
 248         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 249         const struct object_id *oid;
 250         unsigned in_vain = 0;
 251         int got_continue = 0;
 252         int got_ready = 0;
 253         struct strbuf req_buf = STRBUF_INIT;
 254         size_t state_len = 0;
 255         struct packet_reader reader;
 256
 257         if (args->stateless_rpc && multi_ack == 1)
 258                 die(_("--stateless-rpc requires multi_ack_detailed"));
 259
 260         packet_reader_init(&reader, fd[0], NULL, 0,
 261                            PACKET_READ_CHOMP_NEWLINE |
 262                            PACKET_READ_DIE_ON_ERR_PACKET);
 263
 264         if (!args->no_dependents) {
 265                 mark_tips(negotiator, args->negotiation_tips);
 266                 for_each_cached_alternate(negotiator, insert_one_alternate_object);
 267         }
 268
 269         fetching = 0;
 270         for ( ; refs ; refs = refs->next) {
 271                 struct object_id *remote = &refs->old_oid;
 272                 const char *remote_hex;
 273                 struct object *o;
 274
 275                 /*
 276                  * If that object is complete (i.e. it is an ancestor of a
 277                  * local ref), we tell them we have it but do not have to
 278                  * tell them about its ancestors, which they already know
 279                  * about.
 280                  *
 281                  * We use lookup_object here because we are only
 282                  * interested in the case we *know* the object is
 283                  * reachable and we have already scanned it.
 284                  *
 285                  * Do this only if args->no_dependents is false (if it is true,
 286                  * we cannot trust the object flags).
 287                  */
 288                 if (!args->no_dependents &&
 289                     ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
 290                                 (o->flags & COMPLETE)) {
 291                         continue;
 292                 }
 293
 294                 remote_hex = oid_to_hex(remote);
 295                 if (!fetching) {
 296                         struct strbuf c = STRBUF_INIT;
 297                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 298                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 299                         if (no_done)            strbuf_addstr(&c, " no-done");
 300                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 301                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 302                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 303                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 304                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 305                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 306                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 307                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 308                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 309                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 310                                                             git_user_agent_sanitized());
 311                         if (args->filter_options.choice)
 312                                 strbuf_addstr(&c, " filter");
 313                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 314                         strbuf_release(&c);
 315                 } else
 316                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 317                 fetching++;
 318         }
 319
 320         if (!fetching) {
 321                 strbuf_release(&req_buf);
 322                 packet_flush(fd[1]);
 323                 return 1;
 324         }
 325
 326         if (is_repository_shallow(the_repository))
 327                 write_shallow_commits(&req_buf, 1, NULL);
 328         if (args->depth > 0)
 329                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 330         if (args->deepen_since) {
 331                 timestamp_t max_age = approxidate(args->deepen_since);
 332                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 333         }
 334         if (args->deepen_not) {
 335                 int i;
 336                 for (i = 0; i < args->deepen_not->nr; i++) {
 337                         struct string_list_item *s = args->deepen_not->items + i;
 338                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 339                 }
 340         }
 341         if (server_supports_filtering && args->filter_options.choice) {
 342                 struct strbuf expanded_filter_spec = STRBUF_INIT;
 343                 expand_list_objects_filter_spec(&args->filter_options,
 344                                                 &expanded_filter_spec);
 345                 packet_buf_write(&req_buf, "filter %s",
 346                                  expanded_filter_spec.buf);
 347                 strbuf_release(&expanded_filter_spec);
 348         }
 349         packet_buf_flush(&req_buf);
 350         state_len = req_buf.len;
 351
 352         if (args->deepen) {
 353                 const char *arg;
 354                 struct object_id oid;
 355
 356                 send_request(args, fd[1], &req_buf);
 357                 while (packet_reader_read(&reader) == PACKET_READ_NORMAL) {
 358                         if (skip_prefix(reader.line, "shallow ", &arg)) {
 359                                 if (get_oid_hex(arg, &oid))
 360                                         die(_("invalid shallow line: %s"), reader.line);
 361                                 register_shallow(the_repository, &oid);
 362                                 continue;
 363                         }
 364                         if (skip_prefix(reader.line, "unshallow ", &arg)) {
 365                                 if (get_oid_hex(arg, &oid))
 366                                         die(_("invalid unshallow line: %s"), reader.line);
 367                                 if (!lookup_object(the_repository, oid.hash))
 368                                         die(_("object not found: %s"), reader.line);
 369                                 /* make sure that it is parsed as shallow */
 370                                 if (!parse_object(the_repository, &oid))
 371                                         die(_("error in object: %s"), reader.line);
 372                                 if (unregister_shallow(&oid))
 373                                         die(_("no shallow found: %s"), reader.line);
 374                                 continue;
 375                         }
 376                         die(_("expected shallow/unshallow, got %s"), reader.line);
 377                 }
 378         } else if (!args->stateless_rpc)
 379                 send_request(args, fd[1], &req_buf);
 380
 381         if (!args->stateless_rpc) {
 382                 /* If we aren't using the stateless-rpc interface
 383                  * we don't need to retain the headers.
 384                  */
 385                 strbuf_setlen(&req_buf, 0);
 386                 state_len = 0;
 387         }
 388
 389         flushes = 0;
 390         retval = -1;
 391         if (args->no_dependents)
 392                 goto done;
 393         while ((oid = negotiator->next(negotiator))) {
 394                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 395                 print_verbose(args, "have %s", oid_to_hex(oid));
 396                 in_vain++;
 397                 if (flush_at <= ++count) {
 398                         int ack;
 399
 400                         packet_buf_flush(&req_buf);
 401                         send_request(args, fd[1], &req_buf);
 402                         strbuf_setlen(&req_buf, state_len);
 403                         flushes++;
 404                         flush_at = next_flush(args->stateless_rpc, count);
 405
 406                         /*
 407                          * We keep one window "ahead" of the other side, and
 408                          * will wait for an ACK only on the next one
 409                          */
 410                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 411                                 continue;
 412
 413                         consume_shallow_list(args, &reader);
 414                         do {
 415                                 ack = get_ack(&reader, result_oid);
 416                                 if (ack)
 417                                         print_verbose(args, _("got %s %d %s"), "ack",
 418                                                       ack, oid_to_hex(result_oid));
 419                                 switch (ack) {
 420                                 case ACK:
 421                                         flushes = 0;
 422                                         multi_ack = 0;
 423                                         retval = 0;
 424                                         goto done;
 425                                 case ACK_common:
 426                                 case ACK_ready:
 427                                 case ACK_continue: {
 428                                         struct commit *commit =
 429                                                 lookup_commit(the_repository,
 430                                                               result_oid);
 431                                         int was_common;
 432
 433                                         if (!commit)
 434                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
 435                                         was_common = negotiator->ack(negotiator, commit);
 436                                         if (args->stateless_rpc
 437                                          && ack == ACK_common
 438                                          && !was_common) {
 439                                                 /* We need to replay the have for this object
 440                                                  * on the next RPC request so the peer knows
 441                                                  * it is in common with us.
 442                                                  */
 443                                                 const char *hex = oid_to_hex(result_oid);
 444                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 445                                                 state_len = req_buf.len;
 446                                                 /*
 447                                                  * Reset in_vain because an ack
 448                                                  * for this commit has not been
 449                                                  * seen.
 450                                                  */
 451                                                 in_vain = 0;
 452                                         } else if (!args->stateless_rpc
 453                                                    || ack != ACK_common)
 454                                                 in_vain = 0;
 455                                         retval = 0;
 456                                         got_continue = 1;
 457                                         if (ack == ACK_ready)
 458                                                 got_ready = 1;
 459                                         break;
 460                                         }
 461                                 }
 462                         } while (ack);
 463                         flushes--;
 464                         if (got_continue && MAX_IN_VAIN < in_vain) {
 465                                 print_verbose(args, _("giving up"));
 466                                 break; /* give up */
 467                         }
 468                         if (got_ready)
 469                                 break;
 470                 }
 471         }
 472 done:
 473         if (!got_ready || !no_done) {
 474                 packet_buf_write(&req_buf, "done\n");
 475                 send_request(args, fd[1], &req_buf);
 476         }
 477         print_verbose(args, _("done"));
 478         if (retval != 0) {
 479                 multi_ack = 0;
 480                 flushes++;
 481         }
 482         strbuf_release(&req_buf);
 483
 484         if (!got_ready || !no_done)
 485                 consume_shallow_list(args, &reader);
 486         while (flushes || multi_ack) {
 487                 int ack = get_ack(&reader, result_oid);
 488                 if (ack) {
 489                         print_verbose(args, _("got %s (%d) %s"), "ack",
 490                                       ack, oid_to_hex(result_oid));
 491                         if (ack == ACK)
 492                                 return 0;
 493                         multi_ack = 1;
 494                         continue;
 495                 }
 496                 flushes--;
 497         }
 498         /* it is no error to fetch into a completely empty repo */
 499         return count ? retval : 0;
 500 }
 501
 502 static struct commit_list *complete;
 503
 504 static int mark_complete(const struct object_id *oid)
 505 {
 506         struct object *o = parse_object(the_repository, oid);
 507
 508         while (o && o->type == OBJ_TAG) {
 509                 struct tag *t = (struct tag *) o;
 510                 if (!t->tagged)
 511                         break; /* broken repository */
 512                 o->flags |= COMPLETE;
 513                 o = parse_object(the_repository, &t->tagged->oid);
 514         }
 515         if (o && o->type == OBJ_COMMIT) {
 516                 struct commit *commit = (struct commit *)o;
 517                 if (!(commit->object.flags & COMPLETE)) {
 518                         commit->object.flags |= COMPLETE;
 519                         commit_list_insert(commit, &complete);
 520                 }
 521         }
 522         return 0;
 523 }
 524
 525 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 526                              int flag, void *cb_data)
 527 {
 528         return mark_complete(oid);
 529 }
 530
 531 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 532                                          timestamp_t cutoff)
 533 {
 534         while (complete && cutoff <= complete->item->date) {
 535                 print_verbose(args, _("Marking %s as complete"),
 536                               oid_to_hex(&complete->item->object.oid));
 537                 pop_most_recent_commit(&complete, COMPLETE);
 538         }
 539 }
 540
 541 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 542 {
 543         for (; refs; refs = refs->next)
 544                 oidset_insert(oids, &refs->old_oid);
 545 }
 546
 547 static int is_unmatched_ref(const struct ref *ref)
 548 {
 549         struct object_id oid;
 550         const char *p;
 551         return  ref->match_status == REF_NOT_MATCHED &&
 552                 !parse_oid_hex(ref->name, &oid, &p) &&
 553                 *p == '\0' &&
 554                 oideq(&oid, &ref->old_oid);
 555 }
 556
 557 static void filter_refs(struct fetch_pack_args *args,
 558                         struct ref **refs,
 559                         struct ref **sought, int nr_sought)
 560 {
 561         struct ref *newlist = NULL;
 562         struct ref **newtail = &newlist;
 563         struct ref *unmatched = NULL;
 564         struct ref *ref, *next;
 565         struct oidset tip_oids = OIDSET_INIT;
 566         int i;
 567         int strict = !(allow_unadvertised_object_request &
 568                        (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
 569
 570         i = 0;
 571         for (ref = *refs; ref; ref = next) {
 572                 int keep = 0;
 573                 next = ref->next;
 574
 575                 if (starts_with(ref->name, "refs/") &&
 576                     check_refname_format(ref->name, 0))
 577                         ; /* trash */
 578                 else {
 579                         while (i < nr_sought) {
 580                                 int cmp = strcmp(ref->name, sought[i]->name);
 581                                 if (cmp < 0)
 582                                         break; /* definitely do not have it */
 583                                 else if (cmp == 0) {
 584                                         keep = 1; /* definitely have it */
 585                                         sought[i]->match_status = REF_MATCHED;
 586                                 }
 587                                 i++;
 588                         }
 589
 590                         if (!keep && args->fetch_all &&
 591                             (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 592                                 keep = 1;
 593                 }
 594
 595                 if (keep) {
 596                         *newtail = ref;
 597                         ref->next = NULL;
 598                         newtail = &ref->next;
 599                 } else {
 600                         ref->next = unmatched;
 601                         unmatched = ref;
 602                 }
 603         }
 604
 605         if (strict) {
 606                 for (i = 0; i < nr_sought; i++) {
 607                         ref = sought[i];
 608                         if (!is_unmatched_ref(ref))
 609                                 continue;
 610
 611                         add_refs_to_oidset(&tip_oids, unmatched);
 612                         add_refs_to_oidset(&tip_oids, newlist);
 613                         break;
 614                 }
 615         }
 616
 617         /* Append unmatched requests to the list */
 618         for (i = 0; i < nr_sought; i++) {
 619                 ref = sought[i];
 620                 if (!is_unmatched_ref(ref))
 621                         continue;
 622
 623                 if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
 624                         ref->match_status = REF_MATCHED;
 625                         *newtail = copy_ref(ref);
 626                         newtail = &(*newtail)->next;
 627                 } else {
 628                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 629                 }
 630         }
 631
 632         oidset_clear(&tip_oids);
 633         for (ref = unmatched; ref; ref = next) {
 634                 next = ref->next;
 635                 free(ref);
 636         }
 637
 638         *refs = newlist;
 639 }
 640
 641 static void mark_alternate_complete(struct fetch_negotiator *unused,
 642                                     struct object *obj)
 643 {
 644         mark_complete(&obj->oid);
 645 }
 646
 647 struct loose_object_iter {
 648         struct oidset *loose_object_set;
 649         struct ref *refs;
 650 };
 651
 652 /*
 653  * Mark recent commits available locally and reachable from a local ref as
 654  * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 655  * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 656  * thus do not need COMMON_REF marks).
 657  *
 658  * The cutoff time for recency is determined by this heuristic: it is the
 659  * earliest commit time of the objects in refs that are commits and that we know
 660  * the commit time of.
 661  */
 662 static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 663                                          struct fetch_pack_args *args,
 664                                          struct ref **refs)
 665 {
 666         struct ref *ref;
 667         int old_save_commit_buffer = save_commit_buffer;
 668         timestamp_t cutoff = 0;
 669
 670         save_commit_buffer = 0;
 671
 672         for (ref = *refs; ref; ref = ref->next) {
 673                 struct object *o;
 674
 675                 if (!has_object_file_with_flags(&ref->old_oid,
 676                                                 OBJECT_INFO_QUICK))
 677                         continue;
 678                 o = parse_object(the_repository, &ref->old_oid);
 679                 if (!o)
 680                         continue;
 681
 682                 /* We already have it -- which may mean that we were
 683                  * in sync with the other side at some time after
 684                  * that (it is OK if we guess wrong here).
 685                  */
 686                 if (o->type == OBJ_COMMIT) {
 687                         struct commit *commit = (struct commit *)o;
 688                         if (!cutoff || cutoff < commit->date)
 689                                 cutoff = commit->date;
 690                 }
 691         }
 692
 693         if (!args->deepen) {
 694                 for_each_ref(mark_complete_oid, NULL);
 695                 for_each_cached_alternate(NULL, mark_alternate_complete);
 696                 commit_list_sort_by_date(&complete);
 697                 if (cutoff)
 698                         mark_recent_complete_commits(args, cutoff);
 699         }
 700
 701         /*
 702          * Mark all complete remote refs as common refs.
 703          * Don't mark them common yet; the server has to be told so first.
 704          */
 705         for (ref = *refs; ref; ref = ref->next) {
 706                 struct object *o = deref_tag(the_repository,
 707                                              lookup_object(the_repository,
 708                                              ref->old_oid.hash),
 709                                              NULL, 0);
 710
 711                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 712                         continue;
 713
 714                 negotiator->known_common(negotiator,
 715                                          (struct commit *)o);
 716         }
 717
 718         save_commit_buffer = old_save_commit_buffer;
 719 }
 720
 721 /*
 722  * Returns 1 if every object pointed to by the given remote refs is available
 723  * locally and reachable from a local ref, and 0 otherwise.
 724  */
 725 static int everything_local(struct fetch_pack_args *args,
 726                             struct ref **refs)
 727 {
 728         struct ref *ref;
 729         int retval;
 730
 731         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 732                 const struct object_id *remote = &ref->old_oid;
 733                 struct object *o;
 734
 735                 o = lookup_object(the_repository, remote->hash);
 736                 if (!o || !(o->flags & COMPLETE)) {
 737                         retval = 0;
 738                         print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 739                                       ref->name);
 740                         continue;
 741                 }
 742                 print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 743                               ref->name);
 744         }
 745
 746         return retval;
 747 }
 748
 749 static int sideband_demux(int in, int out, void *data)
 750 {
 751         int *xd = data;
 752         int ret;
 753
 754         ret = recv_sideband("fetch-pack", xd[0], out);
 755         close(out);
 756         return ret;
 757 }
 758
 759 static int get_pack(struct fetch_pack_args *args,
 760                     int xd[2], char **pack_lockfile)
 761 {
 762         struct async demux;
 763         int do_keep = args->keep_pack;
 764         const char *cmd_name;
 765         struct pack_header header;
 766         int pass_header = 0;
 767         struct child_process cmd = CHILD_PROCESS_INIT;
 768         int ret;
 769
 770         memset(&demux, 0, sizeof(demux));
 771         if (use_sideband) {
 772                 /* xd[] is talking with upload-pack; subprocess reads from
 773                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 774                  * through demux->out.
 775                  */
 776                 demux.proc = sideband_demux;
 777                 demux.data = xd;
 778                 demux.out = -1;
 779                 demux.isolate_sigpipe = 1;
 780                 if (start_async(&demux))
 781                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 782         }
 783         else
 784                 demux.out = xd[0];
 785
 786         if (!args->keep_pack && unpack_limit) {
 787
 788                 if (read_pack_header(demux.out, &header))
 789                         die(_("protocol error: bad pack header"));
 790                 pass_header = 1;
 791                 if (ntohl(header.hdr_entries) < unpack_limit)
 792                         do_keep = 0;
 793                 else
 794                         do_keep = 1;
 795         }
 796
 797         if (alternate_shallow_file) {
 798                 argv_array_push(&cmd.args, "--shallow-file");
 799                 argv_array_push(&cmd.args, alternate_shallow_file);
 800         }
 801
 802         if (do_keep || args->from_promisor) {
 803                 if (pack_lockfile)
 804                         cmd.out = -1;
 805                 cmd_name = "index-pack";
 806                 argv_array_push(&cmd.args, cmd_name);
 807                 argv_array_push(&cmd.args, "--stdin");
 808                 if (!args->quiet && !args->no_progress)
 809                         argv_array_push(&cmd.args, "-v");
 810                 if (args->use_thin_pack)
 811                         argv_array_push(&cmd.args, "--fix-thin");
 812                 if (do_keep && (args->lock_pack || unpack_limit)) {
 813                         char hostname[HOST_NAME_MAX + 1];
 814                         if (xgethostname(hostname, sizeof(hostname)))
 815                                 xsnprintf(hostname, sizeof(hostname), "localhost");
 816                         argv_array_pushf(&cmd.args,
 817                                         "--keep=fetch-pack %"PRIuMAX " on %s",
 818                                         (uintmax_t)getpid(), hostname);
 819                 }
 820                 if (args->check_self_contained_and_connected)
 821                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 822                 if (args->from_promisor)
 823                         argv_array_push(&cmd.args, "--promisor");
 824         }
 825         else {
 826                 cmd_name = "unpack-objects";
 827                 argv_array_push(&cmd.args, cmd_name);
 828                 if (args->quiet || args->no_progress)
 829                         argv_array_push(&cmd.args, "-q");
 830                 args->check_self_contained_and_connected = 0;
 831         }
 832
 833         if (pass_header)
 834                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 835                                  ntohl(header.hdr_version),
 836                                  ntohl(header.hdr_entries));
 837         if (fetch_fsck_objects >= 0
 838             ? fetch_fsck_objects
 839             : transfer_fsck_objects >= 0
 840             ? transfer_fsck_objects
 841             : 0) {
 842                 if (args->from_promisor)
 843                         /*
 844                          * We cannot use --strict in index-pack because it
 845                          * checks both broken objects and links, but we only
 846                          * want to check for broken objects.
 847                          */
 848                         argv_array_push(&cmd.args, "--fsck-objects");
 849                 else
 850                         argv_array_pushf(&cmd.args, "--strict%s",
 851                                          fsck_msg_types.buf);
 852         }
 853
 854         cmd.in = demux.out;
 855         cmd.git_cmd = 1;
 856         if (start_command(&cmd))
 857                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
 858         if (do_keep && pack_lockfile) {
 859                 *pack_lockfile = index_pack_lockfile(cmd.out);
 860                 close(cmd.out);
 861         }
 862
 863         if (!use_sideband)
 864                 /* Closed by start_command() */
 865                 xd[0] = -1;
 866
 867         ret = finish_command(&cmd);
 868         if (!ret || (args->check_self_contained_and_connected && ret == 1))
 869                 args->self_contained_and_connected =
 870                         args->check_self_contained_and_connected &&
 871                         ret == 0;
 872         else
 873                 die(_("%s failed"), cmd_name);
 874         if (use_sideband && finish_async(&demux))
 875                 die(_("error in sideband demultiplexer"));
 876         return 0;
 877 }
 878
 879 static int cmp_ref_by_name(const void *a_, const void *b_)
 880 {
 881         const struct ref *a = *((const struct ref **)a_);
 882         const struct ref *b = *((const struct ref **)b_);
 883         return strcmp(a->name, b->name);
 884 }
 885
 886 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 887                                  int fd[2],
 888                                  const struct ref *orig_ref,
 889                                  struct ref **sought, int nr_sought,
 890                                  struct shallow_info *si,
 891                                  char **pack_lockfile)
 892 {
 893         struct ref *ref = copy_ref_list(orig_ref);
 894         struct object_id oid;
 895         const char *agent_feature;
 896         int agent_len;
 897         struct fetch_negotiator negotiator;
 898         fetch_negotiator_init(&negotiator, negotiation_algorithm);
 899
 900         sort_ref_list(&ref, ref_compare_name);
 901         QSORT(sought, nr_sought, cmp_ref_by_name);
 902
 903         if ((args->depth > 0 || is_repository_shallow(the_repository)) && !server_supports("shallow"))
 904                 die(_("Server does not support shallow clients"));
 905         if (args->depth > 0 || args->deepen_since || args->deepen_not)
 906                 args->deepen = 1;
 907         if (server_supports("multi_ack_detailed")) {
 908                 print_verbose(args, _("Server supports multi_ack_detailed"));
 909                 multi_ack = 2;
 910                 if (server_supports("no-done")) {
 911                         print_verbose(args, _("Server supports no-done"));
 912                         if (args->stateless_rpc)
 913                                 no_done = 1;
 914                 }
 915         }
 916         else if (server_supports("multi_ack")) {
 917                 print_verbose(args, _("Server supports multi_ack"));
 918                 multi_ack = 1;
 919         }
 920         if (server_supports("side-band-64k")) {
 921                 print_verbose(args, _("Server supports side-band-64k"));
 922                 use_sideband = 2;
 923         }
 924         else if (server_supports("side-band")) {
 925                 print_verbose(args, _("Server supports side-band"));
 926                 use_sideband = 1;
 927         }
 928         if (server_supports("allow-tip-sha1-in-want")) {
 929                 print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 930                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 931         }
 932         if (server_supports("allow-reachable-sha1-in-want")) {
 933                 print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 934                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 935         }
 936         if (!server_supports("thin-pack"))
 937                 args->use_thin_pack = 0;
 938         if (!server_supports("no-progress"))
 939                 args->no_progress = 0;
 940         if (!server_supports("include-tag"))
 941                 args->include_tag = 0;
 942         if (server_supports("ofs-delta"))
 943                 print_verbose(args, _("Server supports ofs-delta"));
 944         else
 945                 prefer_ofs_delta = 0;
 946
 947         if (server_supports("filter")) {
 948                 server_supports_filtering = 1;
 949                 print_verbose(args, _("Server supports filter"));
 950         } else if (args->filter_options.choice) {
 951                 warning("filtering not recognized by server, ignoring");
 952         }
 953
 954         if ((agent_feature = server_feature_value("agent", &agent_len))) {
 955                 agent_supported = 1;
 956                 if (agent_len)
 957                         print_verbose(args, _("Server version is %.*s"),
 958                                       agent_len, agent_feature);
 959         }
 960         if (server_supports("deepen-since"))
 961                 deepen_since_ok = 1;
 962         else if (args->deepen_since)
 963                 die(_("Server does not support --shallow-since"));
 964         if (server_supports("deepen-not"))
 965                 deepen_not_ok = 1;
 966         else if (args->deepen_not)
 967                 die(_("Server does not support --shallow-exclude"));
 968         if (!server_supports("deepen-relative") && args->deepen_relative)
 969                 die(_("Server does not support --deepen"));
 970
 971         if (!args->no_dependents) {
 972                 mark_complete_and_common_ref(&negotiator, args, &ref);
 973                 filter_refs(args, &ref, sought, nr_sought);
 974                 if (everything_local(args, &ref)) {
 975                         packet_flush(fd[1]);
 976                         goto all_done;
 977                 }
 978         } else {
 979                 filter_refs(args, &ref, sought, nr_sought);
 980         }
 981         if (find_common(&negotiator, args, fd, &oid, ref) < 0)
 982                 if (!args->keep_pack)
 983                         /* When cloning, it is not unusual to have
 984                          * no common commit.
 985                          */
 986                         warning(_("no common commits"));
 987
 988         if (args->stateless_rpc)
 989                 packet_flush(fd[1]);
 990         if (args->deepen)
 991                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
 992                                         NULL);
 993         else if (si->nr_ours || si->nr_theirs)
 994                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
 995         else
 996                 alternate_shallow_file = NULL;
 997         if (get_pack(args, fd, pack_lockfile))
 998                 die(_("git fetch-pack: fetch failed."));
 999
1000  all_done:
1001         negotiator.release(&negotiator);
1002         return ref;
1003 }
1004
1005 static void add_shallow_requests(struct strbuf *req_buf,
1006                                  const struct fetch_pack_args *args)
1007 {
1008         if (is_repository_shallow(the_repository))
1009                 write_shallow_commits(req_buf, 1, NULL);
1010         if (args->depth > 0)
1011                 packet_buf_write(req_buf, "deepen %d", args->depth);
1012         if (args->deepen_since) {
1013                 timestamp_t max_age = approxidate(args->deepen_since);
1014                 packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1015         }
1016         if (args->deepen_not) {
1017                 int i;
1018                 for (i = 0; i < args->deepen_not->nr; i++) {
1019                         struct string_list_item *s = args->deepen_not->items + i;
1020                         packet_buf_write(req_buf, "deepen-not %s", s->string);
1021                 }
1022         }
1023         if (args->deepen_relative)
1024                 packet_buf_write(req_buf, "deepen-relative\n");
1025 }
1026
1027 static void add_wants(int no_dependents, const struct ref *wants, struct strbuf *req_buf)
1028 {
1029         int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1030
1031         for ( ; wants ; wants = wants->next) {
1032                 const struct object_id *remote = &wants->old_oid;
1033                 struct object *o;
1034
1035                 /*
1036                  * If that object is complete (i.e. it is an ancestor of a
1037                  * local ref), we tell them we have it but do not have to
1038                  * tell them about its ancestors, which they already know
1039                  * about.
1040                  *
1041                  * We use lookup_object here because we are only
1042                  * interested in the case we *know* the object is
1043                  * reachable and we have already scanned it.
1044                  *
1045                  * Do this only if args->no_dependents is false (if it is true,
1046                  * we cannot trust the object flags).
1047                  */
1048                 if (!no_dependents &&
1049                     ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
1050                     (o->flags & COMPLETE)) {
1051                         continue;
1052                 }
1053
1054                 if (!use_ref_in_want || wants->exact_oid)
1055                         packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1056                 else
1057                         packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1058         }
1059 }
1060
1061 static void add_common(struct strbuf *req_buf, struct oidset *common)
1062 {
1063         struct oidset_iter iter;
1064         const struct object_id *oid;
1065         oidset_iter_init(common, &iter);
1066
1067         while ((oid = oidset_iter_next(&iter))) {
1068                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1069         }
1070 }
1071
1072 static int add_haves(struct fetch_negotiator *negotiator,
1073                      struct strbuf *req_buf,
1074                      int *haves_to_send, int *in_vain)
1075 {
1076         int ret = 0;
1077         int haves_added = 0;
1078         const struct object_id *oid;
1079
1080         while ((oid = negotiator->next(negotiator))) {
1081                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1082                 if (++haves_added >= *haves_to_send)
1083                         break;
1084         }
1085
1086         *in_vain += haves_added;
1087         if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1088                 /* Send Done */
1089                 packet_buf_write(req_buf, "done\n");
1090                 ret = 1;
1091         }
1092
1093         /* Increase haves to send on next round */
1094         *haves_to_send = next_flush(1, *haves_to_send);
1095
1096         return ret;
1097 }
1098
1099 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1100                               const struct fetch_pack_args *args,
1101                               const struct ref *wants, struct oidset *common,
1102                               int *haves_to_send, int *in_vain,
1103                               int sideband_all)
1104 {
1105         int ret = 0;
1106         struct strbuf req_buf = STRBUF_INIT;
1107
1108         if (server_supports_v2("fetch", 1))
1109                 packet_buf_write(&req_buf, "command=fetch");
1110         if (server_supports_v2("agent", 0))
1111                 packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1112         if (args->server_options && args->server_options->nr &&
1113             server_supports_v2("server-option", 1)) {
1114                 int i;
1115                 for (i = 0; i < args->server_options->nr; i++)
1116                         packet_write_fmt(fd_out, "server-option=%s",
1117                                          args->server_options->items[i].string);
1118         }
1119
1120         packet_buf_delim(&req_buf);
1121         if (args->use_thin_pack)
1122                 packet_buf_write(&req_buf, "thin-pack");
1123         if (args->no_progress)
1124                 packet_buf_write(&req_buf, "no-progress");
1125         if (args->include_tag)
1126                 packet_buf_write(&req_buf, "include-tag");
1127         if (prefer_ofs_delta)
1128                 packet_buf_write(&req_buf, "ofs-delta");
1129         if (sideband_all)
1130                 packet_buf_write(&req_buf, "sideband-all");
1131
1132         /* Add shallow-info and deepen request */
1133         if (server_supports_feature("fetch", "shallow", 0))
1134                 add_shallow_requests(&req_buf, args);
1135         else if (is_repository_shallow(the_repository) || args->deepen)
1136                 die(_("Server does not support shallow requests"));
1137
1138         /* Add filter */
1139         if (server_supports_feature("fetch", "filter", 0) &&
1140             args->filter_options.choice) {
1141                 struct strbuf expanded_filter_spec = STRBUF_INIT;
1142                 print_verbose(args, _("Server supports filter"));
1143                 expand_list_objects_filter_spec(&args->filter_options,
1144                                                 &expanded_filter_spec);
1145                 packet_buf_write(&req_buf, "filter %s",
1146                                  expanded_filter_spec.buf);
1147                 strbuf_release(&expanded_filter_spec);
1148         } else if (args->filter_options.choice) {
1149                 warning("filtering not recognized by server, ignoring");
1150         }
1151
1152         /* add wants */
1153         add_wants(args->no_dependents, wants, &req_buf);
1154
1155         if (args->no_dependents) {
1156                 packet_buf_write(&req_buf, "done");
1157                 ret = 1;
1158         } else {
1159                 /* Add all of the common commits we've found in previous rounds */
1160                 add_common(&req_buf, common);
1161
1162                 /* Add initial haves */
1163                 ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1164         }
1165
1166         /* Send request */
1167         packet_buf_flush(&req_buf);
1168         if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
1169                 die_errno(_("unable to write request to remote"));
1170
1171         strbuf_release(&req_buf);
1172         return ret;
1173 }
1174
1175 /*
1176  * Processes a section header in a server's response and checks if it matches
1177  * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1178  * not consumed); if 0, the line will be consumed and the function will die if
1179  * the section header doesn't match what was expected.
1180  */
1181 static int process_section_header(struct packet_reader *reader,
1182                                   const char *section, int peek)
1183 {
1184         int ret;
1185
1186         if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1187                 die(_("error reading section header '%s'"), section);
1188
1189         ret = !strcmp(reader->line, section);
1190
1191         if (!peek) {
1192                 if (!ret)
1193                         die(_("expected '%s', received '%s'"),
1194                             section, reader->line);
1195                 packet_reader_read(reader);
1196         }
1197
1198         return ret;
1199 }
1200
1201 static int process_acks(struct fetch_negotiator *negotiator,
1202                         struct packet_reader *reader,
1203                         struct oidset *common)
1204 {
1205         /* received */
1206         int received_ready = 0;
1207         int received_ack = 0;
1208
1209         process_section_header(reader, "acknowledgments", 0);
1210         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1211                 const char *arg;
1212
1213                 if (!strcmp(reader->line, "NAK"))
1214                         continue;
1215
1216                 if (skip_prefix(reader->line, "ACK ", &arg)) {
1217                         struct object_id oid;
1218                         if (!get_oid_hex(arg, &oid)) {
1219                                 struct commit *commit;
1220                                 oidset_insert(common, &oid);
1221                                 commit = lookup_commit(the_repository, &oid);
1222                                 negotiator->ack(negotiator, commit);
1223                         }
1224                         continue;
1225                 }
1226
1227                 if (!strcmp(reader->line, "ready")) {
1228                         received_ready = 1;
1229                         continue;
1230                 }
1231
1232                 die(_("unexpected acknowledgment line: '%s'"), reader->line);
1233         }
1234
1235         if (reader->status != PACKET_READ_FLUSH &&
1236             reader->status != PACKET_READ_DELIM)
1237                 die(_("error processing acks: %d"), reader->status);
1238
1239         /*
1240          * If an "acknowledgments" section is sent, a packfile is sent if and
1241          * only if "ready" was sent in this section. The other sections
1242          * ("shallow-info" and "wanted-refs") are sent only if a packfile is
1243          * sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
1244          * otherwise.
1245          */
1246         if (received_ready && reader->status != PACKET_READ_DELIM)
1247                 die(_("expected packfile to be sent after 'ready'"));
1248         if (!received_ready && reader->status != PACKET_READ_FLUSH)
1249                 die(_("expected no other sections to be sent after no 'ready'"));
1250
1251         /* return 0 if no common, 1 if there are common, or 2 if ready */
1252         return received_ready ? 2 : (received_ack ? 1 : 0);
1253 }
1254
1255 static void receive_shallow_info(struct fetch_pack_args *args,
1256                                  struct packet_reader *reader)
1257 {
1258         int line_received = 0;
1259
1260         process_section_header(reader, "shallow-info", 0);
1261         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1262                 const char *arg;
1263                 struct object_id oid;
1264
1265                 if (skip_prefix(reader->line, "shallow ", &arg)) {
1266                         if (get_oid_hex(arg, &oid))
1267                                 die(_("invalid shallow line: %s"), reader->line);
1268                         register_shallow(the_repository, &oid);
1269                         line_received = 1;
1270                         continue;
1271                 }
1272                 if (skip_prefix(reader->line, "unshallow ", &arg)) {
1273                         if (get_oid_hex(arg, &oid))
1274                                 die(_("invalid unshallow line: %s"), reader->line);
1275                         if (!lookup_object(the_repository, oid.hash))
1276                                 die(_("object not found: %s"), reader->line);
1277                         /* make sure that it is parsed as shallow */
1278                         if (!parse_object(the_repository, &oid))
1279                                 die(_("error in object: %s"), reader->line);
1280                         if (unregister_shallow(&oid))
1281                                 die(_("no shallow found: %s"), reader->line);
1282                         line_received = 1;
1283                         continue;
1284                 }
1285                 die(_("expected shallow/unshallow, got %s"), reader->line);
1286         }
1287
1288         if (reader->status != PACKET_READ_FLUSH &&
1289             reader->status != PACKET_READ_DELIM)
1290                 die(_("error processing shallow info: %d"), reader->status);
1291
1292         if (line_received) {
1293                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1294                                         NULL);
1295                 args->deepen = 1;
1296         } else {
1297                 alternate_shallow_file = NULL;
1298         }
1299 }
1300
1301 static void receive_wanted_refs(struct packet_reader *reader,
1302                                 struct ref **sought, int nr_sought)
1303 {
1304         process_section_header(reader, "wanted-refs", 0);
1305         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1306                 struct object_id oid;
1307                 const char *end;
1308                 int i;
1309
1310                 if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1311                         die(_("expected wanted-ref, got '%s'"), reader->line);
1312
1313                 for (i = 0; i < nr_sought; i++) {
1314                         if (!strcmp(end, sought[i]->name)) {
1315                                 oidcpy(&sought[i]->old_oid, &oid);
1316                                 break;
1317                         }
1318                 }
1319
1320                 if (i == nr_sought)
1321                         die(_("unexpected wanted-ref: '%s'"), reader->line);
1322         }
1323
1324         if (reader->status != PACKET_READ_DELIM)
1325                 die(_("error processing wanted refs: %d"), reader->status);
1326 }
1327
1328 enum fetch_state {
1329         FETCH_CHECK_LOCAL = 0,
1330         FETCH_SEND_REQUEST,
1331         FETCH_PROCESS_ACKS,
1332         FETCH_GET_PACK,
1333         FETCH_DONE,
1334 };
1335
1336 static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1337                                     int fd[2],
1338                                     const struct ref *orig_ref,
1339                                     struct ref **sought, int nr_sought,
1340                                     char **pack_lockfile)
1341 {
1342         struct ref *ref = copy_ref_list(orig_ref);
1343         enum fetch_state state = FETCH_CHECK_LOCAL;
1344         struct oidset common = OIDSET_INIT;
1345         struct packet_reader reader;
1346         int in_vain = 0;
1347         int haves_to_send = INITIAL_FLUSH;
1348         struct fetch_negotiator negotiator;
1349         fetch_negotiator_init(&negotiator, negotiation_algorithm);
1350         packet_reader_init(&reader, fd[0], NULL, 0,
1351                            PACKET_READ_CHOMP_NEWLINE |
1352                            PACKET_READ_DIE_ON_ERR_PACKET);
1353         if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
1354             server_supports_feature("fetch", "sideband-all", 0)) {
1355                 reader.use_sideband = 1;
1356                 reader.me = "fetch-pack";
1357         }
1358
1359         while (state != FETCH_DONE) {
1360                 switch (state) {
1361                 case FETCH_CHECK_LOCAL:
1362                         sort_ref_list(&ref, ref_compare_name);
1363                         QSORT(sought, nr_sought, cmp_ref_by_name);
1364
1365                         /* v2 supports these by default */
1366                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1367                         use_sideband = 2;
1368                         if (args->depth > 0 || args->deepen_since || args->deepen_not)
1369                                 args->deepen = 1;
1370
1371                         /* Filter 'ref' by 'sought' and those that aren't local */
1372                         if (!args->no_dependents) {
1373                                 mark_complete_and_common_ref(&negotiator, args, &ref);
1374                                 filter_refs(args, &ref, sought, nr_sought);
1375                                 if (everything_local(args, &ref))
1376                                         state = FETCH_DONE;
1377                                 else
1378                                         state = FETCH_SEND_REQUEST;
1379
1380                                 mark_tips(&negotiator, args->negotiation_tips);
1381                                 for_each_cached_alternate(&negotiator,
1382                                                           insert_one_alternate_object);
1383                         } else {
1384                                 filter_refs(args, &ref, sought, nr_sought);
1385                                 state = FETCH_SEND_REQUEST;
1386                         }
1387                         break;
1388                 case FETCH_SEND_REQUEST:
1389                         if (send_fetch_request(&negotiator, fd[1], args, ref,
1390                                                &common,
1391                                                &haves_to_send, &in_vain,
1392                                                reader.use_sideband))
1393                                 state = FETCH_GET_PACK;
1394                         else
1395                                 state = FETCH_PROCESS_ACKS;
1396                         break;
1397                 case FETCH_PROCESS_ACKS:
1398                         /* Process ACKs/NAKs */
1399                         switch (process_acks(&negotiator, &reader, &common)) {
1400                         case 2:
1401                                 state = FETCH_GET_PACK;
1402                                 break;
1403                         case 1:
1404                                 in_vain = 0;
1405                                 /* fallthrough */
1406                         default:
1407                                 state = FETCH_SEND_REQUEST;
1408                                 break;
1409                         }
1410                         break;
1411                 case FETCH_GET_PACK:
1412                         /* Check for shallow-info section */
1413                         if (process_section_header(&reader, "shallow-info", 1))
1414                                 receive_shallow_info(args, &reader);
1415
1416                         if (process_section_header(&reader, "wanted-refs", 1))
1417                                 receive_wanted_refs(&reader, sought, nr_sought);
1418
1419                         /* get the pack */
1420                         process_section_header(&reader, "packfile", 0);
1421                         if (get_pack(args, fd, pack_lockfile))
1422                                 die(_("git fetch-pack: fetch failed."));
1423
1424                         state = FETCH_DONE;
1425                         break;
1426                 case FETCH_DONE:
1427                         continue;
1428                 }
1429         }
1430
1431         negotiator.release(&negotiator);
1432         oidset_clear(&common);
1433         return ref;
1434 }
1435
1436 static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1437 {
1438         if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1439                 const char *path;
1440
1441                 if (git_config_pathname(&path, var, value))
1442                         return 1;
1443                 strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1444                         fsck_msg_types.len ? ',' : '=', path);
1445                 free((char *)path);
1446                 return 0;
1447         }
1448
1449         if (skip_prefix(var, "fetch.fsck.", &var)) {
1450                 if (is_valid_msg_type(var, value))
1451                         strbuf_addf(&fsck_msg_types, "%c%s=%s",
1452                                 fsck_msg_types.len ? ',' : '=', var, value);
1453                 else
1454                         warning("Skipping unknown msg id '%s'", var);
1455                 return 0;
1456         }
1457
1458         return git_default_config(var, value, cb);
1459 }
1460
1461 static void fetch_pack_config(void)
1462 {
1463         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1464         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1465         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1466         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1467         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1468         git_config_get_string("fetch.negotiationalgorithm",
1469                               &negotiation_algorithm);
1470
1471         git_config(fetch_pack_config_cb, NULL);
1472 }
1473
1474 static void fetch_pack_setup(void)
1475 {
1476         static int did_setup;
1477         if (did_setup)
1478                 return;
1479         fetch_pack_config();
1480         if (0 <= transfer_unpack_limit)
1481                 unpack_limit = transfer_unpack_limit;
1482         else if (0 <= fetch_unpack_limit)
1483                 unpack_limit = fetch_unpack_limit;
1484         did_setup = 1;
1485 }
1486
1487 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1488 {
1489         struct string_list names = STRING_LIST_INIT_NODUP;
1490         int src, dst;
1491
1492         for (src = dst = 0; src < nr; src++) {
1493                 struct string_list_item *item;
1494                 item = string_list_insert(&names, ref[src]->name);
1495                 if (item->util)
1496                         continue; /* already have it */
1497                 item->util = ref[src];
1498                 if (src != dst)
1499                         ref[dst] = ref[src];
1500                 dst++;
1501         }
1502         for (src = dst; src < nr; src++)
1503                 ref[src] = NULL;
1504         string_list_clear(&names, 0);
1505         return dst;
1506 }
1507
1508 static void update_shallow(struct fetch_pack_args *args,
1509                            struct ref **sought, int nr_sought,
1510                            struct shallow_info *si)
1511 {
1512         struct oid_array ref = OID_ARRAY_INIT;
1513         int *status;
1514         int i;
1515
1516         if (args->deepen && alternate_shallow_file) {
1517                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1518                         unlink_or_warn(git_path_shallow(the_repository));
1519                         rollback_lock_file(&shallow_lock);
1520                 } else
1521                         commit_lock_file(&shallow_lock);
1522                 alternate_shallow_file = NULL;
1523                 return;
1524         }
1525
1526         if (!si->shallow || !si->shallow->nr)
1527                 return;
1528
1529         if (args->cloning) {
1530                 /*
1531                  * remote is shallow, but this is a clone, there are
1532                  * no objects in repo to worry about. Accept any
1533                  * shallow points that exist in the pack (iow in repo
1534                  * after get_pack() and reprepare_packed_git())
1535                  */
1536                 struct oid_array extra = OID_ARRAY_INIT;
1537                 struct object_id *oid = si->shallow->oid;
1538                 for (i = 0; i < si->shallow->nr; i++)
1539                         if (has_object_file(&oid[i]))
1540                                 oid_array_append(&extra, &oid[i]);
1541                 if (extra.nr) {
1542                         setup_alternate_shallow(&shallow_lock,
1543                                                 &alternate_shallow_file,
1544                                                 &extra);
1545                         commit_lock_file(&shallow_lock);
1546                         alternate_shallow_file = NULL;
1547                 }
1548                 oid_array_clear(&extra);
1549                 return;
1550         }
1551
1552         if (!si->nr_ours && !si->nr_theirs)
1553                 return;
1554
1555         remove_nonexistent_theirs_shallow(si);
1556         if (!si->nr_ours && !si->nr_theirs)
1557                 return;
1558         for (i = 0; i < nr_sought; i++)
1559                 oid_array_append(&ref, &sought[i]->old_oid);
1560         si->ref = &ref;
1561
1562         if (args->update_shallow) {
1563                 /*
1564                  * remote is also shallow, .git/shallow may be updated
1565                  * so all refs can be accepted. Make sure we only add
1566                  * shallow roots that are actually reachable from new
1567                  * refs.
1568                  */
1569                 struct oid_array extra = OID_ARRAY_INIT;
1570                 struct object_id *oid = si->shallow->oid;
1571                 assign_shallow_commits_to_refs(si, NULL, NULL);
1572                 if (!si->nr_ours && !si->nr_theirs) {
1573                         oid_array_clear(&ref);
1574                         return;
1575                 }
1576                 for (i = 0; i < si->nr_ours; i++)
1577                         oid_array_append(&extra, &oid[si->ours[i]]);
1578                 for (i = 0; i < si->nr_theirs; i++)
1579                         oid_array_append(&extra, &oid[si->theirs[i]]);
1580                 setup_alternate_shallow(&shallow_lock,
1581                                         &alternate_shallow_file,
1582                                         &extra);
1583                 commit_lock_file(&shallow_lock);
1584                 oid_array_clear(&extra);
1585                 oid_array_clear(&ref);
1586                 alternate_shallow_file = NULL;
1587                 return;
1588         }
1589
1590         /*
1591          * remote is also shallow, check what ref is safe to update
1592          * without updating .git/shallow
1593          */
1594         status = xcalloc(nr_sought, sizeof(*status));
1595         assign_shallow_commits_to_refs(si, NULL, status);
1596         if (si->nr_ours || si->nr_theirs) {
1597                 for (i = 0; i < nr_sought; i++)
1598                         if (status[i])
1599                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1600         }
1601         free(status);
1602         oid_array_clear(&ref);
1603 }
1604
1605 static int iterate_ref_map(void *cb_data, struct object_id *oid)
1606 {
1607         struct ref **rm = cb_data;
1608         struct ref *ref = *rm;
1609
1610         if (!ref)
1611                 return -1; /* end of the list */
1612         *rm = ref->next;
1613         oidcpy(oid, &ref->old_oid);
1614         return 0;
1615 }
1616
1617 struct ref *fetch_pack(struct fetch_pack_args *args,
1618                        int fd[],
1619                        const struct ref *ref,
1620                        struct ref **sought, int nr_sought,
1621                        struct oid_array *shallow,
1622                        char **pack_lockfile,
1623                        enum protocol_version version)
1624 {
1625         struct ref *ref_cpy;
1626         struct shallow_info si;
1627
1628         fetch_pack_setup();
1629         if (nr_sought)
1630                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1631
1632         if (args->no_dependents && !args->filter_options.choice) {
1633                 /*
1634                  * The protocol does not support requesting that only the
1635                  * wanted objects be sent, so approximate this by setting a
1636                  * "blob:none" filter if no filter is already set. This works
1637                  * for all object types: note that wanted blobs will still be
1638                  * sent because they are directly specified as a "want".
1639                  *
1640                  * NEEDSWORK: Add an option in the protocol to request that
1641                  * only the wanted objects be sent, and implement it.
1642                  */
1643                 parse_list_objects_filter(&args->filter_options, "blob:none");
1644         }
1645
1646         if (version != protocol_v2 && !ref) {
1647                 packet_flush(fd[1]);
1648                 die(_("no matching remote head"));
1649         }
1650         prepare_shallow_info(&si, shallow);
1651         if (version == protocol_v2)
1652                 ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1653                                            pack_lockfile);
1654         else
1655                 ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1656                                         &si, pack_lockfile);
1657         reprepare_packed_git(the_repository);
1658
1659         if (!args->cloning && args->deepen) {
1660                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
1661                 struct ref *iterator = ref_cpy;
1662                 opt.shallow_file = alternate_shallow_file;
1663                 if (args->deepen)
1664                         opt.is_deepening_fetch = 1;
1665                 if (check_connected(iterate_ref_map, &iterator, &opt)) {
1666                         error(_("remote did not send all necessary objects"));
1667                         free_refs(ref_cpy);
1668                         ref_cpy = NULL;
1669                         rollback_lock_file(&shallow_lock);
1670                         goto cleanup;
1671                 }
1672                 args->connectivity_checked = 1;
1673         }
1674
1675         update_shallow(args, sought, nr_sought, &si);
1676 cleanup:
1677         clear_shallow_info(&si);
1678         return ref_cpy;
1679 }
1680
1681 int report_unmatched_refs(struct ref **sought, int nr_sought)
1682 {
1683         int i, ret = 0;
1684
1685         for (i = 0; i < nr_sought; i++) {
1686                 if (!sought[i])
1687                         continue;
1688                 switch (sought[i]->match_status) {
1689                 case REF_MATCHED:
1690                         continue;
1691                 case REF_NOT_MATCHED:
1692                         error(_("no such remote ref %s"), sought[i]->name);
1693                         break;
1694                 case REF_UNADVERTISED_NOT_ALLOWED:
1695                         error(_("Server does not allow request for unadvertised object %s"),
1696                               sought[i]->name);
1697                         break;
1698                 }
1699                 ret = 1;
1700         }
1701         return ret;
1702 }