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