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