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

   1 #include "cache.h"
   2 #include "repository.h"
   3 #include "config.h"
   4 #include "lockfile.h"
   5 #include "refs.h"
   6 #include "pkt-line.h"
   7 #include "commit.h"
   8 #include "tag.h"
   9 #include "exec-cmd.h"
  10 #include "pack.h"
  11 #include "sideband.h"
  12 #include "fetch-pack.h"
  13 #include "remote.h"
  14 #include "run-command.h"
  15 #include "connect.h"
  16 #include "transport.h"
  17 #include "version.h"
  18 #include "sha1-array.h"
  19 #include "oidset.h"
  20 #include "packfile.h"
  21 #include "object-store.h"
  22 #include "connected.h"
  23 #include "fetch-negotiator.h"
  24 #include "fsck.h"
  25
  26 static int transfer_unpack_limit = -1;
  27 static int fetch_unpack_limit = -1;
  28 static int unpack_limit = 100;
  29 static int prefer_ofs_delta = 1;
  30 static int no_done;
  31 static int deepen_since_ok;
  32 static int deepen_not_ok;
  33 static int fetch_fsck_objects = -1;
  34 static int transfer_fsck_objects = -1;
  35 static int agent_supported;
  36 static int server_supports_filtering;
  37 static struct lock_file shallow_lock;
  38 static const char *alternate_shallow_file;
  39 static char *negotiation_algorithm;
  40 static struct strbuf fsck_msg_types = STRBUF_INIT;
  41
  42 /* Remember to update object flag allocation in object.h */
  43 #define COMPLETE        (1U << 0)
  44 #define ALTERNATE       (1U << 1)
  45
  46 /*
  47  * After sending this many "have"s if we do not get any new ACK , we
  48  * give up traversing our history.
  49  */
  50 #define MAX_IN_VAIN 256
  51
  52 static int multi_ack, use_sideband;
  53 /* Allow specifying sha1 if it is a ref tip. */
  54 #define ALLOW_TIP_SHA1  01
  55 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  56 #define ALLOW_REACHABLE_SHA1    02
  57 static unsigned int allow_unadvertised_object_request;
  58
  59 __attribute__((format (printf, 2, 3)))
  60 static inline void print_verbose(const struct fetch_pack_args *args,
  61                                  const char *fmt, ...)
  62 {
  63         va_list params;
  64
  65         if (!args->verbose)
  66                 return;
  67
  68         va_start(params, fmt);
  69         vfprintf(stderr, fmt, params);
  70         va_end(params);
  71         fputc('\n', stderr);
  72 }
  73
  74 struct alternate_object_cache {
  75         struct object **items;
  76         size_t nr, alloc;
  77 };
  78
  79 static void cache_one_alternate(const struct object_id *oid,
  80                                 void *vcache)
  81 {
  82         struct alternate_object_cache *cache = vcache;
  83         struct object *obj = parse_object(the_repository, oid);
  84
  85         if (!obj || (obj->flags & ALTERNATE))
  86                 return;
  87
  88         obj->flags |= ALTERNATE;
  89         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  90         cache->items[cache->nr++] = obj;
  91 }
  92
  93 static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
  94                                       void (*cb)(struct fetch_negotiator *,
  95                                                  struct object *))
  96 {
  97         static int initialized;
  98         static struct alternate_object_cache cache;
  99         size_t i;
 100
 101         if (!initialized) {
 102                 for_each_alternate_ref(cache_one_alternate, &cache);
 103                 initialized = 1;
 104         }
 105
 106         for (i = 0; i < cache.nr; i++)
 107                 cb(negotiator, cache.items[i]);
 108 }
 109
 110 static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
 111                                const char *refname,
 112                                const struct object_id *oid)
 113 {
 114         struct object *o = deref_tag(the_repository,
 115                                      parse_object(the_repository, oid),
 116                                      refname, 0);
 117
 118         if (o && o->type == OBJ_COMMIT)
 119                 negotiator->add_tip(negotiator, (struct commit *)o);
 120
 121         return 0;
 122 }
 123
 124 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 125                                    int flag, void *cb_data)
 126 {
 127         return rev_list_insert_ref(cb_data, refname, oid);
 128 }
 129
 130 enum ack_type {
 131         NAK = 0,
 132         ACK,
 133         ACK_continue,
 134         ACK_common,
 135         ACK_ready
 136 };
 137
 138 static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 139 {
 140         if (args->stateless_rpc && args->deepen) {
 141                 /* If we sent a depth we will get back "duplicate"
 142                  * shallow and unshallow commands every time there
 143                  * is a block of have lines exchanged.
 144                  */
 145                 char *line;
 146                 while ((line = packet_read_line(fd, NULL))) {
 147                         if (starts_with(line, "shallow "))
 148                                 continue;
 149                         if (starts_with(line, "unshallow "))
 150                                 continue;
 151                         die(_("git fetch-pack: expected shallow list"));
 152                 }
 153         }
 154 }
 155
 156 static enum ack_type get_ack(int fd, struct object_id *result_oid)
 157 {
 158         int len;
 159         char *line = packet_read_line(fd, &len);
 160         const char *arg;
 161
 162         if (!line)
 163                 die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 164         if (!strcmp(line, "NAK"))
 165                 return NAK;
 166         if (skip_prefix(line, "ACK ", &arg)) {
 167                 if (!get_oid_hex(arg, result_oid)) {
 168                         arg += 40;
 169                         len -= arg - line;
 170                         if (len < 1)
 171                                 return ACK;
 172                         if (strstr(arg, "continue"))
 173                                 return ACK_continue;
 174                         if (strstr(arg, "common"))
 175                                 return ACK_common;
 176                         if (strstr(arg, "ready"))
 177                                 return ACK_ready;
 178                         return ACK;
 179                 }
 180         }
 181         if (skip_prefix(line, "ERR ", &arg))
 182                 die(_("remote error: %s"), arg);
 183         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 184 }
 185
 186 static void send_request(struct fetch_pack_args *args,
 187                          int fd, struct strbuf *buf)
 188 {
 189         if (args->stateless_rpc) {
 190                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 191                 packet_flush(fd);
 192         } else
 193                 write_or_die(fd, buf->buf, buf->len);
 194 }
 195
 196 static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 197                                         struct object *obj)
 198 {
 199         rev_list_insert_ref(negotiator, NULL, &obj->oid);
 200 }
 201
 202 #define INITIAL_FLUSH 16
 203 #define PIPESAFE_FLUSH 32
 204 #define LARGE_FLUSH 16384
 205
 206 static int next_flush(int stateless_rpc, int count)
 207 {
 208         if (stateless_rpc) {
 209                 if (count < LARGE_FLUSH)
 210                         count <<= 1;
 211                 else
 212                         count = count * 11 / 10;
 213         } else {
 214                 if (count < PIPESAFE_FLUSH)
 215                         count <<= 1;
 216                 else
 217                         count += PIPESAFE_FLUSH;
 218         }
 219         return count;
 220 }
 221
 222 static void mark_tips(struct fetch_negotiator *negotiator,
 223                       const struct oid_array *negotiation_tips)
 224 {
 225         int i;
 226
 227         if (!negotiation_tips) {
 228                 for_each_ref(rev_list_insert_ref_oid, negotiator);
 229                 return;
 230         }
 231
 232         for (i = 0; i < negotiation_tips->nr; i++)
 233                 rev_list_insert_ref(negotiator, NULL,
 234                                     &negotiation_tips->oid[i]);
 235         return;
 236 }
 237
 238 static int find_common(struct fetch_negotiator *negotiator,
 239                        struct fetch_pack_args *args,
 240                        int fd[2], struct object_id *result_oid,
 241                        struct ref *refs)
 242 {
 243         int fetching;
 244         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 245         const struct object_id *oid;
 246         unsigned in_vain = 0;
 247         int got_continue = 0;
 248         int got_ready = 0;
 249         struct strbuf req_buf = STRBUF_INIT;
 250         size_t state_len = 0;
 251
 252         if (args->stateless_rpc && multi_ack == 1)
 253                 die(_("--stateless-rpc requires multi_ack_detailed"));
 254
 255         if (!args->no_dependents) {
 256                 mark_tips(negotiator, args->negotiation_tips);
 257                 for_each_cached_alternate(negotiator, insert_one_alternate_object);
 258         }
 259
 260         fetching = 0;
 261         for ( ; refs ; refs = refs->next) {
 262                 struct object_id *remote = &refs->old_oid;
 263                 const char *remote_hex;
 264                 struct object *o;
 265
 266                 /*
 267                  * If that object is complete (i.e. it is an ancestor of a
 268                  * local ref), we tell them we have it but do not have to
 269                  * tell them about its ancestors, which they already know
 270                  * about.
 271                  *
 272                  * We use lookup_object here because we are only
 273                  * interested in the case we *know* the object is
 274                  * reachable and we have already scanned it.
 275                  *
 276                  * Do this only if args->no_dependents is false (if it is true,
 277                  * we cannot trust the object flags).
 278                  */
 279                 if (!args->no_dependents &&
 280                     ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
 281                                 (o->flags & COMPLETE)) {
 282                         continue;
 283                 }
 284
 285                 remote_hex = oid_to_hex(remote);
 286                 if (!fetching) {
 287                         struct strbuf c = STRBUF_INIT;
 288                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 289                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 290                         if (no_done)            strbuf_addstr(&c, " no-done");
 291                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 292                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 293                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 294                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 295                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 296                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 297                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 298                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 299                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 300                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 301                                                             git_user_agent_sanitized());
 302                         if (args->filter_options.choice)
 303                                 strbuf_addstr(&c, " filter");
 304                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 305                         strbuf_release(&c);
 306                 } else
 307                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 308                 fetching++;
 309         }
 310
 311         if (!fetching) {
 312                 strbuf_release(&req_buf);
 313                 packet_flush(fd[1]);
 314                 return 1;
 315         }
 316
 317         if (is_repository_shallow(the_repository))
 318                 write_shallow_commits(&req_buf, 1, NULL);
 319         if (args->depth > 0)
 320                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 321         if (args->deepen_since) {
 322                 timestamp_t max_age = approxidate(args->deepen_since);
 323                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 324         }
 325         if (args->deepen_not) {
 326                 int i;
 327                 for (i = 0; i < args->deepen_not->nr; i++) {
 328                         struct string_list_item *s = args->deepen_not->items + i;
 329                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 330                 }
 331         }
 332         if (server_supports_filtering && args->filter_options.choice) {
 333                 struct strbuf expanded_filter_spec = STRBUF_INIT;
 334                 expand_list_objects_filter_spec(&args->filter_options,
 335                                                 &expanded_filter_spec);
 336                 packet_buf_write(&req_buf, "filter %s",
 337                                  expanded_filter_spec.buf);
 338                 strbuf_release(&expanded_filter_spec);
 339         }
 340         packet_buf_flush(&req_buf);
 341         state_len = req_buf.len;
 342
 343         if (args->deepen) {
 344                 char *line;
 345                 const char *arg;
 346                 struct object_id oid;
 347
 348                 send_request(args, fd[1], &req_buf);
 349                 while ((line = packet_read_line(fd[0], NULL))) {
 350                         if (skip_prefix(line, "shallow ", &arg)) {
 351                                 if (get_oid_hex(arg, &oid))
 352                                         die(_("invalid shallow line: %s"), line);
 353                                 register_shallow(the_repository, &oid);
 354                                 continue;
 355                         }
 356                         if (skip_prefix(line, "unshallow ", &arg)) {
 357                                 if (get_oid_hex(arg, &oid))
 358                                         die(_("invalid unshallow line: %s"), line);
 359                                 if (!lookup_object(the_repository, oid.hash))
 360                                         die(_("object not found: %s"), line);
 361                                 /* make sure that it is parsed as shallow */
 362                                 if (!parse_object(the_repository, &oid))
 363                                         die(_("error in object: %s"), line);
 364                                 if (unregister_shallow(&oid))
 365                                         die(_("no shallow found: %s"), line);
 366                                 continue;
 367                         }
 368                         die(_("expected shallow/unshallow, got %s"), line);
 369                 }
 370         } else if (!args->stateless_rpc)
 371                 send_request(args, fd[1], &req_buf);
 372
 373         if (!args->stateless_rpc) {
 374                 /* If we aren't using the stateless-rpc interface
 375                  * we don't need to retain the headers.
 376                  */
 377                 strbuf_setlen(&req_buf, 0);
 378                 state_len = 0;
 379         }
 380
 381         flushes = 0;
 382         retval = -1;
 383         if (args->no_dependents)
 384                 goto done;
 385         while ((oid = negotiator->next(negotiator))) {
 386                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 387                 print_verbose(args, "have %s", oid_to_hex(oid));
 388                 in_vain++;
 389                 if (flush_at <= ++count) {
 390                         int ack;
 391
 392                         packet_buf_flush(&req_buf);
 393                         send_request(args, fd[1], &req_buf);
 394                         strbuf_setlen(&req_buf, state_len);
 395                         flushes++;
 396                         flush_at = next_flush(args->stateless_rpc, count);
 397
 398                         /*
 399                          * We keep one window "ahead" of the other side, and
 400                          * will wait for an ACK only on the next one
 401                          */
 402                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 403                                 continue;
 404
 405                         consume_shallow_list(args, fd[0]);
 406                         do {
 407                                 ack = get_ack(fd[0], result_oid);
 408                                 if (ack)
 409                                         print_verbose(args, _("got %s %d %s"), "ack",
 410                                                       ack, oid_to_hex(result_oid));
 411                                 switch (ack) {
 412                                 case ACK:
 413                                         flushes = 0;
 414                                         multi_ack = 0;
 415                                         retval = 0;
 416                                         goto done;
 417                                 case ACK_common:
 418                                 case ACK_ready:
 419                                 case ACK_continue: {
 420                                         struct commit *commit =
 421                                                 lookup_commit(the_repository,
 422                                                               result_oid);
 423                                         int was_common;
 424
 425                                         if (!commit)
 426                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
 427                                         was_common = negotiator->ack(negotiator, commit);
 428                                         if (args->stateless_rpc
 429                                          && ack == ACK_common
 430                                          && !was_common) {
 431                                                 /* We need to replay the have for this object
 432                                                  * on the next RPC request so the peer knows
 433                                                  * it is in common with us.
 434                                                  */
 435                                                 const char *hex = oid_to_hex(result_oid);
 436                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 437                                                 state_len = req_buf.len;
 438                                                 /*
 439                                                  * Reset in_vain because an ack
 440                                                  * for this commit has not been
 441                                                  * seen.
 442                                                  */
 443                                                 in_vain = 0;
 444                                         } else if (!args->stateless_rpc
 445                                                    || ack != ACK_common)
 446                                                 in_vain = 0;
 447                                         retval = 0;
 448                                         got_continue = 1;
 449                                         if (ack == ACK_ready)
 450                                                 got_ready = 1;
 451                                         break;
 452                                         }
 453                                 }
 454                         } while (ack);
 455                         flushes--;
 456                         if (got_continue && MAX_IN_VAIN < in_vain) {
 457                                 print_verbose(args, _("giving up"));
 458                                 break; /* give up */
 459                         }
 460                         if (got_ready)
 461                                 break;
 462                 }
 463         }
 464 done:
 465         if (!got_ready || !no_done) {
 466                 packet_buf_write(&req_buf, "done\n");
 467                 send_request(args, fd[1], &req_buf);
 468         }
 469         print_verbose(args, _("done"));
 470         if (retval != 0) {
 471                 multi_ack = 0;
 472                 flushes++;
 473         }
 474         strbuf_release(&req_buf);
 475
 476         if (!got_ready || !no_done)
 477                 consume_shallow_list(args, fd[0]);
 478         while (flushes || multi_ack) {
 479                 int ack = get_ack(fd[0], result_oid);
 480                 if (ack) {
 481                         print_verbose(args, _("got %s (%d) %s"), "ack",
 482                                       ack, oid_to_hex(result_oid));
 483                         if (ack == ACK)
 484                                 return 0;
 485                         multi_ack = 1;
 486                         continue;
 487                 }
 488                 flushes--;
 489         }
 490         /* it is no error to fetch into a completely empty repo */
 491         return count ? retval : 0;
 492 }
 493
 494 static struct commit_list *complete;
 495
 496 static int mark_complete(const struct object_id *oid)
 497 {
 498         struct object *o = parse_object(the_repository, oid);
 499
 500         while (o && o->type == OBJ_TAG) {
 501                 struct tag *t = (struct tag *) o;
 502                 if (!t->tagged)
 503                         break; /* broken repository */
 504                 o->flags |= COMPLETE;
 505                 o = parse_object(the_repository, &t->tagged->oid);
 506         }
 507         if (o && o->type == OBJ_COMMIT) {
 508                 struct commit *commit = (struct commit *)o;
 509                 if (!(commit->object.flags & COMPLETE)) {
 510                         commit->object.flags |= COMPLETE;
 511                         commit_list_insert(commit, &complete);
 512                 }
 513         }
 514         return 0;
 515 }
 516
 517 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 518                              int flag, void *cb_data)
 519 {
 520         return mark_complete(oid);
 521 }
 522
 523 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 524                                          timestamp_t cutoff)
 525 {
 526         while (complete && cutoff <= complete->item->date) {
 527                 print_verbose(args, _("Marking %s as complete"),
 528                               oid_to_hex(&complete->item->object.oid));
 529                 pop_most_recent_commit(&complete, COMPLETE);
 530         }
 531 }
 532
 533 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 534 {
 535         for (; refs; refs = refs->next)
 536                 oidset_insert(oids, &refs->old_oid);
 537 }
 538
 539 static int is_unmatched_ref(const struct ref *ref)
 540 {
 541         struct object_id oid;
 542         const char *p;
 543         return  ref->match_status == REF_NOT_MATCHED &&
 544                 !parse_oid_hex(ref->name, &oid, &p) &&
 545                 *p == '\0' &&
 546                 oideq(&oid, &ref->old_oid);
 547 }
 548
 549 static void filter_refs(struct fetch_pack_args *args,
 550                         struct ref **refs,
 551                         struct ref **sought, int nr_sought)
 552 {
 553         struct ref *newlist = NULL;
 554         struct ref **newtail = &newlist;
 555         struct ref *unmatched = NULL;
 556         struct ref *ref, *next;
 557         struct oidset tip_oids = OIDSET_INIT;
 558         int i;
 559         int strict = !(allow_unadvertised_object_request &
 560                        (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
 561
 562         i = 0;
 563         for (ref = *refs; ref; ref = next) {
 564                 int keep = 0;
 565                 next = ref->next;
 566
 567                 if (starts_with(ref->name, "refs/") &&
 568                     check_refname_format(ref->name, 0))
 569                         ; /* trash */
 570                 else {
 571                         while (i < nr_sought) {
 572                                 int cmp = strcmp(ref->name, sought[i]->name);
 573                                 if (cmp < 0)
 574                                         break; /* definitely do not have it */
 575                                 else if (cmp == 0) {
 576                                         keep = 1; /* definitely have it */
 577                                         sought[i]->match_status = REF_MATCHED;
 578                                 }
 579                                 i++;
 580                         }
 581
 582                         if (!keep && args->fetch_all &&
 583                             (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 584                                 keep = 1;
 585                 }
 586
 587                 if (keep) {
 588                         *newtail = ref;
 589                         ref->next = NULL;
 590                         newtail = &ref->next;
 591                 } else {
 592                         ref->next = unmatched;
 593                         unmatched = ref;
 594                 }
 595         }
 596
 597         if (strict) {
 598                 for (i = 0; i < nr_sought; i++) {
 599                         ref = sought[i];
 600                         if (!is_unmatched_ref(ref))
 601                                 continue;
 602
 603                         add_refs_to_oidset(&tip_oids, unmatched);
 604                         add_refs_to_oidset(&tip_oids, newlist);
 605                         break;
 606                 }
 607         }
 608
 609         /* Append unmatched requests to the list */
 610         for (i = 0; i < nr_sought; i++) {
 611                 ref = sought[i];
 612                 if (!is_unmatched_ref(ref))
 613                         continue;
 614
 615                 if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
 616                         ref->match_status = REF_MATCHED;
 617                         *newtail = copy_ref(ref);
 618                         newtail = &(*newtail)->next;
 619                 } else {
 620                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 621                 }
 622         }
 623
 624         oidset_clear(&tip_oids);
 625         for (ref = unmatched; ref; ref = next) {
 626                 next = ref->next;
 627                 free(ref);
 628         }
 629
 630         *refs = newlist;
 631 }
 632
 633 static void mark_alternate_complete(struct fetch_negotiator *unused,
 634                                     struct object *obj)
 635 {
 636         mark_complete(&obj->oid);
 637 }
 638
 639 struct loose_object_iter {
 640         struct oidset *loose_object_set;
 641         struct ref *refs;
 642 };
 643
 644 /*
 645  *  If the number of refs is not larger than the number of loose objects,
 646  *  this function stops inserting.
 647  */
 648 static int add_loose_objects_to_set(const struct object_id *oid,
 649                                     const char *path,
 650                                     void *data)
 651 {
 652         struct loose_object_iter *iter = data;
 653         oidset_insert(iter->loose_object_set, oid);
 654         if (iter->refs == NULL)
 655                 return 1;
 656
 657         iter->refs = iter->refs->next;
 658         return 0;
 659 }
 660
 661 /*
 662  * Mark recent commits available locally and reachable from a local ref as
 663  * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 664  * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 665  * thus do not need COMMON_REF marks).
 666  *
 667  * The cutoff time for recency is determined by this heuristic: it is the
 668  * earliest commit time of the objects in refs that are commits and that we know
 669  * the commit time of.
 670  */
 671 static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 672                                          struct fetch_pack_args *args,
 673                                          struct ref **refs)
 674 {
 675         struct ref *ref;
 676         int old_save_commit_buffer = save_commit_buffer;
 677         timestamp_t cutoff = 0;
 678         struct oidset loose_oid_set = OIDSET_INIT;
 679         int use_oidset = 0;
 680         struct loose_object_iter iter = {&loose_oid_set, *refs};
 681
 682         /* Enumerate all loose objects or know refs are not so many. */
 683         use_oidset = !for_each_loose_object(add_loose_objects_to_set,
 684                                             &iter, 0);
 685
 686         save_commit_buffer = 0;
 687
 688         for (ref = *refs; ref; ref = ref->next) {
 689                 struct object *o;
 690                 unsigned int flags = OBJECT_INFO_QUICK;
 691
 692                 if (use_oidset &&
 693                     !oidset_contains(&loose_oid_set, &ref->old_oid)) {
 694                         /*
 695                          * I know this does not exist in the loose form,
 696                          * so check if it exists in a non-loose form.
 697                          */
 698                         flags |= OBJECT_INFO_IGNORE_LOOSE;
 699                 }
 700
 701                 if (!has_object_file_with_flags(&ref->old_oid, flags))
 702                         continue;
 703                 o = parse_object(the_repository, &ref->old_oid);
 704                 if (!o)
 705                         continue;
 706
 707                 /* We already have it -- which may mean that we were
 708                  * in sync with the other side at some time after
 709                  * that (it is OK if we guess wrong here).
 710                  */
 711                 if (o->type == OBJ_COMMIT) {
 712                         struct commit *commit = (struct commit *)o;
 713                         if (!cutoff || cutoff < commit->date)
 714                                 cutoff = commit->date;
 715                 }
 716         }
 717
 718         oidset_clear(&loose_oid_set);
 719
 720         if (!args->deepen) {
 721                 for_each_ref(mark_complete_oid, NULL);
 722                 for_each_cached_alternate(NULL, mark_alternate_complete);
 723                 commit_list_sort_by_date(&complete);
 724                 if (cutoff)
 725                         mark_recent_complete_commits(args, cutoff);
 726         }
 727
 728         /*
 729          * Mark all complete remote refs as common refs.
 730          * Don't mark them common yet; the server has to be told so first.
 731          */
 732         for (ref = *refs; ref; ref = ref->next) {
 733                 struct object *o = deref_tag(the_repository,
 734                                              lookup_object(the_repository,
 735                                              ref->old_oid.hash),
 736                                              NULL, 0);
 737
 738                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 739                         continue;
 740
 741                 negotiator->known_common(negotiator,
 742                                          (struct commit *)o);
 743         }
 744
 745         save_commit_buffer = old_save_commit_buffer;
 746 }
 747
 748 /*
 749  * Returns 1 if every object pointed to by the given remote refs is available
 750  * locally and reachable from a local ref, and 0 otherwise.
 751  */
 752 static int everything_local(struct fetch_pack_args *args,
 753                             struct ref **refs)
 754 {
 755         struct ref *ref;
 756         int retval;
 757
 758         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 759                 const struct object_id *remote = &ref->old_oid;
 760                 struct object *o;
 761
 762                 o = lookup_object(the_repository, remote->hash);
 763                 if (!o || !(o->flags & COMPLETE)) {
 764                         retval = 0;
 765                         print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 766                                       ref->name);
 767                         continue;
 768                 }
 769                 print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 770                               ref->name);
 771         }
 772
 773         return retval;
 774 }
 775
 776 static int sideband_demux(int in, int out, void *data)
 777 {
 778         int *xd = data;
 779         int ret;
 780
 781         ret = recv_sideband("fetch-pack", xd[0], out);
 782         close(out);
 783         return ret;
 784 }
 785
 786 static int get_pack(struct fetch_pack_args *args,
 787                     int xd[2], char **pack_lockfile)
 788 {
 789         struct async demux;
 790         int do_keep = args->keep_pack;
 791         const char *cmd_name;
 792         struct pack_header header;
 793         int pass_header = 0;
 794         struct child_process cmd = CHILD_PROCESS_INIT;
 795         int ret;
 796
 797         memset(&demux, 0, sizeof(demux));
 798         if (use_sideband) {
 799                 /* xd[] is talking with upload-pack; subprocess reads from
 800                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 801                  * through demux->out.
 802                  */
 803                 demux.proc = sideband_demux;
 804                 demux.data = xd;
 805                 demux.out = -1;
 806                 demux.isolate_sigpipe = 1;
 807                 if (start_async(&demux))
 808                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 809         }
 810         else
 811                 demux.out = xd[0];
 812
 813         if (!args->keep_pack && unpack_limit) {
 814
 815                 if (read_pack_header(demux.out, &header))
 816                         die(_("protocol error: bad pack header"));
 817                 pass_header = 1;
 818                 if (ntohl(header.hdr_entries) < unpack_limit)
 819                         do_keep = 0;
 820                 else
 821                         do_keep = 1;
 822         }
 823
 824         if (alternate_shallow_file) {
 825                 argv_array_push(&cmd.args, "--shallow-file");
 826                 argv_array_push(&cmd.args, alternate_shallow_file);
 827         }
 828
 829         if (do_keep || args->from_promisor) {
 830                 if (pack_lockfile)
 831                         cmd.out = -1;
 832                 cmd_name = "index-pack";
 833                 argv_array_push(&cmd.args, cmd_name);
 834                 argv_array_push(&cmd.args, "--stdin");
 835                 if (!args->quiet && !args->no_progress)
 836                         argv_array_push(&cmd.args, "-v");
 837                 if (args->use_thin_pack)
 838                         argv_array_push(&cmd.args, "--fix-thin");
 839                 if (do_keep && (args->lock_pack || unpack_limit)) {
 840                         char hostname[HOST_NAME_MAX + 1];
 841                         if (xgethostname(hostname, sizeof(hostname)))
 842                                 xsnprintf(hostname, sizeof(hostname), "localhost");
 843                         argv_array_pushf(&cmd.args,
 844                                         "--keep=fetch-pack %"PRIuMAX " on %s",
 845                                         (uintmax_t)getpid(), hostname);
 846                 }
 847                 if (args->check_self_contained_and_connected)
 848                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 849                 if (args->from_promisor)
 850                         argv_array_push(&cmd.args, "--promisor");
 851         }
 852         else {
 853                 cmd_name = "unpack-objects";
 854                 argv_array_push(&cmd.args, cmd_name);
 855                 if (args->quiet || args->no_progress)
 856                         argv_array_push(&cmd.args, "-q");
 857                 args->check_self_contained_and_connected = 0;
 858         }
 859
 860         if (pass_header)
 861                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 862                                  ntohl(header.hdr_version),
 863                                  ntohl(header.hdr_entries));
 864         if (fetch_fsck_objects >= 0
 865             ? fetch_fsck_objects
 866             : transfer_fsck_objects >= 0
 867             ? transfer_fsck_objects
 868             : 0) {
 869                 if (args->from_promisor)
 870                         /*
 871                          * We cannot use --strict in index-pack because it
 872                          * checks both broken objects and links, but we only
 873                          * want to check for broken objects.
 874                          */
 875                         argv_array_push(&cmd.args, "--fsck-objects");
 876                 else
 877                         argv_array_pushf(&cmd.args, "--strict%s",
 878                                          fsck_msg_types.buf);
 879         }
 880
 881         cmd.in = demux.out;
 882         cmd.git_cmd = 1;
 883         if (start_command(&cmd))
 884                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
 885         if (do_keep && pack_lockfile) {
 886                 *pack_lockfile = index_pack_lockfile(cmd.out);
 887                 close(cmd.out);
 888         }
 889
 890         if (!use_sideband)
 891                 /* Closed by start_command() */
 892                 xd[0] = -1;
 893
 894         ret = finish_command(&cmd);
 895         if (!ret || (args->check_self_contained_and_connected && ret == 1))
 896                 args->self_contained_and_connected =
 897                         args->check_self_contained_and_connected &&
 898                         ret == 0;
 899         else
 900                 die(_("%s failed"), cmd_name);
 901         if (use_sideband && finish_async(&demux))
 902                 die(_("error in sideband demultiplexer"));
 903         return 0;
 904 }
 905
 906 static int cmp_ref_by_name(const void *a_, const void *b_)
 907 {
 908         const struct ref *a = *((const struct ref **)a_);
 909         const struct ref *b = *((const struct ref **)b_);
 910         return strcmp(a->name, b->name);
 911 }
 912
 913 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 914                                  int fd[2],
 915                                  const struct ref *orig_ref,
 916                                  struct ref **sought, int nr_sought,
 917                                  struct shallow_info *si,
 918                                  char **pack_lockfile)
 919 {
 920         struct ref *ref = copy_ref_list(orig_ref);
 921         struct object_id oid;
 922         const char *agent_feature;
 923         int agent_len;
 924         struct fetch_negotiator negotiator;
 925         fetch_negotiator_init(&negotiator, negotiation_algorithm);
 926
 927         sort_ref_list(&ref, ref_compare_name);
 928         QSORT(sought, nr_sought, cmp_ref_by_name);
 929
 930         if ((args->depth > 0 || is_repository_shallow(the_repository)) && !server_supports("shallow"))
 931                 die(_("Server does not support shallow clients"));
 932         if (args->depth > 0 || args->deepen_since || args->deepen_not)
 933                 args->deepen = 1;
 934         if (server_supports("multi_ack_detailed")) {
 935                 print_verbose(args, _("Server supports multi_ack_detailed"));
 936                 multi_ack = 2;
 937                 if (server_supports("no-done")) {
 938                         print_verbose(args, _("Server supports no-done"));
 939                         if (args->stateless_rpc)
 940                                 no_done = 1;
 941                 }
 942         }
 943         else if (server_supports("multi_ack")) {
 944                 print_verbose(args, _("Server supports multi_ack"));
 945                 multi_ack = 1;
 946         }
 947         if (server_supports("side-band-64k")) {
 948                 print_verbose(args, _("Server supports side-band-64k"));
 949                 use_sideband = 2;
 950         }
 951         else if (server_supports("side-band")) {
 952                 print_verbose(args, _("Server supports side-band"));
 953                 use_sideband = 1;
 954         }
 955         if (server_supports("allow-tip-sha1-in-want")) {
 956                 print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 957                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 958         }
 959         if (server_supports("allow-reachable-sha1-in-want")) {
 960                 print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 961                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 962         }
 963         if (!server_supports("thin-pack"))
 964                 args->use_thin_pack = 0;
 965         if (!server_supports("no-progress"))
 966                 args->no_progress = 0;
 967         if (!server_supports("include-tag"))
 968                 args->include_tag = 0;
 969         if (server_supports("ofs-delta"))
 970                 print_verbose(args, _("Server supports ofs-delta"));
 971         else
 972                 prefer_ofs_delta = 0;
 973
 974         if (server_supports("filter")) {
 975                 server_supports_filtering = 1;
 976                 print_verbose(args, _("Server supports filter"));
 977         } else if (args->filter_options.choice) {
 978                 warning("filtering not recognized by server, ignoring");
 979         }
 980
 981         if ((agent_feature = server_feature_value("agent", &agent_len))) {
 982                 agent_supported = 1;
 983                 if (agent_len)
 984                         print_verbose(args, _("Server version is %.*s"),
 985                                       agent_len, agent_feature);
 986         }
 987         if (server_supports("deepen-since"))
 988                 deepen_since_ok = 1;
 989         else if (args->deepen_since)
 990                 die(_("Server does not support --shallow-since"));
 991         if (server_supports("deepen-not"))
 992                 deepen_not_ok = 1;
 993         else if (args->deepen_not)
 994                 die(_("Server does not support --shallow-exclude"));
 995         if (!server_supports("deepen-relative") && args->deepen_relative)
 996                 die(_("Server does not support --deepen"));
 997
 998         if (!args->no_dependents) {
 999                 mark_complete_and_common_ref(&negotiator, args, &ref);
1000                 filter_refs(args, &ref, sought, nr_sought);
1001                 if (everything_local(args, &ref)) {
1002                         packet_flush(fd[1]);
1003                         goto all_done;
1004                 }
1005         } else {
1006                 filter_refs(args, &ref, sought, nr_sought);
1007         }
1008         if (find_common(&negotiator, args, fd, &oid, ref) < 0)
1009                 if (!args->keep_pack)
1010                         /* When cloning, it is not unusual to have
1011                          * no common commit.
1012                          */
1013                         warning(_("no common commits"));
1014
1015         if (args->stateless_rpc)
1016                 packet_flush(fd[1]);
1017         if (args->deepen)
1018                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1019                                         NULL);
1020         else if (si->nr_ours || si->nr_theirs)
1021                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
1022         else
1023                 alternate_shallow_file = NULL;
1024         if (get_pack(args, fd, pack_lockfile))
1025                 die(_("git fetch-pack: fetch failed."));
1026
1027  all_done:
1028         negotiator.release(&negotiator);
1029         return ref;
1030 }
1031
1032 static void add_shallow_requests(struct strbuf *req_buf,
1033                                  const struct fetch_pack_args *args)
1034 {
1035         if (is_repository_shallow(the_repository))
1036                 write_shallow_commits(req_buf, 1, NULL);
1037         if (args->depth > 0)
1038                 packet_buf_write(req_buf, "deepen %d", args->depth);
1039         if (args->deepen_since) {
1040                 timestamp_t max_age = approxidate(args->deepen_since);
1041                 packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1042         }
1043         if (args->deepen_not) {
1044                 int i;
1045                 for (i = 0; i < args->deepen_not->nr; i++) {
1046                         struct string_list_item *s = args->deepen_not->items + i;
1047                         packet_buf_write(req_buf, "deepen-not %s", s->string);
1048                 }
1049         }
1050 }
1051
1052 static void add_wants(int no_dependents, const struct ref *wants, struct strbuf *req_buf)
1053 {
1054         int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1055
1056         for ( ; wants ; wants = wants->next) {
1057                 const struct object_id *remote = &wants->old_oid;
1058                 struct object *o;
1059
1060                 /*
1061                  * If that object is complete (i.e. it is an ancestor of a
1062                  * local ref), we tell them we have it but do not have to
1063                  * tell them about its ancestors, which they already know
1064                  * about.
1065                  *
1066                  * We use lookup_object here because we are only
1067                  * interested in the case we *know* the object is
1068                  * reachable and we have already scanned it.
1069                  *
1070                  * Do this only if args->no_dependents is false (if it is true,
1071                  * we cannot trust the object flags).
1072                  */
1073                 if (!no_dependents &&
1074                     ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
1075                     (o->flags & COMPLETE)) {
1076                         continue;
1077                 }
1078
1079                 if (!use_ref_in_want || wants->exact_oid)
1080                         packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1081                 else
1082                         packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1083         }
1084 }
1085
1086 static void add_common(struct strbuf *req_buf, struct oidset *common)
1087 {
1088         struct oidset_iter iter;
1089         const struct object_id *oid;
1090         oidset_iter_init(common, &iter);
1091
1092         while ((oid = oidset_iter_next(&iter))) {
1093                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1094         }
1095 }
1096
1097 static int add_haves(struct fetch_negotiator *negotiator,
1098                      struct strbuf *req_buf,
1099                      int *haves_to_send, int *in_vain)
1100 {
1101         int ret = 0;
1102         int haves_added = 0;
1103         const struct object_id *oid;
1104
1105         while ((oid = negotiator->next(negotiator))) {
1106                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1107                 if (++haves_added >= *haves_to_send)
1108                         break;
1109         }
1110
1111         *in_vain += haves_added;
1112         if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1113                 /* Send Done */
1114                 packet_buf_write(req_buf, "done\n");
1115                 ret = 1;
1116         }
1117
1118         /* Increase haves to send on next round */
1119         *haves_to_send = next_flush(1, *haves_to_send);
1120
1121         return ret;
1122 }
1123
1124 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1125                               const struct fetch_pack_args *args,
1126                               const struct ref *wants, struct oidset *common,
1127                               int *haves_to_send, int *in_vain)
1128 {
1129         int ret = 0;
1130         struct strbuf req_buf = STRBUF_INIT;
1131
1132         if (server_supports_v2("fetch", 1))
1133                 packet_buf_write(&req_buf, "command=fetch");
1134         if (server_supports_v2("agent", 0))
1135                 packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1136         if (args->server_options && args->server_options->nr &&
1137             server_supports_v2("server-option", 1)) {
1138                 int i;
1139                 for (i = 0; i < args->server_options->nr; i++)
1140                         packet_write_fmt(fd_out, "server-option=%s",
1141                                          args->server_options->items[i].string);
1142         }
1143
1144         packet_buf_delim(&req_buf);
1145         if (args->use_thin_pack)
1146                 packet_buf_write(&req_buf, "thin-pack");
1147         if (args->no_progress)
1148                 packet_buf_write(&req_buf, "no-progress");
1149         if (args->include_tag)
1150                 packet_buf_write(&req_buf, "include-tag");
1151         if (prefer_ofs_delta)
1152                 packet_buf_write(&req_buf, "ofs-delta");
1153
1154         /* Add shallow-info and deepen request */
1155         if (server_supports_feature("fetch", "shallow", 0))
1156                 add_shallow_requests(&req_buf, args);
1157         else if (is_repository_shallow(the_repository) || args->deepen)
1158                 die(_("Server does not support shallow requests"));
1159
1160         /* Add filter */
1161         if (server_supports_feature("fetch", "filter", 0) &&
1162             args->filter_options.choice) {
1163                 struct strbuf expanded_filter_spec = STRBUF_INIT;
1164                 print_verbose(args, _("Server supports filter"));
1165                 expand_list_objects_filter_spec(&args->filter_options,
1166                                                 &expanded_filter_spec);
1167                 packet_buf_write(&req_buf, "filter %s",
1168                                  expanded_filter_spec.buf);
1169                 strbuf_release(&expanded_filter_spec);
1170         } else if (args->filter_options.choice) {
1171                 warning("filtering not recognized by server, ignoring");
1172         }
1173
1174         /* add wants */
1175         add_wants(args->no_dependents, wants, &req_buf);
1176
1177         if (args->no_dependents) {
1178                 packet_buf_write(&req_buf, "done");
1179                 ret = 1;
1180         } else {
1181                 /* Add all of the common commits we've found in previous rounds */
1182                 add_common(&req_buf, common);
1183
1184                 /* Add initial haves */
1185                 ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1186         }
1187
1188         /* Send request */
1189         packet_buf_flush(&req_buf);
1190         write_or_die(fd_out, req_buf.buf, req_buf.len);
1191
1192         strbuf_release(&req_buf);
1193         return ret;
1194 }
1195
1196 /*
1197  * Processes a section header in a server's response and checks if it matches
1198  * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1199  * not consumed); if 0, the line will be consumed and the function will die if
1200  * the section header doesn't match what was expected.
1201  */
1202 static int process_section_header(struct packet_reader *reader,
1203                                   const char *section, int peek)
1204 {
1205         int ret;
1206
1207         if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1208                 die(_("error reading section header '%s'"), section);
1209
1210         ret = !strcmp(reader->line, section);
1211
1212         if (!peek) {
1213                 if (!ret)
1214                         die(_("expected '%s', received '%s'"),
1215                             section, reader->line);
1216                 packet_reader_read(reader);
1217         }
1218
1219         return ret;
1220 }
1221
1222 static int process_acks(struct fetch_negotiator *negotiator,
1223                         struct packet_reader *reader,
1224                         struct oidset *common)
1225 {
1226         /* received */
1227         int received_ready = 0;
1228         int received_ack = 0;
1229
1230         process_section_header(reader, "acknowledgments", 0);
1231         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1232                 const char *arg;
1233
1234                 if (!strcmp(reader->line, "NAK"))
1235                         continue;
1236
1237                 if (skip_prefix(reader->line, "ACK ", &arg)) {
1238                         struct object_id oid;
1239                         if (!get_oid_hex(arg, &oid)) {
1240                                 struct commit *commit;
1241                                 oidset_insert(common, &oid);
1242                                 commit = lookup_commit(the_repository, &oid);
1243                                 negotiator->ack(negotiator, commit);
1244                         }
1245                         continue;
1246                 }
1247
1248                 if (!strcmp(reader->line, "ready")) {
1249                         received_ready = 1;
1250                         continue;
1251                 }
1252
1253                 die(_("unexpected acknowledgment line: '%s'"), reader->line);
1254         }
1255
1256         if (reader->status != PACKET_READ_FLUSH &&
1257             reader->status != PACKET_READ_DELIM)
1258                 die(_("error processing acks: %d"), reader->status);
1259
1260         /*
1261          * If an "acknowledgments" section is sent, a packfile is sent if and
1262          * only if "ready" was sent in this section. The other sections
1263          * ("shallow-info" and "wanted-refs") are sent only if a packfile is
1264          * sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
1265          * otherwise.
1266          */
1267         if (received_ready && reader->status != PACKET_READ_DELIM)
1268                 die(_("expected packfile to be sent after 'ready'"));
1269         if (!received_ready && reader->status != PACKET_READ_FLUSH)
1270                 die(_("expected no other sections to be sent after no 'ready'"));
1271
1272         /* return 0 if no common, 1 if there are common, or 2 if ready */
1273         return received_ready ? 2 : (received_ack ? 1 : 0);
1274 }
1275
1276 static void receive_shallow_info(struct fetch_pack_args *args,
1277                                  struct packet_reader *reader)
1278 {
1279         process_section_header(reader, "shallow-info", 0);
1280         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1281                 const char *arg;
1282                 struct object_id oid;
1283
1284                 if (skip_prefix(reader->line, "shallow ", &arg)) {
1285                         if (get_oid_hex(arg, &oid))
1286                                 die(_("invalid shallow line: %s"), reader->line);
1287                         register_shallow(the_repository, &oid);
1288                         continue;
1289                 }
1290                 if (skip_prefix(reader->line, "unshallow ", &arg)) {
1291                         if (get_oid_hex(arg, &oid))
1292                                 die(_("invalid unshallow line: %s"), reader->line);
1293                         if (!lookup_object(the_repository, oid.hash))
1294                                 die(_("object not found: %s"), reader->line);
1295                         /* make sure that it is parsed as shallow */
1296                         if (!parse_object(the_repository, &oid))
1297                                 die(_("error in object: %s"), reader->line);
1298                         if (unregister_shallow(&oid))
1299                                 die(_("no shallow found: %s"), reader->line);
1300                         continue;
1301                 }
1302                 die(_("expected shallow/unshallow, got %s"), reader->line);
1303         }
1304
1305         if (reader->status != PACKET_READ_FLUSH &&
1306             reader->status != PACKET_READ_DELIM)
1307                 die(_("error processing shallow info: %d"), reader->status);
1308
1309         setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, NULL);
1310         args->deepen = 1;
1311 }
1312
1313 static void receive_wanted_refs(struct packet_reader *reader,
1314                                 struct ref **sought, int nr_sought)
1315 {
1316         process_section_header(reader, "wanted-refs", 0);
1317         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1318                 struct object_id oid;
1319                 const char *end;
1320                 int i;
1321
1322                 if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1323                         die(_("expected wanted-ref, got '%s'"), reader->line);
1324
1325                 for (i = 0; i < nr_sought; i++) {
1326                         if (!strcmp(end, sought[i]->name)) {
1327                                 oidcpy(&sought[i]->old_oid, &oid);
1328                                 break;
1329                         }
1330                 }
1331
1332                 if (i == nr_sought)
1333                         die(_("unexpected wanted-ref: '%s'"), reader->line);
1334         }
1335
1336         if (reader->status != PACKET_READ_DELIM)
1337                 die(_("error processing wanted refs: %d"), reader->status);
1338 }
1339
1340 enum fetch_state {
1341         FETCH_CHECK_LOCAL = 0,
1342         FETCH_SEND_REQUEST,
1343         FETCH_PROCESS_ACKS,
1344         FETCH_GET_PACK,
1345         FETCH_DONE,
1346 };
1347
1348 static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1349                                     int fd[2],
1350                                     const struct ref *orig_ref,
1351                                     struct ref **sought, int nr_sought,
1352                                     char **pack_lockfile)
1353 {
1354         struct ref *ref = copy_ref_list(orig_ref);
1355         enum fetch_state state = FETCH_CHECK_LOCAL;
1356         struct oidset common = OIDSET_INIT;
1357         struct packet_reader reader;
1358         int in_vain = 0;
1359         int haves_to_send = INITIAL_FLUSH;
1360         struct fetch_negotiator negotiator;
1361         fetch_negotiator_init(&negotiator, negotiation_algorithm);
1362         packet_reader_init(&reader, fd[0], NULL, 0,
1363                            PACKET_READ_CHOMP_NEWLINE);
1364
1365         while (state != FETCH_DONE) {
1366                 switch (state) {
1367                 case FETCH_CHECK_LOCAL:
1368                         sort_ref_list(&ref, ref_compare_name);
1369                         QSORT(sought, nr_sought, cmp_ref_by_name);
1370
1371                         /* v2 supports these by default */
1372                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1373                         use_sideband = 2;
1374                         if (args->depth > 0 || args->deepen_since || args->deepen_not)
1375                                 args->deepen = 1;
1376
1377                         /* Filter 'ref' by 'sought' and those that aren't local */
1378                         if (!args->no_dependents) {
1379                                 mark_complete_and_common_ref(&negotiator, args, &ref);
1380                                 filter_refs(args, &ref, sought, nr_sought);
1381                                 if (everything_local(args, &ref))
1382                                         state = FETCH_DONE;
1383                                 else
1384                                         state = FETCH_SEND_REQUEST;
1385
1386                                 mark_tips(&negotiator, args->negotiation_tips);
1387                                 for_each_cached_alternate(&negotiator,
1388                                                           insert_one_alternate_object);
1389                         } else {
1390                                 filter_refs(args, &ref, sought, nr_sought);
1391                                 state = FETCH_SEND_REQUEST;
1392                         }
1393                         break;
1394                 case FETCH_SEND_REQUEST:
1395                         if (send_fetch_request(&negotiator, fd[1], args, ref,
1396                                                &common,
1397                                                &haves_to_send, &in_vain))
1398                                 state = FETCH_GET_PACK;
1399                         else
1400                                 state = FETCH_PROCESS_ACKS;
1401                         break;
1402                 case FETCH_PROCESS_ACKS:
1403                         /* Process ACKs/NAKs */
1404                         switch (process_acks(&negotiator, &reader, &common)) {
1405                         case 2:
1406                                 state = FETCH_GET_PACK;
1407                                 break;
1408                         case 1:
1409                                 in_vain = 0;
1410                                 /* fallthrough */
1411                         default:
1412                                 state = FETCH_SEND_REQUEST;
1413                                 break;
1414                         }
1415                         break;
1416                 case FETCH_GET_PACK:
1417                         /* Check for shallow-info section */
1418                         if (process_section_header(&reader, "shallow-info", 1))
1419                                 receive_shallow_info(args, &reader);
1420
1421                         if (process_section_header(&reader, "wanted-refs", 1))
1422                                 receive_wanted_refs(&reader, sought, nr_sought);
1423
1424                         /* get the pack */
1425                         process_section_header(&reader, "packfile", 0);
1426                         if (get_pack(args, fd, pack_lockfile))
1427                                 die(_("git fetch-pack: fetch failed."));
1428
1429                         state = FETCH_DONE;
1430                         break;
1431                 case FETCH_DONE:
1432                         continue;
1433                 }
1434         }
1435
1436         negotiator.release(&negotiator);
1437         oidset_clear(&common);
1438         return ref;
1439 }
1440
1441 static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1442 {
1443         if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1444                 const char *path;
1445
1446                 if (git_config_pathname(&path, var, value))
1447                         return 1;
1448                 strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1449                         fsck_msg_types.len ? ',' : '=', path);
1450                 free((char *)path);
1451                 return 0;
1452         }
1453
1454         if (skip_prefix(var, "fetch.fsck.", &var)) {
1455                 if (is_valid_msg_type(var, value))
1456                         strbuf_addf(&fsck_msg_types, "%c%s=%s",
1457                                 fsck_msg_types.len ? ',' : '=', var, value);
1458                 else
1459                         warning("Skipping unknown msg id '%s'", var);
1460                 return 0;
1461         }
1462
1463         return git_default_config(var, value, cb);
1464 }
1465
1466 static void fetch_pack_config(void)
1467 {
1468         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1469         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1470         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1471         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1472         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1473         git_config_get_string("fetch.negotiationalgorithm",
1474                               &negotiation_algorithm);
1475
1476         git_config(fetch_pack_config_cb, NULL);
1477 }
1478
1479 static void fetch_pack_setup(void)
1480 {
1481         static int did_setup;
1482         if (did_setup)
1483                 return;
1484         fetch_pack_config();
1485         if (0 <= transfer_unpack_limit)
1486                 unpack_limit = transfer_unpack_limit;
1487         else if (0 <= fetch_unpack_limit)
1488                 unpack_limit = fetch_unpack_limit;
1489         did_setup = 1;
1490 }
1491
1492 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1493 {
1494         struct string_list names = STRING_LIST_INIT_NODUP;
1495         int src, dst;
1496
1497         for (src = dst = 0; src < nr; src++) {
1498                 struct string_list_item *item;
1499                 item = string_list_insert(&names, ref[src]->name);
1500                 if (item->util)
1501                         continue; /* already have it */
1502                 item->util = ref[src];
1503                 if (src != dst)
1504                         ref[dst] = ref[src];
1505                 dst++;
1506         }
1507         for (src = dst; src < nr; src++)
1508                 ref[src] = NULL;
1509         string_list_clear(&names, 0);
1510         return dst;
1511 }
1512
1513 static void update_shallow(struct fetch_pack_args *args,
1514                            struct ref **sought, int nr_sought,
1515                            struct shallow_info *si)
1516 {
1517         struct oid_array ref = OID_ARRAY_INIT;
1518         int *status;
1519         int i;
1520
1521         if (args->deepen && alternate_shallow_file) {
1522                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1523                         unlink_or_warn(git_path_shallow(the_repository));
1524                         rollback_lock_file(&shallow_lock);
1525                 } else
1526                         commit_lock_file(&shallow_lock);
1527                 return;
1528         }
1529
1530         if (!si->shallow || !si->shallow->nr)
1531                 return;
1532
1533         if (args->cloning) {
1534                 /*
1535                  * remote is shallow, but this is a clone, there are
1536                  * no objects in repo to worry about. Accept any
1537                  * shallow points that exist in the pack (iow in repo
1538                  * after get_pack() and reprepare_packed_git())
1539                  */
1540                 struct oid_array extra = OID_ARRAY_INIT;
1541                 struct object_id *oid = si->shallow->oid;
1542                 for (i = 0; i < si->shallow->nr; i++)
1543                         if (has_object_file(&oid[i]))
1544                                 oid_array_append(&extra, &oid[i]);
1545                 if (extra.nr) {
1546                         setup_alternate_shallow(&shallow_lock,
1547                                                 &alternate_shallow_file,
1548                                                 &extra);
1549                         commit_lock_file(&shallow_lock);
1550                 }
1551                 oid_array_clear(&extra);
1552                 return;
1553         }
1554
1555         if (!si->nr_ours && !si->nr_theirs)
1556                 return;
1557
1558         remove_nonexistent_theirs_shallow(si);
1559         if (!si->nr_ours && !si->nr_theirs)
1560                 return;
1561         for (i = 0; i < nr_sought; i++)
1562                 oid_array_append(&ref, &sought[i]->old_oid);
1563         si->ref = &ref;
1564
1565         if (args->update_shallow) {
1566                 /*
1567                  * remote is also shallow, .git/shallow may be updated
1568                  * so all refs can be accepted. Make sure we only add
1569                  * shallow roots that are actually reachable from new
1570                  * refs.
1571                  */
1572                 struct oid_array extra = OID_ARRAY_INIT;
1573                 struct object_id *oid = si->shallow->oid;
1574                 assign_shallow_commits_to_refs(si, NULL, NULL);
1575                 if (!si->nr_ours && !si->nr_theirs) {
1576                         oid_array_clear(&ref);
1577                         return;
1578                 }
1579                 for (i = 0; i < si->nr_ours; i++)
1580                         oid_array_append(&extra, &oid[si->ours[i]]);
1581                 for (i = 0; i < si->nr_theirs; i++)
1582                         oid_array_append(&extra, &oid[si->theirs[i]]);
1583                 setup_alternate_shallow(&shallow_lock,
1584                                         &alternate_shallow_file,
1585                                         &extra);
1586                 commit_lock_file(&shallow_lock);
1587                 oid_array_clear(&extra);
1588                 oid_array_clear(&ref);
1589                 return;
1590         }
1591
1592         /*
1593          * remote is also shallow, check what ref is safe to update
1594          * without updating .git/shallow
1595          */
1596         status = xcalloc(nr_sought, sizeof(*status));
1597         assign_shallow_commits_to_refs(si, NULL, status);
1598         if (si->nr_ours || si->nr_theirs) {
1599                 for (i = 0; i < nr_sought; i++)
1600                         if (status[i])
1601                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1602         }
1603         free(status);
1604         oid_array_clear(&ref);
1605 }
1606
1607 static int iterate_ref_map(void *cb_data, struct object_id *oid)
1608 {
1609         struct ref **rm = cb_data;
1610         struct ref *ref = *rm;
1611
1612         if (!ref)
1613                 return -1; /* end of the list */
1614         *rm = ref->next;
1615         oidcpy(oid, &ref->old_oid);
1616         return 0;
1617 }
1618
1619 struct ref *fetch_pack(struct fetch_pack_args *args,
1620                        int fd[], struct child_process *conn,
1621                        const struct ref *ref,
1622                        const char *dest,
1623                        struct ref **sought, int nr_sought,
1624                        struct oid_array *shallow,
1625                        char **pack_lockfile,
1626                        enum protocol_version version)
1627 {
1628         struct ref *ref_cpy;
1629         struct shallow_info si;
1630
1631         fetch_pack_setup();
1632         if (nr_sought)
1633                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1634
1635         if (args->no_dependents && !args->filter_options.choice) {
1636                 /*
1637                  * The protocol does not support requesting that only the
1638                  * wanted objects be sent, so approximate this by setting a
1639                  * "blob:none" filter if no filter is already set. This works
1640                  * for all object types: note that wanted blobs will still be
1641                  * sent because they are directly specified as a "want".
1642                  *
1643                  * NEEDSWORK: Add an option in the protocol to request that
1644                  * only the wanted objects be sent, and implement it.
1645                  */
1646                 parse_list_objects_filter(&args->filter_options, "blob:none");
1647         }
1648
1649         if (version != protocol_v2 && !ref) {
1650                 packet_flush(fd[1]);
1651                 die(_("no matching remote head"));
1652         }
1653         prepare_shallow_info(&si, shallow);
1654         if (version == protocol_v2)
1655                 ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1656                                            pack_lockfile);
1657         else
1658                 ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1659                                         &si, pack_lockfile);
1660         reprepare_packed_git(the_repository);
1661
1662         if (!args->cloning && args->deepen) {
1663                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
1664                 struct ref *iterator = ref_cpy;
1665                 opt.shallow_file = alternate_shallow_file;
1666                 if (args->deepen)
1667                         opt.is_deepening_fetch = 1;
1668                 if (check_connected(iterate_ref_map, &iterator, &opt)) {
1669                         error(_("remote did not send all necessary objects"));
1670                         free_refs(ref_cpy);
1671                         ref_cpy = NULL;
1672                         rollback_lock_file(&shallow_lock);
1673                         goto cleanup;
1674                 }
1675                 args->connectivity_checked = 1;
1676         }
1677
1678         update_shallow(args, sought, nr_sought, &si);
1679 cleanup:
1680         clear_shallow_info(&si);
1681         return ref_cpy;
1682 }
1683
1684 int report_unmatched_refs(struct ref **sought, int nr_sought)
1685 {
1686         int i, ret = 0;
1687
1688         for (i = 0; i < nr_sought; i++) {
1689                 if (!sought[i])
1690                         continue;
1691                 switch (sought[i]->match_status) {
1692                 case REF_MATCHED:
1693                         continue;
1694                 case REF_NOT_MATCHED:
1695                         error(_("no such remote ref %s"), sought[i]->name);
1696                         break;
1697                 case REF_UNADVERTISED_NOT_ALLOWED:
1698                         error(_("Server does not allow request for unadvertised object %s"),
1699                               sought[i]->name);
1700                         break;
1701                 }
1702                 ret = 1;
1703         }
1704         return ret;
1705 }