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