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