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