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

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "lockfile.h"
   4 #include "refs.h"
   5 #include "pkt-line.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "exec_cmd.h"
   9 #include "pack.h"
  10 #include "sideband.h"
  11 #include "fetch-pack.h"
  12 #include "remote.h"
  13 #include "run-command.h"
  14 #include "connect.h"
  15 #include "transport.h"
  16 #include "version.h"
  17 #include "prio-queue.h"
  18 #include "sha1-array.h"
  19
  20 static int transfer_unpack_limit = -1;
  21 static int fetch_unpack_limit = -1;
  22 static int unpack_limit = 100;
  23 static int prefer_ofs_delta = 1;
  24 static int no_done;
  25 static int deepen_since_ok;
  26 static int deepen_not_ok;
  27 static int fetch_fsck_objects = -1;
  28 static int transfer_fsck_objects = -1;
  29 static int agent_supported;
  30 static struct lock_file shallow_lock;
  31 static const char *alternate_shallow_file;
  32
  33 /* Remember to update object flag allocation in object.h */
  34 #define COMPLETE        (1U << 0)
  35 #define COMMON          (1U << 1)
  36 #define COMMON_REF      (1U << 2)
  37 #define SEEN            (1U << 3)
  38 #define POPPED          (1U << 4)
  39 #define ALTERNATE       (1U << 5)
  40
  41 static int marked;
  42
  43 /*
  44  * After sending this many "have"s if we do not get any new ACK , we
  45  * give up traversing our history.
  46  */
  47 #define MAX_IN_VAIN 256
  48
  49 static struct prio_queue rev_list = { compare_commits_by_commit_date };
  50 static int non_common_revs, multi_ack, use_sideband;
  51 /* Allow specifying sha1 if it is a ref tip. */
  52 #define ALLOW_TIP_SHA1  01
  53 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  54 #define ALLOW_REACHABLE_SHA1    02
  55 static unsigned int allow_unadvertised_object_request;
  56
  57 __attribute__((format (printf, 2, 3)))
  58 static inline void print_verbose(const struct fetch_pack_args *args,
  59                                  const char *fmt, ...)
  60 {
  61         va_list params;
  62
  63         if (!args->verbose)
  64                 return;
  65
  66         va_start(params, fmt);
  67         vfprintf(stderr, fmt, params);
  68         va_end(params);
  69         fputc('\n', stderr);
  70 }
  71
  72 struct alternate_object_cache {
  73         struct object **items;
  74         size_t nr, alloc;
  75 };
  76
  77 static void cache_one_alternate(const char *refname,
  78                                 const struct object_id *oid,
  79                                 void *vcache)
  80 {
  81         struct alternate_object_cache *cache = vcache;
  82         struct object *obj = parse_object(oid->hash);
  83
  84         if (!obj || (obj->flags & ALTERNATE))
  85                 return;
  86
  87         obj->flags |= ALTERNATE;
  88         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  89         cache->items[cache->nr++] = obj;
  90 }
  91
  92 static void for_each_cached_alternate(void (*cb)(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(cache.items[i]);
 105 }
 106
 107 static void rev_list_push(struct commit *commit, int mark)
 108 {
 109         if (!(commit->object.flags & mark)) {
 110                 commit->object.flags |= mark;
 111
 112                 if (parse_commit(commit))
 113                         return;
 114
 115                 prio_queue_put(&rev_list, commit);
 116
 117                 if (!(commit->object.flags & COMMON))
 118                         non_common_revs++;
 119         }
 120 }
 121
 122 static int rev_list_insert_ref(const char *refname, const unsigned char *sha1)
 123 {
 124         struct object *o = deref_tag(parse_object(sha1), refname, 0);
 125
 126         if (o && o->type == OBJ_COMMIT)
 127                 rev_list_push((struct commit *)o, SEEN);
 128
 129         return 0;
 130 }
 131
 132 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 133                                    int flag, void *cb_data)
 134 {
 135         return rev_list_insert_ref(refname, oid->hash);
 136 }
 137
 138 static int clear_marks(const char *refname, const struct object_id *oid,
 139                        int flag, void *cb_data)
 140 {
 141         struct object *o = deref_tag(parse_object(oid->hash), refname, 0);
 142
 143         if (o && o->type == OBJ_COMMIT)
 144                 clear_commit_marks((struct commit *)o,
 145                                    COMMON | COMMON_REF | SEEN | POPPED);
 146         return 0;
 147 }
 148
 149 /*
 150    This function marks a rev and its ancestors as common.
 151    In some cases, it is desirable to mark only the ancestors (for example
 152    when only the server does not yet know that they are common).
 153 */
 154
 155 static void mark_common(struct commit *commit,
 156                 int ancestors_only, int dont_parse)
 157 {
 158         if (commit != NULL && !(commit->object.flags & COMMON)) {
 159                 struct object *o = (struct object *)commit;
 160
 161                 if (!ancestors_only)
 162                         o->flags |= COMMON;
 163
 164                 if (!(o->flags & SEEN))
 165                         rev_list_push(commit, SEEN);
 166                 else {
 167                         struct commit_list *parents;
 168
 169                         if (!ancestors_only && !(o->flags & POPPED))
 170                                 non_common_revs--;
 171                         if (!o->parsed && !dont_parse)
 172                                 if (parse_commit(commit))
 173                                         return;
 174
 175                         for (parents = commit->parents;
 176                                         parents;
 177                                         parents = parents->next)
 178                                 mark_common(parents->item, 0, dont_parse);
 179                 }
 180         }
 181 }
 182
 183 /*
 184   Get the next rev to send, ignoring the common.
 185 */
 186
 187 static const unsigned char *get_rev(void)
 188 {
 189         struct commit *commit = NULL;
 190
 191         while (commit == NULL) {
 192                 unsigned int mark;
 193                 struct commit_list *parents;
 194
 195                 if (rev_list.nr == 0 || non_common_revs == 0)
 196                         return NULL;
 197
 198                 commit = prio_queue_get(&rev_list);
 199                 parse_commit(commit);
 200                 parents = commit->parents;
 201
 202                 commit->object.flags |= POPPED;
 203                 if (!(commit->object.flags & COMMON))
 204                         non_common_revs--;
 205
 206                 if (commit->object.flags & COMMON) {
 207                         /* do not send "have", and ignore ancestors */
 208                         commit = NULL;
 209                         mark = COMMON | SEEN;
 210                 } else if (commit->object.flags & COMMON_REF)
 211                         /* send "have", and ignore ancestors */
 212                         mark = COMMON | SEEN;
 213                 else
 214                         /* send "have", also for its ancestors */
 215                         mark = SEEN;
 216
 217                 while (parents) {
 218                         if (!(parents->item->object.flags & SEEN))
 219                                 rev_list_push(parents->item, mark);
 220                         if (mark & COMMON)
 221                                 mark_common(parents->item, 1, 0);
 222                         parents = parents->next;
 223                 }
 224         }
 225
 226         return commit->object.oid.hash;
 227 }
 228
 229 enum ack_type {
 230         NAK = 0,
 231         ACK,
 232         ACK_continue,
 233         ACK_common,
 234         ACK_ready
 235 };
 236
 237 static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 238 {
 239         if (args->stateless_rpc && args->deepen) {
 240                 /* If we sent a depth we will get back "duplicate"
 241                  * shallow and unshallow commands every time there
 242                  * is a block of have lines exchanged.
 243                  */
 244                 char *line;
 245                 while ((line = packet_read_line(fd, NULL))) {
 246                         if (starts_with(line, "shallow "))
 247                                 continue;
 248                         if (starts_with(line, "unshallow "))
 249                                 continue;
 250                         die(_("git fetch-pack: expected shallow list"));
 251                 }
 252         }
 253 }
 254
 255 static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 256 {
 257         int len;
 258         char *line = packet_read_line(fd, &len);
 259         const char *arg;
 260
 261         if (!len)
 262                 die(_("git fetch-pack: expected ACK/NAK, got EOF"));
 263         if (!strcmp(line, "NAK"))
 264                 return NAK;
 265         if (skip_prefix(line, "ACK ", &arg)) {
 266                 if (!get_sha1_hex(arg, result_sha1)) {
 267                         arg += 40;
 268                         len -= arg - line;
 269                         if (len < 1)
 270                                 return ACK;
 271                         if (strstr(arg, "continue"))
 272                                 return ACK_continue;
 273                         if (strstr(arg, "common"))
 274                                 return ACK_common;
 275                         if (strstr(arg, "ready"))
 276                                 return ACK_ready;
 277                         return ACK;
 278                 }
 279         }
 280         if (skip_prefix(line, "ERR ", &arg))
 281                 die(_("remote error: %s"), arg);
 282         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 283 }
 284
 285 static void send_request(struct fetch_pack_args *args,
 286                          int fd, struct strbuf *buf)
 287 {
 288         if (args->stateless_rpc) {
 289                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 290                 packet_flush(fd);
 291         } else
 292                 write_or_die(fd, buf->buf, buf->len);
 293 }
 294
 295 static void insert_one_alternate_object(struct object *obj)
 296 {
 297         rev_list_insert_ref(NULL, obj->oid.hash);
 298 }
 299
 300 #define INITIAL_FLUSH 16
 301 #define PIPESAFE_FLUSH 32
 302 #define LARGE_FLUSH 16384
 303
 304 static int next_flush(struct fetch_pack_args *args, int count)
 305 {
 306         if (args->stateless_rpc) {
 307                 if (count < LARGE_FLUSH)
 308                         count <<= 1;
 309                 else
 310                         count = count * 11 / 10;
 311         } else {
 312                 if (count < PIPESAFE_FLUSH)
 313                         count <<= 1;
 314                 else
 315                         count += PIPESAFE_FLUSH;
 316         }
 317         return count;
 318 }
 319
 320 static int find_common(struct fetch_pack_args *args,
 321                        int fd[2], unsigned char *result_sha1,
 322                        struct ref *refs)
 323 {
 324         int fetching;
 325         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 326         const unsigned char *sha1;
 327         unsigned in_vain = 0;
 328         int got_continue = 0;
 329         int got_ready = 0;
 330         struct strbuf req_buf = STRBUF_INIT;
 331         size_t state_len = 0;
 332
 333         if (args->stateless_rpc && multi_ack == 1)
 334                 die(_("--stateless-rpc requires multi_ack_detailed"));
 335         if (marked)
 336                 for_each_ref(clear_marks, NULL);
 337         marked = 1;
 338
 339         for_each_ref(rev_list_insert_ref_oid, NULL);
 340         for_each_cached_alternate(insert_one_alternate_object);
 341
 342         fetching = 0;
 343         for ( ; refs ; refs = refs->next) {
 344                 unsigned char *remote = refs->old_oid.hash;
 345                 const char *remote_hex;
 346                 struct object *o;
 347
 348                 /*
 349                  * If that object is complete (i.e. it is an ancestor of a
 350                  * local ref), we tell them we have it but do not have to
 351                  * tell them about its ancestors, which they already know
 352                  * about.
 353                  *
 354                  * We use lookup_object here because we are only
 355                  * interested in the case we *know* the object is
 356                  * reachable and we have already scanned it.
 357                  */
 358                 if (((o = lookup_object(remote)) != NULL) &&
 359                                 (o->flags & COMPLETE)) {
 360                         continue;
 361                 }
 362
 363                 remote_hex = sha1_to_hex(remote);
 364                 if (!fetching) {
 365                         struct strbuf c = STRBUF_INIT;
 366                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 367                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 368                         if (no_done)            strbuf_addstr(&c, " no-done");
 369                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 370                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 371                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 372                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 373                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 374                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 375                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 376                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 377                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 378                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 379                                                             git_user_agent_sanitized());
 380                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 381                         strbuf_release(&c);
 382                 } else
 383                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 384                 fetching++;
 385         }
 386
 387         if (!fetching) {
 388                 strbuf_release(&req_buf);
 389                 packet_flush(fd[1]);
 390                 return 1;
 391         }
 392
 393         if (is_repository_shallow())
 394                 write_shallow_commits(&req_buf, 1, NULL);
 395         if (args->depth > 0)
 396                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 397         if (args->deepen_since) {
 398                 unsigned long max_age = approxidate(args->deepen_since);
 399                 packet_buf_write(&req_buf, "deepen-since %lu", max_age);
 400         }
 401         if (args->deepen_not) {
 402                 int i;
 403                 for (i = 0; i < args->deepen_not->nr; i++) {
 404                         struct string_list_item *s = args->deepen_not->items + i;
 405                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 406                 }
 407         }
 408         packet_buf_flush(&req_buf);
 409         state_len = req_buf.len;
 410
 411         if (args->deepen) {
 412                 char *line;
 413                 const char *arg;
 414                 unsigned char sha1[20];
 415
 416                 send_request(args, fd[1], &req_buf);
 417                 while ((line = packet_read_line(fd[0], NULL))) {
 418                         if (skip_prefix(line, "shallow ", &arg)) {
 419                                 if (get_sha1_hex(arg, sha1))
 420                                         die(_("invalid shallow line: %s"), line);
 421                                 register_shallow(sha1);
 422                                 continue;
 423                         }
 424                         if (skip_prefix(line, "unshallow ", &arg)) {
 425                                 if (get_sha1_hex(arg, sha1))
 426                                         die(_("invalid unshallow line: %s"), line);
 427                                 if (!lookup_object(sha1))
 428                                         die(_("object not found: %s"), line);
 429                                 /* make sure that it is parsed as shallow */
 430                                 if (!parse_object(sha1))
 431                                         die(_("error in object: %s"), line);
 432                                 if (unregister_shallow(sha1))
 433                                         die(_("no shallow found: %s"), line);
 434                                 continue;
 435                         }
 436                         die(_("expected shallow/unshallow, got %s"), line);
 437                 }
 438         } else if (!args->stateless_rpc)
 439                 send_request(args, fd[1], &req_buf);
 440
 441         if (!args->stateless_rpc) {
 442                 /* If we aren't using the stateless-rpc interface
 443                  * we don't need to retain the headers.
 444                  */
 445                 strbuf_setlen(&req_buf, 0);
 446                 state_len = 0;
 447         }
 448
 449         flushes = 0;
 450         retval = -1;
 451         while ((sha1 = get_rev())) {
 452                 packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
 453                 print_verbose(args, "have %s", sha1_to_hex(sha1));
 454                 in_vain++;
 455                 if (flush_at <= ++count) {
 456                         int ack;
 457
 458                         packet_buf_flush(&req_buf);
 459                         send_request(args, fd[1], &req_buf);
 460                         strbuf_setlen(&req_buf, state_len);
 461                         flushes++;
 462                         flush_at = next_flush(args, count);
 463
 464                         /*
 465                          * We keep one window "ahead" of the other side, and
 466                          * will wait for an ACK only on the next one
 467                          */
 468                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 469                                 continue;
 470
 471                         consume_shallow_list(args, fd[0]);
 472                         do {
 473                                 ack = get_ack(fd[0], result_sha1);
 474                                 if (ack)
 475                                         print_verbose(args, _("got %s %d %s"), "ack",
 476                                                       ack, sha1_to_hex(result_sha1));
 477                                 switch (ack) {
 478                                 case ACK:
 479                                         flushes = 0;
 480                                         multi_ack = 0;
 481                                         retval = 0;
 482                                         goto done;
 483                                 case ACK_common:
 484                                 case ACK_ready:
 485                                 case ACK_continue: {
 486                                         struct commit *commit =
 487                                                 lookup_commit(result_sha1);
 488                                         if (!commit)
 489                                                 die(_("invalid commit %s"), sha1_to_hex(result_sha1));
 490                                         if (args->stateless_rpc
 491                                          && ack == ACK_common
 492                                          && !(commit->object.flags & COMMON)) {
 493                                                 /* We need to replay the have for this object
 494                                                  * on the next RPC request so the peer knows
 495                                                  * it is in common with us.
 496                                                  */
 497                                                 const char *hex = sha1_to_hex(result_sha1);
 498                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 499                                                 state_len = req_buf.len;
 500                                                 /*
 501                                                  * Reset in_vain because an ack
 502                                                  * for this commit has not been
 503                                                  * seen.
 504                                                  */
 505                                                 in_vain = 0;
 506                                         } else if (!args->stateless_rpc
 507                                                    || ack != ACK_common)
 508                                                 in_vain = 0;
 509                                         mark_common(commit, 0, 1);
 510                                         retval = 0;
 511                                         got_continue = 1;
 512                                         if (ack == ACK_ready) {
 513                                                 clear_prio_queue(&rev_list);
 514                                                 got_ready = 1;
 515                                         }
 516                                         break;
 517                                         }
 518                                 }
 519                         } while (ack);
 520                         flushes--;
 521                         if (got_continue && MAX_IN_VAIN < in_vain) {
 522                                 print_verbose(args, _("giving up"));
 523                                 break; /* give up */
 524                         }
 525                 }
 526         }
 527 done:
 528         if (!got_ready || !no_done) {
 529                 packet_buf_write(&req_buf, "done\n");
 530                 send_request(args, fd[1], &req_buf);
 531         }
 532         print_verbose(args, _("done"));
 533         if (retval != 0) {
 534                 multi_ack = 0;
 535                 flushes++;
 536         }
 537         strbuf_release(&req_buf);
 538
 539         if (!got_ready || !no_done)
 540                 consume_shallow_list(args, fd[0]);
 541         while (flushes || multi_ack) {
 542                 int ack = get_ack(fd[0], result_sha1);
 543                 if (ack) {
 544                         print_verbose(args, _("got %s (%d) %s"), "ack",
 545                                       ack, sha1_to_hex(result_sha1));
 546                         if (ack == ACK)
 547                                 return 0;
 548                         multi_ack = 1;
 549                         continue;
 550                 }
 551                 flushes--;
 552         }
 553         /* it is no error to fetch into a completely empty repo */
 554         return count ? retval : 0;
 555 }
 556
 557 static struct commit_list *complete;
 558
 559 static int mark_complete(const unsigned char *sha1)
 560 {
 561         struct object *o = parse_object(sha1);
 562
 563         while (o && o->type == OBJ_TAG) {
 564                 struct tag *t = (struct tag *) o;
 565                 if (!t->tagged)
 566                         break; /* broken repository */
 567                 o->flags |= COMPLETE;
 568                 o = parse_object(t->tagged->oid.hash);
 569         }
 570         if (o && o->type == OBJ_COMMIT) {
 571                 struct commit *commit = (struct commit *)o;
 572                 if (!(commit->object.flags & COMPLETE)) {
 573                         commit->object.flags |= COMPLETE;
 574                         commit_list_insert(commit, &complete);
 575                 }
 576         }
 577         return 0;
 578 }
 579
 580 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 581                              int flag, void *cb_data)
 582 {
 583         return mark_complete(oid->hash);
 584 }
 585
 586 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 587                                          unsigned long cutoff)
 588 {
 589         while (complete && cutoff <= complete->item->date) {
 590                 print_verbose(args, _("Marking %s as complete"),
 591                               oid_to_hex(&complete->item->object.oid));
 592                 pop_most_recent_commit(&complete, COMPLETE);
 593         }
 594 }
 595
 596 static void filter_refs(struct fetch_pack_args *args,
 597                         struct ref **refs,
 598                         struct ref **sought, int nr_sought)
 599 {
 600         struct ref *newlist = NULL;
 601         struct ref **newtail = &newlist;
 602         struct ref *ref, *next;
 603         int i;
 604
 605         i = 0;
 606         for (ref = *refs; ref; ref = next) {
 607                 int keep = 0;
 608                 next = ref->next;
 609
 610                 if (starts_with(ref->name, "refs/") &&
 611                     check_refname_format(ref->name, 0))
 612                         ; /* trash */
 613                 else {
 614                         while (i < nr_sought) {
 615                                 int cmp = strcmp(ref->name, sought[i]->name);
 616                                 if (cmp < 0)
 617                                         break; /* definitely do not have it */
 618                                 else if (cmp == 0) {
 619                                         keep = 1; /* definitely have it */
 620                                         sought[i]->match_status = REF_MATCHED;
 621                                 }
 622                                 i++;
 623                         }
 624                 }
 625
 626                 if (!keep && args->fetch_all &&
 627                     (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 628                         keep = 1;
 629
 630                 if (keep) {
 631                         *newtail = ref;
 632                         ref->next = NULL;
 633                         newtail = &ref->next;
 634                 } else {
 635                         free(ref);
 636                 }
 637         }
 638
 639         /* Append unmatched requests to the list */
 640         for (i = 0; i < nr_sought; i++) {
 641                 unsigned char sha1[20];
 642
 643                 ref = sought[i];
 644                 if (ref->match_status != REF_NOT_MATCHED)
 645                         continue;
 646                 if (get_sha1_hex(ref->name, sha1) ||
 647                     ref->name[40] != '\0' ||
 648                     hashcmp(sha1, ref->old_oid.hash))
 649                         continue;
 650
 651                 if ((allow_unadvertised_object_request &
 652                     (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1))) {
 653                         ref->match_status = REF_MATCHED;
 654                         *newtail = copy_ref(ref);
 655                         newtail = &(*newtail)->next;
 656                 } else {
 657                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 658                 }
 659         }
 660         *refs = newlist;
 661 }
 662
 663 static void mark_alternate_complete(struct object *obj)
 664 {
 665         mark_complete(obj->oid.hash);
 666 }
 667
 668 static int everything_local(struct fetch_pack_args *args,
 669                             struct ref **refs,
 670                             struct ref **sought, int nr_sought)
 671 {
 672         struct ref *ref;
 673         int retval;
 674         unsigned long cutoff = 0;
 675
 676         save_commit_buffer = 0;
 677
 678         for (ref = *refs; ref; ref = ref->next) {
 679                 struct object *o;
 680
 681                 if (!has_object_file(&ref->old_oid))
 682                         continue;
 683
 684                 o = parse_object(ref->old_oid.hash);
 685                 if (!o)
 686                         continue;
 687
 688                 /* We already have it -- which may mean that we were
 689                  * in sync with the other side at some time after
 690                  * that (it is OK if we guess wrong here).
 691                  */
 692                 if (o->type == OBJ_COMMIT) {
 693                         struct commit *commit = (struct commit *)o;
 694                         if (!cutoff || cutoff < commit->date)
 695                                 cutoff = commit->date;
 696                 }
 697         }
 698
 699         if (!args->deepen) {
 700                 for_each_ref(mark_complete_oid, NULL);
 701                 for_each_cached_alternate(mark_alternate_complete);
 702                 commit_list_sort_by_date(&complete);
 703                 if (cutoff)
 704                         mark_recent_complete_commits(args, cutoff);
 705         }
 706
 707         /*
 708          * Mark all complete remote refs as common refs.
 709          * Don't mark them common yet; the server has to be told so first.
 710          */
 711         for (ref = *refs; ref; ref = ref->next) {
 712                 struct object *o = deref_tag(lookup_object(ref->old_oid.hash),
 713                                              NULL, 0);
 714
 715                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 716                         continue;
 717
 718                 if (!(o->flags & SEEN)) {
 719                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 720
 721                         mark_common((struct commit *)o, 1, 1);
 722                 }
 723         }
 724
 725         filter_refs(args, refs, sought, nr_sought);
 726
 727         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 728                 const unsigned char *remote = ref->old_oid.hash;
 729                 struct object *o;
 730
 731                 o = lookup_object(remote);
 732                 if (!o || !(o->flags & COMPLETE)) {
 733                         retval = 0;
 734                         print_verbose(args, "want %s (%s)", sha1_to_hex(remote),
 735                                       ref->name);
 736                         continue;
 737                 }
 738                 print_verbose(args, _("already have %s (%s)"), sha1_to_hex(remote),
 739                               ref->name);
 740         }
 741         return retval;
 742 }
 743
 744 static int sideband_demux(int in, int out, void *data)
 745 {
 746         int *xd = data;
 747         int ret;
 748
 749         ret = recv_sideband("fetch-pack", xd[0], out);
 750         close(out);
 751         return ret;
 752 }
 753
 754 static int get_pack(struct fetch_pack_args *args,
 755                     int xd[2], char **pack_lockfile)
 756 {
 757         struct async demux;
 758         int do_keep = args->keep_pack;
 759         const char *cmd_name;
 760         struct pack_header header;
 761         int pass_header = 0;
 762         struct child_process cmd = CHILD_PROCESS_INIT;
 763         int ret;
 764
 765         memset(&demux, 0, sizeof(demux));
 766         if (use_sideband) {
 767                 /* xd[] is talking with upload-pack; subprocess reads from
 768                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 769                  * through demux->out.
 770                  */
 771                 demux.proc = sideband_demux;
 772                 demux.data = xd;
 773                 demux.out = -1;
 774                 demux.isolate_sigpipe = 1;
 775                 if (start_async(&demux))
 776                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 777         }
 778         else
 779                 demux.out = xd[0];
 780
 781         if (!args->keep_pack && unpack_limit) {
 782
 783                 if (read_pack_header(demux.out, &header))
 784                         die(_("protocol error: bad pack header"));
 785                 pass_header = 1;
 786                 if (ntohl(header.hdr_entries) < unpack_limit)
 787                         do_keep = 0;
 788                 else
 789                         do_keep = 1;
 790         }
 791
 792         if (alternate_shallow_file) {
 793                 argv_array_push(&cmd.args, "--shallow-file");
 794                 argv_array_push(&cmd.args, alternate_shallow_file);
 795         }
 796
 797         if (do_keep) {
 798                 if (pack_lockfile)
 799                         cmd.out = -1;
 800                 cmd_name = "index-pack";
 801                 argv_array_push(&cmd.args, cmd_name);
 802                 argv_array_push(&cmd.args, "--stdin");
 803                 if (!args->quiet && !args->no_progress)
 804                         argv_array_push(&cmd.args, "-v");
 805                 if (args->use_thin_pack)
 806                         argv_array_push(&cmd.args, "--fix-thin");
 807                 if (args->lock_pack || unpack_limit) {
 808                         char hostname[HOST_NAME_MAX + 1];
 809                         if (xgethostname(hostname, sizeof(hostname)))
 810                                 xsnprintf(hostname, sizeof(hostname), "localhost");
 811                         argv_array_pushf(&cmd.args,
 812                                         "--keep=fetch-pack %"PRIuMAX " on %s",
 813                                         (uintmax_t)getpid(), hostname);
 814                 }
 815                 if (args->check_self_contained_and_connected)
 816                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 817         }
 818         else {
 819                 cmd_name = "unpack-objects";
 820                 argv_array_push(&cmd.args, cmd_name);
 821                 if (args->quiet || args->no_progress)
 822                         argv_array_push(&cmd.args, "-q");
 823                 args->check_self_contained_and_connected = 0;
 824         }
 825
 826         if (pass_header)
 827                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 828                                  ntohl(header.hdr_version),
 829                                  ntohl(header.hdr_entries));
 830         if (fetch_fsck_objects >= 0
 831             ? fetch_fsck_objects
 832             : transfer_fsck_objects >= 0
 833             ? transfer_fsck_objects
 834             : 0)
 835                 argv_array_push(&cmd.args, "--strict");
 836
 837         cmd.in = demux.out;
 838         cmd.git_cmd = 1;
 839         if (start_command(&cmd))
 840                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
 841         if (do_keep && pack_lockfile) {
 842                 *pack_lockfile = index_pack_lockfile(cmd.out);
 843                 close(cmd.out);
 844         }
 845
 846         if (!use_sideband)
 847                 /* Closed by start_command() */
 848                 xd[0] = -1;
 849
 850         ret = finish_command(&cmd);
 851         if (!ret || (args->check_self_contained_and_connected && ret == 1))
 852                 args->self_contained_and_connected =
 853                         args->check_self_contained_and_connected &&
 854                         ret == 0;
 855         else
 856                 die(_("%s failed"), cmd_name);
 857         if (use_sideband && finish_async(&demux))
 858                 die(_("error in sideband demultiplexer"));
 859         return 0;
 860 }
 861
 862 static int cmp_ref_by_name(const void *a_, const void *b_)
 863 {
 864         const struct ref *a = *((const struct ref **)a_);
 865         const struct ref *b = *((const struct ref **)b_);
 866         return strcmp(a->name, b->name);
 867 }
 868
 869 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 870                                  int fd[2],
 871                                  const struct ref *orig_ref,
 872                                  struct ref **sought, int nr_sought,
 873                                  struct shallow_info *si,
 874                                  char **pack_lockfile)
 875 {
 876         struct ref *ref = copy_ref_list(orig_ref);
 877         unsigned char sha1[20];
 878         const char *agent_feature;
 879         int agent_len;
 880
 881         sort_ref_list(&ref, ref_compare_name);
 882         QSORT(sought, nr_sought, cmp_ref_by_name);
 883
 884         if ((args->depth > 0 || is_repository_shallow()) && !server_supports("shallow"))
 885                 die(_("Server does not support shallow clients"));
 886         if (args->depth > 0 || args->deepen_since || args->deepen_not)
 887                 args->deepen = 1;
 888         if (server_supports("multi_ack_detailed")) {
 889                 print_verbose(args, _("Server supports multi_ack_detailed"));
 890                 multi_ack = 2;
 891                 if (server_supports("no-done")) {
 892                         print_verbose(args, _("Server supports no-done"));
 893                         if (args->stateless_rpc)
 894                                 no_done = 1;
 895                 }
 896         }
 897         else if (server_supports("multi_ack")) {
 898                 print_verbose(args, _("Server supports multi_ack"));
 899                 multi_ack = 1;
 900         }
 901         if (server_supports("side-band-64k")) {
 902                 print_verbose(args, _("Server supports side-band-64k"));
 903                 use_sideband = 2;
 904         }
 905         else if (server_supports("side-band")) {
 906                 print_verbose(args, _("Server supports side-band"));
 907                 use_sideband = 1;
 908         }
 909         if (server_supports("allow-tip-sha1-in-want")) {
 910                 print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 911                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 912         }
 913         if (server_supports("allow-reachable-sha1-in-want")) {
 914                 print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 915                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 916         }
 917         if (!server_supports("thin-pack"))
 918                 args->use_thin_pack = 0;
 919         if (!server_supports("no-progress"))
 920                 args->no_progress = 0;
 921         if (!server_supports("include-tag"))
 922                 args->include_tag = 0;
 923         if (server_supports("ofs-delta"))
 924                 print_verbose(args, _("Server supports ofs-delta"));
 925         else
 926                 prefer_ofs_delta = 0;
 927
 928         if ((agent_feature = server_feature_value("agent", &agent_len))) {
 929                 agent_supported = 1;
 930                 if (agent_len)
 931                         print_verbose(args, _("Server version is %.*s"),
 932                                       agent_len, agent_feature);
 933         }
 934         if (server_supports("deepen-since"))
 935                 deepen_since_ok = 1;
 936         else if (args->deepen_since)
 937                 die(_("Server does not support --shallow-since"));
 938         if (server_supports("deepen-not"))
 939                 deepen_not_ok = 1;
 940         else if (args->deepen_not)
 941                 die(_("Server does not support --shallow-exclude"));
 942         if (!server_supports("deepen-relative") && args->deepen_relative)
 943                 die(_("Server does not support --deepen"));
 944
 945         if (everything_local(args, &ref, sought, nr_sought)) {
 946                 packet_flush(fd[1]);
 947                 goto all_done;
 948         }
 949         if (find_common(args, fd, sha1, ref) < 0)
 950                 if (!args->keep_pack)
 951                         /* When cloning, it is not unusual to have
 952                          * no common commit.
 953                          */
 954                         warning(_("no common commits"));
 955
 956         if (args->stateless_rpc)
 957                 packet_flush(fd[1]);
 958         if (args->deepen)
 959                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
 960                                         NULL);
 961         else if (si->nr_ours || si->nr_theirs)
 962                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
 963         else
 964                 alternate_shallow_file = NULL;
 965         if (get_pack(args, fd, pack_lockfile))
 966                 die(_("git fetch-pack: fetch failed."));
 967
 968  all_done:
 969         return ref;
 970 }
 971
 972 static void fetch_pack_config(void)
 973 {
 974         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
 975         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
 976         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
 977         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
 978         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
 979
 980         git_config(git_default_config, NULL);
 981 }
 982
 983 static void fetch_pack_setup(void)
 984 {
 985         static int did_setup;
 986         if (did_setup)
 987                 return;
 988         fetch_pack_config();
 989         if (0 <= transfer_unpack_limit)
 990                 unpack_limit = transfer_unpack_limit;
 991         else if (0 <= fetch_unpack_limit)
 992                 unpack_limit = fetch_unpack_limit;
 993         did_setup = 1;
 994 }
 995
 996 static int remove_duplicates_in_refs(struct ref **ref, int nr)
 997 {
 998         struct string_list names = STRING_LIST_INIT_NODUP;
 999         int src, dst;
1000
1001         for (src = dst = 0; src < nr; src++) {
1002                 struct string_list_item *item;
1003                 item = string_list_insert(&names, ref[src]->name);
1004                 if (item->util)
1005                         continue; /* already have it */
1006                 item->util = ref[src];
1007                 if (src != dst)
1008                         ref[dst] = ref[src];
1009                 dst++;
1010         }
1011         for (src = dst; src < nr; src++)
1012                 ref[src] = NULL;
1013         string_list_clear(&names, 0);
1014         return dst;
1015 }
1016
1017 static void update_shallow(struct fetch_pack_args *args,
1018                            struct ref **sought, int nr_sought,
1019                            struct shallow_info *si)
1020 {
1021         struct oid_array ref = OID_ARRAY_INIT;
1022         int *status;
1023         int i;
1024
1025         if (args->deepen && alternate_shallow_file) {
1026                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1027                         unlink_or_warn(git_path_shallow());
1028                         rollback_lock_file(&shallow_lock);
1029                 } else
1030                         commit_lock_file(&shallow_lock);
1031                 return;
1032         }
1033
1034         if (!si->shallow || !si->shallow->nr)
1035                 return;
1036
1037         if (args->cloning) {
1038                 /*
1039                  * remote is shallow, but this is a clone, there are
1040                  * no objects in repo to worry about. Accept any
1041                  * shallow points that exist in the pack (iow in repo
1042                  * after get_pack() and reprepare_packed_git())
1043                  */
1044                 struct oid_array extra = OID_ARRAY_INIT;
1045                 struct object_id *oid = si->shallow->oid;
1046                 for (i = 0; i < si->shallow->nr; i++)
1047                         if (has_object_file(&oid[i]))
1048                                 oid_array_append(&extra, &oid[i]);
1049                 if (extra.nr) {
1050                         setup_alternate_shallow(&shallow_lock,
1051                                                 &alternate_shallow_file,
1052                                                 &extra);
1053                         commit_lock_file(&shallow_lock);
1054                 }
1055                 oid_array_clear(&extra);
1056                 return;
1057         }
1058
1059         if (!si->nr_ours && !si->nr_theirs)
1060                 return;
1061
1062         remove_nonexistent_theirs_shallow(si);
1063         if (!si->nr_ours && !si->nr_theirs)
1064                 return;
1065         for (i = 0; i < nr_sought; i++)
1066                 oid_array_append(&ref, &sought[i]->old_oid);
1067         si->ref = &ref;
1068
1069         if (args->update_shallow) {
1070                 /*
1071                  * remote is also shallow, .git/shallow may be updated
1072                  * so all refs can be accepted. Make sure we only add
1073                  * shallow roots that are actually reachable from new
1074                  * refs.
1075                  */
1076                 struct oid_array extra = OID_ARRAY_INIT;
1077                 struct object_id *oid = si->shallow->oid;
1078                 assign_shallow_commits_to_refs(si, NULL, NULL);
1079                 if (!si->nr_ours && !si->nr_theirs) {
1080                         oid_array_clear(&ref);
1081                         return;
1082                 }
1083                 for (i = 0; i < si->nr_ours; i++)
1084                         oid_array_append(&extra, &oid[si->ours[i]]);
1085                 for (i = 0; i < si->nr_theirs; i++)
1086                         oid_array_append(&extra, &oid[si->theirs[i]]);
1087                 setup_alternate_shallow(&shallow_lock,
1088                                         &alternate_shallow_file,
1089                                         &extra);
1090                 commit_lock_file(&shallow_lock);
1091                 oid_array_clear(&extra);
1092                 oid_array_clear(&ref);
1093                 return;
1094         }
1095
1096         /*
1097          * remote is also shallow, check what ref is safe to update
1098          * without updating .git/shallow
1099          */
1100         status = xcalloc(nr_sought, sizeof(*status));
1101         assign_shallow_commits_to_refs(si, NULL, status);
1102         if (si->nr_ours || si->nr_theirs) {
1103                 for (i = 0; i < nr_sought; i++)
1104                         if (status[i])
1105                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1106         }
1107         free(status);
1108         oid_array_clear(&ref);
1109 }
1110
1111 struct ref *fetch_pack(struct fetch_pack_args *args,
1112                        int fd[], struct child_process *conn,
1113                        const struct ref *ref,
1114                        const char *dest,
1115                        struct ref **sought, int nr_sought,
1116                        struct oid_array *shallow,
1117                        char **pack_lockfile)
1118 {
1119         struct ref *ref_cpy;
1120         struct shallow_info si;
1121
1122         fetch_pack_setup();
1123         if (nr_sought)
1124                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1125
1126         if (!ref) {
1127                 packet_flush(fd[1]);
1128                 die(_("no matching remote head"));
1129         }
1130         prepare_shallow_info(&si, shallow);
1131         ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1132                                 &si, pack_lockfile);
1133         reprepare_packed_git();
1134         update_shallow(args, sought, nr_sought, &si);
1135         clear_shallow_info(&si);
1136         return ref_cpy;
1137 }
1138
1139 int report_unmatched_refs(struct ref **sought, int nr_sought)
1140 {
1141         int i, ret = 0;
1142
1143         for (i = 0; i < nr_sought; i++) {
1144                 if (!sought[i])
1145                         continue;
1146                 switch (sought[i]->match_status) {
1147                 case REF_MATCHED:
1148                         continue;
1149                 case REF_NOT_MATCHED:
1150                         error(_("no such remote ref %s"), sought[i]->name);
1151                         break;
1152                 case REF_UNADVERTISED_NOT_ALLOWED:
1153                         error(_("Server does not allow request for unadvertised object %s"),
1154                               sought[i]->name);
1155                         break;
1156                 }
1157                 ret = 1;
1158         }
1159         return ret;
1160 }