fetch-pack.c

   1 #include "cache.h"
   2 #include "lockfile.h"
   3 #include "refs.h"
   4 #include "pkt-line.h"
   5 #include "commit.h"
   6 #include "tag.h"
   7 #include "exec_cmd.h"
   8 #include "pack.h"
   9 #include "sideband.h"
  10 #include "fetch-pack.h"
  11 #include "remote.h"
  12 #include "run-command.h"
  13 #include "connect.h"
  14 #include "transport.h"
  15 #include "version.h"
  16 #include "prio-queue.h"
  17 #include "sha1-array.h"
  18
  19 static int transfer_unpack_limit = -1;
  20 static int fetch_unpack_limit = -1;
  21 static int unpack_limit = 100;
  22 static int prefer_ofs_delta = 1;
  23 static int no_done;
  24 static int deepen_since_ok;
  25 static int deepen_not_ok;
  26 static int fetch_fsck_objects = -1;
  27 static int transfer_fsck_objects = -1;
  28 static int agent_supported;
  29 static struct lock_file shallow_lock;
  30 static const char *alternate_shallow_file;
  31
  32 /* Remember to update object flag allocation in object.h */
  33 #define COMPLETE        (1U << 0)
  34 #define COMMON          (1U << 1)
  35 #define COMMON_REF      (1U << 2)
  36 #define SEEN            (1U << 3)
  37 #define POPPED          (1U << 4)
  38 #define ALTERNATE       (1U << 5)
  39
  40 static int marked;
  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 struct prio_queue rev_list = { compare_commits_by_commit_date };
  49 static int non_common_revs, multi_ack, use_sideband;
  50 /* Allow specifying sha1 if it is a ref tip. */
  51 #define ALLOW_TIP_SHA1  01
  52 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  53 #define ALLOW_REACHABLE_SHA1    02
  54 static unsigned int allow_unadvertised_object_request;
  55
  56 __attribute__((format (printf, 2, 3)))
  57 static inline void print_verbose(const struct fetch_pack_args *args,
  58                                  const char *fmt, ...)
  59 {
  60         va_list params;
  61
  62         if (!args->verbose)
  63                 return;
  64
  65         va_start(params, fmt);
  66         vfprintf(stderr, fmt, params);
  67         va_end(params);
  68         fputc('\n', stderr);
  69 }
  70
  71 struct alternate_object_cache {
  72         struct object **items;
  73         size_t nr, alloc;
  74 };
  75
  76 static void cache_one_alternate(const char *refname,
  77                                 const struct object_id *oid,
  78                                 void *vcache)
  79 {
  80         struct alternate_object_cache *cache = vcache;
  81         struct object *obj = parse_object(oid);
  82
  83         if (!obj || (obj->flags & ALTERNATE))
  84                 return;
  85
  86         obj->flags |= ALTERNATE;
  87         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  88         cache->items[cache->nr++] = obj;
  89 }
  90
  91 static void for_each_cached_alternate(void (*cb)(struct object *))
  92 {
  93         static int initialized;
  94         static struct alternate_object_cache cache;
  95         size_t i;
  96
  97         if (!initialized) {
  98                 for_each_alternate_ref(cache_one_alternate, &cache);
  99                 initialized = 1;
 100         }
 101
 102         for (i = 0; i < cache.nr; i++)
 103                 cb(cache.items[i]);
 104 }
 105
 106 static void rev_list_push(struct commit *commit, int mark)
 107 {
 108         if (!(commit->object.flags & mark)) {
 109                 commit->object.flags |= mark;
 110
 111                 if (parse_commit(commit))
 112                         return;
 113
 114                 prio_queue_put(&rev_list, commit);
 115
 116                 if (!(commit->object.flags & COMMON))
 117                         non_common_revs++;
 118         }
 119 }
 120
 121 static int rev_list_insert_ref(const char *refname, const struct object_id *oid)
 122 {
 123         struct object *o = deref_tag(parse_object(oid), refname, 0);
 124
 125         if (o && o->type == OBJ_COMMIT)
 126                 rev_list_push((struct commit *)o, SEEN);
 127
 128         return 0;
 129 }
 130
 131 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 132                                    int flag, void *cb_data)
 133 {
 134         return rev_list_insert_ref(refname, oid);
 135 }
 136
 137 static int clear_marks(const char *refname, const struct object_id *oid,
 138                        int flag, void *cb_data)
 139 {
 140         struct object *o = deref_tag(parse_object(oid), refname, 0);
 141
 142         if (o && o->type == OBJ_COMMIT)
 143                 clear_commit_marks((struct commit *)o,
 144                                    COMMON | COMMON_REF | SEEN | POPPED);
 145         return 0;
 146 }
 147
 148 /*
 149    This function marks a rev and its ancestors as common.
 150    In some cases, it is desirable to mark only the ancestors (for example
 151    when only the server does not yet know that they are common).
 152 */
 153
 154 static void mark_common(struct commit *commit,
 155                 int ancestors_only, int dont_parse)
 156 {
 157         if (commit != NULL && !(commit->object.flags & COMMON)) {
 158                 struct object *o = (struct object *)commit;
 159
 160                 if (!ancestors_only)
 161                         o->flags |= COMMON;
 162
 163                 if (!(o->flags & SEEN))
 164                         rev_list_push(commit, SEEN);
 165                 else {
 166                         struct commit_list *parents;
 167
 168                         if (!ancestors_only && !(o->flags & POPPED))
 169                                 non_common_revs--;
 170                         if (!o->parsed && !dont_parse)
 171                                 if (parse_commit(commit))
 172                                         return;
 173
 174                         for (parents = commit->parents;
 175                                         parents;
 176                                         parents = parents->next)
 177                                 mark_common(parents->item, 0, dont_parse);
 178                 }
 179         }
 180 }
 181
 182 /*
 183   Get the next rev to send, ignoring the common.
 184 */
 185
 186 static const struct object_id *get_rev(void)
 187 {
 188         struct commit *commit = NULL;
 189
 190         while (commit == NULL) {
 191                 unsigned int mark;
 192                 struct commit_list *parents;
 193
 194                 if (rev_list.nr == 0 || non_common_revs == 0)
 195                         return NULL;
 196
 197                 commit = prio_queue_get(&rev_list);
 198                 parse_commit(commit);
 199                 parents = commit->parents;
 200
 201                 commit->object.flags |= POPPED;
 202                 if (!(commit->object.flags & COMMON))
 203                         non_common_revs--;
 204
 205                 if (commit->object.flags & COMMON) {
 206                         /* do not send "have", and ignore ancestors */
 207                         commit = NULL;
 208                         mark = COMMON | SEEN;
 209                 } else if (commit->object.flags & COMMON_REF)
 210                         /* send "have", and ignore ancestors */
 211                         mark = COMMON | SEEN;
 212                 else
 213                         /* send "have", also for its ancestors */
 214                         mark = SEEN;
 215
 216                 while (parents) {
 217                         if (!(parents->item->object.flags & SEEN))
 218                                 rev_list_push(parents->item, mark);
 219                         if (mark & COMMON)
 220                                 mark_common(parents->item, 1, 0);
 221                         parents = parents->next;
 222                 }
 223         }
 224
 225         return &commit->object.oid;
 226 }
 227
 228 enum ack_type {
 229         NAK = 0,
 230         ACK,
 231         ACK_continue,
 232         ACK_common,
 233         ACK_ready
 234 };
 235
 236 static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 237 {
 238         if (args->stateless_rpc && args->deepen) {
 239                 /* If we sent a depth we will get back "duplicate"
 240                  * shallow and unshallow commands every time there
 241                  * is a block of have lines exchanged.
 242                  */
 243                 char *line;
 244                 while ((line = packet_read_line(fd, NULL))) {
 245                         if (starts_with(line, "shallow "))
 246                                 continue;
 247                         if (starts_with(line, "unshallow "))
 248                                 continue;
 249                         die(_("git fetch-pack: expected shallow list"));
 250                 }
 251         }
 252 }
 253
 254 static enum ack_type get_ack(int fd, struct object_id *result_oid)
 255 {
 256         int len;
 257         char *line = packet_read_line(fd, &len);
 258         const char *arg;
 259
 260         if (!len)
 261                 die(_("git fetch-pack: expected ACK/NAK, got EOF"));
 262         if (!strcmp(line, "NAK"))
 263                 return NAK;
 264         if (skip_prefix(line, "ACK ", &arg)) {
 265                 if (!get_oid_hex(arg, result_oid)) {
 266                         arg += 40;
 267                         len -= arg - line;
 268                         if (len < 1)
 269                                 return ACK;
 270                         if (strstr(arg, "continue"))
 271                                 return ACK_continue;
 272                         if (strstr(arg, "common"))
 273                                 return ACK_common;
 274                         if (strstr(arg, "ready"))
 275                                 return ACK_ready;
 276                         return ACK;
 277                 }
 278         }
 279         if (skip_prefix(line, "ERR ", &arg))
 280                 die(_("remote error: %s"), arg);
 281         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 282 }
 283
 284 static void send_request(struct fetch_pack_args *args,
 285                          int fd, struct strbuf *buf)
 286 {
 287         if (args->stateless_rpc) {
 288                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 289                 packet_flush(fd);
 290         } else
 291                 write_or_die(fd, buf->buf, buf->len);
 292 }
 293
 294 static void insert_one_alternate_object(struct object *obj)
 295 {
 296         rev_list_insert_ref(NULL, &obj->oid);
 297 }
 298
 299 #define INITIAL_FLUSH 16
 300 #define PIPESAFE_FLUSH 32
 301 #define LARGE_FLUSH 16384
 302
 303 static int next_flush(struct fetch_pack_args *args, int count)
 304 {
 305         if (args->stateless_rpc) {
 306                 if (count < LARGE_FLUSH)
 307                         count <<= 1;
 308                 else
 309                         count = count * 11 / 10;
 310         } else {
 311                 if (count < PIPESAFE_FLUSH)
 312                         count <<= 1;
 313                 else
 314                         count += PIPESAFE_FLUSH;
 315         }
 316         return count;
 317 }
 318
 319 static int find_common(struct fetch_pack_args *args,
 320                        int fd[2], struct object_id *result_oid,
 321                        struct ref *refs)
 322 {
 323         int fetching;
 324         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 325         const struct object_id *oid;
 326         unsigned in_vain = 0;
 327         int got_continue = 0;
 328         int got_ready = 0;
 329         struct strbuf req_buf = STRBUF_INIT;
 330         size_t state_len = 0;
 331
 332         if (args->stateless_rpc && multi_ack == 1)
 333                 die(_("--stateless-rpc requires multi_ack_detailed"));
 334         if (marked)
 335                 for_each_ref(clear_marks, NULL);
 336         marked = 1;
 337
 338         for_each_ref(rev_list_insert_ref_oid, NULL);
 339         for_each_cached_alternate(insert_one_alternate_object);
 340
 341         fetching = 0;
 342         for ( ; refs ; refs = refs->next) {
 343                 struct object_id *remote = &refs->old_oid;
 344                 const char *remote_hex;
 345                 struct object *o;
 346
 347                 /*
 348                  * If that object is complete (i.e. it is an ancestor of a
 349                  * local ref), we tell them we have it but do not have to
 350                  * tell them about its ancestors, which they already know
 351                  * about.
 352                  *
 353                  * We use lookup_object here because we are only
 354                  * interested in the case we *know* the object is
 355                  * reachable and we have already scanned it.
 356                  */
 357                 if (((o = lookup_object(remote->hash)) != NULL) &&
 358                                 (o->flags & COMPLETE)) {
 359                         continue;
 360                 }
 361
 362                 remote_hex = oid_to_hex(remote);
 363                 if (!fetching) {
 364                         struct strbuf c = STRBUF_INIT;
 365                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 366                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 367                         if (no_done)            strbuf_addstr(&c, " no-done");
 368                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 369                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 370                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 371                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 372                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 373                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 374                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 375                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 376                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 377                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 378                                                             git_user_agent_sanitized());
 379                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 380                         strbuf_release(&c);
 381                 } else
 382                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 383                 fetching++;
 384         }
 385
 386         if (!fetching) {
 387                 strbuf_release(&req_buf);
 388                 packet_flush(fd[1]);
 389                 return 1;
 390         }
 391
 392         if (is_repository_shallow())
 393                 write_shallow_commits(&req_buf, 1, NULL);
 394         if (args->depth > 0)
 395                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 396         if (args->deepen_since) {
 397                 timestamp_t max_age = approxidate(args->deepen_since);
 398                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 399         }
 400         if (args->deepen_not) {
 401                 int i;
 402                 for (i = 0; i < args->deepen_not->nr; i++) {
 403                         struct string_list_item *s = args->deepen_not->items + i;
 404                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 405                 }
 406         }
 407         packet_buf_flush(&req_buf);
 408         state_len = req_buf.len;
 409
 410         if (args->deepen) {
 411                 char *line;
 412                 const char *arg;
 413                 struct object_id oid;
 414
 415                 send_request(args, fd[1], &req_buf);
 416                 while ((line = packet_read_line(fd[0], NULL))) {
 417                         if (skip_prefix(line, "shallow ", &arg)) {
 418                                 if (get_oid_hex(arg, &oid))
 419                                         die(_("invalid shallow line: %s"), line);
 420                                 register_shallow(&oid);
 421                                 continue;
 422                         }
 423                         if (skip_prefix(line, "unshallow ", &arg)) {
 424                                 if (get_oid_hex(arg, &oid))
 425                                         die(_("invalid unshallow line: %s"), line);
 426                                 if (!lookup_object(oid.hash))
 427                                         die(_("object not found: %s"), line);
 428                                 /* make sure that it is parsed as shallow */
 429                                 if (!parse_object(&oid))
 430                                         die(_("error in object: %s"), line);
 431                                 if (unregister_shallow(&oid))
 432                                         die(_("no shallow found: %s"), line);
 433                                 continue;
 434                         }
 435                         die(_("expected shallow/unshallow, got %s"), line);
 436                 }
 437         } else if (!args->stateless_rpc)
 438                 send_request(args, fd[1], &req_buf);
 439
 440         if (!args->stateless_rpc) {
 441                 /* If we aren't using the stateless-rpc interface
 442                  * we don't need to retain the headers.
 443                  */
 444                 strbuf_setlen(&req_buf, 0);
 445                 state_len = 0;
 446         }
 447
 448         flushes = 0;
 449         retval = -1;
 450         while ((oid = get_rev())) {
 451                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 452                 print_verbose(args, "have %s", oid_to_hex(oid));
 453                 in_vain++;
 454                 if (flush_at <= ++count) {
 455                         int ack;
 456
 457                         packet_buf_flush(&req_buf);
 458                         send_request(args, fd[1], &req_buf);
 459                         strbuf_setlen(&req_buf, state_len);
 460                         flushes++;
 461                         flush_at = next_flush(args, count);
 462
 463                         /*
 464                          * We keep one window "ahead" of the other side, and
 465                          * will wait for an ACK only on the next one
 466                          */
 467                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 468                                 continue;
 469
 470                         consume_shallow_list(args, fd[0]);
 471                         do {
 472                                 ack = get_ack(fd[0], result_oid);
 473                                 if (ack)
 474                                         print_verbose(args, _("got %s %d %s"), "ack",
 475                                                       ack, oid_to_hex(result_oid));
 476                                 switch (ack) {
 477                                 case ACK:
 478                                         flushes = 0;
 479                                         multi_ack = 0;
 480                                         retval = 0;
 481                                         goto done;
 482                                 case ACK_common:
 483                                 case ACK_ready:
 484                                 case ACK_continue: {
 485                                         struct commit *commit =
 486                                                 lookup_commit(result_oid);
 487                                         if (!commit)
 488                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
 489                                         if (args->stateless_rpc
 490                                          && ack == ACK_common
 491                                          && !(commit->object.flags & COMMON)) {
 492                                                 /* We need to replay the have for this object
 493                                                  * on the next RPC request so the peer knows
 494                                                  * it is in common with us.
 495                                                  */
 496                                                 const char *hex = oid_to_hex(result_oid);
 497                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 498                                                 state_len = req_buf.len;
 499                                                 /*
 500                                                  * Reset in_vain because an ack
 501                                                  * for this commit has not been
 502                                                  * seen.
 503                                                  */
 504                                                 in_vain = 0;
 505                                         } else if (!args->stateless_rpc
 506                                                    || ack != ACK_common)
 507                                                 in_vain = 0;
 508                                         mark_common(commit, 0, 1);
 509                                         retval = 0;
 510                                         got_continue = 1;
 511                                         if (ack == ACK_ready) {
 512                                                 clear_prio_queue(&rev_list);
 513                                                 got_ready = 1;
 514                                         }
 515                                         break;
 516                                         }
 517                                 }
 518                         } while (ack);
 519                         flushes--;
 520                         if (got_continue && MAX_IN_VAIN < in_vain) {
 521                                 print_verbose(args, _("giving up"));
 522                                 break; /* give up */
 523                         }
 524                 }
 525         }
 526 done:
 527         if (!got_ready || !no_done) {
 528                 packet_buf_write(&req_buf, "done\n");
 529                 send_request(args, fd[1], &req_buf);
 530         }
 531         print_verbose(args, _("done"));
 532         if (retval != 0) {
 533                 multi_ack = 0;
 534                 flushes++;
 535         }
 536         strbuf_release(&req_buf);
 537
 538         if (!got_ready || !no_done)
 539                 consume_shallow_list(args, fd[0]);
 540         while (flushes || multi_ack) {
 541                 int ack = get_ack(fd[0], result_oid);
 542                 if (ack) {
 543                         print_verbose(args, _("got %s (%d) %s"), "ack",
 544                                       ack, oid_to_hex(result_oid));
 545                         if (ack == ACK)
 546                                 return 0;
 547                         multi_ack = 1;
 548                         continue;
 549                 }
 550                 flushes--;
 551         }
 552         /* it is no error to fetch into a completely empty repo */
 553         return count ? retval : 0;
 554 }
 555
 556 static struct commit_list *complete;
 557
 558 static int mark_complete(const struct object_id *oid)
 559 {
 560         struct object *o = parse_object(oid);
 561
 562         while (o && o->type == OBJ_TAG) {
 563                 struct tag *t = (struct tag *) o;
 564                 if (!t->tagged)
 565                         break; /* broken repository */
 566                 o->flags |= COMPLETE;
 567                 o = parse_object(&t->tagged->oid);
 568         }
 569         if (o && o->type == OBJ_COMMIT) {
 570                 struct commit *commit = (struct commit *)o;
 571                 if (!(commit->object.flags & COMPLETE)) {
 572                         commit->object.flags |= COMPLETE;
 573                         commit_list_insert(commit, &complete);
 574                 }
 575         }
 576         return 0;
 577 }
 578
 579 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 580                              int flag, void *cb_data)
 581 {
 582         return mark_complete(oid);
 583 }
 584
 585 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 586                                          timestamp_t cutoff)
 587 {
 588         while (complete && cutoff <= complete->item->date) {
 589                 print_verbose(args, _("Marking %s as complete"),
 590                               oid_to_hex(&complete->item->object.oid));
 591                 pop_most_recent_commit(&complete, COMPLETE);
 592         }
 593 }
 594
 595 static void filter_refs(struct fetch_pack_args *args,
 596                         struct ref **refs,
 597                         struct ref **sought, int nr_sought)
 598 {
 599         struct ref *newlist = NULL;
 600         struct ref **newtail = &newlist;
 601         struct ref *ref, *next;
 602         int i;
 603
 604         i = 0;
 605         for (ref = *refs; ref; ref = next) {
 606                 int keep = 0;
 607                 next = ref->next;
 608
 609                 if (starts_with(ref->name, "refs/") &&
 610                     check_refname_format(ref->name, 0))
 611                         ; /* trash */
 612                 else {
 613                         while (i < nr_sought) {
 614                                 int cmp = strcmp(ref->name, sought[i]->name);
 615                                 if (cmp < 0)
 616                                         break; /* definitely do not have it */
 617                                 else if (cmp == 0) {
 618                                         keep = 1; /* definitely have it */
 619                                         sought[i]->match_status = REF_MATCHED;
 620                                 }
 621                                 i++;
 622                         }
 623                 }
 624
 625                 if (!keep && args->fetch_all &&
 626                     (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 627                         keep = 1;
 628
 629                 if (keep) {
 630                         *newtail = ref;
 631                         ref->next = NULL;
 632                         newtail = &ref->next;
 633                 } else {
 634                         free(ref);
 635                 }
 636         }
 637
 638         /* Append unmatched requests to the list */
 639         for (i = 0; i < nr_sought; i++) {
 640                 struct object_id oid;
 641                 const char *p;
 642
 643                 ref = sought[i];
 644                 if (ref->match_status != REF_NOT_MATCHED)
 645                         continue;
 646                 if (parse_oid_hex(ref->name, &oid, &p) ||
 647                     *p != '\0' ||
 648                     oidcmp(&oid, &ref->old_oid))
 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);
 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         timestamp_t 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);
 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 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         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         struct object_id oid;
 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, &oid, 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 }