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 #include "oidset.h"
  20
  21 static int transfer_unpack_limit = -1;
  22 static int fetch_unpack_limit = -1;
  23 static int unpack_limit = 100;
  24 static int prefer_ofs_delta = 1;
  25 static int no_done;
  26 static int deepen_since_ok;
  27 static int deepen_not_ok;
  28 static int fetch_fsck_objects = -1;
  29 static int transfer_fsck_objects = -1;
  30 static int agent_supported;
  31 static struct lock_file shallow_lock;
  32 static const char *alternate_shallow_file;
  33
  34 /* Remember to update object flag allocation in object.h */
  35 #define COMPLETE        (1U << 0)
  36 #define COMMON          (1U << 1)
  37 #define COMMON_REF      (1U << 2)
  38 #define SEEN            (1U << 3)
  39 #define POPPED          (1U << 4)
  40 #define ALTERNATE       (1U << 5)
  41
  42 static int marked;
  43
  44 /*
  45  * After sending this many "have"s if we do not get any new ACK , we
  46  * give up traversing our history.
  47  */
  48 #define MAX_IN_VAIN 256
  49
  50 static struct prio_queue rev_list = { compare_commits_by_commit_date };
  51 static int non_common_revs, multi_ack, use_sideband;
  52 /* Allow specifying sha1 if it is a ref tip. */
  53 #define ALLOW_TIP_SHA1  01
  54 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  55 #define ALLOW_REACHABLE_SHA1    02
  56 static unsigned int allow_unadvertised_object_request;
  57
  58 __attribute__((format (printf, 2, 3)))
  59 static inline void print_verbose(const struct fetch_pack_args *args,
  60                                  const char *fmt, ...)
  61 {
  62         va_list params;
  63
  64         if (!args->verbose)
  65                 return;
  66
  67         va_start(params, fmt);
  68         vfprintf(stderr, fmt, params);
  69         va_end(params);
  70         fputc('\n', stderr);
  71 }
  72
  73 struct alternate_object_cache {
  74         struct object **items;
  75         size_t nr, alloc;
  76 };
  77
  78 static void cache_one_alternate(const char *refname,
  79                                 const struct object_id *oid,
  80                                 void *vcache)
  81 {
  82         struct alternate_object_cache *cache = vcache;
  83         struct object *obj = parse_object(oid);
  84
  85         if (!obj || (obj->flags & ALTERNATE))
  86                 return;
  87
  88         obj->flags |= ALTERNATE;
  89         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  90         cache->items[cache->nr++] = obj;
  91 }
  92
  93 static void for_each_cached_alternate(void (*cb)(struct object *))
  94 {
  95         static int initialized;
  96         static struct alternate_object_cache cache;
  97         size_t i;
  98
  99         if (!initialized) {
 100                 for_each_alternate_ref(cache_one_alternate, &cache);
 101                 initialized = 1;
 102         }
 103
 104         for (i = 0; i < cache.nr; i++)
 105                 cb(cache.items[i]);
 106 }
 107
 108 static void rev_list_push(struct commit *commit, int mark)
 109 {
 110         if (!(commit->object.flags & mark)) {
 111                 commit->object.flags |= mark;
 112
 113                 if (parse_commit(commit))
 114                         return;
 115
 116                 prio_queue_put(&rev_list, commit);
 117
 118                 if (!(commit->object.flags & COMMON))
 119                         non_common_revs++;
 120         }
 121 }
 122
 123 static int rev_list_insert_ref(const char *refname, const struct object_id *oid)
 124 {
 125         struct object *o = deref_tag(parse_object(oid), refname, 0);
 126
 127         if (o && o->type == OBJ_COMMIT)
 128                 rev_list_push((struct commit *)o, SEEN);
 129
 130         return 0;
 131 }
 132
 133 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 134                                    int flag, void *cb_data)
 135 {
 136         return rev_list_insert_ref(refname, oid);
 137 }
 138
 139 static int clear_marks(const char *refname, const struct object_id *oid,
 140                        int flag, void *cb_data)
 141 {
 142         struct object *o = deref_tag(parse_object(oid), refname, 0);
 143
 144         if (o && o->type == OBJ_COMMIT)
 145                 clear_commit_marks((struct commit *)o,
 146                                    COMMON | COMMON_REF | SEEN | POPPED);
 147         return 0;
 148 }
 149
 150 /*
 151    This function marks a rev and its ancestors as common.
 152    In some cases, it is desirable to mark only the ancestors (for example
 153    when only the server does not yet know that they are common).
 154 */
 155
 156 static void mark_common(struct commit *commit,
 157                 int ancestors_only, int dont_parse)
 158 {
 159         if (commit != NULL && !(commit->object.flags & COMMON)) {
 160                 struct object *o = (struct object *)commit;
 161
 162                 if (!ancestors_only)
 163                         o->flags |= COMMON;
 164
 165                 if (!(o->flags & SEEN))
 166                         rev_list_push(commit, SEEN);
 167                 else {
 168                         struct commit_list *parents;
 169
 170                         if (!ancestors_only && !(o->flags & POPPED))
 171                                 non_common_revs--;
 172                         if (!o->parsed && !dont_parse)
 173                                 if (parse_commit(commit))
 174                                         return;
 175
 176                         for (parents = commit->parents;
 177                                         parents;
 178                                         parents = parents->next)
 179                                 mark_common(parents->item, 0, dont_parse);
 180                 }
 181         }
 182 }
 183
 184 /*
 185   Get the next rev to send, ignoring the common.
 186 */
 187
 188 static const struct object_id *get_rev(void)
 189 {
 190         struct commit *commit = NULL;
 191
 192         while (commit == NULL) {
 193                 unsigned int mark;
 194                 struct commit_list *parents;
 195
 196                 if (rev_list.nr == 0 || non_common_revs == 0)
 197                         return NULL;
 198
 199                 commit = prio_queue_get(&rev_list);
 200                 parse_commit(commit);
 201                 parents = commit->parents;
 202
 203                 commit->object.flags |= POPPED;
 204                 if (!(commit->object.flags & COMMON))
 205                         non_common_revs--;
 206
 207                 if (commit->object.flags & COMMON) {
 208                         /* do not send "have", and ignore ancestors */
 209                         commit = NULL;
 210                         mark = COMMON | SEEN;
 211                 } else if (commit->object.flags & COMMON_REF)
 212                         /* send "have", and ignore ancestors */
 213                         mark = COMMON | SEEN;
 214                 else
 215                         /* send "have", also for its ancestors */
 216                         mark = SEEN;
 217
 218                 while (parents) {
 219                         if (!(parents->item->object.flags & SEEN))
 220                                 rev_list_push(parents->item, mark);
 221                         if (mark & COMMON)
 222                                 mark_common(parents->item, 1, 0);
 223                         parents = parents->next;
 224                 }
 225         }
 226
 227         return &commit->object.oid;
 228 }
 229
 230 enum ack_type {
 231         NAK = 0,
 232         ACK,
 233         ACK_continue,
 234         ACK_common,
 235         ACK_ready
 236 };
 237
 238 static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 239 {
 240         if (args->stateless_rpc && args->deepen) {
 241                 /* If we sent a depth we will get back "duplicate"
 242                  * shallow and unshallow commands every time there
 243                  * is a block of have lines exchanged.
 244                  */
 245                 char *line;
 246                 while ((line = packet_read_line(fd, NULL))) {
 247                         if (starts_with(line, "shallow "))
 248                                 continue;
 249                         if (starts_with(line, "unshallow "))
 250                                 continue;
 251                         die(_("git fetch-pack: expected shallow list"));
 252                 }
 253         }
 254 }
 255
 256 static enum ack_type get_ack(int fd, struct object_id *result_oid)
 257 {
 258         int len;
 259         char *line = packet_read_line(fd, &len);
 260         const char *arg;
 261
 262         if (!len)
 263                 die(_("git fetch-pack: expected ACK/NAK, got EOF"));
 264         if (!strcmp(line, "NAK"))
 265                 return NAK;
 266         if (skip_prefix(line, "ACK ", &arg)) {
 267                 if (!get_oid_hex(arg, result_oid)) {
 268                         arg += 40;
 269                         len -= arg - line;
 270                         if (len < 1)
 271                                 return ACK;
 272                         if (strstr(arg, "continue"))
 273                                 return ACK_continue;
 274                         if (strstr(arg, "common"))
 275                                 return ACK_common;
 276                         if (strstr(arg, "ready"))
 277                                 return ACK_ready;
 278                         return ACK;
 279                 }
 280         }
 281         if (skip_prefix(line, "ERR ", &arg))
 282                 die(_("remote error: %s"), arg);
 283         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 284 }
 285
 286 static void send_request(struct fetch_pack_args *args,
 287                          int fd, struct strbuf *buf)
 288 {
 289         if (args->stateless_rpc) {
 290                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 291                 packet_flush(fd);
 292         } else
 293                 write_or_die(fd, buf->buf, buf->len);
 294 }
 295
 296 static void insert_one_alternate_object(struct object *obj)
 297 {
 298         rev_list_insert_ref(NULL, &obj->oid);
 299 }
 300
 301 #define INITIAL_FLUSH 16
 302 #define PIPESAFE_FLUSH 32
 303 #define LARGE_FLUSH 16384
 304
 305 static int next_flush(struct fetch_pack_args *args, int count)
 306 {
 307         if (args->stateless_rpc) {
 308                 if (count < LARGE_FLUSH)
 309                         count <<= 1;
 310                 else
 311                         count = count * 11 / 10;
 312         } else {
 313                 if (count < PIPESAFE_FLUSH)
 314                         count <<= 1;
 315                 else
 316                         count += PIPESAFE_FLUSH;
 317         }
 318         return count;
 319 }
 320
 321 static int find_common(struct fetch_pack_args *args,
 322                        int fd[2], struct object_id *result_oid,
 323                        struct ref *refs)
 324 {
 325         int fetching;
 326         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 327         const struct object_id *oid;
 328         unsigned in_vain = 0;
 329         int got_continue = 0;
 330         int got_ready = 0;
 331         struct strbuf req_buf = STRBUF_INIT;
 332         size_t state_len = 0;
 333
 334         if (args->stateless_rpc && multi_ack == 1)
 335                 die(_("--stateless-rpc requires multi_ack_detailed"));
 336         if (marked)
 337                 for_each_ref(clear_marks, NULL);
 338         marked = 1;
 339
 340         for_each_ref(rev_list_insert_ref_oid, NULL);
 341         for_each_cached_alternate(insert_one_alternate_object);
 342
 343         fetching = 0;
 344         for ( ; refs ; refs = refs->next) {
 345                 struct object_id *remote = &refs->old_oid;
 346                 const char *remote_hex;
 347                 struct object *o;
 348
 349                 /*
 350                  * If that object is complete (i.e. it is an ancestor of a
 351                  * local ref), we tell them we have it but do not have to
 352                  * tell them about its ancestors, which they already know
 353                  * about.
 354                  *
 355                  * We use lookup_object here because we are only
 356                  * interested in the case we *know* the object is
 357                  * reachable and we have already scanned it.
 358                  */
 359                 if (((o = lookup_object(remote->hash)) != NULL) &&
 360                                 (o->flags & COMPLETE)) {
 361                         continue;
 362                 }
 363
 364                 remote_hex = oid_to_hex(remote);
 365                 if (!fetching) {
 366                         struct strbuf c = STRBUF_INIT;
 367                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 368                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 369                         if (no_done)            strbuf_addstr(&c, " no-done");
 370                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 371                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 372                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 373                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 374                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 375                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 376                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 377                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 378                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 379                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 380                                                             git_user_agent_sanitized());
 381                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 382                         strbuf_release(&c);
 383                 } else
 384                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 385                 fetching++;
 386         }
 387
 388         if (!fetching) {
 389                 strbuf_release(&req_buf);
 390                 packet_flush(fd[1]);
 391                 return 1;
 392         }
 393
 394         if (is_repository_shallow())
 395                 write_shallow_commits(&req_buf, 1, NULL);
 396         if (args->depth > 0)
 397                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 398         if (args->deepen_since) {
 399                 timestamp_t max_age = approxidate(args->deepen_since);
 400                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 401         }
 402         if (args->deepen_not) {
 403                 int i;
 404                 for (i = 0; i < args->deepen_not->nr; i++) {
 405                         struct string_list_item *s = args->deepen_not->items + i;
 406                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 407                 }
 408         }
 409         packet_buf_flush(&req_buf);
 410         state_len = req_buf.len;
 411
 412         if (args->deepen) {
 413                 char *line;
 414                 const char *arg;
 415                 struct object_id oid;
 416
 417                 send_request(args, fd[1], &req_buf);
 418                 while ((line = packet_read_line(fd[0], NULL))) {
 419                         if (skip_prefix(line, "shallow ", &arg)) {
 420                                 if (get_oid_hex(arg, &oid))
 421                                         die(_("invalid shallow line: %s"), line);
 422                                 register_shallow(&oid);
 423                                 continue;
 424                         }
 425                         if (skip_prefix(line, "unshallow ", &arg)) {
 426                                 if (get_oid_hex(arg, &oid))
 427                                         die(_("invalid unshallow line: %s"), line);
 428                                 if (!lookup_object(oid.hash))
 429                                         die(_("object not found: %s"), line);
 430                                 /* make sure that it is parsed as shallow */
 431                                 if (!parse_object(&oid))
 432                                         die(_("error in object: %s"), line);
 433                                 if (unregister_shallow(&oid))
 434                                         die(_("no shallow found: %s"), line);
 435                                 continue;
 436                         }
 437                         die(_("expected shallow/unshallow, got %s"), line);
 438                 }
 439         } else if (!args->stateless_rpc)
 440                 send_request(args, fd[1], &req_buf);
 441
 442         if (!args->stateless_rpc) {
 443                 /* If we aren't using the stateless-rpc interface
 444                  * we don't need to retain the headers.
 445                  */
 446                 strbuf_setlen(&req_buf, 0);
 447                 state_len = 0;
 448         }
 449
 450         flushes = 0;
 451         retval = -1;
 452         while ((oid = get_rev())) {
 453                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 454                 print_verbose(args, "have %s", oid_to_hex(oid));
 455                 in_vain++;
 456                 if (flush_at <= ++count) {
 457                         int ack;
 458
 459                         packet_buf_flush(&req_buf);
 460                         send_request(args, fd[1], &req_buf);
 461                         strbuf_setlen(&req_buf, state_len);
 462                         flushes++;
 463                         flush_at = next_flush(args, count);
 464
 465                         /*
 466                          * We keep one window "ahead" of the other side, and
 467                          * will wait for an ACK only on the next one
 468                          */
 469                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 470                                 continue;
 471
 472                         consume_shallow_list(args, fd[0]);
 473                         do {
 474                                 ack = get_ack(fd[0], result_oid);
 475                                 if (ack)
 476                                         print_verbose(args, _("got %s %d %s"), "ack",
 477                                                       ack, oid_to_hex(result_oid));
 478                                 switch (ack) {
 479                                 case ACK:
 480                                         flushes = 0;
 481                                         multi_ack = 0;
 482                                         retval = 0;
 483                                         goto done;
 484                                 case ACK_common:
 485                                 case ACK_ready:
 486                                 case ACK_continue: {
 487                                         struct commit *commit =
 488                                                 lookup_commit(result_oid);
 489                                         if (!commit)
 490                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
 491                                         if (args->stateless_rpc
 492                                          && ack == ACK_common
 493                                          && !(commit->object.flags & COMMON)) {
 494                                                 /* We need to replay the have for this object
 495                                                  * on the next RPC request so the peer knows
 496                                                  * it is in common with us.
 497                                                  */
 498                                                 const char *hex = oid_to_hex(result_oid);
 499                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 500                                                 state_len = req_buf.len;
 501                                                 /*
 502                                                  * Reset in_vain because an ack
 503                                                  * for this commit has not been
 504                                                  * seen.
 505                                                  */
 506                                                 in_vain = 0;
 507                                         } else if (!args->stateless_rpc
 508                                                    || ack != ACK_common)
 509                                                 in_vain = 0;
 510                                         mark_common(commit, 0, 1);
 511                                         retval = 0;
 512                                         got_continue = 1;
 513                                         if (ack == ACK_ready) {
 514                                                 clear_prio_queue(&rev_list);
 515                                                 got_ready = 1;
 516                                         }
 517                                         break;
 518                                         }
 519                                 }
 520                         } while (ack);
 521                         flushes--;
 522                         if (got_continue && MAX_IN_VAIN < in_vain) {
 523                                 print_verbose(args, _("giving up"));
 524                                 break; /* give up */
 525                         }
 526                 }
 527         }
 528 done:
 529         if (!got_ready || !no_done) {
 530                 packet_buf_write(&req_buf, "done\n");
 531                 send_request(args, fd[1], &req_buf);
 532         }
 533         print_verbose(args, _("done"));
 534         if (retval != 0) {
 535                 multi_ack = 0;
 536                 flushes++;
 537         }
 538         strbuf_release(&req_buf);
 539
 540         if (!got_ready || !no_done)
 541                 consume_shallow_list(args, fd[0]);
 542         while (flushes || multi_ack) {
 543                 int ack = get_ack(fd[0], result_oid);
 544                 if (ack) {
 545                         print_verbose(args, _("got %s (%d) %s"), "ack",
 546                                       ack, oid_to_hex(result_oid));
 547                         if (ack == ACK)
 548                                 return 0;
 549                         multi_ack = 1;
 550                         continue;
 551                 }
 552                 flushes--;
 553         }
 554         /* it is no error to fetch into a completely empty repo */
 555         return count ? retval : 0;
 556 }
 557
 558 static struct commit_list *complete;
 559
 560 static int mark_complete(const struct object_id *oid)
 561 {
 562         struct object *o = parse_object(oid);
 563
 564         while (o && o->type == OBJ_TAG) {
 565                 struct tag *t = (struct tag *) o;
 566                 if (!t->tagged)
 567                         break; /* broken repository */
 568                 o->flags |= COMPLETE;
 569                 o = parse_object(&t->tagged->oid);
 570         }
 571         if (o && o->type == OBJ_COMMIT) {
 572                 struct commit *commit = (struct commit *)o;
 573                 if (!(commit->object.flags & COMPLETE)) {
 574                         commit->object.flags |= COMPLETE;
 575                         commit_list_insert(commit, &complete);
 576                 }
 577         }
 578         return 0;
 579 }
 580
 581 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 582                              int flag, void *cb_data)
 583 {
 584         return mark_complete(oid);
 585 }
 586
 587 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 588                                          timestamp_t cutoff)
 589 {
 590         while (complete && cutoff <= complete->item->date) {
 591                 print_verbose(args, _("Marking %s as complete"),
 592                               oid_to_hex(&complete->item->object.oid));
 593                 pop_most_recent_commit(&complete, COMPLETE);
 594         }
 595 }
 596
 597 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 598 {
 599         for (; refs; refs = refs->next)
 600                 oidset_insert(oids, &refs->old_oid);
 601 }
 602
 603 static int tip_oids_contain(struct oidset *tip_oids,
 604                             struct ref *unmatched, struct ref *newlist,
 605                             const struct object_id *id)
 606 {
 607         /*
 608          * Note that this only looks at the ref lists the first time it's
 609          * called. This works out in filter_refs() because even though it may
 610          * add to "newlist" between calls, the additions will always be for
 611          * oids that are already in the set.
 612          */
 613         if (!tip_oids->map.tablesize) {
 614                 add_refs_to_oidset(tip_oids, unmatched);
 615                 add_refs_to_oidset(tip_oids, newlist);
 616         }
 617         return oidset_contains(tip_oids, id);
 618 }
 619
 620 static void filter_refs(struct fetch_pack_args *args,
 621                         struct ref **refs,
 622                         struct ref **sought, int nr_sought)
 623 {
 624         struct ref *newlist = NULL;
 625         struct ref **newtail = &newlist;
 626         struct ref *unmatched = NULL;
 627         struct ref *ref, *next;
 628         struct oidset tip_oids = OIDSET_INIT;
 629         int i;
 630
 631         i = 0;
 632         for (ref = *refs; ref; ref = next) {
 633                 int keep = 0;
 634                 next = ref->next;
 635
 636                 if (starts_with(ref->name, "refs/") &&
 637                     check_refname_format(ref->name, 0))
 638                         ; /* trash */
 639                 else {
 640                         while (i < nr_sought) {
 641                                 int cmp = strcmp(ref->name, sought[i]->name);
 642                                 if (cmp < 0)
 643                                         break; /* definitely do not have it */
 644                                 else if (cmp == 0) {
 645                                         keep = 1; /* definitely have it */
 646                                         sought[i]->match_status = REF_MATCHED;
 647                                 }
 648                                 i++;
 649                         }
 650                 }
 651
 652                 if (!keep && args->fetch_all &&
 653                     (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 654                         keep = 1;
 655
 656                 if (keep) {
 657                         *newtail = ref;
 658                         ref->next = NULL;
 659                         newtail = &ref->next;
 660                 } else {
 661                         ref->next = unmatched;
 662                         unmatched = ref;
 663                 }
 664         }
 665
 666         /* Append unmatched requests to the list */
 667         for (i = 0; i < nr_sought; i++) {
 668                 struct object_id oid;
 669                 const char *p;
 670
 671                 ref = sought[i];
 672                 if (ref->match_status != REF_NOT_MATCHED)
 673                         continue;
 674                 if (parse_oid_hex(ref->name, &oid, &p) ||
 675                     *p != '\0' ||
 676                     oidcmp(&oid, &ref->old_oid))
 677                         continue;
 678
 679                 if ((allow_unadvertised_object_request &
 680                      (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1)) ||
 681                     tip_oids_contain(&tip_oids, unmatched, newlist,
 682                                      &ref->old_oid)) {
 683                         ref->match_status = REF_MATCHED;
 684                         *newtail = copy_ref(ref);
 685                         newtail = &(*newtail)->next;
 686                 } else {
 687                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 688                 }
 689         }
 690
 691         oidset_clear(&tip_oids);
 692         for (ref = unmatched; ref; ref = next) {
 693                 next = ref->next;
 694                 free(ref);
 695         }
 696
 697         *refs = newlist;
 698 }
 699
 700 static void mark_alternate_complete(struct object *obj)
 701 {
 702         mark_complete(&obj->oid);
 703 }
 704
 705 static int everything_local(struct fetch_pack_args *args,
 706                             struct ref **refs,
 707                             struct ref **sought, int nr_sought)
 708 {
 709         struct ref *ref;
 710         int retval;
 711         timestamp_t cutoff = 0;
 712
 713         save_commit_buffer = 0;
 714
 715         for (ref = *refs; ref; ref = ref->next) {
 716                 struct object *o;
 717
 718                 if (!has_object_file_with_flags(&ref->old_oid,
 719                                                 OBJECT_INFO_QUICK))
 720                         continue;
 721
 722                 o = parse_object(&ref->old_oid);
 723                 if (!o)
 724                         continue;
 725
 726                 /* We already have it -- which may mean that we were
 727                  * in sync with the other side at some time after
 728                  * that (it is OK if we guess wrong here).
 729                  */
 730                 if (o->type == OBJ_COMMIT) {
 731                         struct commit *commit = (struct commit *)o;
 732                         if (!cutoff || cutoff < commit->date)
 733                                 cutoff = commit->date;
 734                 }
 735         }
 736
 737         if (!args->deepen) {
 738                 for_each_ref(mark_complete_oid, NULL);
 739                 for_each_cached_alternate(mark_alternate_complete);
 740                 commit_list_sort_by_date(&complete);
 741                 if (cutoff)
 742                         mark_recent_complete_commits(args, cutoff);
 743         }
 744
 745         /*
 746          * Mark all complete remote refs as common refs.
 747          * Don't mark them common yet; the server has to be told so first.
 748          */
 749         for (ref = *refs; ref; ref = ref->next) {
 750                 struct object *o = deref_tag(lookup_object(ref->old_oid.hash),
 751                                              NULL, 0);
 752
 753                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 754                         continue;
 755
 756                 if (!(o->flags & SEEN)) {
 757                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 758
 759                         mark_common((struct commit *)o, 1, 1);
 760                 }
 761         }
 762
 763         filter_refs(args, refs, sought, nr_sought);
 764
 765         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 766                 const struct object_id *remote = &ref->old_oid;
 767                 struct object *o;
 768
 769                 o = lookup_object(remote->hash);
 770                 if (!o || !(o->flags & COMPLETE)) {
 771                         retval = 0;
 772                         print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 773                                       ref->name);
 774                         continue;
 775                 }
 776                 print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 777                               ref->name);
 778         }
 779         return retval;
 780 }
 781
 782 static int sideband_demux(int in, int out, void *data)
 783 {
 784         int *xd = data;
 785         int ret;
 786
 787         ret = recv_sideband("fetch-pack", xd[0], out);
 788         close(out);
 789         return ret;
 790 }
 791
 792 static int get_pack(struct fetch_pack_args *args,
 793                     int xd[2], char **pack_lockfile)
 794 {
 795         struct async demux;
 796         int do_keep = args->keep_pack;
 797         const char *cmd_name;
 798         struct pack_header header;
 799         int pass_header = 0;
 800         struct child_process cmd = CHILD_PROCESS_INIT;
 801         int ret;
 802
 803         memset(&demux, 0, sizeof(demux));
 804         if (use_sideband) {
 805                 /* xd[] is talking with upload-pack; subprocess reads from
 806                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 807                  * through demux->out.
 808                  */
 809                 demux.proc = sideband_demux;
 810                 demux.data = xd;
 811                 demux.out = -1;
 812                 demux.isolate_sigpipe = 1;
 813                 if (start_async(&demux))
 814                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 815         }
 816         else
 817                 demux.out = xd[0];
 818
 819         if (!args->keep_pack && unpack_limit) {
 820
 821                 if (read_pack_header(demux.out, &header))
 822                         die(_("protocol error: bad pack header"));
 823                 pass_header = 1;
 824                 if (ntohl(header.hdr_entries) < unpack_limit)
 825                         do_keep = 0;
 826                 else
 827                         do_keep = 1;
 828         }
 829
 830         if (alternate_shallow_file) {
 831                 argv_array_push(&cmd.args, "--shallow-file");
 832                 argv_array_push(&cmd.args, alternate_shallow_file);
 833         }
 834
 835         if (do_keep) {
 836                 if (pack_lockfile)
 837                         cmd.out = -1;
 838                 cmd_name = "index-pack";
 839                 argv_array_push(&cmd.args, cmd_name);
 840                 argv_array_push(&cmd.args, "--stdin");
 841                 if (!args->quiet && !args->no_progress)
 842                         argv_array_push(&cmd.args, "-v");
 843                 if (args->use_thin_pack)
 844                         argv_array_push(&cmd.args, "--fix-thin");
 845                 if (args->lock_pack || unpack_limit) {
 846                         char hostname[HOST_NAME_MAX + 1];
 847                         if (xgethostname(hostname, sizeof(hostname)))
 848                                 xsnprintf(hostname, sizeof(hostname), "localhost");
 849                         argv_array_pushf(&cmd.args,
 850                                         "--keep=fetch-pack %"PRIuMAX " on %s",
 851                                         (uintmax_t)getpid(), hostname);
 852                 }
 853                 if (args->check_self_contained_and_connected)
 854                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 855         }
 856         else {
 857                 cmd_name = "unpack-objects";
 858                 argv_array_push(&cmd.args, cmd_name);
 859                 if (args->quiet || args->no_progress)
 860                         argv_array_push(&cmd.args, "-q");
 861                 args->check_self_contained_and_connected = 0;
 862         }
 863
 864         if (pass_header)
 865                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 866                                  ntohl(header.hdr_version),
 867                                  ntohl(header.hdr_entries));
 868         if (fetch_fsck_objects >= 0
 869             ? fetch_fsck_objects
 870             : transfer_fsck_objects >= 0
 871             ? transfer_fsck_objects
 872             : 0)
 873                 argv_array_push(&cmd.args, "--strict");
 874
 875         cmd.in = demux.out;
 876         cmd.git_cmd = 1;
 877         if (start_command(&cmd))
 878                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
 879         if (do_keep && pack_lockfile) {
 880                 *pack_lockfile = index_pack_lockfile(cmd.out);
 881                 close(cmd.out);
 882         }
 883
 884         if (!use_sideband)
 885                 /* Closed by start_command() */
 886                 xd[0] = -1;
 887
 888         ret = finish_command(&cmd);
 889         if (!ret || (args->check_self_contained_and_connected && ret == 1))
 890                 args->self_contained_and_connected =
 891                         args->check_self_contained_and_connected &&
 892                         ret == 0;
 893         else
 894                 die(_("%s failed"), cmd_name);
 895         if (use_sideband && finish_async(&demux))
 896                 die(_("error in sideband demultiplexer"));
 897         return 0;
 898 }
 899
 900 static int cmp_ref_by_name(const void *a_, const void *b_)
 901 {
 902         const struct ref *a = *((const struct ref **)a_);
 903         const struct ref *b = *((const struct ref **)b_);
 904         return strcmp(a->name, b->name);
 905 }
 906
 907 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 908                                  int fd[2],
 909                                  const struct ref *orig_ref,
 910                                  struct ref **sought, int nr_sought,
 911                                  struct shallow_info *si,
 912                                  char **pack_lockfile)
 913 {
 914         struct ref *ref = copy_ref_list(orig_ref);
 915         struct object_id oid;
 916         const char *agent_feature;
 917         int agent_len;
 918
 919         sort_ref_list(&ref, ref_compare_name);
 920         QSORT(sought, nr_sought, cmp_ref_by_name);
 921
 922         if ((args->depth > 0 || is_repository_shallow()) && !server_supports("shallow"))
 923                 die(_("Server does not support shallow clients"));
 924         if (args->depth > 0 || args->deepen_since || args->deepen_not)
 925                 args->deepen = 1;
 926         if (server_supports("multi_ack_detailed")) {
 927                 print_verbose(args, _("Server supports multi_ack_detailed"));
 928                 multi_ack = 2;
 929                 if (server_supports("no-done")) {
 930                         print_verbose(args, _("Server supports no-done"));
 931                         if (args->stateless_rpc)
 932                                 no_done = 1;
 933                 }
 934         }
 935         else if (server_supports("multi_ack")) {
 936                 print_verbose(args, _("Server supports multi_ack"));
 937                 multi_ack = 1;
 938         }
 939         if (server_supports("side-band-64k")) {
 940                 print_verbose(args, _("Server supports side-band-64k"));
 941                 use_sideband = 2;
 942         }
 943         else if (server_supports("side-band")) {
 944                 print_verbose(args, _("Server supports side-band"));
 945                 use_sideband = 1;
 946         }
 947         if (server_supports("allow-tip-sha1-in-want")) {
 948                 print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 949                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 950         }
 951         if (server_supports("allow-reachable-sha1-in-want")) {
 952                 print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 953                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 954         }
 955         if (!server_supports("thin-pack"))
 956                 args->use_thin_pack = 0;
 957         if (!server_supports("no-progress"))
 958                 args->no_progress = 0;
 959         if (!server_supports("include-tag"))
 960                 args->include_tag = 0;
 961         if (server_supports("ofs-delta"))
 962                 print_verbose(args, _("Server supports ofs-delta"));
 963         else
 964                 prefer_ofs_delta = 0;
 965
 966         if ((agent_feature = server_feature_value("agent", &agent_len))) {
 967                 agent_supported = 1;
 968                 if (agent_len)
 969                         print_verbose(args, _("Server version is %.*s"),
 970                                       agent_len, agent_feature);
 971         }
 972         if (server_supports("deepen-since"))
 973                 deepen_since_ok = 1;
 974         else if (args->deepen_since)
 975                 die(_("Server does not support --shallow-since"));
 976         if (server_supports("deepen-not"))
 977                 deepen_not_ok = 1;
 978         else if (args->deepen_not)
 979                 die(_("Server does not support --shallow-exclude"));
 980         if (!server_supports("deepen-relative") && args->deepen_relative)
 981                 die(_("Server does not support --deepen"));
 982
 983         if (everything_local(args, &ref, sought, nr_sought)) {
 984                 packet_flush(fd[1]);
 985                 goto all_done;
 986         }
 987         if (find_common(args, fd, &oid, ref) < 0)
 988                 if (!args->keep_pack)
 989                         /* When cloning, it is not unusual to have
 990                          * no common commit.
 991                          */
 992                         warning(_("no common commits"));
 993
 994         if (args->stateless_rpc)
 995                 packet_flush(fd[1]);
 996         if (args->deepen)
 997                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
 998                                         NULL);
 999         else if (si->nr_ours || si->nr_theirs)
1000                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
1001         else
1002                 alternate_shallow_file = NULL;
1003         if (get_pack(args, fd, pack_lockfile))
1004                 die(_("git fetch-pack: fetch failed."));
1005
1006  all_done:
1007         return ref;
1008 }
1009
1010 static void fetch_pack_config(void)
1011 {
1012         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1013         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1014         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1015         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1016         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1017
1018         git_config(git_default_config, NULL);
1019 }
1020
1021 static void fetch_pack_setup(void)
1022 {
1023         static int did_setup;
1024         if (did_setup)
1025                 return;
1026         fetch_pack_config();
1027         if (0 <= transfer_unpack_limit)
1028                 unpack_limit = transfer_unpack_limit;
1029         else if (0 <= fetch_unpack_limit)
1030                 unpack_limit = fetch_unpack_limit;
1031         did_setup = 1;
1032 }
1033
1034 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1035 {
1036         struct string_list names = STRING_LIST_INIT_NODUP;
1037         int src, dst;
1038
1039         for (src = dst = 0; src < nr; src++) {
1040                 struct string_list_item *item;
1041                 item = string_list_insert(&names, ref[src]->name);
1042                 if (item->util)
1043                         continue; /* already have it */
1044                 item->util = ref[src];
1045                 if (src != dst)
1046                         ref[dst] = ref[src];
1047                 dst++;
1048         }
1049         for (src = dst; src < nr; src++)
1050                 ref[src] = NULL;
1051         string_list_clear(&names, 0);
1052         return dst;
1053 }
1054
1055 static void update_shallow(struct fetch_pack_args *args,
1056                            struct ref **sought, int nr_sought,
1057                            struct shallow_info *si)
1058 {
1059         struct oid_array ref = OID_ARRAY_INIT;
1060         int *status;
1061         int i;
1062
1063         if (args->deepen && alternate_shallow_file) {
1064                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1065                         unlink_or_warn(git_path_shallow());
1066                         rollback_lock_file(&shallow_lock);
1067                 } else
1068                         commit_lock_file(&shallow_lock);
1069                 return;
1070         }
1071
1072         if (!si->shallow || !si->shallow->nr)
1073                 return;
1074
1075         if (args->cloning) {
1076                 /*
1077                  * remote is shallow, but this is a clone, there are
1078                  * no objects in repo to worry about. Accept any
1079                  * shallow points that exist in the pack (iow in repo
1080                  * after get_pack() and reprepare_packed_git())
1081                  */
1082                 struct oid_array extra = OID_ARRAY_INIT;
1083                 struct object_id *oid = si->shallow->oid;
1084                 for (i = 0; i < si->shallow->nr; i++)
1085                         if (has_object_file(&oid[i]))
1086                                 oid_array_append(&extra, &oid[i]);
1087                 if (extra.nr) {
1088                         setup_alternate_shallow(&shallow_lock,
1089                                                 &alternate_shallow_file,
1090                                                 &extra);
1091                         commit_lock_file(&shallow_lock);
1092                 }
1093                 oid_array_clear(&extra);
1094                 return;
1095         }
1096
1097         if (!si->nr_ours && !si->nr_theirs)
1098                 return;
1099
1100         remove_nonexistent_theirs_shallow(si);
1101         if (!si->nr_ours && !si->nr_theirs)
1102                 return;
1103         for (i = 0; i < nr_sought; i++)
1104                 oid_array_append(&ref, &sought[i]->old_oid);
1105         si->ref = &ref;
1106
1107         if (args->update_shallow) {
1108                 /*
1109                  * remote is also shallow, .git/shallow may be updated
1110                  * so all refs can be accepted. Make sure we only add
1111                  * shallow roots that are actually reachable from new
1112                  * refs.
1113                  */
1114                 struct oid_array extra = OID_ARRAY_INIT;
1115                 struct object_id *oid = si->shallow->oid;
1116                 assign_shallow_commits_to_refs(si, NULL, NULL);
1117                 if (!si->nr_ours && !si->nr_theirs) {
1118                         oid_array_clear(&ref);
1119                         return;
1120                 }
1121                 for (i = 0; i < si->nr_ours; i++)
1122                         oid_array_append(&extra, &oid[si->ours[i]]);
1123                 for (i = 0; i < si->nr_theirs; i++)
1124                         oid_array_append(&extra, &oid[si->theirs[i]]);
1125                 setup_alternate_shallow(&shallow_lock,
1126                                         &alternate_shallow_file,
1127                                         &extra);
1128                 commit_lock_file(&shallow_lock);
1129                 oid_array_clear(&extra);
1130                 oid_array_clear(&ref);
1131                 return;
1132         }
1133
1134         /*
1135          * remote is also shallow, check what ref is safe to update
1136          * without updating .git/shallow
1137          */
1138         status = xcalloc(nr_sought, sizeof(*status));
1139         assign_shallow_commits_to_refs(si, NULL, status);
1140         if (si->nr_ours || si->nr_theirs) {
1141                 for (i = 0; i < nr_sought; i++)
1142                         if (status[i])
1143                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1144         }
1145         free(status);
1146         oid_array_clear(&ref);
1147 }
1148
1149 struct ref *fetch_pack(struct fetch_pack_args *args,
1150                        int fd[], struct child_process *conn,
1151                        const struct ref *ref,
1152                        const char *dest,
1153                        struct ref **sought, int nr_sought,
1154                        struct oid_array *shallow,
1155                        char **pack_lockfile)
1156 {
1157         struct ref *ref_cpy;
1158         struct shallow_info si;
1159
1160         fetch_pack_setup();
1161         if (nr_sought)
1162                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1163
1164         if (!ref) {
1165                 packet_flush(fd[1]);
1166                 die(_("no matching remote head"));
1167         }
1168         prepare_shallow_info(&si, shallow);
1169         ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1170                                 &si, pack_lockfile);
1171         reprepare_packed_git();
1172         update_shallow(args, sought, nr_sought, &si);
1173         clear_shallow_info(&si);
1174         return ref_cpy;
1175 }
1176
1177 int report_unmatched_refs(struct ref **sought, int nr_sought)
1178 {
1179         int i, ret = 0;
1180
1181         for (i = 0; i < nr_sought; i++) {
1182                 if (!sought[i])
1183                         continue;
1184                 switch (sought[i]->match_status) {
1185                 case REF_MATCHED:
1186                         continue;
1187                 case REF_NOT_MATCHED:
1188                         error(_("no such remote ref %s"), sought[i]->name);
1189                         break;
1190                 case REF_UNADVERTISED_NOT_ALLOWED:
1191                         error(_("Server does not allow request for unadvertised object %s"),
1192                               sought[i]->name);
1193                         break;
1194                 }
1195                 ret = 1;
1196         }
1197         return ret;
1198 }