git.oblomov.eu Git - git/blob - 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 #include "oidset.h"
  19
  20 static int transfer_unpack_limit = -1;
  21 static int fetch_unpack_limit = -1;
  22 static int unpack_limit = 100;
  23 static int prefer_ofs_delta = 1;
  24 static int no_done;
  25 static int deepen_since_ok;
  26 static int deepen_not_ok;
  27 static int fetch_fsck_objects = -1;
  28 static int transfer_fsck_objects = -1;
  29 static int agent_supported;
  30 static struct lock_file shallow_lock;
  31 static const char *alternate_shallow_file;
  32
  33 /* Remember to update object flag allocation in object.h */
  34 #define COMPLETE        (1U << 0)
  35 #define COMMON          (1U << 1)
  36 #define COMMON_REF      (1U << 2)
  37 #define SEEN            (1U << 3)
  38 #define POPPED          (1U << 4)
  39 #define ALTERNATE       (1U << 5)
  40
  41 static int marked;
  42
  43 /*
  44  * After sending this many "have"s if we do not get any new ACK , we
  45  * give up traversing our history.
  46  */
  47 #define MAX_IN_VAIN 256
  48
  49 static struct prio_queue rev_list = { compare_commits_by_commit_date };
  50 static int non_common_revs, multi_ack, use_sideband;
  51 /* Allow specifying sha1 if it is a ref tip. */
  52 #define ALLOW_TIP_SHA1  01
  53 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  54 #define ALLOW_REACHABLE_SHA1    02
  55 static unsigned int allow_unadvertised_object_request;
  56
  57 __attribute__((format (printf, 2, 3)))
  58 static inline void print_verbose(const struct fetch_pack_args *args,
  59                                  const char *fmt, ...)
  60 {
  61         va_list params;
  62
  63         if (!args->verbose)
  64                 return;
  65
  66         va_start(params, fmt);
  67         vfprintf(stderr, fmt, params);
  68         va_end(params);
  69         fputc('\n', stderr);
  70 }
  71
  72 struct alternate_object_cache {
  73         struct object **items;
  74         size_t nr, alloc;
  75 };
  76
  77 static void cache_one_alternate(const char *refname,
  78                                 const struct object_id *oid,
  79                                 void *vcache)
  80 {
  81         struct alternate_object_cache *cache = vcache;
  82         struct object *obj = parse_object(oid->hash);
  83
  84         if (!obj || (obj->flags & ALTERNATE))
  85                 return;
  86
  87         obj->flags |= ALTERNATE;
  88         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  89         cache->items[cache->nr++] = obj;
  90 }
  91
  92 static void for_each_cached_alternate(void (*cb)(struct object *))
  93 {
  94         static int initialized;
  95         static struct alternate_object_cache cache;
  96         size_t i;
  97
  98         if (!initialized) {
  99                 for_each_alternate_ref(cache_one_alternate, &cache);
 100                 initialized = 1;
 101         }
 102
 103         for (i = 0; i < cache.nr; i++)
 104                 cb(cache.items[i]);
 105 }
 106
 107 static void rev_list_push(struct commit *commit, int mark)
 108 {
 109         if (!(commit->object.flags & mark)) {
 110                 commit->object.flags |= mark;
 111
 112                 if (parse_commit(commit))
 113                         return;
 114
 115                 prio_queue_put(&rev_list, commit);
 116
 117                 if (!(commit->object.flags & COMMON))
 118                         non_common_revs++;
 119         }
 120 }
 121
 122 static int rev_list_insert_ref(const char *refname, const unsigned char *sha1)
 123 {
 124         struct object *o = deref_tag(parse_object(sha1), refname, 0);
 125
 126         if (o && o->type == OBJ_COMMIT)
 127                 rev_list_push((struct commit *)o, SEEN);
 128
 129         return 0;
 130 }
 131
 132 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 133                                    int flag, void *cb_data)
 134 {
 135         return rev_list_insert_ref(refname, oid->hash);
 136 }
 137
 138 static int clear_marks(const char *refname, const struct object_id *oid,
 139                        int flag, void *cb_data)
 140 {
 141         struct object *o = deref_tag(parse_object(oid->hash), refname, 0);
 142
 143         if (o && o->type == OBJ_COMMIT)
 144                 clear_commit_marks((struct commit *)o,
 145                                    COMMON | COMMON_REF | SEEN | POPPED);
 146         return 0;
 147 }
 148
 149 /*
 150    This function marks a rev and its ancestors as common.
 151    In some cases, it is desirable to mark only the ancestors (for example
 152    when only the server does not yet know that they are common).
 153 */
 154
 155 static void mark_common(struct commit *commit,
 156                 int ancestors_only, int dont_parse)
 157 {
 158         if (commit != NULL && !(commit->object.flags & COMMON)) {
 159                 struct object *o = (struct object *)commit;
 160
 161                 if (!ancestors_only)
 162                         o->flags |= COMMON;
 163
 164                 if (!(o->flags & SEEN))
 165                         rev_list_push(commit, SEEN);
 166                 else {
 167                         struct commit_list *parents;
 168
 169                         if (!ancestors_only && !(o->flags & POPPED))
 170                                 non_common_revs--;
 171                         if (!o->parsed && !dont_parse)
 172                                 if (parse_commit(commit))
 173                                         return;
 174
 175                         for (parents = commit->parents;
 176                                         parents;
 177                                         parents = parents->next)
 178                                 mark_common(parents->item, 0, dont_parse);
 179                 }
 180         }
 181 }
 182
 183 /*
 184   Get the next rev to send, ignoring the common.
 185 */
 186
 187 static const unsigned char *get_rev(void)
 188 {
 189         struct commit *commit = NULL;
 190
 191         while (commit == NULL) {
 192                 unsigned int mark;
 193                 struct commit_list *parents;
 194
 195                 if (rev_list.nr == 0 || non_common_revs == 0)
 196                         return NULL;
 197
 198                 commit = prio_queue_get(&rev_list);
 199                 parse_commit(commit);
 200                 parents = commit->parents;
 201
 202                 commit->object.flags |= POPPED;
 203                 if (!(commit->object.flags & COMMON))
 204                         non_common_revs--;
 205
 206                 if (commit->object.flags & COMMON) {
 207                         /* do not send "have", and ignore ancestors */
 208                         commit = NULL;
 209                         mark = COMMON | SEEN;
 210                 } else if (commit->object.flags & COMMON_REF)
 211                         /* send "have", and ignore ancestors */
 212                         mark = COMMON | SEEN;
 213                 else
 214                         /* send "have", also for its ancestors */
 215                         mark = SEEN;
 216
 217                 while (parents) {
 218                         if (!(parents->item->object.flags & SEEN))
 219                                 rev_list_push(parents->item, mark);
 220                         if (mark & COMMON)
 221                                 mark_common(parents->item, 1, 0);
 222                         parents = parents->next;
 223                 }
 224         }
 225
 226         return commit->object.oid.hash;
 227 }
 228
 229 enum ack_type {
 230         NAK = 0,
 231         ACK,
 232         ACK_continue,
 233         ACK_common,
 234         ACK_ready
 235 };
 236
 237 static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 238 {
 239         if (args->stateless_rpc && args->deepen) {
 240                 /* If we sent a depth we will get back "duplicate"
 241                  * shallow and unshallow commands every time there
 242                  * is a block of have lines exchanged.
 243                  */
 244                 char *line;
 245                 while ((line = packet_read_line(fd, NULL))) {
 246                         if (starts_with(line, "shallow "))
 247                                 continue;
 248                         if (starts_with(line, "unshallow "))
 249                                 continue;
 250                         die(_("git fetch-pack: expected shallow list"));
 251                 }
 252         }
 253 }
 254
 255 static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 256 {
 257         int len;
 258         char *line = packet_read_line(fd, &len);
 259         const char *arg;
 260
 261         if (!len)
 262                 die(_("git fetch-pack: expected ACK/NAK, got EOF"));
 263         if (!strcmp(line, "NAK"))
 264                 return NAK;
 265         if (skip_prefix(line, "ACK ", &arg)) {
 266                 if (!get_sha1_hex(arg, result_sha1)) {
 267                         arg += 40;
 268                         len -= arg - line;
 269                         if (len < 1)
 270                                 return ACK;
 271                         if (strstr(arg, "continue"))
 272                                 return ACK_continue;
 273                         if (strstr(arg, "common"))
 274                                 return ACK_common;
 275                         if (strstr(arg, "ready"))
 276                                 return ACK_ready;
 277                         return ACK;
 278                 }
 279         }
 280         if (skip_prefix(line, "ERR ", &arg))
 281                 die(_("remote error: %s"), arg);
 282         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 283 }
 284
 285 static void send_request(struct fetch_pack_args *args,
 286                          int fd, struct strbuf *buf)
 287 {
 288         if (args->stateless_rpc) {
 289                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 290                 packet_flush(fd);
 291         } else
 292                 write_or_die(fd, buf->buf, buf->len);
 293 }
 294
 295 static void insert_one_alternate_object(struct object *obj)
 296 {
 297         rev_list_insert_ref(NULL, obj->oid.hash);
 298 }
 299
 300 #define INITIAL_FLUSH 16
 301 #define PIPESAFE_FLUSH 32
 302 #define LARGE_FLUSH 16384
 303
 304 static int next_flush(struct fetch_pack_args *args, int count)
 305 {
 306         if (args->stateless_rpc) {
 307                 if (count < LARGE_FLUSH)
 308                         count <<= 1;
 309                 else
 310                         count = count * 11 / 10;
 311         } else {
 312                 if (count < PIPESAFE_FLUSH)
 313                         count <<= 1;
 314                 else
 315                         count += PIPESAFE_FLUSH;
 316         }
 317         return count;
 318 }
 319
 320 static int find_common(struct fetch_pack_args *args,
 321                        int fd[2], unsigned char *result_sha1,
 322                        struct ref *refs)
 323 {
 324         int fetching;
 325         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 326         const unsigned char *sha1;
 327         unsigned in_vain = 0;
 328         int got_continue = 0;
 329         int got_ready = 0;
 330         struct strbuf req_buf = STRBUF_INIT;
 331         size_t state_len = 0;
 332
 333         if (args->stateless_rpc && multi_ack == 1)
 334                 die(_("--stateless-rpc requires multi_ack_detailed"));
 335         if (marked)
 336                 for_each_ref(clear_marks, NULL);
 337         marked = 1;
 338
 339         for_each_ref(rev_list_insert_ref_oid, NULL);
 340         for_each_cached_alternate(insert_one_alternate_object);
 341
 342         fetching = 0;
 343         for ( ; refs ; refs = refs->next) {
 344                 unsigned char *remote = refs->old_oid.hash;
 345                 const char *remote_hex;
 346                 struct object *o;
 347
 348                 /*
 349                  * If that object is complete (i.e. it is an ancestor of a
 350                  * local ref), we tell them we have it but do not have to
 351                  * tell them about its ancestors, which they already know
 352                  * about.
 353                  *
 354                  * We use lookup_object here because we are only
 355                  * interested in the case we *know* the object is
 356                  * reachable and we have already scanned it.
 357                  */
 358                 if (((o = lookup_object(remote)) != NULL) &&
 359                                 (o->flags & COMPLETE)) {
 360                         continue;
 361                 }
 362
 363                 remote_hex = sha1_to_hex(remote);
 364                 if (!fetching) {
 365                         struct strbuf c = STRBUF_INIT;
 366                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 367                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 368                         if (no_done)            strbuf_addstr(&c, " no-done");
 369                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 370                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 371                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 372                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 373                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 374                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 375                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 376                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 377                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 378                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 379                                                             git_user_agent_sanitized());
 380                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 381                         strbuf_release(&c);
 382                 } else
 383                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 384                 fetching++;
 385         }
 386
 387         if (!fetching) {
 388                 strbuf_release(&req_buf);
 389                 packet_flush(fd[1]);
 390                 return 1;
 391         }
 392
 393         if (is_repository_shallow())
 394                 write_shallow_commits(&req_buf, 1, NULL);
 395         if (args->depth > 0)
 396                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 397         if (args->deepen_since) {
 398                 unsigned long max_age = approxidate(args->deepen_since);
 399                 packet_buf_write(&req_buf, "deepen-since %lu", max_age);
 400         }
 401         if (args->deepen_not) {
 402                 int i;
 403                 for (i = 0; i < args->deepen_not->nr; i++) {
 404                         struct string_list_item *s = args->deepen_not->items + i;
 405                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 406                 }
 407         }
 408         packet_buf_flush(&req_buf);
 409         state_len = req_buf.len;
 410
 411         if (args->deepen) {
 412                 char *line;
 413                 const char *arg;
 414                 unsigned char sha1[20];
 415
 416                 send_request(args, fd[1], &req_buf);
 417                 while ((line = packet_read_line(fd[0], NULL))) {
 418                         if (skip_prefix(line, "shallow ", &arg)) {
 419                                 if (get_sha1_hex(arg, sha1))
 420                                         die(_("invalid shallow line: %s"), line);
 421                                 register_shallow(sha1);
 422                                 continue;
 423                         }
 424                         if (skip_prefix(line, "unshallow ", &arg)) {
 425                                 if (get_sha1_hex(arg, sha1))
 426                                         die(_("invalid unshallow line: %s"), line);
 427                                 if (!lookup_object(sha1))
 428                                         die(_("object not found: %s"), line);
 429                                 /* make sure that it is parsed as shallow */
 430                                 if (!parse_object(sha1))
 431                                         die(_("error in object: %s"), line);
 432                                 if (unregister_shallow(sha1))
 433                                         die(_("no shallow found: %s"), line);
 434                                 continue;
 435                         }
 436                         die(_("expected shallow/unshallow, got %s"), line);
 437                 }
 438         } else if (!args->stateless_rpc)
 439                 send_request(args, fd[1], &req_buf);
 440
 441         if (!args->stateless_rpc) {
 442                 /* If we aren't using the stateless-rpc interface
 443                  * we don't need to retain the headers.
 444                  */
 445                 strbuf_setlen(&req_buf, 0);
 446                 state_len = 0;
 447         }
 448
 449         flushes = 0;
 450         retval = -1;
 451         while ((sha1 = get_rev())) {
 452                 packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
 453                 print_verbose(args, "have %s", sha1_to_hex(sha1));
 454                 in_vain++;
 455                 if (flush_at <= ++count) {
 456                         int ack;
 457
 458                         packet_buf_flush(&req_buf);
 459                         send_request(args, fd[1], &req_buf);
 460                         strbuf_setlen(&req_buf, state_len);
 461                         flushes++;
 462                         flush_at = next_flush(args, count);
 463
 464                         /*
 465                          * We keep one window "ahead" of the other side, and
 466                          * will wait for an ACK only on the next one
 467                          */
 468                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 469                                 continue;
 470
 471                         consume_shallow_list(args, fd[0]);
 472                         do {
 473                                 ack = get_ack(fd[0], result_sha1);
 474                                 if (ack)
 475                                         print_verbose(args, _("got %s %d %s"), "ack",
 476                                                       ack, sha1_to_hex(result_sha1));
 477                                 switch (ack) {
 478                                 case ACK:
 479                                         flushes = 0;
 480                                         multi_ack = 0;
 481                                         retval = 0;
 482                                         goto done;
 483                                 case ACK_common:
 484                                 case ACK_ready:
 485                                 case ACK_continue: {
 486                                         struct commit *commit =
 487                                                 lookup_commit(result_sha1);
 488                                         if (!commit)
 489                                                 die(_("invalid commit %s"), sha1_to_hex(result_sha1));
 490                                         if (args->stateless_rpc
 491                                          && ack == ACK_common
 492                                          && !(commit->object.flags & COMMON)) {
 493                                                 /* We need to replay the have for this object
 494                                                  * on the next RPC request so the peer knows
 495                                                  * it is in common with us.
 496                                                  */
 497                                                 const char *hex = sha1_to_hex(result_sha1);
 498                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 499                                                 state_len = req_buf.len;
 500                                                 /*
 501                                                  * Reset in_vain because an ack
 502                                                  * for this commit has not been
 503                                                  * seen.
 504                                                  */
 505                                                 in_vain = 0;
 506                                         } else if (!args->stateless_rpc
 507                                                    || ack != ACK_common)
 508                                                 in_vain = 0;
 509                                         mark_common(commit, 0, 1);
 510                                         retval = 0;
 511                                         got_continue = 1;
 512                                         if (ack == ACK_ready) {
 513                                                 clear_prio_queue(&rev_list);
 514                                                 got_ready = 1;
 515                                         }
 516                                         break;
 517                                         }
 518                                 }
 519                         } while (ack);
 520                         flushes--;
 521                         if (got_continue && MAX_IN_VAIN < in_vain) {
 522                                 print_verbose(args, _("giving up"));
 523                                 break; /* give up */
 524                         }
 525                 }
 526         }
 527 done:
 528         if (!got_ready || !no_done) {
 529                 packet_buf_write(&req_buf, "done\n");
 530                 send_request(args, fd[1], &req_buf);
 531         }
 532         print_verbose(args, _("done"));
 533         if (retval != 0) {
 534                 multi_ack = 0;
 535                 flushes++;
 536         }
 537         strbuf_release(&req_buf);
 538
 539         if (!got_ready || !no_done)
 540                 consume_shallow_list(args, fd[0]);
 541         while (flushes || multi_ack) {
 542                 int ack = get_ack(fd[0], result_sha1);
 543                 if (ack) {
 544                         print_verbose(args, _("got %s (%d) %s"), "ack",
 545                                       ack, sha1_to_hex(result_sha1));
 546                         if (ack == ACK)
 547                                 return 0;
 548                         multi_ack = 1;
 549                         continue;
 550                 }
 551                 flushes--;
 552         }
 553         /* it is no error to fetch into a completely empty repo */
 554         return count ? retval : 0;
 555 }
 556
 557 static struct commit_list *complete;
 558
 559 static int mark_complete(const unsigned char *sha1)
 560 {
 561         struct object *o = parse_object(sha1);
 562
 563         while (o && o->type == OBJ_TAG) {
 564                 struct tag *t = (struct tag *) o;
 565                 if (!t->tagged)
 566                         break; /* broken repository */
 567                 o->flags |= COMPLETE;
 568                 o = parse_object(t->tagged->oid.hash);
 569         }
 570         if (o && o->type == OBJ_COMMIT) {
 571                 struct commit *commit = (struct commit *)o;
 572                 if (!(commit->object.flags & COMPLETE)) {
 573                         commit->object.flags |= COMPLETE;
 574                         commit_list_insert(commit, &complete);
 575                 }
 576         }
 577         return 0;
 578 }
 579
 580 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 581                              int flag, void *cb_data)
 582 {
 583         return mark_complete(oid->hash);
 584 }
 585
 586 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 587                                          unsigned long cutoff)
 588 {
 589         while (complete && cutoff <= complete->item->date) {
 590                 print_verbose(args, _("Marking %s as complete"),
 591                               oid_to_hex(&complete->item->object.oid));
 592                 pop_most_recent_commit(&complete, COMPLETE);
 593         }
 594 }
 595
 596 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 597 {
 598         for (; refs; refs = refs->next)
 599                 oidset_insert(oids, &refs->old_oid);
 600 }
 601
 602 static int tip_oids_contain(struct oidset *tip_oids,
 603                             struct ref *unmatched, struct ref *newlist,
 604                             const struct object_id *id)
 605 {
 606         /*
 607          * Note that this only looks at the ref lists the first time it's
 608          * called. This works out in filter_refs() because even though it may
 609          * add to "newlist" between calls, the additions will always be for
 610          * oids that are already in the set.
 611          */
 612         if (!tip_oids->map.tablesize) {
 613                 add_refs_to_oidset(tip_oids, unmatched);
 614                 add_refs_to_oidset(tip_oids, newlist);
 615         }
 616         return oidset_contains(tip_oids, id);
 617 }
 618
 619 static void filter_refs(struct fetch_pack_args *args,
 620                         struct ref **refs,
 621                         struct ref **sought, int nr_sought)
 622 {
 623         struct ref *newlist = NULL;
 624         struct ref **newtail = &newlist;
 625         struct ref *unmatched = NULL;
 626         struct ref *ref, *next;
 627         struct oidset tip_oids = OIDSET_INIT;
 628         int i;
 629
 630         i = 0;
 631         for (ref = *refs; ref; ref = next) {
 632                 int keep = 0;
 633                 next = ref->next;
 634
 635                 if (starts_with(ref->name, "refs/") &&
 636                     check_refname_format(ref->name, 0))
 637                         ; /* trash */
 638                 else {
 639                         while (i < nr_sought) {
 640                                 int cmp = strcmp(ref->name, sought[i]->name);
 641                                 if (cmp < 0)
 642                                         break; /* definitely do not have it */
 643                                 else if (cmp == 0) {
 644                                         keep = 1; /* definitely have it */
 645                                         sought[i]->match_status = REF_MATCHED;
 646                                 }
 647                                 i++;
 648                         }
 649                 }
 650
 651                 if (!keep && args->fetch_all &&
 652                     (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 653                         keep = 1;
 654
 655                 if (keep) {
 656                         *newtail = ref;
 657                         ref->next = NULL;
 658                         newtail = &ref->next;
 659                 } else {
 660                         ref->next = unmatched;
 661                         unmatched = ref;
 662                 }
 663         }
 664
 665         /* Append unmatched requests to the list */
 666         for (i = 0; i < nr_sought; i++) {
 667                 unsigned char sha1[20];
 668
 669                 ref = sought[i];
 670                 if (ref->match_status != REF_NOT_MATCHED)
 671                         continue;
 672                 if (get_sha1_hex(ref->name, sha1) ||
 673                     ref->name[40] != '\0' ||
 674                     hashcmp(sha1, ref->old_oid.hash))
 675                         continue;
 676
 677                 if ((allow_unadvertised_object_request &
 678                      (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1)) ||
 679                     tip_oids_contain(&tip_oids, unmatched, newlist,
 680                                      &ref->old_oid)) {
 681                         ref->match_status = REF_MATCHED;
 682                         *newtail = copy_ref(ref);
 683                         newtail = &(*newtail)->next;
 684                 } else {
 685                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 686                 }
 687         }
 688
 689         oidset_clear(&tip_oids);
 690         for (ref = unmatched; ref; ref = next) {
 691                 next = ref->next;
 692                 free(ref);
 693         }
 694
 695         *refs = newlist;
 696 }
 697
 698 static void mark_alternate_complete(struct object *obj)
 699 {
 700         mark_complete(obj->oid.hash);
 701 }
 702
 703 static int everything_local(struct fetch_pack_args *args,
 704                             struct ref **refs,
 705                             struct ref **sought, int nr_sought)
 706 {
 707         struct ref *ref;
 708         int retval;
 709         unsigned long cutoff = 0;
 710
 711         save_commit_buffer = 0;
 712
 713         for (ref = *refs; ref; ref = ref->next) {
 714                 struct object *o;
 715
 716                 if (!has_object_file(&ref->old_oid))
 717                         continue;
 718
 719                 o = parse_object(ref->old_oid.hash);
 720                 if (!o)
 721                         continue;
 722
 723                 /* We already have it -- which may mean that we were
 724                  * in sync with the other side at some time after
 725                  * that (it is OK if we guess wrong here).
 726                  */
 727                 if (o->type == OBJ_COMMIT) {
 728                         struct commit *commit = (struct commit *)o;
 729                         if (!cutoff || cutoff < commit->date)
 730                                 cutoff = commit->date;
 731                 }
 732         }
 733
 734         if (!args->deepen) {
 735                 for_each_ref(mark_complete_oid, NULL);
 736                 for_each_cached_alternate(mark_alternate_complete);
 737                 commit_list_sort_by_date(&complete);
 738                 if (cutoff)
 739                         mark_recent_complete_commits(args, cutoff);
 740         }
 741
 742         /*
 743          * Mark all complete remote refs as common refs.
 744          * Don't mark them common yet; the server has to be told so first.
 745          */
 746         for (ref = *refs; ref; ref = ref->next) {
 747                 struct object *o = deref_tag(lookup_object(ref->old_oid.hash),
 748                                              NULL, 0);
 749
 750                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 751                         continue;
 752
 753                 if (!(o->flags & SEEN)) {
 754                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 755
 756                         mark_common((struct commit *)o, 1, 1);
 757                 }
 758         }
 759
 760         filter_refs(args, refs, sought, nr_sought);
 761
 762         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 763                 const unsigned char *remote = ref->old_oid.hash;
 764                 struct object *o;
 765
 766                 o = lookup_object(remote);
 767                 if (!o || !(o->flags & COMPLETE)) {
 768                         retval = 0;
 769                         print_verbose(args, "want %s (%s)", sha1_to_hex(remote),
 770                                       ref->name);
 771                         continue;
 772                 }
 773                 print_verbose(args, _("already have %s (%s)"), sha1_to_hex(remote),
 774                               ref->name);
 775         }
 776         return retval;
 777 }
 778
 779 static int sideband_demux(int in, int out, void *data)
 780 {
 781         int *xd = data;
 782         int ret;
 783
 784         ret = recv_sideband("fetch-pack", xd[0], out);
 785         close(out);
 786         return ret;
 787 }
 788
 789 static int get_pack(struct fetch_pack_args *args,
 790                     int xd[2], char **pack_lockfile)
 791 {
 792         struct async demux;
 793         int do_keep = args->keep_pack;
 794         const char *cmd_name;
 795         struct pack_header header;
 796         int pass_header = 0;
 797         struct child_process cmd = CHILD_PROCESS_INIT;
 798         int ret;
 799
 800         memset(&demux, 0, sizeof(demux));
 801         if (use_sideband) {
 802                 /* xd[] is talking with upload-pack; subprocess reads from
 803                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 804                  * through demux->out.
 805                  */
 806                 demux.proc = sideband_demux;
 807                 demux.data = xd;
 808                 demux.out = -1;
 809                 demux.isolate_sigpipe = 1;
 810                 if (start_async(&demux))
 811                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 812         }
 813         else
 814                 demux.out = xd[0];
 815
 816         if (!args->keep_pack && unpack_limit) {
 817
 818                 if (read_pack_header(demux.out, &header))
 819                         die(_("protocol error: bad pack header"));
 820                 pass_header = 1;
 821                 if (ntohl(header.hdr_entries) < unpack_limit)
 822                         do_keep = 0;
 823                 else
 824                         do_keep = 1;
 825         }
 826
 827         if (alternate_shallow_file) {
 828                 argv_array_push(&cmd.args, "--shallow-file");
 829                 argv_array_push(&cmd.args, alternate_shallow_file);
 830         }
 831
 832         if (do_keep) {
 833                 if (pack_lockfile)
 834                         cmd.out = -1;
 835                 cmd_name = "index-pack";
 836                 argv_array_push(&cmd.args, cmd_name);
 837                 argv_array_push(&cmd.args, "--stdin");
 838                 if (!args->quiet && !args->no_progress)
 839                         argv_array_push(&cmd.args, "-v");
 840                 if (args->use_thin_pack)
 841                         argv_array_push(&cmd.args, "--fix-thin");
 842                 if (args->lock_pack || unpack_limit) {
 843                         char hostname[HOST_NAME_MAX + 1];
 844                         if (xgethostname(hostname, sizeof(hostname)))
 845                                 xsnprintf(hostname, sizeof(hostname), "localhost");
 846                         argv_array_pushf(&cmd.args,
 847                                         "--keep=fetch-pack %"PRIuMAX " on %s",
 848                                         (uintmax_t)getpid(), hostname);
 849                 }
 850                 if (args->check_self_contained_and_connected)
 851                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 852         }
 853         else {
 854                 cmd_name = "unpack-objects";
 855                 argv_array_push(&cmd.args, cmd_name);
 856                 if (args->quiet || args->no_progress)
 857                         argv_array_push(&cmd.args, "-q");
 858                 args->check_self_contained_and_connected = 0;
 859         }
 860
 861         if (pass_header)
 862                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 863                                  ntohl(header.hdr_version),
 864                                  ntohl(header.hdr_entries));
 865         if (fetch_fsck_objects >= 0
 866             ? fetch_fsck_objects
 867             : transfer_fsck_objects >= 0
 868             ? transfer_fsck_objects
 869             : 0)
 870                 argv_array_push(&cmd.args, "--strict");
 871
 872         cmd.in = demux.out;
 873         cmd.git_cmd = 1;
 874         if (start_command(&cmd))
 875                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
 876         if (do_keep && pack_lockfile) {
 877                 *pack_lockfile = index_pack_lockfile(cmd.out);
 878                 close(cmd.out);
 879         }
 880
 881         if (!use_sideband)
 882                 /* Closed by start_command() */
 883                 xd[0] = -1;
 884
 885         ret = finish_command(&cmd);
 886         if (!ret || (args->check_self_contained_and_connected && ret == 1))
 887                 args->self_contained_and_connected =
 888                         args->check_self_contained_and_connected &&
 889                         ret == 0;
 890         else
 891                 die(_("%s failed"), cmd_name);
 892         if (use_sideband && finish_async(&demux))
 893                 die(_("error in sideband demultiplexer"));
 894         return 0;
 895 }
 896
 897 static int cmp_ref_by_name(const void *a_, const void *b_)
 898 {
 899         const struct ref *a = *((const struct ref **)a_);
 900         const struct ref *b = *((const struct ref **)b_);
 901         return strcmp(a->name, b->name);
 902 }
 903
 904 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 905                                  int fd[2],
 906                                  const struct ref *orig_ref,
 907                                  struct ref **sought, int nr_sought,
 908                                  struct shallow_info *si,
 909                                  char **pack_lockfile)
 910 {
 911         struct ref *ref = copy_ref_list(orig_ref);
 912         unsigned char sha1[20];
 913         const char *agent_feature;
 914         int agent_len;
 915
 916         sort_ref_list(&ref, ref_compare_name);
 917         QSORT(sought, nr_sought, cmp_ref_by_name);
 918
 919         if ((args->depth > 0 || is_repository_shallow()) && !server_supports("shallow"))
 920                 die(_("Server does not support shallow clients"));
 921         if (args->depth > 0 || args->deepen_since || args->deepen_not)
 922                 args->deepen = 1;
 923         if (server_supports("multi_ack_detailed")) {
 924                 print_verbose(args, _("Server supports multi_ack_detailed"));
 925                 multi_ack = 2;
 926                 if (server_supports("no-done")) {
 927                         print_verbose(args, _("Server supports no-done"));
 928                         if (args->stateless_rpc)
 929                                 no_done = 1;
 930                 }
 931         }
 932         else if (server_supports("multi_ack")) {
 933                 print_verbose(args, _("Server supports multi_ack"));
 934                 multi_ack = 1;
 935         }
 936         if (server_supports("side-band-64k")) {
 937                 print_verbose(args, _("Server supports side-band-64k"));
 938                 use_sideband = 2;
 939         }
 940         else if (server_supports("side-band")) {
 941                 print_verbose(args, _("Server supports side-band"));
 942                 use_sideband = 1;
 943         }
 944         if (server_supports("allow-tip-sha1-in-want")) {
 945                 print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 946                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 947         }
 948         if (server_supports("allow-reachable-sha1-in-want")) {
 949                 print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 950                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 951         }
 952         if (!server_supports("thin-pack"))
 953                 args->use_thin_pack = 0;
 954         if (!server_supports("no-progress"))
 955                 args->no_progress = 0;
 956         if (!server_supports("include-tag"))
 957                 args->include_tag = 0;
 958         if (server_supports("ofs-delta"))
 959                 print_verbose(args, _("Server supports ofs-delta"));
 960         else
 961                 prefer_ofs_delta = 0;
 962
 963         if ((agent_feature = server_feature_value("agent", &agent_len))) {
 964                 agent_supported = 1;
 965                 if (agent_len)
 966                         print_verbose(args, _("Server version is %.*s"),
 967                                       agent_len, agent_feature);
 968         }
 969         if (server_supports("deepen-since"))
 970                 deepen_since_ok = 1;
 971         else if (args->deepen_since)
 972                 die(_("Server does not support --shallow-since"));
 973         if (server_supports("deepen-not"))
 974                 deepen_not_ok = 1;
 975         else if (args->deepen_not)
 976                 die(_("Server does not support --shallow-exclude"));
 977         if (!server_supports("deepen-relative") && args->deepen_relative)
 978                 die(_("Server does not support --deepen"));
 979
 980         if (everything_local(args, &ref, sought, nr_sought)) {
 981                 packet_flush(fd[1]);
 982                 goto all_done;
 983         }
 984         if (find_common(args, fd, sha1, ref) < 0)
 985                 if (!args->keep_pack)
 986                         /* When cloning, it is not unusual to have
 987                          * no common commit.
 988                          */
 989                         warning(_("no common commits"));
 990
 991         if (args->stateless_rpc)
 992                 packet_flush(fd[1]);
 993         if (args->deepen)
 994                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
 995                                         NULL);
 996         else if (si->nr_ours || si->nr_theirs)
 997                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
 998         else
 999                 alternate_shallow_file = NULL;
1000         if (get_pack(args, fd, pack_lockfile))
1001                 die(_("git fetch-pack: fetch failed."));
1002
1003  all_done:
1004         return ref;
1005 }
1006
1007 static void fetch_pack_config(void)
1008 {
1009         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1010         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1011         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1012         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1013         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1014
1015         git_config(git_default_config, NULL);
1016 }
1017
1018 static void fetch_pack_setup(void)
1019 {
1020         static int did_setup;
1021         if (did_setup)
1022                 return;
1023         fetch_pack_config();
1024         if (0 <= transfer_unpack_limit)
1025                 unpack_limit = transfer_unpack_limit;
1026         else if (0 <= fetch_unpack_limit)
1027                 unpack_limit = fetch_unpack_limit;
1028         did_setup = 1;
1029 }
1030
1031 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1032 {
1033         struct string_list names = STRING_LIST_INIT_NODUP;
1034         int src, dst;
1035
1036         for (src = dst = 0; src < nr; src++) {
1037                 struct string_list_item *item;
1038                 item = string_list_insert(&names, ref[src]->name);
1039                 if (item->util)
1040                         continue; /* already have it */
1041                 item->util = ref[src];
1042                 if (src != dst)
1043                         ref[dst] = ref[src];
1044                 dst++;
1045         }
1046         for (src = dst; src < nr; src++)
1047                 ref[src] = NULL;
1048         string_list_clear(&names, 0);
1049         return dst;
1050 }
1051
1052 static void update_shallow(struct fetch_pack_args *args,
1053                            struct ref **sought, int nr_sought,
1054                            struct shallow_info *si)
1055 {
1056         struct oid_array ref = OID_ARRAY_INIT;
1057         int *status;
1058         int i;
1059
1060         if (args->deepen && alternate_shallow_file) {
1061                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1062                         unlink_or_warn(git_path_shallow());
1063                         rollback_lock_file(&shallow_lock);
1064                 } else
1065                         commit_lock_file(&shallow_lock);
1066                 return;
1067         }
1068
1069         if (!si->shallow || !si->shallow->nr)
1070                 return;
1071
1072         if (args->cloning) {
1073                 /*
1074                  * remote is shallow, but this is a clone, there are
1075                  * no objects in repo to worry about. Accept any
1076                  * shallow points that exist in the pack (iow in repo
1077                  * after get_pack() and reprepare_packed_git())
1078                  */
1079                 struct oid_array extra = OID_ARRAY_INIT;
1080                 struct object_id *oid = si->shallow->oid;
1081                 for (i = 0; i < si->shallow->nr; i++)
1082                         if (has_object_file(&oid[i]))
1083                                 oid_array_append(&extra, &oid[i]);
1084                 if (extra.nr) {
1085                         setup_alternate_shallow(&shallow_lock,
1086                                                 &alternate_shallow_file,
1087                                                 &extra);
1088                         commit_lock_file(&shallow_lock);
1089                 }
1090                 oid_array_clear(&extra);
1091                 return;
1092         }
1093
1094         if (!si->nr_ours && !si->nr_theirs)
1095                 return;
1096
1097         remove_nonexistent_theirs_shallow(si);
1098         if (!si->nr_ours && !si->nr_theirs)
1099                 return;
1100         for (i = 0; i < nr_sought; i++)
1101                 oid_array_append(&ref, &sought[i]->old_oid);
1102         si->ref = &ref;
1103
1104         if (args->update_shallow) {
1105                 /*
1106                  * remote is also shallow, .git/shallow may be updated
1107                  * so all refs can be accepted. Make sure we only add
1108                  * shallow roots that are actually reachable from new
1109                  * refs.
1110                  */
1111                 struct oid_array extra = OID_ARRAY_INIT;
1112                 struct object_id *oid = si->shallow->oid;
1113                 assign_shallow_commits_to_refs(si, NULL, NULL);
1114                 if (!si->nr_ours && !si->nr_theirs) {
1115                         oid_array_clear(&ref);
1116                         return;
1117                 }
1118                 for (i = 0; i < si->nr_ours; i++)
1119                         oid_array_append(&extra, &oid[si->ours[i]]);
1120                 for (i = 0; i < si->nr_theirs; i++)
1121                         oid_array_append(&extra, &oid[si->theirs[i]]);
1122                 setup_alternate_shallow(&shallow_lock,
1123                                         &alternate_shallow_file,
1124                                         &extra);
1125                 commit_lock_file(&shallow_lock);
1126                 oid_array_clear(&extra);
1127                 oid_array_clear(&ref);
1128                 return;
1129         }
1130
1131         /*
1132          * remote is also shallow, check what ref is safe to update
1133          * without updating .git/shallow
1134          */
1135         status = xcalloc(nr_sought, sizeof(*status));
1136         assign_shallow_commits_to_refs(si, NULL, status);
1137         if (si->nr_ours || si->nr_theirs) {
1138                 for (i = 0; i < nr_sought; i++)
1139                         if (status[i])
1140                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1141         }
1142         free(status);
1143         oid_array_clear(&ref);
1144 }
1145
1146 struct ref *fetch_pack(struct fetch_pack_args *args,
1147                        int fd[], struct child_process *conn,
1148                        const struct ref *ref,
1149                        const char *dest,
1150                        struct ref **sought, int nr_sought,
1151                        struct oid_array *shallow,
1152                        char **pack_lockfile)
1153 {
1154         struct ref *ref_cpy;
1155         struct shallow_info si;
1156
1157         fetch_pack_setup();
1158         if (nr_sought)
1159                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1160
1161         if (!ref) {
1162                 packet_flush(fd[1]);
1163                 die(_("no matching remote head"));
1164         }
1165         prepare_shallow_info(&si, shallow);
1166         ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1167                                 &si, pack_lockfile);
1168         reprepare_packed_git();
1169         update_shallow(args, sought, nr_sought, &si);
1170         clear_shallow_info(&si);
1171         return ref_cpy;
1172 }
1173
1174 int report_unmatched_refs(struct ref **sought, int nr_sought)
1175 {
1176         int i, ret = 0;
1177
1178         for (i = 0; i < nr_sought; i++) {
1179                 if (!sought[i])
1180                         continue;
1181                 switch (sought[i]->match_status) {
1182                 case REF_MATCHED:
1183                         continue;
1184                 case REF_NOT_MATCHED:
1185                         error(_("no such remote ref %s"), sought[i]->name);
1186                         break;
1187                 case REF_UNADVERTISED_NOT_ALLOWED:
1188                         error(_("Server does not allow request for unadvertised object %s"),
1189                               sought[i]->name);
1190                         break;
1191                 }
1192                 ret = 1;
1193         }
1194         return ret;
1195 }