builtin/fetch-pack.c

   1 #include "builtin.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include "commit.h"
   5 #include "tag.h"
   6 #include "exec_cmd.h"
   7 #include "pack.h"
   8 #include "sideband.h"
   9 #include "fetch-pack.h"
  10 #include "remote.h"
  11 #include "run-command.h"
  12 #include "transport.h"
  13 #include "version.h"
  14
  15 static int transfer_unpack_limit = -1;
  16 static int fetch_unpack_limit = -1;
  17 static int unpack_limit = 100;
  18 static int prefer_ofs_delta = 1;
  19 static int no_done;
  20 static int fetch_fsck_objects = -1;
  21 static int transfer_fsck_objects = -1;
  22 static int agent_supported;
  23 static struct fetch_pack_args args = {
  24         /* .uploadpack = */ "git-upload-pack",
  25 };
  26
  27 static const char fetch_pack_usage[] =
  28 "git fetch-pack [--all] [--stdin] [--quiet|-q] [--keep|-k] [--thin] "
  29 "[--include-tag] [--upload-pack=<git-upload-pack>] [--depth=<n>] "
  30 "[--no-progress] [-v] [<host>:]<directory> [<refs>...]";
  31
  32 #define COMPLETE        (1U << 0)
  33 #define COMMON          (1U << 1)
  34 #define COMMON_REF      (1U << 2)
  35 #define SEEN            (1U << 3)
  36 #define POPPED          (1U << 4)
  37
  38 static int marked;
  39
  40 /*
  41  * After sending this many "have"s if we do not get any new ACK , we
  42  * give up traversing our history.
  43  */
  44 #define MAX_IN_VAIN 256
  45
  46 static struct commit_list *rev_list;
  47 static int non_common_revs, multi_ack, use_sideband;
  48
  49 static void rev_list_push(struct commit *commit, int mark)
  50 {
  51         if (!(commit->object.flags & mark)) {
  52                 commit->object.flags |= mark;
  53
  54                 if (!(commit->object.parsed))
  55                         if (parse_commit(commit))
  56                                 return;
  57
  58                 commit_list_insert_by_date(commit, &rev_list);
  59
  60                 if (!(commit->object.flags & COMMON))
  61                         non_common_revs++;
  62         }
  63 }
  64
  65 static int rev_list_insert_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
  66 {
  67         struct object *o = deref_tag(parse_object(sha1), refname, 0);
  68
  69         if (o && o->type == OBJ_COMMIT)
  70                 rev_list_push((struct commit *)o, SEEN);
  71
  72         return 0;
  73 }
  74
  75 static int clear_marks(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
  76 {
  77         struct object *o = deref_tag(parse_object(sha1), refname, 0);
  78
  79         if (o && o->type == OBJ_COMMIT)
  80                 clear_commit_marks((struct commit *)o,
  81                                    COMMON | COMMON_REF | SEEN | POPPED);
  82         return 0;
  83 }
  84
  85 /*
  86    This function marks a rev and its ancestors as common.
  87    In some cases, it is desirable to mark only the ancestors (for example
  88    when only the server does not yet know that they are common).
  89 */
  90
  91 static void mark_common(struct commit *commit,
  92                 int ancestors_only, int dont_parse)
  93 {
  94         if (commit != NULL && !(commit->object.flags & COMMON)) {
  95                 struct object *o = (struct object *)commit;
  96
  97                 if (!ancestors_only)
  98                         o->flags |= COMMON;
  99
 100                 if (!(o->flags & SEEN))
 101                         rev_list_push(commit, SEEN);
 102                 else {
 103                         struct commit_list *parents;
 104
 105                         if (!ancestors_only && !(o->flags & POPPED))
 106                                 non_common_revs--;
 107                         if (!o->parsed && !dont_parse)
 108                                 if (parse_commit(commit))
 109                                         return;
 110
 111                         for (parents = commit->parents;
 112                                         parents;
 113                                         parents = parents->next)
 114                                 mark_common(parents->item, 0, dont_parse);
 115                 }
 116         }
 117 }
 118
 119 /*
 120   Get the next rev to send, ignoring the common.
 121 */
 122
 123 static const unsigned char *get_rev(void)
 124 {
 125         struct commit *commit = NULL;
 126
 127         while (commit == NULL) {
 128                 unsigned int mark;
 129                 struct commit_list *parents;
 130
 131                 if (rev_list == NULL || non_common_revs == 0)
 132                         return NULL;
 133
 134                 commit = rev_list->item;
 135                 if (!commit->object.parsed)
 136                         parse_commit(commit);
 137                 parents = commit->parents;
 138
 139                 commit->object.flags |= POPPED;
 140                 if (!(commit->object.flags & COMMON))
 141                         non_common_revs--;
 142
 143                 if (commit->object.flags & COMMON) {
 144                         /* do not send "have", and ignore ancestors */
 145                         commit = NULL;
 146                         mark = COMMON | SEEN;
 147                 } else if (commit->object.flags & COMMON_REF)
 148                         /* send "have", and ignore ancestors */
 149                         mark = COMMON | SEEN;
 150                 else
 151                         /* send "have", also for its ancestors */
 152                         mark = SEEN;
 153
 154                 while (parents) {
 155                         if (!(parents->item->object.flags & SEEN))
 156                                 rev_list_push(parents->item, mark);
 157                         if (mark & COMMON)
 158                                 mark_common(parents->item, 1, 0);
 159                         parents = parents->next;
 160                 }
 161
 162                 rev_list = rev_list->next;
 163         }
 164
 165         return commit->object.sha1;
 166 }
 167
 168 enum ack_type {
 169         NAK = 0,
 170         ACK,
 171         ACK_continue,
 172         ACK_common,
 173         ACK_ready
 174 };
 175
 176 static void consume_shallow_list(int fd)
 177 {
 178         if (args.stateless_rpc && args.depth > 0) {
 179                 /* If we sent a depth we will get back "duplicate"
 180                  * shallow and unshallow commands every time there
 181                  * is a block of have lines exchanged.
 182                  */
 183                 char line[1000];
 184                 while (packet_read_line(fd, line, sizeof(line))) {
 185                         if (!prefixcmp(line, "shallow "))
 186                                 continue;
 187                         if (!prefixcmp(line, "unshallow "))
 188                                 continue;
 189                         die("git fetch-pack: expected shallow list");
 190                 }
 191         }
 192 }
 193
 194 struct write_shallow_data {
 195         struct strbuf *out;
 196         int use_pack_protocol;
 197         int count;
 198 };
 199
 200 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 201 {
 202         struct write_shallow_data *data = cb_data;
 203         const char *hex = sha1_to_hex(graft->sha1);
 204         data->count++;
 205         if (data->use_pack_protocol)
 206                 packet_buf_write(data->out, "shallow %s", hex);
 207         else {
 208                 strbuf_addstr(data->out, hex);
 209                 strbuf_addch(data->out, '\n');
 210         }
 211         return 0;
 212 }
 213
 214 static int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
 215 {
 216         struct write_shallow_data data;
 217         data.out = out;
 218         data.use_pack_protocol = use_pack_protocol;
 219         data.count = 0;
 220         for_each_commit_graft(write_one_shallow, &data);
 221         return data.count;
 222 }
 223
 224 static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 225 {
 226         static char line[1000];
 227         int len = packet_read_line(fd, line, sizeof(line));
 228
 229         if (!len)
 230                 die("git fetch-pack: expected ACK/NAK, got EOF");
 231         if (line[len-1] == '\n')
 232                 line[--len] = 0;
 233         if (!strcmp(line, "NAK"))
 234                 return NAK;
 235         if (!prefixcmp(line, "ACK ")) {
 236                 if (!get_sha1_hex(line+4, result_sha1)) {
 237                         if (strstr(line+45, "continue"))
 238                                 return ACK_continue;
 239                         if (strstr(line+45, "common"))
 240                                 return ACK_common;
 241                         if (strstr(line+45, "ready"))
 242                                 return ACK_ready;
 243                         return ACK;
 244                 }
 245         }
 246         die("git fetch_pack: expected ACK/NAK, got '%s'", line);
 247 }
 248
 249 static void send_request(int fd, struct strbuf *buf)
 250 {
 251         if (args.stateless_rpc) {
 252                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 253                 packet_flush(fd);
 254         } else
 255                 safe_write(fd, buf->buf, buf->len);
 256 }
 257
 258 static void insert_one_alternate_ref(const struct ref *ref, void *unused)
 259 {
 260         rev_list_insert_ref(NULL, ref->old_sha1, 0, NULL);
 261 }
 262
 263 #define INITIAL_FLUSH 16
 264 #define PIPESAFE_FLUSH 32
 265 #define LARGE_FLUSH 1024
 266
 267 static int next_flush(int count)
 268 {
 269         int flush_limit = args.stateless_rpc ? LARGE_FLUSH : PIPESAFE_FLUSH;
 270
 271         if (count < flush_limit)
 272                 count <<= 1;
 273         else
 274                 count += flush_limit;
 275         return count;
 276 }
 277
 278 static int find_common(int fd[2], unsigned char *result_sha1,
 279                        struct ref *refs)
 280 {
 281         int fetching;
 282         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 283         const unsigned char *sha1;
 284         unsigned in_vain = 0;
 285         int got_continue = 0;
 286         int got_ready = 0;
 287         struct strbuf req_buf = STRBUF_INIT;
 288         size_t state_len = 0;
 289
 290         if (args.stateless_rpc && multi_ack == 1)
 291                 die("--stateless-rpc requires multi_ack_detailed");
 292         if (marked)
 293                 for_each_ref(clear_marks, NULL);
 294         marked = 1;
 295
 296         for_each_ref(rev_list_insert_ref, NULL);
 297         for_each_alternate_ref(insert_one_alternate_ref, NULL);
 298
 299         fetching = 0;
 300         for ( ; refs ; refs = refs->next) {
 301                 unsigned char *remote = refs->old_sha1;
 302                 const char *remote_hex;
 303                 struct object *o;
 304
 305                 /*
 306                  * If that object is complete (i.e. it is an ancestor of a
 307                  * local ref), we tell them we have it but do not have to
 308                  * tell them about its ancestors, which they already know
 309                  * about.
 310                  *
 311                  * We use lookup_object here because we are only
 312                  * interested in the case we *know* the object is
 313                  * reachable and we have already scanned it.
 314                  */
 315                 if (((o = lookup_object(remote)) != NULL) &&
 316                                 (o->flags & COMPLETE)) {
 317                         continue;
 318                 }
 319
 320                 remote_hex = sha1_to_hex(remote);
 321                 if (!fetching) {
 322                         struct strbuf c = STRBUF_INIT;
 323                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 324                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 325                         if (no_done)            strbuf_addstr(&c, " no-done");
 326                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 327                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 328                         if (args.use_thin_pack) strbuf_addstr(&c, " thin-pack");
 329                         if (args.no_progress)   strbuf_addstr(&c, " no-progress");
 330                         if (args.include_tag)   strbuf_addstr(&c, " include-tag");
 331                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 332                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 333                                                             git_user_agent_sanitized());
 334                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 335                         strbuf_release(&c);
 336                 } else
 337                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 338                 fetching++;
 339         }
 340
 341         if (!fetching) {
 342                 strbuf_release(&req_buf);
 343                 packet_flush(fd[1]);
 344                 return 1;
 345         }
 346
 347         if (is_repository_shallow())
 348                 write_shallow_commits(&req_buf, 1);
 349         if (args.depth > 0)
 350                 packet_buf_write(&req_buf, "deepen %d", args.depth);
 351         packet_buf_flush(&req_buf);
 352         state_len = req_buf.len;
 353
 354         if (args.depth > 0) {
 355                 char line[1024];
 356                 unsigned char sha1[20];
 357
 358                 send_request(fd[1], &req_buf);
 359                 while (packet_read_line(fd[0], line, sizeof(line))) {
 360                         if (!prefixcmp(line, "shallow ")) {
 361                                 if (get_sha1_hex(line + 8, sha1))
 362                                         die("invalid shallow line: %s", line);
 363                                 register_shallow(sha1);
 364                                 continue;
 365                         }
 366                         if (!prefixcmp(line, "unshallow ")) {
 367                                 if (get_sha1_hex(line + 10, sha1))
 368                                         die("invalid unshallow line: %s", line);
 369                                 if (!lookup_object(sha1))
 370                                         die("object not found: %s", line);
 371                                 /* make sure that it is parsed as shallow */
 372                                 if (!parse_object(sha1))
 373                                         die("error in object: %s", line);
 374                                 if (unregister_shallow(sha1))
 375                                         die("no shallow found: %s", line);
 376                                 continue;
 377                         }
 378                         die("expected shallow/unshallow, got %s", line);
 379                 }
 380         } else if (!args.stateless_rpc)
 381                 send_request(fd[1], &req_buf);
 382
 383         if (!args.stateless_rpc) {
 384                 /* If we aren't using the stateless-rpc interface
 385                  * we don't need to retain the headers.
 386                  */
 387                 strbuf_setlen(&req_buf, 0);
 388                 state_len = 0;
 389         }
 390
 391         flushes = 0;
 392         retval = -1;
 393         while ((sha1 = get_rev())) {
 394                 packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
 395                 if (args.verbose)
 396                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 397                 in_vain++;
 398                 if (flush_at <= ++count) {
 399                         int ack;
 400
 401                         packet_buf_flush(&req_buf);
 402                         send_request(fd[1], &req_buf);
 403                         strbuf_setlen(&req_buf, state_len);
 404                         flushes++;
 405                         flush_at = next_flush(count);
 406
 407                         /*
 408                          * We keep one window "ahead" of the other side, and
 409                          * will wait for an ACK only on the next one
 410                          */
 411                         if (!args.stateless_rpc && count == INITIAL_FLUSH)
 412                                 continue;
 413
 414                         consume_shallow_list(fd[0]);
 415                         do {
 416                                 ack = get_ack(fd[0], result_sha1);
 417                                 if (args.verbose && ack)
 418                                         fprintf(stderr, "got ack %d %s\n", ack,
 419                                                         sha1_to_hex(result_sha1));
 420                                 switch (ack) {
 421                                 case ACK:
 422                                         flushes = 0;
 423                                         multi_ack = 0;
 424                                         retval = 0;
 425                                         goto done;
 426                                 case ACK_common:
 427                                 case ACK_ready:
 428                                 case ACK_continue: {
 429                                         struct commit *commit =
 430                                                 lookup_commit(result_sha1);
 431                                         if (!commit)
 432                                                 die("invalid commit %s", sha1_to_hex(result_sha1));
 433                                         if (args.stateless_rpc
 434                                          && ack == ACK_common
 435                                          && !(commit->object.flags & COMMON)) {
 436                                                 /* We need to replay the have for this object
 437                                                  * on the next RPC request so the peer knows
 438                                                  * it is in common with us.
 439                                                  */
 440                                                 const char *hex = sha1_to_hex(result_sha1);
 441                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 442                                                 state_len = req_buf.len;
 443                                         }
 444                                         mark_common(commit, 0, 1);
 445                                         retval = 0;
 446                                         in_vain = 0;
 447                                         got_continue = 1;
 448                                         if (ack == ACK_ready) {
 449                                                 rev_list = NULL;
 450                                                 got_ready = 1;
 451                                         }
 452                                         break;
 453                                         }
 454                                 }
 455                         } while (ack);
 456                         flushes--;
 457                         if (got_continue && MAX_IN_VAIN < in_vain) {
 458                                 if (args.verbose)
 459                                         fprintf(stderr, "giving up\n");
 460                                 break; /* give up */
 461                         }
 462                 }
 463         }
 464 done:
 465         if (!got_ready || !no_done) {
 466                 packet_buf_write(&req_buf, "done\n");
 467                 send_request(fd[1], &req_buf);
 468         }
 469         if (args.verbose)
 470                 fprintf(stderr, "done\n");
 471         if (retval != 0) {
 472                 multi_ack = 0;
 473                 flushes++;
 474         }
 475         strbuf_release(&req_buf);
 476
 477         consume_shallow_list(fd[0]);
 478         while (flushes || multi_ack) {
 479                 int ack = get_ack(fd[0], result_sha1);
 480                 if (ack) {
 481                         if (args.verbose)
 482                                 fprintf(stderr, "got ack (%d) %s\n", ack,
 483                                         sha1_to_hex(result_sha1));
 484                         if (ack == ACK)
 485                                 return 0;
 486                         multi_ack = 1;
 487                         continue;
 488                 }
 489                 flushes--;
 490         }
 491         /* it is no error to fetch into a completely empty repo */
 492         return count ? retval : 0;
 493 }
 494
 495 static struct commit_list *complete;
 496
 497 static int mark_complete(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 498 {
 499         struct object *o = parse_object(sha1);
 500
 501         while (o && o->type == OBJ_TAG) {
 502                 struct tag *t = (struct tag *) o;
 503                 if (!t->tagged)
 504                         break; /* broken repository */
 505                 o->flags |= COMPLETE;
 506                 o = parse_object(t->tagged->sha1);
 507         }
 508         if (o && o->type == OBJ_COMMIT) {
 509                 struct commit *commit = (struct commit *)o;
 510                 if (!(commit->object.flags & COMPLETE)) {
 511                         commit->object.flags |= COMPLETE;
 512                         commit_list_insert_by_date(commit, &complete);
 513                 }
 514         }
 515         return 0;
 516 }
 517
 518 static void mark_recent_complete_commits(unsigned long cutoff)
 519 {
 520         while (complete && cutoff <= complete->item->date) {
 521                 if (args.verbose)
 522                         fprintf(stderr, "Marking %s as complete\n",
 523                                 sha1_to_hex(complete->item->object.sha1));
 524                 pop_most_recent_commit(&complete, COMPLETE);
 525         }
 526 }
 527
 528 static int non_matching_ref(struct string_list_item *item, void *unused)
 529 {
 530         if (item->util) {
 531                 item->util = NULL;
 532                 return 0;
 533         }
 534         else
 535                 return 1;
 536 }
 537
 538 static void filter_refs(struct ref **refs, struct string_list *sought)
 539 {
 540         struct ref **return_refs;
 541         struct ref *newlist = NULL;
 542         struct ref **newtail = &newlist;
 543         struct ref *ref, *next;
 544         struct ref *fastarray[32];
 545         int sought_pos;
 546
 547         if (sought->nr && !args.fetch_all) {
 548                 if (ARRAY_SIZE(fastarray) < sought->nr)
 549                         return_refs = xcalloc(sought->nr, sizeof(struct ref *));
 550                 else {
 551                         return_refs = fastarray;
 552                         memset(return_refs, 0, sizeof(struct ref *) * sought->nr);
 553                 }
 554         }
 555         else
 556                 return_refs = NULL;
 557
 558         sought_pos = 0;
 559         for (ref = *refs; ref; ref = next) {
 560                 next = ref->next;
 561                 if (!memcmp(ref->name, "refs/", 5) &&
 562                     check_refname_format(ref->name + 5, 0))
 563                         ; /* trash */
 564                 else if (args.fetch_all &&
 565                          (!args.depth || prefixcmp(ref->name, "refs/tags/") )) {
 566                         *newtail = ref;
 567                         ref->next = NULL;
 568                         newtail = &ref->next;
 569                         continue;
 570                 }
 571                 else {
 572                         int cmp = -1;
 573                         while (sought_pos < sought->nr) {
 574                                 cmp = strcmp(ref->name, sought->items[sought_pos].string);
 575                                 if (cmp < 0) /* definitely do not have it */
 576                                         break;
 577                                 else if (cmp == 0) { /* definitely have it */
 578                                         return_refs[sought_pos] = ref;
 579                                         sought->items[sought_pos++].util = "matched";
 580                                         break;
 581                                 }
 582                                 else /* might have it; keep looking */
 583                                         sought_pos++;
 584                         }
 585                         if (!cmp)
 586                                 continue; /* we will link it later */
 587                 }
 588                 free(ref);
 589         }
 590
 591         if (!args.fetch_all) {
 592                 int i;
 593                 for (i = 0; i < sought->nr; i++) {
 594                         ref = return_refs[i];
 595                         if (ref) {
 596                                 *newtail = ref;
 597                                 ref->next = NULL;
 598                                 newtail = &ref->next;
 599                         }
 600                 }
 601                 if (return_refs != fastarray)
 602                         free(return_refs);
 603                 filter_string_list(sought, 0, non_matching_ref, NULL);
 604         }
 605         *refs = newlist;
 606 }
 607
 608 static void mark_alternate_complete(const struct ref *ref, void *unused)
 609 {
 610         mark_complete(NULL, ref->old_sha1, 0, NULL);
 611 }
 612
 613 static int everything_local(struct ref **refs, struct string_list *sought)
 614 {
 615         struct ref *ref;
 616         int retval;
 617         unsigned long cutoff = 0;
 618
 619         save_commit_buffer = 0;
 620
 621         for (ref = *refs; ref; ref = ref->next) {
 622                 struct object *o;
 623
 624                 o = parse_object(ref->old_sha1);
 625                 if (!o)
 626                         continue;
 627
 628                 /* We already have it -- which may mean that we were
 629                  * in sync with the other side at some time after
 630                  * that (it is OK if we guess wrong here).
 631                  */
 632                 if (o->type == OBJ_COMMIT) {
 633                         struct commit *commit = (struct commit *)o;
 634                         if (!cutoff || cutoff < commit->date)
 635                                 cutoff = commit->date;
 636                 }
 637         }
 638
 639         if (!args.depth) {
 640                 for_each_ref(mark_complete, NULL);
 641                 for_each_alternate_ref(mark_alternate_complete, NULL);
 642                 if (cutoff)
 643                         mark_recent_complete_commits(cutoff);
 644         }
 645
 646         /*
 647          * Mark all complete remote refs as common refs.
 648          * Don't mark them common yet; the server has to be told so first.
 649          */
 650         for (ref = *refs; ref; ref = ref->next) {
 651                 struct object *o = deref_tag(lookup_object(ref->old_sha1),
 652                                              NULL, 0);
 653
 654                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 655                         continue;
 656
 657                 if (!(o->flags & SEEN)) {
 658                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 659
 660                         mark_common((struct commit *)o, 1, 1);
 661                 }
 662         }
 663
 664         filter_refs(refs, sought);
 665
 666         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 667                 const unsigned char *remote = ref->old_sha1;
 668                 unsigned char local[20];
 669                 struct object *o;
 670
 671                 o = lookup_object(remote);
 672                 if (!o || !(o->flags & COMPLETE)) {
 673                         retval = 0;
 674                         if (!args.verbose)
 675                                 continue;
 676                         fprintf(stderr,
 677                                 "want %s (%s)\n", sha1_to_hex(remote),
 678                                 ref->name);
 679                         continue;
 680                 }
 681
 682                 hashcpy(ref->new_sha1, local);
 683                 if (!args.verbose)
 684                         continue;
 685                 fprintf(stderr,
 686                         "already have %s (%s)\n", sha1_to_hex(remote),
 687                         ref->name);
 688         }
 689         return retval;
 690 }
 691
 692 static int sideband_demux(int in, int out, void *data)
 693 {
 694         int *xd = data;
 695
 696         int ret = recv_sideband("fetch-pack", xd[0], out);
 697         close(out);
 698         return ret;
 699 }
 700
 701 static int get_pack(int xd[2], char **pack_lockfile)
 702 {
 703         struct async demux;
 704         const char *argv[20];
 705         char keep_arg[256];
 706         char hdr_arg[256];
 707         const char **av;
 708         int do_keep = args.keep_pack;
 709         struct child_process cmd;
 710
 711         memset(&demux, 0, sizeof(demux));
 712         if (use_sideband) {
 713                 /* xd[] is talking with upload-pack; subprocess reads from
 714                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 715                  * through demux->out.
 716                  */
 717                 demux.proc = sideband_demux;
 718                 demux.data = xd;
 719                 demux.out = -1;
 720                 if (start_async(&demux))
 721                         die("fetch-pack: unable to fork off sideband"
 722                             " demultiplexer");
 723         }
 724         else
 725                 demux.out = xd[0];
 726
 727         memset(&cmd, 0, sizeof(cmd));
 728         cmd.argv = argv;
 729         av = argv;
 730         *hdr_arg = 0;
 731         if (!args.keep_pack && unpack_limit) {
 732                 struct pack_header header;
 733
 734                 if (read_pack_header(demux.out, &header))
 735                         die("protocol error: bad pack header");
 736                 snprintf(hdr_arg, sizeof(hdr_arg),
 737                          "--pack_header=%"PRIu32",%"PRIu32,
 738                          ntohl(header.hdr_version), ntohl(header.hdr_entries));
 739                 if (ntohl(header.hdr_entries) < unpack_limit)
 740                         do_keep = 0;
 741                 else
 742                         do_keep = 1;
 743         }
 744
 745         if (do_keep) {
 746                 if (pack_lockfile)
 747                         cmd.out = -1;
 748                 *av++ = "index-pack";
 749                 *av++ = "--stdin";
 750                 if (!args.quiet && !args.no_progress)
 751                         *av++ = "-v";
 752                 if (args.use_thin_pack)
 753                         *av++ = "--fix-thin";
 754                 if (args.lock_pack || unpack_limit) {
 755                         int s = sprintf(keep_arg,
 756                                         "--keep=fetch-pack %"PRIuMAX " on ", (uintmax_t) getpid());
 757                         if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 758                                 strcpy(keep_arg + s, "localhost");
 759                         *av++ = keep_arg;
 760                 }
 761         }
 762         else {
 763                 *av++ = "unpack-objects";
 764                 if (args.quiet || args.no_progress)
 765                         *av++ = "-q";
 766         }
 767         if (*hdr_arg)
 768                 *av++ = hdr_arg;
 769         if (fetch_fsck_objects >= 0
 770             ? fetch_fsck_objects
 771             : transfer_fsck_objects >= 0
 772             ? transfer_fsck_objects
 773             : 0)
 774                 *av++ = "--strict";
 775         *av++ = NULL;
 776
 777         cmd.in = demux.out;
 778         cmd.git_cmd = 1;
 779         if (start_command(&cmd))
 780                 die("fetch-pack: unable to fork off %s", argv[0]);
 781         if (do_keep && pack_lockfile) {
 782                 *pack_lockfile = index_pack_lockfile(cmd.out);
 783                 close(cmd.out);
 784         }
 785
 786         if (finish_command(&cmd))
 787                 die("%s failed", argv[0]);
 788         if (use_sideband && finish_async(&demux))
 789                 die("error in sideband demultiplexer");
 790         return 0;
 791 }
 792
 793 static struct ref *do_fetch_pack(int fd[2],
 794                 const struct ref *orig_ref,
 795                 struct string_list *sought,
 796                 char **pack_lockfile)
 797 {
 798         struct ref *ref = copy_ref_list(orig_ref);
 799         unsigned char sha1[20];
 800         const char *agent_feature;
 801         int agent_len;
 802
 803         sort_ref_list(&ref, ref_compare_name);
 804
 805         if (is_repository_shallow() && !server_supports("shallow"))
 806                 die("Server does not support shallow clients");
 807         if (server_supports("multi_ack_detailed")) {
 808                 if (args.verbose)
 809                         fprintf(stderr, "Server supports multi_ack_detailed\n");
 810                 multi_ack = 2;
 811                 if (server_supports("no-done")) {
 812                         if (args.verbose)
 813                                 fprintf(stderr, "Server supports no-done\n");
 814                         if (args.stateless_rpc)
 815                                 no_done = 1;
 816                 }
 817         }
 818         else if (server_supports("multi_ack")) {
 819                 if (args.verbose)
 820                         fprintf(stderr, "Server supports multi_ack\n");
 821                 multi_ack = 1;
 822         }
 823         if (server_supports("side-band-64k")) {
 824                 if (args.verbose)
 825                         fprintf(stderr, "Server supports side-band-64k\n");
 826                 use_sideband = 2;
 827         }
 828         else if (server_supports("side-band")) {
 829                 if (args.verbose)
 830                         fprintf(stderr, "Server supports side-band\n");
 831                 use_sideband = 1;
 832         }
 833         if (!server_supports("thin-pack"))
 834                 args.use_thin_pack = 0;
 835         if (!server_supports("no-progress"))
 836                 args.no_progress = 0;
 837         if (!server_supports("include-tag"))
 838                 args.include_tag = 0;
 839         if (server_supports("ofs-delta")) {
 840                 if (args.verbose)
 841                         fprintf(stderr, "Server supports ofs-delta\n");
 842         } else
 843                 prefer_ofs_delta = 0;
 844
 845         if ((agent_feature = server_feature_value("agent", &agent_len))) {
 846                 agent_supported = 1;
 847                 if (args.verbose && agent_len)
 848                         fprintf(stderr, "Server version is %.*s\n",
 849                                 agent_len, agent_feature);
 850         }
 851
 852         if (everything_local(&ref, sought)) {
 853                 packet_flush(fd[1]);
 854                 goto all_done;
 855         }
 856         if (find_common(fd, sha1, ref) < 0)
 857                 if (!args.keep_pack)
 858                         /* When cloning, it is not unusual to have
 859                          * no common commit.
 860                          */
 861                         warning("no common commits");
 862
 863         if (args.stateless_rpc)
 864                 packet_flush(fd[1]);
 865         if (get_pack(fd, pack_lockfile))
 866                 die("git fetch-pack: fetch failed.");
 867
 868  all_done:
 869         return ref;
 870 }
 871
 872 static int fetch_pack_config(const char *var, const char *value, void *cb)
 873 {
 874         if (strcmp(var, "fetch.unpacklimit") == 0) {
 875                 fetch_unpack_limit = git_config_int(var, value);
 876                 return 0;
 877         }
 878
 879         if (strcmp(var, "transfer.unpacklimit") == 0) {
 880                 transfer_unpack_limit = git_config_int(var, value);
 881                 return 0;
 882         }
 883
 884         if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
 885                 prefer_ofs_delta = git_config_bool(var, value);
 886                 return 0;
 887         }
 888
 889         if (!strcmp(var, "fetch.fsckobjects")) {
 890                 fetch_fsck_objects = git_config_bool(var, value);
 891                 return 0;
 892         }
 893
 894         if (!strcmp(var, "transfer.fsckobjects")) {
 895                 transfer_fsck_objects = git_config_bool(var, value);
 896                 return 0;
 897         }
 898
 899         return git_default_config(var, value, cb);
 900 }
 901
 902 static struct lock_file lock;
 903
 904 static void fetch_pack_setup(void)
 905 {
 906         static int did_setup;
 907         if (did_setup)
 908                 return;
 909         git_config(fetch_pack_config, NULL);
 910         if (0 <= transfer_unpack_limit)
 911                 unpack_limit = transfer_unpack_limit;
 912         else if (0 <= fetch_unpack_limit)
 913                 unpack_limit = fetch_unpack_limit;
 914         did_setup = 1;
 915 }
 916
 917 int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 918 {
 919         int i, ret;
 920         struct ref *ref = NULL;
 921         const char *dest = NULL;
 922         struct string_list sought = STRING_LIST_INIT_DUP;
 923         int fd[2];
 924         char *pack_lockfile = NULL;
 925         char **pack_lockfile_ptr = NULL;
 926         struct child_process *conn;
 927
 928         packet_trace_identity("fetch-pack");
 929
 930         for (i = 1; i < argc && *argv[i] == '-'; i++) {
 931                 const char *arg = argv[i];
 932
 933                 if (!prefixcmp(arg, "--upload-pack=")) {
 934                         args.uploadpack = arg + 14;
 935                         continue;
 936                 }
 937                 if (!prefixcmp(arg, "--exec=")) {
 938                         args.uploadpack = arg + 7;
 939                         continue;
 940                 }
 941                 if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
 942                         args.quiet = 1;
 943                         continue;
 944                 }
 945                 if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
 946                         args.lock_pack = args.keep_pack;
 947                         args.keep_pack = 1;
 948                         continue;
 949                 }
 950                 if (!strcmp("--thin", arg)) {
 951                         args.use_thin_pack = 1;
 952                         continue;
 953                 }
 954                 if (!strcmp("--include-tag", arg)) {
 955                         args.include_tag = 1;
 956                         continue;
 957                 }
 958                 if (!strcmp("--all", arg)) {
 959                         args.fetch_all = 1;
 960                         continue;
 961                 }
 962                 if (!strcmp("--stdin", arg)) {
 963                         args.stdin_refs = 1;
 964                         continue;
 965                 }
 966                 if (!strcmp("-v", arg)) {
 967                         args.verbose = 1;
 968                         continue;
 969                 }
 970                 if (!prefixcmp(arg, "--depth=")) {
 971                         args.depth = strtol(arg + 8, NULL, 0);
 972                         continue;
 973                 }
 974                 if (!strcmp("--no-progress", arg)) {
 975                         args.no_progress = 1;
 976                         continue;
 977                 }
 978                 if (!strcmp("--stateless-rpc", arg)) {
 979                         args.stateless_rpc = 1;
 980                         continue;
 981                 }
 982                 if (!strcmp("--lock-pack", arg)) {
 983                         args.lock_pack = 1;
 984                         pack_lockfile_ptr = &pack_lockfile;
 985                         continue;
 986                 }
 987                 usage(fetch_pack_usage);
 988         }
 989
 990         if (i < argc)
 991                 dest = argv[i++];
 992         else
 993                 usage(fetch_pack_usage);
 994
 995         /*
 996          * Copy refs from cmdline to growable list, then append any
 997          * refs from the standard input:
 998          */
 999         for (; i < argc; i++)
1000                 string_list_append(&sought, xstrdup(argv[i]));
1001         if (args.stdin_refs) {
1002                 if (args.stateless_rpc) {
1003                         /* in stateless RPC mode we use pkt-line to read
1004                          * from stdin, until we get a flush packet
1005                          */
1006                         static char line[1000];
1007                         for (;;) {
1008                                 int n = packet_read_line(0, line, sizeof(line));
1009                                 if (!n)
1010                                         break;
1011                                 if (line[n-1] == '\n')
1012                                         n--;
1013                                 string_list_append(&sought, xmemdupz(line, n));
1014                         }
1015                 }
1016                 else {
1017                         /* read from stdin one ref per line, until EOF */
1018                         struct strbuf line = STRBUF_INIT;
1019                         while (strbuf_getline(&line, stdin, '\n') != EOF)
1020                                 string_list_append(&sought, strbuf_detach(&line, NULL));
1021                         strbuf_release(&line);
1022                 }
1023         }
1024
1025         if (args.stateless_rpc) {
1026                 conn = NULL;
1027                 fd[0] = 0;
1028                 fd[1] = 1;
1029         } else {
1030                 conn = git_connect(fd, dest, args.uploadpack,
1031                                    args.verbose ? CONNECT_VERBOSE : 0);
1032         }
1033
1034         get_remote_heads(fd[0], &ref, 0, NULL);
1035
1036         ref = fetch_pack(&args, fd, conn, ref, dest,
1037                          &sought, pack_lockfile_ptr);
1038         if (pack_lockfile) {
1039                 printf("lock %s\n", pack_lockfile);
1040                 fflush(stdout);
1041         }
1042         close(fd[0]);
1043         close(fd[1]);
1044         if (finish_connect(conn))
1045                 ref = NULL;
1046         ret = !ref;
1047
1048         if (!ret && sought.nr) {
1049                 /* If the heads to pull were given, we should have
1050                  * consumed all of them by matching the remote.
1051                  * Otherwise, 'git fetch remote no-such-ref' would
1052                  * silently succeed without issuing an error.
1053                  */
1054                 for (i = 0; i < sought.nr; i++)
1055                         error("no such remote ref %s", sought.items[i].string);
1056                 ret = 1;
1057         }
1058         while (ref) {
1059                 printf("%s %s\n",
1060                        sha1_to_hex(ref->old_sha1), ref->name);
1061                 ref = ref->next;
1062         }
1063
1064         return ret;
1065 }
1066
1067 struct ref *fetch_pack(struct fetch_pack_args *my_args,
1068                        int fd[], struct child_process *conn,
1069                        const struct ref *ref,
1070                        const char *dest,
1071                        struct string_list *sought,
1072                        char **pack_lockfile)
1073 {
1074         struct stat st;
1075         struct ref *ref_cpy;
1076
1077         fetch_pack_setup();
1078         if (&args != my_args)
1079                 memcpy(&args, my_args, sizeof(args));
1080         if (args.depth > 0) {
1081                 if (stat(git_path("shallow"), &st))
1082                         st.st_mtime = 0;
1083         }
1084
1085         if (sought->nr) {
1086                 sort_string_list(sought);
1087                 string_list_remove_duplicates(sought, 0);
1088         }
1089
1090         if (!ref) {
1091                 packet_flush(fd[1]);
1092                 die("no matching remote head");
1093         }
1094         ref_cpy = do_fetch_pack(fd, ref, sought, pack_lockfile);
1095
1096         if (args.depth > 0) {
1097                 struct cache_time mtime;
1098                 struct strbuf sb = STRBUF_INIT;
1099                 char *shallow = git_path("shallow");
1100                 int fd;
1101
1102                 mtime.sec = st.st_mtime;
1103                 mtime.nsec = ST_MTIME_NSEC(st);
1104                 if (stat(shallow, &st)) {
1105                         if (mtime.sec)
1106                                 die("shallow file was removed during fetch");
1107                 } else if (st.st_mtime != mtime.sec
1108 #ifdef USE_NSEC
1109                                 || ST_MTIME_NSEC(st) != mtime.nsec
1110 #endif
1111                           )
1112                         die("shallow file was changed during fetch");
1113
1114                 fd = hold_lock_file_for_update(&lock, shallow,
1115                                                LOCK_DIE_ON_ERROR);
1116                 if (!write_shallow_commits(&sb, 0)
1117                  || write_in_full(fd, sb.buf, sb.len) != sb.len) {
1118                         unlink_or_warn(shallow);
1119                         rollback_lock_file(&lock);
1120                 } else {
1121                         commit_lock_file(&lock);
1122                 }
1123                 strbuf_release(&sb);
1124         }
1125
1126         reprepare_packed_git();
1127         return ref_cpy;
1128 }