fetch-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include "commit.h"
   5 #include "tag.h"
   6
   7 static int keep_pack;
   8 static int quiet;
   9 static int verbose;
  10 static int fetch_all;
  11 static const char fetch_pack_usage[] =
  12 "git-fetch-pack [--all] [-q] [-v] [-k] [--thin] [--exec=upload-pack] [host:]directory <refs>...";
  13 static const char *exec = "git-upload-pack";
  14
  15 #define COMPLETE        (1U << 0)
  16 #define COMMON          (1U << 1)
  17 #define COMMON_REF      (1U << 2)
  18 #define SEEN            (1U << 3)
  19 #define POPPED          (1U << 4)
  20
  21 /*
  22  * After sending this many "have"s if we do not get any new ACK , we
  23  * give up traversing our history.
  24  */
  25 #define MAX_IN_VAIN 256
  26
  27 static struct commit_list *rev_list;
  28 static int non_common_revs, multi_ack, use_thin_pack, use_sideband;
  29
  30 static void rev_list_push(struct commit *commit, int mark)
  31 {
  32         if (!(commit->object.flags & mark)) {
  33                 commit->object.flags |= mark;
  34
  35                 if (!(commit->object.parsed))
  36                         parse_commit(commit);
  37
  38                 insert_by_date(commit, &rev_list);
  39
  40                 if (!(commit->object.flags & COMMON))
  41                         non_common_revs++;
  42         }
  43 }
  44
  45 static int rev_list_insert_ref(const char *path, const unsigned char *sha1)
  46 {
  47         struct object *o = deref_tag(parse_object(sha1), path, 0);
  48
  49         if (o && o->type == OBJ_COMMIT)
  50                 rev_list_push((struct commit *)o, SEEN);
  51
  52         return 0;
  53 }
  54
  55 /*
  56    This function marks a rev and its ancestors as common.
  57    In some cases, it is desirable to mark only the ancestors (for example
  58    when only the server does not yet know that they are common).
  59 */
  60
  61 static void mark_common(struct commit *commit,
  62                 int ancestors_only, int dont_parse)
  63 {
  64         if (commit != NULL && !(commit->object.flags & COMMON)) {
  65                 struct object *o = (struct object *)commit;
  66
  67                 if (!ancestors_only)
  68                         o->flags |= COMMON;
  69
  70                 if (!(o->flags & SEEN))
  71                         rev_list_push(commit, SEEN);
  72                 else {
  73                         struct commit_list *parents;
  74
  75                         if (!ancestors_only && !(o->flags & POPPED))
  76                                 non_common_revs--;
  77                         if (!o->parsed && !dont_parse)
  78                                 parse_commit(commit);
  79
  80                         for (parents = commit->parents;
  81                                         parents;
  82                                         parents = parents->next)
  83                                 mark_common(parents->item, 0, dont_parse);
  84                 }
  85         }
  86 }
  87
  88 /*
  89   Get the next rev to send, ignoring the common.
  90 */
  91
  92 static const unsigned char* get_rev(void)
  93 {
  94         struct commit *commit = NULL;
  95
  96         while (commit == NULL) {
  97                 unsigned int mark;
  98                 struct commit_list* parents;
  99
 100                 if (rev_list == NULL || non_common_revs == 0)
 101                         return NULL;
 102
 103                 commit = rev_list->item;
 104                 if (!(commit->object.parsed))
 105                         parse_commit(commit);
 106                 commit->object.flags |= POPPED;
 107                 if (!(commit->object.flags & COMMON))
 108                         non_common_revs--;
 109
 110                 parents = commit->parents;
 111
 112                 if (commit->object.flags & COMMON) {
 113                         /* do not send "have", and ignore ancestors */
 114                         commit = NULL;
 115                         mark = COMMON | SEEN;
 116                 } else if (commit->object.flags & COMMON_REF)
 117                         /* send "have", and ignore ancestors */
 118                         mark = COMMON | SEEN;
 119                 else
 120                         /* send "have", also for its ancestors */
 121                         mark = SEEN;
 122
 123                 while (parents) {
 124                         if (!(parents->item->object.flags & SEEN))
 125                                 rev_list_push(parents->item, mark);
 126                         if (mark & COMMON)
 127                                 mark_common(parents->item, 1, 0);
 128                         parents = parents->next;
 129                 }
 130
 131                 rev_list = rev_list->next;
 132         }
 133
 134         return commit->object.sha1;
 135 }
 136
 137 static int find_common(int fd[2], unsigned char *result_sha1,
 138                        struct ref *refs)
 139 {
 140         int fetching;
 141         int count = 0, flushes = 0, retval;
 142         const unsigned char *sha1;
 143         unsigned in_vain = 0;
 144         int got_continue = 0;
 145
 146         for_each_ref(rev_list_insert_ref);
 147
 148         fetching = 0;
 149         for ( ; refs ; refs = refs->next) {
 150                 unsigned char *remote = refs->old_sha1;
 151                 struct object *o;
 152
 153                 /*
 154                  * If that object is complete (i.e. it is an ancestor of a
 155                  * local ref), we tell them we have it but do not have to
 156                  * tell them about its ancestors, which they already know
 157                  * about.
 158                  *
 159                  * We use lookup_object here because we are only
 160                  * interested in the case we *know* the object is
 161                  * reachable and we have already scanned it.
 162                  */
 163                 if (((o = lookup_object(remote)) != NULL) &&
 164                                 (o->flags & COMPLETE)) {
 165                         continue;
 166                 }
 167
 168                 if (!fetching)
 169                         packet_write(fd[1], "want %s%s%s%s%s%s\n",
 170                                      sha1_to_hex(remote),
 171                                      (multi_ack ? " multi_ack" : ""),
 172                                      (use_sideband == 2 ? " side-band-64k" : ""),
 173                                      (use_sideband == 1 ? " side-band" : ""),
 174                                      (use_thin_pack ? " thin-pack" : ""),
 175                                      " ofs-delta");
 176                 else
 177                         packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
 178                 fetching++;
 179         }
 180         packet_flush(fd[1]);
 181         if (!fetching)
 182                 return 1;
 183
 184         flushes = 0;
 185         retval = -1;
 186         while ((sha1 = get_rev())) {
 187                 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
 188                 if (verbose)
 189                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 190                 in_vain++;
 191                 if (!(31 & ++count)) {
 192                         int ack;
 193
 194                         packet_flush(fd[1]);
 195                         flushes++;
 196
 197                         /*
 198                          * We keep one window "ahead" of the other side, and
 199                          * will wait for an ACK only on the next one
 200                          */
 201                         if (count == 32)
 202                                 continue;
 203
 204                         do {
 205                                 ack = get_ack(fd[0], result_sha1);
 206                                 if (verbose && ack)
 207                                         fprintf(stderr, "got ack %d %s\n", ack,
 208                                                         sha1_to_hex(result_sha1));
 209                                 if (ack == 1) {
 210                                         flushes = 0;
 211                                         multi_ack = 0;
 212                                         retval = 0;
 213                                         goto done;
 214                                 } else if (ack == 2) {
 215                                         struct commit *commit =
 216                                                 lookup_commit(result_sha1);
 217                                         mark_common(commit, 0, 1);
 218                                         retval = 0;
 219                                         in_vain = 0;
 220                                         got_continue = 1;
 221                                 }
 222                         } while (ack);
 223                         flushes--;
 224                         if (got_continue && MAX_IN_VAIN < in_vain) {
 225                                 if (verbose)
 226                                         fprintf(stderr, "giving up\n");
 227                                 break; /* give up */
 228                         }
 229                 }
 230         }
 231 done:
 232         packet_write(fd[1], "done\n");
 233         if (verbose)
 234                 fprintf(stderr, "done\n");
 235         if (retval != 0) {
 236                 multi_ack = 0;
 237                 flushes++;
 238         }
 239         while (flushes || multi_ack) {
 240                 int ack = get_ack(fd[0], result_sha1);
 241                 if (ack) {
 242                         if (verbose)
 243                                 fprintf(stderr, "got ack (%d) %s\n", ack,
 244                                         sha1_to_hex(result_sha1));
 245                         if (ack == 1)
 246                                 return 0;
 247                         multi_ack = 1;
 248                         continue;
 249                 }
 250                 flushes--;
 251         }
 252         return retval;
 253 }
 254
 255 static struct commit_list *complete;
 256
 257 static int mark_complete(const char *path, const unsigned char *sha1)
 258 {
 259         struct object *o = parse_object(sha1);
 260
 261         while (o && o->type == OBJ_TAG) {
 262                 struct tag *t = (struct tag *) o;
 263                 if (!t->tagged)
 264                         break; /* broken repository */
 265                 o->flags |= COMPLETE;
 266                 o = parse_object(t->tagged->sha1);
 267         }
 268         if (o && o->type == OBJ_COMMIT) {
 269                 struct commit *commit = (struct commit *)o;
 270                 commit->object.flags |= COMPLETE;
 271                 insert_by_date(commit, &complete);
 272         }
 273         return 0;
 274 }
 275
 276 static void mark_recent_complete_commits(unsigned long cutoff)
 277 {
 278         while (complete && cutoff <= complete->item->date) {
 279                 if (verbose)
 280                         fprintf(stderr, "Marking %s as complete\n",
 281                                 sha1_to_hex(complete->item->object.sha1));
 282                 pop_most_recent_commit(&complete, COMPLETE);
 283         }
 284 }
 285
 286 static void filter_refs(struct ref **refs, int nr_match, char **match)
 287 {
 288         struct ref **return_refs;
 289         struct ref *newlist = NULL;
 290         struct ref **newtail = &newlist;
 291         struct ref *ref, *next;
 292         struct ref *fastarray[32];
 293
 294         if (nr_match && !fetch_all) {
 295                 if (ARRAY_SIZE(fastarray) < nr_match)
 296                         return_refs = xcalloc(nr_match, sizeof(struct ref *));
 297                 else {
 298                         return_refs = fastarray;
 299                         memset(return_refs, 0, sizeof(struct ref *) * nr_match);
 300                 }
 301         }
 302         else
 303                 return_refs = NULL;
 304
 305         for (ref = *refs; ref; ref = next) {
 306                 next = ref->next;
 307                 if (!memcmp(ref->name, "refs/", 5) &&
 308                     check_ref_format(ref->name + 5))
 309                         ; /* trash */
 310                 else if (fetch_all) {
 311                         *newtail = ref;
 312                         ref->next = NULL;
 313                         newtail = &ref->next;
 314                         continue;
 315                 }
 316                 else {
 317                         int order = path_match(ref->name, nr_match, match);
 318                         if (order) {
 319                                 return_refs[order-1] = ref;
 320                                 continue; /* we will link it later */
 321                         }
 322                 }
 323                 free(ref);
 324         }
 325
 326         if (!fetch_all) {
 327                 int i;
 328                 for (i = 0; i < nr_match; i++) {
 329                         ref = return_refs[i];
 330                         if (ref) {
 331                                 *newtail = ref;
 332                                 ref->next = NULL;
 333                                 newtail = &ref->next;
 334                         }
 335                 }
 336                 if (return_refs != fastarray)
 337                         free(return_refs);
 338         }
 339         *refs = newlist;
 340 }
 341
 342 static int everything_local(struct ref **refs, int nr_match, char **match)
 343 {
 344         struct ref *ref;
 345         int retval;
 346         unsigned long cutoff = 0;
 347
 348         track_object_refs = 0;
 349         save_commit_buffer = 0;
 350
 351         for (ref = *refs; ref; ref = ref->next) {
 352                 struct object *o;
 353
 354                 o = parse_object(ref->old_sha1);
 355                 if (!o)
 356                         continue;
 357
 358                 /* We already have it -- which may mean that we were
 359                  * in sync with the other side at some time after
 360                  * that (it is OK if we guess wrong here).
 361                  */
 362                 if (o->type == OBJ_COMMIT) {
 363                         struct commit *commit = (struct commit *)o;
 364                         if (!cutoff || cutoff < commit->date)
 365                                 cutoff = commit->date;
 366                 }
 367         }
 368
 369         for_each_ref(mark_complete);
 370         if (cutoff)
 371                 mark_recent_complete_commits(cutoff);
 372
 373         /*
 374          * Mark all complete remote refs as common refs.
 375          * Don't mark them common yet; the server has to be told so first.
 376          */
 377         for (ref = *refs; ref; ref = ref->next) {
 378                 struct object *o = deref_tag(lookup_object(ref->old_sha1),
 379                                              NULL, 0);
 380
 381                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 382                         continue;
 383
 384                 if (!(o->flags & SEEN)) {
 385                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 386
 387                         mark_common((struct commit *)o, 1, 1);
 388                 }
 389         }
 390
 391         filter_refs(refs, nr_match, match);
 392
 393         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 394                 const unsigned char *remote = ref->old_sha1;
 395                 unsigned char local[20];
 396                 struct object *o;
 397
 398                 o = lookup_object(remote);
 399                 if (!o || !(o->flags & COMPLETE)) {
 400                         retval = 0;
 401                         if (!verbose)
 402                                 continue;
 403                         fprintf(stderr,
 404                                 "want %s (%s)\n", sha1_to_hex(remote),
 405                                 ref->name);
 406                         continue;
 407                 }
 408
 409                 hashcpy(ref->new_sha1, local);
 410                 if (!verbose)
 411                         continue;
 412                 fprintf(stderr,
 413                         "already have %s (%s)\n", sha1_to_hex(remote),
 414                         ref->name);
 415         }
 416         return retval;
 417 }
 418
 419 static int fetch_pack(int fd[2], int nr_match, char **match)
 420 {
 421         struct ref *ref;
 422         unsigned char sha1[20];
 423         int status;
 424
 425         get_remote_heads(fd[0], &ref, 0, NULL, 0);
 426         if (server_supports("multi_ack")) {
 427                 if (verbose)
 428                         fprintf(stderr, "Server supports multi_ack\n");
 429                 multi_ack = 1;
 430         }
 431         if (server_supports("side-band-64k")) {
 432                 if (verbose)
 433                         fprintf(stderr, "Server supports side-band-64k\n");
 434                 use_sideband = 2;
 435         }
 436         else if (server_supports("side-band")) {
 437                 if (verbose)
 438                         fprintf(stderr, "Server supports side-band\n");
 439                 use_sideband = 1;
 440         }
 441         if (!ref) {
 442                 packet_flush(fd[1]);
 443                 die("no matching remote head");
 444         }
 445         if (everything_local(&ref, nr_match, match)) {
 446                 packet_flush(fd[1]);
 447                 goto all_done;
 448         }
 449         if (find_common(fd, sha1, ref) < 0)
 450                 if (!keep_pack)
 451                         /* When cloning, it is not unusual to have
 452                          * no common commit.
 453                          */
 454                         fprintf(stderr, "warning: no common commits\n");
 455
 456         if (keep_pack)
 457                 status = receive_keep_pack(fd, "git-fetch-pack", quiet, use_sideband);
 458         else
 459                 status = receive_unpack_pack(fd, "git-fetch-pack", quiet, use_sideband);
 460
 461         if (status)
 462                 die("git-fetch-pack: fetch failed.");
 463
 464  all_done:
 465         while (ref) {
 466                 printf("%s %s\n",
 467                        sha1_to_hex(ref->old_sha1), ref->name);
 468                 ref = ref->next;
 469         }
 470         return 0;
 471 }
 472
 473 int main(int argc, char **argv)
 474 {
 475         int i, ret, nr_heads;
 476         char *dest = NULL, **heads;
 477         int fd[2];
 478         pid_t pid;
 479
 480         setup_git_directory();
 481
 482         nr_heads = 0;
 483         heads = NULL;
 484         for (i = 1; i < argc; i++) {
 485                 char *arg = argv[i];
 486
 487                 if (*arg == '-') {
 488                         if (!strncmp("--exec=", arg, 7)) {
 489                                 exec = arg + 7;
 490                                 continue;
 491                         }
 492                         if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
 493                                 quiet = 1;
 494                                 continue;
 495                         }
 496                         if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
 497                                 keep_pack = 1;
 498                                 continue;
 499                         }
 500                         if (!strcmp("--thin", arg)) {
 501                                 use_thin_pack = 1;
 502                                 continue;
 503                         }
 504                         if (!strcmp("--all", arg)) {
 505                                 fetch_all = 1;
 506                                 continue;
 507                         }
 508                         if (!strcmp("-v", arg)) {
 509                                 verbose = 1;
 510                                 continue;
 511                         }
 512                         usage(fetch_pack_usage);
 513                 }
 514                 dest = arg;
 515                 heads = argv + i + 1;
 516                 nr_heads = argc - i - 1;
 517                 break;
 518         }
 519         if (!dest)
 520                 usage(fetch_pack_usage);
 521         if (keep_pack)
 522                 use_thin_pack = 0;
 523         pid = git_connect(fd, dest, exec);
 524         if (pid < 0)
 525                 return 1;
 526         ret = fetch_pack(fd, nr_heads, heads);
 527         close(fd[0]);
 528         close(fd[1]);
 529         ret |= finish_connect(pid);
 530
 531         if (!ret && nr_heads) {
 532                 /* If the heads to pull were given, we should have
 533                  * consumed all of them by matching the remote.
 534                  * Otherwise, 'git-fetch remote no-such-ref' would
 535                  * silently succeed without issuing an error.
 536                  */
 537                 for (i = 0; i < nr_heads; i++)
 538                         if (heads[i] && heads[i][0]) {
 539                                 error("no such remote ref %s", heads[i]);
 540                                 ret = 1;
 541                         }
 542         }
 543
 544         return !!ret;
 545 }