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