upload-pack.con commit git-fetch: use fetch--tool pick-rref to avoid local fetch from alternate (e3c6f24)
   1#include "cache.h"
   2#include "refs.h"
   3#include "pkt-line.h"
   4#include "sideband.h"
   5#include "tag.h"
   6#include "object.h"
   7#include "commit.h"
   8#include "exec_cmd.h"
   9#include "diff.h"
  10#include "revision.h"
  11#include "list-objects.h"
  12
  13static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
  14
  15/* bits #0..7 in revision.h, #8..10 in commit.c */
  16#define THEY_HAVE       (1u << 11)
  17#define OUR_REF         (1u << 12)
  18#define WANTED          (1u << 13)
  19#define COMMON_KNOWN    (1u << 14)
  20#define REACHABLE       (1u << 15)
  21
  22#define SHALLOW         (1u << 16)
  23#define NOT_SHALLOW     (1u << 17)
  24#define CLIENT_SHALLOW  (1u << 18)
  25
  26static unsigned long oldest_have;
  27
  28static int multi_ack, nr_our_refs;
  29static int use_thin_pack, use_ofs_delta, no_progress;
  30static struct object_array have_obj;
  31static struct object_array want_obj;
  32static unsigned int timeout;
  33/* 0 for no sideband,
  34 * otherwise maximum packet size (up to 65520 bytes).
  35 */
  36static int use_sideband;
  37
  38static void reset_timeout(void)
  39{
  40        alarm(timeout);
  41}
  42
  43static int strip(char *line, int len)
  44{
  45        if (len && line[len-1] == '\n')
  46                line[--len] = 0;
  47        return len;
  48}
  49
  50static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
  51{
  52        if (use_sideband)
  53                return send_sideband(1, fd, data, sz, use_sideband);
  54        if (fd == 3)
  55                /* emergency quit */
  56                fd = 2;
  57        if (fd == 2) {
  58                /* XXX: are we happy to lose stuff here? */
  59                xwrite(fd, data, sz);
  60                return sz;
  61        }
  62        return safe_write(fd, data, sz);
  63}
  64
  65FILE *pack_pipe = NULL;
  66static void show_commit(struct commit *commit)
  67{
  68        if (commit->object.flags & BOUNDARY)
  69                fputc('-', pack_pipe);
  70        if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
  71                die("broken output pipe");
  72        fputc('\n', pack_pipe);
  73        fflush(pack_pipe);
  74        free(commit->buffer);
  75        commit->buffer = NULL;
  76}
  77
  78static void show_object(struct object_array_entry *p)
  79{
  80        /* An object with name "foo\n0000000..." can be used to
  81         * confuse downstream git-pack-objects very badly.
  82         */
  83        const char *ep = strchr(p->name, '\n');
  84        if (ep) {
  85                fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(p->item->sha1),
  86                       (int) (ep - p->name),
  87                       p->name);
  88        }
  89        else
  90                fprintf(pack_pipe, "%s %s\n",
  91                                sha1_to_hex(p->item->sha1), p->name);
  92}
  93
  94static void show_edge(struct commit *commit)
  95{
  96        fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
  97}
  98
  99static void create_pack_file(void)
 100{
 101        /* Pipes between rev-list to pack-objects, pack-objects to us
 102         * and pack-objects error stream for progress bar.
 103         */
 104        int lp_pipe[2], pu_pipe[2], pe_pipe[2];
 105        pid_t pid_rev_list, pid_pack_objects;
 106        int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
 107        char data[8193], progress[128];
 108        char abort_msg[] = "aborting due to possible repository "
 109                "corruption on the remote side.";
 110        int buffered = -1;
 111
 112        if (pipe(lp_pipe) < 0)
 113                die("git-upload-pack: unable to create pipe");
 114        pid_rev_list = fork();
 115        if (pid_rev_list < 0)
 116                die("git-upload-pack: unable to fork git-rev-list");
 117
 118        if (!pid_rev_list) {
 119                int i;
 120                struct rev_info revs;
 121
 122                close(lp_pipe[0]);
 123                pack_pipe = fdopen(lp_pipe[1], "w");
 124
 125                if (create_full_pack)
 126                        use_thin_pack = 0; /* no point doing it */
 127                init_revisions(&revs, NULL);
 128                revs.tag_objects = 1;
 129                revs.tree_objects = 1;
 130                revs.blob_objects = 1;
 131                if (use_thin_pack)
 132                        revs.edge_hint = 1;
 133
 134                if (create_full_pack) {
 135                        const char *args[] = {"rev-list", "--all", NULL};
 136                        setup_revisions(2, args, &revs, NULL);
 137                } else {
 138                        for (i = 0; i < want_obj.nr; i++) {
 139                                struct object *o = want_obj.objects[i].item;
 140                                /* why??? */
 141                                o->flags &= ~UNINTERESTING;
 142                                add_pending_object(&revs, o, NULL);
 143                        }
 144                        for (i = 0; i < have_obj.nr; i++) {
 145                                struct object *o = have_obj.objects[i].item;
 146                                o->flags |= UNINTERESTING;
 147                                add_pending_object(&revs, o, NULL);
 148                        }
 149                        setup_revisions(0, NULL, &revs, NULL);
 150                }
 151                prepare_revision_walk(&revs);
 152                mark_edges_uninteresting(revs.commits, &revs, show_edge);
 153                traverse_commit_list(&revs, show_commit, show_object);
 154                exit(0);
 155        }
 156
 157        if (pipe(pu_pipe) < 0)
 158                die("git-upload-pack: unable to create pipe");
 159        if (pipe(pe_pipe) < 0)
 160                die("git-upload-pack: unable to create pipe");
 161        pid_pack_objects = fork();
 162        if (pid_pack_objects < 0) {
 163                /* daemon sets things up to ignore TERM */
 164                kill(pid_rev_list, SIGKILL);
 165                die("git-upload-pack: unable to fork git-pack-objects");
 166        }
 167        if (!pid_pack_objects) {
 168                const char *argv[10];
 169                int i = 0;
 170
 171                dup2(lp_pipe[0], 0);
 172                dup2(pu_pipe[1], 1);
 173                dup2(pe_pipe[1], 2);
 174
 175                close(lp_pipe[0]);
 176                close(lp_pipe[1]);
 177                close(pu_pipe[0]);
 178                close(pu_pipe[1]);
 179                close(pe_pipe[0]);
 180                close(pe_pipe[1]);
 181
 182                argv[i++] = "pack-objects";
 183                argv[i++] = "--stdout";
 184                if (!no_progress)
 185                        argv[i++] = "--progress";
 186                if (use_ofs_delta)
 187                        argv[i++] = "--delta-base-offset";
 188                argv[i++] = NULL;
 189
 190                execv_git_cmd(argv);
 191                kill(pid_rev_list, SIGKILL);
 192                die("git-upload-pack: unable to exec git-pack-objects");
 193        }
 194
 195        close(lp_pipe[0]);
 196        close(lp_pipe[1]);
 197
 198        /* We read from pe_pipe[0] to capture stderr output for
 199         * progress bar, and pu_pipe[0] to capture the pack data.
 200         */
 201        close(pe_pipe[1]);
 202        close(pu_pipe[1]);
 203
 204        while (1) {
 205                const char *who;
 206                struct pollfd pfd[2];
 207                pid_t pid;
 208                int status;
 209                ssize_t sz;
 210                int pe, pu, pollsize;
 211
 212                reset_timeout();
 213
 214                pollsize = 0;
 215                pe = pu = -1;
 216
 217                if (0 <= pu_pipe[0]) {
 218                        pfd[pollsize].fd = pu_pipe[0];
 219                        pfd[pollsize].events = POLLIN;
 220                        pu = pollsize;
 221                        pollsize++;
 222                }
 223                if (0 <= pe_pipe[0]) {
 224                        pfd[pollsize].fd = pe_pipe[0];
 225                        pfd[pollsize].events = POLLIN;
 226                        pe = pollsize;
 227                        pollsize++;
 228                }
 229
 230                if (pollsize) {
 231                        if (poll(pfd, pollsize, -1) < 0) {
 232                                if (errno != EINTR) {
 233                                        error("poll failed, resuming: %s",
 234                                              strerror(errno));
 235                                        sleep(1);
 236                                }
 237                                continue;
 238                        }
 239                        if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 240                                /* Data ready; we keep the last byte
 241                                 * to ourselves in case we detect
 242                                 * broken rev-list, so that we can
 243                                 * leave the stream corrupted.  This
 244                                 * is unfortunate -- unpack-objects
 245                                 * would happily accept a valid pack
 246                                 * data with trailing garbage, so
 247                                 * appending garbage after we pass all
 248                                 * the pack data is not good enough to
 249                                 * signal breakage to downstream.
 250                                 */
 251                                char *cp = data;
 252                                ssize_t outsz = 0;
 253                                if (0 <= buffered) {
 254                                        *cp++ = buffered;
 255                                        outsz++;
 256                                }
 257                                sz = xread(pu_pipe[0], cp,
 258                                          sizeof(data) - outsz);
 259                                if (0 < sz)
 260                                                ;
 261                                else if (sz == 0) {
 262                                        close(pu_pipe[0]);
 263                                        pu_pipe[0] = -1;
 264                                }
 265                                else
 266                                        goto fail;
 267                                sz += outsz;
 268                                if (1 < sz) {
 269                                        buffered = data[sz-1] & 0xFF;
 270                                        sz--;
 271                                }
 272                                else
 273                                        buffered = -1;
 274                                sz = send_client_data(1, data, sz);
 275                                if (sz < 0)
 276                                        goto fail;
 277                        }
 278                        if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 279                                /* Status ready; we ship that in the side-band
 280                                 * or dump to the standard error.
 281                                 */
 282                                sz = xread(pe_pipe[0], progress,
 283                                          sizeof(progress));
 284                                if (0 < sz)
 285                                        send_client_data(2, progress, sz);
 286                                else if (sz == 0) {
 287                                        close(pe_pipe[0]);
 288                                        pe_pipe[0] = -1;
 289                                }
 290                                else
 291                                        goto fail;
 292                        }
 293                }
 294
 295                /* See if the children are still there */
 296                if (pid_rev_list || pid_pack_objects) {
 297                        pid = waitpid(-1, &status, WNOHANG);
 298                        if (!pid)
 299                                continue;
 300                        who = ((pid == pid_rev_list) ? "git-rev-list" :
 301                               (pid == pid_pack_objects) ? "git-pack-objects" :
 302                               NULL);
 303                        if (!who) {
 304                                if (pid < 0) {
 305                                        error("git-upload-pack: %s",
 306                                              strerror(errno));
 307                                        goto fail;
 308                                }
 309                                error("git-upload-pack: we weren't "
 310                                      "waiting for %d", pid);
 311                                continue;
 312                        }
 313                        if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 314                                error("git-upload-pack: %s died with error.",
 315                                      who);
 316                                goto fail;
 317                        }
 318                        if (pid == pid_rev_list)
 319                                pid_rev_list = 0;
 320                        if (pid == pid_pack_objects)
 321                                pid_pack_objects = 0;
 322                        if (pid_rev_list || pid_pack_objects)
 323                                continue;
 324                }
 325
 326                /* both died happily */
 327                if (pollsize)
 328                        continue;
 329
 330                /* flush the data */
 331                if (0 <= buffered) {
 332                        data[0] = buffered;
 333                        sz = send_client_data(1, data, 1);
 334                        if (sz < 0)
 335                                goto fail;
 336                        fprintf(stderr, "flushed.\n");
 337                }
 338                if (use_sideband)
 339                        packet_flush(1);
 340                return;
 341        }
 342 fail:
 343        if (pid_pack_objects)
 344                kill(pid_pack_objects, SIGKILL);
 345        if (pid_rev_list)
 346                kill(pid_rev_list, SIGKILL);
 347        send_client_data(3, abort_msg, sizeof(abort_msg));
 348        die("git-upload-pack: %s", abort_msg);
 349}
 350
 351static int got_sha1(char *hex, unsigned char *sha1)
 352{
 353        struct object *o;
 354        int we_knew_they_have = 0;
 355
 356        if (get_sha1_hex(hex, sha1))
 357                die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 358        if (!has_sha1_file(sha1))
 359                return -1;
 360
 361        o = lookup_object(sha1);
 362        if (!(o && o->parsed))
 363                o = parse_object(sha1);
 364        if (!o)
 365                die("oops (%s)", sha1_to_hex(sha1));
 366        if (o->type == OBJ_COMMIT) {
 367                struct commit_list *parents;
 368                struct commit *commit = (struct commit *)o;
 369                if (o->flags & THEY_HAVE)
 370                        we_knew_they_have = 1;
 371                else
 372                        o->flags |= THEY_HAVE;
 373                if (!oldest_have || (commit->date < oldest_have))
 374                        oldest_have = commit->date;
 375                for (parents = commit->parents;
 376                     parents;
 377                     parents = parents->next)
 378                        parents->item->object.flags |= THEY_HAVE;
 379        }
 380        if (!we_knew_they_have) {
 381                add_object_array(o, NULL, &have_obj);
 382                return 1;
 383        }
 384        return 0;
 385}
 386
 387static int reachable(struct commit *want)
 388{
 389        struct commit_list *work = NULL;
 390
 391        insert_by_date(want, &work);
 392        while (work) {
 393                struct commit_list *list = work->next;
 394                struct commit *commit = work->item;
 395                free(work);
 396                work = list;
 397
 398                if (commit->object.flags & THEY_HAVE) {
 399                        want->object.flags |= COMMON_KNOWN;
 400                        break;
 401                }
 402                if (!commit->object.parsed)
 403                        parse_object(commit->object.sha1);
 404                if (commit->object.flags & REACHABLE)
 405                        continue;
 406                commit->object.flags |= REACHABLE;
 407                if (commit->date < oldest_have)
 408                        continue;
 409                for (list = commit->parents; list; list = list->next) {
 410                        struct commit *parent = list->item;
 411                        if (!(parent->object.flags & REACHABLE))
 412                                insert_by_date(parent, &work);
 413                }
 414        }
 415        want->object.flags |= REACHABLE;
 416        clear_commit_marks(want, REACHABLE);
 417        free_commit_list(work);
 418        return (want->object.flags & COMMON_KNOWN);
 419}
 420
 421static int ok_to_give_up(void)
 422{
 423        int i;
 424
 425        if (!have_obj.nr)
 426                return 0;
 427
 428        for (i = 0; i < want_obj.nr; i++) {
 429                struct object *want = want_obj.objects[i].item;
 430
 431                if (want->flags & COMMON_KNOWN)
 432                        continue;
 433                want = deref_tag(want, "a want line", 0);
 434                if (!want || want->type != OBJ_COMMIT) {
 435                        /* no way to tell if this is reachable by
 436                         * looking at the ancestry chain alone, so
 437                         * leave a note to ourselves not to worry about
 438                         * this object anymore.
 439                         */
 440                        want_obj.objects[i].item->flags |= COMMON_KNOWN;
 441                        continue;
 442                }
 443                if (!reachable((struct commit *)want))
 444                        return 0;
 445        }
 446        return 1;
 447}
 448
 449static int get_common_commits(void)
 450{
 451        static char line[1000];
 452        unsigned char sha1[20];
 453        char hex[41], last_hex[41];
 454        int len;
 455
 456        track_object_refs = 0;
 457        save_commit_buffer = 0;
 458
 459        for(;;) {
 460                len = packet_read_line(0, line, sizeof(line));
 461                reset_timeout();
 462
 463                if (!len) {
 464                        if (have_obj.nr == 0 || multi_ack)
 465                                packet_write(1, "NAK\n");
 466                        continue;
 467                }
 468                len = strip(line, len);
 469                if (!prefixcmp(line, "have ")) {
 470                        switch (got_sha1(line+5, sha1)) {
 471                        case -1: /* they have what we do not */
 472                                if (multi_ack && ok_to_give_up())
 473                                        packet_write(1, "ACK %s continue\n",
 474                                                     sha1_to_hex(sha1));
 475                                break;
 476                        default:
 477                                memcpy(hex, sha1_to_hex(sha1), 41);
 478                                if (multi_ack) {
 479                                        const char *msg = "ACK %s continue\n";
 480                                        packet_write(1, msg, hex);
 481                                        memcpy(last_hex, hex, 41);
 482                                }
 483                                else if (have_obj.nr == 1)
 484                                        packet_write(1, "ACK %s\n", hex);
 485                                break;
 486                        }
 487                        continue;
 488                }
 489                if (!strcmp(line, "done")) {
 490                        if (have_obj.nr > 0) {
 491                                if (multi_ack)
 492                                        packet_write(1, "ACK %s\n", last_hex);
 493                                return 0;
 494                        }
 495                        packet_write(1, "NAK\n");
 496                        return -1;
 497                }
 498                die("git-upload-pack: expected SHA1 list, got '%s'", line);
 499        }
 500}
 501
 502static void receive_needs(void)
 503{
 504        struct object_array shallows = {0, 0, NULL};
 505        static char line[1000];
 506        int len, depth = 0;
 507
 508        for (;;) {
 509                struct object *o;
 510                unsigned char sha1_buf[20];
 511                len = packet_read_line(0, line, sizeof(line));
 512                reset_timeout();
 513                if (!len)
 514                        break;
 515
 516                if (!prefixcmp(line, "shallow ")) {
 517                        unsigned char sha1[20];
 518                        struct object *object;
 519                        use_thin_pack = 0;
 520                        if (get_sha1(line + 8, sha1))
 521                                die("invalid shallow line: %s", line);
 522                        object = parse_object(sha1);
 523                        if (!object)
 524                                die("did not find object for %s", line);
 525                        object->flags |= CLIENT_SHALLOW;
 526                        add_object_array(object, NULL, &shallows);
 527                        continue;
 528                }
 529                if (!prefixcmp(line, "deepen ")) {
 530                        char *end;
 531                        use_thin_pack = 0;
 532                        depth = strtol(line + 7, &end, 0);
 533                        if (end == line + 7 || depth <= 0)
 534                                die("Invalid deepen: %s", line);
 535                        continue;
 536                }
 537                if (prefixcmp(line, "want ") ||
 538                    get_sha1_hex(line+5, sha1_buf))
 539                        die("git-upload-pack: protocol error, "
 540                            "expected to get sha, not '%s'", line);
 541                if (strstr(line+45, "multi_ack"))
 542                        multi_ack = 1;
 543                if (strstr(line+45, "thin-pack"))
 544                        use_thin_pack = 1;
 545                if (strstr(line+45, "ofs-delta"))
 546                        use_ofs_delta = 1;
 547                if (strstr(line+45, "side-band-64k"))
 548                        use_sideband = LARGE_PACKET_MAX;
 549                else if (strstr(line+45, "side-band"))
 550                        use_sideband = DEFAULT_PACKET_MAX;
 551                if (strstr(line+45, "no-progress"))
 552                        no_progress = 1;
 553
 554                /* We have sent all our refs already, and the other end
 555                 * should have chosen out of them; otherwise they are
 556                 * asking for nonsense.
 557                 *
 558                 * Hmph.  We may later want to allow "want" line that
 559                 * asks for something like "master~10" (symbolic)...
 560                 * would it make sense?  I don't know.
 561                 */
 562                o = lookup_object(sha1_buf);
 563                if (!o || !(o->flags & OUR_REF))
 564                        die("git-upload-pack: not our ref %s", line+5);
 565                if (!(o->flags & WANTED)) {
 566                        o->flags |= WANTED;
 567                        add_object_array(o, NULL, &want_obj);
 568                }
 569        }
 570        if (depth == 0 && shallows.nr == 0)
 571                return;
 572        if (depth > 0) {
 573                struct commit_list *result, *backup;
 574                int i;
 575                backup = result = get_shallow_commits(&want_obj, depth,
 576                        SHALLOW, NOT_SHALLOW);
 577                while (result) {
 578                        struct object *object = &result->item->object;
 579                        if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
 580                                packet_write(1, "shallow %s",
 581                                                sha1_to_hex(object->sha1));
 582                                register_shallow(object->sha1);
 583                        }
 584                        result = result->next;
 585                }
 586                free_commit_list(backup);
 587                for (i = 0; i < shallows.nr; i++) {
 588                        struct object *object = shallows.objects[i].item;
 589                        if (object->flags & NOT_SHALLOW) {
 590                                struct commit_list *parents;
 591                                packet_write(1, "unshallow %s",
 592                                        sha1_to_hex(object->sha1));
 593                                object->flags &= ~CLIENT_SHALLOW;
 594                                /* make sure the real parents are parsed */
 595                                unregister_shallow(object->sha1);
 596                                object->parsed = 0;
 597                                parse_commit((struct commit *)object);
 598                                parents = ((struct commit *)object)->parents;
 599                                while (parents) {
 600                                        add_object_array(&parents->item->object,
 601                                                        NULL, &want_obj);
 602                                        parents = parents->next;
 603                                }
 604                        }
 605                        /* make sure commit traversal conforms to client */
 606                        register_shallow(object->sha1);
 607                }
 608                packet_flush(1);
 609        } else
 610                if (shallows.nr > 0) {
 611                        int i;
 612                        for (i = 0; i < shallows.nr; i++)
 613                                register_shallow(shallows.objects[i].item->sha1);
 614                }
 615        free(shallows.objects);
 616}
 617
 618static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 619{
 620        static const char *capabilities = "multi_ack thin-pack side-band"
 621                " side-band-64k ofs-delta shallow no-progress";
 622        struct object *o = parse_object(sha1);
 623
 624        if (!o)
 625                die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 626
 627        if (capabilities)
 628                packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 629                        0, capabilities);
 630        else
 631                packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 632        capabilities = NULL;
 633        if (!(o->flags & OUR_REF)) {
 634                o->flags |= OUR_REF;
 635                nr_our_refs++;
 636        }
 637        if (o->type == OBJ_TAG) {
 638                o = deref_tag(o, refname, 0);
 639                packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 640        }
 641        return 0;
 642}
 643
 644static void upload_pack(void)
 645{
 646        reset_timeout();
 647        head_ref(send_ref, NULL);
 648        for_each_ref(send_ref, NULL);
 649        packet_flush(1);
 650        receive_needs();
 651        if (want_obj.nr) {
 652                get_common_commits();
 653                create_pack_file();
 654        }
 655}
 656
 657int main(int argc, char **argv)
 658{
 659        char *dir;
 660        int i;
 661        int strict = 0;
 662
 663        for (i = 1; i < argc; i++) {
 664                char *arg = argv[i];
 665
 666                if (arg[0] != '-')
 667                        break;
 668                if (!strcmp(arg, "--strict")) {
 669                        strict = 1;
 670                        continue;
 671                }
 672                if (!prefixcmp(arg, "--timeout=")) {
 673                        timeout = atoi(arg+10);
 674                        continue;
 675                }
 676                if (!strcmp(arg, "--")) {
 677                        i++;
 678                        break;
 679                }
 680        }
 681        
 682        if (i != argc-1)
 683                usage(upload_pack_usage);
 684        dir = argv[i];
 685
 686        if (!enter_repo(dir, strict))
 687                die("'%s': unable to chdir or not a git archive", dir);
 688        if (is_repository_shallow())
 689                die("attempt to fetch/clone from a shallow repository");
 690        upload_pack();
 691        return 0;
 692}