upload-pack.con commit upload-pack: Move the revision walker into a separate function. (80ccaa7)
   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#include "run-command.h"
  13
  14static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
  15
  16/* bits #0..7 in revision.h, #8..10 in commit.c */
  17#define THEY_HAVE       (1u << 11)
  18#define OUR_REF         (1u << 12)
  19#define WANTED          (1u << 13)
  20#define COMMON_KNOWN    (1u << 14)
  21#define REACHABLE       (1u << 15)
  22
  23#define SHALLOW         (1u << 16)
  24#define NOT_SHALLOW     (1u << 17)
  25#define CLIENT_SHALLOW  (1u << 18)
  26
  27static unsigned long oldest_have;
  28
  29static int multi_ack, nr_our_refs;
  30static int use_thin_pack, use_ofs_delta, no_progress;
  31static struct object_array have_obj;
  32static struct object_array want_obj;
  33static unsigned int timeout;
  34/* 0 for no sideband,
  35 * otherwise maximum packet size (up to 65520 bytes).
  36 */
  37static int use_sideband;
  38
  39static void reset_timeout(void)
  40{
  41        alarm(timeout);
  42}
  43
  44static int strip(char *line, int len)
  45{
  46        if (len && line[len-1] == '\n')
  47                line[--len] = 0;
  48        return len;
  49}
  50
  51static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
  52{
  53        if (use_sideband)
  54                return send_sideband(1, fd, data, sz, use_sideband);
  55        if (fd == 3)
  56                /* emergency quit */
  57                fd = 2;
  58        if (fd == 2) {
  59                /* XXX: are we happy to lose stuff here? */
  60                xwrite(fd, data, sz);
  61                return sz;
  62        }
  63        return safe_write(fd, data, sz);
  64}
  65
  66static FILE *pack_pipe = NULL;
  67static void show_commit(struct commit *commit)
  68{
  69        if (commit->object.flags & BOUNDARY)
  70                fputc('-', pack_pipe);
  71        if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
  72                die("broken output pipe");
  73        fputc('\n', pack_pipe);
  74        fflush(pack_pipe);
  75        free(commit->buffer);
  76        commit->buffer = NULL;
  77}
  78
  79static void show_object(struct object_array_entry *p)
  80{
  81        /* An object with name "foo\n0000000..." can be used to
  82         * confuse downstream git-pack-objects very badly.
  83         */
  84        const char *ep = strchr(p->name, '\n');
  85        if (ep) {
  86                fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(p->item->sha1),
  87                       (int) (ep - p->name),
  88                       p->name);
  89        }
  90        else
  91                fprintf(pack_pipe, "%s %s\n",
  92                                sha1_to_hex(p->item->sha1), p->name);
  93}
  94
  95static void show_edge(struct commit *commit)
  96{
  97        fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
  98}
  99
 100static void do_rev_list(int create_full_pack)
 101{
 102        int i;
 103        struct rev_info revs;
 104
 105        if (create_full_pack)
 106                use_thin_pack = 0; /* no point doing it */
 107        init_revisions(&revs, NULL);
 108        revs.tag_objects = 1;
 109        revs.tree_objects = 1;
 110        revs.blob_objects = 1;
 111        if (use_thin_pack)
 112                revs.edge_hint = 1;
 113
 114        if (create_full_pack) {
 115                const char *args[] = {"rev-list", "--all", NULL};
 116                setup_revisions(2, args, &revs, NULL);
 117        } else {
 118                for (i = 0; i < want_obj.nr; i++) {
 119                        struct object *o = want_obj.objects[i].item;
 120                        /* why??? */
 121                        o->flags &= ~UNINTERESTING;
 122                        add_pending_object(&revs, o, NULL);
 123                }
 124                for (i = 0; i < have_obj.nr; i++) {
 125                        struct object *o = have_obj.objects[i].item;
 126                        o->flags |= UNINTERESTING;
 127                        add_pending_object(&revs, o, NULL);
 128                }
 129                setup_revisions(0, NULL, &revs, NULL);
 130        }
 131        prepare_revision_walk(&revs);
 132        mark_edges_uninteresting(revs.commits, &revs, show_edge);
 133        traverse_commit_list(&revs, show_commit, show_object);
 134}
 135
 136static void create_pack_file(void)
 137{
 138        /* Pipe from rev-list to pack-objects
 139         */
 140        int lp_pipe[2];
 141        pid_t pid_rev_list;
 142        struct child_process pack_objects;
 143        int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
 144        char data[8193], progress[128];
 145        char abort_msg[] = "aborting due to possible repository "
 146                "corruption on the remote side.";
 147        int buffered = -1;
 148        const char *argv[10];
 149        int arg = 0;
 150
 151        if (pipe(lp_pipe) < 0)
 152                die("git-upload-pack: unable to create pipe");
 153        pid_rev_list = fork();
 154        if (pid_rev_list < 0)
 155                die("git-upload-pack: unable to fork git-rev-list");
 156
 157        if (!pid_rev_list) {
 158                close(lp_pipe[0]);
 159                pack_pipe = fdopen(lp_pipe[1], "w");
 160                do_rev_list(create_full_pack);
 161                exit(0);
 162        }
 163
 164        /* writable pipe end must not be inherited by pack_objects */
 165        close(lp_pipe[1]);
 166
 167        argv[arg++] = "pack-objects";
 168        argv[arg++] = "--stdout";
 169        if (!no_progress)
 170                argv[arg++] = "--progress";
 171        if (use_ofs_delta)
 172                argv[arg++] = "--delta-base-offset";
 173        argv[arg++] = NULL;
 174
 175        memset(&pack_objects, 0, sizeof(pack_objects));
 176        pack_objects.in = lp_pipe[0];   /* start_command closes it */
 177        pack_objects.out = -1;
 178        pack_objects.err = -1;
 179        pack_objects.git_cmd = 1;
 180        pack_objects.argv = argv;
 181        if (start_command(&pack_objects)) {
 182                /* daemon sets things up to ignore TERM */
 183                kill(pid_rev_list, SIGKILL);
 184                die("git-upload-pack: unable to fork git-pack-objects");
 185        }
 186
 187        /* We read from pack_objects.err to capture stderr output for
 188         * progress bar, and pack_objects.out to capture the pack data.
 189         */
 190
 191        while (1) {
 192                const char *who;
 193                struct pollfd pfd[2];
 194                pid_t pid;
 195                int status;
 196                ssize_t sz;
 197                int pe, pu, pollsize;
 198
 199                reset_timeout();
 200
 201                pollsize = 0;
 202                pe = pu = -1;
 203
 204                if (0 <= pack_objects.out) {
 205                        pfd[pollsize].fd = pack_objects.out;
 206                        pfd[pollsize].events = POLLIN;
 207                        pu = pollsize;
 208                        pollsize++;
 209                }
 210                if (0 <= pack_objects.err) {
 211                        pfd[pollsize].fd = pack_objects.err;
 212                        pfd[pollsize].events = POLLIN;
 213                        pe = pollsize;
 214                        pollsize++;
 215                }
 216
 217                if (pollsize) {
 218                        if (poll(pfd, pollsize, -1) < 0) {
 219                                if (errno != EINTR) {
 220                                        error("poll failed, resuming: %s",
 221                                              strerror(errno));
 222                                        sleep(1);
 223                                }
 224                                continue;
 225                        }
 226                        if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 227                                /* Data ready; we keep the last byte
 228                                 * to ourselves in case we detect
 229                                 * broken rev-list, so that we can
 230                                 * leave the stream corrupted.  This
 231                                 * is unfortunate -- unpack-objects
 232                                 * would happily accept a valid pack
 233                                 * data with trailing garbage, so
 234                                 * appending garbage after we pass all
 235                                 * the pack data is not good enough to
 236                                 * signal breakage to downstream.
 237                                 */
 238                                char *cp = data;
 239                                ssize_t outsz = 0;
 240                                if (0 <= buffered) {
 241                                        *cp++ = buffered;
 242                                        outsz++;
 243                                }
 244                                sz = xread(pack_objects.out, cp,
 245                                          sizeof(data) - outsz);
 246                                if (0 < sz)
 247                                                ;
 248                                else if (sz == 0) {
 249                                        close(pack_objects.out);
 250                                        pack_objects.out = -1;
 251                                }
 252                                else
 253                                        goto fail;
 254                                sz += outsz;
 255                                if (1 < sz) {
 256                                        buffered = data[sz-1] & 0xFF;
 257                                        sz--;
 258                                }
 259                                else
 260                                        buffered = -1;
 261                                sz = send_client_data(1, data, sz);
 262                                if (sz < 0)
 263                                        goto fail;
 264                        }
 265                        if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 266                                /* Status ready; we ship that in the side-band
 267                                 * or dump to the standard error.
 268                                 */
 269                                sz = xread(pack_objects.err, progress,
 270                                          sizeof(progress));
 271                                if (0 < sz)
 272                                        send_client_data(2, progress, sz);
 273                                else if (sz == 0) {
 274                                        close(pack_objects.err);
 275                                        pack_objects.err = -1;
 276                                }
 277                                else
 278                                        goto fail;
 279                        }
 280                }
 281
 282                /* See if the children are still there */
 283                if (pid_rev_list || pack_objects.pid) {
 284                        pid = waitpid(-1, &status, WNOHANG);
 285                        if (!pid)
 286                                continue;
 287                        who = ((pid == pid_rev_list) ? "git-rev-list" :
 288                               (pid == pack_objects.pid) ? "git-pack-objects" :
 289                               NULL);
 290                        if (!who) {
 291                                if (pid < 0) {
 292                                        error("git-upload-pack: %s",
 293                                              strerror(errno));
 294                                        goto fail;
 295                                }
 296                                error("git-upload-pack: we weren't "
 297                                      "waiting for %d", pid);
 298                                continue;
 299                        }
 300                        if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 301                                error("git-upload-pack: %s died with error.",
 302                                      who);
 303                                goto fail;
 304                        }
 305                        if (pid == pid_rev_list)
 306                                pid_rev_list = 0;
 307                        if (pid == pack_objects.pid)
 308                                pack_objects.pid = 0;
 309                        if (pid_rev_list || pack_objects.pid)
 310                                continue;
 311                }
 312
 313                /* both died happily */
 314                if (pollsize)
 315                        continue;
 316
 317                /* flush the data */
 318                if (0 <= buffered) {
 319                        data[0] = buffered;
 320                        sz = send_client_data(1, data, 1);
 321                        if (sz < 0)
 322                                goto fail;
 323                        fprintf(stderr, "flushed.\n");
 324                }
 325                if (use_sideband)
 326                        packet_flush(1);
 327                return;
 328        }
 329 fail:
 330        if (pack_objects.pid)
 331                kill(pack_objects.pid, SIGKILL);
 332        if (pid_rev_list)
 333                kill(pid_rev_list, SIGKILL);
 334        send_client_data(3, abort_msg, sizeof(abort_msg));
 335        die("git-upload-pack: %s", abort_msg);
 336}
 337
 338static int got_sha1(char *hex, unsigned char *sha1)
 339{
 340        struct object *o;
 341        int we_knew_they_have = 0;
 342
 343        if (get_sha1_hex(hex, sha1))
 344                die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 345        if (!has_sha1_file(sha1))
 346                return -1;
 347
 348        o = lookup_object(sha1);
 349        if (!(o && o->parsed))
 350                o = parse_object(sha1);
 351        if (!o)
 352                die("oops (%s)", sha1_to_hex(sha1));
 353        if (o->type == OBJ_COMMIT) {
 354                struct commit_list *parents;
 355                struct commit *commit = (struct commit *)o;
 356                if (o->flags & THEY_HAVE)
 357                        we_knew_they_have = 1;
 358                else
 359                        o->flags |= THEY_HAVE;
 360                if (!oldest_have || (commit->date < oldest_have))
 361                        oldest_have = commit->date;
 362                for (parents = commit->parents;
 363                     parents;
 364                     parents = parents->next)
 365                        parents->item->object.flags |= THEY_HAVE;
 366        }
 367        if (!we_knew_they_have) {
 368                add_object_array(o, NULL, &have_obj);
 369                return 1;
 370        }
 371        return 0;
 372}
 373
 374static int reachable(struct commit *want)
 375{
 376        struct commit_list *work = NULL;
 377
 378        insert_by_date(want, &work);
 379        while (work) {
 380                struct commit_list *list = work->next;
 381                struct commit *commit = work->item;
 382                free(work);
 383                work = list;
 384
 385                if (commit->object.flags & THEY_HAVE) {
 386                        want->object.flags |= COMMON_KNOWN;
 387                        break;
 388                }
 389                if (!commit->object.parsed)
 390                        parse_object(commit->object.sha1);
 391                if (commit->object.flags & REACHABLE)
 392                        continue;
 393                commit->object.flags |= REACHABLE;
 394                if (commit->date < oldest_have)
 395                        continue;
 396                for (list = commit->parents; list; list = list->next) {
 397                        struct commit *parent = list->item;
 398                        if (!(parent->object.flags & REACHABLE))
 399                                insert_by_date(parent, &work);
 400                }
 401        }
 402        want->object.flags |= REACHABLE;
 403        clear_commit_marks(want, REACHABLE);
 404        free_commit_list(work);
 405        return (want->object.flags & COMMON_KNOWN);
 406}
 407
 408static int ok_to_give_up(void)
 409{
 410        int i;
 411
 412        if (!have_obj.nr)
 413                return 0;
 414
 415        for (i = 0; i < want_obj.nr; i++) {
 416                struct object *want = want_obj.objects[i].item;
 417
 418                if (want->flags & COMMON_KNOWN)
 419                        continue;
 420                want = deref_tag(want, "a want line", 0);
 421                if (!want || want->type != OBJ_COMMIT) {
 422                        /* no way to tell if this is reachable by
 423                         * looking at the ancestry chain alone, so
 424                         * leave a note to ourselves not to worry about
 425                         * this object anymore.
 426                         */
 427                        want_obj.objects[i].item->flags |= COMMON_KNOWN;
 428                        continue;
 429                }
 430                if (!reachable((struct commit *)want))
 431                        return 0;
 432        }
 433        return 1;
 434}
 435
 436static int get_common_commits(void)
 437{
 438        static char line[1000];
 439        unsigned char sha1[20];
 440        char hex[41], last_hex[41];
 441        int len;
 442
 443        track_object_refs = 0;
 444        save_commit_buffer = 0;
 445
 446        for(;;) {
 447                len = packet_read_line(0, line, sizeof(line));
 448                reset_timeout();
 449
 450                if (!len) {
 451                        if (have_obj.nr == 0 || multi_ack)
 452                                packet_write(1, "NAK\n");
 453                        continue;
 454                }
 455                len = strip(line, len);
 456                if (!prefixcmp(line, "have ")) {
 457                        switch (got_sha1(line+5, sha1)) {
 458                        case -1: /* they have what we do not */
 459                                if (multi_ack && ok_to_give_up())
 460                                        packet_write(1, "ACK %s continue\n",
 461                                                     sha1_to_hex(sha1));
 462                                break;
 463                        default:
 464                                memcpy(hex, sha1_to_hex(sha1), 41);
 465                                if (multi_ack) {
 466                                        const char *msg = "ACK %s continue\n";
 467                                        packet_write(1, msg, hex);
 468                                        memcpy(last_hex, hex, 41);
 469                                }
 470                                else if (have_obj.nr == 1)
 471                                        packet_write(1, "ACK %s\n", hex);
 472                                break;
 473                        }
 474                        continue;
 475                }
 476                if (!strcmp(line, "done")) {
 477                        if (have_obj.nr > 0) {
 478                                if (multi_ack)
 479                                        packet_write(1, "ACK %s\n", last_hex);
 480                                return 0;
 481                        }
 482                        packet_write(1, "NAK\n");
 483                        return -1;
 484                }
 485                die("git-upload-pack: expected SHA1 list, got '%s'", line);
 486        }
 487}
 488
 489static void receive_needs(void)
 490{
 491        struct object_array shallows = {0, 0, NULL};
 492        static char line[1000];
 493        int len, depth = 0;
 494
 495        for (;;) {
 496                struct object *o;
 497                unsigned char sha1_buf[20];
 498                len = packet_read_line(0, line, sizeof(line));
 499                reset_timeout();
 500                if (!len)
 501                        break;
 502
 503                if (!prefixcmp(line, "shallow ")) {
 504                        unsigned char sha1[20];
 505                        struct object *object;
 506                        use_thin_pack = 0;
 507                        if (get_sha1(line + 8, sha1))
 508                                die("invalid shallow line: %s", line);
 509                        object = parse_object(sha1);
 510                        if (!object)
 511                                die("did not find object for %s", line);
 512                        object->flags |= CLIENT_SHALLOW;
 513                        add_object_array(object, NULL, &shallows);
 514                        continue;
 515                }
 516                if (!prefixcmp(line, "deepen ")) {
 517                        char *end;
 518                        use_thin_pack = 0;
 519                        depth = strtol(line + 7, &end, 0);
 520                        if (end == line + 7 || depth <= 0)
 521                                die("Invalid deepen: %s", line);
 522                        continue;
 523                }
 524                if (prefixcmp(line, "want ") ||
 525                    get_sha1_hex(line+5, sha1_buf))
 526                        die("git-upload-pack: protocol error, "
 527                            "expected to get sha, not '%s'", line);
 528                if (strstr(line+45, "multi_ack"))
 529                        multi_ack = 1;
 530                if (strstr(line+45, "thin-pack"))
 531                        use_thin_pack = 1;
 532                if (strstr(line+45, "ofs-delta"))
 533                        use_ofs_delta = 1;
 534                if (strstr(line+45, "side-band-64k"))
 535                        use_sideband = LARGE_PACKET_MAX;
 536                else if (strstr(line+45, "side-band"))
 537                        use_sideband = DEFAULT_PACKET_MAX;
 538                if (strstr(line+45, "no-progress"))
 539                        no_progress = 1;
 540
 541                /* We have sent all our refs already, and the other end
 542                 * should have chosen out of them; otherwise they are
 543                 * asking for nonsense.
 544                 *
 545                 * Hmph.  We may later want to allow "want" line that
 546                 * asks for something like "master~10" (symbolic)...
 547                 * would it make sense?  I don't know.
 548                 */
 549                o = lookup_object(sha1_buf);
 550                if (!o || !(o->flags & OUR_REF))
 551                        die("git-upload-pack: not our ref %s", line+5);
 552                if (!(o->flags & WANTED)) {
 553                        o->flags |= WANTED;
 554                        add_object_array(o, NULL, &want_obj);
 555                }
 556        }
 557        if (depth == 0 && shallows.nr == 0)
 558                return;
 559        if (depth > 0) {
 560                struct commit_list *result, *backup;
 561                int i;
 562                backup = result = get_shallow_commits(&want_obj, depth,
 563                        SHALLOW, NOT_SHALLOW);
 564                while (result) {
 565                        struct object *object = &result->item->object;
 566                        if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
 567                                packet_write(1, "shallow %s",
 568                                                sha1_to_hex(object->sha1));
 569                                register_shallow(object->sha1);
 570                        }
 571                        result = result->next;
 572                }
 573                free_commit_list(backup);
 574                for (i = 0; i < shallows.nr; i++) {
 575                        struct object *object = shallows.objects[i].item;
 576                        if (object->flags & NOT_SHALLOW) {
 577                                struct commit_list *parents;
 578                                packet_write(1, "unshallow %s",
 579                                        sha1_to_hex(object->sha1));
 580                                object->flags &= ~CLIENT_SHALLOW;
 581                                /* make sure the real parents are parsed */
 582                                unregister_shallow(object->sha1);
 583                                object->parsed = 0;
 584                                parse_commit((struct commit *)object);
 585                                parents = ((struct commit *)object)->parents;
 586                                while (parents) {
 587                                        add_object_array(&parents->item->object,
 588                                                        NULL, &want_obj);
 589                                        parents = parents->next;
 590                                }
 591                        }
 592                        /* make sure commit traversal conforms to client */
 593                        register_shallow(object->sha1);
 594                }
 595                packet_flush(1);
 596        } else
 597                if (shallows.nr > 0) {
 598                        int i;
 599                        for (i = 0; i < shallows.nr; i++)
 600                                register_shallow(shallows.objects[i].item->sha1);
 601                }
 602        free(shallows.objects);
 603}
 604
 605static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 606{
 607        static const char *capabilities = "multi_ack thin-pack side-band"
 608                " side-band-64k ofs-delta shallow no-progress";
 609        struct object *o = parse_object(sha1);
 610
 611        if (!o)
 612                die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 613
 614        if (capabilities)
 615                packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 616                        0, capabilities);
 617        else
 618                packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 619        capabilities = NULL;
 620        if (!(o->flags & OUR_REF)) {
 621                o->flags |= OUR_REF;
 622                nr_our_refs++;
 623        }
 624        if (o->type == OBJ_TAG) {
 625                o = deref_tag(o, refname, 0);
 626                packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 627        }
 628        return 0;
 629}
 630
 631static void upload_pack(void)
 632{
 633        reset_timeout();
 634        head_ref(send_ref, NULL);
 635        for_each_ref(send_ref, NULL);
 636        packet_flush(1);
 637        receive_needs();
 638        if (want_obj.nr) {
 639                get_common_commits();
 640                create_pack_file();
 641        }
 642}
 643
 644int main(int argc, char **argv)
 645{
 646        char *dir;
 647        int i;
 648        int strict = 0;
 649
 650        for (i = 1; i < argc; i++) {
 651                char *arg = argv[i];
 652
 653                if (arg[0] != '-')
 654                        break;
 655                if (!strcmp(arg, "--strict")) {
 656                        strict = 1;
 657                        continue;
 658                }
 659                if (!prefixcmp(arg, "--timeout=")) {
 660                        timeout = atoi(arg+10);
 661                        continue;
 662                }
 663                if (!strcmp(arg, "--")) {
 664                        i++;
 665                        break;
 666                }
 667        }
 668
 669        if (i != argc-1)
 670                usage(upload_pack_usage);
 671        dir = argv[i];
 672
 673        if (!enter_repo(dir, strict))
 674                die("'%s': unable to chdir or not a git archive", dir);
 675        if (is_repository_shallow())
 676                die("attempt to fetch/clone from a shallow repository");
 677        upload_pack();
 678        return 0;
 679}