upload-pack.con commit upload-pack: Run rev-list in an asynchronous function. (21edd3f)
   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 int do_rev_list(int fd, void *create_full_pack)
 101{
 102        int i;
 103        struct rev_info revs;
 104
 105        pack_pipe = fdopen(fd, "w");
 106        if (create_full_pack)
 107                use_thin_pack = 0; /* no point doing it */
 108        init_revisions(&revs, NULL);
 109        revs.tag_objects = 1;
 110        revs.tree_objects = 1;
 111        revs.blob_objects = 1;
 112        if (use_thin_pack)
 113                revs.edge_hint = 1;
 114
 115        if (create_full_pack) {
 116                const char *args[] = {"rev-list", "--all", NULL};
 117                setup_revisions(2, args, &revs, NULL);
 118        } else {
 119                for (i = 0; i < want_obj.nr; i++) {
 120                        struct object *o = want_obj.objects[i].item;
 121                        /* why??? */
 122                        o->flags &= ~UNINTERESTING;
 123                        add_pending_object(&revs, o, NULL);
 124                }
 125                for (i = 0; i < have_obj.nr; i++) {
 126                        struct object *o = have_obj.objects[i].item;
 127                        o->flags |= UNINTERESTING;
 128                        add_pending_object(&revs, o, NULL);
 129                }
 130                setup_revisions(0, NULL, &revs, NULL);
 131        }
 132        prepare_revision_walk(&revs);
 133        mark_edges_uninteresting(revs.commits, &revs, show_edge);
 134        traverse_commit_list(&revs, show_commit, show_object);
 135        return 0;
 136}
 137
 138static void create_pack_file(void)
 139{
 140        struct async rev_list;
 141        struct child_process pack_objects;
 142        int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
 143        char data[8193], progress[128];
 144        char abort_msg[] = "aborting due to possible repository "
 145                "corruption on the remote side.";
 146        int buffered = -1;
 147        const char *argv[10];
 148        int arg = 0;
 149
 150        rev_list.proc = do_rev_list;
 151        /* .data is just a boolean: any non-NULL value will do */
 152        rev_list.data = create_full_pack ? &rev_list : NULL;
 153        if (start_async(&rev_list))
 154                die("git-upload-pack: unable to fork git-rev-list");
 155
 156        argv[arg++] = "pack-objects";
 157        argv[arg++] = "--stdout";
 158        if (!no_progress)
 159                argv[arg++] = "--progress";
 160        if (use_ofs_delta)
 161                argv[arg++] = "--delta-base-offset";
 162        argv[arg++] = NULL;
 163
 164        memset(&pack_objects, 0, sizeof(pack_objects));
 165        pack_objects.in = rev_list.out; /* start_command closes it */
 166        pack_objects.out = -1;
 167        pack_objects.err = -1;
 168        pack_objects.git_cmd = 1;
 169        pack_objects.argv = argv;
 170
 171        if (start_command(&pack_objects)) {
 172                /* daemon sets things up to ignore TERM */
 173                kill(rev_list.pid, SIGKILL);
 174                die("git-upload-pack: unable to fork git-pack-objects");
 175        }
 176
 177        /* We read from pack_objects.err to capture stderr output for
 178         * progress bar, and pack_objects.out to capture the pack data.
 179         */
 180
 181        while (1) {
 182                const char *who;
 183                struct pollfd pfd[2];
 184                pid_t pid;
 185                int status;
 186                ssize_t sz;
 187                int pe, pu, pollsize;
 188
 189                reset_timeout();
 190
 191                pollsize = 0;
 192                pe = pu = -1;
 193
 194                if (0 <= pack_objects.out) {
 195                        pfd[pollsize].fd = pack_objects.out;
 196                        pfd[pollsize].events = POLLIN;
 197                        pu = pollsize;
 198                        pollsize++;
 199                }
 200                if (0 <= pack_objects.err) {
 201                        pfd[pollsize].fd = pack_objects.err;
 202                        pfd[pollsize].events = POLLIN;
 203                        pe = pollsize;
 204                        pollsize++;
 205                }
 206
 207                if (pollsize) {
 208                        if (poll(pfd, pollsize, -1) < 0) {
 209                                if (errno != EINTR) {
 210                                        error("poll failed, resuming: %s",
 211                                              strerror(errno));
 212                                        sleep(1);
 213                                }
 214                                continue;
 215                        }
 216                        if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 217                                /* Data ready; we keep the last byte
 218                                 * to ourselves in case we detect
 219                                 * broken rev-list, so that we can
 220                                 * leave the stream corrupted.  This
 221                                 * is unfortunate -- unpack-objects
 222                                 * would happily accept a valid pack
 223                                 * data with trailing garbage, so
 224                                 * appending garbage after we pass all
 225                                 * the pack data is not good enough to
 226                                 * signal breakage to downstream.
 227                                 */
 228                                char *cp = data;
 229                                ssize_t outsz = 0;
 230                                if (0 <= buffered) {
 231                                        *cp++ = buffered;
 232                                        outsz++;
 233                                }
 234                                sz = xread(pack_objects.out, cp,
 235                                          sizeof(data) - outsz);
 236                                if (0 < sz)
 237                                                ;
 238                                else if (sz == 0) {
 239                                        close(pack_objects.out);
 240                                        pack_objects.out = -1;
 241                                }
 242                                else
 243                                        goto fail;
 244                                sz += outsz;
 245                                if (1 < sz) {
 246                                        buffered = data[sz-1] & 0xFF;
 247                                        sz--;
 248                                }
 249                                else
 250                                        buffered = -1;
 251                                sz = send_client_data(1, data, sz);
 252                                if (sz < 0)
 253                                        goto fail;
 254                        }
 255                        if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 256                                /* Status ready; we ship that in the side-band
 257                                 * or dump to the standard error.
 258                                 */
 259                                sz = xread(pack_objects.err, progress,
 260                                          sizeof(progress));
 261                                if (0 < sz)
 262                                        send_client_data(2, progress, sz);
 263                                else if (sz == 0) {
 264                                        close(pack_objects.err);
 265                                        pack_objects.err = -1;
 266                                }
 267                                else
 268                                        goto fail;
 269                        }
 270                }
 271
 272                /* See if the children are still there */
 273                if (rev_list.pid || pack_objects.pid) {
 274                        pid = waitpid(-1, &status, WNOHANG);
 275                        if (!pid)
 276                                continue;
 277                        who = ((pid == rev_list.pid) ? "git-rev-list" :
 278                               (pid == pack_objects.pid) ? "git-pack-objects" :
 279                               NULL);
 280                        if (!who) {
 281                                if (pid < 0) {
 282                                        error("git-upload-pack: %s",
 283                                              strerror(errno));
 284                                        goto fail;
 285                                }
 286                                error("git-upload-pack: we weren't "
 287                                      "waiting for %d", pid);
 288                                continue;
 289                        }
 290                        if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 291                                error("git-upload-pack: %s died with error.",
 292                                      who);
 293                                goto fail;
 294                        }
 295                        if (pid == rev_list.pid)
 296                                rev_list.pid = 0;
 297                        if (pid == pack_objects.pid)
 298                                pack_objects.pid = 0;
 299                        if (rev_list.pid || pack_objects.pid)
 300                                continue;
 301                }
 302
 303                /* both died happily */
 304                if (pollsize)
 305                        continue;
 306
 307                /* flush the data */
 308                if (0 <= buffered) {
 309                        data[0] = buffered;
 310                        sz = send_client_data(1, data, 1);
 311                        if (sz < 0)
 312                                goto fail;
 313                        fprintf(stderr, "flushed.\n");
 314                }
 315                if (use_sideband)
 316                        packet_flush(1);
 317                return;
 318        }
 319 fail:
 320        if (pack_objects.pid)
 321                kill(pack_objects.pid, SIGKILL);
 322        if (rev_list.pid)
 323                kill(rev_list.pid, SIGKILL);
 324        send_client_data(3, abort_msg, sizeof(abort_msg));
 325        die("git-upload-pack: %s", abort_msg);
 326}
 327
 328static int got_sha1(char *hex, unsigned char *sha1)
 329{
 330        struct object *o;
 331        int we_knew_they_have = 0;
 332
 333        if (get_sha1_hex(hex, sha1))
 334                die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 335        if (!has_sha1_file(sha1))
 336                return -1;
 337
 338        o = lookup_object(sha1);
 339        if (!(o && o->parsed))
 340                o = parse_object(sha1);
 341        if (!o)
 342                die("oops (%s)", sha1_to_hex(sha1));
 343        if (o->type == OBJ_COMMIT) {
 344                struct commit_list *parents;
 345                struct commit *commit = (struct commit *)o;
 346                if (o->flags & THEY_HAVE)
 347                        we_knew_they_have = 1;
 348                else
 349                        o->flags |= THEY_HAVE;
 350                if (!oldest_have || (commit->date < oldest_have))
 351                        oldest_have = commit->date;
 352                for (parents = commit->parents;
 353                     parents;
 354                     parents = parents->next)
 355                        parents->item->object.flags |= THEY_HAVE;
 356        }
 357        if (!we_knew_they_have) {
 358                add_object_array(o, NULL, &have_obj);
 359                return 1;
 360        }
 361        return 0;
 362}
 363
 364static int reachable(struct commit *want)
 365{
 366        struct commit_list *work = NULL;
 367
 368        insert_by_date(want, &work);
 369        while (work) {
 370                struct commit_list *list = work->next;
 371                struct commit *commit = work->item;
 372                free(work);
 373                work = list;
 374
 375                if (commit->object.flags & THEY_HAVE) {
 376                        want->object.flags |= COMMON_KNOWN;
 377                        break;
 378                }
 379                if (!commit->object.parsed)
 380                        parse_object(commit->object.sha1);
 381                if (commit->object.flags & REACHABLE)
 382                        continue;
 383                commit->object.flags |= REACHABLE;
 384                if (commit->date < oldest_have)
 385                        continue;
 386                for (list = commit->parents; list; list = list->next) {
 387                        struct commit *parent = list->item;
 388                        if (!(parent->object.flags & REACHABLE))
 389                                insert_by_date(parent, &work);
 390                }
 391        }
 392        want->object.flags |= REACHABLE;
 393        clear_commit_marks(want, REACHABLE);
 394        free_commit_list(work);
 395        return (want->object.flags & COMMON_KNOWN);
 396}
 397
 398static int ok_to_give_up(void)
 399{
 400        int i;
 401
 402        if (!have_obj.nr)
 403                return 0;
 404
 405        for (i = 0; i < want_obj.nr; i++) {
 406                struct object *want = want_obj.objects[i].item;
 407
 408                if (want->flags & COMMON_KNOWN)
 409                        continue;
 410                want = deref_tag(want, "a want line", 0);
 411                if (!want || want->type != OBJ_COMMIT) {
 412                        /* no way to tell if this is reachable by
 413                         * looking at the ancestry chain alone, so
 414                         * leave a note to ourselves not to worry about
 415                         * this object anymore.
 416                         */
 417                        want_obj.objects[i].item->flags |= COMMON_KNOWN;
 418                        continue;
 419                }
 420                if (!reachable((struct commit *)want))
 421                        return 0;
 422        }
 423        return 1;
 424}
 425
 426static int get_common_commits(void)
 427{
 428        static char line[1000];
 429        unsigned char sha1[20];
 430        char hex[41], last_hex[41];
 431        int len;
 432
 433        track_object_refs = 0;
 434        save_commit_buffer = 0;
 435
 436        for(;;) {
 437                len = packet_read_line(0, line, sizeof(line));
 438                reset_timeout();
 439
 440                if (!len) {
 441                        if (have_obj.nr == 0 || multi_ack)
 442                                packet_write(1, "NAK\n");
 443                        continue;
 444                }
 445                len = strip(line, len);
 446                if (!prefixcmp(line, "have ")) {
 447                        switch (got_sha1(line+5, sha1)) {
 448                        case -1: /* they have what we do not */
 449                                if (multi_ack && ok_to_give_up())
 450                                        packet_write(1, "ACK %s continue\n",
 451                                                     sha1_to_hex(sha1));
 452                                break;
 453                        default:
 454                                memcpy(hex, sha1_to_hex(sha1), 41);
 455                                if (multi_ack) {
 456                                        const char *msg = "ACK %s continue\n";
 457                                        packet_write(1, msg, hex);
 458                                        memcpy(last_hex, hex, 41);
 459                                }
 460                                else if (have_obj.nr == 1)
 461                                        packet_write(1, "ACK %s\n", hex);
 462                                break;
 463                        }
 464                        continue;
 465                }
 466                if (!strcmp(line, "done")) {
 467                        if (have_obj.nr > 0) {
 468                                if (multi_ack)
 469                                        packet_write(1, "ACK %s\n", last_hex);
 470                                return 0;
 471                        }
 472                        packet_write(1, "NAK\n");
 473                        return -1;
 474                }
 475                die("git-upload-pack: expected SHA1 list, got '%s'", line);
 476        }
 477}
 478
 479static void receive_needs(void)
 480{
 481        struct object_array shallows = {0, 0, NULL};
 482        static char line[1000];
 483        int len, depth = 0;
 484
 485        for (;;) {
 486                struct object *o;
 487                unsigned char sha1_buf[20];
 488                len = packet_read_line(0, line, sizeof(line));
 489                reset_timeout();
 490                if (!len)
 491                        break;
 492
 493                if (!prefixcmp(line, "shallow ")) {
 494                        unsigned char sha1[20];
 495                        struct object *object;
 496                        use_thin_pack = 0;
 497                        if (get_sha1(line + 8, sha1))
 498                                die("invalid shallow line: %s", line);
 499                        object = parse_object(sha1);
 500                        if (!object)
 501                                die("did not find object for %s", line);
 502                        object->flags |= CLIENT_SHALLOW;
 503                        add_object_array(object, NULL, &shallows);
 504                        continue;
 505                }
 506                if (!prefixcmp(line, "deepen ")) {
 507                        char *end;
 508                        use_thin_pack = 0;
 509                        depth = strtol(line + 7, &end, 0);
 510                        if (end == line + 7 || depth <= 0)
 511                                die("Invalid deepen: %s", line);
 512                        continue;
 513                }
 514                if (prefixcmp(line, "want ") ||
 515                    get_sha1_hex(line+5, sha1_buf))
 516                        die("git-upload-pack: protocol error, "
 517                            "expected to get sha, not '%s'", line);
 518                if (strstr(line+45, "multi_ack"))
 519                        multi_ack = 1;
 520                if (strstr(line+45, "thin-pack"))
 521                        use_thin_pack = 1;
 522                if (strstr(line+45, "ofs-delta"))
 523                        use_ofs_delta = 1;
 524                if (strstr(line+45, "side-band-64k"))
 525                        use_sideband = LARGE_PACKET_MAX;
 526                else if (strstr(line+45, "side-band"))
 527                        use_sideband = DEFAULT_PACKET_MAX;
 528                if (strstr(line+45, "no-progress"))
 529                        no_progress = 1;
 530
 531                /* We have sent all our refs already, and the other end
 532                 * should have chosen out of them; otherwise they are
 533                 * asking for nonsense.
 534                 *
 535                 * Hmph.  We may later want to allow "want" line that
 536                 * asks for something like "master~10" (symbolic)...
 537                 * would it make sense?  I don't know.
 538                 */
 539                o = lookup_object(sha1_buf);
 540                if (!o || !(o->flags & OUR_REF))
 541                        die("git-upload-pack: not our ref %s", line+5);
 542                if (!(o->flags & WANTED)) {
 543                        o->flags |= WANTED;
 544                        add_object_array(o, NULL, &want_obj);
 545                }
 546        }
 547        if (depth == 0 && shallows.nr == 0)
 548                return;
 549        if (depth > 0) {
 550                struct commit_list *result, *backup;
 551                int i;
 552                backup = result = get_shallow_commits(&want_obj, depth,
 553                        SHALLOW, NOT_SHALLOW);
 554                while (result) {
 555                        struct object *object = &result->item->object;
 556                        if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
 557                                packet_write(1, "shallow %s",
 558                                                sha1_to_hex(object->sha1));
 559                                register_shallow(object->sha1);
 560                        }
 561                        result = result->next;
 562                }
 563                free_commit_list(backup);
 564                for (i = 0; i < shallows.nr; i++) {
 565                        struct object *object = shallows.objects[i].item;
 566                        if (object->flags & NOT_SHALLOW) {
 567                                struct commit_list *parents;
 568                                packet_write(1, "unshallow %s",
 569                                        sha1_to_hex(object->sha1));
 570                                object->flags &= ~CLIENT_SHALLOW;
 571                                /* make sure the real parents are parsed */
 572                                unregister_shallow(object->sha1);
 573                                object->parsed = 0;
 574                                parse_commit((struct commit *)object);
 575                                parents = ((struct commit *)object)->parents;
 576                                while (parents) {
 577                                        add_object_array(&parents->item->object,
 578                                                        NULL, &want_obj);
 579                                        parents = parents->next;
 580                                }
 581                        }
 582                        /* make sure commit traversal conforms to client */
 583                        register_shallow(object->sha1);
 584                }
 585                packet_flush(1);
 586        } else
 587                if (shallows.nr > 0) {
 588                        int i;
 589                        for (i = 0; i < shallows.nr; i++)
 590                                register_shallow(shallows.objects[i].item->sha1);
 591                }
 592        free(shallows.objects);
 593}
 594
 595static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 596{
 597        static const char *capabilities = "multi_ack thin-pack side-band"
 598                " side-band-64k ofs-delta shallow no-progress";
 599        struct object *o = parse_object(sha1);
 600
 601        if (!o)
 602                die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 603
 604        if (capabilities)
 605                packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 606                        0, capabilities);
 607        else
 608                packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 609        capabilities = NULL;
 610        if (!(o->flags & OUR_REF)) {
 611                o->flags |= OUR_REF;
 612                nr_our_refs++;
 613        }
 614        if (o->type == OBJ_TAG) {
 615                o = deref_tag(o, refname, 0);
 616                packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 617        }
 618        return 0;
 619}
 620
 621static void upload_pack(void)
 622{
 623        reset_timeout();
 624        head_ref(send_ref, NULL);
 625        for_each_ref(send_ref, NULL);
 626        packet_flush(1);
 627        receive_needs();
 628        if (want_obj.nr) {
 629                get_common_commits();
 630                create_pack_file();
 631        }
 632}
 633
 634int main(int argc, char **argv)
 635{
 636        char *dir;
 637        int i;
 638        int strict = 0;
 639
 640        for (i = 1; i < argc; i++) {
 641                char *arg = argv[i];
 642
 643                if (arg[0] != '-')
 644                        break;
 645                if (!strcmp(arg, "--strict")) {
 646                        strict = 1;
 647                        continue;
 648                }
 649                if (!prefixcmp(arg, "--timeout=")) {
 650                        timeout = atoi(arg+10);
 651                        continue;
 652                }
 653                if (!strcmp(arg, "--")) {
 654                        i++;
 655                        break;
 656                }
 657        }
 658
 659        if (i != argc-1)
 660                usage(upload_pack_usage);
 661        dir = argv[i];
 662
 663        if (!enter_repo(dir, strict))
 664                die("'%s': unable to chdir or not a git archive", dir);
 665        if (is_repository_shallow())
 666                die("attempt to fetch/clone from a shallow repository");
 667        upload_pack();
 668        return 0;
 669}