upload-pack.con commit show-branch --reflog: add documentation. (abc8ab1)
   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
  10static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
  11
  12/* bits #0..7 in revision.h, #8..10 in commit.c */
  13#define THEY_HAVE       (1u << 11)
  14#define OUR_REF         (1u << 12)
  15#define WANTED          (1u << 13)
  16#define COMMON_KNOWN    (1u << 14)
  17#define REACHABLE       (1u << 15)
  18
  19static unsigned long oldest_have;
  20
  21static int multi_ack, nr_our_refs;
  22static int use_thin_pack, use_ofs_delta;
  23static struct object_array have_obj;
  24static struct object_array want_obj;
  25static unsigned int timeout;
  26/* 0 for no sideband,
  27 * otherwise maximum packet size (up to 65520 bytes).
  28 */
  29static int use_sideband;
  30
  31static void reset_timeout(void)
  32{
  33        alarm(timeout);
  34}
  35
  36static int strip(char *line, int len)
  37{
  38        if (len && line[len-1] == '\n')
  39                line[--len] = 0;
  40        return len;
  41}
  42
  43static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
  44{
  45        if (use_sideband)
  46                return send_sideband(1, fd, data, sz, use_sideband);
  47        if (fd == 3)
  48                /* emergency quit */
  49                fd = 2;
  50        if (fd == 2) {
  51                xwrite(fd, data, sz);
  52                return sz;
  53        }
  54        return safe_write(fd, data, sz);
  55}
  56
  57static void create_pack_file(void)
  58{
  59        /* Pipes between rev-list to pack-objects, pack-objects to us
  60         * and pack-objects error stream for progress bar.
  61         */
  62        int lp_pipe[2], pu_pipe[2], pe_pipe[2];
  63        pid_t pid_rev_list, pid_pack_objects;
  64        int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
  65        char data[8193], progress[128];
  66        char abort_msg[] = "aborting due to possible repository "
  67                "corruption on the remote side.";
  68        int buffered = -1;
  69
  70        if (pipe(lp_pipe) < 0)
  71                die("git-upload-pack: unable to create pipe");
  72        pid_rev_list = fork();
  73        if (pid_rev_list < 0)
  74                die("git-upload-pack: unable to fork git-rev-list");
  75
  76        if (!pid_rev_list) {
  77                int i;
  78                int args;
  79                const char **argv;
  80                const char **p;
  81                char *buf;
  82
  83                if (create_full_pack) {
  84                        args = 10;
  85                        use_thin_pack = 0; /* no point doing it */
  86                }
  87                else
  88                        args = have_obj.nr + want_obj.nr + 5;
  89                p = xmalloc(args * sizeof(char *));
  90                argv = (const char **) p;
  91                buf = xmalloc(args * 45);
  92
  93                dup2(lp_pipe[1], 1);
  94                close(0);
  95                close(lp_pipe[0]);
  96                close(lp_pipe[1]);
  97                *p++ = "rev-list";
  98                *p++ = use_thin_pack ? "--objects-edge" : "--objects";
  99                if (create_full_pack)
 100                        *p++ = "--all";
 101                else {
 102                        for (i = 0; i < want_obj.nr; i++) {
 103                                struct object *o = want_obj.objects[i].item;
 104                                *p++ = buf;
 105                                memcpy(buf, sha1_to_hex(o->sha1), 41);
 106                                buf += 41;
 107                        }
 108                }
 109                if (!create_full_pack)
 110                        for (i = 0; i < have_obj.nr; i++) {
 111                                struct object *o = have_obj.objects[i].item;
 112                                *p++ = buf;
 113                                *buf++ = '^';
 114                                memcpy(buf, sha1_to_hex(o->sha1), 41);
 115                                buf += 41;
 116                        }
 117                *p++ = NULL;
 118                execv_git_cmd(argv);
 119                die("git-upload-pack: unable to exec git-rev-list");
 120        }
 121
 122        if (pipe(pu_pipe) < 0)
 123                die("git-upload-pack: unable to create pipe");
 124        if (pipe(pe_pipe) < 0)
 125                die("git-upload-pack: unable to create pipe");
 126        pid_pack_objects = fork();
 127        if (pid_pack_objects < 0) {
 128                /* daemon sets things up to ignore TERM */
 129                kill(pid_rev_list, SIGKILL);
 130                die("git-upload-pack: unable to fork git-pack-objects");
 131        }
 132        if (!pid_pack_objects) {
 133                dup2(lp_pipe[0], 0);
 134                dup2(pu_pipe[1], 1);
 135                dup2(pe_pipe[1], 2);
 136
 137                close(lp_pipe[0]);
 138                close(lp_pipe[1]);
 139                close(pu_pipe[0]);
 140                close(pu_pipe[1]);
 141                close(pe_pipe[0]);
 142                close(pe_pipe[1]);
 143                execl_git_cmd("pack-objects", "--stdout", "--progress",
 144                              use_ofs_delta ? "--delta-base-offset" : NULL,
 145                              NULL);
 146                kill(pid_rev_list, SIGKILL);
 147                die("git-upload-pack: unable to exec git-pack-objects");
 148        }
 149
 150        close(lp_pipe[0]);
 151        close(lp_pipe[1]);
 152
 153        /* We read from pe_pipe[0] to capture stderr output for
 154         * progress bar, and pu_pipe[0] to capture the pack data.
 155         */
 156        close(pe_pipe[1]);
 157        close(pu_pipe[1]);
 158
 159        while (1) {
 160                const char *who;
 161                struct pollfd pfd[2];
 162                pid_t pid;
 163                int status;
 164                ssize_t sz;
 165                int pe, pu, pollsize;
 166
 167                reset_timeout();
 168
 169                pollsize = 0;
 170                pe = pu = -1;
 171
 172                if (0 <= pu_pipe[0]) {
 173                        pfd[pollsize].fd = pu_pipe[0];
 174                        pfd[pollsize].events = POLLIN;
 175                        pu = pollsize;
 176                        pollsize++;
 177                }
 178                if (0 <= pe_pipe[0]) {
 179                        pfd[pollsize].fd = pe_pipe[0];
 180                        pfd[pollsize].events = POLLIN;
 181                        pe = pollsize;
 182                        pollsize++;
 183                }
 184
 185                if (pollsize) {
 186                        if (poll(pfd, pollsize, -1) < 0) {
 187                                if (errno != EINTR) {
 188                                        error("poll failed, resuming: %s",
 189                                              strerror(errno));
 190                                        sleep(1);
 191                                }
 192                                continue;
 193                        }
 194                        if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 195                                /* Data ready; we keep the last byte
 196                                 * to ourselves in case we detect
 197                                 * broken rev-list, so that we can
 198                                 * leave the stream corrupted.  This
 199                                 * is unfortunate -- unpack-objects
 200                                 * would happily accept a valid pack
 201                                 * data with trailing garbage, so
 202                                 * appending garbage after we pass all
 203                                 * the pack data is not good enough to
 204                                 * signal breakage to downstream.
 205                                 */
 206                                char *cp = data;
 207                                ssize_t outsz = 0;
 208                                if (0 <= buffered) {
 209                                        *cp++ = buffered;
 210                                        outsz++;
 211                                }
 212                                sz = read(pu_pipe[0], cp,
 213                                          sizeof(data) - outsz);
 214                                if (0 < sz)
 215                                                ;
 216                                else if (sz == 0) {
 217                                        close(pu_pipe[0]);
 218                                        pu_pipe[0] = -1;
 219                                }
 220                                else
 221                                        goto fail;
 222                                sz += outsz;
 223                                if (1 < sz) {
 224                                        buffered = data[sz-1] & 0xFF;
 225                                        sz--;
 226                                }
 227                                else
 228                                        buffered = -1;
 229                                sz = send_client_data(1, data, sz);
 230                                if (sz < 0)
 231                                        goto fail;
 232                        }
 233                        if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 234                                /* Status ready; we ship that in the side-band
 235                                 * or dump to the standard error.
 236                                 */
 237                                sz = read(pe_pipe[0], progress,
 238                                          sizeof(progress));
 239                                if (0 < sz)
 240                                        send_client_data(2, progress, sz);
 241                                else if (sz == 0) {
 242                                        close(pe_pipe[0]);
 243                                        pe_pipe[0] = -1;
 244                                }
 245                                else
 246                                        goto fail;
 247                        }
 248                }
 249
 250                /* See if the children are still there */
 251                if (pid_rev_list || pid_pack_objects) {
 252                        pid = waitpid(-1, &status, WNOHANG);
 253                        if (!pid)
 254                                continue;
 255                        who = ((pid == pid_rev_list) ? "git-rev-list" :
 256                               (pid == pid_pack_objects) ? "git-pack-objects" :
 257                               NULL);
 258                        if (!who) {
 259                                if (pid < 0) {
 260                                        error("git-upload-pack: %s",
 261                                              strerror(errno));
 262                                        goto fail;
 263                                }
 264                                error("git-upload-pack: we weren't "
 265                                      "waiting for %d", pid);
 266                                continue;
 267                        }
 268                        if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 269                                error("git-upload-pack: %s died with error.",
 270                                      who);
 271                                goto fail;
 272                        }
 273                        if (pid == pid_rev_list)
 274                                pid_rev_list = 0;
 275                        if (pid == pid_pack_objects)
 276                                pid_pack_objects = 0;
 277                        if (pid_rev_list || pid_pack_objects)
 278                                continue;
 279                }
 280
 281                /* both died happily */
 282                if (pollsize)
 283                        continue;
 284
 285                /* flush the data */
 286                if (0 <= buffered) {
 287                        data[0] = buffered;
 288                        sz = send_client_data(1, data, 1);
 289                        if (sz < 0)
 290                                goto fail;
 291                        fprintf(stderr, "flushed.\n");
 292                }
 293                if (use_sideband)
 294                        packet_flush(1);
 295                return;
 296        }
 297 fail:
 298        if (pid_pack_objects)
 299                kill(pid_pack_objects, SIGKILL);
 300        if (pid_rev_list)
 301                kill(pid_rev_list, SIGKILL);
 302        send_client_data(3, abort_msg, sizeof(abort_msg));
 303        die("git-upload-pack: %s", abort_msg);
 304}
 305
 306static int got_sha1(char *hex, unsigned char *sha1)
 307{
 308        struct object *o;
 309        int we_knew_they_have = 0;
 310
 311        if (get_sha1_hex(hex, sha1))
 312                die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 313        if (!has_sha1_file(sha1))
 314                return -1;
 315
 316        o = lookup_object(sha1);
 317        if (!(o && o->parsed))
 318                o = parse_object(sha1);
 319        if (!o)
 320                die("oops (%s)", sha1_to_hex(sha1));
 321        if (o->type == OBJ_COMMIT) {
 322                struct commit_list *parents;
 323                struct commit *commit = (struct commit *)o;
 324                if (o->flags & THEY_HAVE)
 325                        we_knew_they_have = 1;
 326                else
 327                        o->flags |= THEY_HAVE;
 328                if (!oldest_have || (commit->date < oldest_have))
 329                        oldest_have = commit->date;
 330                for (parents = commit->parents;
 331                     parents;
 332                     parents = parents->next)
 333                        parents->item->object.flags |= THEY_HAVE;
 334        }
 335        if (!we_knew_they_have) {
 336                add_object_array(o, NULL, &have_obj);
 337                return 1;
 338        }
 339        return 0;
 340}
 341
 342static int reachable(struct commit *want)
 343{
 344        struct commit_list *work = NULL;
 345
 346        insert_by_date(want, &work);
 347        while (work) {
 348                struct commit_list *list = work->next;
 349                struct commit *commit = work->item;
 350                free(work);
 351                work = list;
 352
 353                if (commit->object.flags & THEY_HAVE) {
 354                        want->object.flags |= COMMON_KNOWN;
 355                        break;
 356                }
 357                if (!commit->object.parsed)
 358                        parse_object(commit->object.sha1);
 359                if (commit->object.flags & REACHABLE)
 360                        continue;
 361                commit->object.flags |= REACHABLE;
 362                if (commit->date < oldest_have)
 363                        continue;
 364                for (list = commit->parents; list; list = list->next) {
 365                        struct commit *parent = list->item;
 366                        if (!(parent->object.flags & REACHABLE))
 367                                insert_by_date(parent, &work);
 368                }
 369        }
 370        want->object.flags |= REACHABLE;
 371        clear_commit_marks(want, REACHABLE);
 372        free_commit_list(work);
 373        return (want->object.flags & COMMON_KNOWN);
 374}
 375
 376static int ok_to_give_up(void)
 377{
 378        int i;
 379
 380        if (!have_obj.nr)
 381                return 0;
 382
 383        for (i = 0; i < want_obj.nr; i++) {
 384                struct object *want = want_obj.objects[i].item;
 385
 386                if (want->flags & COMMON_KNOWN)
 387                        continue;
 388                want = deref_tag(want, "a want line", 0);
 389                if (!want || want->type != OBJ_COMMIT) {
 390                        /* no way to tell if this is reachable by
 391                         * looking at the ancestry chain alone, so
 392                         * leave a note to ourselves not to worry about
 393                         * this object anymore.
 394                         */
 395                        want_obj.objects[i].item->flags |= COMMON_KNOWN;
 396                        continue;
 397                }
 398                if (!reachable((struct commit *)want))
 399                        return 0;
 400        }
 401        return 1;
 402}
 403
 404static int get_common_commits(void)
 405{
 406        static char line[1000];
 407        unsigned char sha1[20];
 408        char hex[41], last_hex[41];
 409        int len;
 410
 411        track_object_refs = 0;
 412        save_commit_buffer = 0;
 413
 414        for(;;) {
 415                len = packet_read_line(0, line, sizeof(line));
 416                reset_timeout();
 417
 418                if (!len) {
 419                        if (have_obj.nr == 0 || multi_ack)
 420                                packet_write(1, "NAK\n");
 421                        continue;
 422                }
 423                len = strip(line, len);
 424                if (!strncmp(line, "have ", 5)) {
 425                        switch (got_sha1(line+5, sha1)) {
 426                        case -1: /* they have what we do not */
 427                                if (multi_ack && ok_to_give_up())
 428                                        packet_write(1, "ACK %s continue\n",
 429                                                     sha1_to_hex(sha1));
 430                                break;
 431                        default:
 432                                memcpy(hex, sha1_to_hex(sha1), 41);
 433                                if (multi_ack) {
 434                                        const char *msg = "ACK %s continue\n";
 435                                        packet_write(1, msg, hex);
 436                                        memcpy(last_hex, hex, 41);
 437                                }
 438                                else if (have_obj.nr == 1)
 439                                        packet_write(1, "ACK %s\n", hex);
 440                                break;
 441                        }
 442                        continue;
 443                }
 444                if (!strcmp(line, "done")) {
 445                        if (have_obj.nr > 0) {
 446                                if (multi_ack)
 447                                        packet_write(1, "ACK %s\n", last_hex);
 448                                return 0;
 449                        }
 450                        packet_write(1, "NAK\n");
 451                        return -1;
 452                }
 453                die("git-upload-pack: expected SHA1 list, got '%s'", line);
 454        }
 455}
 456
 457static void receive_needs(void)
 458{
 459        static char line[1000];
 460        int len;
 461
 462        for (;;) {
 463                struct object *o;
 464                unsigned char sha1_buf[20];
 465                len = packet_read_line(0, line, sizeof(line));
 466                reset_timeout();
 467                if (!len)
 468                        return;
 469
 470                if (strncmp("want ", line, 5) ||
 471                    get_sha1_hex(line+5, sha1_buf))
 472                        die("git-upload-pack: protocol error, "
 473                            "expected to get sha, not '%s'", line);
 474                if (strstr(line+45, "multi_ack"))
 475                        multi_ack = 1;
 476                if (strstr(line+45, "thin-pack"))
 477                        use_thin_pack = 1;
 478                if (strstr(line+45, "ofs-delta"))
 479                        use_ofs_delta = 1;
 480                if (strstr(line+45, "side-band-64k"))
 481                        use_sideband = LARGE_PACKET_MAX;
 482                else if (strstr(line+45, "side-band"))
 483                        use_sideband = DEFAULT_PACKET_MAX;
 484
 485                /* We have sent all our refs already, and the other end
 486                 * should have chosen out of them; otherwise they are
 487                 * asking for nonsense.
 488                 *
 489                 * Hmph.  We may later want to allow "want" line that
 490                 * asks for something like "master~10" (symbolic)...
 491                 * would it make sense?  I don't know.
 492                 */
 493                o = lookup_object(sha1_buf);
 494                if (!o || !(o->flags & OUR_REF))
 495                        die("git-upload-pack: not our ref %s", line+5);
 496                if (!(o->flags & WANTED)) {
 497                        o->flags |= WANTED;
 498                        add_object_array(o, NULL, &want_obj);
 499                }
 500        }
 501}
 502
 503static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 504{
 505        static const char *capabilities = "multi_ack thin-pack side-band side-band-64k ofs-delta";
 506        struct object *o = parse_object(sha1);
 507
 508        if (!o)
 509                die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 510
 511        if (capabilities)
 512                packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 513                        0, capabilities);
 514        else
 515                packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 516        capabilities = NULL;
 517        if (!(o->flags & OUR_REF)) {
 518                o->flags |= OUR_REF;
 519                nr_our_refs++;
 520        }
 521        if (o->type == OBJ_TAG) {
 522                o = deref_tag(o, refname, 0);
 523                packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 524        }
 525        return 0;
 526}
 527
 528static void upload_pack(void)
 529{
 530        reset_timeout();
 531        head_ref(send_ref, NULL);
 532        for_each_ref(send_ref, NULL);
 533        packet_flush(1);
 534        receive_needs();
 535        if (want_obj.nr) {
 536                get_common_commits();
 537                create_pack_file();
 538        }
 539}
 540
 541int main(int argc, char **argv)
 542{
 543        char *dir;
 544        int i;
 545        int strict = 0;
 546
 547        for (i = 1; i < argc; i++) {
 548                char *arg = argv[i];
 549
 550                if (arg[0] != '-')
 551                        break;
 552                if (!strcmp(arg, "--strict")) {
 553                        strict = 1;
 554                        continue;
 555                }
 556                if (!strncmp(arg, "--timeout=", 10)) {
 557                        timeout = atoi(arg+10);
 558                        continue;
 559                }
 560                if (!strcmp(arg, "--")) {
 561                        i++;
 562                        break;
 563                }
 564        }
 565        
 566        if (i != argc-1)
 567                usage(upload_pack_usage);
 568        dir = argv[i];
 569
 570        if (!enter_repo(dir, strict))
 571                die("'%s': unable to chdir or not a git archive", dir);
 572
 573        upload_pack();
 574        return 0;
 575}