Andrew's git / gitweb.git / builtin-fetch-pack.c
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builtin-fetch-pack.con commit status: don't require the repository to be writable (ab68545)
   1#include "cache.h"
   2#include "refs.h"
   3#include "pkt-line.h"
   4#include "commit.h"
   5#include "tag.h"
   6#include "exec_cmd.h"
   7#include "pack.h"
   8#include "sideband.h"
   9#include "fetch-pack.h"
  10#include "remote.h"
  11#include "run-command.h"
  12
  13static int transfer_unpack_limit = -1;
  14static int fetch_unpack_limit = -1;
  15static int unpack_limit = 100;
  16static int prefer_ofs_delta = 1;
  17static struct fetch_pack_args args = {
  18        /* .uploadpack = */ "git-upload-pack",
  19};
  20
  21static const char fetch_pack_usage[] =
  22"git fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--include-tag] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
  23
  24#define COMPLETE        (1U << 0)
  25#define COMMON          (1U << 1)
  26#define COMMON_REF      (1U << 2)
  27#define SEEN            (1U << 3)
  28#define POPPED          (1U << 4)
  29
  30static int marked;
  31
  32/*
  33 * After sending this many "have"s if we do not get any new ACK , we
  34 * give up traversing our history.
  35 */
  36#define MAX_IN_VAIN 256
  37
  38static struct commit_list *rev_list;
  39static int non_common_revs, multi_ack, use_sideband;
  40
  41static void rev_list_push(struct commit *commit, int mark)
  42{
  43        if (!(commit->object.flags & mark)) {
  44                commit->object.flags |= mark;
  45
  46                if (!(commit->object.parsed))
  47                        if (parse_commit(commit))
  48                                return;
  49
  50                insert_by_date(commit, &rev_list);
  51
  52                if (!(commit->object.flags & COMMON))
  53                        non_common_revs++;
  54        }
  55}
  56
  57static int rev_list_insert_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  58{
  59        struct object *o = deref_tag(parse_object(sha1), path, 0);
  60
  61        if (o && o->type == OBJ_COMMIT)
  62                rev_list_push((struct commit *)o, SEEN);
  63
  64        return 0;
  65}
  66
  67static int clear_marks(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  68{
  69        struct object *o = deref_tag(parse_object(sha1), path, 0);
  70
  71        if (o && o->type == OBJ_COMMIT)
  72                clear_commit_marks((struct commit *)o,
  73                                   COMMON | COMMON_REF | SEEN | POPPED);
  74        return 0;
  75}
  76
  77/*
  78   This function marks a rev and its ancestors as common.
  79   In some cases, it is desirable to mark only the ancestors (for example
  80   when only the server does not yet know that they are common).
  81*/
  82
  83static void mark_common(struct commit *commit,
  84                int ancestors_only, int dont_parse)
  85{
  86        if (commit != NULL && !(commit->object.flags & COMMON)) {
  87                struct object *o = (struct object *)commit;
  88
  89                if (!ancestors_only)
  90                        o->flags |= COMMON;
  91
  92                if (!(o->flags & SEEN))
  93                        rev_list_push(commit, SEEN);
  94                else {
  95                        struct commit_list *parents;
  96
  97                        if (!ancestors_only && !(o->flags & POPPED))
  98                                non_common_revs--;
  99                        if (!o->parsed && !dont_parse)
 100                                if (parse_commit(commit))
 101                                        return;
 102
 103                        for (parents = commit->parents;
 104                                        parents;
 105                                        parents = parents->next)
 106                                mark_common(parents->item, 0, dont_parse);
 107                }
 108        }
 109}
 110
 111/*
 112  Get the next rev to send, ignoring the common.
 113*/
 114
 115static const unsigned char *get_rev(void)
 116{
 117        struct commit *commit = NULL;
 118
 119        while (commit == NULL) {
 120                unsigned int mark;
 121                struct commit_list *parents;
 122
 123                if (rev_list == NULL || non_common_revs == 0)
 124                        return NULL;
 125
 126                commit = rev_list->item;
 127                if (!commit->object.parsed)
 128                        parse_commit(commit);
 129                parents = commit->parents;
 130
 131                commit->object.flags |= POPPED;
 132                if (!(commit->object.flags & COMMON))
 133                        non_common_revs--;
 134
 135                if (commit->object.flags & COMMON) {
 136                        /* do not send "have", and ignore ancestors */
 137                        commit = NULL;
 138                        mark = COMMON | SEEN;
 139                } else if (commit->object.flags & COMMON_REF)
 140                        /* send "have", and ignore ancestors */
 141                        mark = COMMON | SEEN;
 142                else
 143                        /* send "have", also for its ancestors */
 144                        mark = SEEN;
 145
 146                while (parents) {
 147                        if (!(parents->item->object.flags & SEEN))
 148                                rev_list_push(parents->item, mark);
 149                        if (mark & COMMON)
 150                                mark_common(parents->item, 1, 0);
 151                        parents = parents->next;
 152                }
 153
 154                rev_list = rev_list->next;
 155        }
 156
 157        return commit->object.sha1;
 158}
 159
 160enum ack_type {
 161        NAK = 0,
 162        ACK,
 163        ACK_continue,
 164        ACK_common,
 165        ACK_ready
 166};
 167
 168static void consume_shallow_list(int fd)
 169{
 170        if (args.stateless_rpc && args.depth > 0) {
 171                /* If we sent a depth we will get back "duplicate"
 172                 * shallow and unshallow commands every time there
 173                 * is a block of have lines exchanged.
 174                 */
 175                char line[1000];
 176                while (packet_read_line(fd, line, sizeof(line))) {
 177                        if (!prefixcmp(line, "shallow "))
 178                                continue;
 179                        if (!prefixcmp(line, "unshallow "))
 180                                continue;
 181                        die("git fetch-pack: expected shallow list");
 182                }
 183        }
 184}
 185
 186static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 187{
 188        static char line[1000];
 189        int len = packet_read_line(fd, line, sizeof(line));
 190
 191        if (!len)
 192                die("git fetch-pack: expected ACK/NAK, got EOF");
 193        if (line[len-1] == '\n')
 194                line[--len] = 0;
 195        if (!strcmp(line, "NAK"))
 196                return NAK;
 197        if (!prefixcmp(line, "ACK ")) {
 198                if (!get_sha1_hex(line+4, result_sha1)) {
 199                        if (strstr(line+45, "continue"))
 200                                return ACK_continue;
 201                        if (strstr(line+45, "common"))
 202                                return ACK_common;
 203                        if (strstr(line+45, "ready"))
 204                                return ACK_ready;
 205                        return ACK;
 206                }
 207        }
 208        die("git fetch_pack: expected ACK/NAK, got '%s'", line);
 209}
 210
 211static void send_request(int fd, struct strbuf *buf)
 212{
 213        if (args.stateless_rpc) {
 214                send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 215                packet_flush(fd);
 216        } else
 217                safe_write(fd, buf->buf, buf->len);
 218}
 219
 220static int find_common(int fd[2], unsigned char *result_sha1,
 221                       struct ref *refs)
 222{
 223        int fetching;
 224        int count = 0, flushes = 0, retval;
 225        const unsigned char *sha1;
 226        unsigned in_vain = 0;
 227        int got_continue = 0;
 228        struct strbuf req_buf = STRBUF_INIT;
 229        size_t state_len = 0;
 230
 231        if (args.stateless_rpc && multi_ack == 1)
 232                die("--stateless-rpc requires multi_ack_detailed");
 233        if (marked)
 234                for_each_ref(clear_marks, NULL);
 235        marked = 1;
 236
 237        for_each_ref(rev_list_insert_ref, NULL);
 238
 239        fetching = 0;
 240        for ( ; refs ; refs = refs->next) {
 241                unsigned char *remote = refs->old_sha1;
 242                const char *remote_hex;
 243                struct object *o;
 244
 245                /*
 246                 * If that object is complete (i.e. it is an ancestor of a
 247                 * local ref), we tell them we have it but do not have to
 248                 * tell them about its ancestors, which they already know
 249                 * about.
 250                 *
 251                 * We use lookup_object here because we are only
 252                 * interested in the case we *know* the object is
 253                 * reachable and we have already scanned it.
 254                 */
 255                if (((o = lookup_object(remote)) != NULL) &&
 256                                (o->flags & COMPLETE)) {
 257                        continue;
 258                }
 259
 260                remote_hex = sha1_to_hex(remote);
 261                if (!fetching) {
 262                        struct strbuf c = STRBUF_INIT;
 263                        if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 264                        if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 265                        if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 266                        if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 267                        if (args.use_thin_pack) strbuf_addstr(&c, " thin-pack");
 268                        if (args.no_progress)   strbuf_addstr(&c, " no-progress");
 269                        if (args.include_tag)   strbuf_addstr(&c, " include-tag");
 270                        if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 271                        packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 272                        strbuf_release(&c);
 273                } else
 274                        packet_buf_write(&req_buf, "want %s\n", remote_hex);
 275                fetching++;
 276        }
 277
 278        if (!fetching) {
 279                strbuf_release(&req_buf);
 280                packet_flush(fd[1]);
 281                return 1;
 282        }
 283
 284        if (is_repository_shallow())
 285                write_shallow_commits(&req_buf, 1);
 286        if (args.depth > 0)
 287                packet_buf_write(&req_buf, "deepen %d", args.depth);
 288        packet_buf_flush(&req_buf);
 289        state_len = req_buf.len;
 290
 291        if (args.depth > 0) {
 292                char line[1024];
 293                unsigned char sha1[20];
 294
 295                send_request(fd[1], &req_buf);
 296                while (packet_read_line(fd[0], line, sizeof(line))) {
 297                        if (!prefixcmp(line, "shallow ")) {
 298                                if (get_sha1_hex(line + 8, sha1))
 299                                        die("invalid shallow line: %s", line);
 300                                register_shallow(sha1);
 301                                continue;
 302                        }
 303                        if (!prefixcmp(line, "unshallow ")) {
 304                                if (get_sha1_hex(line + 10, sha1))
 305                                        die("invalid unshallow line: %s", line);
 306                                if (!lookup_object(sha1))
 307                                        die("object not found: %s", line);
 308                                /* make sure that it is parsed as shallow */
 309                                if (!parse_object(sha1))
 310                                        die("error in object: %s", line);
 311                                if (unregister_shallow(sha1))
 312                                        die("no shallow found: %s", line);
 313                                continue;
 314                        }
 315                        die("expected shallow/unshallow, got %s", line);
 316                }
 317        } else if (!args.stateless_rpc)
 318                send_request(fd[1], &req_buf);
 319
 320        if (!args.stateless_rpc) {
 321                /* If we aren't using the stateless-rpc interface
 322                 * we don't need to retain the headers.
 323                 */
 324                strbuf_setlen(&req_buf, 0);
 325                state_len = 0;
 326        }
 327
 328        flushes = 0;
 329        retval = -1;
 330        while ((sha1 = get_rev())) {
 331                packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
 332                if (args.verbose)
 333                        fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 334                in_vain++;
 335                if (!(31 & ++count)) {
 336                        int ack;
 337
 338                        packet_buf_flush(&req_buf);
 339                        send_request(fd[1], &req_buf);
 340                        strbuf_setlen(&req_buf, state_len);
 341                        flushes++;
 342
 343                        /*
 344                         * We keep one window "ahead" of the other side, and
 345                         * will wait for an ACK only on the next one
 346                         */
 347                        if (!args.stateless_rpc && count == 32)
 348                                continue;
 349
 350                        consume_shallow_list(fd[0]);
 351                        do {
 352                                ack = get_ack(fd[0], result_sha1);
 353                                if (args.verbose && ack)
 354                                        fprintf(stderr, "got ack %d %s\n", ack,
 355                                                        sha1_to_hex(result_sha1));
 356                                switch (ack) {
 357                                case ACK:
 358                                        flushes = 0;
 359                                        multi_ack = 0;
 360                                        retval = 0;
 361                                        goto done;
 362                                case ACK_common:
 363                                case ACK_ready:
 364                                case ACK_continue: {
 365                                        struct commit *commit =
 366                                                lookup_commit(result_sha1);
 367                                        if (args.stateless_rpc
 368                                         && ack == ACK_common
 369                                         && !(commit->object.flags & COMMON)) {
 370                                                /* We need to replay the have for this object
 371                                                 * on the next RPC request so the peer knows
 372                                                 * it is in common with us.
 373                                                 */
 374                                                const char *hex = sha1_to_hex(result_sha1);
 375                                                packet_buf_write(&req_buf, "have %s\n", hex);
 376                                                state_len = req_buf.len;
 377                                        }
 378                                        mark_common(commit, 0, 1);
 379                                        retval = 0;
 380                                        in_vain = 0;
 381                                        got_continue = 1;
 382                                        break;
 383                                        }
 384                                }
 385                        } while (ack);
 386                        flushes--;
 387                        if (got_continue && MAX_IN_VAIN < in_vain) {
 388                                if (args.verbose)
 389                                        fprintf(stderr, "giving up\n");
 390                                break; /* give up */
 391                        }
 392                }
 393        }
 394done:
 395        packet_buf_write(&req_buf, "done\n");
 396        send_request(fd[1], &req_buf);
 397        if (args.verbose)
 398                fprintf(stderr, "done\n");
 399        if (retval != 0) {
 400                multi_ack = 0;
 401                flushes++;
 402        }
 403        strbuf_release(&req_buf);
 404
 405        consume_shallow_list(fd[0]);
 406        while (flushes || multi_ack) {
 407                int ack = get_ack(fd[0], result_sha1);
 408                if (ack) {
 409                        if (args.verbose)
 410                                fprintf(stderr, "got ack (%d) %s\n", ack,
 411                                        sha1_to_hex(result_sha1));
 412                        if (ack == ACK)
 413                                return 0;
 414                        multi_ack = 1;
 415                        continue;
 416                }
 417                flushes--;
 418        }
 419        /* it is no error to fetch into a completely empty repo */
 420        return count ? retval : 0;
 421}
 422
 423static struct commit_list *complete;
 424
 425static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 426{
 427        struct object *o = parse_object(sha1);
 428
 429        while (o && o->type == OBJ_TAG) {
 430                struct tag *t = (struct tag *) o;
 431                if (!t->tagged)
 432                        break; /* broken repository */
 433                o->flags |= COMPLETE;
 434                o = parse_object(t->tagged->sha1);
 435        }
 436        if (o && o->type == OBJ_COMMIT) {
 437                struct commit *commit = (struct commit *)o;
 438                commit->object.flags |= COMPLETE;
 439                insert_by_date(commit, &complete);
 440        }
 441        return 0;
 442}
 443
 444static void mark_recent_complete_commits(unsigned long cutoff)
 445{
 446        while (complete && cutoff <= complete->item->date) {
 447                if (args.verbose)
 448                        fprintf(stderr, "Marking %s as complete\n",
 449                                sha1_to_hex(complete->item->object.sha1));
 450                pop_most_recent_commit(&complete, COMPLETE);
 451        }
 452}
 453
 454static void filter_refs(struct ref **refs, int nr_match, char **match)
 455{
 456        struct ref **return_refs;
 457        struct ref *newlist = NULL;
 458        struct ref **newtail = &newlist;
 459        struct ref *ref, *next;
 460        struct ref *fastarray[32];
 461
 462        if (nr_match && !args.fetch_all) {
 463                if (ARRAY_SIZE(fastarray) < nr_match)
 464                        return_refs = xcalloc(nr_match, sizeof(struct ref *));
 465                else {
 466                        return_refs = fastarray;
 467                        memset(return_refs, 0, sizeof(struct ref *) * nr_match);
 468                }
 469        }
 470        else
 471                return_refs = NULL;
 472
 473        for (ref = *refs; ref; ref = next) {
 474                next = ref->next;
 475                if (!memcmp(ref->name, "refs/", 5) &&
 476                    check_ref_format(ref->name + 5))
 477                        ; /* trash */
 478                else if (args.fetch_all &&
 479                         (!args.depth || prefixcmp(ref->name, "refs/tags/") )) {
 480                        *newtail = ref;
 481                        ref->next = NULL;
 482                        newtail = &ref->next;
 483                        continue;
 484                }
 485                else {
 486                        int order = path_match(ref->name, nr_match, match);
 487                        if (order) {
 488                                return_refs[order-1] = ref;
 489                                continue; /* we will link it later */
 490                        }
 491                }
 492                free(ref);
 493        }
 494
 495        if (!args.fetch_all) {
 496                int i;
 497                for (i = 0; i < nr_match; i++) {
 498                        ref = return_refs[i];
 499                        if (ref) {
 500                                *newtail = ref;
 501                                ref->next = NULL;
 502                                newtail = &ref->next;
 503                        }
 504                }
 505                if (return_refs != fastarray)
 506                        free(return_refs);
 507        }
 508        *refs = newlist;
 509}
 510
 511static int everything_local(struct ref **refs, int nr_match, char **match)
 512{
 513        struct ref *ref;
 514        int retval;
 515        unsigned long cutoff = 0;
 516
 517        save_commit_buffer = 0;
 518
 519        for (ref = *refs; ref; ref = ref->next) {
 520                struct object *o;
 521
 522                o = parse_object(ref->old_sha1);
 523                if (!o)
 524                        continue;
 525
 526                /* We already have it -- which may mean that we were
 527                 * in sync with the other side at some time after
 528                 * that (it is OK if we guess wrong here).
 529                 */
 530                if (o->type == OBJ_COMMIT) {
 531                        struct commit *commit = (struct commit *)o;
 532                        if (!cutoff || cutoff < commit->date)
 533                                cutoff = commit->date;
 534                }
 535        }
 536
 537        if (!args.depth) {
 538                for_each_ref(mark_complete, NULL);
 539                if (cutoff)
 540                        mark_recent_complete_commits(cutoff);
 541        }
 542
 543        /*
 544         * Mark all complete remote refs as common refs.
 545         * Don't mark them common yet; the server has to be told so first.
 546         */
 547        for (ref = *refs; ref; ref = ref->next) {
 548                struct object *o = deref_tag(lookup_object(ref->old_sha1),
 549                                             NULL, 0);
 550
 551                if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 552                        continue;
 553
 554                if (!(o->flags & SEEN)) {
 555                        rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 556
 557                        mark_common((struct commit *)o, 1, 1);
 558                }
 559        }
 560
 561        filter_refs(refs, nr_match, match);
 562
 563        for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 564                const unsigned char *remote = ref->old_sha1;
 565                unsigned char local[20];
 566                struct object *o;
 567
 568                o = lookup_object(remote);
 569                if (!o || !(o->flags & COMPLETE)) {
 570                        retval = 0;
 571                        if (!args.verbose)
 572                                continue;
 573                        fprintf(stderr,
 574                                "want %s (%s)\n", sha1_to_hex(remote),
 575                                ref->name);
 576                        continue;
 577                }
 578
 579                hashcpy(ref->new_sha1, local);
 580                if (!args.verbose)
 581                        continue;
 582                fprintf(stderr,
 583                        "already have %s (%s)\n", sha1_to_hex(remote),
 584                        ref->name);
 585        }
 586        return retval;
 587}
 588
 589static int sideband_demux(int fd, void *data)
 590{
 591        int *xd = data;
 592
 593        int ret = recv_sideband("fetch-pack", xd[0], fd);
 594        close(fd);
 595        return ret;
 596}
 597
 598static int get_pack(int xd[2], char **pack_lockfile)
 599{
 600        struct async demux;
 601        const char *argv[20];
 602        char keep_arg[256];
 603        char hdr_arg[256];
 604        const char **av;
 605        int do_keep = args.keep_pack;
 606        struct child_process cmd;
 607
 608        memset(&demux, 0, sizeof(demux));
 609        if (use_sideband) {
 610                /* xd[] is talking with upload-pack; subprocess reads from
 611                 * xd[0], spits out band#2 to stderr, and feeds us band#1
 612                 * through demux->out.
 613                 */
 614                demux.proc = sideband_demux;
 615                demux.data = xd;
 616                if (start_async(&demux))
 617                        die("fetch-pack: unable to fork off sideband"
 618                            " demultiplexer");
 619        }
 620        else
 621                demux.out = xd[0];
 622
 623        memset(&cmd, 0, sizeof(cmd));
 624        cmd.argv = argv;
 625        av = argv;
 626        *hdr_arg = 0;
 627        if (!args.keep_pack && unpack_limit) {
 628                struct pack_header header;
 629
 630                if (read_pack_header(demux.out, &header))
 631                        die("protocol error: bad pack header");
 632                snprintf(hdr_arg, sizeof(hdr_arg),
 633                         "--pack_header=%"PRIu32",%"PRIu32,
 634                         ntohl(header.hdr_version), ntohl(header.hdr_entries));
 635                if (ntohl(header.hdr_entries) < unpack_limit)
 636                        do_keep = 0;
 637                else
 638                        do_keep = 1;
 639        }
 640
 641        if (do_keep) {
 642                if (pack_lockfile)
 643                        cmd.out = -1;
 644                *av++ = "index-pack";
 645                *av++ = "--stdin";
 646                if (!args.quiet && !args.no_progress)
 647                        *av++ = "-v";
 648                if (args.use_thin_pack)
 649                        *av++ = "--fix-thin";
 650                if (args.lock_pack || unpack_limit) {
 651                        int s = sprintf(keep_arg,
 652                                        "--keep=fetch-pack %"PRIuMAX " on ", (uintmax_t) getpid());
 653                        if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 654                                strcpy(keep_arg + s, "localhost");
 655                        *av++ = keep_arg;
 656                }
 657        }
 658        else {
 659                *av++ = "unpack-objects";
 660                if (args.quiet)
 661                        *av++ = "-q";
 662        }
 663        if (*hdr_arg)
 664                *av++ = hdr_arg;
 665        *av++ = NULL;
 666
 667        cmd.in = demux.out;
 668        cmd.git_cmd = 1;
 669        if (start_command(&cmd))
 670                die("fetch-pack: unable to fork off %s", argv[0]);
 671        if (do_keep && pack_lockfile) {
 672                *pack_lockfile = index_pack_lockfile(cmd.out);
 673                close(cmd.out);
 674        }
 675
 676        if (finish_command(&cmd))
 677                die("%s failed", argv[0]);
 678        if (use_sideband && finish_async(&demux))
 679                die("error in sideband demultiplexer");
 680        return 0;
 681}
 682
 683static struct ref *do_fetch_pack(int fd[2],
 684                const struct ref *orig_ref,
 685                int nr_match,
 686                char **match,
 687                char **pack_lockfile)
 688{
 689        struct ref *ref = copy_ref_list(orig_ref);
 690        unsigned char sha1[20];
 691
 692        if (is_repository_shallow() && !server_supports("shallow"))
 693                die("Server does not support shallow clients");
 694        if (server_supports("multi_ack_detailed")) {
 695                if (args.verbose)
 696                        fprintf(stderr, "Server supports multi_ack_detailed\n");
 697                multi_ack = 2;
 698        }
 699        else if (server_supports("multi_ack")) {
 700                if (args.verbose)
 701                        fprintf(stderr, "Server supports multi_ack\n");
 702                multi_ack = 1;
 703        }
 704        if (server_supports("side-band-64k")) {
 705                if (args.verbose)
 706                        fprintf(stderr, "Server supports side-band-64k\n");
 707                use_sideband = 2;
 708        }
 709        else if (server_supports("side-band")) {
 710                if (args.verbose)
 711                        fprintf(stderr, "Server supports side-band\n");
 712                use_sideband = 1;
 713        }
 714        if (server_supports("ofs-delta")) {
 715                if (args.verbose)
 716                        fprintf(stderr, "Server supports ofs-delta\n");
 717        } else
 718                prefer_ofs_delta = 0;
 719        if (everything_local(&ref, nr_match, match)) {
 720                packet_flush(fd[1]);
 721                goto all_done;
 722        }
 723        if (find_common(fd, sha1, ref) < 0)
 724                if (!args.keep_pack)
 725                        /* When cloning, it is not unusual to have
 726                         * no common commit.
 727                         */
 728                        warning("no common commits");
 729
 730        if (args.stateless_rpc)
 731                packet_flush(fd[1]);
 732        if (get_pack(fd, pack_lockfile))
 733                die("git fetch-pack: fetch failed.");
 734
 735 all_done:
 736        return ref;
 737}
 738
 739static int remove_duplicates(int nr_heads, char **heads)
 740{
 741        int src, dst;
 742
 743        for (src = dst = 0; src < nr_heads; src++) {
 744                /* If heads[src] is different from any of
 745                 * heads[0..dst], push it in.
 746                 */
 747                int i;
 748                for (i = 0; i < dst; i++) {
 749                        if (!strcmp(heads[i], heads[src]))
 750                                break;
 751                }
 752                if (i < dst)
 753                        continue;
 754                if (src != dst)
 755                        heads[dst] = heads[src];
 756                dst++;
 757        }
 758        return dst;
 759}
 760
 761static int fetch_pack_config(const char *var, const char *value, void *cb)
 762{
 763        if (strcmp(var, "fetch.unpacklimit") == 0) {
 764                fetch_unpack_limit = git_config_int(var, value);
 765                return 0;
 766        }
 767
 768        if (strcmp(var, "transfer.unpacklimit") == 0) {
 769                transfer_unpack_limit = git_config_int(var, value);
 770                return 0;
 771        }
 772
 773        if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
 774                prefer_ofs_delta = git_config_bool(var, value);
 775                return 0;
 776        }
 777
 778        return git_default_config(var, value, cb);
 779}
 780
 781static struct lock_file lock;
 782
 783static void fetch_pack_setup(void)
 784{
 785        static int did_setup;
 786        if (did_setup)
 787                return;
 788        git_config(fetch_pack_config, NULL);
 789        if (0 <= transfer_unpack_limit)
 790                unpack_limit = transfer_unpack_limit;
 791        else if (0 <= fetch_unpack_limit)
 792                unpack_limit = fetch_unpack_limit;
 793        did_setup = 1;
 794}
 795
 796int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 797{
 798        int i, ret, nr_heads;
 799        struct ref *ref = NULL;
 800        char *dest = NULL, **heads;
 801        int fd[2];
 802        char *pack_lockfile = NULL;
 803        char **pack_lockfile_ptr = NULL;
 804        struct child_process *conn;
 805
 806        nr_heads = 0;
 807        heads = NULL;
 808        for (i = 1; i < argc; i++) {
 809                const char *arg = argv[i];
 810
 811                if (*arg == '-') {
 812                        if (!prefixcmp(arg, "--upload-pack=")) {
 813                                args.uploadpack = arg + 14;
 814                                continue;
 815                        }
 816                        if (!prefixcmp(arg, "--exec=")) {
 817                                args.uploadpack = arg + 7;
 818                                continue;
 819                        }
 820                        if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
 821                                args.quiet = 1;
 822                                continue;
 823                        }
 824                        if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
 825                                args.lock_pack = args.keep_pack;
 826                                args.keep_pack = 1;
 827                                continue;
 828                        }
 829                        if (!strcmp("--thin", arg)) {
 830                                args.use_thin_pack = 1;
 831                                continue;
 832                        }
 833                        if (!strcmp("--include-tag", arg)) {
 834                                args.include_tag = 1;
 835                                continue;
 836                        }
 837                        if (!strcmp("--all", arg)) {
 838                                args.fetch_all = 1;
 839                                continue;
 840                        }
 841                        if (!strcmp("-v", arg)) {
 842                                args.verbose = 1;
 843                                continue;
 844                        }
 845                        if (!prefixcmp(arg, "--depth=")) {
 846                                args.depth = strtol(arg + 8, NULL, 0);
 847                                continue;
 848                        }
 849                        if (!strcmp("--no-progress", arg)) {
 850                                args.no_progress = 1;
 851                                continue;
 852                        }
 853                        if (!strcmp("--stateless-rpc", arg)) {
 854                                args.stateless_rpc = 1;
 855                                continue;
 856                        }
 857                        if (!strcmp("--lock-pack", arg)) {
 858                                args.lock_pack = 1;
 859                                pack_lockfile_ptr = &pack_lockfile;
 860                                continue;
 861                        }
 862                        usage(fetch_pack_usage);
 863                }
 864                dest = (char *)arg;
 865                heads = (char **)(argv + i + 1);
 866                nr_heads = argc - i - 1;
 867                break;
 868        }
 869        if (!dest)
 870                usage(fetch_pack_usage);
 871
 872        if (args.stateless_rpc) {
 873                conn = NULL;
 874                fd[0] = 0;
 875                fd[1] = 1;
 876        } else {
 877                conn = git_connect(fd, (char *)dest, args.uploadpack,
 878                                   args.verbose ? CONNECT_VERBOSE : 0);
 879        }
 880
 881        get_remote_heads(fd[0], &ref, 0, NULL, 0, NULL);
 882
 883        ref = fetch_pack(&args, fd, conn, ref, dest,
 884                nr_heads, heads, pack_lockfile_ptr);
 885        if (pack_lockfile) {
 886                printf("lock %s\n", pack_lockfile);
 887                fflush(stdout);
 888        }
 889        close(fd[0]);
 890        close(fd[1]);
 891        if (finish_connect(conn))
 892                ref = NULL;
 893        ret = !ref;
 894
 895        if (!ret && nr_heads) {
 896                /* If the heads to pull were given, we should have
 897                 * consumed all of them by matching the remote.
 898                 * Otherwise, 'git fetch remote no-such-ref' would
 899                 * silently succeed without issuing an error.
 900                 */
 901                for (i = 0; i < nr_heads; i++)
 902                        if (heads[i] && heads[i][0]) {
 903                                error("no such remote ref %s", heads[i]);
 904                                ret = 1;
 905                        }
 906        }
 907        while (ref) {
 908                printf("%s %s\n",
 909                       sha1_to_hex(ref->old_sha1), ref->name);
 910                ref = ref->next;
 911        }
 912
 913        return ret;
 914}
 915
 916struct ref *fetch_pack(struct fetch_pack_args *my_args,
 917                       int fd[], struct child_process *conn,
 918                       const struct ref *ref,
 919                const char *dest,
 920                int nr_heads,
 921                char **heads,
 922                char **pack_lockfile)
 923{
 924        struct stat st;
 925        struct ref *ref_cpy;
 926
 927        fetch_pack_setup();
 928        if (&args != my_args)
 929                memcpy(&args, my_args, sizeof(args));
 930        if (args.depth > 0) {
 931                if (stat(git_path("shallow"), &st))
 932                        st.st_mtime = 0;
 933        }
 934
 935        if (heads && nr_heads)
 936                nr_heads = remove_duplicates(nr_heads, heads);
 937        if (!ref) {
 938                packet_flush(fd[1]);
 939                die("no matching remote head");
 940        }
 941        ref_cpy = do_fetch_pack(fd, ref, nr_heads, heads, pack_lockfile);
 942
 943        if (args.depth > 0) {
 944                struct cache_time mtime;
 945                struct strbuf sb = STRBUF_INIT;
 946                char *shallow = git_path("shallow");
 947                int fd;
 948
 949                mtime.sec = st.st_mtime;
 950                mtime.nsec = ST_MTIME_NSEC(st);
 951                if (stat(shallow, &st)) {
 952                        if (mtime.sec)
 953                                die("shallow file was removed during fetch");
 954                } else if (st.st_mtime != mtime.sec
 955#ifdef USE_NSEC
 956                                || ST_MTIME_NSEC(st) != mtime.nsec
 957#endif
 958                          )
 959                        die("shallow file was changed during fetch");
 960
 961                fd = hold_lock_file_for_update(&lock, shallow,
 962                                               LOCK_DIE_ON_ERROR);
 963                if (!write_shallow_commits(&sb, 0)
 964                 || write_in_full(fd, sb.buf, sb.len) != sb.len) {
 965                        unlink_or_warn(shallow);
 966                        rollback_lock_file(&lock);
 967                } else {
 968                        commit_lock_file(&lock);
 969                }
 970                strbuf_release(&sb);
 971        }
 972
 973        reprepare_packed_git();
 974        return ref_cpy;
 975}