fetch-pack.con commit merge: remove drop_save() in favor of remove_merge_branch_state() (b643355)
   1#include "cache.h"
   2#include "repository.h"
   3#include "config.h"
   4#include "lockfile.h"
   5#include "refs.h"
   6#include "pkt-line.h"
   7#include "commit.h"
   8#include "tag.h"
   9#include "exec-cmd.h"
  10#include "pack.h"
  11#include "sideband.h"
  12#include "fetch-pack.h"
  13#include "remote.h"
  14#include "run-command.h"
  15#include "connect.h"
  16#include "transport.h"
  17#include "version.h"
  18#include "sha1-array.h"
  19#include "oidset.h"
  20#include "packfile.h"
  21#include "object-store.h"
  22#include "connected.h"
  23#include "fetch-negotiator.h"
  24#include "fsck.h"
  25
  26static int transfer_unpack_limit = -1;
  27static int fetch_unpack_limit = -1;
  28static int unpack_limit = 100;
  29static int prefer_ofs_delta = 1;
  30static int no_done;
  31static int deepen_since_ok;
  32static int deepen_not_ok;
  33static int fetch_fsck_objects = -1;
  34static int transfer_fsck_objects = -1;
  35static int agent_supported;
  36static int server_supports_filtering;
  37static struct lock_file shallow_lock;
  38static const char *alternate_shallow_file;
  39static char *negotiation_algorithm;
  40static struct strbuf fsck_msg_types = STRBUF_INIT;
  41
  42/* Remember to update object flag allocation in object.h */
  43#define COMPLETE        (1U << 0)
  44#define ALTERNATE       (1U << 1)
  45
  46/*
  47 * After sending this many "have"s if we do not get any new ACK , we
  48 * give up traversing our history.
  49 */
  50#define MAX_IN_VAIN 256
  51
  52static int multi_ack, use_sideband;
  53/* Allow specifying sha1 if it is a ref tip. */
  54#define ALLOW_TIP_SHA1  01
  55/* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  56#define ALLOW_REACHABLE_SHA1    02
  57static unsigned int allow_unadvertised_object_request;
  58
  59__attribute__((format (printf, 2, 3)))
  60static inline void print_verbose(const struct fetch_pack_args *args,
  61                                 const char *fmt, ...)
  62{
  63        va_list params;
  64
  65        if (!args->verbose)
  66                return;
  67
  68        va_start(params, fmt);
  69        vfprintf(stderr, fmt, params);
  70        va_end(params);
  71        fputc('\n', stderr);
  72}
  73
  74struct alternate_object_cache {
  75        struct object **items;
  76        size_t nr, alloc;
  77};
  78
  79static void cache_one_alternate(const struct object_id *oid,
  80                                void *vcache)
  81{
  82        struct alternate_object_cache *cache = vcache;
  83        struct object *obj = parse_object(the_repository, oid);
  84
  85        if (!obj || (obj->flags & ALTERNATE))
  86                return;
  87
  88        obj->flags |= ALTERNATE;
  89        ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  90        cache->items[cache->nr++] = obj;
  91}
  92
  93static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
  94                                      void (*cb)(struct fetch_negotiator *,
  95                                                 struct object *))
  96{
  97        static int initialized;
  98        static struct alternate_object_cache cache;
  99        size_t i;
 100
 101        if (!initialized) {
 102                for_each_alternate_ref(cache_one_alternate, &cache);
 103                initialized = 1;
 104        }
 105
 106        for (i = 0; i < cache.nr; i++)
 107                cb(negotiator, cache.items[i]);
 108}
 109
 110static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
 111                               const char *refname,
 112                               const struct object_id *oid)
 113{
 114        struct object *o = deref_tag(the_repository,
 115                                     parse_object(the_repository, oid),
 116                                     refname, 0);
 117
 118        if (o && o->type == OBJ_COMMIT)
 119                negotiator->add_tip(negotiator, (struct commit *)o);
 120
 121        return 0;
 122}
 123
 124static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 125                                   int flag, void *cb_data)
 126{
 127        return rev_list_insert_ref(cb_data, refname, oid);
 128}
 129
 130enum ack_type {
 131        NAK = 0,
 132        ACK,
 133        ACK_continue,
 134        ACK_common,
 135        ACK_ready
 136};
 137
 138static void consume_shallow_list(struct fetch_pack_args *args,
 139                                 struct packet_reader *reader)
 140{
 141        if (args->stateless_rpc && args->deepen) {
 142                /* If we sent a depth we will get back "duplicate"
 143                 * shallow and unshallow commands every time there
 144                 * is a block of have lines exchanged.
 145                 */
 146                while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 147                        if (starts_with(reader->line, "shallow "))
 148                                continue;
 149                        if (starts_with(reader->line, "unshallow "))
 150                                continue;
 151                        die(_("git fetch-pack: expected shallow list"));
 152                }
 153                if (reader->status != PACKET_READ_FLUSH)
 154                        die(_("git fetch-pack: expected a flush packet after shallow list"));
 155        }
 156}
 157
 158static enum ack_type get_ack(struct packet_reader *reader,
 159                             struct object_id *result_oid)
 160{
 161        int len;
 162        const char *arg;
 163
 164        if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 165                die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 166        len = reader->pktlen;
 167
 168        if (!strcmp(reader->line, "NAK"))
 169                return NAK;
 170        if (skip_prefix(reader->line, "ACK ", &arg)) {
 171                if (!get_oid_hex(arg, result_oid)) {
 172                        arg += 40;
 173                        len -= arg - reader->line;
 174                        if (len < 1)
 175                                return ACK;
 176                        if (strstr(arg, "continue"))
 177                                return ACK_continue;
 178                        if (strstr(arg, "common"))
 179                                return ACK_common;
 180                        if (strstr(arg, "ready"))
 181                                return ACK_ready;
 182                        return ACK;
 183                }
 184        }
 185        die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
 186}
 187
 188static void send_request(struct fetch_pack_args *args,
 189                         int fd, struct strbuf *buf)
 190{
 191        if (args->stateless_rpc) {
 192                send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 193                packet_flush(fd);
 194        } else
 195                write_or_die(fd, buf->buf, buf->len);
 196}
 197
 198static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 199                                        struct object *obj)
 200{
 201        rev_list_insert_ref(negotiator, NULL, &obj->oid);
 202}
 203
 204#define INITIAL_FLUSH 16
 205#define PIPESAFE_FLUSH 32
 206#define LARGE_FLUSH 16384
 207
 208static int next_flush(int stateless_rpc, int count)
 209{
 210        if (stateless_rpc) {
 211                if (count < LARGE_FLUSH)
 212                        count <<= 1;
 213                else
 214                        count = count * 11 / 10;
 215        } else {
 216                if (count < PIPESAFE_FLUSH)
 217                        count <<= 1;
 218                else
 219                        count += PIPESAFE_FLUSH;
 220        }
 221        return count;
 222}
 223
 224static void mark_tips(struct fetch_negotiator *negotiator,
 225                      const struct oid_array *negotiation_tips)
 226{
 227        int i;
 228
 229        if (!negotiation_tips) {
 230                for_each_ref(rev_list_insert_ref_oid, negotiator);
 231                return;
 232        }
 233
 234        for (i = 0; i < negotiation_tips->nr; i++)
 235                rev_list_insert_ref(negotiator, NULL,
 236                                    &negotiation_tips->oid[i]);
 237        return;
 238}
 239
 240static int find_common(struct fetch_negotiator *negotiator,
 241                       struct fetch_pack_args *args,
 242                       int fd[2], struct object_id *result_oid,
 243                       struct ref *refs)
 244{
 245        int fetching;
 246        int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 247        const struct object_id *oid;
 248        unsigned in_vain = 0;
 249        int got_continue = 0;
 250        int got_ready = 0;
 251        struct strbuf req_buf = STRBUF_INIT;
 252        size_t state_len = 0;
 253        struct packet_reader reader;
 254
 255        if (args->stateless_rpc && multi_ack == 1)
 256                die(_("--stateless-rpc requires multi_ack_detailed"));
 257
 258        packet_reader_init(&reader, fd[0], NULL, 0,
 259                           PACKET_READ_CHOMP_NEWLINE |
 260                           PACKET_READ_DIE_ON_ERR_PACKET);
 261
 262        if (!args->no_dependents) {
 263                mark_tips(negotiator, args->negotiation_tips);
 264                for_each_cached_alternate(negotiator, insert_one_alternate_object);
 265        }
 266
 267        fetching = 0;
 268        for ( ; refs ; refs = refs->next) {
 269                struct object_id *remote = &refs->old_oid;
 270                const char *remote_hex;
 271                struct object *o;
 272
 273                /*
 274                 * If that object is complete (i.e. it is an ancestor of a
 275                 * local ref), we tell them we have it but do not have to
 276                 * tell them about its ancestors, which they already know
 277                 * about.
 278                 *
 279                 * We use lookup_object here because we are only
 280                 * interested in the case we *know* the object is
 281                 * reachable and we have already scanned it.
 282                 *
 283                 * Do this only if args->no_dependents is false (if it is true,
 284                 * we cannot trust the object flags).
 285                 */
 286                if (!args->no_dependents &&
 287                    ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
 288                                (o->flags & COMPLETE)) {
 289                        continue;
 290                }
 291
 292                remote_hex = oid_to_hex(remote);
 293                if (!fetching) {
 294                        struct strbuf c = STRBUF_INIT;
 295                        if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 296                        if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 297                        if (no_done)            strbuf_addstr(&c, " no-done");
 298                        if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 299                        if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 300                        if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 301                        if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 302                        if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 303                        if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 304                        if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 305                        if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 306                        if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 307                        if (agent_supported)    strbuf_addf(&c, " agent=%s",
 308                                                            git_user_agent_sanitized());
 309                        if (args->filter_options.choice)
 310                                strbuf_addstr(&c, " filter");
 311                        packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 312                        strbuf_release(&c);
 313                } else
 314                        packet_buf_write(&req_buf, "want %s\n", remote_hex);
 315                fetching++;
 316        }
 317
 318        if (!fetching) {
 319                strbuf_release(&req_buf);
 320                packet_flush(fd[1]);
 321                return 1;
 322        }
 323
 324        if (is_repository_shallow(the_repository))
 325                write_shallow_commits(&req_buf, 1, NULL);
 326        if (args->depth > 0)
 327                packet_buf_write(&req_buf, "deepen %d", args->depth);
 328        if (args->deepen_since) {
 329                timestamp_t max_age = approxidate(args->deepen_since);
 330                packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 331        }
 332        if (args->deepen_not) {
 333                int i;
 334                for (i = 0; i < args->deepen_not->nr; i++) {
 335                        struct string_list_item *s = args->deepen_not->items + i;
 336                        packet_buf_write(&req_buf, "deepen-not %s", s->string);
 337                }
 338        }
 339        if (server_supports_filtering && args->filter_options.choice) {
 340                struct strbuf expanded_filter_spec = STRBUF_INIT;
 341                expand_list_objects_filter_spec(&args->filter_options,
 342                                                &expanded_filter_spec);
 343                packet_buf_write(&req_buf, "filter %s",
 344                                 expanded_filter_spec.buf);
 345                strbuf_release(&expanded_filter_spec);
 346        }
 347        packet_buf_flush(&req_buf);
 348        state_len = req_buf.len;
 349
 350        if (args->deepen) {
 351                const char *arg;
 352                struct object_id oid;
 353
 354                send_request(args, fd[1], &req_buf);
 355                while (packet_reader_read(&reader) == PACKET_READ_NORMAL) {
 356                        if (skip_prefix(reader.line, "shallow ", &arg)) {
 357                                if (get_oid_hex(arg, &oid))
 358                                        die(_("invalid shallow line: %s"), reader.line);
 359                                register_shallow(the_repository, &oid);
 360                                continue;
 361                        }
 362                        if (skip_prefix(reader.line, "unshallow ", &arg)) {
 363                                if (get_oid_hex(arg, &oid))
 364                                        die(_("invalid unshallow line: %s"), reader.line);
 365                                if (!lookup_object(the_repository, oid.hash))
 366                                        die(_("object not found: %s"), reader.line);
 367                                /* make sure that it is parsed as shallow */
 368                                if (!parse_object(the_repository, &oid))
 369                                        die(_("error in object: %s"), reader.line);
 370                                if (unregister_shallow(&oid))
 371                                        die(_("no shallow found: %s"), reader.line);
 372                                continue;
 373                        }
 374                        die(_("expected shallow/unshallow, got %s"), reader.line);
 375                }
 376        } else if (!args->stateless_rpc)
 377                send_request(args, fd[1], &req_buf);
 378
 379        if (!args->stateless_rpc) {
 380                /* If we aren't using the stateless-rpc interface
 381                 * we don't need to retain the headers.
 382                 */
 383                strbuf_setlen(&req_buf, 0);
 384                state_len = 0;
 385        }
 386
 387        flushes = 0;
 388        retval = -1;
 389        if (args->no_dependents)
 390                goto done;
 391        while ((oid = negotiator->next(negotiator))) {
 392                packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 393                print_verbose(args, "have %s", oid_to_hex(oid));
 394                in_vain++;
 395                if (flush_at <= ++count) {
 396                        int ack;
 397
 398                        packet_buf_flush(&req_buf);
 399                        send_request(args, fd[1], &req_buf);
 400                        strbuf_setlen(&req_buf, state_len);
 401                        flushes++;
 402                        flush_at = next_flush(args->stateless_rpc, count);
 403
 404                        /*
 405                         * We keep one window "ahead" of the other side, and
 406                         * will wait for an ACK only on the next one
 407                         */
 408                        if (!args->stateless_rpc && count == INITIAL_FLUSH)
 409                                continue;
 410
 411                        consume_shallow_list(args, &reader);
 412                        do {
 413                                ack = get_ack(&reader, result_oid);
 414                                if (ack)
 415                                        print_verbose(args, _("got %s %d %s"), "ack",
 416                                                      ack, oid_to_hex(result_oid));
 417                                switch (ack) {
 418                                case ACK:
 419                                        flushes = 0;
 420                                        multi_ack = 0;
 421                                        retval = 0;
 422                                        goto done;
 423                                case ACK_common:
 424                                case ACK_ready:
 425                                case ACK_continue: {
 426                                        struct commit *commit =
 427                                                lookup_commit(the_repository,
 428                                                              result_oid);
 429                                        int was_common;
 430
 431                                        if (!commit)
 432                                                die(_("invalid commit %s"), oid_to_hex(result_oid));
 433                                        was_common = negotiator->ack(negotiator, commit);
 434                                        if (args->stateless_rpc
 435                                         && ack == ACK_common
 436                                         && !was_common) {
 437                                                /* We need to replay the have for this object
 438                                                 * on the next RPC request so the peer knows
 439                                                 * it is in common with us.
 440                                                 */
 441                                                const char *hex = oid_to_hex(result_oid);
 442                                                packet_buf_write(&req_buf, "have %s\n", hex);
 443                                                state_len = req_buf.len;
 444                                                /*
 445                                                 * Reset in_vain because an ack
 446                                                 * for this commit has not been
 447                                                 * seen.
 448                                                 */
 449                                                in_vain = 0;
 450                                        } else if (!args->stateless_rpc
 451                                                   || ack != ACK_common)
 452                                                in_vain = 0;
 453                                        retval = 0;
 454                                        got_continue = 1;
 455                                        if (ack == ACK_ready)
 456                                                got_ready = 1;
 457                                        break;
 458                                        }
 459                                }
 460                        } while (ack);
 461                        flushes--;
 462                        if (got_continue && MAX_IN_VAIN < in_vain) {
 463                                print_verbose(args, _("giving up"));
 464                                break; /* give up */
 465                        }
 466                        if (got_ready)
 467                                break;
 468                }
 469        }
 470done:
 471        if (!got_ready || !no_done) {
 472                packet_buf_write(&req_buf, "done\n");
 473                send_request(args, fd[1], &req_buf);
 474        }
 475        print_verbose(args, _("done"));
 476        if (retval != 0) {
 477                multi_ack = 0;
 478                flushes++;
 479        }
 480        strbuf_release(&req_buf);
 481
 482        if (!got_ready || !no_done)
 483                consume_shallow_list(args, &reader);
 484        while (flushes || multi_ack) {
 485                int ack = get_ack(&reader, result_oid);
 486                if (ack) {
 487                        print_verbose(args, _("got %s (%d) %s"), "ack",
 488                                      ack, oid_to_hex(result_oid));
 489                        if (ack == ACK)
 490                                return 0;
 491                        multi_ack = 1;
 492                        continue;
 493                }
 494                flushes--;
 495        }
 496        /* it is no error to fetch into a completely empty repo */
 497        return count ? retval : 0;
 498}
 499
 500static struct commit_list *complete;
 501
 502static int mark_complete(const struct object_id *oid)
 503{
 504        struct object *o = parse_object(the_repository, oid);
 505
 506        while (o && o->type == OBJ_TAG) {
 507                struct tag *t = (struct tag *) o;
 508                if (!t->tagged)
 509                        break; /* broken repository */
 510                o->flags |= COMPLETE;
 511                o = parse_object(the_repository, &t->tagged->oid);
 512        }
 513        if (o && o->type == OBJ_COMMIT) {
 514                struct commit *commit = (struct commit *)o;
 515                if (!(commit->object.flags & COMPLETE)) {
 516                        commit->object.flags |= COMPLETE;
 517                        commit_list_insert(commit, &complete);
 518                }
 519        }
 520        return 0;
 521}
 522
 523static int mark_complete_oid(const char *refname, const struct object_id *oid,
 524                             int flag, void *cb_data)
 525{
 526        return mark_complete(oid);
 527}
 528
 529static void mark_recent_complete_commits(struct fetch_pack_args *args,
 530                                         timestamp_t cutoff)
 531{
 532        while (complete && cutoff <= complete->item->date) {
 533                print_verbose(args, _("Marking %s as complete"),
 534                              oid_to_hex(&complete->item->object.oid));
 535                pop_most_recent_commit(&complete, COMPLETE);
 536        }
 537}
 538
 539static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 540{
 541        for (; refs; refs = refs->next)
 542                oidset_insert(oids, &refs->old_oid);
 543}
 544
 545static int is_unmatched_ref(const struct ref *ref)
 546{
 547        struct object_id oid;
 548        const char *p;
 549        return  ref->match_status == REF_NOT_MATCHED &&
 550                !parse_oid_hex(ref->name, &oid, &p) &&
 551                *p == '\0' &&
 552                oideq(&oid, &ref->old_oid);
 553}
 554
 555static void filter_refs(struct fetch_pack_args *args,
 556                        struct ref **refs,
 557                        struct ref **sought, int nr_sought)
 558{
 559        struct ref *newlist = NULL;
 560        struct ref **newtail = &newlist;
 561        struct ref *unmatched = NULL;
 562        struct ref *ref, *next;
 563        struct oidset tip_oids = OIDSET_INIT;
 564        int i;
 565        int strict = !(allow_unadvertised_object_request &
 566                       (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
 567
 568        i = 0;
 569        for (ref = *refs; ref; ref = next) {
 570                int keep = 0;
 571                next = ref->next;
 572
 573                if (starts_with(ref->name, "refs/") &&
 574                    check_refname_format(ref->name, 0))
 575                        ; /* trash */
 576                else {
 577                        while (i < nr_sought) {
 578                                int cmp = strcmp(ref->name, sought[i]->name);
 579                                if (cmp < 0)
 580                                        break; /* definitely do not have it */
 581                                else if (cmp == 0) {
 582                                        keep = 1; /* definitely have it */
 583                                        sought[i]->match_status = REF_MATCHED;
 584                                }
 585                                i++;
 586                        }
 587
 588                        if (!keep && args->fetch_all &&
 589                            (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 590                                keep = 1;
 591                }
 592
 593                if (keep) {
 594                        *newtail = ref;
 595                        ref->next = NULL;
 596                        newtail = &ref->next;
 597                } else {
 598                        ref->next = unmatched;
 599                        unmatched = ref;
 600                }
 601        }
 602
 603        if (strict) {
 604                for (i = 0; i < nr_sought; i++) {
 605                        ref = sought[i];
 606                        if (!is_unmatched_ref(ref))
 607                                continue;
 608
 609                        add_refs_to_oidset(&tip_oids, unmatched);
 610                        add_refs_to_oidset(&tip_oids, newlist);
 611                        break;
 612                }
 613        }
 614
 615        /* Append unmatched requests to the list */
 616        for (i = 0; i < nr_sought; i++) {
 617                ref = sought[i];
 618                if (!is_unmatched_ref(ref))
 619                        continue;
 620
 621                if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
 622                        ref->match_status = REF_MATCHED;
 623                        *newtail = copy_ref(ref);
 624                        newtail = &(*newtail)->next;
 625                } else {
 626                        ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 627                }
 628        }
 629
 630        oidset_clear(&tip_oids);
 631        for (ref = unmatched; ref; ref = next) {
 632                next = ref->next;
 633                free(ref);
 634        }
 635
 636        *refs = newlist;
 637}
 638
 639static void mark_alternate_complete(struct fetch_negotiator *unused,
 640                                    struct object *obj)
 641{
 642        mark_complete(&obj->oid);
 643}
 644
 645struct loose_object_iter {
 646        struct oidset *loose_object_set;
 647        struct ref *refs;
 648};
 649
 650/*
 651 * Mark recent commits available locally and reachable from a local ref as
 652 * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 653 * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 654 * thus do not need COMMON_REF marks).
 655 *
 656 * The cutoff time for recency is determined by this heuristic: it is the
 657 * earliest commit time of the objects in refs that are commits and that we know
 658 * the commit time of.
 659 */
 660static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 661                                         struct fetch_pack_args *args,
 662                                         struct ref **refs)
 663{
 664        struct ref *ref;
 665        int old_save_commit_buffer = save_commit_buffer;
 666        timestamp_t cutoff = 0;
 667
 668        save_commit_buffer = 0;
 669
 670        for (ref = *refs; ref; ref = ref->next) {
 671                struct object *o;
 672
 673                if (!has_object_file_with_flags(&ref->old_oid,
 674                                                OBJECT_INFO_QUICK))
 675                        continue;
 676                o = parse_object(the_repository, &ref->old_oid);
 677                if (!o)
 678                        continue;
 679
 680                /* We already have it -- which may mean that we were
 681                 * in sync with the other side at some time after
 682                 * that (it is OK if we guess wrong here).
 683                 */
 684                if (o->type == OBJ_COMMIT) {
 685                        struct commit *commit = (struct commit *)o;
 686                        if (!cutoff || cutoff < commit->date)
 687                                cutoff = commit->date;
 688                }
 689        }
 690
 691        if (!args->deepen) {
 692                for_each_ref(mark_complete_oid, NULL);
 693                for_each_cached_alternate(NULL, mark_alternate_complete);
 694                commit_list_sort_by_date(&complete);
 695                if (cutoff)
 696                        mark_recent_complete_commits(args, cutoff);
 697        }
 698
 699        /*
 700         * Mark all complete remote refs as common refs.
 701         * Don't mark them common yet; the server has to be told so first.
 702         */
 703        for (ref = *refs; ref; ref = ref->next) {
 704                struct object *o = deref_tag(the_repository,
 705                                             lookup_object(the_repository,
 706                                             ref->old_oid.hash),
 707                                             NULL, 0);
 708
 709                if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 710                        continue;
 711
 712                negotiator->known_common(negotiator,
 713                                         (struct commit *)o);
 714        }
 715
 716        save_commit_buffer = old_save_commit_buffer;
 717}
 718
 719/*
 720 * Returns 1 if every object pointed to by the given remote refs is available
 721 * locally and reachable from a local ref, and 0 otherwise.
 722 */
 723static int everything_local(struct fetch_pack_args *args,
 724                            struct ref **refs)
 725{
 726        struct ref *ref;
 727        int retval;
 728
 729        for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 730                const struct object_id *remote = &ref->old_oid;
 731                struct object *o;
 732
 733                o = lookup_object(the_repository, remote->hash);
 734                if (!o || !(o->flags & COMPLETE)) {
 735                        retval = 0;
 736                        print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 737                                      ref->name);
 738                        continue;
 739                }
 740                print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 741                              ref->name);
 742        }
 743
 744        return retval;
 745}
 746
 747static int sideband_demux(int in, int out, void *data)
 748{
 749        int *xd = data;
 750        int ret;
 751
 752        ret = recv_sideband("fetch-pack", xd[0], out);
 753        close(out);
 754        return ret;
 755}
 756
 757static int get_pack(struct fetch_pack_args *args,
 758                    int xd[2], char **pack_lockfile)
 759{
 760        struct async demux;
 761        int do_keep = args->keep_pack;
 762        const char *cmd_name;
 763        struct pack_header header;
 764        int pass_header = 0;
 765        struct child_process cmd = CHILD_PROCESS_INIT;
 766        int ret;
 767
 768        memset(&demux, 0, sizeof(demux));
 769        if (use_sideband) {
 770                /* xd[] is talking with upload-pack; subprocess reads from
 771                 * xd[0], spits out band#2 to stderr, and feeds us band#1
 772                 * through demux->out.
 773                 */
 774                demux.proc = sideband_demux;
 775                demux.data = xd;
 776                demux.out = -1;
 777                demux.isolate_sigpipe = 1;
 778                if (start_async(&demux))
 779                        die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 780        }
 781        else
 782                demux.out = xd[0];
 783
 784        if (!args->keep_pack && unpack_limit) {
 785
 786                if (read_pack_header(demux.out, &header))
 787                        die(_("protocol error: bad pack header"));
 788                pass_header = 1;
 789                if (ntohl(header.hdr_entries) < unpack_limit)
 790                        do_keep = 0;
 791                else
 792                        do_keep = 1;
 793        }
 794
 795        if (alternate_shallow_file) {
 796                argv_array_push(&cmd.args, "--shallow-file");
 797                argv_array_push(&cmd.args, alternate_shallow_file);
 798        }
 799
 800        if (do_keep || args->from_promisor) {
 801                if (pack_lockfile)
 802                        cmd.out = -1;
 803                cmd_name = "index-pack";
 804                argv_array_push(&cmd.args, cmd_name);
 805                argv_array_push(&cmd.args, "--stdin");
 806                if (!args->quiet && !args->no_progress)
 807                        argv_array_push(&cmd.args, "-v");
 808                if (args->use_thin_pack)
 809                        argv_array_push(&cmd.args, "--fix-thin");
 810                if (do_keep && (args->lock_pack || unpack_limit)) {
 811                        char hostname[HOST_NAME_MAX + 1];
 812                        if (xgethostname(hostname, sizeof(hostname)))
 813                                xsnprintf(hostname, sizeof(hostname), "localhost");
 814                        argv_array_pushf(&cmd.args,
 815                                        "--keep=fetch-pack %"PRIuMAX " on %s",
 816                                        (uintmax_t)getpid(), hostname);
 817                }
 818                if (args->check_self_contained_and_connected)
 819                        argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 820                if (args->from_promisor)
 821                        argv_array_push(&cmd.args, "--promisor");
 822        }
 823        else {
 824                cmd_name = "unpack-objects";
 825                argv_array_push(&cmd.args, cmd_name);
 826                if (args->quiet || args->no_progress)
 827                        argv_array_push(&cmd.args, "-q");
 828                args->check_self_contained_and_connected = 0;
 829        }
 830
 831        if (pass_header)
 832                argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 833                                 ntohl(header.hdr_version),
 834                                 ntohl(header.hdr_entries));
 835        if (fetch_fsck_objects >= 0
 836            ? fetch_fsck_objects
 837            : transfer_fsck_objects >= 0
 838            ? transfer_fsck_objects
 839            : 0) {
 840                if (args->from_promisor)
 841                        /*
 842                         * We cannot use --strict in index-pack because it
 843                         * checks both broken objects and links, but we only
 844                         * want to check for broken objects.
 845                         */
 846                        argv_array_push(&cmd.args, "--fsck-objects");
 847                else
 848                        argv_array_pushf(&cmd.args, "--strict%s",
 849                                         fsck_msg_types.buf);
 850        }
 851
 852        cmd.in = demux.out;
 853        cmd.git_cmd = 1;
 854        if (start_command(&cmd))
 855                die(_("fetch-pack: unable to fork off %s"), cmd_name);
 856        if (do_keep && pack_lockfile) {
 857                *pack_lockfile = index_pack_lockfile(cmd.out);
 858                close(cmd.out);
 859        }
 860
 861        if (!use_sideband)
 862                /* Closed by start_command() */
 863                xd[0] = -1;
 864
 865        ret = finish_command(&cmd);
 866        if (!ret || (args->check_self_contained_and_connected && ret == 1))
 867                args->self_contained_and_connected =
 868                        args->check_self_contained_and_connected &&
 869                        ret == 0;
 870        else
 871                die(_("%s failed"), cmd_name);
 872        if (use_sideband && finish_async(&demux))
 873                die(_("error in sideband demultiplexer"));
 874        return 0;
 875}
 876
 877static int cmp_ref_by_name(const void *a_, const void *b_)
 878{
 879        const struct ref *a = *((const struct ref **)a_);
 880        const struct ref *b = *((const struct ref **)b_);
 881        return strcmp(a->name, b->name);
 882}
 883
 884static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 885                                 int fd[2],
 886                                 const struct ref *orig_ref,
 887                                 struct ref **sought, int nr_sought,
 888                                 struct shallow_info *si,
 889                                 char **pack_lockfile)
 890{
 891        struct ref *ref = copy_ref_list(orig_ref);
 892        struct object_id oid;
 893        const char *agent_feature;
 894        int agent_len;
 895        struct fetch_negotiator negotiator;
 896        fetch_negotiator_init(&negotiator, negotiation_algorithm);
 897
 898        sort_ref_list(&ref, ref_compare_name);
 899        QSORT(sought, nr_sought, cmp_ref_by_name);
 900
 901        if ((args->depth > 0 || is_repository_shallow(the_repository)) && !server_supports("shallow"))
 902                die(_("Server does not support shallow clients"));
 903        if (args->depth > 0 || args->deepen_since || args->deepen_not)
 904                args->deepen = 1;
 905        if (server_supports("multi_ack_detailed")) {
 906                print_verbose(args, _("Server supports multi_ack_detailed"));
 907                multi_ack = 2;
 908                if (server_supports("no-done")) {
 909                        print_verbose(args, _("Server supports no-done"));
 910                        if (args->stateless_rpc)
 911                                no_done = 1;
 912                }
 913        }
 914        else if (server_supports("multi_ack")) {
 915                print_verbose(args, _("Server supports multi_ack"));
 916                multi_ack = 1;
 917        }
 918        if (server_supports("side-band-64k")) {
 919                print_verbose(args, _("Server supports side-band-64k"));
 920                use_sideband = 2;
 921        }
 922        else if (server_supports("side-band")) {
 923                print_verbose(args, _("Server supports side-band"));
 924                use_sideband = 1;
 925        }
 926        if (server_supports("allow-tip-sha1-in-want")) {
 927                print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 928                allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 929        }
 930        if (server_supports("allow-reachable-sha1-in-want")) {
 931                print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 932                allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 933        }
 934        if (!server_supports("thin-pack"))
 935                args->use_thin_pack = 0;
 936        if (!server_supports("no-progress"))
 937                args->no_progress = 0;
 938        if (!server_supports("include-tag"))
 939                args->include_tag = 0;
 940        if (server_supports("ofs-delta"))
 941                print_verbose(args, _("Server supports ofs-delta"));
 942        else
 943                prefer_ofs_delta = 0;
 944
 945        if (server_supports("filter")) {
 946                server_supports_filtering = 1;
 947                print_verbose(args, _("Server supports filter"));
 948        } else if (args->filter_options.choice) {
 949                warning("filtering not recognized by server, ignoring");
 950        }
 951
 952        if ((agent_feature = server_feature_value("agent", &agent_len))) {
 953                agent_supported = 1;
 954                if (agent_len)
 955                        print_verbose(args, _("Server version is %.*s"),
 956                                      agent_len, agent_feature);
 957        }
 958        if (server_supports("deepen-since"))
 959                deepen_since_ok = 1;
 960        else if (args->deepen_since)
 961                die(_("Server does not support --shallow-since"));
 962        if (server_supports("deepen-not"))
 963                deepen_not_ok = 1;
 964        else if (args->deepen_not)
 965                die(_("Server does not support --shallow-exclude"));
 966        if (!server_supports("deepen-relative") && args->deepen_relative)
 967                die(_("Server does not support --deepen"));
 968
 969        if (!args->no_dependents) {
 970                mark_complete_and_common_ref(&negotiator, args, &ref);
 971                filter_refs(args, &ref, sought, nr_sought);
 972                if (everything_local(args, &ref)) {
 973                        packet_flush(fd[1]);
 974                        goto all_done;
 975                }
 976        } else {
 977                filter_refs(args, &ref, sought, nr_sought);
 978        }
 979        if (find_common(&negotiator, args, fd, &oid, ref) < 0)
 980                if (!args->keep_pack)
 981                        /* When cloning, it is not unusual to have
 982                         * no common commit.
 983                         */
 984                        warning(_("no common commits"));
 985
 986        if (args->stateless_rpc)
 987                packet_flush(fd[1]);
 988        if (args->deepen)
 989                setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
 990                                        NULL);
 991        else if (si->nr_ours || si->nr_theirs)
 992                alternate_shallow_file = setup_temporary_shallow(si->shallow);
 993        else
 994                alternate_shallow_file = NULL;
 995        if (get_pack(args, fd, pack_lockfile))
 996                die(_("git fetch-pack: fetch failed."));
 997
 998 all_done:
 999        negotiator.release(&negotiator);
1000        return ref;
1001}
1002
1003static void add_shallow_requests(struct strbuf *req_buf,
1004                                 const struct fetch_pack_args *args)
1005{
1006        if (is_repository_shallow(the_repository))
1007                write_shallow_commits(req_buf, 1, NULL);
1008        if (args->depth > 0)
1009                packet_buf_write(req_buf, "deepen %d", args->depth);
1010        if (args->deepen_since) {
1011                timestamp_t max_age = approxidate(args->deepen_since);
1012                packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1013        }
1014        if (args->deepen_not) {
1015                int i;
1016                for (i = 0; i < args->deepen_not->nr; i++) {
1017                        struct string_list_item *s = args->deepen_not->items + i;
1018                        packet_buf_write(req_buf, "deepen-not %s", s->string);
1019                }
1020        }
1021        if (args->deepen_relative)
1022                packet_buf_write(req_buf, "deepen-relative\n");
1023}
1024
1025static void add_wants(int no_dependents, const struct ref *wants, struct strbuf *req_buf)
1026{
1027        int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1028
1029        for ( ; wants ; wants = wants->next) {
1030                const struct object_id *remote = &wants->old_oid;
1031                struct object *o;
1032
1033                /*
1034                 * If that object is complete (i.e. it is an ancestor of a
1035                 * local ref), we tell them we have it but do not have to
1036                 * tell them about its ancestors, which they already know
1037                 * about.
1038                 *
1039                 * We use lookup_object here because we are only
1040                 * interested in the case we *know* the object is
1041                 * reachable and we have already scanned it.
1042                 *
1043                 * Do this only if args->no_dependents is false (if it is true,
1044                 * we cannot trust the object flags).
1045                 */
1046                if (!no_dependents &&
1047                    ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
1048                    (o->flags & COMPLETE)) {
1049                        continue;
1050                }
1051
1052                if (!use_ref_in_want || wants->exact_oid)
1053                        packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1054                else
1055                        packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1056        }
1057}
1058
1059static void add_common(struct strbuf *req_buf, struct oidset *common)
1060{
1061        struct oidset_iter iter;
1062        const struct object_id *oid;
1063        oidset_iter_init(common, &iter);
1064
1065        while ((oid = oidset_iter_next(&iter))) {
1066                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1067        }
1068}
1069
1070static int add_haves(struct fetch_negotiator *negotiator,
1071                     struct strbuf *req_buf,
1072                     int *haves_to_send, int *in_vain)
1073{
1074        int ret = 0;
1075        int haves_added = 0;
1076        const struct object_id *oid;
1077
1078        while ((oid = negotiator->next(negotiator))) {
1079                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1080                if (++haves_added >= *haves_to_send)
1081                        break;
1082        }
1083
1084        *in_vain += haves_added;
1085        if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1086                /* Send Done */
1087                packet_buf_write(req_buf, "done\n");
1088                ret = 1;
1089        }
1090
1091        /* Increase haves to send on next round */
1092        *haves_to_send = next_flush(1, *haves_to_send);
1093
1094        return ret;
1095}
1096
1097static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1098                              const struct fetch_pack_args *args,
1099                              const struct ref *wants, struct oidset *common,
1100                              int *haves_to_send, int *in_vain,
1101                              int sideband_all)
1102{
1103        int ret = 0;
1104        struct strbuf req_buf = STRBUF_INIT;
1105
1106        if (server_supports_v2("fetch", 1))
1107                packet_buf_write(&req_buf, "command=fetch");
1108        if (server_supports_v2("agent", 0))
1109                packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1110        if (args->server_options && args->server_options->nr &&
1111            server_supports_v2("server-option", 1)) {
1112                int i;
1113                for (i = 0; i < args->server_options->nr; i++)
1114                        packet_write_fmt(fd_out, "server-option=%s",
1115                                         args->server_options->items[i].string);
1116        }
1117
1118        packet_buf_delim(&req_buf);
1119        if (args->use_thin_pack)
1120                packet_buf_write(&req_buf, "thin-pack");
1121        if (args->no_progress)
1122                packet_buf_write(&req_buf, "no-progress");
1123        if (args->include_tag)
1124                packet_buf_write(&req_buf, "include-tag");
1125        if (prefer_ofs_delta)
1126                packet_buf_write(&req_buf, "ofs-delta");
1127        if (sideband_all)
1128                packet_buf_write(&req_buf, "sideband-all");
1129
1130        /* Add shallow-info and deepen request */
1131        if (server_supports_feature("fetch", "shallow", 0))
1132                add_shallow_requests(&req_buf, args);
1133        else if (is_repository_shallow(the_repository) || args->deepen)
1134                die(_("Server does not support shallow requests"));
1135
1136        /* Add filter */
1137        if (server_supports_feature("fetch", "filter", 0) &&
1138            args->filter_options.choice) {
1139                struct strbuf expanded_filter_spec = STRBUF_INIT;
1140                print_verbose(args, _("Server supports filter"));
1141                expand_list_objects_filter_spec(&args->filter_options,
1142                                                &expanded_filter_spec);
1143                packet_buf_write(&req_buf, "filter %s",
1144                                 expanded_filter_spec.buf);
1145                strbuf_release(&expanded_filter_spec);
1146        } else if (args->filter_options.choice) {
1147                warning("filtering not recognized by server, ignoring");
1148        }
1149
1150        /* add wants */
1151        add_wants(args->no_dependents, wants, &req_buf);
1152
1153        if (args->no_dependents) {
1154                packet_buf_write(&req_buf, "done");
1155                ret = 1;
1156        } else {
1157                /* Add all of the common commits we've found in previous rounds */
1158                add_common(&req_buf, common);
1159
1160                /* Add initial haves */
1161                ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1162        }
1163
1164        /* Send request */
1165        packet_buf_flush(&req_buf);
1166        write_or_die(fd_out, req_buf.buf, req_buf.len);
1167
1168        strbuf_release(&req_buf);
1169        return ret;
1170}
1171
1172/*
1173 * Processes a section header in a server's response and checks if it matches
1174 * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1175 * not consumed); if 0, the line will be consumed and the function will die if
1176 * the section header doesn't match what was expected.
1177 */
1178static int process_section_header(struct packet_reader *reader,
1179                                  const char *section, int peek)
1180{
1181        int ret;
1182
1183        if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1184                die(_("error reading section header '%s'"), section);
1185
1186        ret = !strcmp(reader->line, section);
1187
1188        if (!peek) {
1189                if (!ret)
1190                        die(_("expected '%s', received '%s'"),
1191                            section, reader->line);
1192                packet_reader_read(reader);
1193        }
1194
1195        return ret;
1196}
1197
1198static int process_acks(struct fetch_negotiator *negotiator,
1199                        struct packet_reader *reader,
1200                        struct oidset *common)
1201{
1202        /* received */
1203        int received_ready = 0;
1204        int received_ack = 0;
1205
1206        process_section_header(reader, "acknowledgments", 0);
1207        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1208                const char *arg;
1209
1210                if (!strcmp(reader->line, "NAK"))
1211                        continue;
1212
1213                if (skip_prefix(reader->line, "ACK ", &arg)) {
1214                        struct object_id oid;
1215                        if (!get_oid_hex(arg, &oid)) {
1216                                struct commit *commit;
1217                                oidset_insert(common, &oid);
1218                                commit = lookup_commit(the_repository, &oid);
1219                                negotiator->ack(negotiator, commit);
1220                        }
1221                        continue;
1222                }
1223
1224                if (!strcmp(reader->line, "ready")) {
1225                        received_ready = 1;
1226                        continue;
1227                }
1228
1229                die(_("unexpected acknowledgment line: '%s'"), reader->line);
1230        }
1231
1232        if (reader->status != PACKET_READ_FLUSH &&
1233            reader->status != PACKET_READ_DELIM)
1234                die(_("error processing acks: %d"), reader->status);
1235
1236        /*
1237         * If an "acknowledgments" section is sent, a packfile is sent if and
1238         * only if "ready" was sent in this section. The other sections
1239         * ("shallow-info" and "wanted-refs") are sent only if a packfile is
1240         * sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
1241         * otherwise.
1242         */
1243        if (received_ready && reader->status != PACKET_READ_DELIM)
1244                die(_("expected packfile to be sent after 'ready'"));
1245        if (!received_ready && reader->status != PACKET_READ_FLUSH)
1246                die(_("expected no other sections to be sent after no 'ready'"));
1247
1248        /* return 0 if no common, 1 if there are common, or 2 if ready */
1249        return received_ready ? 2 : (received_ack ? 1 : 0);
1250}
1251
1252static void receive_shallow_info(struct fetch_pack_args *args,
1253                                 struct packet_reader *reader)
1254{
1255        int line_received = 0;
1256
1257        process_section_header(reader, "shallow-info", 0);
1258        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1259                const char *arg;
1260                struct object_id oid;
1261
1262                if (skip_prefix(reader->line, "shallow ", &arg)) {
1263                        if (get_oid_hex(arg, &oid))
1264                                die(_("invalid shallow line: %s"), reader->line);
1265                        register_shallow(the_repository, &oid);
1266                        line_received = 1;
1267                        continue;
1268                }
1269                if (skip_prefix(reader->line, "unshallow ", &arg)) {
1270                        if (get_oid_hex(arg, &oid))
1271                                die(_("invalid unshallow line: %s"), reader->line);
1272                        if (!lookup_object(the_repository, oid.hash))
1273                                die(_("object not found: %s"), reader->line);
1274                        /* make sure that it is parsed as shallow */
1275                        if (!parse_object(the_repository, &oid))
1276                                die(_("error in object: %s"), reader->line);
1277                        if (unregister_shallow(&oid))
1278                                die(_("no shallow found: %s"), reader->line);
1279                        line_received = 1;
1280                        continue;
1281                }
1282                die(_("expected shallow/unshallow, got %s"), reader->line);
1283        }
1284
1285        if (reader->status != PACKET_READ_FLUSH &&
1286            reader->status != PACKET_READ_DELIM)
1287                die(_("error processing shallow info: %d"), reader->status);
1288
1289        if (line_received) {
1290                setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1291                                        NULL);
1292                args->deepen = 1;
1293        } else {
1294                alternate_shallow_file = NULL;
1295        }
1296}
1297
1298static void receive_wanted_refs(struct packet_reader *reader,
1299                                struct ref **sought, int nr_sought)
1300{
1301        process_section_header(reader, "wanted-refs", 0);
1302        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1303                struct object_id oid;
1304                const char *end;
1305                int i;
1306
1307                if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1308                        die(_("expected wanted-ref, got '%s'"), reader->line);
1309
1310                for (i = 0; i < nr_sought; i++) {
1311                        if (!strcmp(end, sought[i]->name)) {
1312                                oidcpy(&sought[i]->old_oid, &oid);
1313                                break;
1314                        }
1315                }
1316
1317                if (i == nr_sought)
1318                        die(_("unexpected wanted-ref: '%s'"), reader->line);
1319        }
1320
1321        if (reader->status != PACKET_READ_DELIM)
1322                die(_("error processing wanted refs: %d"), reader->status);
1323}
1324
1325enum fetch_state {
1326        FETCH_CHECK_LOCAL = 0,
1327        FETCH_SEND_REQUEST,
1328        FETCH_PROCESS_ACKS,
1329        FETCH_GET_PACK,
1330        FETCH_DONE,
1331};
1332
1333static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1334                                    int fd[2],
1335                                    const struct ref *orig_ref,
1336                                    struct ref **sought, int nr_sought,
1337                                    char **pack_lockfile)
1338{
1339        struct ref *ref = copy_ref_list(orig_ref);
1340        enum fetch_state state = FETCH_CHECK_LOCAL;
1341        struct oidset common = OIDSET_INIT;
1342        struct packet_reader reader;
1343        int in_vain = 0;
1344        int haves_to_send = INITIAL_FLUSH;
1345        struct fetch_negotiator negotiator;
1346        fetch_negotiator_init(&negotiator, negotiation_algorithm);
1347        packet_reader_init(&reader, fd[0], NULL, 0,
1348                           PACKET_READ_CHOMP_NEWLINE |
1349                           PACKET_READ_DIE_ON_ERR_PACKET);
1350        if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
1351            server_supports_feature("fetch", "sideband-all", 0)) {
1352                reader.use_sideband = 1;
1353                reader.me = "fetch-pack";
1354        }
1355
1356        while (state != FETCH_DONE) {
1357                switch (state) {
1358                case FETCH_CHECK_LOCAL:
1359                        sort_ref_list(&ref, ref_compare_name);
1360                        QSORT(sought, nr_sought, cmp_ref_by_name);
1361
1362                        /* v2 supports these by default */
1363                        allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1364                        use_sideband = 2;
1365                        if (args->depth > 0 || args->deepen_since || args->deepen_not)
1366                                args->deepen = 1;
1367
1368                        /* Filter 'ref' by 'sought' and those that aren't local */
1369                        if (!args->no_dependents) {
1370                                mark_complete_and_common_ref(&negotiator, args, &ref);
1371                                filter_refs(args, &ref, sought, nr_sought);
1372                                if (everything_local(args, &ref))
1373                                        state = FETCH_DONE;
1374                                else
1375                                        state = FETCH_SEND_REQUEST;
1376
1377                                mark_tips(&negotiator, args->negotiation_tips);
1378                                for_each_cached_alternate(&negotiator,
1379                                                          insert_one_alternate_object);
1380                        } else {
1381                                filter_refs(args, &ref, sought, nr_sought);
1382                                state = FETCH_SEND_REQUEST;
1383                        }
1384                        break;
1385                case FETCH_SEND_REQUEST:
1386                        if (send_fetch_request(&negotiator, fd[1], args, ref,
1387                                               &common,
1388                                               &haves_to_send, &in_vain,
1389                                               reader.use_sideband))
1390                                state = FETCH_GET_PACK;
1391                        else
1392                                state = FETCH_PROCESS_ACKS;
1393                        break;
1394                case FETCH_PROCESS_ACKS:
1395                        /* Process ACKs/NAKs */
1396                        switch (process_acks(&negotiator, &reader, &common)) {
1397                        case 2:
1398                                state = FETCH_GET_PACK;
1399                                break;
1400                        case 1:
1401                                in_vain = 0;
1402                                /* fallthrough */
1403                        default:
1404                                state = FETCH_SEND_REQUEST;
1405                                break;
1406                        }
1407                        break;
1408                case FETCH_GET_PACK:
1409                        /* Check for shallow-info section */
1410                        if (process_section_header(&reader, "shallow-info", 1))
1411                                receive_shallow_info(args, &reader);
1412
1413                        if (process_section_header(&reader, "wanted-refs", 1))
1414                                receive_wanted_refs(&reader, sought, nr_sought);
1415
1416                        /* get the pack */
1417                        process_section_header(&reader, "packfile", 0);
1418                        if (get_pack(args, fd, pack_lockfile))
1419                                die(_("git fetch-pack: fetch failed."));
1420
1421                        state = FETCH_DONE;
1422                        break;
1423                case FETCH_DONE:
1424                        continue;
1425                }
1426        }
1427
1428        negotiator.release(&negotiator);
1429        oidset_clear(&common);
1430        return ref;
1431}
1432
1433static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1434{
1435        if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1436                const char *path;
1437
1438                if (git_config_pathname(&path, var, value))
1439                        return 1;
1440                strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1441                        fsck_msg_types.len ? ',' : '=', path);
1442                free((char *)path);
1443                return 0;
1444        }
1445
1446        if (skip_prefix(var, "fetch.fsck.", &var)) {
1447                if (is_valid_msg_type(var, value))
1448                        strbuf_addf(&fsck_msg_types, "%c%s=%s",
1449                                fsck_msg_types.len ? ',' : '=', var, value);
1450                else
1451                        warning("Skipping unknown msg id '%s'", var);
1452                return 0;
1453        }
1454
1455        return git_default_config(var, value, cb);
1456}
1457
1458static void fetch_pack_config(void)
1459{
1460        git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1461        git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1462        git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1463        git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1464        git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1465        git_config_get_string("fetch.negotiationalgorithm",
1466                              &negotiation_algorithm);
1467
1468        git_config(fetch_pack_config_cb, NULL);
1469}
1470
1471static void fetch_pack_setup(void)
1472{
1473        static int did_setup;
1474        if (did_setup)
1475                return;
1476        fetch_pack_config();
1477        if (0 <= transfer_unpack_limit)
1478                unpack_limit = transfer_unpack_limit;
1479        else if (0 <= fetch_unpack_limit)
1480                unpack_limit = fetch_unpack_limit;
1481        did_setup = 1;
1482}
1483
1484static int remove_duplicates_in_refs(struct ref **ref, int nr)
1485{
1486        struct string_list names = STRING_LIST_INIT_NODUP;
1487        int src, dst;
1488
1489        for (src = dst = 0; src < nr; src++) {
1490                struct string_list_item *item;
1491                item = string_list_insert(&names, ref[src]->name);
1492                if (item->util)
1493                        continue; /* already have it */
1494                item->util = ref[src];
1495                if (src != dst)
1496                        ref[dst] = ref[src];
1497                dst++;
1498        }
1499        for (src = dst; src < nr; src++)
1500                ref[src] = NULL;
1501        string_list_clear(&names, 0);
1502        return dst;
1503}
1504
1505static void update_shallow(struct fetch_pack_args *args,
1506                           struct ref **sought, int nr_sought,
1507                           struct shallow_info *si)
1508{
1509        struct oid_array ref = OID_ARRAY_INIT;
1510        int *status;
1511        int i;
1512
1513        if (args->deepen && alternate_shallow_file) {
1514                if (*alternate_shallow_file == '\0') { /* --unshallow */
1515                        unlink_or_warn(git_path_shallow(the_repository));
1516                        rollback_lock_file(&shallow_lock);
1517                } else
1518                        commit_lock_file(&shallow_lock);
1519                alternate_shallow_file = NULL;
1520                return;
1521        }
1522
1523        if (!si->shallow || !si->shallow->nr)
1524                return;
1525
1526        if (args->cloning) {
1527                /*
1528                 * remote is shallow, but this is a clone, there are
1529                 * no objects in repo to worry about. Accept any
1530                 * shallow points that exist in the pack (iow in repo
1531                 * after get_pack() and reprepare_packed_git())
1532                 */
1533                struct oid_array extra = OID_ARRAY_INIT;
1534                struct object_id *oid = si->shallow->oid;
1535                for (i = 0; i < si->shallow->nr; i++)
1536                        if (has_object_file(&oid[i]))
1537                                oid_array_append(&extra, &oid[i]);
1538                if (extra.nr) {
1539                        setup_alternate_shallow(&shallow_lock,
1540                                                &alternate_shallow_file,
1541                                                &extra);
1542                        commit_lock_file(&shallow_lock);
1543                        alternate_shallow_file = NULL;
1544                }
1545                oid_array_clear(&extra);
1546                return;
1547        }
1548
1549        if (!si->nr_ours && !si->nr_theirs)
1550                return;
1551
1552        remove_nonexistent_theirs_shallow(si);
1553        if (!si->nr_ours && !si->nr_theirs)
1554                return;
1555        for (i = 0; i < nr_sought; i++)
1556                oid_array_append(&ref, &sought[i]->old_oid);
1557        si->ref = &ref;
1558
1559        if (args->update_shallow) {
1560                /*
1561                 * remote is also shallow, .git/shallow may be updated
1562                 * so all refs can be accepted. Make sure we only add
1563                 * shallow roots that are actually reachable from new
1564                 * refs.
1565                 */
1566                struct oid_array extra = OID_ARRAY_INIT;
1567                struct object_id *oid = si->shallow->oid;
1568                assign_shallow_commits_to_refs(si, NULL, NULL);
1569                if (!si->nr_ours && !si->nr_theirs) {
1570                        oid_array_clear(&ref);
1571                        return;
1572                }
1573                for (i = 0; i < si->nr_ours; i++)
1574                        oid_array_append(&extra, &oid[si->ours[i]]);
1575                for (i = 0; i < si->nr_theirs; i++)
1576                        oid_array_append(&extra, &oid[si->theirs[i]]);
1577                setup_alternate_shallow(&shallow_lock,
1578                                        &alternate_shallow_file,
1579                                        &extra);
1580                commit_lock_file(&shallow_lock);
1581                oid_array_clear(&extra);
1582                oid_array_clear(&ref);
1583                alternate_shallow_file = NULL;
1584                return;
1585        }
1586
1587        /*
1588         * remote is also shallow, check what ref is safe to update
1589         * without updating .git/shallow
1590         */
1591        status = xcalloc(nr_sought, sizeof(*status));
1592        assign_shallow_commits_to_refs(si, NULL, status);
1593        if (si->nr_ours || si->nr_theirs) {
1594                for (i = 0; i < nr_sought; i++)
1595                        if (status[i])
1596                                sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1597        }
1598        free(status);
1599        oid_array_clear(&ref);
1600}
1601
1602static int iterate_ref_map(void *cb_data, struct object_id *oid)
1603{
1604        struct ref **rm = cb_data;
1605        struct ref *ref = *rm;
1606
1607        if (!ref)
1608                return -1; /* end of the list */
1609        *rm = ref->next;
1610        oidcpy(oid, &ref->old_oid);
1611        return 0;
1612}
1613
1614struct ref *fetch_pack(struct fetch_pack_args *args,
1615                       int fd[], struct child_process *conn,
1616                       const struct ref *ref,
1617                       const char *dest,
1618                       struct ref **sought, int nr_sought,
1619                       struct oid_array *shallow,
1620                       char **pack_lockfile,
1621                       enum protocol_version version)
1622{
1623        struct ref *ref_cpy;
1624        struct shallow_info si;
1625
1626        fetch_pack_setup();
1627        if (nr_sought)
1628                nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1629
1630        if (args->no_dependents && !args->filter_options.choice) {
1631                /*
1632                 * The protocol does not support requesting that only the
1633                 * wanted objects be sent, so approximate this by setting a
1634                 * "blob:none" filter if no filter is already set. This works
1635                 * for all object types: note that wanted blobs will still be
1636                 * sent because they are directly specified as a "want".
1637                 *
1638                 * NEEDSWORK: Add an option in the protocol to request that
1639                 * only the wanted objects be sent, and implement it.
1640                 */
1641                parse_list_objects_filter(&args->filter_options, "blob:none");
1642        }
1643
1644        if (version != protocol_v2 && !ref) {
1645                packet_flush(fd[1]);
1646                die(_("no matching remote head"));
1647        }
1648        prepare_shallow_info(&si, shallow);
1649        if (version == protocol_v2)
1650                ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1651                                           pack_lockfile);
1652        else
1653                ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1654                                        &si, pack_lockfile);
1655        reprepare_packed_git(the_repository);
1656
1657        if (!args->cloning && args->deepen) {
1658                struct check_connected_options opt = CHECK_CONNECTED_INIT;
1659                struct ref *iterator = ref_cpy;
1660                opt.shallow_file = alternate_shallow_file;
1661                if (args->deepen)
1662                        opt.is_deepening_fetch = 1;
1663                if (check_connected(iterate_ref_map, &iterator, &opt)) {
1664                        error(_("remote did not send all necessary objects"));
1665                        free_refs(ref_cpy);
1666                        ref_cpy = NULL;
1667                        rollback_lock_file(&shallow_lock);
1668                        goto cleanup;
1669                }
1670                args->connectivity_checked = 1;
1671        }
1672
1673        update_shallow(args, sought, nr_sought, &si);
1674cleanup:
1675        clear_shallow_info(&si);
1676        return ref_cpy;
1677}
1678
1679int report_unmatched_refs(struct ref **sought, int nr_sought)
1680{
1681        int i, ret = 0;
1682
1683        for (i = 0; i < nr_sought; i++) {
1684                if (!sought[i])
1685                        continue;
1686                switch (sought[i]->match_status) {
1687                case REF_MATCHED:
1688                        continue;
1689                case REF_NOT_MATCHED:
1690                        error(_("no such remote ref %s"), sought[i]->name);
1691                        break;
1692                case REF_UNADVERTISED_NOT_ALLOWED:
1693                        error(_("Server does not allow request for unadvertised object %s"),
1694                              sought[i]->name);
1695                        break;
1696                }
1697                ret = 1;
1698        }
1699        return ret;
1700}