fetch-pack.con commit Merge branch 'ds/reachable-final-cleanup' (e366d0c)
   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 char *refname,
  80                                const struct object_id *oid,
  81                                void *vcache)
  82{
  83        struct alternate_object_cache *cache = vcache;
  84        struct object *obj = parse_object(the_repository, oid);
  85
  86        if (!obj || (obj->flags & ALTERNATE))
  87                return;
  88
  89        obj->flags |= ALTERNATE;
  90        ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  91        cache->items[cache->nr++] = obj;
  92}
  93
  94static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
  95                                      void (*cb)(struct fetch_negotiator *,
  96                                                 struct object *))
  97{
  98        static int initialized;
  99        static struct alternate_object_cache cache;
 100        size_t i;
 101
 102        if (!initialized) {
 103                for_each_alternate_ref(cache_one_alternate, &cache);
 104                initialized = 1;
 105        }
 106
 107        for (i = 0; i < cache.nr; i++)
 108                cb(negotiator, cache.items[i]);
 109}
 110
 111static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
 112                               const char *refname,
 113                               const struct object_id *oid)
 114{
 115        struct object *o = deref_tag(the_repository,
 116                                     parse_object(the_repository, oid),
 117                                     refname, 0);
 118
 119        if (o && o->type == OBJ_COMMIT)
 120                negotiator->add_tip(negotiator, (struct commit *)o);
 121
 122        return 0;
 123}
 124
 125static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 126                                   int flag, void *cb_data)
 127{
 128        return rev_list_insert_ref(cb_data, refname, oid);
 129}
 130
 131enum ack_type {
 132        NAK = 0,
 133        ACK,
 134        ACK_continue,
 135        ACK_common,
 136        ACK_ready
 137};
 138
 139static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 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                char *line;
 147                while ((line = packet_read_line(fd, NULL))) {
 148                        if (starts_with(line, "shallow "))
 149                                continue;
 150                        if (starts_with(line, "unshallow "))
 151                                continue;
 152                        die(_("git fetch-pack: expected shallow list"));
 153                }
 154        }
 155}
 156
 157static enum ack_type get_ack(int fd, struct object_id *result_oid)
 158{
 159        int len;
 160        char *line = packet_read_line(fd, &len);
 161        const char *arg;
 162
 163        if (!line)
 164                die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 165        if (!strcmp(line, "NAK"))
 166                return NAK;
 167        if (skip_prefix(line, "ACK ", &arg)) {
 168                if (!get_oid_hex(arg, result_oid)) {
 169                        arg += 40;
 170                        len -= arg - line;
 171                        if (len < 1)
 172                                return ACK;
 173                        if (strstr(arg, "continue"))
 174                                return ACK_continue;
 175                        if (strstr(arg, "common"))
 176                                return ACK_common;
 177                        if (strstr(arg, "ready"))
 178                                return ACK_ready;
 179                        return ACK;
 180                }
 181        }
 182        if (skip_prefix(line, "ERR ", &arg))
 183                die(_("remote error: %s"), arg);
 184        die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 185}
 186
 187static void send_request(struct fetch_pack_args *args,
 188                         int fd, struct strbuf *buf)
 189{
 190        if (args->stateless_rpc) {
 191                send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 192                packet_flush(fd);
 193        } else
 194                write_or_die(fd, buf->buf, buf->len);
 195}
 196
 197static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 198                                        struct object *obj)
 199{
 200        rev_list_insert_ref(negotiator, NULL, &obj->oid);
 201}
 202
 203#define INITIAL_FLUSH 16
 204#define PIPESAFE_FLUSH 32
 205#define LARGE_FLUSH 16384
 206
 207static int next_flush(int stateless_rpc, int count)
 208{
 209        if (stateless_rpc) {
 210                if (count < LARGE_FLUSH)
 211                        count <<= 1;
 212                else
 213                        count = count * 11 / 10;
 214        } else {
 215                if (count < PIPESAFE_FLUSH)
 216                        count <<= 1;
 217                else
 218                        count += PIPESAFE_FLUSH;
 219        }
 220        return count;
 221}
 222
 223static void mark_tips(struct fetch_negotiator *negotiator,
 224                      const struct oid_array *negotiation_tips)
 225{
 226        int i;
 227
 228        if (!negotiation_tips) {
 229                for_each_ref(rev_list_insert_ref_oid, negotiator);
 230                return;
 231        }
 232
 233        for (i = 0; i < negotiation_tips->nr; i++)
 234                rev_list_insert_ref(negotiator, NULL,
 235                                    &negotiation_tips->oid[i]);
 236        return;
 237}
 238
 239static int find_common(struct fetch_negotiator *negotiator,
 240                       struct fetch_pack_args *args,
 241                       int fd[2], struct object_id *result_oid,
 242                       struct ref *refs)
 243{
 244        int fetching;
 245        int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 246        const struct object_id *oid;
 247        unsigned in_vain = 0;
 248        int got_continue = 0;
 249        int got_ready = 0;
 250        struct strbuf req_buf = STRBUF_INIT;
 251        size_t state_len = 0;
 252
 253        if (args->stateless_rpc && multi_ack == 1)
 254                die(_("--stateless-rpc requires multi_ack_detailed"));
 255
 256        mark_tips(negotiator, args->negotiation_tips);
 257        for_each_cached_alternate(negotiator, insert_one_alternate_object);
 258
 259        fetching = 0;
 260        for ( ; refs ; refs = refs->next) {
 261                struct object_id *remote = &refs->old_oid;
 262                const char *remote_hex;
 263                struct object *o;
 264
 265                /*
 266                 * If that object is complete (i.e. it is an ancestor of a
 267                 * local ref), we tell them we have it but do not have to
 268                 * tell them about its ancestors, which they already know
 269                 * about.
 270                 *
 271                 * We use lookup_object here because we are only
 272                 * interested in the case we *know* the object is
 273                 * reachable and we have already scanned it.
 274                 */
 275                if (((o = lookup_object(the_repository, remote->hash)) != NULL) &&
 276                                (o->flags & COMPLETE)) {
 277                        continue;
 278                }
 279
 280                remote_hex = oid_to_hex(remote);
 281                if (!fetching) {
 282                        struct strbuf c = STRBUF_INIT;
 283                        if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 284                        if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 285                        if (no_done)            strbuf_addstr(&c, " no-done");
 286                        if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 287                        if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 288                        if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 289                        if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 290                        if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 291                        if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 292                        if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 293                        if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 294                        if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 295                        if (agent_supported)    strbuf_addf(&c, " agent=%s",
 296                                                            git_user_agent_sanitized());
 297                        if (args->filter_options.choice)
 298                                strbuf_addstr(&c, " filter");
 299                        packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 300                        strbuf_release(&c);
 301                } else
 302                        packet_buf_write(&req_buf, "want %s\n", remote_hex);
 303                fetching++;
 304        }
 305
 306        if (!fetching) {
 307                strbuf_release(&req_buf);
 308                packet_flush(fd[1]);
 309                return 1;
 310        }
 311
 312        if (is_repository_shallow(the_repository))
 313                write_shallow_commits(&req_buf, 1, NULL);
 314        if (args->depth > 0)
 315                packet_buf_write(&req_buf, "deepen %d", args->depth);
 316        if (args->deepen_since) {
 317                timestamp_t max_age = approxidate(args->deepen_since);
 318                packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 319        }
 320        if (args->deepen_not) {
 321                int i;
 322                for (i = 0; i < args->deepen_not->nr; i++) {
 323                        struct string_list_item *s = args->deepen_not->items + i;
 324                        packet_buf_write(&req_buf, "deepen-not %s", s->string);
 325                }
 326        }
 327        if (server_supports_filtering && args->filter_options.choice)
 328                packet_buf_write(&req_buf, "filter %s",
 329                                 args->filter_options.filter_spec);
 330        packet_buf_flush(&req_buf);
 331        state_len = req_buf.len;
 332
 333        if (args->deepen) {
 334                char *line;
 335                const char *arg;
 336                struct object_id oid;
 337
 338                send_request(args, fd[1], &req_buf);
 339                while ((line = packet_read_line(fd[0], NULL))) {
 340                        if (skip_prefix(line, "shallow ", &arg)) {
 341                                if (get_oid_hex(arg, &oid))
 342                                        die(_("invalid shallow line: %s"), line);
 343                                register_shallow(the_repository, &oid);
 344                                continue;
 345                        }
 346                        if (skip_prefix(line, "unshallow ", &arg)) {
 347                                if (get_oid_hex(arg, &oid))
 348                                        die(_("invalid unshallow line: %s"), line);
 349                                if (!lookup_object(the_repository, oid.hash))
 350                                        die(_("object not found: %s"), line);
 351                                /* make sure that it is parsed as shallow */
 352                                if (!parse_object(the_repository, &oid))
 353                                        die(_("error in object: %s"), line);
 354                                if (unregister_shallow(&oid))
 355                                        die(_("no shallow found: %s"), line);
 356                                continue;
 357                        }
 358                        die(_("expected shallow/unshallow, got %s"), line);
 359                }
 360        } else if (!args->stateless_rpc)
 361                send_request(args, fd[1], &req_buf);
 362
 363        if (!args->stateless_rpc) {
 364                /* If we aren't using the stateless-rpc interface
 365                 * we don't need to retain the headers.
 366                 */
 367                strbuf_setlen(&req_buf, 0);
 368                state_len = 0;
 369        }
 370
 371        flushes = 0;
 372        retval = -1;
 373        if (args->no_dependents)
 374                goto done;
 375        while ((oid = negotiator->next(negotiator))) {
 376                packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 377                print_verbose(args, "have %s", oid_to_hex(oid));
 378                in_vain++;
 379                if (flush_at <= ++count) {
 380                        int ack;
 381
 382                        packet_buf_flush(&req_buf);
 383                        send_request(args, fd[1], &req_buf);
 384                        strbuf_setlen(&req_buf, state_len);
 385                        flushes++;
 386                        flush_at = next_flush(args->stateless_rpc, count);
 387
 388                        /*
 389                         * We keep one window "ahead" of the other side, and
 390                         * will wait for an ACK only on the next one
 391                         */
 392                        if (!args->stateless_rpc && count == INITIAL_FLUSH)
 393                                continue;
 394
 395                        consume_shallow_list(args, fd[0]);
 396                        do {
 397                                ack = get_ack(fd[0], result_oid);
 398                                if (ack)
 399                                        print_verbose(args, _("got %s %d %s"), "ack",
 400                                                      ack, oid_to_hex(result_oid));
 401                                switch (ack) {
 402                                case ACK:
 403                                        flushes = 0;
 404                                        multi_ack = 0;
 405                                        retval = 0;
 406                                        goto done;
 407                                case ACK_common:
 408                                case ACK_ready:
 409                                case ACK_continue: {
 410                                        struct commit *commit =
 411                                                lookup_commit(the_repository,
 412                                                              result_oid);
 413                                        int was_common;
 414
 415                                        if (!commit)
 416                                                die(_("invalid commit %s"), oid_to_hex(result_oid));
 417                                        was_common = negotiator->ack(negotiator, commit);
 418                                        if (args->stateless_rpc
 419                                         && ack == ACK_common
 420                                         && !was_common) {
 421                                                /* We need to replay the have for this object
 422                                                 * on the next RPC request so the peer knows
 423                                                 * it is in common with us.
 424                                                 */
 425                                                const char *hex = oid_to_hex(result_oid);
 426                                                packet_buf_write(&req_buf, "have %s\n", hex);
 427                                                state_len = req_buf.len;
 428                                                /*
 429                                                 * Reset in_vain because an ack
 430                                                 * for this commit has not been
 431                                                 * seen.
 432                                                 */
 433                                                in_vain = 0;
 434                                        } else if (!args->stateless_rpc
 435                                                   || ack != ACK_common)
 436                                                in_vain = 0;
 437                                        retval = 0;
 438                                        got_continue = 1;
 439                                        if (ack == ACK_ready)
 440                                                got_ready = 1;
 441                                        break;
 442                                        }
 443                                }
 444                        } while (ack);
 445                        flushes--;
 446                        if (got_continue && MAX_IN_VAIN < in_vain) {
 447                                print_verbose(args, _("giving up"));
 448                                break; /* give up */
 449                        }
 450                        if (got_ready)
 451                                break;
 452                }
 453        }
 454done:
 455        if (!got_ready || !no_done) {
 456                packet_buf_write(&req_buf, "done\n");
 457                send_request(args, fd[1], &req_buf);
 458        }
 459        print_verbose(args, _("done"));
 460        if (retval != 0) {
 461                multi_ack = 0;
 462                flushes++;
 463        }
 464        strbuf_release(&req_buf);
 465
 466        if (!got_ready || !no_done)
 467                consume_shallow_list(args, fd[0]);
 468        while (flushes || multi_ack) {
 469                int ack = get_ack(fd[0], result_oid);
 470                if (ack) {
 471                        print_verbose(args, _("got %s (%d) %s"), "ack",
 472                                      ack, oid_to_hex(result_oid));
 473                        if (ack == ACK)
 474                                return 0;
 475                        multi_ack = 1;
 476                        continue;
 477                }
 478                flushes--;
 479        }
 480        /* it is no error to fetch into a completely empty repo */
 481        return count ? retval : 0;
 482}
 483
 484static struct commit_list *complete;
 485
 486static int mark_complete(const struct object_id *oid)
 487{
 488        struct object *o = parse_object(the_repository, oid);
 489
 490        while (o && o->type == OBJ_TAG) {
 491                struct tag *t = (struct tag *) o;
 492                if (!t->tagged)
 493                        break; /* broken repository */
 494                o->flags |= COMPLETE;
 495                o = parse_object(the_repository, &t->tagged->oid);
 496        }
 497        if (o && o->type == OBJ_COMMIT) {
 498                struct commit *commit = (struct commit *)o;
 499                if (!(commit->object.flags & COMPLETE)) {
 500                        commit->object.flags |= COMPLETE;
 501                        commit_list_insert(commit, &complete);
 502                }
 503        }
 504        return 0;
 505}
 506
 507static int mark_complete_oid(const char *refname, const struct object_id *oid,
 508                             int flag, void *cb_data)
 509{
 510        return mark_complete(oid);
 511}
 512
 513static void mark_recent_complete_commits(struct fetch_pack_args *args,
 514                                         timestamp_t cutoff)
 515{
 516        while (complete && cutoff <= complete->item->date) {
 517                print_verbose(args, _("Marking %s as complete"),
 518                              oid_to_hex(&complete->item->object.oid));
 519                pop_most_recent_commit(&complete, COMPLETE);
 520        }
 521}
 522
 523static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 524{
 525        for (; refs; refs = refs->next)
 526                oidset_insert(oids, &refs->old_oid);
 527}
 528
 529static int tip_oids_contain(struct oidset *tip_oids,
 530                            struct ref *unmatched, struct ref *newlist,
 531                            const struct object_id *id)
 532{
 533        /*
 534         * Note that this only looks at the ref lists the first time it's
 535         * called. This works out in filter_refs() because even though it may
 536         * add to "newlist" between calls, the additions will always be for
 537         * oids that are already in the set.
 538         */
 539        if (!tip_oids->map.map.tablesize) {
 540                add_refs_to_oidset(tip_oids, unmatched);
 541                add_refs_to_oidset(tip_oids, newlist);
 542        }
 543        return oidset_contains(tip_oids, id);
 544}
 545
 546static void filter_refs(struct fetch_pack_args *args,
 547                        struct ref **refs,
 548                        struct ref **sought, int nr_sought)
 549{
 550        struct ref *newlist = NULL;
 551        struct ref **newtail = &newlist;
 552        struct ref *unmatched = NULL;
 553        struct ref *ref, *next;
 554        struct oidset tip_oids = OIDSET_INIT;
 555        int i;
 556
 557        i = 0;
 558        for (ref = *refs; ref; ref = next) {
 559                int keep = 0;
 560                next = ref->next;
 561
 562                if (starts_with(ref->name, "refs/") &&
 563                    check_refname_format(ref->name, 0))
 564                        ; /* trash */
 565                else {
 566                        while (i < nr_sought) {
 567                                int cmp = strcmp(ref->name, sought[i]->name);
 568                                if (cmp < 0)
 569                                        break; /* definitely do not have it */
 570                                else if (cmp == 0) {
 571                                        keep = 1; /* definitely have it */
 572                                        sought[i]->match_status = REF_MATCHED;
 573                                }
 574                                i++;
 575                        }
 576
 577                        if (!keep && args->fetch_all &&
 578                            (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 579                                keep = 1;
 580                }
 581
 582                if (keep) {
 583                        *newtail = ref;
 584                        ref->next = NULL;
 585                        newtail = &ref->next;
 586                } else {
 587                        ref->next = unmatched;
 588                        unmatched = ref;
 589                }
 590        }
 591
 592        /* Append unmatched requests to the list */
 593        for (i = 0; i < nr_sought; i++) {
 594                struct object_id oid;
 595                const char *p;
 596
 597                ref = sought[i];
 598                if (ref->match_status != REF_NOT_MATCHED)
 599                        continue;
 600                if (parse_oid_hex(ref->name, &oid, &p) ||
 601                    *p != '\0' ||
 602                    !oideq(&oid, &ref->old_oid))
 603                        continue;
 604
 605                if ((allow_unadvertised_object_request &
 606                     (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1)) ||
 607                    tip_oids_contain(&tip_oids, unmatched, newlist,
 608                                     &ref->old_oid)) {
 609                        ref->match_status = REF_MATCHED;
 610                        *newtail = copy_ref(ref);
 611                        newtail = &(*newtail)->next;
 612                } else {
 613                        ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 614                }
 615        }
 616
 617        oidset_clear(&tip_oids);
 618        for (ref = unmatched; ref; ref = next) {
 619                next = ref->next;
 620                free(ref);
 621        }
 622
 623        *refs = newlist;
 624}
 625
 626static void mark_alternate_complete(struct fetch_negotiator *unused,
 627                                    struct object *obj)
 628{
 629        mark_complete(&obj->oid);
 630}
 631
 632struct loose_object_iter {
 633        struct oidset *loose_object_set;
 634        struct ref *refs;
 635};
 636
 637/*
 638 *  If the number of refs is not larger than the number of loose objects,
 639 *  this function stops inserting.
 640 */
 641static int add_loose_objects_to_set(const struct object_id *oid,
 642                                    const char *path,
 643                                    void *data)
 644{
 645        struct loose_object_iter *iter = data;
 646        oidset_insert(iter->loose_object_set, oid);
 647        if (iter->refs == NULL)
 648                return 1;
 649
 650        iter->refs = iter->refs->next;
 651        return 0;
 652}
 653
 654/*
 655 * Mark recent commits available locally and reachable from a local ref as
 656 * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 657 * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 658 * thus do not need COMMON_REF marks).
 659 *
 660 * The cutoff time for recency is determined by this heuristic: it is the
 661 * earliest commit time of the objects in refs that are commits and that we know
 662 * the commit time of.
 663 */
 664static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 665                                         struct fetch_pack_args *args,
 666                                         struct ref **refs)
 667{
 668        struct ref *ref;
 669        int old_save_commit_buffer = save_commit_buffer;
 670        timestamp_t cutoff = 0;
 671        struct oidset loose_oid_set = OIDSET_INIT;
 672        int use_oidset = 0;
 673        struct loose_object_iter iter = {&loose_oid_set, *refs};
 674
 675        /* Enumerate all loose objects or know refs are not so many. */
 676        use_oidset = !for_each_loose_object(add_loose_objects_to_set,
 677                                            &iter, 0);
 678
 679        save_commit_buffer = 0;
 680
 681        for (ref = *refs; ref; ref = ref->next) {
 682                struct object *o;
 683                unsigned int flags = OBJECT_INFO_QUICK;
 684
 685                if (use_oidset &&
 686                    !oidset_contains(&loose_oid_set, &ref->old_oid)) {
 687                        /*
 688                         * I know this does not exist in the loose form,
 689                         * so check if it exists in a non-loose form.
 690                         */
 691                        flags |= OBJECT_INFO_IGNORE_LOOSE;
 692                }
 693
 694                if (!has_object_file_with_flags(&ref->old_oid, flags))
 695                        continue;
 696                o = parse_object(the_repository, &ref->old_oid);
 697                if (!o)
 698                        continue;
 699
 700                /* We already have it -- which may mean that we were
 701                 * in sync with the other side at some time after
 702                 * that (it is OK if we guess wrong here).
 703                 */
 704                if (o->type == OBJ_COMMIT) {
 705                        struct commit *commit = (struct commit *)o;
 706                        if (!cutoff || cutoff < commit->date)
 707                                cutoff = commit->date;
 708                }
 709        }
 710
 711        oidset_clear(&loose_oid_set);
 712
 713        if (!args->no_dependents) {
 714                if (!args->deepen) {
 715                        for_each_ref(mark_complete_oid, NULL);
 716                        for_each_cached_alternate(NULL, mark_alternate_complete);
 717                        commit_list_sort_by_date(&complete);
 718                        if (cutoff)
 719                                mark_recent_complete_commits(args, cutoff);
 720                }
 721
 722                /*
 723                 * Mark all complete remote refs as common refs.
 724                 * Don't mark them common yet; the server has to be told so first.
 725                 */
 726                for (ref = *refs; ref; ref = ref->next) {
 727                        struct object *o = deref_tag(the_repository,
 728                                                     lookup_object(the_repository,
 729                                                     ref->old_oid.hash),
 730                                                     NULL, 0);
 731
 732                        if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 733                                continue;
 734
 735                        negotiator->known_common(negotiator,
 736                                                 (struct commit *)o);
 737                }
 738        }
 739
 740        save_commit_buffer = old_save_commit_buffer;
 741}
 742
 743/*
 744 * Returns 1 if every object pointed to by the given remote refs is available
 745 * locally and reachable from a local ref, and 0 otherwise.
 746 */
 747static int everything_local(struct fetch_pack_args *args,
 748                            struct ref **refs)
 749{
 750        struct ref *ref;
 751        int retval;
 752
 753        for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 754                const struct object_id *remote = &ref->old_oid;
 755                struct object *o;
 756
 757                o = lookup_object(the_repository, remote->hash);
 758                if (!o || !(o->flags & COMPLETE)) {
 759                        retval = 0;
 760                        print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 761                                      ref->name);
 762                        continue;
 763                }
 764                print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 765                              ref->name);
 766        }
 767
 768        return retval;
 769}
 770
 771static int sideband_demux(int in, int out, void *data)
 772{
 773        int *xd = data;
 774        int ret;
 775
 776        ret = recv_sideband("fetch-pack", xd[0], out);
 777        close(out);
 778        return ret;
 779}
 780
 781static int get_pack(struct fetch_pack_args *args,
 782                    int xd[2], char **pack_lockfile)
 783{
 784        struct async demux;
 785        int do_keep = args->keep_pack;
 786        const char *cmd_name;
 787        struct pack_header header;
 788        int pass_header = 0;
 789        struct child_process cmd = CHILD_PROCESS_INIT;
 790        int ret;
 791
 792        memset(&demux, 0, sizeof(demux));
 793        if (use_sideband) {
 794                /* xd[] is talking with upload-pack; subprocess reads from
 795                 * xd[0], spits out band#2 to stderr, and feeds us band#1
 796                 * through demux->out.
 797                 */
 798                demux.proc = sideband_demux;
 799                demux.data = xd;
 800                demux.out = -1;
 801                demux.isolate_sigpipe = 1;
 802                if (start_async(&demux))
 803                        die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 804        }
 805        else
 806                demux.out = xd[0];
 807
 808        if (!args->keep_pack && unpack_limit) {
 809
 810                if (read_pack_header(demux.out, &header))
 811                        die(_("protocol error: bad pack header"));
 812                pass_header = 1;
 813                if (ntohl(header.hdr_entries) < unpack_limit)
 814                        do_keep = 0;
 815                else
 816                        do_keep = 1;
 817        }
 818
 819        if (alternate_shallow_file) {
 820                argv_array_push(&cmd.args, "--shallow-file");
 821                argv_array_push(&cmd.args, alternate_shallow_file);
 822        }
 823
 824        if (do_keep || args->from_promisor) {
 825                if (pack_lockfile)
 826                        cmd.out = -1;
 827                cmd_name = "index-pack";
 828                argv_array_push(&cmd.args, cmd_name);
 829                argv_array_push(&cmd.args, "--stdin");
 830                if (!args->quiet && !args->no_progress)
 831                        argv_array_push(&cmd.args, "-v");
 832                if (args->use_thin_pack)
 833                        argv_array_push(&cmd.args, "--fix-thin");
 834                if (do_keep && (args->lock_pack || unpack_limit)) {
 835                        char hostname[HOST_NAME_MAX + 1];
 836                        if (xgethostname(hostname, sizeof(hostname)))
 837                                xsnprintf(hostname, sizeof(hostname), "localhost");
 838                        argv_array_pushf(&cmd.args,
 839                                        "--keep=fetch-pack %"PRIuMAX " on %s",
 840                                        (uintmax_t)getpid(), hostname);
 841                }
 842                if (args->check_self_contained_and_connected)
 843                        argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 844                if (args->from_promisor)
 845                        argv_array_push(&cmd.args, "--promisor");
 846        }
 847        else {
 848                cmd_name = "unpack-objects";
 849                argv_array_push(&cmd.args, cmd_name);
 850                if (args->quiet || args->no_progress)
 851                        argv_array_push(&cmd.args, "-q");
 852                args->check_self_contained_and_connected = 0;
 853        }
 854
 855        if (pass_header)
 856                argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 857                                 ntohl(header.hdr_version),
 858                                 ntohl(header.hdr_entries));
 859        if (fetch_fsck_objects >= 0
 860            ? fetch_fsck_objects
 861            : transfer_fsck_objects >= 0
 862            ? transfer_fsck_objects
 863            : 0) {
 864                if (args->from_promisor)
 865                        /*
 866                         * We cannot use --strict in index-pack because it
 867                         * checks both broken objects and links, but we only
 868                         * want to check for broken objects.
 869                         */
 870                        argv_array_push(&cmd.args, "--fsck-objects");
 871                else
 872                        argv_array_pushf(&cmd.args, "--strict%s",
 873                                         fsck_msg_types.buf);
 874        }
 875
 876        cmd.in = demux.out;
 877        cmd.git_cmd = 1;
 878        if (start_command(&cmd))
 879                die(_("fetch-pack: unable to fork off %s"), cmd_name);
 880        if (do_keep && pack_lockfile) {
 881                *pack_lockfile = index_pack_lockfile(cmd.out);
 882                close(cmd.out);
 883        }
 884
 885        if (!use_sideband)
 886                /* Closed by start_command() */
 887                xd[0] = -1;
 888
 889        ret = finish_command(&cmd);
 890        if (!ret || (args->check_self_contained_and_connected && ret == 1))
 891                args->self_contained_and_connected =
 892                        args->check_self_contained_and_connected &&
 893                        ret == 0;
 894        else
 895                die(_("%s failed"), cmd_name);
 896        if (use_sideband && finish_async(&demux))
 897                die(_("error in sideband demultiplexer"));
 898        return 0;
 899}
 900
 901static int cmp_ref_by_name(const void *a_, const void *b_)
 902{
 903        const struct ref *a = *((const struct ref **)a_);
 904        const struct ref *b = *((const struct ref **)b_);
 905        return strcmp(a->name, b->name);
 906}
 907
 908static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 909                                 int fd[2],
 910                                 const struct ref *orig_ref,
 911                                 struct ref **sought, int nr_sought,
 912                                 struct shallow_info *si,
 913                                 char **pack_lockfile)
 914{
 915        struct ref *ref = copy_ref_list(orig_ref);
 916        struct object_id oid;
 917        const char *agent_feature;
 918        int agent_len;
 919        struct fetch_negotiator negotiator;
 920        fetch_negotiator_init(&negotiator, negotiation_algorithm);
 921
 922        sort_ref_list(&ref, ref_compare_name);
 923        QSORT(sought, nr_sought, cmp_ref_by_name);
 924
 925        if ((args->depth > 0 || is_repository_shallow(the_repository)) && !server_supports("shallow"))
 926                die(_("Server does not support shallow clients"));
 927        if (args->depth > 0 || args->deepen_since || args->deepen_not)
 928                args->deepen = 1;
 929        if (server_supports("multi_ack_detailed")) {
 930                print_verbose(args, _("Server supports multi_ack_detailed"));
 931                multi_ack = 2;
 932                if (server_supports("no-done")) {
 933                        print_verbose(args, _("Server supports no-done"));
 934                        if (args->stateless_rpc)
 935                                no_done = 1;
 936                }
 937        }
 938        else if (server_supports("multi_ack")) {
 939                print_verbose(args, _("Server supports multi_ack"));
 940                multi_ack = 1;
 941        }
 942        if (server_supports("side-band-64k")) {
 943                print_verbose(args, _("Server supports side-band-64k"));
 944                use_sideband = 2;
 945        }
 946        else if (server_supports("side-band")) {
 947                print_verbose(args, _("Server supports side-band"));
 948                use_sideband = 1;
 949        }
 950        if (server_supports("allow-tip-sha1-in-want")) {
 951                print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 952                allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 953        }
 954        if (server_supports("allow-reachable-sha1-in-want")) {
 955                print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 956                allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 957        }
 958        if (!server_supports("thin-pack"))
 959                args->use_thin_pack = 0;
 960        if (!server_supports("no-progress"))
 961                args->no_progress = 0;
 962        if (!server_supports("include-tag"))
 963                args->include_tag = 0;
 964        if (server_supports("ofs-delta"))
 965                print_verbose(args, _("Server supports ofs-delta"));
 966        else
 967                prefer_ofs_delta = 0;
 968
 969        if (server_supports("filter")) {
 970                server_supports_filtering = 1;
 971                print_verbose(args, _("Server supports filter"));
 972        } else if (args->filter_options.choice) {
 973                warning("filtering not recognized by server, ignoring");
 974        }
 975
 976        if ((agent_feature = server_feature_value("agent", &agent_len))) {
 977                agent_supported = 1;
 978                if (agent_len)
 979                        print_verbose(args, _("Server version is %.*s"),
 980                                      agent_len, agent_feature);
 981        }
 982        if (server_supports("deepen-since"))
 983                deepen_since_ok = 1;
 984        else if (args->deepen_since)
 985                die(_("Server does not support --shallow-since"));
 986        if (server_supports("deepen-not"))
 987                deepen_not_ok = 1;
 988        else if (args->deepen_not)
 989                die(_("Server does not support --shallow-exclude"));
 990        if (!server_supports("deepen-relative") && args->deepen_relative)
 991                die(_("Server does not support --deepen"));
 992
 993        mark_complete_and_common_ref(&negotiator, args, &ref);
 994        filter_refs(args, &ref, sought, nr_sought);
 995        if (everything_local(args, &ref)) {
 996                packet_flush(fd[1]);
 997                goto all_done;
 998        }
 999        if (find_common(&negotiator, args, fd, &oid, ref) < 0)
1000                if (!args->keep_pack)
1001                        /* When cloning, it is not unusual to have
1002                         * no common commit.
1003                         */
1004                        warning(_("no common commits"));
1005
1006        if (args->stateless_rpc)
1007                packet_flush(fd[1]);
1008        if (args->deepen)
1009                setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1010                                        NULL);
1011        else if (si->nr_ours || si->nr_theirs)
1012                alternate_shallow_file = setup_temporary_shallow(si->shallow);
1013        else
1014                alternate_shallow_file = NULL;
1015        if (get_pack(args, fd, pack_lockfile))
1016                die(_("git fetch-pack: fetch failed."));
1017
1018 all_done:
1019        negotiator.release(&negotiator);
1020        return ref;
1021}
1022
1023static void add_shallow_requests(struct strbuf *req_buf,
1024                                 const struct fetch_pack_args *args)
1025{
1026        if (is_repository_shallow(the_repository))
1027                write_shallow_commits(req_buf, 1, NULL);
1028        if (args->depth > 0)
1029                packet_buf_write(req_buf, "deepen %d", args->depth);
1030        if (args->deepen_since) {
1031                timestamp_t max_age = approxidate(args->deepen_since);
1032                packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1033        }
1034        if (args->deepen_not) {
1035                int i;
1036                for (i = 0; i < args->deepen_not->nr; i++) {
1037                        struct string_list_item *s = args->deepen_not->items + i;
1038                        packet_buf_write(req_buf, "deepen-not %s", s->string);
1039                }
1040        }
1041}
1042
1043static void add_wants(const struct ref *wants, struct strbuf *req_buf)
1044{
1045        int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1046
1047        for ( ; wants ; wants = wants->next) {
1048                const struct object_id *remote = &wants->old_oid;
1049                struct object *o;
1050
1051                /*
1052                 * If that object is complete (i.e. it is an ancestor of a
1053                 * local ref), we tell them we have it but do not have to
1054                 * tell them about its ancestors, which they already know
1055                 * about.
1056                 *
1057                 * We use lookup_object here because we are only
1058                 * interested in the case we *know* the object is
1059                 * reachable and we have already scanned it.
1060                 */
1061                if (((o = lookup_object(the_repository, remote->hash)) != NULL) &&
1062                    (o->flags & COMPLETE)) {
1063                        continue;
1064                }
1065
1066                if (!use_ref_in_want || wants->exact_oid)
1067                        packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1068                else
1069                        packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1070        }
1071}
1072
1073static void add_common(struct strbuf *req_buf, struct oidset *common)
1074{
1075        struct oidset_iter iter;
1076        const struct object_id *oid;
1077        oidset_iter_init(common, &iter);
1078
1079        while ((oid = oidset_iter_next(&iter))) {
1080                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1081        }
1082}
1083
1084static int add_haves(struct fetch_negotiator *negotiator,
1085                     struct strbuf *req_buf,
1086                     int *haves_to_send, int *in_vain)
1087{
1088        int ret = 0;
1089        int haves_added = 0;
1090        const struct object_id *oid;
1091
1092        while ((oid = negotiator->next(negotiator))) {
1093                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1094                if (++haves_added >= *haves_to_send)
1095                        break;
1096        }
1097
1098        *in_vain += haves_added;
1099        if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1100                /* Send Done */
1101                packet_buf_write(req_buf, "done\n");
1102                ret = 1;
1103        }
1104
1105        /* Increase haves to send on next round */
1106        *haves_to_send = next_flush(1, *haves_to_send);
1107
1108        return ret;
1109}
1110
1111static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1112                              const struct fetch_pack_args *args,
1113                              const struct ref *wants, struct oidset *common,
1114                              int *haves_to_send, int *in_vain)
1115{
1116        int ret = 0;
1117        struct strbuf req_buf = STRBUF_INIT;
1118
1119        if (server_supports_v2("fetch", 1))
1120                packet_buf_write(&req_buf, "command=fetch");
1121        if (server_supports_v2("agent", 0))
1122                packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1123        if (args->server_options && args->server_options->nr &&
1124            server_supports_v2("server-option", 1)) {
1125                int i;
1126                for (i = 0; i < args->server_options->nr; i++)
1127                        packet_write_fmt(fd_out, "server-option=%s",
1128                                         args->server_options->items[i].string);
1129        }
1130
1131        packet_buf_delim(&req_buf);
1132        if (args->use_thin_pack)
1133                packet_buf_write(&req_buf, "thin-pack");
1134        if (args->no_progress)
1135                packet_buf_write(&req_buf, "no-progress");
1136        if (args->include_tag)
1137                packet_buf_write(&req_buf, "include-tag");
1138        if (prefer_ofs_delta)
1139                packet_buf_write(&req_buf, "ofs-delta");
1140
1141        /* Add shallow-info and deepen request */
1142        if (server_supports_feature("fetch", "shallow", 0))
1143                add_shallow_requests(&req_buf, args);
1144        else if (is_repository_shallow(the_repository) || args->deepen)
1145                die(_("Server does not support shallow requests"));
1146
1147        /* Add filter */
1148        if (server_supports_feature("fetch", "filter", 0) &&
1149            args->filter_options.choice) {
1150                print_verbose(args, _("Server supports filter"));
1151                packet_buf_write(&req_buf, "filter %s",
1152                                 args->filter_options.filter_spec);
1153        } else if (args->filter_options.choice) {
1154                warning("filtering not recognized by server, ignoring");
1155        }
1156
1157        /* add wants */
1158        add_wants(wants, &req_buf);
1159
1160        if (args->no_dependents) {
1161                packet_buf_write(&req_buf, "done");
1162                ret = 1;
1163        } else {
1164                /* Add all of the common commits we've found in previous rounds */
1165                add_common(&req_buf, common);
1166
1167                /* Add initial haves */
1168                ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1169        }
1170
1171        /* Send request */
1172        packet_buf_flush(&req_buf);
1173        write_or_die(fd_out, req_buf.buf, req_buf.len);
1174
1175        strbuf_release(&req_buf);
1176        return ret;
1177}
1178
1179/*
1180 * Processes a section header in a server's response and checks if it matches
1181 * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1182 * not consumed); if 0, the line will be consumed and the function will die if
1183 * the section header doesn't match what was expected.
1184 */
1185static int process_section_header(struct packet_reader *reader,
1186                                  const char *section, int peek)
1187{
1188        int ret;
1189
1190        if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1191                die(_("error reading section header '%s'"), section);
1192
1193        ret = !strcmp(reader->line, section);
1194
1195        if (!peek) {
1196                if (!ret)
1197                        die(_("expected '%s', received '%s'"),
1198                            section, reader->line);
1199                packet_reader_read(reader);
1200        }
1201
1202        return ret;
1203}
1204
1205static int process_acks(struct fetch_negotiator *negotiator,
1206                        struct packet_reader *reader,
1207                        struct oidset *common)
1208{
1209        /* received */
1210        int received_ready = 0;
1211        int received_ack = 0;
1212
1213        process_section_header(reader, "acknowledgments", 0);
1214        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1215                const char *arg;
1216
1217                if (!strcmp(reader->line, "NAK"))
1218                        continue;
1219
1220                if (skip_prefix(reader->line, "ACK ", &arg)) {
1221                        struct object_id oid;
1222                        if (!get_oid_hex(arg, &oid)) {
1223                                struct commit *commit;
1224                                oidset_insert(common, &oid);
1225                                commit = lookup_commit(the_repository, &oid);
1226                                negotiator->ack(negotiator, commit);
1227                        }
1228                        continue;
1229                }
1230
1231                if (!strcmp(reader->line, "ready")) {
1232                        received_ready = 1;
1233                        continue;
1234                }
1235
1236                die(_("unexpected acknowledgment line: '%s'"), reader->line);
1237        }
1238
1239        if (reader->status != PACKET_READ_FLUSH &&
1240            reader->status != PACKET_READ_DELIM)
1241                die(_("error processing acks: %d"), reader->status);
1242
1243        /* return 0 if no common, 1 if there are common, or 2 if ready */
1244        return received_ready ? 2 : (received_ack ? 1 : 0);
1245}
1246
1247static void receive_shallow_info(struct fetch_pack_args *args,
1248                                 struct packet_reader *reader)
1249{
1250        process_section_header(reader, "shallow-info", 0);
1251        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1252                const char *arg;
1253                struct object_id oid;
1254
1255                if (skip_prefix(reader->line, "shallow ", &arg)) {
1256                        if (get_oid_hex(arg, &oid))
1257                                die(_("invalid shallow line: %s"), reader->line);
1258                        register_shallow(the_repository, &oid);
1259                        continue;
1260                }
1261                if (skip_prefix(reader->line, "unshallow ", &arg)) {
1262                        if (get_oid_hex(arg, &oid))
1263                                die(_("invalid unshallow line: %s"), reader->line);
1264                        if (!lookup_object(the_repository, oid.hash))
1265                                die(_("object not found: %s"), reader->line);
1266                        /* make sure that it is parsed as shallow */
1267                        if (!parse_object(the_repository, &oid))
1268                                die(_("error in object: %s"), reader->line);
1269                        if (unregister_shallow(&oid))
1270                                die(_("no shallow found: %s"), reader->line);
1271                        continue;
1272                }
1273                die(_("expected shallow/unshallow, got %s"), reader->line);
1274        }
1275
1276        if (reader->status != PACKET_READ_FLUSH &&
1277            reader->status != PACKET_READ_DELIM)
1278                die(_("error processing shallow info: %d"), reader->status);
1279
1280        setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, NULL);
1281        args->deepen = 1;
1282}
1283
1284static void receive_wanted_refs(struct packet_reader *reader,
1285                                struct ref **sought, int nr_sought)
1286{
1287        process_section_header(reader, "wanted-refs", 0);
1288        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1289                struct object_id oid;
1290                const char *end;
1291                int i;
1292
1293                if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1294                        die(_("expected wanted-ref, got '%s'"), reader->line);
1295
1296                for (i = 0; i < nr_sought; i++) {
1297                        if (!strcmp(end, sought[i]->name)) {
1298                                oidcpy(&sought[i]->old_oid, &oid);
1299                                break;
1300                        }
1301                }
1302
1303                if (i == nr_sought)
1304                        die(_("unexpected wanted-ref: '%s'"), reader->line);
1305        }
1306
1307        if (reader->status != PACKET_READ_DELIM)
1308                die(_("error processing wanted refs: %d"), reader->status);
1309}
1310
1311enum fetch_state {
1312        FETCH_CHECK_LOCAL = 0,
1313        FETCH_SEND_REQUEST,
1314        FETCH_PROCESS_ACKS,
1315        FETCH_GET_PACK,
1316        FETCH_DONE,
1317};
1318
1319static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1320                                    int fd[2],
1321                                    const struct ref *orig_ref,
1322                                    struct ref **sought, int nr_sought,
1323                                    char **pack_lockfile)
1324{
1325        struct ref *ref = copy_ref_list(orig_ref);
1326        enum fetch_state state = FETCH_CHECK_LOCAL;
1327        struct oidset common = OIDSET_INIT;
1328        struct packet_reader reader;
1329        int in_vain = 0;
1330        int haves_to_send = INITIAL_FLUSH;
1331        struct fetch_negotiator negotiator;
1332        fetch_negotiator_init(&negotiator, negotiation_algorithm);
1333        packet_reader_init(&reader, fd[0], NULL, 0,
1334                           PACKET_READ_CHOMP_NEWLINE);
1335
1336        while (state != FETCH_DONE) {
1337                switch (state) {
1338                case FETCH_CHECK_LOCAL:
1339                        sort_ref_list(&ref, ref_compare_name);
1340                        QSORT(sought, nr_sought, cmp_ref_by_name);
1341
1342                        /* v2 supports these by default */
1343                        allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1344                        use_sideband = 2;
1345                        if (args->depth > 0 || args->deepen_since || args->deepen_not)
1346                                args->deepen = 1;
1347
1348                        /* Filter 'ref' by 'sought' and those that aren't local */
1349                        mark_complete_and_common_ref(&negotiator, args, &ref);
1350                        filter_refs(args, &ref, sought, nr_sought);
1351                        if (everything_local(args, &ref))
1352                                state = FETCH_DONE;
1353                        else
1354                                state = FETCH_SEND_REQUEST;
1355
1356                        mark_tips(&negotiator, args->negotiation_tips);
1357                        for_each_cached_alternate(&negotiator,
1358                                                  insert_one_alternate_object);
1359                        break;
1360                case FETCH_SEND_REQUEST:
1361                        if (send_fetch_request(&negotiator, fd[1], args, ref,
1362                                               &common,
1363                                               &haves_to_send, &in_vain))
1364                                state = FETCH_GET_PACK;
1365                        else
1366                                state = FETCH_PROCESS_ACKS;
1367                        break;
1368                case FETCH_PROCESS_ACKS:
1369                        /* Process ACKs/NAKs */
1370                        switch (process_acks(&negotiator, &reader, &common)) {
1371                        case 2:
1372                                state = FETCH_GET_PACK;
1373                                break;
1374                        case 1:
1375                                in_vain = 0;
1376                                /* fallthrough */
1377                        default:
1378                                state = FETCH_SEND_REQUEST;
1379                                break;
1380                        }
1381                        break;
1382                case FETCH_GET_PACK:
1383                        /* Check for shallow-info section */
1384                        if (process_section_header(&reader, "shallow-info", 1))
1385                                receive_shallow_info(args, &reader);
1386
1387                        if (process_section_header(&reader, "wanted-refs", 1))
1388                                receive_wanted_refs(&reader, sought, nr_sought);
1389
1390                        /* get the pack */
1391                        process_section_header(&reader, "packfile", 0);
1392                        if (get_pack(args, fd, pack_lockfile))
1393                                die(_("git fetch-pack: fetch failed."));
1394
1395                        state = FETCH_DONE;
1396                        break;
1397                case FETCH_DONE:
1398                        continue;
1399                }
1400        }
1401
1402        negotiator.release(&negotiator);
1403        oidset_clear(&common);
1404        return ref;
1405}
1406
1407static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1408{
1409        if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1410                const char *path;
1411
1412                if (git_config_pathname(&path, var, value))
1413                        return 1;
1414                strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1415                        fsck_msg_types.len ? ',' : '=', path);
1416                free((char *)path);
1417                return 0;
1418        }
1419
1420        if (skip_prefix(var, "fetch.fsck.", &var)) {
1421                if (is_valid_msg_type(var, value))
1422                        strbuf_addf(&fsck_msg_types, "%c%s=%s",
1423                                fsck_msg_types.len ? ',' : '=', var, value);
1424                else
1425                        warning("Skipping unknown msg id '%s'", var);
1426                return 0;
1427        }
1428
1429        return git_default_config(var, value, cb);
1430}
1431
1432static void fetch_pack_config(void)
1433{
1434        git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1435        git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1436        git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1437        git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1438        git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1439        git_config_get_string("fetch.negotiationalgorithm",
1440                              &negotiation_algorithm);
1441
1442        git_config(fetch_pack_config_cb, NULL);
1443}
1444
1445static void fetch_pack_setup(void)
1446{
1447        static int did_setup;
1448        if (did_setup)
1449                return;
1450        fetch_pack_config();
1451        if (0 <= transfer_unpack_limit)
1452                unpack_limit = transfer_unpack_limit;
1453        else if (0 <= fetch_unpack_limit)
1454                unpack_limit = fetch_unpack_limit;
1455        did_setup = 1;
1456}
1457
1458static int remove_duplicates_in_refs(struct ref **ref, int nr)
1459{
1460        struct string_list names = STRING_LIST_INIT_NODUP;
1461        int src, dst;
1462
1463        for (src = dst = 0; src < nr; src++) {
1464                struct string_list_item *item;
1465                item = string_list_insert(&names, ref[src]->name);
1466                if (item->util)
1467                        continue; /* already have it */
1468                item->util = ref[src];
1469                if (src != dst)
1470                        ref[dst] = ref[src];
1471                dst++;
1472        }
1473        for (src = dst; src < nr; src++)
1474                ref[src] = NULL;
1475        string_list_clear(&names, 0);
1476        return dst;
1477}
1478
1479static void update_shallow(struct fetch_pack_args *args,
1480                           struct ref **sought, int nr_sought,
1481                           struct shallow_info *si)
1482{
1483        struct oid_array ref = OID_ARRAY_INIT;
1484        int *status;
1485        int i;
1486
1487        if (args->deepen && alternate_shallow_file) {
1488                if (*alternate_shallow_file == '\0') { /* --unshallow */
1489                        unlink_or_warn(git_path_shallow(the_repository));
1490                        rollback_lock_file(&shallow_lock);
1491                } else
1492                        commit_lock_file(&shallow_lock);
1493                return;
1494        }
1495
1496        if (!si->shallow || !si->shallow->nr)
1497                return;
1498
1499        if (args->cloning) {
1500                /*
1501                 * remote is shallow, but this is a clone, there are
1502                 * no objects in repo to worry about. Accept any
1503                 * shallow points that exist in the pack (iow in repo
1504                 * after get_pack() and reprepare_packed_git())
1505                 */
1506                struct oid_array extra = OID_ARRAY_INIT;
1507                struct object_id *oid = si->shallow->oid;
1508                for (i = 0; i < si->shallow->nr; i++)
1509                        if (has_object_file(&oid[i]))
1510                                oid_array_append(&extra, &oid[i]);
1511                if (extra.nr) {
1512                        setup_alternate_shallow(&shallow_lock,
1513                                                &alternate_shallow_file,
1514                                                &extra);
1515                        commit_lock_file(&shallow_lock);
1516                }
1517                oid_array_clear(&extra);
1518                return;
1519        }
1520
1521        if (!si->nr_ours && !si->nr_theirs)
1522                return;
1523
1524        remove_nonexistent_theirs_shallow(si);
1525        if (!si->nr_ours && !si->nr_theirs)
1526                return;
1527        for (i = 0; i < nr_sought; i++)
1528                oid_array_append(&ref, &sought[i]->old_oid);
1529        si->ref = &ref;
1530
1531        if (args->update_shallow) {
1532                /*
1533                 * remote is also shallow, .git/shallow may be updated
1534                 * so all refs can be accepted. Make sure we only add
1535                 * shallow roots that are actually reachable from new
1536                 * refs.
1537                 */
1538                struct oid_array extra = OID_ARRAY_INIT;
1539                struct object_id *oid = si->shallow->oid;
1540                assign_shallow_commits_to_refs(si, NULL, NULL);
1541                if (!si->nr_ours && !si->nr_theirs) {
1542                        oid_array_clear(&ref);
1543                        return;
1544                }
1545                for (i = 0; i < si->nr_ours; i++)
1546                        oid_array_append(&extra, &oid[si->ours[i]]);
1547                for (i = 0; i < si->nr_theirs; i++)
1548                        oid_array_append(&extra, &oid[si->theirs[i]]);
1549                setup_alternate_shallow(&shallow_lock,
1550                                        &alternate_shallow_file,
1551                                        &extra);
1552                commit_lock_file(&shallow_lock);
1553                oid_array_clear(&extra);
1554                oid_array_clear(&ref);
1555                return;
1556        }
1557
1558        /*
1559         * remote is also shallow, check what ref is safe to update
1560         * without updating .git/shallow
1561         */
1562        status = xcalloc(nr_sought, sizeof(*status));
1563        assign_shallow_commits_to_refs(si, NULL, status);
1564        if (si->nr_ours || si->nr_theirs) {
1565                for (i = 0; i < nr_sought; i++)
1566                        if (status[i])
1567                                sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1568        }
1569        free(status);
1570        oid_array_clear(&ref);
1571}
1572
1573static int iterate_ref_map(void *cb_data, struct object_id *oid)
1574{
1575        struct ref **rm = cb_data;
1576        struct ref *ref = *rm;
1577
1578        if (!ref)
1579                return -1; /* end of the list */
1580        *rm = ref->next;
1581        oidcpy(oid, &ref->old_oid);
1582        return 0;
1583}
1584
1585struct ref *fetch_pack(struct fetch_pack_args *args,
1586                       int fd[], struct child_process *conn,
1587                       const struct ref *ref,
1588                       const char *dest,
1589                       struct ref **sought, int nr_sought,
1590                       struct oid_array *shallow,
1591                       char **pack_lockfile,
1592                       enum protocol_version version)
1593{
1594        struct ref *ref_cpy;
1595        struct shallow_info si;
1596
1597        fetch_pack_setup();
1598        if (nr_sought)
1599                nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1600
1601        if (!ref) {
1602                packet_flush(fd[1]);
1603                die(_("no matching remote head"));
1604        }
1605        prepare_shallow_info(&si, shallow);
1606        if (version == protocol_v2)
1607                ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1608                                           pack_lockfile);
1609        else
1610                ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1611                                        &si, pack_lockfile);
1612        reprepare_packed_git(the_repository);
1613
1614        if (!args->cloning && args->deepen) {
1615                struct check_connected_options opt = CHECK_CONNECTED_INIT;
1616                struct ref *iterator = ref_cpy;
1617                opt.shallow_file = alternate_shallow_file;
1618                if (args->deepen)
1619                        opt.is_deepening_fetch = 1;
1620                if (check_connected(iterate_ref_map, &iterator, &opt)) {
1621                        error(_("remote did not send all necessary objects"));
1622                        free_refs(ref_cpy);
1623                        ref_cpy = NULL;
1624                        rollback_lock_file(&shallow_lock);
1625                        goto cleanup;
1626                }
1627                args->connectivity_checked = 1;
1628        }
1629
1630        update_shallow(args, sought, nr_sought, &si);
1631cleanup:
1632        clear_shallow_info(&si);
1633        return ref_cpy;
1634}
1635
1636int report_unmatched_refs(struct ref **sought, int nr_sought)
1637{
1638        int i, ret = 0;
1639
1640        for (i = 0; i < nr_sought; i++) {
1641                if (!sought[i])
1642                        continue;
1643                switch (sought[i]->match_status) {
1644                case REF_MATCHED:
1645                        continue;
1646                case REF_NOT_MATCHED:
1647                        error(_("no such remote ref %s"), sought[i]->name);
1648                        break;
1649                case REF_UNADVERTISED_NOT_ALLOWED:
1650                        error(_("Server does not allow request for unadvertised object %s"),
1651                              sought[i]->name);
1652                        break;
1653                }
1654                ret = 1;
1655        }
1656        return ret;
1657}