fetch-pack.con commit sequencer: refactor sequencer_add_exec_commands() to work on a todo_list (683153a)
   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, int fd)
 139{
 140        if (args->stateless_rpc && args->deepen) {
 141                /* If we sent a depth we will get back "duplicate"
 142                 * shallow and unshallow commands every time there
 143                 * is a block of have lines exchanged.
 144                 */
 145                char *line;
 146                while ((line = packet_read_line(fd, NULL))) {
 147                        if (starts_with(line, "shallow "))
 148                                continue;
 149                        if (starts_with(line, "unshallow "))
 150                                continue;
 151                        die(_("git fetch-pack: expected shallow list"));
 152                }
 153        }
 154}
 155
 156static enum ack_type get_ack(int fd, struct object_id *result_oid)
 157{
 158        int len;
 159        char *line = packet_read_line(fd, &len);
 160        const char *arg;
 161
 162        if (!line)
 163                die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 164        if (!strcmp(line, "NAK"))
 165                return NAK;
 166        if (skip_prefix(line, "ACK ", &arg)) {
 167                if (!get_oid_hex(arg, result_oid)) {
 168                        arg += 40;
 169                        len -= arg - line;
 170                        if (len < 1)
 171                                return ACK;
 172                        if (strstr(arg, "continue"))
 173                                return ACK_continue;
 174                        if (strstr(arg, "common"))
 175                                return ACK_common;
 176                        if (strstr(arg, "ready"))
 177                                return ACK_ready;
 178                        return ACK;
 179                }
 180        }
 181        if (skip_prefix(line, "ERR ", &arg))
 182                die(_("remote error: %s"), arg);
 183        die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 184}
 185
 186static void send_request(struct fetch_pack_args *args,
 187                         int fd, struct strbuf *buf)
 188{
 189        if (args->stateless_rpc) {
 190                send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 191                packet_flush(fd);
 192        } else
 193                write_or_die(fd, buf->buf, buf->len);
 194}
 195
 196static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 197                                        struct object *obj)
 198{
 199        rev_list_insert_ref(negotiator, NULL, &obj->oid);
 200}
 201
 202#define INITIAL_FLUSH 16
 203#define PIPESAFE_FLUSH 32
 204#define LARGE_FLUSH 16384
 205
 206static int next_flush(int stateless_rpc, int count)
 207{
 208        if (stateless_rpc) {
 209                if (count < LARGE_FLUSH)
 210                        count <<= 1;
 211                else
 212                        count = count * 11 / 10;
 213        } else {
 214                if (count < PIPESAFE_FLUSH)
 215                        count <<= 1;
 216                else
 217                        count += PIPESAFE_FLUSH;
 218        }
 219        return count;
 220}
 221
 222static void mark_tips(struct fetch_negotiator *negotiator,
 223                      const struct oid_array *negotiation_tips)
 224{
 225        int i;
 226
 227        if (!negotiation_tips) {
 228                for_each_ref(rev_list_insert_ref_oid, negotiator);
 229                return;
 230        }
 231
 232        for (i = 0; i < negotiation_tips->nr; i++)
 233                rev_list_insert_ref(negotiator, NULL,
 234                                    &negotiation_tips->oid[i]);
 235        return;
 236}
 237
 238static int find_common(struct fetch_negotiator *negotiator,
 239                       struct fetch_pack_args *args,
 240                       int fd[2], struct object_id *result_oid,
 241                       struct ref *refs)
 242{
 243        int fetching;
 244        int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 245        const struct object_id *oid;
 246        unsigned in_vain = 0;
 247        int got_continue = 0;
 248        int got_ready = 0;
 249        struct strbuf req_buf = STRBUF_INIT;
 250        size_t state_len = 0;
 251
 252        if (args->stateless_rpc && multi_ack == 1)
 253                die(_("--stateless-rpc requires multi_ack_detailed"));
 254
 255        if (!args->no_dependents) {
 256                mark_tips(negotiator, args->negotiation_tips);
 257                for_each_cached_alternate(negotiator, insert_one_alternate_object);
 258        }
 259
 260        fetching = 0;
 261        for ( ; refs ; refs = refs->next) {
 262                struct object_id *remote = &refs->old_oid;
 263                const char *remote_hex;
 264                struct object *o;
 265
 266                /*
 267                 * If that object is complete (i.e. it is an ancestor of a
 268                 * local ref), we tell them we have it but do not have to
 269                 * tell them about its ancestors, which they already know
 270                 * about.
 271                 *
 272                 * We use lookup_object here because we are only
 273                 * interested in the case we *know* the object is
 274                 * reachable and we have already scanned it.
 275                 *
 276                 * Do this only if args->no_dependents is false (if it is true,
 277                 * we cannot trust the object flags).
 278                 */
 279                if (!args->no_dependents &&
 280                    ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
 281                                (o->flags & COMPLETE)) {
 282                        continue;
 283                }
 284
 285                remote_hex = oid_to_hex(remote);
 286                if (!fetching) {
 287                        struct strbuf c = STRBUF_INIT;
 288                        if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 289                        if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 290                        if (no_done)            strbuf_addstr(&c, " no-done");
 291                        if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 292                        if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 293                        if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 294                        if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 295                        if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 296                        if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 297                        if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 298                        if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 299                        if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 300                        if (agent_supported)    strbuf_addf(&c, " agent=%s",
 301                                                            git_user_agent_sanitized());
 302                        if (args->filter_options.choice)
 303                                strbuf_addstr(&c, " filter");
 304                        packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 305                        strbuf_release(&c);
 306                } else
 307                        packet_buf_write(&req_buf, "want %s\n", remote_hex);
 308                fetching++;
 309        }
 310
 311        if (!fetching) {
 312                strbuf_release(&req_buf);
 313                packet_flush(fd[1]);
 314                return 1;
 315        }
 316
 317        if (is_repository_shallow(the_repository))
 318                write_shallow_commits(&req_buf, 1, NULL);
 319        if (args->depth > 0)
 320                packet_buf_write(&req_buf, "deepen %d", args->depth);
 321        if (args->deepen_since) {
 322                timestamp_t max_age = approxidate(args->deepen_since);
 323                packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 324        }
 325        if (args->deepen_not) {
 326                int i;
 327                for (i = 0; i < args->deepen_not->nr; i++) {
 328                        struct string_list_item *s = args->deepen_not->items + i;
 329                        packet_buf_write(&req_buf, "deepen-not %s", s->string);
 330                }
 331        }
 332        if (server_supports_filtering && args->filter_options.choice)
 333                packet_buf_write(&req_buf, "filter %s",
 334                                 args->filter_options.filter_spec);
 335        packet_buf_flush(&req_buf);
 336        state_len = req_buf.len;
 337
 338        if (args->deepen) {
 339                char *line;
 340                const char *arg;
 341                struct object_id oid;
 342
 343                send_request(args, fd[1], &req_buf);
 344                while ((line = packet_read_line(fd[0], NULL))) {
 345                        if (skip_prefix(line, "shallow ", &arg)) {
 346                                if (get_oid_hex(arg, &oid))
 347                                        die(_("invalid shallow line: %s"), line);
 348                                register_shallow(the_repository, &oid);
 349                                continue;
 350                        }
 351                        if (skip_prefix(line, "unshallow ", &arg)) {
 352                                if (get_oid_hex(arg, &oid))
 353                                        die(_("invalid unshallow line: %s"), line);
 354                                if (!lookup_object(the_repository, oid.hash))
 355                                        die(_("object not found: %s"), line);
 356                                /* make sure that it is parsed as shallow */
 357                                if (!parse_object(the_repository, &oid))
 358                                        die(_("error in object: %s"), line);
 359                                if (unregister_shallow(&oid))
 360                                        die(_("no shallow found: %s"), line);
 361                                continue;
 362                        }
 363                        die(_("expected shallow/unshallow, got %s"), line);
 364                }
 365        } else if (!args->stateless_rpc)
 366                send_request(args, fd[1], &req_buf);
 367
 368        if (!args->stateless_rpc) {
 369                /* If we aren't using the stateless-rpc interface
 370                 * we don't need to retain the headers.
 371                 */
 372                strbuf_setlen(&req_buf, 0);
 373                state_len = 0;
 374        }
 375
 376        flushes = 0;
 377        retval = -1;
 378        if (args->no_dependents)
 379                goto done;
 380        while ((oid = negotiator->next(negotiator))) {
 381                packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 382                print_verbose(args, "have %s", oid_to_hex(oid));
 383                in_vain++;
 384                if (flush_at <= ++count) {
 385                        int ack;
 386
 387                        packet_buf_flush(&req_buf);
 388                        send_request(args, fd[1], &req_buf);
 389                        strbuf_setlen(&req_buf, state_len);
 390                        flushes++;
 391                        flush_at = next_flush(args->stateless_rpc, count);
 392
 393                        /*
 394                         * We keep one window "ahead" of the other side, and
 395                         * will wait for an ACK only on the next one
 396                         */
 397                        if (!args->stateless_rpc && count == INITIAL_FLUSH)
 398                                continue;
 399
 400                        consume_shallow_list(args, fd[0]);
 401                        do {
 402                                ack = get_ack(fd[0], result_oid);
 403                                if (ack)
 404                                        print_verbose(args, _("got %s %d %s"), "ack",
 405                                                      ack, oid_to_hex(result_oid));
 406                                switch (ack) {
 407                                case ACK:
 408                                        flushes = 0;
 409                                        multi_ack = 0;
 410                                        retval = 0;
 411                                        goto done;
 412                                case ACK_common:
 413                                case ACK_ready:
 414                                case ACK_continue: {
 415                                        struct commit *commit =
 416                                                lookup_commit(the_repository,
 417                                                              result_oid);
 418                                        int was_common;
 419
 420                                        if (!commit)
 421                                                die(_("invalid commit %s"), oid_to_hex(result_oid));
 422                                        was_common = negotiator->ack(negotiator, commit);
 423                                        if (args->stateless_rpc
 424                                         && ack == ACK_common
 425                                         && !was_common) {
 426                                                /* We need to replay the have for this object
 427                                                 * on the next RPC request so the peer knows
 428                                                 * it is in common with us.
 429                                                 */
 430                                                const char *hex = oid_to_hex(result_oid);
 431                                                packet_buf_write(&req_buf, "have %s\n", hex);
 432                                                state_len = req_buf.len;
 433                                                /*
 434                                                 * Reset in_vain because an ack
 435                                                 * for this commit has not been
 436                                                 * seen.
 437                                                 */
 438                                                in_vain = 0;
 439                                        } else if (!args->stateless_rpc
 440                                                   || ack != ACK_common)
 441                                                in_vain = 0;
 442                                        retval = 0;
 443                                        got_continue = 1;
 444                                        if (ack == ACK_ready)
 445                                                got_ready = 1;
 446                                        break;
 447                                        }
 448                                }
 449                        } while (ack);
 450                        flushes--;
 451                        if (got_continue && MAX_IN_VAIN < in_vain) {
 452                                print_verbose(args, _("giving up"));
 453                                break; /* give up */
 454                        }
 455                        if (got_ready)
 456                                break;
 457                }
 458        }
 459done:
 460        if (!got_ready || !no_done) {
 461                packet_buf_write(&req_buf, "done\n");
 462                send_request(args, fd[1], &req_buf);
 463        }
 464        print_verbose(args, _("done"));
 465        if (retval != 0) {
 466                multi_ack = 0;
 467                flushes++;
 468        }
 469        strbuf_release(&req_buf);
 470
 471        if (!got_ready || !no_done)
 472                consume_shallow_list(args, fd[0]);
 473        while (flushes || multi_ack) {
 474                int ack = get_ack(fd[0], result_oid);
 475                if (ack) {
 476                        print_verbose(args, _("got %s (%d) %s"), "ack",
 477                                      ack, oid_to_hex(result_oid));
 478                        if (ack == ACK)
 479                                return 0;
 480                        multi_ack = 1;
 481                        continue;
 482                }
 483                flushes--;
 484        }
 485        /* it is no error to fetch into a completely empty repo */
 486        return count ? retval : 0;
 487}
 488
 489static struct commit_list *complete;
 490
 491static int mark_complete(const struct object_id *oid)
 492{
 493        struct object *o = parse_object(the_repository, oid);
 494
 495        while (o && o->type == OBJ_TAG) {
 496                struct tag *t = (struct tag *) o;
 497                if (!t->tagged)
 498                        break; /* broken repository */
 499                o->flags |= COMPLETE;
 500                o = parse_object(the_repository, &t->tagged->oid);
 501        }
 502        if (o && o->type == OBJ_COMMIT) {
 503                struct commit *commit = (struct commit *)o;
 504                if (!(commit->object.flags & COMPLETE)) {
 505                        commit->object.flags |= COMPLETE;
 506                        commit_list_insert(commit, &complete);
 507                }
 508        }
 509        return 0;
 510}
 511
 512static int mark_complete_oid(const char *refname, const struct object_id *oid,
 513                             int flag, void *cb_data)
 514{
 515        return mark_complete(oid);
 516}
 517
 518static void mark_recent_complete_commits(struct fetch_pack_args *args,
 519                                         timestamp_t cutoff)
 520{
 521        while (complete && cutoff <= complete->item->date) {
 522                print_verbose(args, _("Marking %s as complete"),
 523                              oid_to_hex(&complete->item->object.oid));
 524                pop_most_recent_commit(&complete, COMPLETE);
 525        }
 526}
 527
 528static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 529{
 530        for (; refs; refs = refs->next)
 531                oidset_insert(oids, &refs->old_oid);
 532}
 533
 534static int is_unmatched_ref(const struct ref *ref)
 535{
 536        struct object_id oid;
 537        const char *p;
 538        return  ref->match_status == REF_NOT_MATCHED &&
 539                !parse_oid_hex(ref->name, &oid, &p) &&
 540                *p == '\0' &&
 541                oideq(&oid, &ref->old_oid);
 542}
 543
 544static void filter_refs(struct fetch_pack_args *args,
 545                        struct ref **refs,
 546                        struct ref **sought, int nr_sought)
 547{
 548        struct ref *newlist = NULL;
 549        struct ref **newtail = &newlist;
 550        struct ref *unmatched = NULL;
 551        struct ref *ref, *next;
 552        struct oidset tip_oids = OIDSET_INIT;
 553        int i;
 554        int strict = !(allow_unadvertised_object_request &
 555                       (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
 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        if (strict) {
 593                for (i = 0; i < nr_sought; i++) {
 594                        ref = sought[i];
 595                        if (!is_unmatched_ref(ref))
 596                                continue;
 597
 598                        add_refs_to_oidset(&tip_oids, unmatched);
 599                        add_refs_to_oidset(&tip_oids, newlist);
 600                        break;
 601                }
 602        }
 603
 604        /* Append unmatched requests to the list */
 605        for (i = 0; i < nr_sought; i++) {
 606                ref = sought[i];
 607                if (!is_unmatched_ref(ref))
 608                        continue;
 609
 610                if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
 611                        ref->match_status = REF_MATCHED;
 612                        *newtail = copy_ref(ref);
 613                        newtail = &(*newtail)->next;
 614                } else {
 615                        ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 616                }
 617        }
 618
 619        oidset_clear(&tip_oids);
 620        for (ref = unmatched; ref; ref = next) {
 621                next = ref->next;
 622                free(ref);
 623        }
 624
 625        *refs = newlist;
 626}
 627
 628static void mark_alternate_complete(struct fetch_negotiator *unused,
 629                                    struct object *obj)
 630{
 631        mark_complete(&obj->oid);
 632}
 633
 634struct loose_object_iter {
 635        struct oidset *loose_object_set;
 636        struct ref *refs;
 637};
 638
 639/*
 640 * Mark recent commits available locally and reachable from a local ref as
 641 * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 642 * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 643 * thus do not need COMMON_REF marks).
 644 *
 645 * The cutoff time for recency is determined by this heuristic: it is the
 646 * earliest commit time of the objects in refs that are commits and that we know
 647 * the commit time of.
 648 */
 649static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 650                                         struct fetch_pack_args *args,
 651                                         struct ref **refs)
 652{
 653        struct ref *ref;
 654        int old_save_commit_buffer = save_commit_buffer;
 655        timestamp_t cutoff = 0;
 656
 657        save_commit_buffer = 0;
 658
 659        for (ref = *refs; ref; ref = ref->next) {
 660                struct object *o;
 661
 662                if (!has_object_file_with_flags(&ref->old_oid,
 663                                                OBJECT_INFO_QUICK))
 664                        continue;
 665                o = parse_object(the_repository, &ref->old_oid);
 666                if (!o)
 667                        continue;
 668
 669                /* We already have it -- which may mean that we were
 670                 * in sync with the other side at some time after
 671                 * that (it is OK if we guess wrong here).
 672                 */
 673                if (o->type == OBJ_COMMIT) {
 674                        struct commit *commit = (struct commit *)o;
 675                        if (!cutoff || cutoff < commit->date)
 676                                cutoff = commit->date;
 677                }
 678        }
 679
 680        if (!args->deepen) {
 681                for_each_ref(mark_complete_oid, NULL);
 682                for_each_cached_alternate(NULL, mark_alternate_complete);
 683                commit_list_sort_by_date(&complete);
 684                if (cutoff)
 685                        mark_recent_complete_commits(args, cutoff);
 686        }
 687
 688        /*
 689         * Mark all complete remote refs as common refs.
 690         * Don't mark them common yet; the server has to be told so first.
 691         */
 692        for (ref = *refs; ref; ref = ref->next) {
 693                struct object *o = deref_tag(the_repository,
 694                                             lookup_object(the_repository,
 695                                             ref->old_oid.hash),
 696                                             NULL, 0);
 697
 698                if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 699                        continue;
 700
 701                negotiator->known_common(negotiator,
 702                                         (struct commit *)o);
 703        }
 704
 705        save_commit_buffer = old_save_commit_buffer;
 706}
 707
 708/*
 709 * Returns 1 if every object pointed to by the given remote refs is available
 710 * locally and reachable from a local ref, and 0 otherwise.
 711 */
 712static int everything_local(struct fetch_pack_args *args,
 713                            struct ref **refs)
 714{
 715        struct ref *ref;
 716        int retval;
 717
 718        for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 719                const struct object_id *remote = &ref->old_oid;
 720                struct object *o;
 721
 722                o = lookup_object(the_repository, remote->hash);
 723                if (!o || !(o->flags & COMPLETE)) {
 724                        retval = 0;
 725                        print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 726                                      ref->name);
 727                        continue;
 728                }
 729                print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 730                              ref->name);
 731        }
 732
 733        return retval;
 734}
 735
 736static int sideband_demux(int in, int out, void *data)
 737{
 738        int *xd = data;
 739        int ret;
 740
 741        ret = recv_sideband("fetch-pack", xd[0], out);
 742        close(out);
 743        return ret;
 744}
 745
 746static int get_pack(struct fetch_pack_args *args,
 747                    int xd[2], char **pack_lockfile)
 748{
 749        struct async demux;
 750        int do_keep = args->keep_pack;
 751        const char *cmd_name;
 752        struct pack_header header;
 753        int pass_header = 0;
 754        struct child_process cmd = CHILD_PROCESS_INIT;
 755        int ret;
 756
 757        memset(&demux, 0, sizeof(demux));
 758        if (use_sideband) {
 759                /* xd[] is talking with upload-pack; subprocess reads from
 760                 * xd[0], spits out band#2 to stderr, and feeds us band#1
 761                 * through demux->out.
 762                 */
 763                demux.proc = sideband_demux;
 764                demux.data = xd;
 765                demux.out = -1;
 766                demux.isolate_sigpipe = 1;
 767                if (start_async(&demux))
 768                        die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 769        }
 770        else
 771                demux.out = xd[0];
 772
 773        if (!args->keep_pack && unpack_limit) {
 774
 775                if (read_pack_header(demux.out, &header))
 776                        die(_("protocol error: bad pack header"));
 777                pass_header = 1;
 778                if (ntohl(header.hdr_entries) < unpack_limit)
 779                        do_keep = 0;
 780                else
 781                        do_keep = 1;
 782        }
 783
 784        if (alternate_shallow_file) {
 785                argv_array_push(&cmd.args, "--shallow-file");
 786                argv_array_push(&cmd.args, alternate_shallow_file);
 787        }
 788
 789        if (do_keep || args->from_promisor) {
 790                if (pack_lockfile)
 791                        cmd.out = -1;
 792                cmd_name = "index-pack";
 793                argv_array_push(&cmd.args, cmd_name);
 794                argv_array_push(&cmd.args, "--stdin");
 795                if (!args->quiet && !args->no_progress)
 796                        argv_array_push(&cmd.args, "-v");
 797                if (args->use_thin_pack)
 798                        argv_array_push(&cmd.args, "--fix-thin");
 799                if (do_keep && (args->lock_pack || unpack_limit)) {
 800                        char hostname[HOST_NAME_MAX + 1];
 801                        if (xgethostname(hostname, sizeof(hostname)))
 802                                xsnprintf(hostname, sizeof(hostname), "localhost");
 803                        argv_array_pushf(&cmd.args,
 804                                        "--keep=fetch-pack %"PRIuMAX " on %s",
 805                                        (uintmax_t)getpid(), hostname);
 806                }
 807                if (args->check_self_contained_and_connected)
 808                        argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 809                if (args->from_promisor)
 810                        argv_array_push(&cmd.args, "--promisor");
 811        }
 812        else {
 813                cmd_name = "unpack-objects";
 814                argv_array_push(&cmd.args, cmd_name);
 815                if (args->quiet || args->no_progress)
 816                        argv_array_push(&cmd.args, "-q");
 817                args->check_self_contained_and_connected = 0;
 818        }
 819
 820        if (pass_header)
 821                argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 822                                 ntohl(header.hdr_version),
 823                                 ntohl(header.hdr_entries));
 824        if (fetch_fsck_objects >= 0
 825            ? fetch_fsck_objects
 826            : transfer_fsck_objects >= 0
 827            ? transfer_fsck_objects
 828            : 0) {
 829                if (args->from_promisor)
 830                        /*
 831                         * We cannot use --strict in index-pack because it
 832                         * checks both broken objects and links, but we only
 833                         * want to check for broken objects.
 834                         */
 835                        argv_array_push(&cmd.args, "--fsck-objects");
 836                else
 837                        argv_array_pushf(&cmd.args, "--strict%s",
 838                                         fsck_msg_types.buf);
 839        }
 840
 841        cmd.in = demux.out;
 842        cmd.git_cmd = 1;
 843        if (start_command(&cmd))
 844                die(_("fetch-pack: unable to fork off %s"), cmd_name);
 845        if (do_keep && pack_lockfile) {
 846                *pack_lockfile = index_pack_lockfile(cmd.out);
 847                close(cmd.out);
 848        }
 849
 850        if (!use_sideband)
 851                /* Closed by start_command() */
 852                xd[0] = -1;
 853
 854        ret = finish_command(&cmd);
 855        if (!ret || (args->check_self_contained_and_connected && ret == 1))
 856                args->self_contained_and_connected =
 857                        args->check_self_contained_and_connected &&
 858                        ret == 0;
 859        else
 860                die(_("%s failed"), cmd_name);
 861        if (use_sideband && finish_async(&demux))
 862                die(_("error in sideband demultiplexer"));
 863        return 0;
 864}
 865
 866static int cmp_ref_by_name(const void *a_, const void *b_)
 867{
 868        const struct ref *a = *((const struct ref **)a_);
 869        const struct ref *b = *((const struct ref **)b_);
 870        return strcmp(a->name, b->name);
 871}
 872
 873static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 874                                 int fd[2],
 875                                 const struct ref *orig_ref,
 876                                 struct ref **sought, int nr_sought,
 877                                 struct shallow_info *si,
 878                                 char **pack_lockfile)
 879{
 880        struct ref *ref = copy_ref_list(orig_ref);
 881        struct object_id oid;
 882        const char *agent_feature;
 883        int agent_len;
 884        struct fetch_negotiator negotiator;
 885        fetch_negotiator_init(&negotiator, negotiation_algorithm);
 886
 887        sort_ref_list(&ref, ref_compare_name);
 888        QSORT(sought, nr_sought, cmp_ref_by_name);
 889
 890        if ((args->depth > 0 || is_repository_shallow(the_repository)) && !server_supports("shallow"))
 891                die(_("Server does not support shallow clients"));
 892        if (args->depth > 0 || args->deepen_since || args->deepen_not)
 893                args->deepen = 1;
 894        if (server_supports("multi_ack_detailed")) {
 895                print_verbose(args, _("Server supports multi_ack_detailed"));
 896                multi_ack = 2;
 897                if (server_supports("no-done")) {
 898                        print_verbose(args, _("Server supports no-done"));
 899                        if (args->stateless_rpc)
 900                                no_done = 1;
 901                }
 902        }
 903        else if (server_supports("multi_ack")) {
 904                print_verbose(args, _("Server supports multi_ack"));
 905                multi_ack = 1;
 906        }
 907        if (server_supports("side-band-64k")) {
 908                print_verbose(args, _("Server supports side-band-64k"));
 909                use_sideband = 2;
 910        }
 911        else if (server_supports("side-band")) {
 912                print_verbose(args, _("Server supports side-band"));
 913                use_sideband = 1;
 914        }
 915        if (server_supports("allow-tip-sha1-in-want")) {
 916                print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 917                allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 918        }
 919        if (server_supports("allow-reachable-sha1-in-want")) {
 920                print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 921                allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 922        }
 923        if (!server_supports("thin-pack"))
 924                args->use_thin_pack = 0;
 925        if (!server_supports("no-progress"))
 926                args->no_progress = 0;
 927        if (!server_supports("include-tag"))
 928                args->include_tag = 0;
 929        if (server_supports("ofs-delta"))
 930                print_verbose(args, _("Server supports ofs-delta"));
 931        else
 932                prefer_ofs_delta = 0;
 933
 934        if (server_supports("filter")) {
 935                server_supports_filtering = 1;
 936                print_verbose(args, _("Server supports filter"));
 937        } else if (args->filter_options.choice) {
 938                warning("filtering not recognized by server, ignoring");
 939        }
 940
 941        if ((agent_feature = server_feature_value("agent", &agent_len))) {
 942                agent_supported = 1;
 943                if (agent_len)
 944                        print_verbose(args, _("Server version is %.*s"),
 945                                      agent_len, agent_feature);
 946        }
 947        if (server_supports("deepen-since"))
 948                deepen_since_ok = 1;
 949        else if (args->deepen_since)
 950                die(_("Server does not support --shallow-since"));
 951        if (server_supports("deepen-not"))
 952                deepen_not_ok = 1;
 953        else if (args->deepen_not)
 954                die(_("Server does not support --shallow-exclude"));
 955        if (!server_supports("deepen-relative") && args->deepen_relative)
 956                die(_("Server does not support --deepen"));
 957
 958        if (!args->no_dependents) {
 959                mark_complete_and_common_ref(&negotiator, args, &ref);
 960                filter_refs(args, &ref, sought, nr_sought);
 961                if (everything_local(args, &ref)) {
 962                        packet_flush(fd[1]);
 963                        goto all_done;
 964                }
 965        } else {
 966                filter_refs(args, &ref, sought, nr_sought);
 967        }
 968        if (find_common(&negotiator, args, fd, &oid, ref) < 0)
 969                if (!args->keep_pack)
 970                        /* When cloning, it is not unusual to have
 971                         * no common commit.
 972                         */
 973                        warning(_("no common commits"));
 974
 975        if (args->stateless_rpc)
 976                packet_flush(fd[1]);
 977        if (args->deepen)
 978                setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
 979                                        NULL);
 980        else if (si->nr_ours || si->nr_theirs)
 981                alternate_shallow_file = setup_temporary_shallow(si->shallow);
 982        else
 983                alternate_shallow_file = NULL;
 984        if (get_pack(args, fd, pack_lockfile))
 985                die(_("git fetch-pack: fetch failed."));
 986
 987 all_done:
 988        negotiator.release(&negotiator);
 989        return ref;
 990}
 991
 992static void add_shallow_requests(struct strbuf *req_buf,
 993                                 const struct fetch_pack_args *args)
 994{
 995        if (is_repository_shallow(the_repository))
 996                write_shallow_commits(req_buf, 1, NULL);
 997        if (args->depth > 0)
 998                packet_buf_write(req_buf, "deepen %d", args->depth);
 999        if (args->deepen_since) {
1000                timestamp_t max_age = approxidate(args->deepen_since);
1001                packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1002        }
1003        if (args->deepen_not) {
1004                int i;
1005                for (i = 0; i < args->deepen_not->nr; i++) {
1006                        struct string_list_item *s = args->deepen_not->items + i;
1007                        packet_buf_write(req_buf, "deepen-not %s", s->string);
1008                }
1009        }
1010}
1011
1012static void add_wants(int no_dependents, const struct ref *wants, struct strbuf *req_buf)
1013{
1014        int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1015
1016        for ( ; wants ; wants = wants->next) {
1017                const struct object_id *remote = &wants->old_oid;
1018                struct object *o;
1019
1020                /*
1021                 * If that object is complete (i.e. it is an ancestor of a
1022                 * local ref), we tell them we have it but do not have to
1023                 * tell them about its ancestors, which they already know
1024                 * about.
1025                 *
1026                 * We use lookup_object here because we are only
1027                 * interested in the case we *know* the object is
1028                 * reachable and we have already scanned it.
1029                 *
1030                 * Do this only if args->no_dependents is false (if it is true,
1031                 * we cannot trust the object flags).
1032                 */
1033                if (!no_dependents &&
1034                    ((o = lookup_object(the_repository, remote->hash)) != NULL) &&
1035                    (o->flags & COMPLETE)) {
1036                        continue;
1037                }
1038
1039                if (!use_ref_in_want || wants->exact_oid)
1040                        packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1041                else
1042                        packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1043        }
1044}
1045
1046static void add_common(struct strbuf *req_buf, struct oidset *common)
1047{
1048        struct oidset_iter iter;
1049        const struct object_id *oid;
1050        oidset_iter_init(common, &iter);
1051
1052        while ((oid = oidset_iter_next(&iter))) {
1053                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1054        }
1055}
1056
1057static int add_haves(struct fetch_negotiator *negotiator,
1058                     struct strbuf *req_buf,
1059                     int *haves_to_send, int *in_vain)
1060{
1061        int ret = 0;
1062        int haves_added = 0;
1063        const struct object_id *oid;
1064
1065        while ((oid = negotiator->next(negotiator))) {
1066                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1067                if (++haves_added >= *haves_to_send)
1068                        break;
1069        }
1070
1071        *in_vain += haves_added;
1072        if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1073                /* Send Done */
1074                packet_buf_write(req_buf, "done\n");
1075                ret = 1;
1076        }
1077
1078        /* Increase haves to send on next round */
1079        *haves_to_send = next_flush(1, *haves_to_send);
1080
1081        return ret;
1082}
1083
1084static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1085                              const struct fetch_pack_args *args,
1086                              const struct ref *wants, struct oidset *common,
1087                              int *haves_to_send, int *in_vain)
1088{
1089        int ret = 0;
1090        struct strbuf req_buf = STRBUF_INIT;
1091
1092        if (server_supports_v2("fetch", 1))
1093                packet_buf_write(&req_buf, "command=fetch");
1094        if (server_supports_v2("agent", 0))
1095                packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1096        if (args->server_options && args->server_options->nr &&
1097            server_supports_v2("server-option", 1)) {
1098                int i;
1099                for (i = 0; i < args->server_options->nr; i++)
1100                        packet_write_fmt(fd_out, "server-option=%s",
1101                                         args->server_options->items[i].string);
1102        }
1103
1104        packet_buf_delim(&req_buf);
1105        if (args->use_thin_pack)
1106                packet_buf_write(&req_buf, "thin-pack");
1107        if (args->no_progress)
1108                packet_buf_write(&req_buf, "no-progress");
1109        if (args->include_tag)
1110                packet_buf_write(&req_buf, "include-tag");
1111        if (prefer_ofs_delta)
1112                packet_buf_write(&req_buf, "ofs-delta");
1113
1114        /* Add shallow-info and deepen request */
1115        if (server_supports_feature("fetch", "shallow", 0))
1116                add_shallow_requests(&req_buf, args);
1117        else if (is_repository_shallow(the_repository) || args->deepen)
1118                die(_("Server does not support shallow requests"));
1119
1120        /* Add filter */
1121        if (server_supports_feature("fetch", "filter", 0) &&
1122            args->filter_options.choice) {
1123                print_verbose(args, _("Server supports filter"));
1124                packet_buf_write(&req_buf, "filter %s",
1125                                 args->filter_options.filter_spec);
1126        } else if (args->filter_options.choice) {
1127                warning("filtering not recognized by server, ignoring");
1128        }
1129
1130        /* add wants */
1131        add_wants(args->no_dependents, wants, &req_buf);
1132
1133        if (args->no_dependents) {
1134                packet_buf_write(&req_buf, "done");
1135                ret = 1;
1136        } else {
1137                /* Add all of the common commits we've found in previous rounds */
1138                add_common(&req_buf, common);
1139
1140                /* Add initial haves */
1141                ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1142        }
1143
1144        /* Send request */
1145        packet_buf_flush(&req_buf);
1146        write_or_die(fd_out, req_buf.buf, req_buf.len);
1147
1148        strbuf_release(&req_buf);
1149        return ret;
1150}
1151
1152/*
1153 * Processes a section header in a server's response and checks if it matches
1154 * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1155 * not consumed); if 0, the line will be consumed and the function will die if
1156 * the section header doesn't match what was expected.
1157 */
1158static int process_section_header(struct packet_reader *reader,
1159                                  const char *section, int peek)
1160{
1161        int ret;
1162
1163        if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1164                die(_("error reading section header '%s'"), section);
1165
1166        ret = !strcmp(reader->line, section);
1167
1168        if (!peek) {
1169                if (!ret)
1170                        die(_("expected '%s', received '%s'"),
1171                            section, reader->line);
1172                packet_reader_read(reader);
1173        }
1174
1175        return ret;
1176}
1177
1178static int process_acks(struct fetch_negotiator *negotiator,
1179                        struct packet_reader *reader,
1180                        struct oidset *common)
1181{
1182        /* received */
1183        int received_ready = 0;
1184        int received_ack = 0;
1185
1186        process_section_header(reader, "acknowledgments", 0);
1187        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1188                const char *arg;
1189
1190                if (!strcmp(reader->line, "NAK"))
1191                        continue;
1192
1193                if (skip_prefix(reader->line, "ACK ", &arg)) {
1194                        struct object_id oid;
1195                        if (!get_oid_hex(arg, &oid)) {
1196                                struct commit *commit;
1197                                oidset_insert(common, &oid);
1198                                commit = lookup_commit(the_repository, &oid);
1199                                negotiator->ack(negotiator, commit);
1200                        }
1201                        continue;
1202                }
1203
1204                if (!strcmp(reader->line, "ready")) {
1205                        received_ready = 1;
1206                        continue;
1207                }
1208
1209                die(_("unexpected acknowledgment line: '%s'"), reader->line);
1210        }
1211
1212        if (reader->status != PACKET_READ_FLUSH &&
1213            reader->status != PACKET_READ_DELIM)
1214                die(_("error processing acks: %d"), reader->status);
1215
1216        /*
1217         * If an "acknowledgments" section is sent, a packfile is sent if and
1218         * only if "ready" was sent in this section. The other sections
1219         * ("shallow-info" and "wanted-refs") are sent only if a packfile is
1220         * sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
1221         * otherwise.
1222         */
1223        if (received_ready && reader->status != PACKET_READ_DELIM)
1224                die(_("expected packfile to be sent after 'ready'"));
1225        if (!received_ready && reader->status != PACKET_READ_FLUSH)
1226                die(_("expected no other sections to be sent after no 'ready'"));
1227
1228        /* return 0 if no common, 1 if there are common, or 2 if ready */
1229        return received_ready ? 2 : (received_ack ? 1 : 0);
1230}
1231
1232static void receive_shallow_info(struct fetch_pack_args *args,
1233                                 struct packet_reader *reader)
1234{
1235        process_section_header(reader, "shallow-info", 0);
1236        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1237                const char *arg;
1238                struct object_id oid;
1239
1240                if (skip_prefix(reader->line, "shallow ", &arg)) {
1241                        if (get_oid_hex(arg, &oid))
1242                                die(_("invalid shallow line: %s"), reader->line);
1243                        register_shallow(the_repository, &oid);
1244                        continue;
1245                }
1246                if (skip_prefix(reader->line, "unshallow ", &arg)) {
1247                        if (get_oid_hex(arg, &oid))
1248                                die(_("invalid unshallow line: %s"), reader->line);
1249                        if (!lookup_object(the_repository, oid.hash))
1250                                die(_("object not found: %s"), reader->line);
1251                        /* make sure that it is parsed as shallow */
1252                        if (!parse_object(the_repository, &oid))
1253                                die(_("error in object: %s"), reader->line);
1254                        if (unregister_shallow(&oid))
1255                                die(_("no shallow found: %s"), reader->line);
1256                        continue;
1257                }
1258                die(_("expected shallow/unshallow, got %s"), reader->line);
1259        }
1260
1261        if (reader->status != PACKET_READ_FLUSH &&
1262            reader->status != PACKET_READ_DELIM)
1263                die(_("error processing shallow info: %d"), reader->status);
1264
1265        setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, NULL);
1266        args->deepen = 1;
1267}
1268
1269static void receive_wanted_refs(struct packet_reader *reader,
1270                                struct ref **sought, int nr_sought)
1271{
1272        process_section_header(reader, "wanted-refs", 0);
1273        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1274                struct object_id oid;
1275                const char *end;
1276                int i;
1277
1278                if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1279                        die(_("expected wanted-ref, got '%s'"), reader->line);
1280
1281                for (i = 0; i < nr_sought; i++) {
1282                        if (!strcmp(end, sought[i]->name)) {
1283                                oidcpy(&sought[i]->old_oid, &oid);
1284                                break;
1285                        }
1286                }
1287
1288                if (i == nr_sought)
1289                        die(_("unexpected wanted-ref: '%s'"), reader->line);
1290        }
1291
1292        if (reader->status != PACKET_READ_DELIM)
1293                die(_("error processing wanted refs: %d"), reader->status);
1294}
1295
1296enum fetch_state {
1297        FETCH_CHECK_LOCAL = 0,
1298        FETCH_SEND_REQUEST,
1299        FETCH_PROCESS_ACKS,
1300        FETCH_GET_PACK,
1301        FETCH_DONE,
1302};
1303
1304static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1305                                    int fd[2],
1306                                    const struct ref *orig_ref,
1307                                    struct ref **sought, int nr_sought,
1308                                    char **pack_lockfile)
1309{
1310        struct ref *ref = copy_ref_list(orig_ref);
1311        enum fetch_state state = FETCH_CHECK_LOCAL;
1312        struct oidset common = OIDSET_INIT;
1313        struct packet_reader reader;
1314        int in_vain = 0;
1315        int haves_to_send = INITIAL_FLUSH;
1316        struct fetch_negotiator negotiator;
1317        fetch_negotiator_init(&negotiator, negotiation_algorithm);
1318        packet_reader_init(&reader, fd[0], NULL, 0,
1319                           PACKET_READ_CHOMP_NEWLINE);
1320
1321        while (state != FETCH_DONE) {
1322                switch (state) {
1323                case FETCH_CHECK_LOCAL:
1324                        sort_ref_list(&ref, ref_compare_name);
1325                        QSORT(sought, nr_sought, cmp_ref_by_name);
1326
1327                        /* v2 supports these by default */
1328                        allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1329                        use_sideband = 2;
1330                        if (args->depth > 0 || args->deepen_since || args->deepen_not)
1331                                args->deepen = 1;
1332
1333                        /* Filter 'ref' by 'sought' and those that aren't local */
1334                        if (!args->no_dependents) {
1335                                mark_complete_and_common_ref(&negotiator, args, &ref);
1336                                filter_refs(args, &ref, sought, nr_sought);
1337                                if (everything_local(args, &ref))
1338                                        state = FETCH_DONE;
1339                                else
1340                                        state = FETCH_SEND_REQUEST;
1341
1342                                mark_tips(&negotiator, args->negotiation_tips);
1343                                for_each_cached_alternate(&negotiator,
1344                                                          insert_one_alternate_object);
1345                        } else {
1346                                filter_refs(args, &ref, sought, nr_sought);
1347                                state = FETCH_SEND_REQUEST;
1348                        }
1349                        break;
1350                case FETCH_SEND_REQUEST:
1351                        if (send_fetch_request(&negotiator, fd[1], args, ref,
1352                                               &common,
1353                                               &haves_to_send, &in_vain))
1354                                state = FETCH_GET_PACK;
1355                        else
1356                                state = FETCH_PROCESS_ACKS;
1357                        break;
1358                case FETCH_PROCESS_ACKS:
1359                        /* Process ACKs/NAKs */
1360                        switch (process_acks(&negotiator, &reader, &common)) {
1361                        case 2:
1362                                state = FETCH_GET_PACK;
1363                                break;
1364                        case 1:
1365                                in_vain = 0;
1366                                /* fallthrough */
1367                        default:
1368                                state = FETCH_SEND_REQUEST;
1369                                break;
1370                        }
1371                        break;
1372                case FETCH_GET_PACK:
1373                        /* Check for shallow-info section */
1374                        if (process_section_header(&reader, "shallow-info", 1))
1375                                receive_shallow_info(args, &reader);
1376
1377                        if (process_section_header(&reader, "wanted-refs", 1))
1378                                receive_wanted_refs(&reader, sought, nr_sought);
1379
1380                        /* get the pack */
1381                        process_section_header(&reader, "packfile", 0);
1382                        if (get_pack(args, fd, pack_lockfile))
1383                                die(_("git fetch-pack: fetch failed."));
1384
1385                        state = FETCH_DONE;
1386                        break;
1387                case FETCH_DONE:
1388                        continue;
1389                }
1390        }
1391
1392        negotiator.release(&negotiator);
1393        oidset_clear(&common);
1394        return ref;
1395}
1396
1397static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1398{
1399        if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1400                const char *path;
1401
1402                if (git_config_pathname(&path, var, value))
1403                        return 1;
1404                strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1405                        fsck_msg_types.len ? ',' : '=', path);
1406                free((char *)path);
1407                return 0;
1408        }
1409
1410        if (skip_prefix(var, "fetch.fsck.", &var)) {
1411                if (is_valid_msg_type(var, value))
1412                        strbuf_addf(&fsck_msg_types, "%c%s=%s",
1413                                fsck_msg_types.len ? ',' : '=', var, value);
1414                else
1415                        warning("Skipping unknown msg id '%s'", var);
1416                return 0;
1417        }
1418
1419        return git_default_config(var, value, cb);
1420}
1421
1422static void fetch_pack_config(void)
1423{
1424        git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1425        git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1426        git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1427        git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1428        git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1429        git_config_get_string("fetch.negotiationalgorithm",
1430                              &negotiation_algorithm);
1431
1432        git_config(fetch_pack_config_cb, NULL);
1433}
1434
1435static void fetch_pack_setup(void)
1436{
1437        static int did_setup;
1438        if (did_setup)
1439                return;
1440        fetch_pack_config();
1441        if (0 <= transfer_unpack_limit)
1442                unpack_limit = transfer_unpack_limit;
1443        else if (0 <= fetch_unpack_limit)
1444                unpack_limit = fetch_unpack_limit;
1445        did_setup = 1;
1446}
1447
1448static int remove_duplicates_in_refs(struct ref **ref, int nr)
1449{
1450        struct string_list names = STRING_LIST_INIT_NODUP;
1451        int src, dst;
1452
1453        for (src = dst = 0; src < nr; src++) {
1454                struct string_list_item *item;
1455                item = string_list_insert(&names, ref[src]->name);
1456                if (item->util)
1457                        continue; /* already have it */
1458                item->util = ref[src];
1459                if (src != dst)
1460                        ref[dst] = ref[src];
1461                dst++;
1462        }
1463        for (src = dst; src < nr; src++)
1464                ref[src] = NULL;
1465        string_list_clear(&names, 0);
1466        return dst;
1467}
1468
1469static void update_shallow(struct fetch_pack_args *args,
1470                           struct ref **sought, int nr_sought,
1471                           struct shallow_info *si)
1472{
1473        struct oid_array ref = OID_ARRAY_INIT;
1474        int *status;
1475        int i;
1476
1477        if (args->deepen && alternate_shallow_file) {
1478                if (*alternate_shallow_file == '\0') { /* --unshallow */
1479                        unlink_or_warn(git_path_shallow(the_repository));
1480                        rollback_lock_file(&shallow_lock);
1481                } else
1482                        commit_lock_file(&shallow_lock);
1483                return;
1484        }
1485
1486        if (!si->shallow || !si->shallow->nr)
1487                return;
1488
1489        if (args->cloning) {
1490                /*
1491                 * remote is shallow, but this is a clone, there are
1492                 * no objects in repo to worry about. Accept any
1493                 * shallow points that exist in the pack (iow in repo
1494                 * after get_pack() and reprepare_packed_git())
1495                 */
1496                struct oid_array extra = OID_ARRAY_INIT;
1497                struct object_id *oid = si->shallow->oid;
1498                for (i = 0; i < si->shallow->nr; i++)
1499                        if (has_object_file(&oid[i]))
1500                                oid_array_append(&extra, &oid[i]);
1501                if (extra.nr) {
1502                        setup_alternate_shallow(&shallow_lock,
1503                                                &alternate_shallow_file,
1504                                                &extra);
1505                        commit_lock_file(&shallow_lock);
1506                }
1507                oid_array_clear(&extra);
1508                return;
1509        }
1510
1511        if (!si->nr_ours && !si->nr_theirs)
1512                return;
1513
1514        remove_nonexistent_theirs_shallow(si);
1515        if (!si->nr_ours && !si->nr_theirs)
1516                return;
1517        for (i = 0; i < nr_sought; i++)
1518                oid_array_append(&ref, &sought[i]->old_oid);
1519        si->ref = &ref;
1520
1521        if (args->update_shallow) {
1522                /*
1523                 * remote is also shallow, .git/shallow may be updated
1524                 * so all refs can be accepted. Make sure we only add
1525                 * shallow roots that are actually reachable from new
1526                 * refs.
1527                 */
1528                struct oid_array extra = OID_ARRAY_INIT;
1529                struct object_id *oid = si->shallow->oid;
1530                assign_shallow_commits_to_refs(si, NULL, NULL);
1531                if (!si->nr_ours && !si->nr_theirs) {
1532                        oid_array_clear(&ref);
1533                        return;
1534                }
1535                for (i = 0; i < si->nr_ours; i++)
1536                        oid_array_append(&extra, &oid[si->ours[i]]);
1537                for (i = 0; i < si->nr_theirs; i++)
1538                        oid_array_append(&extra, &oid[si->theirs[i]]);
1539                setup_alternate_shallow(&shallow_lock,
1540                                        &alternate_shallow_file,
1541                                        &extra);
1542                commit_lock_file(&shallow_lock);
1543                oid_array_clear(&extra);
1544                oid_array_clear(&ref);
1545                return;
1546        }
1547
1548        /*
1549         * remote is also shallow, check what ref is safe to update
1550         * without updating .git/shallow
1551         */
1552        status = xcalloc(nr_sought, sizeof(*status));
1553        assign_shallow_commits_to_refs(si, NULL, status);
1554        if (si->nr_ours || si->nr_theirs) {
1555                for (i = 0; i < nr_sought; i++)
1556                        if (status[i])
1557                                sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1558        }
1559        free(status);
1560        oid_array_clear(&ref);
1561}
1562
1563static int iterate_ref_map(void *cb_data, struct object_id *oid)
1564{
1565        struct ref **rm = cb_data;
1566        struct ref *ref = *rm;
1567
1568        if (!ref)
1569                return -1; /* end of the list */
1570        *rm = ref->next;
1571        oidcpy(oid, &ref->old_oid);
1572        return 0;
1573}
1574
1575struct ref *fetch_pack(struct fetch_pack_args *args,
1576                       int fd[], struct child_process *conn,
1577                       const struct ref *ref,
1578                       const char *dest,
1579                       struct ref **sought, int nr_sought,
1580                       struct oid_array *shallow,
1581                       char **pack_lockfile,
1582                       enum protocol_version version)
1583{
1584        struct ref *ref_cpy;
1585        struct shallow_info si;
1586
1587        fetch_pack_setup();
1588        if (nr_sought)
1589                nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1590
1591        if (args->no_dependents && !args->filter_options.choice) {
1592                /*
1593                 * The protocol does not support requesting that only the
1594                 * wanted objects be sent, so approximate this by setting a
1595                 * "blob:none" filter if no filter is already set. This works
1596                 * for all object types: note that wanted blobs will still be
1597                 * sent because they are directly specified as a "want".
1598                 *
1599                 * NEEDSWORK: Add an option in the protocol to request that
1600                 * only the wanted objects be sent, and implement it.
1601                 */
1602                parse_list_objects_filter(&args->filter_options, "blob:none");
1603        }
1604
1605        if (version != protocol_v2 && !ref) {
1606                packet_flush(fd[1]);
1607                die(_("no matching remote head"));
1608        }
1609        prepare_shallow_info(&si, shallow);
1610        if (version == protocol_v2)
1611                ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1612                                           pack_lockfile);
1613        else
1614                ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1615                                        &si, pack_lockfile);
1616        reprepare_packed_git(the_repository);
1617
1618        if (!args->cloning && args->deepen) {
1619                struct check_connected_options opt = CHECK_CONNECTED_INIT;
1620                struct ref *iterator = ref_cpy;
1621                opt.shallow_file = alternate_shallow_file;
1622                if (args->deepen)
1623                        opt.is_deepening_fetch = 1;
1624                if (check_connected(iterate_ref_map, &iterator, &opt)) {
1625                        error(_("remote did not send all necessary objects"));
1626                        free_refs(ref_cpy);
1627                        ref_cpy = NULL;
1628                        rollback_lock_file(&shallow_lock);
1629                        goto cleanup;
1630                }
1631                args->connectivity_checked = 1;
1632        }
1633
1634        update_shallow(args, sought, nr_sought, &si);
1635cleanup:
1636        clear_shallow_info(&si);
1637        return ref_cpy;
1638}
1639
1640int report_unmatched_refs(struct ref **sought, int nr_sought)
1641{
1642        int i, ret = 0;
1643
1644        for (i = 0; i < nr_sought; i++) {
1645                if (!sought[i])
1646                        continue;
1647                switch (sought[i]->match_status) {
1648                case REF_MATCHED:
1649                        continue;
1650                case REF_NOT_MATCHED:
1651                        error(_("no such remote ref %s"), sought[i]->name);
1652                        break;
1653                case REF_UNADVERTISED_NOT_ALLOWED:
1654                        error(_("Server does not allow request for unadvertised object %s"),
1655                              sought[i]->name);
1656                        break;
1657                }
1658                ret = 1;
1659        }
1660        return ret;
1661}