fetch-pack.con commit fetch-pack: introduce negotiator API (ec06283)
   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 "fetch-negotiator.h"
  22
  23static int transfer_unpack_limit = -1;
  24static int fetch_unpack_limit = -1;
  25static int unpack_limit = 100;
  26static int prefer_ofs_delta = 1;
  27static int no_done;
  28static int deepen_since_ok;
  29static int deepen_not_ok;
  30static int fetch_fsck_objects = -1;
  31static int transfer_fsck_objects = -1;
  32static int agent_supported;
  33static int server_supports_filtering;
  34static struct lock_file shallow_lock;
  35static const char *alternate_shallow_file;
  36
  37/* Remember to update object flag allocation in object.h */
  38#define COMPLETE        (1U << 0)
  39#define ALTERNATE       (1U << 1)
  40
  41/*
  42 * After sending this many "have"s if we do not get any new ACK , we
  43 * give up traversing our history.
  44 */
  45#define MAX_IN_VAIN 256
  46
  47static int multi_ack, use_sideband;
  48/* Allow specifying sha1 if it is a ref tip. */
  49#define ALLOW_TIP_SHA1  01
  50/* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  51#define ALLOW_REACHABLE_SHA1    02
  52static unsigned int allow_unadvertised_object_request;
  53
  54__attribute__((format (printf, 2, 3)))
  55static inline void print_verbose(const struct fetch_pack_args *args,
  56                                 const char *fmt, ...)
  57{
  58        va_list params;
  59
  60        if (!args->verbose)
  61                return;
  62
  63        va_start(params, fmt);
  64        vfprintf(stderr, fmt, params);
  65        va_end(params);
  66        fputc('\n', stderr);
  67}
  68
  69struct alternate_object_cache {
  70        struct object **items;
  71        size_t nr, alloc;
  72};
  73
  74static void cache_one_alternate(const char *refname,
  75                                const struct object_id *oid,
  76                                void *vcache)
  77{
  78        struct alternate_object_cache *cache = vcache;
  79        struct object *obj = parse_object(oid);
  80
  81        if (!obj || (obj->flags & ALTERNATE))
  82                return;
  83
  84        obj->flags |= ALTERNATE;
  85        ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  86        cache->items[cache->nr++] = obj;
  87}
  88
  89static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
  90                                      void (*cb)(struct fetch_negotiator *,
  91                                                 struct object *))
  92{
  93        static int initialized;
  94        static struct alternate_object_cache cache;
  95        size_t i;
  96
  97        if (!initialized) {
  98                for_each_alternate_ref(cache_one_alternate, &cache);
  99                initialized = 1;
 100        }
 101
 102        for (i = 0; i < cache.nr; i++)
 103                cb(negotiator, cache.items[i]);
 104}
 105
 106static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
 107                               const char *refname,
 108                               const struct object_id *oid)
 109{
 110        struct object *o = deref_tag(parse_object(oid), refname, 0);
 111
 112        if (o && o->type == OBJ_COMMIT)
 113                negotiator->add_tip(negotiator, (struct commit *)o);
 114
 115        return 0;
 116}
 117
 118static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 119                                   int flag, void *cb_data)
 120{
 121        return rev_list_insert_ref(cb_data, refname, oid);
 122}
 123
 124enum ack_type {
 125        NAK = 0,
 126        ACK,
 127        ACK_continue,
 128        ACK_common,
 129        ACK_ready
 130};
 131
 132static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 133{
 134        if (args->stateless_rpc && args->deepen) {
 135                /* If we sent a depth we will get back "duplicate"
 136                 * shallow and unshallow commands every time there
 137                 * is a block of have lines exchanged.
 138                 */
 139                char *line;
 140                while ((line = packet_read_line(fd, NULL))) {
 141                        if (starts_with(line, "shallow "))
 142                                continue;
 143                        if (starts_with(line, "unshallow "))
 144                                continue;
 145                        die(_("git fetch-pack: expected shallow list"));
 146                }
 147        }
 148}
 149
 150static enum ack_type get_ack(int fd, struct object_id *result_oid)
 151{
 152        int len;
 153        char *line = packet_read_line(fd, &len);
 154        const char *arg;
 155
 156        if (!line)
 157                die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 158        if (!strcmp(line, "NAK"))
 159                return NAK;
 160        if (skip_prefix(line, "ACK ", &arg)) {
 161                if (!get_oid_hex(arg, result_oid)) {
 162                        arg += 40;
 163                        len -= arg - line;
 164                        if (len < 1)
 165                                return ACK;
 166                        if (strstr(arg, "continue"))
 167                                return ACK_continue;
 168                        if (strstr(arg, "common"))
 169                                return ACK_common;
 170                        if (strstr(arg, "ready"))
 171                                return ACK_ready;
 172                        return ACK;
 173                }
 174        }
 175        if (skip_prefix(line, "ERR ", &arg))
 176                die(_("remote error: %s"), arg);
 177        die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 178}
 179
 180static void send_request(struct fetch_pack_args *args,
 181                         int fd, struct strbuf *buf)
 182{
 183        if (args->stateless_rpc) {
 184                send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 185                packet_flush(fd);
 186        } else
 187                write_or_die(fd, buf->buf, buf->len);
 188}
 189
 190static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 191                                        struct object *obj)
 192{
 193        rev_list_insert_ref(negotiator, NULL, &obj->oid);
 194}
 195
 196#define INITIAL_FLUSH 16
 197#define PIPESAFE_FLUSH 32
 198#define LARGE_FLUSH 16384
 199
 200static int next_flush(int stateless_rpc, int count)
 201{
 202        if (stateless_rpc) {
 203                if (count < LARGE_FLUSH)
 204                        count <<= 1;
 205                else
 206                        count = count * 11 / 10;
 207        } else {
 208                if (count < PIPESAFE_FLUSH)
 209                        count <<= 1;
 210                else
 211                        count += PIPESAFE_FLUSH;
 212        }
 213        return count;
 214}
 215
 216static int find_common(struct fetch_negotiator *negotiator,
 217                       struct fetch_pack_args *args,
 218                       int fd[2], struct object_id *result_oid,
 219                       struct ref *refs)
 220{
 221        int fetching;
 222        int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 223        const struct object_id *oid;
 224        unsigned in_vain = 0;
 225        int got_continue = 0;
 226        int got_ready = 0;
 227        struct strbuf req_buf = STRBUF_INIT;
 228        size_t state_len = 0;
 229
 230        if (args->stateless_rpc && multi_ack == 1)
 231                die(_("--stateless-rpc requires multi_ack_detailed"));
 232
 233        for_each_ref(rev_list_insert_ref_oid, negotiator);
 234        for_each_cached_alternate(negotiator, insert_one_alternate_object);
 235
 236        fetching = 0;
 237        for ( ; refs ; refs = refs->next) {
 238                struct object_id *remote = &refs->old_oid;
 239                const char *remote_hex;
 240                struct object *o;
 241
 242                /*
 243                 * If that object is complete (i.e. it is an ancestor of a
 244                 * local ref), we tell them we have it but do not have to
 245                 * tell them about its ancestors, which they already know
 246                 * about.
 247                 *
 248                 * We use lookup_object here because we are only
 249                 * interested in the case we *know* the object is
 250                 * reachable and we have already scanned it.
 251                 */
 252                if (((o = lookup_object(remote->hash)) != NULL) &&
 253                                (o->flags & COMPLETE)) {
 254                        continue;
 255                }
 256
 257                remote_hex = oid_to_hex(remote);
 258                if (!fetching) {
 259                        struct strbuf c = STRBUF_INIT;
 260                        if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 261                        if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 262                        if (no_done)            strbuf_addstr(&c, " no-done");
 263                        if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 264                        if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 265                        if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 266                        if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 267                        if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 268                        if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 269                        if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 270                        if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 271                        if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 272                        if (agent_supported)    strbuf_addf(&c, " agent=%s",
 273                                                            git_user_agent_sanitized());
 274                        if (args->filter_options.choice)
 275                                strbuf_addstr(&c, " filter");
 276                        packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 277                        strbuf_release(&c);
 278                } else
 279                        packet_buf_write(&req_buf, "want %s\n", remote_hex);
 280                fetching++;
 281        }
 282
 283        if (!fetching) {
 284                strbuf_release(&req_buf);
 285                packet_flush(fd[1]);
 286                return 1;
 287        }
 288
 289        if (is_repository_shallow())
 290                write_shallow_commits(&req_buf, 1, NULL);
 291        if (args->depth > 0)
 292                packet_buf_write(&req_buf, "deepen %d", args->depth);
 293        if (args->deepen_since) {
 294                timestamp_t max_age = approxidate(args->deepen_since);
 295                packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 296        }
 297        if (args->deepen_not) {
 298                int i;
 299                for (i = 0; i < args->deepen_not->nr; i++) {
 300                        struct string_list_item *s = args->deepen_not->items + i;
 301                        packet_buf_write(&req_buf, "deepen-not %s", s->string);
 302                }
 303        }
 304        if (server_supports_filtering && args->filter_options.choice)
 305                packet_buf_write(&req_buf, "filter %s",
 306                                 args->filter_options.filter_spec);
 307        packet_buf_flush(&req_buf);
 308        state_len = req_buf.len;
 309
 310        if (args->deepen) {
 311                char *line;
 312                const char *arg;
 313                struct object_id oid;
 314
 315                send_request(args, fd[1], &req_buf);
 316                while ((line = packet_read_line(fd[0], NULL))) {
 317                        if (skip_prefix(line, "shallow ", &arg)) {
 318                                if (get_oid_hex(arg, &oid))
 319                                        die(_("invalid shallow line: %s"), line);
 320                                register_shallow(&oid);
 321                                continue;
 322                        }
 323                        if (skip_prefix(line, "unshallow ", &arg)) {
 324                                if (get_oid_hex(arg, &oid))
 325                                        die(_("invalid unshallow line: %s"), line);
 326                                if (!lookup_object(oid.hash))
 327                                        die(_("object not found: %s"), line);
 328                                /* make sure that it is parsed as shallow */
 329                                if (!parse_object(&oid))
 330                                        die(_("error in object: %s"), line);
 331                                if (unregister_shallow(&oid))
 332                                        die(_("no shallow found: %s"), line);
 333                                continue;
 334                        }
 335                        die(_("expected shallow/unshallow, got %s"), line);
 336                }
 337        } else if (!args->stateless_rpc)
 338                send_request(args, fd[1], &req_buf);
 339
 340        if (!args->stateless_rpc) {
 341                /* If we aren't using the stateless-rpc interface
 342                 * we don't need to retain the headers.
 343                 */
 344                strbuf_setlen(&req_buf, 0);
 345                state_len = 0;
 346        }
 347
 348        flushes = 0;
 349        retval = -1;
 350        if (args->no_dependents)
 351                goto done;
 352        while ((oid = negotiator->next(negotiator))) {
 353                packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 354                print_verbose(args, "have %s", oid_to_hex(oid));
 355                in_vain++;
 356                if (flush_at <= ++count) {
 357                        int ack;
 358
 359                        packet_buf_flush(&req_buf);
 360                        send_request(args, fd[1], &req_buf);
 361                        strbuf_setlen(&req_buf, state_len);
 362                        flushes++;
 363                        flush_at = next_flush(args->stateless_rpc, count);
 364
 365                        /*
 366                         * We keep one window "ahead" of the other side, and
 367                         * will wait for an ACK only on the next one
 368                         */
 369                        if (!args->stateless_rpc && count == INITIAL_FLUSH)
 370                                continue;
 371
 372                        consume_shallow_list(args, fd[0]);
 373                        do {
 374                                ack = get_ack(fd[0], result_oid);
 375                                if (ack)
 376                                        print_verbose(args, _("got %s %d %s"), "ack",
 377                                                      ack, oid_to_hex(result_oid));
 378                                switch (ack) {
 379                                case ACK:
 380                                        flushes = 0;
 381                                        multi_ack = 0;
 382                                        retval = 0;
 383                                        goto done;
 384                                case ACK_common:
 385                                case ACK_ready:
 386                                case ACK_continue: {
 387                                        struct commit *commit =
 388                                                lookup_commit(result_oid);
 389                                        int was_common;
 390                                        if (!commit)
 391                                                die(_("invalid commit %s"), oid_to_hex(result_oid));
 392                                        was_common = negotiator->ack(negotiator, commit);
 393                                        if (args->stateless_rpc
 394                                         && ack == ACK_common
 395                                         && !was_common) {
 396                                                /* We need to replay the have for this object
 397                                                 * on the next RPC request so the peer knows
 398                                                 * it is in common with us.
 399                                                 */
 400                                                const char *hex = oid_to_hex(result_oid);
 401                                                packet_buf_write(&req_buf, "have %s\n", hex);
 402                                                state_len = req_buf.len;
 403                                                /*
 404                                                 * Reset in_vain because an ack
 405                                                 * for this commit has not been
 406                                                 * seen.
 407                                                 */
 408                                                in_vain = 0;
 409                                        } else if (!args->stateless_rpc
 410                                                   || ack != ACK_common)
 411                                                in_vain = 0;
 412                                        retval = 0;
 413                                        got_continue = 1;
 414                                        if (ack == ACK_ready)
 415                                                got_ready = 1;
 416                                        break;
 417                                        }
 418                                }
 419                        } while (ack);
 420                        flushes--;
 421                        if (got_continue && MAX_IN_VAIN < in_vain) {
 422                                print_verbose(args, _("giving up"));
 423                                break; /* give up */
 424                        }
 425                        if (got_ready)
 426                                break;
 427                }
 428        }
 429done:
 430        if (!got_ready || !no_done) {
 431                packet_buf_write(&req_buf, "done\n");
 432                send_request(args, fd[1], &req_buf);
 433        }
 434        print_verbose(args, _("done"));
 435        if (retval != 0) {
 436                multi_ack = 0;
 437                flushes++;
 438        }
 439        strbuf_release(&req_buf);
 440
 441        if (!got_ready || !no_done)
 442                consume_shallow_list(args, fd[0]);
 443        while (flushes || multi_ack) {
 444                int ack = get_ack(fd[0], result_oid);
 445                if (ack) {
 446                        print_verbose(args, _("got %s (%d) %s"), "ack",
 447                                      ack, oid_to_hex(result_oid));
 448                        if (ack == ACK)
 449                                return 0;
 450                        multi_ack = 1;
 451                        continue;
 452                }
 453                flushes--;
 454        }
 455        /* it is no error to fetch into a completely empty repo */
 456        return count ? retval : 0;
 457}
 458
 459static struct commit_list *complete;
 460
 461static int mark_complete(const struct object_id *oid)
 462{
 463        struct object *o = parse_object(oid);
 464
 465        while (o && o->type == OBJ_TAG) {
 466                struct tag *t = (struct tag *) o;
 467                if (!t->tagged)
 468                        break; /* broken repository */
 469                o->flags |= COMPLETE;
 470                o = parse_object(&t->tagged->oid);
 471        }
 472        if (o && o->type == OBJ_COMMIT) {
 473                struct commit *commit = (struct commit *)o;
 474                if (!(commit->object.flags & COMPLETE)) {
 475                        commit->object.flags |= COMPLETE;
 476                        commit_list_insert(commit, &complete);
 477                }
 478        }
 479        return 0;
 480}
 481
 482static int mark_complete_oid(const char *refname, const struct object_id *oid,
 483                             int flag, void *cb_data)
 484{
 485        return mark_complete(oid);
 486}
 487
 488static void mark_recent_complete_commits(struct fetch_pack_args *args,
 489                                         timestamp_t cutoff)
 490{
 491        while (complete && cutoff <= complete->item->date) {
 492                print_verbose(args, _("Marking %s as complete"),
 493                              oid_to_hex(&complete->item->object.oid));
 494                pop_most_recent_commit(&complete, COMPLETE);
 495        }
 496}
 497
 498static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 499{
 500        for (; refs; refs = refs->next)
 501                oidset_insert(oids, &refs->old_oid);
 502}
 503
 504static int tip_oids_contain(struct oidset *tip_oids,
 505                            struct ref *unmatched, struct ref *newlist,
 506                            const struct object_id *id)
 507{
 508        /*
 509         * Note that this only looks at the ref lists the first time it's
 510         * called. This works out in filter_refs() because even though it may
 511         * add to "newlist" between calls, the additions will always be for
 512         * oids that are already in the set.
 513         */
 514        if (!tip_oids->map.map.tablesize) {
 515                add_refs_to_oidset(tip_oids, unmatched);
 516                add_refs_to_oidset(tip_oids, newlist);
 517        }
 518        return oidset_contains(tip_oids, id);
 519}
 520
 521static void filter_refs(struct fetch_pack_args *args,
 522                        struct ref **refs,
 523                        struct ref **sought, int nr_sought)
 524{
 525        struct ref *newlist = NULL;
 526        struct ref **newtail = &newlist;
 527        struct ref *unmatched = NULL;
 528        struct ref *ref, *next;
 529        struct oidset tip_oids = OIDSET_INIT;
 530        int i;
 531
 532        i = 0;
 533        for (ref = *refs; ref; ref = next) {
 534                int keep = 0;
 535                next = ref->next;
 536
 537                if (starts_with(ref->name, "refs/") &&
 538                    check_refname_format(ref->name, 0))
 539                        ; /* trash */
 540                else {
 541                        while (i < nr_sought) {
 542                                int cmp = strcmp(ref->name, sought[i]->name);
 543                                if (cmp < 0)
 544                                        break; /* definitely do not have it */
 545                                else if (cmp == 0) {
 546                                        keep = 1; /* definitely have it */
 547                                        sought[i]->match_status = REF_MATCHED;
 548                                }
 549                                i++;
 550                        }
 551                }
 552
 553                if (!keep && args->fetch_all &&
 554                    (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 555                        keep = 1;
 556
 557                if (keep) {
 558                        *newtail = ref;
 559                        ref->next = NULL;
 560                        newtail = &ref->next;
 561                } else {
 562                        ref->next = unmatched;
 563                        unmatched = ref;
 564                }
 565        }
 566
 567        /* Append unmatched requests to the list */
 568        for (i = 0; i < nr_sought; i++) {
 569                struct object_id oid;
 570                const char *p;
 571
 572                ref = sought[i];
 573                if (ref->match_status != REF_NOT_MATCHED)
 574                        continue;
 575                if (parse_oid_hex(ref->name, &oid, &p) ||
 576                    *p != '\0' ||
 577                    oidcmp(&oid, &ref->old_oid))
 578                        continue;
 579
 580                if ((allow_unadvertised_object_request &
 581                     (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1)) ||
 582                    tip_oids_contain(&tip_oids, unmatched, newlist,
 583                                     &ref->old_oid)) {
 584                        ref->match_status = REF_MATCHED;
 585                        *newtail = copy_ref(ref);
 586                        newtail = &(*newtail)->next;
 587                } else {
 588                        ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 589                }
 590        }
 591
 592        oidset_clear(&tip_oids);
 593        for (ref = unmatched; ref; ref = next) {
 594                next = ref->next;
 595                free(ref);
 596        }
 597
 598        *refs = newlist;
 599}
 600
 601static void mark_alternate_complete(struct fetch_negotiator *unused,
 602                                    struct object *obj)
 603{
 604        mark_complete(&obj->oid);
 605}
 606
 607struct loose_object_iter {
 608        struct oidset *loose_object_set;
 609        struct ref *refs;
 610};
 611
 612/*
 613 *  If the number of refs is not larger than the number of loose objects,
 614 *  this function stops inserting.
 615 */
 616static int add_loose_objects_to_set(const struct object_id *oid,
 617                                    const char *path,
 618                                    void *data)
 619{
 620        struct loose_object_iter *iter = data;
 621        oidset_insert(iter->loose_object_set, oid);
 622        if (iter->refs == NULL)
 623                return 1;
 624
 625        iter->refs = iter->refs->next;
 626        return 0;
 627}
 628
 629/*
 630 * Mark recent commits available locally and reachable from a local ref as
 631 * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 632 * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 633 * thus do not need COMMON_REF marks).
 634 *
 635 * The cutoff time for recency is determined by this heuristic: it is the
 636 * earliest commit time of the objects in refs that are commits and that we know
 637 * the commit time of.
 638 */
 639static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 640                                         struct fetch_pack_args *args,
 641                                         struct ref **refs)
 642{
 643        struct ref *ref;
 644        int old_save_commit_buffer = save_commit_buffer;
 645        timestamp_t cutoff = 0;
 646        struct oidset loose_oid_set = OIDSET_INIT;
 647        int use_oidset = 0;
 648        struct loose_object_iter iter = {&loose_oid_set, *refs};
 649
 650        /* Enumerate all loose objects or know refs are not so many. */
 651        use_oidset = !for_each_loose_object(add_loose_objects_to_set,
 652                                            &iter, 0);
 653
 654        save_commit_buffer = 0;
 655
 656        for (ref = *refs; ref; ref = ref->next) {
 657                struct object *o;
 658                unsigned int flags = OBJECT_INFO_QUICK;
 659
 660                if (use_oidset &&
 661                    !oidset_contains(&loose_oid_set, &ref->old_oid)) {
 662                        /*
 663                         * I know this does not exist in the loose form,
 664                         * so check if it exists in a non-loose form.
 665                         */
 666                        flags |= OBJECT_INFO_IGNORE_LOOSE;
 667                }
 668
 669                if (!has_object_file_with_flags(&ref->old_oid, flags))
 670                        continue;
 671                o = parse_object(&ref->old_oid);
 672                if (!o)
 673                        continue;
 674
 675                /* We already have it -- which may mean that we were
 676                 * in sync with the other side at some time after
 677                 * that (it is OK if we guess wrong here).
 678                 */
 679                if (o->type == OBJ_COMMIT) {
 680                        struct commit *commit = (struct commit *)o;
 681                        if (!cutoff || cutoff < commit->date)
 682                                cutoff = commit->date;
 683                }
 684        }
 685
 686        oidset_clear(&loose_oid_set);
 687
 688        if (!args->no_dependents) {
 689                if (!args->deepen) {
 690                        for_each_ref(mark_complete_oid, NULL);
 691                        for_each_cached_alternate(NULL, mark_alternate_complete);
 692                        commit_list_sort_by_date(&complete);
 693                        if (cutoff)
 694                                mark_recent_complete_commits(args, cutoff);
 695                }
 696
 697                /*
 698                 * Mark all complete remote refs as common refs.
 699                 * Don't mark them common yet; the server has to be told so first.
 700                 */
 701                for (ref = *refs; ref; ref = ref->next) {
 702                        struct object *o = deref_tag(lookup_object(ref->old_oid.hash),
 703                                                     NULL, 0);
 704
 705                        if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 706                                continue;
 707
 708                        negotiator->known_common(negotiator,
 709                                                 (struct commit *)o);
 710                }
 711        }
 712
 713        save_commit_buffer = old_save_commit_buffer;
 714}
 715
 716/*
 717 * Returns 1 if every object pointed to by the given remote refs is available
 718 * locally and reachable from a local ref, and 0 otherwise.
 719 */
 720static int everything_local(struct fetch_pack_args *args,
 721                            struct ref **refs)
 722{
 723        struct ref *ref;
 724        int retval;
 725
 726        for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 727                const struct object_id *remote = &ref->old_oid;
 728                struct object *o;
 729
 730                o = lookup_object(remote->hash);
 731                if (!o || !(o->flags & COMPLETE)) {
 732                        retval = 0;
 733                        print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 734                                      ref->name);
 735                        continue;
 736                }
 737                print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 738                              ref->name);
 739        }
 740
 741        return retval;
 742}
 743
 744static int sideband_demux(int in, int out, void *data)
 745{
 746        int *xd = data;
 747        int ret;
 748
 749        ret = recv_sideband("fetch-pack", xd[0], out);
 750        close(out);
 751        return ret;
 752}
 753
 754static int get_pack(struct fetch_pack_args *args,
 755                    int xd[2], char **pack_lockfile)
 756{
 757        struct async demux;
 758        int do_keep = args->keep_pack;
 759        const char *cmd_name;
 760        struct pack_header header;
 761        int pass_header = 0;
 762        struct child_process cmd = CHILD_PROCESS_INIT;
 763        int ret;
 764
 765        memset(&demux, 0, sizeof(demux));
 766        if (use_sideband) {
 767                /* xd[] is talking with upload-pack; subprocess reads from
 768                 * xd[0], spits out band#2 to stderr, and feeds us band#1
 769                 * through demux->out.
 770                 */
 771                demux.proc = sideband_demux;
 772                demux.data = xd;
 773                demux.out = -1;
 774                demux.isolate_sigpipe = 1;
 775                if (start_async(&demux))
 776                        die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 777        }
 778        else
 779                demux.out = xd[0];
 780
 781        if (!args->keep_pack && unpack_limit) {
 782
 783                if (read_pack_header(demux.out, &header))
 784                        die(_("protocol error: bad pack header"));
 785                pass_header = 1;
 786                if (ntohl(header.hdr_entries) < unpack_limit)
 787                        do_keep = 0;
 788                else
 789                        do_keep = 1;
 790        }
 791
 792        if (alternate_shallow_file) {
 793                argv_array_push(&cmd.args, "--shallow-file");
 794                argv_array_push(&cmd.args, alternate_shallow_file);
 795        }
 796
 797        if (do_keep || args->from_promisor) {
 798                if (pack_lockfile)
 799                        cmd.out = -1;
 800                cmd_name = "index-pack";
 801                argv_array_push(&cmd.args, cmd_name);
 802                argv_array_push(&cmd.args, "--stdin");
 803                if (!args->quiet && !args->no_progress)
 804                        argv_array_push(&cmd.args, "-v");
 805                if (args->use_thin_pack)
 806                        argv_array_push(&cmd.args, "--fix-thin");
 807                if (do_keep && (args->lock_pack || unpack_limit)) {
 808                        char hostname[HOST_NAME_MAX + 1];
 809                        if (xgethostname(hostname, sizeof(hostname)))
 810                                xsnprintf(hostname, sizeof(hostname), "localhost");
 811                        argv_array_pushf(&cmd.args,
 812                                        "--keep=fetch-pack %"PRIuMAX " on %s",
 813                                        (uintmax_t)getpid(), hostname);
 814                }
 815                if (args->check_self_contained_and_connected)
 816                        argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 817                if (args->from_promisor)
 818                        argv_array_push(&cmd.args, "--promisor");
 819        }
 820        else {
 821                cmd_name = "unpack-objects";
 822                argv_array_push(&cmd.args, cmd_name);
 823                if (args->quiet || args->no_progress)
 824                        argv_array_push(&cmd.args, "-q");
 825                args->check_self_contained_and_connected = 0;
 826        }
 827
 828        if (pass_header)
 829                argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 830                                 ntohl(header.hdr_version),
 831                                 ntohl(header.hdr_entries));
 832        if (fetch_fsck_objects >= 0
 833            ? fetch_fsck_objects
 834            : transfer_fsck_objects >= 0
 835            ? transfer_fsck_objects
 836            : 0) {
 837                if (args->from_promisor)
 838                        /*
 839                         * We cannot use --strict in index-pack because it
 840                         * checks both broken objects and links, but we only
 841                         * want to check for broken objects.
 842                         */
 843                        argv_array_push(&cmd.args, "--fsck-objects");
 844                else
 845                        argv_array_push(&cmd.args, "--strict");
 846        }
 847
 848        cmd.in = demux.out;
 849        cmd.git_cmd = 1;
 850        if (start_command(&cmd))
 851                die(_("fetch-pack: unable to fork off %s"), cmd_name);
 852        if (do_keep && pack_lockfile) {
 853                *pack_lockfile = index_pack_lockfile(cmd.out);
 854                close(cmd.out);
 855        }
 856
 857        if (!use_sideband)
 858                /* Closed by start_command() */
 859                xd[0] = -1;
 860
 861        ret = finish_command(&cmd);
 862        if (!ret || (args->check_self_contained_and_connected && ret == 1))
 863                args->self_contained_and_connected =
 864                        args->check_self_contained_and_connected &&
 865                        ret == 0;
 866        else
 867                die(_("%s failed"), cmd_name);
 868        if (use_sideband && finish_async(&demux))
 869                die(_("error in sideband demultiplexer"));
 870        return 0;
 871}
 872
 873static int cmp_ref_by_name(const void *a_, const void *b_)
 874{
 875        const struct ref *a = *((const struct ref **)a_);
 876        const struct ref *b = *((const struct ref **)b_);
 877        return strcmp(a->name, b->name);
 878}
 879
 880static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 881                                 int fd[2],
 882                                 const struct ref *orig_ref,
 883                                 struct ref **sought, int nr_sought,
 884                                 struct shallow_info *si,
 885                                 char **pack_lockfile)
 886{
 887        struct ref *ref = copy_ref_list(orig_ref);
 888        struct object_id oid;
 889        const char *agent_feature;
 890        int agent_len;
 891        struct fetch_negotiator negotiator;
 892        fetch_negotiator_init(&negotiator);
 893
 894        sort_ref_list(&ref, ref_compare_name);
 895        QSORT(sought, nr_sought, cmp_ref_by_name);
 896
 897        if ((args->depth > 0 || is_repository_shallow()) && !server_supports("shallow"))
 898                die(_("Server does not support shallow clients"));
 899        if (args->depth > 0 || args->deepen_since || args->deepen_not)
 900                args->deepen = 1;
 901        if (server_supports("multi_ack_detailed")) {
 902                print_verbose(args, _("Server supports multi_ack_detailed"));
 903                multi_ack = 2;
 904                if (server_supports("no-done")) {
 905                        print_verbose(args, _("Server supports no-done"));
 906                        if (args->stateless_rpc)
 907                                no_done = 1;
 908                }
 909        }
 910        else if (server_supports("multi_ack")) {
 911                print_verbose(args, _("Server supports multi_ack"));
 912                multi_ack = 1;
 913        }
 914        if (server_supports("side-band-64k")) {
 915                print_verbose(args, _("Server supports side-band-64k"));
 916                use_sideband = 2;
 917        }
 918        else if (server_supports("side-band")) {
 919                print_verbose(args, _("Server supports side-band"));
 920                use_sideband = 1;
 921        }
 922        if (server_supports("allow-tip-sha1-in-want")) {
 923                print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 924                allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 925        }
 926        if (server_supports("allow-reachable-sha1-in-want")) {
 927                print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 928                allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 929        }
 930        if (!server_supports("thin-pack"))
 931                args->use_thin_pack = 0;
 932        if (!server_supports("no-progress"))
 933                args->no_progress = 0;
 934        if (!server_supports("include-tag"))
 935                args->include_tag = 0;
 936        if (server_supports("ofs-delta"))
 937                print_verbose(args, _("Server supports ofs-delta"));
 938        else
 939                prefer_ofs_delta = 0;
 940
 941        if (server_supports("filter")) {
 942                server_supports_filtering = 1;
 943                print_verbose(args, _("Server supports filter"));
 944        } else if (args->filter_options.choice) {
 945                warning("filtering not recognized by server, ignoring");
 946        }
 947
 948        if ((agent_feature = server_feature_value("agent", &agent_len))) {
 949                agent_supported = 1;
 950                if (agent_len)
 951                        print_verbose(args, _("Server version is %.*s"),
 952                                      agent_len, agent_feature);
 953        }
 954        if (server_supports("deepen-since"))
 955                deepen_since_ok = 1;
 956        else if (args->deepen_since)
 957                die(_("Server does not support --shallow-since"));
 958        if (server_supports("deepen-not"))
 959                deepen_not_ok = 1;
 960        else if (args->deepen_not)
 961                die(_("Server does not support --shallow-exclude"));
 962        if (!server_supports("deepen-relative") && args->deepen_relative)
 963                die(_("Server does not support --deepen"));
 964
 965        mark_complete_and_common_ref(&negotiator, args, &ref);
 966        filter_refs(args, &ref, sought, nr_sought);
 967        if (everything_local(args, &ref)) {
 968                packet_flush(fd[1]);
 969                goto all_done;
 970        }
 971        if (find_common(&negotiator, args, fd, &oid, ref) < 0)
 972                if (!args->keep_pack)
 973                        /* When cloning, it is not unusual to have
 974                         * no common commit.
 975                         */
 976                        warning(_("no common commits"));
 977
 978        if (args->stateless_rpc)
 979                packet_flush(fd[1]);
 980        if (args->deepen)
 981                setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
 982                                        NULL);
 983        else if (si->nr_ours || si->nr_theirs)
 984                alternate_shallow_file = setup_temporary_shallow(si->shallow);
 985        else
 986                alternate_shallow_file = NULL;
 987        if (get_pack(args, fd, pack_lockfile))
 988                die(_("git fetch-pack: fetch failed."));
 989
 990 all_done:
 991        negotiator.release(&negotiator);
 992        return ref;
 993}
 994
 995static void add_shallow_requests(struct strbuf *req_buf,
 996                                 const struct fetch_pack_args *args)
 997{
 998        if (is_repository_shallow())
 999                write_shallow_commits(req_buf, 1, NULL);
1000        if (args->depth > 0)
1001                packet_buf_write(req_buf, "deepen %d", args->depth);
1002        if (args->deepen_since) {
1003                timestamp_t max_age = approxidate(args->deepen_since);
1004                packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1005        }
1006        if (args->deepen_not) {
1007                int i;
1008                for (i = 0; i < args->deepen_not->nr; i++) {
1009                        struct string_list_item *s = args->deepen_not->items + i;
1010                        packet_buf_write(req_buf, "deepen-not %s", s->string);
1011                }
1012        }
1013}
1014
1015static void add_wants(const struct ref *wants, struct strbuf *req_buf)
1016{
1017        for ( ; wants ; wants = wants->next) {
1018                const struct object_id *remote = &wants->old_oid;
1019                const char *remote_hex;
1020                struct object *o;
1021
1022                /*
1023                 * If that object is complete (i.e. it is an ancestor of a
1024                 * local ref), we tell them we have it but do not have to
1025                 * tell them about its ancestors, which they already know
1026                 * about.
1027                 *
1028                 * We use lookup_object here because we are only
1029                 * interested in the case we *know* the object is
1030                 * reachable and we have already scanned it.
1031                 */
1032                if (((o = lookup_object(remote->hash)) != NULL) &&
1033                    (o->flags & COMPLETE)) {
1034                        continue;
1035                }
1036
1037                remote_hex = oid_to_hex(remote);
1038                packet_buf_write(req_buf, "want %s\n", remote_hex);
1039        }
1040}
1041
1042static void add_common(struct strbuf *req_buf, struct oidset *common)
1043{
1044        struct oidset_iter iter;
1045        const struct object_id *oid;
1046        oidset_iter_init(common, &iter);
1047
1048        while ((oid = oidset_iter_next(&iter))) {
1049                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1050        }
1051}
1052
1053static int add_haves(struct fetch_negotiator *negotiator,
1054                     struct strbuf *req_buf,
1055                     int *haves_to_send, int *in_vain)
1056{
1057        int ret = 0;
1058        int haves_added = 0;
1059        const struct object_id *oid;
1060
1061        while ((oid = negotiator->next(negotiator))) {
1062                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1063                if (++haves_added >= *haves_to_send)
1064                        break;
1065        }
1066
1067        *in_vain += haves_added;
1068        if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1069                /* Send Done */
1070                packet_buf_write(req_buf, "done\n");
1071                ret = 1;
1072        }
1073
1074        /* Increase haves to send on next round */
1075        *haves_to_send = next_flush(1, *haves_to_send);
1076
1077        return ret;
1078}
1079
1080static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1081                              const struct fetch_pack_args *args,
1082                              const struct ref *wants, struct oidset *common,
1083                              int *haves_to_send, int *in_vain)
1084{
1085        int ret = 0;
1086        struct strbuf req_buf = STRBUF_INIT;
1087
1088        if (server_supports_v2("fetch", 1))
1089                packet_buf_write(&req_buf, "command=fetch");
1090        if (server_supports_v2("agent", 0))
1091                packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1092        if (args->server_options && args->server_options->nr &&
1093            server_supports_v2("server-option", 1)) {
1094                int i;
1095                for (i = 0; i < args->server_options->nr; i++)
1096                        packet_write_fmt(fd_out, "server-option=%s",
1097                                         args->server_options->items[i].string);
1098        }
1099
1100        packet_buf_delim(&req_buf);
1101        if (args->use_thin_pack)
1102                packet_buf_write(&req_buf, "thin-pack");
1103        if (args->no_progress)
1104                packet_buf_write(&req_buf, "no-progress");
1105        if (args->include_tag)
1106                packet_buf_write(&req_buf, "include-tag");
1107        if (prefer_ofs_delta)
1108                packet_buf_write(&req_buf, "ofs-delta");
1109
1110        /* Add shallow-info and deepen request */
1111        if (server_supports_feature("fetch", "shallow", 0))
1112                add_shallow_requests(&req_buf, args);
1113        else if (is_repository_shallow() || args->deepen)
1114                die(_("Server does not support shallow requests"));
1115
1116        /* Add filter */
1117        if (server_supports_feature("fetch", "filter", 0) &&
1118            args->filter_options.choice) {
1119                print_verbose(args, _("Server supports filter"));
1120                packet_buf_write(&req_buf, "filter %s",
1121                                 args->filter_options.filter_spec);
1122        } else if (args->filter_options.choice) {
1123                warning("filtering not recognized by server, ignoring");
1124        }
1125
1126        /* add wants */
1127        add_wants(wants, &req_buf);
1128
1129        if (args->no_dependents) {
1130                packet_buf_write(&req_buf, "done");
1131                ret = 1;
1132        } else {
1133                /* Add all of the common commits we've found in previous rounds */
1134                add_common(&req_buf, common);
1135
1136                /* Add initial haves */
1137                ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1138        }
1139
1140        /* Send request */
1141        packet_buf_flush(&req_buf);
1142        write_or_die(fd_out, req_buf.buf, req_buf.len);
1143
1144        strbuf_release(&req_buf);
1145        return ret;
1146}
1147
1148/*
1149 * Processes a section header in a server's response and checks if it matches
1150 * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1151 * not consumed); if 0, the line will be consumed and the function will die if
1152 * the section header doesn't match what was expected.
1153 */
1154static int process_section_header(struct packet_reader *reader,
1155                                  const char *section, int peek)
1156{
1157        int ret;
1158
1159        if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1160                die("error reading section header '%s'", section);
1161
1162        ret = !strcmp(reader->line, section);
1163
1164        if (!peek) {
1165                if (!ret)
1166                        die("expected '%s', received '%s'",
1167                            section, reader->line);
1168                packet_reader_read(reader);
1169        }
1170
1171        return ret;
1172}
1173
1174static int process_acks(struct fetch_negotiator *negotiator,
1175                        struct packet_reader *reader,
1176                        struct oidset *common)
1177{
1178        /* received */
1179        int received_ready = 0;
1180        int received_ack = 0;
1181
1182        process_section_header(reader, "acknowledgments", 0);
1183        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1184                const char *arg;
1185
1186                if (!strcmp(reader->line, "NAK"))
1187                        continue;
1188
1189                if (skip_prefix(reader->line, "ACK ", &arg)) {
1190                        struct object_id oid;
1191                        if (!get_oid_hex(arg, &oid)) {
1192                                struct commit *commit;
1193                                oidset_insert(common, &oid);
1194                                commit = lookup_commit(&oid);
1195                                negotiator->ack(negotiator, commit);
1196                        }
1197                        continue;
1198                }
1199
1200                if (!strcmp(reader->line, "ready")) {
1201                        received_ready = 1;
1202                        continue;
1203                }
1204
1205                die("unexpected acknowledgment line: '%s'", reader->line);
1206        }
1207
1208        if (reader->status != PACKET_READ_FLUSH &&
1209            reader->status != PACKET_READ_DELIM)
1210                die("error processing acks: %d", reader->status);
1211
1212        /* return 0 if no common, 1 if there are common, or 2 if ready */
1213        return received_ready ? 2 : (received_ack ? 1 : 0);
1214}
1215
1216static void receive_shallow_info(struct fetch_pack_args *args,
1217                                 struct packet_reader *reader)
1218{
1219        process_section_header(reader, "shallow-info", 0);
1220        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1221                const char *arg;
1222                struct object_id oid;
1223
1224                if (skip_prefix(reader->line, "shallow ", &arg)) {
1225                        if (get_oid_hex(arg, &oid))
1226                                die(_("invalid shallow line: %s"), reader->line);
1227                        register_shallow(&oid);
1228                        continue;
1229                }
1230                if (skip_prefix(reader->line, "unshallow ", &arg)) {
1231                        if (get_oid_hex(arg, &oid))
1232                                die(_("invalid unshallow line: %s"), reader->line);
1233                        if (!lookup_object(oid.hash))
1234                                die(_("object not found: %s"), reader->line);
1235                        /* make sure that it is parsed as shallow */
1236                        if (!parse_object(&oid))
1237                                die(_("error in object: %s"), reader->line);
1238                        if (unregister_shallow(&oid))
1239                                die(_("no shallow found: %s"), reader->line);
1240                        continue;
1241                }
1242                die(_("expected shallow/unshallow, got %s"), reader->line);
1243        }
1244
1245        if (reader->status != PACKET_READ_FLUSH &&
1246            reader->status != PACKET_READ_DELIM)
1247                die("error processing shallow info: %d", reader->status);
1248
1249        setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, NULL);
1250        args->deepen = 1;
1251}
1252
1253enum fetch_state {
1254        FETCH_CHECK_LOCAL = 0,
1255        FETCH_SEND_REQUEST,
1256        FETCH_PROCESS_ACKS,
1257        FETCH_GET_PACK,
1258        FETCH_DONE,
1259};
1260
1261static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1262                                    int fd[2],
1263                                    const struct ref *orig_ref,
1264                                    struct ref **sought, int nr_sought,
1265                                    char **pack_lockfile)
1266{
1267        struct ref *ref = copy_ref_list(orig_ref);
1268        enum fetch_state state = FETCH_CHECK_LOCAL;
1269        struct oidset common = OIDSET_INIT;
1270        struct packet_reader reader;
1271        int in_vain = 0;
1272        int haves_to_send = INITIAL_FLUSH;
1273        struct fetch_negotiator negotiator;
1274        fetch_negotiator_init(&negotiator);
1275        packet_reader_init(&reader, fd[0], NULL, 0,
1276                           PACKET_READ_CHOMP_NEWLINE);
1277
1278        while (state != FETCH_DONE) {
1279                switch (state) {
1280                case FETCH_CHECK_LOCAL:
1281                        sort_ref_list(&ref, ref_compare_name);
1282                        QSORT(sought, nr_sought, cmp_ref_by_name);
1283
1284                        /* v2 supports these by default */
1285                        allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1286                        use_sideband = 2;
1287                        if (args->depth > 0 || args->deepen_since || args->deepen_not)
1288                                args->deepen = 1;
1289
1290                        /* Filter 'ref' by 'sought' and those that aren't local */
1291                        mark_complete_and_common_ref(&negotiator, args, &ref);
1292                        filter_refs(args, &ref, sought, nr_sought);
1293                        if (everything_local(args, &ref))
1294                                state = FETCH_DONE;
1295                        else
1296                                state = FETCH_SEND_REQUEST;
1297
1298                        for_each_ref(rev_list_insert_ref_oid, &negotiator);
1299                        for_each_cached_alternate(&negotiator,
1300                                                  insert_one_alternate_object);
1301                        break;
1302                case FETCH_SEND_REQUEST:
1303                        if (send_fetch_request(&negotiator, fd[1], args, ref,
1304                                               &common,
1305                                               &haves_to_send, &in_vain))
1306                                state = FETCH_GET_PACK;
1307                        else
1308                                state = FETCH_PROCESS_ACKS;
1309                        break;
1310                case FETCH_PROCESS_ACKS:
1311                        /* Process ACKs/NAKs */
1312                        switch (process_acks(&negotiator, &reader, &common)) {
1313                        case 2:
1314                                state = FETCH_GET_PACK;
1315                                break;
1316                        case 1:
1317                                in_vain = 0;
1318                                /* fallthrough */
1319                        default:
1320                                state = FETCH_SEND_REQUEST;
1321                                break;
1322                        }
1323                        break;
1324                case FETCH_GET_PACK:
1325                        /* Check for shallow-info section */
1326                        if (process_section_header(&reader, "shallow-info", 1))
1327                                receive_shallow_info(args, &reader);
1328
1329                        /* get the pack */
1330                        process_section_header(&reader, "packfile", 0);
1331                        if (get_pack(args, fd, pack_lockfile))
1332                                die(_("git fetch-pack: fetch failed."));
1333
1334                        state = FETCH_DONE;
1335                        break;
1336                case FETCH_DONE:
1337                        continue;
1338                }
1339        }
1340
1341        negotiator.release(&negotiator);
1342        oidset_clear(&common);
1343        return ref;
1344}
1345
1346static void fetch_pack_config(void)
1347{
1348        git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1349        git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1350        git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1351        git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1352        git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1353
1354        git_config(git_default_config, NULL);
1355}
1356
1357static void fetch_pack_setup(void)
1358{
1359        static int did_setup;
1360        if (did_setup)
1361                return;
1362        fetch_pack_config();
1363        if (0 <= transfer_unpack_limit)
1364                unpack_limit = transfer_unpack_limit;
1365        else if (0 <= fetch_unpack_limit)
1366                unpack_limit = fetch_unpack_limit;
1367        did_setup = 1;
1368}
1369
1370static int remove_duplicates_in_refs(struct ref **ref, int nr)
1371{
1372        struct string_list names = STRING_LIST_INIT_NODUP;
1373        int src, dst;
1374
1375        for (src = dst = 0; src < nr; src++) {
1376                struct string_list_item *item;
1377                item = string_list_insert(&names, ref[src]->name);
1378                if (item->util)
1379                        continue; /* already have it */
1380                item->util = ref[src];
1381                if (src != dst)
1382                        ref[dst] = ref[src];
1383                dst++;
1384        }
1385        for (src = dst; src < nr; src++)
1386                ref[src] = NULL;
1387        string_list_clear(&names, 0);
1388        return dst;
1389}
1390
1391static void update_shallow(struct fetch_pack_args *args,
1392                           struct ref **sought, int nr_sought,
1393                           struct shallow_info *si)
1394{
1395        struct oid_array ref = OID_ARRAY_INIT;
1396        int *status;
1397        int i;
1398
1399        if (args->deepen && alternate_shallow_file) {
1400                if (*alternate_shallow_file == '\0') { /* --unshallow */
1401                        unlink_or_warn(git_path_shallow());
1402                        rollback_lock_file(&shallow_lock);
1403                } else
1404                        commit_lock_file(&shallow_lock);
1405                return;
1406        }
1407
1408        if (!si->shallow || !si->shallow->nr)
1409                return;
1410
1411        if (args->cloning) {
1412                /*
1413                 * remote is shallow, but this is a clone, there are
1414                 * no objects in repo to worry about. Accept any
1415                 * shallow points that exist in the pack (iow in repo
1416                 * after get_pack() and reprepare_packed_git())
1417                 */
1418                struct oid_array extra = OID_ARRAY_INIT;
1419                struct object_id *oid = si->shallow->oid;
1420                for (i = 0; i < si->shallow->nr; i++)
1421                        if (has_object_file(&oid[i]))
1422                                oid_array_append(&extra, &oid[i]);
1423                if (extra.nr) {
1424                        setup_alternate_shallow(&shallow_lock,
1425                                                &alternate_shallow_file,
1426                                                &extra);
1427                        commit_lock_file(&shallow_lock);
1428                }
1429                oid_array_clear(&extra);
1430                return;
1431        }
1432
1433        if (!si->nr_ours && !si->nr_theirs)
1434                return;
1435
1436        remove_nonexistent_theirs_shallow(si);
1437        if (!si->nr_ours && !si->nr_theirs)
1438                return;
1439        for (i = 0; i < nr_sought; i++)
1440                oid_array_append(&ref, &sought[i]->old_oid);
1441        si->ref = &ref;
1442
1443        if (args->update_shallow) {
1444                /*
1445                 * remote is also shallow, .git/shallow may be updated
1446                 * so all refs can be accepted. Make sure we only add
1447                 * shallow roots that are actually reachable from new
1448                 * refs.
1449                 */
1450                struct oid_array extra = OID_ARRAY_INIT;
1451                struct object_id *oid = si->shallow->oid;
1452                assign_shallow_commits_to_refs(si, NULL, NULL);
1453                if (!si->nr_ours && !si->nr_theirs) {
1454                        oid_array_clear(&ref);
1455                        return;
1456                }
1457                for (i = 0; i < si->nr_ours; i++)
1458                        oid_array_append(&extra, &oid[si->ours[i]]);
1459                for (i = 0; i < si->nr_theirs; i++)
1460                        oid_array_append(&extra, &oid[si->theirs[i]]);
1461                setup_alternate_shallow(&shallow_lock,
1462                                        &alternate_shallow_file,
1463                                        &extra);
1464                commit_lock_file(&shallow_lock);
1465                oid_array_clear(&extra);
1466                oid_array_clear(&ref);
1467                return;
1468        }
1469
1470        /*
1471         * remote is also shallow, check what ref is safe to update
1472         * without updating .git/shallow
1473         */
1474        status = xcalloc(nr_sought, sizeof(*status));
1475        assign_shallow_commits_to_refs(si, NULL, status);
1476        if (si->nr_ours || si->nr_theirs) {
1477                for (i = 0; i < nr_sought; i++)
1478                        if (status[i])
1479                                sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1480        }
1481        free(status);
1482        oid_array_clear(&ref);
1483}
1484
1485struct ref *fetch_pack(struct fetch_pack_args *args,
1486                       int fd[], struct child_process *conn,
1487                       const struct ref *ref,
1488                       const char *dest,
1489                       struct ref **sought, int nr_sought,
1490                       struct oid_array *shallow,
1491                       char **pack_lockfile,
1492                       enum protocol_version version)
1493{
1494        struct ref *ref_cpy;
1495        struct shallow_info si;
1496
1497        fetch_pack_setup();
1498        if (nr_sought)
1499                nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1500
1501        if (!ref) {
1502                packet_flush(fd[1]);
1503                die(_("no matching remote head"));
1504        }
1505        prepare_shallow_info(&si, shallow);
1506        if (version == protocol_v2)
1507                ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1508                                           pack_lockfile);
1509        else
1510                ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1511                                        &si, pack_lockfile);
1512        reprepare_packed_git(the_repository);
1513        update_shallow(args, sought, nr_sought, &si);
1514        clear_shallow_info(&si);
1515        return ref_cpy;
1516}
1517
1518int report_unmatched_refs(struct ref **sought, int nr_sought)
1519{
1520        int i, ret = 0;
1521
1522        for (i = 0; i < nr_sought; i++) {
1523                if (!sought[i])
1524                        continue;
1525                switch (sought[i]->match_status) {
1526                case REF_MATCHED:
1527                        continue;
1528                case REF_NOT_MATCHED:
1529                        error(_("no such remote ref %s"), sought[i]->name);
1530                        break;
1531                case REF_UNADVERTISED_NOT_ALLOWED:
1532                        error(_("Server does not allow request for unadvertised object %s"),
1533                              sought[i]->name);
1534                        break;
1535                }
1536                ret = 1;
1537        }
1538        return ret;
1539}