fetch-pack.con commit Merge branch 'jt/fetch-nego-tip' into ab/fetch-nego (35e22d5)
   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;
  36static char *negotiation_algorithm;
  37
  38/* Remember to update object flag allocation in object.h */
  39#define COMPLETE        (1U << 0)
  40#define ALTERNATE       (1U << 1)
  41
  42/*
  43 * After sending this many "have"s if we do not get any new ACK , we
  44 * give up traversing our history.
  45 */
  46#define MAX_IN_VAIN 256
  47
  48static int multi_ack, use_sideband;
  49/* Allow specifying sha1 if it is a ref tip. */
  50#define ALLOW_TIP_SHA1  01
  51/* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  52#define ALLOW_REACHABLE_SHA1    02
  53static unsigned int allow_unadvertised_object_request;
  54
  55__attribute__((format (printf, 2, 3)))
  56static inline void print_verbose(const struct fetch_pack_args *args,
  57                                 const char *fmt, ...)
  58{
  59        va_list params;
  60
  61        if (!args->verbose)
  62                return;
  63
  64        va_start(params, fmt);
  65        vfprintf(stderr, fmt, params);
  66        va_end(params);
  67        fputc('\n', stderr);
  68}
  69
  70struct alternate_object_cache {
  71        struct object **items;
  72        size_t nr, alloc;
  73};
  74
  75static void cache_one_alternate(const char *refname,
  76                                const struct object_id *oid,
  77                                void *vcache)
  78{
  79        struct alternate_object_cache *cache = vcache;
  80        struct object *obj = parse_object(oid);
  81
  82        if (!obj || (obj->flags & ALTERNATE))
  83                return;
  84
  85        obj->flags |= ALTERNATE;
  86        ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  87        cache->items[cache->nr++] = obj;
  88}
  89
  90static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
  91                                      void (*cb)(struct fetch_negotiator *,
  92                                                 struct object *))
  93{
  94        static int initialized;
  95        static struct alternate_object_cache cache;
  96        size_t i;
  97
  98        if (!initialized) {
  99                for_each_alternate_ref(cache_one_alternate, &cache);
 100                initialized = 1;
 101        }
 102
 103        for (i = 0; i < cache.nr; i++)
 104                cb(negotiator, cache.items[i]);
 105}
 106
 107static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
 108                               const char *refname,
 109                               const struct object_id *oid)
 110{
 111        struct object *o = deref_tag(parse_object(oid), refname, 0);
 112
 113        if (o && o->type == OBJ_COMMIT)
 114                negotiator->add_tip(negotiator, (struct commit *)o);
 115
 116        return 0;
 117}
 118
 119static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 120                                   int flag, void *cb_data)
 121{
 122        return rev_list_insert_ref(cb_data, refname, oid);
 123}
 124
 125enum ack_type {
 126        NAK = 0,
 127        ACK,
 128        ACK_continue,
 129        ACK_common,
 130        ACK_ready
 131};
 132
 133static void consume_shallow_list(struct fetch_pack_args *args, int fd)
 134{
 135        if (args->stateless_rpc && args->deepen) {
 136                /* If we sent a depth we will get back "duplicate"
 137                 * shallow and unshallow commands every time there
 138                 * is a block of have lines exchanged.
 139                 */
 140                char *line;
 141                while ((line = packet_read_line(fd, NULL))) {
 142                        if (starts_with(line, "shallow "))
 143                                continue;
 144                        if (starts_with(line, "unshallow "))
 145                                continue;
 146                        die(_("git fetch-pack: expected shallow list"));
 147                }
 148        }
 149}
 150
 151static enum ack_type get_ack(int fd, struct object_id *result_oid)
 152{
 153        int len;
 154        char *line = packet_read_line(fd, &len);
 155        const char *arg;
 156
 157        if (!line)
 158                die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 159        if (!strcmp(line, "NAK"))
 160                return NAK;
 161        if (skip_prefix(line, "ACK ", &arg)) {
 162                if (!get_oid_hex(arg, result_oid)) {
 163                        arg += 40;
 164                        len -= arg - line;
 165                        if (len < 1)
 166                                return ACK;
 167                        if (strstr(arg, "continue"))
 168                                return ACK_continue;
 169                        if (strstr(arg, "common"))
 170                                return ACK_common;
 171                        if (strstr(arg, "ready"))
 172                                return ACK_ready;
 173                        return ACK;
 174                }
 175        }
 176        if (skip_prefix(line, "ERR ", &arg))
 177                die(_("remote error: %s"), arg);
 178        die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
 179}
 180
 181static void send_request(struct fetch_pack_args *args,
 182                         int fd, struct strbuf *buf)
 183{
 184        if (args->stateless_rpc) {
 185                send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 186                packet_flush(fd);
 187        } else
 188                write_or_die(fd, buf->buf, buf->len);
 189}
 190
 191static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 192                                        struct object *obj)
 193{
 194        rev_list_insert_ref(negotiator, NULL, &obj->oid);
 195}
 196
 197#define INITIAL_FLUSH 16
 198#define PIPESAFE_FLUSH 32
 199#define LARGE_FLUSH 16384
 200
 201static int next_flush(int stateless_rpc, int count)
 202{
 203        if (stateless_rpc) {
 204                if (count < LARGE_FLUSH)
 205                        count <<= 1;
 206                else
 207                        count = count * 11 / 10;
 208        } else {
 209                if (count < PIPESAFE_FLUSH)
 210                        count <<= 1;
 211                else
 212                        count += PIPESAFE_FLUSH;
 213        }
 214        return count;
 215}
 216
 217static void mark_tips(struct fetch_negotiator *negotiator,
 218                      const struct oid_array *negotiation_tips)
 219{
 220        int i;
 221
 222        if (!negotiation_tips) {
 223                for_each_ref(rev_list_insert_ref_oid, negotiator);
 224                return;
 225        }
 226
 227        for (i = 0; i < negotiation_tips->nr; i++)
 228                rev_list_insert_ref(negotiator, NULL,
 229                                    &negotiation_tips->oid[i]);
 230        return;
 231}
 232
 233static int find_common(struct fetch_negotiator *negotiator,
 234                       struct fetch_pack_args *args,
 235                       int fd[2], struct object_id *result_oid,
 236                       struct ref *refs)
 237{
 238        int fetching;
 239        int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 240        const struct object_id *oid;
 241        unsigned in_vain = 0;
 242        int got_continue = 0;
 243        int got_ready = 0;
 244        struct strbuf req_buf = STRBUF_INIT;
 245        size_t state_len = 0;
 246
 247        if (args->stateless_rpc && multi_ack == 1)
 248                die(_("--stateless-rpc requires multi_ack_detailed"));
 249
 250        mark_tips(negotiator, args->negotiation_tips);
 251        for_each_cached_alternate(negotiator, insert_one_alternate_object);
 252
 253        fetching = 0;
 254        for ( ; refs ; refs = refs->next) {
 255                struct object_id *remote = &refs->old_oid;
 256                const char *remote_hex;
 257                struct object *o;
 258
 259                /*
 260                 * If that object is complete (i.e. it is an ancestor of a
 261                 * local ref), we tell them we have it but do not have to
 262                 * tell them about its ancestors, which they already know
 263                 * about.
 264                 *
 265                 * We use lookup_object here because we are only
 266                 * interested in the case we *know* the object is
 267                 * reachable and we have already scanned it.
 268                 */
 269                if (((o = lookup_object(remote->hash)) != NULL) &&
 270                                (o->flags & COMPLETE)) {
 271                        continue;
 272                }
 273
 274                remote_hex = oid_to_hex(remote);
 275                if (!fetching) {
 276                        struct strbuf c = STRBUF_INIT;
 277                        if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 278                        if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 279                        if (no_done)            strbuf_addstr(&c, " no-done");
 280                        if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 281                        if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 282                        if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 283                        if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 284                        if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 285                        if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 286                        if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 287                        if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 288                        if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 289                        if (agent_supported)    strbuf_addf(&c, " agent=%s",
 290                                                            git_user_agent_sanitized());
 291                        if (args->filter_options.choice)
 292                                strbuf_addstr(&c, " filter");
 293                        packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 294                        strbuf_release(&c);
 295                } else
 296                        packet_buf_write(&req_buf, "want %s\n", remote_hex);
 297                fetching++;
 298        }
 299
 300        if (!fetching) {
 301                strbuf_release(&req_buf);
 302                packet_flush(fd[1]);
 303                return 1;
 304        }
 305
 306        if (is_repository_shallow())
 307                write_shallow_commits(&req_buf, 1, NULL);
 308        if (args->depth > 0)
 309                packet_buf_write(&req_buf, "deepen %d", args->depth);
 310        if (args->deepen_since) {
 311                timestamp_t max_age = approxidate(args->deepen_since);
 312                packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 313        }
 314        if (args->deepen_not) {
 315                int i;
 316                for (i = 0; i < args->deepen_not->nr; i++) {
 317                        struct string_list_item *s = args->deepen_not->items + i;
 318                        packet_buf_write(&req_buf, "deepen-not %s", s->string);
 319                }
 320        }
 321        if (server_supports_filtering && args->filter_options.choice)
 322                packet_buf_write(&req_buf, "filter %s",
 323                                 args->filter_options.filter_spec);
 324        packet_buf_flush(&req_buf);
 325        state_len = req_buf.len;
 326
 327        if (args->deepen) {
 328                char *line;
 329                const char *arg;
 330                struct object_id oid;
 331
 332                send_request(args, fd[1], &req_buf);
 333                while ((line = packet_read_line(fd[0], NULL))) {
 334                        if (skip_prefix(line, "shallow ", &arg)) {
 335                                if (get_oid_hex(arg, &oid))
 336                                        die(_("invalid shallow line: %s"), line);
 337                                register_shallow(&oid);
 338                                continue;
 339                        }
 340                        if (skip_prefix(line, "unshallow ", &arg)) {
 341                                if (get_oid_hex(arg, &oid))
 342                                        die(_("invalid unshallow line: %s"), line);
 343                                if (!lookup_object(oid.hash))
 344                                        die(_("object not found: %s"), line);
 345                                /* make sure that it is parsed as shallow */
 346                                if (!parse_object(&oid))
 347                                        die(_("error in object: %s"), line);
 348                                if (unregister_shallow(&oid))
 349                                        die(_("no shallow found: %s"), line);
 350                                continue;
 351                        }
 352                        die(_("expected shallow/unshallow, got %s"), line);
 353                }
 354        } else if (!args->stateless_rpc)
 355                send_request(args, fd[1], &req_buf);
 356
 357        if (!args->stateless_rpc) {
 358                /* If we aren't using the stateless-rpc interface
 359                 * we don't need to retain the headers.
 360                 */
 361                strbuf_setlen(&req_buf, 0);
 362                state_len = 0;
 363        }
 364
 365        flushes = 0;
 366        retval = -1;
 367        if (args->no_dependents)
 368                goto done;
 369        while ((oid = negotiator->next(negotiator))) {
 370                packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 371                print_verbose(args, "have %s", oid_to_hex(oid));
 372                in_vain++;
 373                if (flush_at <= ++count) {
 374                        int ack;
 375
 376                        packet_buf_flush(&req_buf);
 377                        send_request(args, fd[1], &req_buf);
 378                        strbuf_setlen(&req_buf, state_len);
 379                        flushes++;
 380                        flush_at = next_flush(args->stateless_rpc, count);
 381
 382                        /*
 383                         * We keep one window "ahead" of the other side, and
 384                         * will wait for an ACK only on the next one
 385                         */
 386                        if (!args->stateless_rpc && count == INITIAL_FLUSH)
 387                                continue;
 388
 389                        consume_shallow_list(args, fd[0]);
 390                        do {
 391                                ack = get_ack(fd[0], result_oid);
 392                                if (ack)
 393                                        print_verbose(args, _("got %s %d %s"), "ack",
 394                                                      ack, oid_to_hex(result_oid));
 395                                switch (ack) {
 396                                case ACK:
 397                                        flushes = 0;
 398                                        multi_ack = 0;
 399                                        retval = 0;
 400                                        goto done;
 401                                case ACK_common:
 402                                case ACK_ready:
 403                                case ACK_continue: {
 404                                        struct commit *commit =
 405                                                lookup_commit(result_oid);
 406                                        int was_common;
 407                                        if (!commit)
 408                                                die(_("invalid commit %s"), oid_to_hex(result_oid));
 409                                        was_common = negotiator->ack(negotiator, commit);
 410                                        if (args->stateless_rpc
 411                                         && ack == ACK_common
 412                                         && !was_common) {
 413                                                /* We need to replay the have for this object
 414                                                 * on the next RPC request so the peer knows
 415                                                 * it is in common with us.
 416                                                 */
 417                                                const char *hex = oid_to_hex(result_oid);
 418                                                packet_buf_write(&req_buf, "have %s\n", hex);
 419                                                state_len = req_buf.len;
 420                                                /*
 421                                                 * Reset in_vain because an ack
 422                                                 * for this commit has not been
 423                                                 * seen.
 424                                                 */
 425                                                in_vain = 0;
 426                                        } else if (!args->stateless_rpc
 427                                                   || ack != ACK_common)
 428                                                in_vain = 0;
 429                                        retval = 0;
 430                                        got_continue = 1;
 431                                        if (ack == ACK_ready)
 432                                                got_ready = 1;
 433                                        break;
 434                                        }
 435                                }
 436                        } while (ack);
 437                        flushes--;
 438                        if (got_continue && MAX_IN_VAIN < in_vain) {
 439                                print_verbose(args, _("giving up"));
 440                                break; /* give up */
 441                        }
 442                        if (got_ready)
 443                                break;
 444                }
 445        }
 446done:
 447        if (!got_ready || !no_done) {
 448                packet_buf_write(&req_buf, "done\n");
 449                send_request(args, fd[1], &req_buf);
 450        }
 451        print_verbose(args, _("done"));
 452        if (retval != 0) {
 453                multi_ack = 0;
 454                flushes++;
 455        }
 456        strbuf_release(&req_buf);
 457
 458        if (!got_ready || !no_done)
 459                consume_shallow_list(args, fd[0]);
 460        while (flushes || multi_ack) {
 461                int ack = get_ack(fd[0], result_oid);
 462                if (ack) {
 463                        print_verbose(args, _("got %s (%d) %s"), "ack",
 464                                      ack, oid_to_hex(result_oid));
 465                        if (ack == ACK)
 466                                return 0;
 467                        multi_ack = 1;
 468                        continue;
 469                }
 470                flushes--;
 471        }
 472        /* it is no error to fetch into a completely empty repo */
 473        return count ? retval : 0;
 474}
 475
 476static struct commit_list *complete;
 477
 478static int mark_complete(const struct object_id *oid)
 479{
 480        struct object *o = parse_object(oid);
 481
 482        while (o && o->type == OBJ_TAG) {
 483                struct tag *t = (struct tag *) o;
 484                if (!t->tagged)
 485                        break; /* broken repository */
 486                o->flags |= COMPLETE;
 487                o = parse_object(&t->tagged->oid);
 488        }
 489        if (o && o->type == OBJ_COMMIT) {
 490                struct commit *commit = (struct commit *)o;
 491                if (!(commit->object.flags & COMPLETE)) {
 492                        commit->object.flags |= COMPLETE;
 493                        commit_list_insert(commit, &complete);
 494                }
 495        }
 496        return 0;
 497}
 498
 499static int mark_complete_oid(const char *refname, const struct object_id *oid,
 500                             int flag, void *cb_data)
 501{
 502        return mark_complete(oid);
 503}
 504
 505static void mark_recent_complete_commits(struct fetch_pack_args *args,
 506                                         timestamp_t cutoff)
 507{
 508        while (complete && cutoff <= complete->item->date) {
 509                print_verbose(args, _("Marking %s as complete"),
 510                              oid_to_hex(&complete->item->object.oid));
 511                pop_most_recent_commit(&complete, COMPLETE);
 512        }
 513}
 514
 515static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 516{
 517        for (; refs; refs = refs->next)
 518                oidset_insert(oids, &refs->old_oid);
 519}
 520
 521static int tip_oids_contain(struct oidset *tip_oids,
 522                            struct ref *unmatched, struct ref *newlist,
 523                            const struct object_id *id)
 524{
 525        /*
 526         * Note that this only looks at the ref lists the first time it's
 527         * called. This works out in filter_refs() because even though it may
 528         * add to "newlist" between calls, the additions will always be for
 529         * oids that are already in the set.
 530         */
 531        if (!tip_oids->map.map.tablesize) {
 532                add_refs_to_oidset(tip_oids, unmatched);
 533                add_refs_to_oidset(tip_oids, newlist);
 534        }
 535        return oidset_contains(tip_oids, id);
 536}
 537
 538static void filter_refs(struct fetch_pack_args *args,
 539                        struct ref **refs,
 540                        struct ref **sought, int nr_sought)
 541{
 542        struct ref *newlist = NULL;
 543        struct ref **newtail = &newlist;
 544        struct ref *unmatched = NULL;
 545        struct ref *ref, *next;
 546        struct oidset tip_oids = OIDSET_INIT;
 547        int i;
 548
 549        i = 0;
 550        for (ref = *refs; ref; ref = next) {
 551                int keep = 0;
 552                next = ref->next;
 553
 554                if (starts_with(ref->name, "refs/") &&
 555                    check_refname_format(ref->name, 0))
 556                        ; /* trash */
 557                else {
 558                        while (i < nr_sought) {
 559                                int cmp = strcmp(ref->name, sought[i]->name);
 560                                if (cmp < 0)
 561                                        break; /* definitely do not have it */
 562                                else if (cmp == 0) {
 563                                        keep = 1; /* definitely have it */
 564                                        sought[i]->match_status = REF_MATCHED;
 565                                }
 566                                i++;
 567                        }
 568                }
 569
 570                if (!keep && args->fetch_all &&
 571                    (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 572                        keep = 1;
 573
 574                if (keep) {
 575                        *newtail = ref;
 576                        ref->next = NULL;
 577                        newtail = &ref->next;
 578                } else {
 579                        ref->next = unmatched;
 580                        unmatched = ref;
 581                }
 582        }
 583
 584        /* Append unmatched requests to the list */
 585        for (i = 0; i < nr_sought; i++) {
 586                struct object_id oid;
 587                const char *p;
 588
 589                ref = sought[i];
 590                if (ref->match_status != REF_NOT_MATCHED)
 591                        continue;
 592                if (parse_oid_hex(ref->name, &oid, &p) ||
 593                    *p != '\0' ||
 594                    oidcmp(&oid, &ref->old_oid))
 595                        continue;
 596
 597                if ((allow_unadvertised_object_request &
 598                     (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1)) ||
 599                    tip_oids_contain(&tip_oids, unmatched, newlist,
 600                                     &ref->old_oid)) {
 601                        ref->match_status = REF_MATCHED;
 602                        *newtail = copy_ref(ref);
 603                        newtail = &(*newtail)->next;
 604                } else {
 605                        ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 606                }
 607        }
 608
 609        oidset_clear(&tip_oids);
 610        for (ref = unmatched; ref; ref = next) {
 611                next = ref->next;
 612                free(ref);
 613        }
 614
 615        *refs = newlist;
 616}
 617
 618static void mark_alternate_complete(struct fetch_negotiator *unused,
 619                                    struct object *obj)
 620{
 621        mark_complete(&obj->oid);
 622}
 623
 624struct loose_object_iter {
 625        struct oidset *loose_object_set;
 626        struct ref *refs;
 627};
 628
 629/*
 630 *  If the number of refs is not larger than the number of loose objects,
 631 *  this function stops inserting.
 632 */
 633static int add_loose_objects_to_set(const struct object_id *oid,
 634                                    const char *path,
 635                                    void *data)
 636{
 637        struct loose_object_iter *iter = data;
 638        oidset_insert(iter->loose_object_set, oid);
 639        if (iter->refs == NULL)
 640                return 1;
 641
 642        iter->refs = iter->refs->next;
 643        return 0;
 644}
 645
 646/*
 647 * Mark recent commits available locally and reachable from a local ref as
 648 * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 649 * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 650 * thus do not need COMMON_REF marks).
 651 *
 652 * The cutoff time for recency is determined by this heuristic: it is the
 653 * earliest commit time of the objects in refs that are commits and that we know
 654 * the commit time of.
 655 */
 656static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 657                                         struct fetch_pack_args *args,
 658                                         struct ref **refs)
 659{
 660        struct ref *ref;
 661        int old_save_commit_buffer = save_commit_buffer;
 662        timestamp_t cutoff = 0;
 663        struct oidset loose_oid_set = OIDSET_INIT;
 664        int use_oidset = 0;
 665        struct loose_object_iter iter = {&loose_oid_set, *refs};
 666
 667        /* Enumerate all loose objects or know refs are not so many. */
 668        use_oidset = !for_each_loose_object(add_loose_objects_to_set,
 669                                            &iter, 0);
 670
 671        save_commit_buffer = 0;
 672
 673        for (ref = *refs; ref; ref = ref->next) {
 674                struct object *o;
 675                unsigned int flags = OBJECT_INFO_QUICK;
 676
 677                if (use_oidset &&
 678                    !oidset_contains(&loose_oid_set, &ref->old_oid)) {
 679                        /*
 680                         * I know this does not exist in the loose form,
 681                         * so check if it exists in a non-loose form.
 682                         */
 683                        flags |= OBJECT_INFO_IGNORE_LOOSE;
 684                }
 685
 686                if (!has_object_file_with_flags(&ref->old_oid, flags))
 687                        continue;
 688                o = parse_object(&ref->old_oid);
 689                if (!o)
 690                        continue;
 691
 692                /* We already have it -- which may mean that we were
 693                 * in sync with the other side at some time after
 694                 * that (it is OK if we guess wrong here).
 695                 */
 696                if (o->type == OBJ_COMMIT) {
 697                        struct commit *commit = (struct commit *)o;
 698                        if (!cutoff || cutoff < commit->date)
 699                                cutoff = commit->date;
 700                }
 701        }
 702
 703        oidset_clear(&loose_oid_set);
 704
 705        if (!args->no_dependents) {
 706                if (!args->deepen) {
 707                        for_each_ref(mark_complete_oid, NULL);
 708                        for_each_cached_alternate(NULL, mark_alternate_complete);
 709                        commit_list_sort_by_date(&complete);
 710                        if (cutoff)
 711                                mark_recent_complete_commits(args, cutoff);
 712                }
 713
 714                /*
 715                 * Mark all complete remote refs as common refs.
 716                 * Don't mark them common yet; the server has to be told so first.
 717                 */
 718                for (ref = *refs; ref; ref = ref->next) {
 719                        struct object *o = deref_tag(lookup_object(ref->old_oid.hash),
 720                                                     NULL, 0);
 721
 722                        if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 723                                continue;
 724
 725                        negotiator->known_common(negotiator,
 726                                                 (struct commit *)o);
 727                }
 728        }
 729
 730        save_commit_buffer = old_save_commit_buffer;
 731}
 732
 733/*
 734 * Returns 1 if every object pointed to by the given remote refs is available
 735 * locally and reachable from a local ref, and 0 otherwise.
 736 */
 737static int everything_local(struct fetch_pack_args *args,
 738                            struct ref **refs)
 739{
 740        struct ref *ref;
 741        int retval;
 742
 743        for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 744                const struct object_id *remote = &ref->old_oid;
 745                struct object *o;
 746
 747                o = lookup_object(remote->hash);
 748                if (!o || !(o->flags & COMPLETE)) {
 749                        retval = 0;
 750                        print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 751                                      ref->name);
 752                        continue;
 753                }
 754                print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 755                              ref->name);
 756        }
 757
 758        return retval;
 759}
 760
 761static int sideband_demux(int in, int out, void *data)
 762{
 763        int *xd = data;
 764        int ret;
 765
 766        ret = recv_sideband("fetch-pack", xd[0], out);
 767        close(out);
 768        return ret;
 769}
 770
 771static int get_pack(struct fetch_pack_args *args,
 772                    int xd[2], char **pack_lockfile)
 773{
 774        struct async demux;
 775        int do_keep = args->keep_pack;
 776        const char *cmd_name;
 777        struct pack_header header;
 778        int pass_header = 0;
 779        struct child_process cmd = CHILD_PROCESS_INIT;
 780        int ret;
 781
 782        memset(&demux, 0, sizeof(demux));
 783        if (use_sideband) {
 784                /* xd[] is talking with upload-pack; subprocess reads from
 785                 * xd[0], spits out band#2 to stderr, and feeds us band#1
 786                 * through demux->out.
 787                 */
 788                demux.proc = sideband_demux;
 789                demux.data = xd;
 790                demux.out = -1;
 791                demux.isolate_sigpipe = 1;
 792                if (start_async(&demux))
 793                        die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 794        }
 795        else
 796                demux.out = xd[0];
 797
 798        if (!args->keep_pack && unpack_limit) {
 799
 800                if (read_pack_header(demux.out, &header))
 801                        die(_("protocol error: bad pack header"));
 802                pass_header = 1;
 803                if (ntohl(header.hdr_entries) < unpack_limit)
 804                        do_keep = 0;
 805                else
 806                        do_keep = 1;
 807        }
 808
 809        if (alternate_shallow_file) {
 810                argv_array_push(&cmd.args, "--shallow-file");
 811                argv_array_push(&cmd.args, alternate_shallow_file);
 812        }
 813
 814        if (do_keep || args->from_promisor) {
 815                if (pack_lockfile)
 816                        cmd.out = -1;
 817                cmd_name = "index-pack";
 818                argv_array_push(&cmd.args, cmd_name);
 819                argv_array_push(&cmd.args, "--stdin");
 820                if (!args->quiet && !args->no_progress)
 821                        argv_array_push(&cmd.args, "-v");
 822                if (args->use_thin_pack)
 823                        argv_array_push(&cmd.args, "--fix-thin");
 824                if (do_keep && (args->lock_pack || unpack_limit)) {
 825                        char hostname[HOST_NAME_MAX + 1];
 826                        if (xgethostname(hostname, sizeof(hostname)))
 827                                xsnprintf(hostname, sizeof(hostname), "localhost");
 828                        argv_array_pushf(&cmd.args,
 829                                        "--keep=fetch-pack %"PRIuMAX " on %s",
 830                                        (uintmax_t)getpid(), hostname);
 831                }
 832                if (args->check_self_contained_and_connected)
 833                        argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 834                if (args->from_promisor)
 835                        argv_array_push(&cmd.args, "--promisor");
 836        }
 837        else {
 838                cmd_name = "unpack-objects";
 839                argv_array_push(&cmd.args, cmd_name);
 840                if (args->quiet || args->no_progress)
 841                        argv_array_push(&cmd.args, "-q");
 842                args->check_self_contained_and_connected = 0;
 843        }
 844
 845        if (pass_header)
 846                argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 847                                 ntohl(header.hdr_version),
 848                                 ntohl(header.hdr_entries));
 849        if (fetch_fsck_objects >= 0
 850            ? fetch_fsck_objects
 851            : transfer_fsck_objects >= 0
 852            ? transfer_fsck_objects
 853            : 0) {
 854                if (args->from_promisor)
 855                        /*
 856                         * We cannot use --strict in index-pack because it
 857                         * checks both broken objects and links, but we only
 858                         * want to check for broken objects.
 859                         */
 860                        argv_array_push(&cmd.args, "--fsck-objects");
 861                else
 862                        argv_array_push(&cmd.args, "--strict");
 863        }
 864
 865        cmd.in = demux.out;
 866        cmd.git_cmd = 1;
 867        if (start_command(&cmd))
 868                die(_("fetch-pack: unable to fork off %s"), cmd_name);
 869        if (do_keep && pack_lockfile) {
 870                *pack_lockfile = index_pack_lockfile(cmd.out);
 871                close(cmd.out);
 872        }
 873
 874        if (!use_sideband)
 875                /* Closed by start_command() */
 876                xd[0] = -1;
 877
 878        ret = finish_command(&cmd);
 879        if (!ret || (args->check_self_contained_and_connected && ret == 1))
 880                args->self_contained_and_connected =
 881                        args->check_self_contained_and_connected &&
 882                        ret == 0;
 883        else
 884                die(_("%s failed"), cmd_name);
 885        if (use_sideband && finish_async(&demux))
 886                die(_("error in sideband demultiplexer"));
 887        return 0;
 888}
 889
 890static int cmp_ref_by_name(const void *a_, const void *b_)
 891{
 892        const struct ref *a = *((const struct ref **)a_);
 893        const struct ref *b = *((const struct ref **)b_);
 894        return strcmp(a->name, b->name);
 895}
 896
 897static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 898                                 int fd[2],
 899                                 const struct ref *orig_ref,
 900                                 struct ref **sought, int nr_sought,
 901                                 struct shallow_info *si,
 902                                 char **pack_lockfile)
 903{
 904        struct ref *ref = copy_ref_list(orig_ref);
 905        struct object_id oid;
 906        const char *agent_feature;
 907        int agent_len;
 908        struct fetch_negotiator negotiator;
 909        fetch_negotiator_init(&negotiator, negotiation_algorithm);
 910
 911        sort_ref_list(&ref, ref_compare_name);
 912        QSORT(sought, nr_sought, cmp_ref_by_name);
 913
 914        if ((args->depth > 0 || is_repository_shallow()) && !server_supports("shallow"))
 915                die(_("Server does not support shallow clients"));
 916        if (args->depth > 0 || args->deepen_since || args->deepen_not)
 917                args->deepen = 1;
 918        if (server_supports("multi_ack_detailed")) {
 919                print_verbose(args, _("Server supports multi_ack_detailed"));
 920                multi_ack = 2;
 921                if (server_supports("no-done")) {
 922                        print_verbose(args, _("Server supports no-done"));
 923                        if (args->stateless_rpc)
 924                                no_done = 1;
 925                }
 926        }
 927        else if (server_supports("multi_ack")) {
 928                print_verbose(args, _("Server supports multi_ack"));
 929                multi_ack = 1;
 930        }
 931        if (server_supports("side-band-64k")) {
 932                print_verbose(args, _("Server supports side-band-64k"));
 933                use_sideband = 2;
 934        }
 935        else if (server_supports("side-band")) {
 936                print_verbose(args, _("Server supports side-band"));
 937                use_sideband = 1;
 938        }
 939        if (server_supports("allow-tip-sha1-in-want")) {
 940                print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 941                allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 942        }
 943        if (server_supports("allow-reachable-sha1-in-want")) {
 944                print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 945                allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 946        }
 947        if (!server_supports("thin-pack"))
 948                args->use_thin_pack = 0;
 949        if (!server_supports("no-progress"))
 950                args->no_progress = 0;
 951        if (!server_supports("include-tag"))
 952                args->include_tag = 0;
 953        if (server_supports("ofs-delta"))
 954                print_verbose(args, _("Server supports ofs-delta"));
 955        else
 956                prefer_ofs_delta = 0;
 957
 958        if (server_supports("filter")) {
 959                server_supports_filtering = 1;
 960                print_verbose(args, _("Server supports filter"));
 961        } else if (args->filter_options.choice) {
 962                warning("filtering not recognized by server, ignoring");
 963        }
 964
 965        if ((agent_feature = server_feature_value("agent", &agent_len))) {
 966                agent_supported = 1;
 967                if (agent_len)
 968                        print_verbose(args, _("Server version is %.*s"),
 969                                      agent_len, agent_feature);
 970        }
 971        if (server_supports("deepen-since"))
 972                deepen_since_ok = 1;
 973        else if (args->deepen_since)
 974                die(_("Server does not support --shallow-since"));
 975        if (server_supports("deepen-not"))
 976                deepen_not_ok = 1;
 977        else if (args->deepen_not)
 978                die(_("Server does not support --shallow-exclude"));
 979        if (!server_supports("deepen-relative") && args->deepen_relative)
 980                die(_("Server does not support --deepen"));
 981
 982        mark_complete_and_common_ref(&negotiator, args, &ref);
 983        filter_refs(args, &ref, sought, nr_sought);
 984        if (everything_local(args, &ref)) {
 985                packet_flush(fd[1]);
 986                goto all_done;
 987        }
 988        if (find_common(&negotiator, args, fd, &oid, ref) < 0)
 989                if (!args->keep_pack)
 990                        /* When cloning, it is not unusual to have
 991                         * no common commit.
 992                         */
 993                        warning(_("no common commits"));
 994
 995        if (args->stateless_rpc)
 996                packet_flush(fd[1]);
 997        if (args->deepen)
 998                setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
 999                                        NULL);
1000        else if (si->nr_ours || si->nr_theirs)
1001                alternate_shallow_file = setup_temporary_shallow(si->shallow);
1002        else
1003                alternate_shallow_file = NULL;
1004        if (get_pack(args, fd, pack_lockfile))
1005                die(_("git fetch-pack: fetch failed."));
1006
1007 all_done:
1008        negotiator.release(&negotiator);
1009        return ref;
1010}
1011
1012static void add_shallow_requests(struct strbuf *req_buf,
1013                                 const struct fetch_pack_args *args)
1014{
1015        if (is_repository_shallow())
1016                write_shallow_commits(req_buf, 1, NULL);
1017        if (args->depth > 0)
1018                packet_buf_write(req_buf, "deepen %d", args->depth);
1019        if (args->deepen_since) {
1020                timestamp_t max_age = approxidate(args->deepen_since);
1021                packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1022        }
1023        if (args->deepen_not) {
1024                int i;
1025                for (i = 0; i < args->deepen_not->nr; i++) {
1026                        struct string_list_item *s = args->deepen_not->items + i;
1027                        packet_buf_write(req_buf, "deepen-not %s", s->string);
1028                }
1029        }
1030}
1031
1032static void add_wants(const struct ref *wants, struct strbuf *req_buf)
1033{
1034        for ( ; wants ; wants = wants->next) {
1035                const struct object_id *remote = &wants->old_oid;
1036                const char *remote_hex;
1037                struct object *o;
1038
1039                /*
1040                 * If that object is complete (i.e. it is an ancestor of a
1041                 * local ref), we tell them we have it but do not have to
1042                 * tell them about its ancestors, which they already know
1043                 * about.
1044                 *
1045                 * We use lookup_object here because we are only
1046                 * interested in the case we *know* the object is
1047                 * reachable and we have already scanned it.
1048                 */
1049                if (((o = lookup_object(remote->hash)) != NULL) &&
1050                    (o->flags & COMPLETE)) {
1051                        continue;
1052                }
1053
1054                remote_hex = oid_to_hex(remote);
1055                packet_buf_write(req_buf, "want %s\n", remote_hex);
1056        }
1057}
1058
1059static void add_common(struct strbuf *req_buf, struct oidset *common)
1060{
1061        struct oidset_iter iter;
1062        const struct object_id *oid;
1063        oidset_iter_init(common, &iter);
1064
1065        while ((oid = oidset_iter_next(&iter))) {
1066                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1067        }
1068}
1069
1070static int add_haves(struct fetch_negotiator *negotiator,
1071                     struct strbuf *req_buf,
1072                     int *haves_to_send, int *in_vain)
1073{
1074        int ret = 0;
1075        int haves_added = 0;
1076        const struct object_id *oid;
1077
1078        while ((oid = negotiator->next(negotiator))) {
1079                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1080                if (++haves_added >= *haves_to_send)
1081                        break;
1082        }
1083
1084        *in_vain += haves_added;
1085        if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1086                /* Send Done */
1087                packet_buf_write(req_buf, "done\n");
1088                ret = 1;
1089        }
1090
1091        /* Increase haves to send on next round */
1092        *haves_to_send = next_flush(1, *haves_to_send);
1093
1094        return ret;
1095}
1096
1097static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1098                              const struct fetch_pack_args *args,
1099                              const struct ref *wants, struct oidset *common,
1100                              int *haves_to_send, int *in_vain)
1101{
1102        int ret = 0;
1103        struct strbuf req_buf = STRBUF_INIT;
1104
1105        if (server_supports_v2("fetch", 1))
1106                packet_buf_write(&req_buf, "command=fetch");
1107        if (server_supports_v2("agent", 0))
1108                packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1109        if (args->server_options && args->server_options->nr &&
1110            server_supports_v2("server-option", 1)) {
1111                int i;
1112                for (i = 0; i < args->server_options->nr; i++)
1113                        packet_write_fmt(fd_out, "server-option=%s",
1114                                         args->server_options->items[i].string);
1115        }
1116
1117        packet_buf_delim(&req_buf);
1118        if (args->use_thin_pack)
1119                packet_buf_write(&req_buf, "thin-pack");
1120        if (args->no_progress)
1121                packet_buf_write(&req_buf, "no-progress");
1122        if (args->include_tag)
1123                packet_buf_write(&req_buf, "include-tag");
1124        if (prefer_ofs_delta)
1125                packet_buf_write(&req_buf, "ofs-delta");
1126
1127        /* Add shallow-info and deepen request */
1128        if (server_supports_feature("fetch", "shallow", 0))
1129                add_shallow_requests(&req_buf, args);
1130        else if (is_repository_shallow() || args->deepen)
1131                die(_("Server does not support shallow requests"));
1132
1133        /* Add filter */
1134        if (server_supports_feature("fetch", "filter", 0) &&
1135            args->filter_options.choice) {
1136                print_verbose(args, _("Server supports filter"));
1137                packet_buf_write(&req_buf, "filter %s",
1138                                 args->filter_options.filter_spec);
1139        } else if (args->filter_options.choice) {
1140                warning("filtering not recognized by server, ignoring");
1141        }
1142
1143        /* add wants */
1144        add_wants(wants, &req_buf);
1145
1146        if (args->no_dependents) {
1147                packet_buf_write(&req_buf, "done");
1148                ret = 1;
1149        } else {
1150                /* Add all of the common commits we've found in previous rounds */
1151                add_common(&req_buf, common);
1152
1153                /* Add initial haves */
1154                ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1155        }
1156
1157        /* Send request */
1158        packet_buf_flush(&req_buf);
1159        write_or_die(fd_out, req_buf.buf, req_buf.len);
1160
1161        strbuf_release(&req_buf);
1162        return ret;
1163}
1164
1165/*
1166 * Processes a section header in a server's response and checks if it matches
1167 * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1168 * not consumed); if 0, the line will be consumed and the function will die if
1169 * the section header doesn't match what was expected.
1170 */
1171static int process_section_header(struct packet_reader *reader,
1172                                  const char *section, int peek)
1173{
1174        int ret;
1175
1176        if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1177                die("error reading section header '%s'", section);
1178
1179        ret = !strcmp(reader->line, section);
1180
1181        if (!peek) {
1182                if (!ret)
1183                        die("expected '%s', received '%s'",
1184                            section, reader->line);
1185                packet_reader_read(reader);
1186        }
1187
1188        return ret;
1189}
1190
1191static int process_acks(struct fetch_negotiator *negotiator,
1192                        struct packet_reader *reader,
1193                        struct oidset *common)
1194{
1195        /* received */
1196        int received_ready = 0;
1197        int received_ack = 0;
1198
1199        process_section_header(reader, "acknowledgments", 0);
1200        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1201                const char *arg;
1202
1203                if (!strcmp(reader->line, "NAK"))
1204                        continue;
1205
1206                if (skip_prefix(reader->line, "ACK ", &arg)) {
1207                        struct object_id oid;
1208                        if (!get_oid_hex(arg, &oid)) {
1209                                struct commit *commit;
1210                                oidset_insert(common, &oid);
1211                                commit = lookup_commit(&oid);
1212                                negotiator->ack(negotiator, commit);
1213                        }
1214                        continue;
1215                }
1216
1217                if (!strcmp(reader->line, "ready")) {
1218                        received_ready = 1;
1219                        continue;
1220                }
1221
1222                die("unexpected acknowledgment line: '%s'", reader->line);
1223        }
1224
1225        if (reader->status != PACKET_READ_FLUSH &&
1226            reader->status != PACKET_READ_DELIM)
1227                die("error processing acks: %d", reader->status);
1228
1229        /* return 0 if no common, 1 if there are common, or 2 if ready */
1230        return received_ready ? 2 : (received_ack ? 1 : 0);
1231}
1232
1233static void receive_shallow_info(struct fetch_pack_args *args,
1234                                 struct packet_reader *reader)
1235{
1236        process_section_header(reader, "shallow-info", 0);
1237        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1238                const char *arg;
1239                struct object_id oid;
1240
1241                if (skip_prefix(reader->line, "shallow ", &arg)) {
1242                        if (get_oid_hex(arg, &oid))
1243                                die(_("invalid shallow line: %s"), reader->line);
1244                        register_shallow(&oid);
1245                        continue;
1246                }
1247                if (skip_prefix(reader->line, "unshallow ", &arg)) {
1248                        if (get_oid_hex(arg, &oid))
1249                                die(_("invalid unshallow line: %s"), reader->line);
1250                        if (!lookup_object(oid.hash))
1251                                die(_("object not found: %s"), reader->line);
1252                        /* make sure that it is parsed as shallow */
1253                        if (!parse_object(&oid))
1254                                die(_("error in object: %s"), reader->line);
1255                        if (unregister_shallow(&oid))
1256                                die(_("no shallow found: %s"), reader->line);
1257                        continue;
1258                }
1259                die(_("expected shallow/unshallow, got %s"), reader->line);
1260        }
1261
1262        if (reader->status != PACKET_READ_FLUSH &&
1263            reader->status != PACKET_READ_DELIM)
1264                die("error processing shallow info: %d", reader->status);
1265
1266        setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, NULL);
1267        args->deepen = 1;
1268}
1269
1270enum fetch_state {
1271        FETCH_CHECK_LOCAL = 0,
1272        FETCH_SEND_REQUEST,
1273        FETCH_PROCESS_ACKS,
1274        FETCH_GET_PACK,
1275        FETCH_DONE,
1276};
1277
1278static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1279                                    int fd[2],
1280                                    const struct ref *orig_ref,
1281                                    struct ref **sought, int nr_sought,
1282                                    char **pack_lockfile)
1283{
1284        struct ref *ref = copy_ref_list(orig_ref);
1285        enum fetch_state state = FETCH_CHECK_LOCAL;
1286        struct oidset common = OIDSET_INIT;
1287        struct packet_reader reader;
1288        int in_vain = 0;
1289        int haves_to_send = INITIAL_FLUSH;
1290        struct fetch_negotiator negotiator;
1291        fetch_negotiator_init(&negotiator, negotiation_algorithm);
1292        packet_reader_init(&reader, fd[0], NULL, 0,
1293                           PACKET_READ_CHOMP_NEWLINE);
1294
1295        while (state != FETCH_DONE) {
1296                switch (state) {
1297                case FETCH_CHECK_LOCAL:
1298                        sort_ref_list(&ref, ref_compare_name);
1299                        QSORT(sought, nr_sought, cmp_ref_by_name);
1300
1301                        /* v2 supports these by default */
1302                        allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1303                        use_sideband = 2;
1304                        if (args->depth > 0 || args->deepen_since || args->deepen_not)
1305                                args->deepen = 1;
1306
1307                        /* Filter 'ref' by 'sought' and those that aren't local */
1308                        mark_complete_and_common_ref(&negotiator, args, &ref);
1309                        filter_refs(args, &ref, sought, nr_sought);
1310                        if (everything_local(args, &ref))
1311                                state = FETCH_DONE;
1312                        else
1313                                state = FETCH_SEND_REQUEST;
1314
1315                        mark_tips(&negotiator, args->negotiation_tips);
1316                        for_each_cached_alternate(&negotiator,
1317                                                  insert_one_alternate_object);
1318                        break;
1319                case FETCH_SEND_REQUEST:
1320                        if (send_fetch_request(&negotiator, fd[1], args, ref,
1321                                               &common,
1322                                               &haves_to_send, &in_vain))
1323                                state = FETCH_GET_PACK;
1324                        else
1325                                state = FETCH_PROCESS_ACKS;
1326                        break;
1327                case FETCH_PROCESS_ACKS:
1328                        /* Process ACKs/NAKs */
1329                        switch (process_acks(&negotiator, &reader, &common)) {
1330                        case 2:
1331                                state = FETCH_GET_PACK;
1332                                break;
1333                        case 1:
1334                                in_vain = 0;
1335                                /* fallthrough */
1336                        default:
1337                                state = FETCH_SEND_REQUEST;
1338                                break;
1339                        }
1340                        break;
1341                case FETCH_GET_PACK:
1342                        /* Check for shallow-info section */
1343                        if (process_section_header(&reader, "shallow-info", 1))
1344                                receive_shallow_info(args, &reader);
1345
1346                        /* get the pack */
1347                        process_section_header(&reader, "packfile", 0);
1348                        if (get_pack(args, fd, pack_lockfile))
1349                                die(_("git fetch-pack: fetch failed."));
1350
1351                        state = FETCH_DONE;
1352                        break;
1353                case FETCH_DONE:
1354                        continue;
1355                }
1356        }
1357
1358        negotiator.release(&negotiator);
1359        oidset_clear(&common);
1360        return ref;
1361}
1362
1363static void fetch_pack_config(void)
1364{
1365        git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1366        git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1367        git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1368        git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1369        git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1370        git_config_get_string("fetch.negotiationalgorithm",
1371                              &negotiation_algorithm);
1372
1373        git_config(git_default_config, NULL);
1374}
1375
1376static void fetch_pack_setup(void)
1377{
1378        static int did_setup;
1379        if (did_setup)
1380                return;
1381        fetch_pack_config();
1382        if (0 <= transfer_unpack_limit)
1383                unpack_limit = transfer_unpack_limit;
1384        else if (0 <= fetch_unpack_limit)
1385                unpack_limit = fetch_unpack_limit;
1386        did_setup = 1;
1387}
1388
1389static int remove_duplicates_in_refs(struct ref **ref, int nr)
1390{
1391        struct string_list names = STRING_LIST_INIT_NODUP;
1392        int src, dst;
1393
1394        for (src = dst = 0; src < nr; src++) {
1395                struct string_list_item *item;
1396                item = string_list_insert(&names, ref[src]->name);
1397                if (item->util)
1398                        continue; /* already have it */
1399                item->util = ref[src];
1400                if (src != dst)
1401                        ref[dst] = ref[src];
1402                dst++;
1403        }
1404        for (src = dst; src < nr; src++)
1405                ref[src] = NULL;
1406        string_list_clear(&names, 0);
1407        return dst;
1408}
1409
1410static void update_shallow(struct fetch_pack_args *args,
1411                           struct ref **sought, int nr_sought,
1412                           struct shallow_info *si)
1413{
1414        struct oid_array ref = OID_ARRAY_INIT;
1415        int *status;
1416        int i;
1417
1418        if (args->deepen && alternate_shallow_file) {
1419                if (*alternate_shallow_file == '\0') { /* --unshallow */
1420                        unlink_or_warn(git_path_shallow());
1421                        rollback_lock_file(&shallow_lock);
1422                } else
1423                        commit_lock_file(&shallow_lock);
1424                return;
1425        }
1426
1427        if (!si->shallow || !si->shallow->nr)
1428                return;
1429
1430        if (args->cloning) {
1431                /*
1432                 * remote is shallow, but this is a clone, there are
1433                 * no objects in repo to worry about. Accept any
1434                 * shallow points that exist in the pack (iow in repo
1435                 * after get_pack() and reprepare_packed_git())
1436                 */
1437                struct oid_array extra = OID_ARRAY_INIT;
1438                struct object_id *oid = si->shallow->oid;
1439                for (i = 0; i < si->shallow->nr; i++)
1440                        if (has_object_file(&oid[i]))
1441                                oid_array_append(&extra, &oid[i]);
1442                if (extra.nr) {
1443                        setup_alternate_shallow(&shallow_lock,
1444                                                &alternate_shallow_file,
1445                                                &extra);
1446                        commit_lock_file(&shallow_lock);
1447                }
1448                oid_array_clear(&extra);
1449                return;
1450        }
1451
1452        if (!si->nr_ours && !si->nr_theirs)
1453                return;
1454
1455        remove_nonexistent_theirs_shallow(si);
1456        if (!si->nr_ours && !si->nr_theirs)
1457                return;
1458        for (i = 0; i < nr_sought; i++)
1459                oid_array_append(&ref, &sought[i]->old_oid);
1460        si->ref = &ref;
1461
1462        if (args->update_shallow) {
1463                /*
1464                 * remote is also shallow, .git/shallow may be updated
1465                 * so all refs can be accepted. Make sure we only add
1466                 * shallow roots that are actually reachable from new
1467                 * refs.
1468                 */
1469                struct oid_array extra = OID_ARRAY_INIT;
1470                struct object_id *oid = si->shallow->oid;
1471                assign_shallow_commits_to_refs(si, NULL, NULL);
1472                if (!si->nr_ours && !si->nr_theirs) {
1473                        oid_array_clear(&ref);
1474                        return;
1475                }
1476                for (i = 0; i < si->nr_ours; i++)
1477                        oid_array_append(&extra, &oid[si->ours[i]]);
1478                for (i = 0; i < si->nr_theirs; i++)
1479                        oid_array_append(&extra, &oid[si->theirs[i]]);
1480                setup_alternate_shallow(&shallow_lock,
1481                                        &alternate_shallow_file,
1482                                        &extra);
1483                commit_lock_file(&shallow_lock);
1484                oid_array_clear(&extra);
1485                oid_array_clear(&ref);
1486                return;
1487        }
1488
1489        /*
1490         * remote is also shallow, check what ref is safe to update
1491         * without updating .git/shallow
1492         */
1493        status = xcalloc(nr_sought, sizeof(*status));
1494        assign_shallow_commits_to_refs(si, NULL, status);
1495        if (si->nr_ours || si->nr_theirs) {
1496                for (i = 0; i < nr_sought; i++)
1497                        if (status[i])
1498                                sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1499        }
1500        free(status);
1501        oid_array_clear(&ref);
1502}
1503
1504struct ref *fetch_pack(struct fetch_pack_args *args,
1505                       int fd[], struct child_process *conn,
1506                       const struct ref *ref,
1507                       const char *dest,
1508                       struct ref **sought, int nr_sought,
1509                       struct oid_array *shallow,
1510                       char **pack_lockfile,
1511                       enum protocol_version version)
1512{
1513        struct ref *ref_cpy;
1514        struct shallow_info si;
1515
1516        fetch_pack_setup();
1517        if (nr_sought)
1518                nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1519
1520        if (!ref) {
1521                packet_flush(fd[1]);
1522                die(_("no matching remote head"));
1523        }
1524        prepare_shallow_info(&si, shallow);
1525        if (version == protocol_v2)
1526                ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1527                                           pack_lockfile);
1528        else
1529                ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1530                                        &si, pack_lockfile);
1531        reprepare_packed_git(the_repository);
1532        update_shallow(args, sought, nr_sought, &si);
1533        clear_shallow_info(&si);
1534        return ref_cpy;
1535}
1536
1537int report_unmatched_refs(struct ref **sought, int nr_sought)
1538{
1539        int i, ret = 0;
1540
1541        for (i = 0; i < nr_sought; i++) {
1542                if (!sought[i])
1543                        continue;
1544                switch (sought[i]->match_status) {
1545                case REF_MATCHED:
1546                        continue;
1547                case REF_NOT_MATCHED:
1548                        error(_("no such remote ref %s"), sought[i]->name);
1549                        break;
1550                case REF_UNADVERTISED_NOT_ALLOWED:
1551                        error(_("Server does not allow request for unadvertised object %s"),
1552                              sought[i]->name);
1553                        break;
1554                }
1555                ret = 1;
1556        }
1557        return ret;
1558}