fetch-pack.con commit negotiator/skipping: skip commits during fetch (42cc748)
   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 int find_common(struct fetch_negotiator *negotiator,
 218                       struct fetch_pack_args *args,
 219                       int fd[2], struct object_id *result_oid,
 220                       struct ref *refs)
 221{
 222        int fetching;
 223        int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 224        const struct object_id *oid;
 225        unsigned in_vain = 0;
 226        int got_continue = 0;
 227        int got_ready = 0;
 228        struct strbuf req_buf = STRBUF_INIT;
 229        size_t state_len = 0;
 230
 231        if (args->stateless_rpc && multi_ack == 1)
 232                die(_("--stateless-rpc requires multi_ack_detailed"));
 233
 234        for_each_ref(rev_list_insert_ref_oid, negotiator);
 235        for_each_cached_alternate(negotiator, insert_one_alternate_object);
 236
 237        fetching = 0;
 238        for ( ; refs ; refs = refs->next) {
 239                struct object_id *remote = &refs->old_oid;
 240                const char *remote_hex;
 241                struct object *o;
 242
 243                /*
 244                 * If that object is complete (i.e. it is an ancestor of a
 245                 * local ref), we tell them we have it but do not have to
 246                 * tell them about its ancestors, which they already know
 247                 * about.
 248                 *
 249                 * We use lookup_object here because we are only
 250                 * interested in the case we *know* the object is
 251                 * reachable and we have already scanned it.
 252                 */
 253                if (((o = lookup_object(remote->hash)) != NULL) &&
 254                                (o->flags & COMPLETE)) {
 255                        continue;
 256                }
 257
 258                remote_hex = oid_to_hex(remote);
 259                if (!fetching) {
 260                        struct strbuf c = STRBUF_INIT;
 261                        if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 262                        if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 263                        if (no_done)            strbuf_addstr(&c, " no-done");
 264                        if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 265                        if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 266                        if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 267                        if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 268                        if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 269                        if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 270                        if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 271                        if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 272                        if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 273                        if (agent_supported)    strbuf_addf(&c, " agent=%s",
 274                                                            git_user_agent_sanitized());
 275                        if (args->filter_options.choice)
 276                                strbuf_addstr(&c, " filter");
 277                        packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 278                        strbuf_release(&c);
 279                } else
 280                        packet_buf_write(&req_buf, "want %s\n", remote_hex);
 281                fetching++;
 282        }
 283
 284        if (!fetching) {
 285                strbuf_release(&req_buf);
 286                packet_flush(fd[1]);
 287                return 1;
 288        }
 289
 290        if (is_repository_shallow())
 291                write_shallow_commits(&req_buf, 1, NULL);
 292        if (args->depth > 0)
 293                packet_buf_write(&req_buf, "deepen %d", args->depth);
 294        if (args->deepen_since) {
 295                timestamp_t max_age = approxidate(args->deepen_since);
 296                packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 297        }
 298        if (args->deepen_not) {
 299                int i;
 300                for (i = 0; i < args->deepen_not->nr; i++) {
 301                        struct string_list_item *s = args->deepen_not->items + i;
 302                        packet_buf_write(&req_buf, "deepen-not %s", s->string);
 303                }
 304        }
 305        if (server_supports_filtering && args->filter_options.choice)
 306                packet_buf_write(&req_buf, "filter %s",
 307                                 args->filter_options.filter_spec);
 308        packet_buf_flush(&req_buf);
 309        state_len = req_buf.len;
 310
 311        if (args->deepen) {
 312                char *line;
 313                const char *arg;
 314                struct object_id oid;
 315
 316                send_request(args, fd[1], &req_buf);
 317                while ((line = packet_read_line(fd[0], NULL))) {
 318                        if (skip_prefix(line, "shallow ", &arg)) {
 319                                if (get_oid_hex(arg, &oid))
 320                                        die(_("invalid shallow line: %s"), line);
 321                                register_shallow(&oid);
 322                                continue;
 323                        }
 324                        if (skip_prefix(line, "unshallow ", &arg)) {
 325                                if (get_oid_hex(arg, &oid))
 326                                        die(_("invalid unshallow line: %s"), line);
 327                                if (!lookup_object(oid.hash))
 328                                        die(_("object not found: %s"), line);
 329                                /* make sure that it is parsed as shallow */
 330                                if (!parse_object(&oid))
 331                                        die(_("error in object: %s"), line);
 332                                if (unregister_shallow(&oid))
 333                                        die(_("no shallow found: %s"), line);
 334                                continue;
 335                        }
 336                        die(_("expected shallow/unshallow, got %s"), line);
 337                }
 338        } else if (!args->stateless_rpc)
 339                send_request(args, fd[1], &req_buf);
 340
 341        if (!args->stateless_rpc) {
 342                /* If we aren't using the stateless-rpc interface
 343                 * we don't need to retain the headers.
 344                 */
 345                strbuf_setlen(&req_buf, 0);
 346                state_len = 0;
 347        }
 348
 349        flushes = 0;
 350        retval = -1;
 351        if (args->no_dependents)
 352                goto done;
 353        while ((oid = negotiator->next(negotiator))) {
 354                packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 355                print_verbose(args, "have %s", oid_to_hex(oid));
 356                in_vain++;
 357                if (flush_at <= ++count) {
 358                        int ack;
 359
 360                        packet_buf_flush(&req_buf);
 361                        send_request(args, fd[1], &req_buf);
 362                        strbuf_setlen(&req_buf, state_len);
 363                        flushes++;
 364                        flush_at = next_flush(args->stateless_rpc, count);
 365
 366                        /*
 367                         * We keep one window "ahead" of the other side, and
 368                         * will wait for an ACK only on the next one
 369                         */
 370                        if (!args->stateless_rpc && count == INITIAL_FLUSH)
 371                                continue;
 372
 373                        consume_shallow_list(args, fd[0]);
 374                        do {
 375                                ack = get_ack(fd[0], result_oid);
 376                                if (ack)
 377                                        print_verbose(args, _("got %s %d %s"), "ack",
 378                                                      ack, oid_to_hex(result_oid));
 379                                switch (ack) {
 380                                case ACK:
 381                                        flushes = 0;
 382                                        multi_ack = 0;
 383                                        retval = 0;
 384                                        goto done;
 385                                case ACK_common:
 386                                case ACK_ready:
 387                                case ACK_continue: {
 388                                        struct commit *commit =
 389                                                lookup_commit(result_oid);
 390                                        int was_common;
 391                                        if (!commit)
 392                                                die(_("invalid commit %s"), oid_to_hex(result_oid));
 393                                        was_common = negotiator->ack(negotiator, commit);
 394                                        if (args->stateless_rpc
 395                                         && ack == ACK_common
 396                                         && !was_common) {
 397                                                /* We need to replay the have for this object
 398                                                 * on the next RPC request so the peer knows
 399                                                 * it is in common with us.
 400                                                 */
 401                                                const char *hex = oid_to_hex(result_oid);
 402                                                packet_buf_write(&req_buf, "have %s\n", hex);
 403                                                state_len = req_buf.len;
 404                                                /*
 405                                                 * Reset in_vain because an ack
 406                                                 * for this commit has not been
 407                                                 * seen.
 408                                                 */
 409                                                in_vain = 0;
 410                                        } else if (!args->stateless_rpc
 411                                                   || ack != ACK_common)
 412                                                in_vain = 0;
 413                                        retval = 0;
 414                                        got_continue = 1;
 415                                        if (ack == ACK_ready)
 416                                                got_ready = 1;
 417                                        break;
 418                                        }
 419                                }
 420                        } while (ack);
 421                        flushes--;
 422                        if (got_continue && MAX_IN_VAIN < in_vain) {
 423                                print_verbose(args, _("giving up"));
 424                                break; /* give up */
 425                        }
 426                        if (got_ready)
 427                                break;
 428                }
 429        }
 430done:
 431        if (!got_ready || !no_done) {
 432                packet_buf_write(&req_buf, "done\n");
 433                send_request(args, fd[1], &req_buf);
 434        }
 435        print_verbose(args, _("done"));
 436        if (retval != 0) {
 437                multi_ack = 0;
 438                flushes++;
 439        }
 440        strbuf_release(&req_buf);
 441
 442        if (!got_ready || !no_done)
 443                consume_shallow_list(args, fd[0]);
 444        while (flushes || multi_ack) {
 445                int ack = get_ack(fd[0], result_oid);
 446                if (ack) {
 447                        print_verbose(args, _("got %s (%d) %s"), "ack",
 448                                      ack, oid_to_hex(result_oid));
 449                        if (ack == ACK)
 450                                return 0;
 451                        multi_ack = 1;
 452                        continue;
 453                }
 454                flushes--;
 455        }
 456        /* it is no error to fetch into a completely empty repo */
 457        return count ? retval : 0;
 458}
 459
 460static struct commit_list *complete;
 461
 462static int mark_complete(const struct object_id *oid)
 463{
 464        struct object *o = parse_object(oid);
 465
 466        while (o && o->type == OBJ_TAG) {
 467                struct tag *t = (struct tag *) o;
 468                if (!t->tagged)
 469                        break; /* broken repository */
 470                o->flags |= COMPLETE;
 471                o = parse_object(&t->tagged->oid);
 472        }
 473        if (o && o->type == OBJ_COMMIT) {
 474                struct commit *commit = (struct commit *)o;
 475                if (!(commit->object.flags & COMPLETE)) {
 476                        commit->object.flags |= COMPLETE;
 477                        commit_list_insert(commit, &complete);
 478                }
 479        }
 480        return 0;
 481}
 482
 483static int mark_complete_oid(const char *refname, const struct object_id *oid,
 484                             int flag, void *cb_data)
 485{
 486        return mark_complete(oid);
 487}
 488
 489static void mark_recent_complete_commits(struct fetch_pack_args *args,
 490                                         timestamp_t cutoff)
 491{
 492        while (complete && cutoff <= complete->item->date) {
 493                print_verbose(args, _("Marking %s as complete"),
 494                              oid_to_hex(&complete->item->object.oid));
 495                pop_most_recent_commit(&complete, COMPLETE);
 496        }
 497}
 498
 499static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 500{
 501        for (; refs; refs = refs->next)
 502                oidset_insert(oids, &refs->old_oid);
 503}
 504
 505static int tip_oids_contain(struct oidset *tip_oids,
 506                            struct ref *unmatched, struct ref *newlist,
 507                            const struct object_id *id)
 508{
 509        /*
 510         * Note that this only looks at the ref lists the first time it's
 511         * called. This works out in filter_refs() because even though it may
 512         * add to "newlist" between calls, the additions will always be for
 513         * oids that are already in the set.
 514         */
 515        if (!tip_oids->map.map.tablesize) {
 516                add_refs_to_oidset(tip_oids, unmatched);
 517                add_refs_to_oidset(tip_oids, newlist);
 518        }
 519        return oidset_contains(tip_oids, id);
 520}
 521
 522static void filter_refs(struct fetch_pack_args *args,
 523                        struct ref **refs,
 524                        struct ref **sought, int nr_sought)
 525{
 526        struct ref *newlist = NULL;
 527        struct ref **newtail = &newlist;
 528        struct ref *unmatched = NULL;
 529        struct ref *ref, *next;
 530        struct oidset tip_oids = OIDSET_INIT;
 531        int i;
 532
 533        i = 0;
 534        for (ref = *refs; ref; ref = next) {
 535                int keep = 0;
 536                next = ref->next;
 537
 538                if (starts_with(ref->name, "refs/") &&
 539                    check_refname_format(ref->name, 0))
 540                        ; /* trash */
 541                else {
 542                        while (i < nr_sought) {
 543                                int cmp = strcmp(ref->name, sought[i]->name);
 544                                if (cmp < 0)
 545                                        break; /* definitely do not have it */
 546                                else if (cmp == 0) {
 547                                        keep = 1; /* definitely have it */
 548                                        sought[i]->match_status = REF_MATCHED;
 549                                }
 550                                i++;
 551                        }
 552                }
 553
 554                if (!keep && args->fetch_all &&
 555                    (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 556                        keep = 1;
 557
 558                if (keep) {
 559                        *newtail = ref;
 560                        ref->next = NULL;
 561                        newtail = &ref->next;
 562                } else {
 563                        ref->next = unmatched;
 564                        unmatched = ref;
 565                }
 566        }
 567
 568        /* Append unmatched requests to the list */
 569        for (i = 0; i < nr_sought; i++) {
 570                struct object_id oid;
 571                const char *p;
 572
 573                ref = sought[i];
 574                if (ref->match_status != REF_NOT_MATCHED)
 575                        continue;
 576                if (parse_oid_hex(ref->name, &oid, &p) ||
 577                    *p != '\0' ||
 578                    oidcmp(&oid, &ref->old_oid))
 579                        continue;
 580
 581                if ((allow_unadvertised_object_request &
 582                     (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1)) ||
 583                    tip_oids_contain(&tip_oids, unmatched, newlist,
 584                                     &ref->old_oid)) {
 585                        ref->match_status = REF_MATCHED;
 586                        *newtail = copy_ref(ref);
 587                        newtail = &(*newtail)->next;
 588                } else {
 589                        ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 590                }
 591        }
 592
 593        oidset_clear(&tip_oids);
 594        for (ref = unmatched; ref; ref = next) {
 595                next = ref->next;
 596                free(ref);
 597        }
 598
 599        *refs = newlist;
 600}
 601
 602static void mark_alternate_complete(struct fetch_negotiator *unused,
 603                                    struct object *obj)
 604{
 605        mark_complete(&obj->oid);
 606}
 607
 608struct loose_object_iter {
 609        struct oidset *loose_object_set;
 610        struct ref *refs;
 611};
 612
 613/*
 614 *  If the number of refs is not larger than the number of loose objects,
 615 *  this function stops inserting.
 616 */
 617static int add_loose_objects_to_set(const struct object_id *oid,
 618                                    const char *path,
 619                                    void *data)
 620{
 621        struct loose_object_iter *iter = data;
 622        oidset_insert(iter->loose_object_set, oid);
 623        if (iter->refs == NULL)
 624                return 1;
 625
 626        iter->refs = iter->refs->next;
 627        return 0;
 628}
 629
 630/*
 631 * Mark recent commits available locally and reachable from a local ref as
 632 * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 633 * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 634 * thus do not need COMMON_REF marks).
 635 *
 636 * The cutoff time for recency is determined by this heuristic: it is the
 637 * earliest commit time of the objects in refs that are commits and that we know
 638 * the commit time of.
 639 */
 640static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 641                                         struct fetch_pack_args *args,
 642                                         struct ref **refs)
 643{
 644        struct ref *ref;
 645        int old_save_commit_buffer = save_commit_buffer;
 646        timestamp_t cutoff = 0;
 647        struct oidset loose_oid_set = OIDSET_INIT;
 648        int use_oidset = 0;
 649        struct loose_object_iter iter = {&loose_oid_set, *refs};
 650
 651        /* Enumerate all loose objects or know refs are not so many. */
 652        use_oidset = !for_each_loose_object(add_loose_objects_to_set,
 653                                            &iter, 0);
 654
 655        save_commit_buffer = 0;
 656
 657        for (ref = *refs; ref; ref = ref->next) {
 658                struct object *o;
 659                unsigned int flags = OBJECT_INFO_QUICK;
 660
 661                if (use_oidset &&
 662                    !oidset_contains(&loose_oid_set, &ref->old_oid)) {
 663                        /*
 664                         * I know this does not exist in the loose form,
 665                         * so check if it exists in a non-loose form.
 666                         */
 667                        flags |= OBJECT_INFO_IGNORE_LOOSE;
 668                }
 669
 670                if (!has_object_file_with_flags(&ref->old_oid, flags))
 671                        continue;
 672                o = parse_object(&ref->old_oid);
 673                if (!o)
 674                        continue;
 675
 676                /* We already have it -- which may mean that we were
 677                 * in sync with the other side at some time after
 678                 * that (it is OK if we guess wrong here).
 679                 */
 680                if (o->type == OBJ_COMMIT) {
 681                        struct commit *commit = (struct commit *)o;
 682                        if (!cutoff || cutoff < commit->date)
 683                                cutoff = commit->date;
 684                }
 685        }
 686
 687        oidset_clear(&loose_oid_set);
 688
 689        if (!args->no_dependents) {
 690                if (!args->deepen) {
 691                        for_each_ref(mark_complete_oid, NULL);
 692                        for_each_cached_alternate(NULL, mark_alternate_complete);
 693                        commit_list_sort_by_date(&complete);
 694                        if (cutoff)
 695                                mark_recent_complete_commits(args, cutoff);
 696                }
 697
 698                /*
 699                 * Mark all complete remote refs as common refs.
 700                 * Don't mark them common yet; the server has to be told so first.
 701                 */
 702                for (ref = *refs; ref; ref = ref->next) {
 703                        struct object *o = deref_tag(lookup_object(ref->old_oid.hash),
 704                                                     NULL, 0);
 705
 706                        if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 707                                continue;
 708
 709                        negotiator->known_common(negotiator,
 710                                                 (struct commit *)o);
 711                }
 712        }
 713
 714        save_commit_buffer = old_save_commit_buffer;
 715}
 716
 717/*
 718 * Returns 1 if every object pointed to by the given remote refs is available
 719 * locally and reachable from a local ref, and 0 otherwise.
 720 */
 721static int everything_local(struct fetch_pack_args *args,
 722                            struct ref **refs)
 723{
 724        struct ref *ref;
 725        int retval;
 726
 727        for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 728                const struct object_id *remote = &ref->old_oid;
 729                struct object *o;
 730
 731                o = lookup_object(remote->hash);
 732                if (!o || !(o->flags & COMPLETE)) {
 733                        retval = 0;
 734                        print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 735                                      ref->name);
 736                        continue;
 737                }
 738                print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 739                              ref->name);
 740        }
 741
 742        return retval;
 743}
 744
 745static int sideband_demux(int in, int out, void *data)
 746{
 747        int *xd = data;
 748        int ret;
 749
 750        ret = recv_sideband("fetch-pack", xd[0], out);
 751        close(out);
 752        return ret;
 753}
 754
 755static int get_pack(struct fetch_pack_args *args,
 756                    int xd[2], char **pack_lockfile)
 757{
 758        struct async demux;
 759        int do_keep = args->keep_pack;
 760        const char *cmd_name;
 761        struct pack_header header;
 762        int pass_header = 0;
 763        struct child_process cmd = CHILD_PROCESS_INIT;
 764        int ret;
 765
 766        memset(&demux, 0, sizeof(demux));
 767        if (use_sideband) {
 768                /* xd[] is talking with upload-pack; subprocess reads from
 769                 * xd[0], spits out band#2 to stderr, and feeds us band#1
 770                 * through demux->out.
 771                 */
 772                demux.proc = sideband_demux;
 773                demux.data = xd;
 774                demux.out = -1;
 775                demux.isolate_sigpipe = 1;
 776                if (start_async(&demux))
 777                        die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 778        }
 779        else
 780                demux.out = xd[0];
 781
 782        if (!args->keep_pack && unpack_limit) {
 783
 784                if (read_pack_header(demux.out, &header))
 785                        die(_("protocol error: bad pack header"));
 786                pass_header = 1;
 787                if (ntohl(header.hdr_entries) < unpack_limit)
 788                        do_keep = 0;
 789                else
 790                        do_keep = 1;
 791        }
 792
 793        if (alternate_shallow_file) {
 794                argv_array_push(&cmd.args, "--shallow-file");
 795                argv_array_push(&cmd.args, alternate_shallow_file);
 796        }
 797
 798        if (do_keep || args->from_promisor) {
 799                if (pack_lockfile)
 800                        cmd.out = -1;
 801                cmd_name = "index-pack";
 802                argv_array_push(&cmd.args, cmd_name);
 803                argv_array_push(&cmd.args, "--stdin");
 804                if (!args->quiet && !args->no_progress)
 805                        argv_array_push(&cmd.args, "-v");
 806                if (args->use_thin_pack)
 807                        argv_array_push(&cmd.args, "--fix-thin");
 808                if (do_keep && (args->lock_pack || unpack_limit)) {
 809                        char hostname[HOST_NAME_MAX + 1];
 810                        if (xgethostname(hostname, sizeof(hostname)))
 811                                xsnprintf(hostname, sizeof(hostname), "localhost");
 812                        argv_array_pushf(&cmd.args,
 813                                        "--keep=fetch-pack %"PRIuMAX " on %s",
 814                                        (uintmax_t)getpid(), hostname);
 815                }
 816                if (args->check_self_contained_and_connected)
 817                        argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 818                if (args->from_promisor)
 819                        argv_array_push(&cmd.args, "--promisor");
 820        }
 821        else {
 822                cmd_name = "unpack-objects";
 823                argv_array_push(&cmd.args, cmd_name);
 824                if (args->quiet || args->no_progress)
 825                        argv_array_push(&cmd.args, "-q");
 826                args->check_self_contained_and_connected = 0;
 827        }
 828
 829        if (pass_header)
 830                argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 831                                 ntohl(header.hdr_version),
 832                                 ntohl(header.hdr_entries));
 833        if (fetch_fsck_objects >= 0
 834            ? fetch_fsck_objects
 835            : transfer_fsck_objects >= 0
 836            ? transfer_fsck_objects
 837            : 0) {
 838                if (args->from_promisor)
 839                        /*
 840                         * We cannot use --strict in index-pack because it
 841                         * checks both broken objects and links, but we only
 842                         * want to check for broken objects.
 843                         */
 844                        argv_array_push(&cmd.args, "--fsck-objects");
 845                else
 846                        argv_array_push(&cmd.args, "--strict");
 847        }
 848
 849        cmd.in = demux.out;
 850        cmd.git_cmd = 1;
 851        if (start_command(&cmd))
 852                die(_("fetch-pack: unable to fork off %s"), cmd_name);
 853        if (do_keep && pack_lockfile) {
 854                *pack_lockfile = index_pack_lockfile(cmd.out);
 855                close(cmd.out);
 856        }
 857
 858        if (!use_sideband)
 859                /* Closed by start_command() */
 860                xd[0] = -1;
 861
 862        ret = finish_command(&cmd);
 863        if (!ret || (args->check_self_contained_and_connected && ret == 1))
 864                args->self_contained_and_connected =
 865                        args->check_self_contained_and_connected &&
 866                        ret == 0;
 867        else
 868                die(_("%s failed"), cmd_name);
 869        if (use_sideband && finish_async(&demux))
 870                die(_("error in sideband demultiplexer"));
 871        return 0;
 872}
 873
 874static int cmp_ref_by_name(const void *a_, const void *b_)
 875{
 876        const struct ref *a = *((const struct ref **)a_);
 877        const struct ref *b = *((const struct ref **)b_);
 878        return strcmp(a->name, b->name);
 879}
 880
 881static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 882                                 int fd[2],
 883                                 const struct ref *orig_ref,
 884                                 struct ref **sought, int nr_sought,
 885                                 struct shallow_info *si,
 886                                 char **pack_lockfile)
 887{
 888        struct ref *ref = copy_ref_list(orig_ref);
 889        struct object_id oid;
 890        const char *agent_feature;
 891        int agent_len;
 892        struct fetch_negotiator negotiator;
 893        fetch_negotiator_init(&negotiator, negotiation_algorithm);
 894
 895        sort_ref_list(&ref, ref_compare_name);
 896        QSORT(sought, nr_sought, cmp_ref_by_name);
 897
 898        if ((args->depth > 0 || is_repository_shallow()) && !server_supports("shallow"))
 899                die(_("Server does not support shallow clients"));
 900        if (args->depth > 0 || args->deepen_since || args->deepen_not)
 901                args->deepen = 1;
 902        if (server_supports("multi_ack_detailed")) {
 903                print_verbose(args, _("Server supports multi_ack_detailed"));
 904                multi_ack = 2;
 905                if (server_supports("no-done")) {
 906                        print_verbose(args, _("Server supports no-done"));
 907                        if (args->stateless_rpc)
 908                                no_done = 1;
 909                }
 910        }
 911        else if (server_supports("multi_ack")) {
 912                print_verbose(args, _("Server supports multi_ack"));
 913                multi_ack = 1;
 914        }
 915        if (server_supports("side-band-64k")) {
 916                print_verbose(args, _("Server supports side-band-64k"));
 917                use_sideband = 2;
 918        }
 919        else if (server_supports("side-band")) {
 920                print_verbose(args, _("Server supports side-band"));
 921                use_sideband = 1;
 922        }
 923        if (server_supports("allow-tip-sha1-in-want")) {
 924                print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
 925                allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 926        }
 927        if (server_supports("allow-reachable-sha1-in-want")) {
 928                print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
 929                allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 930        }
 931        if (!server_supports("thin-pack"))
 932                args->use_thin_pack = 0;
 933        if (!server_supports("no-progress"))
 934                args->no_progress = 0;
 935        if (!server_supports("include-tag"))
 936                args->include_tag = 0;
 937        if (server_supports("ofs-delta"))
 938                print_verbose(args, _("Server supports ofs-delta"));
 939        else
 940                prefer_ofs_delta = 0;
 941
 942        if (server_supports("filter")) {
 943                server_supports_filtering = 1;
 944                print_verbose(args, _("Server supports filter"));
 945        } else if (args->filter_options.choice) {
 946                warning("filtering not recognized by server, ignoring");
 947        }
 948
 949        if ((agent_feature = server_feature_value("agent", &agent_len))) {
 950                agent_supported = 1;
 951                if (agent_len)
 952                        print_verbose(args, _("Server version is %.*s"),
 953                                      agent_len, agent_feature);
 954        }
 955        if (server_supports("deepen-since"))
 956                deepen_since_ok = 1;
 957        else if (args->deepen_since)
 958                die(_("Server does not support --shallow-since"));
 959        if (server_supports("deepen-not"))
 960                deepen_not_ok = 1;
 961        else if (args->deepen_not)
 962                die(_("Server does not support --shallow-exclude"));
 963        if (!server_supports("deepen-relative") && args->deepen_relative)
 964                die(_("Server does not support --deepen"));
 965
 966        mark_complete_and_common_ref(&negotiator, args, &ref);
 967        filter_refs(args, &ref, sought, nr_sought);
 968        if (everything_local(args, &ref)) {
 969                packet_flush(fd[1]);
 970                goto all_done;
 971        }
 972        if (find_common(&negotiator, args, fd, &oid, ref) < 0)
 973                if (!args->keep_pack)
 974                        /* When cloning, it is not unusual to have
 975                         * no common commit.
 976                         */
 977                        warning(_("no common commits"));
 978
 979        if (args->stateless_rpc)
 980                packet_flush(fd[1]);
 981        if (args->deepen)
 982                setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
 983                                        NULL);
 984        else if (si->nr_ours || si->nr_theirs)
 985                alternate_shallow_file = setup_temporary_shallow(si->shallow);
 986        else
 987                alternate_shallow_file = NULL;
 988        if (get_pack(args, fd, pack_lockfile))
 989                die(_("git fetch-pack: fetch failed."));
 990
 991 all_done:
 992        negotiator.release(&negotiator);
 993        return ref;
 994}
 995
 996static void add_shallow_requests(struct strbuf *req_buf,
 997                                 const struct fetch_pack_args *args)
 998{
 999        if (is_repository_shallow())
1000                write_shallow_commits(req_buf, 1, NULL);
1001        if (args->depth > 0)
1002                packet_buf_write(req_buf, "deepen %d", args->depth);
1003        if (args->deepen_since) {
1004                timestamp_t max_age = approxidate(args->deepen_since);
1005                packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1006        }
1007        if (args->deepen_not) {
1008                int i;
1009                for (i = 0; i < args->deepen_not->nr; i++) {
1010                        struct string_list_item *s = args->deepen_not->items + i;
1011                        packet_buf_write(req_buf, "deepen-not %s", s->string);
1012                }
1013        }
1014}
1015
1016static void add_wants(const struct ref *wants, struct strbuf *req_buf)
1017{
1018        for ( ; wants ; wants = wants->next) {
1019                const struct object_id *remote = &wants->old_oid;
1020                const char *remote_hex;
1021                struct object *o;
1022
1023                /*
1024                 * If that object is complete (i.e. it is an ancestor of a
1025                 * local ref), we tell them we have it but do not have to
1026                 * tell them about its ancestors, which they already know
1027                 * about.
1028                 *
1029                 * We use lookup_object here because we are only
1030                 * interested in the case we *know* the object is
1031                 * reachable and we have already scanned it.
1032                 */
1033                if (((o = lookup_object(remote->hash)) != NULL) &&
1034                    (o->flags & COMPLETE)) {
1035                        continue;
1036                }
1037
1038                remote_hex = oid_to_hex(remote);
1039                packet_buf_write(req_buf, "want %s\n", remote_hex);
1040        }
1041}
1042
1043static void add_common(struct strbuf *req_buf, struct oidset *common)
1044{
1045        struct oidset_iter iter;
1046        const struct object_id *oid;
1047        oidset_iter_init(common, &iter);
1048
1049        while ((oid = oidset_iter_next(&iter))) {
1050                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1051        }
1052}
1053
1054static int add_haves(struct fetch_negotiator *negotiator,
1055                     struct strbuf *req_buf,
1056                     int *haves_to_send, int *in_vain)
1057{
1058        int ret = 0;
1059        int haves_added = 0;
1060        const struct object_id *oid;
1061
1062        while ((oid = negotiator->next(negotiator))) {
1063                packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1064                if (++haves_added >= *haves_to_send)
1065                        break;
1066        }
1067
1068        *in_vain += haves_added;
1069        if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1070                /* Send Done */
1071                packet_buf_write(req_buf, "done\n");
1072                ret = 1;
1073        }
1074
1075        /* Increase haves to send on next round */
1076        *haves_to_send = next_flush(1, *haves_to_send);
1077
1078        return ret;
1079}
1080
1081static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1082                              const struct fetch_pack_args *args,
1083                              const struct ref *wants, struct oidset *common,
1084                              int *haves_to_send, int *in_vain)
1085{
1086        int ret = 0;
1087        struct strbuf req_buf = STRBUF_INIT;
1088
1089        if (server_supports_v2("fetch", 1))
1090                packet_buf_write(&req_buf, "command=fetch");
1091        if (server_supports_v2("agent", 0))
1092                packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1093        if (args->server_options && args->server_options->nr &&
1094            server_supports_v2("server-option", 1)) {
1095                int i;
1096                for (i = 0; i < args->server_options->nr; i++)
1097                        packet_write_fmt(fd_out, "server-option=%s",
1098                                         args->server_options->items[i].string);
1099        }
1100
1101        packet_buf_delim(&req_buf);
1102        if (args->use_thin_pack)
1103                packet_buf_write(&req_buf, "thin-pack");
1104        if (args->no_progress)
1105                packet_buf_write(&req_buf, "no-progress");
1106        if (args->include_tag)
1107                packet_buf_write(&req_buf, "include-tag");
1108        if (prefer_ofs_delta)
1109                packet_buf_write(&req_buf, "ofs-delta");
1110
1111        /* Add shallow-info and deepen request */
1112        if (server_supports_feature("fetch", "shallow", 0))
1113                add_shallow_requests(&req_buf, args);
1114        else if (is_repository_shallow() || args->deepen)
1115                die(_("Server does not support shallow requests"));
1116
1117        /* Add filter */
1118        if (server_supports_feature("fetch", "filter", 0) &&
1119            args->filter_options.choice) {
1120                print_verbose(args, _("Server supports filter"));
1121                packet_buf_write(&req_buf, "filter %s",
1122                                 args->filter_options.filter_spec);
1123        } else if (args->filter_options.choice) {
1124                warning("filtering not recognized by server, ignoring");
1125        }
1126
1127        /* add wants */
1128        add_wants(wants, &req_buf);
1129
1130        if (args->no_dependents) {
1131                packet_buf_write(&req_buf, "done");
1132                ret = 1;
1133        } else {
1134                /* Add all of the common commits we've found in previous rounds */
1135                add_common(&req_buf, common);
1136
1137                /* Add initial haves */
1138                ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1139        }
1140
1141        /* Send request */
1142        packet_buf_flush(&req_buf);
1143        write_or_die(fd_out, req_buf.buf, req_buf.len);
1144
1145        strbuf_release(&req_buf);
1146        return ret;
1147}
1148
1149/*
1150 * Processes a section header in a server's response and checks if it matches
1151 * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1152 * not consumed); if 0, the line will be consumed and the function will die if
1153 * the section header doesn't match what was expected.
1154 */
1155static int process_section_header(struct packet_reader *reader,
1156                                  const char *section, int peek)
1157{
1158        int ret;
1159
1160        if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1161                die("error reading section header '%s'", section);
1162
1163        ret = !strcmp(reader->line, section);
1164
1165        if (!peek) {
1166                if (!ret)
1167                        die("expected '%s', received '%s'",
1168                            section, reader->line);
1169                packet_reader_read(reader);
1170        }
1171
1172        return ret;
1173}
1174
1175static int process_acks(struct fetch_negotiator *negotiator,
1176                        struct packet_reader *reader,
1177                        struct oidset *common)
1178{
1179        /* received */
1180        int received_ready = 0;
1181        int received_ack = 0;
1182
1183        process_section_header(reader, "acknowledgments", 0);
1184        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1185                const char *arg;
1186
1187                if (!strcmp(reader->line, "NAK"))
1188                        continue;
1189
1190                if (skip_prefix(reader->line, "ACK ", &arg)) {
1191                        struct object_id oid;
1192                        if (!get_oid_hex(arg, &oid)) {
1193                                struct commit *commit;
1194                                oidset_insert(common, &oid);
1195                                commit = lookup_commit(&oid);
1196                                negotiator->ack(negotiator, commit);
1197                        }
1198                        continue;
1199                }
1200
1201                if (!strcmp(reader->line, "ready")) {
1202                        received_ready = 1;
1203                        continue;
1204                }
1205
1206                die("unexpected acknowledgment line: '%s'", reader->line);
1207        }
1208
1209        if (reader->status != PACKET_READ_FLUSH &&
1210            reader->status != PACKET_READ_DELIM)
1211                die("error processing acks: %d", reader->status);
1212
1213        /* return 0 if no common, 1 if there are common, or 2 if ready */
1214        return received_ready ? 2 : (received_ack ? 1 : 0);
1215}
1216
1217static void receive_shallow_info(struct fetch_pack_args *args,
1218                                 struct packet_reader *reader)
1219{
1220        process_section_header(reader, "shallow-info", 0);
1221        while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1222                const char *arg;
1223                struct object_id oid;
1224
1225                if (skip_prefix(reader->line, "shallow ", &arg)) {
1226                        if (get_oid_hex(arg, &oid))
1227                                die(_("invalid shallow line: %s"), reader->line);
1228                        register_shallow(&oid);
1229                        continue;
1230                }
1231                if (skip_prefix(reader->line, "unshallow ", &arg)) {
1232                        if (get_oid_hex(arg, &oid))
1233                                die(_("invalid unshallow line: %s"), reader->line);
1234                        if (!lookup_object(oid.hash))
1235                                die(_("object not found: %s"), reader->line);
1236                        /* make sure that it is parsed as shallow */
1237                        if (!parse_object(&oid))
1238                                die(_("error in object: %s"), reader->line);
1239                        if (unregister_shallow(&oid))
1240                                die(_("no shallow found: %s"), reader->line);
1241                        continue;
1242                }
1243                die(_("expected shallow/unshallow, got %s"), reader->line);
1244        }
1245
1246        if (reader->status != PACKET_READ_FLUSH &&
1247            reader->status != PACKET_READ_DELIM)
1248                die("error processing shallow info: %d", reader->status);
1249
1250        setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, NULL);
1251        args->deepen = 1;
1252}
1253
1254enum fetch_state {
1255        FETCH_CHECK_LOCAL = 0,
1256        FETCH_SEND_REQUEST,
1257        FETCH_PROCESS_ACKS,
1258        FETCH_GET_PACK,
1259        FETCH_DONE,
1260};
1261
1262static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1263                                    int fd[2],
1264                                    const struct ref *orig_ref,
1265                                    struct ref **sought, int nr_sought,
1266                                    char **pack_lockfile)
1267{
1268        struct ref *ref = copy_ref_list(orig_ref);
1269        enum fetch_state state = FETCH_CHECK_LOCAL;
1270        struct oidset common = OIDSET_INIT;
1271        struct packet_reader reader;
1272        int in_vain = 0;
1273        int haves_to_send = INITIAL_FLUSH;
1274        struct fetch_negotiator negotiator;
1275        fetch_negotiator_init(&negotiator, negotiation_algorithm);
1276        packet_reader_init(&reader, fd[0], NULL, 0,
1277                           PACKET_READ_CHOMP_NEWLINE);
1278
1279        while (state != FETCH_DONE) {
1280                switch (state) {
1281                case FETCH_CHECK_LOCAL:
1282                        sort_ref_list(&ref, ref_compare_name);
1283                        QSORT(sought, nr_sought, cmp_ref_by_name);
1284
1285                        /* v2 supports these by default */
1286                        allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1287                        use_sideband = 2;
1288                        if (args->depth > 0 || args->deepen_since || args->deepen_not)
1289                                args->deepen = 1;
1290
1291                        /* Filter 'ref' by 'sought' and those that aren't local */
1292                        mark_complete_and_common_ref(&negotiator, args, &ref);
1293                        filter_refs(args, &ref, sought, nr_sought);
1294                        if (everything_local(args, &ref))
1295                                state = FETCH_DONE;
1296                        else
1297                                state = FETCH_SEND_REQUEST;
1298
1299                        for_each_ref(rev_list_insert_ref_oid, &negotiator);
1300                        for_each_cached_alternate(&negotiator,
1301                                                  insert_one_alternate_object);
1302                        break;
1303                case FETCH_SEND_REQUEST:
1304                        if (send_fetch_request(&negotiator, fd[1], args, ref,
1305                                               &common,
1306                                               &haves_to_send, &in_vain))
1307                                state = FETCH_GET_PACK;
1308                        else
1309                                state = FETCH_PROCESS_ACKS;
1310                        break;
1311                case FETCH_PROCESS_ACKS:
1312                        /* Process ACKs/NAKs */
1313                        switch (process_acks(&negotiator, &reader, &common)) {
1314                        case 2:
1315                                state = FETCH_GET_PACK;
1316                                break;
1317                        case 1:
1318                                in_vain = 0;
1319                                /* fallthrough */
1320                        default:
1321                                state = FETCH_SEND_REQUEST;
1322                                break;
1323                        }
1324                        break;
1325                case FETCH_GET_PACK:
1326                        /* Check for shallow-info section */
1327                        if (process_section_header(&reader, "shallow-info", 1))
1328                                receive_shallow_info(args, &reader);
1329
1330                        /* get the pack */
1331                        process_section_header(&reader, "packfile", 0);
1332                        if (get_pack(args, fd, pack_lockfile))
1333                                die(_("git fetch-pack: fetch failed."));
1334
1335                        state = FETCH_DONE;
1336                        break;
1337                case FETCH_DONE:
1338                        continue;
1339                }
1340        }
1341
1342        negotiator.release(&negotiator);
1343        oidset_clear(&common);
1344        return ref;
1345}
1346
1347static void fetch_pack_config(void)
1348{
1349        git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1350        git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1351        git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1352        git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1353        git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1354        git_config_get_string("fetch.negotiationalgorithm",
1355                              &negotiation_algorithm);
1356
1357        git_config(git_default_config, NULL);
1358}
1359
1360static void fetch_pack_setup(void)
1361{
1362        static int did_setup;
1363        if (did_setup)
1364                return;
1365        fetch_pack_config();
1366        if (0 <= transfer_unpack_limit)
1367                unpack_limit = transfer_unpack_limit;
1368        else if (0 <= fetch_unpack_limit)
1369                unpack_limit = fetch_unpack_limit;
1370        did_setup = 1;
1371}
1372
1373static int remove_duplicates_in_refs(struct ref **ref, int nr)
1374{
1375        struct string_list names = STRING_LIST_INIT_NODUP;
1376        int src, dst;
1377
1378        for (src = dst = 0; src < nr; src++) {
1379                struct string_list_item *item;
1380                item = string_list_insert(&names, ref[src]->name);
1381                if (item->util)
1382                        continue; /* already have it */
1383                item->util = ref[src];
1384                if (src != dst)
1385                        ref[dst] = ref[src];
1386                dst++;
1387        }
1388        for (src = dst; src < nr; src++)
1389                ref[src] = NULL;
1390        string_list_clear(&names, 0);
1391        return dst;
1392}
1393
1394static void update_shallow(struct fetch_pack_args *args,
1395                           struct ref **sought, int nr_sought,
1396                           struct shallow_info *si)
1397{
1398        struct oid_array ref = OID_ARRAY_INIT;
1399        int *status;
1400        int i;
1401
1402        if (args->deepen && alternate_shallow_file) {
1403                if (*alternate_shallow_file == '\0') { /* --unshallow */
1404                        unlink_or_warn(git_path_shallow());
1405                        rollback_lock_file(&shallow_lock);
1406                } else
1407                        commit_lock_file(&shallow_lock);
1408                return;
1409        }
1410
1411        if (!si->shallow || !si->shallow->nr)
1412                return;
1413
1414        if (args->cloning) {
1415                /*
1416                 * remote is shallow, but this is a clone, there are
1417                 * no objects in repo to worry about. Accept any
1418                 * shallow points that exist in the pack (iow in repo
1419                 * after get_pack() and reprepare_packed_git())
1420                 */
1421                struct oid_array extra = OID_ARRAY_INIT;
1422                struct object_id *oid = si->shallow->oid;
1423                for (i = 0; i < si->shallow->nr; i++)
1424                        if (has_object_file(&oid[i]))
1425                                oid_array_append(&extra, &oid[i]);
1426                if (extra.nr) {
1427                        setup_alternate_shallow(&shallow_lock,
1428                                                &alternate_shallow_file,
1429                                                &extra);
1430                        commit_lock_file(&shallow_lock);
1431                }
1432                oid_array_clear(&extra);
1433                return;
1434        }
1435
1436        if (!si->nr_ours && !si->nr_theirs)
1437                return;
1438
1439        remove_nonexistent_theirs_shallow(si);
1440        if (!si->nr_ours && !si->nr_theirs)
1441                return;
1442        for (i = 0; i < nr_sought; i++)
1443                oid_array_append(&ref, &sought[i]->old_oid);
1444        si->ref = &ref;
1445
1446        if (args->update_shallow) {
1447                /*
1448                 * remote is also shallow, .git/shallow may be updated
1449                 * so all refs can be accepted. Make sure we only add
1450                 * shallow roots that are actually reachable from new
1451                 * refs.
1452                 */
1453                struct oid_array extra = OID_ARRAY_INIT;
1454                struct object_id *oid = si->shallow->oid;
1455                assign_shallow_commits_to_refs(si, NULL, NULL);
1456                if (!si->nr_ours && !si->nr_theirs) {
1457                        oid_array_clear(&ref);
1458                        return;
1459                }
1460                for (i = 0; i < si->nr_ours; i++)
1461                        oid_array_append(&extra, &oid[si->ours[i]]);
1462                for (i = 0; i < si->nr_theirs; i++)
1463                        oid_array_append(&extra, &oid[si->theirs[i]]);
1464                setup_alternate_shallow(&shallow_lock,
1465                                        &alternate_shallow_file,
1466                                        &extra);
1467                commit_lock_file(&shallow_lock);
1468                oid_array_clear(&extra);
1469                oid_array_clear(&ref);
1470                return;
1471        }
1472
1473        /*
1474         * remote is also shallow, check what ref is safe to update
1475         * without updating .git/shallow
1476         */
1477        status = xcalloc(nr_sought, sizeof(*status));
1478        assign_shallow_commits_to_refs(si, NULL, status);
1479        if (si->nr_ours || si->nr_theirs) {
1480                for (i = 0; i < nr_sought; i++)
1481                        if (status[i])
1482                                sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1483        }
1484        free(status);
1485        oid_array_clear(&ref);
1486}
1487
1488struct ref *fetch_pack(struct fetch_pack_args *args,
1489                       int fd[], struct child_process *conn,
1490                       const struct ref *ref,
1491                       const char *dest,
1492                       struct ref **sought, int nr_sought,
1493                       struct oid_array *shallow,
1494                       char **pack_lockfile,
1495                       enum protocol_version version)
1496{
1497        struct ref *ref_cpy;
1498        struct shallow_info si;
1499
1500        fetch_pack_setup();
1501        if (nr_sought)
1502                nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1503
1504        if (!ref) {
1505                packet_flush(fd[1]);
1506                die(_("no matching remote head"));
1507        }
1508        prepare_shallow_info(&si, shallow);
1509        if (version == protocol_v2)
1510                ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1511                                           pack_lockfile);
1512        else
1513                ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1514                                        &si, pack_lockfile);
1515        reprepare_packed_git(the_repository);
1516        update_shallow(args, sought, nr_sought, &si);
1517        clear_shallow_info(&si);
1518        return ref_cpy;
1519}
1520
1521int report_unmatched_refs(struct ref **sought, int nr_sought)
1522{
1523        int i, ret = 0;
1524
1525        for (i = 0; i < nr_sought; i++) {
1526                if (!sought[i])
1527                        continue;
1528                switch (sought[i]->match_status) {
1529                case REF_MATCHED:
1530                        continue;
1531                case REF_NOT_MATCHED:
1532                        error(_("no such remote ref %s"), sought[i]->name);
1533                        break;
1534                case REF_UNADVERTISED_NOT_ALLOWED:
1535                        error(_("Server does not allow request for unadvertised object %s"),
1536                              sought[i]->name);
1537                        break;
1538                }
1539                ret = 1;
1540        }
1541        return ret;
1542}