packfile.con commit Merge branch 'sg/clean-nested-repo-with-ignored' (026428c)
   1#include "cache.h"
   2#include "list.h"
   3#include "pack.h"
   4#include "repository.h"
   5#include "dir.h"
   6#include "mergesort.h"
   7#include "packfile.h"
   8#include "delta.h"
   9#include "list.h"
  10#include "streaming.h"
  11#include "sha1-lookup.h"
  12#include "commit.h"
  13#include "object.h"
  14#include "tag.h"
  15#include "tree-walk.h"
  16#include "tree.h"
  17#include "object-store.h"
  18#include "midx.h"
  19#include "commit-graph.h"
  20#include "promisor-remote.h"
  21
  22char *odb_pack_name(struct strbuf *buf,
  23                    const unsigned char *sha1,
  24                    const char *ext)
  25{
  26        strbuf_reset(buf);
  27        strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
  28                    sha1_to_hex(sha1), ext);
  29        return buf->buf;
  30}
  31
  32char *sha1_pack_name(const unsigned char *sha1)
  33{
  34        static struct strbuf buf = STRBUF_INIT;
  35        return odb_pack_name(&buf, sha1, "pack");
  36}
  37
  38char *sha1_pack_index_name(const unsigned char *sha1)
  39{
  40        static struct strbuf buf = STRBUF_INIT;
  41        return odb_pack_name(&buf, sha1, "idx");
  42}
  43
  44static unsigned int pack_used_ctr;
  45static unsigned int pack_mmap_calls;
  46static unsigned int peak_pack_open_windows;
  47static unsigned int pack_open_windows;
  48static unsigned int pack_open_fds;
  49static unsigned int pack_max_fds;
  50static size_t peak_pack_mapped;
  51static size_t pack_mapped;
  52
  53#define SZ_FMT PRIuMAX
  54static inline uintmax_t sz_fmt(size_t s) { return s; }
  55
  56void pack_report(void)
  57{
  58        fprintf(stderr,
  59                "pack_report: getpagesize()            = %10" SZ_FMT "\n"
  60                "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
  61                "pack_report: core.packedGitLimit      = %10" SZ_FMT "\n",
  62                sz_fmt(getpagesize()),
  63                sz_fmt(packed_git_window_size),
  64                sz_fmt(packed_git_limit));
  65        fprintf(stderr,
  66                "pack_report: pack_used_ctr            = %10u\n"
  67                "pack_report: pack_mmap_calls          = %10u\n"
  68                "pack_report: pack_open_windows        = %10u / %10u\n"
  69                "pack_report: pack_mapped              = "
  70                        "%10" SZ_FMT " / %10" SZ_FMT "\n",
  71                pack_used_ctr,
  72                pack_mmap_calls,
  73                pack_open_windows, peak_pack_open_windows,
  74                sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
  75}
  76
  77/*
  78 * Open and mmap the index file at path, perform a couple of
  79 * consistency checks, then record its information to p.  Return 0 on
  80 * success.
  81 */
  82static int check_packed_git_idx(const char *path, struct packed_git *p)
  83{
  84        void *idx_map;
  85        size_t idx_size;
  86        int fd = git_open(path), ret;
  87        struct stat st;
  88        const unsigned int hashsz = the_hash_algo->rawsz;
  89
  90        if (fd < 0)
  91                return -1;
  92        if (fstat(fd, &st)) {
  93                close(fd);
  94                return -1;
  95        }
  96        idx_size = xsize_t(st.st_size);
  97        if (idx_size < 4 * 256 + hashsz + hashsz) {
  98                close(fd);
  99                return error("index file %s is too small", path);
 100        }
 101        idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
 102        close(fd);
 103
 104        ret = load_idx(path, hashsz, idx_map, idx_size, p);
 105
 106        if (ret)
 107                munmap(idx_map, idx_size);
 108
 109        return ret;
 110}
 111
 112int load_idx(const char *path, const unsigned int hashsz, void *idx_map,
 113             size_t idx_size, struct packed_git *p)
 114{
 115        struct pack_idx_header *hdr = idx_map;
 116        uint32_t version, nr, i, *index;
 117
 118        if (idx_size < 4 * 256 + hashsz + hashsz)
 119                return error("index file %s is too small", path);
 120        if (idx_map == NULL)
 121                return error("empty data");
 122
 123        if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
 124                version = ntohl(hdr->idx_version);
 125                if (version < 2 || version > 2)
 126                        return error("index file %s is version %"PRIu32
 127                                     " and is not supported by this binary"
 128                                     " (try upgrading GIT to a newer version)",
 129                                     path, version);
 130        } else
 131                version = 1;
 132
 133        nr = 0;
 134        index = idx_map;
 135        if (version > 1)
 136                index += 2;  /* skip index header */
 137        for (i = 0; i < 256; i++) {
 138                uint32_t n = ntohl(index[i]);
 139                if (n < nr)
 140                        return error("non-monotonic index %s", path);
 141                nr = n;
 142        }
 143
 144        if (version == 1) {
 145                /*
 146                 * Total size:
 147                 *  - 256 index entries 4 bytes each
 148                 *  - 24-byte entries * nr (object ID + 4-byte offset)
 149                 *  - hash of the packfile
 150                 *  - file checksum
 151                 */
 152                if (idx_size != 4 * 256 + nr * (hashsz + 4) + hashsz + hashsz)
 153                        return error("wrong index v1 file size in %s", path);
 154        } else if (version == 2) {
 155                /*
 156                 * Minimum size:
 157                 *  - 8 bytes of header
 158                 *  - 256 index entries 4 bytes each
 159                 *  - object ID entry * nr
 160                 *  - 4-byte crc entry * nr
 161                 *  - 4-byte offset entry * nr
 162                 *  - hash of the packfile
 163                 *  - file checksum
 164                 * And after the 4-byte offset table might be a
 165                 * variable sized table containing 8-byte entries
 166                 * for offsets larger than 2^31.
 167                 */
 168                unsigned long min_size = 8 + 4*256 + nr*(hashsz + 4 + 4) + hashsz + hashsz;
 169                unsigned long max_size = min_size;
 170                if (nr)
 171                        max_size += (nr - 1)*8;
 172                if (idx_size < min_size || idx_size > max_size)
 173                        return error("wrong index v2 file size in %s", path);
 174                if (idx_size != min_size &&
 175                    /*
 176                     * make sure we can deal with large pack offsets.
 177                     * 31-bit signed offset won't be enough, neither
 178                     * 32-bit unsigned one will be.
 179                     */
 180                    (sizeof(off_t) <= 4))
 181                        return error("pack too large for current definition of off_t in %s", path);
 182        }
 183
 184        p->index_version = version;
 185        p->index_data = idx_map;
 186        p->index_size = idx_size;
 187        p->num_objects = nr;
 188        return 0;
 189}
 190
 191int open_pack_index(struct packed_git *p)
 192{
 193        char *idx_name;
 194        size_t len;
 195        int ret;
 196
 197        if (p->index_data)
 198                return 0;
 199
 200        if (!strip_suffix(p->pack_name, ".pack", &len))
 201                BUG("pack_name does not end in .pack");
 202        idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
 203        ret = check_packed_git_idx(idx_name, p);
 204        free(idx_name);
 205        return ret;
 206}
 207
 208uint32_t get_pack_fanout(struct packed_git *p, uint32_t value)
 209{
 210        const uint32_t *level1_ofs = p->index_data;
 211
 212        if (!level1_ofs) {
 213                if (open_pack_index(p))
 214                        return 0;
 215                level1_ofs = p->index_data;
 216        }
 217
 218        if (p->index_version > 1) {
 219                level1_ofs += 2;
 220        }
 221
 222        return ntohl(level1_ofs[value]);
 223}
 224
 225static struct packed_git *alloc_packed_git(int extra)
 226{
 227        struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
 228        memset(p, 0, sizeof(*p));
 229        p->pack_fd = -1;
 230        return p;
 231}
 232
 233struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
 234{
 235        const char *path = sha1_pack_name(sha1);
 236        size_t alloc = st_add(strlen(path), 1);
 237        struct packed_git *p = alloc_packed_git(alloc);
 238
 239        memcpy(p->pack_name, path, alloc); /* includes NUL */
 240        hashcpy(p->hash, sha1);
 241        if (check_packed_git_idx(idx_path, p)) {
 242                free(p);
 243                return NULL;
 244        }
 245
 246        return p;
 247}
 248
 249static void scan_windows(struct packed_git *p,
 250        struct packed_git **lru_p,
 251        struct pack_window **lru_w,
 252        struct pack_window **lru_l)
 253{
 254        struct pack_window *w, *w_l;
 255
 256        for (w_l = NULL, w = p->windows; w; w = w->next) {
 257                if (!w->inuse_cnt) {
 258                        if (!*lru_w || w->last_used < (*lru_w)->last_used) {
 259                                *lru_p = p;
 260                                *lru_w = w;
 261                                *lru_l = w_l;
 262                        }
 263                }
 264                w_l = w;
 265        }
 266}
 267
 268static int unuse_one_window(struct packed_git *current)
 269{
 270        struct packed_git *p, *lru_p = NULL;
 271        struct pack_window *lru_w = NULL, *lru_l = NULL;
 272
 273        if (current)
 274                scan_windows(current, &lru_p, &lru_w, &lru_l);
 275        for (p = the_repository->objects->packed_git; p; p = p->next)
 276                scan_windows(p, &lru_p, &lru_w, &lru_l);
 277        if (lru_p) {
 278                munmap(lru_w->base, lru_w->len);
 279                pack_mapped -= lru_w->len;
 280                if (lru_l)
 281                        lru_l->next = lru_w->next;
 282                else
 283                        lru_p->windows = lru_w->next;
 284                free(lru_w);
 285                pack_open_windows--;
 286                return 1;
 287        }
 288        return 0;
 289}
 290
 291void close_pack_windows(struct packed_git *p)
 292{
 293        while (p->windows) {
 294                struct pack_window *w = p->windows;
 295
 296                if (w->inuse_cnt)
 297                        die("pack '%s' still has open windows to it",
 298                            p->pack_name);
 299                munmap(w->base, w->len);
 300                pack_mapped -= w->len;
 301                pack_open_windows--;
 302                p->windows = w->next;
 303                free(w);
 304        }
 305}
 306
 307int close_pack_fd(struct packed_git *p)
 308{
 309        if (p->pack_fd < 0)
 310                return 0;
 311
 312        close(p->pack_fd);
 313        pack_open_fds--;
 314        p->pack_fd = -1;
 315
 316        return 1;
 317}
 318
 319void close_pack_index(struct packed_git *p)
 320{
 321        if (p->index_data) {
 322                munmap((void *)p->index_data, p->index_size);
 323                p->index_data = NULL;
 324        }
 325}
 326
 327void close_pack(struct packed_git *p)
 328{
 329        close_pack_windows(p);
 330        close_pack_fd(p);
 331        close_pack_index(p);
 332}
 333
 334void close_object_store(struct raw_object_store *o)
 335{
 336        struct packed_git *p;
 337
 338        for (p = o->packed_git; p; p = p->next)
 339                if (p->do_not_close)
 340                        BUG("want to close pack marked 'do-not-close'");
 341                else
 342                        close_pack(p);
 343
 344        if (o->multi_pack_index) {
 345                close_midx(o->multi_pack_index);
 346                o->multi_pack_index = NULL;
 347        }
 348
 349        close_commit_graph(o);
 350}
 351
 352void unlink_pack_path(const char *pack_name, int force_delete)
 353{
 354        static const char *exts[] = {".pack", ".idx", ".keep", ".bitmap", ".promisor"};
 355        int i;
 356        struct strbuf buf = STRBUF_INIT;
 357        size_t plen;
 358
 359        strbuf_addstr(&buf, pack_name);
 360        strip_suffix_mem(buf.buf, &buf.len, ".pack");
 361        plen = buf.len;
 362
 363        if (!force_delete) {
 364                strbuf_addstr(&buf, ".keep");
 365                if (!access(buf.buf, F_OK)) {
 366                        strbuf_release(&buf);
 367                        return;
 368                }
 369        }
 370
 371        for (i = 0; i < ARRAY_SIZE(exts); i++) {
 372                strbuf_setlen(&buf, plen);
 373                strbuf_addstr(&buf, exts[i]);
 374                unlink(buf.buf);
 375        }
 376
 377        strbuf_release(&buf);
 378}
 379
 380/*
 381 * The LRU pack is the one with the oldest MRU window, preferring packs
 382 * with no used windows, or the oldest mtime if it has no windows allocated.
 383 */
 384static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
 385{
 386        struct pack_window *w, *this_mru_w;
 387        int has_windows_inuse = 0;
 388
 389        /*
 390         * Reject this pack if it has windows and the previously selected
 391         * one does not.  If this pack does not have windows, reject
 392         * it if the pack file is newer than the previously selected one.
 393         */
 394        if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
 395                return;
 396
 397        for (w = this_mru_w = p->windows; w; w = w->next) {
 398                /*
 399                 * Reject this pack if any of its windows are in use,
 400                 * but the previously selected pack did not have any
 401                 * inuse windows.  Otherwise, record that this pack
 402                 * has windows in use.
 403                 */
 404                if (w->inuse_cnt) {
 405                        if (*accept_windows_inuse)
 406                                has_windows_inuse = 1;
 407                        else
 408                                return;
 409                }
 410
 411                if (w->last_used > this_mru_w->last_used)
 412                        this_mru_w = w;
 413
 414                /*
 415                 * Reject this pack if it has windows that have been
 416                 * used more recently than the previously selected pack.
 417                 * If the previously selected pack had windows inuse and
 418                 * we have not encountered a window in this pack that is
 419                 * inuse, skip this check since we prefer a pack with no
 420                 * inuse windows to one that has inuse windows.
 421                 */
 422                if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
 423                    this_mru_w->last_used > (*mru_w)->last_used)
 424                        return;
 425        }
 426
 427        /*
 428         * Select this pack.
 429         */
 430        *mru_w = this_mru_w;
 431        *lru_p = p;
 432        *accept_windows_inuse = has_windows_inuse;
 433}
 434
 435static int close_one_pack(void)
 436{
 437        struct packed_git *p, *lru_p = NULL;
 438        struct pack_window *mru_w = NULL;
 439        int accept_windows_inuse = 1;
 440
 441        for (p = the_repository->objects->packed_git; p; p = p->next) {
 442                if (p->pack_fd == -1)
 443                        continue;
 444                find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
 445        }
 446
 447        if (lru_p)
 448                return close_pack_fd(lru_p);
 449
 450        return 0;
 451}
 452
 453static unsigned int get_max_fd_limit(void)
 454{
 455#ifdef RLIMIT_NOFILE
 456        {
 457                struct rlimit lim;
 458
 459                if (!getrlimit(RLIMIT_NOFILE, &lim))
 460                        return lim.rlim_cur;
 461        }
 462#endif
 463
 464#ifdef _SC_OPEN_MAX
 465        {
 466                long open_max = sysconf(_SC_OPEN_MAX);
 467                if (0 < open_max)
 468                        return open_max;
 469                /*
 470                 * Otherwise, we got -1 for one of the two
 471                 * reasons:
 472                 *
 473                 * (1) sysconf() did not understand _SC_OPEN_MAX
 474                 *     and signaled an error with -1; or
 475                 * (2) sysconf() said there is no limit.
 476                 *
 477                 * We _could_ clear errno before calling sysconf() to
 478                 * tell these two cases apart and return a huge number
 479                 * in the latter case to let the caller cap it to a
 480                 * value that is not so selfish, but letting the
 481                 * fallback OPEN_MAX codepath take care of these cases
 482                 * is a lot simpler.
 483                 */
 484        }
 485#endif
 486
 487#ifdef OPEN_MAX
 488        return OPEN_MAX;
 489#else
 490        return 1; /* see the caller ;-) */
 491#endif
 492}
 493
 494const char *pack_basename(struct packed_git *p)
 495{
 496        const char *ret = strrchr(p->pack_name, '/');
 497        if (ret)
 498                ret = ret + 1; /* skip past slash */
 499        else
 500                ret = p->pack_name; /* we only have a base */
 501        return ret;
 502}
 503
 504/*
 505 * Do not call this directly as this leaks p->pack_fd on error return;
 506 * call open_packed_git() instead.
 507 */
 508static int open_packed_git_1(struct packed_git *p)
 509{
 510        struct stat st;
 511        struct pack_header hdr;
 512        unsigned char hash[GIT_MAX_RAWSZ];
 513        unsigned char *idx_hash;
 514        long fd_flag;
 515        ssize_t read_result;
 516        const unsigned hashsz = the_hash_algo->rawsz;
 517
 518        if (!p->index_data) {
 519                struct multi_pack_index *m;
 520                const char *pack_name = pack_basename(p);
 521
 522                for (m = the_repository->objects->multi_pack_index;
 523                     m; m = m->next) {
 524                        if (midx_contains_pack(m, pack_name))
 525                                break;
 526                }
 527
 528                if (!m && open_pack_index(p))
 529                        return error("packfile %s index unavailable", p->pack_name);
 530        }
 531
 532        if (!pack_max_fds) {
 533                unsigned int max_fds = get_max_fd_limit();
 534
 535                /* Save 3 for stdin/stdout/stderr, 22 for work */
 536                if (25 < max_fds)
 537                        pack_max_fds = max_fds - 25;
 538                else
 539                        pack_max_fds = 1;
 540        }
 541
 542        while (pack_max_fds <= pack_open_fds && close_one_pack())
 543                ; /* nothing */
 544
 545        p->pack_fd = git_open(p->pack_name);
 546        if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
 547                return -1;
 548        pack_open_fds++;
 549
 550        /* If we created the struct before we had the pack we lack size. */
 551        if (!p->pack_size) {
 552                if (!S_ISREG(st.st_mode))
 553                        return error("packfile %s not a regular file", p->pack_name);
 554                p->pack_size = st.st_size;
 555        } else if (p->pack_size != st.st_size)
 556                return error("packfile %s size changed", p->pack_name);
 557
 558        /* We leave these file descriptors open with sliding mmap;
 559         * there is no point keeping them open across exec(), though.
 560         */
 561        fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
 562        if (fd_flag < 0)
 563                return error("cannot determine file descriptor flags");
 564        fd_flag |= FD_CLOEXEC;
 565        if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
 566                return error("cannot set FD_CLOEXEC");
 567
 568        /* Verify we recognize this pack file format. */
 569        read_result = read_in_full(p->pack_fd, &hdr, sizeof(hdr));
 570        if (read_result < 0)
 571                return error_errno("error reading from %s", p->pack_name);
 572        if (read_result != sizeof(hdr))
 573                return error("file %s is far too short to be a packfile", p->pack_name);
 574        if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
 575                return error("file %s is not a GIT packfile", p->pack_name);
 576        if (!pack_version_ok(hdr.hdr_version))
 577                return error("packfile %s is version %"PRIu32" and not"
 578                        " supported (try upgrading GIT to a newer version)",
 579                        p->pack_name, ntohl(hdr.hdr_version));
 580
 581        /* Skip index checking if in multi-pack-index */
 582        if (!p->index_data)
 583                return 0;
 584
 585        /* Verify the pack matches its index. */
 586        if (p->num_objects != ntohl(hdr.hdr_entries))
 587                return error("packfile %s claims to have %"PRIu32" objects"
 588                             " while index indicates %"PRIu32" objects",
 589                             p->pack_name, ntohl(hdr.hdr_entries),
 590                             p->num_objects);
 591        if (lseek(p->pack_fd, p->pack_size - hashsz, SEEK_SET) == -1)
 592                return error("end of packfile %s is unavailable", p->pack_name);
 593        read_result = read_in_full(p->pack_fd, hash, hashsz);
 594        if (read_result < 0)
 595                return error_errno("error reading from %s", p->pack_name);
 596        if (read_result != hashsz)
 597                return error("packfile %s signature is unavailable", p->pack_name);
 598        idx_hash = ((unsigned char *)p->index_data) + p->index_size - hashsz * 2;
 599        if (!hasheq(hash, idx_hash))
 600                return error("packfile %s does not match index", p->pack_name);
 601        return 0;
 602}
 603
 604static int open_packed_git(struct packed_git *p)
 605{
 606        if (!open_packed_git_1(p))
 607                return 0;
 608        close_pack_fd(p);
 609        return -1;
 610}
 611
 612static int in_window(struct pack_window *win, off_t offset)
 613{
 614        /* We must promise at least one full hash after the
 615         * offset is available from this window, otherwise the offset
 616         * is not actually in this window and a different window (which
 617         * has that one hash excess) must be used.  This is to support
 618         * the object header and delta base parsing routines below.
 619         */
 620        off_t win_off = win->offset;
 621        return win_off <= offset
 622                && (offset + the_hash_algo->rawsz) <= (win_off + win->len);
 623}
 624
 625unsigned char *use_pack(struct packed_git *p,
 626                struct pack_window **w_cursor,
 627                off_t offset,
 628                unsigned long *left)
 629{
 630        struct pack_window *win = *w_cursor;
 631
 632        /* Since packfiles end in a hash of their content and it's
 633         * pointless to ask for an offset into the middle of that
 634         * hash, and the in_window function above wouldn't match
 635         * don't allow an offset too close to the end of the file.
 636         */
 637        if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
 638                die("packfile %s cannot be accessed", p->pack_name);
 639        if (offset > (p->pack_size - the_hash_algo->rawsz))
 640                die("offset beyond end of packfile (truncated pack?)");
 641        if (offset < 0)
 642                die(_("offset before end of packfile (broken .idx?)"));
 643
 644        if (!win || !in_window(win, offset)) {
 645                if (win)
 646                        win->inuse_cnt--;
 647                for (win = p->windows; win; win = win->next) {
 648                        if (in_window(win, offset))
 649                                break;
 650                }
 651                if (!win) {
 652                        size_t window_align = packed_git_window_size / 2;
 653                        off_t len;
 654
 655                        if (p->pack_fd == -1 && open_packed_git(p))
 656                                die("packfile %s cannot be accessed", p->pack_name);
 657
 658                        win = xcalloc(1, sizeof(*win));
 659                        win->offset = (offset / window_align) * window_align;
 660                        len = p->pack_size - win->offset;
 661                        if (len > packed_git_window_size)
 662                                len = packed_git_window_size;
 663                        win->len = (size_t)len;
 664                        pack_mapped += win->len;
 665                        while (packed_git_limit < pack_mapped
 666                                && unuse_one_window(p))
 667                                ; /* nothing */
 668                        win->base = xmmap_gently(NULL, win->len,
 669                                PROT_READ, MAP_PRIVATE,
 670                                p->pack_fd, win->offset);
 671                        if (win->base == MAP_FAILED)
 672                                die_errno("packfile %s cannot be mapped",
 673                                          p->pack_name);
 674                        if (!win->offset && win->len == p->pack_size
 675                                && !p->do_not_close)
 676                                close_pack_fd(p);
 677                        pack_mmap_calls++;
 678                        pack_open_windows++;
 679                        if (pack_mapped > peak_pack_mapped)
 680                                peak_pack_mapped = pack_mapped;
 681                        if (pack_open_windows > peak_pack_open_windows)
 682                                peak_pack_open_windows = pack_open_windows;
 683                        win->next = p->windows;
 684                        p->windows = win;
 685                }
 686        }
 687        if (win != *w_cursor) {
 688                win->last_used = pack_used_ctr++;
 689                win->inuse_cnt++;
 690                *w_cursor = win;
 691        }
 692        offset -= win->offset;
 693        if (left)
 694                *left = win->len - xsize_t(offset);
 695        return win->base + offset;
 696}
 697
 698void unuse_pack(struct pack_window **w_cursor)
 699{
 700        struct pack_window *w = *w_cursor;
 701        if (w) {
 702                w->inuse_cnt--;
 703                *w_cursor = NULL;
 704        }
 705}
 706
 707struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
 708{
 709        struct stat st;
 710        size_t alloc;
 711        struct packed_git *p;
 712
 713        /*
 714         * Make sure a corresponding .pack file exists and that
 715         * the index looks sane.
 716         */
 717        if (!strip_suffix_mem(path, &path_len, ".idx"))
 718                return NULL;
 719
 720        /*
 721         * ".promisor" is long enough to hold any suffix we're adding (and
 722         * the use xsnprintf double-checks that)
 723         */
 724        alloc = st_add3(path_len, strlen(".promisor"), 1);
 725        p = alloc_packed_git(alloc);
 726        memcpy(p->pack_name, path, path_len);
 727
 728        xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
 729        if (!access(p->pack_name, F_OK))
 730                p->pack_keep = 1;
 731
 732        xsnprintf(p->pack_name + path_len, alloc - path_len, ".promisor");
 733        if (!access(p->pack_name, F_OK))
 734                p->pack_promisor = 1;
 735
 736        xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
 737        if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
 738                free(p);
 739                return NULL;
 740        }
 741
 742        /* ok, it looks sane as far as we can check without
 743         * actually mapping the pack file.
 744         */
 745        p->pack_size = st.st_size;
 746        p->pack_local = local;
 747        p->mtime = st.st_mtime;
 748        if (path_len < the_hash_algo->hexsz ||
 749            get_sha1_hex(path + path_len - the_hash_algo->hexsz, p->hash))
 750                hashclr(p->hash);
 751        return p;
 752}
 753
 754void install_packed_git(struct repository *r, struct packed_git *pack)
 755{
 756        if (pack->pack_fd != -1)
 757                pack_open_fds++;
 758
 759        pack->next = r->objects->packed_git;
 760        r->objects->packed_git = pack;
 761}
 762
 763void (*report_garbage)(unsigned seen_bits, const char *path);
 764
 765static void report_helper(const struct string_list *list,
 766                          int seen_bits, int first, int last)
 767{
 768        if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
 769                return;
 770
 771        for (; first < last; first++)
 772                report_garbage(seen_bits, list->items[first].string);
 773}
 774
 775static void report_pack_garbage(struct string_list *list)
 776{
 777        int i, baselen = -1, first = 0, seen_bits = 0;
 778
 779        if (!report_garbage)
 780                return;
 781
 782        string_list_sort(list);
 783
 784        for (i = 0; i < list->nr; i++) {
 785                const char *path = list->items[i].string;
 786                if (baselen != -1 &&
 787                    strncmp(path, list->items[first].string, baselen)) {
 788                        report_helper(list, seen_bits, first, i);
 789                        baselen = -1;
 790                        seen_bits = 0;
 791                }
 792                if (baselen == -1) {
 793                        const char *dot = strrchr(path, '.');
 794                        if (!dot) {
 795                                report_garbage(PACKDIR_FILE_GARBAGE, path);
 796                                continue;
 797                        }
 798                        baselen = dot - path + 1;
 799                        first = i;
 800                }
 801                if (!strcmp(path + baselen, "pack"))
 802                        seen_bits |= 1;
 803                else if (!strcmp(path + baselen, "idx"))
 804                        seen_bits |= 2;
 805        }
 806        report_helper(list, seen_bits, first, list->nr);
 807}
 808
 809void for_each_file_in_pack_dir(const char *objdir,
 810                               each_file_in_pack_dir_fn fn,
 811                               void *data)
 812{
 813        struct strbuf path = STRBUF_INIT;
 814        size_t dirnamelen;
 815        DIR *dir;
 816        struct dirent *de;
 817
 818        strbuf_addstr(&path, objdir);
 819        strbuf_addstr(&path, "/pack");
 820        dir = opendir(path.buf);
 821        if (!dir) {
 822                if (errno != ENOENT)
 823                        error_errno("unable to open object pack directory: %s",
 824                                    path.buf);
 825                strbuf_release(&path);
 826                return;
 827        }
 828        strbuf_addch(&path, '/');
 829        dirnamelen = path.len;
 830        while ((de = readdir(dir)) != NULL) {
 831                if (is_dot_or_dotdot(de->d_name))
 832                        continue;
 833
 834                strbuf_setlen(&path, dirnamelen);
 835                strbuf_addstr(&path, de->d_name);
 836
 837                fn(path.buf, path.len, de->d_name, data);
 838        }
 839
 840        closedir(dir);
 841        strbuf_release(&path);
 842}
 843
 844struct prepare_pack_data {
 845        struct repository *r;
 846        struct string_list *garbage;
 847        int local;
 848        struct multi_pack_index *m;
 849};
 850
 851static void prepare_pack(const char *full_name, size_t full_name_len,
 852                         const char *file_name, void *_data)
 853{
 854        struct prepare_pack_data *data = (struct prepare_pack_data *)_data;
 855        struct packed_git *p;
 856        size_t base_len = full_name_len;
 857
 858        if (strip_suffix_mem(full_name, &base_len, ".idx") &&
 859            !(data->m && midx_contains_pack(data->m, file_name))) {
 860                /* Don't reopen a pack we already have. */
 861                for (p = data->r->objects->packed_git; p; p = p->next) {
 862                        size_t len;
 863                        if (strip_suffix(p->pack_name, ".pack", &len) &&
 864                            len == base_len &&
 865                            !memcmp(p->pack_name, full_name, len))
 866                                break;
 867                }
 868
 869                if (!p) {
 870                        p = add_packed_git(full_name, full_name_len, data->local);
 871                        if (p)
 872                                install_packed_git(data->r, p);
 873                }
 874        }
 875
 876        if (!report_garbage)
 877                return;
 878
 879        if (!strcmp(file_name, "multi-pack-index"))
 880                return;
 881        if (ends_with(file_name, ".idx") ||
 882            ends_with(file_name, ".pack") ||
 883            ends_with(file_name, ".bitmap") ||
 884            ends_with(file_name, ".keep") ||
 885            ends_with(file_name, ".promisor"))
 886                string_list_append(data->garbage, full_name);
 887        else
 888                report_garbage(PACKDIR_FILE_GARBAGE, full_name);
 889}
 890
 891static void prepare_packed_git_one(struct repository *r, char *objdir, int local)
 892{
 893        struct prepare_pack_data data;
 894        struct string_list garbage = STRING_LIST_INIT_DUP;
 895
 896        data.m = r->objects->multi_pack_index;
 897
 898        /* look for the multi-pack-index for this object directory */
 899        while (data.m && strcmp(data.m->object_dir, objdir))
 900                data.m = data.m->next;
 901
 902        data.r = r;
 903        data.garbage = &garbage;
 904        data.local = local;
 905
 906        for_each_file_in_pack_dir(objdir, prepare_pack, &data);
 907
 908        report_pack_garbage(data.garbage);
 909        string_list_clear(data.garbage, 0);
 910}
 911
 912static void prepare_packed_git(struct repository *r);
 913/*
 914 * Give a fast, rough count of the number of objects in the repository. This
 915 * ignores loose objects completely. If you have a lot of them, then either
 916 * you should repack because your performance will be awful, or they are
 917 * all unreachable objects about to be pruned, in which case they're not really
 918 * interesting as a measure of repo size in the first place.
 919 */
 920unsigned long repo_approximate_object_count(struct repository *r)
 921{
 922        if (!r->objects->approximate_object_count_valid) {
 923                unsigned long count;
 924                struct multi_pack_index *m;
 925                struct packed_git *p;
 926
 927                prepare_packed_git(r);
 928                count = 0;
 929                for (m = get_multi_pack_index(r); m; m = m->next)
 930                        count += m->num_objects;
 931                for (p = r->objects->packed_git; p; p = p->next) {
 932                        if (open_pack_index(p))
 933                                continue;
 934                        count += p->num_objects;
 935                }
 936                r->objects->approximate_object_count = count;
 937        }
 938        return r->objects->approximate_object_count;
 939}
 940
 941static void *get_next_packed_git(const void *p)
 942{
 943        return ((const struct packed_git *)p)->next;
 944}
 945
 946static void set_next_packed_git(void *p, void *next)
 947{
 948        ((struct packed_git *)p)->next = next;
 949}
 950
 951static int sort_pack(const void *a_, const void *b_)
 952{
 953        const struct packed_git *a = a_;
 954        const struct packed_git *b = b_;
 955        int st;
 956
 957        /*
 958         * Local packs tend to contain objects specific to our
 959         * variant of the project than remote ones.  In addition,
 960         * remote ones could be on a network mounted filesystem.
 961         * Favor local ones for these reasons.
 962         */
 963        st = a->pack_local - b->pack_local;
 964        if (st)
 965                return -st;
 966
 967        /*
 968         * Younger packs tend to contain more recent objects,
 969         * and more recent objects tend to get accessed more
 970         * often.
 971         */
 972        if (a->mtime < b->mtime)
 973                return 1;
 974        else if (a->mtime == b->mtime)
 975                return 0;
 976        return -1;
 977}
 978
 979static void rearrange_packed_git(struct repository *r)
 980{
 981        r->objects->packed_git = llist_mergesort(
 982                r->objects->packed_git, get_next_packed_git,
 983                set_next_packed_git, sort_pack);
 984}
 985
 986static void prepare_packed_git_mru(struct repository *r)
 987{
 988        struct packed_git *p;
 989
 990        INIT_LIST_HEAD(&r->objects->packed_git_mru);
 991
 992        for (p = r->objects->packed_git; p; p = p->next)
 993                list_add_tail(&p->mru, &r->objects->packed_git_mru);
 994}
 995
 996static void prepare_packed_git(struct repository *r)
 997{
 998        struct object_directory *odb;
 999
1000        if (r->objects->packed_git_initialized)
1001                return;
1002
1003        prepare_alt_odb(r);
1004        for (odb = r->objects->odb; odb; odb = odb->next) {
1005                int local = (odb == r->objects->odb);
1006                prepare_multi_pack_index_one(r, odb->path, local);
1007                prepare_packed_git_one(r, odb->path, local);
1008        }
1009        rearrange_packed_git(r);
1010
1011        prepare_packed_git_mru(r);
1012        r->objects->packed_git_initialized = 1;
1013}
1014
1015void reprepare_packed_git(struct repository *r)
1016{
1017        struct object_directory *odb;
1018
1019        for (odb = r->objects->odb; odb; odb = odb->next)
1020                odb_clear_loose_cache(odb);
1021
1022        r->objects->approximate_object_count_valid = 0;
1023        r->objects->packed_git_initialized = 0;
1024        prepare_packed_git(r);
1025}
1026
1027struct packed_git *get_packed_git(struct repository *r)
1028{
1029        prepare_packed_git(r);
1030        return r->objects->packed_git;
1031}
1032
1033struct multi_pack_index *get_multi_pack_index(struct repository *r)
1034{
1035        prepare_packed_git(r);
1036        return r->objects->multi_pack_index;
1037}
1038
1039struct packed_git *get_all_packs(struct repository *r)
1040{
1041        struct multi_pack_index *m;
1042
1043        prepare_packed_git(r);
1044        for (m = r->objects->multi_pack_index; m; m = m->next) {
1045                uint32_t i;
1046                for (i = 0; i < m->num_packs; i++)
1047                        prepare_midx_pack(r, m, i);
1048        }
1049
1050        return r->objects->packed_git;
1051}
1052
1053struct list_head *get_packed_git_mru(struct repository *r)
1054{
1055        prepare_packed_git(r);
1056        return &r->objects->packed_git_mru;
1057}
1058
1059unsigned long unpack_object_header_buffer(const unsigned char *buf,
1060                unsigned long len, enum object_type *type, unsigned long *sizep)
1061{
1062        unsigned shift;
1063        unsigned long size, c;
1064        unsigned long used = 0;
1065
1066        c = buf[used++];
1067        *type = (c >> 4) & 7;
1068        size = c & 15;
1069        shift = 4;
1070        while (c & 0x80) {
1071                if (len <= used || bitsizeof(long) <= shift) {
1072                        error("bad object header");
1073                        size = used = 0;
1074                        break;
1075                }
1076                c = buf[used++];
1077                size += (c & 0x7f) << shift;
1078                shift += 7;
1079        }
1080        *sizep = size;
1081        return used;
1082}
1083
1084unsigned long get_size_from_delta(struct packed_git *p,
1085                                  struct pack_window **w_curs,
1086                                  off_t curpos)
1087{
1088        const unsigned char *data;
1089        unsigned char delta_head[20], *in;
1090        git_zstream stream;
1091        int st;
1092
1093        memset(&stream, 0, sizeof(stream));
1094        stream.next_out = delta_head;
1095        stream.avail_out = sizeof(delta_head);
1096
1097        git_inflate_init(&stream);
1098        do {
1099                in = use_pack(p, w_curs, curpos, &stream.avail_in);
1100                stream.next_in = in;
1101                st = git_inflate(&stream, Z_FINISH);
1102                curpos += stream.next_in - in;
1103        } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1104                 stream.total_out < sizeof(delta_head));
1105        git_inflate_end(&stream);
1106        if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1107                error("delta data unpack-initial failed");
1108                return 0;
1109        }
1110
1111        /* Examine the initial part of the delta to figure out
1112         * the result size.
1113         */
1114        data = delta_head;
1115
1116        /* ignore base size */
1117        get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1118
1119        /* Read the result size */
1120        return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1121}
1122
1123int unpack_object_header(struct packed_git *p,
1124                         struct pack_window **w_curs,
1125                         off_t *curpos,
1126                         unsigned long *sizep)
1127{
1128        unsigned char *base;
1129        unsigned long left;
1130        unsigned long used;
1131        enum object_type type;
1132
1133        /* use_pack() assures us we have [base, base + 20) available
1134         * as a range that we can look at.  (Its actually the hash
1135         * size that is assured.)  With our object header encoding
1136         * the maximum deflated object size is 2^137, which is just
1137         * insane, so we know won't exceed what we have been given.
1138         */
1139        base = use_pack(p, w_curs, *curpos, &left);
1140        used = unpack_object_header_buffer(base, left, &type, sizep);
1141        if (!used) {
1142                type = OBJ_BAD;
1143        } else
1144                *curpos += used;
1145
1146        return type;
1147}
1148
1149void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1)
1150{
1151        unsigned i;
1152        const unsigned hashsz = the_hash_algo->rawsz;
1153        for (i = 0; i < p->num_bad_objects; i++)
1154                if (hasheq(sha1, p->bad_object_sha1 + hashsz * i))
1155                        return;
1156        p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1157                                      st_mult(GIT_MAX_RAWSZ,
1158                                              st_add(p->num_bad_objects, 1)));
1159        hashcpy(p->bad_object_sha1 + hashsz * p->num_bad_objects, sha1);
1160        p->num_bad_objects++;
1161}
1162
1163const struct packed_git *has_packed_and_bad(struct repository *r,
1164                                            const unsigned char *sha1)
1165{
1166        struct packed_git *p;
1167        unsigned i;
1168
1169        for (p = r->objects->packed_git; p; p = p->next)
1170                for (i = 0; i < p->num_bad_objects; i++)
1171                        if (hasheq(sha1,
1172                                   p->bad_object_sha1 + the_hash_algo->rawsz * i))
1173                                return p;
1174        return NULL;
1175}
1176
1177static off_t get_delta_base(struct packed_git *p,
1178                                    struct pack_window **w_curs,
1179                                    off_t *curpos,
1180                                    enum object_type type,
1181                                    off_t delta_obj_offset)
1182{
1183        unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1184        off_t base_offset;
1185
1186        /* use_pack() assured us we have [base_info, base_info + 20)
1187         * as a range that we can look at without walking off the
1188         * end of the mapped window.  Its actually the hash size
1189         * that is assured.  An OFS_DELTA longer than the hash size
1190         * is stupid, as then a REF_DELTA would be smaller to store.
1191         */
1192        if (type == OBJ_OFS_DELTA) {
1193                unsigned used = 0;
1194                unsigned char c = base_info[used++];
1195                base_offset = c & 127;
1196                while (c & 128) {
1197                        base_offset += 1;
1198                        if (!base_offset || MSB(base_offset, 7))
1199                                return 0;  /* overflow */
1200                        c = base_info[used++];
1201                        base_offset = (base_offset << 7) + (c & 127);
1202                }
1203                base_offset = delta_obj_offset - base_offset;
1204                if (base_offset <= 0 || base_offset >= delta_obj_offset)
1205                        return 0;  /* out of bound */
1206                *curpos += used;
1207        } else if (type == OBJ_REF_DELTA) {
1208                /* The base entry _must_ be in the same pack */
1209                base_offset = find_pack_entry_one(base_info, p);
1210                *curpos += the_hash_algo->rawsz;
1211        } else
1212                die("I am totally screwed");
1213        return base_offset;
1214}
1215
1216/*
1217 * Like get_delta_base above, but we return the sha1 instead of the pack
1218 * offset. This means it is cheaper for REF deltas (we do not have to do
1219 * the final object lookup), but more expensive for OFS deltas (we
1220 * have to load the revidx to convert the offset back into a sha1).
1221 */
1222static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1223                                                struct pack_window **w_curs,
1224                                                off_t curpos,
1225                                                enum object_type type,
1226                                                off_t delta_obj_offset)
1227{
1228        if (type == OBJ_REF_DELTA) {
1229                unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1230                return base;
1231        } else if (type == OBJ_OFS_DELTA) {
1232                struct revindex_entry *revidx;
1233                off_t base_offset = get_delta_base(p, w_curs, &curpos,
1234                                                   type, delta_obj_offset);
1235
1236                if (!base_offset)
1237                        return NULL;
1238
1239                revidx = find_pack_revindex(p, base_offset);
1240                if (!revidx)
1241                        return NULL;
1242
1243                return nth_packed_object_sha1(p, revidx->nr);
1244        } else
1245                return NULL;
1246}
1247
1248static int retry_bad_packed_offset(struct repository *r,
1249                                   struct packed_git *p,
1250                                   off_t obj_offset)
1251{
1252        int type;
1253        struct revindex_entry *revidx;
1254        struct object_id oid;
1255        revidx = find_pack_revindex(p, obj_offset);
1256        if (!revidx)
1257                return OBJ_BAD;
1258        nth_packed_object_oid(&oid, p, revidx->nr);
1259        mark_bad_packed_object(p, oid.hash);
1260        type = oid_object_info(r, &oid, NULL);
1261        if (type <= OBJ_NONE)
1262                return OBJ_BAD;
1263        return type;
1264}
1265
1266#define POI_STACK_PREALLOC 64
1267
1268static enum object_type packed_to_object_type(struct repository *r,
1269                                              struct packed_git *p,
1270                                              off_t obj_offset,
1271                                              enum object_type type,
1272                                              struct pack_window **w_curs,
1273                                              off_t curpos)
1274{
1275        off_t small_poi_stack[POI_STACK_PREALLOC];
1276        off_t *poi_stack = small_poi_stack;
1277        int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1278
1279        while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1280                off_t base_offset;
1281                unsigned long size;
1282                /* Push the object we're going to leave behind */
1283                if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1284                        poi_stack_alloc = alloc_nr(poi_stack_nr);
1285                        ALLOC_ARRAY(poi_stack, poi_stack_alloc);
1286                        COPY_ARRAY(poi_stack, small_poi_stack, poi_stack_nr);
1287                } else {
1288                        ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1289                }
1290                poi_stack[poi_stack_nr++] = obj_offset;
1291                /* If parsing the base offset fails, just unwind */
1292                base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1293                if (!base_offset)
1294                        goto unwind;
1295                curpos = obj_offset = base_offset;
1296                type = unpack_object_header(p, w_curs, &curpos, &size);
1297                if (type <= OBJ_NONE) {
1298                        /* If getting the base itself fails, we first
1299                         * retry the base, otherwise unwind */
1300                        type = retry_bad_packed_offset(r, p, base_offset);
1301                        if (type > OBJ_NONE)
1302                                goto out;
1303                        goto unwind;
1304                }
1305        }
1306
1307        switch (type) {
1308        case OBJ_BAD:
1309        case OBJ_COMMIT:
1310        case OBJ_TREE:
1311        case OBJ_BLOB:
1312        case OBJ_TAG:
1313                break;
1314        default:
1315                error("unknown object type %i at offset %"PRIuMAX" in %s",
1316                      type, (uintmax_t)obj_offset, p->pack_name);
1317                type = OBJ_BAD;
1318        }
1319
1320out:
1321        if (poi_stack != small_poi_stack)
1322                free(poi_stack);
1323        return type;
1324
1325unwind:
1326        while (poi_stack_nr) {
1327                obj_offset = poi_stack[--poi_stack_nr];
1328                type = retry_bad_packed_offset(r, p, obj_offset);
1329                if (type > OBJ_NONE)
1330                        goto out;
1331        }
1332        type = OBJ_BAD;
1333        goto out;
1334}
1335
1336static struct hashmap delta_base_cache;
1337static size_t delta_base_cached;
1338
1339static LIST_HEAD(delta_base_cache_lru);
1340
1341struct delta_base_cache_key {
1342        struct packed_git *p;
1343        off_t base_offset;
1344};
1345
1346struct delta_base_cache_entry {
1347        struct hashmap hash;
1348        struct delta_base_cache_key key;
1349        struct list_head lru;
1350        void *data;
1351        unsigned long size;
1352        enum object_type type;
1353};
1354
1355static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
1356{
1357        unsigned int hash;
1358
1359        hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
1360        hash += (hash >> 8) + (hash >> 16);
1361        return hash;
1362}
1363
1364static struct delta_base_cache_entry *
1365get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
1366{
1367        struct hashmap_entry entry;
1368        struct delta_base_cache_key key;
1369
1370        if (!delta_base_cache.cmpfn)
1371                return NULL;
1372
1373        hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
1374        key.p = p;
1375        key.base_offset = base_offset;
1376        return hashmap_get(&delta_base_cache, &entry, &key);
1377}
1378
1379static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
1380                                   const struct delta_base_cache_key *b)
1381{
1382        return a->p == b->p && a->base_offset == b->base_offset;
1383}
1384
1385static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
1386                                     const void *va, const void *vb,
1387                                     const void *vkey)
1388{
1389        const struct delta_base_cache_entry *a = va, *b = vb;
1390        const struct delta_base_cache_key *key = vkey;
1391        if (key)
1392                return !delta_base_cache_key_eq(&a->key, key);
1393        else
1394                return !delta_base_cache_key_eq(&a->key, &b->key);
1395}
1396
1397static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1398{
1399        return !!get_delta_base_cache_entry(p, base_offset);
1400}
1401
1402/*
1403 * Remove the entry from the cache, but do _not_ free the associated
1404 * entry data. The caller takes ownership of the "data" buffer, and
1405 * should copy out any fields it wants before detaching.
1406 */
1407static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
1408{
1409        hashmap_remove(&delta_base_cache, ent, &ent->key);
1410        list_del(&ent->lru);
1411        delta_base_cached -= ent->size;
1412        free(ent);
1413}
1414
1415static void *cache_or_unpack_entry(struct repository *r, struct packed_git *p,
1416                                   off_t base_offset, unsigned long *base_size,
1417                                   enum object_type *type)
1418{
1419        struct delta_base_cache_entry *ent;
1420
1421        ent = get_delta_base_cache_entry(p, base_offset);
1422        if (!ent)
1423                return unpack_entry(r, p, base_offset, type, base_size);
1424
1425        if (type)
1426                *type = ent->type;
1427        if (base_size)
1428                *base_size = ent->size;
1429        return xmemdupz(ent->data, ent->size);
1430}
1431
1432static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1433{
1434        free(ent->data);
1435        detach_delta_base_cache_entry(ent);
1436}
1437
1438void clear_delta_base_cache(void)
1439{
1440        struct list_head *lru, *tmp;
1441        list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1442                struct delta_base_cache_entry *entry =
1443                        list_entry(lru, struct delta_base_cache_entry, lru);
1444                release_delta_base_cache(entry);
1445        }
1446}
1447
1448static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1449        void *base, unsigned long base_size, enum object_type type)
1450{
1451        struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
1452        struct list_head *lru, *tmp;
1453
1454        delta_base_cached += base_size;
1455
1456        list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1457                struct delta_base_cache_entry *f =
1458                        list_entry(lru, struct delta_base_cache_entry, lru);
1459                if (delta_base_cached <= delta_base_cache_limit)
1460                        break;
1461                release_delta_base_cache(f);
1462        }
1463
1464        ent->key.p = p;
1465        ent->key.base_offset = base_offset;
1466        ent->type = type;
1467        ent->data = base;
1468        ent->size = base_size;
1469        list_add_tail(&ent->lru, &delta_base_cache_lru);
1470
1471        if (!delta_base_cache.cmpfn)
1472                hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
1473        hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
1474        hashmap_add(&delta_base_cache, ent);
1475}
1476
1477int packed_object_info(struct repository *r, struct packed_git *p,
1478                       off_t obj_offset, struct object_info *oi)
1479{
1480        struct pack_window *w_curs = NULL;
1481        unsigned long size;
1482        off_t curpos = obj_offset;
1483        enum object_type type;
1484
1485        /*
1486         * We always get the representation type, but only convert it to
1487         * a "real" type later if the caller is interested.
1488         */
1489        if (oi->contentp) {
1490                *oi->contentp = cache_or_unpack_entry(r, p, obj_offset, oi->sizep,
1491                                                      &type);
1492                if (!*oi->contentp)
1493                        type = OBJ_BAD;
1494        } else {
1495                type = unpack_object_header(p, &w_curs, &curpos, &size);
1496        }
1497
1498        if (!oi->contentp && oi->sizep) {
1499                if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1500                        off_t tmp_pos = curpos;
1501                        off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1502                                                           type, obj_offset);
1503                        if (!base_offset) {
1504                                type = OBJ_BAD;
1505                                goto out;
1506                        }
1507                        *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1508                        if (*oi->sizep == 0) {
1509                                type = OBJ_BAD;
1510                                goto out;
1511                        }
1512                } else {
1513                        *oi->sizep = size;
1514                }
1515        }
1516
1517        if (oi->disk_sizep) {
1518                struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1519                *oi->disk_sizep = revidx[1].offset - obj_offset;
1520        }
1521
1522        if (oi->typep || oi->type_name) {
1523                enum object_type ptot;
1524                ptot = packed_to_object_type(r, p, obj_offset,
1525                                             type, &w_curs, curpos);
1526                if (oi->typep)
1527                        *oi->typep = ptot;
1528                if (oi->type_name) {
1529                        const char *tn = type_name(ptot);
1530                        if (tn)
1531                                strbuf_addstr(oi->type_name, tn);
1532                }
1533                if (ptot < 0) {
1534                        type = OBJ_BAD;
1535                        goto out;
1536                }
1537        }
1538
1539        if (oi->delta_base_sha1) {
1540                if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1541                        const unsigned char *base;
1542
1543                        base = get_delta_base_sha1(p, &w_curs, curpos,
1544                                                   type, obj_offset);
1545                        if (!base) {
1546                                type = OBJ_BAD;
1547                                goto out;
1548                        }
1549
1550                        hashcpy(oi->delta_base_sha1, base);
1551                } else
1552                        hashclr(oi->delta_base_sha1);
1553        }
1554
1555        oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
1556                                                          OI_PACKED;
1557
1558out:
1559        unuse_pack(&w_curs);
1560        return type;
1561}
1562
1563static void *unpack_compressed_entry(struct packed_git *p,
1564                                    struct pack_window **w_curs,
1565                                    off_t curpos,
1566                                    unsigned long size)
1567{
1568        int st;
1569        git_zstream stream;
1570        unsigned char *buffer, *in;
1571
1572        buffer = xmallocz_gently(size);
1573        if (!buffer)
1574                return NULL;
1575        memset(&stream, 0, sizeof(stream));
1576        stream.next_out = buffer;
1577        stream.avail_out = size + 1;
1578
1579        git_inflate_init(&stream);
1580        do {
1581                in = use_pack(p, w_curs, curpos, &stream.avail_in);
1582                stream.next_in = in;
1583                st = git_inflate(&stream, Z_FINISH);
1584                if (!stream.avail_out)
1585                        break; /* the payload is larger than it should be */
1586                curpos += stream.next_in - in;
1587        } while (st == Z_OK || st == Z_BUF_ERROR);
1588        git_inflate_end(&stream);
1589        if ((st != Z_STREAM_END) || stream.total_out != size) {
1590                free(buffer);
1591                return NULL;
1592        }
1593
1594        /* versions of zlib can clobber unconsumed portion of outbuf */
1595        buffer[size] = '\0';
1596
1597        return buffer;
1598}
1599
1600static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
1601{
1602        static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
1603        trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
1604                         p->pack_name, (uintmax_t)obj_offset);
1605}
1606
1607int do_check_packed_object_crc;
1608
1609#define UNPACK_ENTRY_STACK_PREALLOC 64
1610struct unpack_entry_stack_ent {
1611        off_t obj_offset;
1612        off_t curpos;
1613        unsigned long size;
1614};
1615
1616static void *read_object(struct repository *r,
1617                         const struct object_id *oid,
1618                         enum object_type *type,
1619                         unsigned long *size)
1620{
1621        struct object_info oi = OBJECT_INFO_INIT;
1622        void *content;
1623        oi.typep = type;
1624        oi.sizep = size;
1625        oi.contentp = &content;
1626
1627        if (oid_object_info_extended(r, oid, &oi, 0) < 0)
1628                return NULL;
1629        return content;
1630}
1631
1632void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
1633                   enum object_type *final_type, unsigned long *final_size)
1634{
1635        struct pack_window *w_curs = NULL;
1636        off_t curpos = obj_offset;
1637        void *data = NULL;
1638        unsigned long size;
1639        enum object_type type;
1640        struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
1641        struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
1642        int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
1643        int base_from_cache = 0;
1644
1645        write_pack_access_log(p, obj_offset);
1646
1647        /* PHASE 1: drill down to the innermost base object */
1648        for (;;) {
1649                off_t base_offset;
1650                int i;
1651                struct delta_base_cache_entry *ent;
1652
1653                ent = get_delta_base_cache_entry(p, curpos);
1654                if (ent) {
1655                        type = ent->type;
1656                        data = ent->data;
1657                        size = ent->size;
1658                        detach_delta_base_cache_entry(ent);
1659                        base_from_cache = 1;
1660                        break;
1661                }
1662
1663                if (do_check_packed_object_crc && p->index_version > 1) {
1664                        struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1665                        off_t len = revidx[1].offset - obj_offset;
1666                        if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1667                                struct object_id oid;
1668                                nth_packed_object_oid(&oid, p, revidx->nr);
1669                                error("bad packed object CRC for %s",
1670                                      oid_to_hex(&oid));
1671                                mark_bad_packed_object(p, oid.hash);
1672                                data = NULL;
1673                                goto out;
1674                        }
1675                }
1676
1677                type = unpack_object_header(p, &w_curs, &curpos, &size);
1678                if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
1679                        break;
1680
1681                base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1682                if (!base_offset) {
1683                        error("failed to validate delta base reference "
1684                              "at offset %"PRIuMAX" from %s",
1685                              (uintmax_t)curpos, p->pack_name);
1686                        /* bail to phase 2, in hopes of recovery */
1687                        data = NULL;
1688                        break;
1689                }
1690
1691                /* push object, proceed to base */
1692                if (delta_stack_nr >= delta_stack_alloc
1693                    && delta_stack == small_delta_stack) {
1694                        delta_stack_alloc = alloc_nr(delta_stack_nr);
1695                        ALLOC_ARRAY(delta_stack, delta_stack_alloc);
1696                        COPY_ARRAY(delta_stack, small_delta_stack,
1697                                   delta_stack_nr);
1698                } else {
1699                        ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
1700                }
1701                i = delta_stack_nr++;
1702                delta_stack[i].obj_offset = obj_offset;
1703                delta_stack[i].curpos = curpos;
1704                delta_stack[i].size = size;
1705
1706                curpos = obj_offset = base_offset;
1707        }
1708
1709        /* PHASE 2: handle the base */
1710        switch (type) {
1711        case OBJ_OFS_DELTA:
1712        case OBJ_REF_DELTA:
1713                if (data)
1714                        BUG("unpack_entry: left loop at a valid delta");
1715                break;
1716        case OBJ_COMMIT:
1717        case OBJ_TREE:
1718        case OBJ_BLOB:
1719        case OBJ_TAG:
1720                if (!base_from_cache)
1721                        data = unpack_compressed_entry(p, &w_curs, curpos, size);
1722                break;
1723        default:
1724                data = NULL;
1725                error("unknown object type %i at offset %"PRIuMAX" in %s",
1726                      type, (uintmax_t)obj_offset, p->pack_name);
1727        }
1728
1729        /* PHASE 3: apply deltas in order */
1730
1731        /* invariants:
1732         *   'data' holds the base data, or NULL if there was corruption
1733         */
1734        while (delta_stack_nr) {
1735                void *delta_data;
1736                void *base = data;
1737                void *external_base = NULL;
1738                unsigned long delta_size, base_size = size;
1739                int i;
1740
1741                data = NULL;
1742
1743                if (base)
1744                        add_delta_base_cache(p, obj_offset, base, base_size, type);
1745
1746                if (!base) {
1747                        /*
1748                         * We're probably in deep shit, but let's try to fetch
1749                         * the required base anyway from another pack or loose.
1750                         * This is costly but should happen only in the presence
1751                         * of a corrupted pack, and is better than failing outright.
1752                         */
1753                        struct revindex_entry *revidx;
1754                        struct object_id base_oid;
1755                        revidx = find_pack_revindex(p, obj_offset);
1756                        if (revidx) {
1757                                nth_packed_object_oid(&base_oid, p, revidx->nr);
1758                                error("failed to read delta base object %s"
1759                                      " at offset %"PRIuMAX" from %s",
1760                                      oid_to_hex(&base_oid), (uintmax_t)obj_offset,
1761                                      p->pack_name);
1762                                mark_bad_packed_object(p, base_oid.hash);
1763                                base = read_object(r, &base_oid, &type, &base_size);
1764                                external_base = base;
1765                        }
1766                }
1767
1768                i = --delta_stack_nr;
1769                obj_offset = delta_stack[i].obj_offset;
1770                curpos = delta_stack[i].curpos;
1771                delta_size = delta_stack[i].size;
1772
1773                if (!base)
1774                        continue;
1775
1776                delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
1777
1778                if (!delta_data) {
1779                        error("failed to unpack compressed delta "
1780                              "at offset %"PRIuMAX" from %s",
1781                              (uintmax_t)curpos, p->pack_name);
1782                        data = NULL;
1783                        free(external_base);
1784                        continue;
1785                }
1786
1787                data = patch_delta(base, base_size,
1788                                   delta_data, delta_size,
1789                                   &size);
1790
1791                /*
1792                 * We could not apply the delta; warn the user, but keep going.
1793                 * Our failure will be noticed either in the next iteration of
1794                 * the loop, or if this is the final delta, in the caller when
1795                 * we return NULL. Those code paths will take care of making
1796                 * a more explicit warning and retrying with another copy of
1797                 * the object.
1798                 */
1799                if (!data)
1800                        error("failed to apply delta");
1801
1802                free(delta_data);
1803                free(external_base);
1804        }
1805
1806        if (final_type)
1807                *final_type = type;
1808        if (final_size)
1809                *final_size = size;
1810
1811out:
1812        unuse_pack(&w_curs);
1813
1814        if (delta_stack != small_delta_stack)
1815                free(delta_stack);
1816
1817        return data;
1818}
1819
1820int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result)
1821{
1822        const unsigned char *index_fanout = p->index_data;
1823        const unsigned char *index_lookup;
1824        const unsigned int hashsz = the_hash_algo->rawsz;
1825        int index_lookup_width;
1826
1827        if (!index_fanout)
1828                BUG("bsearch_pack called without a valid pack-index");
1829
1830        index_lookup = index_fanout + 4 * 256;
1831        if (p->index_version == 1) {
1832                index_lookup_width = hashsz + 4;
1833                index_lookup += 4;
1834        } else {
1835                index_lookup_width = hashsz;
1836                index_fanout += 8;
1837                index_lookup += 8;
1838        }
1839
1840        return bsearch_hash(oid->hash, (const uint32_t*)index_fanout,
1841                            index_lookup, index_lookup_width, result);
1842}
1843
1844const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1845                                            uint32_t n)
1846{
1847        const unsigned char *index = p->index_data;
1848        const unsigned int hashsz = the_hash_algo->rawsz;
1849        if (!index) {
1850                if (open_pack_index(p))
1851                        return NULL;
1852                index = p->index_data;
1853        }
1854        if (n >= p->num_objects)
1855                return NULL;
1856        index += 4 * 256;
1857        if (p->index_version == 1) {
1858                return index + (hashsz + 4) * n + 4;
1859        } else {
1860                index += 8;
1861                return index + hashsz * n;
1862        }
1863}
1864
1865const struct object_id *nth_packed_object_oid(struct object_id *oid,
1866                                              struct packed_git *p,
1867                                              uint32_t n)
1868{
1869        const unsigned char *hash = nth_packed_object_sha1(p, n);
1870        if (!hash)
1871                return NULL;
1872        hashcpy(oid->hash, hash);
1873        return oid;
1874}
1875
1876void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
1877{
1878        const unsigned char *ptr = vptr;
1879        const unsigned char *start = p->index_data;
1880        const unsigned char *end = start + p->index_size;
1881        if (ptr < start)
1882                die(_("offset before start of pack index for %s (corrupt index?)"),
1883                    p->pack_name);
1884        /* No need to check for underflow; .idx files must be at least 8 bytes */
1885        if (ptr >= end - 8)
1886                die(_("offset beyond end of pack index for %s (truncated index?)"),
1887                    p->pack_name);
1888}
1889
1890off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1891{
1892        const unsigned char *index = p->index_data;
1893        const unsigned int hashsz = the_hash_algo->rawsz;
1894        index += 4 * 256;
1895        if (p->index_version == 1) {
1896                return ntohl(*((uint32_t *)(index + (hashsz + 4) * n)));
1897        } else {
1898                uint32_t off;
1899                index += 8 + p->num_objects * (hashsz + 4);
1900                off = ntohl(*((uint32_t *)(index + 4 * n)));
1901                if (!(off & 0x80000000))
1902                        return off;
1903                index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1904                check_pack_index_ptr(p, index);
1905                return get_be64(index);
1906        }
1907}
1908
1909off_t find_pack_entry_one(const unsigned char *sha1,
1910                                  struct packed_git *p)
1911{
1912        const unsigned char *index = p->index_data;
1913        struct object_id oid;
1914        uint32_t result;
1915
1916        if (!index) {
1917                if (open_pack_index(p))
1918                        return 0;
1919        }
1920
1921        hashcpy(oid.hash, sha1);
1922        if (bsearch_pack(&oid, p, &result))
1923                return nth_packed_object_offset(p, result);
1924        return 0;
1925}
1926
1927int is_pack_valid(struct packed_git *p)
1928{
1929        /* An already open pack is known to be valid. */
1930        if (p->pack_fd != -1)
1931                return 1;
1932
1933        /* If the pack has one window completely covering the
1934         * file size, the pack is known to be valid even if
1935         * the descriptor is not currently open.
1936         */
1937        if (p->windows) {
1938                struct pack_window *w = p->windows;
1939
1940                if (!w->offset && w->len == p->pack_size)
1941                        return 1;
1942        }
1943
1944        /* Force the pack to open to prove its valid. */
1945        return !open_packed_git(p);
1946}
1947
1948struct packed_git *find_sha1_pack(const unsigned char *sha1,
1949                                  struct packed_git *packs)
1950{
1951        struct packed_git *p;
1952
1953        for (p = packs; p; p = p->next) {
1954                if (find_pack_entry_one(sha1, p))
1955                        return p;
1956        }
1957        return NULL;
1958
1959}
1960
1961static int fill_pack_entry(const struct object_id *oid,
1962                           struct pack_entry *e,
1963                           struct packed_git *p)
1964{
1965        off_t offset;
1966
1967        if (p->num_bad_objects) {
1968                unsigned i;
1969                for (i = 0; i < p->num_bad_objects; i++)
1970                        if (hasheq(oid->hash,
1971                                   p->bad_object_sha1 + the_hash_algo->rawsz * i))
1972                                return 0;
1973        }
1974
1975        offset = find_pack_entry_one(oid->hash, p);
1976        if (!offset)
1977                return 0;
1978
1979        /*
1980         * We are about to tell the caller where they can locate the
1981         * requested object.  We better make sure the packfile is
1982         * still here and can be accessed before supplying that
1983         * answer, as it may have been deleted since the index was
1984         * loaded!
1985         */
1986        if (!is_pack_valid(p))
1987                return 0;
1988        e->offset = offset;
1989        e->p = p;
1990        return 1;
1991}
1992
1993int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
1994{
1995        struct list_head *pos;
1996        struct multi_pack_index *m;
1997
1998        prepare_packed_git(r);
1999        if (!r->objects->packed_git && !r->objects->multi_pack_index)
2000                return 0;
2001
2002        for (m = r->objects->multi_pack_index; m; m = m->next) {
2003                if (fill_midx_entry(r, oid, e, m))
2004                        return 1;
2005        }
2006
2007        list_for_each(pos, &r->objects->packed_git_mru) {
2008                struct packed_git *p = list_entry(pos, struct packed_git, mru);
2009                if (!p->multi_pack_index && fill_pack_entry(oid, e, p)) {
2010                        list_move(&p->mru, &r->objects->packed_git_mru);
2011                        return 1;
2012                }
2013        }
2014        return 0;
2015}
2016
2017int has_object_pack(const struct object_id *oid)
2018{
2019        struct pack_entry e;
2020        return find_pack_entry(the_repository, oid, &e);
2021}
2022
2023int has_pack_index(const unsigned char *sha1)
2024{
2025        struct stat st;
2026        if (stat(sha1_pack_index_name(sha1), &st))
2027                return 0;
2028        return 1;
2029}
2030
2031int for_each_object_in_pack(struct packed_git *p,
2032                            each_packed_object_fn cb, void *data,
2033                            enum for_each_object_flags flags)
2034{
2035        uint32_t i;
2036        int r = 0;
2037
2038        if (flags & FOR_EACH_OBJECT_PACK_ORDER) {
2039                if (load_pack_revindex(p))
2040                        return -1;
2041        }
2042
2043        for (i = 0; i < p->num_objects; i++) {
2044                uint32_t pos;
2045                struct object_id oid;
2046
2047                if (flags & FOR_EACH_OBJECT_PACK_ORDER)
2048                        pos = p->revindex[i].nr;
2049                else
2050                        pos = i;
2051
2052                if (!nth_packed_object_oid(&oid, p, pos))
2053                        return error("unable to get sha1 of object %u in %s",
2054                                     pos, p->pack_name);
2055
2056                r = cb(&oid, p, pos, data);
2057                if (r)
2058                        break;
2059        }
2060        return r;
2061}
2062
2063int for_each_packed_object(each_packed_object_fn cb, void *data,
2064                           enum for_each_object_flags flags)
2065{
2066        struct packed_git *p;
2067        int r = 0;
2068        int pack_errors = 0;
2069
2070        prepare_packed_git(the_repository);
2071        for (p = get_all_packs(the_repository); p; p = p->next) {
2072                if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
2073                        continue;
2074                if ((flags & FOR_EACH_OBJECT_PROMISOR_ONLY) &&
2075                    !p->pack_promisor)
2076                        continue;
2077                if (open_pack_index(p)) {
2078                        pack_errors = 1;
2079                        continue;
2080                }
2081                r = for_each_object_in_pack(p, cb, data, flags);
2082                if (r)
2083                        break;
2084        }
2085        return r ? r : pack_errors;
2086}
2087
2088static int add_promisor_object(const struct object_id *oid,
2089                               struct packed_git *pack,
2090                               uint32_t pos,
2091                               void *set_)
2092{
2093        struct oidset *set = set_;
2094        struct object *obj = parse_object(the_repository, oid);
2095        if (!obj)
2096                return 1;
2097
2098        oidset_insert(set, oid);
2099
2100        /*
2101         * If this is a tree, commit, or tag, the objects it refers
2102         * to are also promisor objects. (Blobs refer to no objects->)
2103         */
2104        if (obj->type == OBJ_TREE) {
2105                struct tree *tree = (struct tree *)obj;
2106                struct tree_desc desc;
2107                struct name_entry entry;
2108                if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
2109                        /*
2110                         * Error messages are given when packs are
2111                         * verified, so do not print any here.
2112                         */
2113                        return 0;
2114                while (tree_entry_gently(&desc, &entry))
2115                        oidset_insert(set, &entry.oid);
2116        } else if (obj->type == OBJ_COMMIT) {
2117                struct commit *commit = (struct commit *) obj;
2118                struct commit_list *parents = commit->parents;
2119
2120                oidset_insert(set, get_commit_tree_oid(commit));
2121                for (; parents; parents = parents->next)
2122                        oidset_insert(set, &parents->item->object.oid);
2123        } else if (obj->type == OBJ_TAG) {
2124                struct tag *tag = (struct tag *) obj;
2125                oidset_insert(set, get_tagged_oid(tag));
2126        }
2127        return 0;
2128}
2129
2130int is_promisor_object(const struct object_id *oid)
2131{
2132        static struct oidset promisor_objects;
2133        static int promisor_objects_prepared;
2134
2135        if (!promisor_objects_prepared) {
2136                if (has_promisor_remote()) {
2137                        for_each_packed_object(add_promisor_object,
2138                                               &promisor_objects,
2139                                               FOR_EACH_OBJECT_PROMISOR_ONLY);
2140                }
2141                promisor_objects_prepared = 1;
2142        }
2143        return oidset_contains(&promisor_objects, oid);
2144}