packfile.con commit commit-graph: release strbufs after use (0aa6bce)
   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
  21char *odb_pack_name(struct strbuf *buf,
  22                    const unsigned char *sha1,
  23                    const char *ext)
  24{
  25        strbuf_reset(buf);
  26        strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
  27                    sha1_to_hex(sha1), ext);
  28        return buf->buf;
  29}
  30
  31char *sha1_pack_name(const unsigned char *sha1)
  32{
  33        static struct strbuf buf = STRBUF_INIT;
  34        return odb_pack_name(&buf, sha1, "pack");
  35}
  36
  37char *sha1_pack_index_name(const unsigned char *sha1)
  38{
  39        static struct strbuf buf = STRBUF_INIT;
  40        return odb_pack_name(&buf, sha1, "idx");
  41}
  42
  43static unsigned int pack_used_ctr;
  44static unsigned int pack_mmap_calls;
  45static unsigned int peak_pack_open_windows;
  46static unsigned int pack_open_windows;
  47static unsigned int pack_open_fds;
  48static unsigned int pack_max_fds;
  49static size_t peak_pack_mapped;
  50static size_t pack_mapped;
  51
  52#define SZ_FMT PRIuMAX
  53static inline uintmax_t sz_fmt(size_t s) { return s; }
  54
  55void pack_report(void)
  56{
  57        fprintf(stderr,
  58                "pack_report: getpagesize()            = %10" SZ_FMT "\n"
  59                "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
  60                "pack_report: core.packedGitLimit      = %10" SZ_FMT "\n",
  61                sz_fmt(getpagesize()),
  62                sz_fmt(packed_git_window_size),
  63                sz_fmt(packed_git_limit));
  64        fprintf(stderr,
  65                "pack_report: pack_used_ctr            = %10u\n"
  66                "pack_report: pack_mmap_calls          = %10u\n"
  67                "pack_report: pack_open_windows        = %10u / %10u\n"
  68                "pack_report: pack_mapped              = "
  69                        "%10" SZ_FMT " / %10" SZ_FMT "\n",
  70                pack_used_ctr,
  71                pack_mmap_calls,
  72                pack_open_windows, peak_pack_open_windows,
  73                sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
  74}
  75
  76/*
  77 * Open and mmap the index file at path, perform a couple of
  78 * consistency checks, then record its information to p.  Return 0 on
  79 * success.
  80 */
  81static int check_packed_git_idx(const char *path, struct packed_git *p)
  82{
  83        void *idx_map;
  84        size_t idx_size;
  85        int fd = git_open(path), ret;
  86        struct stat st;
  87        const unsigned int hashsz = the_hash_algo->rawsz;
  88
  89        if (fd < 0)
  90                return -1;
  91        if (fstat(fd, &st)) {
  92                close(fd);
  93                return -1;
  94        }
  95        idx_size = xsize_t(st.st_size);
  96        if (idx_size < 4 * 256 + hashsz + hashsz) {
  97                close(fd);
  98                return error("index file %s is too small", path);
  99        }
 100        idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
 101        close(fd);
 102
 103        ret = load_idx(path, hashsz, idx_map, idx_size, p);
 104
 105        if (ret)
 106                munmap(idx_map, idx_size);
 107
 108        return ret;
 109}
 110
 111int load_idx(const char *path, const unsigned int hashsz, void *idx_map,
 112             size_t idx_size, struct packed_git *p)
 113{
 114        struct pack_idx_header *hdr = idx_map;
 115        uint32_t version, nr, i, *index;
 116
 117        if (idx_size < 4 * 256 + hashsz + hashsz)
 118                return error("index file %s is too small", path);
 119        if (idx_map == NULL)
 120                return error("empty data");
 121
 122        if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
 123                version = ntohl(hdr->idx_version);
 124                if (version < 2 || version > 2)
 125                        return error("index file %s is version %"PRIu32
 126                                     " and is not supported by this binary"
 127                                     " (try upgrading GIT to a newer version)",
 128                                     path, version);
 129        } else
 130                version = 1;
 131
 132        nr = 0;
 133        index = idx_map;
 134        if (version > 1)
 135                index += 2;  /* skip index header */
 136        for (i = 0; i < 256; i++) {
 137                uint32_t n = ntohl(index[i]);
 138                if (n < nr)
 139                        return error("non-monotonic index %s", path);
 140                nr = n;
 141        }
 142
 143        if (version == 1) {
 144                /*
 145                 * Total size:
 146                 *  - 256 index entries 4 bytes each
 147                 *  - 24-byte entries * nr (object ID + 4-byte offset)
 148                 *  - hash of the packfile
 149                 *  - file checksum
 150                 */
 151                if (idx_size != 4 * 256 + nr * (hashsz + 4) + hashsz + hashsz)
 152                        return error("wrong index v1 file size in %s", path);
 153        } else if (version == 2) {
 154                /*
 155                 * Minimum size:
 156                 *  - 8 bytes of header
 157                 *  - 256 index entries 4 bytes each
 158                 *  - object ID entry * nr
 159                 *  - 4-byte crc entry * nr
 160                 *  - 4-byte offset entry * nr
 161                 *  - hash of the packfile
 162                 *  - file checksum
 163                 * And after the 4-byte offset table might be a
 164                 * variable sized table containing 8-byte entries
 165                 * for offsets larger than 2^31.
 166                 */
 167                unsigned long min_size = 8 + 4*256 + nr*(hashsz + 4 + 4) + hashsz + hashsz;
 168                unsigned long max_size = min_size;
 169                if (nr)
 170                        max_size += (nr - 1)*8;
 171                if (idx_size < min_size || idx_size > max_size)
 172                        return error("wrong index v2 file size in %s", path);
 173                if (idx_size != min_size &&
 174                    /*
 175                     * make sure we can deal with large pack offsets.
 176                     * 31-bit signed offset won't be enough, neither
 177                     * 32-bit unsigned one will be.
 178                     */
 179                    (sizeof(off_t) <= 4))
 180                        return error("pack too large for current definition of off_t in %s", path);
 181        }
 182
 183        p->index_version = version;
 184        p->index_data = idx_map;
 185        p->index_size = idx_size;
 186        p->num_objects = nr;
 187        return 0;
 188}
 189
 190int open_pack_index(struct packed_git *p)
 191{
 192        char *idx_name;
 193        size_t len;
 194        int ret;
 195
 196        if (p->index_data)
 197                return 0;
 198
 199        if (!strip_suffix(p->pack_name, ".pack", &len))
 200                BUG("pack_name does not end in .pack");
 201        idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
 202        ret = check_packed_git_idx(idx_name, p);
 203        free(idx_name);
 204        return ret;
 205}
 206
 207uint32_t get_pack_fanout(struct packed_git *p, uint32_t value)
 208{
 209        const uint32_t *level1_ofs = p->index_data;
 210
 211        if (!level1_ofs) {
 212                if (open_pack_index(p))
 213                        return 0;
 214                level1_ofs = p->index_data;
 215        }
 216
 217        if (p->index_version > 1) {
 218                level1_ofs += 2;
 219        }
 220
 221        return ntohl(level1_ofs[value]);
 222}
 223
 224static struct packed_git *alloc_packed_git(int extra)
 225{
 226        struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
 227        memset(p, 0, sizeof(*p));
 228        p->pack_fd = -1;
 229        return p;
 230}
 231
 232struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
 233{
 234        const char *path = sha1_pack_name(sha1);
 235        size_t alloc = st_add(strlen(path), 1);
 236        struct packed_git *p = alloc_packed_git(alloc);
 237
 238        memcpy(p->pack_name, path, alloc); /* includes NUL */
 239        hashcpy(p->sha1, sha1);
 240        if (check_packed_git_idx(idx_path, p)) {
 241                free(p);
 242                return NULL;
 243        }
 244
 245        return p;
 246}
 247
 248static void scan_windows(struct packed_git *p,
 249        struct packed_git **lru_p,
 250        struct pack_window **lru_w,
 251        struct pack_window **lru_l)
 252{
 253        struct pack_window *w, *w_l;
 254
 255        for (w_l = NULL, w = p->windows; w; w = w->next) {
 256                if (!w->inuse_cnt) {
 257                        if (!*lru_w || w->last_used < (*lru_w)->last_used) {
 258                                *lru_p = p;
 259                                *lru_w = w;
 260                                *lru_l = w_l;
 261                        }
 262                }
 263                w_l = w;
 264        }
 265}
 266
 267static int unuse_one_window(struct packed_git *current)
 268{
 269        struct packed_git *p, *lru_p = NULL;
 270        struct pack_window *lru_w = NULL, *lru_l = NULL;
 271
 272        if (current)
 273                scan_windows(current, &lru_p, &lru_w, &lru_l);
 274        for (p = the_repository->objects->packed_git; p; p = p->next)
 275                scan_windows(p, &lru_p, &lru_w, &lru_l);
 276        if (lru_p) {
 277                munmap(lru_w->base, lru_w->len);
 278                pack_mapped -= lru_w->len;
 279                if (lru_l)
 280                        lru_l->next = lru_w->next;
 281                else
 282                        lru_p->windows = lru_w->next;
 283                free(lru_w);
 284                pack_open_windows--;
 285                return 1;
 286        }
 287        return 0;
 288}
 289
 290void release_pack_memory(size_t need)
 291{
 292        size_t cur = pack_mapped;
 293        while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
 294                ; /* nothing */
 295}
 296
 297void close_pack_windows(struct packed_git *p)
 298{
 299        while (p->windows) {
 300                struct pack_window *w = p->windows;
 301
 302                if (w->inuse_cnt)
 303                        die("pack '%s' still has open windows to it",
 304                            p->pack_name);
 305                munmap(w->base, w->len);
 306                pack_mapped -= w->len;
 307                pack_open_windows--;
 308                p->windows = w->next;
 309                free(w);
 310        }
 311}
 312
 313static int close_pack_fd(struct packed_git *p)
 314{
 315        if (p->pack_fd < 0)
 316                return 0;
 317
 318        close(p->pack_fd);
 319        pack_open_fds--;
 320        p->pack_fd = -1;
 321
 322        return 1;
 323}
 324
 325void close_pack_index(struct packed_git *p)
 326{
 327        if (p->index_data) {
 328                munmap((void *)p->index_data, p->index_size);
 329                p->index_data = NULL;
 330        }
 331}
 332
 333void close_pack(struct packed_git *p)
 334{
 335        close_pack_windows(p);
 336        close_pack_fd(p);
 337        close_pack_index(p);
 338}
 339
 340void close_object_store(struct raw_object_store *o)
 341{
 342        struct packed_git *p;
 343
 344        for (p = o->packed_git; p; p = p->next)
 345                if (p->do_not_close)
 346                        BUG("want to close pack marked 'do-not-close'");
 347                else
 348                        close_pack(p);
 349
 350        if (o->multi_pack_index) {
 351                close_midx(o->multi_pack_index);
 352                o->multi_pack_index = NULL;
 353        }
 354
 355        close_commit_graph(o);
 356}
 357
 358/*
 359 * The LRU pack is the one with the oldest MRU window, preferring packs
 360 * with no used windows, or the oldest mtime if it has no windows allocated.
 361 */
 362static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
 363{
 364        struct pack_window *w, *this_mru_w;
 365        int has_windows_inuse = 0;
 366
 367        /*
 368         * Reject this pack if it has windows and the previously selected
 369         * one does not.  If this pack does not have windows, reject
 370         * it if the pack file is newer than the previously selected one.
 371         */
 372        if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
 373                return;
 374
 375        for (w = this_mru_w = p->windows; w; w = w->next) {
 376                /*
 377                 * Reject this pack if any of its windows are in use,
 378                 * but the previously selected pack did not have any
 379                 * inuse windows.  Otherwise, record that this pack
 380                 * has windows in use.
 381                 */
 382                if (w->inuse_cnt) {
 383                        if (*accept_windows_inuse)
 384                                has_windows_inuse = 1;
 385                        else
 386                                return;
 387                }
 388
 389                if (w->last_used > this_mru_w->last_used)
 390                        this_mru_w = w;
 391
 392                /*
 393                 * Reject this pack if it has windows that have been
 394                 * used more recently than the previously selected pack.
 395                 * If the previously selected pack had windows inuse and
 396                 * we have not encountered a window in this pack that is
 397                 * inuse, skip this check since we prefer a pack with no
 398                 * inuse windows to one that has inuse windows.
 399                 */
 400                if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
 401                    this_mru_w->last_used > (*mru_w)->last_used)
 402                        return;
 403        }
 404
 405        /*
 406         * Select this pack.
 407         */
 408        *mru_w = this_mru_w;
 409        *lru_p = p;
 410        *accept_windows_inuse = has_windows_inuse;
 411}
 412
 413static int close_one_pack(void)
 414{
 415        struct packed_git *p, *lru_p = NULL;
 416        struct pack_window *mru_w = NULL;
 417        int accept_windows_inuse = 1;
 418
 419        for (p = the_repository->objects->packed_git; p; p = p->next) {
 420                if (p->pack_fd == -1)
 421                        continue;
 422                find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
 423        }
 424
 425        if (lru_p)
 426                return close_pack_fd(lru_p);
 427
 428        return 0;
 429}
 430
 431static unsigned int get_max_fd_limit(void)
 432{
 433#ifdef RLIMIT_NOFILE
 434        {
 435                struct rlimit lim;
 436
 437                if (!getrlimit(RLIMIT_NOFILE, &lim))
 438                        return lim.rlim_cur;
 439        }
 440#endif
 441
 442#ifdef _SC_OPEN_MAX
 443        {
 444                long open_max = sysconf(_SC_OPEN_MAX);
 445                if (0 < open_max)
 446                        return open_max;
 447                /*
 448                 * Otherwise, we got -1 for one of the two
 449                 * reasons:
 450                 *
 451                 * (1) sysconf() did not understand _SC_OPEN_MAX
 452                 *     and signaled an error with -1; or
 453                 * (2) sysconf() said there is no limit.
 454                 *
 455                 * We _could_ clear errno before calling sysconf() to
 456                 * tell these two cases apart and return a huge number
 457                 * in the latter case to let the caller cap it to a
 458                 * value that is not so selfish, but letting the
 459                 * fallback OPEN_MAX codepath take care of these cases
 460                 * is a lot simpler.
 461                 */
 462        }
 463#endif
 464
 465#ifdef OPEN_MAX
 466        return OPEN_MAX;
 467#else
 468        return 1; /* see the caller ;-) */
 469#endif
 470}
 471
 472/*
 473 * Do not call this directly as this leaks p->pack_fd on error return;
 474 * call open_packed_git() instead.
 475 */
 476static int open_packed_git_1(struct packed_git *p)
 477{
 478        struct stat st;
 479        struct pack_header hdr;
 480        unsigned char hash[GIT_MAX_RAWSZ];
 481        unsigned char *idx_hash;
 482        long fd_flag;
 483        ssize_t read_result;
 484        const unsigned hashsz = the_hash_algo->rawsz;
 485
 486        if (!p->index_data) {
 487                struct multi_pack_index *m;
 488                const char *pack_name = strrchr(p->pack_name, '/');
 489
 490                for (m = the_repository->objects->multi_pack_index;
 491                     m; m = m->next) {
 492                        if (midx_contains_pack(m, pack_name))
 493                                break;
 494                }
 495
 496                if (!m && open_pack_index(p))
 497                        return error("packfile %s index unavailable", p->pack_name);
 498        }
 499
 500        if (!pack_max_fds) {
 501                unsigned int max_fds = get_max_fd_limit();
 502
 503                /* Save 3 for stdin/stdout/stderr, 22 for work */
 504                if (25 < max_fds)
 505                        pack_max_fds = max_fds - 25;
 506                else
 507                        pack_max_fds = 1;
 508        }
 509
 510        while (pack_max_fds <= pack_open_fds && close_one_pack())
 511                ; /* nothing */
 512
 513        p->pack_fd = git_open(p->pack_name);
 514        if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
 515                return -1;
 516        pack_open_fds++;
 517
 518        /* If we created the struct before we had the pack we lack size. */
 519        if (!p->pack_size) {
 520                if (!S_ISREG(st.st_mode))
 521                        return error("packfile %s not a regular file", p->pack_name);
 522                p->pack_size = st.st_size;
 523        } else if (p->pack_size != st.st_size)
 524                return error("packfile %s size changed", p->pack_name);
 525
 526        /* We leave these file descriptors open with sliding mmap;
 527         * there is no point keeping them open across exec(), though.
 528         */
 529        fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
 530        if (fd_flag < 0)
 531                return error("cannot determine file descriptor flags");
 532        fd_flag |= FD_CLOEXEC;
 533        if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
 534                return error("cannot set FD_CLOEXEC");
 535
 536        /* Verify we recognize this pack file format. */
 537        read_result = read_in_full(p->pack_fd, &hdr, sizeof(hdr));
 538        if (read_result < 0)
 539                return error_errno("error reading from %s", p->pack_name);
 540        if (read_result != sizeof(hdr))
 541                return error("file %s is far too short to be a packfile", p->pack_name);
 542        if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
 543                return error("file %s is not a GIT packfile", p->pack_name);
 544        if (!pack_version_ok(hdr.hdr_version))
 545                return error("packfile %s is version %"PRIu32" and not"
 546                        " supported (try upgrading GIT to a newer version)",
 547                        p->pack_name, ntohl(hdr.hdr_version));
 548
 549        /* Skip index checking if in multi-pack-index */
 550        if (!p->index_data)
 551                return 0;
 552
 553        /* Verify the pack matches its index. */
 554        if (p->num_objects != ntohl(hdr.hdr_entries))
 555                return error("packfile %s claims to have %"PRIu32" objects"
 556                             " while index indicates %"PRIu32" objects",
 557                             p->pack_name, ntohl(hdr.hdr_entries),
 558                             p->num_objects);
 559        if (lseek(p->pack_fd, p->pack_size - hashsz, SEEK_SET) == -1)
 560                return error("end of packfile %s is unavailable", p->pack_name);
 561        read_result = read_in_full(p->pack_fd, hash, hashsz);
 562        if (read_result < 0)
 563                return error_errno("error reading from %s", p->pack_name);
 564        if (read_result != hashsz)
 565                return error("packfile %s signature is unavailable", p->pack_name);
 566        idx_hash = ((unsigned char *)p->index_data) + p->index_size - hashsz * 2;
 567        if (!hasheq(hash, idx_hash))
 568                return error("packfile %s does not match index", p->pack_name);
 569        return 0;
 570}
 571
 572static int open_packed_git(struct packed_git *p)
 573{
 574        if (!open_packed_git_1(p))
 575                return 0;
 576        close_pack_fd(p);
 577        return -1;
 578}
 579
 580static int in_window(struct pack_window *win, off_t offset)
 581{
 582        /* We must promise at least one full hash after the
 583         * offset is available from this window, otherwise the offset
 584         * is not actually in this window and a different window (which
 585         * has that one hash excess) must be used.  This is to support
 586         * the object header and delta base parsing routines below.
 587         */
 588        off_t win_off = win->offset;
 589        return win_off <= offset
 590                && (offset + the_hash_algo->rawsz) <= (win_off + win->len);
 591}
 592
 593unsigned char *use_pack(struct packed_git *p,
 594                struct pack_window **w_cursor,
 595                off_t offset,
 596                unsigned long *left)
 597{
 598        struct pack_window *win = *w_cursor;
 599
 600        /* Since packfiles end in a hash of their content and it's
 601         * pointless to ask for an offset into the middle of that
 602         * hash, and the in_window function above wouldn't match
 603         * don't allow an offset too close to the end of the file.
 604         */
 605        if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
 606                die("packfile %s cannot be accessed", p->pack_name);
 607        if (offset > (p->pack_size - the_hash_algo->rawsz))
 608                die("offset beyond end of packfile (truncated pack?)");
 609        if (offset < 0)
 610                die(_("offset before end of packfile (broken .idx?)"));
 611
 612        if (!win || !in_window(win, offset)) {
 613                if (win)
 614                        win->inuse_cnt--;
 615                for (win = p->windows; win; win = win->next) {
 616                        if (in_window(win, offset))
 617                                break;
 618                }
 619                if (!win) {
 620                        size_t window_align = packed_git_window_size / 2;
 621                        off_t len;
 622
 623                        if (p->pack_fd == -1 && open_packed_git(p))
 624                                die("packfile %s cannot be accessed", p->pack_name);
 625
 626                        win = xcalloc(1, sizeof(*win));
 627                        win->offset = (offset / window_align) * window_align;
 628                        len = p->pack_size - win->offset;
 629                        if (len > packed_git_window_size)
 630                                len = packed_git_window_size;
 631                        win->len = (size_t)len;
 632                        pack_mapped += win->len;
 633                        while (packed_git_limit < pack_mapped
 634                                && unuse_one_window(p))
 635                                ; /* nothing */
 636                        win->base = xmmap(NULL, win->len,
 637                                PROT_READ, MAP_PRIVATE,
 638                                p->pack_fd, win->offset);
 639                        if (win->base == MAP_FAILED)
 640                                die_errno("packfile %s cannot be mapped",
 641                                          p->pack_name);
 642                        if (!win->offset && win->len == p->pack_size
 643                                && !p->do_not_close)
 644                                close_pack_fd(p);
 645                        pack_mmap_calls++;
 646                        pack_open_windows++;
 647                        if (pack_mapped > peak_pack_mapped)
 648                                peak_pack_mapped = pack_mapped;
 649                        if (pack_open_windows > peak_pack_open_windows)
 650                                peak_pack_open_windows = pack_open_windows;
 651                        win->next = p->windows;
 652                        p->windows = win;
 653                }
 654        }
 655        if (win != *w_cursor) {
 656                win->last_used = pack_used_ctr++;
 657                win->inuse_cnt++;
 658                *w_cursor = win;
 659        }
 660        offset -= win->offset;
 661        if (left)
 662                *left = win->len - xsize_t(offset);
 663        return win->base + offset;
 664}
 665
 666void unuse_pack(struct pack_window **w_cursor)
 667{
 668        struct pack_window *w = *w_cursor;
 669        if (w) {
 670                w->inuse_cnt--;
 671                *w_cursor = NULL;
 672        }
 673}
 674
 675static void try_to_free_pack_memory(size_t size)
 676{
 677        release_pack_memory(size);
 678}
 679
 680struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
 681{
 682        static int have_set_try_to_free_routine;
 683        struct stat st;
 684        size_t alloc;
 685        struct packed_git *p;
 686
 687        if (!have_set_try_to_free_routine) {
 688                have_set_try_to_free_routine = 1;
 689                set_try_to_free_routine(try_to_free_pack_memory);
 690        }
 691
 692        /*
 693         * Make sure a corresponding .pack file exists and that
 694         * the index looks sane.
 695         */
 696        if (!strip_suffix_mem(path, &path_len, ".idx"))
 697                return NULL;
 698
 699        /*
 700         * ".promisor" is long enough to hold any suffix we're adding (and
 701         * the use xsnprintf double-checks that)
 702         */
 703        alloc = st_add3(path_len, strlen(".promisor"), 1);
 704        p = alloc_packed_git(alloc);
 705        memcpy(p->pack_name, path, path_len);
 706
 707        xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
 708        if (!access(p->pack_name, F_OK))
 709                p->pack_keep = 1;
 710
 711        xsnprintf(p->pack_name + path_len, alloc - path_len, ".promisor");
 712        if (!access(p->pack_name, F_OK))
 713                p->pack_promisor = 1;
 714
 715        xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
 716        if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
 717                free(p);
 718                return NULL;
 719        }
 720
 721        /* ok, it looks sane as far as we can check without
 722         * actually mapping the pack file.
 723         */
 724        p->pack_size = st.st_size;
 725        p->pack_local = local;
 726        p->mtime = st.st_mtime;
 727        if (path_len < the_hash_algo->hexsz ||
 728            get_sha1_hex(path + path_len - the_hash_algo->hexsz, p->sha1))
 729                hashclr(p->sha1);
 730        return p;
 731}
 732
 733void install_packed_git(struct repository *r, struct packed_git *pack)
 734{
 735        if (pack->pack_fd != -1)
 736                pack_open_fds++;
 737
 738        pack->next = r->objects->packed_git;
 739        r->objects->packed_git = pack;
 740}
 741
 742void (*report_garbage)(unsigned seen_bits, const char *path);
 743
 744static void report_helper(const struct string_list *list,
 745                          int seen_bits, int first, int last)
 746{
 747        if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
 748                return;
 749
 750        for (; first < last; first++)
 751                report_garbage(seen_bits, list->items[first].string);
 752}
 753
 754static void report_pack_garbage(struct string_list *list)
 755{
 756        int i, baselen = -1, first = 0, seen_bits = 0;
 757
 758        if (!report_garbage)
 759                return;
 760
 761        string_list_sort(list);
 762
 763        for (i = 0; i < list->nr; i++) {
 764                const char *path = list->items[i].string;
 765                if (baselen != -1 &&
 766                    strncmp(path, list->items[first].string, baselen)) {
 767                        report_helper(list, seen_bits, first, i);
 768                        baselen = -1;
 769                        seen_bits = 0;
 770                }
 771                if (baselen == -1) {
 772                        const char *dot = strrchr(path, '.');
 773                        if (!dot) {
 774                                report_garbage(PACKDIR_FILE_GARBAGE, path);
 775                                continue;
 776                        }
 777                        baselen = dot - path + 1;
 778                        first = i;
 779                }
 780                if (!strcmp(path + baselen, "pack"))
 781                        seen_bits |= 1;
 782                else if (!strcmp(path + baselen, "idx"))
 783                        seen_bits |= 2;
 784        }
 785        report_helper(list, seen_bits, first, list->nr);
 786}
 787
 788void for_each_file_in_pack_dir(const char *objdir,
 789                               each_file_in_pack_dir_fn fn,
 790                               void *data)
 791{
 792        struct strbuf path = STRBUF_INIT;
 793        size_t dirnamelen;
 794        DIR *dir;
 795        struct dirent *de;
 796
 797        strbuf_addstr(&path, objdir);
 798        strbuf_addstr(&path, "/pack");
 799        dir = opendir(path.buf);
 800        if (!dir) {
 801                if (errno != ENOENT)
 802                        error_errno("unable to open object pack directory: %s",
 803                                    path.buf);
 804                strbuf_release(&path);
 805                return;
 806        }
 807        strbuf_addch(&path, '/');
 808        dirnamelen = path.len;
 809        while ((de = readdir(dir)) != NULL) {
 810                if (is_dot_or_dotdot(de->d_name))
 811                        continue;
 812
 813                strbuf_setlen(&path, dirnamelen);
 814                strbuf_addstr(&path, de->d_name);
 815
 816                fn(path.buf, path.len, de->d_name, data);
 817        }
 818
 819        closedir(dir);
 820        strbuf_release(&path);
 821}
 822
 823struct prepare_pack_data {
 824        struct repository *r;
 825        struct string_list *garbage;
 826        int local;
 827        struct multi_pack_index *m;
 828};
 829
 830static void prepare_pack(const char *full_name, size_t full_name_len,
 831                         const char *file_name, void *_data)
 832{
 833        struct prepare_pack_data *data = (struct prepare_pack_data *)_data;
 834        struct packed_git *p;
 835        size_t base_len = full_name_len;
 836
 837        if (strip_suffix_mem(full_name, &base_len, ".idx") &&
 838            !(data->m && midx_contains_pack(data->m, file_name))) {
 839                /* Don't reopen a pack we already have. */
 840                for (p = data->r->objects->packed_git; p; p = p->next) {
 841                        size_t len;
 842                        if (strip_suffix(p->pack_name, ".pack", &len) &&
 843                            len == base_len &&
 844                            !memcmp(p->pack_name, full_name, len))
 845                                break;
 846                }
 847
 848                if (!p) {
 849                        p = add_packed_git(full_name, full_name_len, data->local);
 850                        if (p)
 851                                install_packed_git(data->r, p);
 852                }
 853        }
 854
 855        if (!report_garbage)
 856                return;
 857
 858        if (!strcmp(file_name, "multi-pack-index"))
 859                return;
 860        if (ends_with(file_name, ".idx") ||
 861            ends_with(file_name, ".pack") ||
 862            ends_with(file_name, ".bitmap") ||
 863            ends_with(file_name, ".keep") ||
 864            ends_with(file_name, ".promisor"))
 865                string_list_append(data->garbage, full_name);
 866        else
 867                report_garbage(PACKDIR_FILE_GARBAGE, full_name);
 868}
 869
 870static void prepare_packed_git_one(struct repository *r, char *objdir, int local)
 871{
 872        struct prepare_pack_data data;
 873        struct string_list garbage = STRING_LIST_INIT_DUP;
 874
 875        data.m = r->objects->multi_pack_index;
 876
 877        /* look for the multi-pack-index for this object directory */
 878        while (data.m && strcmp(data.m->object_dir, objdir))
 879                data.m = data.m->next;
 880
 881        data.r = r;
 882        data.garbage = &garbage;
 883        data.local = local;
 884
 885        for_each_file_in_pack_dir(objdir, prepare_pack, &data);
 886
 887        report_pack_garbage(data.garbage);
 888        string_list_clear(data.garbage, 0);
 889}
 890
 891static void prepare_packed_git(struct repository *r);
 892/*
 893 * Give a fast, rough count of the number of objects in the repository. This
 894 * ignores loose objects completely. If you have a lot of them, then either
 895 * you should repack because your performance will be awful, or they are
 896 * all unreachable objects about to be pruned, in which case they're not really
 897 * interesting as a measure of repo size in the first place.
 898 */
 899unsigned long approximate_object_count(void)
 900{
 901        if (!the_repository->objects->approximate_object_count_valid) {
 902                unsigned long count;
 903                struct multi_pack_index *m;
 904                struct packed_git *p;
 905
 906                prepare_packed_git(the_repository);
 907                count = 0;
 908                for (m = get_multi_pack_index(the_repository); m; m = m->next)
 909                        count += m->num_objects;
 910                for (p = the_repository->objects->packed_git; p; p = p->next) {
 911                        if (open_pack_index(p))
 912                                continue;
 913                        count += p->num_objects;
 914                }
 915                the_repository->objects->approximate_object_count = count;
 916        }
 917        return the_repository->objects->approximate_object_count;
 918}
 919
 920static void *get_next_packed_git(const void *p)
 921{
 922        return ((const struct packed_git *)p)->next;
 923}
 924
 925static void set_next_packed_git(void *p, void *next)
 926{
 927        ((struct packed_git *)p)->next = next;
 928}
 929
 930static int sort_pack(const void *a_, const void *b_)
 931{
 932        const struct packed_git *a = a_;
 933        const struct packed_git *b = b_;
 934        int st;
 935
 936        /*
 937         * Local packs tend to contain objects specific to our
 938         * variant of the project than remote ones.  In addition,
 939         * remote ones could be on a network mounted filesystem.
 940         * Favor local ones for these reasons.
 941         */
 942        st = a->pack_local - b->pack_local;
 943        if (st)
 944                return -st;
 945
 946        /*
 947         * Younger packs tend to contain more recent objects,
 948         * and more recent objects tend to get accessed more
 949         * often.
 950         */
 951        if (a->mtime < b->mtime)
 952                return 1;
 953        else if (a->mtime == b->mtime)
 954                return 0;
 955        return -1;
 956}
 957
 958static void rearrange_packed_git(struct repository *r)
 959{
 960        r->objects->packed_git = llist_mergesort(
 961                r->objects->packed_git, get_next_packed_git,
 962                set_next_packed_git, sort_pack);
 963}
 964
 965static void prepare_packed_git_mru(struct repository *r)
 966{
 967        struct packed_git *p;
 968
 969        INIT_LIST_HEAD(&r->objects->packed_git_mru);
 970
 971        for (p = r->objects->packed_git; p; p = p->next)
 972                list_add_tail(&p->mru, &r->objects->packed_git_mru);
 973}
 974
 975static void prepare_packed_git(struct repository *r)
 976{
 977        struct object_directory *odb;
 978
 979        if (r->objects->packed_git_initialized)
 980                return;
 981
 982        prepare_alt_odb(r);
 983        for (odb = r->objects->odb; odb; odb = odb->next) {
 984                int local = (odb == r->objects->odb);
 985                prepare_multi_pack_index_one(r, odb->path, local);
 986                prepare_packed_git_one(r, odb->path, local);
 987        }
 988        rearrange_packed_git(r);
 989
 990        r->objects->all_packs = NULL;
 991
 992        prepare_packed_git_mru(r);
 993        r->objects->packed_git_initialized = 1;
 994}
 995
 996void reprepare_packed_git(struct repository *r)
 997{
 998        struct object_directory *odb;
 999
1000        for (odb = r->objects->odb; odb; odb = odb->next)
1001                odb_clear_loose_cache(odb);
1002
1003        r->objects->approximate_object_count_valid = 0;
1004        r->objects->packed_git_initialized = 0;
1005        prepare_packed_git(r);
1006}
1007
1008struct packed_git *get_packed_git(struct repository *r)
1009{
1010        prepare_packed_git(r);
1011        return r->objects->packed_git;
1012}
1013
1014struct multi_pack_index *get_multi_pack_index(struct repository *r)
1015{
1016        prepare_packed_git(r);
1017        return r->objects->multi_pack_index;
1018}
1019
1020struct packed_git *get_all_packs(struct repository *r)
1021{
1022        prepare_packed_git(r);
1023
1024        if (!r->objects->all_packs) {
1025                struct packed_git *p = r->objects->packed_git;
1026                struct multi_pack_index *m;
1027
1028                for (m = r->objects->multi_pack_index; m; m = m->next) {
1029                        uint32_t i;
1030                        for (i = 0; i < m->num_packs; i++) {
1031                                if (!prepare_midx_pack(m, i)) {
1032                                        m->packs[i]->next = p;
1033                                        p = m->packs[i];
1034                                }
1035                        }
1036                }
1037
1038                r->objects->all_packs = p;
1039        }
1040
1041        return r->objects->all_packs;
1042}
1043
1044struct list_head *get_packed_git_mru(struct repository *r)
1045{
1046        prepare_packed_git(r);
1047        return &r->objects->packed_git_mru;
1048}
1049
1050unsigned long unpack_object_header_buffer(const unsigned char *buf,
1051                unsigned long len, enum object_type *type, unsigned long *sizep)
1052{
1053        unsigned shift;
1054        unsigned long size, c;
1055        unsigned long used = 0;
1056
1057        c = buf[used++];
1058        *type = (c >> 4) & 7;
1059        size = c & 15;
1060        shift = 4;
1061        while (c & 0x80) {
1062                if (len <= used || bitsizeof(long) <= shift) {
1063                        error("bad object header");
1064                        size = used = 0;
1065                        break;
1066                }
1067                c = buf[used++];
1068                size += (c & 0x7f) << shift;
1069                shift += 7;
1070        }
1071        *sizep = size;
1072        return used;
1073}
1074
1075unsigned long get_size_from_delta(struct packed_git *p,
1076                                  struct pack_window **w_curs,
1077                                  off_t curpos)
1078{
1079        const unsigned char *data;
1080        unsigned char delta_head[20], *in;
1081        git_zstream stream;
1082        int st;
1083
1084        memset(&stream, 0, sizeof(stream));
1085        stream.next_out = delta_head;
1086        stream.avail_out = sizeof(delta_head);
1087
1088        git_inflate_init(&stream);
1089        do {
1090                in = use_pack(p, w_curs, curpos, &stream.avail_in);
1091                stream.next_in = in;
1092                st = git_inflate(&stream, Z_FINISH);
1093                curpos += stream.next_in - in;
1094        } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1095                 stream.total_out < sizeof(delta_head));
1096        git_inflate_end(&stream);
1097        if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1098                error("delta data unpack-initial failed");
1099                return 0;
1100        }
1101
1102        /* Examine the initial part of the delta to figure out
1103         * the result size.
1104         */
1105        data = delta_head;
1106
1107        /* ignore base size */
1108        get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1109
1110        /* Read the result size */
1111        return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1112}
1113
1114int unpack_object_header(struct packed_git *p,
1115                         struct pack_window **w_curs,
1116                         off_t *curpos,
1117                         unsigned long *sizep)
1118{
1119        unsigned char *base;
1120        unsigned long left;
1121        unsigned long used;
1122        enum object_type type;
1123
1124        /* use_pack() assures us we have [base, base + 20) available
1125         * as a range that we can look at.  (Its actually the hash
1126         * size that is assured.)  With our object header encoding
1127         * the maximum deflated object size is 2^137, which is just
1128         * insane, so we know won't exceed what we have been given.
1129         */
1130        base = use_pack(p, w_curs, *curpos, &left);
1131        used = unpack_object_header_buffer(base, left, &type, sizep);
1132        if (!used) {
1133                type = OBJ_BAD;
1134        } else
1135                *curpos += used;
1136
1137        return type;
1138}
1139
1140void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1)
1141{
1142        unsigned i;
1143        const unsigned hashsz = the_hash_algo->rawsz;
1144        for (i = 0; i < p->num_bad_objects; i++)
1145                if (hasheq(sha1, p->bad_object_sha1 + hashsz * i))
1146                        return;
1147        p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1148                                      st_mult(GIT_MAX_RAWSZ,
1149                                              st_add(p->num_bad_objects, 1)));
1150        hashcpy(p->bad_object_sha1 + hashsz * p->num_bad_objects, sha1);
1151        p->num_bad_objects++;
1152}
1153
1154const struct packed_git *has_packed_and_bad(struct repository *r,
1155                                            const unsigned char *sha1)
1156{
1157        struct packed_git *p;
1158        unsigned i;
1159
1160        for (p = r->objects->packed_git; p; p = p->next)
1161                for (i = 0; i < p->num_bad_objects; i++)
1162                        if (hasheq(sha1,
1163                                   p->bad_object_sha1 + the_hash_algo->rawsz * i))
1164                                return p;
1165        return NULL;
1166}
1167
1168static off_t get_delta_base(struct packed_git *p,
1169                                    struct pack_window **w_curs,
1170                                    off_t *curpos,
1171                                    enum object_type type,
1172                                    off_t delta_obj_offset)
1173{
1174        unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1175        off_t base_offset;
1176
1177        /* use_pack() assured us we have [base_info, base_info + 20)
1178         * as a range that we can look at without walking off the
1179         * end of the mapped window.  Its actually the hash size
1180         * that is assured.  An OFS_DELTA longer than the hash size
1181         * is stupid, as then a REF_DELTA would be smaller to store.
1182         */
1183        if (type == OBJ_OFS_DELTA) {
1184                unsigned used = 0;
1185                unsigned char c = base_info[used++];
1186                base_offset = c & 127;
1187                while (c & 128) {
1188                        base_offset += 1;
1189                        if (!base_offset || MSB(base_offset, 7))
1190                                return 0;  /* overflow */
1191                        c = base_info[used++];
1192                        base_offset = (base_offset << 7) + (c & 127);
1193                }
1194                base_offset = delta_obj_offset - base_offset;
1195                if (base_offset <= 0 || base_offset >= delta_obj_offset)
1196                        return 0;  /* out of bound */
1197                *curpos += used;
1198        } else if (type == OBJ_REF_DELTA) {
1199                /* The base entry _must_ be in the same pack */
1200                base_offset = find_pack_entry_one(base_info, p);
1201                *curpos += the_hash_algo->rawsz;
1202        } else
1203                die("I am totally screwed");
1204        return base_offset;
1205}
1206
1207/*
1208 * Like get_delta_base above, but we return the sha1 instead of the pack
1209 * offset. This means it is cheaper for REF deltas (we do not have to do
1210 * the final object lookup), but more expensive for OFS deltas (we
1211 * have to load the revidx to convert the offset back into a sha1).
1212 */
1213static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1214                                                struct pack_window **w_curs,
1215                                                off_t curpos,
1216                                                enum object_type type,
1217                                                off_t delta_obj_offset)
1218{
1219        if (type == OBJ_REF_DELTA) {
1220                unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1221                return base;
1222        } else if (type == OBJ_OFS_DELTA) {
1223                struct revindex_entry *revidx;
1224                off_t base_offset = get_delta_base(p, w_curs, &curpos,
1225                                                   type, delta_obj_offset);
1226
1227                if (!base_offset)
1228                        return NULL;
1229
1230                revidx = find_pack_revindex(p, base_offset);
1231                if (!revidx)
1232                        return NULL;
1233
1234                return nth_packed_object_sha1(p, revidx->nr);
1235        } else
1236                return NULL;
1237}
1238
1239static int retry_bad_packed_offset(struct repository *r,
1240                                   struct packed_git *p,
1241                                   off_t obj_offset)
1242{
1243        int type;
1244        struct revindex_entry *revidx;
1245        struct object_id oid;
1246        revidx = find_pack_revindex(p, obj_offset);
1247        if (!revidx)
1248                return OBJ_BAD;
1249        nth_packed_object_oid(&oid, p, revidx->nr);
1250        mark_bad_packed_object(p, oid.hash);
1251        type = oid_object_info(r, &oid, NULL);
1252        if (type <= OBJ_NONE)
1253                return OBJ_BAD;
1254        return type;
1255}
1256
1257#define POI_STACK_PREALLOC 64
1258
1259static enum object_type packed_to_object_type(struct repository *r,
1260                                              struct packed_git *p,
1261                                              off_t obj_offset,
1262                                              enum object_type type,
1263                                              struct pack_window **w_curs,
1264                                              off_t curpos)
1265{
1266        off_t small_poi_stack[POI_STACK_PREALLOC];
1267        off_t *poi_stack = small_poi_stack;
1268        int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1269
1270        while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1271                off_t base_offset;
1272                unsigned long size;
1273                /* Push the object we're going to leave behind */
1274                if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1275                        poi_stack_alloc = alloc_nr(poi_stack_nr);
1276                        ALLOC_ARRAY(poi_stack, poi_stack_alloc);
1277                        memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1278                } else {
1279                        ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1280                }
1281                poi_stack[poi_stack_nr++] = obj_offset;
1282                /* If parsing the base offset fails, just unwind */
1283                base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1284                if (!base_offset)
1285                        goto unwind;
1286                curpos = obj_offset = base_offset;
1287                type = unpack_object_header(p, w_curs, &curpos, &size);
1288                if (type <= OBJ_NONE) {
1289                        /* If getting the base itself fails, we first
1290                         * retry the base, otherwise unwind */
1291                        type = retry_bad_packed_offset(r, p, base_offset);
1292                        if (type > OBJ_NONE)
1293                                goto out;
1294                        goto unwind;
1295                }
1296        }
1297
1298        switch (type) {
1299        case OBJ_BAD:
1300        case OBJ_COMMIT:
1301        case OBJ_TREE:
1302        case OBJ_BLOB:
1303        case OBJ_TAG:
1304                break;
1305        default:
1306                error("unknown object type %i at offset %"PRIuMAX" in %s",
1307                      type, (uintmax_t)obj_offset, p->pack_name);
1308                type = OBJ_BAD;
1309        }
1310
1311out:
1312        if (poi_stack != small_poi_stack)
1313                free(poi_stack);
1314        return type;
1315
1316unwind:
1317        while (poi_stack_nr) {
1318                obj_offset = poi_stack[--poi_stack_nr];
1319                type = retry_bad_packed_offset(r, p, obj_offset);
1320                if (type > OBJ_NONE)
1321                        goto out;
1322        }
1323        type = OBJ_BAD;
1324        goto out;
1325}
1326
1327static struct hashmap delta_base_cache;
1328static size_t delta_base_cached;
1329
1330static LIST_HEAD(delta_base_cache_lru);
1331
1332struct delta_base_cache_key {
1333        struct packed_git *p;
1334        off_t base_offset;
1335};
1336
1337struct delta_base_cache_entry {
1338        struct hashmap hash;
1339        struct delta_base_cache_key key;
1340        struct list_head lru;
1341        void *data;
1342        unsigned long size;
1343        enum object_type type;
1344};
1345
1346static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
1347{
1348        unsigned int hash;
1349
1350        hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
1351        hash += (hash >> 8) + (hash >> 16);
1352        return hash;
1353}
1354
1355static struct delta_base_cache_entry *
1356get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
1357{
1358        struct hashmap_entry entry;
1359        struct delta_base_cache_key key;
1360
1361        if (!delta_base_cache.cmpfn)
1362                return NULL;
1363
1364        hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
1365        key.p = p;
1366        key.base_offset = base_offset;
1367        return hashmap_get(&delta_base_cache, &entry, &key);
1368}
1369
1370static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
1371                                   const struct delta_base_cache_key *b)
1372{
1373        return a->p == b->p && a->base_offset == b->base_offset;
1374}
1375
1376static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
1377                                     const void *va, const void *vb,
1378                                     const void *vkey)
1379{
1380        const struct delta_base_cache_entry *a = va, *b = vb;
1381        const struct delta_base_cache_key *key = vkey;
1382        if (key)
1383                return !delta_base_cache_key_eq(&a->key, key);
1384        else
1385                return !delta_base_cache_key_eq(&a->key, &b->key);
1386}
1387
1388static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1389{
1390        return !!get_delta_base_cache_entry(p, base_offset);
1391}
1392
1393/*
1394 * Remove the entry from the cache, but do _not_ free the associated
1395 * entry data. The caller takes ownership of the "data" buffer, and
1396 * should copy out any fields it wants before detaching.
1397 */
1398static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
1399{
1400        hashmap_remove(&delta_base_cache, ent, &ent->key);
1401        list_del(&ent->lru);
1402        delta_base_cached -= ent->size;
1403        free(ent);
1404}
1405
1406static void *cache_or_unpack_entry(struct repository *r, struct packed_git *p,
1407                                   off_t base_offset, unsigned long *base_size,
1408                                   enum object_type *type)
1409{
1410        struct delta_base_cache_entry *ent;
1411
1412        ent = get_delta_base_cache_entry(p, base_offset);
1413        if (!ent)
1414                return unpack_entry(r, p, base_offset, type, base_size);
1415
1416        if (type)
1417                *type = ent->type;
1418        if (base_size)
1419                *base_size = ent->size;
1420        return xmemdupz(ent->data, ent->size);
1421}
1422
1423static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1424{
1425        free(ent->data);
1426        detach_delta_base_cache_entry(ent);
1427}
1428
1429void clear_delta_base_cache(void)
1430{
1431        struct list_head *lru, *tmp;
1432        list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1433                struct delta_base_cache_entry *entry =
1434                        list_entry(lru, struct delta_base_cache_entry, lru);
1435                release_delta_base_cache(entry);
1436        }
1437}
1438
1439static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1440        void *base, unsigned long base_size, enum object_type type)
1441{
1442        struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
1443        struct list_head *lru, *tmp;
1444
1445        delta_base_cached += base_size;
1446
1447        list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1448                struct delta_base_cache_entry *f =
1449                        list_entry(lru, struct delta_base_cache_entry, lru);
1450                if (delta_base_cached <= delta_base_cache_limit)
1451                        break;
1452                release_delta_base_cache(f);
1453        }
1454
1455        ent->key.p = p;
1456        ent->key.base_offset = base_offset;
1457        ent->type = type;
1458        ent->data = base;
1459        ent->size = base_size;
1460        list_add_tail(&ent->lru, &delta_base_cache_lru);
1461
1462        if (!delta_base_cache.cmpfn)
1463                hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
1464        hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
1465        hashmap_add(&delta_base_cache, ent);
1466}
1467
1468int packed_object_info(struct repository *r, struct packed_git *p,
1469                       off_t obj_offset, struct object_info *oi)
1470{
1471        struct pack_window *w_curs = NULL;
1472        unsigned long size;
1473        off_t curpos = obj_offset;
1474        enum object_type type;
1475
1476        /*
1477         * We always get the representation type, but only convert it to
1478         * a "real" type later if the caller is interested.
1479         */
1480        if (oi->contentp) {
1481                *oi->contentp = cache_or_unpack_entry(r, p, obj_offset, oi->sizep,
1482                                                      &type);
1483                if (!*oi->contentp)
1484                        type = OBJ_BAD;
1485        } else {
1486                type = unpack_object_header(p, &w_curs, &curpos, &size);
1487        }
1488
1489        if (!oi->contentp && oi->sizep) {
1490                if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1491                        off_t tmp_pos = curpos;
1492                        off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1493                                                           type, obj_offset);
1494                        if (!base_offset) {
1495                                type = OBJ_BAD;
1496                                goto out;
1497                        }
1498                        *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1499                        if (*oi->sizep == 0) {
1500                                type = OBJ_BAD;
1501                                goto out;
1502                        }
1503                } else {
1504                        *oi->sizep = size;
1505                }
1506        }
1507
1508        if (oi->disk_sizep) {
1509                struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1510                *oi->disk_sizep = revidx[1].offset - obj_offset;
1511        }
1512
1513        if (oi->typep || oi->type_name) {
1514                enum object_type ptot;
1515                ptot = packed_to_object_type(r, p, obj_offset,
1516                                             type, &w_curs, curpos);
1517                if (oi->typep)
1518                        *oi->typep = ptot;
1519                if (oi->type_name) {
1520                        const char *tn = type_name(ptot);
1521                        if (tn)
1522                                strbuf_addstr(oi->type_name, tn);
1523                }
1524                if (ptot < 0) {
1525                        type = OBJ_BAD;
1526                        goto out;
1527                }
1528        }
1529
1530        if (oi->delta_base_sha1) {
1531                if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1532                        const unsigned char *base;
1533
1534                        base = get_delta_base_sha1(p, &w_curs, curpos,
1535                                                   type, obj_offset);
1536                        if (!base) {
1537                                type = OBJ_BAD;
1538                                goto out;
1539                        }
1540
1541                        hashcpy(oi->delta_base_sha1, base);
1542                } else
1543                        hashclr(oi->delta_base_sha1);
1544        }
1545
1546        oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
1547                                                          OI_PACKED;
1548
1549out:
1550        unuse_pack(&w_curs);
1551        return type;
1552}
1553
1554static void *unpack_compressed_entry(struct packed_git *p,
1555                                    struct pack_window **w_curs,
1556                                    off_t curpos,
1557                                    unsigned long size)
1558{
1559        int st;
1560        git_zstream stream;
1561        unsigned char *buffer, *in;
1562
1563        buffer = xmallocz_gently(size);
1564        if (!buffer)
1565                return NULL;
1566        memset(&stream, 0, sizeof(stream));
1567        stream.next_out = buffer;
1568        stream.avail_out = size + 1;
1569
1570        git_inflate_init(&stream);
1571        do {
1572                in = use_pack(p, w_curs, curpos, &stream.avail_in);
1573                stream.next_in = in;
1574                st = git_inflate(&stream, Z_FINISH);
1575                if (!stream.avail_out)
1576                        break; /* the payload is larger than it should be */
1577                curpos += stream.next_in - in;
1578        } while (st == Z_OK || st == Z_BUF_ERROR);
1579        git_inflate_end(&stream);
1580        if ((st != Z_STREAM_END) || stream.total_out != size) {
1581                free(buffer);
1582                return NULL;
1583        }
1584
1585        /* versions of zlib can clobber unconsumed portion of outbuf */
1586        buffer[size] = '\0';
1587
1588        return buffer;
1589}
1590
1591static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
1592{
1593        static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
1594        trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
1595                         p->pack_name, (uintmax_t)obj_offset);
1596}
1597
1598int do_check_packed_object_crc;
1599
1600#define UNPACK_ENTRY_STACK_PREALLOC 64
1601struct unpack_entry_stack_ent {
1602        off_t obj_offset;
1603        off_t curpos;
1604        unsigned long size;
1605};
1606
1607static void *read_object(struct repository *r,
1608                         const struct object_id *oid,
1609                         enum object_type *type,
1610                         unsigned long *size)
1611{
1612        struct object_info oi = OBJECT_INFO_INIT;
1613        void *content;
1614        oi.typep = type;
1615        oi.sizep = size;
1616        oi.contentp = &content;
1617
1618        if (oid_object_info_extended(r, oid, &oi, 0) < 0)
1619                return NULL;
1620        return content;
1621}
1622
1623void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
1624                   enum object_type *final_type, unsigned long *final_size)
1625{
1626        struct pack_window *w_curs = NULL;
1627        off_t curpos = obj_offset;
1628        void *data = NULL;
1629        unsigned long size;
1630        enum object_type type;
1631        struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
1632        struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
1633        int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
1634        int base_from_cache = 0;
1635
1636        write_pack_access_log(p, obj_offset);
1637
1638        /* PHASE 1: drill down to the innermost base object */
1639        for (;;) {
1640                off_t base_offset;
1641                int i;
1642                struct delta_base_cache_entry *ent;
1643
1644                ent = get_delta_base_cache_entry(p, curpos);
1645                if (ent) {
1646                        type = ent->type;
1647                        data = ent->data;
1648                        size = ent->size;
1649                        detach_delta_base_cache_entry(ent);
1650                        base_from_cache = 1;
1651                        break;
1652                }
1653
1654                if (do_check_packed_object_crc && p->index_version > 1) {
1655                        struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1656                        off_t len = revidx[1].offset - obj_offset;
1657                        if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1658                                struct object_id oid;
1659                                nth_packed_object_oid(&oid, p, revidx->nr);
1660                                error("bad packed object CRC for %s",
1661                                      oid_to_hex(&oid));
1662                                mark_bad_packed_object(p, oid.hash);
1663                                data = NULL;
1664                                goto out;
1665                        }
1666                }
1667
1668                type = unpack_object_header(p, &w_curs, &curpos, &size);
1669                if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
1670                        break;
1671
1672                base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1673                if (!base_offset) {
1674                        error("failed to validate delta base reference "
1675                              "at offset %"PRIuMAX" from %s",
1676                              (uintmax_t)curpos, p->pack_name);
1677                        /* bail to phase 2, in hopes of recovery */
1678                        data = NULL;
1679                        break;
1680                }
1681
1682                /* push object, proceed to base */
1683                if (delta_stack_nr >= delta_stack_alloc
1684                    && delta_stack == small_delta_stack) {
1685                        delta_stack_alloc = alloc_nr(delta_stack_nr);
1686                        ALLOC_ARRAY(delta_stack, delta_stack_alloc);
1687                        memcpy(delta_stack, small_delta_stack,
1688                               sizeof(*delta_stack)*delta_stack_nr);
1689                } else {
1690                        ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
1691                }
1692                i = delta_stack_nr++;
1693                delta_stack[i].obj_offset = obj_offset;
1694                delta_stack[i].curpos = curpos;
1695                delta_stack[i].size = size;
1696
1697                curpos = obj_offset = base_offset;
1698        }
1699
1700        /* PHASE 2: handle the base */
1701        switch (type) {
1702        case OBJ_OFS_DELTA:
1703        case OBJ_REF_DELTA:
1704                if (data)
1705                        BUG("unpack_entry: left loop at a valid delta");
1706                break;
1707        case OBJ_COMMIT:
1708        case OBJ_TREE:
1709        case OBJ_BLOB:
1710        case OBJ_TAG:
1711                if (!base_from_cache)
1712                        data = unpack_compressed_entry(p, &w_curs, curpos, size);
1713                break;
1714        default:
1715                data = NULL;
1716                error("unknown object type %i at offset %"PRIuMAX" in %s",
1717                      type, (uintmax_t)obj_offset, p->pack_name);
1718        }
1719
1720        /* PHASE 3: apply deltas in order */
1721
1722        /* invariants:
1723         *   'data' holds the base data, or NULL if there was corruption
1724         */
1725        while (delta_stack_nr) {
1726                void *delta_data;
1727                void *base = data;
1728                void *external_base = NULL;
1729                unsigned long delta_size, base_size = size;
1730                int i;
1731
1732                data = NULL;
1733
1734                if (base)
1735                        add_delta_base_cache(p, obj_offset, base, base_size, type);
1736
1737                if (!base) {
1738                        /*
1739                         * We're probably in deep shit, but let's try to fetch
1740                         * the required base anyway from another pack or loose.
1741                         * This is costly but should happen only in the presence
1742                         * of a corrupted pack, and is better than failing outright.
1743                         */
1744                        struct revindex_entry *revidx;
1745                        struct object_id base_oid;
1746                        revidx = find_pack_revindex(p, obj_offset);
1747                        if (revidx) {
1748                                nth_packed_object_oid(&base_oid, p, revidx->nr);
1749                                error("failed to read delta base object %s"
1750                                      " at offset %"PRIuMAX" from %s",
1751                                      oid_to_hex(&base_oid), (uintmax_t)obj_offset,
1752                                      p->pack_name);
1753                                mark_bad_packed_object(p, base_oid.hash);
1754                                base = read_object(r, &base_oid, &type, &base_size);
1755                                external_base = base;
1756                        }
1757                }
1758
1759                i = --delta_stack_nr;
1760                obj_offset = delta_stack[i].obj_offset;
1761                curpos = delta_stack[i].curpos;
1762                delta_size = delta_stack[i].size;
1763
1764                if (!base)
1765                        continue;
1766
1767                delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
1768
1769                if (!delta_data) {
1770                        error("failed to unpack compressed delta "
1771                              "at offset %"PRIuMAX" from %s",
1772                              (uintmax_t)curpos, p->pack_name);
1773                        data = NULL;
1774                        free(external_base);
1775                        continue;
1776                }
1777
1778                data = patch_delta(base, base_size,
1779                                   delta_data, delta_size,
1780                                   &size);
1781
1782                /*
1783                 * We could not apply the delta; warn the user, but keep going.
1784                 * Our failure will be noticed either in the next iteration of
1785                 * the loop, or if this is the final delta, in the caller when
1786                 * we return NULL. Those code paths will take care of making
1787                 * a more explicit warning and retrying with another copy of
1788                 * the object.
1789                 */
1790                if (!data)
1791                        error("failed to apply delta");
1792
1793                free(delta_data);
1794                free(external_base);
1795        }
1796
1797        if (final_type)
1798                *final_type = type;
1799        if (final_size)
1800                *final_size = size;
1801
1802out:
1803        unuse_pack(&w_curs);
1804
1805        if (delta_stack != small_delta_stack)
1806                free(delta_stack);
1807
1808        return data;
1809}
1810
1811int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result)
1812{
1813        const unsigned char *index_fanout = p->index_data;
1814        const unsigned char *index_lookup;
1815        const unsigned int hashsz = the_hash_algo->rawsz;
1816        int index_lookup_width;
1817
1818        if (!index_fanout)
1819                BUG("bsearch_pack called without a valid pack-index");
1820
1821        index_lookup = index_fanout + 4 * 256;
1822        if (p->index_version == 1) {
1823                index_lookup_width = hashsz + 4;
1824                index_lookup += 4;
1825        } else {
1826                index_lookup_width = hashsz;
1827                index_fanout += 8;
1828                index_lookup += 8;
1829        }
1830
1831        return bsearch_hash(oid->hash, (const uint32_t*)index_fanout,
1832                            index_lookup, index_lookup_width, result);
1833}
1834
1835const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1836                                            uint32_t n)
1837{
1838        const unsigned char *index = p->index_data;
1839        const unsigned int hashsz = the_hash_algo->rawsz;
1840        if (!index) {
1841                if (open_pack_index(p))
1842                        return NULL;
1843                index = p->index_data;
1844        }
1845        if (n >= p->num_objects)
1846                return NULL;
1847        index += 4 * 256;
1848        if (p->index_version == 1) {
1849                return index + (hashsz + 4) * n + 4;
1850        } else {
1851                index += 8;
1852                return index + hashsz * n;
1853        }
1854}
1855
1856const struct object_id *nth_packed_object_oid(struct object_id *oid,
1857                                              struct packed_git *p,
1858                                              uint32_t n)
1859{
1860        const unsigned char *hash = nth_packed_object_sha1(p, n);
1861        if (!hash)
1862                return NULL;
1863        hashcpy(oid->hash, hash);
1864        return oid;
1865}
1866
1867void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
1868{
1869        const unsigned char *ptr = vptr;
1870        const unsigned char *start = p->index_data;
1871        const unsigned char *end = start + p->index_size;
1872        if (ptr < start)
1873                die(_("offset before start of pack index for %s (corrupt index?)"),
1874                    p->pack_name);
1875        /* No need to check for underflow; .idx files must be at least 8 bytes */
1876        if (ptr >= end - 8)
1877                die(_("offset beyond end of pack index for %s (truncated index?)"),
1878                    p->pack_name);
1879}
1880
1881off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1882{
1883        const unsigned char *index = p->index_data;
1884        const unsigned int hashsz = the_hash_algo->rawsz;
1885        index += 4 * 256;
1886        if (p->index_version == 1) {
1887                return ntohl(*((uint32_t *)(index + (hashsz + 4) * n)));
1888        } else {
1889                uint32_t off;
1890                index += 8 + p->num_objects * (hashsz + 4);
1891                off = ntohl(*((uint32_t *)(index + 4 * n)));
1892                if (!(off & 0x80000000))
1893                        return off;
1894                index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1895                check_pack_index_ptr(p, index);
1896                return get_be64(index);
1897        }
1898}
1899
1900off_t find_pack_entry_one(const unsigned char *sha1,
1901                                  struct packed_git *p)
1902{
1903        const unsigned char *index = p->index_data;
1904        struct object_id oid;
1905        uint32_t result;
1906
1907        if (!index) {
1908                if (open_pack_index(p))
1909                        return 0;
1910        }
1911
1912        hashcpy(oid.hash, sha1);
1913        if (bsearch_pack(&oid, p, &result))
1914                return nth_packed_object_offset(p, result);
1915        return 0;
1916}
1917
1918int is_pack_valid(struct packed_git *p)
1919{
1920        /* An already open pack is known to be valid. */
1921        if (p->pack_fd != -1)
1922                return 1;
1923
1924        /* If the pack has one window completely covering the
1925         * file size, the pack is known to be valid even if
1926         * the descriptor is not currently open.
1927         */
1928        if (p->windows) {
1929                struct pack_window *w = p->windows;
1930
1931                if (!w->offset && w->len == p->pack_size)
1932                        return 1;
1933        }
1934
1935        /* Force the pack to open to prove its valid. */
1936        return !open_packed_git(p);
1937}
1938
1939struct packed_git *find_sha1_pack(const unsigned char *sha1,
1940                                  struct packed_git *packs)
1941{
1942        struct packed_git *p;
1943
1944        for (p = packs; p; p = p->next) {
1945                if (find_pack_entry_one(sha1, p))
1946                        return p;
1947        }
1948        return NULL;
1949
1950}
1951
1952static int fill_pack_entry(const struct object_id *oid,
1953                           struct pack_entry *e,
1954                           struct packed_git *p)
1955{
1956        off_t offset;
1957
1958        if (p->num_bad_objects) {
1959                unsigned i;
1960                for (i = 0; i < p->num_bad_objects; i++)
1961                        if (hasheq(oid->hash,
1962                                   p->bad_object_sha1 + the_hash_algo->rawsz * i))
1963                                return 0;
1964        }
1965
1966        offset = find_pack_entry_one(oid->hash, p);
1967        if (!offset)
1968                return 0;
1969
1970        /*
1971         * We are about to tell the caller where they can locate the
1972         * requested object.  We better make sure the packfile is
1973         * still here and can be accessed before supplying that
1974         * answer, as it may have been deleted since the index was
1975         * loaded!
1976         */
1977        if (!is_pack_valid(p))
1978                return 0;
1979        e->offset = offset;
1980        e->p = p;
1981        return 1;
1982}
1983
1984int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
1985{
1986        struct list_head *pos;
1987        struct multi_pack_index *m;
1988
1989        prepare_packed_git(r);
1990        if (!r->objects->packed_git && !r->objects->multi_pack_index)
1991                return 0;
1992
1993        for (m = r->objects->multi_pack_index; m; m = m->next) {
1994                if (fill_midx_entry(oid, e, m))
1995                        return 1;
1996        }
1997
1998        list_for_each(pos, &r->objects->packed_git_mru) {
1999                struct packed_git *p = list_entry(pos, struct packed_git, mru);
2000                if (fill_pack_entry(oid, e, p)) {
2001                        list_move(&p->mru, &r->objects->packed_git_mru);
2002                        return 1;
2003                }
2004        }
2005        return 0;
2006}
2007
2008int has_object_pack(const struct object_id *oid)
2009{
2010        struct pack_entry e;
2011        return find_pack_entry(the_repository, oid, &e);
2012}
2013
2014int has_pack_index(const unsigned char *sha1)
2015{
2016        struct stat st;
2017        if (stat(sha1_pack_index_name(sha1), &st))
2018                return 0;
2019        return 1;
2020}
2021
2022int for_each_object_in_pack(struct packed_git *p,
2023                            each_packed_object_fn cb, void *data,
2024                            enum for_each_object_flags flags)
2025{
2026        uint32_t i;
2027        int r = 0;
2028
2029        if (flags & FOR_EACH_OBJECT_PACK_ORDER)
2030                load_pack_revindex(p);
2031
2032        for (i = 0; i < p->num_objects; i++) {
2033                uint32_t pos;
2034                struct object_id oid;
2035
2036                if (flags & FOR_EACH_OBJECT_PACK_ORDER)
2037                        pos = p->revindex[i].nr;
2038                else
2039                        pos = i;
2040
2041                if (!nth_packed_object_oid(&oid, p, pos))
2042                        return error("unable to get sha1 of object %u in %s",
2043                                     pos, p->pack_name);
2044
2045                r = cb(&oid, p, pos, data);
2046                if (r)
2047                        break;
2048        }
2049        return r;
2050}
2051
2052int for_each_packed_object(each_packed_object_fn cb, void *data,
2053                           enum for_each_object_flags flags)
2054{
2055        struct packed_git *p;
2056        int r = 0;
2057        int pack_errors = 0;
2058
2059        prepare_packed_git(the_repository);
2060        for (p = get_all_packs(the_repository); p; p = p->next) {
2061                if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
2062                        continue;
2063                if ((flags & FOR_EACH_OBJECT_PROMISOR_ONLY) &&
2064                    !p->pack_promisor)
2065                        continue;
2066                if (open_pack_index(p)) {
2067                        pack_errors = 1;
2068                        continue;
2069                }
2070                r = for_each_object_in_pack(p, cb, data, flags);
2071                if (r)
2072                        break;
2073        }
2074        return r ? r : pack_errors;
2075}
2076
2077static int add_promisor_object(const struct object_id *oid,
2078                               struct packed_git *pack,
2079                               uint32_t pos,
2080                               void *set_)
2081{
2082        struct oidset *set = set_;
2083        struct object *obj = parse_object(the_repository, oid);
2084        if (!obj)
2085                return 1;
2086
2087        oidset_insert(set, oid);
2088
2089        /*
2090         * If this is a tree, commit, or tag, the objects it refers
2091         * to are also promisor objects. (Blobs refer to no objects->)
2092         */
2093        if (obj->type == OBJ_TREE) {
2094                struct tree *tree = (struct tree *)obj;
2095                struct tree_desc desc;
2096                struct name_entry entry;
2097                if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
2098                        /*
2099                         * Error messages are given when packs are
2100                         * verified, so do not print any here.
2101                         */
2102                        return 0;
2103                while (tree_entry_gently(&desc, &entry))
2104                        oidset_insert(set, &entry.oid);
2105        } else if (obj->type == OBJ_COMMIT) {
2106                struct commit *commit = (struct commit *) obj;
2107                struct commit_list *parents = commit->parents;
2108
2109                oidset_insert(set, get_commit_tree_oid(commit));
2110                for (; parents; parents = parents->next)
2111                        oidset_insert(set, &parents->item->object.oid);
2112        } else if (obj->type == OBJ_TAG) {
2113                struct tag *tag = (struct tag *) obj;
2114                oidset_insert(set, &tag->tagged->oid);
2115        }
2116        return 0;
2117}
2118
2119int is_promisor_object(const struct object_id *oid)
2120{
2121        static struct oidset promisor_objects;
2122        static int promisor_objects_prepared;
2123
2124        if (!promisor_objects_prepared) {
2125                if (repository_format_partial_clone) {
2126                        for_each_packed_object(add_promisor_object,
2127                                               &promisor_objects,
2128                                               FOR_EACH_OBJECT_PROMISOR_ONLY);
2129                }
2130                promisor_objects_prepared = 1;
2131        }
2132        return oidset_contains(&promisor_objects, oid);
2133}