sha1-file.con commit ci: restore running httpd tests (3960290)
   1/*
   2 * GIT - The information manager from hell
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 *
   6 * This handles basic git sha1 object files - packing, unpacking,
   7 * creation etc.
   8 */
   9#include "cache.h"
  10#include "config.h"
  11#include "string-list.h"
  12#include "lockfile.h"
  13#include "delta.h"
  14#include "pack.h"
  15#include "blob.h"
  16#include "commit.h"
  17#include "run-command.h"
  18#include "tag.h"
  19#include "tree.h"
  20#include "tree-walk.h"
  21#include "refs.h"
  22#include "pack-revindex.h"
  23#include "sha1-lookup.h"
  24#include "bulk-checkin.h"
  25#include "repository.h"
  26#include "replace-object.h"
  27#include "streaming.h"
  28#include "dir.h"
  29#include "list.h"
  30#include "mergesort.h"
  31#include "quote.h"
  32#include "packfile.h"
  33#include "fetch-object.h"
  34#include "object-store.h"
  35
  36/* The maximum size for an object header. */
  37#define MAX_HEADER_LEN 32
  38
  39
  40#define EMPTY_TREE_SHA1_BIN_LITERAL \
  41         "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60" \
  42         "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04"
  43#define EMPTY_TREE_SHA256_BIN_LITERAL \
  44        "\x6e\xf1\x9b\x41\x22\x5c\x53\x69\xf1\xc1" \
  45        "\x04\xd4\x5d\x8d\x85\xef\xa9\xb0\x57\xb5" \
  46        "\x3b\x14\xb4\xb9\xb9\x39\xdd\x74\xde\xcc" \
  47        "\x53\x21"
  48
  49#define EMPTY_BLOB_SHA1_BIN_LITERAL \
  50        "\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \
  51        "\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91"
  52#define EMPTY_BLOB_SHA256_BIN_LITERAL \
  53        "\x47\x3a\x0f\x4c\x3b\xe8\xa9\x36\x81\xa2" \
  54        "\x67\xe3\xb1\xe9\xa7\xdc\xda\x11\x85\x43" \
  55        "\x6f\xe1\x41\xf7\x74\x91\x20\xa3\x03\x72" \
  56        "\x18\x13"
  57
  58const unsigned char null_sha1[GIT_MAX_RAWSZ];
  59const struct object_id null_oid;
  60static const struct object_id empty_tree_oid = {
  61        EMPTY_TREE_SHA1_BIN_LITERAL
  62};
  63static const struct object_id empty_blob_oid = {
  64        EMPTY_BLOB_SHA1_BIN_LITERAL
  65};
  66static const struct object_id empty_tree_oid_sha256 = {
  67        EMPTY_TREE_SHA256_BIN_LITERAL
  68};
  69static const struct object_id empty_blob_oid_sha256 = {
  70        EMPTY_BLOB_SHA256_BIN_LITERAL
  71};
  72
  73static void git_hash_sha1_init(git_hash_ctx *ctx)
  74{
  75        git_SHA1_Init(&ctx->sha1);
  76}
  77
  78static void git_hash_sha1_update(git_hash_ctx *ctx, const void *data, size_t len)
  79{
  80        git_SHA1_Update(&ctx->sha1, data, len);
  81}
  82
  83static void git_hash_sha1_final(unsigned char *hash, git_hash_ctx *ctx)
  84{
  85        git_SHA1_Final(hash, &ctx->sha1);
  86}
  87
  88
  89static void git_hash_sha256_init(git_hash_ctx *ctx)
  90{
  91        git_SHA256_Init(&ctx->sha256);
  92}
  93
  94static void git_hash_sha256_update(git_hash_ctx *ctx, const void *data, size_t len)
  95{
  96        git_SHA256_Update(&ctx->sha256, data, len);
  97}
  98
  99static void git_hash_sha256_final(unsigned char *hash, git_hash_ctx *ctx)
 100{
 101        git_SHA256_Final(hash, &ctx->sha256);
 102}
 103
 104static void git_hash_unknown_init(git_hash_ctx *ctx)
 105{
 106        BUG("trying to init unknown hash");
 107}
 108
 109static void git_hash_unknown_update(git_hash_ctx *ctx, const void *data, size_t len)
 110{
 111        BUG("trying to update unknown hash");
 112}
 113
 114static void git_hash_unknown_final(unsigned char *hash, git_hash_ctx *ctx)
 115{
 116        BUG("trying to finalize unknown hash");
 117}
 118
 119const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
 120        {
 121                NULL,
 122                0x00000000,
 123                0,
 124                0,
 125                0,
 126                git_hash_unknown_init,
 127                git_hash_unknown_update,
 128                git_hash_unknown_final,
 129                NULL,
 130                NULL,
 131        },
 132        {
 133                "sha1",
 134                /* "sha1", big-endian */
 135                0x73686131,
 136                GIT_SHA1_RAWSZ,
 137                GIT_SHA1_HEXSZ,
 138                GIT_SHA1_BLKSZ,
 139                git_hash_sha1_init,
 140                git_hash_sha1_update,
 141                git_hash_sha1_final,
 142                &empty_tree_oid,
 143                &empty_blob_oid,
 144        },
 145        {
 146                "sha256",
 147                /* "s256", big-endian */
 148                0x73323536,
 149                GIT_SHA256_RAWSZ,
 150                GIT_SHA256_HEXSZ,
 151                GIT_SHA256_BLKSZ,
 152                git_hash_sha256_init,
 153                git_hash_sha256_update,
 154                git_hash_sha256_final,
 155                &empty_tree_oid_sha256,
 156                &empty_blob_oid_sha256,
 157        }
 158};
 159
 160const char *empty_tree_oid_hex(void)
 161{
 162        static char buf[GIT_MAX_HEXSZ + 1];
 163        return oid_to_hex_r(buf, the_hash_algo->empty_tree);
 164}
 165
 166const char *empty_blob_oid_hex(void)
 167{
 168        static char buf[GIT_MAX_HEXSZ + 1];
 169        return oid_to_hex_r(buf, the_hash_algo->empty_blob);
 170}
 171
 172int hash_algo_by_name(const char *name)
 173{
 174        int i;
 175        if (!name)
 176                return GIT_HASH_UNKNOWN;
 177        for (i = 1; i < GIT_HASH_NALGOS; i++)
 178                if (!strcmp(name, hash_algos[i].name))
 179                        return i;
 180        return GIT_HASH_UNKNOWN;
 181}
 182
 183int hash_algo_by_id(uint32_t format_id)
 184{
 185        int i;
 186        for (i = 1; i < GIT_HASH_NALGOS; i++)
 187                if (format_id == hash_algos[i].format_id)
 188                        return i;
 189        return GIT_HASH_UNKNOWN;
 190}
 191
 192int hash_algo_by_length(int len)
 193{
 194        int i;
 195        for (i = 1; i < GIT_HASH_NALGOS; i++)
 196                if (len == hash_algos[i].rawsz)
 197                        return i;
 198        return GIT_HASH_UNKNOWN;
 199}
 200
 201/*
 202 * This is meant to hold a *small* number of objects that you would
 203 * want read_object_file() to be able to return, but yet you do not want
 204 * to write them into the object store (e.g. a browse-only
 205 * application).
 206 */
 207static struct cached_object {
 208        struct object_id oid;
 209        enum object_type type;
 210        void *buf;
 211        unsigned long size;
 212} *cached_objects;
 213static int cached_object_nr, cached_object_alloc;
 214
 215static struct cached_object empty_tree = {
 216        { EMPTY_TREE_SHA1_BIN_LITERAL },
 217        OBJ_TREE,
 218        "",
 219        0
 220};
 221
 222static struct cached_object *find_cached_object(const struct object_id *oid)
 223{
 224        int i;
 225        struct cached_object *co = cached_objects;
 226
 227        for (i = 0; i < cached_object_nr; i++, co++) {
 228                if (oideq(&co->oid, oid))
 229                        return co;
 230        }
 231        if (oideq(oid, the_hash_algo->empty_tree))
 232                return &empty_tree;
 233        return NULL;
 234}
 235
 236
 237static int get_conv_flags(unsigned flags)
 238{
 239        if (flags & HASH_RENORMALIZE)
 240                return CONV_EOL_RENORMALIZE;
 241        else if (flags & HASH_WRITE_OBJECT)
 242                return global_conv_flags_eol | CONV_WRITE_OBJECT;
 243        else
 244                return 0;
 245}
 246
 247
 248int mkdir_in_gitdir(const char *path)
 249{
 250        if (mkdir(path, 0777)) {
 251                int saved_errno = errno;
 252                struct stat st;
 253                struct strbuf sb = STRBUF_INIT;
 254
 255                if (errno != EEXIST)
 256                        return -1;
 257                /*
 258                 * Are we looking at a path in a symlinked worktree
 259                 * whose original repository does not yet have it?
 260                 * e.g. .git/rr-cache pointing at its original
 261                 * repository in which the user hasn't performed any
 262                 * conflict resolution yet?
 263                 */
 264                if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
 265                    strbuf_readlink(&sb, path, st.st_size) ||
 266                    !is_absolute_path(sb.buf) ||
 267                    mkdir(sb.buf, 0777)) {
 268                        strbuf_release(&sb);
 269                        errno = saved_errno;
 270                        return -1;
 271                }
 272                strbuf_release(&sb);
 273        }
 274        return adjust_shared_perm(path);
 275}
 276
 277enum scld_error safe_create_leading_directories(char *path)
 278{
 279        char *next_component = path + offset_1st_component(path);
 280        enum scld_error ret = SCLD_OK;
 281
 282        while (ret == SCLD_OK && next_component) {
 283                struct stat st;
 284                char *slash = next_component, slash_character;
 285
 286                while (*slash && !is_dir_sep(*slash))
 287                        slash++;
 288
 289                if (!*slash)
 290                        break;
 291
 292                next_component = slash + 1;
 293                while (is_dir_sep(*next_component))
 294                        next_component++;
 295                if (!*next_component)
 296                        break;
 297
 298                slash_character = *slash;
 299                *slash = '\0';
 300                if (!stat(path, &st)) {
 301                        /* path exists */
 302                        if (!S_ISDIR(st.st_mode)) {
 303                                errno = ENOTDIR;
 304                                ret = SCLD_EXISTS;
 305                        }
 306                } else if (mkdir(path, 0777)) {
 307                        if (errno == EEXIST &&
 308                            !stat(path, &st) && S_ISDIR(st.st_mode))
 309                                ; /* somebody created it since we checked */
 310                        else if (errno == ENOENT)
 311                                /*
 312                                 * Either mkdir() failed because
 313                                 * somebody just pruned the containing
 314                                 * directory, or stat() failed because
 315                                 * the file that was in our way was
 316                                 * just removed.  Either way, inform
 317                                 * the caller that it might be worth
 318                                 * trying again:
 319                                 */
 320                                ret = SCLD_VANISHED;
 321                        else
 322                                ret = SCLD_FAILED;
 323                } else if (adjust_shared_perm(path)) {
 324                        ret = SCLD_PERMS;
 325                }
 326                *slash = slash_character;
 327        }
 328        return ret;
 329}
 330
 331enum scld_error safe_create_leading_directories_const(const char *path)
 332{
 333        int save_errno;
 334        /* path points to cache entries, so xstrdup before messing with it */
 335        char *buf = xstrdup(path);
 336        enum scld_error result = safe_create_leading_directories(buf);
 337
 338        save_errno = errno;
 339        free(buf);
 340        errno = save_errno;
 341        return result;
 342}
 343
 344int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
 345{
 346        /*
 347         * The number of times we will try to remove empty directories
 348         * in the way of path. This is only 1 because if another
 349         * process is racily creating directories that conflict with
 350         * us, we don't want to fight against them.
 351         */
 352        int remove_directories_remaining = 1;
 353
 354        /*
 355         * The number of times that we will try to create the
 356         * directories containing path. We are willing to attempt this
 357         * more than once, because another process could be trying to
 358         * clean up empty directories at the same time as we are
 359         * trying to create them.
 360         */
 361        int create_directories_remaining = 3;
 362
 363        /* A scratch copy of path, filled lazily if we need it: */
 364        struct strbuf path_copy = STRBUF_INIT;
 365
 366        int ret, save_errno;
 367
 368        /* Sanity check: */
 369        assert(*path);
 370
 371retry_fn:
 372        ret = fn(path, cb);
 373        save_errno = errno;
 374        if (!ret)
 375                goto out;
 376
 377        if (errno == EISDIR && remove_directories_remaining-- > 0) {
 378                /*
 379                 * A directory is in the way. Maybe it is empty; try
 380                 * to remove it:
 381                 */
 382                if (!path_copy.len)
 383                        strbuf_addstr(&path_copy, path);
 384
 385                if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
 386                        goto retry_fn;
 387        } else if (errno == ENOENT && create_directories_remaining-- > 0) {
 388                /*
 389                 * Maybe the containing directory didn't exist, or
 390                 * maybe it was just deleted by a process that is
 391                 * racing with us to clean up empty directories. Try
 392                 * to create it:
 393                 */
 394                enum scld_error scld_result;
 395
 396                if (!path_copy.len)
 397                        strbuf_addstr(&path_copy, path);
 398
 399                do {
 400                        scld_result = safe_create_leading_directories(path_copy.buf);
 401                        if (scld_result == SCLD_OK)
 402                                goto retry_fn;
 403                } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
 404        }
 405
 406out:
 407        strbuf_release(&path_copy);
 408        errno = save_errno;
 409        return ret;
 410}
 411
 412static void fill_loose_path(struct strbuf *buf, const struct object_id *oid)
 413{
 414        int i;
 415        for (i = 0; i < the_hash_algo->rawsz; i++) {
 416                static char hex[] = "0123456789abcdef";
 417                unsigned int val = oid->hash[i];
 418                strbuf_addch(buf, hex[val >> 4]);
 419                strbuf_addch(buf, hex[val & 0xf]);
 420                if (!i)
 421                        strbuf_addch(buf, '/');
 422        }
 423}
 424
 425static const char *odb_loose_path(struct object_directory *odb,
 426                                  struct strbuf *buf,
 427                                  const struct object_id *oid)
 428{
 429        strbuf_reset(buf);
 430        strbuf_addstr(buf, odb->path);
 431        strbuf_addch(buf, '/');
 432        fill_loose_path(buf, oid);
 433        return buf->buf;
 434}
 435
 436const char *loose_object_path(struct repository *r, struct strbuf *buf,
 437                              const struct object_id *oid)
 438{
 439        return odb_loose_path(r->objects->odb, buf, oid);
 440}
 441
 442/*
 443 * Return non-zero iff the path is usable as an alternate object database.
 444 */
 445static int alt_odb_usable(struct raw_object_store *o,
 446                          struct strbuf *path,
 447                          const char *normalized_objdir)
 448{
 449        struct object_directory *odb;
 450
 451        /* Detect cases where alternate disappeared */
 452        if (!is_directory(path->buf)) {
 453                error(_("object directory %s does not exist; "
 454                        "check .git/objects/info/alternates"),
 455                      path->buf);
 456                return 0;
 457        }
 458
 459        /*
 460         * Prevent the common mistake of listing the same
 461         * thing twice, or object directory itself.
 462         */
 463        for (odb = o->odb; odb; odb = odb->next) {
 464                if (!fspathcmp(path->buf, odb->path))
 465                        return 0;
 466        }
 467        if (!fspathcmp(path->buf, normalized_objdir))
 468                return 0;
 469
 470        return 1;
 471}
 472
 473/*
 474 * Prepare alternate object database registry.
 475 *
 476 * The variable alt_odb_list points at the list of struct
 477 * object_directory.  The elements on this list come from
 478 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
 479 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
 480 * whose contents is similar to that environment variable but can be
 481 * LF separated.  Its base points at a statically allocated buffer that
 482 * contains "/the/directory/corresponding/to/.git/objects/...", while
 483 * its name points just after the slash at the end of ".git/objects/"
 484 * in the example above, and has enough space to hold 40-byte hex
 485 * SHA1, an extra slash for the first level indirection, and the
 486 * terminating NUL.
 487 */
 488static void read_info_alternates(struct repository *r,
 489                                 const char *relative_base,
 490                                 int depth);
 491static int link_alt_odb_entry(struct repository *r, const char *entry,
 492        const char *relative_base, int depth, const char *normalized_objdir)
 493{
 494        struct object_directory *ent;
 495        struct strbuf pathbuf = STRBUF_INIT;
 496
 497        if (!is_absolute_path(entry) && relative_base) {
 498                strbuf_realpath(&pathbuf, relative_base, 1);
 499                strbuf_addch(&pathbuf, '/');
 500        }
 501        strbuf_addstr(&pathbuf, entry);
 502
 503        if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
 504                error(_("unable to normalize alternate object path: %s"),
 505                      pathbuf.buf);
 506                strbuf_release(&pathbuf);
 507                return -1;
 508        }
 509
 510        /*
 511         * The trailing slash after the directory name is given by
 512         * this function at the end. Remove duplicates.
 513         */
 514        while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
 515                strbuf_setlen(&pathbuf, pathbuf.len - 1);
 516
 517        if (!alt_odb_usable(r->objects, &pathbuf, normalized_objdir)) {
 518                strbuf_release(&pathbuf);
 519                return -1;
 520        }
 521
 522        ent = xcalloc(1, sizeof(*ent));
 523        ent->path = xstrdup(pathbuf.buf);
 524
 525        /* add the alternate entry */
 526        *r->objects->odb_tail = ent;
 527        r->objects->odb_tail = &(ent->next);
 528        ent->next = NULL;
 529
 530        /* recursively add alternates */
 531        read_info_alternates(r, pathbuf.buf, depth + 1);
 532
 533        strbuf_release(&pathbuf);
 534        return 0;
 535}
 536
 537static const char *parse_alt_odb_entry(const char *string,
 538                                       int sep,
 539                                       struct strbuf *out)
 540{
 541        const char *end;
 542
 543        strbuf_reset(out);
 544
 545        if (*string == '#') {
 546                /* comment; consume up to next separator */
 547                end = strchrnul(string, sep);
 548        } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
 549                /*
 550                 * quoted path; unquote_c_style has copied the
 551                 * data for us and set "end". Broken quoting (e.g.,
 552                 * an entry that doesn't end with a quote) falls
 553                 * back to the unquoted case below.
 554                 */
 555        } else {
 556                /* normal, unquoted path */
 557                end = strchrnul(string, sep);
 558                strbuf_add(out, string, end - string);
 559        }
 560
 561        if (*end)
 562                end++;
 563        return end;
 564}
 565
 566static void link_alt_odb_entries(struct repository *r, const char *alt,
 567                                 int sep, const char *relative_base, int depth)
 568{
 569        struct strbuf objdirbuf = STRBUF_INIT;
 570        struct strbuf entry = STRBUF_INIT;
 571
 572        if (!alt || !*alt)
 573                return;
 574
 575        if (depth > 5) {
 576                error(_("%s: ignoring alternate object stores, nesting too deep"),
 577                                relative_base);
 578                return;
 579        }
 580
 581        strbuf_add_absolute_path(&objdirbuf, r->objects->odb->path);
 582        if (strbuf_normalize_path(&objdirbuf) < 0)
 583                die(_("unable to normalize object directory: %s"),
 584                    objdirbuf.buf);
 585
 586        while (*alt) {
 587                alt = parse_alt_odb_entry(alt, sep, &entry);
 588                if (!entry.len)
 589                        continue;
 590                link_alt_odb_entry(r, entry.buf,
 591                                   relative_base, depth, objdirbuf.buf);
 592        }
 593        strbuf_release(&entry);
 594        strbuf_release(&objdirbuf);
 595}
 596
 597static void read_info_alternates(struct repository *r,
 598                                 const char *relative_base,
 599                                 int depth)
 600{
 601        char *path;
 602        struct strbuf buf = STRBUF_INIT;
 603
 604        path = xstrfmt("%s/info/alternates", relative_base);
 605        if (strbuf_read_file(&buf, path, 1024) < 0) {
 606                warn_on_fopen_errors(path);
 607                free(path);
 608                return;
 609        }
 610
 611        link_alt_odb_entries(r, buf.buf, '\n', relative_base, depth);
 612        strbuf_release(&buf);
 613        free(path);
 614}
 615
 616void add_to_alternates_file(const char *reference)
 617{
 618        struct lock_file lock = LOCK_INIT;
 619        char *alts = git_pathdup("objects/info/alternates");
 620        FILE *in, *out;
 621        int found = 0;
 622
 623        hold_lock_file_for_update(&lock, alts, LOCK_DIE_ON_ERROR);
 624        out = fdopen_lock_file(&lock, "w");
 625        if (!out)
 626                die_errno(_("unable to fdopen alternates lockfile"));
 627
 628        in = fopen(alts, "r");
 629        if (in) {
 630                struct strbuf line = STRBUF_INIT;
 631
 632                while (strbuf_getline(&line, in) != EOF) {
 633                        if (!strcmp(reference, line.buf)) {
 634                                found = 1;
 635                                break;
 636                        }
 637                        fprintf_or_die(out, "%s\n", line.buf);
 638                }
 639
 640                strbuf_release(&line);
 641                fclose(in);
 642        }
 643        else if (errno != ENOENT)
 644                die_errno(_("unable to read alternates file"));
 645
 646        if (found) {
 647                rollback_lock_file(&lock);
 648        } else {
 649                fprintf_or_die(out, "%s\n", reference);
 650                if (commit_lock_file(&lock))
 651                        die_errno(_("unable to move new alternates file into place"));
 652                if (the_repository->objects->loaded_alternates)
 653                        link_alt_odb_entries(the_repository, reference,
 654                                             '\n', NULL, 0);
 655        }
 656        free(alts);
 657}
 658
 659void add_to_alternates_memory(const char *reference)
 660{
 661        /*
 662         * Make sure alternates are initialized, or else our entry may be
 663         * overwritten when they are.
 664         */
 665        prepare_alt_odb(the_repository);
 666
 667        link_alt_odb_entries(the_repository, reference,
 668                             '\n', NULL, 0);
 669}
 670
 671/*
 672 * Compute the exact path an alternate is at and returns it. In case of
 673 * error NULL is returned and the human readable error is added to `err`
 674 * `path` may be relative and should point to $GIT_DIR.
 675 * `err` must not be null.
 676 */
 677char *compute_alternate_path(const char *path, struct strbuf *err)
 678{
 679        char *ref_git = NULL;
 680        const char *repo, *ref_git_s;
 681        int seen_error = 0;
 682
 683        ref_git_s = real_path_if_valid(path);
 684        if (!ref_git_s) {
 685                seen_error = 1;
 686                strbuf_addf(err, _("path '%s' does not exist"), path);
 687                goto out;
 688        } else
 689                /*
 690                 * Beware: read_gitfile(), real_path() and mkpath()
 691                 * return static buffer
 692                 */
 693                ref_git = xstrdup(ref_git_s);
 694
 695        repo = read_gitfile(ref_git);
 696        if (!repo)
 697                repo = read_gitfile(mkpath("%s/.git", ref_git));
 698        if (repo) {
 699                free(ref_git);
 700                ref_git = xstrdup(repo);
 701        }
 702
 703        if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
 704                char *ref_git_git = mkpathdup("%s/.git", ref_git);
 705                free(ref_git);
 706                ref_git = ref_git_git;
 707        } else if (!is_directory(mkpath("%s/objects", ref_git))) {
 708                struct strbuf sb = STRBUF_INIT;
 709                seen_error = 1;
 710                if (get_common_dir(&sb, ref_git)) {
 711                        strbuf_addf(err,
 712                                    _("reference repository '%s' as a linked "
 713                                      "checkout is not supported yet."),
 714                                    path);
 715                        goto out;
 716                }
 717
 718                strbuf_addf(err, _("reference repository '%s' is not a "
 719                                        "local repository."), path);
 720                goto out;
 721        }
 722
 723        if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
 724                strbuf_addf(err, _("reference repository '%s' is shallow"),
 725                            path);
 726                seen_error = 1;
 727                goto out;
 728        }
 729
 730        if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
 731                strbuf_addf(err,
 732                            _("reference repository '%s' is grafted"),
 733                            path);
 734                seen_error = 1;
 735                goto out;
 736        }
 737
 738out:
 739        if (seen_error) {
 740                FREE_AND_NULL(ref_git);
 741        }
 742
 743        return ref_git;
 744}
 745
 746static void fill_alternate_refs_command(struct child_process *cmd,
 747                                        const char *repo_path)
 748{
 749        const char *value;
 750
 751        if (!git_config_get_value("core.alternateRefsCommand", &value)) {
 752                cmd->use_shell = 1;
 753
 754                argv_array_push(&cmd->args, value);
 755                argv_array_push(&cmd->args, repo_path);
 756        } else {
 757                cmd->git_cmd = 1;
 758
 759                argv_array_pushf(&cmd->args, "--git-dir=%s", repo_path);
 760                argv_array_push(&cmd->args, "for-each-ref");
 761                argv_array_push(&cmd->args, "--format=%(objectname)");
 762
 763                if (!git_config_get_value("core.alternateRefsPrefixes", &value)) {
 764                        argv_array_push(&cmd->args, "--");
 765                        argv_array_split(&cmd->args, value);
 766                }
 767        }
 768
 769        cmd->env = local_repo_env;
 770        cmd->out = -1;
 771}
 772
 773static void read_alternate_refs(const char *path,
 774                                alternate_ref_fn *cb,
 775                                void *data)
 776{
 777        struct child_process cmd = CHILD_PROCESS_INIT;
 778        struct strbuf line = STRBUF_INIT;
 779        FILE *fh;
 780
 781        fill_alternate_refs_command(&cmd, path);
 782
 783        if (start_command(&cmd))
 784                return;
 785
 786        fh = xfdopen(cmd.out, "r");
 787        while (strbuf_getline_lf(&line, fh) != EOF) {
 788                struct object_id oid;
 789                const char *p;
 790
 791                if (parse_oid_hex(line.buf, &oid, &p) || *p) {
 792                        warning(_("invalid line while parsing alternate refs: %s"),
 793                                line.buf);
 794                        break;
 795                }
 796
 797                cb(&oid, data);
 798        }
 799
 800        fclose(fh);
 801        finish_command(&cmd);
 802        strbuf_release(&line);
 803}
 804
 805struct alternate_refs_data {
 806        alternate_ref_fn *fn;
 807        void *data;
 808};
 809
 810static int refs_from_alternate_cb(struct object_directory *e,
 811                                  void *data)
 812{
 813        struct strbuf path = STRBUF_INIT;
 814        size_t base_len;
 815        struct alternate_refs_data *cb = data;
 816
 817        if (!strbuf_realpath(&path, e->path, 0))
 818                goto out;
 819        if (!strbuf_strip_suffix(&path, "/objects"))
 820                goto out;
 821        base_len = path.len;
 822
 823        /* Is this a git repository with refs? */
 824        strbuf_addstr(&path, "/refs");
 825        if (!is_directory(path.buf))
 826                goto out;
 827        strbuf_setlen(&path, base_len);
 828
 829        read_alternate_refs(path.buf, cb->fn, cb->data);
 830
 831out:
 832        strbuf_release(&path);
 833        return 0;
 834}
 835
 836void for_each_alternate_ref(alternate_ref_fn fn, void *data)
 837{
 838        struct alternate_refs_data cb;
 839        cb.fn = fn;
 840        cb.data = data;
 841        foreach_alt_odb(refs_from_alternate_cb, &cb);
 842}
 843
 844int foreach_alt_odb(alt_odb_fn fn, void *cb)
 845{
 846        struct object_directory *ent;
 847        int r = 0;
 848
 849        prepare_alt_odb(the_repository);
 850        for (ent = the_repository->objects->odb->next; ent; ent = ent->next) {
 851                r = fn(ent, cb);
 852                if (r)
 853                        break;
 854        }
 855        return r;
 856}
 857
 858void prepare_alt_odb(struct repository *r)
 859{
 860        if (r->objects->loaded_alternates)
 861                return;
 862
 863        link_alt_odb_entries(r, r->objects->alternate_db, PATH_SEP, NULL, 0);
 864
 865        read_info_alternates(r, r->objects->odb->path, 0);
 866        r->objects->loaded_alternates = 1;
 867}
 868
 869/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
 870static int freshen_file(const char *fn)
 871{
 872        struct utimbuf t;
 873        t.actime = t.modtime = time(NULL);
 874        return !utime(fn, &t);
 875}
 876
 877/*
 878 * All of the check_and_freshen functions return 1 if the file exists and was
 879 * freshened (if freshening was requested), 0 otherwise. If they return
 880 * 0, you should not assume that it is safe to skip a write of the object (it
 881 * either does not exist on disk, or has a stale mtime and may be subject to
 882 * pruning).
 883 */
 884int check_and_freshen_file(const char *fn, int freshen)
 885{
 886        if (access(fn, F_OK))
 887                return 0;
 888        if (freshen && !freshen_file(fn))
 889                return 0;
 890        return 1;
 891}
 892
 893static int check_and_freshen_odb(struct object_directory *odb,
 894                                 const struct object_id *oid,
 895                                 int freshen)
 896{
 897        static struct strbuf path = STRBUF_INIT;
 898        odb_loose_path(odb, &path, oid);
 899        return check_and_freshen_file(path.buf, freshen);
 900}
 901
 902static int check_and_freshen_local(const struct object_id *oid, int freshen)
 903{
 904        return check_and_freshen_odb(the_repository->objects->odb, oid, freshen);
 905}
 906
 907static int check_and_freshen_nonlocal(const struct object_id *oid, int freshen)
 908{
 909        struct object_directory *odb;
 910
 911        prepare_alt_odb(the_repository);
 912        for (odb = the_repository->objects->odb->next; odb; odb = odb->next) {
 913                if (check_and_freshen_odb(odb, oid, freshen))
 914                        return 1;
 915        }
 916        return 0;
 917}
 918
 919static int check_and_freshen(const struct object_id *oid, int freshen)
 920{
 921        return check_and_freshen_local(oid, freshen) ||
 922               check_and_freshen_nonlocal(oid, freshen);
 923}
 924
 925int has_loose_object_nonlocal(const struct object_id *oid)
 926{
 927        return check_and_freshen_nonlocal(oid, 0);
 928}
 929
 930static int has_loose_object(const struct object_id *oid)
 931{
 932        return check_and_freshen(oid, 0);
 933}
 934
 935static void mmap_limit_check(size_t length)
 936{
 937        static size_t limit = 0;
 938        if (!limit) {
 939                limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
 940                if (!limit)
 941                        limit = SIZE_MAX;
 942        }
 943        if (length > limit)
 944                die(_("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX),
 945                    (uintmax_t)length, (uintmax_t)limit);
 946}
 947
 948void *xmmap_gently(void *start, size_t length,
 949                  int prot, int flags, int fd, off_t offset)
 950{
 951        void *ret;
 952
 953        mmap_limit_check(length);
 954        ret = mmap(start, length, prot, flags, fd, offset);
 955        if (ret == MAP_FAILED) {
 956                if (!length)
 957                        return NULL;
 958                release_pack_memory(length);
 959                ret = mmap(start, length, prot, flags, fd, offset);
 960        }
 961        return ret;
 962}
 963
 964void *xmmap(void *start, size_t length,
 965        int prot, int flags, int fd, off_t offset)
 966{
 967        void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
 968        if (ret == MAP_FAILED)
 969                die_errno(_("mmap failed"));
 970        return ret;
 971}
 972
 973/*
 974 * With an in-core object data in "map", rehash it to make sure the
 975 * object name actually matches "oid" to detect object corruption.
 976 * With "map" == NULL, try reading the object named with "oid" using
 977 * the streaming interface and rehash it to do the same.
 978 */
 979int check_object_signature(const struct object_id *oid, void *map,
 980                           unsigned long size, const char *type)
 981{
 982        struct object_id real_oid;
 983        enum object_type obj_type;
 984        struct git_istream *st;
 985        git_hash_ctx c;
 986        char hdr[MAX_HEADER_LEN];
 987        int hdrlen;
 988
 989        if (map) {
 990                hash_object_file(map, size, type, &real_oid);
 991                return !oideq(oid, &real_oid) ? -1 : 0;
 992        }
 993
 994        st = open_istream(oid, &obj_type, &size, NULL);
 995        if (!st)
 996                return -1;
 997
 998        /* Generate the header */
 999        hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(obj_type), (uintmax_t)size) + 1;
1000
1001        /* Sha1.. */
1002        the_hash_algo->init_fn(&c);
1003        the_hash_algo->update_fn(&c, hdr, hdrlen);
1004        for (;;) {
1005                char buf[1024 * 16];
1006                ssize_t readlen = read_istream(st, buf, sizeof(buf));
1007
1008                if (readlen < 0) {
1009                        close_istream(st);
1010                        return -1;
1011                }
1012                if (!readlen)
1013                        break;
1014                the_hash_algo->update_fn(&c, buf, readlen);
1015        }
1016        the_hash_algo->final_fn(real_oid.hash, &c);
1017        close_istream(st);
1018        return !oideq(oid, &real_oid) ? -1 : 0;
1019}
1020
1021int git_open_cloexec(const char *name, int flags)
1022{
1023        int fd;
1024        static int o_cloexec = O_CLOEXEC;
1025
1026        fd = open(name, flags | o_cloexec);
1027        if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
1028                /* Try again w/o O_CLOEXEC: the kernel might not support it */
1029                o_cloexec &= ~O_CLOEXEC;
1030                fd = open(name, flags | o_cloexec);
1031        }
1032
1033#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
1034        {
1035                static int fd_cloexec = FD_CLOEXEC;
1036
1037                if (!o_cloexec && 0 <= fd && fd_cloexec) {
1038                        /* Opened w/o O_CLOEXEC?  try with fcntl(2) to add it */
1039                        int flags = fcntl(fd, F_GETFD);
1040                        if (fcntl(fd, F_SETFD, flags | fd_cloexec))
1041                                fd_cloexec = 0;
1042                }
1043        }
1044#endif
1045        return fd;
1046}
1047
1048/*
1049 * Find "oid" as a loose object in the local repository or in an alternate.
1050 * Returns 0 on success, negative on failure.
1051 *
1052 * The "path" out-parameter will give the path of the object we found (if any).
1053 * Note that it may point to static storage and is only valid until another
1054 * call to stat_loose_object().
1055 */
1056static int stat_loose_object(struct repository *r, const struct object_id *oid,
1057                             struct stat *st, const char **path)
1058{
1059        struct object_directory *odb;
1060        static struct strbuf buf = STRBUF_INIT;
1061
1062        prepare_alt_odb(r);
1063        for (odb = r->objects->odb; odb; odb = odb->next) {
1064                *path = odb_loose_path(odb, &buf, oid);
1065                if (!lstat(*path, st))
1066                        return 0;
1067        }
1068
1069        return -1;
1070}
1071
1072/*
1073 * Like stat_loose_object(), but actually open the object and return the
1074 * descriptor. See the caveats on the "path" parameter above.
1075 */
1076static int open_loose_object(struct repository *r,
1077                             const struct object_id *oid, const char **path)
1078{
1079        int fd;
1080        struct object_directory *odb;
1081        int most_interesting_errno = ENOENT;
1082        static struct strbuf buf = STRBUF_INIT;
1083
1084        prepare_alt_odb(r);
1085        for (odb = r->objects->odb; odb; odb = odb->next) {
1086                *path = odb_loose_path(odb, &buf, oid);
1087                fd = git_open(*path);
1088                if (fd >= 0)
1089                        return fd;
1090
1091                if (most_interesting_errno == ENOENT)
1092                        most_interesting_errno = errno;
1093        }
1094        errno = most_interesting_errno;
1095        return -1;
1096}
1097
1098static int quick_has_loose(struct repository *r,
1099                           const struct object_id *oid)
1100{
1101        struct object_directory *odb;
1102
1103        prepare_alt_odb(r);
1104        for (odb = r->objects->odb; odb; odb = odb->next) {
1105                if (oid_array_lookup(odb_loose_cache(odb, oid), oid) >= 0)
1106                        return 1;
1107        }
1108        return 0;
1109}
1110
1111/*
1112 * Map the loose object at "path" if it is not NULL, or the path found by
1113 * searching for a loose object named "oid".
1114 */
1115static void *map_loose_object_1(struct repository *r, const char *path,
1116                             const struct object_id *oid, unsigned long *size)
1117{
1118        void *map;
1119        int fd;
1120
1121        if (path)
1122                fd = git_open(path);
1123        else
1124                fd = open_loose_object(r, oid, &path);
1125        map = NULL;
1126        if (fd >= 0) {
1127                struct stat st;
1128
1129                if (!fstat(fd, &st)) {
1130                        *size = xsize_t(st.st_size);
1131                        if (!*size) {
1132                                /* mmap() is forbidden on empty files */
1133                                error(_("object file %s is empty"), path);
1134                                close(fd);
1135                                return NULL;
1136                        }
1137                        map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1138                }
1139                close(fd);
1140        }
1141        return map;
1142}
1143
1144void *map_loose_object(struct repository *r,
1145                       const struct object_id *oid,
1146                       unsigned long *size)
1147{
1148        return map_loose_object_1(r, NULL, oid, size);
1149}
1150
1151static int unpack_loose_short_header(git_zstream *stream,
1152                                     unsigned char *map, unsigned long mapsize,
1153                                     void *buffer, unsigned long bufsiz)
1154{
1155        /* Get the data stream */
1156        memset(stream, 0, sizeof(*stream));
1157        stream->next_in = map;
1158        stream->avail_in = mapsize;
1159        stream->next_out = buffer;
1160        stream->avail_out = bufsiz;
1161
1162        git_inflate_init(stream);
1163        return git_inflate(stream, 0);
1164}
1165
1166int unpack_loose_header(git_zstream *stream,
1167                        unsigned char *map, unsigned long mapsize,
1168                        void *buffer, unsigned long bufsiz)
1169{
1170        int status = unpack_loose_short_header(stream, map, mapsize,
1171                                               buffer, bufsiz);
1172
1173        if (status < Z_OK)
1174                return status;
1175
1176        /* Make sure we have the terminating NUL */
1177        if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1178                return -1;
1179        return 0;
1180}
1181
1182static int unpack_loose_header_to_strbuf(git_zstream *stream, unsigned char *map,
1183                                         unsigned long mapsize, void *buffer,
1184                                         unsigned long bufsiz, struct strbuf *header)
1185{
1186        int status;
1187
1188        status = unpack_loose_short_header(stream, map, mapsize, buffer, bufsiz);
1189        if (status < Z_OK)
1190                return -1;
1191
1192        /*
1193         * Check if entire header is unpacked in the first iteration.
1194         */
1195        if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1196                return 0;
1197
1198        /*
1199         * buffer[0..bufsiz] was not large enough.  Copy the partial
1200         * result out to header, and then append the result of further
1201         * reading the stream.
1202         */
1203        strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1204        stream->next_out = buffer;
1205        stream->avail_out = bufsiz;
1206
1207        do {
1208                status = git_inflate(stream, 0);
1209                strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1210                if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1211                        return 0;
1212                stream->next_out = buffer;
1213                stream->avail_out = bufsiz;
1214        } while (status != Z_STREAM_END);
1215        return -1;
1216}
1217
1218static void *unpack_loose_rest(git_zstream *stream,
1219                               void *buffer, unsigned long size,
1220                               const struct object_id *oid)
1221{
1222        int bytes = strlen(buffer) + 1;
1223        unsigned char *buf = xmallocz(size);
1224        unsigned long n;
1225        int status = Z_OK;
1226
1227        n = stream->total_out - bytes;
1228        if (n > size)
1229                n = size;
1230        memcpy(buf, (char *) buffer + bytes, n);
1231        bytes = n;
1232        if (bytes <= size) {
1233                /*
1234                 * The above condition must be (bytes <= size), not
1235                 * (bytes < size).  In other words, even though we
1236                 * expect no more output and set avail_out to zero,
1237                 * the input zlib stream may have bytes that express
1238                 * "this concludes the stream", and we *do* want to
1239                 * eat that input.
1240                 *
1241                 * Otherwise we would not be able to test that we
1242                 * consumed all the input to reach the expected size;
1243                 * we also want to check that zlib tells us that all
1244                 * went well with status == Z_STREAM_END at the end.
1245                 */
1246                stream->next_out = buf + bytes;
1247                stream->avail_out = size - bytes;
1248                while (status == Z_OK)
1249                        status = git_inflate(stream, Z_FINISH);
1250        }
1251        if (status == Z_STREAM_END && !stream->avail_in) {
1252                git_inflate_end(stream);
1253                return buf;
1254        }
1255
1256        if (status < 0)
1257                error(_("corrupt loose object '%s'"), oid_to_hex(oid));
1258        else if (stream->avail_in)
1259                error(_("garbage at end of loose object '%s'"),
1260                      oid_to_hex(oid));
1261        free(buf);
1262        return NULL;
1263}
1264
1265/*
1266 * We used to just use "sscanf()", but that's actually way
1267 * too permissive for what we want to check. So do an anal
1268 * object header parse by hand.
1269 */
1270static int parse_loose_header_extended(const char *hdr, struct object_info *oi,
1271                                       unsigned int flags)
1272{
1273        const char *type_buf = hdr;
1274        unsigned long size;
1275        int type, type_len = 0;
1276
1277        /*
1278         * The type can be of any size but is followed by
1279         * a space.
1280         */
1281        for (;;) {
1282                char c = *hdr++;
1283                if (!c)
1284                        return -1;
1285                if (c == ' ')
1286                        break;
1287                type_len++;
1288        }
1289
1290        type = type_from_string_gently(type_buf, type_len, 1);
1291        if (oi->type_name)
1292                strbuf_add(oi->type_name, type_buf, type_len);
1293        /*
1294         * Set type to 0 if its an unknown object and
1295         * we're obtaining the type using '--allow-unknown-type'
1296         * option.
1297         */
1298        if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
1299                type = 0;
1300        else if (type < 0)
1301                die(_("invalid object type"));
1302        if (oi->typep)
1303                *oi->typep = type;
1304
1305        /*
1306         * The length must follow immediately, and be in canonical
1307         * decimal format (ie "010" is not valid).
1308         */
1309        size = *hdr++ - '0';
1310        if (size > 9)
1311                return -1;
1312        if (size) {
1313                for (;;) {
1314                        unsigned long c = *hdr - '0';
1315                        if (c > 9)
1316                                break;
1317                        hdr++;
1318                        size = size * 10 + c;
1319                }
1320        }
1321
1322        if (oi->sizep)
1323                *oi->sizep = size;
1324
1325        /*
1326         * The length must be followed by a zero byte
1327         */
1328        return *hdr ? -1 : type;
1329}
1330
1331int parse_loose_header(const char *hdr, unsigned long *sizep)
1332{
1333        struct object_info oi = OBJECT_INFO_INIT;
1334
1335        oi.sizep = sizep;
1336        return parse_loose_header_extended(hdr, &oi, 0);
1337}
1338
1339static int loose_object_info(struct repository *r,
1340                             const struct object_id *oid,
1341                             struct object_info *oi, int flags)
1342{
1343        int status = 0;
1344        unsigned long mapsize;
1345        void *map;
1346        git_zstream stream;
1347        char hdr[MAX_HEADER_LEN];
1348        struct strbuf hdrbuf = STRBUF_INIT;
1349        unsigned long size_scratch;
1350
1351        if (oi->delta_base_sha1)
1352                hashclr(oi->delta_base_sha1);
1353
1354        /*
1355         * If we don't care about type or size, then we don't
1356         * need to look inside the object at all. Note that we
1357         * do not optimize out the stat call, even if the
1358         * caller doesn't care about the disk-size, since our
1359         * return value implicitly indicates whether the
1360         * object even exists.
1361         */
1362        if (!oi->typep && !oi->type_name && !oi->sizep && !oi->contentp) {
1363                const char *path;
1364                struct stat st;
1365                if (!oi->disk_sizep && (flags & OBJECT_INFO_QUICK))
1366                        return quick_has_loose(r, oid) ? 0 : -1;
1367                if (stat_loose_object(r, oid, &st, &path) < 0)
1368                        return -1;
1369                if (oi->disk_sizep)
1370                        *oi->disk_sizep = st.st_size;
1371                return 0;
1372        }
1373
1374        map = map_loose_object(r, oid, &mapsize);
1375        if (!map)
1376                return -1;
1377
1378        if (!oi->sizep)
1379                oi->sizep = &size_scratch;
1380
1381        if (oi->disk_sizep)
1382                *oi->disk_sizep = mapsize;
1383        if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
1384                if (unpack_loose_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
1385                        status = error(_("unable to unpack %s header with --allow-unknown-type"),
1386                                       oid_to_hex(oid));
1387        } else if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1388                status = error(_("unable to unpack %s header"),
1389                               oid_to_hex(oid));
1390        if (status < 0)
1391                ; /* Do nothing */
1392        else if (hdrbuf.len) {
1393                if ((status = parse_loose_header_extended(hdrbuf.buf, oi, flags)) < 0)
1394                        status = error(_("unable to parse %s header with --allow-unknown-type"),
1395                                       oid_to_hex(oid));
1396        } else if ((status = parse_loose_header_extended(hdr, oi, flags)) < 0)
1397                status = error(_("unable to parse %s header"), oid_to_hex(oid));
1398
1399        if (status >= 0 && oi->contentp) {
1400                *oi->contentp = unpack_loose_rest(&stream, hdr,
1401                                                  *oi->sizep, oid);
1402                if (!*oi->contentp) {
1403                        git_inflate_end(&stream);
1404                        status = -1;
1405                }
1406        } else
1407                git_inflate_end(&stream);
1408
1409        munmap(map, mapsize);
1410        if (status && oi->typep)
1411                *oi->typep = status;
1412        if (oi->sizep == &size_scratch)
1413                oi->sizep = NULL;
1414        strbuf_release(&hdrbuf);
1415        oi->whence = OI_LOOSE;
1416        return (status < 0) ? status : 0;
1417}
1418
1419int fetch_if_missing = 1;
1420
1421int oid_object_info_extended(struct repository *r, const struct object_id *oid,
1422                             struct object_info *oi, unsigned flags)
1423{
1424        static struct object_info blank_oi = OBJECT_INFO_INIT;
1425        struct pack_entry e;
1426        int rtype;
1427        const struct object_id *real = oid;
1428        int already_retried = 0;
1429
1430        if (flags & OBJECT_INFO_LOOKUP_REPLACE)
1431                real = lookup_replace_object(r, oid);
1432
1433        if (is_null_oid(real))
1434                return -1;
1435
1436        if (!oi)
1437                oi = &blank_oi;
1438
1439        if (!(flags & OBJECT_INFO_SKIP_CACHED)) {
1440                struct cached_object *co = find_cached_object(real);
1441                if (co) {
1442                        if (oi->typep)
1443                                *(oi->typep) = co->type;
1444                        if (oi->sizep)
1445                                *(oi->sizep) = co->size;
1446                        if (oi->disk_sizep)
1447                                *(oi->disk_sizep) = 0;
1448                        if (oi->delta_base_sha1)
1449                                hashclr(oi->delta_base_sha1);
1450                        if (oi->type_name)
1451                                strbuf_addstr(oi->type_name, type_name(co->type));
1452                        if (oi->contentp)
1453                                *oi->contentp = xmemdupz(co->buf, co->size);
1454                        oi->whence = OI_CACHED;
1455                        return 0;
1456                }
1457        }
1458
1459        while (1) {
1460                if (find_pack_entry(r, real, &e))
1461                        break;
1462
1463                if (flags & OBJECT_INFO_IGNORE_LOOSE)
1464                        return -1;
1465
1466                /* Most likely it's a loose object. */
1467                if (!loose_object_info(r, real, oi, flags))
1468                        return 0;
1469
1470                /* Not a loose object; someone else may have just packed it. */
1471                if (!(flags & OBJECT_INFO_QUICK)) {
1472                        reprepare_packed_git(r);
1473                        if (find_pack_entry(r, real, &e))
1474                                break;
1475                }
1476
1477                /* Check if it is a missing object */
1478                if (fetch_if_missing && repository_format_partial_clone &&
1479                    !already_retried && r == the_repository &&
1480                    !(flags & OBJECT_INFO_SKIP_FETCH_OBJECT)) {
1481                        /*
1482                         * TODO Investigate having fetch_object() return
1483                         * TODO error/success and stopping the music here.
1484                         * TODO Pass a repository struct through fetch_object,
1485                         * such that arbitrary repositories work.
1486                         */
1487                        fetch_objects(repository_format_partial_clone, real, 1);
1488                        already_retried = 1;
1489                        continue;
1490                }
1491
1492                return -1;
1493        }
1494
1495        if (oi == &blank_oi)
1496                /*
1497                 * We know that the caller doesn't actually need the
1498                 * information below, so return early.
1499                 */
1500                return 0;
1501        rtype = packed_object_info(r, e.p, e.offset, oi);
1502        if (rtype < 0) {
1503                mark_bad_packed_object(e.p, real->hash);
1504                return oid_object_info_extended(r, real, oi, 0);
1505        } else if (oi->whence == OI_PACKED) {
1506                oi->u.packed.offset = e.offset;
1507                oi->u.packed.pack = e.p;
1508                oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
1509                                         rtype == OBJ_OFS_DELTA);
1510        }
1511
1512        return 0;
1513}
1514
1515/* returns enum object_type or negative */
1516int oid_object_info(struct repository *r,
1517                    const struct object_id *oid,
1518                    unsigned long *sizep)
1519{
1520        enum object_type type;
1521        struct object_info oi = OBJECT_INFO_INIT;
1522
1523        oi.typep = &type;
1524        oi.sizep = sizep;
1525        if (oid_object_info_extended(r, oid, &oi,
1526                                      OBJECT_INFO_LOOKUP_REPLACE) < 0)
1527                return -1;
1528        return type;
1529}
1530
1531static void *read_object(struct repository *r,
1532                         const struct object_id *oid, enum object_type *type,
1533                         unsigned long *size)
1534{
1535        struct object_info oi = OBJECT_INFO_INIT;
1536        void *content;
1537        oi.typep = type;
1538        oi.sizep = size;
1539        oi.contentp = &content;
1540
1541        if (oid_object_info_extended(r, oid, &oi, 0) < 0)
1542                return NULL;
1543        return content;
1544}
1545
1546int pretend_object_file(void *buf, unsigned long len, enum object_type type,
1547                        struct object_id *oid)
1548{
1549        struct cached_object *co;
1550
1551        hash_object_file(buf, len, type_name(type), oid);
1552        if (has_object_file(oid) || find_cached_object(oid))
1553                return 0;
1554        ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
1555        co = &cached_objects[cached_object_nr++];
1556        co->size = len;
1557        co->type = type;
1558        co->buf = xmalloc(len);
1559        memcpy(co->buf, buf, len);
1560        oidcpy(&co->oid, oid);
1561        return 0;
1562}
1563
1564/*
1565 * This function dies on corrupt objects; the callers who want to
1566 * deal with them should arrange to call read_object() and give error
1567 * messages themselves.
1568 */
1569void *read_object_file_extended(struct repository *r,
1570                                const struct object_id *oid,
1571                                enum object_type *type,
1572                                unsigned long *size,
1573                                int lookup_replace)
1574{
1575        void *data;
1576        const struct packed_git *p;
1577        const char *path;
1578        struct stat st;
1579        const struct object_id *repl = lookup_replace ?
1580                lookup_replace_object(r, oid) : oid;
1581
1582        errno = 0;
1583        data = read_object(r, repl, type, size);
1584        if (data)
1585                return data;
1586
1587        if (errno && errno != ENOENT)
1588                die_errno(_("failed to read object %s"), oid_to_hex(oid));
1589
1590        /* die if we replaced an object with one that does not exist */
1591        if (repl != oid)
1592                die(_("replacement %s not found for %s"),
1593                    oid_to_hex(repl), oid_to_hex(oid));
1594
1595        if (!stat_loose_object(r, repl, &st, &path))
1596                die(_("loose object %s (stored in %s) is corrupt"),
1597                    oid_to_hex(repl), path);
1598
1599        if ((p = has_packed_and_bad(r, repl->hash)) != NULL)
1600                die(_("packed object %s (stored in %s) is corrupt"),
1601                    oid_to_hex(repl), p->pack_name);
1602
1603        return NULL;
1604}
1605
1606void *read_object_with_reference(struct repository *r,
1607                                 const struct object_id *oid,
1608                                 const char *required_type_name,
1609                                 unsigned long *size,
1610                                 struct object_id *actual_oid_return)
1611{
1612        enum object_type type, required_type;
1613        void *buffer;
1614        unsigned long isize;
1615        struct object_id actual_oid;
1616
1617        required_type = type_from_string(required_type_name);
1618        oidcpy(&actual_oid, oid);
1619        while (1) {
1620                int ref_length = -1;
1621                const char *ref_type = NULL;
1622
1623                buffer = repo_read_object_file(r, &actual_oid, &type, &isize);
1624                if (!buffer)
1625                        return NULL;
1626                if (type == required_type) {
1627                        *size = isize;
1628                        if (actual_oid_return)
1629                                oidcpy(actual_oid_return, &actual_oid);
1630                        return buffer;
1631                }
1632                /* Handle references */
1633                else if (type == OBJ_COMMIT)
1634                        ref_type = "tree ";
1635                else if (type == OBJ_TAG)
1636                        ref_type = "object ";
1637                else {
1638                        free(buffer);
1639                        return NULL;
1640                }
1641                ref_length = strlen(ref_type);
1642
1643                if (ref_length + the_hash_algo->hexsz > isize ||
1644                    memcmp(buffer, ref_type, ref_length) ||
1645                    get_oid_hex((char *) buffer + ref_length, &actual_oid)) {
1646                        free(buffer);
1647                        return NULL;
1648                }
1649                free(buffer);
1650                /* Now we have the ID of the referred-to object in
1651                 * actual_oid.  Check again. */
1652        }
1653}
1654
1655static void write_object_file_prepare(const void *buf, unsigned long len,
1656                                      const char *type, struct object_id *oid,
1657                                      char *hdr, int *hdrlen)
1658{
1659        git_hash_ctx c;
1660
1661        /* Generate the header */
1662        *hdrlen = xsnprintf(hdr, *hdrlen, "%s %"PRIuMAX , type, (uintmax_t)len)+1;
1663
1664        /* Sha1.. */
1665        the_hash_algo->init_fn(&c);
1666        the_hash_algo->update_fn(&c, hdr, *hdrlen);
1667        the_hash_algo->update_fn(&c, buf, len);
1668        the_hash_algo->final_fn(oid->hash, &c);
1669}
1670
1671/*
1672 * Move the just written object into its final resting place.
1673 */
1674int finalize_object_file(const char *tmpfile, const char *filename)
1675{
1676        int ret = 0;
1677
1678        if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
1679                goto try_rename;
1680        else if (link(tmpfile, filename))
1681                ret = errno;
1682
1683        /*
1684         * Coda hack - coda doesn't like cross-directory links,
1685         * so we fall back to a rename, which will mean that it
1686         * won't be able to check collisions, but that's not a
1687         * big deal.
1688         *
1689         * The same holds for FAT formatted media.
1690         *
1691         * When this succeeds, we just return.  We have nothing
1692         * left to unlink.
1693         */
1694        if (ret && ret != EEXIST) {
1695        try_rename:
1696                if (!rename(tmpfile, filename))
1697                        goto out;
1698                ret = errno;
1699        }
1700        unlink_or_warn(tmpfile);
1701        if (ret) {
1702                if (ret != EEXIST) {
1703                        return error_errno(_("unable to write file %s"), filename);
1704                }
1705                /* FIXME!!! Collision check here ? */
1706        }
1707
1708out:
1709        if (adjust_shared_perm(filename))
1710                return error(_("unable to set permission to '%s'"), filename);
1711        return 0;
1712}
1713
1714static int write_buffer(int fd, const void *buf, size_t len)
1715{
1716        if (write_in_full(fd, buf, len) < 0)
1717                return error_errno(_("file write error"));
1718        return 0;
1719}
1720
1721int hash_object_file(const void *buf, unsigned long len, const char *type,
1722                     struct object_id *oid)
1723{
1724        char hdr[MAX_HEADER_LEN];
1725        int hdrlen = sizeof(hdr);
1726        write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1727        return 0;
1728}
1729
1730/* Finalize a file on disk, and close it. */
1731static void close_loose_object(int fd)
1732{
1733        if (fsync_object_files)
1734                fsync_or_die(fd, "loose object file");
1735        if (close(fd) != 0)
1736                die_errno(_("error when closing loose object file"));
1737}
1738
1739/* Size of directory component, including the ending '/' */
1740static inline int directory_size(const char *filename)
1741{
1742        const char *s = strrchr(filename, '/');
1743        if (!s)
1744                return 0;
1745        return s - filename + 1;
1746}
1747
1748/*
1749 * This creates a temporary file in the same directory as the final
1750 * 'filename'
1751 *
1752 * We want to avoid cross-directory filename renames, because those
1753 * can have problems on various filesystems (FAT, NFS, Coda).
1754 */
1755static int create_tmpfile(struct strbuf *tmp, const char *filename)
1756{
1757        int fd, dirlen = directory_size(filename);
1758
1759        strbuf_reset(tmp);
1760        strbuf_add(tmp, filename, dirlen);
1761        strbuf_addstr(tmp, "tmp_obj_XXXXXX");
1762        fd = git_mkstemp_mode(tmp->buf, 0444);
1763        if (fd < 0 && dirlen && errno == ENOENT) {
1764                /*
1765                 * Make sure the directory exists; note that the contents
1766                 * of the buffer are undefined after mkstemp returns an
1767                 * error, so we have to rewrite the whole buffer from
1768                 * scratch.
1769                 */
1770                strbuf_reset(tmp);
1771                strbuf_add(tmp, filename, dirlen - 1);
1772                if (mkdir(tmp->buf, 0777) && errno != EEXIST)
1773                        return -1;
1774                if (adjust_shared_perm(tmp->buf))
1775                        return -1;
1776
1777                /* Try again */
1778                strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
1779                fd = git_mkstemp_mode(tmp->buf, 0444);
1780        }
1781        return fd;
1782}
1783
1784static int write_loose_object(const struct object_id *oid, char *hdr,
1785                              int hdrlen, const void *buf, unsigned long len,
1786                              time_t mtime)
1787{
1788        int fd, ret;
1789        unsigned char compressed[4096];
1790        git_zstream stream;
1791        git_hash_ctx c;
1792        struct object_id parano_oid;
1793        static struct strbuf tmp_file = STRBUF_INIT;
1794        static struct strbuf filename = STRBUF_INIT;
1795
1796        loose_object_path(the_repository, &filename, oid);
1797
1798        fd = create_tmpfile(&tmp_file, filename.buf);
1799        if (fd < 0) {
1800                if (errno == EACCES)
1801                        return error(_("insufficient permission for adding an object to repository database %s"), get_object_directory());
1802                else
1803                        return error_errno(_("unable to create temporary file"));
1804        }
1805
1806        /* Set it up */
1807        git_deflate_init(&stream, zlib_compression_level);
1808        stream.next_out = compressed;
1809        stream.avail_out = sizeof(compressed);
1810        the_hash_algo->init_fn(&c);
1811
1812        /* First header.. */
1813        stream.next_in = (unsigned char *)hdr;
1814        stream.avail_in = hdrlen;
1815        while (git_deflate(&stream, 0) == Z_OK)
1816                ; /* nothing */
1817        the_hash_algo->update_fn(&c, hdr, hdrlen);
1818
1819        /* Then the data itself.. */
1820        stream.next_in = (void *)buf;
1821        stream.avail_in = len;
1822        do {
1823                unsigned char *in0 = stream.next_in;
1824                ret = git_deflate(&stream, Z_FINISH);
1825                the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
1826                if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
1827                        die(_("unable to write loose object file"));
1828                stream.next_out = compressed;
1829                stream.avail_out = sizeof(compressed);
1830        } while (ret == Z_OK);
1831
1832        if (ret != Z_STREAM_END)
1833                die(_("unable to deflate new object %s (%d)"), oid_to_hex(oid),
1834                    ret);
1835        ret = git_deflate_end_gently(&stream);
1836        if (ret != Z_OK)
1837                die(_("deflateEnd on object %s failed (%d)"), oid_to_hex(oid),
1838                    ret);
1839        the_hash_algo->final_fn(parano_oid.hash, &c);
1840        if (!oideq(oid, &parano_oid))
1841                die(_("confused by unstable object source data for %s"),
1842                    oid_to_hex(oid));
1843
1844        close_loose_object(fd);
1845
1846        if (mtime) {
1847                struct utimbuf utb;
1848                utb.actime = mtime;
1849                utb.modtime = mtime;
1850                if (utime(tmp_file.buf, &utb) < 0)
1851                        warning_errno(_("failed utime() on %s"), tmp_file.buf);
1852        }
1853
1854        return finalize_object_file(tmp_file.buf, filename.buf);
1855}
1856
1857static int freshen_loose_object(const struct object_id *oid)
1858{
1859        return check_and_freshen(oid, 1);
1860}
1861
1862static int freshen_packed_object(const struct object_id *oid)
1863{
1864        struct pack_entry e;
1865        if (!find_pack_entry(the_repository, oid, &e))
1866                return 0;
1867        if (e.p->freshened)
1868                return 1;
1869        if (!freshen_file(e.p->pack_name))
1870                return 0;
1871        e.p->freshened = 1;
1872        return 1;
1873}
1874
1875int write_object_file(const void *buf, unsigned long len, const char *type,
1876                      struct object_id *oid)
1877{
1878        char hdr[MAX_HEADER_LEN];
1879        int hdrlen = sizeof(hdr);
1880
1881        /* Normally if we have it in the pack then we do not bother writing
1882         * it out into .git/objects/??/?{38} file.
1883         */
1884        write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1885        if (freshen_packed_object(oid) || freshen_loose_object(oid))
1886                return 0;
1887        return write_loose_object(oid, hdr, hdrlen, buf, len, 0);
1888}
1889
1890int hash_object_file_literally(const void *buf, unsigned long len,
1891                               const char *type, struct object_id *oid,
1892                               unsigned flags)
1893{
1894        char *header;
1895        int hdrlen, status = 0;
1896
1897        /* type string, SP, %lu of the length plus NUL must fit this */
1898        hdrlen = strlen(type) + MAX_HEADER_LEN;
1899        header = xmalloc(hdrlen);
1900        write_object_file_prepare(buf, len, type, oid, header, &hdrlen);
1901
1902        if (!(flags & HASH_WRITE_OBJECT))
1903                goto cleanup;
1904        if (freshen_packed_object(oid) || freshen_loose_object(oid))
1905                goto cleanup;
1906        status = write_loose_object(oid, header, hdrlen, buf, len, 0);
1907
1908cleanup:
1909        free(header);
1910        return status;
1911}
1912
1913int force_object_loose(const struct object_id *oid, time_t mtime)
1914{
1915        void *buf;
1916        unsigned long len;
1917        enum object_type type;
1918        char hdr[MAX_HEADER_LEN];
1919        int hdrlen;
1920        int ret;
1921
1922        if (has_loose_object(oid))
1923                return 0;
1924        buf = read_object(the_repository, oid, &type, &len);
1925        if (!buf)
1926                return error(_("cannot read object for %s"), oid_to_hex(oid));
1927        hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(type), (uintmax_t)len) + 1;
1928        ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
1929        free(buf);
1930
1931        return ret;
1932}
1933
1934int repo_has_object_file_with_flags(struct repository *r,
1935                                    const struct object_id *oid, int flags)
1936{
1937        if (!startup_info->have_repository)
1938                return 0;
1939        return oid_object_info_extended(r, oid, NULL,
1940                                        flags | OBJECT_INFO_SKIP_CACHED) >= 0;
1941}
1942
1943int repo_has_object_file(struct repository *r,
1944                         const struct object_id *oid)
1945{
1946        return repo_has_object_file_with_flags(r, oid, 0);
1947}
1948
1949static void check_tree(const void *buf, size_t size)
1950{
1951        struct tree_desc desc;
1952        struct name_entry entry;
1953
1954        init_tree_desc(&desc, buf, size);
1955        while (tree_entry(&desc, &entry))
1956                /* do nothing
1957                 * tree_entry() will die() on malformed entries */
1958                ;
1959}
1960
1961static void check_commit(const void *buf, size_t size)
1962{
1963        struct commit c;
1964        memset(&c, 0, sizeof(c));
1965        if (parse_commit_buffer(the_repository, &c, buf, size, 0))
1966                die(_("corrupt commit"));
1967}
1968
1969static void check_tag(const void *buf, size_t size)
1970{
1971        struct tag t;
1972        memset(&t, 0, sizeof(t));
1973        if (parse_tag_buffer(the_repository, &t, buf, size))
1974                die(_("corrupt tag"));
1975}
1976
1977static int index_mem(struct index_state *istate,
1978                     struct object_id *oid, void *buf, size_t size,
1979                     enum object_type type,
1980                     const char *path, unsigned flags)
1981{
1982        int ret, re_allocated = 0;
1983        int write_object = flags & HASH_WRITE_OBJECT;
1984
1985        if (!type)
1986                type = OBJ_BLOB;
1987
1988        /*
1989         * Convert blobs to git internal format
1990         */
1991        if ((type == OBJ_BLOB) && path) {
1992                struct strbuf nbuf = STRBUF_INIT;
1993                if (convert_to_git(istate, path, buf, size, &nbuf,
1994                                   get_conv_flags(flags))) {
1995                        buf = strbuf_detach(&nbuf, &size);
1996                        re_allocated = 1;
1997                }
1998        }
1999        if (flags & HASH_FORMAT_CHECK) {
2000                if (type == OBJ_TREE)
2001                        check_tree(buf, size);
2002                if (type == OBJ_COMMIT)
2003                        check_commit(buf, size);
2004                if (type == OBJ_TAG)
2005                        check_tag(buf, size);
2006        }
2007
2008        if (write_object)
2009                ret = write_object_file(buf, size, type_name(type), oid);
2010        else
2011                ret = hash_object_file(buf, size, type_name(type), oid);
2012        if (re_allocated)
2013                free(buf);
2014        return ret;
2015}
2016
2017static int index_stream_convert_blob(struct index_state *istate,
2018                                     struct object_id *oid,
2019                                     int fd,
2020                                     const char *path,
2021                                     unsigned flags)
2022{
2023        int ret;
2024        const int write_object = flags & HASH_WRITE_OBJECT;
2025        struct strbuf sbuf = STRBUF_INIT;
2026
2027        assert(path);
2028        assert(would_convert_to_git_filter_fd(istate, path));
2029
2030        convert_to_git_filter_fd(istate, path, fd, &sbuf,
2031                                 get_conv_flags(flags));
2032
2033        if (write_object)
2034                ret = write_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
2035                                        oid);
2036        else
2037                ret = hash_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
2038                                       oid);
2039        strbuf_release(&sbuf);
2040        return ret;
2041}
2042
2043static int index_pipe(struct index_state *istate, struct object_id *oid,
2044                      int fd, enum object_type type,
2045                      const char *path, unsigned flags)
2046{
2047        struct strbuf sbuf = STRBUF_INIT;
2048        int ret;
2049
2050        if (strbuf_read(&sbuf, fd, 4096) >= 0)
2051                ret = index_mem(istate, oid, sbuf.buf, sbuf.len, type, path, flags);
2052        else
2053                ret = -1;
2054        strbuf_release(&sbuf);
2055        return ret;
2056}
2057
2058#define SMALL_FILE_SIZE (32*1024)
2059
2060static int index_core(struct index_state *istate,
2061                      struct object_id *oid, int fd, size_t size,
2062                      enum object_type type, const char *path,
2063                      unsigned flags)
2064{
2065        int ret;
2066
2067        if (!size) {
2068                ret = index_mem(istate, oid, "", size, type, path, flags);
2069        } else if (size <= SMALL_FILE_SIZE) {
2070                char *buf = xmalloc(size);
2071                ssize_t read_result = read_in_full(fd, buf, size);
2072                if (read_result < 0)
2073                        ret = error_errno(_("read error while indexing %s"),
2074                                          path ? path : "<unknown>");
2075                else if (read_result != size)
2076                        ret = error(_("short read while indexing %s"),
2077                                    path ? path : "<unknown>");
2078                else
2079                        ret = index_mem(istate, oid, buf, size, type, path, flags);
2080                free(buf);
2081        } else {
2082                void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2083                ret = index_mem(istate, oid, buf, size, type, path, flags);
2084                munmap(buf, size);
2085        }
2086        return ret;
2087}
2088
2089/*
2090 * This creates one packfile per large blob unless bulk-checkin
2091 * machinery is "plugged".
2092 *
2093 * This also bypasses the usual "convert-to-git" dance, and that is on
2094 * purpose. We could write a streaming version of the converting
2095 * functions and insert that before feeding the data to fast-import
2096 * (or equivalent in-core API described above). However, that is
2097 * somewhat complicated, as we do not know the size of the filter
2098 * result, which we need to know beforehand when writing a git object.
2099 * Since the primary motivation for trying to stream from the working
2100 * tree file and to avoid mmaping it in core is to deal with large
2101 * binary blobs, they generally do not want to get any conversion, and
2102 * callers should avoid this code path when filters are requested.
2103 */
2104static int index_stream(struct object_id *oid, int fd, size_t size,
2105                        enum object_type type, const char *path,
2106                        unsigned flags)
2107{
2108        return index_bulk_checkin(oid, fd, size, type, path, flags);
2109}
2110
2111int index_fd(struct index_state *istate, struct object_id *oid,
2112             int fd, struct stat *st,
2113             enum object_type type, const char *path, unsigned flags)
2114{
2115        int ret;
2116
2117        /*
2118         * Call xsize_t() only when needed to avoid potentially unnecessary
2119         * die() for large files.
2120         */
2121        if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(istate, path))
2122                ret = index_stream_convert_blob(istate, oid, fd, path, flags);
2123        else if (!S_ISREG(st->st_mode))
2124                ret = index_pipe(istate, oid, fd, type, path, flags);
2125        else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
2126                 (path && would_convert_to_git(istate, path)))
2127                ret = index_core(istate, oid, fd, xsize_t(st->st_size),
2128                                 type, path, flags);
2129        else
2130                ret = index_stream(oid, fd, xsize_t(st->st_size), type, path,
2131                                   flags);
2132        close(fd);
2133        return ret;
2134}
2135
2136int index_path(struct index_state *istate, struct object_id *oid,
2137               const char *path, struct stat *st, unsigned flags)
2138{
2139        int fd;
2140        struct strbuf sb = STRBUF_INIT;
2141        int rc = 0;
2142
2143        switch (st->st_mode & S_IFMT) {
2144        case S_IFREG:
2145                fd = open(path, O_RDONLY);
2146                if (fd < 0)
2147                        return error_errno("open(\"%s\")", path);
2148                if (index_fd(istate, oid, fd, st, OBJ_BLOB, path, flags) < 0)
2149                        return error(_("%s: failed to insert into database"),
2150                                     path);
2151                break;
2152        case S_IFLNK:
2153                if (strbuf_readlink(&sb, path, st->st_size))
2154                        return error_errno("readlink(\"%s\")", path);
2155                if (!(flags & HASH_WRITE_OBJECT))
2156                        hash_object_file(sb.buf, sb.len, blob_type, oid);
2157                else if (write_object_file(sb.buf, sb.len, blob_type, oid))
2158                        rc = error(_("%s: failed to insert into database"), path);
2159                strbuf_release(&sb);
2160                break;
2161        case S_IFDIR:
2162                return resolve_gitlink_ref(path, "HEAD", oid);
2163        default:
2164                return error(_("%s: unsupported file type"), path);
2165        }
2166        return rc;
2167}
2168
2169int read_pack_header(int fd, struct pack_header *header)
2170{
2171        if (read_in_full(fd, header, sizeof(*header)) != sizeof(*header))
2172                /* "eof before pack header was fully read" */
2173                return PH_ERROR_EOF;
2174
2175        if (header->hdr_signature != htonl(PACK_SIGNATURE))
2176                /* "protocol error (pack signature mismatch detected)" */
2177                return PH_ERROR_PACK_SIGNATURE;
2178        if (!pack_version_ok(header->hdr_version))
2179                /* "protocol error (pack version unsupported)" */
2180                return PH_ERROR_PROTOCOL;
2181        return 0;
2182}
2183
2184void assert_oid_type(const struct object_id *oid, enum object_type expect)
2185{
2186        enum object_type type = oid_object_info(the_repository, oid, NULL);
2187        if (type < 0)
2188                die(_("%s is not a valid object"), oid_to_hex(oid));
2189        if (type != expect)
2190                die(_("%s is not a valid '%s' object"), oid_to_hex(oid),
2191                    type_name(expect));
2192}
2193
2194int for_each_file_in_obj_subdir(unsigned int subdir_nr,
2195                                struct strbuf *path,
2196                                each_loose_object_fn obj_cb,
2197                                each_loose_cruft_fn cruft_cb,
2198                                each_loose_subdir_fn subdir_cb,
2199                                void *data)
2200{
2201        size_t origlen, baselen;
2202        DIR *dir;
2203        struct dirent *de;
2204        int r = 0;
2205        struct object_id oid;
2206
2207        if (subdir_nr > 0xff)
2208                BUG("invalid loose object subdirectory: %x", subdir_nr);
2209
2210        origlen = path->len;
2211        strbuf_complete(path, '/');
2212        strbuf_addf(path, "%02x", subdir_nr);
2213
2214        dir = opendir(path->buf);
2215        if (!dir) {
2216                if (errno != ENOENT)
2217                        r = error_errno(_("unable to open %s"), path->buf);
2218                strbuf_setlen(path, origlen);
2219                return r;
2220        }
2221
2222        oid.hash[0] = subdir_nr;
2223        strbuf_addch(path, '/');
2224        baselen = path->len;
2225
2226        while ((de = readdir(dir))) {
2227                size_t namelen;
2228                if (is_dot_or_dotdot(de->d_name))
2229                        continue;
2230
2231                namelen = strlen(de->d_name);
2232                strbuf_setlen(path, baselen);
2233                strbuf_add(path, de->d_name, namelen);
2234                if (namelen == the_hash_algo->hexsz - 2 &&
2235                    !hex_to_bytes(oid.hash + 1, de->d_name,
2236                                  the_hash_algo->rawsz - 1)) {
2237                        if (obj_cb) {
2238                                r = obj_cb(&oid, path->buf, data);
2239                                if (r)
2240                                        break;
2241                        }
2242                        continue;
2243                }
2244
2245                if (cruft_cb) {
2246                        r = cruft_cb(de->d_name, path->buf, data);
2247                        if (r)
2248                                break;
2249                }
2250        }
2251        closedir(dir);
2252
2253        strbuf_setlen(path, baselen - 1);
2254        if (!r && subdir_cb)
2255                r = subdir_cb(subdir_nr, path->buf, data);
2256
2257        strbuf_setlen(path, origlen);
2258
2259        return r;
2260}
2261
2262int for_each_loose_file_in_objdir_buf(struct strbuf *path,
2263                            each_loose_object_fn obj_cb,
2264                            each_loose_cruft_fn cruft_cb,
2265                            each_loose_subdir_fn subdir_cb,
2266                            void *data)
2267{
2268        int r = 0;
2269        int i;
2270
2271        for (i = 0; i < 256; i++) {
2272                r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
2273                                                subdir_cb, data);
2274                if (r)
2275                        break;
2276        }
2277
2278        return r;
2279}
2280
2281int for_each_loose_file_in_objdir(const char *path,
2282                                  each_loose_object_fn obj_cb,
2283                                  each_loose_cruft_fn cruft_cb,
2284                                  each_loose_subdir_fn subdir_cb,
2285                                  void *data)
2286{
2287        struct strbuf buf = STRBUF_INIT;
2288        int r;
2289
2290        strbuf_addstr(&buf, path);
2291        r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
2292                                              subdir_cb, data);
2293        strbuf_release(&buf);
2294
2295        return r;
2296}
2297
2298int for_each_loose_object(each_loose_object_fn cb, void *data,
2299                          enum for_each_object_flags flags)
2300{
2301        struct object_directory *odb;
2302
2303        prepare_alt_odb(the_repository);
2304        for (odb = the_repository->objects->odb; odb; odb = odb->next) {
2305                int r = for_each_loose_file_in_objdir(odb->path, cb, NULL,
2306                                                      NULL, data);
2307                if (r)
2308                        return r;
2309
2310                if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
2311                        break;
2312        }
2313
2314        return 0;
2315}
2316
2317static int append_loose_object(const struct object_id *oid, const char *path,
2318                               void *data)
2319{
2320        oid_array_append(data, oid);
2321        return 0;
2322}
2323
2324struct oid_array *odb_loose_cache(struct object_directory *odb,
2325                                  const struct object_id *oid)
2326{
2327        int subdir_nr = oid->hash[0];
2328        struct strbuf buf = STRBUF_INIT;
2329
2330        if (subdir_nr < 0 ||
2331            subdir_nr >= ARRAY_SIZE(odb->loose_objects_subdir_seen))
2332                BUG("subdir_nr out of range");
2333
2334        if (odb->loose_objects_subdir_seen[subdir_nr])
2335                return &odb->loose_objects_cache[subdir_nr];
2336
2337        strbuf_addstr(&buf, odb->path);
2338        for_each_file_in_obj_subdir(subdir_nr, &buf,
2339                                    append_loose_object,
2340                                    NULL, NULL,
2341                                    &odb->loose_objects_cache[subdir_nr]);
2342        odb->loose_objects_subdir_seen[subdir_nr] = 1;
2343        strbuf_release(&buf);
2344        return &odb->loose_objects_cache[subdir_nr];
2345}
2346
2347void odb_clear_loose_cache(struct object_directory *odb)
2348{
2349        int i;
2350
2351        for (i = 0; i < ARRAY_SIZE(odb->loose_objects_cache); i++)
2352                oid_array_clear(&odb->loose_objects_cache[i]);
2353        memset(&odb->loose_objects_subdir_seen, 0,
2354               sizeof(odb->loose_objects_subdir_seen));
2355}
2356
2357static int check_stream_oid(git_zstream *stream,
2358                            const char *hdr,
2359                            unsigned long size,
2360                            const char *path,
2361                            const struct object_id *expected_oid)
2362{
2363        git_hash_ctx c;
2364        struct object_id real_oid;
2365        unsigned char buf[4096];
2366        unsigned long total_read;
2367        int status = Z_OK;
2368
2369        the_hash_algo->init_fn(&c);
2370        the_hash_algo->update_fn(&c, hdr, stream->total_out);
2371
2372        /*
2373         * We already read some bytes into hdr, but the ones up to the NUL
2374         * do not count against the object's content size.
2375         */
2376        total_read = stream->total_out - strlen(hdr) - 1;
2377
2378        /*
2379         * This size comparison must be "<=" to read the final zlib packets;
2380         * see the comment in unpack_loose_rest for details.
2381         */
2382        while (total_read <= size &&
2383               (status == Z_OK ||
2384                (status == Z_BUF_ERROR && !stream->avail_out))) {
2385                stream->next_out = buf;
2386                stream->avail_out = sizeof(buf);
2387                if (size - total_read < stream->avail_out)
2388                        stream->avail_out = size - total_read;
2389                status = git_inflate(stream, Z_FINISH);
2390                the_hash_algo->update_fn(&c, buf, stream->next_out - buf);
2391                total_read += stream->next_out - buf;
2392        }
2393        git_inflate_end(stream);
2394
2395        if (status != Z_STREAM_END) {
2396                error(_("corrupt loose object '%s'"), oid_to_hex(expected_oid));
2397                return -1;
2398        }
2399        if (stream->avail_in) {
2400                error(_("garbage at end of loose object '%s'"),
2401                      oid_to_hex(expected_oid));
2402                return -1;
2403        }
2404
2405        the_hash_algo->final_fn(real_oid.hash, &c);
2406        if (!oideq(expected_oid, &real_oid)) {
2407                error(_("hash mismatch for %s (expected %s)"), path,
2408                      oid_to_hex(expected_oid));
2409                return -1;
2410        }
2411
2412        return 0;
2413}
2414
2415int read_loose_object(const char *path,
2416                      const struct object_id *expected_oid,
2417                      enum object_type *type,
2418                      unsigned long *size,
2419                      void **contents)
2420{
2421        int ret = -1;
2422        void *map = NULL;
2423        unsigned long mapsize;
2424        git_zstream stream;
2425        char hdr[MAX_HEADER_LEN];
2426
2427        *contents = NULL;
2428
2429        map = map_loose_object_1(the_repository, path, NULL, &mapsize);
2430        if (!map) {
2431                error_errno(_("unable to mmap %s"), path);
2432                goto out;
2433        }
2434
2435        if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
2436                error(_("unable to unpack header of %s"), path);
2437                goto out;
2438        }
2439
2440        *type = parse_loose_header(hdr, size);
2441        if (*type < 0) {
2442                error(_("unable to parse header of %s"), path);
2443                git_inflate_end(&stream);
2444                goto out;
2445        }
2446
2447        if (*type == OBJ_BLOB && *size > big_file_threshold) {
2448                if (check_stream_oid(&stream, hdr, *size, path, expected_oid) < 0)
2449                        goto out;
2450        } else {
2451                *contents = unpack_loose_rest(&stream, hdr, *size, expected_oid);
2452                if (!*contents) {
2453                        error(_("unable to unpack contents of %s"), path);
2454                        git_inflate_end(&stream);
2455                        goto out;
2456                }
2457                if (check_object_signature(expected_oid, *contents,
2458                                         *size, type_name(*type))) {
2459                        error(_("hash mismatch for %s (expected %s)"), path,
2460                              oid_to_hex(expected_oid));
2461                        free(*contents);
2462                        goto out;
2463                }
2464        }
2465
2466        ret = 0; /* everything checks out */
2467
2468out:
2469        if (map)
2470                munmap(map, mapsize);
2471        return ret;
2472}