sha1_file.con commit git-fetch --tags: deal with tags with spaces in them. (221e743)
   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 <sys/types.h>
  10#include <dirent.h>
  11#include "cache.h"
  12#include "delta.h"
  13#include "pack.h"
  14
  15#ifndef O_NOATIME
  16#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
  17#define O_NOATIME 01000000
  18#else
  19#define O_NOATIME 0
  20#endif
  21#endif
  22
  23const unsigned char null_sha1[20] = { 0, };
  24
  25static unsigned int sha1_file_open_flag = O_NOATIME;
  26
  27static unsigned hexval(char c)
  28{
  29        if (c >= '0' && c <= '9')
  30                return c - '0';
  31        if (c >= 'a' && c <= 'f')
  32                return c - 'a' + 10;
  33        if (c >= 'A' && c <= 'F')
  34                return c - 'A' + 10;
  35        return ~0;
  36}
  37
  38int get_sha1_hex(const char *hex, unsigned char *sha1)
  39{
  40        int i;
  41        for (i = 0; i < 20; i++) {
  42                unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
  43                if (val & ~0xff)
  44                        return -1;
  45                *sha1++ = val;
  46                hex += 2;
  47        }
  48        return 0;
  49}
  50
  51int safe_create_leading_directories(char *path)
  52{
  53        char *pos = path;
  54
  55        while (pos) {
  56                pos = strchr(pos, '/');
  57                if (!pos)
  58                        break;
  59                *pos = 0;
  60                if (mkdir(path, 0777) < 0)
  61                        if (errno != EEXIST) {
  62                                *pos = '/';
  63                                return -1;
  64                        }
  65                *pos++ = '/';
  66        }
  67        return 0;
  68}
  69
  70char * sha1_to_hex(const unsigned char *sha1)
  71{
  72        static char buffer[50];
  73        static const char hex[] = "0123456789abcdef";
  74        char *buf = buffer;
  75        int i;
  76
  77        for (i = 0; i < 20; i++) {
  78                unsigned int val = *sha1++;
  79                *buf++ = hex[val >> 4];
  80                *buf++ = hex[val & 0xf];
  81        }
  82        return buffer;
  83}
  84
  85static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
  86{
  87        int i;
  88        for (i = 0; i < 20; i++) {
  89                static char hex[] = "0123456789abcdef";
  90                unsigned int val = sha1[i];
  91                char *pos = pathbuf + i*2 + (i > 0);
  92                *pos++ = hex[val >> 4];
  93                *pos = hex[val & 0xf];
  94        }
  95}
  96
  97/*
  98 * NOTE! This returns a statically allocated buffer, so you have to be
  99 * careful about using it. Do a "strdup()" if you need to save the
 100 * filename.
 101 *
 102 * Also note that this returns the location for creating.  Reading
 103 * SHA1 file can happen from any alternate directory listed in the
 104 * DB_ENVIRONMENT environment variable if it is not found in
 105 * the primary object database.
 106 */
 107char *sha1_file_name(const unsigned char *sha1)
 108{
 109        static char *name, *base;
 110
 111        if (!base) {
 112                const char *sha1_file_directory = get_object_directory();
 113                int len = strlen(sha1_file_directory);
 114                base = xmalloc(len + 60);
 115                memcpy(base, sha1_file_directory, len);
 116                memset(base+len, 0, 60);
 117                base[len] = '/';
 118                base[len+3] = '/';
 119                name = base + len + 1;
 120        }
 121        fill_sha1_path(name, sha1);
 122        return base;
 123}
 124
 125char *sha1_pack_name(const unsigned char *sha1)
 126{
 127        static const char hex[] = "0123456789abcdef";
 128        static char *name, *base, *buf;
 129        int i;
 130
 131        if (!base) {
 132                const char *sha1_file_directory = get_object_directory();
 133                int len = strlen(sha1_file_directory);
 134                base = xmalloc(len + 60);
 135                sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
 136                name = base + len + 11;
 137        }
 138
 139        buf = name;
 140
 141        for (i = 0; i < 20; i++) {
 142                unsigned int val = *sha1++;
 143                *buf++ = hex[val >> 4];
 144                *buf++ = hex[val & 0xf];
 145        }
 146        
 147        return base;
 148}
 149
 150char *sha1_pack_index_name(const unsigned char *sha1)
 151{
 152        static const char hex[] = "0123456789abcdef";
 153        static char *name, *base, *buf;
 154        int i;
 155
 156        if (!base) {
 157                const char *sha1_file_directory = get_object_directory();
 158                int len = strlen(sha1_file_directory);
 159                base = xmalloc(len + 60);
 160                sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
 161                name = base + len + 11;
 162        }
 163
 164        buf = name;
 165
 166        for (i = 0; i < 20; i++) {
 167                unsigned int val = *sha1++;
 168                *buf++ = hex[val >> 4];
 169                *buf++ = hex[val & 0xf];
 170        }
 171        
 172        return base;
 173}
 174
 175struct alternate_object_database *alt_odb_list;
 176static struct alternate_object_database **alt_odb_tail;
 177
 178/*
 179 * Prepare alternate object database registry.
 180 *
 181 * The variable alt_odb_list points at the list of struct
 182 * alternate_object_database.  The elements on this list come from
 183 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
 184 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
 185 * whose contents is exactly in the same format as that environment
 186 * variable.  Its base points at a statically allocated buffer that
 187 * contains "/the/directory/corresponding/to/.git/objects/...", while
 188 * its name points just after the slash at the end of ".git/objects/"
 189 * in the example above, and has enough space to hold 40-byte hex
 190 * SHA1, an extra slash for the first level indirection, and the
 191 * terminating NUL.
 192 */
 193static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
 194                                 const char *relative_base)
 195{
 196        const char *cp, *last;
 197        struct alternate_object_database *ent;
 198        int base_len = -1;
 199
 200        last = alt;
 201        while (last < ep) {
 202                cp = last;
 203                if (cp < ep && *cp == '#') {
 204                        while (cp < ep && *cp != sep)
 205                                cp++;
 206                        last = cp + 1;
 207                        continue;
 208                }
 209                for ( ; cp < ep && *cp != sep; cp++)
 210                        ;
 211                if (last != cp) {
 212                        /* 43 = 40-byte + 2 '/' + terminating NUL */
 213                        int pfxlen = cp - last;
 214                        int entlen = pfxlen + 43;
 215
 216                        if (*last != '/' && relative_base) {
 217                                /* Relative alt-odb */
 218                                if (base_len < 0)
 219                                        base_len = strlen(relative_base) + 1;
 220                                entlen += base_len;
 221                                pfxlen += base_len;
 222                        }
 223                        ent = xmalloc(sizeof(*ent) + entlen);
 224                        *alt_odb_tail = ent;
 225                        alt_odb_tail = &(ent->next);
 226                        ent->next = NULL;
 227                        if (*last != '/' && relative_base) {
 228                                memcpy(ent->base, relative_base, base_len - 1);
 229                                ent->base[base_len - 1] = '/';
 230                                memcpy(ent->base + base_len,
 231                                       last, cp - last);
 232                        }
 233                        else
 234                                memcpy(ent->base, last, pfxlen);
 235                        ent->name = ent->base + pfxlen + 1;
 236                        ent->base[pfxlen] = ent->base[pfxlen + 3] = '/';
 237                        ent->base[entlen-1] = 0;
 238                }
 239                while (cp < ep && *cp == sep)
 240                        cp++;
 241                last = cp;
 242        }
 243}
 244
 245void prepare_alt_odb(void)
 246{
 247        char path[PATH_MAX];
 248        char *map;
 249        int fd;
 250        struct stat st;
 251        char *alt;
 252
 253        alt = getenv(ALTERNATE_DB_ENVIRONMENT);
 254        if (!alt) alt = "";
 255
 256        if (alt_odb_tail)
 257                return;
 258        alt_odb_tail = &alt_odb_list;
 259        link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL);
 260
 261        sprintf(path, "%s/info/alternates", get_object_directory());
 262        fd = open(path, O_RDONLY);
 263        if (fd < 0)
 264                return;
 265        if (fstat(fd, &st) || (st.st_size == 0)) {
 266                close(fd);
 267                return;
 268        }
 269        map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 270        close(fd);
 271        if (map == MAP_FAILED)
 272                return;
 273
 274        link_alt_odb_entries(map, map + st.st_size, '\n',
 275                             get_object_directory());
 276        munmap(map, st.st_size);
 277}
 278
 279static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
 280{
 281        char *name = sha1_file_name(sha1);
 282        struct alternate_object_database *alt;
 283
 284        if (!stat(name, st))
 285                return name;
 286        prepare_alt_odb();
 287        for (alt = alt_odb_list; alt; alt = alt->next) {
 288                name = alt->name;
 289                fill_sha1_path(name, sha1);
 290                if (!stat(alt->base, st))
 291                        return alt->base;
 292        }
 293        return NULL;
 294}
 295
 296#define PACK_MAX_SZ (1<<26)
 297static int pack_used_ctr;
 298static unsigned long pack_mapped;
 299struct packed_git *packed_git;
 300
 301static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
 302                                void **idx_map_)
 303{
 304        void *idx_map;
 305        unsigned int *index;
 306        unsigned long idx_size;
 307        int nr, i;
 308        int fd = open(path, O_RDONLY);
 309        struct stat st;
 310        if (fd < 0)
 311                return -1;
 312        if (fstat(fd, &st)) {
 313                close(fd);
 314                return -1;
 315        }
 316        idx_size = st.st_size;
 317        idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
 318        close(fd);
 319        if (idx_map == MAP_FAILED)
 320                return -1;
 321
 322        index = idx_map;
 323        *idx_map_ = idx_map;
 324        *idx_size_ = idx_size;
 325
 326        /* check index map */
 327        if (idx_size < 4*256 + 20 + 20)
 328                return error("index file too small");
 329        nr = 0;
 330        for (i = 0; i < 256; i++) {
 331                unsigned int n = ntohl(index[i]);
 332                if (n < nr)
 333                        return error("non-monotonic index");
 334                nr = n;
 335        }
 336
 337        /*
 338         * Total size:
 339         *  - 256 index entries 4 bytes each
 340         *  - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
 341         *  - 20-byte SHA1 of the packfile
 342         *  - 20-byte SHA1 file checksum
 343         */
 344        if (idx_size != 4*256 + nr * 24 + 20 + 20)
 345                return error("wrong index file size");
 346
 347        return 0;
 348}
 349
 350static int unuse_one_packed_git(void)
 351{
 352        struct packed_git *p, *lru = NULL;
 353
 354        for (p = packed_git; p; p = p->next) {
 355                if (p->pack_use_cnt || !p->pack_base)
 356                        continue;
 357                if (!lru || p->pack_last_used < lru->pack_last_used)
 358                        lru = p;
 359        }
 360        if (!lru)
 361                return 0;
 362        munmap(lru->pack_base, lru->pack_size);
 363        lru->pack_base = NULL;
 364        return 1;
 365}
 366
 367void unuse_packed_git(struct packed_git *p)
 368{
 369        p->pack_use_cnt--;
 370}
 371
 372int use_packed_git(struct packed_git *p)
 373{
 374        if (!p->pack_size) {
 375                struct stat st;
 376                // We created the struct before we had the pack
 377                stat(p->pack_name, &st);
 378                if (!S_ISREG(st.st_mode))
 379                        die("packfile %s not a regular file", p->pack_name);
 380                p->pack_size = st.st_size;
 381        }
 382        if (!p->pack_base) {
 383                int fd;
 384                struct stat st;
 385                void *map;
 386
 387                pack_mapped += p->pack_size;
 388                while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
 389                        ; /* nothing */
 390                fd = open(p->pack_name, O_RDONLY);
 391                if (fd < 0)
 392                        die("packfile %s cannot be opened", p->pack_name);
 393                if (fstat(fd, &st)) {
 394                        close(fd);
 395                        die("packfile %s cannot be opened", p->pack_name);
 396                }
 397                if (st.st_size != p->pack_size)
 398                        die("packfile %s size mismatch.", p->pack_name);
 399                map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
 400                close(fd);
 401                if (map == MAP_FAILED)
 402                        die("packfile %s cannot be mapped.", p->pack_name);
 403                p->pack_base = map;
 404
 405                /* Check if the pack file matches with the index file.
 406                 * this is cheap.
 407                 */
 408                if (memcmp((char*)(p->index_base) + p->index_size - 40,
 409                           p->pack_base + p->pack_size - 20, 20)) {
 410                              
 411                        die("packfile %s does not match index.", p->pack_name);
 412                }
 413        }
 414        p->pack_last_used = pack_used_ctr++;
 415        p->pack_use_cnt++;
 416        return 0;
 417}
 418
 419struct packed_git *add_packed_git(char *path, int path_len)
 420{
 421        struct stat st;
 422        struct packed_git *p;
 423        unsigned long idx_size;
 424        void *idx_map;
 425
 426        if (check_packed_git_idx(path, &idx_size, &idx_map))
 427                return NULL;
 428
 429        /* do we have a corresponding .pack file? */
 430        strcpy(path + path_len - 4, ".pack");
 431        if (stat(path, &st) || !S_ISREG(st.st_mode)) {
 432                munmap(idx_map, idx_size);
 433                return NULL;
 434        }
 435        /* ok, it looks sane as far as we can check without
 436         * actually mapping the pack file.
 437         */
 438        p = xmalloc(sizeof(*p) + path_len + 2);
 439        strcpy(p->pack_name, path);
 440        p->index_size = idx_size;
 441        p->pack_size = st.st_size;
 442        p->index_base = idx_map;
 443        p->next = NULL;
 444        p->pack_base = NULL;
 445        p->pack_last_used = 0;
 446        p->pack_use_cnt = 0;
 447        return p;
 448}
 449
 450struct packed_git *parse_pack_index(unsigned char *sha1)
 451{
 452        char *path = sha1_pack_index_name(sha1);
 453        return parse_pack_index_file(sha1, path);
 454}
 455
 456struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
 457{
 458        struct packed_git *p;
 459        unsigned long idx_size;
 460        void *idx_map;
 461        char *path;
 462
 463        if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
 464                return NULL;
 465
 466        path = sha1_pack_name(sha1);
 467
 468        p = xmalloc(sizeof(*p) + strlen(path) + 2);
 469        strcpy(p->pack_name, path);
 470        p->index_size = idx_size;
 471        p->pack_size = 0;
 472        p->index_base = idx_map;
 473        p->next = NULL;
 474        p->pack_base = NULL;
 475        p->pack_last_used = 0;
 476        p->pack_use_cnt = 0;
 477        memcpy(p->sha1, sha1, 20);
 478        return p;
 479}
 480
 481void install_packed_git(struct packed_git *pack)
 482{
 483        pack->next = packed_git;
 484        packed_git = pack;
 485}
 486
 487static void prepare_packed_git_one(char *objdir)
 488{
 489        char path[PATH_MAX];
 490        int len;
 491        DIR *dir;
 492        struct dirent *de;
 493
 494        sprintf(path, "%s/pack", objdir);
 495        len = strlen(path);
 496        dir = opendir(path);
 497        if (!dir)
 498                return;
 499        path[len++] = '/';
 500        while ((de = readdir(dir)) != NULL) {
 501                int namelen = strlen(de->d_name);
 502                struct packed_git *p;
 503
 504                if (strcmp(de->d_name + namelen - 4, ".idx"))
 505                        continue;
 506
 507                /* we have .idx.  Is it a file we can map? */
 508                strcpy(path + len, de->d_name);
 509                p = add_packed_git(path, len + namelen);
 510                if (!p)
 511                        continue;
 512                p->next = packed_git;
 513                packed_git = p;
 514        }
 515        closedir(dir);
 516}
 517
 518void prepare_packed_git(void)
 519{
 520        static int run_once = 0;
 521        struct alternate_object_database *alt;
 522
 523        if (run_once)
 524                return;
 525        prepare_packed_git_one(get_object_directory());
 526        prepare_alt_odb();
 527        for (alt = alt_odb_list; alt; alt = alt->next) {
 528                alt->name[0] = 0;
 529                prepare_packed_git_one(alt->base);
 530        }
 531        run_once = 1;
 532}
 533
 534int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
 535{
 536        char header[100];
 537        unsigned char real_sha1[20];
 538        SHA_CTX c;
 539
 540        SHA1_Init(&c);
 541        SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
 542        SHA1_Update(&c, map, size);
 543        SHA1_Final(real_sha1, &c);
 544        return memcmp(sha1, real_sha1, 20) ? -1 : 0;
 545}
 546
 547static void *map_sha1_file_internal(const unsigned char *sha1,
 548                                    unsigned long *size)
 549{
 550        struct stat st;
 551        void *map;
 552        int fd;
 553        char *filename = find_sha1_file(sha1, &st);
 554
 555        if (!filename) {
 556                return NULL;
 557        }
 558
 559        fd = open(filename, O_RDONLY | sha1_file_open_flag);
 560        if (fd < 0) {
 561                /* See if it works without O_NOATIME */
 562                switch (sha1_file_open_flag) {
 563                default:
 564                        fd = open(filename, O_RDONLY);
 565                        if (fd >= 0)
 566                                break;
 567                /* Fallthrough */
 568                case 0:
 569                        return NULL;
 570                }
 571
 572                /* If it failed once, it will probably fail again.
 573                 * Stop using O_NOATIME
 574                 */
 575                sha1_file_open_flag = 0;
 576        }
 577        map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 578        close(fd);
 579        if (map == MAP_FAILED)
 580                return NULL;
 581        *size = st.st_size;
 582        return map;
 583}
 584
 585int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
 586{
 587        /* Get the data stream */
 588        memset(stream, 0, sizeof(*stream));
 589        stream->next_in = map;
 590        stream->avail_in = mapsize;
 591        stream->next_out = buffer;
 592        stream->avail_out = size;
 593
 594        inflateInit(stream);
 595        return inflate(stream, 0);
 596}
 597
 598static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
 599{
 600        int bytes = strlen(buffer) + 1;
 601        unsigned char *buf = xmalloc(1+size);
 602
 603        memcpy(buf, buffer + bytes, stream->total_out - bytes);
 604        bytes = stream->total_out - bytes;
 605        if (bytes < size) {
 606                stream->next_out = buf + bytes;
 607                stream->avail_out = size - bytes;
 608                while (inflate(stream, Z_FINISH) == Z_OK)
 609                        /* nothing */;
 610        }
 611        buf[size] = 0;
 612        inflateEnd(stream);
 613        return buf;
 614}
 615
 616/*
 617 * We used to just use "sscanf()", but that's actually way
 618 * too permissive for what we want to check. So do an anal
 619 * object header parse by hand.
 620 */
 621int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
 622{
 623        int i;
 624        unsigned long size;
 625
 626        /*
 627         * The type can be at most ten bytes (including the 
 628         * terminating '\0' that we add), and is followed by
 629         * a space. 
 630         */
 631        i = 10;
 632        for (;;) {
 633                char c = *hdr++;
 634                if (c == ' ')
 635                        break;
 636                if (!--i)
 637                        return -1;
 638                *type++ = c;
 639        }
 640        *type = 0;
 641
 642        /*
 643         * The length must follow immediately, and be in canonical
 644         * decimal format (ie "010" is not valid).
 645         */
 646        size = *hdr++ - '0';
 647        if (size > 9)
 648                return -1;
 649        if (size) {
 650                for (;;) {
 651                        unsigned long c = *hdr - '0';
 652                        if (c > 9)
 653                                break;
 654                        hdr++;
 655                        size = size * 10 + c;
 656                }
 657        }
 658        *sizep = size;
 659
 660        /*
 661         * The length must be followed by a zero byte
 662         */
 663        return *hdr ? -1 : 0;
 664}
 665
 666void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
 667{
 668        int ret;
 669        z_stream stream;
 670        char hdr[8192];
 671
 672        ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
 673        if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
 674                return NULL;
 675
 676        return unpack_sha1_rest(&stream, hdr, *size);
 677}
 678
 679/* forward declaration for a mutually recursive function */
 680static int packed_object_info(struct pack_entry *entry,
 681                              char *type, unsigned long *sizep);
 682
 683static int packed_delta_info(unsigned char *base_sha1,
 684                             unsigned long delta_size,
 685                             unsigned long left,
 686                             char *type,
 687                             unsigned long *sizep,
 688                             struct packed_git *p)
 689{
 690        struct pack_entry base_ent;
 691
 692        if (left < 20)
 693                die("truncated pack file");
 694
 695        /* The base entry _must_ be in the same pack */
 696        if (!find_pack_entry_one(base_sha1, &base_ent, p))
 697                die("failed to find delta-pack base object %s",
 698                    sha1_to_hex(base_sha1));
 699
 700        /* We choose to only get the type of the base object and
 701         * ignore potentially corrupt pack file that expects the delta
 702         * based on a base with a wrong size.  This saves tons of
 703         * inflate() calls.
 704         */
 705
 706        if (packed_object_info(&base_ent, type, NULL))
 707                die("cannot get info for delta-pack base");
 708
 709        if (sizep) {
 710                const unsigned char *data;
 711                unsigned char delta_head[64];
 712                unsigned long result_size;
 713                z_stream stream;
 714                int st;
 715
 716                memset(&stream, 0, sizeof(stream));
 717
 718                data = stream.next_in = base_sha1 + 20;
 719                stream.avail_in = left - 20;
 720                stream.next_out = delta_head;
 721                stream.avail_out = sizeof(delta_head);
 722
 723                inflateInit(&stream);
 724                st = inflate(&stream, Z_FINISH);
 725                inflateEnd(&stream);
 726                if ((st != Z_STREAM_END) &&
 727                    stream.total_out != sizeof(delta_head))
 728                        die("delta data unpack-initial failed");
 729
 730                /* Examine the initial part of the delta to figure out
 731                 * the result size.
 732                 */
 733                data = delta_head;
 734                get_delta_hdr_size(&data); /* ignore base size */
 735
 736                /* Read the result size */
 737                result_size = get_delta_hdr_size(&data);
 738                *sizep = result_size;
 739        }
 740        return 0;
 741}
 742
 743static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
 744        enum object_type *type, unsigned long *sizep)
 745{
 746        unsigned shift;
 747        unsigned char *pack, c;
 748        unsigned long size;
 749
 750        if (offset >= p->pack_size)
 751                die("object offset outside of pack file");
 752
 753        pack =  p->pack_base + offset;
 754        c = *pack++;
 755        offset++;
 756        *type = (c >> 4) & 7;
 757        size = c & 15;
 758        shift = 4;
 759        while (c & 0x80) {
 760                if (offset >= p->pack_size)
 761                        die("object offset outside of pack file");
 762                c = *pack++;
 763                offset++;
 764                size += (c & 0x7f) << shift;
 765                shift += 7;
 766        }
 767        *sizep = size;
 768        return offset;
 769}
 770
 771void packed_object_info_detail(struct pack_entry *e,
 772                               char *type,
 773                               unsigned long *size,
 774                               unsigned long *store_size,
 775                               int *delta_chain_length,
 776                               unsigned char *base_sha1)
 777{
 778        struct packed_git *p = e->p;
 779        unsigned long offset, left;
 780        unsigned char *pack;
 781        enum object_type kind;
 782
 783        offset = unpack_object_header(p, e->offset, &kind, size);
 784        pack = p->pack_base + offset;
 785        left = p->pack_size - offset;
 786        if (kind != OBJ_DELTA)
 787                *delta_chain_length = 0;
 788        else {
 789                int chain_length = 0;
 790                memcpy(base_sha1, pack, 20);
 791                do {
 792                        struct pack_entry base_ent;
 793                        unsigned long junk;
 794
 795                        find_pack_entry_one(pack, &base_ent, p);
 796                        offset = unpack_object_header(p, base_ent.offset,
 797                                                      &kind, &junk);
 798                        pack = p->pack_base + offset;
 799                        chain_length++;
 800                } while (kind == OBJ_DELTA);
 801                *delta_chain_length = chain_length;
 802        }
 803        switch (kind) {
 804        case OBJ_COMMIT:
 805                strcpy(type, "commit");
 806                break;
 807        case OBJ_TREE:
 808                strcpy(type, "tree");
 809                break;
 810        case OBJ_BLOB:
 811                strcpy(type, "blob");
 812                break;
 813        case OBJ_TAG:
 814                strcpy(type, "tag");
 815                break;
 816        default:
 817                die("corrupted pack file %s containing object of kind %d",
 818                    p->pack_name, kind);
 819        }
 820        *store_size = 0; /* notyet */
 821}
 822
 823static int packed_object_info(struct pack_entry *entry,
 824                              char *type, unsigned long *sizep)
 825{
 826        struct packed_git *p = entry->p;
 827        unsigned long offset, size, left;
 828        unsigned char *pack;
 829        enum object_type kind;
 830        int retval;
 831
 832        if (use_packed_git(p))
 833                die("cannot map packed file");
 834
 835        offset = unpack_object_header(p, entry->offset, &kind, &size);
 836        pack = p->pack_base + offset;
 837        left = p->pack_size - offset;
 838
 839        switch (kind) {
 840        case OBJ_DELTA:
 841                retval = packed_delta_info(pack, size, left, type, sizep, p);
 842                unuse_packed_git(p);
 843                return retval;
 844        case OBJ_COMMIT:
 845                strcpy(type, "commit");
 846                break;
 847        case OBJ_TREE:
 848                strcpy(type, "tree");
 849                break;
 850        case OBJ_BLOB:
 851                strcpy(type, "blob");
 852                break;
 853        case OBJ_TAG:
 854                strcpy(type, "tag");
 855                break;
 856        default:
 857                die("corrupted pack file %s containing object of kind %d",
 858                    p->pack_name, kind);
 859        }
 860        if (sizep)
 861                *sizep = size;
 862        unuse_packed_git(p);
 863        return 0;
 864}
 865
 866/* forward declaration for a mutually recursive function */
 867static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
 868
 869static void *unpack_delta_entry(unsigned char *base_sha1,
 870                                unsigned long delta_size,
 871                                unsigned long left,
 872                                char *type,
 873                                unsigned long *sizep,
 874                                struct packed_git *p)
 875{
 876        struct pack_entry base_ent;
 877        void *data, *delta_data, *result, *base;
 878        unsigned long data_size, result_size, base_size;
 879        z_stream stream;
 880        int st;
 881
 882        if (left < 20)
 883                die("truncated pack file");
 884        data = base_sha1 + 20;
 885        data_size = left - 20;
 886        delta_data = xmalloc(delta_size);
 887
 888        memset(&stream, 0, sizeof(stream));
 889
 890        stream.next_in = data;
 891        stream.avail_in = data_size;
 892        stream.next_out = delta_data;
 893        stream.avail_out = delta_size;
 894
 895        inflateInit(&stream);
 896        st = inflate(&stream, Z_FINISH);
 897        inflateEnd(&stream);
 898        if ((st != Z_STREAM_END) || stream.total_out != delta_size)
 899                die("delta data unpack failed");
 900
 901        /* The base entry _must_ be in the same pack */
 902        if (!find_pack_entry_one(base_sha1, &base_ent, p))
 903                die("failed to find delta-pack base object %s",
 904                    sha1_to_hex(base_sha1));
 905        base = unpack_entry_gently(&base_ent, type, &base_size);
 906        if (!base)
 907                die("failed to read delta-pack base object %s",
 908                    sha1_to_hex(base_sha1));
 909        result = patch_delta(base, base_size,
 910                             delta_data, delta_size,
 911                             &result_size);
 912        if (!result)
 913                die("failed to apply delta");
 914        free(delta_data);
 915        free(base);
 916        *sizep = result_size;
 917        return result;
 918}
 919
 920static void *unpack_non_delta_entry(unsigned char *data,
 921                                    unsigned long size,
 922                                    unsigned long left)
 923{
 924        int st;
 925        z_stream stream;
 926        unsigned char *buffer;
 927
 928        buffer = xmalloc(size + 1);
 929        buffer[size] = 0;
 930        memset(&stream, 0, sizeof(stream));
 931        stream.next_in = data;
 932        stream.avail_in = left;
 933        stream.next_out = buffer;
 934        stream.avail_out = size;
 935
 936        inflateInit(&stream);
 937        st = inflate(&stream, Z_FINISH);
 938        inflateEnd(&stream);
 939        if ((st != Z_STREAM_END) || stream.total_out != size) {
 940                free(buffer);
 941                return NULL;
 942        }
 943
 944        return buffer;
 945}
 946
 947static void *unpack_entry(struct pack_entry *entry,
 948                          char *type, unsigned long *sizep)
 949{
 950        struct packed_git *p = entry->p;
 951        void *retval;
 952
 953        if (use_packed_git(p))
 954                die("cannot map packed file");
 955        retval = unpack_entry_gently(entry, type, sizep);
 956        unuse_packed_git(p);
 957        if (!retval)
 958                die("corrupted pack file %s", p->pack_name);
 959        return retval;
 960}
 961
 962/* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
 963void *unpack_entry_gently(struct pack_entry *entry,
 964                          char *type, unsigned long *sizep)
 965{
 966        struct packed_git *p = entry->p;
 967        unsigned long offset, size, left;
 968        unsigned char *pack;
 969        enum object_type kind;
 970        void *retval;
 971
 972        offset = unpack_object_header(p, entry->offset, &kind, &size);
 973        pack = p->pack_base + offset;
 974        left = p->pack_size - offset;
 975        switch (kind) {
 976        case OBJ_DELTA:
 977                retval = unpack_delta_entry(pack, size, left, type, sizep, p);
 978                return retval;
 979        case OBJ_COMMIT:
 980                strcpy(type, "commit");
 981                break;
 982        case OBJ_TREE:
 983                strcpy(type, "tree");
 984                break;
 985        case OBJ_BLOB:
 986                strcpy(type, "blob");
 987                break;
 988        case OBJ_TAG:
 989                strcpy(type, "tag");
 990                break;
 991        default:
 992                return NULL;
 993        }
 994        *sizep = size;
 995        retval = unpack_non_delta_entry(pack, size, left);
 996        return retval;
 997}
 998
 999int num_packed_objects(const struct packed_git *p)
1000{
1001        /* See check_packed_git_idx() */
1002        return (p->index_size - 20 - 20 - 4*256) / 24;
1003}
1004
1005int nth_packed_object_sha1(const struct packed_git *p, int n,
1006                           unsigned char* sha1)
1007{
1008        void *index = p->index_base + 256;
1009        if (n < 0 || num_packed_objects(p) <= n)
1010                return -1;
1011        memcpy(sha1, (index + 24 * n + 4), 20);
1012        return 0;
1013}
1014
1015int find_pack_entry_one(const unsigned char *sha1,
1016                        struct pack_entry *e, struct packed_git *p)
1017{
1018        unsigned int *level1_ofs = p->index_base;
1019        int hi = ntohl(level1_ofs[*sha1]);
1020        int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1021        void *index = p->index_base + 256;
1022
1023        do {
1024                int mi = (lo + hi) / 2;
1025                int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
1026                if (!cmp) {
1027                        e->offset = ntohl(*((int*)(index + 24 * mi)));
1028                        memcpy(e->sha1, sha1, 20);
1029                        e->p = p;
1030                        return 1;
1031                }
1032                if (cmp > 0)
1033                        hi = mi;
1034                else
1035                        lo = mi+1;
1036        } while (lo < hi);
1037        return 0;
1038}
1039
1040static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1041{
1042        struct packed_git *p;
1043        prepare_packed_git();
1044
1045        for (p = packed_git; p; p = p->next) {
1046                if (find_pack_entry_one(sha1, e, p))
1047                        return 1;
1048        }
1049        return 0;
1050}
1051
1052struct packed_git *find_sha1_pack(const unsigned char *sha1, 
1053                                  struct packed_git *packs)
1054{
1055        struct packed_git *p;
1056        struct pack_entry e;
1057
1058        for (p = packs; p; p = p->next) {
1059                if (find_pack_entry_one(sha1, &e, p))
1060                        return p;
1061        }
1062        return NULL;
1063        
1064}
1065
1066int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1067{
1068        int status;
1069        unsigned long mapsize, size;
1070        void *map;
1071        z_stream stream;
1072        char hdr[128];
1073
1074        map = map_sha1_file_internal(sha1, &mapsize);
1075        if (!map) {
1076                struct pack_entry e;
1077
1078                if (!find_pack_entry(sha1, &e))
1079                        return error("unable to find %s", sha1_to_hex(sha1));
1080                return packed_object_info(&e, type, sizep);
1081        }
1082        if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1083                status = error("unable to unpack %s header",
1084                               sha1_to_hex(sha1));
1085        if (parse_sha1_header(hdr, type, &size) < 0)
1086                status = error("unable to parse %s header", sha1_to_hex(sha1));
1087        else {
1088                status = 0;
1089                if (sizep)
1090                        *sizep = size;
1091        }
1092        inflateEnd(&stream);
1093        munmap(map, mapsize);
1094        return status;
1095}
1096
1097static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1098{
1099        struct pack_entry e;
1100
1101        if (!find_pack_entry(sha1, &e)) {
1102                error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1103                return NULL;
1104        }
1105        return unpack_entry(&e, type, size);
1106}
1107
1108void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1109{
1110        unsigned long mapsize;
1111        void *map, *buf;
1112        struct pack_entry e;
1113
1114        if (find_pack_entry(sha1, &e))
1115                return read_packed_sha1(sha1, type, size);
1116        map = map_sha1_file_internal(sha1, &mapsize);
1117        if (map) {
1118                buf = unpack_sha1_file(map, mapsize, type, size);
1119                munmap(map, mapsize);
1120                return buf;
1121        }
1122        return NULL;
1123}
1124
1125void *read_object_with_reference(const unsigned char *sha1,
1126                                 const char *required_type,
1127                                 unsigned long *size,
1128                                 unsigned char *actual_sha1_return)
1129{
1130        char type[20];
1131        void *buffer;
1132        unsigned long isize;
1133        unsigned char actual_sha1[20];
1134
1135        memcpy(actual_sha1, sha1, 20);
1136        while (1) {
1137                int ref_length = -1;
1138                const char *ref_type = NULL;
1139
1140                buffer = read_sha1_file(actual_sha1, type, &isize);
1141                if (!buffer)
1142                        return NULL;
1143                if (!strcmp(type, required_type)) {
1144                        *size = isize;
1145                        if (actual_sha1_return)
1146                                memcpy(actual_sha1_return, actual_sha1, 20);
1147                        return buffer;
1148                }
1149                /* Handle references */
1150                else if (!strcmp(type, "commit"))
1151                        ref_type = "tree ";
1152                else if (!strcmp(type, "tag"))
1153                        ref_type = "object ";
1154                else {
1155                        free(buffer);
1156                        return NULL;
1157                }
1158                ref_length = strlen(ref_type);
1159
1160                if (memcmp(buffer, ref_type, ref_length) ||
1161                    get_sha1_hex(buffer + ref_length, actual_sha1)) {
1162                        free(buffer);
1163                        return NULL;
1164                }
1165                free(buffer);
1166                /* Now we have the ID of the referred-to object in
1167                 * actual_sha1.  Check again. */
1168        }
1169}
1170
1171char *write_sha1_file_prepare(void *buf,
1172                              unsigned long len,
1173                              const char *type,
1174                              unsigned char *sha1,
1175                              unsigned char *hdr,
1176                              int *hdrlen)
1177{
1178        SHA_CTX c;
1179
1180        /* Generate the header */
1181        *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1182
1183        /* Sha1.. */
1184        SHA1_Init(&c);
1185        SHA1_Update(&c, hdr, *hdrlen);
1186        SHA1_Update(&c, buf, len);
1187        SHA1_Final(sha1, &c);
1188
1189        return sha1_file_name(sha1);
1190}
1191
1192/*
1193 * Link the tempfile to the final place, possibly creating the
1194 * last directory level as you do so.
1195 *
1196 * Returns the errno on failure, 0 on success.
1197 */
1198static int link_temp_to_file(const char *tmpfile, char *filename)
1199{
1200        int ret;
1201
1202        if (!link(tmpfile, filename))
1203                return 0;
1204
1205        /*
1206         * Try to mkdir the last path component if that failed
1207         * with an ENOENT.
1208         *
1209         * Re-try the "link()" regardless of whether the mkdir
1210         * succeeds, since a race might mean that somebody
1211         * else succeeded.
1212         */
1213        ret = errno;
1214        if (ret == ENOENT) {
1215                char *dir = strrchr(filename, '/');
1216                if (dir) {
1217                        *dir = 0;
1218                        mkdir(filename, 0777);
1219                        *dir = '/';
1220                        if (!link(tmpfile, filename))
1221                                return 0;
1222                        ret = errno;
1223                }
1224        }
1225        return ret;
1226}
1227
1228/*
1229 * Move the just written object into its final resting place
1230 */
1231int move_temp_to_file(const char *tmpfile, char *filename)
1232{
1233        int ret = link_temp_to_file(tmpfile, filename);
1234        if (ret) {
1235                /*
1236                 * Coda hack - coda doesn't like cross-directory links,
1237                 * so we fall back to a rename, which will mean that it
1238                 * won't be able to check collisions, but that's not a
1239                 * big deal.
1240                 *
1241                 * When this succeeds, we just return 0. We have nothing
1242                 * left to unlink.
1243                 */
1244                if (ret == EXDEV && !rename(tmpfile, filename))
1245                        return 0;
1246        }
1247        unlink(tmpfile);
1248        if (ret) {
1249                if (ret != EEXIST) {
1250                        fprintf(stderr, "unable to write sha1 filename %s: %s", filename, strerror(ret));
1251                        return -1;
1252                }
1253                /* FIXME!!! Collision check here ? */
1254        }
1255
1256        return 0;
1257}
1258
1259int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1260{
1261        int size;
1262        unsigned char *compressed;
1263        z_stream stream;
1264        unsigned char sha1[20];
1265        char *filename;
1266        static char tmpfile[PATH_MAX];
1267        unsigned char hdr[50];
1268        int fd, hdrlen;
1269
1270        /* Normally if we have it in the pack then we do not bother writing
1271         * it out into .git/objects/??/?{38} file.
1272         */
1273        filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1274        if (returnsha1)
1275                memcpy(returnsha1, sha1, 20);
1276        if (has_sha1_file(sha1))
1277                return 0;
1278        fd = open(filename, O_RDONLY);
1279        if (fd >= 0) {
1280                /*
1281                 * FIXME!!! We might do collision checking here, but we'd
1282                 * need to uncompress the old file and check it. Later.
1283                 */
1284                close(fd);
1285                return 0;
1286        }
1287
1288        if (errno != ENOENT) {
1289                fprintf(stderr, "sha1 file %s: %s", filename, strerror(errno));
1290                return -1;
1291        }
1292
1293        snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1294
1295        fd = mkstemp(tmpfile);
1296        if (fd < 0) {
1297                fprintf(stderr, "unable to create temporary sha1 filename %s: %s", tmpfile, strerror(errno));
1298                return -1;
1299        }
1300
1301        /* Set it up */
1302        memset(&stream, 0, sizeof(stream));
1303        deflateInit(&stream, Z_BEST_COMPRESSION);
1304        size = deflateBound(&stream, len+hdrlen);
1305        compressed = xmalloc(size);
1306
1307        /* Compress it */
1308        stream.next_out = compressed;
1309        stream.avail_out = size;
1310
1311        /* First header.. */
1312        stream.next_in = hdr;
1313        stream.avail_in = hdrlen;
1314        while (deflate(&stream, 0) == Z_OK)
1315                /* nothing */;
1316
1317        /* Then the data itself.. */
1318        stream.next_in = buf;
1319        stream.avail_in = len;
1320        while (deflate(&stream, Z_FINISH) == Z_OK)
1321                /* nothing */;
1322        deflateEnd(&stream);
1323        size = stream.total_out;
1324
1325        if (write(fd, compressed, size) != size)
1326                die("unable to write file");
1327        fchmod(fd, 0444);
1328        close(fd);
1329        free(compressed);
1330
1331        return move_temp_to_file(tmpfile, filename);
1332}
1333
1334int write_sha1_to_fd(int fd, const unsigned char *sha1)
1335{
1336        ssize_t size;
1337        unsigned long objsize;
1338        int posn = 0;
1339        void *map = map_sha1_file_internal(sha1, &objsize);
1340        void *buf = map;
1341        void *temp_obj = NULL;
1342        z_stream stream;
1343
1344        if (!buf) {
1345                unsigned char *unpacked;
1346                unsigned long len;
1347                char type[20];
1348                char hdr[50];
1349                int hdrlen;
1350                // need to unpack and recompress it by itself
1351                unpacked = read_packed_sha1(sha1, type, &len);
1352
1353                hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1354
1355                /* Set it up */
1356                memset(&stream, 0, sizeof(stream));
1357                deflateInit(&stream, Z_BEST_COMPRESSION);
1358                size = deflateBound(&stream, len + hdrlen);
1359                temp_obj = buf = xmalloc(size);
1360
1361                /* Compress it */
1362                stream.next_out = buf;
1363                stream.avail_out = size;
1364                
1365                /* First header.. */
1366                stream.next_in = (void *)hdr;
1367                stream.avail_in = hdrlen;
1368                while (deflate(&stream, 0) == Z_OK)
1369                        /* nothing */;
1370
1371                /* Then the data itself.. */
1372                stream.next_in = unpacked;
1373                stream.avail_in = len;
1374                while (deflate(&stream, Z_FINISH) == Z_OK)
1375                        /* nothing */;
1376                deflateEnd(&stream);
1377                free(unpacked);
1378                
1379                objsize = stream.total_out;
1380        }
1381
1382        do {
1383                size = write(fd, buf + posn, objsize - posn);
1384                if (size <= 0) {
1385                        if (!size) {
1386                                fprintf(stderr, "write closed");
1387                        } else {
1388                                perror("write ");
1389                        }
1390                        return -1;
1391                }
1392                posn += size;
1393        } while (posn < objsize);
1394
1395        if (map)
1396                munmap(map, objsize);
1397        if (temp_obj)
1398                free(temp_obj);
1399
1400        return 0;
1401}
1402
1403int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1404                       size_t bufsize, size_t *bufposn)
1405{
1406        char tmpfile[PATH_MAX];
1407        int local;
1408        z_stream stream;
1409        unsigned char real_sha1[20];
1410        unsigned char discard[4096];
1411        int ret;
1412        SHA_CTX c;
1413
1414        snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1415
1416        local = mkstemp(tmpfile);
1417        if (local < 0)
1418                return error("Couldn't open %s for %s\n", tmpfile, sha1_to_hex(sha1));
1419
1420        memset(&stream, 0, sizeof(stream));
1421
1422        inflateInit(&stream);
1423
1424        SHA1_Init(&c);
1425
1426        do {
1427                ssize_t size;
1428                if (*bufposn) {
1429                        stream.avail_in = *bufposn;
1430                        stream.next_in = (unsigned char *) buffer;
1431                        do {
1432                                stream.next_out = discard;
1433                                stream.avail_out = sizeof(discard);
1434                                ret = inflate(&stream, Z_SYNC_FLUSH);
1435                                SHA1_Update(&c, discard, sizeof(discard) -
1436                                            stream.avail_out);
1437                        } while (stream.avail_in && ret == Z_OK);
1438                        write(local, buffer, *bufposn - stream.avail_in);
1439                        memmove(buffer, buffer + *bufposn - stream.avail_in,
1440                                stream.avail_in);
1441                        *bufposn = stream.avail_in;
1442                        if (ret != Z_OK)
1443                                break;
1444                }
1445                size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1446                if (size <= 0) {
1447                        close(local);
1448                        unlink(tmpfile);
1449                        if (!size)
1450                                return error("Connection closed?");
1451                        perror("Reading from connection");
1452                        return -1;
1453                }
1454                *bufposn += size;
1455        } while (1);
1456        inflateEnd(&stream);
1457
1458        close(local);
1459        SHA1_Final(real_sha1, &c);
1460        if (ret != Z_STREAM_END) {
1461                unlink(tmpfile);
1462                return error("File %s corrupted", sha1_to_hex(sha1));
1463        }
1464        if (memcmp(sha1, real_sha1, 20)) {
1465                unlink(tmpfile);
1466                return error("File %s has bad hash\n", sha1_to_hex(sha1));
1467        }
1468
1469        return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1470}
1471
1472int has_pack_index(const unsigned char *sha1)
1473{
1474        struct stat st;
1475        if (stat(sha1_pack_index_name(sha1), &st))
1476                return 0;
1477        return 1;
1478}
1479
1480int has_pack_file(const unsigned char *sha1)
1481{
1482        struct stat st;
1483        if (stat(sha1_pack_name(sha1), &st))
1484                return 0;
1485        return 1;
1486}
1487
1488int has_sha1_pack(const unsigned char *sha1)
1489{
1490        struct pack_entry e;
1491        return find_pack_entry(sha1, &e);
1492}
1493
1494int has_sha1_file(const unsigned char *sha1)
1495{
1496        struct stat st;
1497        struct pack_entry e;
1498
1499        if (find_pack_entry(sha1, &e))
1500                return 1;
1501        return find_sha1_file(sha1, &st) ? 1 : 0;
1502}
1503
1504int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1505{
1506        unsigned long size = st->st_size;
1507        void *buf;
1508        int ret;
1509        unsigned char hdr[50];
1510        int hdrlen;
1511
1512        buf = "";
1513        if (size)
1514                buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1515        close(fd);
1516        if (buf == MAP_FAILED)
1517                return -1;
1518
1519        if (!type)
1520                type = "blob";
1521        if (write_object)
1522                ret = write_sha1_file(buf, size, type, sha1);
1523        else {
1524                write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1525                ret = 0;
1526        }
1527        if (size)
1528                munmap(buf, size);
1529        return ret;
1530}
1531
1532int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1533{
1534        int fd;
1535        char *target;
1536
1537        switch (st->st_mode & S_IFMT) {
1538        case S_IFREG:
1539                fd = open(path, O_RDONLY);
1540                if (fd < 0)
1541                        return error("open(\"%s\"): %s", path,
1542                                     strerror(errno));
1543                if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1544                        return error("%s: failed to insert into database",
1545                                     path);
1546                break;
1547        case S_IFLNK:
1548                target = xmalloc(st->st_size+1);
1549                if (readlink(path, target, st->st_size+1) != st->st_size) {
1550                        char *errstr = strerror(errno);
1551                        free(target);
1552                        return error("readlink(\"%s\"): %s", path,
1553                                     errstr);
1554                }
1555                if (!write_object) {
1556                        unsigned char hdr[50];
1557                        int hdrlen;
1558                        write_sha1_file_prepare(target, st->st_size, "blob",
1559                                                sha1, hdr, &hdrlen);
1560                } else if (write_sha1_file(target, st->st_size, "blob", sha1))
1561                        return error("%s: failed to insert into database",
1562                                     path);
1563                free(target);
1564                break;
1565        default:
1566                return error("%s: unsupported file type", path);
1567        }
1568        return 0;
1569}