sha1_file.c

   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
  23 const unsigned char null_sha1[20] = { 0, };
  24
  25 static unsigned int sha1_file_open_flag = O_NOATIME;
  26
  27 static 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
  38 int 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
  51 int safe_create_leading_directories(char *path)
  52 {
  53         char *pos = path;
  54         if (*pos == '/')
  55                 pos++;
  56
  57         while (pos) {
  58                 pos = strchr(pos, '/');
  59                 if (!pos)
  60                         break;
  61                 *pos = 0;
  62                 if (mkdir(path, 0777) < 0)
  63                         if (errno != EEXIST) {
  64                                 *pos = '/';
  65                                 return -1;
  66                         }
  67                 *pos++ = '/';
  68         }
  69         return 0;
  70 }
  71
  72 char * sha1_to_hex(const unsigned char *sha1)
  73 {
  74         static char buffer[50];
  75         static const char hex[] = "0123456789abcdef";
  76         char *buf = buffer;
  77         int i;
  78
  79         for (i = 0; i < 20; i++) {
  80                 unsigned int val = *sha1++;
  81                 *buf++ = hex[val >> 4];
  82                 *buf++ = hex[val & 0xf];
  83         }
  84         *buf = '\0';
  85
  86         return buffer;
  87 }
  88
  89 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
  90 {
  91         int i;
  92         for (i = 0; i < 20; i++) {
  93                 static char hex[] = "0123456789abcdef";
  94                 unsigned int val = sha1[i];
  95                 char *pos = pathbuf + i*2 + (i > 0);
  96                 *pos++ = hex[val >> 4];
  97                 *pos = hex[val & 0xf];
  98         }
  99 }
 100
 101 /*
 102  * NOTE! This returns a statically allocated buffer, so you have to be
 103  * careful about using it. Do a "strdup()" if you need to save the
 104  * filename.
 105  *
 106  * Also note that this returns the location for creating.  Reading
 107  * SHA1 file can happen from any alternate directory listed in the
 108  * DB_ENVIRONMENT environment variable if it is not found in
 109  * the primary object database.
 110  */
 111 char *sha1_file_name(const unsigned char *sha1)
 112 {
 113         static char *name, *base;
 114
 115         if (!base) {
 116                 const char *sha1_file_directory = get_object_directory();
 117                 int len = strlen(sha1_file_directory);
 118                 base = xmalloc(len + 60);
 119                 memcpy(base, sha1_file_directory, len);
 120                 memset(base+len, 0, 60);
 121                 base[len] = '/';
 122                 base[len+3] = '/';
 123                 name = base + len + 1;
 124         }
 125         fill_sha1_path(name, sha1);
 126         return base;
 127 }
 128
 129 char *sha1_pack_name(const unsigned char *sha1)
 130 {
 131         static const char hex[] = "0123456789abcdef";
 132         static char *name, *base, *buf;
 133         int i;
 134
 135         if (!base) {
 136                 const char *sha1_file_directory = get_object_directory();
 137                 int len = strlen(sha1_file_directory);
 138                 base = xmalloc(len + 60);
 139                 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
 140                 name = base + len + 11;
 141         }
 142
 143         buf = name;
 144
 145         for (i = 0; i < 20; i++) {
 146                 unsigned int val = *sha1++;
 147                 *buf++ = hex[val >> 4];
 148                 *buf++ = hex[val & 0xf];
 149         }
 150
 151         return base;
 152 }
 153
 154 char *sha1_pack_index_name(const unsigned char *sha1)
 155 {
 156         static const char hex[] = "0123456789abcdef";
 157         static char *name, *base, *buf;
 158         int i;
 159
 160         if (!base) {
 161                 const char *sha1_file_directory = get_object_directory();
 162                 int len = strlen(sha1_file_directory);
 163                 base = xmalloc(len + 60);
 164                 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
 165                 name = base + len + 11;
 166         }
 167
 168         buf = name;
 169
 170         for (i = 0; i < 20; i++) {
 171                 unsigned int val = *sha1++;
 172                 *buf++ = hex[val >> 4];
 173                 *buf++ = hex[val & 0xf];
 174         }
 175
 176         return base;
 177 }
 178
 179 struct alternate_object_database *alt_odb_list;
 180 static struct alternate_object_database **alt_odb_tail;
 181
 182 /*
 183  * Prepare alternate object database registry.
 184  *
 185  * The variable alt_odb_list points at the list of struct
 186  * alternate_object_database.  The elements on this list come from
 187  * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
 188  * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
 189  * whose contents is similar to that environment variable but can be
 190  * LF separated.  Its base points at a statically allocated buffer that
 191  * contains "/the/directory/corresponding/to/.git/objects/...", while
 192  * its name points just after the slash at the end of ".git/objects/"
 193  * in the example above, and has enough space to hold 40-byte hex
 194  * SHA1, an extra slash for the first level indirection, and the
 195  * terminating NUL.
 196  */
 197 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
 198                                  const char *relative_base)
 199 {
 200         const char *cp, *last;
 201         struct alternate_object_database *ent;
 202         const char *objdir = get_object_directory();
 203         int base_len = -1;
 204
 205         last = alt;
 206         while (last < ep) {
 207                 cp = last;
 208                 if (cp < ep && *cp == '#') {
 209                         while (cp < ep && *cp != sep)
 210                                 cp++;
 211                         last = cp + 1;
 212                         continue;
 213                 }
 214                 for ( ; cp < ep && *cp != sep; cp++)
 215                         ;
 216                 if (last != cp) {
 217                         struct alternate_object_database *alt;
 218                         /* 43 = 40-byte + 2 '/' + terminating NUL */
 219                         int pfxlen = cp - last;
 220                         int entlen = pfxlen + 43;
 221
 222                         if (*last != '/' && relative_base) {
 223                                 /* Relative alt-odb */
 224                                 if (base_len < 0)
 225                                         base_len = strlen(relative_base) + 1;
 226                                 entlen += base_len;
 227                                 pfxlen += base_len;
 228                         }
 229                         ent = xmalloc(sizeof(*ent) + entlen);
 230
 231                         if (*last != '/' && relative_base) {
 232                                 memcpy(ent->base, relative_base, base_len - 1);
 233                                 ent->base[base_len - 1] = '/';
 234                                 memcpy(ent->base + base_len,
 235                                        last, cp - last);
 236                         }
 237                         else
 238                                 memcpy(ent->base, last, pfxlen);
 239                         ent->name = ent->base + pfxlen + 1;
 240                         ent->base[pfxlen] = ent->base[pfxlen + 3] = '/';
 241                         ent->base[entlen-1] = 0;
 242
 243                         /* Prevent the common mistake of listing the same
 244                          * thing twice, or object directory itself.
 245                          */
 246                         for (alt = alt_odb_list; alt; alt = alt->next)
 247                                 if (!memcmp(ent->base, alt->base, pfxlen))
 248                                         goto bad;
 249                         if (!memcmp(ent->base, objdir, pfxlen)) {
 250                         bad:
 251                                 free(ent);
 252                         }
 253                         else {
 254                                 *alt_odb_tail = ent;
 255                                 alt_odb_tail = &(ent->next);
 256                                 ent->next = NULL;
 257                         }
 258                 }
 259                 while (cp < ep && *cp == sep)
 260                         cp++;
 261                 last = cp;
 262         }
 263 }
 264
 265 void prepare_alt_odb(void)
 266 {
 267         char path[PATH_MAX];
 268         char *map;
 269         int fd;
 270         struct stat st;
 271         char *alt;
 272
 273         alt = getenv(ALTERNATE_DB_ENVIRONMENT);
 274         if (!alt) alt = "";
 275
 276         if (alt_odb_tail)
 277                 return;
 278         alt_odb_tail = &alt_odb_list;
 279         link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL);
 280
 281         sprintf(path, "%s/info/alternates", get_object_directory());
 282         fd = open(path, O_RDONLY);
 283         if (fd < 0)
 284                 return;
 285         if (fstat(fd, &st) || (st.st_size == 0)) {
 286                 close(fd);
 287                 return;
 288         }
 289         map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 290         close(fd);
 291         if (map == MAP_FAILED)
 292                 return;
 293
 294         link_alt_odb_entries(map, map + st.st_size, '\n',
 295                              get_object_directory());
 296         munmap(map, st.st_size);
 297 }
 298
 299 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
 300 {
 301         char *name = sha1_file_name(sha1);
 302         struct alternate_object_database *alt;
 303
 304         if (!stat(name, st))
 305                 return name;
 306         prepare_alt_odb();
 307         for (alt = alt_odb_list; alt; alt = alt->next) {
 308                 name = alt->name;
 309                 fill_sha1_path(name, sha1);
 310                 if (!stat(alt->base, st))
 311                         return alt->base;
 312         }
 313         return NULL;
 314 }
 315
 316 #define PACK_MAX_SZ (1<<26)
 317 static int pack_used_ctr;
 318 static unsigned long pack_mapped;
 319 struct packed_git *packed_git;
 320
 321 static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
 322                                 void **idx_map_)
 323 {
 324         void *idx_map;
 325         unsigned int *index;
 326         unsigned long idx_size;
 327         int nr, i;
 328         int fd = open(path, O_RDONLY);
 329         struct stat st;
 330         if (fd < 0)
 331                 return -1;
 332         if (fstat(fd, &st)) {
 333                 close(fd);
 334                 return -1;
 335         }
 336         idx_size = st.st_size;
 337         idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
 338         close(fd);
 339         if (idx_map == MAP_FAILED)
 340                 return -1;
 341
 342         index = idx_map;
 343         *idx_map_ = idx_map;
 344         *idx_size_ = idx_size;
 345
 346         /* check index map */
 347         if (idx_size < 4*256 + 20 + 20)
 348                 return error("index file too small");
 349         nr = 0;
 350         for (i = 0; i < 256; i++) {
 351                 unsigned int n = ntohl(index[i]);
 352                 if (n < nr)
 353                         return error("non-monotonic index");
 354                 nr = n;
 355         }
 356
 357         /*
 358          * Total size:
 359          *  - 256 index entries 4 bytes each
 360          *  - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
 361          *  - 20-byte SHA1 of the packfile
 362          *  - 20-byte SHA1 file checksum
 363          */
 364         if (idx_size != 4*256 + nr * 24 + 20 + 20)
 365                 return error("wrong index file size");
 366
 367         return 0;
 368 }
 369
 370 static int unuse_one_packed_git(void)
 371 {
 372         struct packed_git *p, *lru = NULL;
 373
 374         for (p = packed_git; p; p = p->next) {
 375                 if (p->pack_use_cnt || !p->pack_base)
 376                         continue;
 377                 if (!lru || p->pack_last_used < lru->pack_last_used)
 378                         lru = p;
 379         }
 380         if (!lru)
 381                 return 0;
 382         munmap(lru->pack_base, lru->pack_size);
 383         lru->pack_base = NULL;
 384         return 1;
 385 }
 386
 387 void unuse_packed_git(struct packed_git *p)
 388 {
 389         p->pack_use_cnt--;
 390 }
 391
 392 int use_packed_git(struct packed_git *p)
 393 {
 394         if (!p->pack_size) {
 395                 struct stat st;
 396                 // We created the struct before we had the pack
 397                 stat(p->pack_name, &st);
 398                 if (!S_ISREG(st.st_mode))
 399                         die("packfile %s not a regular file", p->pack_name);
 400                 p->pack_size = st.st_size;
 401         }
 402         if (!p->pack_base) {
 403                 int fd;
 404                 struct stat st;
 405                 void *map;
 406
 407                 pack_mapped += p->pack_size;
 408                 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
 409                         ; /* nothing */
 410                 fd = open(p->pack_name, O_RDONLY);
 411                 if (fd < 0)
 412                         die("packfile %s cannot be opened", p->pack_name);
 413                 if (fstat(fd, &st)) {
 414                         close(fd);
 415                         die("packfile %s cannot be opened", p->pack_name);
 416                 }
 417                 if (st.st_size != p->pack_size)
 418                         die("packfile %s size mismatch.", p->pack_name);
 419                 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
 420                 close(fd);
 421                 if (map == MAP_FAILED)
 422                         die("packfile %s cannot be mapped.", p->pack_name);
 423                 p->pack_base = map;
 424
 425                 /* Check if the pack file matches with the index file.
 426                  * this is cheap.
 427                  */
 428                 if (memcmp((char*)(p->index_base) + p->index_size - 40,
 429                            p->pack_base + p->pack_size - 20, 20)) {
 430
 431                         die("packfile %s does not match index.", p->pack_name);
 432                 }
 433         }
 434         p->pack_last_used = pack_used_ctr++;
 435         p->pack_use_cnt++;
 436         return 0;
 437 }
 438
 439 struct packed_git *add_packed_git(char *path, int path_len, int local)
 440 {
 441         struct stat st;
 442         struct packed_git *p;
 443         unsigned long idx_size;
 444         void *idx_map;
 445         unsigned char sha1[20];
 446
 447         if (check_packed_git_idx(path, &idx_size, &idx_map))
 448                 return NULL;
 449
 450         /* do we have a corresponding .pack file? */
 451         strcpy(path + path_len - 4, ".pack");
 452         if (stat(path, &st) || !S_ISREG(st.st_mode)) {
 453                 munmap(idx_map, idx_size);
 454                 return NULL;
 455         }
 456         /* ok, it looks sane as far as we can check without
 457          * actually mapping the pack file.
 458          */
 459         p = xmalloc(sizeof(*p) + path_len + 2);
 460         strcpy(p->pack_name, path);
 461         p->index_size = idx_size;
 462         p->pack_size = st.st_size;
 463         p->index_base = idx_map;
 464         p->next = NULL;
 465         p->pack_base = NULL;
 466         p->pack_last_used = 0;
 467         p->pack_use_cnt = 0;
 468         p->pack_local = local;
 469         if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
 470                 memcpy(p->sha1, sha1, 20);
 471         return p;
 472 }
 473
 474 struct packed_git *parse_pack_index(unsigned char *sha1)
 475 {
 476         char *path = sha1_pack_index_name(sha1);
 477         return parse_pack_index_file(sha1, path);
 478 }
 479
 480 struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
 481 {
 482         struct packed_git *p;
 483         unsigned long idx_size;
 484         void *idx_map;
 485         char *path;
 486
 487         if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
 488                 return NULL;
 489
 490         path = sha1_pack_name(sha1);
 491
 492         p = xmalloc(sizeof(*p) + strlen(path) + 2);
 493         strcpy(p->pack_name, path);
 494         p->index_size = idx_size;
 495         p->pack_size = 0;
 496         p->index_base = idx_map;
 497         p->next = NULL;
 498         p->pack_base = NULL;
 499         p->pack_last_used = 0;
 500         p->pack_use_cnt = 0;
 501         memcpy(p->sha1, sha1, 20);
 502         return p;
 503 }
 504
 505 void install_packed_git(struct packed_git *pack)
 506 {
 507         pack->next = packed_git;
 508         packed_git = pack;
 509 }
 510
 511 static void prepare_packed_git_one(char *objdir, int local)
 512 {
 513         char path[PATH_MAX];
 514         int len;
 515         DIR *dir;
 516         struct dirent *de;
 517
 518         sprintf(path, "%s/pack", objdir);
 519         len = strlen(path);
 520         dir = opendir(path);
 521         if (!dir)
 522                 return;
 523         path[len++] = '/';
 524         while ((de = readdir(dir)) != NULL) {
 525                 int namelen = strlen(de->d_name);
 526                 struct packed_git *p;
 527
 528                 if (strcmp(de->d_name + namelen - 4, ".idx"))
 529                         continue;
 530
 531                 /* we have .idx.  Is it a file we can map? */
 532                 strcpy(path + len, de->d_name);
 533                 p = add_packed_git(path, len + namelen, local);
 534                 if (!p)
 535                         continue;
 536                 p->next = packed_git;
 537                 packed_git = p;
 538         }
 539         closedir(dir);
 540 }
 541
 542 void prepare_packed_git(void)
 543 {
 544         static int run_once = 0;
 545         struct alternate_object_database *alt;
 546
 547         if (run_once)
 548                 return;
 549         prepare_packed_git_one(get_object_directory(), 1);
 550         prepare_alt_odb();
 551         for (alt = alt_odb_list; alt; alt = alt->next) {
 552                 alt->name[-1] = 0;
 553                 prepare_packed_git_one(alt->base, 0);
 554                 alt->name[-1] = '/';
 555         }
 556         run_once = 1;
 557 }
 558
 559 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
 560 {
 561         char header[100];
 562         unsigned char real_sha1[20];
 563         SHA_CTX c;
 564
 565         SHA1_Init(&c);
 566         SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
 567         SHA1_Update(&c, map, size);
 568         SHA1_Final(real_sha1, &c);
 569         return memcmp(sha1, real_sha1, 20) ? -1 : 0;
 570 }
 571
 572 static void *map_sha1_file_internal(const unsigned char *sha1,
 573                                     unsigned long *size)
 574 {
 575         struct stat st;
 576         void *map;
 577         int fd;
 578         char *filename = find_sha1_file(sha1, &st);
 579
 580         if (!filename) {
 581                 return NULL;
 582         }
 583
 584         fd = open(filename, O_RDONLY | sha1_file_open_flag);
 585         if (fd < 0) {
 586                 /* See if it works without O_NOATIME */
 587                 switch (sha1_file_open_flag) {
 588                 default:
 589                         fd = open(filename, O_RDONLY);
 590                         if (fd >= 0)
 591                                 break;
 592                 /* Fallthrough */
 593                 case 0:
 594                         return NULL;
 595                 }
 596
 597                 /* If it failed once, it will probably fail again.
 598                  * Stop using O_NOATIME
 599                  */
 600                 sha1_file_open_flag = 0;
 601         }
 602         map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 603         close(fd);
 604         if (map == MAP_FAILED)
 605                 return NULL;
 606         *size = st.st_size;
 607         return map;
 608 }
 609
 610 int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
 611 {
 612         /* Get the data stream */
 613         memset(stream, 0, sizeof(*stream));
 614         stream->next_in = map;
 615         stream->avail_in = mapsize;
 616         stream->next_out = buffer;
 617         stream->avail_out = size;
 618
 619         inflateInit(stream);
 620         return inflate(stream, 0);
 621 }
 622
 623 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
 624 {
 625         int bytes = strlen(buffer) + 1;
 626         unsigned char *buf = xmalloc(1+size);
 627
 628         memcpy(buf, buffer + bytes, stream->total_out - bytes);
 629         bytes = stream->total_out - bytes;
 630         if (bytes < size) {
 631                 stream->next_out = buf + bytes;
 632                 stream->avail_out = size - bytes;
 633                 while (inflate(stream, Z_FINISH) == Z_OK)
 634                         /* nothing */;
 635         }
 636         buf[size] = 0;
 637         inflateEnd(stream);
 638         return buf;
 639 }
 640
 641 /*
 642  * We used to just use "sscanf()", but that's actually way
 643  * too permissive for what we want to check. So do an anal
 644  * object header parse by hand.
 645  */
 646 int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
 647 {
 648         int i;
 649         unsigned long size;
 650
 651         /*
 652          * The type can be at most ten bytes (including the
 653          * terminating '\0' that we add), and is followed by
 654          * a space.
 655          */
 656         i = 10;
 657         for (;;) {
 658                 char c = *hdr++;
 659                 if (c == ' ')
 660                         break;
 661                 if (!--i)
 662                         return -1;
 663                 *type++ = c;
 664         }
 665         *type = 0;
 666
 667         /*
 668          * The length must follow immediately, and be in canonical
 669          * decimal format (ie "010" is not valid).
 670          */
 671         size = *hdr++ - '0';
 672         if (size > 9)
 673                 return -1;
 674         if (size) {
 675                 for (;;) {
 676                         unsigned long c = *hdr - '0';
 677                         if (c > 9)
 678                                 break;
 679                         hdr++;
 680                         size = size * 10 + c;
 681                 }
 682         }
 683         *sizep = size;
 684
 685         /*
 686          * The length must be followed by a zero byte
 687          */
 688         return *hdr ? -1 : 0;
 689 }
 690
 691 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
 692 {
 693         int ret;
 694         z_stream stream;
 695         char hdr[8192];
 696
 697         ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
 698         if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
 699                 return NULL;
 700
 701         return unpack_sha1_rest(&stream, hdr, *size);
 702 }
 703
 704 /* forward declaration for a mutually recursive function */
 705 static int packed_object_info(struct pack_entry *entry,
 706                               char *type, unsigned long *sizep);
 707
 708 static int packed_delta_info(unsigned char *base_sha1,
 709                              unsigned long delta_size,
 710                              unsigned long left,
 711                              char *type,
 712                              unsigned long *sizep,
 713                              struct packed_git *p)
 714 {
 715         struct pack_entry base_ent;
 716
 717         if (left < 20)
 718                 die("truncated pack file");
 719
 720         /* The base entry _must_ be in the same pack */
 721         if (!find_pack_entry_one(base_sha1, &base_ent, p))
 722                 die("failed to find delta-pack base object %s",
 723                     sha1_to_hex(base_sha1));
 724
 725         /* We choose to only get the type of the base object and
 726          * ignore potentially corrupt pack file that expects the delta
 727          * based on a base with a wrong size.  This saves tons of
 728          * inflate() calls.
 729          */
 730
 731         if (packed_object_info(&base_ent, type, NULL))
 732                 die("cannot get info for delta-pack base");
 733
 734         if (sizep) {
 735                 const unsigned char *data;
 736                 unsigned char delta_head[64];
 737                 unsigned long result_size;
 738                 z_stream stream;
 739                 int st;
 740
 741                 memset(&stream, 0, sizeof(stream));
 742
 743                 data = stream.next_in = base_sha1 + 20;
 744                 stream.avail_in = left - 20;
 745                 stream.next_out = delta_head;
 746                 stream.avail_out = sizeof(delta_head);
 747
 748                 inflateInit(&stream);
 749                 st = inflate(&stream, Z_FINISH);
 750                 inflateEnd(&stream);
 751                 if ((st != Z_STREAM_END) &&
 752                     stream.total_out != sizeof(delta_head))
 753                         die("delta data unpack-initial failed");
 754
 755                 /* Examine the initial part of the delta to figure out
 756                  * the result size.
 757                  */
 758                 data = delta_head;
 759                 get_delta_hdr_size(&data); /* ignore base size */
 760
 761                 /* Read the result size */
 762                 result_size = get_delta_hdr_size(&data);
 763                 *sizep = result_size;
 764         }
 765         return 0;
 766 }
 767
 768 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
 769         enum object_type *type, unsigned long *sizep)
 770 {
 771         unsigned shift;
 772         unsigned char *pack, c;
 773         unsigned long size;
 774
 775         if (offset >= p->pack_size)
 776                 die("object offset outside of pack file");
 777
 778         pack =  p->pack_base + offset;
 779         c = *pack++;
 780         offset++;
 781         *type = (c >> 4) & 7;
 782         size = c & 15;
 783         shift = 4;
 784         while (c & 0x80) {
 785                 if (offset >= p->pack_size)
 786                         die("object offset outside of pack file");
 787                 c = *pack++;
 788                 offset++;
 789                 size += (c & 0x7f) << shift;
 790                 shift += 7;
 791         }
 792         *sizep = size;
 793         return offset;
 794 }
 795
 796 void packed_object_info_detail(struct pack_entry *e,
 797                                char *type,
 798                                unsigned long *size,
 799                                unsigned long *store_size,
 800                                int *delta_chain_length,
 801                                unsigned char *base_sha1)
 802 {
 803         struct packed_git *p = e->p;
 804         unsigned long offset, left;
 805         unsigned char *pack;
 806         enum object_type kind;
 807
 808         offset = unpack_object_header(p, e->offset, &kind, size);
 809         pack = p->pack_base + offset;
 810         left = p->pack_size - offset;
 811         if (kind != OBJ_DELTA)
 812                 *delta_chain_length = 0;
 813         else {
 814                 int chain_length = 0;
 815                 memcpy(base_sha1, pack, 20);
 816                 do {
 817                         struct pack_entry base_ent;
 818                         unsigned long junk;
 819
 820                         find_pack_entry_one(pack, &base_ent, p);
 821                         offset = unpack_object_header(p, base_ent.offset,
 822                                                       &kind, &junk);
 823                         pack = p->pack_base + offset;
 824                         chain_length++;
 825                 } while (kind == OBJ_DELTA);
 826                 *delta_chain_length = chain_length;
 827         }
 828         switch (kind) {
 829         case OBJ_COMMIT:
 830                 strcpy(type, "commit");
 831                 break;
 832         case OBJ_TREE:
 833                 strcpy(type, "tree");
 834                 break;
 835         case OBJ_BLOB:
 836                 strcpy(type, "blob");
 837                 break;
 838         case OBJ_TAG:
 839                 strcpy(type, "tag");
 840                 break;
 841         default:
 842                 die("corrupted pack file %s containing object of kind %d",
 843                     p->pack_name, kind);
 844         }
 845         *store_size = 0; /* notyet */
 846 }
 847
 848 static int packed_object_info(struct pack_entry *entry,
 849                               char *type, unsigned long *sizep)
 850 {
 851         struct packed_git *p = entry->p;
 852         unsigned long offset, size, left;
 853         unsigned char *pack;
 854         enum object_type kind;
 855         int retval;
 856
 857         if (use_packed_git(p))
 858                 die("cannot map packed file");
 859
 860         offset = unpack_object_header(p, entry->offset, &kind, &size);
 861         pack = p->pack_base + offset;
 862         left = p->pack_size - offset;
 863
 864         switch (kind) {
 865         case OBJ_DELTA:
 866                 retval = packed_delta_info(pack, size, left, type, sizep, p);
 867                 unuse_packed_git(p);
 868                 return retval;
 869         case OBJ_COMMIT:
 870                 strcpy(type, "commit");
 871                 break;
 872         case OBJ_TREE:
 873                 strcpy(type, "tree");
 874                 break;
 875         case OBJ_BLOB:
 876                 strcpy(type, "blob");
 877                 break;
 878         case OBJ_TAG:
 879                 strcpy(type, "tag");
 880                 break;
 881         default:
 882                 die("corrupted pack file %s containing object of kind %d",
 883                     p->pack_name, kind);
 884         }
 885         if (sizep)
 886                 *sizep = size;
 887         unuse_packed_git(p);
 888         return 0;
 889 }
 890
 891 /* forward declaration for a mutually recursive function */
 892 static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
 893
 894 static void *unpack_delta_entry(unsigned char *base_sha1,
 895                                 unsigned long delta_size,
 896                                 unsigned long left,
 897                                 char *type,
 898                                 unsigned long *sizep,
 899                                 struct packed_git *p)
 900 {
 901         struct pack_entry base_ent;
 902         void *data, *delta_data, *result, *base;
 903         unsigned long data_size, result_size, base_size;
 904         z_stream stream;
 905         int st;
 906
 907         if (left < 20)
 908                 die("truncated pack file");
 909         data = base_sha1 + 20;
 910         data_size = left - 20;
 911         delta_data = xmalloc(delta_size);
 912
 913         memset(&stream, 0, sizeof(stream));
 914
 915         stream.next_in = data;
 916         stream.avail_in = data_size;
 917         stream.next_out = delta_data;
 918         stream.avail_out = delta_size;
 919
 920         inflateInit(&stream);
 921         st = inflate(&stream, Z_FINISH);
 922         inflateEnd(&stream);
 923         if ((st != Z_STREAM_END) || stream.total_out != delta_size)
 924                 die("delta data unpack failed");
 925
 926         /* The base entry _must_ be in the same pack */
 927         if (!find_pack_entry_one(base_sha1, &base_ent, p))
 928                 die("failed to find delta-pack base object %s",
 929                     sha1_to_hex(base_sha1));
 930         base = unpack_entry_gently(&base_ent, type, &base_size);
 931         if (!base)
 932                 die("failed to read delta-pack base object %s",
 933                     sha1_to_hex(base_sha1));
 934         result = patch_delta(base, base_size,
 935                              delta_data, delta_size,
 936                              &result_size);
 937         if (!result)
 938                 die("failed to apply delta");
 939         free(delta_data);
 940         free(base);
 941         *sizep = result_size;
 942         return result;
 943 }
 944
 945 static void *unpack_non_delta_entry(unsigned char *data,
 946                                     unsigned long size,
 947                                     unsigned long left)
 948 {
 949         int st;
 950         z_stream stream;
 951         unsigned char *buffer;
 952
 953         buffer = xmalloc(size + 1);
 954         buffer[size] = 0;
 955         memset(&stream, 0, sizeof(stream));
 956         stream.next_in = data;
 957         stream.avail_in = left;
 958         stream.next_out = buffer;
 959         stream.avail_out = size;
 960
 961         inflateInit(&stream);
 962         st = inflate(&stream, Z_FINISH);
 963         inflateEnd(&stream);
 964         if ((st != Z_STREAM_END) || stream.total_out != size) {
 965                 free(buffer);
 966                 return NULL;
 967         }
 968
 969         return buffer;
 970 }
 971
 972 static void *unpack_entry(struct pack_entry *entry,
 973                           char *type, unsigned long *sizep)
 974 {
 975         struct packed_git *p = entry->p;
 976         void *retval;
 977
 978         if (use_packed_git(p))
 979                 die("cannot map packed file");
 980         retval = unpack_entry_gently(entry, type, sizep);
 981         unuse_packed_git(p);
 982         if (!retval)
 983                 die("corrupted pack file %s", p->pack_name);
 984         return retval;
 985 }
 986
 987 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
 988 void *unpack_entry_gently(struct pack_entry *entry,
 989                           char *type, unsigned long *sizep)
 990 {
 991         struct packed_git *p = entry->p;
 992         unsigned long offset, size, left;
 993         unsigned char *pack;
 994         enum object_type kind;
 995         void *retval;
 996
 997         offset = unpack_object_header(p, entry->offset, &kind, &size);
 998         pack = p->pack_base + offset;
 999         left = p->pack_size - offset;
1000         switch (kind) {
1001         case OBJ_DELTA:
1002                 retval = unpack_delta_entry(pack, size, left, type, sizep, p);
1003                 return retval;
1004         case OBJ_COMMIT:
1005                 strcpy(type, "commit");
1006                 break;
1007         case OBJ_TREE:
1008                 strcpy(type, "tree");
1009                 break;
1010         case OBJ_BLOB:
1011                 strcpy(type, "blob");
1012                 break;
1013         case OBJ_TAG:
1014                 strcpy(type, "tag");
1015                 break;
1016         default:
1017                 return NULL;
1018         }
1019         *sizep = size;
1020         retval = unpack_non_delta_entry(pack, size, left);
1021         return retval;
1022 }
1023
1024 int num_packed_objects(const struct packed_git *p)
1025 {
1026         /* See check_packed_git_idx() */
1027         return (p->index_size - 20 - 20 - 4*256) / 24;
1028 }
1029
1030 int nth_packed_object_sha1(const struct packed_git *p, int n,
1031                            unsigned char* sha1)
1032 {
1033         void *index = p->index_base + 256;
1034         if (n < 0 || num_packed_objects(p) <= n)
1035                 return -1;
1036         memcpy(sha1, (index + 24 * n + 4), 20);
1037         return 0;
1038 }
1039
1040 int find_pack_entry_one(const unsigned char *sha1,
1041                         struct pack_entry *e, struct packed_git *p)
1042 {
1043         unsigned int *level1_ofs = p->index_base;
1044         int hi = ntohl(level1_ofs[*sha1]);
1045         int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1046         void *index = p->index_base + 256;
1047
1048         do {
1049                 int mi = (lo + hi) / 2;
1050                 int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
1051                 if (!cmp) {
1052                         e->offset = ntohl(*((int*)(index + 24 * mi)));
1053                         memcpy(e->sha1, sha1, 20);
1054                         e->p = p;
1055                         return 1;
1056                 }
1057                 if (cmp > 0)
1058                         hi = mi;
1059                 else
1060                         lo = mi+1;
1061         } while (lo < hi);
1062         return 0;
1063 }
1064
1065 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1066 {
1067         struct packed_git *p;
1068         prepare_packed_git();
1069
1070         for (p = packed_git; p; p = p->next) {
1071                 if (find_pack_entry_one(sha1, e, p))
1072                         return 1;
1073         }
1074         return 0;
1075 }
1076
1077 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1078                                   struct packed_git *packs)
1079 {
1080         struct packed_git *p;
1081         struct pack_entry e;
1082
1083         for (p = packs; p; p = p->next) {
1084                 if (find_pack_entry_one(sha1, &e, p))
1085                         return p;
1086         }
1087         return NULL;
1088
1089 }
1090
1091 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1092 {
1093         int status;
1094         unsigned long mapsize, size;
1095         void *map;
1096         z_stream stream;
1097         char hdr[128];
1098
1099         map = map_sha1_file_internal(sha1, &mapsize);
1100         if (!map) {
1101                 struct pack_entry e;
1102
1103                 if (!find_pack_entry(sha1, &e))
1104                         return error("unable to find %s", sha1_to_hex(sha1));
1105                 return packed_object_info(&e, type, sizep);
1106         }
1107         if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1108                 status = error("unable to unpack %s header",
1109                                sha1_to_hex(sha1));
1110         if (parse_sha1_header(hdr, type, &size) < 0)
1111                 status = error("unable to parse %s header", sha1_to_hex(sha1));
1112         else {
1113                 status = 0;
1114                 if (sizep)
1115                         *sizep = size;
1116         }
1117         inflateEnd(&stream);
1118         munmap(map, mapsize);
1119         return status;
1120 }
1121
1122 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1123 {
1124         struct pack_entry e;
1125
1126         if (!find_pack_entry(sha1, &e)) {
1127                 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1128                 return NULL;
1129         }
1130         return unpack_entry(&e, type, size);
1131 }
1132
1133 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1134 {
1135         unsigned long mapsize;
1136         void *map, *buf;
1137         struct pack_entry e;
1138
1139         if (find_pack_entry(sha1, &e))
1140                 return read_packed_sha1(sha1, type, size);
1141         map = map_sha1_file_internal(sha1, &mapsize);
1142         if (map) {
1143                 buf = unpack_sha1_file(map, mapsize, type, size);
1144                 munmap(map, mapsize);
1145                 return buf;
1146         }
1147         return NULL;
1148 }
1149
1150 void *read_object_with_reference(const unsigned char *sha1,
1151                                  const char *required_type,
1152                                  unsigned long *size,
1153                                  unsigned char *actual_sha1_return)
1154 {
1155         char type[20];
1156         void *buffer;
1157         unsigned long isize;
1158         unsigned char actual_sha1[20];
1159
1160         memcpy(actual_sha1, sha1, 20);
1161         while (1) {
1162                 int ref_length = -1;
1163                 const char *ref_type = NULL;
1164
1165                 buffer = read_sha1_file(actual_sha1, type, &isize);
1166                 if (!buffer)
1167                         return NULL;
1168                 if (!strcmp(type, required_type)) {
1169                         *size = isize;
1170                         if (actual_sha1_return)
1171                                 memcpy(actual_sha1_return, actual_sha1, 20);
1172                         return buffer;
1173                 }
1174                 /* Handle references */
1175                 else if (!strcmp(type, "commit"))
1176                         ref_type = "tree ";
1177                 else if (!strcmp(type, "tag"))
1178                         ref_type = "object ";
1179                 else {
1180                         free(buffer);
1181                         return NULL;
1182                 }
1183                 ref_length = strlen(ref_type);
1184
1185                 if (memcmp(buffer, ref_type, ref_length) ||
1186                     get_sha1_hex(buffer + ref_length, actual_sha1)) {
1187                         free(buffer);
1188                         return NULL;
1189                 }
1190                 free(buffer);
1191                 /* Now we have the ID of the referred-to object in
1192                  * actual_sha1.  Check again. */
1193         }
1194 }
1195
1196 char *write_sha1_file_prepare(void *buf,
1197                               unsigned long len,
1198                               const char *type,
1199                               unsigned char *sha1,
1200                               unsigned char *hdr,
1201                               int *hdrlen)
1202 {
1203         SHA_CTX c;
1204
1205         /* Generate the header */
1206         *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1207
1208         /* Sha1.. */
1209         SHA1_Init(&c);
1210         SHA1_Update(&c, hdr, *hdrlen);
1211         SHA1_Update(&c, buf, len);
1212         SHA1_Final(sha1, &c);
1213
1214         return sha1_file_name(sha1);
1215 }
1216
1217 /*
1218  * Link the tempfile to the final place, possibly creating the
1219  * last directory level as you do so.
1220  *
1221  * Returns the errno on failure, 0 on success.
1222  */
1223 static int link_temp_to_file(const char *tmpfile, char *filename)
1224 {
1225         int ret;
1226
1227         if (!link(tmpfile, filename))
1228                 return 0;
1229
1230         /*
1231          * Try to mkdir the last path component if that failed
1232          * with an ENOENT.
1233          *
1234          * Re-try the "link()" regardless of whether the mkdir
1235          * succeeds, since a race might mean that somebody
1236          * else succeeded.
1237          */
1238         ret = errno;
1239         if (ret == ENOENT) {
1240                 char *dir = strrchr(filename, '/');
1241                 if (dir) {
1242                         *dir = 0;
1243                         mkdir(filename, 0777);
1244                         *dir = '/';
1245                         if (!link(tmpfile, filename))
1246                                 return 0;
1247                         ret = errno;
1248                 }
1249         }
1250         return ret;
1251 }
1252
1253 /*
1254  * Move the just written object into its final resting place
1255  */
1256 int move_temp_to_file(const char *tmpfile, char *filename)
1257 {
1258         int ret = link_temp_to_file(tmpfile, filename);
1259
1260         /*
1261          * Coda hack - coda doesn't like cross-directory links,
1262          * so we fall back to a rename, which will mean that it
1263          * won't be able to check collisions, but that's not a
1264          * big deal.
1265          *
1266          * The same holds for FAT formatted media.
1267          *
1268          * When this succeeds, we just return 0. We have nothing
1269          * left to unlink.
1270          */
1271         if (ret && ret != EEXIST) {
1272                 if (!rename(tmpfile, filename))
1273                         return 0;
1274                 ret = errno;
1275         }
1276         unlink(tmpfile);
1277         if (ret) {
1278                 if (ret != EEXIST) {
1279                         fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1280                         return -1;
1281                 }
1282                 /* FIXME!!! Collision check here ? */
1283         }
1284
1285         return 0;
1286 }
1287
1288 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1289 {
1290         int size;
1291         unsigned char *compressed;
1292         z_stream stream;
1293         unsigned char sha1[20];
1294         char *filename;
1295         static char tmpfile[PATH_MAX];
1296         unsigned char hdr[50];
1297         int fd, hdrlen;
1298
1299         /* Normally if we have it in the pack then we do not bother writing
1300          * it out into .git/objects/??/?{38} file.
1301          */
1302         filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1303         if (returnsha1)
1304                 memcpy(returnsha1, sha1, 20);
1305         if (has_sha1_file(sha1))
1306                 return 0;
1307         fd = open(filename, O_RDONLY);
1308         if (fd >= 0) {
1309                 /*
1310                  * FIXME!!! We might do collision checking here, but we'd
1311                  * need to uncompress the old file and check it. Later.
1312                  */
1313                 close(fd);
1314                 return 0;
1315         }
1316
1317         if (errno != ENOENT) {
1318                 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
1319                 return -1;
1320         }
1321
1322         snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1323
1324         fd = mkstemp(tmpfile);
1325         if (fd < 0) {
1326                 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1327                 return -1;
1328         }
1329
1330         /* Set it up */
1331         memset(&stream, 0, sizeof(stream));
1332         deflateInit(&stream, Z_BEST_COMPRESSION);
1333         size = deflateBound(&stream, len+hdrlen);
1334         compressed = xmalloc(size);
1335
1336         /* Compress it */
1337         stream.next_out = compressed;
1338         stream.avail_out = size;
1339
1340         /* First header.. */
1341         stream.next_in = hdr;
1342         stream.avail_in = hdrlen;
1343         while (deflate(&stream, 0) == Z_OK)
1344                 /* nothing */;
1345
1346         /* Then the data itself.. */
1347         stream.next_in = buf;
1348         stream.avail_in = len;
1349         while (deflate(&stream, Z_FINISH) == Z_OK)
1350                 /* nothing */;
1351         deflateEnd(&stream);
1352         size = stream.total_out;
1353
1354         if (write(fd, compressed, size) != size)
1355                 die("unable to write file");
1356         fchmod(fd, 0444);
1357         close(fd);
1358         free(compressed);
1359
1360         return move_temp_to_file(tmpfile, filename);
1361 }
1362
1363 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1364 {
1365         ssize_t size;
1366         unsigned long objsize;
1367         int posn = 0;
1368         void *map = map_sha1_file_internal(sha1, &objsize);
1369         void *buf = map;
1370         void *temp_obj = NULL;
1371         z_stream stream;
1372
1373         if (!buf) {
1374                 unsigned char *unpacked;
1375                 unsigned long len;
1376                 char type[20];
1377                 char hdr[50];
1378                 int hdrlen;
1379                 // need to unpack and recompress it by itself
1380                 unpacked = read_packed_sha1(sha1, type, &len);
1381
1382                 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1383
1384                 /* Set it up */
1385                 memset(&stream, 0, sizeof(stream));
1386                 deflateInit(&stream, Z_BEST_COMPRESSION);
1387                 size = deflateBound(&stream, len + hdrlen);
1388                 temp_obj = buf = xmalloc(size);
1389
1390                 /* Compress it */
1391                 stream.next_out = buf;
1392                 stream.avail_out = size;
1393
1394                 /* First header.. */
1395                 stream.next_in = (void *)hdr;
1396                 stream.avail_in = hdrlen;
1397                 while (deflate(&stream, 0) == Z_OK)
1398                         /* nothing */;
1399
1400                 /* Then the data itself.. */
1401                 stream.next_in = unpacked;
1402                 stream.avail_in = len;
1403                 while (deflate(&stream, Z_FINISH) == Z_OK)
1404                         /* nothing */;
1405                 deflateEnd(&stream);
1406                 free(unpacked);
1407
1408                 objsize = stream.total_out;
1409         }
1410
1411         do {
1412                 size = write(fd, buf + posn, objsize - posn);
1413                 if (size <= 0) {
1414                         if (!size) {
1415                                 fprintf(stderr, "write closed\n");
1416                         } else {
1417                                 perror("write ");
1418                         }
1419                         return -1;
1420                 }
1421                 posn += size;
1422         } while (posn < objsize);
1423
1424         if (map)
1425                 munmap(map, objsize);
1426         if (temp_obj)
1427                 free(temp_obj);
1428
1429         return 0;
1430 }
1431
1432 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1433                        size_t bufsize, size_t *bufposn)
1434 {
1435         char tmpfile[PATH_MAX];
1436         int local;
1437         z_stream stream;
1438         unsigned char real_sha1[20];
1439         unsigned char discard[4096];
1440         int ret;
1441         SHA_CTX c;
1442
1443         snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1444
1445         local = mkstemp(tmpfile);
1446         if (local < 0)
1447                 return error("Couldn't open %s for %s\n", tmpfile, sha1_to_hex(sha1));
1448
1449         memset(&stream, 0, sizeof(stream));
1450
1451         inflateInit(&stream);
1452
1453         SHA1_Init(&c);
1454
1455         do {
1456                 ssize_t size;
1457                 if (*bufposn) {
1458                         stream.avail_in = *bufposn;
1459                         stream.next_in = (unsigned char *) buffer;
1460                         do {
1461                                 stream.next_out = discard;
1462                                 stream.avail_out = sizeof(discard);
1463                                 ret = inflate(&stream, Z_SYNC_FLUSH);
1464                                 SHA1_Update(&c, discard, sizeof(discard) -
1465                                             stream.avail_out);
1466                         } while (stream.avail_in && ret == Z_OK);
1467                         write(local, buffer, *bufposn - stream.avail_in);
1468                         memmove(buffer, buffer + *bufposn - stream.avail_in,
1469                                 stream.avail_in);
1470                         *bufposn = stream.avail_in;
1471                         if (ret != Z_OK)
1472                                 break;
1473                 }
1474                 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1475                 if (size <= 0) {
1476                         close(local);
1477                         unlink(tmpfile);
1478                         if (!size)
1479                                 return error("Connection closed?");
1480                         perror("Reading from connection");
1481                         return -1;
1482                 }
1483                 *bufposn += size;
1484         } while (1);
1485         inflateEnd(&stream);
1486
1487         close(local);
1488         SHA1_Final(real_sha1, &c);
1489         if (ret != Z_STREAM_END) {
1490                 unlink(tmpfile);
1491                 return error("File %s corrupted", sha1_to_hex(sha1));
1492         }
1493         if (memcmp(sha1, real_sha1, 20)) {
1494                 unlink(tmpfile);
1495                 return error("File %s has bad hash\n", sha1_to_hex(sha1));
1496         }
1497
1498         return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1499 }
1500
1501 int has_pack_index(const unsigned char *sha1)
1502 {
1503         struct stat st;
1504         if (stat(sha1_pack_index_name(sha1), &st))
1505                 return 0;
1506         return 1;
1507 }
1508
1509 int has_pack_file(const unsigned char *sha1)
1510 {
1511         struct stat st;
1512         if (stat(sha1_pack_name(sha1), &st))
1513                 return 0;
1514         return 1;
1515 }
1516
1517 int has_sha1_pack(const unsigned char *sha1)
1518 {
1519         struct pack_entry e;
1520         return find_pack_entry(sha1, &e);
1521 }
1522
1523 int has_sha1_file(const unsigned char *sha1)
1524 {
1525         struct stat st;
1526         struct pack_entry e;
1527
1528         if (find_pack_entry(sha1, &e))
1529                 return 1;
1530         return find_sha1_file(sha1, &st) ? 1 : 0;
1531 }
1532
1533 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1534 {
1535         unsigned long size = 4096;
1536         char *buf = malloc(size);
1537         int iret, ret;
1538         unsigned long off = 0;
1539         unsigned char hdr[50];
1540         int hdrlen;
1541         do {
1542                 iret = read(fd, buf + off, size - off);
1543                 if (iret > 0) {
1544                         off += iret;
1545                         if (off == size) {
1546                                 size *= 2;
1547                                 buf = realloc(buf, size);
1548                         }
1549                 }
1550         } while (iret > 0);
1551         if (iret < 0) {
1552                 free(buf);
1553                 return -1;
1554         }
1555         if (!type)
1556                 type = "blob";
1557         if (write_object)
1558                 ret = write_sha1_file(buf, off, type, sha1);
1559         else {
1560                 write_sha1_file_prepare(buf, off, type, sha1, hdr, &hdrlen);
1561                 ret = 0;
1562         }
1563         free(buf);
1564         return ret;
1565 }
1566
1567 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1568 {
1569         unsigned long size = st->st_size;
1570         void *buf;
1571         int ret;
1572         unsigned char hdr[50];
1573         int hdrlen;
1574
1575         buf = "";
1576         if (size)
1577                 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1578         close(fd);
1579         if (buf == MAP_FAILED)
1580                 return -1;
1581
1582         if (!type)
1583                 type = "blob";
1584         if (write_object)
1585                 ret = write_sha1_file(buf, size, type, sha1);
1586         else {
1587                 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1588                 ret = 0;
1589         }
1590         if (size)
1591                 munmap(buf, size);
1592         return ret;
1593 }
1594
1595 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1596 {
1597         int fd;
1598         char *target;
1599
1600         switch (st->st_mode & S_IFMT) {
1601         case S_IFREG:
1602                 fd = open(path, O_RDONLY);
1603                 if (fd < 0)
1604                         return error("open(\"%s\"): %s", path,
1605                                      strerror(errno));
1606                 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1607                         return error("%s: failed to insert into database",
1608                                      path);
1609                 break;
1610         case S_IFLNK:
1611                 target = xmalloc(st->st_size+1);
1612                 if (readlink(path, target, st->st_size+1) != st->st_size) {
1613                         char *errstr = strerror(errno);
1614                         free(target);
1615                         return error("readlink(\"%s\"): %s", path,
1616                                      errstr);
1617                 }
1618                 if (!write_object) {
1619                         unsigned char hdr[50];
1620                         int hdrlen;
1621                         write_sha1_file_prepare(target, st->st_size, "blob",
1622                                                 sha1, hdr, &hdrlen);
1623                 } else if (write_sha1_file(target, st->st_size, "blob", sha1))
1624                         return error("%s: failed to insert into database",
1625                                      path);
1626                 free(target);
1627                 break;
1628         default:
1629                 return error("%s: unsupported file type", path);
1630         }
1631         return 0;
1632 }