git.oblomov.eu Git - git/blob - index-pack.c

   1 #include "cache.h"
   2 #include "delta.h"
   3 #include "pack.h"
   4 #include "csum-file.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "progress.h"
  10
  11 static const char index_pack_usage[] =
  12 "git-index-pack [-v] [-o <index-file>] [{ ---keep | --keep=<msg> }] { <pack-file> | --stdin [--fix-thin] [<pack-file>] }";
  13
  14 struct object_entry
  15 {
  16         struct pack_idx_entry idx;
  17         unsigned long size;
  18         unsigned int hdr_size;
  19         enum object_type type;
  20         enum object_type real_type;
  21 };
  22
  23 union delta_base {
  24         unsigned char sha1[20];
  25         off_t offset;
  26 };
  27
  28 /*
  29  * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
  30  * to memcmp() only the first 20 bytes.
  31  */
  32 #define UNION_BASE_SZ   20
  33
  34 struct delta_entry
  35 {
  36         union delta_base base;
  37         int obj_no;
  38 };
  39
  40 static struct object_entry *objects;
  41 static struct delta_entry *deltas;
  42 static int nr_objects;
  43 static int nr_deltas;
  44 static int nr_resolved_deltas;
  45
  46 static int from_stdin;
  47 static int verbose;
  48
  49 static struct progress *progress;
  50
  51 /* We always read in 4kB chunks. */
  52 static unsigned char input_buffer[4096];
  53 static unsigned int input_offset, input_len;
  54 static off_t consumed_bytes;
  55 static SHA_CTX input_ctx;
  56 static uint32_t input_crc32;
  57 static int input_fd, output_fd, pack_fd;
  58
  59 /* Discard current buffer used content. */
  60 static void flush(void)
  61 {
  62         if (input_offset) {
  63                 if (output_fd >= 0)
  64                         write_or_die(output_fd, input_buffer, input_offset);
  65                 SHA1_Update(&input_ctx, input_buffer, input_offset);
  66                 memmove(input_buffer, input_buffer + input_offset, input_len);
  67                 input_offset = 0;
  68         }
  69 }
  70
  71 /*
  72  * Make sure at least "min" bytes are available in the buffer, and
  73  * return the pointer to the buffer.
  74  */
  75 static void *fill(int min)
  76 {
  77         if (min <= input_len)
  78                 return input_buffer + input_offset;
  79         if (min > sizeof(input_buffer))
  80                 die("cannot fill %d bytes", min);
  81         flush();
  82         do {
  83                 ssize_t ret = xread(input_fd, input_buffer + input_len,
  84                                 sizeof(input_buffer) - input_len);
  85                 if (ret <= 0) {
  86                         if (!ret)
  87                                 die("early EOF");
  88                         die("read error on input: %s", strerror(errno));
  89                 }
  90                 input_len += ret;
  91         } while (input_len < min);
  92         return input_buffer;
  93 }
  94
  95 static void use(int bytes)
  96 {
  97         if (bytes > input_len)
  98                 die("used more bytes than were available");
  99         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 100         input_len -= bytes;
 101         input_offset += bytes;
 102
 103         /* make sure off_t is sufficiently large not to wrap */
 104         if (consumed_bytes > consumed_bytes + bytes)
 105                 die("pack too large for current definition of off_t");
 106         consumed_bytes += bytes;
 107 }
 108
 109 static char *open_pack_file(char *pack_name)
 110 {
 111         if (from_stdin) {
 112                 input_fd = 0;
 113                 if (!pack_name) {
 114                         static char tmpfile[PATH_MAX];
 115                         snprintf(tmpfile, sizeof(tmpfile),
 116                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 117                         output_fd = xmkstemp(tmpfile);
 118                         pack_name = xstrdup(tmpfile);
 119                 } else
 120                         output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 121                 if (output_fd < 0)
 122                         die("unable to create %s: %s\n", pack_name, strerror(errno));
 123                 pack_fd = output_fd;
 124         } else {
 125                 input_fd = open(pack_name, O_RDONLY);
 126                 if (input_fd < 0)
 127                         die("cannot open packfile '%s': %s",
 128                             pack_name, strerror(errno));
 129                 output_fd = -1;
 130                 pack_fd = input_fd;
 131         }
 132         SHA1_Init(&input_ctx);
 133         return pack_name;
 134 }
 135
 136 static void parse_pack_header(void)
 137 {
 138         struct pack_header *hdr = fill(sizeof(struct pack_header));
 139
 140         /* Header consistency check */
 141         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 142                 die("pack signature mismatch");
 143         if (!pack_version_ok(hdr->hdr_version))
 144                 die("pack version %d unsupported", ntohl(hdr->hdr_version));
 145
 146         nr_objects = ntohl(hdr->hdr_entries);
 147         use(sizeof(struct pack_header));
 148 }
 149
 150 static void bad_object(unsigned long offset, const char *format,
 151                        ...) NORETURN __attribute__((format (printf, 2, 3)));
 152
 153 static void bad_object(unsigned long offset, const char *format, ...)
 154 {
 155         va_list params;
 156         char buf[1024];
 157
 158         va_start(params, format);
 159         vsnprintf(buf, sizeof(buf), format, params);
 160         va_end(params);
 161         die("pack has bad object at offset %lu: %s", offset, buf);
 162 }
 163
 164 static void *unpack_entry_data(unsigned long offset, unsigned long size)
 165 {
 166         z_stream stream;
 167         void *buf = xmalloc(size);
 168
 169         memset(&stream, 0, sizeof(stream));
 170         stream.next_out = buf;
 171         stream.avail_out = size;
 172         stream.next_in = fill(1);
 173         stream.avail_in = input_len;
 174         inflateInit(&stream);
 175
 176         for (;;) {
 177                 int ret = inflate(&stream, 0);
 178                 use(input_len - stream.avail_in);
 179                 if (stream.total_out == size && ret == Z_STREAM_END)
 180                         break;
 181                 if (ret != Z_OK)
 182                         bad_object(offset, "inflate returned %d", ret);
 183                 stream.next_in = fill(1);
 184                 stream.avail_in = input_len;
 185         }
 186         inflateEnd(&stream);
 187         return buf;
 188 }
 189
 190 static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
 191 {
 192         unsigned char *p, c;
 193         unsigned long size;
 194         off_t base_offset;
 195         unsigned shift;
 196         void *data;
 197
 198         obj->idx.offset = consumed_bytes;
 199         input_crc32 = crc32(0, Z_NULL, 0);
 200
 201         p = fill(1);
 202         c = *p;
 203         use(1);
 204         obj->type = (c >> 4) & 7;
 205         size = (c & 15);
 206         shift = 4;
 207         while (c & 0x80) {
 208                 p = fill(1);
 209                 c = *p;
 210                 use(1);
 211                 size += (c & 0x7fUL) << shift;
 212                 shift += 7;
 213         }
 214         obj->size = size;
 215
 216         switch (obj->type) {
 217         case OBJ_REF_DELTA:
 218                 hashcpy(delta_base->sha1, fill(20));
 219                 use(20);
 220                 break;
 221         case OBJ_OFS_DELTA:
 222                 memset(delta_base, 0, sizeof(*delta_base));
 223                 p = fill(1);
 224                 c = *p;
 225                 use(1);
 226                 base_offset = c & 127;
 227                 while (c & 128) {
 228                         base_offset += 1;
 229                         if (!base_offset || MSB(base_offset, 7))
 230                                 bad_object(obj->idx.offset, "offset value overflow for delta base object");
 231                         p = fill(1);
 232                         c = *p;
 233                         use(1);
 234                         base_offset = (base_offset << 7) + (c & 127);
 235                 }
 236                 delta_base->offset = obj->idx.offset - base_offset;
 237                 if (delta_base->offset >= obj->idx.offset)
 238                         bad_object(obj->idx.offset, "delta base offset is out of bound");
 239                 break;
 240         case OBJ_COMMIT:
 241         case OBJ_TREE:
 242         case OBJ_BLOB:
 243         case OBJ_TAG:
 244                 break;
 245         default:
 246                 bad_object(obj->idx.offset, "unknown object type %d", obj->type);
 247         }
 248         obj->hdr_size = consumed_bytes - obj->idx.offset;
 249
 250         data = unpack_entry_data(obj->idx.offset, obj->size);
 251         obj->idx.crc32 = input_crc32;
 252         return data;
 253 }
 254
 255 static void *get_data_from_pack(struct object_entry *obj)
 256 {
 257         unsigned long from = obj[0].idx.offset + obj[0].hdr_size;
 258         unsigned long len = obj[1].idx.offset - from;
 259         unsigned long rdy = 0;
 260         unsigned char *src, *data;
 261         z_stream stream;
 262         int st;
 263
 264         src = xmalloc(len);
 265         data = src;
 266         do {
 267                 ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
 268                 if (n <= 0)
 269                         die("cannot pread pack file: %s", strerror(errno));
 270                 rdy += n;
 271         } while (rdy < len);
 272         data = xmalloc(obj->size);
 273         memset(&stream, 0, sizeof(stream));
 274         stream.next_out = data;
 275         stream.avail_out = obj->size;
 276         stream.next_in = src;
 277         stream.avail_in = len;
 278         inflateInit(&stream);
 279         while ((st = inflate(&stream, Z_FINISH)) == Z_OK);
 280         inflateEnd(&stream);
 281         if (st != Z_STREAM_END || stream.total_out != obj->size)
 282                 die("serious inflate inconsistency");
 283         free(src);
 284         return data;
 285 }
 286
 287 static int find_delta(const union delta_base *base)
 288 {
 289         int first = 0, last = nr_deltas;
 290
 291         while (first < last) {
 292                 int next = (first + last) / 2;
 293                 struct delta_entry *delta = &deltas[next];
 294                 int cmp;
 295
 296                 cmp = memcmp(base, &delta->base, UNION_BASE_SZ);
 297                 if (!cmp)
 298                         return next;
 299                 if (cmp < 0) {
 300                         last = next;
 301                         continue;
 302                 }
 303                 first = next+1;
 304         }
 305         return -first-1;
 306 }
 307
 308 static int find_delta_children(const union delta_base *base,
 309                                int *first_index, int *last_index)
 310 {
 311         int first = find_delta(base);
 312         int last = first;
 313         int end = nr_deltas - 1;
 314
 315         if (first < 0)
 316                 return -1;
 317         while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 318                 --first;
 319         while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 320                 ++last;
 321         *first_index = first;
 322         *last_index = last;
 323         return 0;
 324 }
 325
 326 static void sha1_object(const void *data, unsigned long size,
 327                         enum object_type type, unsigned char *sha1)
 328 {
 329         hash_sha1_file(data, size, typename(type), sha1);
 330         if (has_sha1_file(sha1)) {
 331                 void *has_data;
 332                 enum object_type has_type;
 333                 unsigned long has_size;
 334                 has_data = read_sha1_file(sha1, &has_type, &has_size);
 335                 if (!has_data)
 336                         die("cannot read existing object %s", sha1_to_hex(sha1));
 337                 if (size != has_size || type != has_type ||
 338                     memcmp(data, has_data, size) != 0)
 339                         die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1));
 340                 free(has_data);
 341         }
 342 }
 343
 344 static void resolve_delta(struct object_entry *delta_obj, void *base_data,
 345                           unsigned long base_size, enum object_type type)
 346 {
 347         void *delta_data;
 348         unsigned long delta_size;
 349         void *result;
 350         unsigned long result_size;
 351         union delta_base delta_base;
 352         int j, first, last;
 353
 354         delta_obj->real_type = type;
 355         delta_data = get_data_from_pack(delta_obj);
 356         delta_size = delta_obj->size;
 357         result = patch_delta(base_data, base_size, delta_data, delta_size,
 358                              &result_size);
 359         free(delta_data);
 360         if (!result)
 361                 bad_object(delta_obj->idx.offset, "failed to apply delta");
 362         sha1_object(result, result_size, type, delta_obj->idx.sha1);
 363         nr_resolved_deltas++;
 364
 365         hashcpy(delta_base.sha1, delta_obj->idx.sha1);
 366         if (!find_delta_children(&delta_base, &first, &last)) {
 367                 for (j = first; j <= last; j++) {
 368                         struct object_entry *child = objects + deltas[j].obj_no;
 369                         if (child->real_type == OBJ_REF_DELTA)
 370                                 resolve_delta(child, result, result_size, type);
 371                 }
 372         }
 373
 374         memset(&delta_base, 0, sizeof(delta_base));
 375         delta_base.offset = delta_obj->idx.offset;
 376         if (!find_delta_children(&delta_base, &first, &last)) {
 377                 for (j = first; j <= last; j++) {
 378                         struct object_entry *child = objects + deltas[j].obj_no;
 379                         if (child->real_type == OBJ_OFS_DELTA)
 380                                 resolve_delta(child, result, result_size, type);
 381                 }
 382         }
 383
 384         free(result);
 385 }
 386
 387 static int compare_delta_entry(const void *a, const void *b)
 388 {
 389         const struct delta_entry *delta_a = a;
 390         const struct delta_entry *delta_b = b;
 391         return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ);
 392 }
 393
 394 /* Parse all objects and return the pack content SHA1 hash */
 395 static void parse_pack_objects(unsigned char *sha1)
 396 {
 397         int i;
 398         struct delta_entry *delta = deltas;
 399         void *data;
 400         struct stat st;
 401
 402         /*
 403          * First pass:
 404          * - find locations of all objects;
 405          * - calculate SHA1 of all non-delta objects;
 406          * - remember base (SHA1 or offset) for all deltas.
 407          */
 408         if (verbose)
 409                 progress = start_progress("Indexing objects", nr_objects);
 410         for (i = 0; i < nr_objects; i++) {
 411                 struct object_entry *obj = &objects[i];
 412                 data = unpack_raw_entry(obj, &delta->base);
 413                 obj->real_type = obj->type;
 414                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
 415                         nr_deltas++;
 416                         delta->obj_no = i;
 417                         delta++;
 418                 } else
 419                         sha1_object(data, obj->size, obj->type, obj->idx.sha1);
 420                 free(data);
 421                 display_progress(progress, i+1);
 422         }
 423         objects[i].idx.offset = consumed_bytes;
 424         stop_progress(&progress);
 425
 426         /* Check pack integrity */
 427         flush();
 428         SHA1_Final(sha1, &input_ctx);
 429         if (hashcmp(fill(20), sha1))
 430                 die("pack is corrupted (SHA1 mismatch)");
 431         use(20);
 432
 433         /* If input_fd is a file, we should have reached its end now. */
 434         if (fstat(input_fd, &st))
 435                 die("cannot fstat packfile: %s", strerror(errno));
 436         if (S_ISREG(st.st_mode) &&
 437                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
 438                 die("pack has junk at the end");
 439
 440         if (!nr_deltas)
 441                 return;
 442
 443         /* Sort deltas by base SHA1/offset for fast searching */
 444         qsort(deltas, nr_deltas, sizeof(struct delta_entry),
 445               compare_delta_entry);
 446
 447         /*
 448          * Second pass:
 449          * - for all non-delta objects, look if it is used as a base for
 450          *   deltas;
 451          * - if used as a base, uncompress the object and apply all deltas,
 452          *   recursively checking if the resulting object is used as a base
 453          *   for some more deltas.
 454          */
 455         if (verbose)
 456                 progress = start_progress("Resolving deltas", nr_deltas);
 457         for (i = 0; i < nr_objects; i++) {
 458                 struct object_entry *obj = &objects[i];
 459                 union delta_base base;
 460                 int j, ref, ref_first, ref_last, ofs, ofs_first, ofs_last;
 461
 462                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
 463                         continue;
 464                 hashcpy(base.sha1, obj->idx.sha1);
 465                 ref = !find_delta_children(&base, &ref_first, &ref_last);
 466                 memset(&base, 0, sizeof(base));
 467                 base.offset = obj->idx.offset;
 468                 ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
 469                 if (!ref && !ofs)
 470                         continue;
 471                 data = get_data_from_pack(obj);
 472                 if (ref)
 473                         for (j = ref_first; j <= ref_last; j++) {
 474                                 struct object_entry *child = objects + deltas[j].obj_no;
 475                                 if (child->real_type == OBJ_REF_DELTA)
 476                                         resolve_delta(child, data,
 477                                                       obj->size, obj->type);
 478                         }
 479                 if (ofs)
 480                         for (j = ofs_first; j <= ofs_last; j++) {
 481                                 struct object_entry *child = objects + deltas[j].obj_no;
 482                                 if (child->real_type == OBJ_OFS_DELTA)
 483                                         resolve_delta(child, data,
 484                                                       obj->size, obj->type);
 485                         }
 486                 free(data);
 487                 display_progress(progress, nr_resolved_deltas);
 488         }
 489 }
 490
 491 static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_crc)
 492 {
 493         z_stream stream;
 494         unsigned long maxsize;
 495         void *out;
 496
 497         memset(&stream, 0, sizeof(stream));
 498         deflateInit(&stream, zlib_compression_level);
 499         maxsize = deflateBound(&stream, size);
 500         out = xmalloc(maxsize);
 501
 502         /* Compress it */
 503         stream.next_in = in;
 504         stream.avail_in = size;
 505         stream.next_out = out;
 506         stream.avail_out = maxsize;
 507         while (deflate(&stream, Z_FINISH) == Z_OK);
 508         deflateEnd(&stream);
 509
 510         size = stream.total_out;
 511         write_or_die(fd, out, size);
 512         *obj_crc = crc32(*obj_crc, out, size);
 513         free(out);
 514         return size;
 515 }
 516
 517 static void append_obj_to_pack(const unsigned char *sha1, void *buf,
 518                                unsigned long size, enum object_type type)
 519 {
 520         struct object_entry *obj = &objects[nr_objects++];
 521         unsigned char header[10];
 522         unsigned long s = size;
 523         int n = 0;
 524         unsigned char c = (type << 4) | (s & 15);
 525         s >>= 4;
 526         while (s) {
 527                 header[n++] = c | 0x80;
 528                 c = s & 0x7f;
 529                 s >>= 7;
 530         }
 531         header[n++] = c;
 532         write_or_die(output_fd, header, n);
 533         obj[0].idx.crc32 = crc32(0, Z_NULL, 0);
 534         obj[0].idx.crc32 = crc32(obj[0].idx.crc32, header, n);
 535         obj[1].idx.offset = obj[0].idx.offset + n;
 536         obj[1].idx.offset += write_compressed(output_fd, buf, size, &obj[0].idx.crc32);
 537         hashcpy(obj->idx.sha1, sha1);
 538 }
 539
 540 static int delta_pos_compare(const void *_a, const void *_b)
 541 {
 542         struct delta_entry *a = *(struct delta_entry **)_a;
 543         struct delta_entry *b = *(struct delta_entry **)_b;
 544         return a->obj_no - b->obj_no;
 545 }
 546
 547 static void fix_unresolved_deltas(int nr_unresolved)
 548 {
 549         struct delta_entry **sorted_by_pos;
 550         int i, n = 0;
 551
 552         /*
 553          * Since many unresolved deltas may well be themselves base objects
 554          * for more unresolved deltas, we really want to include the
 555          * smallest number of base objects that would cover as much delta
 556          * as possible by picking the
 557          * trunc deltas first, allowing for other deltas to resolve without
 558          * additional base objects.  Since most base objects are to be found
 559          * before deltas depending on them, a good heuristic is to start
 560          * resolving deltas in the same order as their position in the pack.
 561          */
 562         sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
 563         for (i = 0; i < nr_deltas; i++) {
 564                 if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
 565                         continue;
 566                 sorted_by_pos[n++] = &deltas[i];
 567         }
 568         qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
 569
 570         for (i = 0; i < n; i++) {
 571                 struct delta_entry *d = sorted_by_pos[i];
 572                 void *data;
 573                 unsigned long size;
 574                 enum object_type type;
 575                 int j, first, last;
 576
 577                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
 578                         continue;
 579                 data = read_sha1_file(d->base.sha1, &type, &size);
 580                 if (!data)
 581                         continue;
 582
 583                 find_delta_children(&d->base, &first, &last);
 584                 for (j = first; j <= last; j++) {
 585                         struct object_entry *child = objects + deltas[j].obj_no;
 586                         if (child->real_type == OBJ_REF_DELTA)
 587                                 resolve_delta(child, data, size, type);
 588                 }
 589
 590                 if (check_sha1_signature(d->base.sha1, data, size, typename(type)))
 591                         die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
 592                 append_obj_to_pack(d->base.sha1, data, size, type);
 593                 free(data);
 594                 display_progress(progress, nr_resolved_deltas);
 595         }
 596         free(sorted_by_pos);
 597 }
 598
 599 static void final(const char *final_pack_name, const char *curr_pack_name,
 600                   const char *final_index_name, const char *curr_index_name,
 601                   const char *keep_name, const char *keep_msg,
 602                   unsigned char *sha1)
 603 {
 604         const char *report = "pack";
 605         char name[PATH_MAX];
 606         int err;
 607
 608         if (!from_stdin) {
 609                 close(input_fd);
 610         } else {
 611                 err = close(output_fd);
 612                 if (err)
 613                         die("error while closing pack file: %s", strerror(errno));
 614                 chmod(curr_pack_name, 0444);
 615         }
 616
 617         if (keep_msg) {
 618                 int keep_fd, keep_msg_len = strlen(keep_msg);
 619                 if (!keep_name) {
 620                         snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
 621                                  get_object_directory(), sha1_to_hex(sha1));
 622                         keep_name = name;
 623                 }
 624                 keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
 625                 if (keep_fd < 0) {
 626                         if (errno != EEXIST)
 627                                 die("cannot write keep file");
 628                 } else {
 629                         if (keep_msg_len > 0) {
 630                                 write_or_die(keep_fd, keep_msg, keep_msg_len);
 631                                 write_or_die(keep_fd, "\n", 1);
 632                         }
 633                         if (close(keep_fd) != 0)
 634                                 die("cannot write keep file");
 635                         report = "keep";
 636                 }
 637         }
 638
 639         if (final_pack_name != curr_pack_name) {
 640                 if (!final_pack_name) {
 641                         snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
 642                                  get_object_directory(), sha1_to_hex(sha1));
 643                         final_pack_name = name;
 644                 }
 645                 if (move_temp_to_file(curr_pack_name, final_pack_name))
 646                         die("cannot store pack file");
 647         }
 648
 649         chmod(curr_index_name, 0444);
 650         if (final_index_name != curr_index_name) {
 651                 if (!final_index_name) {
 652                         snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
 653                                  get_object_directory(), sha1_to_hex(sha1));
 654                         final_index_name = name;
 655                 }
 656                 if (move_temp_to_file(curr_index_name, final_index_name))
 657                         die("cannot store index file");
 658         }
 659
 660         if (!from_stdin) {
 661                 printf("%s\n", sha1_to_hex(sha1));
 662         } else {
 663                 char buf[48];
 664                 int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
 665                                    report, sha1_to_hex(sha1));
 666                 write_or_die(1, buf, len);
 667
 668                 /*
 669                  * Let's just mimic git-unpack-objects here and write
 670                  * the last part of the input buffer to stdout.
 671                  */
 672                 while (input_len) {
 673                         err = xwrite(1, input_buffer + input_offset, input_len);
 674                         if (err <= 0)
 675                                 break;
 676                         input_len -= err;
 677                         input_offset += err;
 678                 }
 679         }
 680 }
 681
 682 int main(int argc, char **argv)
 683 {
 684         int i, fix_thin_pack = 0;
 685         char *curr_pack, *pack_name = NULL;
 686         char *curr_index, *index_name = NULL;
 687         const char *keep_name = NULL, *keep_msg = NULL;
 688         char *index_name_buf = NULL, *keep_name_buf = NULL;
 689         struct pack_idx_entry **idx_objects;
 690         unsigned char sha1[20];
 691
 692         for (i = 1; i < argc; i++) {
 693                 char *arg = argv[i];
 694
 695                 if (*arg == '-') {
 696                         if (!strcmp(arg, "--stdin")) {
 697                                 from_stdin = 1;
 698                         } else if (!strcmp(arg, "--fix-thin")) {
 699                                 fix_thin_pack = 1;
 700                         } else if (!strcmp(arg, "--keep")) {
 701                                 keep_msg = "";
 702                         } else if (!prefixcmp(arg, "--keep=")) {
 703                                 keep_msg = arg + 7;
 704                         } else if (!prefixcmp(arg, "--pack_header=")) {
 705                                 struct pack_header *hdr;
 706                                 char *c;
 707
 708                                 hdr = (struct pack_header *)input_buffer;
 709                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
 710                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
 711                                 if (*c != ',')
 712                                         die("bad %s", arg);
 713                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
 714                                 if (*c)
 715                                         die("bad %s", arg);
 716                                 input_len = sizeof(*hdr);
 717                         } else if (!strcmp(arg, "-v")) {
 718                                 verbose = 1;
 719                         } else if (!strcmp(arg, "-o")) {
 720                                 if (index_name || (i+1) >= argc)
 721                                         usage(index_pack_usage);
 722                                 index_name = argv[++i];
 723                         } else if (!prefixcmp(arg, "--index-version=")) {
 724                                 char *c;
 725                                 pack_idx_default_version = strtoul(arg + 16, &c, 10);
 726                                 if (pack_idx_default_version > 2)
 727                                         die("bad %s", arg);
 728                                 if (*c == ',')
 729                                         pack_idx_off32_limit = strtoul(c+1, &c, 0);
 730                                 if (*c || pack_idx_off32_limit & 0x80000000)
 731                                         die("bad %s", arg);
 732                         } else
 733                                 usage(index_pack_usage);
 734                         continue;
 735                 }
 736
 737                 if (pack_name)
 738                         usage(index_pack_usage);
 739                 pack_name = arg;
 740         }
 741
 742         if (!pack_name && !from_stdin)
 743                 usage(index_pack_usage);
 744         if (fix_thin_pack && !from_stdin)
 745                 die("--fix-thin cannot be used without --stdin");
 746         if (!index_name && pack_name) {
 747                 int len = strlen(pack_name);
 748                 if (!has_extension(pack_name, ".pack"))
 749                         die("packfile name '%s' does not end with '.pack'",
 750                             pack_name);
 751                 index_name_buf = xmalloc(len);
 752                 memcpy(index_name_buf, pack_name, len - 5);
 753                 strcpy(index_name_buf + len - 5, ".idx");
 754                 index_name = index_name_buf;
 755         }
 756         if (keep_msg && !keep_name && pack_name) {
 757                 int len = strlen(pack_name);
 758                 if (!has_extension(pack_name, ".pack"))
 759                         die("packfile name '%s' does not end with '.pack'",
 760                             pack_name);
 761                 keep_name_buf = xmalloc(len);
 762                 memcpy(keep_name_buf, pack_name, len - 5);
 763                 strcpy(keep_name_buf + len - 5, ".keep");
 764                 keep_name = keep_name_buf;
 765         }
 766
 767         curr_pack = open_pack_file(pack_name);
 768         parse_pack_header();
 769         objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
 770         deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
 771         parse_pack_objects(sha1);
 772         if (nr_deltas == nr_resolved_deltas) {
 773                 stop_progress(&progress);
 774                 /* Flush remaining pack final 20-byte SHA1. */
 775                 flush();
 776         } else {
 777                 if (fix_thin_pack) {
 778                         int nr_unresolved = nr_deltas - nr_resolved_deltas;
 779                         int nr_objects_initial = nr_objects;
 780                         if (nr_unresolved <= 0)
 781                                 die("confusion beyond insanity");
 782                         objects = xrealloc(objects,
 783                                            (nr_objects + nr_unresolved + 1)
 784                                            * sizeof(*objects));
 785                         fix_unresolved_deltas(nr_unresolved);
 786                         stop_progress(&progress);
 787                         if (verbose)
 788                                 fprintf(stderr, "%d objects were added to complete this thin pack.\n",
 789                                         nr_objects - nr_objects_initial);
 790                         fixup_pack_header_footer(output_fd, sha1,
 791                                 curr_pack, nr_objects);
 792                 }
 793                 if (nr_deltas != nr_resolved_deltas)
 794                         die("pack has %d unresolved deltas",
 795                             nr_deltas - nr_resolved_deltas);
 796         }
 797         free(deltas);
 798
 799         idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
 800         for (i = 0; i < nr_objects; i++)
 801                 idx_objects[i] = &objects[i].idx;
 802         curr_index = write_idx_file(index_name, idx_objects, nr_objects, sha1);
 803         free(idx_objects);
 804
 805         final(pack_name, curr_pack,
 806                 index_name, curr_index,
 807                 keep_name, keep_msg,
 808                 sha1);
 809         free(objects);
 810         free(index_name_buf);
 811         free(keep_name_buf);
 812         if (pack_name == NULL)
 813                 free(curr_pack);
 814         if (index_name == NULL)
 815                 free(curr_index);
 816
 817         return 0;
 818 }