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 #include "fsck.h"
  11
  12 static const char index_pack_usage[] =
  13 "git-index-pack [-v] [-o <index-file>] [{ ---keep | --keep=<msg> }] [--strict] { <pack-file> | --stdin [--fix-thin] [<pack-file>] }";
  14
  15 struct object_entry
  16 {
  17         struct pack_idx_entry idx;
  18         unsigned long size;
  19         unsigned int hdr_size;
  20         enum object_type type;
  21         enum object_type real_type;
  22 };
  23
  24 union delta_base {
  25         unsigned char sha1[20];
  26         off_t offset;
  27 };
  28
  29 /*
  30  * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
  31  * to memcmp() only the first 20 bytes.
  32  */
  33 #define UNION_BASE_SZ   20
  34
  35 #define FLAG_LINK (1u<<20)
  36 #define FLAG_CHECKED (1u<<21)
  37
  38 struct delta_entry
  39 {
  40         union delta_base base;
  41         int obj_no;
  42 };
  43
  44 static struct object_entry *objects;
  45 static struct delta_entry *deltas;
  46 static int nr_objects;
  47 static int nr_deltas;
  48 static int nr_resolved_deltas;
  49
  50 static int from_stdin;
  51 static int strict;
  52 static int verbose;
  53
  54 static struct progress *progress;
  55
  56 /* We always read in 4kB chunks. */
  57 static unsigned char input_buffer[4096];
  58 static unsigned int input_offset, input_len;
  59 static off_t consumed_bytes;
  60 static SHA_CTX input_ctx;
  61 static uint32_t input_crc32;
  62 static int input_fd, output_fd, pack_fd;
  63
  64 static int mark_link(struct object *obj, int type, void *data)
  65 {
  66         if (!obj)
  67                 return -1;
  68
  69         if (type != OBJ_ANY && obj->type != type)
  70                 die("object type mismatch at %s", sha1_to_hex(obj->sha1));
  71
  72         obj->flags |= FLAG_LINK;
  73         return 0;
  74 }
  75
  76 /* The content of each linked object must have been checked
  77    or it must be already present in the object database */
  78 static void check_object(struct object *obj)
  79 {
  80         if (!obj)
  81                 return;
  82
  83         if (!(obj->flags & FLAG_LINK))
  84                 return;
  85
  86         if (!(obj->flags & FLAG_CHECKED)) {
  87                 unsigned long size;
  88                 int type = sha1_object_info(obj->sha1, &size);
  89                 if (type != obj->type || type <= 0)
  90                         die("object of unexpected type");
  91                 obj->flags |= FLAG_CHECKED;
  92                 return;
  93         }
  94 }
  95
  96 static void check_objects(void)
  97 {
  98         unsigned i, max;
  99
 100         max = get_max_object_index();
 101         for (i = 0; i < max; i++)
 102                 check_object(get_indexed_object(i));
 103 }
 104
 105
 106 /* Discard current buffer used content. */
 107 static void flush(void)
 108 {
 109         if (input_offset) {
 110                 if (output_fd >= 0)
 111                         write_or_die(output_fd, input_buffer, input_offset);
 112                 SHA1_Update(&input_ctx, input_buffer, input_offset);
 113                 memmove(input_buffer, input_buffer + input_offset, input_len);
 114                 input_offset = 0;
 115         }
 116 }
 117
 118 /*
 119  * Make sure at least "min" bytes are available in the buffer, and
 120  * return the pointer to the buffer.
 121  */
 122 static void *fill(int min)
 123 {
 124         if (min <= input_len)
 125                 return input_buffer + input_offset;
 126         if (min > sizeof(input_buffer))
 127                 die("cannot fill %d bytes", min);
 128         flush();
 129         do {
 130                 ssize_t ret = xread(input_fd, input_buffer + input_len,
 131                                 sizeof(input_buffer) - input_len);
 132                 if (ret <= 0) {
 133                         if (!ret)
 134                                 die("early EOF");
 135                         die("read error on input: %s", strerror(errno));
 136                 }
 137                 input_len += ret;
 138                 if (from_stdin)
 139                         display_throughput(progress, consumed_bytes + input_len);
 140         } while (input_len < min);
 141         return input_buffer;
 142 }
 143
 144 static void use(int bytes)
 145 {
 146         if (bytes > input_len)
 147                 die("used more bytes than were available");
 148         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 149         input_len -= bytes;
 150         input_offset += bytes;
 151
 152         /* make sure off_t is sufficiently large not to wrap */
 153         if (consumed_bytes > consumed_bytes + bytes)
 154                 die("pack too large for current definition of off_t");
 155         consumed_bytes += bytes;
 156 }
 157
 158 static char *open_pack_file(char *pack_name)
 159 {
 160         if (from_stdin) {
 161                 input_fd = 0;
 162                 if (!pack_name) {
 163                         static char tmpfile[PATH_MAX];
 164                         snprintf(tmpfile, sizeof(tmpfile),
 165                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 166                         output_fd = xmkstemp(tmpfile);
 167                         pack_name = xstrdup(tmpfile);
 168                 } else
 169                         output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 170                 if (output_fd < 0)
 171                         die("unable to create %s: %s\n", pack_name, strerror(errno));
 172                 pack_fd = output_fd;
 173         } else {
 174                 input_fd = open(pack_name, O_RDONLY);
 175                 if (input_fd < 0)
 176                         die("cannot open packfile '%s': %s",
 177                             pack_name, strerror(errno));
 178                 output_fd = -1;
 179                 pack_fd = input_fd;
 180         }
 181         SHA1_Init(&input_ctx);
 182         return pack_name;
 183 }
 184
 185 static void parse_pack_header(void)
 186 {
 187         struct pack_header *hdr = fill(sizeof(struct pack_header));
 188
 189         /* Header consistency check */
 190         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 191                 die("pack signature mismatch");
 192         if (!pack_version_ok(hdr->hdr_version))
 193                 die("pack version %"PRIu32" unsupported",
 194                         ntohl(hdr->hdr_version));
 195
 196         nr_objects = ntohl(hdr->hdr_entries);
 197         use(sizeof(struct pack_header));
 198 }
 199
 200 static void bad_object(unsigned long offset, const char *format,
 201                        ...) NORETURN __attribute__((format (printf, 2, 3)));
 202
 203 static void bad_object(unsigned long offset, const char *format, ...)
 204 {
 205         va_list params;
 206         char buf[1024];
 207
 208         va_start(params, format);
 209         vsnprintf(buf, sizeof(buf), format, params);
 210         va_end(params);
 211         die("pack has bad object at offset %lu: %s", offset, buf);
 212 }
 213
 214 static void *unpack_entry_data(unsigned long offset, unsigned long size)
 215 {
 216         z_stream stream;
 217         void *buf = xmalloc(size);
 218
 219         memset(&stream, 0, sizeof(stream));
 220         stream.next_out = buf;
 221         stream.avail_out = size;
 222         stream.next_in = fill(1);
 223         stream.avail_in = input_len;
 224         inflateInit(&stream);
 225
 226         for (;;) {
 227                 int ret = inflate(&stream, 0);
 228                 use(input_len - stream.avail_in);
 229                 if (stream.total_out == size && ret == Z_STREAM_END)
 230                         break;
 231                 if (ret != Z_OK)
 232                         bad_object(offset, "inflate returned %d", ret);
 233                 stream.next_in = fill(1);
 234                 stream.avail_in = input_len;
 235         }
 236         inflateEnd(&stream);
 237         return buf;
 238 }
 239
 240 static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
 241 {
 242         unsigned char *p, c;
 243         unsigned long size;
 244         off_t base_offset;
 245         unsigned shift;
 246         void *data;
 247
 248         obj->idx.offset = consumed_bytes;
 249         input_crc32 = crc32(0, Z_NULL, 0);
 250
 251         p = fill(1);
 252         c = *p;
 253         use(1);
 254         obj->type = (c >> 4) & 7;
 255         size = (c & 15);
 256         shift = 4;
 257         while (c & 0x80) {
 258                 p = fill(1);
 259                 c = *p;
 260                 use(1);
 261                 size += (c & 0x7fUL) << shift;
 262                 shift += 7;
 263         }
 264         obj->size = size;
 265
 266         switch (obj->type) {
 267         case OBJ_REF_DELTA:
 268                 hashcpy(delta_base->sha1, fill(20));
 269                 use(20);
 270                 break;
 271         case OBJ_OFS_DELTA:
 272                 memset(delta_base, 0, sizeof(*delta_base));
 273                 p = fill(1);
 274                 c = *p;
 275                 use(1);
 276                 base_offset = c & 127;
 277                 while (c & 128) {
 278                         base_offset += 1;
 279                         if (!base_offset || MSB(base_offset, 7))
 280                                 bad_object(obj->idx.offset, "offset value overflow for delta base object");
 281                         p = fill(1);
 282                         c = *p;
 283                         use(1);
 284                         base_offset = (base_offset << 7) + (c & 127);
 285                 }
 286                 delta_base->offset = obj->idx.offset - base_offset;
 287                 if (delta_base->offset >= obj->idx.offset)
 288                         bad_object(obj->idx.offset, "delta base offset is out of bound");
 289                 break;
 290         case OBJ_COMMIT:
 291         case OBJ_TREE:
 292         case OBJ_BLOB:
 293         case OBJ_TAG:
 294                 break;
 295         default:
 296                 bad_object(obj->idx.offset, "unknown object type %d", obj->type);
 297         }
 298         obj->hdr_size = consumed_bytes - obj->idx.offset;
 299
 300         data = unpack_entry_data(obj->idx.offset, obj->size);
 301         obj->idx.crc32 = input_crc32;
 302         return data;
 303 }
 304
 305 static void *get_data_from_pack(struct object_entry *obj)
 306 {
 307         off_t from = obj[0].idx.offset + obj[0].hdr_size;
 308         unsigned long len = obj[1].idx.offset - from;
 309         unsigned long rdy = 0;
 310         unsigned char *src, *data;
 311         z_stream stream;
 312         int st;
 313
 314         src = xmalloc(len);
 315         data = src;
 316         do {
 317                 ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
 318                 if (n <= 0)
 319                         die("cannot pread pack file: %s", strerror(errno));
 320                 rdy += n;
 321         } while (rdy < len);
 322         data = xmalloc(obj->size);
 323         memset(&stream, 0, sizeof(stream));
 324         stream.next_out = data;
 325         stream.avail_out = obj->size;
 326         stream.next_in = src;
 327         stream.avail_in = len;
 328         inflateInit(&stream);
 329         while ((st = inflate(&stream, Z_FINISH)) == Z_OK);
 330         inflateEnd(&stream);
 331         if (st != Z_STREAM_END || stream.total_out != obj->size)
 332                 die("serious inflate inconsistency");
 333         free(src);
 334         return data;
 335 }
 336
 337 static int find_delta(const union delta_base *base)
 338 {
 339         int first = 0, last = nr_deltas;
 340
 341         while (first < last) {
 342                 int next = (first + last) / 2;
 343                 struct delta_entry *delta = &deltas[next];
 344                 int cmp;
 345
 346                 cmp = memcmp(base, &delta->base, UNION_BASE_SZ);
 347                 if (!cmp)
 348                         return next;
 349                 if (cmp < 0) {
 350                         last = next;
 351                         continue;
 352                 }
 353                 first = next+1;
 354         }
 355         return -first-1;
 356 }
 357
 358 static int find_delta_children(const union delta_base *base,
 359                                int *first_index, int *last_index)
 360 {
 361         int first = find_delta(base);
 362         int last = first;
 363         int end = nr_deltas - 1;
 364
 365         if (first < 0)
 366                 return -1;
 367         while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 368                 --first;
 369         while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 370                 ++last;
 371         *first_index = first;
 372         *last_index = last;
 373         return 0;
 374 }
 375
 376 static void sha1_object(const void *data, unsigned long size,
 377                         enum object_type type, unsigned char *sha1)
 378 {
 379         hash_sha1_file(data, size, typename(type), sha1);
 380         if (has_sha1_file(sha1)) {
 381                 void *has_data;
 382                 enum object_type has_type;
 383                 unsigned long has_size;
 384                 has_data = read_sha1_file(sha1, &has_type, &has_size);
 385                 if (!has_data)
 386                         die("cannot read existing object %s", sha1_to_hex(sha1));
 387                 if (size != has_size || type != has_type ||
 388                     memcmp(data, has_data, size) != 0)
 389                         die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1));
 390                 free(has_data);
 391         }
 392         if (strict) {
 393                 if (type == OBJ_BLOB) {
 394                         struct blob *blob = lookup_blob(sha1);
 395                         if (blob)
 396                                 blob->object.flags |= FLAG_CHECKED;
 397                         else
 398                                 die("invalid blob object %s", sha1_to_hex(sha1));
 399                 } else {
 400                         struct object *obj;
 401                         int eaten;
 402                         void *buf = (void *) data;
 403
 404                         /*
 405                          * we do not need to free the memory here, as the
 406                          * buf is deleted by the caller.
 407                          */
 408                         obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 409                         if (!obj)
 410                                 die("invalid %s", typename(type));
 411                         if (fsck_object(obj, 1, fsck_error_function))
 412                                 die("Error in object");
 413                         if (fsck_walk(obj, mark_link, 0))
 414                                 die("Not all child objects of %s are reachable", sha1_to_hex(obj->sha1));
 415
 416                         if (obj->type == OBJ_TREE) {
 417                                 struct tree *item = (struct tree *) obj;
 418                                 item->buffer = NULL;
 419                         }
 420                         if (obj->type == OBJ_COMMIT) {
 421                                 struct commit *commit = (struct commit *) obj;
 422                                 commit->buffer = NULL;
 423                         }
 424                         obj->flags |= FLAG_CHECKED;
 425                 }
 426         }
 427 }
 428
 429 static void resolve_delta(struct object_entry *delta_obj, void *base_data,
 430                           unsigned long base_size, enum object_type type)
 431 {
 432         void *delta_data;
 433         unsigned long delta_size;
 434         void *result;
 435         unsigned long result_size;
 436         union delta_base delta_base;
 437         int j, first, last;
 438
 439         delta_obj->real_type = type;
 440         delta_data = get_data_from_pack(delta_obj);
 441         delta_size = delta_obj->size;
 442         result = patch_delta(base_data, base_size, delta_data, delta_size,
 443                              &result_size);
 444         free(delta_data);
 445         if (!result)
 446                 bad_object(delta_obj->idx.offset, "failed to apply delta");
 447         sha1_object(result, result_size, type, delta_obj->idx.sha1);
 448         nr_resolved_deltas++;
 449
 450         hashcpy(delta_base.sha1, delta_obj->idx.sha1);
 451         if (!find_delta_children(&delta_base, &first, &last)) {
 452                 for (j = first; j <= last; j++) {
 453                         struct object_entry *child = objects + deltas[j].obj_no;
 454                         if (child->real_type == OBJ_REF_DELTA)
 455                                 resolve_delta(child, result, result_size, type);
 456                 }
 457         }
 458
 459         memset(&delta_base, 0, sizeof(delta_base));
 460         delta_base.offset = delta_obj->idx.offset;
 461         if (!find_delta_children(&delta_base, &first, &last)) {
 462                 for (j = first; j <= last; j++) {
 463                         struct object_entry *child = objects + deltas[j].obj_no;
 464                         if (child->real_type == OBJ_OFS_DELTA)
 465                                 resolve_delta(child, result, result_size, type);
 466                 }
 467         }
 468
 469         free(result);
 470 }
 471
 472 static int compare_delta_entry(const void *a, const void *b)
 473 {
 474         const struct delta_entry *delta_a = a;
 475         const struct delta_entry *delta_b = b;
 476         return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ);
 477 }
 478
 479 /* Parse all objects and return the pack content SHA1 hash */
 480 static void parse_pack_objects(unsigned char *sha1)
 481 {
 482         int i;
 483         struct delta_entry *delta = deltas;
 484         void *data;
 485         struct stat st;
 486
 487         /*
 488          * First pass:
 489          * - find locations of all objects;
 490          * - calculate SHA1 of all non-delta objects;
 491          * - remember base (SHA1 or offset) for all deltas.
 492          */
 493         if (verbose)
 494                 progress = start_progress(
 495                                 from_stdin ? "Receiving objects" : "Indexing objects",
 496                                 nr_objects);
 497         for (i = 0; i < nr_objects; i++) {
 498                 struct object_entry *obj = &objects[i];
 499                 data = unpack_raw_entry(obj, &delta->base);
 500                 obj->real_type = obj->type;
 501                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
 502                         nr_deltas++;
 503                         delta->obj_no = i;
 504                         delta++;
 505                 } else
 506                         sha1_object(data, obj->size, obj->type, obj->idx.sha1);
 507                 free(data);
 508                 display_progress(progress, i+1);
 509         }
 510         objects[i].idx.offset = consumed_bytes;
 511         stop_progress(&progress);
 512
 513         /* Check pack integrity */
 514         flush();
 515         SHA1_Final(sha1, &input_ctx);
 516         if (hashcmp(fill(20), sha1))
 517                 die("pack is corrupted (SHA1 mismatch)");
 518         use(20);
 519
 520         /* If input_fd is a file, we should have reached its end now. */
 521         if (fstat(input_fd, &st))
 522                 die("cannot fstat packfile: %s", strerror(errno));
 523         if (S_ISREG(st.st_mode) &&
 524                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
 525                 die("pack has junk at the end");
 526
 527         if (!nr_deltas)
 528                 return;
 529
 530         /* Sort deltas by base SHA1/offset for fast searching */
 531         qsort(deltas, nr_deltas, sizeof(struct delta_entry),
 532               compare_delta_entry);
 533
 534         /*
 535          * Second pass:
 536          * - for all non-delta objects, look if it is used as a base for
 537          *   deltas;
 538          * - if used as a base, uncompress the object and apply all deltas,
 539          *   recursively checking if the resulting object is used as a base
 540          *   for some more deltas.
 541          */
 542         if (verbose)
 543                 progress = start_progress("Resolving deltas", nr_deltas);
 544         for (i = 0; i < nr_objects; i++) {
 545                 struct object_entry *obj = &objects[i];
 546                 union delta_base base;
 547                 int j, ref, ref_first, ref_last, ofs, ofs_first, ofs_last;
 548
 549                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
 550                         continue;
 551                 hashcpy(base.sha1, obj->idx.sha1);
 552                 ref = !find_delta_children(&base, &ref_first, &ref_last);
 553                 memset(&base, 0, sizeof(base));
 554                 base.offset = obj->idx.offset;
 555                 ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
 556                 if (!ref && !ofs)
 557                         continue;
 558                 data = get_data_from_pack(obj);
 559                 if (ref)
 560                         for (j = ref_first; j <= ref_last; j++) {
 561                                 struct object_entry *child = objects + deltas[j].obj_no;
 562                                 if (child->real_type == OBJ_REF_DELTA)
 563                                         resolve_delta(child, data,
 564                                                       obj->size, obj->type);
 565                         }
 566                 if (ofs)
 567                         for (j = ofs_first; j <= ofs_last; j++) {
 568                                 struct object_entry *child = objects + deltas[j].obj_no;
 569                                 if (child->real_type == OBJ_OFS_DELTA)
 570                                         resolve_delta(child, data,
 571                                                       obj->size, obj->type);
 572                         }
 573                 free(data);
 574                 display_progress(progress, nr_resolved_deltas);
 575         }
 576 }
 577
 578 static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_crc)
 579 {
 580         z_stream stream;
 581         unsigned long maxsize;
 582         void *out;
 583
 584         memset(&stream, 0, sizeof(stream));
 585         deflateInit(&stream, zlib_compression_level);
 586         maxsize = deflateBound(&stream, size);
 587         out = xmalloc(maxsize);
 588
 589         /* Compress it */
 590         stream.next_in = in;
 591         stream.avail_in = size;
 592         stream.next_out = out;
 593         stream.avail_out = maxsize;
 594         while (deflate(&stream, Z_FINISH) == Z_OK);
 595         deflateEnd(&stream);
 596
 597         size = stream.total_out;
 598         write_or_die(fd, out, size);
 599         *obj_crc = crc32(*obj_crc, out, size);
 600         free(out);
 601         return size;
 602 }
 603
 604 static void append_obj_to_pack(const unsigned char *sha1, void *buf,
 605                                unsigned long size, enum object_type type)
 606 {
 607         struct object_entry *obj = &objects[nr_objects++];
 608         unsigned char header[10];
 609         unsigned long s = size;
 610         int n = 0;
 611         unsigned char c = (type << 4) | (s & 15);
 612         s >>= 4;
 613         while (s) {
 614                 header[n++] = c | 0x80;
 615                 c = s & 0x7f;
 616                 s >>= 7;
 617         }
 618         header[n++] = c;
 619         write_or_die(output_fd, header, n);
 620         obj[0].idx.crc32 = crc32(0, Z_NULL, 0);
 621         obj[0].idx.crc32 = crc32(obj[0].idx.crc32, header, n);
 622         obj[1].idx.offset = obj[0].idx.offset + n;
 623         obj[1].idx.offset += write_compressed(output_fd, buf, size, &obj[0].idx.crc32);
 624         hashcpy(obj->idx.sha1, sha1);
 625 }
 626
 627 static int delta_pos_compare(const void *_a, const void *_b)
 628 {
 629         struct delta_entry *a = *(struct delta_entry **)_a;
 630         struct delta_entry *b = *(struct delta_entry **)_b;
 631         return a->obj_no - b->obj_no;
 632 }
 633
 634 static void fix_unresolved_deltas(int nr_unresolved)
 635 {
 636         struct delta_entry **sorted_by_pos;
 637         int i, n = 0;
 638
 639         /*
 640          * Since many unresolved deltas may well be themselves base objects
 641          * for more unresolved deltas, we really want to include the
 642          * smallest number of base objects that would cover as much delta
 643          * as possible by picking the
 644          * trunc deltas first, allowing for other deltas to resolve without
 645          * additional base objects.  Since most base objects are to be found
 646          * before deltas depending on them, a good heuristic is to start
 647          * resolving deltas in the same order as their position in the pack.
 648          */
 649         sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
 650         for (i = 0; i < nr_deltas; i++) {
 651                 if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
 652                         continue;
 653                 sorted_by_pos[n++] = &deltas[i];
 654         }
 655         qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
 656
 657         for (i = 0; i < n; i++) {
 658                 struct delta_entry *d = sorted_by_pos[i];
 659                 void *data;
 660                 unsigned long size;
 661                 enum object_type type;
 662                 int j, first, last;
 663
 664                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
 665                         continue;
 666                 data = read_sha1_file(d->base.sha1, &type, &size);
 667                 if (!data)
 668                         continue;
 669
 670                 find_delta_children(&d->base, &first, &last);
 671                 for (j = first; j <= last; j++) {
 672                         struct object_entry *child = objects + deltas[j].obj_no;
 673                         if (child->real_type == OBJ_REF_DELTA)
 674                                 resolve_delta(child, data, size, type);
 675                 }
 676
 677                 if (check_sha1_signature(d->base.sha1, data, size, typename(type)))
 678                         die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
 679                 append_obj_to_pack(d->base.sha1, data, size, type);
 680                 free(data);
 681                 display_progress(progress, nr_resolved_deltas);
 682         }
 683         free(sorted_by_pos);
 684 }
 685
 686 static void final(const char *final_pack_name, const char *curr_pack_name,
 687                   const char *final_index_name, const char *curr_index_name,
 688                   const char *keep_name, const char *keep_msg,
 689                   unsigned char *sha1)
 690 {
 691         const char *report = "pack";
 692         char name[PATH_MAX];
 693         int err;
 694
 695         if (!from_stdin) {
 696                 close(input_fd);
 697         } else {
 698                 fsync_or_die(output_fd, curr_pack_name);
 699                 err = close(output_fd);
 700                 if (err)
 701                         die("error while closing pack file: %s", strerror(errno));
 702                 chmod(curr_pack_name, 0444);
 703         }
 704
 705         if (keep_msg) {
 706                 int keep_fd, keep_msg_len = strlen(keep_msg);
 707                 if (!keep_name) {
 708                         snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
 709                                  get_object_directory(), sha1_to_hex(sha1));
 710                         keep_name = name;
 711                 }
 712                 keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
 713                 if (keep_fd < 0) {
 714                         if (errno != EEXIST)
 715                                 die("cannot write keep file");
 716                 } else {
 717                         if (keep_msg_len > 0) {
 718                                 write_or_die(keep_fd, keep_msg, keep_msg_len);
 719                                 write_or_die(keep_fd, "\n", 1);
 720                         }
 721                         if (close(keep_fd) != 0)
 722                                 die("cannot write keep file");
 723                         report = "keep";
 724                 }
 725         }
 726
 727         if (final_pack_name != curr_pack_name) {
 728                 if (!final_pack_name) {
 729                         snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
 730                                  get_object_directory(), sha1_to_hex(sha1));
 731                         final_pack_name = name;
 732                 }
 733                 if (move_temp_to_file(curr_pack_name, final_pack_name))
 734                         die("cannot store pack file");
 735         }
 736
 737         chmod(curr_index_name, 0444);
 738         if (final_index_name != curr_index_name) {
 739                 if (!final_index_name) {
 740                         snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
 741                                  get_object_directory(), sha1_to_hex(sha1));
 742                         final_index_name = name;
 743                 }
 744                 if (move_temp_to_file(curr_index_name, final_index_name))
 745                         die("cannot store index file");
 746         }
 747
 748         if (!from_stdin) {
 749                 printf("%s\n", sha1_to_hex(sha1));
 750         } else {
 751                 char buf[48];
 752                 int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
 753                                    report, sha1_to_hex(sha1));
 754                 write_or_die(1, buf, len);
 755
 756                 /*
 757                  * Let's just mimic git-unpack-objects here and write
 758                  * the last part of the input buffer to stdout.
 759                  */
 760                 while (input_len) {
 761                         err = xwrite(1, input_buffer + input_offset, input_len);
 762                         if (err <= 0)
 763                                 break;
 764                         input_len -= err;
 765                         input_offset += err;
 766                 }
 767         }
 768 }
 769
 770 static int git_index_pack_config(const char *k, const char *v, void *cb)
 771 {
 772         if (!strcmp(k, "pack.indexversion")) {
 773                 pack_idx_default_version = git_config_int(k, v);
 774                 if (pack_idx_default_version > 2)
 775                         die("bad pack.indexversion=%"PRIu32,
 776                                 pack_idx_default_version);
 777                 return 0;
 778         }
 779         return git_default_config(k, v, cb);
 780 }
 781
 782 int main(int argc, char **argv)
 783 {
 784         int i, fix_thin_pack = 0;
 785         char *curr_pack, *pack_name = NULL;
 786         char *curr_index, *index_name = NULL;
 787         const char *keep_name = NULL, *keep_msg = NULL;
 788         char *index_name_buf = NULL, *keep_name_buf = NULL;
 789         struct pack_idx_entry **idx_objects;
 790         unsigned char sha1[20];
 791
 792         git_config(git_index_pack_config, NULL);
 793
 794         for (i = 1; i < argc; i++) {
 795                 char *arg = argv[i];
 796
 797                 if (*arg == '-') {
 798                         if (!strcmp(arg, "--stdin")) {
 799                                 from_stdin = 1;
 800                         } else if (!strcmp(arg, "--fix-thin")) {
 801                                 fix_thin_pack = 1;
 802                         } else if (!strcmp(arg, "--strict")) {
 803                                 strict = 1;
 804                         } else if (!strcmp(arg, "--keep")) {
 805                                 keep_msg = "";
 806                         } else if (!prefixcmp(arg, "--keep=")) {
 807                                 keep_msg = arg + 7;
 808                         } else if (!prefixcmp(arg, "--pack_header=")) {
 809                                 struct pack_header *hdr;
 810                                 char *c;
 811
 812                                 hdr = (struct pack_header *)input_buffer;
 813                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
 814                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
 815                                 if (*c != ',')
 816                                         die("bad %s", arg);
 817                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
 818                                 if (*c)
 819                                         die("bad %s", arg);
 820                                 input_len = sizeof(*hdr);
 821                         } else if (!strcmp(arg, "-v")) {
 822                                 verbose = 1;
 823                         } else if (!strcmp(arg, "-o")) {
 824                                 if (index_name || (i+1) >= argc)
 825                                         usage(index_pack_usage);
 826                                 index_name = argv[++i];
 827                         } else if (!prefixcmp(arg, "--index-version=")) {
 828                                 char *c;
 829                                 pack_idx_default_version = strtoul(arg + 16, &c, 10);
 830                                 if (pack_idx_default_version > 2)
 831                                         die("bad %s", arg);
 832                                 if (*c == ',')
 833                                         pack_idx_off32_limit = strtoul(c+1, &c, 0);
 834                                 if (*c || pack_idx_off32_limit & 0x80000000)
 835                                         die("bad %s", arg);
 836                         } else
 837                                 usage(index_pack_usage);
 838                         continue;
 839                 }
 840
 841                 if (pack_name)
 842                         usage(index_pack_usage);
 843                 pack_name = arg;
 844         }
 845
 846         if (!pack_name && !from_stdin)
 847                 usage(index_pack_usage);
 848         if (fix_thin_pack && !from_stdin)
 849                 die("--fix-thin cannot be used without --stdin");
 850         if (!index_name && pack_name) {
 851                 int len = strlen(pack_name);
 852                 if (!has_extension(pack_name, ".pack"))
 853                         die("packfile name '%s' does not end with '.pack'",
 854                             pack_name);
 855                 index_name_buf = xmalloc(len);
 856                 memcpy(index_name_buf, pack_name, len - 5);
 857                 strcpy(index_name_buf + len - 5, ".idx");
 858                 index_name = index_name_buf;
 859         }
 860         if (keep_msg && !keep_name && pack_name) {
 861                 int len = strlen(pack_name);
 862                 if (!has_extension(pack_name, ".pack"))
 863                         die("packfile name '%s' does not end with '.pack'",
 864                             pack_name);
 865                 keep_name_buf = xmalloc(len);
 866                 memcpy(keep_name_buf, pack_name, len - 5);
 867                 strcpy(keep_name_buf + len - 5, ".keep");
 868                 keep_name = keep_name_buf;
 869         }
 870
 871         curr_pack = open_pack_file(pack_name);
 872         parse_pack_header();
 873         objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
 874         deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
 875         parse_pack_objects(sha1);
 876         if (nr_deltas == nr_resolved_deltas) {
 877                 stop_progress(&progress);
 878                 /* Flush remaining pack final 20-byte SHA1. */
 879                 flush();
 880         } else {
 881                 if (fix_thin_pack) {
 882                         char msg[48];
 883                         int nr_unresolved = nr_deltas - nr_resolved_deltas;
 884                         int nr_objects_initial = nr_objects;
 885                         if (nr_unresolved <= 0)
 886                                 die("confusion beyond insanity");
 887                         objects = xrealloc(objects,
 888                                            (nr_objects + nr_unresolved + 1)
 889                                            * sizeof(*objects));
 890                         fix_unresolved_deltas(nr_unresolved);
 891                         sprintf(msg, "completed with %d local objects",
 892                                 nr_objects - nr_objects_initial);
 893                         stop_progress_msg(&progress, msg);
 894                         fixup_pack_header_footer(output_fd, sha1,
 895                                                  curr_pack, nr_objects);
 896                 }
 897                 if (nr_deltas != nr_resolved_deltas)
 898                         die("pack has %d unresolved deltas",
 899                             nr_deltas - nr_resolved_deltas);
 900         }
 901         free(deltas);
 902         if (strict)
 903                 check_objects();
 904
 905         idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
 906         for (i = 0; i < nr_objects; i++)
 907                 idx_objects[i] = &objects[i].idx;
 908         curr_index = write_idx_file(index_name, idx_objects, nr_objects, sha1);
 909         free(idx_objects);
 910
 911         final(pack_name, curr_pack,
 912                 index_name, curr_index,
 913                 keep_name, keep_msg,
 914                 sha1);
 915         free(objects);
 916         free(index_name_buf);
 917         free(keep_name_buf);
 918         if (pack_name == NULL)
 919                 free(curr_pack);
 920         if (index_name == NULL)
 921                 free(curr_index);
 922
 923         return 0;
 924 }