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 struct base_data {
  30         struct base_data *base;
  31         struct base_data *child;
  32         void *data;
  33         unsigned long size;
  34 };
  35
  36 /*
  37  * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
  38  * to memcmp() only the first 20 bytes.
  39  */
  40 #define UNION_BASE_SZ   20
  41
  42 #define FLAG_LINK (1u<<20)
  43 #define FLAG_CHECKED (1u<<21)
  44
  45 struct delta_entry
  46 {
  47         union delta_base base;
  48         int obj_no;
  49 };
  50
  51 static struct object_entry *objects;
  52 static struct delta_entry *deltas;
  53 static struct base_data *base_cache;
  54 static int nr_objects;
  55 static int nr_deltas;
  56 static int nr_resolved_deltas;
  57
  58 static int from_stdin;
  59 static int strict;
  60 static int verbose;
  61
  62 static struct progress *progress;
  63
  64 /* We always read in 4kB chunks. */
  65 static unsigned char input_buffer[4096];
  66 static unsigned int input_offset, input_len;
  67 static off_t consumed_bytes;
  68 static SHA_CTX input_ctx;
  69 static uint32_t input_crc32;
  70 static int input_fd, output_fd, pack_fd;
  71
  72 static int mark_link(struct object *obj, int type, void *data)
  73 {
  74         if (!obj)
  75                 return -1;
  76
  77         if (type != OBJ_ANY && obj->type != type)
  78                 die("object type mismatch at %s", sha1_to_hex(obj->sha1));
  79
  80         obj->flags |= FLAG_LINK;
  81         return 0;
  82 }
  83
  84 /* The content of each linked object must have been checked
  85    or it must be already present in the object database */
  86 static void check_object(struct object *obj)
  87 {
  88         if (!obj)
  89                 return;
  90
  91         if (!(obj->flags & FLAG_LINK))
  92                 return;
  93
  94         if (!(obj->flags & FLAG_CHECKED)) {
  95                 unsigned long size;
  96                 int type = sha1_object_info(obj->sha1, &size);
  97                 if (type != obj->type || type <= 0)
  98                         die("object of unexpected type");
  99                 obj->flags |= FLAG_CHECKED;
 100                 return;
 101         }
 102 }
 103
 104 static void check_objects(void)
 105 {
 106         unsigned i, max;
 107
 108         max = get_max_object_index();
 109         for (i = 0; i < max; i++)
 110                 check_object(get_indexed_object(i));
 111 }
 112
 113
 114 /* Discard current buffer used content. */
 115 static void flush(void)
 116 {
 117         if (input_offset) {
 118                 if (output_fd >= 0)
 119                         write_or_die(output_fd, input_buffer, input_offset);
 120                 SHA1_Update(&input_ctx, input_buffer, input_offset);
 121                 memmove(input_buffer, input_buffer + input_offset, input_len);
 122                 input_offset = 0;
 123         }
 124 }
 125
 126 /*
 127  * Make sure at least "min" bytes are available in the buffer, and
 128  * return the pointer to the buffer.
 129  */
 130 static void *fill(int min)
 131 {
 132         if (min <= input_len)
 133                 return input_buffer + input_offset;
 134         if (min > sizeof(input_buffer))
 135                 die("cannot fill %d bytes", min);
 136         flush();
 137         do {
 138                 ssize_t ret = xread(input_fd, input_buffer + input_len,
 139                                 sizeof(input_buffer) - input_len);
 140                 if (ret <= 0) {
 141                         if (!ret)
 142                                 die("early EOF");
 143                         die("read error on input: %s", strerror(errno));
 144                 }
 145                 input_len += ret;
 146                 if (from_stdin)
 147                         display_throughput(progress, consumed_bytes + input_len);
 148         } while (input_len < min);
 149         return input_buffer;
 150 }
 151
 152 static void use(int bytes)
 153 {
 154         if (bytes > input_len)
 155                 die("used more bytes than were available");
 156         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 157         input_len -= bytes;
 158         input_offset += bytes;
 159
 160         /* make sure off_t is sufficiently large not to wrap */
 161         if (consumed_bytes > consumed_bytes + bytes)
 162                 die("pack too large for current definition of off_t");
 163         consumed_bytes += bytes;
 164 }
 165
 166 static char *open_pack_file(char *pack_name)
 167 {
 168         if (from_stdin) {
 169                 input_fd = 0;
 170                 if (!pack_name) {
 171                         static char tmpfile[PATH_MAX];
 172                         snprintf(tmpfile, sizeof(tmpfile),
 173                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 174                         output_fd = xmkstemp(tmpfile);
 175                         pack_name = xstrdup(tmpfile);
 176                 } else
 177                         output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 178                 if (output_fd < 0)
 179                         die("unable to create %s: %s\n", pack_name, strerror(errno));
 180                 pack_fd = output_fd;
 181         } else {
 182                 input_fd = open(pack_name, O_RDONLY);
 183                 if (input_fd < 0)
 184                         die("cannot open packfile '%s': %s",
 185                             pack_name, strerror(errno));
 186                 output_fd = -1;
 187                 pack_fd = input_fd;
 188         }
 189         SHA1_Init(&input_ctx);
 190         return pack_name;
 191 }
 192
 193 static void parse_pack_header(void)
 194 {
 195         struct pack_header *hdr = fill(sizeof(struct pack_header));
 196
 197         /* Header consistency check */
 198         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 199                 die("pack signature mismatch");
 200         if (!pack_version_ok(hdr->hdr_version))
 201                 die("pack version %d unsupported", ntohl(hdr->hdr_version));
 202
 203         nr_objects = ntohl(hdr->hdr_entries);
 204         use(sizeof(struct pack_header));
 205 }
 206
 207 static void bad_object(unsigned long offset, const char *format,
 208                        ...) NORETURN __attribute__((format (printf, 2, 3)));
 209
 210 static void bad_object(unsigned long offset, const char *format, ...)
 211 {
 212         va_list params;
 213         char buf[1024];
 214
 215         va_start(params, format);
 216         vsnprintf(buf, sizeof(buf), format, params);
 217         va_end(params);
 218         die("pack has bad object at offset %lu: %s", offset, buf);
 219 }
 220
 221 static void link_base_data(struct base_data *base, struct base_data *c)
 222 {
 223         if (base)
 224                 base->child = c;
 225         else
 226                 base_cache = c;
 227
 228         c->base = base;
 229         c->child = NULL;
 230 }
 231
 232 static void unlink_base_data(struct base_data *c)
 233 {
 234         struct base_data *base = c->base;
 235         if (base)
 236                 base->child = NULL;
 237         else
 238                 base_cache = NULL;
 239         free(c->data);
 240 }
 241
 242 static void *unpack_entry_data(unsigned long offset, unsigned long size)
 243 {
 244         z_stream stream;
 245         void *buf = xmalloc(size);
 246
 247         memset(&stream, 0, sizeof(stream));
 248         stream.next_out = buf;
 249         stream.avail_out = size;
 250         stream.next_in = fill(1);
 251         stream.avail_in = input_len;
 252         inflateInit(&stream);
 253
 254         for (;;) {
 255                 int ret = inflate(&stream, 0);
 256                 use(input_len - stream.avail_in);
 257                 if (stream.total_out == size && ret == Z_STREAM_END)
 258                         break;
 259                 if (ret != Z_OK)
 260                         bad_object(offset, "inflate returned %d", ret);
 261                 stream.next_in = fill(1);
 262                 stream.avail_in = input_len;
 263         }
 264         inflateEnd(&stream);
 265         return buf;
 266 }
 267
 268 static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
 269 {
 270         unsigned char *p, c;
 271         unsigned long size;
 272         off_t base_offset;
 273         unsigned shift;
 274         void *data;
 275
 276         obj->idx.offset = consumed_bytes;
 277         input_crc32 = crc32(0, Z_NULL, 0);
 278
 279         p = fill(1);
 280         c = *p;
 281         use(1);
 282         obj->type = (c >> 4) & 7;
 283         size = (c & 15);
 284         shift = 4;
 285         while (c & 0x80) {
 286                 p = fill(1);
 287                 c = *p;
 288                 use(1);
 289                 size += (c & 0x7fUL) << shift;
 290                 shift += 7;
 291         }
 292         obj->size = size;
 293
 294         switch (obj->type) {
 295         case OBJ_REF_DELTA:
 296                 hashcpy(delta_base->sha1, fill(20));
 297                 use(20);
 298                 break;
 299         case OBJ_OFS_DELTA:
 300                 memset(delta_base, 0, sizeof(*delta_base));
 301                 p = fill(1);
 302                 c = *p;
 303                 use(1);
 304                 base_offset = c & 127;
 305                 while (c & 128) {
 306                         base_offset += 1;
 307                         if (!base_offset || MSB(base_offset, 7))
 308                                 bad_object(obj->idx.offset, "offset value overflow for delta base object");
 309                         p = fill(1);
 310                         c = *p;
 311                         use(1);
 312                         base_offset = (base_offset << 7) + (c & 127);
 313                 }
 314                 delta_base->offset = obj->idx.offset - base_offset;
 315                 if (delta_base->offset >= obj->idx.offset)
 316                         bad_object(obj->idx.offset, "delta base offset is out of bound");
 317                 break;
 318         case OBJ_COMMIT:
 319         case OBJ_TREE:
 320         case OBJ_BLOB:
 321         case OBJ_TAG:
 322                 break;
 323         default:
 324                 bad_object(obj->idx.offset, "unknown object type %d", obj->type);
 325         }
 326         obj->hdr_size = consumed_bytes - obj->idx.offset;
 327
 328         data = unpack_entry_data(obj->idx.offset, obj->size);
 329         obj->idx.crc32 = input_crc32;
 330         return data;
 331 }
 332
 333 static void *get_data_from_pack(struct object_entry *obj)
 334 {
 335         off_t from = obj[0].idx.offset + obj[0].hdr_size;
 336         unsigned long len = obj[1].idx.offset - from;
 337         unsigned long rdy = 0;
 338         unsigned char *src, *data;
 339         z_stream stream;
 340         int st;
 341
 342         src = xmalloc(len);
 343         data = src;
 344         do {
 345                 ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
 346                 if (n <= 0)
 347                         die("cannot pread pack file: %s", strerror(errno));
 348                 rdy += n;
 349         } while (rdy < len);
 350         data = xmalloc(obj->size);
 351         memset(&stream, 0, sizeof(stream));
 352         stream.next_out = data;
 353         stream.avail_out = obj->size;
 354         stream.next_in = src;
 355         stream.avail_in = len;
 356         inflateInit(&stream);
 357         while ((st = inflate(&stream, Z_FINISH)) == Z_OK);
 358         inflateEnd(&stream);
 359         if (st != Z_STREAM_END || stream.total_out != obj->size)
 360                 die("serious inflate inconsistency");
 361         free(src);
 362         return data;
 363 }
 364
 365 static int find_delta(const union delta_base *base)
 366 {
 367         int first = 0, last = nr_deltas;
 368
 369         while (first < last) {
 370                 int next = (first + last) / 2;
 371                 struct delta_entry *delta = &deltas[next];
 372                 int cmp;
 373
 374                 cmp = memcmp(base, &delta->base, UNION_BASE_SZ);
 375                 if (!cmp)
 376                         return next;
 377                 if (cmp < 0) {
 378                         last = next;
 379                         continue;
 380                 }
 381                 first = next+1;
 382         }
 383         return -first-1;
 384 }
 385
 386 static int find_delta_children(const union delta_base *base,
 387                                int *first_index, int *last_index)
 388 {
 389         int first = find_delta(base);
 390         int last = first;
 391         int end = nr_deltas - 1;
 392
 393         if (first < 0)
 394                 return -1;
 395         while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 396                 --first;
 397         while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 398                 ++last;
 399         *first_index = first;
 400         *last_index = last;
 401         return 0;
 402 }
 403
 404 static void sha1_object(const void *data, unsigned long size,
 405                         enum object_type type, unsigned char *sha1)
 406 {
 407         hash_sha1_file(data, size, typename(type), sha1);
 408         if (has_sha1_file(sha1)) {
 409                 void *has_data;
 410                 enum object_type has_type;
 411                 unsigned long has_size;
 412                 has_data = read_sha1_file(sha1, &has_type, &has_size);
 413                 if (!has_data)
 414                         die("cannot read existing object %s", sha1_to_hex(sha1));
 415                 if (size != has_size || type != has_type ||
 416                     memcmp(data, has_data, size) != 0)
 417                         die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1));
 418                 free(has_data);
 419         }
 420         if (strict) {
 421                 if (type == OBJ_BLOB) {
 422                         struct blob *blob = lookup_blob(sha1);
 423                         if (blob)
 424                                 blob->object.flags |= FLAG_CHECKED;
 425                         else
 426                                 die("invalid blob object %s", sha1_to_hex(sha1));
 427                 } else {
 428                         struct object *obj;
 429                         int eaten;
 430                         void *buf = (void *) data;
 431
 432                         /*
 433                          * we do not need to free the memory here, as the
 434                          * buf is deleted by the caller.
 435                          */
 436                         obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 437                         if (!obj)
 438                                 die("invalid %s", typename(type));
 439                         if (fsck_object(obj, 1, fsck_error_function))
 440                                 die("Error in object");
 441                         if (fsck_walk(obj, mark_link, 0))
 442                                 die("Not all child objects of %s are reachable", sha1_to_hex(obj->sha1));
 443
 444                         if (obj->type == OBJ_TREE) {
 445                                 struct tree *item = (struct tree *) obj;
 446                                 item->buffer = NULL;
 447                         }
 448                         if (obj->type == OBJ_COMMIT) {
 449                                 struct commit *commit = (struct commit *) obj;
 450                                 commit->buffer = NULL;
 451                         }
 452                         obj->flags |= FLAG_CHECKED;
 453                 }
 454         }
 455 }
 456
 457 static void resolve_delta(struct object_entry *delta_obj,
 458                           struct base_data *base_obj, enum object_type type)
 459 {
 460         void *delta_data;
 461         unsigned long delta_size;
 462         union delta_base delta_base;
 463         int j, first, last;
 464         struct base_data result;
 465
 466         delta_obj->real_type = type;
 467         delta_data = get_data_from_pack(delta_obj);
 468         delta_size = delta_obj->size;
 469         result.data = patch_delta(base_obj->data, base_obj->size,
 470                              delta_data, delta_size,
 471                              &result.size);
 472         free(delta_data);
 473         if (!result.data)
 474                 bad_object(delta_obj->idx.offset, "failed to apply delta");
 475         sha1_object(result.data, result.size, type, delta_obj->idx.sha1);
 476         nr_resolved_deltas++;
 477
 478         link_base_data(base_obj, &result);
 479
 480         hashcpy(delta_base.sha1, delta_obj->idx.sha1);
 481         if (!find_delta_children(&delta_base, &first, &last)) {
 482                 for (j = first; j <= last; j++) {
 483                         struct object_entry *child = objects + deltas[j].obj_no;
 484                         if (child->real_type == OBJ_REF_DELTA)
 485                                 resolve_delta(child, &result, type);
 486                 }
 487         }
 488
 489         memset(&delta_base, 0, sizeof(delta_base));
 490         delta_base.offset = delta_obj->idx.offset;
 491         if (!find_delta_children(&delta_base, &first, &last)) {
 492                 for (j = first; j <= last; j++) {
 493                         struct object_entry *child = objects + deltas[j].obj_no;
 494                         if (child->real_type == OBJ_OFS_DELTA)
 495                                 resolve_delta(child, &result, type);
 496                 }
 497         }
 498
 499         unlink_base_data(&result);
 500 }
 501
 502 static int compare_delta_entry(const void *a, const void *b)
 503 {
 504         const struct delta_entry *delta_a = a;
 505         const struct delta_entry *delta_b = b;
 506         return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ);
 507 }
 508
 509 /* Parse all objects and return the pack content SHA1 hash */
 510 static void parse_pack_objects(unsigned char *sha1)
 511 {
 512         int i;
 513         struct delta_entry *delta = deltas;
 514         struct stat st;
 515
 516         /*
 517          * First pass:
 518          * - find locations of all objects;
 519          * - calculate SHA1 of all non-delta objects;
 520          * - remember base (SHA1 or offset) for all deltas.
 521          */
 522         if (verbose)
 523                 progress = start_progress(
 524                                 from_stdin ? "Receiving objects" : "Indexing objects",
 525                                 nr_objects);
 526         for (i = 0; i < nr_objects; i++) {
 527                 struct object_entry *obj = &objects[i];
 528                 void *data = unpack_raw_entry(obj, &delta->base);
 529                 obj->real_type = obj->type;
 530                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
 531                         nr_deltas++;
 532                         delta->obj_no = i;
 533                         delta++;
 534                 } else
 535                         sha1_object(data, obj->size, obj->type, obj->idx.sha1);
 536                 free(data);
 537                 display_progress(progress, i+1);
 538         }
 539         objects[i].idx.offset = consumed_bytes;
 540         stop_progress(&progress);
 541
 542         /* Check pack integrity */
 543         flush();
 544         SHA1_Final(sha1, &input_ctx);
 545         if (hashcmp(fill(20), sha1))
 546                 die("pack is corrupted (SHA1 mismatch)");
 547         use(20);
 548
 549         /* If input_fd is a file, we should have reached its end now. */
 550         if (fstat(input_fd, &st))
 551                 die("cannot fstat packfile: %s", strerror(errno));
 552         if (S_ISREG(st.st_mode) &&
 553                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
 554                 die("pack has junk at the end");
 555
 556         if (!nr_deltas)
 557                 return;
 558
 559         /* Sort deltas by base SHA1/offset for fast searching */
 560         qsort(deltas, nr_deltas, sizeof(struct delta_entry),
 561               compare_delta_entry);
 562
 563         /*
 564          * Second pass:
 565          * - for all non-delta objects, look if it is used as a base for
 566          *   deltas;
 567          * - if used as a base, uncompress the object and apply all deltas,
 568          *   recursively checking if the resulting object is used as a base
 569          *   for some more deltas.
 570          */
 571         if (verbose)
 572                 progress = start_progress("Resolving deltas", nr_deltas);
 573         for (i = 0; i < nr_objects; i++) {
 574                 struct object_entry *obj = &objects[i];
 575                 union delta_base base;
 576                 int j, ref, ref_first, ref_last, ofs, ofs_first, ofs_last;
 577                 struct base_data base_obj;
 578
 579                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
 580                         continue;
 581                 hashcpy(base.sha1, obj->idx.sha1);
 582                 ref = !find_delta_children(&base, &ref_first, &ref_last);
 583                 memset(&base, 0, sizeof(base));
 584                 base.offset = obj->idx.offset;
 585                 ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
 586                 if (!ref && !ofs)
 587                         continue;
 588                 base_obj.data = get_data_from_pack(obj);
 589                 base_obj.size = obj->size;
 590                 link_base_data(NULL, &base_obj);
 591
 592                 if (ref)
 593                         for (j = ref_first; j <= ref_last; j++) {
 594                                 struct object_entry *child = objects + deltas[j].obj_no;
 595                                 if (child->real_type == OBJ_REF_DELTA)
 596                                         resolve_delta(child, &base_obj, obj->type);
 597                         }
 598                 if (ofs)
 599                         for (j = ofs_first; j <= ofs_last; j++) {
 600                                 struct object_entry *child = objects + deltas[j].obj_no;
 601                                 if (child->real_type == OBJ_OFS_DELTA)
 602                                         resolve_delta(child, &base_obj, obj->type);
 603                         }
 604                 unlink_base_data(&base_obj);
 605                 display_progress(progress, nr_resolved_deltas);
 606         }
 607 }
 608
 609 static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_crc)
 610 {
 611         z_stream stream;
 612         unsigned long maxsize;
 613         void *out;
 614
 615         memset(&stream, 0, sizeof(stream));
 616         deflateInit(&stream, zlib_compression_level);
 617         maxsize = deflateBound(&stream, size);
 618         out = xmalloc(maxsize);
 619
 620         /* Compress it */
 621         stream.next_in = in;
 622         stream.avail_in = size;
 623         stream.next_out = out;
 624         stream.avail_out = maxsize;
 625         while (deflate(&stream, Z_FINISH) == Z_OK);
 626         deflateEnd(&stream);
 627
 628         size = stream.total_out;
 629         write_or_die(fd, out, size);
 630         *obj_crc = crc32(*obj_crc, out, size);
 631         free(out);
 632         return size;
 633 }
 634
 635 static void append_obj_to_pack(const unsigned char *sha1, void *buf,
 636                                unsigned long size, enum object_type type)
 637 {
 638         struct object_entry *obj = &objects[nr_objects++];
 639         unsigned char header[10];
 640         unsigned long s = size;
 641         int n = 0;
 642         unsigned char c = (type << 4) | (s & 15);
 643         s >>= 4;
 644         while (s) {
 645                 header[n++] = c | 0x80;
 646                 c = s & 0x7f;
 647                 s >>= 7;
 648         }
 649         header[n++] = c;
 650         write_or_die(output_fd, header, n);
 651         obj[0].idx.crc32 = crc32(0, Z_NULL, 0);
 652         obj[0].idx.crc32 = crc32(obj[0].idx.crc32, header, n);
 653         obj[1].idx.offset = obj[0].idx.offset + n;
 654         obj[1].idx.offset += write_compressed(output_fd, buf, size, &obj[0].idx.crc32);
 655         hashcpy(obj->idx.sha1, sha1);
 656 }
 657
 658 static int delta_pos_compare(const void *_a, const void *_b)
 659 {
 660         struct delta_entry *a = *(struct delta_entry **)_a;
 661         struct delta_entry *b = *(struct delta_entry **)_b;
 662         return a->obj_no - b->obj_no;
 663 }
 664
 665 static void fix_unresolved_deltas(int nr_unresolved)
 666 {
 667         struct delta_entry **sorted_by_pos;
 668         int i, n = 0;
 669
 670         /*
 671          * Since many unresolved deltas may well be themselves base objects
 672          * for more unresolved deltas, we really want to include the
 673          * smallest number of base objects that would cover as much delta
 674          * as possible by picking the
 675          * trunc deltas first, allowing for other deltas to resolve without
 676          * additional base objects.  Since most base objects are to be found
 677          * before deltas depending on them, a good heuristic is to start
 678          * resolving deltas in the same order as their position in the pack.
 679          */
 680         sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
 681         for (i = 0; i < nr_deltas; i++) {
 682                 if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
 683                         continue;
 684                 sorted_by_pos[n++] = &deltas[i];
 685         }
 686         qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
 687
 688         for (i = 0; i < n; i++) {
 689                 struct delta_entry *d = sorted_by_pos[i];
 690                 enum object_type type;
 691                 int j, first, last;
 692                 struct base_data base_obj;
 693
 694                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
 695                         continue;
 696                 base_obj.data = read_sha1_file(d->base.sha1, &type, &base_obj.size);
 697                 if (!base_obj.data)
 698                         continue;
 699                 link_base_data(NULL, &base_obj);
 700
 701                 find_delta_children(&d->base, &first, &last);
 702                 for (j = first; j <= last; j++) {
 703                         struct object_entry *child = objects + deltas[j].obj_no;
 704                         if (child->real_type == OBJ_REF_DELTA)
 705                                 resolve_delta(child, &base_obj, type);
 706                 }
 707
 708                 if (check_sha1_signature(d->base.sha1, base_obj.data,
 709                                 base_obj.size, typename(type)))
 710                         die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
 711                 append_obj_to_pack(d->base.sha1, base_obj.data,
 712                         base_obj.size, type);
 713                 unlink_base_data(&base_obj);
 714                 display_progress(progress, nr_resolved_deltas);
 715         }
 716         free(sorted_by_pos);
 717 }
 718
 719 static void final(const char *final_pack_name, const char *curr_pack_name,
 720                   const char *final_index_name, const char *curr_index_name,
 721                   const char *keep_name, const char *keep_msg,
 722                   unsigned char *sha1)
 723 {
 724         const char *report = "pack";
 725         char name[PATH_MAX];
 726         int err;
 727
 728         if (!from_stdin) {
 729                 close(input_fd);
 730         } else {
 731                 fsync_or_die(output_fd, curr_pack_name);
 732                 err = close(output_fd);
 733                 if (err)
 734                         die("error while closing pack file: %s", strerror(errno));
 735                 chmod(curr_pack_name, 0444);
 736         }
 737
 738         if (keep_msg) {
 739                 int keep_fd, keep_msg_len = strlen(keep_msg);
 740                 if (!keep_name) {
 741                         snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
 742                                  get_object_directory(), sha1_to_hex(sha1));
 743                         keep_name = name;
 744                 }
 745                 keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
 746                 if (keep_fd < 0) {
 747                         if (errno != EEXIST)
 748                                 die("cannot write keep file");
 749                 } else {
 750                         if (keep_msg_len > 0) {
 751                                 write_or_die(keep_fd, keep_msg, keep_msg_len);
 752                                 write_or_die(keep_fd, "\n", 1);
 753                         }
 754                         if (close(keep_fd) != 0)
 755                                 die("cannot write keep file");
 756                         report = "keep";
 757                 }
 758         }
 759
 760         if (final_pack_name != curr_pack_name) {
 761                 if (!final_pack_name) {
 762                         snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
 763                                  get_object_directory(), sha1_to_hex(sha1));
 764                         final_pack_name = name;
 765                 }
 766                 if (move_temp_to_file(curr_pack_name, final_pack_name))
 767                         die("cannot store pack file");
 768         }
 769
 770         chmod(curr_index_name, 0444);
 771         if (final_index_name != curr_index_name) {
 772                 if (!final_index_name) {
 773                         snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
 774                                  get_object_directory(), sha1_to_hex(sha1));
 775                         final_index_name = name;
 776                 }
 777                 if (move_temp_to_file(curr_index_name, final_index_name))
 778                         die("cannot store index file");
 779         }
 780
 781         if (!from_stdin) {
 782                 printf("%s\n", sha1_to_hex(sha1));
 783         } else {
 784                 char buf[48];
 785                 int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
 786                                    report, sha1_to_hex(sha1));
 787                 write_or_die(1, buf, len);
 788
 789                 /*
 790                  * Let's just mimic git-unpack-objects here and write
 791                  * the last part of the input buffer to stdout.
 792                  */
 793                 while (input_len) {
 794                         err = xwrite(1, input_buffer + input_offset, input_len);
 795                         if (err <= 0)
 796                                 break;
 797                         input_len -= err;
 798                         input_offset += err;
 799                 }
 800         }
 801 }
 802
 803 static int git_index_pack_config(const char *k, const char *v, void *cb)
 804 {
 805         if (!strcmp(k, "pack.indexversion")) {
 806                 pack_idx_default_version = git_config_int(k, v);
 807                 if (pack_idx_default_version > 2)
 808                         die("bad pack.indexversion=%d", pack_idx_default_version);
 809                 return 0;
 810         }
 811         return git_default_config(k, v, cb);
 812 }
 813
 814 int main(int argc, char **argv)
 815 {
 816         int i, fix_thin_pack = 0;
 817         char *curr_pack, *pack_name = NULL;
 818         char *curr_index, *index_name = NULL;
 819         const char *keep_name = NULL, *keep_msg = NULL;
 820         char *index_name_buf = NULL, *keep_name_buf = NULL;
 821         struct pack_idx_entry **idx_objects;
 822         unsigned char sha1[20];
 823
 824         git_config(git_index_pack_config, NULL);
 825
 826         for (i = 1; i < argc; i++) {
 827                 char *arg = argv[i];
 828
 829                 if (*arg == '-') {
 830                         if (!strcmp(arg, "--stdin")) {
 831                                 from_stdin = 1;
 832                         } else if (!strcmp(arg, "--fix-thin")) {
 833                                 fix_thin_pack = 1;
 834                         } else if (!strcmp(arg, "--strict")) {
 835                                 strict = 1;
 836                         } else if (!strcmp(arg, "--keep")) {
 837                                 keep_msg = "";
 838                         } else if (!prefixcmp(arg, "--keep=")) {
 839                                 keep_msg = arg + 7;
 840                         } else if (!prefixcmp(arg, "--pack_header=")) {
 841                                 struct pack_header *hdr;
 842                                 char *c;
 843
 844                                 hdr = (struct pack_header *)input_buffer;
 845                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
 846                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
 847                                 if (*c != ',')
 848                                         die("bad %s", arg);
 849                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
 850                                 if (*c)
 851                                         die("bad %s", arg);
 852                                 input_len = sizeof(*hdr);
 853                         } else if (!strcmp(arg, "-v")) {
 854                                 verbose = 1;
 855                         } else if (!strcmp(arg, "-o")) {
 856                                 if (index_name || (i+1) >= argc)
 857                                         usage(index_pack_usage);
 858                                 index_name = argv[++i];
 859                         } else if (!prefixcmp(arg, "--index-version=")) {
 860                                 char *c;
 861                                 pack_idx_default_version = strtoul(arg + 16, &c, 10);
 862                                 if (pack_idx_default_version > 2)
 863                                         die("bad %s", arg);
 864                                 if (*c == ',')
 865                                         pack_idx_off32_limit = strtoul(c+1, &c, 0);
 866                                 if (*c || pack_idx_off32_limit & 0x80000000)
 867                                         die("bad %s", arg);
 868                         } else
 869                                 usage(index_pack_usage);
 870                         continue;
 871                 }
 872
 873                 if (pack_name)
 874                         usage(index_pack_usage);
 875                 pack_name = arg;
 876         }
 877
 878         if (!pack_name && !from_stdin)
 879                 usage(index_pack_usage);
 880         if (fix_thin_pack && !from_stdin)
 881                 die("--fix-thin cannot be used without --stdin");
 882         if (!index_name && pack_name) {
 883                 int len = strlen(pack_name);
 884                 if (!has_extension(pack_name, ".pack"))
 885                         die("packfile name '%s' does not end with '.pack'",
 886                             pack_name);
 887                 index_name_buf = xmalloc(len);
 888                 memcpy(index_name_buf, pack_name, len - 5);
 889                 strcpy(index_name_buf + len - 5, ".idx");
 890                 index_name = index_name_buf;
 891         }
 892         if (keep_msg && !keep_name && pack_name) {
 893                 int len = strlen(pack_name);
 894                 if (!has_extension(pack_name, ".pack"))
 895                         die("packfile name '%s' does not end with '.pack'",
 896                             pack_name);
 897                 keep_name_buf = xmalloc(len);
 898                 memcpy(keep_name_buf, pack_name, len - 5);
 899                 strcpy(keep_name_buf + len - 5, ".keep");
 900                 keep_name = keep_name_buf;
 901         }
 902
 903         curr_pack = open_pack_file(pack_name);
 904         parse_pack_header();
 905         objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
 906         deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
 907         parse_pack_objects(sha1);
 908         if (nr_deltas == nr_resolved_deltas) {
 909                 stop_progress(&progress);
 910                 /* Flush remaining pack final 20-byte SHA1. */
 911                 flush();
 912         } else {
 913                 if (fix_thin_pack) {
 914                         char msg[48];
 915                         int nr_unresolved = nr_deltas - nr_resolved_deltas;
 916                         int nr_objects_initial = nr_objects;
 917                         if (nr_unresolved <= 0)
 918                                 die("confusion beyond insanity");
 919                         objects = xrealloc(objects,
 920                                            (nr_objects + nr_unresolved + 1)
 921                                            * sizeof(*objects));
 922                         fix_unresolved_deltas(nr_unresolved);
 923                         sprintf(msg, "completed with %d local objects",
 924                                 nr_objects - nr_objects_initial);
 925                         stop_progress_msg(&progress, msg);
 926                         fixup_pack_header_footer(output_fd, sha1,
 927                                                  curr_pack, nr_objects);
 928                 }
 929                 if (nr_deltas != nr_resolved_deltas)
 930                         die("pack has %d unresolved deltas",
 931                             nr_deltas - nr_resolved_deltas);
 932         }
 933         free(deltas);
 934         if (strict)
 935                 check_objects();
 936
 937         idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
 938         for (i = 0; i < nr_objects; i++)
 939                 idx_objects[i] = &objects[i].idx;
 940         curr_index = write_idx_file(index_name, idx_objects, nr_objects, sha1);
 941         free(idx_objects);
 942
 943         final(pack_name, curr_pack,
 944                 index_name, curr_index,
 945                 keep_name, keep_msg,
 946                 sha1);
 947         free(objects);
 948         free(index_name_buf);
 949         free(keep_name_buf);
 950         if (pack_name == NULL)
 951                 free(curr_pack);
 952         if (index_name == NULL)
 953                 free(curr_index);
 954
 955         return 0;
 956 }