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

   1 #include "builtin.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 #include "exec_cmd.h"
  12 #include "thread-utils.h"
  13
  14 static const char index_pack_usage[] =
  15 "git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  16
  17 struct object_entry {
  18         struct pack_idx_entry idx;
  19         unsigned long size;
  20         unsigned int hdr_size;
  21         enum object_type type;
  22         enum object_type real_type;
  23         unsigned delta_depth;
  24         int base_object_no;
  25 };
  26
  27 union delta_base {
  28         unsigned char sha1[20];
  29         off_t offset;
  30 };
  31
  32 struct base_data {
  33         struct base_data *base;
  34         struct base_data *child;
  35         struct object_entry *obj;
  36         void *data;
  37         unsigned long size;
  38         int ref_first, ref_last;
  39         int ofs_first, ofs_last;
  40 };
  41
  42 struct thread_local {
  43 #ifndef NO_PTHREADS
  44         pthread_t thread;
  45 #endif
  46         struct base_data *base_cache;
  47         size_t base_cache_used;
  48 };
  49
  50 /*
  51  * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
  52  * to memcmp() only the first 20 bytes.
  53  */
  54 #define UNION_BASE_SZ   20
  55
  56 #define FLAG_LINK (1u<<20)
  57 #define FLAG_CHECKED (1u<<21)
  58
  59 struct delta_entry {
  60         union delta_base base;
  61         int obj_no;
  62 };
  63
  64 static struct object_entry *objects;
  65 static struct delta_entry *deltas;
  66 static struct thread_local nothread_data;
  67 static int nr_objects;
  68 static int nr_deltas;
  69 static int nr_resolved_deltas;
  70 static int nr_threads;
  71
  72 static int from_stdin;
  73 static int strict;
  74 static int verbose;
  75
  76 static struct progress *progress;
  77
  78 /* We always read in 4kB chunks. */
  79 static unsigned char input_buffer[4096];
  80 static unsigned int input_offset, input_len;
  81 static off_t consumed_bytes;
  82 static unsigned deepest_delta;
  83 static git_SHA_CTX input_ctx;
  84 static uint32_t input_crc32;
  85 static int input_fd, output_fd, pack_fd;
  86
  87 #ifndef NO_PTHREADS
  88
  89 static struct thread_local *thread_data;
  90 static int nr_dispatched;
  91 static int threads_active;
  92
  93 static pthread_mutex_t read_mutex;
  94 #define read_lock()             lock_mutex(&read_mutex)
  95 #define read_unlock()           unlock_mutex(&read_mutex)
  96
  97 static pthread_mutex_t counter_mutex;
  98 #define counter_lock()          lock_mutex(&counter_mutex)
  99 #define counter_unlock()        unlock_mutex(&counter_mutex)
 100
 101 static pthread_mutex_t work_mutex;
 102 #define work_lock()             lock_mutex(&work_mutex)
 103 #define work_unlock()           unlock_mutex(&work_mutex)
 104
 105 static pthread_key_t key;
 106
 107 static inline void lock_mutex(pthread_mutex_t *mutex)
 108 {
 109         if (threads_active)
 110                 pthread_mutex_lock(mutex);
 111 }
 112
 113 static inline void unlock_mutex(pthread_mutex_t *mutex)
 114 {
 115         if (threads_active)
 116                 pthread_mutex_unlock(mutex);
 117 }
 118
 119 /*
 120  * Mutex and conditional variable can't be statically-initialized on Windows.
 121  */
 122 static void init_thread(void)
 123 {
 124         init_recursive_mutex(&read_mutex);
 125         pthread_mutex_init(&counter_mutex, NULL);
 126         pthread_mutex_init(&work_mutex, NULL);
 127         pthread_key_create(&key, NULL);
 128         thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 129         threads_active = 1;
 130 }
 131
 132 static void cleanup_thread(void)
 133 {
 134         if (!threads_active)
 135                 return;
 136         threads_active = 0;
 137         pthread_mutex_destroy(&read_mutex);
 138         pthread_mutex_destroy(&counter_mutex);
 139         pthread_mutex_destroy(&work_mutex);
 140         pthread_key_delete(key);
 141         free(thread_data);
 142 }
 143
 144 #else
 145
 146 #define read_lock()
 147 #define read_unlock()
 148
 149 #define counter_lock()
 150 #define counter_unlock()
 151
 152 #define work_lock()
 153 #define work_unlock()
 154
 155 #endif
 156
 157
 158 static int mark_link(struct object *obj, int type, void *data)
 159 {
 160         if (!obj)
 161                 return -1;
 162
 163         if (type != OBJ_ANY && obj->type != type)
 164                 die("object type mismatch at %s", sha1_to_hex(obj->sha1));
 165
 166         obj->flags |= FLAG_LINK;
 167         return 0;
 168 }
 169
 170 /* The content of each linked object must have been checked
 171    or it must be already present in the object database */
 172 static void check_object(struct object *obj)
 173 {
 174         if (!obj)
 175                 return;
 176
 177         if (!(obj->flags & FLAG_LINK))
 178                 return;
 179
 180         if (!(obj->flags & FLAG_CHECKED)) {
 181                 unsigned long size;
 182                 int type = sha1_object_info(obj->sha1, &size);
 183                 if (type != obj->type || type <= 0)
 184                         die("object of unexpected type");
 185                 obj->flags |= FLAG_CHECKED;
 186                 return;
 187         }
 188 }
 189
 190 static void check_objects(void)
 191 {
 192         unsigned i, max;
 193
 194         max = get_max_object_index();
 195         for (i = 0; i < max; i++)
 196                 check_object(get_indexed_object(i));
 197 }
 198
 199
 200 /* Discard current buffer used content. */
 201 static void flush(void)
 202 {
 203         if (input_offset) {
 204                 if (output_fd >= 0)
 205                         write_or_die(output_fd, input_buffer, input_offset);
 206                 git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 207                 memmove(input_buffer, input_buffer + input_offset, input_len);
 208                 input_offset = 0;
 209         }
 210 }
 211
 212 /*
 213  * Make sure at least "min" bytes are available in the buffer, and
 214  * return the pointer to the buffer.
 215  */
 216 static void *fill(int min)
 217 {
 218         if (min <= input_len)
 219                 return input_buffer + input_offset;
 220         if (min > sizeof(input_buffer))
 221                 die("cannot fill %d bytes", min);
 222         flush();
 223         do {
 224                 ssize_t ret = xread(input_fd, input_buffer + input_len,
 225                                 sizeof(input_buffer) - input_len);
 226                 if (ret <= 0) {
 227                         if (!ret)
 228                                 die("early EOF");
 229                         die_errno("read error on input");
 230                 }
 231                 input_len += ret;
 232                 if (from_stdin)
 233                         display_throughput(progress, consumed_bytes + input_len);
 234         } while (input_len < min);
 235         return input_buffer;
 236 }
 237
 238 static void use(int bytes)
 239 {
 240         if (bytes > input_len)
 241                 die("used more bytes than were available");
 242         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 243         input_len -= bytes;
 244         input_offset += bytes;
 245
 246         /* make sure off_t is sufficiently large not to wrap */
 247         if (signed_add_overflows(consumed_bytes, bytes))
 248                 die("pack too large for current definition of off_t");
 249         consumed_bytes += bytes;
 250 }
 251
 252 static const char *open_pack_file(const char *pack_name)
 253 {
 254         if (from_stdin) {
 255                 input_fd = 0;
 256                 if (!pack_name) {
 257                         static char tmp_file[PATH_MAX];
 258                         output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 259                                                 "pack/tmp_pack_XXXXXX");
 260                         pack_name = xstrdup(tmp_file);
 261                 } else
 262                         output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 263                 if (output_fd < 0)
 264                         die_errno("unable to create '%s'", pack_name);
 265                 pack_fd = output_fd;
 266         } else {
 267                 input_fd = open(pack_name, O_RDONLY);
 268                 if (input_fd < 0)
 269                         die_errno("cannot open packfile '%s'", pack_name);
 270                 output_fd = -1;
 271                 pack_fd = input_fd;
 272         }
 273         git_SHA1_Init(&input_ctx);
 274         return pack_name;
 275 }
 276
 277 static void parse_pack_header(void)
 278 {
 279         struct pack_header *hdr = fill(sizeof(struct pack_header));
 280
 281         /* Header consistency check */
 282         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 283                 die("pack signature mismatch");
 284         if (!pack_version_ok(hdr->hdr_version))
 285                 die("pack version %"PRIu32" unsupported",
 286                         ntohl(hdr->hdr_version));
 287
 288         nr_objects = ntohl(hdr->hdr_entries);
 289         use(sizeof(struct pack_header));
 290 }
 291
 292 static NORETURN void bad_object(unsigned long offset, const char *format,
 293                        ...) __attribute__((format (printf, 2, 3)));
 294
 295 static NORETURN void bad_object(unsigned long offset, const char *format, ...)
 296 {
 297         va_list params;
 298         char buf[1024];
 299
 300         va_start(params, format);
 301         vsnprintf(buf, sizeof(buf), format, params);
 302         va_end(params);
 303         die("pack has bad object at offset %lu: %s", offset, buf);
 304 }
 305
 306 static inline struct thread_local *get_thread_data(void)
 307 {
 308 #ifndef NO_PTHREADS
 309         if (threads_active)
 310                 return pthread_getspecific(key);
 311         assert(!threads_active &&
 312                "This should only be reached when all threads are gone");
 313 #endif
 314         return &nothread_data;
 315 }
 316
 317 #ifndef NO_PTHREADS
 318 static void set_thread_data(struct thread_local *data)
 319 {
 320         if (threads_active)
 321                 pthread_setspecific(key, data);
 322 }
 323 #endif
 324
 325 static struct base_data *alloc_base_data(void)
 326 {
 327         struct base_data *base = xmalloc(sizeof(struct base_data));
 328         memset(base, 0, sizeof(*base));
 329         base->ref_last = -1;
 330         base->ofs_last = -1;
 331         return base;
 332 }
 333
 334 static void free_base_data(struct base_data *c)
 335 {
 336         if (c->data) {
 337                 free(c->data);
 338                 c->data = NULL;
 339                 get_thread_data()->base_cache_used -= c->size;
 340         }
 341 }
 342
 343 static void prune_base_data(struct base_data *retain)
 344 {
 345         struct base_data *b;
 346         struct thread_local *data = get_thread_data();
 347         for (b = data->base_cache;
 348              data->base_cache_used > delta_base_cache_limit && b;
 349              b = b->child) {
 350                 if (b->data && b != retain)
 351                         free_base_data(b);
 352         }
 353 }
 354
 355 static void link_base_data(struct base_data *base, struct base_data *c)
 356 {
 357         if (base)
 358                 base->child = c;
 359         else
 360                 get_thread_data()->base_cache = c;
 361
 362         c->base = base;
 363         c->child = NULL;
 364         if (c->data)
 365                 get_thread_data()->base_cache_used += c->size;
 366         prune_base_data(c);
 367 }
 368
 369 static void unlink_base_data(struct base_data *c)
 370 {
 371         struct base_data *base = c->base;
 372         if (base)
 373                 base->child = NULL;
 374         else
 375                 get_thread_data()->base_cache = NULL;
 376         free_base_data(c);
 377 }
 378
 379 static void *unpack_entry_data(unsigned long offset, unsigned long size)
 380 {
 381         int status;
 382         git_zstream stream;
 383         void *buf = xmalloc(size);
 384
 385         memset(&stream, 0, sizeof(stream));
 386         git_inflate_init(&stream);
 387         stream.next_out = buf;
 388         stream.avail_out = size;
 389
 390         do {
 391                 stream.next_in = fill(1);
 392                 stream.avail_in = input_len;
 393                 status = git_inflate(&stream, 0);
 394                 use(input_len - stream.avail_in);
 395         } while (status == Z_OK);
 396         if (stream.total_out != size || status != Z_STREAM_END)
 397                 bad_object(offset, "inflate returned %d", status);
 398         git_inflate_end(&stream);
 399         return buf;
 400 }
 401
 402 static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
 403 {
 404         unsigned char *p;
 405         unsigned long size, c;
 406         off_t base_offset;
 407         unsigned shift;
 408         void *data;
 409
 410         obj->idx.offset = consumed_bytes;
 411         input_crc32 = crc32(0, NULL, 0);
 412
 413         p = fill(1);
 414         c = *p;
 415         use(1);
 416         obj->type = (c >> 4) & 7;
 417         size = (c & 15);
 418         shift = 4;
 419         while (c & 0x80) {
 420                 p = fill(1);
 421                 c = *p;
 422                 use(1);
 423                 size += (c & 0x7f) << shift;
 424                 shift += 7;
 425         }
 426         obj->size = size;
 427
 428         switch (obj->type) {
 429         case OBJ_REF_DELTA:
 430                 hashcpy(delta_base->sha1, fill(20));
 431                 use(20);
 432                 break;
 433         case OBJ_OFS_DELTA:
 434                 memset(delta_base, 0, sizeof(*delta_base));
 435                 p = fill(1);
 436                 c = *p;
 437                 use(1);
 438                 base_offset = c & 127;
 439                 while (c & 128) {
 440                         base_offset += 1;
 441                         if (!base_offset || MSB(base_offset, 7))
 442                                 bad_object(obj->idx.offset, "offset value overflow for delta base object");
 443                         p = fill(1);
 444                         c = *p;
 445                         use(1);
 446                         base_offset = (base_offset << 7) + (c & 127);
 447                 }
 448                 delta_base->offset = obj->idx.offset - base_offset;
 449                 if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
 450                         bad_object(obj->idx.offset, "delta base offset is out of bound");
 451                 break;
 452         case OBJ_COMMIT:
 453         case OBJ_TREE:
 454         case OBJ_BLOB:
 455         case OBJ_TAG:
 456                 break;
 457         default:
 458                 bad_object(obj->idx.offset, "unknown object type %d", obj->type);
 459         }
 460         obj->hdr_size = consumed_bytes - obj->idx.offset;
 461
 462         data = unpack_entry_data(obj->idx.offset, obj->size);
 463         obj->idx.crc32 = input_crc32;
 464         return data;
 465 }
 466
 467 static void *get_data_from_pack(struct object_entry *obj)
 468 {
 469         off_t from = obj[0].idx.offset + obj[0].hdr_size;
 470         unsigned long len = obj[1].idx.offset - from;
 471         unsigned char *data, *inbuf;
 472         git_zstream stream;
 473         int status;
 474
 475         data = xmalloc(obj->size);
 476         inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
 477
 478         memset(&stream, 0, sizeof(stream));
 479         git_inflate_init(&stream);
 480         stream.next_out = data;
 481         stream.avail_out = obj->size;
 482
 483         do {
 484                 ssize_t n = (len < 64*1024) ? len : 64*1024;
 485                 n = pread(pack_fd, inbuf, n, from);
 486                 if (n < 0)
 487                         die_errno("cannot pread pack file");
 488                 if (!n)
 489                         die("premature end of pack file, %lu bytes missing", len);
 490                 from += n;
 491                 len -= n;
 492                 stream.next_in = inbuf;
 493                 stream.avail_in = n;
 494                 status = git_inflate(&stream, 0);
 495         } while (len && status == Z_OK && !stream.avail_in);
 496
 497         /* This has been inflated OK when first encountered, so... */
 498         if (status != Z_STREAM_END || stream.total_out != obj->size)
 499                 die("serious inflate inconsistency");
 500
 501         git_inflate_end(&stream);
 502         free(inbuf);
 503         return data;
 504 }
 505
 506 static int compare_delta_bases(const union delta_base *base1,
 507                                const union delta_base *base2,
 508                                enum object_type type1,
 509                                enum object_type type2)
 510 {
 511         int cmp = type1 - type2;
 512         if (cmp)
 513                 return cmp;
 514         return memcmp(base1, base2, UNION_BASE_SZ);
 515 }
 516
 517 static int find_delta(const union delta_base *base, enum object_type type)
 518 {
 519         int first = 0, last = nr_deltas;
 520
 521         while (first < last) {
 522                 int next = (first + last) / 2;
 523                 struct delta_entry *delta = &deltas[next];
 524                 int cmp;
 525
 526                 cmp = compare_delta_bases(base, &delta->base,
 527                                           type, objects[delta->obj_no].type);
 528                 if (!cmp)
 529                         return next;
 530                 if (cmp < 0) {
 531                         last = next;
 532                         continue;
 533                 }
 534                 first = next+1;
 535         }
 536         return -first-1;
 537 }
 538
 539 static void find_delta_children(const union delta_base *base,
 540                                 int *first_index, int *last_index,
 541                                 enum object_type type)
 542 {
 543         int first = find_delta(base, type);
 544         int last = first;
 545         int end = nr_deltas - 1;
 546
 547         if (first < 0) {
 548                 *first_index = 0;
 549                 *last_index = -1;
 550                 return;
 551         }
 552         while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 553                 --first;
 554         while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 555                 ++last;
 556         *first_index = first;
 557         *last_index = last;
 558 }
 559
 560 static void sha1_object(const void *data, unsigned long size,
 561                         enum object_type type, unsigned char *sha1)
 562 {
 563         hash_sha1_file(data, size, typename(type), sha1);
 564         read_lock();
 565         if (has_sha1_file(sha1)) {
 566                 void *has_data;
 567                 enum object_type has_type;
 568                 unsigned long has_size;
 569                 has_data = read_sha1_file(sha1, &has_type, &has_size);
 570                 read_unlock();
 571                 if (!has_data)
 572                         die("cannot read existing object %s", sha1_to_hex(sha1));
 573                 if (size != has_size || type != has_type ||
 574                     memcmp(data, has_data, size) != 0)
 575                         die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1));
 576                 free(has_data);
 577         } else
 578                 read_unlock();
 579
 580         if (strict) {
 581                 read_lock();
 582                 if (type == OBJ_BLOB) {
 583                         struct blob *blob = lookup_blob(sha1);
 584                         if (blob)
 585                                 blob->object.flags |= FLAG_CHECKED;
 586                         else
 587                                 die("invalid blob object %s", sha1_to_hex(sha1));
 588                 } else {
 589                         struct object *obj;
 590                         int eaten;
 591                         void *buf = (void *) data;
 592
 593                         /*
 594                          * we do not need to free the memory here, as the
 595                          * buf is deleted by the caller.
 596                          */
 597                         obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 598                         if (!obj)
 599                                 die("invalid %s", typename(type));
 600                         if (fsck_object(obj, 1, fsck_error_function))
 601                                 die("Error in object");
 602                         if (fsck_walk(obj, mark_link, NULL))
 603                                 die("Not all child objects of %s are reachable", sha1_to_hex(obj->sha1));
 604
 605                         if (obj->type == OBJ_TREE) {
 606                                 struct tree *item = (struct tree *) obj;
 607                                 item->buffer = NULL;
 608                         }
 609                         if (obj->type == OBJ_COMMIT) {
 610                                 struct commit *commit = (struct commit *) obj;
 611                                 commit->buffer = NULL;
 612                         }
 613                         obj->flags |= FLAG_CHECKED;
 614                 }
 615                 read_unlock();
 616         }
 617 }
 618
 619 static int is_delta_type(enum object_type type)
 620 {
 621         return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 622 }
 623
 624 /*
 625  * This function is part of find_unresolved_deltas(). There are two
 626  * walkers going in the opposite ways.
 627  *
 628  * The first one in find_unresolved_deltas() traverses down from
 629  * parent node to children, deflating nodes along the way. However,
 630  * memory for deflated nodes is limited by delta_base_cache_limit, so
 631  * at some point parent node's deflated content may be freed.
 632  *
 633  * The second walker is this function, which goes from current node up
 634  * to top parent if necessary to deflate the node. In normal
 635  * situation, its parent node would be already deflated, so it just
 636  * needs to apply delta.
 637  *
 638  * In the worst case scenario, parent node is no longer deflated because
 639  * we're running out of delta_base_cache_limit; we need to re-deflate
 640  * parents, possibly up to the top base.
 641  *
 642  * All deflated objects here are subject to be freed if we exceed
 643  * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 644  * just need to make sure the last node is not freed.
 645  */
 646 static void *get_base_data(struct base_data *c)
 647 {
 648         if (!c->data) {
 649                 struct object_entry *obj = c->obj;
 650                 struct base_data **delta = NULL;
 651                 int delta_nr = 0, delta_alloc = 0;
 652
 653                 while (is_delta_type(c->obj->type) && !c->data) {
 654                         ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 655                         delta[delta_nr++] = c;
 656                         c = c->base;
 657                 }
 658                 if (!delta_nr) {
 659                         c->data = get_data_from_pack(obj);
 660                         c->size = obj->size;
 661                         get_thread_data()->base_cache_used += c->size;
 662                         prune_base_data(c);
 663                 }
 664                 for (; delta_nr > 0; delta_nr--) {
 665                         void *base, *raw;
 666                         c = delta[delta_nr - 1];
 667                         obj = c->obj;
 668                         base = get_base_data(c->base);
 669                         raw = get_data_from_pack(obj);
 670                         c->data = patch_delta(
 671                                 base, c->base->size,
 672                                 raw, obj->size,
 673                                 &c->size);
 674                         free(raw);
 675                         if (!c->data)
 676                                 bad_object(obj->idx.offset, "failed to apply delta");
 677                         get_thread_data()->base_cache_used += c->size;
 678                         prune_base_data(c);
 679                 }
 680                 free(delta);
 681         }
 682         return c->data;
 683 }
 684
 685 static void resolve_delta(struct object_entry *delta_obj,
 686                           struct base_data *base, struct base_data *result)
 687 {
 688         void *base_data, *delta_data;
 689
 690         delta_obj->real_type = base->obj->real_type;
 691         delta_obj->delta_depth = base->obj->delta_depth + 1;
 692         if (deepest_delta < delta_obj->delta_depth)
 693                 deepest_delta = delta_obj->delta_depth;
 694         delta_obj->base_object_no = base->obj - objects;
 695         delta_data = get_data_from_pack(delta_obj);
 696         base_data = get_base_data(base);
 697         result->obj = delta_obj;
 698         result->data = patch_delta(base_data, base->size,
 699                                    delta_data, delta_obj->size, &result->size);
 700         free(delta_data);
 701         if (!result->data)
 702                 bad_object(delta_obj->idx.offset, "failed to apply delta");
 703         sha1_object(result->data, result->size, delta_obj->real_type,
 704                     delta_obj->idx.sha1);
 705         counter_lock();
 706         nr_resolved_deltas++;
 707         counter_unlock();
 708 }
 709
 710 static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 711                                                   struct base_data *prev_base)
 712 {
 713         if (base->ref_last == -1 && base->ofs_last == -1) {
 714                 union delta_base base_spec;
 715
 716                 hashcpy(base_spec.sha1, base->obj->idx.sha1);
 717                 find_delta_children(&base_spec,
 718                                     &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
 719
 720                 memset(&base_spec, 0, sizeof(base_spec));
 721                 base_spec.offset = base->obj->idx.offset;
 722                 find_delta_children(&base_spec,
 723                                     &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
 724
 725                 if (base->ref_last == -1 && base->ofs_last == -1) {
 726                         free(base->data);
 727                         return NULL;
 728                 }
 729
 730                 link_base_data(prev_base, base);
 731         }
 732
 733         if (base->ref_first <= base->ref_last) {
 734                 struct object_entry *child = objects + deltas[base->ref_first].obj_no;
 735                 struct base_data *result = alloc_base_data();
 736
 737                 assert(child->real_type == OBJ_REF_DELTA);
 738                 resolve_delta(child, base, result);
 739                 if (base->ref_first == base->ref_last && base->ofs_last == -1)
 740                         free_base_data(base);
 741
 742                 base->ref_first++;
 743                 return result;
 744         }
 745
 746         if (base->ofs_first <= base->ofs_last) {
 747                 struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
 748                 struct base_data *result = alloc_base_data();
 749
 750                 assert(child->real_type == OBJ_OFS_DELTA);
 751                 resolve_delta(child, base, result);
 752                 if (base->ofs_first == base->ofs_last)
 753                         free_base_data(base);
 754
 755                 base->ofs_first++;
 756                 return result;
 757         }
 758
 759         unlink_base_data(base);
 760         return NULL;
 761 }
 762
 763 static void find_unresolved_deltas(struct base_data *base)
 764 {
 765         struct base_data *new_base, *prev_base = NULL;
 766         for (;;) {
 767                 new_base = find_unresolved_deltas_1(base, prev_base);
 768
 769                 if (new_base) {
 770                         prev_base = base;
 771                         base = new_base;
 772                 } else {
 773                         free(base);
 774                         base = prev_base;
 775                         if (!base)
 776                                 return;
 777                         prev_base = base->base;
 778                 }
 779         }
 780 }
 781
 782 static int compare_delta_entry(const void *a, const void *b)
 783 {
 784         const struct delta_entry *delta_a = a;
 785         const struct delta_entry *delta_b = b;
 786
 787         /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
 788         return compare_delta_bases(&delta_a->base, &delta_b->base,
 789                                    objects[delta_a->obj_no].type,
 790                                    objects[delta_b->obj_no].type);
 791 }
 792
 793 static void resolve_base(struct object_entry *obj)
 794 {
 795         struct base_data *base_obj = alloc_base_data();
 796         base_obj->obj = obj;
 797         base_obj->data = NULL;
 798         find_unresolved_deltas(base_obj);
 799 }
 800
 801 #ifndef NO_PTHREADS
 802 static void *threaded_second_pass(void *data)
 803 {
 804         set_thread_data(data);
 805         for (;;) {
 806                 int i;
 807                 work_lock();
 808                 display_progress(progress, nr_resolved_deltas);
 809                 while (nr_dispatched < nr_objects &&
 810                        is_delta_type(objects[nr_dispatched].type))
 811                         nr_dispatched++;
 812                 if (nr_dispatched >= nr_objects) {
 813                         work_unlock();
 814                         break;
 815                 }
 816                 i = nr_dispatched++;
 817                 work_unlock();
 818
 819                 resolve_base(&objects[i]);
 820         }
 821         return NULL;
 822 }
 823 #endif
 824
 825 /*
 826  * First pass:
 827  * - find locations of all objects;
 828  * - calculate SHA1 of all non-delta objects;
 829  * - remember base (SHA1 or offset) for all deltas.
 830  */
 831 static void parse_pack_objects(unsigned char *sha1)
 832 {
 833         int i;
 834         struct delta_entry *delta = deltas;
 835         struct stat st;
 836
 837         if (verbose)
 838                 progress = start_progress(
 839                                 from_stdin ? "Receiving objects" : "Indexing objects",
 840                                 nr_objects);
 841         for (i = 0; i < nr_objects; i++) {
 842                 struct object_entry *obj = &objects[i];
 843                 void *data = unpack_raw_entry(obj, &delta->base);
 844                 obj->real_type = obj->type;
 845                 if (is_delta_type(obj->type)) {
 846                         nr_deltas++;
 847                         delta->obj_no = i;
 848                         delta++;
 849                 } else
 850                         sha1_object(data, obj->size, obj->type, obj->idx.sha1);
 851                 free(data);
 852                 display_progress(progress, i+1);
 853         }
 854         objects[i].idx.offset = consumed_bytes;
 855         stop_progress(&progress);
 856
 857         /* Check pack integrity */
 858         flush();
 859         git_SHA1_Final(sha1, &input_ctx);
 860         if (hashcmp(fill(20), sha1))
 861                 die("pack is corrupted (SHA1 mismatch)");
 862         use(20);
 863
 864         /* If input_fd is a file, we should have reached its end now. */
 865         if (fstat(input_fd, &st))
 866                 die_errno("cannot fstat packfile");
 867         if (S_ISREG(st.st_mode) &&
 868                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
 869                 die("pack has junk at the end");
 870 }
 871
 872 /*
 873  * Second pass:
 874  * - for all non-delta objects, look if it is used as a base for
 875  *   deltas;
 876  * - if used as a base, uncompress the object and apply all deltas,
 877  *   recursively checking if the resulting object is used as a base
 878  *   for some more deltas.
 879  */
 880 static void resolve_deltas(void)
 881 {
 882         int i;
 883
 884         if (!nr_deltas)
 885                 return;
 886
 887         /* Sort deltas by base SHA1/offset for fast searching */
 888         qsort(deltas, nr_deltas, sizeof(struct delta_entry),
 889               compare_delta_entry);
 890
 891         if (verbose)
 892                 progress = start_progress("Resolving deltas", nr_deltas);
 893
 894 #ifndef NO_PTHREADS
 895         nr_dispatched = 0;
 896         if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
 897                 init_thread();
 898                 for (i = 0; i < nr_threads; i++) {
 899                         int ret = pthread_create(&thread_data[i].thread, NULL,
 900                                                  threaded_second_pass, thread_data + i);
 901                         if (ret)
 902                                 die("unable to create thread: %s", strerror(ret));
 903                 }
 904                 for (i = 0; i < nr_threads; i++)
 905                         pthread_join(thread_data[i].thread, NULL);
 906                 cleanup_thread();
 907                 return;
 908         }
 909 #endif
 910
 911         for (i = 0; i < nr_objects; i++) {
 912                 struct object_entry *obj = &objects[i];
 913
 914                 if (is_delta_type(obj->type))
 915                         continue;
 916                 resolve_base(obj);
 917                 display_progress(progress, nr_resolved_deltas);
 918         }
 919 }
 920
 921 /*
 922  * Third pass:
 923  * - append objects to convert thin pack to full pack if required
 924  * - write the final 20-byte SHA-1
 925  */
 926 static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
 927 static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
 928 {
 929         if (nr_deltas == nr_resolved_deltas) {
 930                 stop_progress(&progress);
 931                 /* Flush remaining pack final 20-byte SHA1. */
 932                 flush();
 933                 return;
 934         }
 935
 936         if (fix_thin_pack) {
 937                 struct sha1file *f;
 938                 unsigned char read_sha1[20], tail_sha1[20];
 939                 char msg[48];
 940                 int nr_unresolved = nr_deltas - nr_resolved_deltas;
 941                 int nr_objects_initial = nr_objects;
 942                 if (nr_unresolved <= 0)
 943                         die("confusion beyond insanity");
 944                 objects = xrealloc(objects,
 945                                    (nr_objects + nr_unresolved + 1)
 946                                    * sizeof(*objects));
 947                 f = sha1fd(output_fd, curr_pack);
 948                 fix_unresolved_deltas(f, nr_unresolved);
 949                 sprintf(msg, "completed with %d local objects",
 950                         nr_objects - nr_objects_initial);
 951                 stop_progress_msg(&progress, msg);
 952                 sha1close(f, tail_sha1, 0);
 953                 hashcpy(read_sha1, pack_sha1);
 954                 fixup_pack_header_footer(output_fd, pack_sha1,
 955                                          curr_pack, nr_objects,
 956                                          read_sha1, consumed_bytes-20);
 957                 if (hashcmp(read_sha1, tail_sha1) != 0)
 958                         die("Unexpected tail checksum for %s "
 959                             "(disk corruption?)", curr_pack);
 960         }
 961         if (nr_deltas != nr_resolved_deltas)
 962                 die("pack has %d unresolved deltas",
 963                     nr_deltas - nr_resolved_deltas);
 964 }
 965
 966 static int write_compressed(struct sha1file *f, void *in, unsigned int size)
 967 {
 968         git_zstream stream;
 969         int status;
 970         unsigned char outbuf[4096];
 971
 972         memset(&stream, 0, sizeof(stream));
 973         git_deflate_init(&stream, zlib_compression_level);
 974         stream.next_in = in;
 975         stream.avail_in = size;
 976
 977         do {
 978                 stream.next_out = outbuf;
 979                 stream.avail_out = sizeof(outbuf);
 980                 status = git_deflate(&stream, Z_FINISH);
 981                 sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
 982         } while (status == Z_OK);
 983
 984         if (status != Z_STREAM_END)
 985                 die("unable to deflate appended object (%d)", status);
 986         size = stream.total_out;
 987         git_deflate_end(&stream);
 988         return size;
 989 }
 990
 991 static struct object_entry *append_obj_to_pack(struct sha1file *f,
 992                                const unsigned char *sha1, void *buf,
 993                                unsigned long size, enum object_type type)
 994 {
 995         struct object_entry *obj = &objects[nr_objects++];
 996         unsigned char header[10];
 997         unsigned long s = size;
 998         int n = 0;
 999         unsigned char c = (type << 4) | (s & 15);
1000         s >>= 4;
1001         while (s) {
1002                 header[n++] = c | 0x80;
1003                 c = s & 0x7f;
1004                 s >>= 7;
1005         }
1006         header[n++] = c;
1007         crc32_begin(f);
1008         sha1write(f, header, n);
1009         obj[0].size = size;
1010         obj[0].hdr_size = n;
1011         obj[0].type = type;
1012         obj[0].real_type = type;
1013         obj[1].idx.offset = obj[0].idx.offset + n;
1014         obj[1].idx.offset += write_compressed(f, buf, size);
1015         obj[0].idx.crc32 = crc32_end(f);
1016         sha1flush(f);
1017         hashcpy(obj->idx.sha1, sha1);
1018         return obj;
1019 }
1020
1021 static int delta_pos_compare(const void *_a, const void *_b)
1022 {
1023         struct delta_entry *a = *(struct delta_entry **)_a;
1024         struct delta_entry *b = *(struct delta_entry **)_b;
1025         return a->obj_no - b->obj_no;
1026 }
1027
1028 static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
1029 {
1030         struct delta_entry **sorted_by_pos;
1031         int i, n = 0;
1032
1033         /*
1034          * Since many unresolved deltas may well be themselves base objects
1035          * for more unresolved deltas, we really want to include the
1036          * smallest number of base objects that would cover as much delta
1037          * as possible by picking the
1038          * trunc deltas first, allowing for other deltas to resolve without
1039          * additional base objects.  Since most base objects are to be found
1040          * before deltas depending on them, a good heuristic is to start
1041          * resolving deltas in the same order as their position in the pack.
1042          */
1043         sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
1044         for (i = 0; i < nr_deltas; i++) {
1045                 if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
1046                         continue;
1047                 sorted_by_pos[n++] = &deltas[i];
1048         }
1049         qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
1050
1051         for (i = 0; i < n; i++) {
1052                 struct delta_entry *d = sorted_by_pos[i];
1053                 enum object_type type;
1054                 struct base_data *base_obj = alloc_base_data();
1055
1056                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1057                         continue;
1058                 base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
1059                 if (!base_obj->data)
1060                         continue;
1061
1062                 if (check_sha1_signature(d->base.sha1, base_obj->data,
1063                                 base_obj->size, typename(type)))
1064                         die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
1065                 base_obj->obj = append_obj_to_pack(f, d->base.sha1,
1066                                         base_obj->data, base_obj->size, type);
1067                 find_unresolved_deltas(base_obj);
1068                 display_progress(progress, nr_resolved_deltas);
1069         }
1070         free(sorted_by_pos);
1071 }
1072
1073 static void final(const char *final_pack_name, const char *curr_pack_name,
1074                   const char *final_index_name, const char *curr_index_name,
1075                   const char *keep_name, const char *keep_msg,
1076                   unsigned char *sha1)
1077 {
1078         const char *report = "pack";
1079         char name[PATH_MAX];
1080         int err;
1081
1082         if (!from_stdin) {
1083                 close(input_fd);
1084         } else {
1085                 fsync_or_die(output_fd, curr_pack_name);
1086                 err = close(output_fd);
1087                 if (err)
1088                         die_errno("error while closing pack file");
1089         }
1090
1091         if (keep_msg) {
1092                 int keep_fd, keep_msg_len = strlen(keep_msg);
1093
1094                 if (!keep_name)
1095                         keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1096                 else
1097                         keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1098
1099                 if (keep_fd < 0) {
1100                         if (errno != EEXIST)
1101                                 die_errno("cannot write keep file '%s'",
1102                                           keep_name);
1103                 } else {
1104                         if (keep_msg_len > 0) {
1105                                 write_or_die(keep_fd, keep_msg, keep_msg_len);
1106                                 write_or_die(keep_fd, "\n", 1);
1107                         }
1108                         if (close(keep_fd) != 0)
1109                                 die_errno("cannot close written keep file '%s'",
1110                                     keep_name);
1111                         report = "keep";
1112                 }
1113         }
1114
1115         if (final_pack_name != curr_pack_name) {
1116                 if (!final_pack_name) {
1117                         snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1118                                  get_object_directory(), sha1_to_hex(sha1));
1119                         final_pack_name = name;
1120                 }
1121                 if (move_temp_to_file(curr_pack_name, final_pack_name))
1122                         die("cannot store pack file");
1123         } else if (from_stdin)
1124                 chmod(final_pack_name, 0444);
1125
1126         if (final_index_name != curr_index_name) {
1127                 if (!final_index_name) {
1128                         snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1129                                  get_object_directory(), sha1_to_hex(sha1));
1130                         final_index_name = name;
1131                 }
1132                 if (move_temp_to_file(curr_index_name, final_index_name))
1133                         die("cannot store index file");
1134         } else
1135                 chmod(final_index_name, 0444);
1136
1137         if (!from_stdin) {
1138                 printf("%s\n", sha1_to_hex(sha1));
1139         } else {
1140                 char buf[48];
1141                 int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1142                                    report, sha1_to_hex(sha1));
1143                 write_or_die(1, buf, len);
1144
1145                 /*
1146                  * Let's just mimic git-unpack-objects here and write
1147                  * the last part of the input buffer to stdout.
1148                  */
1149                 while (input_len) {
1150                         err = xwrite(1, input_buffer + input_offset, input_len);
1151                         if (err <= 0)
1152                                 break;
1153                         input_len -= err;
1154                         input_offset += err;
1155                 }
1156         }
1157 }
1158
1159 static int git_index_pack_config(const char *k, const char *v, void *cb)
1160 {
1161         struct pack_idx_option *opts = cb;
1162
1163         if (!strcmp(k, "pack.indexversion")) {
1164                 opts->version = git_config_int(k, v);
1165                 if (opts->version > 2)
1166                         die("bad pack.indexversion=%"PRIu32, opts->version);
1167                 return 0;
1168         }
1169         if (!strcmp(k, "pack.threads")) {
1170                 nr_threads = git_config_int(k, v);
1171                 if (nr_threads < 0)
1172                         die("invalid number of threads specified (%d)",
1173                             nr_threads);
1174 #ifdef NO_PTHREADS
1175                 if (nr_threads != 1)
1176                         warning("no threads support, ignoring %s", k);
1177                 nr_threads = 1;
1178 #endif
1179                 return 0;
1180         }
1181         return git_default_config(k, v, cb);
1182 }
1183
1184 static int cmp_uint32(const void *a_, const void *b_)
1185 {
1186         uint32_t a = *((uint32_t *)a_);
1187         uint32_t b = *((uint32_t *)b_);
1188
1189         return (a < b) ? -1 : (a != b);
1190 }
1191
1192 static void read_v2_anomalous_offsets(struct packed_git *p,
1193                                       struct pack_idx_option *opts)
1194 {
1195         const uint32_t *idx1, *idx2;
1196         uint32_t i;
1197
1198         /* The address of the 4-byte offset table */
1199         idx1 = (((const uint32_t *)p->index_data)
1200                 + 2 /* 8-byte header */
1201                 + 256 /* fan out */
1202                 + 5 * p->num_objects /* 20-byte SHA-1 table */
1203                 + p->num_objects /* CRC32 table */
1204                 );
1205
1206         /* The address of the 8-byte offset table */
1207         idx2 = idx1 + p->num_objects;
1208
1209         for (i = 0; i < p->num_objects; i++) {
1210                 uint32_t off = ntohl(idx1[i]);
1211                 if (!(off & 0x80000000))
1212                         continue;
1213                 off = off & 0x7fffffff;
1214                 if (idx2[off * 2])
1215                         continue;
1216                 /*
1217                  * The real offset is ntohl(idx2[off * 2]) in high 4
1218                  * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1219                  * octets.  But idx2[off * 2] is Zero!!!
1220                  */
1221                 ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1222                 opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1223         }
1224
1225         if (1 < opts->anomaly_nr)
1226                 qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1227 }
1228
1229 static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1230 {
1231         struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1232
1233         if (!p)
1234                 die("Cannot open existing pack file '%s'", pack_name);
1235         if (open_pack_index(p))
1236                 die("Cannot open existing pack idx file for '%s'", pack_name);
1237
1238         /* Read the attributes from the existing idx file */
1239         opts->version = p->index_version;
1240
1241         if (opts->version == 2)
1242                 read_v2_anomalous_offsets(p, opts);
1243
1244         /*
1245          * Get rid of the idx file as we do not need it anymore.
1246          * NEEDSWORK: extract this bit from free_pack_by_name() in
1247          * sha1_file.c, perhaps?  It shouldn't matter very much as we
1248          * know we haven't installed this pack (hence we never have
1249          * read anything from it).
1250          */
1251         close_pack_index(p);
1252         free(p);
1253 }
1254
1255 static void show_pack_info(int stat_only)
1256 {
1257         int i, baseobjects = nr_objects - nr_deltas;
1258         unsigned long *chain_histogram = NULL;
1259
1260         if (deepest_delta)
1261                 chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1262
1263         for (i = 0; i < nr_objects; i++) {
1264                 struct object_entry *obj = &objects[i];
1265
1266                 if (is_delta_type(obj->type))
1267                         chain_histogram[obj->delta_depth - 1]++;
1268                 if (stat_only)
1269                         continue;
1270                 printf("%s %-6s %lu %lu %"PRIuMAX,
1271                        sha1_to_hex(obj->idx.sha1),
1272                        typename(obj->real_type), obj->size,
1273                        (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1274                        (uintmax_t)obj->idx.offset);
1275                 if (is_delta_type(obj->type)) {
1276                         struct object_entry *bobj = &objects[obj->base_object_no];
1277                         printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
1278                 }
1279                 putchar('\n');
1280         }
1281
1282         if (baseobjects)
1283                 printf("non delta: %d object%s\n",
1284                        baseobjects, baseobjects > 1 ? "s" : "");
1285         for (i = 0; i < deepest_delta; i++) {
1286                 if (!chain_histogram[i])
1287                         continue;
1288                 printf("chain length = %d: %lu object%s\n",
1289                        i + 1,
1290                        chain_histogram[i],
1291                        chain_histogram[i] > 1 ? "s" : "");
1292         }
1293 }
1294
1295 int cmd_index_pack(int argc, const char **argv, const char *prefix)
1296 {
1297         int i, fix_thin_pack = 0, verify = 0, stat_only = 0, stat = 0;
1298         const char *curr_pack, *curr_index;
1299         const char *index_name = NULL, *pack_name = NULL;
1300         const char *keep_name = NULL, *keep_msg = NULL;
1301         char *index_name_buf = NULL, *keep_name_buf = NULL;
1302         struct pack_idx_entry **idx_objects;
1303         struct pack_idx_option opts;
1304         unsigned char pack_sha1[20];
1305
1306         if (argc == 2 && !strcmp(argv[1], "-h"))
1307                 usage(index_pack_usage);
1308
1309         read_replace_refs = 0;
1310
1311         reset_pack_idx_option(&opts);
1312         git_config(git_index_pack_config, &opts);
1313         if (prefix && chdir(prefix))
1314                 die("Cannot come back to cwd");
1315
1316         for (i = 1; i < argc; i++) {
1317                 const char *arg = argv[i];
1318
1319                 if (*arg == '-') {
1320                         if (!strcmp(arg, "--stdin")) {
1321                                 from_stdin = 1;
1322                         } else if (!strcmp(arg, "--fix-thin")) {
1323                                 fix_thin_pack = 1;
1324                         } else if (!strcmp(arg, "--strict")) {
1325                                 strict = 1;
1326                         } else if (!strcmp(arg, "--verify")) {
1327                                 verify = 1;
1328                         } else if (!strcmp(arg, "--verify-stat")) {
1329                                 verify = 1;
1330                                 stat = 1;
1331                         } else if (!strcmp(arg, "--verify-stat-only")) {
1332                                 verify = 1;
1333                                 stat = 1;
1334                                 stat_only = 1;
1335                         } else if (!strcmp(arg, "--keep")) {
1336                                 keep_msg = "";
1337                         } else if (!prefixcmp(arg, "--keep=")) {
1338                                 keep_msg = arg + 7;
1339                         } else if (!prefixcmp(arg, "--threads=")) {
1340                                 char *end;
1341                                 nr_threads = strtoul(arg+10, &end, 0);
1342                                 if (!arg[10] || *end || nr_threads < 0)
1343                                         usage(index_pack_usage);
1344 #ifdef NO_PTHREADS
1345                                 if (nr_threads != 1)
1346                                         warning("no threads support, "
1347                                                 "ignoring %s", arg);
1348                                 nr_threads = 1;
1349 #endif
1350                         } else if (!prefixcmp(arg, "--pack_header=")) {
1351                                 struct pack_header *hdr;
1352                                 char *c;
1353
1354                                 hdr = (struct pack_header *)input_buffer;
1355                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
1356                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1357                                 if (*c != ',')
1358                                         die("bad %s", arg);
1359                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1360                                 if (*c)
1361                                         die("bad %s", arg);
1362                                 input_len = sizeof(*hdr);
1363                         } else if (!strcmp(arg, "-v")) {
1364                                 verbose = 1;
1365                         } else if (!strcmp(arg, "-o")) {
1366                                 if (index_name || (i+1) >= argc)
1367                                         usage(index_pack_usage);
1368                                 index_name = argv[++i];
1369                         } else if (!prefixcmp(arg, "--index-version=")) {
1370                                 char *c;
1371                                 opts.version = strtoul(arg + 16, &c, 10);
1372                                 if (opts.version > 2)
1373                                         die("bad %s", arg);
1374                                 if (*c == ',')
1375                                         opts.off32_limit = strtoul(c+1, &c, 0);
1376                                 if (*c || opts.off32_limit & 0x80000000)
1377                                         die("bad %s", arg);
1378                         } else
1379                                 usage(index_pack_usage);
1380                         continue;
1381                 }
1382
1383                 if (pack_name)
1384                         usage(index_pack_usage);
1385                 pack_name = arg;
1386         }
1387
1388         if (!pack_name && !from_stdin)
1389                 usage(index_pack_usage);
1390         if (fix_thin_pack && !from_stdin)
1391                 die("--fix-thin cannot be used without --stdin");
1392         if (!index_name && pack_name) {
1393                 int len = strlen(pack_name);
1394                 if (!has_extension(pack_name, ".pack"))
1395                         die("packfile name '%s' does not end with '.pack'",
1396                             pack_name);
1397                 index_name_buf = xmalloc(len);
1398                 memcpy(index_name_buf, pack_name, len - 5);
1399                 strcpy(index_name_buf + len - 5, ".idx");
1400                 index_name = index_name_buf;
1401         }
1402         if (keep_msg && !keep_name && pack_name) {
1403                 int len = strlen(pack_name);
1404                 if (!has_extension(pack_name, ".pack"))
1405                         die("packfile name '%s' does not end with '.pack'",
1406                             pack_name);
1407                 keep_name_buf = xmalloc(len);
1408                 memcpy(keep_name_buf, pack_name, len - 5);
1409                 strcpy(keep_name_buf + len - 5, ".keep");
1410                 keep_name = keep_name_buf;
1411         }
1412         if (verify) {
1413                 if (!index_name)
1414                         die("--verify with no packfile name given");
1415                 read_idx_option(&opts, index_name);
1416                 opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1417         }
1418         if (strict)
1419                 opts.flags |= WRITE_IDX_STRICT;
1420
1421 #ifndef NO_PTHREADS
1422         if (!nr_threads) {
1423                 nr_threads = online_cpus();
1424                 /* An experiment showed that more threads does not mean faster */
1425                 if (nr_threads > 3)
1426                         nr_threads = 3;
1427         }
1428 #endif
1429
1430         curr_pack = open_pack_file(pack_name);
1431         parse_pack_header();
1432         objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1433         deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
1434         parse_pack_objects(pack_sha1);
1435         resolve_deltas();
1436         conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1437         free(deltas);
1438         if (strict)
1439                 check_objects();
1440
1441         if (stat)
1442                 show_pack_info(stat_only);
1443
1444         idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1445         for (i = 0; i < nr_objects; i++)
1446                 idx_objects[i] = &objects[i].idx;
1447         curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1448         free(idx_objects);
1449
1450         if (!verify)
1451                 final(pack_name, curr_pack,
1452                       index_name, curr_index,
1453                       keep_name, keep_msg,
1454                       pack_sha1);
1455         else
1456                 close(input_fd);
1457         free(objects);
1458         free(index_name_buf);
1459         free(keep_name_buf);
1460         if (pack_name == NULL)
1461                 free((void *) curr_pack);
1462         if (index_name == NULL)
1463                 free((void *) curr_index);
1464
1465         return 0;
1466 }