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 #if !defined(NO_PTHREADS) && defined(NO_PREAD)
  43 /* NO_PREAD uses compat/pread.c, which is not thread-safe. Disable threading. */
  44 #define NO_PTHREADS
  45 #endif
  46
  47 struct thread_local {
  48 #ifndef NO_PTHREADS
  49         pthread_t thread;
  50 #endif
  51         struct base_data *base_cache;
  52         size_t base_cache_used;
  53 };
  54
  55 /*
  56  * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
  57  * to memcmp() only the first 20 bytes.
  58  */
  59 #define UNION_BASE_SZ   20
  60
  61 #define FLAG_LINK (1u<<20)
  62 #define FLAG_CHECKED (1u<<21)
  63
  64 struct delta_entry {
  65         union delta_base base;
  66         int obj_no;
  67 };
  68
  69 static struct object_entry *objects;
  70 static struct delta_entry *deltas;
  71 static struct thread_local nothread_data;
  72 static int nr_objects;
  73 static int nr_deltas;
  74 static int nr_resolved_deltas;
  75 static int nr_threads;
  76
  77 static int from_stdin;
  78 static int strict;
  79 static int verbose;
  80
  81 static struct progress *progress;
  82
  83 /* We always read in 4kB chunks. */
  84 static unsigned char input_buffer[4096];
  85 static unsigned int input_offset, input_len;
  86 static off_t consumed_bytes;
  87 static unsigned deepest_delta;
  88 static git_SHA_CTX input_ctx;
  89 static uint32_t input_crc32;
  90 static int input_fd, output_fd, pack_fd;
  91
  92 #ifndef NO_PTHREADS
  93
  94 static struct thread_local *thread_data;
  95 static int nr_dispatched;
  96 static int threads_active;
  97
  98 static pthread_mutex_t read_mutex;
  99 #define read_lock()             lock_mutex(&read_mutex)
 100 #define read_unlock()           unlock_mutex(&read_mutex)
 101
 102 static pthread_mutex_t counter_mutex;
 103 #define counter_lock()          lock_mutex(&counter_mutex)
 104 #define counter_unlock()        unlock_mutex(&counter_mutex)
 105
 106 static pthread_mutex_t work_mutex;
 107 #define work_lock()             lock_mutex(&work_mutex)
 108 #define work_unlock()           unlock_mutex(&work_mutex)
 109
 110 static pthread_key_t key;
 111
 112 static inline void lock_mutex(pthread_mutex_t *mutex)
 113 {
 114         if (threads_active)
 115                 pthread_mutex_lock(mutex);
 116 }
 117
 118 static inline void unlock_mutex(pthread_mutex_t *mutex)
 119 {
 120         if (threads_active)
 121                 pthread_mutex_unlock(mutex);
 122 }
 123
 124 /*
 125  * Mutex and conditional variable can't be statically-initialized on Windows.
 126  */
 127 static void init_thread(void)
 128 {
 129         init_recursive_mutex(&read_mutex);
 130         pthread_mutex_init(&counter_mutex, NULL);
 131         pthread_mutex_init(&work_mutex, NULL);
 132         pthread_key_create(&key, NULL);
 133         thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 134         threads_active = 1;
 135 }
 136
 137 static void cleanup_thread(void)
 138 {
 139         if (!threads_active)
 140                 return;
 141         threads_active = 0;
 142         pthread_mutex_destroy(&read_mutex);
 143         pthread_mutex_destroy(&counter_mutex);
 144         pthread_mutex_destroy(&work_mutex);
 145         pthread_key_delete(key);
 146         free(thread_data);
 147 }
 148
 149 #else
 150
 151 #define read_lock()
 152 #define read_unlock()
 153
 154 #define counter_lock()
 155 #define counter_unlock()
 156
 157 #define work_lock()
 158 #define work_unlock()
 159
 160 #endif
 161
 162
 163 static int mark_link(struct object *obj, int type, void *data)
 164 {
 165         if (!obj)
 166                 return -1;
 167
 168         if (type != OBJ_ANY && obj->type != type)
 169                 die(_("object type mismatch at %s"), sha1_to_hex(obj->sha1));
 170
 171         obj->flags |= FLAG_LINK;
 172         return 0;
 173 }
 174
 175 /* The content of each linked object must have been checked
 176    or it must be already present in the object database */
 177 static void check_object(struct object *obj)
 178 {
 179         if (!obj)
 180                 return;
 181
 182         if (!(obj->flags & FLAG_LINK))
 183                 return;
 184
 185         if (!(obj->flags & FLAG_CHECKED)) {
 186                 unsigned long size;
 187                 int type = sha1_object_info(obj->sha1, &size);
 188                 if (type != obj->type || type <= 0)
 189                         die(_("object of unexpected type"));
 190                 obj->flags |= FLAG_CHECKED;
 191                 return;
 192         }
 193 }
 194
 195 static void check_objects(void)
 196 {
 197         unsigned i, max;
 198
 199         max = get_max_object_index();
 200         for (i = 0; i < max; i++)
 201                 check_object(get_indexed_object(i));
 202 }
 203
 204
 205 /* Discard current buffer used content. */
 206 static void flush(void)
 207 {
 208         if (input_offset) {
 209                 if (output_fd >= 0)
 210                         write_or_die(output_fd, input_buffer, input_offset);
 211                 git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 212                 memmove(input_buffer, input_buffer + input_offset, input_len);
 213                 input_offset = 0;
 214         }
 215 }
 216
 217 /*
 218  * Make sure at least "min" bytes are available in the buffer, and
 219  * return the pointer to the buffer.
 220  */
 221 static void *fill(int min)
 222 {
 223         if (min <= input_len)
 224                 return input_buffer + input_offset;
 225         if (min > sizeof(input_buffer))
 226                 die(Q_("cannot fill %d byte",
 227                        "cannot fill %d bytes",
 228                        min),
 229                     min);
 230         flush();
 231         do {
 232                 ssize_t ret = xread(input_fd, input_buffer + input_len,
 233                                 sizeof(input_buffer) - input_len);
 234                 if (ret <= 0) {
 235                         if (!ret)
 236                                 die(_("early EOF"));
 237                         die_errno(_("read error on input"));
 238                 }
 239                 input_len += ret;
 240                 if (from_stdin)
 241                         display_throughput(progress, consumed_bytes + input_len);
 242         } while (input_len < min);
 243         return input_buffer;
 244 }
 245
 246 static void use(int bytes)
 247 {
 248         if (bytes > input_len)
 249                 die(_("used more bytes than were available"));
 250         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 251         input_len -= bytes;
 252         input_offset += bytes;
 253
 254         /* make sure off_t is sufficiently large not to wrap */
 255         if (signed_add_overflows(consumed_bytes, bytes))
 256                 die(_("pack too large for current definition of off_t"));
 257         consumed_bytes += bytes;
 258 }
 259
 260 static const char *open_pack_file(const char *pack_name)
 261 {
 262         if (from_stdin) {
 263                 input_fd = 0;
 264                 if (!pack_name) {
 265                         static char tmp_file[PATH_MAX];
 266                         output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 267                                                 "pack/tmp_pack_XXXXXX");
 268                         pack_name = xstrdup(tmp_file);
 269                 } else
 270                         output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 271                 if (output_fd < 0)
 272                         die_errno(_("unable to create '%s'"), pack_name);
 273                 pack_fd = output_fd;
 274         } else {
 275                 input_fd = open(pack_name, O_RDONLY);
 276                 if (input_fd < 0)
 277                         die_errno(_("cannot open packfile '%s'"), pack_name);
 278                 output_fd = -1;
 279                 pack_fd = input_fd;
 280         }
 281         git_SHA1_Init(&input_ctx);
 282         return pack_name;
 283 }
 284
 285 static void parse_pack_header(void)
 286 {
 287         struct pack_header *hdr = fill(sizeof(struct pack_header));
 288
 289         /* Header consistency check */
 290         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 291                 die(_("pack signature mismatch"));
 292         if (!pack_version_ok(hdr->hdr_version))
 293                 die("pack version %"PRIu32" unsupported",
 294                         ntohl(hdr->hdr_version));
 295
 296         nr_objects = ntohl(hdr->hdr_entries);
 297         use(sizeof(struct pack_header));
 298 }
 299
 300 static NORETURN void bad_object(unsigned long offset, const char *format,
 301                        ...) __attribute__((format (printf, 2, 3)));
 302
 303 static NORETURN void bad_object(unsigned long offset, const char *format, ...)
 304 {
 305         va_list params;
 306         char buf[1024];
 307
 308         va_start(params, format);
 309         vsnprintf(buf, sizeof(buf), format, params);
 310         va_end(params);
 311         die(_("pack has bad object at offset %lu: %s"), offset, buf);
 312 }
 313
 314 static inline struct thread_local *get_thread_data(void)
 315 {
 316 #ifndef NO_PTHREADS
 317         if (threads_active)
 318                 return pthread_getspecific(key);
 319         assert(!threads_active &&
 320                "This should only be reached when all threads are gone");
 321 #endif
 322         return &nothread_data;
 323 }
 324
 325 #ifndef NO_PTHREADS
 326 static void set_thread_data(struct thread_local *data)
 327 {
 328         if (threads_active)
 329                 pthread_setspecific(key, data);
 330 }
 331 #endif
 332
 333 static struct base_data *alloc_base_data(void)
 334 {
 335         struct base_data *base = xmalloc(sizeof(struct base_data));
 336         memset(base, 0, sizeof(*base));
 337         base->ref_last = -1;
 338         base->ofs_last = -1;
 339         return base;
 340 }
 341
 342 static void free_base_data(struct base_data *c)
 343 {
 344         if (c->data) {
 345                 free(c->data);
 346                 c->data = NULL;
 347                 get_thread_data()->base_cache_used -= c->size;
 348         }
 349 }
 350
 351 static void prune_base_data(struct base_data *retain)
 352 {
 353         struct base_data *b;
 354         struct thread_local *data = get_thread_data();
 355         for (b = data->base_cache;
 356              data->base_cache_used > delta_base_cache_limit && b;
 357              b = b->child) {
 358                 if (b->data && b != retain)
 359                         free_base_data(b);
 360         }
 361 }
 362
 363 static void link_base_data(struct base_data *base, struct base_data *c)
 364 {
 365         if (base)
 366                 base->child = c;
 367         else
 368                 get_thread_data()->base_cache = c;
 369
 370         c->base = base;
 371         c->child = NULL;
 372         if (c->data)
 373                 get_thread_data()->base_cache_used += c->size;
 374         prune_base_data(c);
 375 }
 376
 377 static void unlink_base_data(struct base_data *c)
 378 {
 379         struct base_data *base = c->base;
 380         if (base)
 381                 base->child = NULL;
 382         else
 383                 get_thread_data()->base_cache = NULL;
 384         free_base_data(c);
 385 }
 386
 387 static int is_delta_type(enum object_type type)
 388 {
 389         return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 390 }
 391
 392 static void *unpack_entry_data(unsigned long offset, unsigned long size,
 393                                enum object_type type, unsigned char *sha1)
 394 {
 395         int status;
 396         git_zstream stream;
 397         void *buf = xmalloc(size);
 398         git_SHA_CTX c;
 399         char hdr[32];
 400         int hdrlen;
 401
 402         if (!is_delta_type(type)) {
 403                 hdrlen = sprintf(hdr, "%s %lu", typename(type), size) + 1;
 404                 git_SHA1_Init(&c);
 405                 git_SHA1_Update(&c, hdr, hdrlen);
 406         } else
 407                 sha1 = NULL;
 408
 409         memset(&stream, 0, sizeof(stream));
 410         git_inflate_init(&stream);
 411         stream.next_out = buf;
 412         stream.avail_out = size;
 413
 414         do {
 415                 unsigned char *last_out = stream.next_out;
 416                 stream.next_in = fill(1);
 417                 stream.avail_in = input_len;
 418                 status = git_inflate(&stream, 0);
 419                 use(input_len - stream.avail_in);
 420                 if (sha1)
 421                         git_SHA1_Update(&c, last_out, stream.next_out - last_out);
 422         } while (status == Z_OK);
 423         if (stream.total_out != size || status != Z_STREAM_END)
 424                 bad_object(offset, _("inflate returned %d"), status);
 425         git_inflate_end(&stream);
 426         if (sha1)
 427                 git_SHA1_Final(sha1, &c);
 428         return buf;
 429 }
 430
 431 static void *unpack_raw_entry(struct object_entry *obj,
 432                               union delta_base *delta_base,
 433                               unsigned char *sha1)
 434 {
 435         unsigned char *p;
 436         unsigned long size, c;
 437         off_t base_offset;
 438         unsigned shift;
 439         void *data;
 440
 441         obj->idx.offset = consumed_bytes;
 442         input_crc32 = crc32(0, NULL, 0);
 443
 444         p = fill(1);
 445         c = *p;
 446         use(1);
 447         obj->type = (c >> 4) & 7;
 448         size = (c & 15);
 449         shift = 4;
 450         while (c & 0x80) {
 451                 p = fill(1);
 452                 c = *p;
 453                 use(1);
 454                 size += (c & 0x7f) << shift;
 455                 shift += 7;
 456         }
 457         obj->size = size;
 458
 459         switch (obj->type) {
 460         case OBJ_REF_DELTA:
 461                 hashcpy(delta_base->sha1, fill(20));
 462                 use(20);
 463                 break;
 464         case OBJ_OFS_DELTA:
 465                 memset(delta_base, 0, sizeof(*delta_base));
 466                 p = fill(1);
 467                 c = *p;
 468                 use(1);
 469                 base_offset = c & 127;
 470                 while (c & 128) {
 471                         base_offset += 1;
 472                         if (!base_offset || MSB(base_offset, 7))
 473                                 bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 474                         p = fill(1);
 475                         c = *p;
 476                         use(1);
 477                         base_offset = (base_offset << 7) + (c & 127);
 478                 }
 479                 delta_base->offset = obj->idx.offset - base_offset;
 480                 if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
 481                         bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 482                 break;
 483         case OBJ_COMMIT:
 484         case OBJ_TREE:
 485         case OBJ_BLOB:
 486         case OBJ_TAG:
 487                 break;
 488         default:
 489                 bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 490         }
 491         obj->hdr_size = consumed_bytes - obj->idx.offset;
 492
 493         data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
 494         obj->idx.crc32 = input_crc32;
 495         return data;
 496 }
 497
 498 static void *get_data_from_pack(struct object_entry *obj)
 499 {
 500         off_t from = obj[0].idx.offset + obj[0].hdr_size;
 501         unsigned long len = obj[1].idx.offset - from;
 502         unsigned char *data, *inbuf;
 503         git_zstream stream;
 504         int status;
 505
 506         data = xmalloc(obj->size);
 507         inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
 508
 509         memset(&stream, 0, sizeof(stream));
 510         git_inflate_init(&stream);
 511         stream.next_out = data;
 512         stream.avail_out = obj->size;
 513
 514         do {
 515                 ssize_t n = (len < 64*1024) ? len : 64*1024;
 516                 n = pread(pack_fd, inbuf, n, from);
 517                 if (n < 0)
 518                         die_errno(_("cannot pread pack file"));
 519                 if (!n)
 520                         die(Q_("premature end of pack file, %lu byte missing",
 521                                "premature end of pack file, %lu bytes missing",
 522                                len),
 523                             len);
 524                 from += n;
 525                 len -= n;
 526                 stream.next_in = inbuf;
 527                 stream.avail_in = n;
 528                 status = git_inflate(&stream, 0);
 529         } while (len && status == Z_OK && !stream.avail_in);
 530
 531         /* This has been inflated OK when first encountered, so... */
 532         if (status != Z_STREAM_END || stream.total_out != obj->size)
 533                 die(_("serious inflate inconsistency"));
 534
 535         git_inflate_end(&stream);
 536         free(inbuf);
 537         return data;
 538 }
 539
 540 static int compare_delta_bases(const union delta_base *base1,
 541                                const union delta_base *base2,
 542                                enum object_type type1,
 543                                enum object_type type2)
 544 {
 545         int cmp = type1 - type2;
 546         if (cmp)
 547                 return cmp;
 548         return memcmp(base1, base2, UNION_BASE_SZ);
 549 }
 550
 551 static int find_delta(const union delta_base *base, enum object_type type)
 552 {
 553         int first = 0, last = nr_deltas;
 554
 555         while (first < last) {
 556                 int next = (first + last) / 2;
 557                 struct delta_entry *delta = &deltas[next];
 558                 int cmp;
 559
 560                 cmp = compare_delta_bases(base, &delta->base,
 561                                           type, objects[delta->obj_no].type);
 562                 if (!cmp)
 563                         return next;
 564                 if (cmp < 0) {
 565                         last = next;
 566                         continue;
 567                 }
 568                 first = next+1;
 569         }
 570         return -first-1;
 571 }
 572
 573 static void find_delta_children(const union delta_base *base,
 574                                 int *first_index, int *last_index,
 575                                 enum object_type type)
 576 {
 577         int first = find_delta(base, type);
 578         int last = first;
 579         int end = nr_deltas - 1;
 580
 581         if (first < 0) {
 582                 *first_index = 0;
 583                 *last_index = -1;
 584                 return;
 585         }
 586         while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 587                 --first;
 588         while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 589                 ++last;
 590         *first_index = first;
 591         *last_index = last;
 592 }
 593
 594 static void sha1_object(const void *data, unsigned long size,
 595                         enum object_type type, const unsigned char *sha1)
 596 {
 597         read_lock();
 598         if (has_sha1_file(sha1)) {
 599                 void *has_data;
 600                 enum object_type has_type;
 601                 unsigned long has_size;
 602                 has_data = read_sha1_file(sha1, &has_type, &has_size);
 603                 read_unlock();
 604                 if (!has_data)
 605                         die(_("cannot read existing object %s"), sha1_to_hex(sha1));
 606                 if (size != has_size || type != has_type ||
 607                     memcmp(data, has_data, size) != 0)
 608                         die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 609                 free(has_data);
 610         } else
 611                 read_unlock();
 612
 613         if (strict) {
 614                 read_lock();
 615                 if (type == OBJ_BLOB) {
 616                         struct blob *blob = lookup_blob(sha1);
 617                         if (blob)
 618                                 blob->object.flags |= FLAG_CHECKED;
 619                         else
 620                                 die(_("invalid blob object %s"), sha1_to_hex(sha1));
 621                 } else {
 622                         struct object *obj;
 623                         int eaten;
 624                         void *buf = (void *) data;
 625
 626                         /*
 627                          * we do not need to free the memory here, as the
 628                          * buf is deleted by the caller.
 629                          */
 630                         obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 631                         if (!obj)
 632                                 die(_("invalid %s"), typename(type));
 633                         if (fsck_object(obj, 1, fsck_error_function))
 634                                 die(_("Error in object"));
 635                         if (fsck_walk(obj, mark_link, NULL))
 636                                 die(_("Not all child objects of %s are reachable"), sha1_to_hex(obj->sha1));
 637
 638                         if (obj->type == OBJ_TREE) {
 639                                 struct tree *item = (struct tree *) obj;
 640                                 item->buffer = NULL;
 641                         }
 642                         if (obj->type == OBJ_COMMIT) {
 643                                 struct commit *commit = (struct commit *) obj;
 644                                 commit->buffer = NULL;
 645                         }
 646                         obj->flags |= FLAG_CHECKED;
 647                 }
 648                 read_unlock();
 649         }
 650 }
 651
 652 /*
 653  * This function is part of find_unresolved_deltas(). There are two
 654  * walkers going in the opposite ways.
 655  *
 656  * The first one in find_unresolved_deltas() traverses down from
 657  * parent node to children, deflating nodes along the way. However,
 658  * memory for deflated nodes is limited by delta_base_cache_limit, so
 659  * at some point parent node's deflated content may be freed.
 660  *
 661  * The second walker is this function, which goes from current node up
 662  * to top parent if necessary to deflate the node. In normal
 663  * situation, its parent node would be already deflated, so it just
 664  * needs to apply delta.
 665  *
 666  * In the worst case scenario, parent node is no longer deflated because
 667  * we're running out of delta_base_cache_limit; we need to re-deflate
 668  * parents, possibly up to the top base.
 669  *
 670  * All deflated objects here are subject to be freed if we exceed
 671  * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 672  * just need to make sure the last node is not freed.
 673  */
 674 static void *get_base_data(struct base_data *c)
 675 {
 676         if (!c->data) {
 677                 struct object_entry *obj = c->obj;
 678                 struct base_data **delta = NULL;
 679                 int delta_nr = 0, delta_alloc = 0;
 680
 681                 while (is_delta_type(c->obj->type) && !c->data) {
 682                         ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 683                         delta[delta_nr++] = c;
 684                         c = c->base;
 685                 }
 686                 if (!delta_nr) {
 687                         c->data = get_data_from_pack(obj);
 688                         c->size = obj->size;
 689                         get_thread_data()->base_cache_used += c->size;
 690                         prune_base_data(c);
 691                 }
 692                 for (; delta_nr > 0; delta_nr--) {
 693                         void *base, *raw;
 694                         c = delta[delta_nr - 1];
 695                         obj = c->obj;
 696                         base = get_base_data(c->base);
 697                         raw = get_data_from_pack(obj);
 698                         c->data = patch_delta(
 699                                 base, c->base->size,
 700                                 raw, obj->size,
 701                                 &c->size);
 702                         free(raw);
 703                         if (!c->data)
 704                                 bad_object(obj->idx.offset, _("failed to apply delta"));
 705                         get_thread_data()->base_cache_used += c->size;
 706                         prune_base_data(c);
 707                 }
 708                 free(delta);
 709         }
 710         return c->data;
 711 }
 712
 713 static void resolve_delta(struct object_entry *delta_obj,
 714                           struct base_data *base, struct base_data *result)
 715 {
 716         void *base_data, *delta_data;
 717
 718         delta_obj->real_type = base->obj->real_type;
 719         delta_obj->delta_depth = base->obj->delta_depth + 1;
 720         if (deepest_delta < delta_obj->delta_depth)
 721                 deepest_delta = delta_obj->delta_depth;
 722         delta_obj->base_object_no = base->obj - objects;
 723         delta_data = get_data_from_pack(delta_obj);
 724         base_data = get_base_data(base);
 725         result->obj = delta_obj;
 726         result->data = patch_delta(base_data, base->size,
 727                                    delta_data, delta_obj->size, &result->size);
 728         free(delta_data);
 729         if (!result->data)
 730                 bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 731         hash_sha1_file(result->data, result->size,
 732                        typename(delta_obj->real_type), delta_obj->idx.sha1);
 733         sha1_object(result->data, result->size, delta_obj->real_type,
 734                     delta_obj->idx.sha1);
 735         counter_lock();
 736         nr_resolved_deltas++;
 737         counter_unlock();
 738 }
 739
 740 static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 741                                                   struct base_data *prev_base)
 742 {
 743         if (base->ref_last == -1 && base->ofs_last == -1) {
 744                 union delta_base base_spec;
 745
 746                 hashcpy(base_spec.sha1, base->obj->idx.sha1);
 747                 find_delta_children(&base_spec,
 748                                     &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
 749
 750                 memset(&base_spec, 0, sizeof(base_spec));
 751                 base_spec.offset = base->obj->idx.offset;
 752                 find_delta_children(&base_spec,
 753                                     &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
 754
 755                 if (base->ref_last == -1 && base->ofs_last == -1) {
 756                         free(base->data);
 757                         return NULL;
 758                 }
 759
 760                 link_base_data(prev_base, base);
 761         }
 762
 763         if (base->ref_first <= base->ref_last) {
 764                 struct object_entry *child = objects + deltas[base->ref_first].obj_no;
 765                 struct base_data *result = alloc_base_data();
 766
 767                 assert(child->real_type == OBJ_REF_DELTA);
 768                 resolve_delta(child, base, result);
 769                 if (base->ref_first == base->ref_last && base->ofs_last == -1)
 770                         free_base_data(base);
 771
 772                 base->ref_first++;
 773                 return result;
 774         }
 775
 776         if (base->ofs_first <= base->ofs_last) {
 777                 struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
 778                 struct base_data *result = alloc_base_data();
 779
 780                 assert(child->real_type == OBJ_OFS_DELTA);
 781                 resolve_delta(child, base, result);
 782                 if (base->ofs_first == base->ofs_last)
 783                         free_base_data(base);
 784
 785                 base->ofs_first++;
 786                 return result;
 787         }
 788
 789         unlink_base_data(base);
 790         return NULL;
 791 }
 792
 793 static void find_unresolved_deltas(struct base_data *base)
 794 {
 795         struct base_data *new_base, *prev_base = NULL;
 796         for (;;) {
 797                 new_base = find_unresolved_deltas_1(base, prev_base);
 798
 799                 if (new_base) {
 800                         prev_base = base;
 801                         base = new_base;
 802                 } else {
 803                         free(base);
 804                         base = prev_base;
 805                         if (!base)
 806                                 return;
 807                         prev_base = base->base;
 808                 }
 809         }
 810 }
 811
 812 static int compare_delta_entry(const void *a, const void *b)
 813 {
 814         const struct delta_entry *delta_a = a;
 815         const struct delta_entry *delta_b = b;
 816
 817         /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
 818         return compare_delta_bases(&delta_a->base, &delta_b->base,
 819                                    objects[delta_a->obj_no].type,
 820                                    objects[delta_b->obj_no].type);
 821 }
 822
 823 static void resolve_base(struct object_entry *obj)
 824 {
 825         struct base_data *base_obj = alloc_base_data();
 826         base_obj->obj = obj;
 827         base_obj->data = NULL;
 828         find_unresolved_deltas(base_obj);
 829 }
 830
 831 #ifndef NO_PTHREADS
 832 static void *threaded_second_pass(void *data)
 833 {
 834         set_thread_data(data);
 835         for (;;) {
 836                 int i;
 837                 work_lock();
 838                 display_progress(progress, nr_resolved_deltas);
 839                 while (nr_dispatched < nr_objects &&
 840                        is_delta_type(objects[nr_dispatched].type))
 841                         nr_dispatched++;
 842                 if (nr_dispatched >= nr_objects) {
 843                         work_unlock();
 844                         break;
 845                 }
 846                 i = nr_dispatched++;
 847                 work_unlock();
 848
 849                 resolve_base(&objects[i]);
 850         }
 851         return NULL;
 852 }
 853 #endif
 854
 855 /*
 856  * First pass:
 857  * - find locations of all objects;
 858  * - calculate SHA1 of all non-delta objects;
 859  * - remember base (SHA1 or offset) for all deltas.
 860  */
 861 static void parse_pack_objects(unsigned char *sha1)
 862 {
 863         int i;
 864         struct delta_entry *delta = deltas;
 865         struct stat st;
 866
 867         if (verbose)
 868                 progress = start_progress(
 869                                 from_stdin ? _("Receiving objects") : _("Indexing objects"),
 870                                 nr_objects);
 871         for (i = 0; i < nr_objects; i++) {
 872                 struct object_entry *obj = &objects[i];
 873                 void *data = unpack_raw_entry(obj, &delta->base, obj->idx.sha1);
 874                 obj->real_type = obj->type;
 875                 if (is_delta_type(obj->type)) {
 876                         nr_deltas++;
 877                         delta->obj_no = i;
 878                         delta++;
 879                 } else
 880                         sha1_object(data, obj->size, obj->type, obj->idx.sha1);
 881                 free(data);
 882                 display_progress(progress, i+1);
 883         }
 884         objects[i].idx.offset = consumed_bytes;
 885         stop_progress(&progress);
 886
 887         /* Check pack integrity */
 888         flush();
 889         git_SHA1_Final(sha1, &input_ctx);
 890         if (hashcmp(fill(20), sha1))
 891                 die(_("pack is corrupted (SHA1 mismatch)"));
 892         use(20);
 893
 894         /* If input_fd is a file, we should have reached its end now. */
 895         if (fstat(input_fd, &st))
 896                 die_errno(_("cannot fstat packfile"));
 897         if (S_ISREG(st.st_mode) &&
 898                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
 899                 die(_("pack has junk at the end"));
 900 }
 901
 902 /*
 903  * Second pass:
 904  * - for all non-delta objects, look if it is used as a base for
 905  *   deltas;
 906  * - if used as a base, uncompress the object and apply all deltas,
 907  *   recursively checking if the resulting object is used as a base
 908  *   for some more deltas.
 909  */
 910 static void resolve_deltas(void)
 911 {
 912         int i;
 913
 914         if (!nr_deltas)
 915                 return;
 916
 917         /* Sort deltas by base SHA1/offset for fast searching */
 918         qsort(deltas, nr_deltas, sizeof(struct delta_entry),
 919               compare_delta_entry);
 920
 921         if (verbose)
 922                 progress = start_progress(_("Resolving deltas"), nr_deltas);
 923
 924 #ifndef NO_PTHREADS
 925         nr_dispatched = 0;
 926         if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
 927                 init_thread();
 928                 for (i = 0; i < nr_threads; i++) {
 929                         int ret = pthread_create(&thread_data[i].thread, NULL,
 930                                                  threaded_second_pass, thread_data + i);
 931                         if (ret)
 932                                 die("unable to create thread: %s", strerror(ret));
 933                 }
 934                 for (i = 0; i < nr_threads; i++)
 935                         pthread_join(thread_data[i].thread, NULL);
 936                 cleanup_thread();
 937                 return;
 938         }
 939 #endif
 940
 941         for (i = 0; i < nr_objects; i++) {
 942                 struct object_entry *obj = &objects[i];
 943
 944                 if (is_delta_type(obj->type))
 945                         continue;
 946                 resolve_base(obj);
 947                 display_progress(progress, nr_resolved_deltas);
 948         }
 949 }
 950
 951 /*
 952  * Third pass:
 953  * - append objects to convert thin pack to full pack if required
 954  * - write the final 20-byte SHA-1
 955  */
 956 static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
 957 static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
 958 {
 959         if (nr_deltas == nr_resolved_deltas) {
 960                 stop_progress(&progress);
 961                 /* Flush remaining pack final 20-byte SHA1. */
 962                 flush();
 963                 return;
 964         }
 965
 966         if (fix_thin_pack) {
 967                 struct sha1file *f;
 968                 unsigned char read_sha1[20], tail_sha1[20];
 969                 char msg[48];
 970                 int nr_unresolved = nr_deltas - nr_resolved_deltas;
 971                 int nr_objects_initial = nr_objects;
 972                 if (nr_unresolved <= 0)
 973                         die(_("confusion beyond insanity"));
 974                 objects = xrealloc(objects,
 975                                    (nr_objects + nr_unresolved + 1)
 976                                    * sizeof(*objects));
 977                 f = sha1fd(output_fd, curr_pack);
 978                 fix_unresolved_deltas(f, nr_unresolved);
 979                 sprintf(msg, "completed with %d local objects",
 980                         nr_objects - nr_objects_initial);
 981                 stop_progress_msg(&progress, msg);
 982                 sha1close(f, tail_sha1, 0);
 983                 hashcpy(read_sha1, pack_sha1);
 984                 fixup_pack_header_footer(output_fd, pack_sha1,
 985                                          curr_pack, nr_objects,
 986                                          read_sha1, consumed_bytes-20);
 987                 if (hashcmp(read_sha1, tail_sha1) != 0)
 988                         die("Unexpected tail checksum for %s "
 989                             "(disk corruption?)", curr_pack);
 990         }
 991         if (nr_deltas != nr_resolved_deltas)
 992                 die(Q_("pack has %d unresolved delta",
 993                        "pack has %d unresolved deltas",
 994                        nr_deltas - nr_resolved_deltas),
 995                     nr_deltas - nr_resolved_deltas);
 996 }
 997
 998 static int write_compressed(struct sha1file *f, void *in, unsigned int size)
 999 {
1000         git_zstream stream;
1001         int status;
1002         unsigned char outbuf[4096];
1003
1004         memset(&stream, 0, sizeof(stream));
1005         git_deflate_init(&stream, zlib_compression_level);
1006         stream.next_in = in;
1007         stream.avail_in = size;
1008
1009         do {
1010                 stream.next_out = outbuf;
1011                 stream.avail_out = sizeof(outbuf);
1012                 status = git_deflate(&stream, Z_FINISH);
1013                 sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1014         } while (status == Z_OK);
1015
1016         if (status != Z_STREAM_END)
1017                 die(_("unable to deflate appended object (%d)"), status);
1018         size = stream.total_out;
1019         git_deflate_end(&stream);
1020         return size;
1021 }
1022
1023 static struct object_entry *append_obj_to_pack(struct sha1file *f,
1024                                const unsigned char *sha1, void *buf,
1025                                unsigned long size, enum object_type type)
1026 {
1027         struct object_entry *obj = &objects[nr_objects++];
1028         unsigned char header[10];
1029         unsigned long s = size;
1030         int n = 0;
1031         unsigned char c = (type << 4) | (s & 15);
1032         s >>= 4;
1033         while (s) {
1034                 header[n++] = c | 0x80;
1035                 c = s & 0x7f;
1036                 s >>= 7;
1037         }
1038         header[n++] = c;
1039         crc32_begin(f);
1040         sha1write(f, header, n);
1041         obj[0].size = size;
1042         obj[0].hdr_size = n;
1043         obj[0].type = type;
1044         obj[0].real_type = type;
1045         obj[1].idx.offset = obj[0].idx.offset + n;
1046         obj[1].idx.offset += write_compressed(f, buf, size);
1047         obj[0].idx.crc32 = crc32_end(f);
1048         sha1flush(f);
1049         hashcpy(obj->idx.sha1, sha1);
1050         return obj;
1051 }
1052
1053 static int delta_pos_compare(const void *_a, const void *_b)
1054 {
1055         struct delta_entry *a = *(struct delta_entry **)_a;
1056         struct delta_entry *b = *(struct delta_entry **)_b;
1057         return a->obj_no - b->obj_no;
1058 }
1059
1060 static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
1061 {
1062         struct delta_entry **sorted_by_pos;
1063         int i, n = 0;
1064
1065         /*
1066          * Since many unresolved deltas may well be themselves base objects
1067          * for more unresolved deltas, we really want to include the
1068          * smallest number of base objects that would cover as much delta
1069          * as possible by picking the
1070          * trunc deltas first, allowing for other deltas to resolve without
1071          * additional base objects.  Since most base objects are to be found
1072          * before deltas depending on them, a good heuristic is to start
1073          * resolving deltas in the same order as their position in the pack.
1074          */
1075         sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
1076         for (i = 0; i < nr_deltas; i++) {
1077                 if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
1078                         continue;
1079                 sorted_by_pos[n++] = &deltas[i];
1080         }
1081         qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
1082
1083         for (i = 0; i < n; i++) {
1084                 struct delta_entry *d = sorted_by_pos[i];
1085                 enum object_type type;
1086                 struct base_data *base_obj = alloc_base_data();
1087
1088                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1089                         continue;
1090                 base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
1091                 if (!base_obj->data)
1092                         continue;
1093
1094                 if (check_sha1_signature(d->base.sha1, base_obj->data,
1095                                 base_obj->size, typename(type)))
1096                         die(_("local object %s is corrupt"), sha1_to_hex(d->base.sha1));
1097                 base_obj->obj = append_obj_to_pack(f, d->base.sha1,
1098                                         base_obj->data, base_obj->size, type);
1099                 find_unresolved_deltas(base_obj);
1100                 display_progress(progress, nr_resolved_deltas);
1101         }
1102         free(sorted_by_pos);
1103 }
1104
1105 static void final(const char *final_pack_name, const char *curr_pack_name,
1106                   const char *final_index_name, const char *curr_index_name,
1107                   const char *keep_name, const char *keep_msg,
1108                   unsigned char *sha1)
1109 {
1110         const char *report = "pack";
1111         char name[PATH_MAX];
1112         int err;
1113
1114         if (!from_stdin) {
1115                 close(input_fd);
1116         } else {
1117                 fsync_or_die(output_fd, curr_pack_name);
1118                 err = close(output_fd);
1119                 if (err)
1120                         die_errno(_("error while closing pack file"));
1121         }
1122
1123         if (keep_msg) {
1124                 int keep_fd, keep_msg_len = strlen(keep_msg);
1125
1126                 if (!keep_name)
1127                         keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1128                 else
1129                         keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1130
1131                 if (keep_fd < 0) {
1132                         if (errno != EEXIST)
1133                                 die_errno(_("cannot write keep file '%s'"),
1134                                           keep_name);
1135                 } else {
1136                         if (keep_msg_len > 0) {
1137                                 write_or_die(keep_fd, keep_msg, keep_msg_len);
1138                                 write_or_die(keep_fd, "\n", 1);
1139                         }
1140                         if (close(keep_fd) != 0)
1141                                 die_errno(_("cannot close written keep file '%s'"),
1142                                     keep_name);
1143                         report = "keep";
1144                 }
1145         }
1146
1147         if (final_pack_name != curr_pack_name) {
1148                 if (!final_pack_name) {
1149                         snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1150                                  get_object_directory(), sha1_to_hex(sha1));
1151                         final_pack_name = name;
1152                 }
1153                 if (move_temp_to_file(curr_pack_name, final_pack_name))
1154                         die(_("cannot store pack file"));
1155         } else if (from_stdin)
1156                 chmod(final_pack_name, 0444);
1157
1158         if (final_index_name != curr_index_name) {
1159                 if (!final_index_name) {
1160                         snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1161                                  get_object_directory(), sha1_to_hex(sha1));
1162                         final_index_name = name;
1163                 }
1164                 if (move_temp_to_file(curr_index_name, final_index_name))
1165                         die(_("cannot store index file"));
1166         } else
1167                 chmod(final_index_name, 0444);
1168
1169         if (!from_stdin) {
1170                 printf("%s\n", sha1_to_hex(sha1));
1171         } else {
1172                 char buf[48];
1173                 int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1174                                    report, sha1_to_hex(sha1));
1175                 write_or_die(1, buf, len);
1176
1177                 /*
1178                  * Let's just mimic git-unpack-objects here and write
1179                  * the last part of the input buffer to stdout.
1180                  */
1181                 while (input_len) {
1182                         err = xwrite(1, input_buffer + input_offset, input_len);
1183                         if (err <= 0)
1184                                 break;
1185                         input_len -= err;
1186                         input_offset += err;
1187                 }
1188         }
1189 }
1190
1191 static int git_index_pack_config(const char *k, const char *v, void *cb)
1192 {
1193         struct pack_idx_option *opts = cb;
1194
1195         if (!strcmp(k, "pack.indexversion")) {
1196                 opts->version = git_config_int(k, v);
1197                 if (opts->version > 2)
1198                         die("bad pack.indexversion=%"PRIu32, opts->version);
1199                 return 0;
1200         }
1201         if (!strcmp(k, "pack.threads")) {
1202                 nr_threads = git_config_int(k, v);
1203                 if (nr_threads < 0)
1204                         die("invalid number of threads specified (%d)",
1205                             nr_threads);
1206 #ifdef NO_PTHREADS
1207                 if (nr_threads != 1)
1208                         warning("no threads support, ignoring %s", k);
1209                 nr_threads = 1;
1210 #endif
1211                 return 0;
1212         }
1213         return git_default_config(k, v, cb);
1214 }
1215
1216 static int cmp_uint32(const void *a_, const void *b_)
1217 {
1218         uint32_t a = *((uint32_t *)a_);
1219         uint32_t b = *((uint32_t *)b_);
1220
1221         return (a < b) ? -1 : (a != b);
1222 }
1223
1224 static void read_v2_anomalous_offsets(struct packed_git *p,
1225                                       struct pack_idx_option *opts)
1226 {
1227         const uint32_t *idx1, *idx2;
1228         uint32_t i;
1229
1230         /* The address of the 4-byte offset table */
1231         idx1 = (((const uint32_t *)p->index_data)
1232                 + 2 /* 8-byte header */
1233                 + 256 /* fan out */
1234                 + 5 * p->num_objects /* 20-byte SHA-1 table */
1235                 + p->num_objects /* CRC32 table */
1236                 );
1237
1238         /* The address of the 8-byte offset table */
1239         idx2 = idx1 + p->num_objects;
1240
1241         for (i = 0; i < p->num_objects; i++) {
1242                 uint32_t off = ntohl(idx1[i]);
1243                 if (!(off & 0x80000000))
1244                         continue;
1245                 off = off & 0x7fffffff;
1246                 if (idx2[off * 2])
1247                         continue;
1248                 /*
1249                  * The real offset is ntohl(idx2[off * 2]) in high 4
1250                  * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1251                  * octets.  But idx2[off * 2] is Zero!!!
1252                  */
1253                 ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1254                 opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1255         }
1256
1257         if (1 < opts->anomaly_nr)
1258                 qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1259 }
1260
1261 static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1262 {
1263         struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1264
1265         if (!p)
1266                 die(_("Cannot open existing pack file '%s'"), pack_name);
1267         if (open_pack_index(p))
1268                 die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1269
1270         /* Read the attributes from the existing idx file */
1271         opts->version = p->index_version;
1272
1273         if (opts->version == 2)
1274                 read_v2_anomalous_offsets(p, opts);
1275
1276         /*
1277          * Get rid of the idx file as we do not need it anymore.
1278          * NEEDSWORK: extract this bit from free_pack_by_name() in
1279          * sha1_file.c, perhaps?  It shouldn't matter very much as we
1280          * know we haven't installed this pack (hence we never have
1281          * read anything from it).
1282          */
1283         close_pack_index(p);
1284         free(p);
1285 }
1286
1287 static void show_pack_info(int stat_only)
1288 {
1289         int i, baseobjects = nr_objects - nr_deltas;
1290         unsigned long *chain_histogram = NULL;
1291
1292         if (deepest_delta)
1293                 chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1294
1295         for (i = 0; i < nr_objects; i++) {
1296                 struct object_entry *obj = &objects[i];
1297
1298                 if (is_delta_type(obj->type))
1299                         chain_histogram[obj->delta_depth - 1]++;
1300                 if (stat_only)
1301                         continue;
1302                 printf("%s %-6s %lu %lu %"PRIuMAX,
1303                        sha1_to_hex(obj->idx.sha1),
1304                        typename(obj->real_type), obj->size,
1305                        (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1306                        (uintmax_t)obj->idx.offset);
1307                 if (is_delta_type(obj->type)) {
1308                         struct object_entry *bobj = &objects[obj->base_object_no];
1309                         printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
1310                 }
1311                 putchar('\n');
1312         }
1313
1314         if (baseobjects)
1315                 printf_ln(Q_("non delta: %d object",
1316                              "non delta: %d objects",
1317                              baseobjects),
1318                           baseobjects);
1319         for (i = 0; i < deepest_delta; i++) {
1320                 if (!chain_histogram[i])
1321                         continue;
1322                 printf_ln(Q_("chain length = %d: %lu object",
1323                              "chain length = %d: %lu objects",
1324                              chain_histogram[i]),
1325                           i + 1,
1326                           chain_histogram[i]);
1327         }
1328 }
1329
1330 int cmd_index_pack(int argc, const char **argv, const char *prefix)
1331 {
1332         int i, fix_thin_pack = 0, verify = 0, stat_only = 0, stat = 0;
1333         const char *curr_pack, *curr_index;
1334         const char *index_name = NULL, *pack_name = NULL;
1335         const char *keep_name = NULL, *keep_msg = NULL;
1336         char *index_name_buf = NULL, *keep_name_buf = NULL;
1337         struct pack_idx_entry **idx_objects;
1338         struct pack_idx_option opts;
1339         unsigned char pack_sha1[20];
1340
1341         if (argc == 2 && !strcmp(argv[1], "-h"))
1342                 usage(index_pack_usage);
1343
1344         read_replace_refs = 0;
1345
1346         reset_pack_idx_option(&opts);
1347         git_config(git_index_pack_config, &opts);
1348         if (prefix && chdir(prefix))
1349                 die(_("Cannot come back to cwd"));
1350
1351         for (i = 1; i < argc; i++) {
1352                 const char *arg = argv[i];
1353
1354                 if (*arg == '-') {
1355                         if (!strcmp(arg, "--stdin")) {
1356                                 from_stdin = 1;
1357                         } else if (!strcmp(arg, "--fix-thin")) {
1358                                 fix_thin_pack = 1;
1359                         } else if (!strcmp(arg, "--strict")) {
1360                                 strict = 1;
1361                         } else if (!strcmp(arg, "--verify")) {
1362                                 verify = 1;
1363                         } else if (!strcmp(arg, "--verify-stat")) {
1364                                 verify = 1;
1365                                 stat = 1;
1366                         } else if (!strcmp(arg, "--verify-stat-only")) {
1367                                 verify = 1;
1368                                 stat = 1;
1369                                 stat_only = 1;
1370                         } else if (!strcmp(arg, "--keep")) {
1371                                 keep_msg = "";
1372                         } else if (!prefixcmp(arg, "--keep=")) {
1373                                 keep_msg = arg + 7;
1374                         } else if (!prefixcmp(arg, "--threads=")) {
1375                                 char *end;
1376                                 nr_threads = strtoul(arg+10, &end, 0);
1377                                 if (!arg[10] || *end || nr_threads < 0)
1378                                         usage(index_pack_usage);
1379 #ifdef NO_PTHREADS
1380                                 if (nr_threads != 1)
1381                                         warning("no threads support, "
1382                                                 "ignoring %s", arg);
1383                                 nr_threads = 1;
1384 #endif
1385                         } else if (!prefixcmp(arg, "--pack_header=")) {
1386                                 struct pack_header *hdr;
1387                                 char *c;
1388
1389                                 hdr = (struct pack_header *)input_buffer;
1390                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
1391                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1392                                 if (*c != ',')
1393                                         die(_("bad %s"), arg);
1394                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1395                                 if (*c)
1396                                         die(_("bad %s"), arg);
1397                                 input_len = sizeof(*hdr);
1398                         } else if (!strcmp(arg, "-v")) {
1399                                 verbose = 1;
1400                         } else if (!strcmp(arg, "-o")) {
1401                                 if (index_name || (i+1) >= argc)
1402                                         usage(index_pack_usage);
1403                                 index_name = argv[++i];
1404                         } else if (!prefixcmp(arg, "--index-version=")) {
1405                                 char *c;
1406                                 opts.version = strtoul(arg + 16, &c, 10);
1407                                 if (opts.version > 2)
1408                                         die(_("bad %s"), arg);
1409                                 if (*c == ',')
1410                                         opts.off32_limit = strtoul(c+1, &c, 0);
1411                                 if (*c || opts.off32_limit & 0x80000000)
1412                                         die(_("bad %s"), arg);
1413                         } else
1414                                 usage(index_pack_usage);
1415                         continue;
1416                 }
1417
1418                 if (pack_name)
1419                         usage(index_pack_usage);
1420                 pack_name = arg;
1421         }
1422
1423         if (!pack_name && !from_stdin)
1424                 usage(index_pack_usage);
1425         if (fix_thin_pack && !from_stdin)
1426                 die(_("--fix-thin cannot be used without --stdin"));
1427         if (!index_name && pack_name) {
1428                 int len = strlen(pack_name);
1429                 if (!has_extension(pack_name, ".pack"))
1430                         die(_("packfile name '%s' does not end with '.pack'"),
1431                             pack_name);
1432                 index_name_buf = xmalloc(len);
1433                 memcpy(index_name_buf, pack_name, len - 5);
1434                 strcpy(index_name_buf + len - 5, ".idx");
1435                 index_name = index_name_buf;
1436         }
1437         if (keep_msg && !keep_name && pack_name) {
1438                 int len = strlen(pack_name);
1439                 if (!has_extension(pack_name, ".pack"))
1440                         die(_("packfile name '%s' does not end with '.pack'"),
1441                             pack_name);
1442                 keep_name_buf = xmalloc(len);
1443                 memcpy(keep_name_buf, pack_name, len - 5);
1444                 strcpy(keep_name_buf + len - 5, ".keep");
1445                 keep_name = keep_name_buf;
1446         }
1447         if (verify) {
1448                 if (!index_name)
1449                         die(_("--verify with no packfile name given"));
1450                 read_idx_option(&opts, index_name);
1451                 opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1452         }
1453         if (strict)
1454                 opts.flags |= WRITE_IDX_STRICT;
1455
1456 #ifndef NO_PTHREADS
1457         if (!nr_threads) {
1458                 nr_threads = online_cpus();
1459                 /* An experiment showed that more threads does not mean faster */
1460                 if (nr_threads > 3)
1461                         nr_threads = 3;
1462         }
1463 #endif
1464
1465         curr_pack = open_pack_file(pack_name);
1466         parse_pack_header();
1467         objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1468         deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
1469         parse_pack_objects(pack_sha1);
1470         resolve_deltas();
1471         conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1472         free(deltas);
1473         if (strict)
1474                 check_objects();
1475
1476         if (stat)
1477                 show_pack_info(stat_only);
1478
1479         idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1480         for (i = 0; i < nr_objects; i++)
1481                 idx_objects[i] = &objects[i].idx;
1482         curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1483         free(idx_objects);
1484
1485         if (!verify)
1486                 final(pack_name, curr_pack,
1487                       index_name, curr_index,
1488                       keep_name, keep_msg,
1489                       pack_sha1);
1490         else
1491                 close(input_fd);
1492         free(objects);
1493         free(index_name_buf);
1494         free(keep_name_buf);
1495         if (pack_name == NULL)
1496                 free((void *) curr_pack);
1497         if (index_name == NULL)
1498                 free((void *) curr_index);
1499
1500         return 0;
1501 }