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 #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         static char fixed_buf[8192];
 396         int status;
 397         git_zstream stream;
 398         void *buf;
 399         git_SHA_CTX c;
 400         char hdr[32];
 401         int hdrlen;
 402
 403         if (!is_delta_type(type)) {
 404                 hdrlen = sprintf(hdr, "%s %lu", typename(type), size) + 1;
 405                 git_SHA1_Init(&c);
 406                 git_SHA1_Update(&c, hdr, hdrlen);
 407         } else
 408                 sha1 = NULL;
 409         if (type == OBJ_BLOB && size > big_file_threshold)
 410                 buf = fixed_buf;
 411         else
 412                 buf = xmalloc(size);
 413
 414         memset(&stream, 0, sizeof(stream));
 415         git_inflate_init(&stream);
 416         stream.next_out = buf;
 417         stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 418
 419         do {
 420                 unsigned char *last_out = stream.next_out;
 421                 stream.next_in = fill(1);
 422                 stream.avail_in = input_len;
 423                 status = git_inflate(&stream, 0);
 424                 use(input_len - stream.avail_in);
 425                 if (sha1)
 426                         git_SHA1_Update(&c, last_out, stream.next_out - last_out);
 427                 if (buf == fixed_buf) {
 428                         stream.next_out = buf;
 429                         stream.avail_out = sizeof(fixed_buf);
 430                 }
 431         } while (status == Z_OK);
 432         if (stream.total_out != size || status != Z_STREAM_END)
 433                 bad_object(offset, _("inflate returned %d"), status);
 434         git_inflate_end(&stream);
 435         if (sha1)
 436                 git_SHA1_Final(sha1, &c);
 437         return buf == fixed_buf ? NULL : buf;
 438 }
 439
 440 static void *unpack_raw_entry(struct object_entry *obj,
 441                               union delta_base *delta_base,
 442                               unsigned char *sha1)
 443 {
 444         unsigned char *p;
 445         unsigned long size, c;
 446         off_t base_offset;
 447         unsigned shift;
 448         void *data;
 449
 450         obj->idx.offset = consumed_bytes;
 451         input_crc32 = crc32(0, NULL, 0);
 452
 453         p = fill(1);
 454         c = *p;
 455         use(1);
 456         obj->type = (c >> 4) & 7;
 457         size = (c & 15);
 458         shift = 4;
 459         while (c & 0x80) {
 460                 p = fill(1);
 461                 c = *p;
 462                 use(1);
 463                 size += (c & 0x7f) << shift;
 464                 shift += 7;
 465         }
 466         obj->size = size;
 467
 468         switch (obj->type) {
 469         case OBJ_REF_DELTA:
 470                 hashcpy(delta_base->sha1, fill(20));
 471                 use(20);
 472                 break;
 473         case OBJ_OFS_DELTA:
 474                 memset(delta_base, 0, sizeof(*delta_base));
 475                 p = fill(1);
 476                 c = *p;
 477                 use(1);
 478                 base_offset = c & 127;
 479                 while (c & 128) {
 480                         base_offset += 1;
 481                         if (!base_offset || MSB(base_offset, 7))
 482                                 bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 483                         p = fill(1);
 484                         c = *p;
 485                         use(1);
 486                         base_offset = (base_offset << 7) + (c & 127);
 487                 }
 488                 delta_base->offset = obj->idx.offset - base_offset;
 489                 if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
 490                         bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 491                 break;
 492         case OBJ_COMMIT:
 493         case OBJ_TREE:
 494         case OBJ_BLOB:
 495         case OBJ_TAG:
 496                 break;
 497         default:
 498                 bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 499         }
 500         obj->hdr_size = consumed_bytes - obj->idx.offset;
 501
 502         data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
 503         obj->idx.crc32 = input_crc32;
 504         return data;
 505 }
 506
 507 static void *get_data_from_pack(struct object_entry *obj)
 508 {
 509         off_t from = obj[0].idx.offset + obj[0].hdr_size;
 510         unsigned long len = obj[1].idx.offset - from;
 511         unsigned char *data, *inbuf;
 512         git_zstream stream;
 513         int status;
 514
 515         data = xmalloc(obj->size);
 516         inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
 517
 518         memset(&stream, 0, sizeof(stream));
 519         git_inflate_init(&stream);
 520         stream.next_out = data;
 521         stream.avail_out = obj->size;
 522
 523         do {
 524                 ssize_t n = (len < 64*1024) ? len : 64*1024;
 525                 n = pread(pack_fd, inbuf, n, from);
 526                 if (n < 0)
 527                         die_errno(_("cannot pread pack file"));
 528                 if (!n)
 529                         die(Q_("premature end of pack file, %lu byte missing",
 530                                "premature end of pack file, %lu bytes missing",
 531                                len),
 532                             len);
 533                 from += n;
 534                 len -= n;
 535                 stream.next_in = inbuf;
 536                 stream.avail_in = n;
 537                 status = git_inflate(&stream, 0);
 538         } while (len && status == Z_OK && !stream.avail_in);
 539
 540         /* This has been inflated OK when first encountered, so... */
 541         if (status != Z_STREAM_END || stream.total_out != obj->size)
 542                 die(_("serious inflate inconsistency"));
 543
 544         git_inflate_end(&stream);
 545         free(inbuf);
 546         return data;
 547 }
 548
 549 static int compare_delta_bases(const union delta_base *base1,
 550                                const union delta_base *base2,
 551                                enum object_type type1,
 552                                enum object_type type2)
 553 {
 554         int cmp = type1 - type2;
 555         if (cmp)
 556                 return cmp;
 557         return memcmp(base1, base2, UNION_BASE_SZ);
 558 }
 559
 560 static int find_delta(const union delta_base *base, enum object_type type)
 561 {
 562         int first = 0, last = nr_deltas;
 563
 564         while (first < last) {
 565                 int next = (first + last) / 2;
 566                 struct delta_entry *delta = &deltas[next];
 567                 int cmp;
 568
 569                 cmp = compare_delta_bases(base, &delta->base,
 570                                           type, objects[delta->obj_no].type);
 571                 if (!cmp)
 572                         return next;
 573                 if (cmp < 0) {
 574                         last = next;
 575                         continue;
 576                 }
 577                 first = next+1;
 578         }
 579         return -first-1;
 580 }
 581
 582 static void find_delta_children(const union delta_base *base,
 583                                 int *first_index, int *last_index,
 584                                 enum object_type type)
 585 {
 586         int first = find_delta(base, type);
 587         int last = first;
 588         int end = nr_deltas - 1;
 589
 590         if (first < 0) {
 591                 *first_index = 0;
 592                 *last_index = -1;
 593                 return;
 594         }
 595         while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 596                 --first;
 597         while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 598                 ++last;
 599         *first_index = first;
 600         *last_index = last;
 601 }
 602
 603 static void sha1_object(const void *data, struct object_entry *obj_entry,
 604                         unsigned long size, enum object_type type,
 605                         const unsigned char *sha1)
 606 {
 607         void *new_data = NULL;
 608
 609         assert(data || obj_entry);
 610
 611         read_lock();
 612         if (has_sha1_file(sha1)) {
 613                 void *has_data;
 614                 enum object_type has_type;
 615                 unsigned long has_size;
 616                 if (!data)
 617                         data = new_data = get_data_from_pack(obj_entry);
 618                 has_data = read_sha1_file(sha1, &has_type, &has_size);
 619                 read_unlock();
 620                 if (!has_data)
 621                         die(_("cannot read existing object %s"), sha1_to_hex(sha1));
 622                 if (size != has_size || type != has_type ||
 623                     memcmp(data, has_data, size) != 0)
 624                         die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 625                 free(has_data);
 626         } else
 627                 read_unlock();
 628
 629         if (strict) {
 630                 read_lock();
 631                 if (type == OBJ_BLOB) {
 632                         struct blob *blob = lookup_blob(sha1);
 633                         if (blob)
 634                                 blob->object.flags |= FLAG_CHECKED;
 635                         else
 636                                 die(_("invalid blob object %s"), sha1_to_hex(sha1));
 637                 } else {
 638                         struct object *obj;
 639                         int eaten;
 640                         void *buf = (void *) data;
 641
 642                         if (!buf)
 643                                 buf = new_data = get_data_from_pack(obj_entry);
 644
 645                         /*
 646                          * we do not need to free the memory here, as the
 647                          * buf is deleted by the caller.
 648                          */
 649                         obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 650                         if (!obj)
 651                                 die(_("invalid %s"), typename(type));
 652                         if (fsck_object(obj, 1, fsck_error_function))
 653                                 die(_("Error in object"));
 654                         if (fsck_walk(obj, mark_link, NULL))
 655                                 die(_("Not all child objects of %s are reachable"), sha1_to_hex(obj->sha1));
 656
 657                         if (obj->type == OBJ_TREE) {
 658                                 struct tree *item = (struct tree *) obj;
 659                                 item->buffer = NULL;
 660                         }
 661                         if (obj->type == OBJ_COMMIT) {
 662                                 struct commit *commit = (struct commit *) obj;
 663                                 commit->buffer = NULL;
 664                         }
 665                         obj->flags |= FLAG_CHECKED;
 666                 }
 667                 read_unlock();
 668         }
 669
 670         free(new_data);
 671 }
 672
 673 /*
 674  * This function is part of find_unresolved_deltas(). There are two
 675  * walkers going in the opposite ways.
 676  *
 677  * The first one in find_unresolved_deltas() traverses down from
 678  * parent node to children, deflating nodes along the way. However,
 679  * memory for deflated nodes is limited by delta_base_cache_limit, so
 680  * at some point parent node's deflated content may be freed.
 681  *
 682  * The second walker is this function, which goes from current node up
 683  * to top parent if necessary to deflate the node. In normal
 684  * situation, its parent node would be already deflated, so it just
 685  * needs to apply delta.
 686  *
 687  * In the worst case scenario, parent node is no longer deflated because
 688  * we're running out of delta_base_cache_limit; we need to re-deflate
 689  * parents, possibly up to the top base.
 690  *
 691  * All deflated objects here are subject to be freed if we exceed
 692  * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 693  * just need to make sure the last node is not freed.
 694  */
 695 static void *get_base_data(struct base_data *c)
 696 {
 697         if (!c->data) {
 698                 struct object_entry *obj = c->obj;
 699                 struct base_data **delta = NULL;
 700                 int delta_nr = 0, delta_alloc = 0;
 701
 702                 while (is_delta_type(c->obj->type) && !c->data) {
 703                         ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 704                         delta[delta_nr++] = c;
 705                         c = c->base;
 706                 }
 707                 if (!delta_nr) {
 708                         c->data = get_data_from_pack(obj);
 709                         c->size = obj->size;
 710                         get_thread_data()->base_cache_used += c->size;
 711                         prune_base_data(c);
 712                 }
 713                 for (; delta_nr > 0; delta_nr--) {
 714                         void *base, *raw;
 715                         c = delta[delta_nr - 1];
 716                         obj = c->obj;
 717                         base = get_base_data(c->base);
 718                         raw = get_data_from_pack(obj);
 719                         c->data = patch_delta(
 720                                 base, c->base->size,
 721                                 raw, obj->size,
 722                                 &c->size);
 723                         free(raw);
 724                         if (!c->data)
 725                                 bad_object(obj->idx.offset, _("failed to apply delta"));
 726                         get_thread_data()->base_cache_used += c->size;
 727                         prune_base_data(c);
 728                 }
 729                 free(delta);
 730         }
 731         return c->data;
 732 }
 733
 734 static void resolve_delta(struct object_entry *delta_obj,
 735                           struct base_data *base, struct base_data *result)
 736 {
 737         void *base_data, *delta_data;
 738
 739         delta_obj->real_type = base->obj->real_type;
 740         delta_obj->delta_depth = base->obj->delta_depth + 1;
 741         if (deepest_delta < delta_obj->delta_depth)
 742                 deepest_delta = delta_obj->delta_depth;
 743         delta_obj->base_object_no = base->obj - objects;
 744         delta_data = get_data_from_pack(delta_obj);
 745         base_data = get_base_data(base);
 746         result->obj = delta_obj;
 747         result->data = patch_delta(base_data, base->size,
 748                                    delta_data, delta_obj->size, &result->size);
 749         free(delta_data);
 750         if (!result->data)
 751                 bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 752         hash_sha1_file(result->data, result->size,
 753                        typename(delta_obj->real_type), delta_obj->idx.sha1);
 754         sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 755                     delta_obj->idx.sha1);
 756         counter_lock();
 757         nr_resolved_deltas++;
 758         counter_unlock();
 759 }
 760
 761 static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 762                                                   struct base_data *prev_base)
 763 {
 764         if (base->ref_last == -1 && base->ofs_last == -1) {
 765                 union delta_base base_spec;
 766
 767                 hashcpy(base_spec.sha1, base->obj->idx.sha1);
 768                 find_delta_children(&base_spec,
 769                                     &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
 770
 771                 memset(&base_spec, 0, sizeof(base_spec));
 772                 base_spec.offset = base->obj->idx.offset;
 773                 find_delta_children(&base_spec,
 774                                     &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
 775
 776                 if (base->ref_last == -1 && base->ofs_last == -1) {
 777                         free(base->data);
 778                         return NULL;
 779                 }
 780
 781                 link_base_data(prev_base, base);
 782         }
 783
 784         if (base->ref_first <= base->ref_last) {
 785                 struct object_entry *child = objects + deltas[base->ref_first].obj_no;
 786                 struct base_data *result = alloc_base_data();
 787
 788                 assert(child->real_type == OBJ_REF_DELTA);
 789                 resolve_delta(child, base, result);
 790                 if (base->ref_first == base->ref_last && base->ofs_last == -1)
 791                         free_base_data(base);
 792
 793                 base->ref_first++;
 794                 return result;
 795         }
 796
 797         if (base->ofs_first <= base->ofs_last) {
 798                 struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
 799                 struct base_data *result = alloc_base_data();
 800
 801                 assert(child->real_type == OBJ_OFS_DELTA);
 802                 resolve_delta(child, base, result);
 803                 if (base->ofs_first == base->ofs_last)
 804                         free_base_data(base);
 805
 806                 base->ofs_first++;
 807                 return result;
 808         }
 809
 810         unlink_base_data(base);
 811         return NULL;
 812 }
 813
 814 static void find_unresolved_deltas(struct base_data *base)
 815 {
 816         struct base_data *new_base, *prev_base = NULL;
 817         for (;;) {
 818                 new_base = find_unresolved_deltas_1(base, prev_base);
 819
 820                 if (new_base) {
 821                         prev_base = base;
 822                         base = new_base;
 823                 } else {
 824                         free(base);
 825                         base = prev_base;
 826                         if (!base)
 827                                 return;
 828                         prev_base = base->base;
 829                 }
 830         }
 831 }
 832
 833 static int compare_delta_entry(const void *a, const void *b)
 834 {
 835         const struct delta_entry *delta_a = a;
 836         const struct delta_entry *delta_b = b;
 837
 838         /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
 839         return compare_delta_bases(&delta_a->base, &delta_b->base,
 840                                    objects[delta_a->obj_no].type,
 841                                    objects[delta_b->obj_no].type);
 842 }
 843
 844 static void resolve_base(struct object_entry *obj)
 845 {
 846         struct base_data *base_obj = alloc_base_data();
 847         base_obj->obj = obj;
 848         base_obj->data = NULL;
 849         find_unresolved_deltas(base_obj);
 850 }
 851
 852 #ifndef NO_PTHREADS
 853 static void *threaded_second_pass(void *data)
 854 {
 855         set_thread_data(data);
 856         for (;;) {
 857                 int i;
 858                 work_lock();
 859                 display_progress(progress, nr_resolved_deltas);
 860                 while (nr_dispatched < nr_objects &&
 861                        is_delta_type(objects[nr_dispatched].type))
 862                         nr_dispatched++;
 863                 if (nr_dispatched >= nr_objects) {
 864                         work_unlock();
 865                         break;
 866                 }
 867                 i = nr_dispatched++;
 868                 work_unlock();
 869
 870                 resolve_base(&objects[i]);
 871         }
 872         return NULL;
 873 }
 874 #endif
 875
 876 /*
 877  * First pass:
 878  * - find locations of all objects;
 879  * - calculate SHA1 of all non-delta objects;
 880  * - remember base (SHA1 or offset) for all deltas.
 881  */
 882 static void parse_pack_objects(unsigned char *sha1)
 883 {
 884         int i, nr_delays = 0;
 885         struct delta_entry *delta = deltas;
 886         struct stat st;
 887
 888         if (verbose)
 889                 progress = start_progress(
 890                                 from_stdin ? _("Receiving objects") : _("Indexing objects"),
 891                                 nr_objects);
 892         for (i = 0; i < nr_objects; i++) {
 893                 struct object_entry *obj = &objects[i];
 894                 void *data = unpack_raw_entry(obj, &delta->base, obj->idx.sha1);
 895                 obj->real_type = obj->type;
 896                 if (is_delta_type(obj->type)) {
 897                         nr_deltas++;
 898                         delta->obj_no = i;
 899                         delta++;
 900                 } else if (!data) {
 901                         /* large blobs, check later */
 902                         obj->real_type = OBJ_BAD;
 903                         nr_delays++;
 904                 } else
 905                         sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
 906                 free(data);
 907                 display_progress(progress, i+1);
 908         }
 909         objects[i].idx.offset = consumed_bytes;
 910         stop_progress(&progress);
 911
 912         /* Check pack integrity */
 913         flush();
 914         git_SHA1_Final(sha1, &input_ctx);
 915         if (hashcmp(fill(20), sha1))
 916                 die(_("pack is corrupted (SHA1 mismatch)"));
 917         use(20);
 918
 919         /* If input_fd is a file, we should have reached its end now. */
 920         if (fstat(input_fd, &st))
 921                 die_errno(_("cannot fstat packfile"));
 922         if (S_ISREG(st.st_mode) &&
 923                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
 924                 die(_("pack has junk at the end"));
 925
 926         for (i = 0; i < nr_objects; i++) {
 927                 struct object_entry *obj = &objects[i];
 928                 if (obj->real_type != OBJ_BAD)
 929                         continue;
 930                 obj->real_type = obj->type;
 931                 sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
 932                 nr_delays--;
 933         }
 934         if (nr_delays)
 935                 die(_("confusion beyond insanity in parse_pack_objects()"));
 936 }
 937
 938 /*
 939  * Second pass:
 940  * - for all non-delta objects, look if it is used as a base for
 941  *   deltas;
 942  * - if used as a base, uncompress the object and apply all deltas,
 943  *   recursively checking if the resulting object is used as a base
 944  *   for some more deltas.
 945  */
 946 static void resolve_deltas(void)
 947 {
 948         int i;
 949
 950         if (!nr_deltas)
 951                 return;
 952
 953         /* Sort deltas by base SHA1/offset for fast searching */
 954         qsort(deltas, nr_deltas, sizeof(struct delta_entry),
 955               compare_delta_entry);
 956
 957         if (verbose)
 958                 progress = start_progress(_("Resolving deltas"), nr_deltas);
 959
 960 #ifndef NO_PTHREADS
 961         nr_dispatched = 0;
 962         if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
 963                 init_thread();
 964                 for (i = 0; i < nr_threads; i++) {
 965                         int ret = pthread_create(&thread_data[i].thread, NULL,
 966                                                  threaded_second_pass, thread_data + i);
 967                         if (ret)
 968                                 die("unable to create thread: %s", strerror(ret));
 969                 }
 970                 for (i = 0; i < nr_threads; i++)
 971                         pthread_join(thread_data[i].thread, NULL);
 972                 cleanup_thread();
 973                 return;
 974         }
 975 #endif
 976
 977         for (i = 0; i < nr_objects; i++) {
 978                 struct object_entry *obj = &objects[i];
 979
 980                 if (is_delta_type(obj->type))
 981                         continue;
 982                 resolve_base(obj);
 983                 display_progress(progress, nr_resolved_deltas);
 984         }
 985 }
 986
 987 /*
 988  * Third pass:
 989  * - append objects to convert thin pack to full pack if required
 990  * - write the final 20-byte SHA-1
 991  */
 992 static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
 993 static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
 994 {
 995         if (nr_deltas == nr_resolved_deltas) {
 996                 stop_progress(&progress);
 997                 /* Flush remaining pack final 20-byte SHA1. */
 998                 flush();
 999                 return;
1000         }
1001
1002         if (fix_thin_pack) {
1003                 struct sha1file *f;
1004                 unsigned char read_sha1[20], tail_sha1[20];
1005                 char msg[48];
1006                 int nr_unresolved = nr_deltas - nr_resolved_deltas;
1007                 int nr_objects_initial = nr_objects;
1008                 if (nr_unresolved <= 0)
1009                         die(_("confusion beyond insanity"));
1010                 objects = xrealloc(objects,
1011                                    (nr_objects + nr_unresolved + 1)
1012                                    * sizeof(*objects));
1013                 f = sha1fd(output_fd, curr_pack);
1014                 fix_unresolved_deltas(f, nr_unresolved);
1015                 sprintf(msg, "completed with %d local objects",
1016                         nr_objects - nr_objects_initial);
1017                 stop_progress_msg(&progress, msg);
1018                 sha1close(f, tail_sha1, 0);
1019                 hashcpy(read_sha1, pack_sha1);
1020                 fixup_pack_header_footer(output_fd, pack_sha1,
1021                                          curr_pack, nr_objects,
1022                                          read_sha1, consumed_bytes-20);
1023                 if (hashcmp(read_sha1, tail_sha1) != 0)
1024                         die("Unexpected tail checksum for %s "
1025                             "(disk corruption?)", curr_pack);
1026         }
1027         if (nr_deltas != nr_resolved_deltas)
1028                 die(Q_("pack has %d unresolved delta",
1029                        "pack has %d unresolved deltas",
1030                        nr_deltas - nr_resolved_deltas),
1031                     nr_deltas - nr_resolved_deltas);
1032 }
1033
1034 static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1035 {
1036         git_zstream stream;
1037         int status;
1038         unsigned char outbuf[4096];
1039
1040         memset(&stream, 0, sizeof(stream));
1041         git_deflate_init(&stream, zlib_compression_level);
1042         stream.next_in = in;
1043         stream.avail_in = size;
1044
1045         do {
1046                 stream.next_out = outbuf;
1047                 stream.avail_out = sizeof(outbuf);
1048                 status = git_deflate(&stream, Z_FINISH);
1049                 sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1050         } while (status == Z_OK);
1051
1052         if (status != Z_STREAM_END)
1053                 die(_("unable to deflate appended object (%d)"), status);
1054         size = stream.total_out;
1055         git_deflate_end(&stream);
1056         return size;
1057 }
1058
1059 static struct object_entry *append_obj_to_pack(struct sha1file *f,
1060                                const unsigned char *sha1, void *buf,
1061                                unsigned long size, enum object_type type)
1062 {
1063         struct object_entry *obj = &objects[nr_objects++];
1064         unsigned char header[10];
1065         unsigned long s = size;
1066         int n = 0;
1067         unsigned char c = (type << 4) | (s & 15);
1068         s >>= 4;
1069         while (s) {
1070                 header[n++] = c | 0x80;
1071                 c = s & 0x7f;
1072                 s >>= 7;
1073         }
1074         header[n++] = c;
1075         crc32_begin(f);
1076         sha1write(f, header, n);
1077         obj[0].size = size;
1078         obj[0].hdr_size = n;
1079         obj[0].type = type;
1080         obj[0].real_type = type;
1081         obj[1].idx.offset = obj[0].idx.offset + n;
1082         obj[1].idx.offset += write_compressed(f, buf, size);
1083         obj[0].idx.crc32 = crc32_end(f);
1084         sha1flush(f);
1085         hashcpy(obj->idx.sha1, sha1);
1086         return obj;
1087 }
1088
1089 static int delta_pos_compare(const void *_a, const void *_b)
1090 {
1091         struct delta_entry *a = *(struct delta_entry **)_a;
1092         struct delta_entry *b = *(struct delta_entry **)_b;
1093         return a->obj_no - b->obj_no;
1094 }
1095
1096 static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
1097 {
1098         struct delta_entry **sorted_by_pos;
1099         int i, n = 0;
1100
1101         /*
1102          * Since many unresolved deltas may well be themselves base objects
1103          * for more unresolved deltas, we really want to include the
1104          * smallest number of base objects that would cover as much delta
1105          * as possible by picking the
1106          * trunc deltas first, allowing for other deltas to resolve without
1107          * additional base objects.  Since most base objects are to be found
1108          * before deltas depending on them, a good heuristic is to start
1109          * resolving deltas in the same order as their position in the pack.
1110          */
1111         sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
1112         for (i = 0; i < nr_deltas; i++) {
1113                 if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
1114                         continue;
1115                 sorted_by_pos[n++] = &deltas[i];
1116         }
1117         qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
1118
1119         for (i = 0; i < n; i++) {
1120                 struct delta_entry *d = sorted_by_pos[i];
1121                 enum object_type type;
1122                 struct base_data *base_obj = alloc_base_data();
1123
1124                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1125                         continue;
1126                 base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
1127                 if (!base_obj->data)
1128                         continue;
1129
1130                 if (check_sha1_signature(d->base.sha1, base_obj->data,
1131                                 base_obj->size, typename(type)))
1132                         die(_("local object %s is corrupt"), sha1_to_hex(d->base.sha1));
1133                 base_obj->obj = append_obj_to_pack(f, d->base.sha1,
1134                                         base_obj->data, base_obj->size, type);
1135                 find_unresolved_deltas(base_obj);
1136                 display_progress(progress, nr_resolved_deltas);
1137         }
1138         free(sorted_by_pos);
1139 }
1140
1141 static void final(const char *final_pack_name, const char *curr_pack_name,
1142                   const char *final_index_name, const char *curr_index_name,
1143                   const char *keep_name, const char *keep_msg,
1144                   unsigned char *sha1)
1145 {
1146         const char *report = "pack";
1147         char name[PATH_MAX];
1148         int err;
1149
1150         if (!from_stdin) {
1151                 close(input_fd);
1152         } else {
1153                 fsync_or_die(output_fd, curr_pack_name);
1154                 err = close(output_fd);
1155                 if (err)
1156                         die_errno(_("error while closing pack file"));
1157         }
1158
1159         if (keep_msg) {
1160                 int keep_fd, keep_msg_len = strlen(keep_msg);
1161
1162                 if (!keep_name)
1163                         keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1164                 else
1165                         keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1166
1167                 if (keep_fd < 0) {
1168                         if (errno != EEXIST)
1169                                 die_errno(_("cannot write keep file '%s'"),
1170                                           keep_name);
1171                 } else {
1172                         if (keep_msg_len > 0) {
1173                                 write_or_die(keep_fd, keep_msg, keep_msg_len);
1174                                 write_or_die(keep_fd, "\n", 1);
1175                         }
1176                         if (close(keep_fd) != 0)
1177                                 die_errno(_("cannot close written keep file '%s'"),
1178                                     keep_name);
1179                         report = "keep";
1180                 }
1181         }
1182
1183         if (final_pack_name != curr_pack_name) {
1184                 if (!final_pack_name) {
1185                         snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1186                                  get_object_directory(), sha1_to_hex(sha1));
1187                         final_pack_name = name;
1188                 }
1189                 if (move_temp_to_file(curr_pack_name, final_pack_name))
1190                         die(_("cannot store pack file"));
1191         } else if (from_stdin)
1192                 chmod(final_pack_name, 0444);
1193
1194         if (final_index_name != curr_index_name) {
1195                 if (!final_index_name) {
1196                         snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1197                                  get_object_directory(), sha1_to_hex(sha1));
1198                         final_index_name = name;
1199                 }
1200                 if (move_temp_to_file(curr_index_name, final_index_name))
1201                         die(_("cannot store index file"));
1202         } else
1203                 chmod(final_index_name, 0444);
1204
1205         if (!from_stdin) {
1206                 printf("%s\n", sha1_to_hex(sha1));
1207         } else {
1208                 char buf[48];
1209                 int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1210                                    report, sha1_to_hex(sha1));
1211                 write_or_die(1, buf, len);
1212
1213                 /*
1214                  * Let's just mimic git-unpack-objects here and write
1215                  * the last part of the input buffer to stdout.
1216                  */
1217                 while (input_len) {
1218                         err = xwrite(1, input_buffer + input_offset, input_len);
1219                         if (err <= 0)
1220                                 break;
1221                         input_len -= err;
1222                         input_offset += err;
1223                 }
1224         }
1225 }
1226
1227 static int git_index_pack_config(const char *k, const char *v, void *cb)
1228 {
1229         struct pack_idx_option *opts = cb;
1230
1231         if (!strcmp(k, "pack.indexversion")) {
1232                 opts->version = git_config_int(k, v);
1233                 if (opts->version > 2)
1234                         die("bad pack.indexversion=%"PRIu32, opts->version);
1235                 return 0;
1236         }
1237         if (!strcmp(k, "pack.threads")) {
1238                 nr_threads = git_config_int(k, v);
1239                 if (nr_threads < 0)
1240                         die("invalid number of threads specified (%d)",
1241                             nr_threads);
1242 #ifdef NO_PTHREADS
1243                 if (nr_threads != 1)
1244                         warning("no threads support, ignoring %s", k);
1245                 nr_threads = 1;
1246 #endif
1247                 return 0;
1248         }
1249         return git_default_config(k, v, cb);
1250 }
1251
1252 static int cmp_uint32(const void *a_, const void *b_)
1253 {
1254         uint32_t a = *((uint32_t *)a_);
1255         uint32_t b = *((uint32_t *)b_);
1256
1257         return (a < b) ? -1 : (a != b);
1258 }
1259
1260 static void read_v2_anomalous_offsets(struct packed_git *p,
1261                                       struct pack_idx_option *opts)
1262 {
1263         const uint32_t *idx1, *idx2;
1264         uint32_t i;
1265
1266         /* The address of the 4-byte offset table */
1267         idx1 = (((const uint32_t *)p->index_data)
1268                 + 2 /* 8-byte header */
1269                 + 256 /* fan out */
1270                 + 5 * p->num_objects /* 20-byte SHA-1 table */
1271                 + p->num_objects /* CRC32 table */
1272                 );
1273
1274         /* The address of the 8-byte offset table */
1275         idx2 = idx1 + p->num_objects;
1276
1277         for (i = 0; i < p->num_objects; i++) {
1278                 uint32_t off = ntohl(idx1[i]);
1279                 if (!(off & 0x80000000))
1280                         continue;
1281                 off = off & 0x7fffffff;
1282                 if (idx2[off * 2])
1283                         continue;
1284                 /*
1285                  * The real offset is ntohl(idx2[off * 2]) in high 4
1286                  * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1287                  * octets.  But idx2[off * 2] is Zero!!!
1288                  */
1289                 ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1290                 opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1291         }
1292
1293         if (1 < opts->anomaly_nr)
1294                 qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1295 }
1296
1297 static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1298 {
1299         struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1300
1301         if (!p)
1302                 die(_("Cannot open existing pack file '%s'"), pack_name);
1303         if (open_pack_index(p))
1304                 die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1305
1306         /* Read the attributes from the existing idx file */
1307         opts->version = p->index_version;
1308
1309         if (opts->version == 2)
1310                 read_v2_anomalous_offsets(p, opts);
1311
1312         /*
1313          * Get rid of the idx file as we do not need it anymore.
1314          * NEEDSWORK: extract this bit from free_pack_by_name() in
1315          * sha1_file.c, perhaps?  It shouldn't matter very much as we
1316          * know we haven't installed this pack (hence we never have
1317          * read anything from it).
1318          */
1319         close_pack_index(p);
1320         free(p);
1321 }
1322
1323 static void show_pack_info(int stat_only)
1324 {
1325         int i, baseobjects = nr_objects - nr_deltas;
1326         unsigned long *chain_histogram = NULL;
1327
1328         if (deepest_delta)
1329                 chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1330
1331         for (i = 0; i < nr_objects; i++) {
1332                 struct object_entry *obj = &objects[i];
1333
1334                 if (is_delta_type(obj->type))
1335                         chain_histogram[obj->delta_depth - 1]++;
1336                 if (stat_only)
1337                         continue;
1338                 printf("%s %-6s %lu %lu %"PRIuMAX,
1339                        sha1_to_hex(obj->idx.sha1),
1340                        typename(obj->real_type), obj->size,
1341                        (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1342                        (uintmax_t)obj->idx.offset);
1343                 if (is_delta_type(obj->type)) {
1344                         struct object_entry *bobj = &objects[obj->base_object_no];
1345                         printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
1346                 }
1347                 putchar('\n');
1348         }
1349
1350         if (baseobjects)
1351                 printf_ln(Q_("non delta: %d object",
1352                              "non delta: %d objects",
1353                              baseobjects),
1354                           baseobjects);
1355         for (i = 0; i < deepest_delta; i++) {
1356                 if (!chain_histogram[i])
1357                         continue;
1358                 printf_ln(Q_("chain length = %d: %lu object",
1359                              "chain length = %d: %lu objects",
1360                              chain_histogram[i]),
1361                           i + 1,
1362                           chain_histogram[i]);
1363         }
1364 }
1365
1366 int cmd_index_pack(int argc, const char **argv, const char *prefix)
1367 {
1368         int i, fix_thin_pack = 0, verify = 0, stat_only = 0, stat = 0;
1369         const char *curr_pack, *curr_index;
1370         const char *index_name = NULL, *pack_name = NULL;
1371         const char *keep_name = NULL, *keep_msg = NULL;
1372         char *index_name_buf = NULL, *keep_name_buf = NULL;
1373         struct pack_idx_entry **idx_objects;
1374         struct pack_idx_option opts;
1375         unsigned char pack_sha1[20];
1376
1377         if (argc == 2 && !strcmp(argv[1], "-h"))
1378                 usage(index_pack_usage);
1379
1380         read_replace_refs = 0;
1381
1382         reset_pack_idx_option(&opts);
1383         git_config(git_index_pack_config, &opts);
1384         if (prefix && chdir(prefix))
1385                 die(_("Cannot come back to cwd"));
1386
1387         for (i = 1; i < argc; i++) {
1388                 const char *arg = argv[i];
1389
1390                 if (*arg == '-') {
1391                         if (!strcmp(arg, "--stdin")) {
1392                                 from_stdin = 1;
1393                         } else if (!strcmp(arg, "--fix-thin")) {
1394                                 fix_thin_pack = 1;
1395                         } else if (!strcmp(arg, "--strict")) {
1396                                 strict = 1;
1397                         } else if (!strcmp(arg, "--verify")) {
1398                                 verify = 1;
1399                         } else if (!strcmp(arg, "--verify-stat")) {
1400                                 verify = 1;
1401                                 stat = 1;
1402                         } else if (!strcmp(arg, "--verify-stat-only")) {
1403                                 verify = 1;
1404                                 stat = 1;
1405                                 stat_only = 1;
1406                         } else if (!strcmp(arg, "--keep")) {
1407                                 keep_msg = "";
1408                         } else if (!prefixcmp(arg, "--keep=")) {
1409                                 keep_msg = arg + 7;
1410                         } else if (!prefixcmp(arg, "--threads=")) {
1411                                 char *end;
1412                                 nr_threads = strtoul(arg+10, &end, 0);
1413                                 if (!arg[10] || *end || nr_threads < 0)
1414                                         usage(index_pack_usage);
1415 #ifdef NO_PTHREADS
1416                                 if (nr_threads != 1)
1417                                         warning("no threads support, "
1418                                                 "ignoring %s", arg);
1419                                 nr_threads = 1;
1420 #endif
1421                         } else if (!prefixcmp(arg, "--pack_header=")) {
1422                                 struct pack_header *hdr;
1423                                 char *c;
1424
1425                                 hdr = (struct pack_header *)input_buffer;
1426                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
1427                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1428                                 if (*c != ',')
1429                                         die(_("bad %s"), arg);
1430                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1431                                 if (*c)
1432                                         die(_("bad %s"), arg);
1433                                 input_len = sizeof(*hdr);
1434                         } else if (!strcmp(arg, "-v")) {
1435                                 verbose = 1;
1436                         } else if (!strcmp(arg, "-o")) {
1437                                 if (index_name || (i+1) >= argc)
1438                                         usage(index_pack_usage);
1439                                 index_name = argv[++i];
1440                         } else if (!prefixcmp(arg, "--index-version=")) {
1441                                 char *c;
1442                                 opts.version = strtoul(arg + 16, &c, 10);
1443                                 if (opts.version > 2)
1444                                         die(_("bad %s"), arg);
1445                                 if (*c == ',')
1446                                         opts.off32_limit = strtoul(c+1, &c, 0);
1447                                 if (*c || opts.off32_limit & 0x80000000)
1448                                         die(_("bad %s"), arg);
1449                         } else
1450                                 usage(index_pack_usage);
1451                         continue;
1452                 }
1453
1454                 if (pack_name)
1455                         usage(index_pack_usage);
1456                 pack_name = arg;
1457         }
1458
1459         if (!pack_name && !from_stdin)
1460                 usage(index_pack_usage);
1461         if (fix_thin_pack && !from_stdin)
1462                 die(_("--fix-thin cannot be used without --stdin"));
1463         if (!index_name && pack_name) {
1464                 int len = strlen(pack_name);
1465                 if (!has_extension(pack_name, ".pack"))
1466                         die(_("packfile name '%s' does not end with '.pack'"),
1467                             pack_name);
1468                 index_name_buf = xmalloc(len);
1469                 memcpy(index_name_buf, pack_name, len - 5);
1470                 strcpy(index_name_buf + len - 5, ".idx");
1471                 index_name = index_name_buf;
1472         }
1473         if (keep_msg && !keep_name && pack_name) {
1474                 int len = strlen(pack_name);
1475                 if (!has_extension(pack_name, ".pack"))
1476                         die(_("packfile name '%s' does not end with '.pack'"),
1477                             pack_name);
1478                 keep_name_buf = xmalloc(len);
1479                 memcpy(keep_name_buf, pack_name, len - 5);
1480                 strcpy(keep_name_buf + len - 5, ".keep");
1481                 keep_name = keep_name_buf;
1482         }
1483         if (verify) {
1484                 if (!index_name)
1485                         die(_("--verify with no packfile name given"));
1486                 read_idx_option(&opts, index_name);
1487                 opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1488         }
1489         if (strict)
1490                 opts.flags |= WRITE_IDX_STRICT;
1491
1492 #ifndef NO_PTHREADS
1493         if (!nr_threads) {
1494                 nr_threads = online_cpus();
1495                 /* An experiment showed that more threads does not mean faster */
1496                 if (nr_threads > 3)
1497                         nr_threads = 3;
1498         }
1499 #endif
1500
1501         curr_pack = open_pack_file(pack_name);
1502         parse_pack_header();
1503         objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1504         deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
1505         parse_pack_objects(pack_sha1);
1506         resolve_deltas();
1507         conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1508         free(deltas);
1509         if (strict)
1510                 check_objects();
1511
1512         if (stat)
1513                 show_pack_info(stat_only);
1514
1515         idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1516         for (i = 0; i < nr_objects; i++)
1517                 idx_objects[i] = &objects[i].idx;
1518         curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1519         free(idx_objects);
1520
1521         if (!verify)
1522                 final(pack_name, curr_pack,
1523                       index_name, curr_index,
1524                       keep_name, keep_msg,
1525                       pack_sha1);
1526         else
1527                 close(input_fd);
1528         free(objects);
1529         free(index_name_buf);
1530         free(keep_name_buf);
1531         if (pack_name == NULL)
1532                 free((void *) curr_pack);
1533         if (index_name == NULL)
1534                 free((void *) curr_index);
1535
1536         return 0;
1537 }