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

   1 #include "builtin.h"
   2 #include "config.h"
   3 #include "delta.h"
   4 #include "pack.h"
   5 #include "csum-file.h"
   6 #include "blob.h"
   7 #include "commit.h"
   8 #include "tag.h"
   9 #include "tree.h"
  10 #include "progress.h"
  11 #include "fsck.h"
  12 #include "exec-cmd.h"
  13 #include "streaming.h"
  14 #include "thread-utils.h"
  15 #include "packfile.h"
  16 #include "object-store.h"
  17
  18 static const char index_pack_usage[] =
  19 "git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  20
  21 struct object_entry {
  22         struct pack_idx_entry idx;
  23         unsigned long size;
  24         unsigned char hdr_size;
  25         signed char type;
  26         signed char real_type;
  27 };
  28
  29 struct object_stat {
  30         unsigned delta_depth;
  31         int base_object_no;
  32 };
  33
  34 struct base_data {
  35         struct base_data *base;
  36         struct base_data *child;
  37         struct object_entry *obj;
  38         void *data;
  39         unsigned long size;
  40         int ref_first, ref_last;
  41         int ofs_first, ofs_last;
  42 };
  43
  44 struct thread_local {
  45         pthread_t thread;
  46         struct base_data *base_cache;
  47         size_t base_cache_used;
  48         int pack_fd;
  49 };
  50
  51 /* Remember to update object flag allocation in object.h */
  52 #define FLAG_LINK (1u<<20)
  53 #define FLAG_CHECKED (1u<<21)
  54
  55 struct ofs_delta_entry {
  56         off_t offset;
  57         int obj_no;
  58 };
  59
  60 struct ref_delta_entry {
  61         struct object_id oid;
  62         int obj_no;
  63 };
  64
  65 static struct object_entry *objects;
  66 static struct object_stat *obj_stat;
  67 static struct ofs_delta_entry *ofs_deltas;
  68 static struct ref_delta_entry *ref_deltas;
  69 static struct thread_local nothread_data;
  70 static int nr_objects;
  71 static int nr_ofs_deltas;
  72 static int nr_ref_deltas;
  73 static int ref_deltas_alloc;
  74 static int nr_resolved_deltas;
  75 static int nr_threads;
  76
  77 static int from_stdin;
  78 static int strict;
  79 static int do_fsck_object;
  80 static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
  81 static int verbose;
  82 static int show_resolving_progress;
  83 static int show_stat;
  84 static int check_self_contained_and_connected;
  85
  86 static struct progress *progress;
  87
  88 /* We always read in 4kB chunks. */
  89 static unsigned char input_buffer[4096];
  90 static unsigned int input_offset, input_len;
  91 static off_t consumed_bytes;
  92 static off_t max_input_size;
  93 static unsigned deepest_delta;
  94 static git_hash_ctx input_ctx;
  95 static uint32_t input_crc32;
  96 static int input_fd, output_fd;
  97 static const char *curr_pack;
  98
  99 static struct thread_local *thread_data;
 100 static int nr_dispatched;
 101 static int threads_active;
 102
 103 static pthread_mutex_t read_mutex;
 104 #define read_lock()             lock_mutex(&read_mutex)
 105 #define read_unlock()           unlock_mutex(&read_mutex)
 106
 107 static pthread_mutex_t counter_mutex;
 108 #define counter_lock()          lock_mutex(&counter_mutex)
 109 #define counter_unlock()        unlock_mutex(&counter_mutex)
 110
 111 static pthread_mutex_t work_mutex;
 112 #define work_lock()             lock_mutex(&work_mutex)
 113 #define work_unlock()           unlock_mutex(&work_mutex)
 114
 115 static pthread_mutex_t deepest_delta_mutex;
 116 #define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 117 #define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 118
 119 static pthread_mutex_t type_cas_mutex;
 120 #define type_cas_lock()         lock_mutex(&type_cas_mutex)
 121 #define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 122
 123 static pthread_key_t key;
 124
 125 static inline void lock_mutex(pthread_mutex_t *mutex)
 126 {
 127         if (threads_active)
 128                 pthread_mutex_lock(mutex);
 129 }
 130
 131 static inline void unlock_mutex(pthread_mutex_t *mutex)
 132 {
 133         if (threads_active)
 134                 pthread_mutex_unlock(mutex);
 135 }
 136
 137 /*
 138  * Mutex and conditional variable can't be statically-initialized on Windows.
 139  */
 140 static void init_thread(void)
 141 {
 142         int i;
 143         init_recursive_mutex(&read_mutex);
 144         pthread_mutex_init(&counter_mutex, NULL);
 145         pthread_mutex_init(&work_mutex, NULL);
 146         pthread_mutex_init(&type_cas_mutex, NULL);
 147         if (show_stat)
 148                 pthread_mutex_init(&deepest_delta_mutex, NULL);
 149         pthread_key_create(&key, NULL);
 150         thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 151         for (i = 0; i < nr_threads; i++) {
 152                 thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 153                 if (thread_data[i].pack_fd == -1)
 154                         die_errno(_("unable to open %s"), curr_pack);
 155         }
 156
 157         threads_active = 1;
 158 }
 159
 160 static void cleanup_thread(void)
 161 {
 162         int i;
 163         if (!threads_active)
 164                 return;
 165         threads_active = 0;
 166         pthread_mutex_destroy(&read_mutex);
 167         pthread_mutex_destroy(&counter_mutex);
 168         pthread_mutex_destroy(&work_mutex);
 169         pthread_mutex_destroy(&type_cas_mutex);
 170         if (show_stat)
 171                 pthread_mutex_destroy(&deepest_delta_mutex);
 172         for (i = 0; i < nr_threads; i++)
 173                 close(thread_data[i].pack_fd);
 174         pthread_key_delete(key);
 175         free(thread_data);
 176 }
 177
 178 static int mark_link(struct object *obj, int type, void *data, struct fsck_options *options)
 179 {
 180         if (!obj)
 181                 return -1;
 182
 183         if (type != OBJ_ANY && obj->type != type)
 184                 die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 185
 186         obj->flags |= FLAG_LINK;
 187         return 0;
 188 }
 189
 190 /* The content of each linked object must have been checked
 191    or it must be already present in the object database */
 192 static unsigned check_object(struct object *obj)
 193 {
 194         if (!obj)
 195                 return 0;
 196
 197         if (!(obj->flags & FLAG_LINK))
 198                 return 0;
 199
 200         if (!(obj->flags & FLAG_CHECKED)) {
 201                 unsigned long size;
 202                 int type = oid_object_info(the_repository, &obj->oid, &size);
 203                 if (type <= 0)
 204                         die(_("did not receive expected object %s"),
 205                               oid_to_hex(&obj->oid));
 206                 if (type != obj->type)
 207                         die(_("object %s: expected type %s, found %s"),
 208                             oid_to_hex(&obj->oid),
 209                             type_name(obj->type), type_name(type));
 210                 obj->flags |= FLAG_CHECKED;
 211                 return 1;
 212         }
 213
 214         return 0;
 215 }
 216
 217 static unsigned check_objects(void)
 218 {
 219         unsigned i, max, foreign_nr = 0;
 220
 221         max = get_max_object_index();
 222
 223         if (verbose)
 224                 progress = start_delayed_progress(_("Checking objects"), max);
 225
 226         for (i = 0; i < max; i++) {
 227                 foreign_nr += check_object(get_indexed_object(i));
 228                 display_progress(progress, i + 1);
 229         }
 230
 231         stop_progress(&progress);
 232         return foreign_nr;
 233 }
 234
 235
 236 /* Discard current buffer used content. */
 237 static void flush(void)
 238 {
 239         if (input_offset) {
 240                 if (output_fd >= 0)
 241                         write_or_die(output_fd, input_buffer, input_offset);
 242                 the_hash_algo->update_fn(&input_ctx, input_buffer, input_offset);
 243                 memmove(input_buffer, input_buffer + input_offset, input_len);
 244                 input_offset = 0;
 245         }
 246 }
 247
 248 /*
 249  * Make sure at least "min" bytes are available in the buffer, and
 250  * return the pointer to the buffer.
 251  */
 252 static void *fill(int min)
 253 {
 254         if (min <= input_len)
 255                 return input_buffer + input_offset;
 256         if (min > sizeof(input_buffer))
 257                 die(Q_("cannot fill %d byte",
 258                        "cannot fill %d bytes",
 259                        min),
 260                     min);
 261         flush();
 262         do {
 263                 ssize_t ret = xread(input_fd, input_buffer + input_len,
 264                                 sizeof(input_buffer) - input_len);
 265                 if (ret <= 0) {
 266                         if (!ret)
 267                                 die(_("early EOF"));
 268                         die_errno(_("read error on input"));
 269                 }
 270                 input_len += ret;
 271                 if (from_stdin)
 272                         display_throughput(progress, consumed_bytes + input_len);
 273         } while (input_len < min);
 274         return input_buffer;
 275 }
 276
 277 static void use(int bytes)
 278 {
 279         if (bytes > input_len)
 280                 die(_("used more bytes than were available"));
 281         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 282         input_len -= bytes;
 283         input_offset += bytes;
 284
 285         /* make sure off_t is sufficiently large not to wrap */
 286         if (signed_add_overflows(consumed_bytes, bytes))
 287                 die(_("pack too large for current definition of off_t"));
 288         consumed_bytes += bytes;
 289         if (max_input_size && consumed_bytes > max_input_size)
 290                 die(_("pack exceeds maximum allowed size"));
 291 }
 292
 293 static const char *open_pack_file(const char *pack_name)
 294 {
 295         if (from_stdin) {
 296                 input_fd = 0;
 297                 if (!pack_name) {
 298                         struct strbuf tmp_file = STRBUF_INIT;
 299                         output_fd = odb_mkstemp(&tmp_file,
 300                                                 "pack/tmp_pack_XXXXXX");
 301                         pack_name = strbuf_detach(&tmp_file, NULL);
 302                 } else {
 303                         output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 304                         if (output_fd < 0)
 305                                 die_errno(_("unable to create '%s'"), pack_name);
 306                 }
 307                 nothread_data.pack_fd = output_fd;
 308         } else {
 309                 input_fd = open(pack_name, O_RDONLY);
 310                 if (input_fd < 0)
 311                         die_errno(_("cannot open packfile '%s'"), pack_name);
 312                 output_fd = -1;
 313                 nothread_data.pack_fd = input_fd;
 314         }
 315         the_hash_algo->init_fn(&input_ctx);
 316         return pack_name;
 317 }
 318
 319 static void parse_pack_header(void)
 320 {
 321         struct pack_header *hdr = fill(sizeof(struct pack_header));
 322
 323         /* Header consistency check */
 324         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 325                 die(_("pack signature mismatch"));
 326         if (!pack_version_ok(hdr->hdr_version))
 327                 die(_("pack version %"PRIu32" unsupported"),
 328                         ntohl(hdr->hdr_version));
 329
 330         nr_objects = ntohl(hdr->hdr_entries);
 331         use(sizeof(struct pack_header));
 332 }
 333
 334 static NORETURN void bad_object(off_t offset, const char *format,
 335                        ...) __attribute__((format (printf, 2, 3)));
 336
 337 static NORETURN void bad_object(off_t offset, const char *format, ...)
 338 {
 339         va_list params;
 340         char buf[1024];
 341
 342         va_start(params, format);
 343         vsnprintf(buf, sizeof(buf), format, params);
 344         va_end(params);
 345         die(_("pack has bad object at offset %"PRIuMAX": %s"),
 346             (uintmax_t)offset, buf);
 347 }
 348
 349 static inline struct thread_local *get_thread_data(void)
 350 {
 351         if (HAVE_THREADS) {
 352                 if (threads_active)
 353                         return pthread_getspecific(key);
 354                 assert(!threads_active &&
 355                        "This should only be reached when all threads are gone");
 356         }
 357         return &nothread_data;
 358 }
 359
 360 static void set_thread_data(struct thread_local *data)
 361 {
 362         if (threads_active)
 363                 pthread_setspecific(key, data);
 364 }
 365
 366 static struct base_data *alloc_base_data(void)
 367 {
 368         struct base_data *base = xcalloc(1, sizeof(struct base_data));
 369         base->ref_last = -1;
 370         base->ofs_last = -1;
 371         return base;
 372 }
 373
 374 static void free_base_data(struct base_data *c)
 375 {
 376         if (c->data) {
 377                 FREE_AND_NULL(c->data);
 378                 get_thread_data()->base_cache_used -= c->size;
 379         }
 380 }
 381
 382 static void prune_base_data(struct base_data *retain)
 383 {
 384         struct base_data *b;
 385         struct thread_local *data = get_thread_data();
 386         for (b = data->base_cache;
 387              data->base_cache_used > delta_base_cache_limit && b;
 388              b = b->child) {
 389                 if (b->data && b != retain)
 390                         free_base_data(b);
 391         }
 392 }
 393
 394 static void link_base_data(struct base_data *base, struct base_data *c)
 395 {
 396         if (base)
 397                 base->child = c;
 398         else
 399                 get_thread_data()->base_cache = c;
 400
 401         c->base = base;
 402         c->child = NULL;
 403         if (c->data)
 404                 get_thread_data()->base_cache_used += c->size;
 405         prune_base_data(c);
 406 }
 407
 408 static void unlink_base_data(struct base_data *c)
 409 {
 410         struct base_data *base = c->base;
 411         if (base)
 412                 base->child = NULL;
 413         else
 414                 get_thread_data()->base_cache = NULL;
 415         free_base_data(c);
 416 }
 417
 418 static int is_delta_type(enum object_type type)
 419 {
 420         return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 421 }
 422
 423 static void *unpack_entry_data(off_t offset, unsigned long size,
 424                                enum object_type type, struct object_id *oid)
 425 {
 426         static char fixed_buf[8192];
 427         int status;
 428         git_zstream stream;
 429         void *buf;
 430         git_hash_ctx c;
 431         char hdr[32];
 432         int hdrlen;
 433
 434         if (!is_delta_type(type)) {
 435                 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX,
 436                                    type_name(type),(uintmax_t)size) + 1;
 437                 the_hash_algo->init_fn(&c);
 438                 the_hash_algo->update_fn(&c, hdr, hdrlen);
 439         } else
 440                 oid = NULL;
 441         if (type == OBJ_BLOB && size > big_file_threshold)
 442                 buf = fixed_buf;
 443         else
 444                 buf = xmallocz(size);
 445
 446         memset(&stream, 0, sizeof(stream));
 447         git_inflate_init(&stream);
 448         stream.next_out = buf;
 449         stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 450
 451         do {
 452                 unsigned char *last_out = stream.next_out;
 453                 stream.next_in = fill(1);
 454                 stream.avail_in = input_len;
 455                 status = git_inflate(&stream, 0);
 456                 use(input_len - stream.avail_in);
 457                 if (oid)
 458                         the_hash_algo->update_fn(&c, last_out, stream.next_out - last_out);
 459                 if (buf == fixed_buf) {
 460                         stream.next_out = buf;
 461                         stream.avail_out = sizeof(fixed_buf);
 462                 }
 463         } while (status == Z_OK);
 464         if (stream.total_out != size || status != Z_STREAM_END)
 465                 bad_object(offset, _("inflate returned %d"), status);
 466         git_inflate_end(&stream);
 467         if (oid)
 468                 the_hash_algo->final_fn(oid->hash, &c);
 469         return buf == fixed_buf ? NULL : buf;
 470 }
 471
 472 static void *unpack_raw_entry(struct object_entry *obj,
 473                               off_t *ofs_offset,
 474                               struct object_id *ref_oid,
 475                               struct object_id *oid)
 476 {
 477         unsigned char *p;
 478         unsigned long size, c;
 479         off_t base_offset;
 480         unsigned shift;
 481         void *data;
 482
 483         obj->idx.offset = consumed_bytes;
 484         input_crc32 = crc32(0, NULL, 0);
 485
 486         p = fill(1);
 487         c = *p;
 488         use(1);
 489         obj->type = (c >> 4) & 7;
 490         size = (c & 15);
 491         shift = 4;
 492         while (c & 0x80) {
 493                 p = fill(1);
 494                 c = *p;
 495                 use(1);
 496                 size += (c & 0x7f) << shift;
 497                 shift += 7;
 498         }
 499         obj->size = size;
 500
 501         switch (obj->type) {
 502         case OBJ_REF_DELTA:
 503                 hashcpy(ref_oid->hash, fill(the_hash_algo->rawsz));
 504                 use(the_hash_algo->rawsz);
 505                 break;
 506         case OBJ_OFS_DELTA:
 507                 p = fill(1);
 508                 c = *p;
 509                 use(1);
 510                 base_offset = c & 127;
 511                 while (c & 128) {
 512                         base_offset += 1;
 513                         if (!base_offset || MSB(base_offset, 7))
 514                                 bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 515                         p = fill(1);
 516                         c = *p;
 517                         use(1);
 518                         base_offset = (base_offset << 7) + (c & 127);
 519                 }
 520                 *ofs_offset = obj->idx.offset - base_offset;
 521                 if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 522                         bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 523                 break;
 524         case OBJ_COMMIT:
 525         case OBJ_TREE:
 526         case OBJ_BLOB:
 527         case OBJ_TAG:
 528                 break;
 529         default:
 530                 bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 531         }
 532         obj->hdr_size = consumed_bytes - obj->idx.offset;
 533
 534         data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, oid);
 535         obj->idx.crc32 = input_crc32;
 536         return data;
 537 }
 538
 539 static void *unpack_data(struct object_entry *obj,
 540                          int (*consume)(const unsigned char *, unsigned long, void *),
 541                          void *cb_data)
 542 {
 543         off_t from = obj[0].idx.offset + obj[0].hdr_size;
 544         off_t len = obj[1].idx.offset - from;
 545         unsigned char *data, *inbuf;
 546         git_zstream stream;
 547         int status;
 548
 549         data = xmallocz(consume ? 64*1024 : obj->size);
 550         inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 551
 552         memset(&stream, 0, sizeof(stream));
 553         git_inflate_init(&stream);
 554         stream.next_out = data;
 555         stream.avail_out = consume ? 64*1024 : obj->size;
 556
 557         do {
 558                 ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 559                 n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 560                 if (n < 0)
 561                         die_errno(_("cannot pread pack file"));
 562                 if (!n)
 563                         die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 564                                "premature end of pack file, %"PRIuMAX" bytes missing",
 565                                (unsigned int)len),
 566                             (uintmax_t)len);
 567                 from += n;
 568                 len -= n;
 569                 stream.next_in = inbuf;
 570                 stream.avail_in = n;
 571                 if (!consume)
 572                         status = git_inflate(&stream, 0);
 573                 else {
 574                         do {
 575                                 status = git_inflate(&stream, 0);
 576                                 if (consume(data, stream.next_out - data, cb_data)) {
 577                                         free(inbuf);
 578                                         free(data);
 579                                         return NULL;
 580                                 }
 581                                 stream.next_out = data;
 582                                 stream.avail_out = 64*1024;
 583                         } while (status == Z_OK && stream.avail_in);
 584                 }
 585         } while (len && status == Z_OK && !stream.avail_in);
 586
 587         /* This has been inflated OK when first encountered, so... */
 588         if (status != Z_STREAM_END || stream.total_out != obj->size)
 589                 die(_("serious inflate inconsistency"));
 590
 591         git_inflate_end(&stream);
 592         free(inbuf);
 593         if (consume) {
 594                 FREE_AND_NULL(data);
 595         }
 596         return data;
 597 }
 598
 599 static void *get_data_from_pack(struct object_entry *obj)
 600 {
 601         return unpack_data(obj, NULL, NULL);
 602 }
 603
 604 static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 605                                    enum object_type type1,
 606                                    enum object_type type2)
 607 {
 608         int cmp = type1 - type2;
 609         if (cmp)
 610                 return cmp;
 611         return offset1 < offset2 ? -1 :
 612                offset1 > offset2 ?  1 :
 613                0;
 614 }
 615
 616 static int find_ofs_delta(const off_t offset, enum object_type type)
 617 {
 618         int first = 0, last = nr_ofs_deltas;
 619
 620         while (first < last) {
 621                 int next = first + (last - first) / 2;
 622                 struct ofs_delta_entry *delta = &ofs_deltas[next];
 623                 int cmp;
 624
 625                 cmp = compare_ofs_delta_bases(offset, delta->offset,
 626                                               type, objects[delta->obj_no].type);
 627                 if (!cmp)
 628                         return next;
 629                 if (cmp < 0) {
 630                         last = next;
 631                         continue;
 632                 }
 633                 first = next+1;
 634         }
 635         return -first-1;
 636 }
 637
 638 static void find_ofs_delta_children(off_t offset,
 639                                     int *first_index, int *last_index,
 640                                     enum object_type type)
 641 {
 642         int first = find_ofs_delta(offset, type);
 643         int last = first;
 644         int end = nr_ofs_deltas - 1;
 645
 646         if (first < 0) {
 647                 *first_index = 0;
 648                 *last_index = -1;
 649                 return;
 650         }
 651         while (first > 0 && ofs_deltas[first - 1].offset == offset)
 652                 --first;
 653         while (last < end && ofs_deltas[last + 1].offset == offset)
 654                 ++last;
 655         *first_index = first;
 656         *last_index = last;
 657 }
 658
 659 static int compare_ref_delta_bases(const struct object_id *oid1,
 660                                    const struct object_id *oid2,
 661                                    enum object_type type1,
 662                                    enum object_type type2)
 663 {
 664         int cmp = type1 - type2;
 665         if (cmp)
 666                 return cmp;
 667         return oidcmp(oid1, oid2);
 668 }
 669
 670 static int find_ref_delta(const struct object_id *oid, enum object_type type)
 671 {
 672         int first = 0, last = nr_ref_deltas;
 673
 674         while (first < last) {
 675                 int next = first + (last - first) / 2;
 676                 struct ref_delta_entry *delta = &ref_deltas[next];
 677                 int cmp;
 678
 679                 cmp = compare_ref_delta_bases(oid, &delta->oid,
 680                                               type, objects[delta->obj_no].type);
 681                 if (!cmp)
 682                         return next;
 683                 if (cmp < 0) {
 684                         last = next;
 685                         continue;
 686                 }
 687                 first = next+1;
 688         }
 689         return -first-1;
 690 }
 691
 692 static void find_ref_delta_children(const struct object_id *oid,
 693                                     int *first_index, int *last_index,
 694                                     enum object_type type)
 695 {
 696         int first = find_ref_delta(oid, type);
 697         int last = first;
 698         int end = nr_ref_deltas - 1;
 699
 700         if (first < 0) {
 701                 *first_index = 0;
 702                 *last_index = -1;
 703                 return;
 704         }
 705         while (first > 0 && oideq(&ref_deltas[first - 1].oid, oid))
 706                 --first;
 707         while (last < end && oideq(&ref_deltas[last + 1].oid, oid))
 708                 ++last;
 709         *first_index = first;
 710         *last_index = last;
 711 }
 712
 713 struct compare_data {
 714         struct object_entry *entry;
 715         struct git_istream *st;
 716         unsigned char *buf;
 717         unsigned long buf_size;
 718 };
 719
 720 static int compare_objects(const unsigned char *buf, unsigned long size,
 721                            void *cb_data)
 722 {
 723         struct compare_data *data = cb_data;
 724
 725         if (data->buf_size < size) {
 726                 free(data->buf);
 727                 data->buf = xmalloc(size);
 728                 data->buf_size = size;
 729         }
 730
 731         while (size) {
 732                 ssize_t len = read_istream(data->st, data->buf, size);
 733                 if (len == 0)
 734                         die(_("SHA1 COLLISION FOUND WITH %s !"),
 735                             oid_to_hex(&data->entry->idx.oid));
 736                 if (len < 0)
 737                         die(_("unable to read %s"),
 738                             oid_to_hex(&data->entry->idx.oid));
 739                 if (memcmp(buf, data->buf, len))
 740                         die(_("SHA1 COLLISION FOUND WITH %s !"),
 741                             oid_to_hex(&data->entry->idx.oid));
 742                 size -= len;
 743                 buf += len;
 744         }
 745         return 0;
 746 }
 747
 748 static int check_collison(struct object_entry *entry)
 749 {
 750         struct compare_data data;
 751         enum object_type type;
 752         unsigned long size;
 753
 754         if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 755                 return -1;
 756
 757         memset(&data, 0, sizeof(data));
 758         data.entry = entry;
 759         data.st = open_istream(&entry->idx.oid, &type, &size, NULL);
 760         if (!data.st)
 761                 return -1;
 762         if (size != entry->size || type != entry->type)
 763                 die(_("SHA1 COLLISION FOUND WITH %s !"),
 764                     oid_to_hex(&entry->idx.oid));
 765         unpack_data(entry, compare_objects, &data);
 766         close_istream(data.st);
 767         free(data.buf);
 768         return 0;
 769 }
 770
 771 static void sha1_object(const void *data, struct object_entry *obj_entry,
 772                         unsigned long size, enum object_type type,
 773                         const struct object_id *oid)
 774 {
 775         void *new_data = NULL;
 776         int collision_test_needed = 0;
 777
 778         assert(data || obj_entry);
 779
 780         if (startup_info->have_repository) {
 781                 read_lock();
 782                 collision_test_needed =
 783                         has_object_file_with_flags(oid, OBJECT_INFO_QUICK);
 784                 read_unlock();
 785         }
 786
 787         if (collision_test_needed && !data) {
 788                 read_lock();
 789                 if (!check_collison(obj_entry))
 790                         collision_test_needed = 0;
 791                 read_unlock();
 792         }
 793         if (collision_test_needed) {
 794                 void *has_data;
 795                 enum object_type has_type;
 796                 unsigned long has_size;
 797                 read_lock();
 798                 has_type = oid_object_info(the_repository, oid, &has_size);
 799                 if (has_type < 0)
 800                         die(_("cannot read existing object info %s"), oid_to_hex(oid));
 801                 if (has_type != type || has_size != size)
 802                         die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 803                 has_data = read_object_file(oid, &has_type, &has_size);
 804                 read_unlock();
 805                 if (!data)
 806                         data = new_data = get_data_from_pack(obj_entry);
 807                 if (!has_data)
 808                         die(_("cannot read existing object %s"), oid_to_hex(oid));
 809                 if (size != has_size || type != has_type ||
 810                     memcmp(data, has_data, size) != 0)
 811                         die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 812                 free(has_data);
 813         }
 814
 815         if (strict || do_fsck_object) {
 816                 read_lock();
 817                 if (type == OBJ_BLOB) {
 818                         struct blob *blob = lookup_blob(the_repository, oid);
 819                         if (blob)
 820                                 blob->object.flags |= FLAG_CHECKED;
 821                         else
 822                                 die(_("invalid blob object %s"), oid_to_hex(oid));
 823                         if (do_fsck_object &&
 824                             fsck_object(&blob->object, (void *)data, size, &fsck_options))
 825                                 die(_("fsck error in packed object"));
 826                 } else {
 827                         struct object *obj;
 828                         int eaten;
 829                         void *buf = (void *) data;
 830
 831                         assert(data && "data can only be NULL for large _blobs_");
 832
 833                         /*
 834                          * we do not need to free the memory here, as the
 835                          * buf is deleted by the caller.
 836                          */
 837                         obj = parse_object_buffer(the_repository, oid, type,
 838                                                   size, buf,
 839                                                   &eaten);
 840                         if (!obj)
 841                                 die(_("invalid %s"), type_name(type));
 842                         if (do_fsck_object &&
 843                             fsck_object(obj, buf, size, &fsck_options))
 844                                 die(_("fsck error in packed object"));
 845                         if (strict && fsck_walk(obj, NULL, &fsck_options))
 846                                 die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 847
 848                         if (obj->type == OBJ_TREE) {
 849                                 struct tree *item = (struct tree *) obj;
 850                                 item->buffer = NULL;
 851                                 obj->parsed = 0;
 852                         }
 853                         if (obj->type == OBJ_COMMIT) {
 854                                 struct commit *commit = (struct commit *) obj;
 855                                 if (detach_commit_buffer(commit, NULL) != data)
 856                                         BUG("parse_object_buffer transmogrified our buffer");
 857                         }
 858                         obj->flags |= FLAG_CHECKED;
 859                 }
 860                 read_unlock();
 861         }
 862
 863         free(new_data);
 864 }
 865
 866 /*
 867  * This function is part of find_unresolved_deltas(). There are two
 868  * walkers going in the opposite ways.
 869  *
 870  * The first one in find_unresolved_deltas() traverses down from
 871  * parent node to children, deflating nodes along the way. However,
 872  * memory for deflated nodes is limited by delta_base_cache_limit, so
 873  * at some point parent node's deflated content may be freed.
 874  *
 875  * The second walker is this function, which goes from current node up
 876  * to top parent if necessary to deflate the node. In normal
 877  * situation, its parent node would be already deflated, so it just
 878  * needs to apply delta.
 879  *
 880  * In the worst case scenario, parent node is no longer deflated because
 881  * we're running out of delta_base_cache_limit; we need to re-deflate
 882  * parents, possibly up to the top base.
 883  *
 884  * All deflated objects here are subject to be freed if we exceed
 885  * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 886  * just need to make sure the last node is not freed.
 887  */
 888 static void *get_base_data(struct base_data *c)
 889 {
 890         if (!c->data) {
 891                 struct object_entry *obj = c->obj;
 892                 struct base_data **delta = NULL;
 893                 int delta_nr = 0, delta_alloc = 0;
 894
 895                 while (is_delta_type(c->obj->type) && !c->data) {
 896                         ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 897                         delta[delta_nr++] = c;
 898                         c = c->base;
 899                 }
 900                 if (!delta_nr) {
 901                         c->data = get_data_from_pack(obj);
 902                         c->size = obj->size;
 903                         get_thread_data()->base_cache_used += c->size;
 904                         prune_base_data(c);
 905                 }
 906                 for (; delta_nr > 0; delta_nr--) {
 907                         void *base, *raw;
 908                         c = delta[delta_nr - 1];
 909                         obj = c->obj;
 910                         base = get_base_data(c->base);
 911                         raw = get_data_from_pack(obj);
 912                         c->data = patch_delta(
 913                                 base, c->base->size,
 914                                 raw, obj->size,
 915                                 &c->size);
 916                         free(raw);
 917                         if (!c->data)
 918                                 bad_object(obj->idx.offset, _("failed to apply delta"));
 919                         get_thread_data()->base_cache_used += c->size;
 920                         prune_base_data(c);
 921                 }
 922                 free(delta);
 923         }
 924         return c->data;
 925 }
 926
 927 static void resolve_delta(struct object_entry *delta_obj,
 928                           struct base_data *base, struct base_data *result)
 929 {
 930         void *base_data, *delta_data;
 931
 932         if (show_stat) {
 933                 int i = delta_obj - objects;
 934                 int j = base->obj - objects;
 935                 obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 936                 deepest_delta_lock();
 937                 if (deepest_delta < obj_stat[i].delta_depth)
 938                         deepest_delta = obj_stat[i].delta_depth;
 939                 deepest_delta_unlock();
 940                 obj_stat[i].base_object_no = j;
 941         }
 942         delta_data = get_data_from_pack(delta_obj);
 943         base_data = get_base_data(base);
 944         result->obj = delta_obj;
 945         result->data = patch_delta(base_data, base->size,
 946                                    delta_data, delta_obj->size, &result->size);
 947         free(delta_data);
 948         if (!result->data)
 949                 bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 950         hash_object_file(result->data, result->size,
 951                          type_name(delta_obj->real_type), &delta_obj->idx.oid);
 952         sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 953                     &delta_obj->idx.oid);
 954         counter_lock();
 955         nr_resolved_deltas++;
 956         counter_unlock();
 957 }
 958
 959 /*
 960  * Standard boolean compare-and-swap: atomically check whether "*type" is
 961  * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 962  * and return false.
 963  */
 964 static int compare_and_swap_type(signed char *type,
 965                                  enum object_type want,
 966                                  enum object_type set)
 967 {
 968         enum object_type old;
 969
 970         type_cas_lock();
 971         old = *type;
 972         if (old == want)
 973                 *type = set;
 974         type_cas_unlock();
 975
 976         return old == want;
 977 }
 978
 979 static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 980                                                   struct base_data *prev_base)
 981 {
 982         if (base->ref_last == -1 && base->ofs_last == -1) {
 983                 find_ref_delta_children(&base->obj->idx.oid,
 984                                         &base->ref_first, &base->ref_last,
 985                                         OBJ_REF_DELTA);
 986
 987                 find_ofs_delta_children(base->obj->idx.offset,
 988                                         &base->ofs_first, &base->ofs_last,
 989                                         OBJ_OFS_DELTA);
 990
 991                 if (base->ref_last == -1 && base->ofs_last == -1) {
 992                         free(base->data);
 993                         return NULL;
 994                 }
 995
 996                 link_base_data(prev_base, base);
 997         }
 998
 999         if (base->ref_first <= base->ref_last) {
1000                 struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1001                 struct base_data *result = alloc_base_data();
1002
1003                 if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1004                                            base->obj->real_type))
1005                         BUG("child->real_type != OBJ_REF_DELTA");
1006
1007                 resolve_delta(child, base, result);
1008                 if (base->ref_first == base->ref_last && base->ofs_last == -1)
1009                         free_base_data(base);
1010
1011                 base->ref_first++;
1012                 return result;
1013         }
1014
1015         if (base->ofs_first <= base->ofs_last) {
1016                 struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1017                 struct base_data *result = alloc_base_data();
1018
1019                 assert(child->real_type == OBJ_OFS_DELTA);
1020                 child->real_type = base->obj->real_type;
1021                 resolve_delta(child, base, result);
1022                 if (base->ofs_first == base->ofs_last)
1023                         free_base_data(base);
1024
1025                 base->ofs_first++;
1026                 return result;
1027         }
1028
1029         unlink_base_data(base);
1030         return NULL;
1031 }
1032
1033 static void find_unresolved_deltas(struct base_data *base)
1034 {
1035         struct base_data *new_base, *prev_base = NULL;
1036         for (;;) {
1037                 new_base = find_unresolved_deltas_1(base, prev_base);
1038
1039                 if (new_base) {
1040                         prev_base = base;
1041                         base = new_base;
1042                 } else {
1043                         free(base);
1044                         base = prev_base;
1045                         if (!base)
1046                                 return;
1047                         prev_base = base->base;
1048                 }
1049         }
1050 }
1051
1052 static int compare_ofs_delta_entry(const void *a, const void *b)
1053 {
1054         const struct ofs_delta_entry *delta_a = a;
1055         const struct ofs_delta_entry *delta_b = b;
1056
1057         return delta_a->offset < delta_b->offset ? -1 :
1058                delta_a->offset > delta_b->offset ?  1 :
1059                0;
1060 }
1061
1062 static int compare_ref_delta_entry(const void *a, const void *b)
1063 {
1064         const struct ref_delta_entry *delta_a = a;
1065         const struct ref_delta_entry *delta_b = b;
1066
1067         return oidcmp(&delta_a->oid, &delta_b->oid);
1068 }
1069
1070 static void resolve_base(struct object_entry *obj)
1071 {
1072         struct base_data *base_obj = alloc_base_data();
1073         base_obj->obj = obj;
1074         base_obj->data = NULL;
1075         find_unresolved_deltas(base_obj);
1076 }
1077
1078 static void *threaded_second_pass(void *data)
1079 {
1080         set_thread_data(data);
1081         for (;;) {
1082                 int i;
1083                 counter_lock();
1084                 display_progress(progress, nr_resolved_deltas);
1085                 counter_unlock();
1086                 work_lock();
1087                 while (nr_dispatched < nr_objects &&
1088                        is_delta_type(objects[nr_dispatched].type))
1089                         nr_dispatched++;
1090                 if (nr_dispatched >= nr_objects) {
1091                         work_unlock();
1092                         break;
1093                 }
1094                 i = nr_dispatched++;
1095                 work_unlock();
1096
1097                 resolve_base(&objects[i]);
1098         }
1099         return NULL;
1100 }
1101
1102 /*
1103  * First pass:
1104  * - find locations of all objects;
1105  * - calculate SHA1 of all non-delta objects;
1106  * - remember base (SHA1 or offset) for all deltas.
1107  */
1108 static void parse_pack_objects(unsigned char *hash)
1109 {
1110         int i, nr_delays = 0;
1111         struct ofs_delta_entry *ofs_delta = ofs_deltas;
1112         struct object_id ref_delta_oid;
1113         struct stat st;
1114
1115         if (verbose)
1116                 progress = start_progress(
1117                                 from_stdin ? _("Receiving objects") : _("Indexing objects"),
1118                                 nr_objects);
1119         for (i = 0; i < nr_objects; i++) {
1120                 struct object_entry *obj = &objects[i];
1121                 void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1122                                               &ref_delta_oid,
1123                                               &obj->idx.oid);
1124                 obj->real_type = obj->type;
1125                 if (obj->type == OBJ_OFS_DELTA) {
1126                         nr_ofs_deltas++;
1127                         ofs_delta->obj_no = i;
1128                         ofs_delta++;
1129                 } else if (obj->type == OBJ_REF_DELTA) {
1130                         ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1131                         oidcpy(&ref_deltas[nr_ref_deltas].oid, &ref_delta_oid);
1132                         ref_deltas[nr_ref_deltas].obj_no = i;
1133                         nr_ref_deltas++;
1134                 } else if (!data) {
1135                         /* large blobs, check later */
1136                         obj->real_type = OBJ_BAD;
1137                         nr_delays++;
1138                 } else
1139                         sha1_object(data, NULL, obj->size, obj->type,
1140                                     &obj->idx.oid);
1141                 free(data);
1142                 display_progress(progress, i+1);
1143         }
1144         objects[i].idx.offset = consumed_bytes;
1145         stop_progress(&progress);
1146
1147         /* Check pack integrity */
1148         flush();
1149         the_hash_algo->final_fn(hash, &input_ctx);
1150         if (!hasheq(fill(the_hash_algo->rawsz), hash))
1151                 die(_("pack is corrupted (SHA1 mismatch)"));
1152         use(the_hash_algo->rawsz);
1153
1154         /* If input_fd is a file, we should have reached its end now. */
1155         if (fstat(input_fd, &st))
1156                 die_errno(_("cannot fstat packfile"));
1157         if (S_ISREG(st.st_mode) &&
1158                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1159                 die(_("pack has junk at the end"));
1160
1161         for (i = 0; i < nr_objects; i++) {
1162                 struct object_entry *obj = &objects[i];
1163                 if (obj->real_type != OBJ_BAD)
1164                         continue;
1165                 obj->real_type = obj->type;
1166                 sha1_object(NULL, obj, obj->size, obj->type,
1167                             &obj->idx.oid);
1168                 nr_delays--;
1169         }
1170         if (nr_delays)
1171                 die(_("confusion beyond insanity in parse_pack_objects()"));
1172 }
1173
1174 /*
1175  * Second pass:
1176  * - for all non-delta objects, look if it is used as a base for
1177  *   deltas;
1178  * - if used as a base, uncompress the object and apply all deltas,
1179  *   recursively checking if the resulting object is used as a base
1180  *   for some more deltas.
1181  */
1182 static void resolve_deltas(void)
1183 {
1184         int i;
1185
1186         if (!nr_ofs_deltas && !nr_ref_deltas)
1187                 return;
1188
1189         /* Sort deltas by base SHA1/offset for fast searching */
1190         QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1191         QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1192
1193         if (verbose || show_resolving_progress)
1194                 progress = start_progress(_("Resolving deltas"),
1195                                           nr_ref_deltas + nr_ofs_deltas);
1196
1197         nr_dispatched = 0;
1198         if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1199                 init_thread();
1200                 for (i = 0; i < nr_threads; i++) {
1201                         int ret = pthread_create(&thread_data[i].thread, NULL,
1202                                                  threaded_second_pass, thread_data + i);
1203                         if (ret)
1204                                 die(_("unable to create thread: %s"),
1205                                     strerror(ret));
1206                 }
1207                 for (i = 0; i < nr_threads; i++)
1208                         pthread_join(thread_data[i].thread, NULL);
1209                 cleanup_thread();
1210                 return;
1211         }
1212
1213         for (i = 0; i < nr_objects; i++) {
1214                 struct object_entry *obj = &objects[i];
1215
1216                 if (is_delta_type(obj->type))
1217                         continue;
1218                 resolve_base(obj);
1219                 display_progress(progress, nr_resolved_deltas);
1220         }
1221 }
1222
1223 /*
1224  * Third pass:
1225  * - append objects to convert thin pack to full pack if required
1226  * - write the final pack hash
1227  */
1228 static void fix_unresolved_deltas(struct hashfile *f);
1229 static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_hash)
1230 {
1231         if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1232                 stop_progress(&progress);
1233                 /* Flush remaining pack final hash. */
1234                 flush();
1235                 return;
1236         }
1237
1238         if (fix_thin_pack) {
1239                 struct hashfile *f;
1240                 unsigned char read_hash[GIT_MAX_RAWSZ], tail_hash[GIT_MAX_RAWSZ];
1241                 struct strbuf msg = STRBUF_INIT;
1242                 int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1243                 int nr_objects_initial = nr_objects;
1244                 if (nr_unresolved <= 0)
1245                         die(_("confusion beyond insanity"));
1246                 REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1247                 memset(objects + nr_objects + 1, 0,
1248                        nr_unresolved * sizeof(*objects));
1249                 f = hashfd(output_fd, curr_pack);
1250                 fix_unresolved_deltas(f);
1251                 strbuf_addf(&msg, Q_("completed with %d local object",
1252                                      "completed with %d local objects",
1253                                      nr_objects - nr_objects_initial),
1254                             nr_objects - nr_objects_initial);
1255                 stop_progress_msg(&progress, msg.buf);
1256                 strbuf_release(&msg);
1257                 finalize_hashfile(f, tail_hash, 0);
1258                 hashcpy(read_hash, pack_hash);
1259                 fixup_pack_header_footer(output_fd, pack_hash,
1260                                          curr_pack, nr_objects,
1261                                          read_hash, consumed_bytes-the_hash_algo->rawsz);
1262                 if (!hasheq(read_hash, tail_hash))
1263                         die(_("Unexpected tail checksum for %s "
1264                               "(disk corruption?)"), curr_pack);
1265         }
1266         if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1267                 die(Q_("pack has %d unresolved delta",
1268                        "pack has %d unresolved deltas",
1269                        nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1270                     nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1271 }
1272
1273 static int write_compressed(struct hashfile *f, void *in, unsigned int size)
1274 {
1275         git_zstream stream;
1276         int status;
1277         unsigned char outbuf[4096];
1278
1279         git_deflate_init(&stream, zlib_compression_level);
1280         stream.next_in = in;
1281         stream.avail_in = size;
1282
1283         do {
1284                 stream.next_out = outbuf;
1285                 stream.avail_out = sizeof(outbuf);
1286                 status = git_deflate(&stream, Z_FINISH);
1287                 hashwrite(f, outbuf, sizeof(outbuf) - stream.avail_out);
1288         } while (status == Z_OK);
1289
1290         if (status != Z_STREAM_END)
1291                 die(_("unable to deflate appended object (%d)"), status);
1292         size = stream.total_out;
1293         git_deflate_end(&stream);
1294         return size;
1295 }
1296
1297 static struct object_entry *append_obj_to_pack(struct hashfile *f,
1298                                const unsigned char *sha1, void *buf,
1299                                unsigned long size, enum object_type type)
1300 {
1301         struct object_entry *obj = &objects[nr_objects++];
1302         unsigned char header[10];
1303         unsigned long s = size;
1304         int n = 0;
1305         unsigned char c = (type << 4) | (s & 15);
1306         s >>= 4;
1307         while (s) {
1308                 header[n++] = c | 0x80;
1309                 c = s & 0x7f;
1310                 s >>= 7;
1311         }
1312         header[n++] = c;
1313         crc32_begin(f);
1314         hashwrite(f, header, n);
1315         obj[0].size = size;
1316         obj[0].hdr_size = n;
1317         obj[0].type = type;
1318         obj[0].real_type = type;
1319         obj[1].idx.offset = obj[0].idx.offset + n;
1320         obj[1].idx.offset += write_compressed(f, buf, size);
1321         obj[0].idx.crc32 = crc32_end(f);
1322         hashflush(f);
1323         hashcpy(obj->idx.oid.hash, sha1);
1324         return obj;
1325 }
1326
1327 static int delta_pos_compare(const void *_a, const void *_b)
1328 {
1329         struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1330         struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1331         return a->obj_no - b->obj_no;
1332 }
1333
1334 static void fix_unresolved_deltas(struct hashfile *f)
1335 {
1336         struct ref_delta_entry **sorted_by_pos;
1337         int i;
1338
1339         /*
1340          * Since many unresolved deltas may well be themselves base objects
1341          * for more unresolved deltas, we really want to include the
1342          * smallest number of base objects that would cover as much delta
1343          * as possible by picking the
1344          * trunc deltas first, allowing for other deltas to resolve without
1345          * additional base objects.  Since most base objects are to be found
1346          * before deltas depending on them, a good heuristic is to start
1347          * resolving deltas in the same order as their position in the pack.
1348          */
1349         ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1350         for (i = 0; i < nr_ref_deltas; i++)
1351                 sorted_by_pos[i] = &ref_deltas[i];
1352         QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1353
1354         for (i = 0; i < nr_ref_deltas; i++) {
1355                 struct ref_delta_entry *d = sorted_by_pos[i];
1356                 enum object_type type;
1357                 struct base_data *base_obj = alloc_base_data();
1358
1359                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1360                         continue;
1361                 base_obj->data = read_object_file(&d->oid, &type,
1362                                                   &base_obj->size);
1363                 if (!base_obj->data)
1364                         continue;
1365
1366                 if (check_object_signature(&d->oid, base_obj->data,
1367                                 base_obj->size, type_name(type)))
1368                         die(_("local object %s is corrupt"), oid_to_hex(&d->oid));
1369                 base_obj->obj = append_obj_to_pack(f, d->oid.hash,
1370                                         base_obj->data, base_obj->size, type);
1371                 find_unresolved_deltas(base_obj);
1372                 display_progress(progress, nr_resolved_deltas);
1373         }
1374         free(sorted_by_pos);
1375 }
1376
1377 static const char *derive_filename(const char *pack_name, const char *suffix,
1378                                    struct strbuf *buf)
1379 {
1380         size_t len;
1381         if (!strip_suffix(pack_name, ".pack", &len))
1382                 die(_("packfile name '%s' does not end with '.pack'"),
1383                     pack_name);
1384         strbuf_add(buf, pack_name, len);
1385         strbuf_addch(buf, '.');
1386         strbuf_addstr(buf, suffix);
1387         return buf->buf;
1388 }
1389
1390 static void write_special_file(const char *suffix, const char *msg,
1391                                const char *pack_name, const unsigned char *hash,
1392                                const char **report)
1393 {
1394         struct strbuf name_buf = STRBUF_INIT;
1395         const char *filename;
1396         int fd;
1397         int msg_len = strlen(msg);
1398
1399         if (pack_name)
1400                 filename = derive_filename(pack_name, suffix, &name_buf);
1401         else
1402                 filename = odb_pack_name(&name_buf, hash, suffix);
1403
1404         fd = odb_pack_keep(filename);
1405         if (fd < 0) {
1406                 if (errno != EEXIST)
1407                         die_errno(_("cannot write %s file '%s'"),
1408                                   suffix, filename);
1409         } else {
1410                 if (msg_len > 0) {
1411                         write_or_die(fd, msg, msg_len);
1412                         write_or_die(fd, "\n", 1);
1413                 }
1414                 if (close(fd) != 0)
1415                         die_errno(_("cannot close written %s file '%s'"),
1416                                   suffix, filename);
1417                 if (report)
1418                         *report = suffix;
1419         }
1420         strbuf_release(&name_buf);
1421 }
1422
1423 static void final(const char *final_pack_name, const char *curr_pack_name,
1424                   const char *final_index_name, const char *curr_index_name,
1425                   const char *keep_msg, const char *promisor_msg,
1426                   unsigned char *hash)
1427 {
1428         const char *report = "pack";
1429         struct strbuf pack_name = STRBUF_INIT;
1430         struct strbuf index_name = STRBUF_INIT;
1431         int err;
1432
1433         if (!from_stdin) {
1434                 close(input_fd);
1435         } else {
1436                 fsync_or_die(output_fd, curr_pack_name);
1437                 err = close(output_fd);
1438                 if (err)
1439                         die_errno(_("error while closing pack file"));
1440         }
1441
1442         if (keep_msg)
1443                 write_special_file("keep", keep_msg, final_pack_name, hash,
1444                                    &report);
1445         if (promisor_msg)
1446                 write_special_file("promisor", promisor_msg, final_pack_name,
1447                                    hash, NULL);
1448
1449         if (final_pack_name != curr_pack_name) {
1450                 if (!final_pack_name)
1451                         final_pack_name = odb_pack_name(&pack_name, hash, "pack");
1452                 if (finalize_object_file(curr_pack_name, final_pack_name))
1453                         die(_("cannot store pack file"));
1454         } else if (from_stdin)
1455                 chmod(final_pack_name, 0444);
1456
1457         if (final_index_name != curr_index_name) {
1458                 if (!final_index_name)
1459                         final_index_name = odb_pack_name(&index_name, hash, "idx");
1460                 if (finalize_object_file(curr_index_name, final_index_name))
1461                         die(_("cannot store index file"));
1462         } else
1463                 chmod(final_index_name, 0444);
1464
1465         if (do_fsck_object) {
1466                 struct packed_git *p;
1467                 p = add_packed_git(final_index_name, strlen(final_index_name), 0);
1468                 if (p)
1469                         install_packed_git(the_repository, p);
1470         }
1471
1472         if (!from_stdin) {
1473                 printf("%s\n", sha1_to_hex(hash));
1474         } else {
1475                 struct strbuf buf = STRBUF_INIT;
1476
1477                 strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(hash));
1478                 write_or_die(1, buf.buf, buf.len);
1479                 strbuf_release(&buf);
1480
1481                 /*
1482                  * Let's just mimic git-unpack-objects here and write
1483                  * the last part of the input buffer to stdout.
1484                  */
1485                 while (input_len) {
1486                         err = xwrite(1, input_buffer + input_offset, input_len);
1487                         if (err <= 0)
1488                                 break;
1489                         input_len -= err;
1490                         input_offset += err;
1491                 }
1492         }
1493
1494         strbuf_release(&index_name);
1495         strbuf_release(&pack_name);
1496 }
1497
1498 static int git_index_pack_config(const char *k, const char *v, void *cb)
1499 {
1500         struct pack_idx_option *opts = cb;
1501
1502         if (!strcmp(k, "pack.indexversion")) {
1503                 opts->version = git_config_int(k, v);
1504                 if (opts->version > 2)
1505                         die(_("bad pack.indexversion=%"PRIu32), opts->version);
1506                 return 0;
1507         }
1508         if (!strcmp(k, "pack.threads")) {
1509                 nr_threads = git_config_int(k, v);
1510                 if (nr_threads < 0)
1511                         die(_("invalid number of threads specified (%d)"),
1512                             nr_threads);
1513                 if (!HAVE_THREADS && nr_threads != 1) {
1514                         warning(_("no threads support, ignoring %s"), k);
1515                         nr_threads = 1;
1516                 }
1517                 return 0;
1518         }
1519         return git_default_config(k, v, cb);
1520 }
1521
1522 static int cmp_uint32(const void *a_, const void *b_)
1523 {
1524         uint32_t a = *((uint32_t *)a_);
1525         uint32_t b = *((uint32_t *)b_);
1526
1527         return (a < b) ? -1 : (a != b);
1528 }
1529
1530 static void read_v2_anomalous_offsets(struct packed_git *p,
1531                                       struct pack_idx_option *opts)
1532 {
1533         const uint32_t *idx1, *idx2;
1534         uint32_t i;
1535         const uint32_t hashwords = the_hash_algo->rawsz / sizeof(uint32_t);
1536
1537         /* The address of the 4-byte offset table */
1538         idx1 = (((const uint32_t *)p->index_data)
1539                 + 2 /* 8-byte header */
1540                 + 256 /* fan out */
1541                 + hashwords * p->num_objects /* object ID table */
1542                 + p->num_objects /* CRC32 table */
1543                 );
1544
1545         /* The address of the 8-byte offset table */
1546         idx2 = idx1 + p->num_objects;
1547
1548         for (i = 0; i < p->num_objects; i++) {
1549                 uint32_t off = ntohl(idx1[i]);
1550                 if (!(off & 0x80000000))
1551                         continue;
1552                 off = off & 0x7fffffff;
1553                 check_pack_index_ptr(p, &idx2[off * 2]);
1554                 if (idx2[off * 2])
1555                         continue;
1556                 /*
1557                  * The real offset is ntohl(idx2[off * 2]) in high 4
1558                  * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1559                  * octets.  But idx2[off * 2] is Zero!!!
1560                  */
1561                 ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1562                 opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1563         }
1564
1565         QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1566 }
1567
1568 static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1569 {
1570         struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1571
1572         if (!p)
1573                 die(_("Cannot open existing pack file '%s'"), pack_name);
1574         if (open_pack_index(p))
1575                 die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1576
1577         /* Read the attributes from the existing idx file */
1578         opts->version = p->index_version;
1579
1580         if (opts->version == 2)
1581                 read_v2_anomalous_offsets(p, opts);
1582
1583         /*
1584          * Get rid of the idx file as we do not need it anymore.
1585          * NEEDSWORK: extract this bit from free_pack_by_name() in
1586          * sha1-file.c, perhaps?  It shouldn't matter very much as we
1587          * know we haven't installed this pack (hence we never have
1588          * read anything from it).
1589          */
1590         close_pack_index(p);
1591         free(p);
1592 }
1593
1594 static void show_pack_info(int stat_only)
1595 {
1596         int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1597         unsigned long *chain_histogram = NULL;
1598
1599         if (deepest_delta)
1600                 chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1601
1602         for (i = 0; i < nr_objects; i++) {
1603                 struct object_entry *obj = &objects[i];
1604
1605                 if (is_delta_type(obj->type))
1606                         chain_histogram[obj_stat[i].delta_depth - 1]++;
1607                 if (stat_only)
1608                         continue;
1609                 printf("%s %-6s %"PRIuMAX" %"PRIuMAX" %"PRIuMAX,
1610                        oid_to_hex(&obj->idx.oid),
1611                        type_name(obj->real_type), (uintmax_t)obj->size,
1612                        (uintmax_t)(obj[1].idx.offset - obj->idx.offset),
1613                        (uintmax_t)obj->idx.offset);
1614                 if (is_delta_type(obj->type)) {
1615                         struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1616                         printf(" %u %s", obj_stat[i].delta_depth,
1617                                oid_to_hex(&bobj->idx.oid));
1618                 }
1619                 putchar('\n');
1620         }
1621
1622         if (baseobjects)
1623                 printf_ln(Q_("non delta: %d object",
1624                              "non delta: %d objects",
1625                              baseobjects),
1626                           baseobjects);
1627         for (i = 0; i < deepest_delta; i++) {
1628                 if (!chain_histogram[i])
1629                         continue;
1630                 printf_ln(Q_("chain length = %d: %lu object",
1631                              "chain length = %d: %lu objects",
1632                              chain_histogram[i]),
1633                           i + 1,
1634                           chain_histogram[i]);
1635         }
1636 }
1637
1638 int cmd_index_pack(int argc, const char **argv, const char *prefix)
1639 {
1640         int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1641         const char *curr_index;
1642         const char *index_name = NULL, *pack_name = NULL;
1643         const char *keep_msg = NULL;
1644         const char *promisor_msg = NULL;
1645         struct strbuf index_name_buf = STRBUF_INIT;
1646         struct pack_idx_entry **idx_objects;
1647         struct pack_idx_option opts;
1648         unsigned char pack_hash[GIT_MAX_RAWSZ];
1649         unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1650         int report_end_of_input = 0;
1651
1652         /*
1653          * index-pack never needs to fetch missing objects, since it only
1654          * accesses the repo to do hash collision checks
1655          */
1656         fetch_if_missing = 0;
1657
1658         if (argc == 2 && !strcmp(argv[1], "-h"))
1659                 usage(index_pack_usage);
1660
1661         read_replace_refs = 0;
1662         fsck_options.walk = mark_link;
1663
1664         reset_pack_idx_option(&opts);
1665         git_config(git_index_pack_config, &opts);
1666         if (prefix && chdir(prefix))
1667                 die(_("Cannot come back to cwd"));
1668
1669         for (i = 1; i < argc; i++) {
1670                 const char *arg = argv[i];
1671
1672                 if (*arg == '-') {
1673                         if (!strcmp(arg, "--stdin")) {
1674                                 from_stdin = 1;
1675                         } else if (!strcmp(arg, "--fix-thin")) {
1676                                 fix_thin_pack = 1;
1677                         } else if (skip_to_optional_arg(arg, "--strict", &arg)) {
1678                                 strict = 1;
1679                                 do_fsck_object = 1;
1680                                 fsck_set_msg_types(&fsck_options, arg);
1681                         } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1682                                 strict = 1;
1683                                 check_self_contained_and_connected = 1;
1684                         } else if (!strcmp(arg, "--fsck-objects")) {
1685                                 do_fsck_object = 1;
1686                         } else if (!strcmp(arg, "--verify")) {
1687                                 verify = 1;
1688                         } else if (!strcmp(arg, "--verify-stat")) {
1689                                 verify = 1;
1690                                 show_stat = 1;
1691                         } else if (!strcmp(arg, "--verify-stat-only")) {
1692                                 verify = 1;
1693                                 show_stat = 1;
1694                                 stat_only = 1;
1695                         } else if (skip_to_optional_arg(arg, "--keep", &keep_msg)) {
1696                                 ; /* nothing to do */
1697                         } else if (skip_to_optional_arg(arg, "--promisor", &promisor_msg)) {
1698                                 ; /* already parsed */
1699                         } else if (starts_with(arg, "--threads=")) {
1700                                 char *end;
1701                                 nr_threads = strtoul(arg+10, &end, 0);
1702                                 if (!arg[10] || *end || nr_threads < 0)
1703                                         usage(index_pack_usage);
1704                                 if (!HAVE_THREADS && nr_threads != 1) {
1705                                         warning(_("no threads support, ignoring %s"), arg);
1706                                         nr_threads = 1;
1707                                 }
1708                         } else if (starts_with(arg, "--pack_header=")) {
1709                                 struct pack_header *hdr;
1710                                 char *c;
1711
1712                                 hdr = (struct pack_header *)input_buffer;
1713                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
1714                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1715                                 if (*c != ',')
1716                                         die(_("bad %s"), arg);
1717                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1718                                 if (*c)
1719                                         die(_("bad %s"), arg);
1720                                 input_len = sizeof(*hdr);
1721                         } else if (!strcmp(arg, "-v")) {
1722                                 verbose = 1;
1723                         } else if (!strcmp(arg, "--show-resolving-progress")) {
1724                                 show_resolving_progress = 1;
1725                         } else if (!strcmp(arg, "--report-end-of-input")) {
1726                                 report_end_of_input = 1;
1727                         } else if (!strcmp(arg, "-o")) {
1728                                 if (index_name || (i+1) >= argc)
1729                                         usage(index_pack_usage);
1730                                 index_name = argv[++i];
1731                         } else if (starts_with(arg, "--index-version=")) {
1732                                 char *c;
1733                                 opts.version = strtoul(arg + 16, &c, 10);
1734                                 if (opts.version > 2)
1735                                         die(_("bad %s"), arg);
1736                                 if (*c == ',')
1737                                         opts.off32_limit = strtoul(c+1, &c, 0);
1738                                 if (*c || opts.off32_limit & 0x80000000)
1739                                         die(_("bad %s"), arg);
1740                         } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1741                                 max_input_size = strtoumax(arg, NULL, 10);
1742                         } else
1743                                 usage(index_pack_usage);
1744                         continue;
1745                 }
1746
1747                 if (pack_name)
1748                         usage(index_pack_usage);
1749                 pack_name = arg;
1750         }
1751
1752         if (!pack_name && !from_stdin)
1753                 usage(index_pack_usage);
1754         if (fix_thin_pack && !from_stdin)
1755                 die(_("--fix-thin cannot be used without --stdin"));
1756         if (from_stdin && !startup_info->have_repository)
1757                 die(_("--stdin requires a git repository"));
1758         if (!index_name && pack_name)
1759                 index_name = derive_filename(pack_name, "idx", &index_name_buf);
1760
1761         if (verify) {
1762                 if (!index_name)
1763                         die(_("--verify with no packfile name given"));
1764                 read_idx_option(&opts, index_name);
1765                 opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1766         }
1767         if (strict)
1768                 opts.flags |= WRITE_IDX_STRICT;
1769
1770         if (HAVE_THREADS && !nr_threads) {
1771                 nr_threads = online_cpus();
1772                 /* An experiment showed that more threads does not mean faster */
1773                 if (nr_threads > 3)
1774                         nr_threads = 3;
1775         }
1776
1777         curr_pack = open_pack_file(pack_name);
1778         parse_pack_header();
1779         objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1780         if (show_stat)
1781                 obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1782         ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1783         parse_pack_objects(pack_hash);
1784         if (report_end_of_input)
1785                 write_in_full(2, "\0", 1);
1786         resolve_deltas();
1787         conclude_pack(fix_thin_pack, curr_pack, pack_hash);
1788         free(ofs_deltas);
1789         free(ref_deltas);
1790         if (strict)
1791                 foreign_nr = check_objects();
1792
1793         if (show_stat)
1794                 show_pack_info(stat_only);
1795
1796         ALLOC_ARRAY(idx_objects, nr_objects);
1797         for (i = 0; i < nr_objects; i++)
1798                 idx_objects[i] = &objects[i].idx;
1799         curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_hash);
1800         free(idx_objects);
1801
1802         if (!verify)
1803                 final(pack_name, curr_pack,
1804                       index_name, curr_index,
1805                       keep_msg, promisor_msg,
1806                       pack_hash);
1807         else
1808                 close(input_fd);
1809
1810         if (do_fsck_object && fsck_finish(&fsck_options))
1811                 die(_("fsck error in pack objects"));
1812
1813         free(objects);
1814         strbuf_release(&index_name_buf);
1815         if (pack_name == NULL)
1816                 free((void *) curr_pack);
1817         if (index_name == NULL)
1818                 free((void *) curr_index);
1819
1820         /*
1821          * Let the caller know this pack is not self contained
1822          */
1823         if (check_self_contained_and_connected && foreign_nr)
1824                 return 1;
1825
1826         return 0;
1827 }