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 #include "promisor-remote.h"
  18
  19 static const char index_pack_usage[] =
  20 "git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  21
  22 struct object_entry {
  23         struct pack_idx_entry idx;
  24         unsigned long size;
  25         unsigned char hdr_size;
  26         signed char type;
  27         signed char real_type;
  28 };
  29
  30 struct object_stat {
  31         unsigned delta_depth;
  32         int base_object_no;
  33 };
  34
  35 struct base_data {
  36         struct base_data *base;
  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         size_t base_cache_used;
  47         int pack_fd;
  48 };
  49
  50 /* Remember to update object flag allocation in object.h */
  51 #define FLAG_LINK (1u<<20)
  52 #define FLAG_CHECKED (1u<<21)
  53
  54 struct ofs_delta_entry {
  55         off_t offset;
  56         int obj_no;
  57 };
  58
  59 struct ref_delta_entry {
  60         struct object_id oid;
  61         int obj_no;
  62 };
  63
  64 static struct object_entry *objects;
  65 static struct object_stat *obj_stat;
  66 static struct ofs_delta_entry *ofs_deltas;
  67 static struct ref_delta_entry *ref_deltas;
  68 static struct thread_local nothread_data;
  69 static int nr_objects;
  70 static int nr_ofs_deltas;
  71 static int nr_ref_deltas;
  72 static int ref_deltas_alloc;
  73 static int nr_resolved_deltas;
  74 static int nr_threads;
  75
  76 static int from_stdin;
  77 static int strict;
  78 static int do_fsck_object;
  79 static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
  80 static int verbose;
  81 static int show_resolving_progress;
  82 static int show_stat;
  83 static int check_self_contained_and_connected;
  84
  85 static struct progress *progress;
  86
  87 /* We always read in 4kB chunks. */
  88 static unsigned char input_buffer[4096];
  89 static unsigned int input_offset, input_len;
  90 static off_t consumed_bytes;
  91 static off_t max_input_size;
  92 static unsigned deepest_delta;
  93 static git_hash_ctx input_ctx;
  94 static uint32_t input_crc32;
  95 static int input_fd, output_fd;
  96 static const char *curr_pack;
  97
  98 static struct thread_local *thread_data;
  99 static int nr_dispatched;
 100 static int threads_active;
 101
 102 static pthread_mutex_t read_mutex;
 103 #define read_lock()             lock_mutex(&read_mutex)
 104 #define read_unlock()           unlock_mutex(&read_mutex)
 105
 106 static pthread_mutex_t counter_mutex;
 107 #define counter_lock()          lock_mutex(&counter_mutex)
 108 #define counter_unlock()        unlock_mutex(&counter_mutex)
 109
 110 static pthread_mutex_t work_mutex;
 111 #define work_lock()             lock_mutex(&work_mutex)
 112 #define work_unlock()           unlock_mutex(&work_mutex)
 113
 114 static pthread_mutex_t deepest_delta_mutex;
 115 #define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 116 #define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 117
 118 static pthread_mutex_t type_cas_mutex;
 119 #define type_cas_lock()         lock_mutex(&type_cas_mutex)
 120 #define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 121
 122 static pthread_key_t key;
 123
 124 static inline void lock_mutex(pthread_mutex_t *mutex)
 125 {
 126         if (threads_active)
 127                 pthread_mutex_lock(mutex);
 128 }
 129
 130 static inline void unlock_mutex(pthread_mutex_t *mutex)
 131 {
 132         if (threads_active)
 133                 pthread_mutex_unlock(mutex);
 134 }
 135
 136 /*
 137  * Mutex and conditional variable can't be statically-initialized on Windows.
 138  */
 139 static void init_thread(void)
 140 {
 141         int i;
 142         init_recursive_mutex(&read_mutex);
 143         pthread_mutex_init(&counter_mutex, NULL);
 144         pthread_mutex_init(&work_mutex, NULL);
 145         pthread_mutex_init(&type_cas_mutex, NULL);
 146         if (show_stat)
 147                 pthread_mutex_init(&deepest_delta_mutex, NULL);
 148         pthread_key_create(&key, NULL);
 149         thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 150         for (i = 0; i < nr_threads; i++) {
 151                 thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 152                 if (thread_data[i].pack_fd == -1)
 153                         die_errno(_("unable to open %s"), curr_pack);
 154         }
 155
 156         threads_active = 1;
 157 }
 158
 159 static void cleanup_thread(void)
 160 {
 161         int i;
 162         if (!threads_active)
 163                 return;
 164         threads_active = 0;
 165         pthread_mutex_destroy(&read_mutex);
 166         pthread_mutex_destroy(&counter_mutex);
 167         pthread_mutex_destroy(&work_mutex);
 168         pthread_mutex_destroy(&type_cas_mutex);
 169         if (show_stat)
 170                 pthread_mutex_destroy(&deepest_delta_mutex);
 171         for (i = 0; i < nr_threads; i++)
 172                 close(thread_data[i].pack_fd);
 173         pthread_key_delete(key);
 174         free(thread_data);
 175 }
 176
 177 static int mark_link(struct object *obj, int type, void *data, struct fsck_options *options)
 178 {
 179         if (!obj)
 180                 return -1;
 181
 182         if (type != OBJ_ANY && obj->type != type)
 183                 die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 184
 185         obj->flags |= FLAG_LINK;
 186         return 0;
 187 }
 188
 189 /* The content of each linked object must have been checked
 190    or it must be already present in the object database */
 191 static unsigned check_object(struct object *obj)
 192 {
 193         if (!obj)
 194                 return 0;
 195
 196         if (!(obj->flags & FLAG_LINK))
 197                 return 0;
 198
 199         if (!(obj->flags & FLAG_CHECKED)) {
 200                 unsigned long size;
 201                 int type = oid_object_info(the_repository, &obj->oid, &size);
 202                 if (type <= 0)
 203                         die(_("did not receive expected object %s"),
 204                               oid_to_hex(&obj->oid));
 205                 if (type != obj->type)
 206                         die(_("object %s: expected type %s, found %s"),
 207                             oid_to_hex(&obj->oid),
 208                             type_name(obj->type), type_name(type));
 209                 obj->flags |= FLAG_CHECKED;
 210                 return 1;
 211         }
 212
 213         return 0;
 214 }
 215
 216 static unsigned check_objects(void)
 217 {
 218         unsigned i, max, foreign_nr = 0;
 219
 220         max = get_max_object_index();
 221
 222         if (verbose)
 223                 progress = start_delayed_progress(_("Checking objects"), max);
 224
 225         for (i = 0; i < max; i++) {
 226                 foreign_nr += check_object(get_indexed_object(i));
 227                 display_progress(progress, i + 1);
 228         }
 229
 230         stop_progress(&progress);
 231         return foreign_nr;
 232 }
 233
 234
 235 /* Discard current buffer used content. */
 236 static void flush(void)
 237 {
 238         if (input_offset) {
 239                 if (output_fd >= 0)
 240                         write_or_die(output_fd, input_buffer, input_offset);
 241                 the_hash_algo->update_fn(&input_ctx, input_buffer, input_offset);
 242                 memmove(input_buffer, input_buffer + input_offset, input_len);
 243                 input_offset = 0;
 244         }
 245 }
 246
 247 /*
 248  * Make sure at least "min" bytes are available in the buffer, and
 249  * return the pointer to the buffer.
 250  */
 251 static void *fill(int min)
 252 {
 253         if (min <= input_len)
 254                 return input_buffer + input_offset;
 255         if (min > sizeof(input_buffer))
 256                 die(Q_("cannot fill %d byte",
 257                        "cannot fill %d bytes",
 258                        min),
 259                     min);
 260         flush();
 261         do {
 262                 ssize_t ret = xread(input_fd, input_buffer + input_len,
 263                                 sizeof(input_buffer) - input_len);
 264                 if (ret <= 0) {
 265                         if (!ret)
 266                                 die(_("early EOF"));
 267                         die_errno(_("read error on input"));
 268                 }
 269                 input_len += ret;
 270                 if (from_stdin)
 271                         display_throughput(progress, consumed_bytes + input_len);
 272         } while (input_len < min);
 273         return input_buffer;
 274 }
 275
 276 static void use(int bytes)
 277 {
 278         if (bytes > input_len)
 279                 die(_("used more bytes than were available"));
 280         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 281         input_len -= bytes;
 282         input_offset += bytes;
 283
 284         /* make sure off_t is sufficiently large not to wrap */
 285         if (signed_add_overflows(consumed_bytes, bytes))
 286                 die(_("pack too large for current definition of off_t"));
 287         consumed_bytes += bytes;
 288         if (max_input_size && consumed_bytes > max_input_size)
 289                 die(_("pack exceeds maximum allowed size"));
 290 }
 291
 292 static const char *open_pack_file(const char *pack_name)
 293 {
 294         if (from_stdin) {
 295                 input_fd = 0;
 296                 if (!pack_name) {
 297                         struct strbuf tmp_file = STRBUF_INIT;
 298                         output_fd = odb_mkstemp(&tmp_file,
 299                                                 "pack/tmp_pack_XXXXXX");
 300                         pack_name = strbuf_detach(&tmp_file, NULL);
 301                 } else {
 302                         output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 303                         if (output_fd < 0)
 304                                 die_errno(_("unable to create '%s'"), pack_name);
 305                 }
 306                 nothread_data.pack_fd = output_fd;
 307         } else {
 308                 input_fd = open(pack_name, O_RDONLY);
 309                 if (input_fd < 0)
 310                         die_errno(_("cannot open packfile '%s'"), pack_name);
 311                 output_fd = -1;
 312                 nothread_data.pack_fd = input_fd;
 313         }
 314         the_hash_algo->init_fn(&input_ctx);
 315         return pack_name;
 316 }
 317
 318 static void parse_pack_header(void)
 319 {
 320         struct pack_header *hdr = fill(sizeof(struct pack_header));
 321
 322         /* Header consistency check */
 323         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 324                 die(_("pack signature mismatch"));
 325         if (!pack_version_ok(hdr->hdr_version))
 326                 die(_("pack version %"PRIu32" unsupported"),
 327                         ntohl(hdr->hdr_version));
 328
 329         nr_objects = ntohl(hdr->hdr_entries);
 330         use(sizeof(struct pack_header));
 331 }
 332
 333 static NORETURN void bad_object(off_t offset, const char *format,
 334                        ...) __attribute__((format (printf, 2, 3)));
 335
 336 static NORETURN void bad_object(off_t offset, const char *format, ...)
 337 {
 338         va_list params;
 339         char buf[1024];
 340
 341         va_start(params, format);
 342         vsnprintf(buf, sizeof(buf), format, params);
 343         va_end(params);
 344         die(_("pack has bad object at offset %"PRIuMAX": %s"),
 345             (uintmax_t)offset, buf);
 346 }
 347
 348 static inline struct thread_local *get_thread_data(void)
 349 {
 350         if (HAVE_THREADS) {
 351                 if (threads_active)
 352                         return pthread_getspecific(key);
 353                 assert(!threads_active &&
 354                        "This should only be reached when all threads are gone");
 355         }
 356         return &nothread_data;
 357 }
 358
 359 static void set_thread_data(struct thread_local *data)
 360 {
 361         if (threads_active)
 362                 pthread_setspecific(key, data);
 363 }
 364
 365 static struct base_data *alloc_base_data(void)
 366 {
 367         struct base_data *base = xcalloc(1, sizeof(struct base_data));
 368         base->ref_last = -1;
 369         base->ofs_last = -1;
 370         return base;
 371 }
 372
 373 static void free_base_data(struct base_data *c)
 374 {
 375         if (c->data) {
 376                 FREE_AND_NULL(c->data);
 377                 get_thread_data()->base_cache_used -= c->size;
 378         }
 379 }
 380
 381 static void prune_base_data(struct base_data *youngest_child)
 382 {
 383         struct base_data *b;
 384         struct thread_local *data = get_thread_data();
 385         struct base_data **ancestry = NULL;
 386         size_t nr = 0, alloc = 0;
 387         ssize_t i;
 388
 389         if (data->base_cache_used <= delta_base_cache_limit)
 390                 return;
 391
 392         /*
 393          * Free all ancestors of youngest_child until we have enough space,
 394          * starting with the oldest. (We cannot free youngest_child itself.)
 395          */
 396         for (b = youngest_child->base; b != NULL; b = b->base) {
 397                 ALLOC_GROW(ancestry, nr + 1, alloc);
 398                 ancestry[nr++] = b;
 399         }
 400         for (i = nr - 1;
 401              i >= 0 && data->base_cache_used > delta_base_cache_limit;
 402              i--) {
 403                 if (ancestry[i]->data)
 404                         free_base_data(ancestry[i]);
 405         }
 406         free(ancestry);
 407 }
 408
 409 static void link_base_data(struct base_data *base, struct base_data *c)
 410 {
 411         c->base = base;
 412         if (c->data)
 413                 get_thread_data()->base_cache_used += c->size;
 414         prune_base_data(c);
 415 }
 416
 417 static void unlink_base_data(struct base_data *c)
 418 {
 419         free_base_data(c);
 420 }
 421
 422 static int is_delta_type(enum object_type type)
 423 {
 424         return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 425 }
 426
 427 static void *unpack_entry_data(off_t offset, unsigned long size,
 428                                enum object_type type, struct object_id *oid)
 429 {
 430         static char fixed_buf[8192];
 431         int status;
 432         git_zstream stream;
 433         void *buf;
 434         git_hash_ctx c;
 435         char hdr[32];
 436         int hdrlen;
 437
 438         if (!is_delta_type(type)) {
 439                 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX,
 440                                    type_name(type),(uintmax_t)size) + 1;
 441                 the_hash_algo->init_fn(&c);
 442                 the_hash_algo->update_fn(&c, hdr, hdrlen);
 443         } else
 444                 oid = NULL;
 445         if (type == OBJ_BLOB && size > big_file_threshold)
 446                 buf = fixed_buf;
 447         else
 448                 buf = xmallocz(size);
 449
 450         memset(&stream, 0, sizeof(stream));
 451         git_inflate_init(&stream);
 452         stream.next_out = buf;
 453         stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 454
 455         do {
 456                 unsigned char *last_out = stream.next_out;
 457                 stream.next_in = fill(1);
 458                 stream.avail_in = input_len;
 459                 status = git_inflate(&stream, 0);
 460                 use(input_len - stream.avail_in);
 461                 if (oid)
 462                         the_hash_algo->update_fn(&c, last_out, stream.next_out - last_out);
 463                 if (buf == fixed_buf) {
 464                         stream.next_out = buf;
 465                         stream.avail_out = sizeof(fixed_buf);
 466                 }
 467         } while (status == Z_OK);
 468         if (stream.total_out != size || status != Z_STREAM_END)
 469                 bad_object(offset, _("inflate returned %d"), status);
 470         git_inflate_end(&stream);
 471         if (oid)
 472                 the_hash_algo->final_fn(oid->hash, &c);
 473         return buf == fixed_buf ? NULL : buf;
 474 }
 475
 476 static void *unpack_raw_entry(struct object_entry *obj,
 477                               off_t *ofs_offset,
 478                               struct object_id *ref_oid,
 479                               struct object_id *oid)
 480 {
 481         unsigned char *p;
 482         unsigned long size, c;
 483         off_t base_offset;
 484         unsigned shift;
 485         void *data;
 486
 487         obj->idx.offset = consumed_bytes;
 488         input_crc32 = crc32(0, NULL, 0);
 489
 490         p = fill(1);
 491         c = *p;
 492         use(1);
 493         obj->type = (c >> 4) & 7;
 494         size = (c & 15);
 495         shift = 4;
 496         while (c & 0x80) {
 497                 p = fill(1);
 498                 c = *p;
 499                 use(1);
 500                 size += (c & 0x7f) << shift;
 501                 shift += 7;
 502         }
 503         obj->size = size;
 504
 505         switch (obj->type) {
 506         case OBJ_REF_DELTA:
 507                 hashcpy(ref_oid->hash, fill(the_hash_algo->rawsz));
 508                 use(the_hash_algo->rawsz);
 509                 break;
 510         case OBJ_OFS_DELTA:
 511                 p = fill(1);
 512                 c = *p;
 513                 use(1);
 514                 base_offset = c & 127;
 515                 while (c & 128) {
 516                         base_offset += 1;
 517                         if (!base_offset || MSB(base_offset, 7))
 518                                 bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 519                         p = fill(1);
 520                         c = *p;
 521                         use(1);
 522                         base_offset = (base_offset << 7) + (c & 127);
 523                 }
 524                 *ofs_offset = obj->idx.offset - base_offset;
 525                 if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 526                         bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 527                 break;
 528         case OBJ_COMMIT:
 529         case OBJ_TREE:
 530         case OBJ_BLOB:
 531         case OBJ_TAG:
 532                 break;
 533         default:
 534                 bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 535         }
 536         obj->hdr_size = consumed_bytes - obj->idx.offset;
 537
 538         data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, oid);
 539         obj->idx.crc32 = input_crc32;
 540         return data;
 541 }
 542
 543 static void *unpack_data(struct object_entry *obj,
 544                          int (*consume)(const unsigned char *, unsigned long, void *),
 545                          void *cb_data)
 546 {
 547         off_t from = obj[0].idx.offset + obj[0].hdr_size;
 548         off_t len = obj[1].idx.offset - from;
 549         unsigned char *data, *inbuf;
 550         git_zstream stream;
 551         int status;
 552
 553         data = xmallocz(consume ? 64*1024 : obj->size);
 554         inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 555
 556         memset(&stream, 0, sizeof(stream));
 557         git_inflate_init(&stream);
 558         stream.next_out = data;
 559         stream.avail_out = consume ? 64*1024 : obj->size;
 560
 561         do {
 562                 ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 563                 n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 564                 if (n < 0)
 565                         die_errno(_("cannot pread pack file"));
 566                 if (!n)
 567                         die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 568                                "premature end of pack file, %"PRIuMAX" bytes missing",
 569                                (unsigned int)len),
 570                             (uintmax_t)len);
 571                 from += n;
 572                 len -= n;
 573                 stream.next_in = inbuf;
 574                 stream.avail_in = n;
 575                 if (!consume)
 576                         status = git_inflate(&stream, 0);
 577                 else {
 578                         do {
 579                                 status = git_inflate(&stream, 0);
 580                                 if (consume(data, stream.next_out - data, cb_data)) {
 581                                         free(inbuf);
 582                                         free(data);
 583                                         return NULL;
 584                                 }
 585                                 stream.next_out = data;
 586                                 stream.avail_out = 64*1024;
 587                         } while (status == Z_OK && stream.avail_in);
 588                 }
 589         } while (len && status == Z_OK && !stream.avail_in);
 590
 591         /* This has been inflated OK when first encountered, so... */
 592         if (status != Z_STREAM_END || stream.total_out != obj->size)
 593                 die(_("serious inflate inconsistency"));
 594
 595         git_inflate_end(&stream);
 596         free(inbuf);
 597         if (consume) {
 598                 FREE_AND_NULL(data);
 599         }
 600         return data;
 601 }
 602
 603 static void *get_data_from_pack(struct object_entry *obj)
 604 {
 605         return unpack_data(obj, NULL, NULL);
 606 }
 607
 608 static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 609                                    enum object_type type1,
 610                                    enum object_type type2)
 611 {
 612         int cmp = type1 - type2;
 613         if (cmp)
 614                 return cmp;
 615         return offset1 < offset2 ? -1 :
 616                offset1 > offset2 ?  1 :
 617                0;
 618 }
 619
 620 static int find_ofs_delta(const off_t offset)
 621 {
 622         int first = 0, last = nr_ofs_deltas;
 623
 624         while (first < last) {
 625                 int next = first + (last - first) / 2;
 626                 struct ofs_delta_entry *delta = &ofs_deltas[next];
 627                 int cmp;
 628
 629                 cmp = compare_ofs_delta_bases(offset, delta->offset,
 630                                               OBJ_OFS_DELTA,
 631                                               objects[delta->obj_no].type);
 632                 if (!cmp)
 633                         return next;
 634                 if (cmp < 0) {
 635                         last = next;
 636                         continue;
 637                 }
 638                 first = next+1;
 639         }
 640         return -first-1;
 641 }
 642
 643 static void find_ofs_delta_children(off_t offset,
 644                                     int *first_index, int *last_index)
 645 {
 646         int first = find_ofs_delta(offset);
 647         int last = first;
 648         int end = nr_ofs_deltas - 1;
 649
 650         if (first < 0) {
 651                 *first_index = 0;
 652                 *last_index = -1;
 653                 return;
 654         }
 655         while (first > 0 && ofs_deltas[first - 1].offset == offset)
 656                 --first;
 657         while (last < end && ofs_deltas[last + 1].offset == offset)
 658                 ++last;
 659         *first_index = first;
 660         *last_index = last;
 661 }
 662
 663 static int compare_ref_delta_bases(const struct object_id *oid1,
 664                                    const struct object_id *oid2,
 665                                    enum object_type type1,
 666                                    enum object_type type2)
 667 {
 668         int cmp = type1 - type2;
 669         if (cmp)
 670                 return cmp;
 671         return oidcmp(oid1, oid2);
 672 }
 673
 674 static int find_ref_delta(const struct object_id *oid)
 675 {
 676         int first = 0, last = nr_ref_deltas;
 677
 678         while (first < last) {
 679                 int next = first + (last - first) / 2;
 680                 struct ref_delta_entry *delta = &ref_deltas[next];
 681                 int cmp;
 682
 683                 cmp = compare_ref_delta_bases(oid, &delta->oid,
 684                                               OBJ_REF_DELTA,
 685                                               objects[delta->obj_no].type);
 686                 if (!cmp)
 687                         return next;
 688                 if (cmp < 0) {
 689                         last = next;
 690                         continue;
 691                 }
 692                 first = next+1;
 693         }
 694         return -first-1;
 695 }
 696
 697 static void find_ref_delta_children(const struct object_id *oid,
 698                                     int *first_index, int *last_index)
 699 {
 700         int first = find_ref_delta(oid);
 701         int last = first;
 702         int end = nr_ref_deltas - 1;
 703
 704         if (first < 0) {
 705                 *first_index = 0;
 706                 *last_index = -1;
 707                 return;
 708         }
 709         while (first > 0 && oideq(&ref_deltas[first - 1].oid, oid))
 710                 --first;
 711         while (last < end && oideq(&ref_deltas[last + 1].oid, oid))
 712                 ++last;
 713         *first_index = first;
 714         *last_index = last;
 715 }
 716
 717 struct compare_data {
 718         struct object_entry *entry;
 719         struct git_istream *st;
 720         unsigned char *buf;
 721         unsigned long buf_size;
 722 };
 723
 724 static int compare_objects(const unsigned char *buf, unsigned long size,
 725                            void *cb_data)
 726 {
 727         struct compare_data *data = cb_data;
 728
 729         if (data->buf_size < size) {
 730                 free(data->buf);
 731                 data->buf = xmalloc(size);
 732                 data->buf_size = size;
 733         }
 734
 735         while (size) {
 736                 ssize_t len = read_istream(data->st, data->buf, size);
 737                 if (len == 0)
 738                         die(_("SHA1 COLLISION FOUND WITH %s !"),
 739                             oid_to_hex(&data->entry->idx.oid));
 740                 if (len < 0)
 741                         die(_("unable to read %s"),
 742                             oid_to_hex(&data->entry->idx.oid));
 743                 if (memcmp(buf, data->buf, len))
 744                         die(_("SHA1 COLLISION FOUND WITH %s !"),
 745                             oid_to_hex(&data->entry->idx.oid));
 746                 size -= len;
 747                 buf += len;
 748         }
 749         return 0;
 750 }
 751
 752 static int check_collison(struct object_entry *entry)
 753 {
 754         struct compare_data data;
 755         enum object_type type;
 756         unsigned long size;
 757
 758         if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 759                 return -1;
 760
 761         memset(&data, 0, sizeof(data));
 762         data.entry = entry;
 763         data.st = open_istream(the_repository, &entry->idx.oid, &type, &size,
 764                                NULL);
 765         if (!data.st)
 766                 return -1;
 767         if (size != entry->size || type != entry->type)
 768                 die(_("SHA1 COLLISION FOUND WITH %s !"),
 769                     oid_to_hex(&entry->idx.oid));
 770         unpack_data(entry, compare_objects, &data);
 771         close_istream(data.st);
 772         free(data.buf);
 773         return 0;
 774 }
 775
 776 static void sha1_object(const void *data, struct object_entry *obj_entry,
 777                         unsigned long size, enum object_type type,
 778                         const struct object_id *oid)
 779 {
 780         void *new_data = NULL;
 781         int collision_test_needed = 0;
 782
 783         assert(data || obj_entry);
 784
 785         if (startup_info->have_repository) {
 786                 read_lock();
 787                 collision_test_needed =
 788                         has_object_file_with_flags(oid, OBJECT_INFO_QUICK);
 789                 read_unlock();
 790         }
 791
 792         if (collision_test_needed && !data) {
 793                 read_lock();
 794                 if (!check_collison(obj_entry))
 795                         collision_test_needed = 0;
 796                 read_unlock();
 797         }
 798         if (collision_test_needed) {
 799                 void *has_data;
 800                 enum object_type has_type;
 801                 unsigned long has_size;
 802                 read_lock();
 803                 has_type = oid_object_info(the_repository, oid, &has_size);
 804                 if (has_type < 0)
 805                         die(_("cannot read existing object info %s"), oid_to_hex(oid));
 806                 if (has_type != type || has_size != size)
 807                         die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 808                 has_data = read_object_file(oid, &has_type, &has_size);
 809                 read_unlock();
 810                 if (!data)
 811                         data = new_data = get_data_from_pack(obj_entry);
 812                 if (!has_data)
 813                         die(_("cannot read existing object %s"), oid_to_hex(oid));
 814                 if (size != has_size || type != has_type ||
 815                     memcmp(data, has_data, size) != 0)
 816                         die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 817                 free(has_data);
 818         }
 819
 820         if (strict || do_fsck_object) {
 821                 read_lock();
 822                 if (type == OBJ_BLOB) {
 823                         struct blob *blob = lookup_blob(the_repository, oid);
 824                         if (blob)
 825                                 blob->object.flags |= FLAG_CHECKED;
 826                         else
 827                                 die(_("invalid blob object %s"), oid_to_hex(oid));
 828                         if (do_fsck_object &&
 829                             fsck_object(&blob->object, (void *)data, size, &fsck_options))
 830                                 die(_("fsck error in packed object"));
 831                 } else {
 832                         struct object *obj;
 833                         int eaten;
 834                         void *buf = (void *) data;
 835
 836                         assert(data && "data can only be NULL for large _blobs_");
 837
 838                         /*
 839                          * we do not need to free the memory here, as the
 840                          * buf is deleted by the caller.
 841                          */
 842                         obj = parse_object_buffer(the_repository, oid, type,
 843                                                   size, buf,
 844                                                   &eaten);
 845                         if (!obj)
 846                                 die(_("invalid %s"), type_name(type));
 847                         if (do_fsck_object &&
 848                             fsck_object(obj, buf, size, &fsck_options))
 849                                 die(_("fsck error in packed object"));
 850                         if (strict && fsck_walk(obj, NULL, &fsck_options))
 851                                 die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 852
 853                         if (obj->type == OBJ_TREE) {
 854                                 struct tree *item = (struct tree *) obj;
 855                                 item->buffer = NULL;
 856                                 obj->parsed = 0;
 857                         }
 858                         if (obj->type == OBJ_COMMIT) {
 859                                 struct commit *commit = (struct commit *) obj;
 860                                 if (detach_commit_buffer(commit, NULL) != data)
 861                                         BUG("parse_object_buffer transmogrified our buffer");
 862                         }
 863                         obj->flags |= FLAG_CHECKED;
 864                 }
 865                 read_unlock();
 866         }
 867
 868         free(new_data);
 869 }
 870
 871 /*
 872  * This function is part of find_unresolved_deltas(). There are two
 873  * walkers going in the opposite ways.
 874  *
 875  * The first one in find_unresolved_deltas() traverses down from
 876  * parent node to children, deflating nodes along the way. However,
 877  * memory for deflated nodes is limited by delta_base_cache_limit, so
 878  * at some point parent node's deflated content may be freed.
 879  *
 880  * The second walker is this function, which goes from current node up
 881  * to top parent if necessary to deflate the node. In normal
 882  * situation, its parent node would be already deflated, so it just
 883  * needs to apply delta.
 884  *
 885  * In the worst case scenario, parent node is no longer deflated because
 886  * we're running out of delta_base_cache_limit; we need to re-deflate
 887  * parents, possibly up to the top base.
 888  *
 889  * All deflated objects here are subject to be freed if we exceed
 890  * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 891  * just need to make sure the last node is not freed.
 892  */
 893 static void *get_base_data(struct base_data *c)
 894 {
 895         if (!c->data) {
 896                 struct object_entry *obj = c->obj;
 897                 struct base_data **delta = NULL;
 898                 int delta_nr = 0, delta_alloc = 0;
 899
 900                 while (is_delta_type(c->obj->type) && !c->data) {
 901                         ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 902                         delta[delta_nr++] = c;
 903                         c = c->base;
 904                 }
 905                 if (!delta_nr) {
 906                         c->data = get_data_from_pack(obj);
 907                         c->size = obj->size;
 908                         get_thread_data()->base_cache_used += c->size;
 909                         prune_base_data(c);
 910                 }
 911                 for (; delta_nr > 0; delta_nr--) {
 912                         void *base, *raw;
 913                         c = delta[delta_nr - 1];
 914                         obj = c->obj;
 915                         base = get_base_data(c->base);
 916                         raw = get_data_from_pack(obj);
 917                         c->data = patch_delta(
 918                                 base, c->base->size,
 919                                 raw, obj->size,
 920                                 &c->size);
 921                         free(raw);
 922                         if (!c->data)
 923                                 bad_object(obj->idx.offset, _("failed to apply delta"));
 924                         get_thread_data()->base_cache_used += c->size;
 925                         prune_base_data(c);
 926                 }
 927                 free(delta);
 928         }
 929         return c->data;
 930 }
 931
 932 static void resolve_delta(struct object_entry *delta_obj,
 933                           struct base_data *base, struct base_data *result)
 934 {
 935         void *base_data, *delta_data;
 936
 937         if (show_stat) {
 938                 int i = delta_obj - objects;
 939                 int j = base->obj - objects;
 940                 obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 941                 deepest_delta_lock();
 942                 if (deepest_delta < obj_stat[i].delta_depth)
 943                         deepest_delta = obj_stat[i].delta_depth;
 944                 deepest_delta_unlock();
 945                 obj_stat[i].base_object_no = j;
 946         }
 947         delta_data = get_data_from_pack(delta_obj);
 948         base_data = get_base_data(base);
 949         result->obj = delta_obj;
 950         result->data = patch_delta(base_data, base->size,
 951                                    delta_data, delta_obj->size, &result->size);
 952         free(delta_data);
 953         if (!result->data)
 954                 bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 955         hash_object_file(the_hash_algo, result->data, result->size,
 956                          type_name(delta_obj->real_type), &delta_obj->idx.oid);
 957         sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 958                     &delta_obj->idx.oid);
 959         counter_lock();
 960         nr_resolved_deltas++;
 961         counter_unlock();
 962 }
 963
 964 /*
 965  * Standard boolean compare-and-swap: atomically check whether "*type" is
 966  * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 967  * and return false.
 968  */
 969 static int compare_and_swap_type(signed char *type,
 970                                  enum object_type want,
 971                                  enum object_type set)
 972 {
 973         enum object_type old;
 974
 975         type_cas_lock();
 976         old = *type;
 977         if (old == want)
 978                 *type = set;
 979         type_cas_unlock();
 980
 981         return old == want;
 982 }
 983
 984 static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 985                                                   struct base_data *prev_base)
 986 {
 987         if (base->ref_last == -1 && base->ofs_last == -1) {
 988                 find_ref_delta_children(&base->obj->idx.oid,
 989                                         &base->ref_first, &base->ref_last);
 990
 991                 find_ofs_delta_children(base->obj->idx.offset,
 992                                         &base->ofs_first, &base->ofs_last);
 993
 994                 if (base->ref_last == -1 && base->ofs_last == -1) {
 995                         free(base->data);
 996                         return NULL;
 997                 }
 998
 999                 link_base_data(prev_base, base);
1000         }
1001
1002         if (base->ref_first <= base->ref_last) {
1003                 struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1004                 struct base_data *result = alloc_base_data();
1005
1006                 if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1007                                            base->obj->real_type))
1008                         die("REF_DELTA at offset %"PRIuMAX" already resolved (duplicate base %s?)",
1009                             (uintmax_t)child->idx.offset,
1010                             oid_to_hex(&base->obj->idx.oid));
1011
1012                 resolve_delta(child, base, result);
1013                 if (base->ref_first == base->ref_last && base->ofs_last == -1)
1014                         free_base_data(base);
1015
1016                 base->ref_first++;
1017                 return result;
1018         }
1019
1020         if (base->ofs_first <= base->ofs_last) {
1021                 struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1022                 struct base_data *result = alloc_base_data();
1023
1024                 assert(child->real_type == OBJ_OFS_DELTA);
1025                 child->real_type = base->obj->real_type;
1026                 resolve_delta(child, base, result);
1027                 if (base->ofs_first == base->ofs_last)
1028                         free_base_data(base);
1029
1030                 base->ofs_first++;
1031                 return result;
1032         }
1033
1034         unlink_base_data(base);
1035         return NULL;
1036 }
1037
1038 static void find_unresolved_deltas(struct base_data *base)
1039 {
1040         struct base_data *new_base, *prev_base = NULL;
1041         for (;;) {
1042                 new_base = find_unresolved_deltas_1(base, prev_base);
1043
1044                 if (new_base) {
1045                         prev_base = base;
1046                         base = new_base;
1047                 } else {
1048                         free(base);
1049                         base = prev_base;
1050                         if (!base)
1051                                 return;
1052                         prev_base = base->base;
1053                 }
1054         }
1055 }
1056
1057 static int compare_ofs_delta_entry(const void *a, const void *b)
1058 {
1059         const struct ofs_delta_entry *delta_a = a;
1060         const struct ofs_delta_entry *delta_b = b;
1061
1062         return delta_a->offset < delta_b->offset ? -1 :
1063                delta_a->offset > delta_b->offset ?  1 :
1064                0;
1065 }
1066
1067 static int compare_ref_delta_entry(const void *a, const void *b)
1068 {
1069         const struct ref_delta_entry *delta_a = a;
1070         const struct ref_delta_entry *delta_b = b;
1071
1072         return oidcmp(&delta_a->oid, &delta_b->oid);
1073 }
1074
1075 static void resolve_base(struct object_entry *obj)
1076 {
1077         struct base_data *base_obj = alloc_base_data();
1078         base_obj->obj = obj;
1079         base_obj->data = NULL;
1080         find_unresolved_deltas(base_obj);
1081 }
1082
1083 static void *threaded_second_pass(void *data)
1084 {
1085         set_thread_data(data);
1086         for (;;) {
1087                 int i;
1088                 counter_lock();
1089                 display_progress(progress, nr_resolved_deltas);
1090                 counter_unlock();
1091                 work_lock();
1092                 while (nr_dispatched < nr_objects &&
1093                        is_delta_type(objects[nr_dispatched].type))
1094                         nr_dispatched++;
1095                 if (nr_dispatched >= nr_objects) {
1096                         work_unlock();
1097                         break;
1098                 }
1099                 i = nr_dispatched++;
1100                 work_unlock();
1101
1102                 resolve_base(&objects[i]);
1103         }
1104         return NULL;
1105 }
1106
1107 /*
1108  * First pass:
1109  * - find locations of all objects;
1110  * - calculate SHA1 of all non-delta objects;
1111  * - remember base (SHA1 or offset) for all deltas.
1112  */
1113 static void parse_pack_objects(unsigned char *hash)
1114 {
1115         int i, nr_delays = 0;
1116         struct ofs_delta_entry *ofs_delta = ofs_deltas;
1117         struct object_id ref_delta_oid;
1118         struct stat st;
1119
1120         if (verbose)
1121                 progress = start_progress(
1122                                 from_stdin ? _("Receiving objects") : _("Indexing objects"),
1123                                 nr_objects);
1124         for (i = 0; i < nr_objects; i++) {
1125                 struct object_entry *obj = &objects[i];
1126                 void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1127                                               &ref_delta_oid,
1128                                               &obj->idx.oid);
1129                 obj->real_type = obj->type;
1130                 if (obj->type == OBJ_OFS_DELTA) {
1131                         nr_ofs_deltas++;
1132                         ofs_delta->obj_no = i;
1133                         ofs_delta++;
1134                 } else if (obj->type == OBJ_REF_DELTA) {
1135                         ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1136                         oidcpy(&ref_deltas[nr_ref_deltas].oid, &ref_delta_oid);
1137                         ref_deltas[nr_ref_deltas].obj_no = i;
1138                         nr_ref_deltas++;
1139                 } else if (!data) {
1140                         /* large blobs, check later */
1141                         obj->real_type = OBJ_BAD;
1142                         nr_delays++;
1143                 } else
1144                         sha1_object(data, NULL, obj->size, obj->type,
1145                                     &obj->idx.oid);
1146                 free(data);
1147                 display_progress(progress, i+1);
1148         }
1149         objects[i].idx.offset = consumed_bytes;
1150         stop_progress(&progress);
1151
1152         /* Check pack integrity */
1153         flush();
1154         the_hash_algo->final_fn(hash, &input_ctx);
1155         if (!hasheq(fill(the_hash_algo->rawsz), hash))
1156                 die(_("pack is corrupted (SHA1 mismatch)"));
1157         use(the_hash_algo->rawsz);
1158
1159         /* If input_fd is a file, we should have reached its end now. */
1160         if (fstat(input_fd, &st))
1161                 die_errno(_("cannot fstat packfile"));
1162         if (S_ISREG(st.st_mode) &&
1163                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1164                 die(_("pack has junk at the end"));
1165
1166         for (i = 0; i < nr_objects; i++) {
1167                 struct object_entry *obj = &objects[i];
1168                 if (obj->real_type != OBJ_BAD)
1169                         continue;
1170                 obj->real_type = obj->type;
1171                 sha1_object(NULL, obj, obj->size, obj->type,
1172                             &obj->idx.oid);
1173                 nr_delays--;
1174         }
1175         if (nr_delays)
1176                 die(_("confusion beyond insanity in parse_pack_objects()"));
1177 }
1178
1179 /*
1180  * Second pass:
1181  * - for all non-delta objects, look if it is used as a base for
1182  *   deltas;
1183  * - if used as a base, uncompress the object and apply all deltas,
1184  *   recursively checking if the resulting object is used as a base
1185  *   for some more deltas.
1186  */
1187 static void resolve_deltas(void)
1188 {
1189         int i;
1190
1191         if (!nr_ofs_deltas && !nr_ref_deltas)
1192                 return;
1193
1194         /* Sort deltas by base SHA1/offset for fast searching */
1195         QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1196         QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1197
1198         if (verbose || show_resolving_progress)
1199                 progress = start_progress(_("Resolving deltas"),
1200                                           nr_ref_deltas + nr_ofs_deltas);
1201
1202         nr_dispatched = 0;
1203         if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1204                 init_thread();
1205                 for (i = 0; i < nr_threads; i++) {
1206                         int ret = pthread_create(&thread_data[i].thread, NULL,
1207                                                  threaded_second_pass, thread_data + i);
1208                         if (ret)
1209                                 die(_("unable to create thread: %s"),
1210                                     strerror(ret));
1211                 }
1212                 for (i = 0; i < nr_threads; i++)
1213                         pthread_join(thread_data[i].thread, NULL);
1214                 cleanup_thread();
1215                 return;
1216         }
1217         threaded_second_pass(&nothread_data);
1218 }
1219
1220 /*
1221  * Third pass:
1222  * - append objects to convert thin pack to full pack if required
1223  * - write the final pack hash
1224  */
1225 static void fix_unresolved_deltas(struct hashfile *f);
1226 static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_hash)
1227 {
1228         if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1229                 stop_progress(&progress);
1230                 /* Flush remaining pack final hash. */
1231                 flush();
1232                 return;
1233         }
1234
1235         if (fix_thin_pack) {
1236                 struct hashfile *f;
1237                 unsigned char read_hash[GIT_MAX_RAWSZ], tail_hash[GIT_MAX_RAWSZ];
1238                 struct strbuf msg = STRBUF_INIT;
1239                 int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1240                 int nr_objects_initial = nr_objects;
1241                 if (nr_unresolved <= 0)
1242                         die(_("confusion beyond insanity"));
1243                 REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1244                 memset(objects + nr_objects + 1, 0,
1245                        nr_unresolved * sizeof(*objects));
1246                 f = hashfd(output_fd, curr_pack);
1247                 fix_unresolved_deltas(f);
1248                 strbuf_addf(&msg, Q_("completed with %d local object",
1249                                      "completed with %d local objects",
1250                                      nr_objects - nr_objects_initial),
1251                             nr_objects - nr_objects_initial);
1252                 stop_progress_msg(&progress, msg.buf);
1253                 strbuf_release(&msg);
1254                 finalize_hashfile(f, tail_hash, 0);
1255                 hashcpy(read_hash, pack_hash);
1256                 fixup_pack_header_footer(output_fd, pack_hash,
1257                                          curr_pack, nr_objects,
1258                                          read_hash, consumed_bytes-the_hash_algo->rawsz);
1259                 if (!hasheq(read_hash, tail_hash))
1260                         die(_("Unexpected tail checksum for %s "
1261                               "(disk corruption?)"), curr_pack);
1262         }
1263         if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1264                 die(Q_("pack has %d unresolved delta",
1265                        "pack has %d unresolved deltas",
1266                        nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1267                     nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1268 }
1269
1270 static int write_compressed(struct hashfile *f, void *in, unsigned int size)
1271 {
1272         git_zstream stream;
1273         int status;
1274         unsigned char outbuf[4096];
1275
1276         git_deflate_init(&stream, zlib_compression_level);
1277         stream.next_in = in;
1278         stream.avail_in = size;
1279
1280         do {
1281                 stream.next_out = outbuf;
1282                 stream.avail_out = sizeof(outbuf);
1283                 status = git_deflate(&stream, Z_FINISH);
1284                 hashwrite(f, outbuf, sizeof(outbuf) - stream.avail_out);
1285         } while (status == Z_OK);
1286
1287         if (status != Z_STREAM_END)
1288                 die(_("unable to deflate appended object (%d)"), status);
1289         size = stream.total_out;
1290         git_deflate_end(&stream);
1291         return size;
1292 }
1293
1294 static struct object_entry *append_obj_to_pack(struct hashfile *f,
1295                                const unsigned char *sha1, void *buf,
1296                                unsigned long size, enum object_type type)
1297 {
1298         struct object_entry *obj = &objects[nr_objects++];
1299         unsigned char header[10];
1300         unsigned long s = size;
1301         int n = 0;
1302         unsigned char c = (type << 4) | (s & 15);
1303         s >>= 4;
1304         while (s) {
1305                 header[n++] = c | 0x80;
1306                 c = s & 0x7f;
1307                 s >>= 7;
1308         }
1309         header[n++] = c;
1310         crc32_begin(f);
1311         hashwrite(f, header, n);
1312         obj[0].size = size;
1313         obj[0].hdr_size = n;
1314         obj[0].type = type;
1315         obj[0].real_type = type;
1316         obj[1].idx.offset = obj[0].idx.offset + n;
1317         obj[1].idx.offset += write_compressed(f, buf, size);
1318         obj[0].idx.crc32 = crc32_end(f);
1319         hashflush(f);
1320         hashcpy(obj->idx.oid.hash, sha1);
1321         return obj;
1322 }
1323
1324 static int delta_pos_compare(const void *_a, const void *_b)
1325 {
1326         struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1327         struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1328         return a->obj_no - b->obj_no;
1329 }
1330
1331 static void fix_unresolved_deltas(struct hashfile *f)
1332 {
1333         struct ref_delta_entry **sorted_by_pos;
1334         int i;
1335
1336         /*
1337          * Since many unresolved deltas may well be themselves base objects
1338          * for more unresolved deltas, we really want to include the
1339          * smallest number of base objects that would cover as much delta
1340          * as possible by picking the
1341          * trunc deltas first, allowing for other deltas to resolve without
1342          * additional base objects.  Since most base objects are to be found
1343          * before deltas depending on them, a good heuristic is to start
1344          * resolving deltas in the same order as their position in the pack.
1345          */
1346         ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1347         for (i = 0; i < nr_ref_deltas; i++)
1348                 sorted_by_pos[i] = &ref_deltas[i];
1349         QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1350
1351         if (has_promisor_remote()) {
1352                 /*
1353                  * Prefetch the delta bases.
1354                  */
1355                 struct oid_array to_fetch = OID_ARRAY_INIT;
1356                 for (i = 0; i < nr_ref_deltas; i++) {
1357                         struct ref_delta_entry *d = sorted_by_pos[i];
1358                         if (!oid_object_info_extended(the_repository, &d->oid,
1359                                                       NULL,
1360                                                       OBJECT_INFO_FOR_PREFETCH))
1361                                 continue;
1362                         oid_array_append(&to_fetch, &d->oid);
1363                 }
1364                 promisor_remote_get_direct(the_repository,
1365                                            to_fetch.oid, to_fetch.nr);
1366                 oid_array_clear(&to_fetch);
1367         }
1368
1369         for (i = 0; i < nr_ref_deltas; i++) {
1370                 struct ref_delta_entry *d = sorted_by_pos[i];
1371                 enum object_type type;
1372                 struct base_data *base_obj = alloc_base_data();
1373
1374                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1375                         continue;
1376                 base_obj->data = read_object_file(&d->oid, &type,
1377                                                   &base_obj->size);
1378                 if (!base_obj->data)
1379                         continue;
1380
1381                 if (check_object_signature(the_repository, &d->oid,
1382                                            base_obj->data, base_obj->size,
1383                                            type_name(type)))
1384                         die(_("local object %s is corrupt"), oid_to_hex(&d->oid));
1385                 base_obj->obj = append_obj_to_pack(f, d->oid.hash,
1386                                         base_obj->data, base_obj->size, type);
1387                 find_unresolved_deltas(base_obj);
1388                 display_progress(progress, nr_resolved_deltas);
1389         }
1390         free(sorted_by_pos);
1391 }
1392
1393 static const char *derive_filename(const char *pack_name, const char *suffix,
1394                                    struct strbuf *buf)
1395 {
1396         size_t len;
1397         if (!strip_suffix(pack_name, ".pack", &len))
1398                 die(_("packfile name '%s' does not end with '.pack'"),
1399                     pack_name);
1400         strbuf_add(buf, pack_name, len);
1401         strbuf_addch(buf, '.');
1402         strbuf_addstr(buf, suffix);
1403         return buf->buf;
1404 }
1405
1406 static void write_special_file(const char *suffix, const char *msg,
1407                                const char *pack_name, const unsigned char *hash,
1408                                const char **report)
1409 {
1410         struct strbuf name_buf = STRBUF_INIT;
1411         const char *filename;
1412         int fd;
1413         int msg_len = strlen(msg);
1414
1415         if (pack_name)
1416                 filename = derive_filename(pack_name, suffix, &name_buf);
1417         else
1418                 filename = odb_pack_name(&name_buf, hash, suffix);
1419
1420         fd = odb_pack_keep(filename);
1421         if (fd < 0) {
1422                 if (errno != EEXIST)
1423                         die_errno(_("cannot write %s file '%s'"),
1424                                   suffix, filename);
1425         } else {
1426                 if (msg_len > 0) {
1427                         write_or_die(fd, msg, msg_len);
1428                         write_or_die(fd, "\n", 1);
1429                 }
1430                 if (close(fd) != 0)
1431                         die_errno(_("cannot close written %s file '%s'"),
1432                                   suffix, filename);
1433                 if (report)
1434                         *report = suffix;
1435         }
1436         strbuf_release(&name_buf);
1437 }
1438
1439 static void final(const char *final_pack_name, const char *curr_pack_name,
1440                   const char *final_index_name, const char *curr_index_name,
1441                   const char *keep_msg, const char *promisor_msg,
1442                   unsigned char *hash)
1443 {
1444         const char *report = "pack";
1445         struct strbuf pack_name = STRBUF_INIT;
1446         struct strbuf index_name = STRBUF_INIT;
1447         int err;
1448
1449         if (!from_stdin) {
1450                 close(input_fd);
1451         } else {
1452                 fsync_or_die(output_fd, curr_pack_name);
1453                 err = close(output_fd);
1454                 if (err)
1455                         die_errno(_("error while closing pack file"));
1456         }
1457
1458         if (keep_msg)
1459                 write_special_file("keep", keep_msg, final_pack_name, hash,
1460                                    &report);
1461         if (promisor_msg)
1462                 write_special_file("promisor", promisor_msg, final_pack_name,
1463                                    hash, NULL);
1464
1465         if (final_pack_name != curr_pack_name) {
1466                 if (!final_pack_name)
1467                         final_pack_name = odb_pack_name(&pack_name, hash, "pack");
1468                 if (finalize_object_file(curr_pack_name, final_pack_name))
1469                         die(_("cannot store pack file"));
1470         } else if (from_stdin)
1471                 chmod(final_pack_name, 0444);
1472
1473         if (final_index_name != curr_index_name) {
1474                 if (!final_index_name)
1475                         final_index_name = odb_pack_name(&index_name, hash, "idx");
1476                 if (finalize_object_file(curr_index_name, final_index_name))
1477                         die(_("cannot store index file"));
1478         } else
1479                 chmod(final_index_name, 0444);
1480
1481         if (do_fsck_object) {
1482                 struct packed_git *p;
1483                 p = add_packed_git(final_index_name, strlen(final_index_name), 0);
1484                 if (p)
1485                         install_packed_git(the_repository, p);
1486         }
1487
1488         if (!from_stdin) {
1489                 printf("%s\n", hash_to_hex(hash));
1490         } else {
1491                 struct strbuf buf = STRBUF_INIT;
1492
1493                 strbuf_addf(&buf, "%s\t%s\n", report, hash_to_hex(hash));
1494                 write_or_die(1, buf.buf, buf.len);
1495                 strbuf_release(&buf);
1496
1497                 /*
1498                  * Let's just mimic git-unpack-objects here and write
1499                  * the last part of the input buffer to stdout.
1500                  */
1501                 while (input_len) {
1502                         err = xwrite(1, input_buffer + input_offset, input_len);
1503                         if (err <= 0)
1504                                 break;
1505                         input_len -= err;
1506                         input_offset += err;
1507                 }
1508         }
1509
1510         strbuf_release(&index_name);
1511         strbuf_release(&pack_name);
1512 }
1513
1514 static int git_index_pack_config(const char *k, const char *v, void *cb)
1515 {
1516         struct pack_idx_option *opts = cb;
1517
1518         if (!strcmp(k, "pack.indexversion")) {
1519                 opts->version = git_config_int(k, v);
1520                 if (opts->version > 2)
1521                         die(_("bad pack.indexversion=%"PRIu32), opts->version);
1522                 return 0;
1523         }
1524         if (!strcmp(k, "pack.threads")) {
1525                 nr_threads = git_config_int(k, v);
1526                 if (nr_threads < 0)
1527                         die(_("invalid number of threads specified (%d)"),
1528                             nr_threads);
1529                 if (!HAVE_THREADS && nr_threads != 1) {
1530                         warning(_("no threads support, ignoring %s"), k);
1531                         nr_threads = 1;
1532                 }
1533                 return 0;
1534         }
1535         return git_default_config(k, v, cb);
1536 }
1537
1538 static int cmp_uint32(const void *a_, const void *b_)
1539 {
1540         uint32_t a = *((uint32_t *)a_);
1541         uint32_t b = *((uint32_t *)b_);
1542
1543         return (a < b) ? -1 : (a != b);
1544 }
1545
1546 static void read_v2_anomalous_offsets(struct packed_git *p,
1547                                       struct pack_idx_option *opts)
1548 {
1549         const uint32_t *idx1, *idx2;
1550         uint32_t i;
1551
1552         /* The address of the 4-byte offset table */
1553         idx1 = (((const uint32_t *)((const uint8_t *)p->index_data + p->crc_offset))
1554                 + p->num_objects /* CRC32 table */
1555                 );
1556
1557         /* The address of the 8-byte offset table */
1558         idx2 = idx1 + p->num_objects;
1559
1560         for (i = 0; i < p->num_objects; i++) {
1561                 uint32_t off = ntohl(idx1[i]);
1562                 if (!(off & 0x80000000))
1563                         continue;
1564                 off = off & 0x7fffffff;
1565                 check_pack_index_ptr(p, &idx2[off * 2]);
1566                 if (idx2[off * 2])
1567                         continue;
1568                 /*
1569                  * The real offset is ntohl(idx2[off * 2]) in high 4
1570                  * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1571                  * octets.  But idx2[off * 2] is Zero!!!
1572                  */
1573                 ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1574                 opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1575         }
1576
1577         QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1578 }
1579
1580 static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1581 {
1582         struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1583
1584         if (!p)
1585                 die(_("Cannot open existing pack file '%s'"), pack_name);
1586         if (open_pack_index(p))
1587                 die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1588
1589         /* Read the attributes from the existing idx file */
1590         opts->version = p->index_version;
1591
1592         if (opts->version == 2)
1593                 read_v2_anomalous_offsets(p, opts);
1594
1595         /*
1596          * Get rid of the idx file as we do not need it anymore.
1597          * NEEDSWORK: extract this bit from free_pack_by_name() in
1598          * sha1-file.c, perhaps?  It shouldn't matter very much as we
1599          * know we haven't installed this pack (hence we never have
1600          * read anything from it).
1601          */
1602         close_pack_index(p);
1603         free(p);
1604 }
1605
1606 static void show_pack_info(int stat_only)
1607 {
1608         int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1609         unsigned long *chain_histogram = NULL;
1610
1611         if (deepest_delta)
1612                 chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1613
1614         for (i = 0; i < nr_objects; i++) {
1615                 struct object_entry *obj = &objects[i];
1616
1617                 if (is_delta_type(obj->type))
1618                         chain_histogram[obj_stat[i].delta_depth - 1]++;
1619                 if (stat_only)
1620                         continue;
1621                 printf("%s %-6s %"PRIuMAX" %"PRIuMAX" %"PRIuMAX,
1622                        oid_to_hex(&obj->idx.oid),
1623                        type_name(obj->real_type), (uintmax_t)obj->size,
1624                        (uintmax_t)(obj[1].idx.offset - obj->idx.offset),
1625                        (uintmax_t)obj->idx.offset);
1626                 if (is_delta_type(obj->type)) {
1627                         struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1628                         printf(" %u %s", obj_stat[i].delta_depth,
1629                                oid_to_hex(&bobj->idx.oid));
1630                 }
1631                 putchar('\n');
1632         }
1633
1634         if (baseobjects)
1635                 printf_ln(Q_("non delta: %d object",
1636                              "non delta: %d objects",
1637                              baseobjects),
1638                           baseobjects);
1639         for (i = 0; i < deepest_delta; i++) {
1640                 if (!chain_histogram[i])
1641                         continue;
1642                 printf_ln(Q_("chain length = %d: %lu object",
1643                              "chain length = %d: %lu objects",
1644                              chain_histogram[i]),
1645                           i + 1,
1646                           chain_histogram[i]);
1647         }
1648 }
1649
1650 int cmd_index_pack(int argc, const char **argv, const char *prefix)
1651 {
1652         int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1653         const char *curr_index;
1654         const char *index_name = NULL, *pack_name = NULL;
1655         const char *keep_msg = NULL;
1656         const char *promisor_msg = NULL;
1657         struct strbuf index_name_buf = STRBUF_INIT;
1658         struct pack_idx_entry **idx_objects;
1659         struct pack_idx_option opts;
1660         unsigned char pack_hash[GIT_MAX_RAWSZ];
1661         unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1662         int report_end_of_input = 0;
1663         int hash_algo = 0;
1664
1665         /*
1666          * index-pack never needs to fetch missing objects except when
1667          * REF_DELTA bases are missing (which are explicitly handled). It only
1668          * accesses the repo to do hash collision checks and to check which
1669          * REF_DELTA bases need to be fetched.
1670          */
1671         fetch_if_missing = 0;
1672
1673         if (argc == 2 && !strcmp(argv[1], "-h"))
1674                 usage(index_pack_usage);
1675
1676         read_replace_refs = 0;
1677         fsck_options.walk = mark_link;
1678
1679         reset_pack_idx_option(&opts);
1680         git_config(git_index_pack_config, &opts);
1681         if (prefix && chdir(prefix))
1682                 die(_("Cannot come back to cwd"));
1683
1684         for (i = 1; i < argc; i++) {
1685                 const char *arg = argv[i];
1686
1687                 if (*arg == '-') {
1688                         if (!strcmp(arg, "--stdin")) {
1689                                 from_stdin = 1;
1690                         } else if (!strcmp(arg, "--fix-thin")) {
1691                                 fix_thin_pack = 1;
1692                         } else if (skip_to_optional_arg(arg, "--strict", &arg)) {
1693                                 strict = 1;
1694                                 do_fsck_object = 1;
1695                                 fsck_set_msg_types(&fsck_options, arg);
1696                         } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1697                                 strict = 1;
1698                                 check_self_contained_and_connected = 1;
1699                         } else if (!strcmp(arg, "--fsck-objects")) {
1700                                 do_fsck_object = 1;
1701                         } else if (!strcmp(arg, "--verify")) {
1702                                 verify = 1;
1703                         } else if (!strcmp(arg, "--verify-stat")) {
1704                                 verify = 1;
1705                                 show_stat = 1;
1706                         } else if (!strcmp(arg, "--verify-stat-only")) {
1707                                 verify = 1;
1708                                 show_stat = 1;
1709                                 stat_only = 1;
1710                         } else if (skip_to_optional_arg(arg, "--keep", &keep_msg)) {
1711                                 ; /* nothing to do */
1712                         } else if (skip_to_optional_arg(arg, "--promisor", &promisor_msg)) {
1713                                 ; /* already parsed */
1714                         } else if (starts_with(arg, "--threads=")) {
1715                                 char *end;
1716                                 nr_threads = strtoul(arg+10, &end, 0);
1717                                 if (!arg[10] || *end || nr_threads < 0)
1718                                         usage(index_pack_usage);
1719                                 if (!HAVE_THREADS && nr_threads != 1) {
1720                                         warning(_("no threads support, ignoring %s"), arg);
1721                                         nr_threads = 1;
1722                                 }
1723                         } else if (starts_with(arg, "--pack_header=")) {
1724                                 struct pack_header *hdr;
1725                                 char *c;
1726
1727                                 hdr = (struct pack_header *)input_buffer;
1728                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
1729                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1730                                 if (*c != ',')
1731                                         die(_("bad %s"), arg);
1732                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1733                                 if (*c)
1734                                         die(_("bad %s"), arg);
1735                                 input_len = sizeof(*hdr);
1736                         } else if (!strcmp(arg, "-v")) {
1737                                 verbose = 1;
1738                         } else if (!strcmp(arg, "--show-resolving-progress")) {
1739                                 show_resolving_progress = 1;
1740                         } else if (!strcmp(arg, "--report-end-of-input")) {
1741                                 report_end_of_input = 1;
1742                         } else if (!strcmp(arg, "-o")) {
1743                                 if (index_name || (i+1) >= argc)
1744                                         usage(index_pack_usage);
1745                                 index_name = argv[++i];
1746                         } else if (starts_with(arg, "--index-version=")) {
1747                                 char *c;
1748                                 opts.version = strtoul(arg + 16, &c, 10);
1749                                 if (opts.version > 2)
1750                                         die(_("bad %s"), arg);
1751                                 if (*c == ',')
1752                                         opts.off32_limit = strtoul(c+1, &c, 0);
1753                                 if (*c || opts.off32_limit & 0x80000000)
1754                                         die(_("bad %s"), arg);
1755                         } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1756                                 max_input_size = strtoumax(arg, NULL, 10);
1757                         } else if (skip_prefix(arg, "--object-format=", &arg)) {
1758                                 hash_algo = hash_algo_by_name(arg);
1759                                 if (hash_algo == GIT_HASH_UNKNOWN)
1760                                         die(_("unknown hash algorithm '%s'"), arg);
1761                                 repo_set_hash_algo(the_repository, hash_algo);
1762                         } else
1763                                 usage(index_pack_usage);
1764                         continue;
1765                 }
1766
1767                 if (pack_name)
1768                         usage(index_pack_usage);
1769                 pack_name = arg;
1770         }
1771
1772         if (!pack_name && !from_stdin)
1773                 usage(index_pack_usage);
1774         if (fix_thin_pack && !from_stdin)
1775                 die(_("--fix-thin cannot be used without --stdin"));
1776         if (from_stdin && !startup_info->have_repository)
1777                 die(_("--stdin requires a git repository"));
1778         if (from_stdin && hash_algo)
1779                 die(_("--object-format cannot be used with --stdin"));
1780         if (!index_name && pack_name)
1781                 index_name = derive_filename(pack_name, "idx", &index_name_buf);
1782
1783         if (verify) {
1784                 if (!index_name)
1785                         die(_("--verify with no packfile name given"));
1786                 read_idx_option(&opts, index_name);
1787                 opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1788         }
1789         if (strict)
1790                 opts.flags |= WRITE_IDX_STRICT;
1791
1792         if (HAVE_THREADS && !nr_threads) {
1793                 nr_threads = online_cpus();
1794                 /* An experiment showed that more threads does not mean faster */
1795                 if (nr_threads > 3)
1796                         nr_threads = 3;
1797         }
1798
1799         curr_pack = open_pack_file(pack_name);
1800         parse_pack_header();
1801         objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1802         if (show_stat)
1803                 obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1804         ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1805         parse_pack_objects(pack_hash);
1806         if (report_end_of_input)
1807                 write_in_full(2, "\0", 1);
1808         resolve_deltas();
1809         conclude_pack(fix_thin_pack, curr_pack, pack_hash);
1810         free(ofs_deltas);
1811         free(ref_deltas);
1812         if (strict)
1813                 foreign_nr = check_objects();
1814
1815         if (show_stat)
1816                 show_pack_info(stat_only);
1817
1818         ALLOC_ARRAY(idx_objects, nr_objects);
1819         for (i = 0; i < nr_objects; i++)
1820                 idx_objects[i] = &objects[i].idx;
1821         curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_hash);
1822         free(idx_objects);
1823
1824         if (!verify)
1825                 final(pack_name, curr_pack,
1826                       index_name, curr_index,
1827                       keep_msg, promisor_msg,
1828                       pack_hash);
1829         else
1830                 close(input_fd);
1831
1832         if (do_fsck_object && fsck_finish(&fsck_options))
1833                 die(_("fsck error in pack objects"));
1834
1835         free(objects);
1836         strbuf_release(&index_name_buf);
1837         if (pack_name == NULL)
1838                 free((void *) curr_pack);
1839         if (index_name == NULL)
1840                 free((void *) curr_index);
1841
1842         /*
1843          * Let the caller know this pack is not self contained
1844          */
1845         if (check_self_contained_and_connected && foreign_nr)
1846                 return 1;
1847
1848         return 0;
1849 }