builtin/index-pack.c

   1 #include "builtin.h"
   2 #include "alloc.h"
   3 #include "config.h"
   4 #include "delta.h"
   5 #include "environment.h"
   6 #include "gettext.h"
   7 #include "hex.h"
   8 #include "pack.h"
   9 #include "csum-file.h"
  10 #include "blob.h"
  11 #include "commit.h"
  12 #include "tag.h"
  13 #include "tree.h"
  14 #include "progress.h"
  15 #include "fsck.h"
  16 #include "exec-cmd.h"
  17 #include "streaming.h"
  18 #include "thread-utils.h"
  19 #include "packfile.h"
  20 #include "pack-revindex.h"
  21 #include "object-file.h"
  22 #include "object-store.h"
  23 #include "oid-array.h"
  24 #include "replace-object.h"
  25 #include "promisor-remote.h"
  26 #include "setup.h"
  27 #include "wrapper.h"
  28
  29 static const char index_pack_usage[] =
  30 "git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--[no-]rev-index] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  31
  32 struct object_entry {
  33         struct pack_idx_entry idx;
  34         unsigned long size;
  35         unsigned char hdr_size;
  36         signed char type;
  37         signed char real_type;
  38 };
  39
  40 struct object_stat {
  41         unsigned delta_depth;
  42         int base_object_no;
  43 };
  44
  45 struct base_data {
  46         /* Initialized by make_base(). */
  47         struct base_data *base;
  48         struct object_entry *obj;
  49         int ref_first, ref_last;
  50         int ofs_first, ofs_last;
  51         /*
  52          * Threads should increment retain_data if they are about to call
  53          * patch_delta() using this struct's data as a base, and decrement this
  54          * when they are done. While retain_data is nonzero, this struct's data
  55          * will not be freed even if the delta base cache limit is exceeded.
  56          */
  57         int retain_data;
  58         /*
  59          * The number of direct children that have not been fully processed
  60          * (entered work_head, entered done_head, left done_head). When this
  61          * number reaches zero, this struct base_data can be freed.
  62          */
  63         int children_remaining;
  64
  65         /* Not initialized by make_base(). */
  66         struct list_head list;
  67         void *data;
  68         unsigned long size;
  69 };
  70
  71 /*
  72  * Stack of struct base_data that have unprocessed children.
  73  * threaded_second_pass() uses this as a source of work (the other being the
  74  * objects array).
  75  *
  76  * Guarded by work_mutex.
  77  */
  78 static LIST_HEAD(work_head);
  79
  80 /*
  81  * Stack of struct base_data that have children, all of whom have been
  82  * processed or are being processed, and at least one child is being processed.
  83  * These struct base_data must be kept around until the last child is
  84  * processed.
  85  *
  86  * Guarded by work_mutex.
  87  */
  88 static LIST_HEAD(done_head);
  89
  90 /*
  91  * All threads share one delta base cache.
  92  *
  93  * base_cache_used is guarded by work_mutex, and base_cache_limit is read-only
  94  * in a thread.
  95  */
  96 static size_t base_cache_used;
  97 static size_t base_cache_limit;
  98
  99 struct thread_local {
 100         pthread_t thread;
 101         int pack_fd;
 102 };
 103
 104 /* Remember to update object flag allocation in object.h */
 105 #define FLAG_LINK (1u<<20)
 106 #define FLAG_CHECKED (1u<<21)
 107
 108 struct ofs_delta_entry {
 109         off_t offset;
 110         int obj_no;
 111 };
 112
 113 struct ref_delta_entry {
 114         struct object_id oid;
 115         int obj_no;
 116 };
 117
 118 static struct object_entry *objects;
 119 static struct object_stat *obj_stat;
 120 static struct ofs_delta_entry *ofs_deltas;
 121 static struct ref_delta_entry *ref_deltas;
 122 static struct thread_local nothread_data;
 123 static int nr_objects;
 124 static int nr_ofs_deltas;
 125 static int nr_ref_deltas;
 126 static int ref_deltas_alloc;
 127 static int nr_resolved_deltas;
 128 static int nr_threads;
 129
 130 static int from_stdin;
 131 static int strict;
 132 static int do_fsck_object;
 133 static struct fsck_options fsck_options = FSCK_OPTIONS_MISSING_GITMODULES;
 134 static int verbose;
 135 static const char *progress_title;
 136 static int show_resolving_progress;
 137 static int show_stat;
 138 static int check_self_contained_and_connected;
 139
 140 static struct progress *progress;
 141
 142 /* We always read in 4kB chunks. */
 143 static unsigned char input_buffer[4096];
 144 static unsigned int input_offset, input_len;
 145 static off_t consumed_bytes;
 146 static off_t max_input_size;
 147 static unsigned deepest_delta;
 148 static git_hash_ctx input_ctx;
 149 static uint32_t input_crc32;
 150 static int input_fd, output_fd;
 151 static const char *curr_pack;
 152
 153 static struct thread_local *thread_data;
 154 static int nr_dispatched;
 155 static int threads_active;
 156
 157 static pthread_mutex_t read_mutex;
 158 #define read_lock()             lock_mutex(&read_mutex)
 159 #define read_unlock()           unlock_mutex(&read_mutex)
 160
 161 static pthread_mutex_t counter_mutex;
 162 #define counter_lock()          lock_mutex(&counter_mutex)
 163 #define counter_unlock()        unlock_mutex(&counter_mutex)
 164
 165 static pthread_mutex_t work_mutex;
 166 #define work_lock()             lock_mutex(&work_mutex)
 167 #define work_unlock()           unlock_mutex(&work_mutex)
 168
 169 static pthread_mutex_t deepest_delta_mutex;
 170 #define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 171 #define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 172
 173 static pthread_key_t key;
 174
 175 static inline void lock_mutex(pthread_mutex_t *mutex)
 176 {
 177         if (threads_active)
 178                 pthread_mutex_lock(mutex);
 179 }
 180
 181 static inline void unlock_mutex(pthread_mutex_t *mutex)
 182 {
 183         if (threads_active)
 184                 pthread_mutex_unlock(mutex);
 185 }
 186
 187 /*
 188  * Mutex and conditional variable can't be statically-initialized on Windows.
 189  */
 190 static void init_thread(void)
 191 {
 192         int i;
 193         init_recursive_mutex(&read_mutex);
 194         pthread_mutex_init(&counter_mutex, NULL);
 195         pthread_mutex_init(&work_mutex, NULL);
 196         if (show_stat)
 197                 pthread_mutex_init(&deepest_delta_mutex, NULL);
 198         pthread_key_create(&key, NULL);
 199         CALLOC_ARRAY(thread_data, nr_threads);
 200         for (i = 0; i < nr_threads; i++) {
 201                 thread_data[i].pack_fd = xopen(curr_pack, O_RDONLY);
 202         }
 203
 204         threads_active = 1;
 205 }
 206
 207 static void cleanup_thread(void)
 208 {
 209         int i;
 210         if (!threads_active)
 211                 return;
 212         threads_active = 0;
 213         pthread_mutex_destroy(&read_mutex);
 214         pthread_mutex_destroy(&counter_mutex);
 215         pthread_mutex_destroy(&work_mutex);
 216         if (show_stat)
 217                 pthread_mutex_destroy(&deepest_delta_mutex);
 218         for (i = 0; i < nr_threads; i++)
 219                 close(thread_data[i].pack_fd);
 220         pthread_key_delete(key);
 221         free(thread_data);
 222 }
 223
 224 static int mark_link(struct object *obj, enum object_type type,
 225                      void *data, struct fsck_options *options)
 226 {
 227         if (!obj)
 228                 return -1;
 229
 230         if (type != OBJ_ANY && obj->type != type)
 231                 die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 232
 233         obj->flags |= FLAG_LINK;
 234         return 0;
 235 }
 236
 237 /* The content of each linked object must have been checked
 238    or it must be already present in the object database */
 239 static unsigned check_object(struct object *obj)
 240 {
 241         if (!obj)
 242                 return 0;
 243
 244         if (!(obj->flags & FLAG_LINK))
 245                 return 0;
 246
 247         if (!(obj->flags & FLAG_CHECKED)) {
 248                 unsigned long size;
 249                 int type = oid_object_info(the_repository, &obj->oid, &size);
 250                 if (type <= 0)
 251                         die(_("did not receive expected object %s"),
 252                               oid_to_hex(&obj->oid));
 253                 if (type != obj->type)
 254                         die(_("object %s: expected type %s, found %s"),
 255                             oid_to_hex(&obj->oid),
 256                             type_name(obj->type), type_name(type));
 257                 obj->flags |= FLAG_CHECKED;
 258                 return 1;
 259         }
 260
 261         return 0;
 262 }
 263
 264 static unsigned check_objects(void)
 265 {
 266         unsigned i, max, foreign_nr = 0;
 267
 268         max = get_max_object_index();
 269
 270         if (verbose)
 271                 progress = start_delayed_progress(_("Checking objects"), max);
 272
 273         for (i = 0; i < max; i++) {
 274                 foreign_nr += check_object(get_indexed_object(i));
 275                 display_progress(progress, i + 1);
 276         }
 277
 278         stop_progress(&progress);
 279         return foreign_nr;
 280 }
 281
 282
 283 /* Discard current buffer used content. */
 284 static void flush(void)
 285 {
 286         if (input_offset) {
 287                 if (output_fd >= 0)
 288                         write_or_die(output_fd, input_buffer, input_offset);
 289                 the_hash_algo->update_fn(&input_ctx, input_buffer, input_offset);
 290                 memmove(input_buffer, input_buffer + input_offset, input_len);
 291                 input_offset = 0;
 292         }
 293 }
 294
 295 /*
 296  * Make sure at least "min" bytes are available in the buffer, and
 297  * return the pointer to the buffer.
 298  */
 299 static void *fill(int min)
 300 {
 301         if (min <= input_len)
 302                 return input_buffer + input_offset;
 303         if (min > sizeof(input_buffer))
 304                 die(Q_("cannot fill %d byte",
 305                        "cannot fill %d bytes",
 306                        min),
 307                     min);
 308         flush();
 309         do {
 310                 ssize_t ret = xread(input_fd, input_buffer + input_len,
 311                                 sizeof(input_buffer) - input_len);
 312                 if (ret <= 0) {
 313                         if (!ret)
 314                                 die(_("early EOF"));
 315                         die_errno(_("read error on input"));
 316                 }
 317                 input_len += ret;
 318                 if (from_stdin)
 319                         display_throughput(progress, consumed_bytes + input_len);
 320         } while (input_len < min);
 321         return input_buffer;
 322 }
 323
 324 static void use(int bytes)
 325 {
 326         if (bytes > input_len)
 327                 die(_("used more bytes than were available"));
 328         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 329         input_len -= bytes;
 330         input_offset += bytes;
 331
 332         /* make sure off_t is sufficiently large not to wrap */
 333         if (signed_add_overflows(consumed_bytes, bytes))
 334                 die(_("pack too large for current definition of off_t"));
 335         consumed_bytes += bytes;
 336         if (max_input_size && consumed_bytes > max_input_size) {
 337                 struct strbuf size_limit = STRBUF_INIT;
 338                 strbuf_humanise_bytes(&size_limit, max_input_size);
 339                 die(_("pack exceeds maximum allowed size (%s)"),
 340                     size_limit.buf);
 341         }
 342 }
 343
 344 static const char *open_pack_file(const char *pack_name)
 345 {
 346         if (from_stdin) {
 347                 input_fd = 0;
 348                 if (!pack_name) {
 349                         struct strbuf tmp_file = STRBUF_INIT;
 350                         output_fd = odb_mkstemp(&tmp_file,
 351                                                 "pack/tmp_pack_XXXXXX");
 352                         pack_name = strbuf_detach(&tmp_file, NULL);
 353                 } else {
 354                         output_fd = xopen(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 355                 }
 356                 nothread_data.pack_fd = output_fd;
 357         } else {
 358                 input_fd = xopen(pack_name, O_RDONLY);
 359                 output_fd = -1;
 360                 nothread_data.pack_fd = input_fd;
 361         }
 362         the_hash_algo->init_fn(&input_ctx);
 363         return pack_name;
 364 }
 365
 366 static void parse_pack_header(void)
 367 {
 368         struct pack_header *hdr = fill(sizeof(struct pack_header));
 369
 370         /* Header consistency check */
 371         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 372                 die(_("pack signature mismatch"));
 373         if (!pack_version_ok(hdr->hdr_version))
 374                 die(_("pack version %"PRIu32" unsupported"),
 375                         ntohl(hdr->hdr_version));
 376
 377         nr_objects = ntohl(hdr->hdr_entries);
 378         use(sizeof(struct pack_header));
 379 }
 380
 381 __attribute__((format (printf, 2, 3)))
 382 static NORETURN void bad_object(off_t offset, const char *format, ...)
 383 {
 384         va_list params;
 385         char buf[1024];
 386
 387         va_start(params, format);
 388         vsnprintf(buf, sizeof(buf), format, params);
 389         va_end(params);
 390         die(_("pack has bad object at offset %"PRIuMAX": %s"),
 391             (uintmax_t)offset, buf);
 392 }
 393
 394 static inline struct thread_local *get_thread_data(void)
 395 {
 396         if (HAVE_THREADS) {
 397                 if (threads_active)
 398                         return pthread_getspecific(key);
 399                 assert(!threads_active &&
 400                        "This should only be reached when all threads are gone");
 401         }
 402         return &nothread_data;
 403 }
 404
 405 static void set_thread_data(struct thread_local *data)
 406 {
 407         if (threads_active)
 408                 pthread_setspecific(key, data);
 409 }
 410
 411 static void free_base_data(struct base_data *c)
 412 {
 413         if (c->data) {
 414                 FREE_AND_NULL(c->data);
 415                 base_cache_used -= c->size;
 416         }
 417 }
 418
 419 static void prune_base_data(struct base_data *retain)
 420 {
 421         struct list_head *pos;
 422
 423         if (base_cache_used <= base_cache_limit)
 424                 return;
 425
 426         list_for_each_prev(pos, &done_head) {
 427                 struct base_data *b = list_entry(pos, struct base_data, list);
 428                 if (b->retain_data || b == retain)
 429                         continue;
 430                 if (b->data) {
 431                         free_base_data(b);
 432                         if (base_cache_used <= base_cache_limit)
 433                                 return;
 434                 }
 435         }
 436
 437         list_for_each_prev(pos, &work_head) {
 438                 struct base_data *b = list_entry(pos, struct base_data, list);
 439                 if (b->retain_data || b == retain)
 440                         continue;
 441                 if (b->data) {
 442                         free_base_data(b);
 443                         if (base_cache_used <= base_cache_limit)
 444                                 return;
 445                 }
 446         }
 447 }
 448
 449 static int is_delta_type(enum object_type type)
 450 {
 451         return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 452 }
 453
 454 static void *unpack_entry_data(off_t offset, unsigned long size,
 455                                enum object_type type, struct object_id *oid)
 456 {
 457         static char fixed_buf[8192];
 458         int status;
 459         git_zstream stream;
 460         void *buf;
 461         git_hash_ctx c;
 462         char hdr[32];
 463         int hdrlen;
 464
 465         if (!is_delta_type(type)) {
 466                 hdrlen = format_object_header(hdr, sizeof(hdr), type, size);
 467                 the_hash_algo->init_fn(&c);
 468                 the_hash_algo->update_fn(&c, hdr, hdrlen);
 469         } else
 470                 oid = NULL;
 471         if (type == OBJ_BLOB && size > big_file_threshold)
 472                 buf = fixed_buf;
 473         else
 474                 buf = xmallocz(size);
 475
 476         memset(&stream, 0, sizeof(stream));
 477         git_inflate_init(&stream);
 478         stream.next_out = buf;
 479         stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 480
 481         do {
 482                 unsigned char *last_out = stream.next_out;
 483                 stream.next_in = fill(1);
 484                 stream.avail_in = input_len;
 485                 status = git_inflate(&stream, 0);
 486                 use(input_len - stream.avail_in);
 487                 if (oid)
 488                         the_hash_algo->update_fn(&c, last_out, stream.next_out - last_out);
 489                 if (buf == fixed_buf) {
 490                         stream.next_out = buf;
 491                         stream.avail_out = sizeof(fixed_buf);
 492                 }
 493         } while (status == Z_OK);
 494         if (stream.total_out != size || status != Z_STREAM_END)
 495                 bad_object(offset, _("inflate returned %d"), status);
 496         git_inflate_end(&stream);
 497         if (oid)
 498                 the_hash_algo->final_oid_fn(oid, &c);
 499         return buf == fixed_buf ? NULL : buf;
 500 }
 501
 502 static void *unpack_raw_entry(struct object_entry *obj,
 503                               off_t *ofs_offset,
 504                               struct object_id *ref_oid,
 505                               struct object_id *oid)
 506 {
 507         unsigned char *p;
 508         unsigned long size, c;
 509         off_t base_offset;
 510         unsigned shift;
 511         void *data;
 512
 513         obj->idx.offset = consumed_bytes;
 514         input_crc32 = crc32(0, NULL, 0);
 515
 516         p = fill(1);
 517         c = *p;
 518         use(1);
 519         obj->type = (c >> 4) & 7;
 520         size = (c & 15);
 521         shift = 4;
 522         while (c & 0x80) {
 523                 p = fill(1);
 524                 c = *p;
 525                 use(1);
 526                 size += (c & 0x7f) << shift;
 527                 shift += 7;
 528         }
 529         obj->size = size;
 530
 531         switch (obj->type) {
 532         case OBJ_REF_DELTA:
 533                 oidread(ref_oid, fill(the_hash_algo->rawsz));
 534                 use(the_hash_algo->rawsz);
 535                 break;
 536         case OBJ_OFS_DELTA:
 537                 p = fill(1);
 538                 c = *p;
 539                 use(1);
 540                 base_offset = c & 127;
 541                 while (c & 128) {
 542                         base_offset += 1;
 543                         if (!base_offset || MSB(base_offset, 7))
 544                                 bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 545                         p = fill(1);
 546                         c = *p;
 547                         use(1);
 548                         base_offset = (base_offset << 7) + (c & 127);
 549                 }
 550                 *ofs_offset = obj->idx.offset - base_offset;
 551                 if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 552                         bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 553                 break;
 554         case OBJ_COMMIT:
 555         case OBJ_TREE:
 556         case OBJ_BLOB:
 557         case OBJ_TAG:
 558                 break;
 559         default:
 560                 bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 561         }
 562         obj->hdr_size = consumed_bytes - obj->idx.offset;
 563
 564         data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, oid);
 565         obj->idx.crc32 = input_crc32;
 566         return data;
 567 }
 568
 569 static void *unpack_data(struct object_entry *obj,
 570                          int (*consume)(const unsigned char *, unsigned long, void *),
 571                          void *cb_data)
 572 {
 573         off_t from = obj[0].idx.offset + obj[0].hdr_size;
 574         off_t len = obj[1].idx.offset - from;
 575         unsigned char *data, *inbuf;
 576         git_zstream stream;
 577         int status;
 578
 579         data = xmallocz(consume ? 64*1024 : obj->size);
 580         inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 581
 582         memset(&stream, 0, sizeof(stream));
 583         git_inflate_init(&stream);
 584         stream.next_out = data;
 585         stream.avail_out = consume ? 64*1024 : obj->size;
 586
 587         do {
 588                 ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 589                 n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 590                 if (n < 0)
 591                         die_errno(_("cannot pread pack file"));
 592                 if (!n)
 593                         die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 594                                "premature end of pack file, %"PRIuMAX" bytes missing",
 595                                len),
 596                             (uintmax_t)len);
 597                 from += n;
 598                 len -= n;
 599                 stream.next_in = inbuf;
 600                 stream.avail_in = n;
 601                 if (!consume)
 602                         status = git_inflate(&stream, 0);
 603                 else {
 604                         do {
 605                                 status = git_inflate(&stream, 0);
 606                                 if (consume(data, stream.next_out - data, cb_data)) {
 607                                         free(inbuf);
 608                                         free(data);
 609                                         return NULL;
 610                                 }
 611                                 stream.next_out = data;
 612                                 stream.avail_out = 64*1024;
 613                         } while (status == Z_OK && stream.avail_in);
 614                 }
 615         } while (len && status == Z_OK && !stream.avail_in);
 616
 617         /* This has been inflated OK when first encountered, so... */
 618         if (status != Z_STREAM_END || stream.total_out != obj->size)
 619                 die(_("serious inflate inconsistency"));
 620
 621         git_inflate_end(&stream);
 622         free(inbuf);
 623         if (consume) {
 624                 FREE_AND_NULL(data);
 625         }
 626         return data;
 627 }
 628
 629 static void *get_data_from_pack(struct object_entry *obj)
 630 {
 631         return unpack_data(obj, NULL, NULL);
 632 }
 633
 634 static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 635                                    enum object_type type1,
 636                                    enum object_type type2)
 637 {
 638         int cmp = type1 - type2;
 639         if (cmp)
 640                 return cmp;
 641         return offset1 < offset2 ? -1 :
 642                offset1 > offset2 ?  1 :
 643                0;
 644 }
 645
 646 static int find_ofs_delta(const off_t offset)
 647 {
 648         int first = 0, last = nr_ofs_deltas;
 649
 650         while (first < last) {
 651                 int next = first + (last - first) / 2;
 652                 struct ofs_delta_entry *delta = &ofs_deltas[next];
 653                 int cmp;
 654
 655                 cmp = compare_ofs_delta_bases(offset, delta->offset,
 656                                               OBJ_OFS_DELTA,
 657                                               objects[delta->obj_no].type);
 658                 if (!cmp)
 659                         return next;
 660                 if (cmp < 0) {
 661                         last = next;
 662                         continue;
 663                 }
 664                 first = next+1;
 665         }
 666         return -first-1;
 667 }
 668
 669 static void find_ofs_delta_children(off_t offset,
 670                                     int *first_index, int *last_index)
 671 {
 672         int first = find_ofs_delta(offset);
 673         int last = first;
 674         int end = nr_ofs_deltas - 1;
 675
 676         if (first < 0) {
 677                 *first_index = 0;
 678                 *last_index = -1;
 679                 return;
 680         }
 681         while (first > 0 && ofs_deltas[first - 1].offset == offset)
 682                 --first;
 683         while (last < end && ofs_deltas[last + 1].offset == offset)
 684                 ++last;
 685         *first_index = first;
 686         *last_index = last;
 687 }
 688
 689 static int compare_ref_delta_bases(const struct object_id *oid1,
 690                                    const struct object_id *oid2,
 691                                    enum object_type type1,
 692                                    enum object_type type2)
 693 {
 694         int cmp = type1 - type2;
 695         if (cmp)
 696                 return cmp;
 697         return oidcmp(oid1, oid2);
 698 }
 699
 700 static int find_ref_delta(const struct object_id *oid)
 701 {
 702         int first = 0, last = nr_ref_deltas;
 703
 704         while (first < last) {
 705                 int next = first + (last - first) / 2;
 706                 struct ref_delta_entry *delta = &ref_deltas[next];
 707                 int cmp;
 708
 709                 cmp = compare_ref_delta_bases(oid, &delta->oid,
 710                                               OBJ_REF_DELTA,
 711                                               objects[delta->obj_no].type);
 712                 if (!cmp)
 713                         return next;
 714                 if (cmp < 0) {
 715                         last = next;
 716                         continue;
 717                 }
 718                 first = next+1;
 719         }
 720         return -first-1;
 721 }
 722
 723 static void find_ref_delta_children(const struct object_id *oid,
 724                                     int *first_index, int *last_index)
 725 {
 726         int first = find_ref_delta(oid);
 727         int last = first;
 728         int end = nr_ref_deltas - 1;
 729
 730         if (first < 0) {
 731                 *first_index = 0;
 732                 *last_index = -1;
 733                 return;
 734         }
 735         while (first > 0 && oideq(&ref_deltas[first - 1].oid, oid))
 736                 --first;
 737         while (last < end && oideq(&ref_deltas[last + 1].oid, oid))
 738                 ++last;
 739         *first_index = first;
 740         *last_index = last;
 741 }
 742
 743 struct compare_data {
 744         struct object_entry *entry;
 745         struct git_istream *st;
 746         unsigned char *buf;
 747         unsigned long buf_size;
 748 };
 749
 750 static int compare_objects(const unsigned char *buf, unsigned long size,
 751                            void *cb_data)
 752 {
 753         struct compare_data *data = cb_data;
 754
 755         if (data->buf_size < size) {
 756                 free(data->buf);
 757                 data->buf = xmalloc(size);
 758                 data->buf_size = size;
 759         }
 760
 761         while (size) {
 762                 ssize_t len = read_istream(data->st, data->buf, size);
 763                 if (len == 0)
 764                         die(_("SHA1 COLLISION FOUND WITH %s !"),
 765                             oid_to_hex(&data->entry->idx.oid));
 766                 if (len < 0)
 767                         die(_("unable to read %s"),
 768                             oid_to_hex(&data->entry->idx.oid));
 769                 if (memcmp(buf, data->buf, len))
 770                         die(_("SHA1 COLLISION FOUND WITH %s !"),
 771                             oid_to_hex(&data->entry->idx.oid));
 772                 size -= len;
 773                 buf += len;
 774         }
 775         return 0;
 776 }
 777
 778 static int check_collison(struct object_entry *entry)
 779 {
 780         struct compare_data data;
 781         enum object_type type;
 782         unsigned long size;
 783
 784         if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 785                 return -1;
 786
 787         memset(&data, 0, sizeof(data));
 788         data.entry = entry;
 789         data.st = open_istream(the_repository, &entry->idx.oid, &type, &size,
 790                                NULL);
 791         if (!data.st)
 792                 return -1;
 793         if (size != entry->size || type != entry->type)
 794                 die(_("SHA1 COLLISION FOUND WITH %s !"),
 795                     oid_to_hex(&entry->idx.oid));
 796         unpack_data(entry, compare_objects, &data);
 797         close_istream(data.st);
 798         free(data.buf);
 799         return 0;
 800 }
 801
 802 static void sha1_object(const void *data, struct object_entry *obj_entry,
 803                         unsigned long size, enum object_type type,
 804                         const struct object_id *oid)
 805 {
 806         void *new_data = NULL;
 807         int collision_test_needed = 0;
 808
 809         assert(data || obj_entry);
 810
 811         if (startup_info->have_repository) {
 812                 read_lock();
 813                 collision_test_needed =
 814                         repo_has_object_file_with_flags(the_repository, oid,
 815                                                         OBJECT_INFO_QUICK);
 816                 read_unlock();
 817         }
 818
 819         if (collision_test_needed && !data) {
 820                 read_lock();
 821                 if (!check_collison(obj_entry))
 822                         collision_test_needed = 0;
 823                 read_unlock();
 824         }
 825         if (collision_test_needed) {
 826                 void *has_data;
 827                 enum object_type has_type;
 828                 unsigned long has_size;
 829                 read_lock();
 830                 has_type = oid_object_info(the_repository, oid, &has_size);
 831                 if (has_type < 0)
 832                         die(_("cannot read existing object info %s"), oid_to_hex(oid));
 833                 if (has_type != type || has_size != size)
 834                         die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 835                 has_data = repo_read_object_file(the_repository, oid,
 836                                                  &has_type, &has_size);
 837                 read_unlock();
 838                 if (!data)
 839                         data = new_data = get_data_from_pack(obj_entry);
 840                 if (!has_data)
 841                         die(_("cannot read existing object %s"), oid_to_hex(oid));
 842                 if (size != has_size || type != has_type ||
 843                     memcmp(data, has_data, size) != 0)
 844                         die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 845                 free(has_data);
 846         }
 847
 848         if (strict || do_fsck_object) {
 849                 read_lock();
 850                 if (type == OBJ_BLOB) {
 851                         struct blob *blob = lookup_blob(the_repository, oid);
 852                         if (blob)
 853                                 blob->object.flags |= FLAG_CHECKED;
 854                         else
 855                                 die(_("invalid blob object %s"), oid_to_hex(oid));
 856                         if (do_fsck_object &&
 857                             fsck_object(&blob->object, (void *)data, size, &fsck_options))
 858                                 die(_("fsck error in packed object"));
 859                 } else {
 860                         struct object *obj;
 861                         int eaten;
 862                         void *buf = (void *) data;
 863
 864                         assert(data && "data can only be NULL for large _blobs_");
 865
 866                         /*
 867                          * we do not need to free the memory here, as the
 868                          * buf is deleted by the caller.
 869                          */
 870                         obj = parse_object_buffer(the_repository, oid, type,
 871                                                   size, buf,
 872                                                   &eaten);
 873                         if (!obj)
 874                                 die(_("invalid %s"), type_name(type));
 875                         if (do_fsck_object &&
 876                             fsck_object(obj, buf, size, &fsck_options))
 877                                 die(_("fsck error in packed object"));
 878                         if (strict && fsck_walk(obj, NULL, &fsck_options))
 879                                 die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 880
 881                         if (obj->type == OBJ_TREE) {
 882                                 struct tree *item = (struct tree *) obj;
 883                                 item->buffer = NULL;
 884                                 obj->parsed = 0;
 885                         }
 886                         if (obj->type == OBJ_COMMIT) {
 887                                 struct commit *commit = (struct commit *) obj;
 888                                 if (detach_commit_buffer(commit, NULL) != data)
 889                                         BUG("parse_object_buffer transmogrified our buffer");
 890                         }
 891                         obj->flags |= FLAG_CHECKED;
 892                 }
 893                 read_unlock();
 894         }
 895
 896         free(new_data);
 897 }
 898
 899 /*
 900  * Ensure that this node has been reconstructed and return its contents.
 901  *
 902  * In the typical and best case, this node would already be reconstructed
 903  * (through the invocation to resolve_delta() in threaded_second_pass()) and it
 904  * would not be pruned. However, if pruning of this node was necessary due to
 905  * reaching delta_base_cache_limit, this function will find the closest
 906  * ancestor with reconstructed data that has not been pruned (or if there is
 907  * none, the ultimate base object), and reconstruct each node in the delta
 908  * chain in order to generate the reconstructed data for this node.
 909  */
 910 static void *get_base_data(struct base_data *c)
 911 {
 912         if (!c->data) {
 913                 struct object_entry *obj = c->obj;
 914                 struct base_data **delta = NULL;
 915                 int delta_nr = 0, delta_alloc = 0;
 916
 917                 while (is_delta_type(c->obj->type) && !c->data) {
 918                         ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 919                         delta[delta_nr++] = c;
 920                         c = c->base;
 921                 }
 922                 if (!delta_nr) {
 923                         c->data = get_data_from_pack(obj);
 924                         c->size = obj->size;
 925                         base_cache_used += c->size;
 926                         prune_base_data(c);
 927                 }
 928                 for (; delta_nr > 0; delta_nr--) {
 929                         void *base, *raw;
 930                         c = delta[delta_nr - 1];
 931                         obj = c->obj;
 932                         base = get_base_data(c->base);
 933                         raw = get_data_from_pack(obj);
 934                         c->data = patch_delta(
 935                                 base, c->base->size,
 936                                 raw, obj->size,
 937                                 &c->size);
 938                         free(raw);
 939                         if (!c->data)
 940                                 bad_object(obj->idx.offset, _("failed to apply delta"));
 941                         base_cache_used += c->size;
 942                         prune_base_data(c);
 943                 }
 944                 free(delta);
 945         }
 946         return c->data;
 947 }
 948
 949 static struct base_data *make_base(struct object_entry *obj,
 950                                    struct base_data *parent)
 951 {
 952         struct base_data *base = xcalloc(1, sizeof(struct base_data));
 953         base->base = parent;
 954         base->obj = obj;
 955         find_ref_delta_children(&obj->idx.oid,
 956                                 &base->ref_first, &base->ref_last);
 957         find_ofs_delta_children(obj->idx.offset,
 958                                 &base->ofs_first, &base->ofs_last);
 959         base->children_remaining = base->ref_last - base->ref_first +
 960                 base->ofs_last - base->ofs_first + 2;
 961         return base;
 962 }
 963
 964 static struct base_data *resolve_delta(struct object_entry *delta_obj,
 965                                        struct base_data *base)
 966 {
 967         void *delta_data, *result_data;
 968         struct base_data *result;
 969         unsigned long result_size;
 970
 971         if (show_stat) {
 972                 int i = delta_obj - objects;
 973                 int j = base->obj - objects;
 974                 obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 975                 deepest_delta_lock();
 976                 if (deepest_delta < obj_stat[i].delta_depth)
 977                         deepest_delta = obj_stat[i].delta_depth;
 978                 deepest_delta_unlock();
 979                 obj_stat[i].base_object_no = j;
 980         }
 981         delta_data = get_data_from_pack(delta_obj);
 982         assert(base->data);
 983         result_data = patch_delta(base->data, base->size,
 984                                   delta_data, delta_obj->size, &result_size);
 985         free(delta_data);
 986         if (!result_data)
 987                 bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 988         hash_object_file(the_hash_algo, result_data, result_size,
 989                          delta_obj->real_type, &delta_obj->idx.oid);
 990         sha1_object(result_data, NULL, result_size, delta_obj->real_type,
 991                     &delta_obj->idx.oid);
 992
 993         result = make_base(delta_obj, base);
 994         result->data = result_data;
 995         result->size = result_size;
 996
 997         counter_lock();
 998         nr_resolved_deltas++;
 999         counter_unlock();
1000
1001         return result;
1002 }
1003
1004 static int compare_ofs_delta_entry(const void *a, const void *b)
1005 {
1006         const struct ofs_delta_entry *delta_a = a;
1007         const struct ofs_delta_entry *delta_b = b;
1008
1009         return delta_a->offset < delta_b->offset ? -1 :
1010                delta_a->offset > delta_b->offset ?  1 :
1011                0;
1012 }
1013
1014 static int compare_ref_delta_entry(const void *a, const void *b)
1015 {
1016         const struct ref_delta_entry *delta_a = a;
1017         const struct ref_delta_entry *delta_b = b;
1018
1019         return oidcmp(&delta_a->oid, &delta_b->oid);
1020 }
1021
1022 static void *threaded_second_pass(void *data)
1023 {
1024         if (data)
1025                 set_thread_data(data);
1026         for (;;) {
1027                 struct base_data *parent = NULL;
1028                 struct object_entry *child_obj;
1029                 struct base_data *child;
1030
1031                 counter_lock();
1032                 display_progress(progress, nr_resolved_deltas);
1033                 counter_unlock();
1034
1035                 work_lock();
1036                 if (list_empty(&work_head)) {
1037                         /*
1038                          * Take an object from the object array.
1039                          */
1040                         while (nr_dispatched < nr_objects &&
1041                                is_delta_type(objects[nr_dispatched].type))
1042                                 nr_dispatched++;
1043                         if (nr_dispatched >= nr_objects) {
1044                                 work_unlock();
1045                                 break;
1046                         }
1047                         child_obj = &objects[nr_dispatched++];
1048                 } else {
1049                         /*
1050                          * Peek at the top of the stack, and take a child from
1051                          * it.
1052                          */
1053                         parent = list_first_entry(&work_head, struct base_data,
1054                                                   list);
1055
1056                         if (parent->ref_first <= parent->ref_last) {
1057                                 int offset = ref_deltas[parent->ref_first++].obj_no;
1058                                 child_obj = objects + offset;
1059                                 if (child_obj->real_type != OBJ_REF_DELTA)
1060                                         die("REF_DELTA at offset %"PRIuMAX" already resolved (duplicate base %s?)",
1061                                             (uintmax_t) child_obj->idx.offset,
1062                                             oid_to_hex(&parent->obj->idx.oid));
1063                                 child_obj->real_type = parent->obj->real_type;
1064                         } else {
1065                                 child_obj = objects +
1066                                         ofs_deltas[parent->ofs_first++].obj_no;
1067                                 assert(child_obj->real_type == OBJ_OFS_DELTA);
1068                                 child_obj->real_type = parent->obj->real_type;
1069                         }
1070
1071                         if (parent->ref_first > parent->ref_last &&
1072                             parent->ofs_first > parent->ofs_last) {
1073                                 /*
1074                                  * This parent has run out of children, so move
1075                                  * it to done_head.
1076                                  */
1077                                 list_del(&parent->list);
1078                                 list_add(&parent->list, &done_head);
1079                         }
1080
1081                         /*
1082                          * Ensure that the parent has data, since we will need
1083                          * it later.
1084                          *
1085                          * NEEDSWORK: If parent data needs to be reloaded, this
1086                          * prolongs the time that the current thread spends in
1087                          * the mutex. A mitigating factor is that parent data
1088                          * needs to be reloaded only if the delta base cache
1089                          * limit is exceeded, so in the typical case, this does
1090                          * not happen.
1091                          */
1092                         get_base_data(parent);
1093                         parent->retain_data++;
1094                 }
1095                 work_unlock();
1096
1097                 if (parent) {
1098                         child = resolve_delta(child_obj, parent);
1099                         if (!child->children_remaining)
1100                                 FREE_AND_NULL(child->data);
1101                 } else {
1102                         child = make_base(child_obj, NULL);
1103                         if (child->children_remaining) {
1104                                 /*
1105                                  * Since this child has its own delta children,
1106                                  * we will need this data in the future.
1107                                  * Inflate now so that future iterations will
1108                                  * have access to this object's data while
1109                                  * outside the work mutex.
1110                                  */
1111                                 child->data = get_data_from_pack(child_obj);
1112                                 child->size = child_obj->size;
1113                         }
1114                 }
1115
1116                 work_lock();
1117                 if (parent)
1118                         parent->retain_data--;
1119                 if (child->data) {
1120                         /*
1121                          * This child has its own children, so add it to
1122                          * work_head.
1123                          */
1124                         list_add(&child->list, &work_head);
1125                         base_cache_used += child->size;
1126                         prune_base_data(NULL);
1127                         free_base_data(child);
1128                 } else {
1129                         /*
1130                          * This child does not have its own children. It may be
1131                          * the last descendant of its ancestors; free those
1132                          * that we can.
1133                          */
1134                         struct base_data *p = parent;
1135
1136                         while (p) {
1137                                 struct base_data *next_p;
1138
1139                                 p->children_remaining--;
1140                                 if (p->children_remaining)
1141                                         break;
1142
1143                                 next_p = p->base;
1144                                 free_base_data(p);
1145                                 list_del(&p->list);
1146                                 free(p);
1147
1148                                 p = next_p;
1149                         }
1150                         FREE_AND_NULL(child);
1151                 }
1152                 work_unlock();
1153         }
1154         return NULL;
1155 }
1156
1157 /*
1158  * First pass:
1159  * - find locations of all objects;
1160  * - calculate SHA1 of all non-delta objects;
1161  * - remember base (SHA1 or offset) for all deltas.
1162  */
1163 static void parse_pack_objects(unsigned char *hash)
1164 {
1165         int i, nr_delays = 0;
1166         struct ofs_delta_entry *ofs_delta = ofs_deltas;
1167         struct object_id ref_delta_oid;
1168         struct stat st;
1169
1170         if (verbose)
1171                 progress = start_progress(
1172                                 progress_title ? progress_title :
1173                                 from_stdin ? _("Receiving objects") : _("Indexing objects"),
1174                                 nr_objects);
1175         for (i = 0; i < nr_objects; i++) {
1176                 struct object_entry *obj = &objects[i];
1177                 void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1178                                               &ref_delta_oid,
1179                                               &obj->idx.oid);
1180                 obj->real_type = obj->type;
1181                 if (obj->type == OBJ_OFS_DELTA) {
1182                         nr_ofs_deltas++;
1183                         ofs_delta->obj_no = i;
1184                         ofs_delta++;
1185                 } else if (obj->type == OBJ_REF_DELTA) {
1186                         ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1187                         oidcpy(&ref_deltas[nr_ref_deltas].oid, &ref_delta_oid);
1188                         ref_deltas[nr_ref_deltas].obj_no = i;
1189                         nr_ref_deltas++;
1190                 } else if (!data) {
1191                         /* large blobs, check later */
1192                         obj->real_type = OBJ_BAD;
1193                         nr_delays++;
1194                 } else
1195                         sha1_object(data, NULL, obj->size, obj->type,
1196                                     &obj->idx.oid);
1197                 free(data);
1198                 display_progress(progress, i+1);
1199         }
1200         objects[i].idx.offset = consumed_bytes;
1201         stop_progress(&progress);
1202
1203         /* Check pack integrity */
1204         flush();
1205         the_hash_algo->final_fn(hash, &input_ctx);
1206         if (!hasheq(fill(the_hash_algo->rawsz), hash))
1207                 die(_("pack is corrupted (SHA1 mismatch)"));
1208         use(the_hash_algo->rawsz);
1209
1210         /* If input_fd is a file, we should have reached its end now. */
1211         if (fstat(input_fd, &st))
1212                 die_errno(_("cannot fstat packfile"));
1213         if (S_ISREG(st.st_mode) &&
1214                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1215                 die(_("pack has junk at the end"));
1216
1217         for (i = 0; i < nr_objects; i++) {
1218                 struct object_entry *obj = &objects[i];
1219                 if (obj->real_type != OBJ_BAD)
1220                         continue;
1221                 obj->real_type = obj->type;
1222                 sha1_object(NULL, obj, obj->size, obj->type,
1223                             &obj->idx.oid);
1224                 nr_delays--;
1225         }
1226         if (nr_delays)
1227                 die(_("confusion beyond insanity in parse_pack_objects()"));
1228 }
1229
1230 /*
1231  * Second pass:
1232  * - for all non-delta objects, look if it is used as a base for
1233  *   deltas;
1234  * - if used as a base, uncompress the object and apply all deltas,
1235  *   recursively checking if the resulting object is used as a base
1236  *   for some more deltas.
1237  */
1238 static void resolve_deltas(void)
1239 {
1240         int i;
1241
1242         if (!nr_ofs_deltas && !nr_ref_deltas)
1243                 return;
1244
1245         /* Sort deltas by base SHA1/offset for fast searching */
1246         QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1247         QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1248
1249         if (verbose || show_resolving_progress)
1250                 progress = start_progress(_("Resolving deltas"),
1251                                           nr_ref_deltas + nr_ofs_deltas);
1252
1253         nr_dispatched = 0;
1254         base_cache_limit = delta_base_cache_limit * nr_threads;
1255         if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1256                 init_thread();
1257                 for (i = 0; i < nr_threads; i++) {
1258                         int ret = pthread_create(&thread_data[i].thread, NULL,
1259                                                  threaded_second_pass, thread_data + i);
1260                         if (ret)
1261                                 die(_("unable to create thread: %s"),
1262                                     strerror(ret));
1263                 }
1264                 for (i = 0; i < nr_threads; i++)
1265                         pthread_join(thread_data[i].thread, NULL);
1266                 cleanup_thread();
1267                 return;
1268         }
1269         threaded_second_pass(&nothread_data);
1270 }
1271
1272 /*
1273  * Third pass:
1274  * - append objects to convert thin pack to full pack if required
1275  * - write the final pack hash
1276  */
1277 static void fix_unresolved_deltas(struct hashfile *f);
1278 static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_hash)
1279 {
1280         if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1281                 stop_progress(&progress);
1282                 /* Flush remaining pack final hash. */
1283                 flush();
1284                 return;
1285         }
1286
1287         if (fix_thin_pack) {
1288                 struct hashfile *f;
1289                 unsigned char read_hash[GIT_MAX_RAWSZ], tail_hash[GIT_MAX_RAWSZ];
1290                 struct strbuf msg = STRBUF_INIT;
1291                 int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1292                 int nr_objects_initial = nr_objects;
1293                 if (nr_unresolved <= 0)
1294                         die(_("confusion beyond insanity"));
1295                 REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1296                 memset(objects + nr_objects + 1, 0,
1297                        nr_unresolved * sizeof(*objects));
1298                 f = hashfd(output_fd, curr_pack);
1299                 fix_unresolved_deltas(f);
1300                 strbuf_addf(&msg, Q_("completed with %d local object",
1301                                      "completed with %d local objects",
1302                                      nr_objects - nr_objects_initial),
1303                             nr_objects - nr_objects_initial);
1304                 stop_progress_msg(&progress, msg.buf);
1305                 strbuf_release(&msg);
1306                 finalize_hashfile(f, tail_hash, FSYNC_COMPONENT_PACK, 0);
1307                 hashcpy(read_hash, pack_hash);
1308                 fixup_pack_header_footer(output_fd, pack_hash,
1309                                          curr_pack, nr_objects,
1310                                          read_hash, consumed_bytes-the_hash_algo->rawsz);
1311                 if (!hasheq(read_hash, tail_hash))
1312                         die(_("Unexpected tail checksum for %s "
1313                               "(disk corruption?)"), curr_pack);
1314         }
1315         if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1316                 die(Q_("pack has %d unresolved delta",
1317                        "pack has %d unresolved deltas",
1318                        nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1319                     nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1320 }
1321
1322 static int write_compressed(struct hashfile *f, void *in, unsigned int size)
1323 {
1324         git_zstream stream;
1325         int status;
1326         unsigned char outbuf[4096];
1327
1328         git_deflate_init(&stream, zlib_compression_level);
1329         stream.next_in = in;
1330         stream.avail_in = size;
1331
1332         do {
1333                 stream.next_out = outbuf;
1334                 stream.avail_out = sizeof(outbuf);
1335                 status = git_deflate(&stream, Z_FINISH);
1336                 hashwrite(f, outbuf, sizeof(outbuf) - stream.avail_out);
1337         } while (status == Z_OK);
1338
1339         if (status != Z_STREAM_END)
1340                 die(_("unable to deflate appended object (%d)"), status);
1341         size = stream.total_out;
1342         git_deflate_end(&stream);
1343         return size;
1344 }
1345
1346 static struct object_entry *append_obj_to_pack(struct hashfile *f,
1347                                const unsigned char *sha1, void *buf,
1348                                unsigned long size, enum object_type type)
1349 {
1350         struct object_entry *obj = &objects[nr_objects++];
1351         unsigned char header[10];
1352         unsigned long s = size;
1353         int n = 0;
1354         unsigned char c = (type << 4) | (s & 15);
1355         s >>= 4;
1356         while (s) {
1357                 header[n++] = c | 0x80;
1358                 c = s & 0x7f;
1359                 s >>= 7;
1360         }
1361         header[n++] = c;
1362         crc32_begin(f);
1363         hashwrite(f, header, n);
1364         obj[0].size = size;
1365         obj[0].hdr_size = n;
1366         obj[0].type = type;
1367         obj[0].real_type = type;
1368         obj[1].idx.offset = obj[0].idx.offset + n;
1369         obj[1].idx.offset += write_compressed(f, buf, size);
1370         obj[0].idx.crc32 = crc32_end(f);
1371         hashflush(f);
1372         oidread(&obj->idx.oid, sha1);
1373         return obj;
1374 }
1375
1376 static int delta_pos_compare(const void *_a, const void *_b)
1377 {
1378         struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1379         struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1380         return a->obj_no - b->obj_no;
1381 }
1382
1383 static void fix_unresolved_deltas(struct hashfile *f)
1384 {
1385         struct ref_delta_entry **sorted_by_pos;
1386         int i;
1387
1388         /*
1389          * Since many unresolved deltas may well be themselves base objects
1390          * for more unresolved deltas, we really want to include the
1391          * smallest number of base objects that would cover as much delta
1392          * as possible by picking the
1393          * trunc deltas first, allowing for other deltas to resolve without
1394          * additional base objects.  Since most base objects are to be found
1395          * before deltas depending on them, a good heuristic is to start
1396          * resolving deltas in the same order as their position in the pack.
1397          */
1398         ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1399         for (i = 0; i < nr_ref_deltas; i++)
1400                 sorted_by_pos[i] = &ref_deltas[i];
1401         QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1402
1403         if (repo_has_promisor_remote(the_repository)) {
1404                 /*
1405                  * Prefetch the delta bases.
1406                  */
1407                 struct oid_array to_fetch = OID_ARRAY_INIT;
1408                 for (i = 0; i < nr_ref_deltas; i++) {
1409                         struct ref_delta_entry *d = sorted_by_pos[i];
1410                         if (!oid_object_info_extended(the_repository, &d->oid,
1411                                                       NULL,
1412                                                       OBJECT_INFO_FOR_PREFETCH))
1413                                 continue;
1414                         oid_array_append(&to_fetch, &d->oid);
1415                 }
1416                 promisor_remote_get_direct(the_repository,
1417                                            to_fetch.oid, to_fetch.nr);
1418                 oid_array_clear(&to_fetch);
1419         }
1420
1421         for (i = 0; i < nr_ref_deltas; i++) {
1422                 struct ref_delta_entry *d = sorted_by_pos[i];
1423                 enum object_type type;
1424                 void *data;
1425                 unsigned long size;
1426
1427                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1428                         continue;
1429                 data = repo_read_object_file(the_repository, &d->oid, &type,
1430                                              &size);
1431                 if (!data)
1432                         continue;
1433
1434                 if (check_object_signature(the_repository, &d->oid, data, size,
1435                                            type) < 0)
1436                         die(_("local object %s is corrupt"), oid_to_hex(&d->oid));
1437
1438                 /*
1439                  * Add this as an object to the objects array and call
1440                  * threaded_second_pass() (which will pick up the added
1441                  * object).
1442                  */
1443                 append_obj_to_pack(f, d->oid.hash, data, size, type);
1444                 free(data);
1445                 threaded_second_pass(NULL);
1446
1447                 display_progress(progress, nr_resolved_deltas);
1448         }
1449         free(sorted_by_pos);
1450 }
1451
1452 static const char *derive_filename(const char *pack_name, const char *strip,
1453                                    const char *suffix, struct strbuf *buf)
1454 {
1455         size_t len;
1456         if (!strip_suffix(pack_name, strip, &len) || !len ||
1457             pack_name[len - 1] != '.')
1458                 die(_("packfile name '%s' does not end with '.%s'"),
1459                     pack_name, strip);
1460         strbuf_add(buf, pack_name, len);
1461         strbuf_addstr(buf, suffix);
1462         return buf->buf;
1463 }
1464
1465 static void write_special_file(const char *suffix, const char *msg,
1466                                const char *pack_name, const unsigned char *hash,
1467                                const char **report)
1468 {
1469         struct strbuf name_buf = STRBUF_INIT;
1470         const char *filename;
1471         int fd;
1472         int msg_len = strlen(msg);
1473
1474         if (pack_name)
1475                 filename = derive_filename(pack_name, "pack", suffix, &name_buf);
1476         else
1477                 filename = odb_pack_name(&name_buf, hash, suffix);
1478
1479         fd = odb_pack_keep(filename);
1480         if (fd < 0) {
1481                 if (errno != EEXIST)
1482                         die_errno(_("cannot write %s file '%s'"),
1483                                   suffix, filename);
1484         } else {
1485                 if (msg_len > 0) {
1486                         write_or_die(fd, msg, msg_len);
1487                         write_or_die(fd, "\n", 1);
1488                 }
1489                 if (close(fd) != 0)
1490                         die_errno(_("cannot close written %s file '%s'"),
1491                                   suffix, filename);
1492                 if (report)
1493                         *report = suffix;
1494         }
1495         strbuf_release(&name_buf);
1496 }
1497
1498 static void rename_tmp_packfile(const char **final_name,
1499                                 const char *curr_name,
1500                                 struct strbuf *name, unsigned char *hash,
1501                                 const char *ext, int make_read_only_if_same)
1502 {
1503         if (*final_name != curr_name) {
1504                 if (!*final_name)
1505                         *final_name = odb_pack_name(name, hash, ext);
1506                 if (finalize_object_file(curr_name, *final_name))
1507                         die(_("unable to rename temporary '*.%s' file to '%s'"),
1508                             ext, *final_name);
1509         } else if (make_read_only_if_same) {
1510                 chmod(*final_name, 0444);
1511         }
1512 }
1513
1514 static void final(const char *final_pack_name, const char *curr_pack_name,
1515                   const char *final_index_name, const char *curr_index_name,
1516                   const char *final_rev_index_name, const char *curr_rev_index_name,
1517                   const char *keep_msg, const char *promisor_msg,
1518                   unsigned char *hash)
1519 {
1520         const char *report = "pack";
1521         struct strbuf pack_name = STRBUF_INIT;
1522         struct strbuf index_name = STRBUF_INIT;
1523         struct strbuf rev_index_name = STRBUF_INIT;
1524         int err;
1525
1526         if (!from_stdin) {
1527                 close(input_fd);
1528         } else {
1529                 fsync_component_or_die(FSYNC_COMPONENT_PACK, output_fd, curr_pack_name);
1530                 err = close(output_fd);
1531                 if (err)
1532                         die_errno(_("error while closing pack file"));
1533         }
1534
1535         if (keep_msg)
1536                 write_special_file("keep", keep_msg, final_pack_name, hash,
1537                                    &report);
1538         if (promisor_msg)
1539                 write_special_file("promisor", promisor_msg, final_pack_name,
1540                                    hash, NULL);
1541
1542         rename_tmp_packfile(&final_pack_name, curr_pack_name, &pack_name,
1543                             hash, "pack", from_stdin);
1544         if (curr_rev_index_name)
1545                 rename_tmp_packfile(&final_rev_index_name, curr_rev_index_name,
1546                                     &rev_index_name, hash, "rev", 1);
1547         rename_tmp_packfile(&final_index_name, curr_index_name, &index_name,
1548                             hash, "idx", 1);
1549
1550         if (do_fsck_object) {
1551                 struct packed_git *p;
1552                 p = add_packed_git(final_index_name, strlen(final_index_name), 0);
1553                 if (p)
1554                         install_packed_git(the_repository, p);
1555         }
1556
1557         if (!from_stdin) {
1558                 printf("%s\n", hash_to_hex(hash));
1559         } else {
1560                 struct strbuf buf = STRBUF_INIT;
1561
1562                 strbuf_addf(&buf, "%s\t%s\n", report, hash_to_hex(hash));
1563                 write_or_die(1, buf.buf, buf.len);
1564                 strbuf_release(&buf);
1565
1566                 /*
1567                  * Let's just mimic git-unpack-objects here and write
1568                  * the last part of the input buffer to stdout.
1569                  */
1570                 while (input_len) {
1571                         err = xwrite(1, input_buffer + input_offset, input_len);
1572                         if (err <= 0)
1573                                 break;
1574                         input_len -= err;
1575                         input_offset += err;
1576                 }
1577         }
1578
1579         strbuf_release(&rev_index_name);
1580         strbuf_release(&index_name);
1581         strbuf_release(&pack_name);
1582 }
1583
1584 static int git_index_pack_config(const char *k, const char *v, void *cb)
1585 {
1586         struct pack_idx_option *opts = cb;
1587
1588         if (!strcmp(k, "pack.indexversion")) {
1589                 opts->version = git_config_int(k, v);
1590                 if (opts->version > 2)
1591                         die(_("bad pack.indexVersion=%"PRIu32), opts->version);
1592                 return 0;
1593         }
1594         if (!strcmp(k, "pack.threads")) {
1595                 nr_threads = git_config_int(k, v);
1596                 if (nr_threads < 0)
1597                         die(_("invalid number of threads specified (%d)"),
1598                             nr_threads);
1599                 if (!HAVE_THREADS && nr_threads != 1) {
1600                         warning(_("no threads support, ignoring %s"), k);
1601                         nr_threads = 1;
1602                 }
1603                 return 0;
1604         }
1605         if (!strcmp(k, "pack.writereverseindex")) {
1606                 if (git_config_bool(k, v))
1607                         opts->flags |= WRITE_REV;
1608                 else
1609                         opts->flags &= ~WRITE_REV;
1610         }
1611         return git_default_config(k, v, cb);
1612 }
1613
1614 static int cmp_uint32(const void *a_, const void *b_)
1615 {
1616         uint32_t a = *((uint32_t *)a_);
1617         uint32_t b = *((uint32_t *)b_);
1618
1619         return (a < b) ? -1 : (a != b);
1620 }
1621
1622 static void read_v2_anomalous_offsets(struct packed_git *p,
1623                                       struct pack_idx_option *opts)
1624 {
1625         const uint32_t *idx1, *idx2;
1626         uint32_t i;
1627
1628         /* The address of the 4-byte offset table */
1629         idx1 = (((const uint32_t *)((const uint8_t *)p->index_data + p->crc_offset))
1630                 + (size_t)p->num_objects /* CRC32 table */
1631                 );
1632
1633         /* The address of the 8-byte offset table */
1634         idx2 = idx1 + p->num_objects;
1635
1636         for (i = 0; i < p->num_objects; i++) {
1637                 uint32_t off = ntohl(idx1[i]);
1638                 if (!(off & 0x80000000))
1639                         continue;
1640                 off = off & 0x7fffffff;
1641                 check_pack_index_ptr(p, &idx2[off * 2]);
1642                 if (idx2[off * 2])
1643                         continue;
1644                 /*
1645                  * The real offset is ntohl(idx2[off * 2]) in high 4
1646                  * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1647                  * octets.  But idx2[off * 2] is Zero!!!
1648                  */
1649                 ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1650                 opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1651         }
1652
1653         QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1654 }
1655
1656 static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1657 {
1658         struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1659
1660         if (!p)
1661                 die(_("Cannot open existing pack file '%s'"), pack_name);
1662         if (open_pack_index(p))
1663                 die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1664
1665         /* Read the attributes from the existing idx file */
1666         opts->version = p->index_version;
1667
1668         if (opts->version == 2)
1669                 read_v2_anomalous_offsets(p, opts);
1670
1671         /*
1672          * Get rid of the idx file as we do not need it anymore.
1673          * NEEDSWORK: extract this bit from free_pack_by_name() in
1674          * object-file.c, perhaps?  It shouldn't matter very much as we
1675          * know we haven't installed this pack (hence we never have
1676          * read anything from it).
1677          */
1678         close_pack_index(p);
1679         free(p);
1680 }
1681
1682 static void show_pack_info(int stat_only)
1683 {
1684         int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1685         unsigned long *chain_histogram = NULL;
1686
1687         if (deepest_delta)
1688                 CALLOC_ARRAY(chain_histogram, deepest_delta);
1689
1690         for (i = 0; i < nr_objects; i++) {
1691                 struct object_entry *obj = &objects[i];
1692
1693                 if (is_delta_type(obj->type))
1694                         chain_histogram[obj_stat[i].delta_depth - 1]++;
1695                 if (stat_only)
1696                         continue;
1697                 printf("%s %-6s %"PRIuMAX" %"PRIuMAX" %"PRIuMAX,
1698                        oid_to_hex(&obj->idx.oid),
1699                        type_name(obj->real_type), (uintmax_t)obj->size,
1700                        (uintmax_t)(obj[1].idx.offset - obj->idx.offset),
1701                        (uintmax_t)obj->idx.offset);
1702                 if (is_delta_type(obj->type)) {
1703                         struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1704                         printf(" %u %s", obj_stat[i].delta_depth,
1705                                oid_to_hex(&bobj->idx.oid));
1706                 }
1707                 putchar('\n');
1708         }
1709
1710         if (baseobjects)
1711                 printf_ln(Q_("non delta: %d object",
1712                              "non delta: %d objects",
1713                              baseobjects),
1714                           baseobjects);
1715         for (i = 0; i < deepest_delta; i++) {
1716                 if (!chain_histogram[i])
1717                         continue;
1718                 printf_ln(Q_("chain length = %d: %lu object",
1719                              "chain length = %d: %lu objects",
1720                              chain_histogram[i]),
1721                           i + 1,
1722                           chain_histogram[i]);
1723         }
1724         free(chain_histogram);
1725 }
1726
1727 int cmd_index_pack(int argc, const char **argv, const char *prefix)
1728 {
1729         int i, fix_thin_pack = 0, verify = 0, stat_only = 0, rev_index;
1730         const char *curr_index;
1731         const char *curr_rev_index = NULL;
1732         const char *index_name = NULL, *pack_name = NULL, *rev_index_name = NULL;
1733         const char *keep_msg = NULL;
1734         const char *promisor_msg = NULL;
1735         struct strbuf index_name_buf = STRBUF_INIT;
1736         struct strbuf rev_index_name_buf = STRBUF_INIT;
1737         struct pack_idx_entry **idx_objects;
1738         struct pack_idx_option opts;
1739         unsigned char pack_hash[GIT_MAX_RAWSZ];
1740         unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1741         int report_end_of_input = 0;
1742         int hash_algo = 0;
1743
1744         /*
1745          * index-pack never needs to fetch missing objects except when
1746          * REF_DELTA bases are missing (which are explicitly handled). It only
1747          * accesses the repo to do hash collision checks and to check which
1748          * REF_DELTA bases need to be fetched.
1749          */
1750         fetch_if_missing = 0;
1751
1752         if (argc == 2 && !strcmp(argv[1], "-h"))
1753                 usage(index_pack_usage);
1754
1755         disable_replace_refs();
1756         fsck_options.walk = mark_link;
1757
1758         reset_pack_idx_option(&opts);
1759         opts.flags |= WRITE_REV;
1760         git_config(git_index_pack_config, &opts);
1761         if (prefix && chdir(prefix))
1762                 die(_("Cannot come back to cwd"));
1763
1764         if (git_env_bool(GIT_TEST_NO_WRITE_REV_INDEX, 0))
1765                 rev_index = 0;
1766         else
1767                 rev_index = !!(opts.flags & (WRITE_REV_VERIFY | WRITE_REV));
1768
1769         for (i = 1; i < argc; i++) {
1770                 const char *arg = argv[i];
1771
1772                 if (*arg == '-') {
1773                         if (!strcmp(arg, "--stdin")) {
1774                                 from_stdin = 1;
1775                         } else if (!strcmp(arg, "--fix-thin")) {
1776                                 fix_thin_pack = 1;
1777                         } else if (skip_to_optional_arg(arg, "--strict", &arg)) {
1778                                 strict = 1;
1779                                 do_fsck_object = 1;
1780                                 fsck_set_msg_types(&fsck_options, arg);
1781                         } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1782                                 strict = 1;
1783                                 check_self_contained_and_connected = 1;
1784                         } else if (!strcmp(arg, "--fsck-objects")) {
1785                                 do_fsck_object = 1;
1786                         } else if (!strcmp(arg, "--verify")) {
1787                                 verify = 1;
1788                         } else if (!strcmp(arg, "--verify-stat")) {
1789                                 verify = 1;
1790                                 show_stat = 1;
1791                         } else if (!strcmp(arg, "--verify-stat-only")) {
1792                                 verify = 1;
1793                                 show_stat = 1;
1794                                 stat_only = 1;
1795                         } else if (skip_to_optional_arg(arg, "--keep", &keep_msg)) {
1796                                 ; /* nothing to do */
1797                         } else if (skip_to_optional_arg(arg, "--promisor", &promisor_msg)) {
1798                                 ; /* already parsed */
1799                         } else if (starts_with(arg, "--threads=")) {
1800                                 char *end;
1801                                 nr_threads = strtoul(arg+10, &end, 0);
1802                                 if (!arg[10] || *end || nr_threads < 0)
1803                                         usage(index_pack_usage);
1804                                 if (!HAVE_THREADS && nr_threads != 1) {
1805                                         warning(_("no threads support, ignoring %s"), arg);
1806                                         nr_threads = 1;
1807                                 }
1808                         } else if (starts_with(arg, "--pack_header=")) {
1809                                 struct pack_header *hdr;
1810                                 char *c;
1811
1812                                 hdr = (struct pack_header *)input_buffer;
1813                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
1814                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1815                                 if (*c != ',')
1816                                         die(_("bad %s"), arg);
1817                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1818                                 if (*c)
1819                                         die(_("bad %s"), arg);
1820                                 input_len = sizeof(*hdr);
1821                         } else if (!strcmp(arg, "-v")) {
1822                                 verbose = 1;
1823                         } else if (!strcmp(arg, "--progress-title")) {
1824                                 if (progress_title || (i+1) >= argc)
1825                                         usage(index_pack_usage);
1826                                 progress_title = argv[++i];
1827                         } else if (!strcmp(arg, "--show-resolving-progress")) {
1828                                 show_resolving_progress = 1;
1829                         } else if (!strcmp(arg, "--report-end-of-input")) {
1830                                 report_end_of_input = 1;
1831                         } else if (!strcmp(arg, "-o")) {
1832                                 if (index_name || (i+1) >= argc)
1833                                         usage(index_pack_usage);
1834                                 index_name = argv[++i];
1835                         } else if (starts_with(arg, "--index-version=")) {
1836                                 char *c;
1837                                 opts.version = strtoul(arg + 16, &c, 10);
1838                                 if (opts.version > 2)
1839                                         die(_("bad %s"), arg);
1840                                 if (*c == ',')
1841                                         opts.off32_limit = strtoul(c+1, &c, 0);
1842                                 if (*c || opts.off32_limit & 0x80000000)
1843                                         die(_("bad %s"), arg);
1844                         } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1845                                 max_input_size = strtoumax(arg, NULL, 10);
1846                         } else if (skip_prefix(arg, "--object-format=", &arg)) {
1847                                 hash_algo = hash_algo_by_name(arg);
1848                                 if (hash_algo == GIT_HASH_UNKNOWN)
1849                                         die(_("unknown hash algorithm '%s'"), arg);
1850                                 repo_set_hash_algo(the_repository, hash_algo);
1851                         } else if (!strcmp(arg, "--rev-index")) {
1852                                 rev_index = 1;
1853                         } else if (!strcmp(arg, "--no-rev-index")) {
1854                                 rev_index = 0;
1855                         } else
1856                                 usage(index_pack_usage);
1857                         continue;
1858                 }
1859
1860                 if (pack_name)
1861                         usage(index_pack_usage);
1862                 pack_name = arg;
1863         }
1864
1865         if (!pack_name && !from_stdin)
1866                 usage(index_pack_usage);
1867         if (fix_thin_pack && !from_stdin)
1868                 die(_("the option '%s' requires '%s'"), "--fix-thin", "--stdin");
1869         if (from_stdin && !startup_info->have_repository)
1870                 die(_("--stdin requires a git repository"));
1871         if (from_stdin && hash_algo)
1872                 die(_("options '%s' and '%s' cannot be used together"), "--object-format", "--stdin");
1873         if (!index_name && pack_name)
1874                 index_name = derive_filename(pack_name, "pack", "idx", &index_name_buf);
1875
1876         opts.flags &= ~(WRITE_REV | WRITE_REV_VERIFY);
1877         if (rev_index) {
1878                 opts.flags |= verify ? WRITE_REV_VERIFY : WRITE_REV;
1879                 if (index_name)
1880                         rev_index_name = derive_filename(index_name,
1881                                                          "idx", "rev",
1882                                                          &rev_index_name_buf);
1883         }
1884
1885         if (verify) {
1886                 if (!index_name)
1887                         die(_("--verify with no packfile name given"));
1888                 read_idx_option(&opts, index_name);
1889                 opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1890         }
1891         if (strict)
1892                 opts.flags |= WRITE_IDX_STRICT;
1893
1894         if (HAVE_THREADS && !nr_threads) {
1895                 nr_threads = online_cpus();
1896                 /*
1897                  * Experiments show that going above 20 threads doesn't help,
1898                  * no matter how many cores you have. Below that, we tend to
1899                  * max at half the number of online_cpus(), presumably because
1900                  * half of those are hyperthreads rather than full cores. We'll
1901                  * never reduce the level below "3", though, to match a
1902                  * historical value that nobody complained about.
1903                  */
1904                 if (nr_threads < 4)
1905                         ; /* too few cores to consider capping */
1906                 else if (nr_threads < 6)
1907                         nr_threads = 3; /* historic cap */
1908                 else if (nr_threads < 40)
1909                         nr_threads /= 2;
1910                 else
1911                         nr_threads = 20; /* hard cap */
1912         }
1913
1914         curr_pack = open_pack_file(pack_name);
1915         parse_pack_header();
1916         CALLOC_ARRAY(objects, st_add(nr_objects, 1));
1917         if (show_stat)
1918                 CALLOC_ARRAY(obj_stat, st_add(nr_objects, 1));
1919         CALLOC_ARRAY(ofs_deltas, nr_objects);
1920         parse_pack_objects(pack_hash);
1921         if (report_end_of_input)
1922                 write_in_full(2, "\0", 1);
1923         resolve_deltas();
1924         conclude_pack(fix_thin_pack, curr_pack, pack_hash);
1925         free(ofs_deltas);
1926         free(ref_deltas);
1927         if (strict)
1928                 foreign_nr = check_objects();
1929
1930         if (show_stat)
1931                 show_pack_info(stat_only);
1932
1933         ALLOC_ARRAY(idx_objects, nr_objects);
1934         for (i = 0; i < nr_objects; i++)
1935                 idx_objects[i] = &objects[i].idx;
1936         curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_hash);
1937         if (rev_index)
1938                 curr_rev_index = write_rev_file(rev_index_name, idx_objects,
1939                                                 nr_objects, pack_hash,
1940                                                 opts.flags);
1941         free(idx_objects);
1942
1943         if (!verify)
1944                 final(pack_name, curr_pack,
1945                       index_name, curr_index,
1946                       rev_index_name, curr_rev_index,
1947                       keep_msg, promisor_msg,
1948                       pack_hash);
1949         else
1950                 close(input_fd);
1951
1952         if (do_fsck_object && fsck_finish(&fsck_options))
1953                 die(_("fsck error in pack objects"));
1954
1955         free(opts.anomaly);
1956         free(objects);
1957         strbuf_release(&index_name_buf);
1958         strbuf_release(&rev_index_name_buf);
1959         if (!pack_name)
1960                 free((void *) curr_pack);
1961         if (!index_name)
1962                 free((void *) curr_index);
1963         if (!rev_index_name)
1964                 free((void *) curr_rev_index);
1965
1966         /*
1967          * Let the caller know this pack is not self contained
1968          */
1969         if (check_self_contained_and_connected && foreign_nr)
1970                 return 1;
1971
1972         return 0;
1973 }