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