git.oblomov.eu Git - git/blob - midx.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "csum-file.h"
   4 #include "dir.h"
   5 #include "lockfile.h"
   6 #include "packfile.h"
   7 #include "object-store.h"
   8 #include "hash-lookup.h"
   9 #include "midx.h"
  10 #include "progress.h"
  11 #include "trace2.h"
  12 #include "run-command.h"
  13 #include "repository.h"
  14 #include "chunk-format.h"
  15
  16 #define MIDX_SIGNATURE 0x4d494458 /* "MIDX" */
  17 #define MIDX_VERSION 1
  18 #define MIDX_BYTE_FILE_VERSION 4
  19 #define MIDX_BYTE_HASH_VERSION 5
  20 #define MIDX_BYTE_NUM_CHUNKS 6
  21 #define MIDX_BYTE_NUM_PACKS 8
  22 #define MIDX_HEADER_SIZE 12
  23 #define MIDX_MIN_SIZE (MIDX_HEADER_SIZE + the_hash_algo->rawsz)
  24
  25 #define MIDX_CHUNK_ALIGNMENT 4
  26 #define MIDX_CHUNKID_PACKNAMES 0x504e414d /* "PNAM" */
  27 #define MIDX_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
  28 #define MIDX_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
  29 #define MIDX_CHUNKID_OBJECTOFFSETS 0x4f4f4646 /* "OOFF" */
  30 #define MIDX_CHUNKID_LARGEOFFSETS 0x4c4f4646 /* "LOFF" */
  31 #define MIDX_CHUNK_FANOUT_SIZE (sizeof(uint32_t) * 256)
  32 #define MIDX_CHUNK_OFFSET_WIDTH (2 * sizeof(uint32_t))
  33 #define MIDX_CHUNK_LARGE_OFFSET_WIDTH (sizeof(uint64_t))
  34 #define MIDX_LARGE_OFFSET_NEEDED 0x80000000
  35
  36 #define PACK_EXPIRED UINT_MAX
  37
  38 static uint8_t oid_version(void)
  39 {
  40         switch (hash_algo_by_ptr(the_hash_algo)) {
  41         case GIT_HASH_SHA1:
  42                 return 1;
  43         case GIT_HASH_SHA256:
  44                 return 2;
  45         default:
  46                 die(_("invalid hash version"));
  47         }
  48 }
  49
  50 static char *get_midx_filename(const char *object_dir)
  51 {
  52         return xstrfmt("%s/pack/multi-pack-index", object_dir);
  53 }
  54
  55 static int midx_read_oid_fanout(const unsigned char *chunk_start,
  56                                 size_t chunk_size, void *data)
  57 {
  58         struct multi_pack_index *m = data;
  59         m->chunk_oid_fanout = (uint32_t *)chunk_start;
  60
  61         if (chunk_size != 4 * 256) {
  62                 error(_("multi-pack-index OID fanout is of the wrong size"));
  63                 return 1;
  64         }
  65         return 0;
  66 }
  67
  68 struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local)
  69 {
  70         struct multi_pack_index *m = NULL;
  71         int fd;
  72         struct stat st;
  73         size_t midx_size;
  74         void *midx_map = NULL;
  75         uint32_t hash_version;
  76         char *midx_name = get_midx_filename(object_dir);
  77         uint32_t i;
  78         const char *cur_pack_name;
  79         struct chunkfile *cf = NULL;
  80
  81         fd = git_open(midx_name);
  82
  83         if (fd < 0)
  84                 goto cleanup_fail;
  85         if (fstat(fd, &st)) {
  86                 error_errno(_("failed to read %s"), midx_name);
  87                 goto cleanup_fail;
  88         }
  89
  90         midx_size = xsize_t(st.st_size);
  91
  92         if (midx_size < MIDX_MIN_SIZE) {
  93                 error(_("multi-pack-index file %s is too small"), midx_name);
  94                 goto cleanup_fail;
  95         }
  96
  97         FREE_AND_NULL(midx_name);
  98
  99         midx_map = xmmap(NULL, midx_size, PROT_READ, MAP_PRIVATE, fd, 0);
 100         close(fd);
 101
 102         FLEX_ALLOC_STR(m, object_dir, object_dir);
 103         m->data = midx_map;
 104         m->data_len = midx_size;
 105         m->local = local;
 106
 107         m->signature = get_be32(m->data);
 108         if (m->signature != MIDX_SIGNATURE)
 109                 die(_("multi-pack-index signature 0x%08x does not match signature 0x%08x"),
 110                       m->signature, MIDX_SIGNATURE);
 111
 112         m->version = m->data[MIDX_BYTE_FILE_VERSION];
 113         if (m->version != MIDX_VERSION)
 114                 die(_("multi-pack-index version %d not recognized"),
 115                       m->version);
 116
 117         hash_version = m->data[MIDX_BYTE_HASH_VERSION];
 118         if (hash_version != oid_version()) {
 119                 error(_("multi-pack-index hash version %u does not match version %u"),
 120                       hash_version, oid_version());
 121                 goto cleanup_fail;
 122         }
 123         m->hash_len = the_hash_algo->rawsz;
 124
 125         m->num_chunks = m->data[MIDX_BYTE_NUM_CHUNKS];
 126
 127         m->num_packs = get_be32(m->data + MIDX_BYTE_NUM_PACKS);
 128
 129         cf = init_chunkfile(NULL);
 130
 131         if (read_table_of_contents(cf, m->data, midx_size,
 132                                    MIDX_HEADER_SIZE, m->num_chunks))
 133                 goto cleanup_fail;
 134
 135         if (pair_chunk(cf, MIDX_CHUNKID_PACKNAMES, &m->chunk_pack_names) == CHUNK_NOT_FOUND)
 136                 die(_("multi-pack-index missing required pack-name chunk"));
 137         if (read_chunk(cf, MIDX_CHUNKID_OIDFANOUT, midx_read_oid_fanout, m) == CHUNK_NOT_FOUND)
 138                 die(_("multi-pack-index missing required OID fanout chunk"));
 139         if (pair_chunk(cf, MIDX_CHUNKID_OIDLOOKUP, &m->chunk_oid_lookup) == CHUNK_NOT_FOUND)
 140                 die(_("multi-pack-index missing required OID lookup chunk"));
 141         if (pair_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, &m->chunk_object_offsets) == CHUNK_NOT_FOUND)
 142                 die(_("multi-pack-index missing required object offsets chunk"));
 143
 144         pair_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS, &m->chunk_large_offsets);
 145
 146         m->num_objects = ntohl(m->chunk_oid_fanout[255]);
 147
 148         m->pack_names = xcalloc(m->num_packs, sizeof(*m->pack_names));
 149         m->packs = xcalloc(m->num_packs, sizeof(*m->packs));
 150
 151         cur_pack_name = (const char *)m->chunk_pack_names;
 152         for (i = 0; i < m->num_packs; i++) {
 153                 m->pack_names[i] = cur_pack_name;
 154
 155                 cur_pack_name += strlen(cur_pack_name) + 1;
 156
 157                 if (i && strcmp(m->pack_names[i], m->pack_names[i - 1]) <= 0)
 158                         die(_("multi-pack-index pack names out of order: '%s' before '%s'"),
 159                               m->pack_names[i - 1],
 160                               m->pack_names[i]);
 161         }
 162
 163         trace2_data_intmax("midx", the_repository, "load/num_packs", m->num_packs);
 164         trace2_data_intmax("midx", the_repository, "load/num_objects", m->num_objects);
 165
 166         return m;
 167
 168 cleanup_fail:
 169         free(m);
 170         free(midx_name);
 171         free(cf);
 172         if (midx_map)
 173                 munmap(midx_map, midx_size);
 174         if (0 <= fd)
 175                 close(fd);
 176         return NULL;
 177 }
 178
 179 void close_midx(struct multi_pack_index *m)
 180 {
 181         uint32_t i;
 182
 183         if (!m)
 184                 return;
 185
 186         munmap((unsigned char *)m->data, m->data_len);
 187
 188         for (i = 0; i < m->num_packs; i++) {
 189                 if (m->packs[i])
 190                         m->packs[i]->multi_pack_index = 0;
 191         }
 192         FREE_AND_NULL(m->packs);
 193         FREE_AND_NULL(m->pack_names);
 194 }
 195
 196 int prepare_midx_pack(struct repository *r, struct multi_pack_index *m, uint32_t pack_int_id)
 197 {
 198         struct strbuf pack_name = STRBUF_INIT;
 199         struct packed_git *p;
 200
 201         if (pack_int_id >= m->num_packs)
 202                 die(_("bad pack-int-id: %u (%u total packs)"),
 203                     pack_int_id, m->num_packs);
 204
 205         if (m->packs[pack_int_id])
 206                 return 0;
 207
 208         strbuf_addf(&pack_name, "%s/pack/%s", m->object_dir,
 209                     m->pack_names[pack_int_id]);
 210
 211         p = add_packed_git(pack_name.buf, pack_name.len, m->local);
 212         strbuf_release(&pack_name);
 213
 214         if (!p)
 215                 return 1;
 216
 217         p->multi_pack_index = 1;
 218         m->packs[pack_int_id] = p;
 219         install_packed_git(r, p);
 220         list_add_tail(&p->mru, &r->objects->packed_git_mru);
 221
 222         return 0;
 223 }
 224
 225 int bsearch_midx(const struct object_id *oid, struct multi_pack_index *m, uint32_t *result)
 226 {
 227         return bsearch_hash(oid->hash, m->chunk_oid_fanout, m->chunk_oid_lookup,
 228                             the_hash_algo->rawsz, result);
 229 }
 230
 231 struct object_id *nth_midxed_object_oid(struct object_id *oid,
 232                                         struct multi_pack_index *m,
 233                                         uint32_t n)
 234 {
 235         if (n >= m->num_objects)
 236                 return NULL;
 237
 238         hashcpy(oid->hash, m->chunk_oid_lookup + m->hash_len * n);
 239         return oid;
 240 }
 241
 242 static off_t nth_midxed_offset(struct multi_pack_index *m, uint32_t pos)
 243 {
 244         const unsigned char *offset_data;
 245         uint32_t offset32;
 246
 247         offset_data = m->chunk_object_offsets + (off_t)pos * MIDX_CHUNK_OFFSET_WIDTH;
 248         offset32 = get_be32(offset_data + sizeof(uint32_t));
 249
 250         if (m->chunk_large_offsets && offset32 & MIDX_LARGE_OFFSET_NEEDED) {
 251                 if (sizeof(off_t) < sizeof(uint64_t))
 252                         die(_("multi-pack-index stores a 64-bit offset, but off_t is too small"));
 253
 254                 offset32 ^= MIDX_LARGE_OFFSET_NEEDED;
 255                 return get_be64(m->chunk_large_offsets + sizeof(uint64_t) * offset32);
 256         }
 257
 258         return offset32;
 259 }
 260
 261 static uint32_t nth_midxed_pack_int_id(struct multi_pack_index *m, uint32_t pos)
 262 {
 263         return get_be32(m->chunk_object_offsets +
 264                         (off_t)pos * MIDX_CHUNK_OFFSET_WIDTH);
 265 }
 266
 267 static int nth_midxed_pack_entry(struct repository *r,
 268                                  struct multi_pack_index *m,
 269                                  struct pack_entry *e,
 270                                  uint32_t pos)
 271 {
 272         uint32_t pack_int_id;
 273         struct packed_git *p;
 274
 275         if (pos >= m->num_objects)
 276                 return 0;
 277
 278         pack_int_id = nth_midxed_pack_int_id(m, pos);
 279
 280         if (prepare_midx_pack(r, m, pack_int_id))
 281                 return 0;
 282         p = m->packs[pack_int_id];
 283
 284         /*
 285         * We are about to tell the caller where they can locate the
 286         * requested object.  We better make sure the packfile is
 287         * still here and can be accessed before supplying that
 288         * answer, as it may have been deleted since the MIDX was
 289         * loaded!
 290         */
 291         if (!is_pack_valid(p))
 292                 return 0;
 293
 294         if (p->num_bad_objects) {
 295                 uint32_t i;
 296                 struct object_id oid;
 297                 nth_midxed_object_oid(&oid, m, pos);
 298                 for (i = 0; i < p->num_bad_objects; i++)
 299                         if (hasheq(oid.hash,
 300                                    p->bad_object_sha1 + the_hash_algo->rawsz * i))
 301                                 return 0;
 302         }
 303
 304         e->offset = nth_midxed_offset(m, pos);
 305         e->p = p;
 306
 307         return 1;
 308 }
 309
 310 int fill_midx_entry(struct repository * r,
 311                     const struct object_id *oid,
 312                     struct pack_entry *e,
 313                     struct multi_pack_index *m)
 314 {
 315         uint32_t pos;
 316
 317         if (!bsearch_midx(oid, m, &pos))
 318                 return 0;
 319
 320         return nth_midxed_pack_entry(r, m, e, pos);
 321 }
 322
 323 /* Match "foo.idx" against either "foo.pack" _or_ "foo.idx". */
 324 static int cmp_idx_or_pack_name(const char *idx_or_pack_name,
 325                                 const char *idx_name)
 326 {
 327         /* Skip past any initial matching prefix. */
 328         while (*idx_name && *idx_name == *idx_or_pack_name) {
 329                 idx_name++;
 330                 idx_or_pack_name++;
 331         }
 332
 333         /*
 334          * If we didn't match completely, we may have matched "pack-1234." and
 335          * be left with "idx" and "pack" respectively, which is also OK. We do
 336          * not have to check for "idx" and "idx", because that would have been
 337          * a complete match (and in that case these strcmps will be false, but
 338          * we'll correctly return 0 from the final strcmp() below.
 339          *
 340          * Technically this matches "fooidx" and "foopack", but we'd never have
 341          * such names in the first place.
 342          */
 343         if (!strcmp(idx_name, "idx") && !strcmp(idx_or_pack_name, "pack"))
 344                 return 0;
 345
 346         /*
 347          * This not only checks for a complete match, but also orders based on
 348          * the first non-identical character, which means our ordering will
 349          * match a raw strcmp(). That makes it OK to use this to binary search
 350          * a naively-sorted list.
 351          */
 352         return strcmp(idx_or_pack_name, idx_name);
 353 }
 354
 355 int midx_contains_pack(struct multi_pack_index *m, const char *idx_or_pack_name)
 356 {
 357         uint32_t first = 0, last = m->num_packs;
 358
 359         while (first < last) {
 360                 uint32_t mid = first + (last - first) / 2;
 361                 const char *current;
 362                 int cmp;
 363
 364                 current = m->pack_names[mid];
 365                 cmp = cmp_idx_or_pack_name(idx_or_pack_name, current);
 366                 if (!cmp)
 367                         return 1;
 368                 if (cmp > 0) {
 369                         first = mid + 1;
 370                         continue;
 371                 }
 372                 last = mid;
 373         }
 374
 375         return 0;
 376 }
 377
 378 int prepare_multi_pack_index_one(struct repository *r, const char *object_dir, int local)
 379 {
 380         struct multi_pack_index *m;
 381         struct multi_pack_index *m_search;
 382
 383         prepare_repo_settings(r);
 384         if (!r->settings.core_multi_pack_index)
 385                 return 0;
 386
 387         for (m_search = r->objects->multi_pack_index; m_search; m_search = m_search->next)
 388                 if (!strcmp(object_dir, m_search->object_dir))
 389                         return 1;
 390
 391         m = load_multi_pack_index(object_dir, local);
 392
 393         if (m) {
 394                 struct multi_pack_index *mp = r->objects->multi_pack_index;
 395                 if (mp) {
 396                         m->next = mp->next;
 397                         mp->next = m;
 398                 } else
 399                         r->objects->multi_pack_index = m;
 400                 return 1;
 401         }
 402
 403         return 0;
 404 }
 405
 406 static size_t write_midx_header(struct hashfile *f,
 407                                 unsigned char num_chunks,
 408                                 uint32_t num_packs)
 409 {
 410         hashwrite_be32(f, MIDX_SIGNATURE);
 411         hashwrite_u8(f, MIDX_VERSION);
 412         hashwrite_u8(f, oid_version());
 413         hashwrite_u8(f, num_chunks);
 414         hashwrite_u8(f, 0); /* unused */
 415         hashwrite_be32(f, num_packs);
 416
 417         return MIDX_HEADER_SIZE;
 418 }
 419
 420 struct pack_info {
 421         uint32_t orig_pack_int_id;
 422         char *pack_name;
 423         struct packed_git *p;
 424         unsigned expired : 1;
 425 };
 426
 427 static int pack_info_compare(const void *_a, const void *_b)
 428 {
 429         struct pack_info *a = (struct pack_info *)_a;
 430         struct pack_info *b = (struct pack_info *)_b;
 431         return strcmp(a->pack_name, b->pack_name);
 432 }
 433
 434 struct write_midx_context {
 435         struct pack_info *info;
 436         uint32_t nr;
 437         uint32_t alloc;
 438         struct multi_pack_index *m;
 439         struct progress *progress;
 440         unsigned pack_paths_checked;
 441
 442         struct pack_midx_entry *entries;
 443         uint32_t entries_nr;
 444
 445         uint32_t *pack_perm;
 446         unsigned large_offsets_needed:1;
 447         uint32_t num_large_offsets;
 448 };
 449
 450 static void add_pack_to_midx(const char *full_path, size_t full_path_len,
 451                              const char *file_name, void *data)
 452 {
 453         struct write_midx_context *ctx = data;
 454
 455         if (ends_with(file_name, ".idx")) {
 456                 display_progress(ctx->progress, ++ctx->pack_paths_checked);
 457                 if (ctx->m && midx_contains_pack(ctx->m, file_name))
 458                         return;
 459
 460                 ALLOC_GROW(ctx->info, ctx->nr + 1, ctx->alloc);
 461
 462                 ctx->info[ctx->nr].p = add_packed_git(full_path,
 463                                                       full_path_len,
 464                                                       0);
 465
 466                 if (!ctx->info[ctx->nr].p) {
 467                         warning(_("failed to add packfile '%s'"),
 468                                 full_path);
 469                         return;
 470                 }
 471
 472                 if (open_pack_index(ctx->info[ctx->nr].p)) {
 473                         warning(_("failed to open pack-index '%s'"),
 474                                 full_path);
 475                         close_pack(ctx->info[ctx->nr].p);
 476                         FREE_AND_NULL(ctx->info[ctx->nr].p);
 477                         return;
 478                 }
 479
 480                 ctx->info[ctx->nr].pack_name = xstrdup(file_name);
 481                 ctx->info[ctx->nr].orig_pack_int_id = ctx->nr;
 482                 ctx->info[ctx->nr].expired = 0;
 483                 ctx->nr++;
 484         }
 485 }
 486
 487 struct pack_midx_entry {
 488         struct object_id oid;
 489         uint32_t pack_int_id;
 490         time_t pack_mtime;
 491         uint64_t offset;
 492 };
 493
 494 static int midx_oid_compare(const void *_a, const void *_b)
 495 {
 496         const struct pack_midx_entry *a = (const struct pack_midx_entry *)_a;
 497         const struct pack_midx_entry *b = (const struct pack_midx_entry *)_b;
 498         int cmp = oidcmp(&a->oid, &b->oid);
 499
 500         if (cmp)
 501                 return cmp;
 502
 503         if (a->pack_mtime > b->pack_mtime)
 504                 return -1;
 505         else if (a->pack_mtime < b->pack_mtime)
 506                 return 1;
 507
 508         return a->pack_int_id - b->pack_int_id;
 509 }
 510
 511 static int nth_midxed_pack_midx_entry(struct multi_pack_index *m,
 512                                       struct pack_midx_entry *e,
 513                                       uint32_t pos)
 514 {
 515         if (pos >= m->num_objects)
 516                 return 1;
 517
 518         nth_midxed_object_oid(&e->oid, m, pos);
 519         e->pack_int_id = nth_midxed_pack_int_id(m, pos);
 520         e->offset = nth_midxed_offset(m, pos);
 521
 522         /* consider objects in midx to be from "old" packs */
 523         e->pack_mtime = 0;
 524         return 0;
 525 }
 526
 527 static void fill_pack_entry(uint32_t pack_int_id,
 528                             struct packed_git *p,
 529                             uint32_t cur_object,
 530                             struct pack_midx_entry *entry)
 531 {
 532         if (nth_packed_object_id(&entry->oid, p, cur_object) < 0)
 533                 die(_("failed to locate object %d in packfile"), cur_object);
 534
 535         entry->pack_int_id = pack_int_id;
 536         entry->pack_mtime = p->mtime;
 537
 538         entry->offset = nth_packed_object_offset(p, cur_object);
 539 }
 540
 541 /*
 542  * It is possible to artificially get into a state where there are many
 543  * duplicate copies of objects. That can create high memory pressure if
 544  * we are to create a list of all objects before de-duplication. To reduce
 545  * this memory pressure without a significant performance drop, automatically
 546  * group objects by the first byte of their object id. Use the IDX fanout
 547  * tables to group the data, copy to a local array, then sort.
 548  *
 549  * Copy only the de-duplicated entries (selected by most-recent modified time
 550  * of a packfile containing the object).
 551  */
 552 static struct pack_midx_entry *get_sorted_entries(struct multi_pack_index *m,
 553                                                   struct pack_info *info,
 554                                                   uint32_t nr_packs,
 555                                                   uint32_t *nr_objects)
 556 {
 557         uint32_t cur_fanout, cur_pack, cur_object;
 558         uint32_t alloc_fanout, alloc_objects, total_objects = 0;
 559         struct pack_midx_entry *entries_by_fanout = NULL;
 560         struct pack_midx_entry *deduplicated_entries = NULL;
 561         uint32_t start_pack = m ? m->num_packs : 0;
 562
 563         for (cur_pack = start_pack; cur_pack < nr_packs; cur_pack++)
 564                 total_objects += info[cur_pack].p->num_objects;
 565
 566         /*
 567          * As we de-duplicate by fanout value, we expect the fanout
 568          * slices to be evenly distributed, with some noise. Hence,
 569          * allocate slightly more than one 256th.
 570          */
 571         alloc_objects = alloc_fanout = total_objects > 3200 ? total_objects / 200 : 16;
 572
 573         ALLOC_ARRAY(entries_by_fanout, alloc_fanout);
 574         ALLOC_ARRAY(deduplicated_entries, alloc_objects);
 575         *nr_objects = 0;
 576
 577         for (cur_fanout = 0; cur_fanout < 256; cur_fanout++) {
 578                 uint32_t nr_fanout = 0;
 579
 580                 if (m) {
 581                         uint32_t start = 0, end;
 582
 583                         if (cur_fanout)
 584                                 start = ntohl(m->chunk_oid_fanout[cur_fanout - 1]);
 585                         end = ntohl(m->chunk_oid_fanout[cur_fanout]);
 586
 587                         for (cur_object = start; cur_object < end; cur_object++) {
 588                                 ALLOC_GROW(entries_by_fanout, nr_fanout + 1, alloc_fanout);
 589                                 nth_midxed_pack_midx_entry(m,
 590                                                            &entries_by_fanout[nr_fanout],
 591                                                            cur_object);
 592                                 nr_fanout++;
 593                         }
 594                 }
 595
 596                 for (cur_pack = start_pack; cur_pack < nr_packs; cur_pack++) {
 597                         uint32_t start = 0, end;
 598
 599                         if (cur_fanout)
 600                                 start = get_pack_fanout(info[cur_pack].p, cur_fanout - 1);
 601                         end = get_pack_fanout(info[cur_pack].p, cur_fanout);
 602
 603                         for (cur_object = start; cur_object < end; cur_object++) {
 604                                 ALLOC_GROW(entries_by_fanout, nr_fanout + 1, alloc_fanout);
 605                                 fill_pack_entry(cur_pack, info[cur_pack].p, cur_object, &entries_by_fanout[nr_fanout]);
 606                                 nr_fanout++;
 607                         }
 608                 }
 609
 610                 QSORT(entries_by_fanout, nr_fanout, midx_oid_compare);
 611
 612                 /*
 613                  * The batch is now sorted by OID and then mtime (descending).
 614                  * Take only the first duplicate.
 615                  */
 616                 for (cur_object = 0; cur_object < nr_fanout; cur_object++) {
 617                         if (cur_object && oideq(&entries_by_fanout[cur_object - 1].oid,
 618                                                 &entries_by_fanout[cur_object].oid))
 619                                 continue;
 620
 621                         ALLOC_GROW(deduplicated_entries, *nr_objects + 1, alloc_objects);
 622                         memcpy(&deduplicated_entries[*nr_objects],
 623                                &entries_by_fanout[cur_object],
 624                                sizeof(struct pack_midx_entry));
 625                         (*nr_objects)++;
 626                 }
 627         }
 628
 629         free(entries_by_fanout);
 630         return deduplicated_entries;
 631 }
 632
 633 static int write_midx_pack_names(struct hashfile *f, void *data)
 634 {
 635         struct write_midx_context *ctx = data;
 636         uint32_t i;
 637         unsigned char padding[MIDX_CHUNK_ALIGNMENT];
 638         size_t written = 0;
 639
 640         for (i = 0; i < ctx->nr; i++) {
 641                 size_t writelen;
 642
 643                 if (ctx->info[i].expired)
 644                         continue;
 645
 646                 if (i && strcmp(ctx->info[i].pack_name, ctx->info[i - 1].pack_name) <= 0)
 647                         BUG("incorrect pack-file order: %s before %s",
 648                             ctx->info[i - 1].pack_name,
 649                             ctx->info[i].pack_name);
 650
 651                 writelen = strlen(ctx->info[i].pack_name) + 1;
 652                 hashwrite(f, ctx->info[i].pack_name, writelen);
 653                 written += writelen;
 654         }
 655
 656         /* add padding to be aligned */
 657         i = MIDX_CHUNK_ALIGNMENT - (written % MIDX_CHUNK_ALIGNMENT);
 658         if (i < MIDX_CHUNK_ALIGNMENT) {
 659                 memset(padding, 0, sizeof(padding));
 660                 hashwrite(f, padding, i);
 661         }
 662
 663         return 0;
 664 }
 665
 666 static int write_midx_oid_fanout(struct hashfile *f,
 667                                  void *data)
 668 {
 669         struct write_midx_context *ctx = data;
 670         struct pack_midx_entry *list = ctx->entries;
 671         struct pack_midx_entry *last = ctx->entries + ctx->entries_nr;
 672         uint32_t count = 0;
 673         uint32_t i;
 674
 675         /*
 676         * Write the first-level table (the list is sorted,
 677         * but we use a 256-entry lookup to be able to avoid
 678         * having to do eight extra binary search iterations).
 679         */
 680         for (i = 0; i < 256; i++) {
 681                 struct pack_midx_entry *next = list;
 682
 683                 while (next < last && next->oid.hash[0] == i) {
 684                         count++;
 685                         next++;
 686                 }
 687
 688                 hashwrite_be32(f, count);
 689                 list = next;
 690         }
 691
 692         return 0;
 693 }
 694
 695 static int write_midx_oid_lookup(struct hashfile *f,
 696                                  void *data)
 697 {
 698         struct write_midx_context *ctx = data;
 699         unsigned char hash_len = the_hash_algo->rawsz;
 700         struct pack_midx_entry *list = ctx->entries;
 701         uint32_t i;
 702
 703         for (i = 0; i < ctx->entries_nr; i++) {
 704                 struct pack_midx_entry *obj = list++;
 705
 706                 if (i < ctx->entries_nr - 1) {
 707                         struct pack_midx_entry *next = list;
 708                         if (oidcmp(&obj->oid, &next->oid) >= 0)
 709                                 BUG("OIDs not in order: %s >= %s",
 710                                     oid_to_hex(&obj->oid),
 711                                     oid_to_hex(&next->oid));
 712                 }
 713
 714                 hashwrite(f, obj->oid.hash, (int)hash_len);
 715         }
 716
 717         return 0;
 718 }
 719
 720 static int write_midx_object_offsets(struct hashfile *f,
 721                                      void *data)
 722 {
 723         struct write_midx_context *ctx = data;
 724         struct pack_midx_entry *list = ctx->entries;
 725         uint32_t i, nr_large_offset = 0;
 726
 727         for (i = 0; i < ctx->entries_nr; i++) {
 728                 struct pack_midx_entry *obj = list++;
 729
 730                 if (ctx->pack_perm[obj->pack_int_id] == PACK_EXPIRED)
 731                         BUG("object %s is in an expired pack with int-id %d",
 732                             oid_to_hex(&obj->oid),
 733                             obj->pack_int_id);
 734
 735                 hashwrite_be32(f, ctx->pack_perm[obj->pack_int_id]);
 736
 737                 if (ctx->large_offsets_needed && obj->offset >> 31)
 738                         hashwrite_be32(f, MIDX_LARGE_OFFSET_NEEDED | nr_large_offset++);
 739                 else if (!ctx->large_offsets_needed && obj->offset >> 32)
 740                         BUG("object %s requires a large offset (%"PRIx64") but the MIDX is not writing large offsets!",
 741                             oid_to_hex(&obj->oid),
 742                             obj->offset);
 743                 else
 744                         hashwrite_be32(f, (uint32_t)obj->offset);
 745         }
 746
 747         return 0;
 748 }
 749
 750 static int write_midx_large_offsets(struct hashfile *f,
 751                                     void *data)
 752 {
 753         struct write_midx_context *ctx = data;
 754         struct pack_midx_entry *list = ctx->entries;
 755         struct pack_midx_entry *end = ctx->entries + ctx->entries_nr;
 756         uint32_t nr_large_offset = ctx->num_large_offsets;
 757
 758         while (nr_large_offset) {
 759                 struct pack_midx_entry *obj;
 760                 uint64_t offset;
 761
 762                 if (list >= end)
 763                         BUG("too many large-offset objects");
 764
 765                 obj = list++;
 766                 offset = obj->offset;
 767
 768                 if (!(offset >> 31))
 769                         continue;
 770
 771                 hashwrite_be64(f, offset);
 772
 773                 nr_large_offset--;
 774         }
 775
 776         return 0;
 777 }
 778
 779 static int write_midx_internal(const char *object_dir, struct multi_pack_index *m,
 780                                struct string_list *packs_to_drop, unsigned flags)
 781 {
 782         char *midx_name;
 783         uint32_t i;
 784         struct hashfile *f = NULL;
 785         struct lock_file lk;
 786         struct write_midx_context ctx = { 0 };
 787         int pack_name_concat_len = 0;
 788         int dropped_packs = 0;
 789         int result = 0;
 790         struct chunkfile *cf;
 791
 792         midx_name = get_midx_filename(object_dir);
 793         if (safe_create_leading_directories(midx_name))
 794                 die_errno(_("unable to create leading directories of %s"),
 795                           midx_name);
 796
 797         if (m)
 798                 ctx.m = m;
 799         else
 800                 ctx.m = load_multi_pack_index(object_dir, 1);
 801
 802         ctx.nr = 0;
 803         ctx.alloc = ctx.m ? ctx.m->num_packs : 16;
 804         ctx.info = NULL;
 805         ALLOC_ARRAY(ctx.info, ctx.alloc);
 806
 807         if (ctx.m) {
 808                 for (i = 0; i < ctx.m->num_packs; i++) {
 809                         ALLOC_GROW(ctx.info, ctx.nr + 1, ctx.alloc);
 810
 811                         ctx.info[ctx.nr].orig_pack_int_id = i;
 812                         ctx.info[ctx.nr].pack_name = xstrdup(ctx.m->pack_names[i]);
 813                         ctx.info[ctx.nr].p = NULL;
 814                         ctx.info[ctx.nr].expired = 0;
 815                         ctx.nr++;
 816                 }
 817         }
 818
 819         ctx.pack_paths_checked = 0;
 820         if (flags & MIDX_PROGRESS)
 821                 ctx.progress = start_delayed_progress(_("Adding packfiles to multi-pack-index"), 0);
 822         else
 823                 ctx.progress = NULL;
 824
 825         for_each_file_in_pack_dir(object_dir, add_pack_to_midx, &ctx);
 826         stop_progress(&ctx.progress);
 827
 828         if (ctx.m && ctx.nr == ctx.m->num_packs && !packs_to_drop)
 829                 goto cleanup;
 830
 831         ctx.entries = get_sorted_entries(ctx.m, ctx.info, ctx.nr, &ctx.entries_nr);
 832
 833         ctx.large_offsets_needed = 0;
 834         for (i = 0; i < ctx.entries_nr; i++) {
 835                 if (ctx.entries[i].offset > 0x7fffffff)
 836                         ctx.num_large_offsets++;
 837                 if (ctx.entries[i].offset > 0xffffffff)
 838                         ctx.large_offsets_needed = 1;
 839         }
 840
 841         QSORT(ctx.info, ctx.nr, pack_info_compare);
 842
 843         if (packs_to_drop && packs_to_drop->nr) {
 844                 int drop_index = 0;
 845                 int missing_drops = 0;
 846
 847                 for (i = 0; i < ctx.nr && drop_index < packs_to_drop->nr; i++) {
 848                         int cmp = strcmp(ctx.info[i].pack_name,
 849                                          packs_to_drop->items[drop_index].string);
 850
 851                         if (!cmp) {
 852                                 drop_index++;
 853                                 ctx.info[i].expired = 1;
 854                         } else if (cmp > 0) {
 855                                 error(_("did not see pack-file %s to drop"),
 856                                       packs_to_drop->items[drop_index].string);
 857                                 drop_index++;
 858                                 missing_drops++;
 859                                 i--;
 860                         } else {
 861                                 ctx.info[i].expired = 0;
 862                         }
 863                 }
 864
 865                 if (missing_drops) {
 866                         result = 1;
 867                         goto cleanup;
 868                 }
 869         }
 870
 871         /*
 872          * pack_perm stores a permutation between pack-int-ids from the
 873          * previous multi-pack-index to the new one we are writing:
 874          *
 875          * pack_perm[old_id] = new_id
 876          */
 877         ALLOC_ARRAY(ctx.pack_perm, ctx.nr);
 878         for (i = 0; i < ctx.nr; i++) {
 879                 if (ctx.info[i].expired) {
 880                         dropped_packs++;
 881                         ctx.pack_perm[ctx.info[i].orig_pack_int_id] = PACK_EXPIRED;
 882                 } else {
 883                         ctx.pack_perm[ctx.info[i].orig_pack_int_id] = i - dropped_packs;
 884                 }
 885         }
 886
 887         for (i = 0; i < ctx.nr; i++) {
 888                 if (!ctx.info[i].expired)
 889                         pack_name_concat_len += strlen(ctx.info[i].pack_name) + 1;
 890         }
 891
 892         if (pack_name_concat_len % MIDX_CHUNK_ALIGNMENT)
 893                 pack_name_concat_len += MIDX_CHUNK_ALIGNMENT -
 894                                         (pack_name_concat_len % MIDX_CHUNK_ALIGNMENT);
 895
 896         hold_lock_file_for_update(&lk, midx_name, LOCK_DIE_ON_ERROR);
 897         f = hashfd(get_lock_file_fd(&lk), get_lock_file_path(&lk));
 898         FREE_AND_NULL(midx_name);
 899
 900         if (ctx.m)
 901                 close_midx(ctx.m);
 902
 903         if (ctx.nr - dropped_packs == 0) {
 904                 error(_("no pack files to index."));
 905                 result = 1;
 906                 goto cleanup;
 907         }
 908
 909         cf = init_chunkfile(f);
 910
 911         add_chunk(cf, MIDX_CHUNKID_PACKNAMES, pack_name_concat_len,
 912                   write_midx_pack_names);
 913         add_chunk(cf, MIDX_CHUNKID_OIDFANOUT, MIDX_CHUNK_FANOUT_SIZE,
 914                   write_midx_oid_fanout);
 915         add_chunk(cf, MIDX_CHUNKID_OIDLOOKUP,
 916                   (size_t)ctx.entries_nr * the_hash_algo->rawsz,
 917                   write_midx_oid_lookup);
 918         add_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS,
 919                   (size_t)ctx.entries_nr * MIDX_CHUNK_OFFSET_WIDTH,
 920                   write_midx_object_offsets);
 921
 922         if (ctx.large_offsets_needed)
 923                 add_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS,
 924                         (size_t)ctx.num_large_offsets * MIDX_CHUNK_LARGE_OFFSET_WIDTH,
 925                         write_midx_large_offsets);
 926
 927         write_midx_header(f, get_num_chunks(cf), ctx.nr - dropped_packs);
 928         write_chunkfile(cf, &ctx);
 929
 930         finalize_hashfile(f, NULL, CSUM_FSYNC | CSUM_HASH_IN_STREAM);
 931         free_chunkfile(cf);
 932         commit_lock_file(&lk);
 933
 934 cleanup:
 935         for (i = 0; i < ctx.nr; i++) {
 936                 if (ctx.info[i].p) {
 937                         close_pack(ctx.info[i].p);
 938                         free(ctx.info[i].p);
 939                 }
 940                 free(ctx.info[i].pack_name);
 941         }
 942
 943         free(ctx.info);
 944         free(ctx.entries);
 945         free(ctx.pack_perm);
 946         free(midx_name);
 947         return result;
 948 }
 949
 950 int write_midx_file(const char *object_dir, unsigned flags)
 951 {
 952         return write_midx_internal(object_dir, NULL, NULL, flags);
 953 }
 954
 955 void clear_midx_file(struct repository *r)
 956 {
 957         char *midx = get_midx_filename(r->objects->odb->path);
 958
 959         if (r->objects && r->objects->multi_pack_index) {
 960                 close_midx(r->objects->multi_pack_index);
 961                 r->objects->multi_pack_index = NULL;
 962         }
 963
 964         if (remove_path(midx))
 965                 die(_("failed to clear multi-pack-index at %s"), midx);
 966
 967         free(midx);
 968 }
 969
 970 static int verify_midx_error;
 971
 972 static void midx_report(const char *fmt, ...)
 973 {
 974         va_list ap;
 975         verify_midx_error = 1;
 976         va_start(ap, fmt);
 977         vfprintf(stderr, fmt, ap);
 978         fprintf(stderr, "\n");
 979         va_end(ap);
 980 }
 981
 982 struct pair_pos_vs_id
 983 {
 984         uint32_t pos;
 985         uint32_t pack_int_id;
 986 };
 987
 988 static int compare_pair_pos_vs_id(const void *_a, const void *_b)
 989 {
 990         struct pair_pos_vs_id *a = (struct pair_pos_vs_id *)_a;
 991         struct pair_pos_vs_id *b = (struct pair_pos_vs_id *)_b;
 992
 993         return b->pack_int_id - a->pack_int_id;
 994 }
 995
 996 /*
 997  * Limit calls to display_progress() for performance reasons.
 998  * The interval here was arbitrarily chosen.
 999  */
1000 #define SPARSE_PROGRESS_INTERVAL (1 << 12)
1001 #define midx_display_sparse_progress(progress, n) \
1002         do { \
1003                 uint64_t _n = (n); \
1004                 if ((_n & (SPARSE_PROGRESS_INTERVAL - 1)) == 0) \
1005                         display_progress(progress, _n); \
1006         } while (0)
1007
1008 int verify_midx_file(struct repository *r, const char *object_dir, unsigned flags)
1009 {
1010         struct pair_pos_vs_id *pairs = NULL;
1011         uint32_t i;
1012         struct progress *progress = NULL;
1013         struct multi_pack_index *m = load_multi_pack_index(object_dir, 1);
1014         verify_midx_error = 0;
1015
1016         if (!m) {
1017                 int result = 0;
1018                 struct stat sb;
1019                 char *filename = get_midx_filename(object_dir);
1020                 if (!stat(filename, &sb)) {
1021                         error(_("multi-pack-index file exists, but failed to parse"));
1022                         result = 1;
1023                 }
1024                 free(filename);
1025                 return result;
1026         }
1027
1028         if (flags & MIDX_PROGRESS)
1029                 progress = start_delayed_progress(_("Looking for referenced packfiles"),
1030                                           m->num_packs);
1031         for (i = 0; i < m->num_packs; i++) {
1032                 if (prepare_midx_pack(r, m, i))
1033                         midx_report("failed to load pack in position %d", i);
1034
1035                 display_progress(progress, i + 1);
1036         }
1037         stop_progress(&progress);
1038
1039         for (i = 0; i < 255; i++) {
1040                 uint32_t oid_fanout1 = ntohl(m->chunk_oid_fanout[i]);
1041                 uint32_t oid_fanout2 = ntohl(m->chunk_oid_fanout[i + 1]);
1042
1043                 if (oid_fanout1 > oid_fanout2)
1044                         midx_report(_("oid fanout out of order: fanout[%d] = %"PRIx32" > %"PRIx32" = fanout[%d]"),
1045                                     i, oid_fanout1, oid_fanout2, i + 1);
1046         }
1047
1048         if (m->num_objects == 0) {
1049                 midx_report(_("the midx contains no oid"));
1050                 /*
1051                  * Remaining tests assume that we have objects, so we can
1052                  * return here.
1053                  */
1054                 return verify_midx_error;
1055         }
1056
1057         if (flags & MIDX_PROGRESS)
1058                 progress = start_sparse_progress(_("Verifying OID order in multi-pack-index"),
1059                                                  m->num_objects - 1);
1060         for (i = 0; i < m->num_objects - 1; i++) {
1061                 struct object_id oid1, oid2;
1062
1063                 nth_midxed_object_oid(&oid1, m, i);
1064                 nth_midxed_object_oid(&oid2, m, i + 1);
1065
1066                 if (oidcmp(&oid1, &oid2) >= 0)
1067                         midx_report(_("oid lookup out of order: oid[%d] = %s >= %s = oid[%d]"),
1068                                     i, oid_to_hex(&oid1), oid_to_hex(&oid2), i + 1);
1069
1070                 midx_display_sparse_progress(progress, i + 1);
1071         }
1072         stop_progress(&progress);
1073
1074         /*
1075          * Create an array mapping each object to its packfile id.  Sort it
1076          * to group the objects by packfile.  Use this permutation to visit
1077          * each of the objects and only require 1 packfile to be open at a
1078          * time.
1079          */
1080         ALLOC_ARRAY(pairs, m->num_objects);
1081         for (i = 0; i < m->num_objects; i++) {
1082                 pairs[i].pos = i;
1083                 pairs[i].pack_int_id = nth_midxed_pack_int_id(m, i);
1084         }
1085
1086         if (flags & MIDX_PROGRESS)
1087                 progress = start_sparse_progress(_("Sorting objects by packfile"),
1088                                                  m->num_objects);
1089         display_progress(progress, 0); /* TODO: Measure QSORT() progress */
1090         QSORT(pairs, m->num_objects, compare_pair_pos_vs_id);
1091         stop_progress(&progress);
1092
1093         if (flags & MIDX_PROGRESS)
1094                 progress = start_sparse_progress(_("Verifying object offsets"), m->num_objects);
1095         for (i = 0; i < m->num_objects; i++) {
1096                 struct object_id oid;
1097                 struct pack_entry e;
1098                 off_t m_offset, p_offset;
1099
1100                 if (i > 0 && pairs[i-1].pack_int_id != pairs[i].pack_int_id &&
1101                     m->packs[pairs[i-1].pack_int_id])
1102                 {
1103                         close_pack_fd(m->packs[pairs[i-1].pack_int_id]);
1104                         close_pack_index(m->packs[pairs[i-1].pack_int_id]);
1105                 }
1106
1107                 nth_midxed_object_oid(&oid, m, pairs[i].pos);
1108
1109                 if (!fill_midx_entry(r, &oid, &e, m)) {
1110                         midx_report(_("failed to load pack entry for oid[%d] = %s"),
1111                                     pairs[i].pos, oid_to_hex(&oid));
1112                         continue;
1113                 }
1114
1115                 if (open_pack_index(e.p)) {
1116                         midx_report(_("failed to load pack-index for packfile %s"),
1117                                     e.p->pack_name);
1118                         break;
1119                 }
1120
1121                 m_offset = e.offset;
1122                 p_offset = find_pack_entry_one(oid.hash, e.p);
1123
1124                 if (m_offset != p_offset)
1125                         midx_report(_("incorrect object offset for oid[%d] = %s: %"PRIx64" != %"PRIx64),
1126                                     pairs[i].pos, oid_to_hex(&oid), m_offset, p_offset);
1127
1128                 midx_display_sparse_progress(progress, i + 1);
1129         }
1130         stop_progress(&progress);
1131
1132         free(pairs);
1133
1134         return verify_midx_error;
1135 }
1136
1137 int expire_midx_packs(struct repository *r, const char *object_dir, unsigned flags)
1138 {
1139         uint32_t i, *count, result = 0;
1140         struct string_list packs_to_drop = STRING_LIST_INIT_DUP;
1141         struct multi_pack_index *m = load_multi_pack_index(object_dir, 1);
1142         struct progress *progress = NULL;
1143
1144         if (!m)
1145                 return 0;
1146
1147         count = xcalloc(m->num_packs, sizeof(uint32_t));
1148
1149         if (flags & MIDX_PROGRESS)
1150                 progress = start_delayed_progress(_("Counting referenced objects"),
1151                                           m->num_objects);
1152         for (i = 0; i < m->num_objects; i++) {
1153                 int pack_int_id = nth_midxed_pack_int_id(m, i);
1154                 count[pack_int_id]++;
1155                 display_progress(progress, i + 1);
1156         }
1157         stop_progress(&progress);
1158
1159         if (flags & MIDX_PROGRESS)
1160                 progress = start_delayed_progress(_("Finding and deleting unreferenced packfiles"),
1161                                           m->num_packs);
1162         for (i = 0; i < m->num_packs; i++) {
1163                 char *pack_name;
1164                 display_progress(progress, i + 1);
1165
1166                 if (count[i])
1167                         continue;
1168
1169                 if (prepare_midx_pack(r, m, i))
1170                         continue;
1171
1172                 if (m->packs[i]->pack_keep)
1173                         continue;
1174
1175                 pack_name = xstrdup(m->packs[i]->pack_name);
1176                 close_pack(m->packs[i]);
1177
1178                 string_list_insert(&packs_to_drop, m->pack_names[i]);
1179                 unlink_pack_path(pack_name, 0);
1180                 free(pack_name);
1181         }
1182         stop_progress(&progress);
1183
1184         free(count);
1185
1186         if (packs_to_drop.nr)
1187                 result = write_midx_internal(object_dir, m, &packs_to_drop, flags);
1188
1189         string_list_clear(&packs_to_drop, 0);
1190         return result;
1191 }
1192
1193 struct repack_info {
1194         timestamp_t mtime;
1195         uint32_t referenced_objects;
1196         uint32_t pack_int_id;
1197 };
1198
1199 static int compare_by_mtime(const void *a_, const void *b_)
1200 {
1201         const struct repack_info *a, *b;
1202
1203         a = (const struct repack_info *)a_;
1204         b = (const struct repack_info *)b_;
1205
1206         if (a->mtime < b->mtime)
1207                 return -1;
1208         if (a->mtime > b->mtime)
1209                 return 1;
1210         return 0;
1211 }
1212
1213 static int fill_included_packs_all(struct repository *r,
1214                                    struct multi_pack_index *m,
1215                                    unsigned char *include_pack)
1216 {
1217         uint32_t i, count = 0;
1218         int pack_kept_objects = 0;
1219
1220         repo_config_get_bool(r, "repack.packkeptobjects", &pack_kept_objects);
1221
1222         for (i = 0; i < m->num_packs; i++) {
1223                 if (prepare_midx_pack(r, m, i))
1224                         continue;
1225                 if (!pack_kept_objects && m->packs[i]->pack_keep)
1226                         continue;
1227
1228                 include_pack[i] = 1;
1229                 count++;
1230         }
1231
1232         return count < 2;
1233 }
1234
1235 static int fill_included_packs_batch(struct repository *r,
1236                                      struct multi_pack_index *m,
1237                                      unsigned char *include_pack,
1238                                      size_t batch_size)
1239 {
1240         uint32_t i, packs_to_repack;
1241         size_t total_size;
1242         struct repack_info *pack_info = xcalloc(m->num_packs, sizeof(struct repack_info));
1243         int pack_kept_objects = 0;
1244
1245         repo_config_get_bool(r, "repack.packkeptobjects", &pack_kept_objects);
1246
1247         for (i = 0; i < m->num_packs; i++) {
1248                 pack_info[i].pack_int_id = i;
1249
1250                 if (prepare_midx_pack(r, m, i))
1251                         continue;
1252
1253                 pack_info[i].mtime = m->packs[i]->mtime;
1254         }
1255
1256         for (i = 0; batch_size && i < m->num_objects; i++) {
1257                 uint32_t pack_int_id = nth_midxed_pack_int_id(m, i);
1258                 pack_info[pack_int_id].referenced_objects++;
1259         }
1260
1261         QSORT(pack_info, m->num_packs, compare_by_mtime);
1262
1263         total_size = 0;
1264         packs_to_repack = 0;
1265         for (i = 0; total_size < batch_size && i < m->num_packs; i++) {
1266                 int pack_int_id = pack_info[i].pack_int_id;
1267                 struct packed_git *p = m->packs[pack_int_id];
1268                 size_t expected_size;
1269
1270                 if (!p)
1271                         continue;
1272                 if (!pack_kept_objects && p->pack_keep)
1273                         continue;
1274                 if (open_pack_index(p) || !p->num_objects)
1275                         continue;
1276
1277                 expected_size = (size_t)(p->pack_size
1278                                          * pack_info[i].referenced_objects);
1279                 expected_size /= p->num_objects;
1280
1281                 if (expected_size >= batch_size)
1282                         continue;
1283
1284                 packs_to_repack++;
1285                 total_size += expected_size;
1286                 include_pack[pack_int_id] = 1;
1287         }
1288
1289         free(pack_info);
1290
1291         if (packs_to_repack < 2)
1292                 return 1;
1293
1294         return 0;
1295 }
1296
1297 int midx_repack(struct repository *r, const char *object_dir, size_t batch_size, unsigned flags)
1298 {
1299         int result = 0;
1300         uint32_t i;
1301         unsigned char *include_pack;
1302         struct child_process cmd = CHILD_PROCESS_INIT;
1303         FILE *cmd_in;
1304         struct strbuf base_name = STRBUF_INIT;
1305         struct multi_pack_index *m = load_multi_pack_index(object_dir, 1);
1306
1307         /*
1308          * When updating the default for these configuration
1309          * variables in builtin/repack.c, these must be adjusted
1310          * to match.
1311          */
1312         int delta_base_offset = 1;
1313         int use_delta_islands = 0;
1314
1315         if (!m)
1316                 return 0;
1317
1318         include_pack = xcalloc(m->num_packs, sizeof(unsigned char));
1319
1320         if (batch_size) {
1321                 if (fill_included_packs_batch(r, m, include_pack, batch_size))
1322                         goto cleanup;
1323         } else if (fill_included_packs_all(r, m, include_pack))
1324                 goto cleanup;
1325
1326         repo_config_get_bool(r, "repack.usedeltabaseoffset", &delta_base_offset);
1327         repo_config_get_bool(r, "repack.usedeltaislands", &use_delta_islands);
1328
1329         strvec_push(&cmd.args, "pack-objects");
1330
1331         strbuf_addstr(&base_name, object_dir);
1332         strbuf_addstr(&base_name, "/pack/pack");
1333         strvec_push(&cmd.args, base_name.buf);
1334
1335         if (delta_base_offset)
1336                 strvec_push(&cmd.args, "--delta-base-offset");
1337         if (use_delta_islands)
1338                 strvec_push(&cmd.args, "--delta-islands");
1339
1340         if (flags & MIDX_PROGRESS)
1341                 strvec_push(&cmd.args, "--progress");
1342         else
1343                 strvec_push(&cmd.args, "-q");
1344
1345         strbuf_release(&base_name);
1346
1347         cmd.git_cmd = 1;
1348         cmd.in = cmd.out = -1;
1349
1350         if (start_command(&cmd)) {
1351                 error(_("could not start pack-objects"));
1352                 result = 1;
1353                 goto cleanup;
1354         }
1355
1356         cmd_in = xfdopen(cmd.in, "w");
1357
1358         for (i = 0; i < m->num_objects; i++) {
1359                 struct object_id oid;
1360                 uint32_t pack_int_id = nth_midxed_pack_int_id(m, i);
1361
1362                 if (!include_pack[pack_int_id])
1363                         continue;
1364
1365                 nth_midxed_object_oid(&oid, m, i);
1366                 fprintf(cmd_in, "%s\n", oid_to_hex(&oid));
1367         }
1368         fclose(cmd_in);
1369
1370         if (finish_command(&cmd)) {
1371                 error(_("could not finish pack-objects"));
1372                 result = 1;
1373                 goto cleanup;
1374         }
1375
1376         result = write_midx_internal(object_dir, m, NULL, flags);
1377         m = NULL;
1378
1379 cleanup:
1380         if (m)
1381                 close_midx(m);
1382         free(include_pack);
1383         return result;
1384 }