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

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "repository.h"
   4 #include "config.h"
   5 #include "attr.h"
   6 #include "object.h"
   7 #include "blob.h"
   8 #include "commit.h"
   9 #include "tag.h"
  10 #include "tree.h"
  11 #include "delta.h"
  12 #include "pack.h"
  13 #include "pack-revindex.h"
  14 #include "csum-file.h"
  15 #include "tree-walk.h"
  16 #include "diff.h"
  17 #include "revision.h"
  18 #include "list-objects.h"
  19 #include "list-objects-filter.h"
  20 #include "list-objects-filter-options.h"
  21 #include "pack-objects.h"
  22 #include "progress.h"
  23 #include "refs.h"
  24 #include "streaming.h"
  25 #include "thread-utils.h"
  26 #include "pack-bitmap.h"
  27 #include "delta-islands.h"
  28 #include "reachable.h"
  29 #include "sha1-array.h"
  30 #include "argv-array.h"
  31 #include "list.h"
  32 #include "packfile.h"
  33 #include "object-store.h"
  34 #include "dir.h"
  35 #include "midx.h"
  36 #include "trace2.h"
  37
  38 #define IN_PACK(obj) oe_in_pack(&to_pack, obj)
  39 #define SIZE(obj) oe_size(&to_pack, obj)
  40 #define SET_SIZE(obj,size) oe_set_size(&to_pack, obj, size)
  41 #define DELTA_SIZE(obj) oe_delta_size(&to_pack, obj)
  42 #define DELTA(obj) oe_delta(&to_pack, obj)
  43 #define DELTA_CHILD(obj) oe_delta_child(&to_pack, obj)
  44 #define DELTA_SIBLING(obj) oe_delta_sibling(&to_pack, obj)
  45 #define SET_DELTA(obj, val) oe_set_delta(&to_pack, obj, val)
  46 #define SET_DELTA_EXT(obj, oid) oe_set_delta_ext(&to_pack, obj, oid)
  47 #define SET_DELTA_SIZE(obj, val) oe_set_delta_size(&to_pack, obj, val)
  48 #define SET_DELTA_CHILD(obj, val) oe_set_delta_child(&to_pack, obj, val)
  49 #define SET_DELTA_SIBLING(obj, val) oe_set_delta_sibling(&to_pack, obj, val)
  50
  51 static const char *pack_usage[] = {
  52         N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),
  53         N_("git pack-objects [<options>...] <base-name> [< <ref-list> | < <object-list>]"),
  54         NULL
  55 };
  56
  57 /*
  58  * Objects we are going to pack are collected in the `to_pack` structure.
  59  * It contains an array (dynamically expanded) of the object data, and a map
  60  * that can resolve SHA1s to their position in the array.
  61  */
  62 static struct packing_data to_pack;
  63
  64 static struct pack_idx_entry **written_list;
  65 static uint32_t nr_result, nr_written, nr_seen;
  66 static struct bitmap_index *bitmap_git;
  67 static uint32_t write_layer;
  68
  69 static int non_empty;
  70 static int reuse_delta = 1, reuse_object = 1;
  71 static int keep_unreachable, unpack_unreachable, include_tag;
  72 static timestamp_t unpack_unreachable_expiration;
  73 static int pack_loose_unreachable;
  74 static int local;
  75 static int have_non_local_packs;
  76 static int incremental;
  77 static int ignore_packed_keep_on_disk;
  78 static int ignore_packed_keep_in_core;
  79 static int allow_ofs_delta;
  80 static struct pack_idx_option pack_idx_opts;
  81 static const char *base_name;
  82 static int progress = 1;
  83 static int window = 10;
  84 static unsigned long pack_size_limit;
  85 static int depth = 50;
  86 static int delta_search_threads;
  87 static int pack_to_stdout;
  88 static int sparse;
  89 static int thin;
  90 static int num_preferred_base;
  91 static struct progress *progress_state;
  92
  93 static struct packed_git *reuse_packfile;
  94 static uint32_t reuse_packfile_objects;
  95 static off_t reuse_packfile_offset;
  96
  97 static int use_bitmap_index_default = 1;
  98 static int use_bitmap_index = -1;
  99 static int write_bitmap_index;
 100 static uint16_t write_bitmap_options;
 101
 102 static int exclude_promisor_objects;
 103
 104 static int use_delta_islands;
 105
 106 static unsigned long delta_cache_size = 0;
 107 static unsigned long max_delta_cache_size = DEFAULT_DELTA_CACHE_SIZE;
 108 static unsigned long cache_max_small_delta_size = 1000;
 109
 110 static unsigned long window_memory_limit = 0;
 111
 112 static struct list_objects_filter_options filter_options;
 113
 114 enum missing_action {
 115         MA_ERROR = 0,      /* fail if any missing objects are encountered */
 116         MA_ALLOW_ANY,      /* silently allow ALL missing objects */
 117         MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
 118 };
 119 static enum missing_action arg_missing_action;
 120 static show_object_fn fn_show_object;
 121
 122 /*
 123  * stats
 124  */
 125 static uint32_t written, written_delta;
 126 static uint32_t reused, reused_delta;
 127
 128 /*
 129  * Indexed commits
 130  */
 131 static struct commit **indexed_commits;
 132 static unsigned int indexed_commits_nr;
 133 static unsigned int indexed_commits_alloc;
 134
 135 static void index_commit_for_bitmap(struct commit *commit)
 136 {
 137         if (indexed_commits_nr >= indexed_commits_alloc) {
 138                 indexed_commits_alloc = (indexed_commits_alloc + 32) * 2;
 139                 REALLOC_ARRAY(indexed_commits, indexed_commits_alloc);
 140         }
 141
 142         indexed_commits[indexed_commits_nr++] = commit;
 143 }
 144
 145 static void *get_delta(struct object_entry *entry)
 146 {
 147         unsigned long size, base_size, delta_size;
 148         void *buf, *base_buf, *delta_buf;
 149         enum object_type type;
 150
 151         buf = read_object_file(&entry->idx.oid, &type, &size);
 152         if (!buf)
 153                 die(_("unable to read %s"), oid_to_hex(&entry->idx.oid));
 154         base_buf = read_object_file(&DELTA(entry)->idx.oid, &type,
 155                                     &base_size);
 156         if (!base_buf)
 157                 die("unable to read %s",
 158                     oid_to_hex(&DELTA(entry)->idx.oid));
 159         delta_buf = diff_delta(base_buf, base_size,
 160                                buf, size, &delta_size, 0);
 161         /*
 162          * We succesfully computed this delta once but dropped it for
 163          * memory reasons. Something is very wrong if this time we
 164          * recompute and create a different delta.
 165          */
 166         if (!delta_buf || delta_size != DELTA_SIZE(entry))
 167                 BUG("delta size changed");
 168         free(buf);
 169         free(base_buf);
 170         return delta_buf;
 171 }
 172
 173 static unsigned long do_compress(void **pptr, unsigned long size)
 174 {
 175         git_zstream stream;
 176         void *in, *out;
 177         unsigned long maxsize;
 178
 179         git_deflate_init(&stream, pack_compression_level);
 180         maxsize = git_deflate_bound(&stream, size);
 181
 182         in = *pptr;
 183         out = xmalloc(maxsize);
 184         *pptr = out;
 185
 186         stream.next_in = in;
 187         stream.avail_in = size;
 188         stream.next_out = out;
 189         stream.avail_out = maxsize;
 190         while (git_deflate(&stream, Z_FINISH) == Z_OK)
 191                 ; /* nothing */
 192         git_deflate_end(&stream);
 193
 194         free(in);
 195         return stream.total_out;
 196 }
 197
 198 static unsigned long write_large_blob_data(struct git_istream *st, struct hashfile *f,
 199                                            const struct object_id *oid)
 200 {
 201         git_zstream stream;
 202         unsigned char ibuf[1024 * 16];
 203         unsigned char obuf[1024 * 16];
 204         unsigned long olen = 0;
 205
 206         git_deflate_init(&stream, pack_compression_level);
 207
 208         for (;;) {
 209                 ssize_t readlen;
 210                 int zret = Z_OK;
 211                 readlen = read_istream(st, ibuf, sizeof(ibuf));
 212                 if (readlen == -1)
 213                         die(_("unable to read %s"), oid_to_hex(oid));
 214
 215                 stream.next_in = ibuf;
 216                 stream.avail_in = readlen;
 217                 while ((stream.avail_in || readlen == 0) &&
 218                        (zret == Z_OK || zret == Z_BUF_ERROR)) {
 219                         stream.next_out = obuf;
 220                         stream.avail_out = sizeof(obuf);
 221                         zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
 222                         hashwrite(f, obuf, stream.next_out - obuf);
 223                         olen += stream.next_out - obuf;
 224                 }
 225                 if (stream.avail_in)
 226                         die(_("deflate error (%d)"), zret);
 227                 if (readlen == 0) {
 228                         if (zret != Z_STREAM_END)
 229                                 die(_("deflate error (%d)"), zret);
 230                         break;
 231                 }
 232         }
 233         git_deflate_end(&stream);
 234         return olen;
 235 }
 236
 237 /*
 238  * we are going to reuse the existing object data as is.  make
 239  * sure it is not corrupt.
 240  */
 241 static int check_pack_inflate(struct packed_git *p,
 242                 struct pack_window **w_curs,
 243                 off_t offset,
 244                 off_t len,
 245                 unsigned long expect)
 246 {
 247         git_zstream stream;
 248         unsigned char fakebuf[4096], *in;
 249         int st;
 250
 251         memset(&stream, 0, sizeof(stream));
 252         git_inflate_init(&stream);
 253         do {
 254                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 255                 stream.next_in = in;
 256                 stream.next_out = fakebuf;
 257                 stream.avail_out = sizeof(fakebuf);
 258                 st = git_inflate(&stream, Z_FINISH);
 259                 offset += stream.next_in - in;
 260         } while (st == Z_OK || st == Z_BUF_ERROR);
 261         git_inflate_end(&stream);
 262         return (st == Z_STREAM_END &&
 263                 stream.total_out == expect &&
 264                 stream.total_in == len) ? 0 : -1;
 265 }
 266
 267 static void copy_pack_data(struct hashfile *f,
 268                 struct packed_git *p,
 269                 struct pack_window **w_curs,
 270                 off_t offset,
 271                 off_t len)
 272 {
 273         unsigned char *in;
 274         unsigned long avail;
 275
 276         while (len) {
 277                 in = use_pack(p, w_curs, offset, &avail);
 278                 if (avail > len)
 279                         avail = (unsigned long)len;
 280                 hashwrite(f, in, avail);
 281                 offset += avail;
 282                 len -= avail;
 283         }
 284 }
 285
 286 /* Return 0 if we will bust the pack-size limit */
 287 static unsigned long write_no_reuse_object(struct hashfile *f, struct object_entry *entry,
 288                                            unsigned long limit, int usable_delta)
 289 {
 290         unsigned long size, datalen;
 291         unsigned char header[MAX_PACK_OBJECT_HEADER],
 292                       dheader[MAX_PACK_OBJECT_HEADER];
 293         unsigned hdrlen;
 294         enum object_type type;
 295         void *buf;
 296         struct git_istream *st = NULL;
 297         const unsigned hashsz = the_hash_algo->rawsz;
 298
 299         if (!usable_delta) {
 300                 if (oe_type(entry) == OBJ_BLOB &&
 301                     oe_size_greater_than(&to_pack, entry, big_file_threshold) &&
 302                     (st = open_istream(&entry->idx.oid, &type, &size, NULL)) != NULL)
 303                         buf = NULL;
 304                 else {
 305                         buf = read_object_file(&entry->idx.oid, &type, &size);
 306                         if (!buf)
 307                                 die(_("unable to read %s"),
 308                                     oid_to_hex(&entry->idx.oid));
 309                 }
 310                 /*
 311                  * make sure no cached delta data remains from a
 312                  * previous attempt before a pack split occurred.
 313                  */
 314                 FREE_AND_NULL(entry->delta_data);
 315                 entry->z_delta_size = 0;
 316         } else if (entry->delta_data) {
 317                 size = DELTA_SIZE(entry);
 318                 buf = entry->delta_data;
 319                 entry->delta_data = NULL;
 320                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 321                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 322         } else {
 323                 buf = get_delta(entry);
 324                 size = DELTA_SIZE(entry);
 325                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 326                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 327         }
 328
 329         if (st) /* large blob case, just assume we don't compress well */
 330                 datalen = size;
 331         else if (entry->z_delta_size)
 332                 datalen = entry->z_delta_size;
 333         else
 334                 datalen = do_compress(&buf, size);
 335
 336         /*
 337          * The object header is a byte of 'type' followed by zero or
 338          * more bytes of length.
 339          */
 340         hdrlen = encode_in_pack_object_header(header, sizeof(header),
 341                                               type, size);
 342
 343         if (type == OBJ_OFS_DELTA) {
 344                 /*
 345                  * Deltas with relative base contain an additional
 346                  * encoding of the relative offset for the delta
 347                  * base from this object's position in the pack.
 348                  */
 349                 off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 350                 unsigned pos = sizeof(dheader) - 1;
 351                 dheader[pos] = ofs & 127;
 352                 while (ofs >>= 7)
 353                         dheader[--pos] = 128 | (--ofs & 127);
 354                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 355                         if (st)
 356                                 close_istream(st);
 357                         free(buf);
 358                         return 0;
 359                 }
 360                 hashwrite(f, header, hdrlen);
 361                 hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 362                 hdrlen += sizeof(dheader) - pos;
 363         } else if (type == OBJ_REF_DELTA) {
 364                 /*
 365                  * Deltas with a base reference contain
 366                  * additional bytes for the base object ID.
 367                  */
 368                 if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 369                         if (st)
 370                                 close_istream(st);
 371                         free(buf);
 372                         return 0;
 373                 }
 374                 hashwrite(f, header, hdrlen);
 375                 hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 376                 hdrlen += hashsz;
 377         } else {
 378                 if (limit && hdrlen + datalen + hashsz >= limit) {
 379                         if (st)
 380                                 close_istream(st);
 381                         free(buf);
 382                         return 0;
 383                 }
 384                 hashwrite(f, header, hdrlen);
 385         }
 386         if (st) {
 387                 datalen = write_large_blob_data(st, f, &entry->idx.oid);
 388                 close_istream(st);
 389         } else {
 390                 hashwrite(f, buf, datalen);
 391                 free(buf);
 392         }
 393
 394         return hdrlen + datalen;
 395 }
 396
 397 /* Return 0 if we will bust the pack-size limit */
 398 static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry,
 399                                 unsigned long limit, int usable_delta)
 400 {
 401         struct packed_git *p = IN_PACK(entry);
 402         struct pack_window *w_curs = NULL;
 403         struct revindex_entry *revidx;
 404         off_t offset;
 405         enum object_type type = oe_type(entry);
 406         off_t datalen;
 407         unsigned char header[MAX_PACK_OBJECT_HEADER],
 408                       dheader[MAX_PACK_OBJECT_HEADER];
 409         unsigned hdrlen;
 410         const unsigned hashsz = the_hash_algo->rawsz;
 411         unsigned long entry_size = SIZE(entry);
 412
 413         if (DELTA(entry))
 414                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 415                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 416         hdrlen = encode_in_pack_object_header(header, sizeof(header),
 417                                               type, entry_size);
 418
 419         offset = entry->in_pack_offset;
 420         revidx = find_pack_revindex(p, offset);
 421         datalen = revidx[1].offset - offset;
 422         if (!pack_to_stdout && p->index_version > 1 &&
 423             check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 424                 error(_("bad packed object CRC for %s"),
 425                       oid_to_hex(&entry->idx.oid));
 426                 unuse_pack(&w_curs);
 427                 return write_no_reuse_object(f, entry, limit, usable_delta);
 428         }
 429
 430         offset += entry->in_pack_header_size;
 431         datalen -= entry->in_pack_header_size;
 432
 433         if (!pack_to_stdout && p->index_version == 1 &&
 434             check_pack_inflate(p, &w_curs, offset, datalen, entry_size)) {
 435                 error(_("corrupt packed object for %s"),
 436                       oid_to_hex(&entry->idx.oid));
 437                 unuse_pack(&w_curs);
 438                 return write_no_reuse_object(f, entry, limit, usable_delta);
 439         }
 440
 441         if (type == OBJ_OFS_DELTA) {
 442                 off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 443                 unsigned pos = sizeof(dheader) - 1;
 444                 dheader[pos] = ofs & 127;
 445                 while (ofs >>= 7)
 446                         dheader[--pos] = 128 | (--ofs & 127);
 447                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 448                         unuse_pack(&w_curs);
 449                         return 0;
 450                 }
 451                 hashwrite(f, header, hdrlen);
 452                 hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 453                 hdrlen += sizeof(dheader) - pos;
 454                 reused_delta++;
 455         } else if (type == OBJ_REF_DELTA) {
 456                 if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 457                         unuse_pack(&w_curs);
 458                         return 0;
 459                 }
 460                 hashwrite(f, header, hdrlen);
 461                 hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 462                 hdrlen += hashsz;
 463                 reused_delta++;
 464         } else {
 465                 if (limit && hdrlen + datalen + hashsz >= limit) {
 466                         unuse_pack(&w_curs);
 467                         return 0;
 468                 }
 469                 hashwrite(f, header, hdrlen);
 470         }
 471         copy_pack_data(f, p, &w_curs, offset, datalen);
 472         unuse_pack(&w_curs);
 473         reused++;
 474         return hdrlen + datalen;
 475 }
 476
 477 /* Return 0 if we will bust the pack-size limit */
 478 static off_t write_object(struct hashfile *f,
 479                           struct object_entry *entry,
 480                           off_t write_offset)
 481 {
 482         unsigned long limit;
 483         off_t len;
 484         int usable_delta, to_reuse;
 485
 486         if (!pack_to_stdout)
 487                 crc32_begin(f);
 488
 489         /* apply size limit if limited packsize and not first object */
 490         if (!pack_size_limit || !nr_written)
 491                 limit = 0;
 492         else if (pack_size_limit <= write_offset)
 493                 /*
 494                  * the earlier object did not fit the limit; avoid
 495                  * mistaking this with unlimited (i.e. limit = 0).
 496                  */
 497                 limit = 1;
 498         else
 499                 limit = pack_size_limit - write_offset;
 500
 501         if (!DELTA(entry))
 502                 usable_delta = 0;       /* no delta */
 503         else if (!pack_size_limit)
 504                usable_delta = 1;        /* unlimited packfile */
 505         else if (DELTA(entry)->idx.offset == (off_t)-1)
 506                 usable_delta = 0;       /* base was written to another pack */
 507         else if (DELTA(entry)->idx.offset)
 508                 usable_delta = 1;       /* base already exists in this pack */
 509         else
 510                 usable_delta = 0;       /* base could end up in another pack */
 511
 512         if (!reuse_object)
 513                 to_reuse = 0;   /* explicit */
 514         else if (!IN_PACK(entry))
 515                 to_reuse = 0;   /* can't reuse what we don't have */
 516         else if (oe_type(entry) == OBJ_REF_DELTA ||
 517                  oe_type(entry) == OBJ_OFS_DELTA)
 518                                 /* check_object() decided it for us ... */
 519                 to_reuse = usable_delta;
 520                                 /* ... but pack split may override that */
 521         else if (oe_type(entry) != entry->in_pack_type)
 522                 to_reuse = 0;   /* pack has delta which is unusable */
 523         else if (DELTA(entry))
 524                 to_reuse = 0;   /* we want to pack afresh */
 525         else
 526                 to_reuse = 1;   /* we have it in-pack undeltified,
 527                                  * and we do not need to deltify it.
 528                                  */
 529
 530         if (!to_reuse)
 531                 len = write_no_reuse_object(f, entry, limit, usable_delta);
 532         else
 533                 len = write_reuse_object(f, entry, limit, usable_delta);
 534         if (!len)
 535                 return 0;
 536
 537         if (usable_delta)
 538                 written_delta++;
 539         written++;
 540         if (!pack_to_stdout)
 541                 entry->idx.crc32 = crc32_end(f);
 542         return len;
 543 }
 544
 545 enum write_one_status {
 546         WRITE_ONE_SKIP = -1, /* already written */
 547         WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
 548         WRITE_ONE_WRITTEN = 1, /* normal */
 549         WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
 550 };
 551
 552 static enum write_one_status write_one(struct hashfile *f,
 553                                        struct object_entry *e,
 554                                        off_t *offset)
 555 {
 556         off_t size;
 557         int recursing;
 558
 559         /*
 560          * we set offset to 1 (which is an impossible value) to mark
 561          * the fact that this object is involved in "write its base
 562          * first before writing a deltified object" recursion.
 563          */
 564         recursing = (e->idx.offset == 1);
 565         if (recursing) {
 566                 warning(_("recursive delta detected for object %s"),
 567                         oid_to_hex(&e->idx.oid));
 568                 return WRITE_ONE_RECURSIVE;
 569         } else if (e->idx.offset || e->preferred_base) {
 570                 /* offset is non zero if object is written already. */
 571                 return WRITE_ONE_SKIP;
 572         }
 573
 574         /* if we are deltified, write out base object first. */
 575         if (DELTA(e)) {
 576                 e->idx.offset = 1; /* now recurse */
 577                 switch (write_one(f, DELTA(e), offset)) {
 578                 case WRITE_ONE_RECURSIVE:
 579                         /* we cannot depend on this one */
 580                         SET_DELTA(e, NULL);
 581                         break;
 582                 default:
 583                         break;
 584                 case WRITE_ONE_BREAK:
 585                         e->idx.offset = recursing;
 586                         return WRITE_ONE_BREAK;
 587                 }
 588         }
 589
 590         e->idx.offset = *offset;
 591         size = write_object(f, e, *offset);
 592         if (!size) {
 593                 e->idx.offset = recursing;
 594                 return WRITE_ONE_BREAK;
 595         }
 596         written_list[nr_written++] = &e->idx;
 597
 598         /* make sure off_t is sufficiently large not to wrap */
 599         if (signed_add_overflows(*offset, size))
 600                 die(_("pack too large for current definition of off_t"));
 601         *offset += size;
 602         return WRITE_ONE_WRITTEN;
 603 }
 604
 605 static int mark_tagged(const char *path, const struct object_id *oid, int flag,
 606                        void *cb_data)
 607 {
 608         struct object_id peeled;
 609         struct object_entry *entry = packlist_find(&to_pack, oid->hash, NULL);
 610
 611         if (entry)
 612                 entry->tagged = 1;
 613         if (!peel_ref(path, &peeled)) {
 614                 entry = packlist_find(&to_pack, peeled.hash, NULL);
 615                 if (entry)
 616                         entry->tagged = 1;
 617         }
 618         return 0;
 619 }
 620
 621 static inline void add_to_write_order(struct object_entry **wo,
 622                                unsigned int *endp,
 623                                struct object_entry *e)
 624 {
 625         if (e->filled || oe_layer(&to_pack, e) != write_layer)
 626                 return;
 627         wo[(*endp)++] = e;
 628         e->filled = 1;
 629 }
 630
 631 static void add_descendants_to_write_order(struct object_entry **wo,
 632                                            unsigned int *endp,
 633                                            struct object_entry *e)
 634 {
 635         int add_to_order = 1;
 636         while (e) {
 637                 if (add_to_order) {
 638                         struct object_entry *s;
 639                         /* add this node... */
 640                         add_to_write_order(wo, endp, e);
 641                         /* all its siblings... */
 642                         for (s = DELTA_SIBLING(e); s; s = DELTA_SIBLING(s)) {
 643                                 add_to_write_order(wo, endp, s);
 644                         }
 645                 }
 646                 /* drop down a level to add left subtree nodes if possible */
 647                 if (DELTA_CHILD(e)) {
 648                         add_to_order = 1;
 649                         e = DELTA_CHILD(e);
 650                 } else {
 651                         add_to_order = 0;
 652                         /* our sibling might have some children, it is next */
 653                         if (DELTA_SIBLING(e)) {
 654                                 e = DELTA_SIBLING(e);
 655                                 continue;
 656                         }
 657                         /* go back to our parent node */
 658                         e = DELTA(e);
 659                         while (e && !DELTA_SIBLING(e)) {
 660                                 /* we're on the right side of a subtree, keep
 661                                  * going up until we can go right again */
 662                                 e = DELTA(e);
 663                         }
 664                         if (!e) {
 665                                 /* done- we hit our original root node */
 666                                 return;
 667                         }
 668                         /* pass it off to sibling at this level */
 669                         e = DELTA_SIBLING(e);
 670                 }
 671         };
 672 }
 673
 674 static void add_family_to_write_order(struct object_entry **wo,
 675                                       unsigned int *endp,
 676                                       struct object_entry *e)
 677 {
 678         struct object_entry *root;
 679
 680         for (root = e; DELTA(root); root = DELTA(root))
 681                 ; /* nothing */
 682         add_descendants_to_write_order(wo, endp, root);
 683 }
 684
 685 static void compute_layer_order(struct object_entry **wo, unsigned int *wo_end)
 686 {
 687         unsigned int i, last_untagged;
 688         struct object_entry *objects = to_pack.objects;
 689
 690         for (i = 0; i < to_pack.nr_objects; i++) {
 691                 if (objects[i].tagged)
 692                         break;
 693                 add_to_write_order(wo, wo_end, &objects[i]);
 694         }
 695         last_untagged = i;
 696
 697         /*
 698          * Then fill all the tagged tips.
 699          */
 700         for (; i < to_pack.nr_objects; i++) {
 701                 if (objects[i].tagged)
 702                         add_to_write_order(wo, wo_end, &objects[i]);
 703         }
 704
 705         /*
 706          * And then all remaining commits and tags.
 707          */
 708         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 709                 if (oe_type(&objects[i]) != OBJ_COMMIT &&
 710                     oe_type(&objects[i]) != OBJ_TAG)
 711                         continue;
 712                 add_to_write_order(wo, wo_end, &objects[i]);
 713         }
 714
 715         /*
 716          * And then all the trees.
 717          */
 718         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 719                 if (oe_type(&objects[i]) != OBJ_TREE)
 720                         continue;
 721                 add_to_write_order(wo, wo_end, &objects[i]);
 722         }
 723
 724         /*
 725          * Finally all the rest in really tight order
 726          */
 727         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 728                 if (!objects[i].filled && oe_layer(&to_pack, &objects[i]) == write_layer)
 729                         add_family_to_write_order(wo, wo_end, &objects[i]);
 730         }
 731 }
 732
 733 static struct object_entry **compute_write_order(void)
 734 {
 735         uint32_t max_layers = 1;
 736         unsigned int i, wo_end;
 737
 738         struct object_entry **wo;
 739         struct object_entry *objects = to_pack.objects;
 740
 741         for (i = 0; i < to_pack.nr_objects; i++) {
 742                 objects[i].tagged = 0;
 743                 objects[i].filled = 0;
 744                 SET_DELTA_CHILD(&objects[i], NULL);
 745                 SET_DELTA_SIBLING(&objects[i], NULL);
 746         }
 747
 748         /*
 749          * Fully connect delta_child/delta_sibling network.
 750          * Make sure delta_sibling is sorted in the original
 751          * recency order.
 752          */
 753         for (i = to_pack.nr_objects; i > 0;) {
 754                 struct object_entry *e = &objects[--i];
 755                 if (!DELTA(e))
 756                         continue;
 757                 /* Mark me as the first child */
 758                 e->delta_sibling_idx = DELTA(e)->delta_child_idx;
 759                 SET_DELTA_CHILD(DELTA(e), e);
 760         }
 761
 762         /*
 763          * Mark objects that are at the tip of tags.
 764          */
 765         for_each_tag_ref(mark_tagged, NULL);
 766
 767         if (use_delta_islands)
 768                 max_layers = compute_pack_layers(&to_pack);
 769
 770         ALLOC_ARRAY(wo, to_pack.nr_objects);
 771         wo_end = 0;
 772
 773         for (; write_layer < max_layers; ++write_layer)
 774                 compute_layer_order(wo, &wo_end);
 775
 776         if (wo_end != to_pack.nr_objects)
 777                 die(_("ordered %u objects, expected %"PRIu32),
 778                     wo_end, to_pack.nr_objects);
 779
 780         return wo;
 781 }
 782
 783 static off_t write_reused_pack(struct hashfile *f)
 784 {
 785         unsigned char buffer[8192];
 786         off_t to_write, total;
 787         int fd;
 788
 789         if (!is_pack_valid(reuse_packfile))
 790                 die(_("packfile is invalid: %s"), reuse_packfile->pack_name);
 791
 792         fd = git_open(reuse_packfile->pack_name);
 793         if (fd < 0)
 794                 die_errno(_("unable to open packfile for reuse: %s"),
 795                           reuse_packfile->pack_name);
 796
 797         if (lseek(fd, sizeof(struct pack_header), SEEK_SET) == -1)
 798                 die_errno(_("unable to seek in reused packfile"));
 799
 800         if (reuse_packfile_offset < 0)
 801                 reuse_packfile_offset = reuse_packfile->pack_size - the_hash_algo->rawsz;
 802
 803         total = to_write = reuse_packfile_offset - sizeof(struct pack_header);
 804
 805         while (to_write) {
 806                 int read_pack = xread(fd, buffer, sizeof(buffer));
 807
 808                 if (read_pack <= 0)
 809                         die_errno(_("unable to read from reused packfile"));
 810
 811                 if (read_pack > to_write)
 812                         read_pack = to_write;
 813
 814                 hashwrite(f, buffer, read_pack);
 815                 to_write -= read_pack;
 816
 817                 /*
 818                  * We don't know the actual number of objects written,
 819                  * only how many bytes written, how many bytes total, and
 820                  * how many objects total. So we can fake it by pretending all
 821                  * objects we are writing are the same size. This gives us a
 822                  * smooth progress meter, and at the end it matches the true
 823                  * answer.
 824                  */
 825                 written = reuse_packfile_objects *
 826                                 (((double)(total - to_write)) / total);
 827                 display_progress(progress_state, written);
 828         }
 829
 830         close(fd);
 831         written = reuse_packfile_objects;
 832         display_progress(progress_state, written);
 833         return reuse_packfile_offset - sizeof(struct pack_header);
 834 }
 835
 836 static const char no_split_warning[] = N_(
 837 "disabling bitmap writing, packs are split due to pack.packSizeLimit"
 838 );
 839
 840 static void write_pack_file(void)
 841 {
 842         uint32_t i = 0, j;
 843         struct hashfile *f;
 844         off_t offset;
 845         uint32_t nr_remaining = nr_result;
 846         time_t last_mtime = 0;
 847         struct object_entry **write_order;
 848
 849         if (progress > pack_to_stdout)
 850                 progress_state = start_progress(_("Writing objects"), nr_result);
 851         ALLOC_ARRAY(written_list, to_pack.nr_objects);
 852         write_order = compute_write_order();
 853
 854         do {
 855                 struct object_id oid;
 856                 char *pack_tmp_name = NULL;
 857
 858                 if (pack_to_stdout)
 859                         f = hashfd_throughput(1, "<stdout>", progress_state);
 860                 else
 861                         f = create_tmp_packfile(&pack_tmp_name);
 862
 863                 offset = write_pack_header(f, nr_remaining);
 864
 865                 if (reuse_packfile) {
 866                         off_t packfile_size;
 867                         assert(pack_to_stdout);
 868
 869                         packfile_size = write_reused_pack(f);
 870                         offset += packfile_size;
 871                 }
 872
 873                 nr_written = 0;
 874                 for (; i < to_pack.nr_objects; i++) {
 875                         struct object_entry *e = write_order[i];
 876                         if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
 877                                 break;
 878                         display_progress(progress_state, written);
 879                 }
 880
 881                 /*
 882                  * Did we write the wrong # entries in the header?
 883                  * If so, rewrite it like in fast-import
 884                  */
 885                 if (pack_to_stdout) {
 886                         finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_CLOSE);
 887                 } else if (nr_written == nr_remaining) {
 888                         finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 889                 } else {
 890                         int fd = finalize_hashfile(f, oid.hash, 0);
 891                         fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
 892                                                  nr_written, oid.hash, offset);
 893                         close(fd);
 894                         if (write_bitmap_index) {
 895                                 warning(_(no_split_warning));
 896                                 write_bitmap_index = 0;
 897                         }
 898                 }
 899
 900                 if (!pack_to_stdout) {
 901                         struct stat st;
 902                         struct strbuf tmpname = STRBUF_INIT;
 903
 904                         /*
 905                          * Packs are runtime accessed in their mtime
 906                          * order since newer packs are more likely to contain
 907                          * younger objects.  So if we are creating multiple
 908                          * packs then we should modify the mtime of later ones
 909                          * to preserve this property.
 910                          */
 911                         if (stat(pack_tmp_name, &st) < 0) {
 912                                 warning_errno(_("failed to stat %s"), pack_tmp_name);
 913                         } else if (!last_mtime) {
 914                                 last_mtime = st.st_mtime;
 915                         } else {
 916                                 struct utimbuf utb;
 917                                 utb.actime = st.st_atime;
 918                                 utb.modtime = --last_mtime;
 919                                 if (utime(pack_tmp_name, &utb) < 0)
 920                                         warning_errno(_("failed utime() on %s"), pack_tmp_name);
 921                         }
 922
 923                         strbuf_addf(&tmpname, "%s-", base_name);
 924
 925                         if (write_bitmap_index) {
 926                                 bitmap_writer_set_checksum(oid.hash);
 927                                 bitmap_writer_build_type_index(
 928                                         &to_pack, written_list, nr_written);
 929                         }
 930
 931                         finish_tmp_packfile(&tmpname, pack_tmp_name,
 932                                             written_list, nr_written,
 933                                             &pack_idx_opts, oid.hash);
 934
 935                         if (write_bitmap_index) {
 936                                 strbuf_addf(&tmpname, "%s.bitmap", oid_to_hex(&oid));
 937
 938                                 stop_progress(&progress_state);
 939
 940                                 bitmap_writer_show_progress(progress);
 941                                 bitmap_writer_reuse_bitmaps(&to_pack);
 942                                 bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 943                                 bitmap_writer_build(&to_pack);
 944                                 bitmap_writer_finish(written_list, nr_written,
 945                                                      tmpname.buf, write_bitmap_options);
 946                                 write_bitmap_index = 0;
 947                         }
 948
 949                         strbuf_release(&tmpname);
 950                         free(pack_tmp_name);
 951                         puts(oid_to_hex(&oid));
 952                 }
 953
 954                 /* mark written objects as written to previous pack */
 955                 for (j = 0; j < nr_written; j++) {
 956                         written_list[j]->offset = (off_t)-1;
 957                 }
 958                 nr_remaining -= nr_written;
 959         } while (nr_remaining && i < to_pack.nr_objects);
 960
 961         free(written_list);
 962         free(write_order);
 963         stop_progress(&progress_state);
 964         if (written != nr_result)
 965                 die(_("wrote %"PRIu32" objects while expecting %"PRIu32),
 966                     written, nr_result);
 967 }
 968
 969 static int no_try_delta(const char *path)
 970 {
 971         static struct attr_check *check;
 972
 973         if (!check)
 974                 check = attr_check_initl("delta", NULL);
 975         git_check_attr(the_repository->index, path, check);
 976         if (ATTR_FALSE(check->items[0].value))
 977                 return 1;
 978         return 0;
 979 }
 980
 981 /*
 982  * When adding an object, check whether we have already added it
 983  * to our packing list. If so, we can skip. However, if we are
 984  * being asked to excludei t, but the previous mention was to include
 985  * it, make sure to adjust its flags and tweak our numbers accordingly.
 986  *
 987  * As an optimization, we pass out the index position where we would have
 988  * found the item, since that saves us from having to look it up again a
 989  * few lines later when we want to add the new entry.
 990  */
 991 static int have_duplicate_entry(const struct object_id *oid,
 992                                 int exclude,
 993                                 uint32_t *index_pos)
 994 {
 995         struct object_entry *entry;
 996
 997         entry = packlist_find(&to_pack, oid->hash, index_pos);
 998         if (!entry)
 999                 return 0;
1000
1001         if (exclude) {
1002                 if (!entry->preferred_base)
1003                         nr_result--;
1004                 entry->preferred_base = 1;
1005         }
1006
1007         return 1;
1008 }
1009
1010 static int want_found_object(int exclude, struct packed_git *p)
1011 {
1012         if (exclude)
1013                 return 1;
1014         if (incremental)
1015                 return 0;
1016
1017         /*
1018          * When asked to do --local (do not include an object that appears in a
1019          * pack we borrow from elsewhere) or --honor-pack-keep (do not include
1020          * an object that appears in a pack marked with .keep), finding a pack
1021          * that matches the criteria is sufficient for us to decide to omit it.
1022          * However, even if this pack does not satisfy the criteria, we need to
1023          * make sure no copy of this object appears in _any_ pack that makes us
1024          * to omit the object, so we need to check all the packs.
1025          *
1026          * We can however first check whether these options can possible matter;
1027          * if they do not matter we know we want the object in generated pack.
1028          * Otherwise, we signal "-1" at the end to tell the caller that we do
1029          * not know either way, and it needs to check more packs.
1030          */
1031         if (!ignore_packed_keep_on_disk &&
1032             !ignore_packed_keep_in_core &&
1033             (!local || !have_non_local_packs))
1034                 return 1;
1035
1036         if (local && !p->pack_local)
1037                 return 0;
1038         if (p->pack_local &&
1039             ((ignore_packed_keep_on_disk && p->pack_keep) ||
1040              (ignore_packed_keep_in_core && p->pack_keep_in_core)))
1041                 return 0;
1042
1043         /* we don't know yet; keep looking for more packs */
1044         return -1;
1045 }
1046
1047 /*
1048  * Check whether we want the object in the pack (e.g., we do not want
1049  * objects found in non-local stores if the "--local" option was used).
1050  *
1051  * If the caller already knows an existing pack it wants to take the object
1052  * from, that is passed in *found_pack and *found_offset; otherwise this
1053  * function finds if there is any pack that has the object and returns the pack
1054  * and its offset in these variables.
1055  */
1056 static int want_object_in_pack(const struct object_id *oid,
1057                                int exclude,
1058                                struct packed_git **found_pack,
1059                                off_t *found_offset)
1060 {
1061         int want;
1062         struct list_head *pos;
1063         struct multi_pack_index *m;
1064
1065         if (!exclude && local && has_loose_object_nonlocal(oid))
1066                 return 0;
1067
1068         /*
1069          * If we already know the pack object lives in, start checks from that
1070          * pack - in the usual case when neither --local was given nor .keep files
1071          * are present we will determine the answer right now.
1072          */
1073         if (*found_pack) {
1074                 want = want_found_object(exclude, *found_pack);
1075                 if (want != -1)
1076                         return want;
1077         }
1078
1079         for (m = get_multi_pack_index(the_repository); m; m = m->next) {
1080                 struct pack_entry e;
1081                 if (fill_midx_entry(oid, &e, m)) {
1082                         struct packed_git *p = e.p;
1083                         off_t offset;
1084
1085                         if (p == *found_pack)
1086                                 offset = *found_offset;
1087                         else
1088                                 offset = find_pack_entry_one(oid->hash, p);
1089
1090                         if (offset) {
1091                                 if (!*found_pack) {
1092                                         if (!is_pack_valid(p))
1093                                                 continue;
1094                                         *found_offset = offset;
1095                                         *found_pack = p;
1096                                 }
1097                                 want = want_found_object(exclude, p);
1098                                 if (want != -1)
1099                                         return want;
1100                         }
1101                 }
1102         }
1103
1104         list_for_each(pos, get_packed_git_mru(the_repository)) {
1105                 struct packed_git *p = list_entry(pos, struct packed_git, mru);
1106                 off_t offset;
1107
1108                 if (p == *found_pack)
1109                         offset = *found_offset;
1110                 else
1111                         offset = find_pack_entry_one(oid->hash, p);
1112
1113                 if (offset) {
1114                         if (!*found_pack) {
1115                                 if (!is_pack_valid(p))
1116                                         continue;
1117                                 *found_offset = offset;
1118                                 *found_pack = p;
1119                         }
1120                         want = want_found_object(exclude, p);
1121                         if (!exclude && want > 0)
1122                                 list_move(&p->mru,
1123                                           get_packed_git_mru(the_repository));
1124                         if (want != -1)
1125                                 return want;
1126                 }
1127         }
1128
1129         return 1;
1130 }
1131
1132 static void create_object_entry(const struct object_id *oid,
1133                                 enum object_type type,
1134                                 uint32_t hash,
1135                                 int exclude,
1136                                 int no_try_delta,
1137                                 uint32_t index_pos,
1138                                 struct packed_git *found_pack,
1139                                 off_t found_offset)
1140 {
1141         struct object_entry *entry;
1142
1143         entry = packlist_alloc(&to_pack, oid->hash, index_pos);
1144         entry->hash = hash;
1145         oe_set_type(entry, type);
1146         if (exclude)
1147                 entry->preferred_base = 1;
1148         else
1149                 nr_result++;
1150         if (found_pack) {
1151                 oe_set_in_pack(&to_pack, entry, found_pack);
1152                 entry->in_pack_offset = found_offset;
1153         }
1154
1155         entry->no_try_delta = no_try_delta;
1156 }
1157
1158 static const char no_closure_warning[] = N_(
1159 "disabling bitmap writing, as some objects are not being packed"
1160 );
1161
1162 static int add_object_entry(const struct object_id *oid, enum object_type type,
1163                             const char *name, int exclude)
1164 {
1165         struct packed_git *found_pack = NULL;
1166         off_t found_offset = 0;
1167         uint32_t index_pos;
1168
1169         display_progress(progress_state, ++nr_seen);
1170
1171         if (have_duplicate_entry(oid, exclude, &index_pos))
1172                 return 0;
1173
1174         if (!want_object_in_pack(oid, exclude, &found_pack, &found_offset)) {
1175                 /* The pack is missing an object, so it will not have closure */
1176                 if (write_bitmap_index) {
1177                         warning(_(no_closure_warning));
1178                         write_bitmap_index = 0;
1179                 }
1180                 return 0;
1181         }
1182
1183         create_object_entry(oid, type, pack_name_hash(name),
1184                             exclude, name && no_try_delta(name),
1185                             index_pos, found_pack, found_offset);
1186         return 1;
1187 }
1188
1189 static int add_object_entry_from_bitmap(const struct object_id *oid,
1190                                         enum object_type type,
1191                                         int flags, uint32_t name_hash,
1192                                         struct packed_git *pack, off_t offset)
1193 {
1194         uint32_t index_pos;
1195
1196         display_progress(progress_state, ++nr_seen);
1197
1198         if (have_duplicate_entry(oid, 0, &index_pos))
1199                 return 0;
1200
1201         if (!want_object_in_pack(oid, 0, &pack, &offset))
1202                 return 0;
1203
1204         create_object_entry(oid, type, name_hash, 0, 0, index_pos, pack, offset);
1205         return 1;
1206 }
1207
1208 struct pbase_tree_cache {
1209         struct object_id oid;
1210         int ref;
1211         int temporary;
1212         void *tree_data;
1213         unsigned long tree_size;
1214 };
1215
1216 static struct pbase_tree_cache *(pbase_tree_cache[256]);
1217 static int pbase_tree_cache_ix(const struct object_id *oid)
1218 {
1219         return oid->hash[0] % ARRAY_SIZE(pbase_tree_cache);
1220 }
1221 static int pbase_tree_cache_ix_incr(int ix)
1222 {
1223         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
1224 }
1225
1226 static struct pbase_tree {
1227         struct pbase_tree *next;
1228         /* This is a phony "cache" entry; we are not
1229          * going to evict it or find it through _get()
1230          * mechanism -- this is for the toplevel node that
1231          * would almost always change with any commit.
1232          */
1233         struct pbase_tree_cache pcache;
1234 } *pbase_tree;
1235
1236 static struct pbase_tree_cache *pbase_tree_get(const struct object_id *oid)
1237 {
1238         struct pbase_tree_cache *ent, *nent;
1239         void *data;
1240         unsigned long size;
1241         enum object_type type;
1242         int neigh;
1243         int my_ix = pbase_tree_cache_ix(oid);
1244         int available_ix = -1;
1245
1246         /* pbase-tree-cache acts as a limited hashtable.
1247          * your object will be found at your index or within a few
1248          * slots after that slot if it is cached.
1249          */
1250         for (neigh = 0; neigh < 8; neigh++) {
1251                 ent = pbase_tree_cache[my_ix];
1252                 if (ent && oideq(&ent->oid, oid)) {
1253                         ent->ref++;
1254                         return ent;
1255                 }
1256                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1257                          ((0 <= available_ix) &&
1258                           (!ent && pbase_tree_cache[available_ix])))
1259                         available_ix = my_ix;
1260                 if (!ent)
1261                         break;
1262                 my_ix = pbase_tree_cache_ix_incr(my_ix);
1263         }
1264
1265         /* Did not find one.  Either we got a bogus request or
1266          * we need to read and perhaps cache.
1267          */
1268         data = read_object_file(oid, &type, &size);
1269         if (!data)
1270                 return NULL;
1271         if (type != OBJ_TREE) {
1272                 free(data);
1273                 return NULL;
1274         }
1275
1276         /* We need to either cache or return a throwaway copy */
1277
1278         if (available_ix < 0)
1279                 ent = NULL;
1280         else {
1281                 ent = pbase_tree_cache[available_ix];
1282                 my_ix = available_ix;
1283         }
1284
1285         if (!ent) {
1286                 nent = xmalloc(sizeof(*nent));
1287                 nent->temporary = (available_ix < 0);
1288         }
1289         else {
1290                 /* evict and reuse */
1291                 free(ent->tree_data);
1292                 nent = ent;
1293         }
1294         oidcpy(&nent->oid, oid);
1295         nent->tree_data = data;
1296         nent->tree_size = size;
1297         nent->ref = 1;
1298         if (!nent->temporary)
1299                 pbase_tree_cache[my_ix] = nent;
1300         return nent;
1301 }
1302
1303 static void pbase_tree_put(struct pbase_tree_cache *cache)
1304 {
1305         if (!cache->temporary) {
1306                 cache->ref--;
1307                 return;
1308         }
1309         free(cache->tree_data);
1310         free(cache);
1311 }
1312
1313 static int name_cmp_len(const char *name)
1314 {
1315         int i;
1316         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1317                 ;
1318         return i;
1319 }
1320
1321 static void add_pbase_object(struct tree_desc *tree,
1322                              const char *name,
1323                              int cmplen,
1324                              const char *fullname)
1325 {
1326         struct name_entry entry;
1327         int cmp;
1328
1329         while (tree_entry(tree,&entry)) {
1330                 if (S_ISGITLINK(entry.mode))
1331                         continue;
1332                 cmp = tree_entry_len(&entry) != cmplen ? 1 :
1333                       memcmp(name, entry.path, cmplen);
1334                 if (cmp > 0)
1335                         continue;
1336                 if (cmp < 0)
1337                         return;
1338                 if (name[cmplen] != '/') {
1339                         add_object_entry(&entry.oid,
1340                                          object_type(entry.mode),
1341                                          fullname, 1);
1342                         return;
1343                 }
1344                 if (S_ISDIR(entry.mode)) {
1345                         struct tree_desc sub;
1346                         struct pbase_tree_cache *tree;
1347                         const char *down = name+cmplen+1;
1348                         int downlen = name_cmp_len(down);
1349
1350                         tree = pbase_tree_get(&entry.oid);
1351                         if (!tree)
1352                                 return;
1353                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1354
1355                         add_pbase_object(&sub, down, downlen, fullname);
1356                         pbase_tree_put(tree);
1357                 }
1358         }
1359 }
1360
1361 static unsigned *done_pbase_paths;
1362 static int done_pbase_paths_num;
1363 static int done_pbase_paths_alloc;
1364 static int done_pbase_path_pos(unsigned hash)
1365 {
1366         int lo = 0;
1367         int hi = done_pbase_paths_num;
1368         while (lo < hi) {
1369                 int mi = lo + (hi - lo) / 2;
1370                 if (done_pbase_paths[mi] == hash)
1371                         return mi;
1372                 if (done_pbase_paths[mi] < hash)
1373                         hi = mi;
1374                 else
1375                         lo = mi + 1;
1376         }
1377         return -lo-1;
1378 }
1379
1380 static int check_pbase_path(unsigned hash)
1381 {
1382         int pos = done_pbase_path_pos(hash);
1383         if (0 <= pos)
1384                 return 1;
1385         pos = -pos - 1;
1386         ALLOC_GROW(done_pbase_paths,
1387                    done_pbase_paths_num + 1,
1388                    done_pbase_paths_alloc);
1389         done_pbase_paths_num++;
1390         if (pos < done_pbase_paths_num)
1391                 MOVE_ARRAY(done_pbase_paths + pos + 1, done_pbase_paths + pos,
1392                            done_pbase_paths_num - pos - 1);
1393         done_pbase_paths[pos] = hash;
1394         return 0;
1395 }
1396
1397 static void add_preferred_base_object(const char *name)
1398 {
1399         struct pbase_tree *it;
1400         int cmplen;
1401         unsigned hash = pack_name_hash(name);
1402
1403         if (!num_preferred_base || check_pbase_path(hash))
1404                 return;
1405
1406         cmplen = name_cmp_len(name);
1407         for (it = pbase_tree; it; it = it->next) {
1408                 if (cmplen == 0) {
1409                         add_object_entry(&it->pcache.oid, OBJ_TREE, NULL, 1);
1410                 }
1411                 else {
1412                         struct tree_desc tree;
1413                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1414                         add_pbase_object(&tree, name, cmplen, name);
1415                 }
1416         }
1417 }
1418
1419 static void add_preferred_base(struct object_id *oid)
1420 {
1421         struct pbase_tree *it;
1422         void *data;
1423         unsigned long size;
1424         struct object_id tree_oid;
1425
1426         if (window <= num_preferred_base++)
1427                 return;
1428
1429         data = read_object_with_reference(oid, tree_type, &size, &tree_oid);
1430         if (!data)
1431                 return;
1432
1433         for (it = pbase_tree; it; it = it->next) {
1434                 if (oideq(&it->pcache.oid, &tree_oid)) {
1435                         free(data);
1436                         return;
1437                 }
1438         }
1439
1440         it = xcalloc(1, sizeof(*it));
1441         it->next = pbase_tree;
1442         pbase_tree = it;
1443
1444         oidcpy(&it->pcache.oid, &tree_oid);
1445         it->pcache.tree_data = data;
1446         it->pcache.tree_size = size;
1447 }
1448
1449 static void cleanup_preferred_base(void)
1450 {
1451         struct pbase_tree *it;
1452         unsigned i;
1453
1454         it = pbase_tree;
1455         pbase_tree = NULL;
1456         while (it) {
1457                 struct pbase_tree *tmp = it;
1458                 it = tmp->next;
1459                 free(tmp->pcache.tree_data);
1460                 free(tmp);
1461         }
1462
1463         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1464                 if (!pbase_tree_cache[i])
1465                         continue;
1466                 free(pbase_tree_cache[i]->tree_data);
1467                 FREE_AND_NULL(pbase_tree_cache[i]);
1468         }
1469
1470         FREE_AND_NULL(done_pbase_paths);
1471         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1472 }
1473
1474 /*
1475  * Return 1 iff the object specified by "delta" can be sent
1476  * literally as a delta against the base in "base_sha1". If
1477  * so, then *base_out will point to the entry in our packing
1478  * list, or NULL if we must use the external-base list.
1479  *
1480  * Depth value does not matter - find_deltas() will
1481  * never consider reused delta as the base object to
1482  * deltify other objects against, in order to avoid
1483  * circular deltas.
1484  */
1485 static int can_reuse_delta(const unsigned char *base_sha1,
1486                            struct object_entry *delta,
1487                            struct object_entry **base_out)
1488 {
1489         struct object_entry *base;
1490
1491         if (!base_sha1)
1492                 return 0;
1493
1494         /*
1495          * First see if we're already sending the base (or it's explicitly in
1496          * our "excluded" list).
1497          */
1498         base = packlist_find(&to_pack, base_sha1, NULL);
1499         if (base) {
1500                 if (!in_same_island(&delta->idx.oid, &base->idx.oid))
1501                         return 0;
1502                 *base_out = base;
1503                 return 1;
1504         }
1505
1506         /*
1507          * Otherwise, reachability bitmaps may tell us if the receiver has it,
1508          * even if it was buried too deep in history to make it into the
1509          * packing list.
1510          */
1511         if (thin && bitmap_has_sha1_in_uninteresting(bitmap_git, base_sha1)) {
1512                 if (use_delta_islands) {
1513                         struct object_id base_oid;
1514                         hashcpy(base_oid.hash, base_sha1);
1515                         if (!in_same_island(&delta->idx.oid, &base_oid))
1516                                 return 0;
1517                 }
1518                 *base_out = NULL;
1519                 return 1;
1520         }
1521
1522         return 0;
1523 }
1524
1525 static void check_object(struct object_entry *entry)
1526 {
1527         unsigned long canonical_size;
1528
1529         if (IN_PACK(entry)) {
1530                 struct packed_git *p = IN_PACK(entry);
1531                 struct pack_window *w_curs = NULL;
1532                 const unsigned char *base_ref = NULL;
1533                 struct object_entry *base_entry;
1534                 unsigned long used, used_0;
1535                 unsigned long avail;
1536                 off_t ofs;
1537                 unsigned char *buf, c;
1538                 enum object_type type;
1539                 unsigned long in_pack_size;
1540
1541                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1542
1543                 /*
1544                  * We want in_pack_type even if we do not reuse delta
1545                  * since non-delta representations could still be reused.
1546                  */
1547                 used = unpack_object_header_buffer(buf, avail,
1548                                                    &type,
1549                                                    &in_pack_size);
1550                 if (used == 0)
1551                         goto give_up;
1552
1553                 if (type < 0)
1554                         BUG("invalid type %d", type);
1555                 entry->in_pack_type = type;
1556
1557                 /*
1558                  * Determine if this is a delta and if so whether we can
1559                  * reuse it or not.  Otherwise let's find out as cheaply as
1560                  * possible what the actual type and size for this object is.
1561                  */
1562                 switch (entry->in_pack_type) {
1563                 default:
1564                         /* Not a delta hence we've already got all we need. */
1565                         oe_set_type(entry, entry->in_pack_type);
1566                         SET_SIZE(entry, in_pack_size);
1567                         entry->in_pack_header_size = used;
1568                         if (oe_type(entry) < OBJ_COMMIT || oe_type(entry) > OBJ_BLOB)
1569                                 goto give_up;
1570                         unuse_pack(&w_curs);
1571                         return;
1572                 case OBJ_REF_DELTA:
1573                         if (reuse_delta && !entry->preferred_base)
1574                                 base_ref = use_pack(p, &w_curs,
1575                                                 entry->in_pack_offset + used, NULL);
1576                         entry->in_pack_header_size = used + the_hash_algo->rawsz;
1577                         break;
1578                 case OBJ_OFS_DELTA:
1579                         buf = use_pack(p, &w_curs,
1580                                        entry->in_pack_offset + used, NULL);
1581                         used_0 = 0;
1582                         c = buf[used_0++];
1583                         ofs = c & 127;
1584                         while (c & 128) {
1585                                 ofs += 1;
1586                                 if (!ofs || MSB(ofs, 7)) {
1587                                         error(_("delta base offset overflow in pack for %s"),
1588                                               oid_to_hex(&entry->idx.oid));
1589                                         goto give_up;
1590                                 }
1591                                 c = buf[used_0++];
1592                                 ofs = (ofs << 7) + (c & 127);
1593                         }
1594                         ofs = entry->in_pack_offset - ofs;
1595                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1596                                 error(_("delta base offset out of bound for %s"),
1597                                       oid_to_hex(&entry->idx.oid));
1598                                 goto give_up;
1599                         }
1600                         if (reuse_delta && !entry->preferred_base) {
1601                                 struct revindex_entry *revidx;
1602                                 revidx = find_pack_revindex(p, ofs);
1603                                 if (!revidx)
1604                                         goto give_up;
1605                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1606                         }
1607                         entry->in_pack_header_size = used + used_0;
1608                         break;
1609                 }
1610
1611                 if (can_reuse_delta(base_ref, entry, &base_entry)) {
1612                         oe_set_type(entry, entry->in_pack_type);
1613                         SET_SIZE(entry, in_pack_size); /* delta size */
1614                         SET_DELTA_SIZE(entry, in_pack_size);
1615
1616                         if (base_entry) {
1617                                 SET_DELTA(entry, base_entry);
1618                                 entry->delta_sibling_idx = base_entry->delta_child_idx;
1619                                 SET_DELTA_CHILD(base_entry, entry);
1620                         } else {
1621                                 SET_DELTA_EXT(entry, base_ref);
1622                         }
1623
1624                         unuse_pack(&w_curs);
1625                         return;
1626                 }
1627
1628                 if (oe_type(entry)) {
1629                         off_t delta_pos;
1630
1631                         /*
1632                          * This must be a delta and we already know what the
1633                          * final object type is.  Let's extract the actual
1634                          * object size from the delta header.
1635                          */
1636                         delta_pos = entry->in_pack_offset + entry->in_pack_header_size;
1637                         canonical_size = get_size_from_delta(p, &w_curs, delta_pos);
1638                         if (canonical_size == 0)
1639                                 goto give_up;
1640                         SET_SIZE(entry, canonical_size);
1641                         unuse_pack(&w_curs);
1642                         return;
1643                 }
1644
1645                 /*
1646                  * No choice but to fall back to the recursive delta walk
1647                  * with oid_object_info() to find about the object type
1648                  * at this point...
1649                  */
1650                 give_up:
1651                 unuse_pack(&w_curs);
1652         }
1653
1654         oe_set_type(entry,
1655                     oid_object_info(the_repository, &entry->idx.oid, &canonical_size));
1656         if (entry->type_valid) {
1657                 SET_SIZE(entry, canonical_size);
1658         } else {
1659                 /*
1660                  * Bad object type is checked in prepare_pack().  This is
1661                  * to permit a missing preferred base object to be ignored
1662                  * as a preferred base.  Doing so can result in a larger
1663                  * pack file, but the transfer will still take place.
1664                  */
1665         }
1666 }
1667
1668 static int pack_offset_sort(const void *_a, const void *_b)
1669 {
1670         const struct object_entry *a = *(struct object_entry **)_a;
1671         const struct object_entry *b = *(struct object_entry **)_b;
1672         const struct packed_git *a_in_pack = IN_PACK(a);
1673         const struct packed_git *b_in_pack = IN_PACK(b);
1674
1675         /* avoid filesystem trashing with loose objects */
1676         if (!a_in_pack && !b_in_pack)
1677                 return oidcmp(&a->idx.oid, &b->idx.oid);
1678
1679         if (a_in_pack < b_in_pack)
1680                 return -1;
1681         if (a_in_pack > b_in_pack)
1682                 return 1;
1683         return a->in_pack_offset < b->in_pack_offset ? -1 :
1684                         (a->in_pack_offset > b->in_pack_offset);
1685 }
1686
1687 /*
1688  * Drop an on-disk delta we were planning to reuse. Naively, this would
1689  * just involve blanking out the "delta" field, but we have to deal
1690  * with some extra book-keeping:
1691  *
1692  *   1. Removing ourselves from the delta_sibling linked list.
1693  *
1694  *   2. Updating our size/type to the non-delta representation. These were
1695  *      either not recorded initially (size) or overwritten with the delta type
1696  *      (type) when check_object() decided to reuse the delta.
1697  *
1698  *   3. Resetting our delta depth, as we are now a base object.
1699  */
1700 static void drop_reused_delta(struct object_entry *entry)
1701 {
1702         unsigned *idx = &to_pack.objects[entry->delta_idx - 1].delta_child_idx;
1703         struct object_info oi = OBJECT_INFO_INIT;
1704         enum object_type type;
1705         unsigned long size;
1706
1707         while (*idx) {
1708                 struct object_entry *oe = &to_pack.objects[*idx - 1];
1709
1710                 if (oe == entry)
1711                         *idx = oe->delta_sibling_idx;
1712                 else
1713                         idx = &oe->delta_sibling_idx;
1714         }
1715         SET_DELTA(entry, NULL);
1716         entry->depth = 0;
1717
1718         oi.sizep = &size;
1719         oi.typep = &type;
1720         if (packed_object_info(the_repository, IN_PACK(entry), entry->in_pack_offset, &oi) < 0) {
1721                 /*
1722                  * We failed to get the info from this pack for some reason;
1723                  * fall back to oid_object_info, which may find another copy.
1724                  * And if that fails, the error will be recorded in oe_type(entry)
1725                  * and dealt with in prepare_pack().
1726                  */
1727                 oe_set_type(entry,
1728                             oid_object_info(the_repository, &entry->idx.oid, &size));
1729         } else {
1730                 oe_set_type(entry, type);
1731         }
1732         SET_SIZE(entry, size);
1733 }
1734
1735 /*
1736  * Follow the chain of deltas from this entry onward, throwing away any links
1737  * that cause us to hit a cycle (as determined by the DFS state flags in
1738  * the entries).
1739  *
1740  * We also detect too-long reused chains that would violate our --depth
1741  * limit.
1742  */
1743 static void break_delta_chains(struct object_entry *entry)
1744 {
1745         /*
1746          * The actual depth of each object we will write is stored as an int,
1747          * as it cannot exceed our int "depth" limit. But before we break
1748          * changes based no that limit, we may potentially go as deep as the
1749          * number of objects, which is elsewhere bounded to a uint32_t.
1750          */
1751         uint32_t total_depth;
1752         struct object_entry *cur, *next;
1753
1754         for (cur = entry, total_depth = 0;
1755              cur;
1756              cur = DELTA(cur), total_depth++) {
1757                 if (cur->dfs_state == DFS_DONE) {
1758                         /*
1759                          * We've already seen this object and know it isn't
1760                          * part of a cycle. We do need to append its depth
1761                          * to our count.
1762                          */
1763                         total_depth += cur->depth;
1764                         break;
1765                 }
1766
1767                 /*
1768                  * We break cycles before looping, so an ACTIVE state (or any
1769                  * other cruft which made its way into the state variable)
1770                  * is a bug.
1771                  */
1772                 if (cur->dfs_state != DFS_NONE)
1773                         BUG("confusing delta dfs state in first pass: %d",
1774                             cur->dfs_state);
1775
1776                 /*
1777                  * Now we know this is the first time we've seen the object. If
1778                  * it's not a delta, we're done traversing, but we'll mark it
1779                  * done to save time on future traversals.
1780                  */
1781                 if (!DELTA(cur)) {
1782                         cur->dfs_state = DFS_DONE;
1783                         break;
1784                 }
1785
1786                 /*
1787                  * Mark ourselves as active and see if the next step causes
1788                  * us to cycle to another active object. It's important to do
1789                  * this _before_ we loop, because it impacts where we make the
1790                  * cut, and thus how our total_depth counter works.
1791                  * E.g., We may see a partial loop like:
1792                  *
1793                  *   A -> B -> C -> D -> B
1794                  *
1795                  * Cutting B->C breaks the cycle. But now the depth of A is
1796                  * only 1, and our total_depth counter is at 3. The size of the
1797                  * error is always one less than the size of the cycle we
1798                  * broke. Commits C and D were "lost" from A's chain.
1799                  *
1800                  * If we instead cut D->B, then the depth of A is correct at 3.
1801                  * We keep all commits in the chain that we examined.
1802                  */
1803                 cur->dfs_state = DFS_ACTIVE;
1804                 if (DELTA(cur)->dfs_state == DFS_ACTIVE) {
1805                         drop_reused_delta(cur);
1806                         cur->dfs_state = DFS_DONE;
1807                         break;
1808                 }
1809         }
1810
1811         /*
1812          * And now that we've gone all the way to the bottom of the chain, we
1813          * need to clear the active flags and set the depth fields as
1814          * appropriate. Unlike the loop above, which can quit when it drops a
1815          * delta, we need to keep going to look for more depth cuts. So we need
1816          * an extra "next" pointer to keep going after we reset cur->delta.
1817          */
1818         for (cur = entry; cur; cur = next) {
1819                 next = DELTA(cur);
1820
1821                 /*
1822                  * We should have a chain of zero or more ACTIVE states down to
1823                  * a final DONE. We can quit after the DONE, because either it
1824                  * has no bases, or we've already handled them in a previous
1825                  * call.
1826                  */
1827                 if (cur->dfs_state == DFS_DONE)
1828                         break;
1829                 else if (cur->dfs_state != DFS_ACTIVE)
1830                         BUG("confusing delta dfs state in second pass: %d",
1831                             cur->dfs_state);
1832
1833                 /*
1834                  * If the total_depth is more than depth, then we need to snip
1835                  * the chain into two or more smaller chains that don't exceed
1836                  * the maximum depth. Most of the resulting chains will contain
1837                  * (depth + 1) entries (i.e., depth deltas plus one base), and
1838                  * the last chain (i.e., the one containing entry) will contain
1839                  * whatever entries are left over, namely
1840                  * (total_depth % (depth + 1)) of them.
1841                  *
1842                  * Since we are iterating towards decreasing depth, we need to
1843                  * decrement total_depth as we go, and we need to write to the
1844                  * entry what its final depth will be after all of the
1845                  * snipping. Since we're snipping into chains of length (depth
1846                  * + 1) entries, the final depth of an entry will be its
1847                  * original depth modulo (depth + 1). Any time we encounter an
1848                  * entry whose final depth is supposed to be zero, we snip it
1849                  * from its delta base, thereby making it so.
1850                  */
1851                 cur->depth = (total_depth--) % (depth + 1);
1852                 if (!cur->depth)
1853                         drop_reused_delta(cur);
1854
1855                 cur->dfs_state = DFS_DONE;
1856         }
1857 }
1858
1859 static void get_object_details(void)
1860 {
1861         uint32_t i;
1862         struct object_entry **sorted_by_offset;
1863
1864         if (progress)
1865                 progress_state = start_progress(_("Counting objects"),
1866                                                 to_pack.nr_objects);
1867
1868         sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
1869         for (i = 0; i < to_pack.nr_objects; i++)
1870                 sorted_by_offset[i] = to_pack.objects + i;
1871         QSORT(sorted_by_offset, to_pack.nr_objects, pack_offset_sort);
1872
1873         for (i = 0; i < to_pack.nr_objects; i++) {
1874                 struct object_entry *entry = sorted_by_offset[i];
1875                 check_object(entry);
1876                 if (entry->type_valid &&
1877                     oe_size_greater_than(&to_pack, entry, big_file_threshold))
1878                         entry->no_try_delta = 1;
1879                 display_progress(progress_state, i + 1);
1880         }
1881         stop_progress(&progress_state);
1882
1883         /*
1884          * This must happen in a second pass, since we rely on the delta
1885          * information for the whole list being completed.
1886          */
1887         for (i = 0; i < to_pack.nr_objects; i++)
1888                 break_delta_chains(&to_pack.objects[i]);
1889
1890         free(sorted_by_offset);
1891 }
1892
1893 /*
1894  * We search for deltas in a list sorted by type, by filename hash, and then
1895  * by size, so that we see progressively smaller and smaller files.
1896  * That's because we prefer deltas to be from the bigger file
1897  * to the smaller -- deletes are potentially cheaper, but perhaps
1898  * more importantly, the bigger file is likely the more recent
1899  * one.  The deepest deltas are therefore the oldest objects which are
1900  * less susceptible to be accessed often.
1901  */
1902 static int type_size_sort(const void *_a, const void *_b)
1903 {
1904         const struct object_entry *a = *(struct object_entry **)_a;
1905         const struct object_entry *b = *(struct object_entry **)_b;
1906         const enum object_type a_type = oe_type(a);
1907         const enum object_type b_type = oe_type(b);
1908         const unsigned long a_size = SIZE(a);
1909         const unsigned long b_size = SIZE(b);
1910
1911         if (a_type > b_type)
1912                 return -1;
1913         if (a_type < b_type)
1914                 return 1;
1915         if (a->hash > b->hash)
1916                 return -1;
1917         if (a->hash < b->hash)
1918                 return 1;
1919         if (a->preferred_base > b->preferred_base)
1920                 return -1;
1921         if (a->preferred_base < b->preferred_base)
1922                 return 1;
1923         if (use_delta_islands) {
1924                 const int island_cmp = island_delta_cmp(&a->idx.oid, &b->idx.oid);
1925                 if (island_cmp)
1926                         return island_cmp;
1927         }
1928         if (a_size > b_size)
1929                 return -1;
1930         if (a_size < b_size)
1931                 return 1;
1932         return a < b ? -1 : (a > b);  /* newest first */
1933 }
1934
1935 struct unpacked {
1936         struct object_entry *entry;
1937         void *data;
1938         struct delta_index *index;
1939         unsigned depth;
1940 };
1941
1942 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1943                            unsigned long delta_size)
1944 {
1945         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1946                 return 0;
1947
1948         if (delta_size < cache_max_small_delta_size)
1949                 return 1;
1950
1951         /* cache delta, if objects are large enough compared to delta size */
1952         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1953                 return 1;
1954
1955         return 0;
1956 }
1957
1958 /* Protect delta_cache_size */
1959 static pthread_mutex_t cache_mutex;
1960 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1961 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1962
1963 /*
1964  * Protect object list partitioning (e.g. struct thread_param) and
1965  * progress_state
1966  */
1967 static pthread_mutex_t progress_mutex;
1968 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1969 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1970
1971 /*
1972  * Access to struct object_entry is unprotected since each thread owns
1973  * a portion of the main object list. Just don't access object entries
1974  * ahead in the list because they can be stolen and would need
1975  * progress_mutex for protection.
1976  */
1977
1978 /*
1979  * Return the size of the object without doing any delta
1980  * reconstruction (so non-deltas are true object sizes, but deltas
1981  * return the size of the delta data).
1982  */
1983 unsigned long oe_get_size_slow(struct packing_data *pack,
1984                                const struct object_entry *e)
1985 {
1986         struct packed_git *p;
1987         struct pack_window *w_curs;
1988         unsigned char *buf;
1989         enum object_type type;
1990         unsigned long used, avail, size;
1991
1992         if (e->type_ != OBJ_OFS_DELTA && e->type_ != OBJ_REF_DELTA) {
1993                 packing_data_lock(&to_pack);
1994                 if (oid_object_info(the_repository, &e->idx.oid, &size) < 0)
1995                         die(_("unable to get size of %s"),
1996                             oid_to_hex(&e->idx.oid));
1997                 packing_data_unlock(&to_pack);
1998                 return size;
1999         }
2000
2001         p = oe_in_pack(pack, e);
2002         if (!p)
2003                 BUG("when e->type is a delta, it must belong to a pack");
2004
2005         packing_data_lock(&to_pack);
2006         w_curs = NULL;
2007         buf = use_pack(p, &w_curs, e->in_pack_offset, &avail);
2008         used = unpack_object_header_buffer(buf, avail, &type, &size);
2009         if (used == 0)
2010                 die(_("unable to parse object header of %s"),
2011                     oid_to_hex(&e->idx.oid));
2012
2013         unuse_pack(&w_curs);
2014         packing_data_unlock(&to_pack);
2015         return size;
2016 }
2017
2018 static int try_delta(struct unpacked *trg, struct unpacked *src,
2019                      unsigned max_depth, unsigned long *mem_usage)
2020 {
2021         struct object_entry *trg_entry = trg->entry;
2022         struct object_entry *src_entry = src->entry;
2023         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
2024         unsigned ref_depth;
2025         enum object_type type;
2026         void *delta_buf;
2027
2028         /* Don't bother doing diffs between different types */
2029         if (oe_type(trg_entry) != oe_type(src_entry))
2030                 return -1;
2031
2032         /*
2033          * We do not bother to try a delta that we discarded on an
2034          * earlier try, but only when reusing delta data.  Note that
2035          * src_entry that is marked as the preferred_base should always
2036          * be considered, as even if we produce a suboptimal delta against
2037          * it, we will still save the transfer cost, as we already know
2038          * the other side has it and we won't send src_entry at all.
2039          */
2040         if (reuse_delta && IN_PACK(trg_entry) &&
2041             IN_PACK(trg_entry) == IN_PACK(src_entry) &&
2042             !src_entry->preferred_base &&
2043             trg_entry->in_pack_type != OBJ_REF_DELTA &&
2044             trg_entry->in_pack_type != OBJ_OFS_DELTA)
2045                 return 0;
2046
2047         /* Let's not bust the allowed depth. */
2048         if (src->depth >= max_depth)
2049                 return 0;
2050
2051         /* Now some size filtering heuristics. */
2052         trg_size = SIZE(trg_entry);
2053         if (!DELTA(trg_entry)) {
2054                 max_size = trg_size/2 - the_hash_algo->rawsz;
2055                 ref_depth = 1;
2056         } else {
2057                 max_size = DELTA_SIZE(trg_entry);
2058                 ref_depth = trg->depth;
2059         }
2060         max_size = (uint64_t)max_size * (max_depth - src->depth) /
2061                                                 (max_depth - ref_depth + 1);
2062         if (max_size == 0)
2063                 return 0;
2064         src_size = SIZE(src_entry);
2065         sizediff = src_size < trg_size ? trg_size - src_size : 0;
2066         if (sizediff >= max_size)
2067                 return 0;
2068         if (trg_size < src_size / 32)
2069                 return 0;
2070
2071         if (!in_same_island(&trg->entry->idx.oid, &src->entry->idx.oid))
2072                 return 0;
2073
2074         /* Load data if not already done */
2075         if (!trg->data) {
2076                 packing_data_lock(&to_pack);
2077                 trg->data = read_object_file(&trg_entry->idx.oid, &type, &sz);
2078                 packing_data_unlock(&to_pack);
2079                 if (!trg->data)
2080                         die(_("object %s cannot be read"),
2081                             oid_to_hex(&trg_entry->idx.oid));
2082                 if (sz != trg_size)
2083                         die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
2084                             oid_to_hex(&trg_entry->idx.oid), (uintmax_t)sz,
2085                             (uintmax_t)trg_size);
2086                 *mem_usage += sz;
2087         }
2088         if (!src->data) {
2089                 packing_data_lock(&to_pack);
2090                 src->data = read_object_file(&src_entry->idx.oid, &type, &sz);
2091                 packing_data_unlock(&to_pack);
2092                 if (!src->data) {
2093                         if (src_entry->preferred_base) {
2094                                 static int warned = 0;
2095                                 if (!warned++)
2096                                         warning(_("object %s cannot be read"),
2097                                                 oid_to_hex(&src_entry->idx.oid));
2098                                 /*
2099                                  * Those objects are not included in the
2100                                  * resulting pack.  Be resilient and ignore
2101                                  * them if they can't be read, in case the
2102                                  * pack could be created nevertheless.
2103                                  */
2104                                 return 0;
2105                         }
2106                         die(_("object %s cannot be read"),
2107                             oid_to_hex(&src_entry->idx.oid));
2108                 }
2109                 if (sz != src_size)
2110                         die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
2111                             oid_to_hex(&src_entry->idx.oid), (uintmax_t)sz,
2112                             (uintmax_t)src_size);
2113                 *mem_usage += sz;
2114         }
2115         if (!src->index) {
2116                 src->index = create_delta_index(src->data, src_size);
2117                 if (!src->index) {
2118                         static int warned = 0;
2119                         if (!warned++)
2120                                 warning(_("suboptimal pack - out of memory"));
2121                         return 0;
2122                 }
2123                 *mem_usage += sizeof_delta_index(src->index);
2124         }
2125
2126         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
2127         if (!delta_buf)
2128                 return 0;
2129
2130         if (DELTA(trg_entry)) {
2131                 /* Prefer only shallower same-sized deltas. */
2132                 if (delta_size == DELTA_SIZE(trg_entry) &&
2133                     src->depth + 1 >= trg->depth) {
2134                         free(delta_buf);
2135                         return 0;
2136                 }
2137         }
2138
2139         /*
2140          * Handle memory allocation outside of the cache
2141          * accounting lock.  Compiler will optimize the strangeness
2142          * away when NO_PTHREADS is defined.
2143          */
2144         free(trg_entry->delta_data);
2145         cache_lock();
2146         if (trg_entry->delta_data) {
2147                 delta_cache_size -= DELTA_SIZE(trg_entry);
2148                 trg_entry->delta_data = NULL;
2149         }
2150         if (delta_cacheable(src_size, trg_size, delta_size)) {
2151                 delta_cache_size += delta_size;
2152                 cache_unlock();
2153                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
2154         } else {
2155                 cache_unlock();
2156                 free(delta_buf);
2157         }
2158
2159         SET_DELTA(trg_entry, src_entry);
2160         SET_DELTA_SIZE(trg_entry, delta_size);
2161         trg->depth = src->depth + 1;
2162
2163         return 1;
2164 }
2165
2166 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
2167 {
2168         struct object_entry *child = DELTA_CHILD(me);
2169         unsigned int m = n;
2170         while (child) {
2171                 const unsigned int c = check_delta_limit(child, n + 1);
2172                 if (m < c)
2173                         m = c;
2174                 child = DELTA_SIBLING(child);
2175         }
2176         return m;
2177 }
2178
2179 static unsigned long free_unpacked(struct unpacked *n)
2180 {
2181         unsigned long freed_mem = sizeof_delta_index(n->index);
2182         free_delta_index(n->index);
2183         n->index = NULL;
2184         if (n->data) {
2185                 freed_mem += SIZE(n->entry);
2186                 FREE_AND_NULL(n->data);
2187         }
2188         n->entry = NULL;
2189         n->depth = 0;
2190         return freed_mem;
2191 }
2192
2193 static void find_deltas(struct object_entry **list, unsigned *list_size,
2194                         int window, int depth, unsigned *processed)
2195 {
2196         uint32_t i, idx = 0, count = 0;
2197         struct unpacked *array;
2198         unsigned long mem_usage = 0;
2199
2200         array = xcalloc(window, sizeof(struct unpacked));
2201
2202         for (;;) {
2203                 struct object_entry *entry;
2204                 struct unpacked *n = array + idx;
2205                 int j, max_depth, best_base = -1;
2206
2207                 progress_lock();
2208                 if (!*list_size) {
2209                         progress_unlock();
2210                         break;
2211                 }
2212                 entry = *list++;
2213                 (*list_size)--;
2214                 if (!entry->preferred_base) {
2215                         (*processed)++;
2216                         display_progress(progress_state, *processed);
2217                 }
2218                 progress_unlock();
2219
2220                 mem_usage -= free_unpacked(n);
2221                 n->entry = entry;
2222
2223                 while (window_memory_limit &&
2224                        mem_usage > window_memory_limit &&
2225                        count > 1) {
2226                         const uint32_t tail = (idx + window - count) % window;
2227                         mem_usage -= free_unpacked(array + tail);
2228                         count--;
2229                 }
2230
2231                 /* We do not compute delta to *create* objects we are not
2232                  * going to pack.
2233                  */
2234                 if (entry->preferred_base)
2235                         goto next;
2236
2237                 /*
2238                  * If the current object is at pack edge, take the depth the
2239                  * objects that depend on the current object into account
2240                  * otherwise they would become too deep.
2241                  */
2242                 max_depth = depth;
2243                 if (DELTA_CHILD(entry)) {
2244                         max_depth -= check_delta_limit(entry, 0);
2245                         if (max_depth <= 0)
2246                                 goto next;
2247                 }
2248
2249                 j = window;
2250                 while (--j > 0) {
2251                         int ret;
2252                         uint32_t other_idx = idx + j;
2253                         struct unpacked *m;
2254                         if (other_idx >= window)
2255                                 other_idx -= window;
2256                         m = array + other_idx;
2257                         if (!m->entry)
2258                                 break;
2259                         ret = try_delta(n, m, max_depth, &mem_usage);
2260                         if (ret < 0)
2261                                 break;
2262                         else if (ret > 0)
2263                                 best_base = other_idx;
2264                 }
2265
2266                 /*
2267                  * If we decided to cache the delta data, then it is best
2268                  * to compress it right away.  First because we have to do
2269                  * it anyway, and doing it here while we're threaded will
2270                  * save a lot of time in the non threaded write phase,
2271                  * as well as allow for caching more deltas within
2272                  * the same cache size limit.
2273                  * ...
2274                  * But only if not writing to stdout, since in that case
2275                  * the network is most likely throttling writes anyway,
2276                  * and therefore it is best to go to the write phase ASAP
2277                  * instead, as we can afford spending more time compressing
2278                  * between writes at that moment.
2279                  */
2280                 if (entry->delta_data && !pack_to_stdout) {
2281                         unsigned long size;
2282
2283                         size = do_compress(&entry->delta_data, DELTA_SIZE(entry));
2284                         if (size < (1U << OE_Z_DELTA_BITS)) {
2285                                 entry->z_delta_size = size;
2286                                 cache_lock();
2287                                 delta_cache_size -= DELTA_SIZE(entry);
2288                                 delta_cache_size += entry->z_delta_size;
2289                                 cache_unlock();
2290                         } else {
2291                                 FREE_AND_NULL(entry->delta_data);
2292                                 entry->z_delta_size = 0;
2293                         }
2294                 }
2295
2296                 /* if we made n a delta, and if n is already at max
2297                  * depth, leaving it in the window is pointless.  we
2298                  * should evict it first.
2299                  */
2300                 if (DELTA(entry) && max_depth <= n->depth)
2301                         continue;
2302
2303                 /*
2304                  * Move the best delta base up in the window, after the
2305                  * currently deltified object, to keep it longer.  It will
2306                  * be the first base object to be attempted next.
2307                  */
2308                 if (DELTA(entry)) {
2309                         struct unpacked swap = array[best_base];
2310                         int dist = (window + idx - best_base) % window;
2311                         int dst = best_base;
2312                         while (dist--) {
2313                                 int src = (dst + 1) % window;
2314                                 array[dst] = array[src];
2315                                 dst = src;
2316                         }
2317                         array[dst] = swap;
2318                 }
2319
2320                 next:
2321                 idx++;
2322                 if (count + 1 < window)
2323                         count++;
2324                 if (idx >= window)
2325                         idx = 0;
2326         }
2327
2328         for (i = 0; i < window; ++i) {
2329                 free_delta_index(array[i].index);
2330                 free(array[i].data);
2331         }
2332         free(array);
2333 }
2334
2335 static void try_to_free_from_threads(size_t size)
2336 {
2337         packing_data_lock(&to_pack);
2338         release_pack_memory(size);
2339         packing_data_unlock(&to_pack);
2340 }
2341
2342 static try_to_free_t old_try_to_free_routine;
2343
2344 /*
2345  * The main object list is split into smaller lists, each is handed to
2346  * one worker.
2347  *
2348  * The main thread waits on the condition that (at least) one of the workers
2349  * has stopped working (which is indicated in the .working member of
2350  * struct thread_params).
2351  *
2352  * When a work thread has completed its work, it sets .working to 0 and
2353  * signals the main thread and waits on the condition that .data_ready
2354  * becomes 1.
2355  *
2356  * The main thread steals half of the work from the worker that has
2357  * most work left to hand it to the idle worker.
2358  */
2359
2360 struct thread_params {
2361         pthread_t thread;
2362         struct object_entry **list;
2363         unsigned list_size;
2364         unsigned remaining;
2365         int window;
2366         int depth;
2367         int working;
2368         int data_ready;
2369         pthread_mutex_t mutex;
2370         pthread_cond_t cond;
2371         unsigned *processed;
2372 };
2373
2374 static pthread_cond_t progress_cond;
2375
2376 /*
2377  * Mutex and conditional variable can't be statically-initialized on Windows.
2378  */
2379 static void init_threaded_search(void)
2380 {
2381         pthread_mutex_init(&cache_mutex, NULL);
2382         pthread_mutex_init(&progress_mutex, NULL);
2383         pthread_cond_init(&progress_cond, NULL);
2384         old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
2385 }
2386
2387 static void cleanup_threaded_search(void)
2388 {
2389         set_try_to_free_routine(old_try_to_free_routine);
2390         pthread_cond_destroy(&progress_cond);
2391         pthread_mutex_destroy(&cache_mutex);
2392         pthread_mutex_destroy(&progress_mutex);
2393 }
2394
2395 static void *threaded_find_deltas(void *arg)
2396 {
2397         struct thread_params *me = arg;
2398
2399         progress_lock();
2400         while (me->remaining) {
2401                 progress_unlock();
2402
2403                 find_deltas(me->list, &me->remaining,
2404                             me->window, me->depth, me->processed);
2405
2406                 progress_lock();
2407                 me->working = 0;
2408                 pthread_cond_signal(&progress_cond);
2409                 progress_unlock();
2410
2411                 /*
2412                  * We must not set ->data_ready before we wait on the
2413                  * condition because the main thread may have set it to 1
2414                  * before we get here. In order to be sure that new
2415                  * work is available if we see 1 in ->data_ready, it
2416                  * was initialized to 0 before this thread was spawned
2417                  * and we reset it to 0 right away.
2418                  */
2419                 pthread_mutex_lock(&me->mutex);
2420                 while (!me->data_ready)
2421                         pthread_cond_wait(&me->cond, &me->mutex);
2422                 me->data_ready = 0;
2423                 pthread_mutex_unlock(&me->mutex);
2424
2425                 progress_lock();
2426         }
2427         progress_unlock();
2428         /* leave ->working 1 so that this doesn't get more work assigned */
2429         return NULL;
2430 }
2431
2432 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
2433                            int window, int depth, unsigned *processed)
2434 {
2435         struct thread_params *p;
2436         int i, ret, active_threads = 0;
2437
2438         init_threaded_search();
2439
2440         if (delta_search_threads <= 1) {
2441                 find_deltas(list, &list_size, window, depth, processed);
2442                 cleanup_threaded_search();
2443                 return;
2444         }
2445         if (progress > pack_to_stdout)
2446                 fprintf_ln(stderr, _("Delta compression using up to %d threads"),
2447                            delta_search_threads);
2448         p = xcalloc(delta_search_threads, sizeof(*p));
2449
2450         /* Partition the work amongst work threads. */
2451         for (i = 0; i < delta_search_threads; i++) {
2452                 unsigned sub_size = list_size / (delta_search_threads - i);
2453
2454                 /* don't use too small segments or no deltas will be found */
2455                 if (sub_size < 2*window && i+1 < delta_search_threads)
2456                         sub_size = 0;
2457
2458                 p[i].window = window;
2459                 p[i].depth = depth;
2460                 p[i].processed = processed;
2461                 p[i].working = 1;
2462                 p[i].data_ready = 0;
2463
2464                 /* try to split chunks on "path" boundaries */
2465                 while (sub_size && sub_size < list_size &&
2466                        list[sub_size]->hash &&
2467                        list[sub_size]->hash == list[sub_size-1]->hash)
2468                         sub_size++;
2469
2470                 p[i].list = list;
2471                 p[i].list_size = sub_size;
2472                 p[i].remaining = sub_size;
2473
2474                 list += sub_size;
2475                 list_size -= sub_size;
2476         }
2477
2478         /* Start work threads. */
2479         for (i = 0; i < delta_search_threads; i++) {
2480                 if (!p[i].list_size)
2481                         continue;
2482                 pthread_mutex_init(&p[i].mutex, NULL);
2483                 pthread_cond_init(&p[i].cond, NULL);
2484                 ret = pthread_create(&p[i].thread, NULL,
2485                                      threaded_find_deltas, &p[i]);
2486                 if (ret)
2487                         die(_("unable to create thread: %s"), strerror(ret));
2488                 active_threads++;
2489         }
2490
2491         /*
2492          * Now let's wait for work completion.  Each time a thread is done
2493          * with its work, we steal half of the remaining work from the
2494          * thread with the largest number of unprocessed objects and give
2495          * it to that newly idle thread.  This ensure good load balancing
2496          * until the remaining object list segments are simply too short
2497          * to be worth splitting anymore.
2498          */
2499         while (active_threads) {
2500                 struct thread_params *target = NULL;
2501                 struct thread_params *victim = NULL;
2502                 unsigned sub_size = 0;
2503
2504                 progress_lock();
2505                 for (;;) {
2506                         for (i = 0; !target && i < delta_search_threads; i++)
2507                                 if (!p[i].working)
2508                                         target = &p[i];
2509                         if (target)
2510                                 break;
2511                         pthread_cond_wait(&progress_cond, &progress_mutex);
2512                 }
2513
2514                 for (i = 0; i < delta_search_threads; i++)
2515                         if (p[i].remaining > 2*window &&
2516                             (!victim || victim->remaining < p[i].remaining))
2517                                 victim = &p[i];
2518                 if (victim) {
2519                         sub_size = victim->remaining / 2;
2520                         list = victim->list + victim->list_size - sub_size;
2521                         while (sub_size && list[0]->hash &&
2522                                list[0]->hash == list[-1]->hash) {
2523                                 list++;
2524                                 sub_size--;
2525                         }
2526                         if (!sub_size) {
2527                                 /*
2528                                  * It is possible for some "paths" to have
2529                                  * so many objects that no hash boundary
2530                                  * might be found.  Let's just steal the
2531                                  * exact half in that case.
2532                                  */
2533                                 sub_size = victim->remaining / 2;
2534                                 list -= sub_size;
2535                         }
2536                         target->list = list;
2537                         victim->list_size -= sub_size;
2538                         victim->remaining -= sub_size;
2539                 }
2540                 target->list_size = sub_size;
2541                 target->remaining = sub_size;
2542                 target->working = 1;
2543                 progress_unlock();
2544
2545                 pthread_mutex_lock(&target->mutex);
2546                 target->data_ready = 1;
2547                 pthread_cond_signal(&target->cond);
2548                 pthread_mutex_unlock(&target->mutex);
2549
2550                 if (!sub_size) {
2551                         pthread_join(target->thread, NULL);
2552                         pthread_cond_destroy(&target->cond);
2553                         pthread_mutex_destroy(&target->mutex);
2554                         active_threads--;
2555                 }
2556         }
2557         cleanup_threaded_search();
2558         free(p);
2559 }
2560
2561 static void add_tag_chain(const struct object_id *oid)
2562 {
2563         struct tag *tag;
2564
2565         /*
2566          * We catch duplicates already in add_object_entry(), but we'd
2567          * prefer to do this extra check to avoid having to parse the
2568          * tag at all if we already know that it's being packed (e.g., if
2569          * it was included via bitmaps, we would not have parsed it
2570          * previously).
2571          */
2572         if (packlist_find(&to_pack, oid->hash, NULL))
2573                 return;
2574
2575         tag = lookup_tag(the_repository, oid);
2576         while (1) {
2577                 if (!tag || parse_tag(tag) || !tag->tagged)
2578                         die(_("unable to pack objects reachable from tag %s"),
2579                             oid_to_hex(oid));
2580
2581                 add_object_entry(&tag->object.oid, OBJ_TAG, NULL, 0);
2582
2583                 if (tag->tagged->type != OBJ_TAG)
2584                         return;
2585
2586                 tag = (struct tag *)tag->tagged;
2587         }
2588 }
2589
2590 static int add_ref_tag(const char *path, const struct object_id *oid, int flag, void *cb_data)
2591 {
2592         struct object_id peeled;
2593
2594         if (starts_with(path, "refs/tags/") && /* is a tag? */
2595             !peel_ref(path, &peeled)    && /* peelable? */
2596             packlist_find(&to_pack, peeled.hash, NULL))      /* object packed? */
2597                 add_tag_chain(oid);
2598         return 0;
2599 }
2600
2601 static void prepare_pack(int window, int depth)
2602 {
2603         struct object_entry **delta_list;
2604         uint32_t i, nr_deltas;
2605         unsigned n;
2606
2607         if (use_delta_islands)
2608                 resolve_tree_islands(the_repository, progress, &to_pack);
2609
2610         get_object_details();
2611
2612         /*
2613          * If we're locally repacking then we need to be doubly careful
2614          * from now on in order to make sure no stealth corruption gets
2615          * propagated to the new pack.  Clients receiving streamed packs
2616          * should validate everything they get anyway so no need to incur
2617          * the additional cost here in that case.
2618          */
2619         if (!pack_to_stdout)
2620                 do_check_packed_object_crc = 1;
2621
2622         if (!to_pack.nr_objects || !window || !depth)
2623                 return;
2624
2625         ALLOC_ARRAY(delta_list, to_pack.nr_objects);
2626         nr_deltas = n = 0;
2627
2628         for (i = 0; i < to_pack.nr_objects; i++) {
2629                 struct object_entry *entry = to_pack.objects + i;
2630
2631                 if (DELTA(entry))
2632                         /* This happens if we decided to reuse existing
2633                          * delta from a pack.  "reuse_delta &&" is implied.
2634                          */
2635                         continue;
2636
2637                 if (!entry->type_valid ||
2638                     oe_size_less_than(&to_pack, entry, 50))
2639                         continue;
2640
2641                 if (entry->no_try_delta)
2642                         continue;
2643
2644                 if (!entry->preferred_base) {
2645                         nr_deltas++;
2646                         if (oe_type(entry) < 0)
2647                                 die(_("unable to get type of object %s"),
2648                                     oid_to_hex(&entry->idx.oid));
2649                 } else {
2650                         if (oe_type(entry) < 0) {
2651                                 /*
2652                                  * This object is not found, but we
2653                                  * don't have to include it anyway.
2654                                  */
2655                                 continue;
2656                         }
2657                 }
2658
2659                 delta_list[n++] = entry;
2660         }
2661
2662         if (nr_deltas && n > 1) {
2663                 unsigned nr_done = 0;
2664                 if (progress)
2665                         progress_state = start_progress(_("Compressing objects"),
2666                                                         nr_deltas);
2667                 QSORT(delta_list, n, type_size_sort);
2668                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2669                 stop_progress(&progress_state);
2670                 if (nr_done != nr_deltas)
2671                         die(_("inconsistency with delta count"));
2672         }
2673         free(delta_list);
2674 }
2675
2676 static int git_pack_config(const char *k, const char *v, void *cb)
2677 {
2678         if (!strcmp(k, "pack.window")) {
2679                 window = git_config_int(k, v);
2680                 return 0;
2681         }
2682         if (!strcmp(k, "pack.windowmemory")) {
2683                 window_memory_limit = git_config_ulong(k, v);
2684                 return 0;
2685         }
2686         if (!strcmp(k, "pack.depth")) {
2687                 depth = git_config_int(k, v);
2688                 return 0;
2689         }
2690         if (!strcmp(k, "pack.deltacachesize")) {
2691                 max_delta_cache_size = git_config_int(k, v);
2692                 return 0;
2693         }
2694         if (!strcmp(k, "pack.deltacachelimit")) {
2695                 cache_max_small_delta_size = git_config_int(k, v);
2696                 return 0;
2697         }
2698         if (!strcmp(k, "pack.writebitmaphashcache")) {
2699                 if (git_config_bool(k, v))
2700                         write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
2701                 else
2702                         write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
2703         }
2704         if (!strcmp(k, "pack.usebitmaps")) {
2705                 use_bitmap_index_default = git_config_bool(k, v);
2706                 return 0;
2707         }
2708         if (!strcmp(k, "pack.usesparse")) {
2709                 sparse = git_config_bool(k, v);
2710                 return 0;
2711         }
2712         if (!strcmp(k, "pack.threads")) {
2713                 delta_search_threads = git_config_int(k, v);
2714                 if (delta_search_threads < 0)
2715                         die(_("invalid number of threads specified (%d)"),
2716                             delta_search_threads);
2717                 if (!HAVE_THREADS && delta_search_threads != 1) {
2718                         warning(_("no threads support, ignoring %s"), k);
2719                         delta_search_threads = 0;
2720                 }
2721                 return 0;
2722         }
2723         if (!strcmp(k, "pack.indexversion")) {
2724                 pack_idx_opts.version = git_config_int(k, v);
2725                 if (pack_idx_opts.version > 2)
2726                         die(_("bad pack.indexversion=%"PRIu32),
2727                             pack_idx_opts.version);
2728                 return 0;
2729         }
2730         return git_default_config(k, v, cb);
2731 }
2732
2733 static void read_object_list_from_stdin(void)
2734 {
2735         char line[GIT_MAX_HEXSZ + 1 + PATH_MAX + 2];
2736         struct object_id oid;
2737         const char *p;
2738
2739         for (;;) {
2740                 if (!fgets(line, sizeof(line), stdin)) {
2741                         if (feof(stdin))
2742                                 break;
2743                         if (!ferror(stdin))
2744                                 die("BUG: fgets returned NULL, not EOF, not error!");
2745                         if (errno != EINTR)
2746                                 die_errno("fgets");
2747                         clearerr(stdin);
2748                         continue;
2749                 }
2750                 if (line[0] == '-') {
2751                         if (get_oid_hex(line+1, &oid))
2752                                 die(_("expected edge object ID, got garbage:\n %s"),
2753                                     line);
2754                         add_preferred_base(&oid);
2755                         continue;
2756                 }
2757                 if (parse_oid_hex(line, &oid, &p))
2758                         die(_("expected object ID, got garbage:\n %s"), line);
2759
2760                 add_preferred_base_object(p + 1);
2761                 add_object_entry(&oid, OBJ_NONE, p + 1, 0);
2762         }
2763 }
2764
2765 /* Remember to update object flag allocation in object.h */
2766 #define OBJECT_ADDED (1u<<20)
2767
2768 static void show_commit(struct commit *commit, void *data)
2769 {
2770         add_object_entry(&commit->object.oid, OBJ_COMMIT, NULL, 0);
2771         commit->object.flags |= OBJECT_ADDED;
2772
2773         if (write_bitmap_index)
2774                 index_commit_for_bitmap(commit);
2775
2776         if (use_delta_islands)
2777                 propagate_island_marks(commit);
2778 }
2779
2780 static void show_object(struct object *obj, const char *name, void *data)
2781 {
2782         add_preferred_base_object(name);
2783         add_object_entry(&obj->oid, obj->type, name, 0);
2784         obj->flags |= OBJECT_ADDED;
2785
2786         if (use_delta_islands) {
2787                 const char *p;
2788                 unsigned depth;
2789                 struct object_entry *ent;
2790
2791                 /* the empty string is a root tree, which is depth 0 */
2792                 depth = *name ? 1 : 0;
2793                 for (p = strchr(name, '/'); p; p = strchr(p + 1, '/'))
2794                         depth++;
2795
2796                 ent = packlist_find(&to_pack, obj->oid.hash, NULL);
2797                 if (ent && depth > oe_tree_depth(&to_pack, ent))
2798                         oe_set_tree_depth(&to_pack, ent, depth);
2799         }
2800 }
2801
2802 static void show_object__ma_allow_any(struct object *obj, const char *name, void *data)
2803 {
2804         assert(arg_missing_action == MA_ALLOW_ANY);
2805
2806         /*
2807          * Quietly ignore ALL missing objects.  This avoids problems with
2808          * staging them now and getting an odd error later.
2809          */
2810         if (!has_object_file(&obj->oid))
2811                 return;
2812
2813         show_object(obj, name, data);
2814 }
2815
2816 static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
2817 {
2818         assert(arg_missing_action == MA_ALLOW_PROMISOR);
2819
2820         /*
2821          * Quietly ignore EXPECTED missing objects.  This avoids problems with
2822          * staging them now and getting an odd error later.
2823          */
2824         if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
2825                 return;
2826
2827         show_object(obj, name, data);
2828 }
2829
2830 static int option_parse_missing_action(const struct option *opt,
2831                                        const char *arg, int unset)
2832 {
2833         assert(arg);
2834         assert(!unset);
2835
2836         if (!strcmp(arg, "error")) {
2837                 arg_missing_action = MA_ERROR;
2838                 fn_show_object = show_object;
2839                 return 0;
2840         }
2841
2842         if (!strcmp(arg, "allow-any")) {
2843                 arg_missing_action = MA_ALLOW_ANY;
2844                 fetch_if_missing = 0;
2845                 fn_show_object = show_object__ma_allow_any;
2846                 return 0;
2847         }
2848
2849         if (!strcmp(arg, "allow-promisor")) {
2850                 arg_missing_action = MA_ALLOW_PROMISOR;
2851                 fetch_if_missing = 0;
2852                 fn_show_object = show_object__ma_allow_promisor;
2853                 return 0;
2854         }
2855
2856         die(_("invalid value for --missing"));
2857         return 0;
2858 }
2859
2860 static void show_edge(struct commit *commit)
2861 {
2862         add_preferred_base(&commit->object.oid);
2863 }
2864
2865 struct in_pack_object {
2866         off_t offset;
2867         struct object *object;
2868 };
2869
2870 struct in_pack {
2871         unsigned int alloc;
2872         unsigned int nr;
2873         struct in_pack_object *array;
2874 };
2875
2876 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2877 {
2878         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->oid.hash, p);
2879         in_pack->array[in_pack->nr].object = object;
2880         in_pack->nr++;
2881 }
2882
2883 /*
2884  * Compare the objects in the offset order, in order to emulate the
2885  * "git rev-list --objects" output that produced the pack originally.
2886  */
2887 static int ofscmp(const void *a_, const void *b_)
2888 {
2889         struct in_pack_object *a = (struct in_pack_object *)a_;
2890         struct in_pack_object *b = (struct in_pack_object *)b_;
2891
2892         if (a->offset < b->offset)
2893                 return -1;
2894         else if (a->offset > b->offset)
2895                 return 1;
2896         else
2897                 return oidcmp(&a->object->oid, &b->object->oid);
2898 }
2899
2900 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2901 {
2902         struct packed_git *p;
2903         struct in_pack in_pack;
2904         uint32_t i;
2905
2906         memset(&in_pack, 0, sizeof(in_pack));
2907
2908         for (p = get_all_packs(the_repository); p; p = p->next) {
2909                 struct object_id oid;
2910                 struct object *o;
2911
2912                 if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
2913                         continue;
2914                 if (open_pack_index(p))
2915                         die(_("cannot open pack index"));
2916
2917                 ALLOC_GROW(in_pack.array,
2918                            in_pack.nr + p->num_objects,
2919                            in_pack.alloc);
2920
2921                 for (i = 0; i < p->num_objects; i++) {
2922                         nth_packed_object_oid(&oid, p, i);
2923                         o = lookup_unknown_object(oid.hash);
2924                         if (!(o->flags & OBJECT_ADDED))
2925                                 mark_in_pack_object(o, p, &in_pack);
2926                         o->flags |= OBJECT_ADDED;
2927                 }
2928         }
2929
2930         if (in_pack.nr) {
2931                 QSORT(in_pack.array, in_pack.nr, ofscmp);
2932                 for (i = 0; i < in_pack.nr; i++) {
2933                         struct object *o = in_pack.array[i].object;
2934                         add_object_entry(&o->oid, o->type, "", 0);
2935                 }
2936         }
2937         free(in_pack.array);
2938 }
2939
2940 static int add_loose_object(const struct object_id *oid, const char *path,
2941                             void *data)
2942 {
2943         enum object_type type = oid_object_info(the_repository, oid, NULL);
2944
2945         if (type < 0) {
2946                 warning(_("loose object at %s could not be examined"), path);
2947                 return 0;
2948         }
2949
2950         add_object_entry(oid, type, "", 0);
2951         return 0;
2952 }
2953
2954 /*
2955  * We actually don't even have to worry about reachability here.
2956  * add_object_entry will weed out duplicates, so we just add every
2957  * loose object we find.
2958  */
2959 static void add_unreachable_loose_objects(void)
2960 {
2961         for_each_loose_file_in_objdir(get_object_directory(),
2962                                       add_loose_object,
2963                                       NULL, NULL, NULL);
2964 }
2965
2966 static int has_sha1_pack_kept_or_nonlocal(const struct object_id *oid)
2967 {
2968         static struct packed_git *last_found = (void *)1;
2969         struct packed_git *p;
2970
2971         p = (last_found != (void *)1) ? last_found :
2972                                         get_all_packs(the_repository);
2973
2974         while (p) {
2975                 if ((!p->pack_local || p->pack_keep ||
2976                                 p->pack_keep_in_core) &&
2977                         find_pack_entry_one(oid->hash, p)) {
2978                         last_found = p;
2979                         return 1;
2980                 }
2981                 if (p == last_found)
2982                         p = get_all_packs(the_repository);
2983                 else
2984                         p = p->next;
2985                 if (p == last_found)
2986                         p = p->next;
2987         }
2988         return 0;
2989 }
2990
2991 /*
2992  * Store a list of sha1s that are should not be discarded
2993  * because they are either written too recently, or are
2994  * reachable from another object that was.
2995  *
2996  * This is filled by get_object_list.
2997  */
2998 static struct oid_array recent_objects;
2999
3000 static int loosened_object_can_be_discarded(const struct object_id *oid,
3001                                             timestamp_t mtime)
3002 {
3003         if (!unpack_unreachable_expiration)
3004                 return 0;
3005         if (mtime > unpack_unreachable_expiration)
3006                 return 0;
3007         if (oid_array_lookup(&recent_objects, oid) >= 0)
3008                 return 0;
3009         return 1;
3010 }
3011
3012 static void loosen_unused_packed_objects(struct rev_info *revs)
3013 {
3014         struct packed_git *p;
3015         uint32_t i;
3016         struct object_id oid;
3017
3018         for (p = get_all_packs(the_repository); p; p = p->next) {
3019                 if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
3020                         continue;
3021
3022                 if (open_pack_index(p))
3023                         die(_("cannot open pack index"));
3024
3025                 for (i = 0; i < p->num_objects; i++) {
3026                         nth_packed_object_oid(&oid, p, i);
3027                         if (!packlist_find(&to_pack, oid.hash, NULL) &&
3028                             !has_sha1_pack_kept_or_nonlocal(&oid) &&
3029                             !loosened_object_can_be_discarded(&oid, p->mtime))
3030                                 if (force_object_loose(&oid, p->mtime))
3031                                         die(_("unable to force loose object"));
3032                 }
3033         }
3034 }
3035
3036 /*
3037  * This tracks any options which pack-reuse code expects to be on, or which a
3038  * reader of the pack might not understand, and which would therefore prevent
3039  * blind reuse of what we have on disk.
3040  */
3041 static int pack_options_allow_reuse(void)
3042 {
3043         return pack_to_stdout &&
3044                allow_ofs_delta &&
3045                !ignore_packed_keep_on_disk &&
3046                !ignore_packed_keep_in_core &&
3047                (!local || !have_non_local_packs) &&
3048                !incremental;
3049 }
3050
3051 static int get_object_list_from_bitmap(struct rev_info *revs)
3052 {
3053         if (!(bitmap_git = prepare_bitmap_walk(revs)))
3054                 return -1;
3055
3056         if (pack_options_allow_reuse() &&
3057             !reuse_partial_packfile_from_bitmap(
3058                         bitmap_git,
3059                         &reuse_packfile,
3060                         &reuse_packfile_objects,
3061                         &reuse_packfile_offset)) {
3062                 assert(reuse_packfile_objects);
3063                 nr_result += reuse_packfile_objects;
3064                 display_progress(progress_state, nr_result);
3065         }
3066
3067         traverse_bitmap_commit_list(bitmap_git, &add_object_entry_from_bitmap);
3068         return 0;
3069 }
3070
3071 static void record_recent_object(struct object *obj,
3072                                  const char *name,
3073                                  void *data)
3074 {
3075         oid_array_append(&recent_objects, &obj->oid);
3076 }
3077
3078 static void record_recent_commit(struct commit *commit, void *data)
3079 {
3080         oid_array_append(&recent_objects, &commit->object.oid);
3081 }
3082
3083 static void get_object_list(int ac, const char **av)
3084 {
3085         struct rev_info revs;
3086         struct setup_revision_opt s_r_opt = {
3087                 .allow_exclude_promisor_objects = 1,
3088         };
3089         char line[1000];
3090         int flags = 0;
3091         int save_warning;
3092
3093         repo_init_revisions(the_repository, &revs, NULL);
3094         save_commit_buffer = 0;
3095         setup_revisions(ac, av, &revs, &s_r_opt);
3096
3097         /* make sure shallows are read */
3098         is_repository_shallow(the_repository);
3099
3100         save_warning = warn_on_object_refname_ambiguity;
3101         warn_on_object_refname_ambiguity = 0;
3102
3103         while (fgets(line, sizeof(line), stdin) != NULL) {
3104                 int len = strlen(line);
3105                 if (len && line[len - 1] == '\n')
3106                         line[--len] = 0;
3107                 if (!len)
3108                         break;
3109                 if (*line == '-') {
3110                         if (!strcmp(line, "--not")) {
3111                                 flags ^= UNINTERESTING;
3112                                 write_bitmap_index = 0;
3113                                 continue;
3114                         }
3115                         if (starts_with(line, "--shallow ")) {
3116                                 struct object_id oid;
3117                                 if (get_oid_hex(line + 10, &oid))
3118                                         die("not an SHA-1 '%s'", line + 10);
3119                                 register_shallow(the_repository, &oid);
3120                                 use_bitmap_index = 0;
3121                                 continue;
3122                         }
3123                         die(_("not a rev '%s'"), line);
3124                 }
3125                 if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
3126                         die(_("bad revision '%s'"), line);
3127         }
3128
3129         warn_on_object_refname_ambiguity = save_warning;
3130
3131         if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
3132                 return;
3133
3134         if (use_delta_islands)
3135                 load_delta_islands(the_repository);
3136
3137         if (prepare_revision_walk(&revs))
3138                 die(_("revision walk setup failed"));
3139         mark_edges_uninteresting(&revs, show_edge, sparse);
3140
3141         if (!fn_show_object)
3142                 fn_show_object = show_object;
3143         traverse_commit_list_filtered(&filter_options, &revs,
3144                                       show_commit, fn_show_object, NULL,
3145                                       NULL);
3146
3147         if (unpack_unreachable_expiration) {
3148                 revs.ignore_missing_links = 1;
3149                 if (add_unseen_recent_objects_to_traversal(&revs,
3150                                 unpack_unreachable_expiration))
3151                         die(_("unable to add recent objects"));
3152                 if (prepare_revision_walk(&revs))
3153                         die(_("revision walk setup failed"));
3154                 traverse_commit_list(&revs, record_recent_commit,
3155                                      record_recent_object, NULL);
3156         }
3157
3158         if (keep_unreachable)
3159                 add_objects_in_unpacked_packs(&revs);
3160         if (pack_loose_unreachable)
3161                 add_unreachable_loose_objects();
3162         if (unpack_unreachable)
3163                 loosen_unused_packed_objects(&revs);
3164
3165         oid_array_clear(&recent_objects);
3166 }
3167
3168 static void add_extra_kept_packs(const struct string_list *names)
3169 {
3170         struct packed_git *p;
3171
3172         if (!names->nr)
3173                 return;
3174
3175         for (p = get_all_packs(the_repository); p; p = p->next) {
3176                 const char *name = basename(p->pack_name);
3177                 int i;
3178
3179                 if (!p->pack_local)
3180                         continue;
3181
3182                 for (i = 0; i < names->nr; i++)
3183                         if (!fspathcmp(name, names->items[i].string))
3184                                 break;
3185
3186                 if (i < names->nr) {
3187                         p->pack_keep_in_core = 1;
3188                         ignore_packed_keep_in_core = 1;
3189                         continue;
3190                 }
3191         }
3192 }
3193
3194 static int option_parse_index_version(const struct option *opt,
3195                                       const char *arg, int unset)
3196 {
3197         char *c;
3198         const char *val = arg;
3199
3200         BUG_ON_OPT_NEG(unset);
3201
3202         pack_idx_opts.version = strtoul(val, &c, 10);
3203         if (pack_idx_opts.version > 2)
3204                 die(_("unsupported index version %s"), val);
3205         if (*c == ',' && c[1])
3206                 pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
3207         if (*c || pack_idx_opts.off32_limit & 0x80000000)
3208                 die(_("bad index version '%s'"), val);
3209         return 0;
3210 }
3211
3212 static int option_parse_unpack_unreachable(const struct option *opt,
3213                                            const char *arg, int unset)
3214 {
3215         if (unset) {
3216                 unpack_unreachable = 0;
3217                 unpack_unreachable_expiration = 0;
3218         }
3219         else {
3220                 unpack_unreachable = 1;
3221                 if (arg)
3222                         unpack_unreachable_expiration = approxidate(arg);
3223         }
3224         return 0;
3225 }
3226
3227 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
3228 {
3229         int use_internal_rev_list = 0;
3230         int shallow = 0;
3231         int all_progress_implied = 0;
3232         struct argv_array rp = ARGV_ARRAY_INIT;
3233         int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
3234         int rev_list_index = 0;
3235         struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
3236         struct option pack_objects_options[] = {
3237                 OPT_SET_INT('q', "quiet", &progress,
3238                             N_("do not show progress meter"), 0),
3239                 OPT_SET_INT(0, "progress", &progress,
3240                             N_("show progress meter"), 1),
3241                 OPT_SET_INT(0, "all-progress", &progress,
3242                             N_("show progress meter during object writing phase"), 2),
3243                 OPT_BOOL(0, "all-progress-implied",
3244                          &all_progress_implied,
3245                          N_("similar to --all-progress when progress meter is shown")),
3246                 { OPTION_CALLBACK, 0, "index-version", NULL, N_("<version>[,<offset>]"),
3247                   N_("write the pack index file in the specified idx format version"),
3248                   PARSE_OPT_NONEG, option_parse_index_version },
3249                 OPT_MAGNITUDE(0, "max-pack-size", &pack_size_limit,
3250                               N_("maximum size of each output pack file")),
3251                 OPT_BOOL(0, "local", &local,
3252                          N_("ignore borrowed objects from alternate object store")),
3253                 OPT_BOOL(0, "incremental", &incremental,
3254                          N_("ignore packed objects")),
3255                 OPT_INTEGER(0, "window", &window,
3256                             N_("limit pack window by objects")),
3257                 OPT_MAGNITUDE(0, "window-memory", &window_memory_limit,
3258                               N_("limit pack window by memory in addition to object limit")),
3259                 OPT_INTEGER(0, "depth", &depth,
3260                             N_("maximum length of delta chain allowed in the resulting pack")),
3261                 OPT_BOOL(0, "reuse-delta", &reuse_delta,
3262                          N_("reuse existing deltas")),
3263                 OPT_BOOL(0, "reuse-object", &reuse_object,
3264                          N_("reuse existing objects")),
3265                 OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
3266                          N_("use OFS_DELTA objects")),
3267                 OPT_INTEGER(0, "threads", &delta_search_threads,
3268                             N_("use threads when searching for best delta matches")),
3269                 OPT_BOOL(0, "non-empty", &non_empty,
3270                          N_("do not create an empty pack output")),
3271                 OPT_BOOL(0, "revs", &use_internal_rev_list,
3272                          N_("read revision arguments from standard input")),
3273                 OPT_SET_INT_F(0, "unpacked", &rev_list_unpacked,
3274                               N_("limit the objects to those that are not yet packed"),
3275                               1, PARSE_OPT_NONEG),
3276                 OPT_SET_INT_F(0, "all", &rev_list_all,
3277                               N_("include objects reachable from any reference"),
3278                               1, PARSE_OPT_NONEG),
3279                 OPT_SET_INT_F(0, "reflog", &rev_list_reflog,
3280                               N_("include objects referred by reflog entries"),
3281                               1, PARSE_OPT_NONEG),
3282                 OPT_SET_INT_F(0, "indexed-objects", &rev_list_index,
3283                               N_("include objects referred to by the index"),
3284                               1, PARSE_OPT_NONEG),
3285                 OPT_BOOL(0, "stdout", &pack_to_stdout,
3286                          N_("output pack to stdout")),
3287                 OPT_BOOL(0, "include-tag", &include_tag,
3288                          N_("include tag objects that refer to objects to be packed")),
3289                 OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
3290                          N_("keep unreachable objects")),
3291                 OPT_BOOL(0, "pack-loose-unreachable", &pack_loose_unreachable,
3292                          N_("pack loose unreachable objects")),
3293                 { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
3294                   N_("unpack unreachable objects newer than <time>"),
3295                   PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
3296                 OPT_BOOL(0, "sparse", &sparse,
3297                          N_("use the sparse reachability algorithm")),
3298                 OPT_BOOL(0, "thin", &thin,
3299                          N_("create thin packs")),
3300                 OPT_BOOL(0, "shallow", &shallow,
3301                          N_("create packs suitable for shallow fetches")),
3302                 OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep_on_disk,
3303                          N_("ignore packs that have companion .keep file")),
3304                 OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
3305                                 N_("ignore this pack")),
3306                 OPT_INTEGER(0, "compression", &pack_compression_level,
3307                             N_("pack compression level")),
3308                 OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
3309                             N_("do not hide commits by grafts"), 0),
3310                 OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
3311                          N_("use a bitmap index if available to speed up counting objects")),
3312                 OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
3313                          N_("write a bitmap index together with the pack index")),
3314                 OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
3315                 { OPTION_CALLBACK, 0, "missing", NULL, N_("action"),
3316                   N_("handling for missing objects"), PARSE_OPT_NONEG,
3317                   option_parse_missing_action },
3318                 OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
3319                          N_("do not pack objects in promisor packfiles")),
3320                 OPT_BOOL(0, "delta-islands", &use_delta_islands,
3321                          N_("respect islands during delta compression")),
3322                 OPT_END(),
3323         };
3324
3325         if (DFS_NUM_STATES > (1 << OE_DFS_STATE_BITS))
3326                 BUG("too many dfs states, increase OE_DFS_STATE_BITS");
3327
3328         read_replace_refs = 0;
3329
3330         sparse = git_env_bool("GIT_TEST_PACK_SPARSE", 0);
3331         reset_pack_idx_option(&pack_idx_opts);
3332         git_config(git_pack_config, NULL);
3333
3334         progress = isatty(2);
3335         argc = parse_options(argc, argv, prefix, pack_objects_options,
3336                              pack_usage, 0);
3337
3338         if (argc) {
3339                 base_name = argv[0];
3340                 argc--;
3341         }
3342         if (pack_to_stdout != !base_name || argc)
3343                 usage_with_options(pack_usage, pack_objects_options);
3344
3345         if (depth >= (1 << OE_DEPTH_BITS)) {
3346                 warning(_("delta chain depth %d is too deep, forcing %d"),
3347                         depth, (1 << OE_DEPTH_BITS) - 1);
3348                 depth = (1 << OE_DEPTH_BITS) - 1;
3349         }
3350         if (cache_max_small_delta_size >= (1U << OE_Z_DELTA_BITS)) {
3351                 warning(_("pack.deltaCacheLimit is too high, forcing %d"),
3352                         (1U << OE_Z_DELTA_BITS) - 1);
3353                 cache_max_small_delta_size = (1U << OE_Z_DELTA_BITS) - 1;
3354         }
3355
3356         argv_array_push(&rp, "pack-objects");
3357         if (thin) {
3358                 use_internal_rev_list = 1;
3359                 argv_array_push(&rp, shallow
3360                                 ? "--objects-edge-aggressive"
3361                                 : "--objects-edge");
3362         } else
3363                 argv_array_push(&rp, "--objects");
3364
3365         if (rev_list_all) {
3366                 use_internal_rev_list = 1;
3367                 argv_array_push(&rp, "--all");
3368         }
3369         if (rev_list_reflog) {
3370                 use_internal_rev_list = 1;
3371                 argv_array_push(&rp, "--reflog");
3372         }
3373         if (rev_list_index) {
3374                 use_internal_rev_list = 1;
3375                 argv_array_push(&rp, "--indexed-objects");
3376         }
3377         if (rev_list_unpacked) {
3378                 use_internal_rev_list = 1;
3379                 argv_array_push(&rp, "--unpacked");
3380         }
3381
3382         if (exclude_promisor_objects) {
3383                 use_internal_rev_list = 1;
3384                 fetch_if_missing = 0;
3385                 argv_array_push(&rp, "--exclude-promisor-objects");
3386         }
3387         if (unpack_unreachable || keep_unreachable || pack_loose_unreachable)
3388                 use_internal_rev_list = 1;
3389
3390         if (!reuse_object)
3391                 reuse_delta = 0;
3392         if (pack_compression_level == -1)
3393                 pack_compression_level = Z_DEFAULT_COMPRESSION;
3394         else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
3395                 die(_("bad pack compression level %d"), pack_compression_level);
3396
3397         if (!delta_search_threads)      /* --threads=0 means autodetect */
3398                 delta_search_threads = online_cpus();
3399
3400         if (!HAVE_THREADS && delta_search_threads != 1)
3401                 warning(_("no threads support, ignoring --threads"));
3402         if (!pack_to_stdout && !pack_size_limit)
3403                 pack_size_limit = pack_size_limit_cfg;
3404         if (pack_to_stdout && pack_size_limit)
3405                 die(_("--max-pack-size cannot be used to build a pack for transfer"));
3406         if (pack_size_limit && pack_size_limit < 1024*1024) {
3407                 warning(_("minimum pack size limit is 1 MiB"));
3408                 pack_size_limit = 1024*1024;
3409         }
3410
3411         if (!pack_to_stdout && thin)
3412                 die(_("--thin cannot be used to build an indexable pack"));
3413
3414         if (keep_unreachable && unpack_unreachable)
3415                 die(_("--keep-unreachable and --unpack-unreachable are incompatible"));
3416         if (!rev_list_all || !rev_list_reflog || !rev_list_index)
3417                 unpack_unreachable_expiration = 0;
3418
3419         if (filter_options.choice) {
3420                 if (!pack_to_stdout)
3421                         die(_("cannot use --filter without --stdout"));
3422                 use_bitmap_index = 0;
3423         }
3424
3425         /*
3426          * "soft" reasons not to use bitmaps - for on-disk repack by default we want
3427          *
3428          * - to produce good pack (with bitmap index not-yet-packed objects are
3429          *   packed in suboptimal order).
3430          *
3431          * - to use more robust pack-generation codepath (avoiding possible
3432          *   bugs in bitmap code and possible bitmap index corruption).
3433          */
3434         if (!pack_to_stdout)
3435                 use_bitmap_index_default = 0;
3436
3437         if (use_bitmap_index < 0)
3438                 use_bitmap_index = use_bitmap_index_default;
3439
3440         /* "hard" reasons not to use bitmaps; these just won't work at all */
3441         if (!use_internal_rev_list || (!pack_to_stdout && write_bitmap_index) || is_repository_shallow(the_repository))
3442                 use_bitmap_index = 0;
3443
3444         if (pack_to_stdout || !rev_list_all)
3445                 write_bitmap_index = 0;
3446
3447         if (use_delta_islands)
3448                 argv_array_push(&rp, "--topo-order");
3449
3450         if (progress && all_progress_implied)
3451                 progress = 2;
3452
3453         add_extra_kept_packs(&keep_pack_list);
3454         if (ignore_packed_keep_on_disk) {
3455                 struct packed_git *p;
3456                 for (p = get_all_packs(the_repository); p; p = p->next)
3457                         if (p->pack_local && p->pack_keep)
3458                                 break;
3459                 if (!p) /* no keep-able packs found */
3460                         ignore_packed_keep_on_disk = 0;
3461         }
3462         if (local) {
3463                 /*
3464                  * unlike ignore_packed_keep_on_disk above, we do not
3465                  * want to unset "local" based on looking at packs, as
3466                  * it also covers non-local objects
3467                  */
3468                 struct packed_git *p;
3469                 for (p = get_all_packs(the_repository); p; p = p->next) {
3470                         if (!p->pack_local) {
3471                                 have_non_local_packs = 1;
3472                                 break;
3473                         }
3474                 }
3475         }
3476
3477         trace2_region_enter("pack-objects", "enumerate-objects",
3478                             the_repository);
3479         prepare_packing_data(the_repository, &to_pack);
3480
3481         if (progress)
3482                 progress_state = start_progress(_("Enumerating objects"), 0);
3483         if (!use_internal_rev_list)
3484                 read_object_list_from_stdin();
3485         else {
3486                 get_object_list(rp.argc, rp.argv);
3487                 argv_array_clear(&rp);
3488         }
3489         cleanup_preferred_base();
3490         if (include_tag && nr_result)
3491                 for_each_ref(add_ref_tag, NULL);
3492         stop_progress(&progress_state);
3493         trace2_region_leave("pack-objects", "enumerate-objects",
3494                             the_repository);
3495
3496         if (non_empty && !nr_result)
3497                 return 0;
3498         if (nr_result) {
3499                 trace2_region_enter("pack-objects", "prepare-pack",
3500                                     the_repository);
3501                 prepare_pack(window, depth);
3502                 trace2_region_leave("pack-objects", "prepare-pack",
3503                                     the_repository);
3504         }
3505
3506         trace2_region_enter("pack-objects", "write-pack-file", the_repository);
3507         write_pack_file();
3508         trace2_region_leave("pack-objects", "write-pack-file", the_repository);
3509
3510         if (progress)
3511                 fprintf_ln(stderr,
3512                            _("Total %"PRIu32" (delta %"PRIu32"),"
3513                              " reused %"PRIu32" (delta %"PRIu32")"),
3514                            written, written_delta, reused, reused_delta);
3515         return 0;
3516 }